Test On the Problem of Selecting Interaction Objects
AM8a PCM VF Call Analyzer 用户手册说明书
• DS1 PCM Drop & Insert • Non-Intrusive PCM Measure • SLC ®96 Monitoring• CO Battery, Ring Generator, and Dial Tone Generator Sources• Signalling Monitor/Emulator • Dialed Digit Monitor/Emulator • Dialed Digit Analyzer • Complex Sequence Dialer• VF Level, Frequency, Noise Measure • Dual Multimeter760 Arrow Grand Circle ¥ Covina CA 91722 ¥ +626 915 5441 ¥ Complete Emulation and Analysis ofT1 and Analog SignalingAM8a PCM/VF Call AnalyzerAdvanced Test Equipment Rentals 800-404-ATEC (2832)®E s t a b l i s h e d 1981PABX Demarcation TestingThe AM8a can monitor or emulate the station (line) side or the central office (trunk) side of a PABX. The PABX can be emulated for the purpose of testing the central office trunksignalling, or the central office can be emulated looking toward the PABX.The AM8a has built-in central office battery power supply, loop length emulation, ring gener-ator and dial tone generator. All ofwhich are variable, and programmable to provide for a wide variety of test config-urations. These facilities, for example,allow the unit to simulate DID or 911terminal equipment.Limit testing of all signalling parame-ters is possible due to the full program-mability of the built-in generators and the detailed signalling decode and analysis capability of the built-in receivers.Precise one millisecond time tagging of all decoded signalling events allows easy identification of signalling timing problems.At the PBX or at the central office, demarcation testing is simple and comprehensive.Inter-Exchange or Long Distance Carrier TestingMonitoring or troubleshooting of analog or 1.544 Mbps PCM trunks is easy with the AM8a.The unit can non-intrusively monitor a T1 span and either camp on a specific channel or scan channels for new both-way activity. Signalling detection is completely automatic as the unit automatically differentiates between dial pulse,DTMF or MF signalling and decodes them appro-priately. No more missing unanticipated events.When moving the unit around the central office to different trunk types, reconfiguration of the AM8a is easily accomplished through the set-up “Store and Recall” feature.It is even possible to print out exception reports by connecting an accessory printer and using the built-in signalling thresholds feature to automati-cally screen for problems. This is a very effective feature when dealing with intermittent or elusive problems.Subscriber Line Concentrator (SLC ®) TestingThe AM8a provides a full, comprehensive analysis of AT&T SLC ®96 PCM circuits (or industry equivalent). Signalling problemsbetween the central office and an AT&T SLC ®96remote terminal are easy to detect andtroubleshoot using the AM8a as a signalling monitor.Together with the optional hard copy output capability, the AM8a provides a printed activity report in addition to a powerful problem solving tool.The following SLC ®96 analysis features are provided:1.Ability to monitor SLC ®96 Mode I (unconcen-trated) and Mode II (concentrated) calls and record signalling transitions (off/on hook, digits,tones, etc.)2.Ability to monitor the 4 Kbps data link in Mode II and time stamp to 1ms accuracy any or all Concentrator Field Messages sent by both the RT and the integrated SLC ®.3.Provide monitoring of all Maintenance,Protection and Alarm Field change of values in both TX and RX directions.4.Ability to map a specific channel to its appro-priate time slot assignment for Mode II operation.5.Programmable display fields to allow the user to analyze all events or only those exceedingprogrammed thresholds.AM8a and printer with printout showing SLC ®96 channel assignment.Receive, decode, analyze or emulatechannel associated signalling on DS1 (PCM)circuits or analog lines and trunks.Analog2w Loop Start 2w Ground Start 2w E&M 4w E&M DID SF SS41.544 Mbps PCM (DS1)D3/D4ESFSLC ®Mode I *SLC®Mode II ** Monitor OnlyBuilt-in Programmable Emulation:• C.O. Battery Supply •Ring Generator•Dial Tone Generator •Pulse and DTMF/MF Tone Dialling Generator •Tone GeneratorBuilt-in Programmable Analysis:•Pulse/Tone/Signalling event receiver, decoder, analyzer•AC/DC VoltmeterIntroductionIn a switched public or private telephone network, “signalling” is the process of setting up a call connection through the network at the beginning of a call and tearing it down at the end of the call.A businessman using his telephone sends “signals” into his PBX, the PBX “signals”the local central office, the local central office “signals” into a long distance carrier and so on.The Ameritec Model AM8a is a Call Analyzer capable of observing andtroubleshooting signalling problems on a wide variety of analog or channel-associated PCM circuits.The AM8a is capable of non-intrusive monitoring or intrusive emulation at most points in the signalling path.Highly portable and battery powered, it is equally useful in the field, in the switch room or in laboratory applications.Off Hook Display Selection for Events or Voltmeter Direct Entry KeypadFar End WinkFar End WinkFar End AnswerON/OFF Power ButtonVolume control for speakerMicrophone to communicate over line under test Connection oftelephone handset for private conversationsConnection of external Transmission Impairment Measuring Set (such as Ameritec's AM5XT)• Optional RS232 Port for exception reporting & remote control.• Decoding of MF, DTMF and dial pulse digits without pre-determination of type.• Built-in Speaker.• Optional Battery Pack for 8 Hours UseVisual LED indicators to show configuration of unit.Near End On HookLoop St/Ground St Analog ConnectionE & M Trunk ConnectionsPCM 1.554 Mbps span connectionsGrouping of Direct Function SwitchesScrolling up &down pages within each setup menuScrolling across choices for setup parametersUnit setup includingvariables when emulating.Analyzer Thresholds and Auto Dial sequencesON/OFF Toggles for connection to Trunk inputs & TIMS.Enable of hands-free talk and auto send of start signalMF Digitsincluding KP and STDialed DTMF Digits Elapsed time fromOff-Hook to selected event.(In thisexample a Wink of 247ms duration.)Detailed Call AnalysisFar End On HookComplex Sequence Auto-DialerThrough a front panel keypad the operator can dial any sequence of digits and events either manually or automatically.Up to 10 complex dialing sequences can be stored and later recalled for execution under the "auto dial" function.For example, the following sequence might be used to initiate test calls from a PABX station and use multiple signalling modes to reach and communicate with specialized equipment.PCM Drop & InsertThe AM8a provides two PCM ports with dual receivers and transmitters. These ports can beused for passive monitoring of a PCM span or the AM8a may be inserted in serieswith the PCM span for full duplex drop and insert testing of individual channels.The two PCM ports can also be used for clock synchronization testing of PCM spans where one port is connected to a reference span while the second port is connected to the span under test.The ability to measure VF level, frequency and noise on analog circuits is built into the AM8a.The unit also provides a variety of non-intrusive PCM digital tests, including bit and frame slips,CRC errors, framing errors, bi-polar violations,yellow and blue alarms.For more extensive analog or channel-associated PCM testing, a port is provided (labeled TIMS)which allows connection of a full range test set such as the Ameritec Model AM5XT.Easy SetupCommonly used AM8a test setups can be stored in non-volatile memory for later use. 20non-volatile memories are available for instant recall of personalized AM8a configu-ration setups.An additional 20 memories are available for recall of emulate/analyze parameters.This is in addition to the previously mentioned memories for 10 auto-dial sequences plus last number redial.High Tech, Small SizeThe AM8a incorporates multiple digital signal processors and microprocessors in a highly compact portable package. The unit may be powered from commercial mains where itautomatically adjusts for compatibility with local line voltage and frequency, or it may be powered from an optional internal rechargeable battery pack. An optional RS232 port and aux port allows for automatic hard copy reporting and remote control. A 24-pin LINE/TIMS connector on the rear of the AM8a provides secondaryaccess to all front panel connections and is useful for permanent AM8a installations in systems and other test equipment.Easy setup store and recall.1 of 10 Auto-Dial SequencesDTMF digit, dialed after receipt of start signalPause for Dial Tone DTMF DigitsToggle to MF DialingKP Signal Detailed Digit, Event AnalysisWhen connected to a circuit, the unit will display signaling events occurring in either direction on a large backlighted liquid crystal display (LCD).Up to 80 dialed digits and/or events (on hook, off hook, wink, etc.) may be collected and displayed for each call.By merely placing a cursor under the digit or event of interest, the operator can observe, on the second line of the display, all details associated with that event. For example, when selecting a DTMF digit, the unit will display the time of the digit and its duration, as well as the measured high and low band frequency and level.If the operator had previously entered good/bad mask parameters, then any out-of-spec detail would be high-lighted to the operator.With each event in a complex sequence captured in detail,troubleshooting becomes a matter of solving the problem instead of searching for the problem.Built-in Analog and PCM TestingDisplay of A/B signalling bits for all 24 T1 time slots (transmit and receive).Dual PCM ports.MF DigitsST Signal Rear of AM8a with RS232 ports for hard copy output and remote control.Built-in VoltmeterA dual multimeter with analog and digital display is provided. AC volts, DC volts, andcurrent measurements may be operator selected for tip to ring, tip to ground or ring to ground connec-tions. A display of all 24 PCM channel A/B bits can also be viewed.Portable or Rack MountNo other signaling test set of this type is asfull featured, small and convenient. About thesize and weight of a telephone directory, it is easily transported from lab to field. Forpermanent installations, a rack mounting kit is available which will allow 19" relay rack mounting in only two rack increments ofspace.Accessories and OptionsProvidedModel AM8a, removable front cover withstorage, power cord, monitor cables and instruction manual.Optional BatteryAn optional internal, rechargeable battery pack is available for full portable "cordless" operation. The batteries are of sealed lead-acid type and require no maintenance. A front panel low battery indicator indicates when recharging is needed.The built-in charger allows the batteries to be charged even while the unit is in operation.Options25-0071RS232 Remote ControlPort with Auxiliary RS232 Output Port.24-0018Internal Power Pack(Sealed Rechargeable Lead Acid Batteries) and Internal Charger.85-007619" Rack Mount Kit.48-0062 6 Ft. Bantam to ClipInput Cable.48-0047 6 Ft. Bantam toBantam Input Cable.48-0048 6 Ft. Bantam to 310 Input Cable.87-0070Padded Carrying CaseDual multimeter display showing battery and loop current measurements.AM8a with manual, cables, cover, and optional soft carrying case.AM8a shown in rack mount configuration.。
论文研究方法英文
论文研究方法英文Research Methodology in a ThesisIntroduction:Research methodology refers to the overall approach and systematic process employed in conducting a study or an investigation. It outlines the strategies, techniques, and tools used to gather, analyze, and interpret data in order to draw meaningful conclusions and contribute to knowledge in a particular field. This section will discuss the research methodology used in a thesis, highlighting the various components and their relevance.Research Design:The research design outlines the overall structure and plan for conducting the study. It provides a blueprint for how the study will proceed, including the research questions or hypotheses, variables to be examined, and the overall approach to data collection and analysis. The research design can be qualitative, quantitative, or a combination of both, depending on the nature of the research problem and objectives.Data Collection:Data collection methods involve gathering information or data fromrelevant sources to answer the research questions or test the hypotheses. There are various data collection methods, including interviews, surveys, observations, experiments, and document analysis. The choice of data collection methods depends on the nature of the research problem, availability of resources, and ethical considerations.Sampling:Sampling refers to the process of selecting a subset of individuals, entities, or elements from a population for research purposes. The sample should be representative of the population to ensure that the findings can be generalized. Common sampling methods include random sampling, stratified sampling, and purposive sampling. The sample size should be determined based on statistical considerations, such as the confidence level and desired margin of error.Data Analysis:Data analysis involves transforming raw data into meaningful information through the use of statistical techniques and other analytical tools. The specific data analysis techniques depend on the research design and the type of data collected. Qualitative data analysis may involve coding, categorizing, and thematic analysis, while quantitative data analysis often involves descriptive statistics, inferential statistics,and regression analysis.Validity and Reliability:Validity refers to the extent to which the research findings accurately represent the phenomena under investigation. Reliability refers to the consistency or stability of the research findings over time and across different researchers or study settings. Validity and reliability are critical considerations in ensuring the rigor and credibility of a study. Various strategies, such as triangulation, member checking, and inter-rater reliability, can be employed to enhance validity and reliability.Ethical Considerations:Ethical considerations involve the protection of participants' rights and the ethical conduct of research. This includes obtaining informed consent, ensuring confidentiality and anonymity, minimizing harm and risks, and maintaining integrity in data collection and analysis. Researchers should adhere to ethical guidelines and obtain necessary ethical approvals, particularly when involving human subjects.Conclusion:In summary, the research methodology in a thesis involves the selection of an appropriate research design, data collection methods, sampling,data analysis, and consideration of validity, reliability, and ethical considerations. A rigorous and systematic research methodology enhances the credibility and usefulness of the study findings, contributing to knowledge in the respective field.。
2024THUSSAT中学生标准学术能力诊断性测试英语试题及答案
中学生标准学术能力诊断性测试2024年1月测试英语试卷本试卷共 150分，考试时间100 分钟。
第一部分阅读理解(共两节，满分 60分)第一节(共15 小题；每小题3分，满分 45分)阅读下列短文，从每题所给的A、B、C和D四个选项中，选出最佳选项，并在答题卡上将该项涂黑。
AFrom hawk hikes to private sleepovers at the zoo, there is a great selection of animal-related experiences available to groups. Here are some top options to get closer to various wonderful wildlife.Chester ZooThe newest attractions here are the Madagascar Lemur Walkthrough experience, which gives visitors the opportunity to walk alongside ring-tailed and red-ruffed lemurs, and the interactive American Wetland Aviary, which is home to birds like scarlet ibises and flamingos. Group rates are available for parties of 15or more and there are various catering options, including sit-down meals at the restaurant at the heart of the zoo.ZSL Whipsnade ZooUntil September 2022, it is offering groups of up to 60 the opportunity to experience a private Nature Night, on which they’ll get to explore the zoo privately after the public has left, take part in activities like quizzes, camp overnight, and get up early for a private tour along the green trail before it reopens to the public again.West Midland Safari ParkThe latest attraction at the park is the new African Walking Trail. Opened in May, the trail features three viewpoints that allow visitors to see the park's African animals on foot. There's also a four-mile drive-through safari area with red panda, penguin and lorikeet areas. Groups of ten plus, arriving in the same vehicle, can save more than 40%.Knowsley Safari ParkThe five-mile safari drive through the site takes you past free-roaming lions, rhinos and more than 100cheeky baboons. There's a foot safari area, where the highlight is the Amur Tiger Trail with transparent walled viewing areas where you can get nose-to-nose with 450-pound tigers. Groups of 15 people and more, arriving in one vehicle, qualify for special ticket rates.1. Who is the passage intended for?A. Animal-loving students.B. Forest hiking fans.C. Group tour organizers.D. Wildlife preservationists.2. Visitors can experience private tours in .A. Chester ZooB. ZSL Whipsnade ZooC. West Midland Safari ParkD. Knowsley Safari Park3. From the passage, we know that .A. delicious meals are offered to tourists in the four parksB. private tours are available in the four parksC. all the parks can provide driving-through servicesD. visitors can have access to walking trails in the four parksBScientists regularly make vital new discoveries, but few can claim to have invented an entirely new field of science. Chemist Carolyn Bertozzi is one of them. Her discovery of biorthogonal chemistry(生物正交化学) in 2003 created a brand-new discipline of scientific investigation, which has enabled countless advances in medical science and led to a far greater understanding of biology at a molecular(分子的) level. On October 5, Bertozzi was awarded the Nobel Prize in Chemistry, jointly with two other professors. She is also the only woman to be awarded a Nobel Prize in science this year, after an all-male line-up in 2021.Bertozzi was the middle daughter of an MIT physics professor and a secretary. Few predicted that Bertozzi would be the most famous person in the family. While her academic performance was not bad in high school, she was fond of playing soccer. She end ed up being admitted to Harvard University. Despite her talent in soccer, she found it too time-consuming and quit the sport to devote herself to academics.But before becoming a rock star scientist, Bertozzi almost became an actual rock star. When she started at Harvard, she was tempted to major in music. That idea was “unpopular” with her parents, and she was timid about defying them. Instead, she chose the premed (医学预科的) track that included classes in math and sciences, and declared herself a biology major at the end of her first year of college.Her interest in music did not completely fall by the wayside, however. Bertozzi played keyboards and sang backup vocals for a hair metal band. Bertozzi, however, did not play with the band for long. Once the band's practices and performances conflicted with her labs and classes, there was only one outcome.Plus, she’d soon have organic chemistry to think about a course which is infamous for weeding out pre-meds. Without any clear career ambitions up to that point, Bertozzi had been thinking about possibly becoming a doctor when, in her sophomore year(大二学年), she suddenly fell so head over heels in love with her chemistry course that she couldn't tear herself away from her textbooks long enough to go out onSaturday nights. A torture to many was pure pleasure for her. Bertozzi changed her major from bi ology to chemistry a year later.Bertozzi has sometimes joked about her having missed out on her chance to follow Morello to LosAngeles. “I didn't get on that bus, and my playing is now limited to ‘The Wheel s on the Bus Go Round,’ I'm waiting for my sons to get old enough to appreciate 1980s heavy metal!”4. Which of the following statements is TRUE according to the passage?A. Bertozzi is one of those scientists who made significant new discoveries.B. Bertozzi was the only female to win a Nobel Prize in science in 2021.C. Bertozzi played keyboards and sang backup vocals throughout her college years.D. Bertozzi initially planned to become a doctor.5. The underlined word in Para 3 means .A. tellB. disobeyC. approachD. threaten6. The organic chemistry course Bertozzi took was known to be .A. easy and enjoyableB. difficult to pass for pre-med studentsC. popular among hair metal band playersD. a required course for all college students7. What kind of person do you think Carolyn Bertozzi is?A. Brave and sympathetic.B. Athletic and critical.C. Humble and passionate.D. Talented and creative.CWillie Sutton, a once celebrated American criminal, was partly famous for saying he robbed banks because “that’s where the money is.” Actually, museums are where the money is. In a single gallery there can be paintings worth more, taken together, than a whole fleet of jets. And while banks can hide their money in basements, museums have to put their valuables in plain sight.Nothing could be worse than the thought of a painting as important as The Scream, Edvard Munch's impressive image of a man screaming against the backdrop of a blood-red sky, disappearing into a criminal underworld that doesn't care much about careful treatment of art works. Art theft is a vast problem around the world. As many as 10,000 precious items of all kinds disappear each year. And for smaller museums in particular, it may not be a problem they can afford to solve. The money for insurance on very famous pictures would be budget destroyers even for the largest museums.Although large museums have had their share of embarrassing robberies, the greatest problem is small institutions. Neither can afford heavy security. Large museums attach alarms to their most valuable paintings, but a modest alarm system can cost $500,000 or more. Some museums are looking into tracking equipment that would allow them to follow stolen items once they leave the museums. But conservators are concerned that if they have to insert something, it might damage the object. Meanwhile, smaller museums can barely afford enough guards, relying instead on elderly staff.Thieves sometimes try using artworks as money for other underworld deals. The planners of the 2006robbery of Russborough House near Dublin, who stole 18 paintings, tried in vain to trade them for Irish Republican Army members held in British prison. Others demand a ransom(赎金) from the museum that owns the pictures. Once thieves in Frankfurt, Germany, made off with two major works by J. M. W. Turner from the Tate Gallery in London. The paintings, worth more than $80 million, were recovered in 2012 after the Tate paid more than $5 million to people having “information” about the paintings. Though ransom is illegal in Britain, money for looking into a case is not, provided that police agree the source of the information is unconnected to the crime. All the same, where information money end s and ransom begins is often a gray area.8. Why do smaller museums face a greater challenge in preventing art theft?A. They lack experienced staff.B. They cannot afford high-tech security systems.C. They do not have valuable artworks.D. They lack interest in art conservation.9. What is the concern of conservators regarding the use of tracking equipment to prevent art theft?A. It might damage the artwork.B. It is too expensive for smaller museums.C. It is difficult to insert into the paintings.D. It is ineffective for valuable paintings.10. From Paragraph 4, we can learn that .A. the thieves demanded a ransom from the Tate GalleryB. the Tate Gallery regained the lost paintings illegallyC. the money paid was considered an information fee, not a ransomD. the police requested the Tate Gallery to pay the money11. The purpose of this passage is .A. to remind criminals to protect and preserve the paintingB. to give suggestions on how to avoid the crimes of art theftC. to urge museums to set up more advanced security systemsD. to make people aware of art theft and the necessity of good security systemsDWho cares if people think wrongly that the Internet has had more important influences than the washing machine? Why does it matter that people are more impressed by the most recent changes?It would not matter if these misjudgments were just a matter of people's opinions. However, they have real impacts, as they result in misguided use of scarce resources.The fascination with the ICT(Information and Communication Technology) revolution, represented by the Internet, has made some rich countries wrongly conclude that making things is so “yesterday” that they should try to live on ideas. This belief in “post-industrial society” has led those countries to neglect their manufacturing sector(制造业) with negative consequences for their economies.Even more worryingly, the fascination with the Internet by people in rich countries has moved the international community to worry about the “digital divide” between the rich countries and the poor countries. This has led companies and individuals to donate money to developing countries to buy computer equipment and Internet facilities. The question, however, is whether this is what the developing countries need the most. Perhaps giving money for those less fashionable things such as digging wells, extending electricity networks and making more affordable washing machines would have improved people's lives more than giving every child a laptop computer or setting up Internet centres in rural villages, I am not saying that those things are necessarily more important, but many donators have rushed into fancy programmes without carefully assessing the relative long-term costs and benefits of alternative uses of their money.In yet another example, a fascination with the new has led people to believe that the recent changes in the technologies of communications and transportation are so revolutionary that now we live in a “borderless world”. As a result, in the last twenty years or so, many people have come to believe that whatever change is happening today is the result of great technological progress, going against which will be like trying to turn the clock back. Believing in such a world, many governments have put an end to some of the very necessary regulations on cross-border flows of capital, labour and goods, with poor results.Understanding technological trends is very important for correctly designing economic policies, both at thenational and the international levels, and for making the right career choices at the individual level. However, our fascination with the latest, and our under valuation of what has already become common, can, and has, led us in all sorts of wrong directions.12. What are the effects of people' misjudgments on the influences of new technology?A. It stimulates innovation.B. It affects their personal opinions.C. It influences their use of resources.D. It leads to improved technology.13. Why is the “digital divide” a concern related to the fascination with the Internet in rich countries?A. It leads to competition between rich and poor countries.B. It results in a lack of access to technology in developing countries.C. It increases the cost of computer equipment in rich countries.D. It promotes global digital cooperation.14. From Paragraph 4, we know that .A. donating for technology is always the better optionB. the author does not provide opinions on this matterC. donating for technology and basic needs should be balancedD. donating for basic needs should be prioritized over technology15. What is the passage mainly about?A. Significance of information and communication technology.B. Serious consequences of over-emphasizing high technology.C. Technological trends guiding economic policy making.D. How to use donation money in the new age.第二节(共5小题；每小题3 分，满分 15分)根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。
Trade-offs on the Location of the Core Node in a Network
to gather the information received to create a single composite data flow, which is multicast back to the users. More generally, there exists a class of multicast routing protocols, called center-based multicast protocols, which require an administrative center for each multicast group. In the Core Based Tree (CBT) protocol ([2]), for instance, if a source node wants to reach a multicast group, the data flow is first sent to a core node and then distributed to the group via a shared tree. Note that, in general, the source does not need to be a member of the multicast group. However, in this article we focus on a particular case, called All Receivers Sources in [3], where the set of senders is (or can be approximated as) the set of receivers. As mentioned above, this case is relevant for several multimedia applications. Empirical analysis has been carried out to measure the relationship between the choice of the core location and the performance of the routing scheme (see, i.e., [3], [4], [13]). The performance of such a scheme is usually evaluated in terms of delay and bandwidth consumption. For the sake of simulation, the network is modeled as an undirected graph, the communication delay between two nodes of the network is approximated as the number of links on the path used and the bandwidth consumption is evaluated as the sum of the data flow on each link. If the objective is to minimize the average delay between every pair of users in the group, the optimal routing is achieved on a shortest path tree rooted at the core. In that case, each user-core shortest path is used in both directions, and the optimal location of the core is such as to minimize the sum of the shortest path lengths between the core and every user. In Location Theory terminology, we seek the 1-median of the users. However, to minimize the bandwidth consumption, we must distinguish two different problems. The first one concerns the optimization of the unicast forward paths between the users and the core. Because each corresponding data flow is particular to its sender, we must optimize each user-core path. Therefore, the total bandwidth consumption of these paths is minimized when the core is located at the 1-median of the users. The second problem is
ELAN 使用手册说明书
ELAN for NAIJA. A small manualB. CARON23/06/2012This small manual is a revision of the commands that have been introduced and practiced during the IFRA-Nigeria workshop (Ibadan, June 19-22, 2012)Setting the parameters of a new file with 1 speakerOpen Elan.In the left-hand top corner, click on “FILE – OPEN” Select the Elan file you want to work on (it has an .eaf extension). Click and open.Move your index arrow to the left-hand part of the transcription, where you can see the name of the tiers. Right-click and select SORT BY TIERS and then SORT BY HIERARCHY.Go to the top left part of the screen. Click on the INTERLINEARIZE button. This will open a new working area. Inside this new area, in the top left part, click on the LEXICON tab. In the menu that will open, select “OPEN”. Select your dictionary (it has an .eafl extension) and open it.In the same area as you have found the LEXICON tab, click on the PARAMETER tab. Select INTERLINEARIZE TIER PARAMETERS, then CREATE INTERLINEARIZE TIERS. In the window that opens, click on the down arrow to select the MOT tier. The first time you use Elan, a new window will open with the default parameters. These are mb, ge and rx. Click on OK.If you have used other parameters with Elan before, you should restore them to the original default values : mb for the Segmentation tier; ge for the Annotation tier (gloss); rx for Annotation Tier Name. Click on OK. The new tiers you have created will appear in the right order.Now it’s time to save the parameters you have created before you start interlinearizing. Setting the parameters of a new file with 2 speakersOpen ElanIn the left-hand top corner, click on “FILE – OPEN” Select the Elan file you want to work on (it has an .eaf extension). Click and open.Move your index arrow to the left-hand part of the transcription, where you can see the name of the tiers. Right-click and select SORT BY TIERS and then SORT BY HIERARCHY.Go to the top left part of the screen. Click on the INTERLINEARIZE button. This will open a new working area. Inside this new area, in the top left part, click on the LEXICON tab. In the menu that will open, select “OPEN”. Select your dictionary (it has a .eafl extension) and open it.In the same area as you have found the LEXICON tab, click on the PARAMETER tab. Select INTERLINEARIZE TIER PARAMETERS, then CREATE INTERLINEARIZE TIERS. In the window that opens, click on the down arrow to select the mot@SP1 tier. The first time you use Elan, a new window will open with the default parameters. These are mb, ge and rx. These are meant for files with 1 speaker. You must modify them to fit your 2 speakers file: mb@sp1 for the Segmentation tier; ge@SP1 for the Annotation tier (gloss); rx@SP1 for Annotation Tier Name. Click on OK. The new tiers you have created will appear in the right order.Now it’s time to save the parameters you have created before you start interlinearizing themot@SP1 tier.When you have finished interlinearizing the mot@SP1 line, you will set the parameters for themot@SP2 tier. In the same area as you have found the LEXICON tab, click on the PARAMETER tab. Select INTERLINEARIZE TIER PARAMETERS, then CREATE INTERLINEARIZE TIERS. In the window that opens, click on the down arrow to select the mot@SP2 tier. Click on OK. In the window that opens, you must change the parameters to work on the mot@SP2 tier: mb@sp2 for the Segmentation tier; ge@SP2 for the Annotation tier (gloss); rx@SP2 for Annotation Tier Name. Click on OK. The new tiers you have created will appear in the right order.Now it’s time to save the parameters you have created before you start interlinearizing themot@SP2 tier.InterlinearizingFirst, select the first word in the first cell of your mot tier (the line at the bottom of the cell will turn blue). Click on the INTERLINEARIZE button of your working space, on the right-hand side (NOT the INTERLINEARIZE tab, with the same name as the button, which you used to open the working space). Different things may happen, depending on whether the word in the mot tier is recognized or not by the programme:-The word is recognized by Elan. It will appear, highlighted in blue under the INTERLINEARIZE button. Elan will select in the lexicon the word(s) that match the word in the mot line, andlist it/them on the left-hand side. Double-click on the word that satisfies you, and Elan willinsert the corresponding annotations in the text.-Elan recognizes the word, but the gloss and Tier x labels don’t satisfy you. Right-click on the word under the INTERLINEARIZE button, select INSERT RECORD and insert it into the lexicon.Then click again on the INTERLINEARIZE button, select the word you like in the list appearing on the left-hand side by double-clicking on it, and Elan will insert the correspondingannotations in the text.-Elan does not recognize the word. The word will appear, preceded by an asterisk, highlighted in blue under the INTERLINEARIZE button. Right-click on it, select INSERT RECORD and insert it into the lexicon. Then click again on the INTERLINEARIZE button, select the word on theleft-hand side by double-clicking on it, and Elan will insert the corresponding annotations in the text.Glossing and inserting records in NaijaLexical items:These are: nouns, verbs adverbs, adjectives, (minor) prepositions1, ideophones, etc.1)In the Gloss area (/g tier): All nouns, verbs, adverbs, adjectives, and prepositions,ideophones, etc. are translated, using small letters.2)In the Tier x (/rx tier) area:∙Verbs are labelled V± depending on their ±stative nature; then, if they appear in a verbal series, their order of appearance in the series will be indicated : V-.1 ; V-.2 ; V-.3, etc.∙Nouns are labelled N, followed by a dot and their syntactic status if they are subject, object or modifier: N.SBJ; N.OBJ; N.MOD. Optional: nouns that are objects ofprepositions can be labelled : N.OBJ in Tier x.∙Adjectives = ADJ ; Prepositions = PREP ; Ideophones = IDEOPH (see below, under “Special words”MorphemesMorphemes belong to a closed set. They typically include TAM (verb conjugation), pronouns, particles, etc. They should be glossed with capital letters (e.g. PST; 3SG; REL, etc.) and their part of speech put in the Tier x line (e.g. TAM; PRO.SBJ; PTCL, etc.).Creating a variant in the lexiconWhen you come across a word that you consider to be a variant of another word which you would like to appear as the main entry in the dictionary, you must first create the main entry before you can add the variant.After having clicked on the INTERLINEARIZE button, Right-click on the word that has appeared under the same INTERLINEARIZE button, but instead of keeping the transcription that appears in the window, change it to the transcription of the main entry. Save the main entry. Click again on the INTERLINEARIZE button, but instead of selecting INSERT RECORD, select INSERT VARIANT. Click on the down arrow, choose the main entry in the list of words that appears, and save to create the variant. Click again on the INTERLINEARIZE button, and double click on the word on the left-hand side to annotate.Creating a suffix in the lexiconIf you find a word that has been derived with the help of a suffix (e.g. –is): when the word with an arrow appears under the INTERLINEARIZE button, go to the left-hand side, click on INSERT RECORD, and create the suffix in the lexicon, e.g. (I’m inventing this form)Lexeme -isGloss PLTier X suf1 The « general preposition » for should be glossed, not translated in the “gloss” area. Use labels like DIR (directional), LOC (locative) in the “gloss” area, etc. ; write PREP in the “Tier x” area.Save the new entry. Click again on INSERT RECORD to insert the stem if it does not exist yet.Then click again on INTERLINEARIZE, double-click on the word in the list, then on the suffix in the list and your word should be glossed in the text.ReduplicationNB: reduplicated items should be transcribed as 1 word in the tx tier, and in the mot tier. It you need to create or delete cells on the mot tier, see below under “Editing a transcription”.Examples : plentiplenti, shitishitiProceed as you did for the suffix. After clicking on the INTERLINEARIZE button, go to the left-hand side, click on INSERT RECORD, and create the entry ~ for words with bare reduplication (e.g. ~ for plentiplenti) and ~ followed by a suffix for reduplication with a suffix (e.g. ~i for shitishiti):∙Lexeme ~∙Gloss INT (for intensive); IT (for iteration), etc.∙Tier X red (for reduplication)∙Lexeme ~i∙Gloss INT (for intensive); IT (for iteration), etc.∙Tier X red.suf (for reduplication & suffix)Save the new entry. Click again on INSERT RECORD to insert the stem if it does not exist yet, eg. plenti or shiti:∙Lexeme plenti∙Gloss plenty∙Tier X ADJ∙Lexeme shiti∙Gloss defecate∙Tier X V-Click again on INSERT RECORD, then click on INSERT UNDERLYING FORM. Fill the fields by clicking on the down arrows and selecting in the list the forms you have created, e.g. (1: plenti ; 2: ~) or (1: shit ; 2: ~i). Save your entry.Then click again on INTERLINEARIZE, double-click on the word in the list, then on the suffix in the list and your word should be glossed in the text.Special WordsIdeophones should be glossed using general semantic categories, e.g. ACTION; ATTITUDE; NOISE; COLOUR; MOVEMENT; SHAPE; TASTE; LIGHT; SMELL; RHYTHM; TEMPERATURE, etc. In Tier x, write IDEOPH.NB: the gloss is written in capital letters because these are hyperonyms, not translations.Exclamations (Eng. ouch!; Naija kai!) are roughly translated into English for the gloss and labelled EXCL in Tier x.Interjections (Eng. Hello! Yes! No!) are translated into English for the gloss and labelled INTJ in Tier x. Editing a transcriptionIf you have changed your transcription in the tx tier, and this means either separating a word into 2, or fusing two words into one, this should be reflected in the number of cells in the mot tier.To delete a cell on the mot tier: select the cell (the bottom line of the cell will turn blue). Right-click and select DELETE ANNOTATION.To add a cell on the mot tier: select the cell (the bottom line of the cell will turn blue). Right-click and select INSERT ANNOTATION AFTER or INSERT ANNOTATION BEFORE. Edit the new annotation(s).Provisional list of Naija glossesMeaning GE RX de Continuous (former Incompletive) CONT TAM bin Past PST TAM dɔn Perfect (former Completive) PFV PFVCONS TAM kɔm Consecutive (succession of events in narration;former Realis)go Future (Former Irrealis) FUT TAM nɛva Negative Completive PFV.NEG TAM fo Past Deontic (should have done…) DEON.PST TAM wɛrelative clause introducer REL PTCL se noun clause introducer (e.g. in reported speech) COMP PTCL if conditional clause introducer COND PTCL sha Topic particle TOP PTCL kwanu Topic particle TOP PTCL sef Emphasis particle EMPH PTCL o Emphasis particle EMPH PTCL she ; abi Question particle Q PTCL na Initial focus particle FOC PTCL na copular verb COP.EQ V+ bi copular verb COP.QLT V+ dé copular verb COP.LOC V+ di singular definite article DEF.SG ART dem plural definite article DEF.PL ARTwon singular indefinite article INDEF.SG ART som plural indefinite article/pronoun INDEF.PL ART/PROich each QNTevri every QNTany any QNT both both QNT meni many QNT plenty plenty QNTɔda other QNTdis proximal singular demonstrativePROX.SG DEM/PRO modifier/pronoun;dat distal singular demonstrative modifier/pronoun DIST.SG DEM/PRO diz proximal plural demonstrative modifier/pronoun; PROX.PL DEM/PRO doz/dos distal plural demonstrative modifier/pronoun DIST.PL DEM/PROfor general preposition DIR, DAT, etc PREPfrɔm (yɔ hand) minor preposition from PREPwit minor preposition with PREP。
DS2208数字扫描器产品参考指南说明书
-05 Rev. A
6/2018
Rev. B Software Updates Added: - New Feedback email address. - Grid Matrix parameters - Febraban parameter - USB HID POS (formerly known as Microsoft UWP USB) - Product ID (PID) Type - Product ID (PID) Value - ECLevel
-06 Rev. A
10/2018 - Added Grid Matrix sample bar code. - Moved 123Scan chapter.
-07 Rev. A
11/2019
Added: - SITA and ARINC parameters. - IBM-485 Specification Version.
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(完整版)国际私法英文专业词汇对照表
索引词表中文索引英文索引AADR解决方法Alternative Dispute ResolutionB巴托鲁斯Bartolus 本地法说Local Law Theory 本国法lex partriae 比较损害方法comparative-impairment approach 并入或采纳adoption 跛脚婚姻limping marriage BOT投资方式Build-Operate-Transfer 部分裁决partial award 布鲁歇Brocher 不歧视待遇non-discriminate treatmentC常设仲裁机构permanent arbitration agency 场所支配行为locus regit actum 承认与执行外国法院判决recognition and enforcement of foreign judgments 程序规范procedure rules 重叠适用的冲突规范double conflict rules 冲突法the conflict of laws 冲突规范conflict rules 船舶抵押权ship mortgage 船舶留置权possessors lien on vessel 船舶碰撞collision船舶所有权ownership of ship 船舶优先权maritime lien 垂直的法律冲突vertical conflict of lawsD达让特莱D’Argentre 代理agency 戴赛Dicey 单边冲突规范unilateral conflict rules 单式运输分合同sub-contracts 单一反致single renvoi 单一破产制unitary bankruptcy 当事人合意选择的法律lex voluntatis 当事人意思自治autonomy of will 德帕涅Despagnet 地理标准geographic criterion 地域效力terr ito ria lity 定期租船合同time charter 定性qualification 东道国法律law of host country 动态连结点variable point of contact 杜摩兰Dumoulin 独任仲裁员sole arbitrator对人诉讼管辖权in personam jurisdiction 对物诉讼管辖权in rem jurisdiction多式运输经营人combined transport operatorE二级识别secondary characterization法定继承intestate succession 法定住所sta tu tor y do mic ile 法定管辖sta tu to r y ju r isd ic tio n 法官知法jura novit curia 法律关系本座说Doctrine of the Seat of Particular Legal Relationships法律规避e v a s i o n o f l a w 法律适用规范rules of application of law 法律选择规范choice-of-law rules 法人legal person 法人的国籍nationality of legal person 法人的住所domicile of legal person 法域law district 法院地法lex fori 法则区别说Statutist Theory 反致r e n v o i 非当地化de-localization非国内化d e-n at i o n al i se 非内国裁决标准non-domestic award test 非政府组织nongovernmental organization 非自执行条约non-self-executing treaty 废除豁免论The Doctrine of Abolishing Immunity分割方法choosing and picking, depecage 分类classification 分析法学与比较法说the Theory of Analytical Jurisprudence and Comparative Law 附带问题incidental question 复合破产制pluralism bankruptcy 夫妻关系matrimonial relationship 伏特Voet个案识别说qualification case by case 公共秩序保留reservation of public order 公共政策public policy 共同海损general average 管辖权选择方法jurisdiction-selecting rules 光船租船合同bareboat charter 国籍的积极冲突positive conflict of nationality 国籍的消极冲突negative conflict of nationality 国际保理international factoring 国际贷款协议international loan agreement 国际法律冲突international conflict of laws 国际股票international shares 国际惯例International Usages 国际交往互利Mutual Benefit in International Communication国际礼让说C o m i t y T h e o r y 国际贸易术语解释通则Incoterms 国际民商法International Civil and commercial Law 国际民商事关系International Civil and commercial legal relations 国际民事案件管辖权international civil jurisdiction国际民事诉讼程序international civil litigation 国际民事诉讼法International Civil Procedure Law 国际破产international bankruptcy 国际商会仲裁院Court of Arbitration，ICC 国际商事仲裁international commercial arbitration 国际私法Private International Law 国际私法规范rules of private international law 国际司法协助international judicial assistance 国际条约International Conventions国际统一冲突法条约conventions on conflict of laws 国际统一实体法条约conventions on international uniform substantive law 国际债券international debentures 国际证券international securities 国际仲裁international arbitration 国际组织international organization 国家豁免state immunity 国家及其财产豁免immunities of states and their property 国民待遇National Treatment 国有化nationalizationH海难救助salvage at sea 海事赔偿责任限制limitation of liability for maritime claims 《海牙规则》Hague Rules 《海牙—维斯比规则》Hague-Visby Rules 《汉堡规则》Hamburg Rules 航次租船合同voyage charter 合理的方法rational solution 合同contract 合同缔结地法lex loci contractus 合同自体法理论the proper law of the Contract 横向冲突horizontal conflict 胡伯Huber 互惠说reciprocal 汇票bill of exchange 混合法则statuta mixta 婚姻举行地法lex loci celebrationis继承succession既得权说the Theory of Vested or Acquired Rights监护custody 间接代理indirect agency 间接反致indirect remission间接管辖权indirect international jurisdiction间接送达indirect service abroad 简易陪审团审判Summary Jury Trial交互式ODR模式Interactive ODR Venues结果选择方法result-selecting rules结婚Marriage解决投资争端国际中心International Center for the Settlement of Investment Disputes, ICSID “借用”法规”borrowing” statute 禁治产制度interdiction静态连结点constant point of contact居所residence绝对豁免论The Doctrine of Absolute ImmunityK卡弗斯Cavers 康恩Kahn 客观标志原则the Objective Contacts Doctrine客观连结点the objective point of contact柯里Currie肯塔基方法Kentucky Method空间法律冲突inter-spatial conflict of laws库克Cook库恩K uh n拉贝尔Ra be l 离婚Divorce 离线仲裁调解机构National Arbitration and Mediation 里斯Reese 立遗嘱能力capacity 连结点point of contact 连结对象object of connection 连结因素connecting factor 临时仲裁、特别仲裁ad hoc arbitration agency 领事裁判权consular jurisdiction 领事代理consular agency 领事途径consular mechanism 领域标准territorial testM美国仲裁协会AAA American Arbitration Association 孟西尼Mancini 民法施行法EGBGBN内国裁决domestic awardOODR Online Dispute ResolutionP票据negotiable instruments 聘请法官Rent-a-Judge 平等豁免论The Doctrine of Equal Immunity破产bankruptcy 普遍的效力universality 普遍优惠待遇Treatment of Generalized System of PreferenceQ旗国法law of the flag 起作用的事实operative facts 戚希尔Cheshire 侵权行为t o r t 侵权行为地法law of the place of wrong 侵权行为地法lex loci delicti 亲子关系parent-children relationship 区别制separate system 区际私法private inter-regional law 区际法律冲突inter-regional conflict of lawsR人的法则statuta personalia 人际法律冲突Inter-personal conflict of laws 任意性惯例non-exclusive usages 任意管辖权non-exclusive jurisdiction 瑞典斯德哥尔摩商会仲裁院The Arbitration Institute of Stockholm Chamber of CommerceS萨维尼Savigny 商标trade mark 涉外私法Foreign Private Law 涉外因素foreign elements时际法律冲突Inter-temporal conflict of laws 实际国籍nationalitéeffective 实体规范su b st a n t i v e r u l es 世界知识产权组织仲裁中心WIPO Arbitration Center 时效问题Limitation of actions, statute of limitation 实质性连结因素标准material connecting factors criterion 首席仲裁员chief arbitrator 收养ad o pt i o n 属地管辖权territorial jurisdiction属人法lex personalis 属人管辖权personal jurisdiction 属人理由的豁免immunity ratione personae 属物理由的豁免immunity ratione matrriae 双边冲突规范bilateral conflict rules 双重反致double renvoi 双重可诉原则rule of double actionability 司法标准juridical criterion司法管辖豁免immunity from jurisdiction 斯托雷S t o r y 诉讼代理litigation agency 诉讼费用担保security for costT特殊管辖权specific jurisdiction 特征性履行方法Characteristic Performance 提单Bill of Lading, L/B 调解mediation or conciliation 挑选法院fo r um shopp ing 同一制unitar y syste mW瓦赫特尔Waechter 外国裁决foreign award 外国法的适用application of Foreign Laws 外国法内容的查明ascertainment of foreign law 外国法院说foreign court theory 外交途径diplomatic mechanism 魏斯Weiss 问题的分类classification of issues 物的法则statuta realia 物权Real Rights 物之所在地法lex rei sitae; lex situsX系属公式formula 狭义的反致r em i ssi o n 先决问题preliminary question 限制豁免论The Doctrine of Relative or Restrictive Immunity香港仲裁中心Hong Kong International Arbitration Center, HKIAC 协议管辖jurisdiction by agreement 小型审判Mini Trial 协商negotiation 信托trusts 行为地法lex loci actus 虚假冲突false conflicts 宣告死亡declaration of absence 选择适用的冲突规范alternative conflict rules 选择住所domicile of choiceY一般管辖权general jurisdiction 一般趋势general trends 依功能分析方法functional analysis approach 依规则选择方法Rule-selection Techniques 一级识别primary characterization 意思自治原则Party Autonomy 遗嘱w i l l s 遗嘱方式有效性formal validity 遗嘱撤销revocation 隐存的法律冲突potential conflict of laws 英国伦敦国际仲裁院London Court of International Arbitration 友好仲裁amiable composition 优惠待遇Preferential Treatment 有利益关系的州interested state 有效控制effective control 域外送达service abroad 域外调查取证extraterritorial discovery and taking evidence abroad 原始住所domicile of originZ真实冲突true Conflicts 争议的国际性质标准the international nature of dispute test 政府利益分析说Governmental Interests Analysis 政府间组织inter-governmental organization直接管辖权direct international jurisdiction 直接送达direct service 直接调整方法direct approach 殖民地间的法律冲突intercolonial conflict of laws 支票c h e q u e知识产权intellectual property 治外法权说exterritoriality 执行豁免immunity from execution 仲裁a r b i t r at i o n 仲裁裁决arbitral award 仲裁程序arbitration procedure 仲裁地的主张lex loci sever 仲裁地place of arbitration 仲裁条款arbitration clause 仲裁员异议challenge to arbitrator 仲裁协议arbitration agreement 仲裁协议书submission to arbitration agreement 中国国际经济贸易仲裁委员会China International Economic and Trade ArbitrationC o m m i s s i o n,C I E T A C 中国海事仲裁委员会China Maritime Arbitration Commission, CMAC 中间裁决in te r lo cu to r y awa r d 中央机关途径central authority mechanism 重力中心说the Center of Gravity Test 重力中心地Center of Gravity 纵向冲突ve r tic al c on f lic t 主观连结点subjective point of contact 住所domic ile 住所地法lex domicile 著作权c op yr ig ht 专利权p at ent 专属管辖权excusive jurisdiction 转化transfor mation 转致transmission 准据法applicable law, lex causae 准据法说lex causae准正legitimation 自动执行条约self-executing treaty 自然人权利能力Legal capacity 自然人的行为能力Disposing capacity 自体法说the Proper Law Doctrine 自助式ODR模式Automated ODR Venues 最惠国待遇the Most Favored-nation Treatment, MFN 最密切联系说Doctrine of the Most Significant Relationship 最密切联系地法law of the place of the most significant relationship最密切联系原则the Most Closest Connect Doctrine 最真实联系说the Most Real Contact Doctrine 最终裁决final award。
计算机专业英语试题及答案
计算机专业英语试题及答案1. 选择题1. Which of the following is not a programming language?a) Javab) HTMLc) Pythond) CSS答案: b) HTML2. Which protocol is used for sending and receiving email?a) HTTPSb) FTPc) SMTPd) DNS答案: c) SMTP3. What does the acronym CPU stand for?a) Central Processing Unitb) Computer Processing Unitc) Control Processing Unitd) Central Power Unit答案: a) Central Processing Unit4. Which programming language is commonly used for web development?a) C++b) Javac) JavaScriptd) Swift答案: c) JavaScript5. What does HTML stand for?a) Hyperlinks and Text Markup Languageb) Hyper Text Markup Languagec) Home Tool Markup Languaged) Hyper Text Modeling Language答案: b) Hyper Text Markup Language2. 填空题1. The process of converting high-level programming code into machine code is called ___________.答案: compilation2. HTTP stands for ___________ Transfer Protocol.答案: Hyper Text3. The process of testing software by executing it is called ___________.答案: debugging4. Java is an object-_____________ programming language.答案: oriented5. DNS stands for Domain Name ___________.答案: System3. 简答题1. What is the difference between TCP and UDP?答案: TCP (Transmission Control Protocol) is a connection-oriented protocol, which means it establishes a connection between the sender and receiver before transferring data. It ensures that all packets are received in the correct order and provides error checking. UDP (User Datagram Protocol), on the other hand, is a connectionless protocol that does not establish a direct connection before transmitting data. It does not guarantee packet delivery or order but is faster and more efficient for time-sensitive applications.2. What is the purpose of an operating system?答案: An operating system (OS) is a software that manages computer hardware and software resources and provides common services forcomputer programs. Its primary purpose is to enable the user to interact with the computer and provide a platform for running applications. It manages memory, file systems, input/output devices, and multitasking. The OS also handles system security and resource allocation to ensure optimal performance.4. 解答题请参考下文并给出自己的解答。
StripIntercropping
Intercropping is the practice of producing multiple crops in a given space. Throughout time and around the world, intercrops have been used to better match crop demands to availablesunlight, water, nutrients, and labor. The advantage of intercrop-ping over sole cropping (growing a single crop in a field) is that competition for resources between species is less than exists within the same species.Intercropping has a long history, and is employed in many regions. In tropical agriculture, for example, tall and short crops are grown together to maximize production. In arid regions,intercropping improves the conservation of water. The “three sisters” of corn, beans, and squash grown by native Americans offer another example of intercropping.Strip intercropping is the adaptation of this system tocontemporary, mechanized agricultural practices. The multiple crops are grown in narrow, adjacent strips, that allow interaction between the different species, but also allow management with modern equipment.For many years, crop rotations have been recommended because of the temporal diversity they provide in plant species and their resource requirements. Strip intercropping adds a spatial diversity to species across the landscape. It also distributes the labor requirements of that landscape more evenly through the growing season, and allows complimentary interactions that can boost yields and profits.How does strip intercropping fit into Iowa’s farmland?Approximately 78 percent of the 27 million harvested acres in Iowa are devoted to corn and soybean production. Nearly one-Pm1763 | January 1999Fig. 1. Barley, soybean, and corn crops in a 15 foot strip intercropping system in Northeast Iowa.Strip Intercroppingthird of the corn produced is continuously cropped. Projections indicate that these two crops will continue to dominate the Iowa landscape. Strip intercropping systems have been designed with these two crops in mind. However, strip intercropping encourages the inclusion of third and/or fourth crop (Figure 1). In general,net gains in crop yield and economic return are the main short-term indicators of success or failure of a cropping system. As with any other business, farm managers will ultimately choose practices that maximize yield and economic return. Strip inter-cropping of corn and soybeans also meets this goal when optimized for individual farm needs.Corn and soybean yield respond to a strip intercropping systemThe response of these two crops to strip intercropping is most determined by the width of the strips in which they are grown (Figure 2). The earlier-planted and taller corn intercepts more sunlight at the border or interface with soybeans, and thus produces greater yields. However, soybean yields are suppressed at this border, mainly due to shading, water competition, and nutrient depletion by the adjacent corn (Figure 3.2).In strips wider than four rows, the positive windbreak effect of corn on soybeans offsets some of the negative effects ofshading and nutrient competition. Therefore, as the strips’ width increases, negative impacts on soybean yield will decrease, and only the soybean rows bordering the corn strip will suffer. At the same time, as the strip width increases, corn advantages decrease because the ratio of outside rows to inside rows decreases. When water is not limiting, strip intercropping of corn and soybeans (strip widths greater than six rows) results in higher total produc-tion and net returns than sole-cropped (monoculture) systems.The addition of small grain strips to strip intercropped corn and soybeanThe negative effects of shading and competition between corn and soybean can be reduced by addinganother crop to the system. Small grains, such as oats, can be seeded much earlier to use early spring resources. Oats are planted at least a month before corn and soybeans, and they are already reaching maturity when corn and soybeans begin competing for water, nutrients, and sunlight. The harvest of oats in early summer ends their competition with the adjacent crops (Figure 5). As a result, both corn and soybeans produce greater yields directly adjacent to oats (Figures 3.1 and 3.3) than in strip middles. The oats also benefit from the lack of competition in early spring, and the windbreak effect of corn in summer, which reduces oat lodging.Corn grain yields in a three-crop system show patterns similar to those in the two-crop system. Soybeansintercropped in strips wider than eight rows can outyield sole-cropped soybeans when grown in this three-cropsystem, due to the windbreak effect of the corn and lack of competition after harvest of the adjacent oats. The addition of a fourth crop not only adds to positive rotation effects,but also diminishes negative impact of the shading on the soybean strip. As a result, soybean strips with widths as little as five rows will yield equal to sole-croppedsoybeans. The corn advantage still depends on strip width (Figure 5).Selecting an alternative crop to replace the corn and soybean in any cropping system is a critical task. An alternative crop should be technically, socially,environmentally, and most importantly economically acceptable. These crops have to have agronomic compatibility and complimentary characteristics.On many farms the absence of livestock limits the choice of crops. Inclusion of livestock increase the choice of crops, and allows multiple uses for each crop (i.e. corn for silage and oats for forage). Small farms with diverse production systems are more receptive to the strip intercropping system.Figure 4. Corn soybean potential yield change with three-crop strip intercropping as strip width (number of rows) changes.Fig. 2. Corn and soybean potential yield change with two-crop strip intercropping as strip width (number of rows) changes.Fig. 3.1. The oat/corn border.Fig. 3.2. The soybean/corn border.Fig. 3.3. The oat/soybean border.Fig. 3. Border rows within a three-crop strip intercropping system.Monoculture yieldsCornSoybeanY i e l d e f f e c t %3020100-10-20-303020100-10-20-30146812Strip width (Number of rows)Monoculture yieldsCornSoybeanY i e l d e f f e c t %3020100-10-20-303020100-10-20-30146812Strip width (Number of rows)Effect of row position on crop yieldThe higher yield of crops in a strip intercropping system is referred to as an edge effect. Crop rotation in this system causes an increase in yields in the long-term; however, the edge has short-term impact and is the main positive yield factor in strip intercropping. The positive edge effect in corn occurs mainly in the rows at the crop strip border (Figure 6). This positive effect may extend to the second outside rows; however, the yield in the center of strips wider than four rows is equivalent to sole-cropped corn. The negative edge effect in soybeans occurs in the two rows closest to corn, and yields increase farther from the border with corn. In dry years, soybean rows adjacent to early seeded oat strip yield less than any other rows. Small grains such as oats have increased yields at the crop edge, due to the early-season lack of competition. Mechanical cultivation of the corn andsoybeans becomes critical to maintain the positive edge effect of the oat strip. Crop management and rainfall will alter the position effect and border interaction impacts.Strip direction and crop orientationThe direction of intercrop strips is ultimately determined by topography (Figure 7). Ideally, strips run perpendicular to the slope so that the small grain strips can trap eroded sediment and reduce runoff. Strips perpendicular to wind direction will maximize the windbreak effect of corn, influencing the microclimate experienced by other crops.Strip intercropping benefits are maximized when the strips run north-south rather than east-west. East-west strips in Iowa,where the summer solar azimuth angle is approximately 70degrees, tend to shade the north edge of each corn strip and the south edge of each soybean strip, reducing border benefits. This shading has less effect on the growth of oats, but may delay the drying of mature oats. North-south strips tend to yield higher in the east than west border rows. This is due to the higher rate of photosynthesis during cooler mornings, when sunlight is striking the eastern edge, than during the hot afternoons, when sunlight striking the western border may not be fully used, due to moistureFigure 5. Corn soybean potential yield changes with four-crop strip intercropping as strip width (number of rows)changes.stress and wilting. Soybean in north-south strips often yield better on the west border, where they are shaded from the afternoon sun by corn.Crop orientation may complement and improve the effect of strip direction, for example, when strips have a north-south direction, planting soybeans on the east side of the corn strip benefits both crops (Figure 9).Agronomic challengesPlant population and varietiesIt has been suggested that the increased light availability in the corn border rows should be met with a greater plantpopulation and nitrogen supply than in the center of the strip or in sole-cropped corn. While the additional nitrogen requirement has been demonstrated in research plots, there appears to be little advantage to using populations much greater than 30,000 plants per acre. While the optimal population may be slightly above this amount, it has not yet been pinpointed in research. Different corn varieties have also not been compared in extensive trials,although some on-farm systems currently plant multiple varieties within the corn strip.Pest ProblemsIn strip intercropping, there are both mechanical and chemical challenges to weed control. Equipment must be the appropriate size for each strip, and strips must be precisely placed to avoid overlaps or dead space between crops. Ridge-till may help with the latter challenge. Proper herbicides for each crop must be selected in case of drift. Differences in light availability across a strip can favor or discourage particular weed species, a factor that further complicates selecting an appropriate herbicide.The extensive border between crops found in stripintercropping can provide yield advantages, but they can also provide niches and entry points for insects. Insect pestpopulations may shift according to the range and availability of feeding, mating, and egg-laying ground. Corn stalk borers (Figure 9) and corn root worm may present greater challenges than in continuous corn fields. Pests, such as soybean leafhoppers, may move into the corn strip to feed on damaged plants,and grass hoppers may take advantage of oat strips for entry into the field or egg laying sites.Fig. 6. Yield comparison of a three-crop strip intercropping with monoculture cropping as affected by row position.Monoculture yieldsCornSoybeanY i e l d e f f e c t %3020100-10-20-303020100-10-20-30146812Strip width (Number of rows)CornFig. 7. Strip direction following contour line.Water quality and strip intercroppingSoil management methods such as conservation tillage are appropriate when the strips are rotated annually. Ridge-till, in particular, reduces surface runoff through soil surface and residue management (Figure 10). The presence of multiple crops in a single field reduces the amount of herbicide or fertilizer applied to that field at any one time. Hence, there is a lower risk of surface water or groundwater contamination in case of a heavy rain immediately after application.Small grain strips have the added advantage of slowing surface runoff, thus reducing soil and chemical loads andimproving water quality. The resilient stems of the small grain plants create friction, reducing the carrying energy of the runoff,allowing sediment to settle and chemicals to infiltrate into the soil. It is important, though, that the small grain strip bemaintained to prevent concentrated (channel) runoff flow, which can overwhelm the strip. Among several cropping systems at the Iowa State University Northeast Research Center at Nashua, strip intercropping had the lowest nitrate-N concentration (<7 mg/L) in subsurface drainage water. Research in southwest Iowa indicates that soil erosion losses with no-till strip intercropped corn,soybean, and winter wheat is at least as good as continuous no-till corn on slopes of 12-14 percent.Prepared by M. Ghaffarzadeh, agronomy department, Iowa State University. This publication was prepared, in part, with funds of the USDA Cooperative State Research, Education, and Extension Service contract 95-EWQI-1-9067 and by the College of Agriculture and Iowa State University Extension.Related Publications or ReferencesFrancis, C.A., A. Jones, K. Crookston, K. Wittler, and S. Goodman.1986. Strip cropping corn and grain legumes: A review. Am. J. Altern.Agric. 1:159-164.Ghaffarzadeh, M., F. Garcia, and R.M. Cruse. 1994. Grain yield response of corn, soybean, and oats grown in a strip intercropping system. Am. J.Altern. Agric. 9:171-177.Ghaffarzadeh, M., F. García Précha, and R.M. Cruse. 1997. Tillage effect on soil water content and corn yield in a strip intercropping System.Agron. J. 89:893-899.Fortin, M.C., J. Culley, and M. Edwards. 1994. Soil water, plant growth,and yield of strip-intercropped corn. J. Prod. Agric. 7:63-69.Iragavarapu T.K. and G.W. Randall. 1996. Border effects on yield in a strip-intercropped soybean, corn, and wheat production system. J. Prod.Agric. 9:101-107.West. T.D., and D.R. Griffith. 1992. Effect of strip-intercropping corn and soybean on yield and profit. J. Prod. Agric. 5:107-110.Fig. 8. Three-crop strip intercropping with different crop orientations.Fig. 9. Corn stalk borer migrates into strip borders from previous year’s corn residues. (Photo courtesy of Marlin Rice.)Fig. 10. Strip intercropping (right) reduces runoff and soil erosion compared to untilled soybean ground (left).File: Agronomy 2...and justice for allThe Iowa Cooperative Extension Service’s programs and policies are consistent with pertinent federal and state laws and regulations onnondiscrimination. Many materials can be made available in alternative formats for ADA clients.Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture.Stanley Johnson, director, Cooperative Extension Service, Iowa StateUniversity of Science and Technology, Ames, Iowa.Orientation 2Strip Direction。
2016全国2卷英语七选五
2016全国2卷英语七选五The Seven-Option-Five section of the 2016 National English Test Level 2 posed a unique challenge to students, testing their comprehension, analysis, and criticalthinking skills. This particular section required examinees to analyze a passage and choose the most appropriate sentence or paragraph from a list of seven options to fill in five blanks within the text. The complexity of this task lied not only in understanding the content of the passage but also in matching the tone, style, and logic of the options with the overall flow of the text.The passage itself was well-written and engaging, covering a topic that was both informative and thought-provoking. However, the options provided were carefully crafted to include both correct and incorrect choices, making it necessary for students to carefully analyze each sentence and consider its fit within the context of the passage. This process required a deep understanding of English language structure, vocabulary, and grammar, as well as the ability to recognize the nuances of meaning and tone.One of the key challenges in this section was the need to maintain coherence and consistency throughout the text. Students had to ensure that the chosen sentences not only made sense individually but also contributed to the overall narrative or argument of the passage. This required a keen eye for detail and a strong sense of logical flow.Another challenge was the time constraint. With limited time to read the passage, analyze the options, and make informed decisions, students were forced to prioritize and manage their time effectively. This aspect of the test not only tested linguistic skills but also examined students' ability to handle pressure and make quick decisions.Despite these challenges, the Seven-Option-Five section also presented valuable opportunities for students to demonstrate their proficiency in English. By successfully navigating this section, students were able to showcase their ability to understand and analyze complex texts, as well as their ability to apply their knowledge of language and grammar in a practical setting.Moreover, the Seven-Option-Five section encouraged students to develop critical thinking skills. In order tochoose the correct sentences, students had to evaluate the options critically, considering their relevance, accuracy, and fit within the context of the passage. This process fostered a deeper understanding of the material and promoted the ability to make informed decisions based on evidence and analysis.The 2016 National English Test Level 2, with its Seven-Option-Five section, provided a rigorous assessment of students' English language proficiency and criticalthinking skills. While the section posed significant challenges, it also presented valuable opportunities for students to demonstrate their abilities and further develop their linguistic and cognitive skills. By preparing thoroughly and approaching the test with a critical mindset, students were able to overcome these challenges and succeed in this important aspect of the exam.**2016年全国英语二卷七选五的挑战与机遇：分析与探讨**2016年全国英语二卷的七选五部分对学生提出了独特的挑战，考验着他们的理解、分析和批判性思维能力。
供热供电煤耗的计算方法
供热供电煤耗的计算方法张 陆1 陈 健2(1.南通热电厂,江苏南通 226005; 2.南通市计量检定测试所,江苏南通 226001)[摘 要] 目前热电厂在进行供热供电煤耗的计算中,因计算方法不同,使得管理水平、锅炉效率相近的热电厂相差较大,存在一些不尽一致的地方。
对此通过实例计算提出一种简便实用的计算方法,该方法有助于热电厂技术经济分析。
[关键词] 供热;供电;煤耗;供热比;供热煤耗[中图分类号]TK222 [文献标识码]A [文章编号]1002-3364(2001)01-0022-021 供热比(热电分摊比)的计算方法原电力部提供的供热计算式为:供热比=供热量发电供热总耗热量×100%式中发电、供热总耗热量=各汽轮机进汽的含热量-锅炉给水总含热量+从锅炉至减温减压器及直接对用户的供热量。
1.1 南通热电厂供热比计算方法供热比=供热量发电供热总耗热量×100%式中供热量=∑D r(i r-14.1868t n)。
其中D r为供热汽(水)流量;i r为供热汽(水)热焓;t n为补充水平均自然温度(南通市全年平均气温取15℃)。
由于流量表不全,各汽轮机进汽总含热量为∑0.99D0i0-1.02D0i g。
式中,D0为各锅炉蒸发量;i0为过热蒸汽焓;0.99为管道效率;锅炉给水总含热量也近似于1.02D0。
所以供热比a r=D r(i r-15×4.1868) D0i0×0.99-1.02D0×i g用以上方法计算的南通热电厂背压供热比a r为0.84左右。
1.2 供热比a r简化计算式经过推导验算供热比也可简化为:供热比a r=供热量(G J)×100%总耗标煤量×29.3076(G J)×ηL×ηG D 式中 η1———锅炉效率,%;ηG D———管道效率,%。
2 供热煤耗计算2.1 C b-35/5型机组煤耗计算按制造厂提供的数据和图表对C b-35/5型抽凝式供热机组不同抽汽供汽量下供电供热标准煤耗b g、b r进行计算。
IBM Cognos Transformer V11.0 用户指南说明书
国际私法专业术语
涉 外侵 权的法 律适 用 比较损害 方法 船舶碰撞 侵权行为 侵权行为 地法 双重可诉 原则 侵权行为 准据法 损害结果 发生地 规则 侵权行为 自体法
comparative-impairment approach collision tort law of the place of wrong rule of double actionability applicable law of tort place of impact rule proper law of the torts
冲 突规 范与准 据法 场所支配 行为 重叠适用 的冲突 规范 当事人合 意选择 的法律 定性 动态连结 点 法院地法 分类 附带问题 国际惯例 合同缔结 地法 静态连结 点 客观连结 点 连结点 连结对象 连结因素 旗国法 侵权行为 地法 人际法律 冲突 时际法律 冲突 实体规范 时效问题 属人法 单边冲突 规范 双边冲突 规范 外国法的 适用
autonomy of will choosing and picking, depecage the proper law of the Contract Characteristic Performance place of performance place of making Party Autonomy law of the place of the most significant relationship the Most Closest Connect Doctrine
中 文索 引
国际私法专业术语（中英文对照）
英 文索 引
国 际私 法概论 冲突法 冲突规范 法律适用 规范 法律选择 规范 法域 国际法律 冲突 国际交往 互利 国际私法 国际私法 规范 国际条约 国际统一 程序法 条约 国际统一 冲突法 条约 国际统一 实体法 条约 任意性惯 例 涉外因素 属地管辖 权 属人管辖 权 隐存的法 律冲突 直接调整 方法 间接调整 方法
成长中的困惑与选择英语作文范文
成长中的困惑与选择英语作文范文As I journey through the stages of life, I find myself engulfed in a sea of uncertainty and faced with myriad choices. Growing up is undoubtedly an exhilarating yet bewildering experience, wherein one must navigate a labyrinth of perplexity and make decisions that will shape their future.One of the most prevalent predicaments of adolescence is the struggle to establish one's identity. The quest todiscover who we truly are often prompts introspection andself-reflection. We face questions such as, "What are myvalues and beliefs?" or "What are my passions and aspirations?" These inquiries can be daunting, sometimes leading to confusion and frustration. It is during thesetimes that we seek guidance from our friends, family, and mentors to gain insight and clarity.Furthermore, the pressure to succeed academically weighs heavily on the shoulders of many young individuals. We are bombarded with expectations from our parents, teachers, and society at large. The choice of subjects to study, thepursuit of higher education, and the desire to secure a promising career path all contribute to a sense of overwhelming uncertainty. It is crucial to acknowledge that it is okay to feel lost and unsure during this phase of life. Exploring different fields of knowledge and experimenting with various academic disciplines can aid in shaping our future endeavors.In addition to academic decisions, the choice of friendships and relationships also presents a significant challenge. As we mature, we become more discerning about the people we surround ourselves with. Selecting friends who share our values and support our growth can be a perplexing process. Meanwhile, navigating romantic relationships adds another layer of complexity. The fear of rejection and thedesire for companionship intertwine, making it crucial to strike a balance between protection and vulnerability.The decision-making process during the formative years extends beyond personal matters. It expands to societal issues as we develop a broader understanding of the world. The complexities of politics, economics, and moral dilemmas can be overwhelming. Consequently, we are compelled to make choices that align with our principles and contribute to a just and equitable society. It is imperative to educate ourselves, engage in peaceful dialogue, and critically analyze differing perspectives to make informed decisions.Ultimately, amidst the confusion and choices, it is essential to embrace the growth that accompanies this transformative phase. It is normal to feel perplexed and uncertain, as these emotions are integral to the process of self-discovery. By seeking guidance, exploring interests, andengaging in self-reflection, we can navigate the tumultuous path of growing up and gain a clearer sense of direction.In conclusion, the journey of growing up is riddled with confusion and choices. From establishing our identity to making academic, personal, and societal decisions, the challenges can be daunting. However, this period of uncertainty also offers opportunities for growth and self-discovery. By embracing the process, seeking guidance, and making thoughtful choices, we can navigate the labyrinth of confusion and embark on a path that aligns with our passions and values.。
英语作文总分总格式
英语作文总分总格式英文回答：In the intricately woven tapestry of life, where myriad experiences intertwine, we encounter a plethora of choices. Decisions, both great and small, shape our paths and influence our destiny. Among the most consequential decisions we make is the choice of career. This pivotal decision not only determines our financial well-being but also has a profound impact on our overall happiness and fulfillment.Selecting a career is a multifaceted process that requires careful consideration of our interests, skills, values, and aspirations. It is essential to engage in thorough introspection to identify our passions and what truly drives us. Once we have a clear understanding of our strengths and desires, we can begin to explore different career options that align with our aspirations.Research is paramount in this exploration process. It is imperative to gather as much information as possible about potential career paths. This may involve reading industry publications, attending career fairs, networking with professionals in the field, and conducting informational interviews. Through thorough research, we can gain a comprehensive understanding of the various options available to us, their requirements, and potential career trajectories.It is equally crucial to consider our financial goals and aspirations. While pursuing a career that aligns with our passions is essential, it is also prudent to assess the financial implications of our choice. Some careers offer higher earning potential than others, and it is important to weigh the potential financial rewards against our lifestyle preferences and financial obligations.Ultimately, the decision of which career to pursue is a deeply personal one. There is no right or wrong answer, as the best choice for each individual will vary depending on their unique circumstances and aspirations. However, byengaging in thoughtful consideration and thorough research, we can increase our chances of making a career decisionthat will lead to both financial success and personal fulfillment.中文回答：职业选择是人生中重大而关键的决定之一，它不仅决定了我们的经济状况，而且对我们的整体幸福和成就感也有着深远的影响。
英语明信片 范文高中
英语明信片范文高中The enchanting world of English postcards opens up a captivating realm where words and images seamlessly intertwine, creating a delightful tapestry that transcends language barriers. As a high school student, I have had the privilege of exploring the rich tapestry of English postcards, discovering the power they hold in conveying messages, sharing experiences, and fostering cultural exchange.Postcards have long been a beloved medium for communicating with loved ones, sharing memories, and capturing the essence of a place. In the context of high school, the English postcard serves as a unique and engaging tool for language learning, cultural exploration, and personal expression. Through the creation and exchange of these visual and textual gems, students can not only hone their English language skills but also delve into the diverse landscapes, customs, and perspectives that shape the global community.One of the most captivating aspects of the English postcard is its ability to transport the reader to distant lands, immersing them in the sights, sounds, and experiences of a foreign destination. As ahigh school student, I have been mesmerized by the vivid depictions of iconic landmarks, bustling cityscapes, and serene natural wonders adorning the postcards I have received. These visual representations not only stimulate my imagination but also pique my curiosity, prompting me to learn more about the rich cultural heritage and unique traditions of the places they represent.Beyond the alluring imagery, the written messages on English postcards often serve as a window into the lives and perspectives of their senders. Whether it's a heartfelt greeting, a humorous anecdote, or a thoughtful reflection, these personal accounts provide a glimpse into the diverse experiences and emotions of individuals from around the world. By reading and responding to these messages, I have gained a deeper understanding of the human connections that can be forged through the simple act of sharing a postcard.Moreover, the act of creating and sending an English postcard can be a powerful tool for language learning and self-expression. As a high school student, I have found immense joy in carefully crafting my own postcards, selecting the perfect words and phrases to convey my thoughts and feelings. The process of composing a postcard in English not only challenges me to refine my vocabulary and grammar but also encourages me to think creatively and express myself with clarity and authenticity.Furthermore, the exchange of English postcards can serve as a bridge between cultures, fostering cross-cultural understanding and appreciation. When I receive a postcard from a peer in another country, I am not only captivated by the visual representations but also intrigued by the unique perspectives and cultural references that are woven into the message. This exchange of ideas and experiences helps to break down stereotypes, challenge preconceptions, and cultivate a more inclusive and empathetic worldview.In the context of high school, the English postcard can also be a valuable tool for educational enrichment and personal growth. Teachers can incorporate the creation and analysis of postcards into their curriculum, using them as a springboard for discussions on geography, history, literature, and social studies. By engaging with these multifaceted artifacts, students can develop critical thinking skills, enhance their language proficiency, and gain a deeper appreciation for the diversity of human experiences.Beyond the academic realm, the English postcard can also serve as a means of self-reflection and personal expression for high school students. The act of selecting the perfect image, crafting a thoughtful message, and sharing it with a recipient can be a therapeutic and empowering experience. Through this process, students can explore their own identities, articulate their thoughts and feelings, and forge meaningful connections with others.In conclusion, the English postcard is a captivating and multifaceted medium that holds immense potential for high school students. From the alluring imagery to the personal narratives woven into the written messages, these visual and textual gems offer a unique opportunity for language learning, cultural exploration, and personal growth. By embracing the power of the English postcard, high school students can embark on a journey of discovery, cultivate cross-cultural understanding, and express themselves in meaningful and impactful ways. As I continue to engage with this remarkable form of communication, I am filled with a deep appreciation for the richness and diversity it brings to the high school experience.。
Agilent L Series 多端口电romechanical 复用开关（L7104A B C和
L7106BAgilent L Series Multiport Electromechanical Coaxial SwitchesL7104A/B/C and L7106A/B/C TerminatedL7204A/B/C and L7206A/B/C Unterminated DC to 4 GHz, DC to 20 GHz, DC to 26.5 GHz TechnicalOverviewHigh-performance multiport switchesat an affordable priceGuaranteed 0.03 dB repeatability ensures accuracy and reduces calibration cycles for the entire 2 million cycle operating life.Operating life of 5 million cycles typical Unmatched isolation maximizes measurement accuracy and improves system dynamic range Economical price minimizes budgetary constraints••••In today’s competitive world, automated test systems demand higher accuracyand performance than ever before. The Agilent Technologies L Series L7104A/B/C and L7106A/B/C terminated and L7204A/B/C and L7206A/B/C untermi-nated, multiport switches offer the improvements in insertion loss repeatability and isolation necessary to achieve higher test system performance. Long life, repeatability, and reliability lower the cost of ownership by reducing calibration cycles and increasing test system uptime and are vital to ATS measurement system integrity over time.Description The L7104/L7204A,B,C SP4T and L7106/L7206A,B,C SP6T multiport switches provide the life and reliability required for automated test and measurement, signal monitoring, and routing applications. Innovative design and careful process control creates switches that meet the requirements for highly repeat-able switching elements in test instruments and switching interfaces. The exceptional 0.03 dB insertion loss repeatability is warranted for 2 million cycles at 25° C. This reduces sources of random errors in the measurement path and improves measurement uncertainty. Switch life is a critical consideration in production test systems, satellite and antenna monitoring systems, and test instrumentation. The longevity of these switches increases system uptime, and lowers the cost of ownership by reducing calibration cycles and switch maintenance.High-performance multiport switches for microwave and RF instrumentation and systems SP4T and SP6T confi gurationMagnetic latchingWarranted 0.03 dB insertion loss repeatability for 2 million cycles Excellent isolation, typically > 85 dB at 26.5 GHzOpto-electronic indicators and interruptsTerminated and unterminated portsTTL/5 V CMOS compatible (optional)Figure 1. Agilent L7104A/B/C and L7106A/B/C simplifi ed schematics•••••••Product OverviewFigure 2. Agilent L7204A/B/C and L7206A/B/C unterminated simplifi ed schematicsOperating up to 4 GHz (A models), 20 GHz (B models), and 26.5 GHz (C models), these switches exhibit the exceptional isolation performance required to maintain measurement integrity. Isolation between ports is typically > 90 dB to 12 GHz and > 85 dB to 26.5 GHz. This reduces the infl uence of signals from other channels, sustains the integrity of the measured signal, and reduces system measurement uncertainties. These switches also minimize measurement uncertainty with low insertion loss and refl ection, which make them ideal elements in large multitiered switching systems.All the L7104/L7204A,B,C and L7106/L7206A,B,C are designed to fall within most popular industry footprints. The 2¼ inch square fl ange provides mounting holes, while the rest of the 2½ inch long by 2¼ inch diameter body will easily fi t into most systems. Ribbon cable or optional solder terminal connections accommodate the need for secure and effi cient control cable attachmentOption 100 provides solder terminal connections in place of the 16-pin ribbon drive cable. Option 100 does not incorporate the “open all paths” feature.Opto-electronic interrupts and indicators improve reliability and extend thelife of the switch by eliminating DC circuit contact failures characteristic of conventional electromechanical switches. These switches have an interrupt circuit that provides logic to open all but the selected ports, it then closesthe selected ports cutting off the current to the solenoids of the ports. These switches also offer independent indicators that are controlled by optical inter-rupts in the switch. The indicators provide a closed path between the indicator common pin and the corresponding sense pin of the selected path.ApplicationsMultiport switches fi nd use in a large number of applications, increasing systemfl exibility and simplifying system design.Signal routingThe simplest signal routing scheme takes the form of single input to multipleoutputs. These matrixes are often used on the front of an analyzer to test sev-eral two-port devices sequentially or to test multiport devices. In surveillanceapplications, a multiport switch can be used to select the optimum antennafor intercepting a signal. Two methods can be used to accomplish the singleinput to multiple output arrangement. Traditionally where isolation greater than60 dB was required, a tree matrix composed of SPDT switches was used. Whilethis gave great isolation, it was at the cost of more switches (Figure 3). Theseswitches have port-to-port isolations typically greater than 85 dB at 26.5 GHz,eliminating the need to use a tree matrix in order to achieve high isolation(Figure 4). In addition to the reduced part count, the path lengths are shorter, soinsertion loss is less, and paths are of equal length, so phase shift is constant.Full access switchingFull access switching systems give the fl exibility to route multiple input signalsto multiple outputs simultaneously. Full access switching matrixes are used ingeneric test systems in order to provide fl exible routing of signals to and frommany different devices under test, and stimulus and analysis instrumentation.Cross-point matrixes, using single pole double throw and cross-point switches,have traditionally been used in order to maintain high channel-to-channelisolation (Figure 5). As with the tree matrixes, this is at the cost of hardwareand performance. Full access switching can also be achieved using multiportswitches (Figure 6).The advantage of the multiport matrix over the cross-point matrix is lowerinsertion loss and improved SWR performance due to consistent path lengthand fewer switches and connecting cables.Figure 3. Tree matrixFigure 5. Cross-point matrixDedicated switching There are a number of applications where switching is used, not for fl exibility, but to accomplish a particular function within an instrument. For example,switched fi lter banks for reducing harmonics in the output of sources or to the input of analyzers can use multiport switches in series to select the right fi lter for the band of interest. For larger switching systems, where many switches are used to provide complex signal routing, a switch driver such as the Agilent 11713B/C with L7104/6 or L7204/6 switches is recommended.Driving the switch Each RF path can be closed by applying ground (TTL “High” for Option T24) to the corresponding “drive” pin. In general, all other RF paths are simultaneously opened by internal logic.Standard drive See Figure 11 for drive connection diagrams.Connect pin 1 to supply (+20 VDC to +32 VDC)Connect pin 15 to ground (see Note 1).Select (close) desired RF path by applying ground to the corresponding “drive” pin; for example ground pin 3 to close RF path 1 (see Note 2).To select another RF path, ensure that all unwanted RF path “drive” pins are disconnected from ground (to prevent multiple RF path engagement). Ground the “drive” pin which corresponds to the desired RF path (see Note 3). To open all RF paths, ensure that all RF path “drive” pins are disconnected from ground. Then, connect pin 16 to ground. This feature is not available with Option 100.•••••TTL drive (Option T24) See Figure 15 and 16 for drive connection diagrams.Connect pin 1 to supply (+20 VDC to +32 VDC)Connect pin 15 to ground (see Notes 1, 4).Select (close) desired RF path by applying TTL “High” to the corresponding “drive” pin; for example apply TTL “High” to pin 3 to close RF path 1 (see Note 2).To select another path, ensure that all unwanted RF path “drive” pins are at TTL “Low” (to prevent multiple RF path engagement). Apply TTL “High” to the “drive” pin which corresponds to the desired RF path (see Note 3).To open all RF paths, ensure that all RF path “drive” pins are at TTL “Low.” Then, apply TTL “High” to pin 16. This feature is not available with Option 100.Notes:Pin 15 must always be connected to ground to enable the electronic position-indicating circuitry and drive logic circuitry.CAUTION: IF PIN 15 IS NOT CONNECTED TO POWER SUPPLY GROUND, CATASTROPHIC FAILURE WILL OCCUR.After the RF path is switched and latched, the drive current is interrupted by the electronic position-sensing circuitry. Pulsed control is not necessary, but if implemented, the pulse width must be 15 ms minimum to ensure that the switch is fully latched.The default operation of the switch is break-before-make. Make-before-break switching can be accomplished by simultaneously selecting the old RF path “drive” pin and the new RF path “drive” pin. This will simultaneously close the old RF path and the new RF path. Once the new RF path is closed (15 ms), de-select the old RF path “drive” pin while leaving the new RF path “drive” pin selected. The switch circuitry will automatically open the old RF path while leaving the new RF path engaged.In addition to the quiescent current supplying the electronic position-sensing circuitry, the drive current fl ows out of pin 15 (during switching) on TTL drive switches (Option T24).Electronic position indicatorsThe electronic position indicators consist of optically isolated, solid-state relays which are driven by photo-electric sensors coupled to the mechanical position of the RF path’s moving elements (Figure 7). The circuitry consists of a common which can be connected to an output corresponding to each RF path. If multiple RF paths are engaged, the position indicator corresponding to each closed RF path will be connected to common. The solid state relays are confi gured for AC and/or DC operation. (See indicator specifi cations on page8.) The electronic position indicators require that the supply (20 to 32 VDC) be connected to pin 1 and ground connected to pin 15.•••••1.2.3.4.Figure 7. Pin function diagramSpecifi cations describe the instrument’s warranted performance. Supplementaland typical characteristics are intended to provide information useful in applying the instrument by giving typical, but not warranted performance parameters. Maximum power rating:1 W average into 50 Ωinternal loads Switching:1 W CW for terminated2 W CW for unterminatedNon-switching: 50 W Pk (not to exceed 1 watt average)for terminated100 W Pk (not to exceed 2 watt average)for unterminated Life:2,000,000 cycles minimum Switching speed:15 ms maximum Reference conditions:Cold switching only (NO Hot switching)Ambient temperature of 75°C or lessSea level (0.88 derating at 15,000ft.)Load VSWR < 1.2 (see graph for derating above 1.2 VSWR)Power handling at 25°C is 100 W at 4 GHzFigure 8. Power rating for cold switching at 75 °C•••••Specifi cationsFigure 9. Power derating factor versus VSWR Indicator specifi cations:Maximum withstand voltage: 60 V Maximum current capacity: 150 mA Maximum “ON” resistance: 2.5 ΩMaximum “OFF” resistance:10 G Ω Figure 10. TTL control voltage states (Option T24)Switch drive specifi cations1. Closing one RF path requires 200 mA. Add 200 mA for each additional RF path closed or open. Using all RF paths open (selecting pin 16) requires 200 mA per RF path reset with Vcc=24 VDC.Figure 11. Agilent L Series multiport switch insertion loss versus frequencyFigure 12. Agilent L Series multiport switch isolation versus frequencyFigure 13. Agilent L Series multiport switch SWR versus frequencyEnvironmental specifi cationsOperating temperature:–25 to 75°CStorage temperature:–55 to 85°CTemperature cycling:–55 to 85°C, 10 cycles per MIL-STD-202F,Method 107D, Condition A (modified) Vibration:Operating: 7 g: 5 to 2000 Hz at 0.25 in p-pSurvival: 20 g: 20 to 2000 Hz at 0.06 in p-p,4 min/cycle, 4 cycles/axisRandom: 2.41 g (rms) 10 min/axis Shock:Half-sine: 500 g at 0.5 ms,3 drops/direction, 18 totalOperating:50 g at 6 ms, 6 directionsMoisture resistance:65°C, 95% RH, 10 days per MIL-STD-202F,Method 106EAltitude storage:50,000 feet (15,240 meters perMIL-STD-202F, Method 105C, Condition B) RFI:Radiated Emission per CISPR 11 Magnetic fi eld:< 5 gauss ¼ inch from surfaceFigure 14. Product dimensions for L7104/106 A,B,C and L7204/206 A,B,CFigure 15. Drive connection diagrams with Option 161* Path 1 and 4 not connected for the L7104/L7204 A, B, C** “Open all the paths” pin is not available Figure 16. Drive connection diagrams with Option 100TroubleshootingSymptom Probable cause 1. Will not switch • Not connected to supply• Supply < 20 V • Supply current too low • Not connected to ground • Select line not at ground (std)• TTL “Low” voltage too high (Option 72) • All-path-open line selected 2. Position indicators • Supply not connected do not work • Supply < 20 VDC• Pin 15 not connected to groundOrdering informationSwitchesL7104A DC to 4 GHz, SP4T TerminatedL7104B DC to 20 GHz, SP4T TerminatedL7104C DC to 26.5 GHz, SP4T TerminatedL7204A DC to 4 GHz, SP4T UnterminatedL7204B DC to 20 GHz, SP4T UnterminatedL7204C DC to 26.5 GHz, SP4T UnterminatedL7106A DC to 4 GHz, SP6T TerminatedL7106B DC to 20 GHz, SP6T TerminatedL7106C DC to 26.5 GHz, SP6T TerminatedL7206A DC to 4 GHz, SP6T UnterminatedL7206B DC to 20 GHz, SP6T UnterminatedL7206C DC to 26.5 GHz, SP6T UnterminatedOption 100Solder terminals to replace ribbon cableOption 16116 PIN DIP socket and connector with 24 inchribbon cableOption UK6Commercial calibration test data with certifi cateOption T24TTL/5 V CMOS compatible optionDrivers11713B/C Attenuator switch driverDrive up to 20 sections of switches or attenuators.CablesOption 201 Accessory cableViking connector to bare tinned wires (60 inches long). Use to connect11713B/C to L7104/204/106/206 with Option 100. One required withL7104/L7204 Option 100; two required with L7106/L7206 Option 100.Option 401 Accessory cableDual-viking connector to 16-pin DIP connector.Use to connect 11713B/C to L7106/206 default Option 161.Option 601 Accessory cableViking connector to 16-pin DIP connector.Use to connect 11713B/C to L7104/L7204 default Option 161.Confi guration guideSee publication 5989-7277EN./fi nd/emailupdatesGet the latest information on the products and applications you select.Agilent Email UpdatesRemove all doubtOur repair and calibration serviceswill get your equipment back to you, performing like new, when prom-ised. You will get full value out of your Agilent equipment through-out its lifetime. Your equipment will be serviced by Agilent-trained technicians using the latest factory calibration procedures, automated repair diagnostics and genuine parts. You will always have the utmost confi dence in your measurements. Agilent offers a wide range of ad-ditional expert test and measure-ment services for your equipment, including initial start-up assistance onsite education and training, as well as design, system integration, and project management.For more information on repair and calibration services, go to:/fi nd/removealldoubtFor more information on Agilent T echnologies’ products, applications or services, please contact your local Agilent office. The complete list is available at:/fi nd/contactusAmericasCanada (877) 894-4414 Latin America 305 269 7500United States (800) 829-4444Asia Pacifi c Australia 1 800 629 485China 800 810 0189Hong Kong 800 938 693India 1 800 112 929Japan 0120 (421) 345Korea 080 769 0800Malaysia 1 800 888 848Singapore 180****8100Taiwan 0800 047 866Thailand 1 800 226 008Europe & Middle EastAustria 01 36027 71571Belgium 32 (0) 2 404 93 40 Denmark 45 70 13 15 15Finland 358 (0) 10 855 2100F rance 0825 010 700**0.125 €/minute Germany 07031 464 6333****0.14 €/minuteIreland 1890 924 204Israel 972-3-9288-504/544Italy 39 02 92 60 8484Netherlands 31 (0) 20 547 2111Spain 34 (91) 631 3300Sweden 0200-88 22 55Switzerland 0800 80 53 53United Kingdom 44 (0) 118 9276201Other European Countries: /fi nd/contactusRevised: July 17, 2008Product specifi cations and descriptions in this document subject to change without notice.© Agilent Technologies, Inc. 2008Printed in USA, October 31, 20085989-6030ENL7106B。
种西红柿的劳动实践活动英语作文
种西红柿的劳动实践活动英语作文Embarking on a journey to cultivate tomatoes is not justa gardening endeavor; it's an enriching labor practice that intertwines with the essence of nature's cycle. As the first seeds were sown into the fertile soil, a sense ofanticipation took root alongside them. The process began with selecting the right variety of tomato plants, each promisinga burst of flavor and color that would later adorn our plates.The labor was meticulous, from preparing the soil with a blend of compost and nutrients to ensure a rich environmentfor growth, to the careful planting of each seedling,ensuring proper spacing for ample sunlight and aircirculation. Watering was a daily ritual, a dance with the hose that required patience and a gentle touch to avoid disturbing the tender sprouts.As the weeks unfolded, the plants responded to our care with a flourish of green leaves and the promise of fruit. Pruning became an art, as we learned to remove the lowerleaves and excess suckers to encourage upward growth and prevent disease. The sun's rays were our guide, ensuring that each plant basked in its warmth, while the gentle breeze was our companion, keeping the air fresh and the plants healthy.The true test of our labor came with the first signs of fruit. Tiny green orbs began to form, and with each passing day, they swelled and ripened into the vibrant reds andyellows we had been dreaming of. Harvesting was a moment of triumph, each tomato plucked with a sense of pride and accomplishment.This labor practice was more than just a lesson in horticulture; it was a lesson in patience, diligence, and the joy of seeing one's efforts come to fruition. The tomatoes we grew were not just a crop; they were a testament to the power of nature and the satisfaction that comes from nurturing life from the ground up.。
大学英语四级考试历年真题详解(精讲版)连载
大学英语四级考试2006年6 月真题Part Ⅰ Writing(30 minutes) 注意：此部分试题在答题卡1上。
Directions:For this part, you are allowed 30 minutes to write a short essay on the topic of Students Selecting Their Lecturers. You should write at least 120 words following the outline given below:1.有些大学允许学生自由选择某些课程的任课教师2.学生选择教师时所考虑的主要因素3.学生自选任课教师的益处和可能产生的问题Students Selecting Their LecturersPart Ⅱ Reading Comprehension (Skimming and Scanning）(15 minutes) Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions on Answer Sheet 1. For questions 1-7, mark Y(for YES)if the statement agrees with the information given in the passage; N(for NO）if the statement contradicts the information given in the passage; NG(for NOT GIVEN）if the information is not given in the passage. For questions 8-10, complete the sentences with the information given in the passage.HighwaysEarly in the 20th century, most of the streets and roads in the U.S. were made of dirt, brick, and cedar wood blocks. Built for horse, carriage, and foot traffic, they were usually poorly cared for and too narrow to accommodate (容纳）automobiles.With the increase in auto production, private turnpike (收费公路）companies under local authorities began to spring up, and by 1921 there were 387,000 miles of paved roads. Many were built using specifications of 19th century Scottish engineers Thomas Telford and John Macadam (for whom the macadam surface is named), whose specifications stressed the importance of adequate drainage. Beyond that, there were no national standards for size, weight restrictions, or commercial signs. During World War I, roads throughout the country were nearly destroyed by the weight of trucks. When General Eisenhower returned from Germany in 1919, after serving in the U.S. Army’s first transcontinental motor convoy (车队), he noted: “The old convoy had started me thinking about good, two-lane highways, but Germany’s Autobahn or motorway had made me see the wis dom of broader ribbons across the land”.It would take another war before the federal government would act on a national highway system. During World War II, a tremendous increase in trucks and new roads were required. The war demonstrated how critical highways were to the defense effort: thirteen per cent of defense plants received all their supplies by truck, and almost all other plants shipped more than half of their products by vehicle. The war also revealed that local control of highways had led to a confusing variety of design standards. Even federal and state highways did not follow basic standards. Some states allowed trucks up to 36,000 pounds, while others restricted anything over 7,000 pounds. A government study recommended a national highway system of 33,920 miles, and congress passed the Federal-Aid Highway Act of 1944, which called for strict contract-controlled design criteria.The interstate highway system was finally launched in 1956 and has been hailed as one of the greatest public projects of the century. To build its 44,000 mile web of highways, bridges, andtunnels, hundreds of unique engineering designs and solutions had to be worked out. Consider the many geographic features of the country: mountains, steep grades, wetlands, rivers, deserts and plains. Variables included the slope of the land, and the ability of the pavement to support the load. Innovative designs of roadways, tunnels, bridges, overpasses, and interchanges that could run through or bypass urban areas soon began to weave their way across the country, forever altering the face of America.Long-span, segmented-concrete, cable-stayed bridges such as Hale Boggs in Louisiana and the Sunshine Skyway in Florida, and remarkable tunnels like Fort MC Henry in Maryland and Mr. Baker i n Washington developed under the nation’s physical challenges. Traffic control systems and methods of construction developed under the interstate program soon influenced highway construction around the world, and were invaluable in improving the condition of urban streets and traffic patterns.Today, the interstate system links every major city in the U.S. and the U.S. with Canada and Mexico. Built with safety in mind the highways have wide lanes and shoulders, dividing medians, or barriers, long entry and exit lanes, curves engineered for safe turns, and limited access. The death rate on highways is half that of all other U.S. roads (0.86 deaths per 100 million passenger miles compared to 1.99 deaths per 100 million on all other roads).By opening the North American continent, highways have enabled consumer goods and services to reach people in remote and rural areas of the country, spurred the growth of suburbs, and provided people with greater options in terms of jobs, access to cultural programs, health care, and other benefits. Above all, the interstate system provides individuals with what they enrich most: personal freedom of mobility.The interstate system has been an essential element of the nation’s economic growth in terms of shipping and job creation: more than 75 percent of the nation’s freight deliveries arrive by truck. And most products that arrive by rail or air use interstates for the last leg of the journey by vehicle.Not only has the highway system affected the American economy by providing shipping routes, it has led to the growth of spin-off industries like service stations, motels, restaurants, and shopping centres. It has allowed the relocation of manufacturing plants and other industries from urban areas to rural.By the end of the century there was an immense network of paved roads, residential streets, expressways, and freeways built to support millions of vehicles, the high way system was officially renamed for Eisenhower to honor his vision and leadership. The year construction began he said: “Together, the united forces of our communication and transportation systems are dynamic elements in the very name we bear United States. Without them, we would be a mere alliance of many separate parts.”注意：此部分试题请在答题卡1上作答。
剑7Test3Passage2
剑7Test3Passage2Population Movements and GeneticsA Study of the origins and distribution of human populations used to be based on archaeological and fossil evidence. A number of techniques developed since the 1950s, however, have placed the study of these subjects on a sounder and more objective footing.The best information on early population movements is now being obtained from the 'archaeology of the living body', the clues to be found in genetic material.B Recent work on the problem of when people first entered the Americas is an example of the value of these new techniques. North-east Asia and Siberia have long been accepted as the launching ground for the first human colonizers of the New World. But was there one major wave of migration across the Bering Strait into the Americas, or several? And when did this event, or events, take place?In recent years, new clues have come from research into genetics, including the distribution of genetic markers in modern Native Americans.C An important project, led by the biological anthropologistRobert Williams, focused on the variants (called Gm allotypes) of one particular protein - immunoglobin G- found in the fluid portion of human blood. All proteins 'drift', or produce variants, over the generations, and members of an interbreeding human population will share a set of such variants. Thus, by comparing the Gm allotypes of two different populations (e.g. two Indian tribes), one can establish their genetic 'distance', which itself can be calibrated to give anindication of the length of time since these populations last interbred.D Williams and his colleagues sampled the blood of over 5,000 American Indians in western North America during a twenty- year period. They found that their Gm allotypes could be divided into two groups, one of which also corresponded to the genetic typing of Central and South American Indians. Other tests showed that the Inuit (or Eskimo) and Aleut formed a third group. From this evidence it was deduced that there had been three major waves of migrationacross the Bering Strait. The first, Paleo-lndian, wave more than 15,000 years ago was ancestral to all Central and South American Indians. The second wave, about 14,000-12,000 years ago, brought Na-Dene hunters, ancestors of the Navajo and Apache (who only migrated south from Canada about 600 or 700 years ago). The third wave, perhaps 10,000 or 9,000 years ago, saw the migration from North-east Asia of groups ancestral to the modern Eskimo and Aleut.E How far does other research support these conclusions ?Geneticist Douglas Wallace has studied mitochondrial DNA in blood samples from three widely separated Native American groups: Pima- Papago Indians in Arizona, Maya Indians on the Yucatan peninsula, Mexico, and Ticuna Indians in the Upper Amazon region of Brazil. As would have been predicted by Robert Williams's work, all three groups appear to be descended from the same ancestral (Paleo-lndian) population.F There are two other kinds of research that have thrown some light on the origins of the Native American population; they involve the study of teeth and of languages. The biological anthropologistChristy Turner is an expert in the analysis of changing physical characteristics in human teeth. He argues that tooth crowns and roots have a high genetic component, minimally affected by environmental and other factors. Studies carried out by Turner of many thousands of New and Old World specimens, both ancient and modern, suggest that the majority of prehistoric Americans are linked to Northern Asian populations by crown and root traits such as incisor shoveling (a scooping out on one or both surfaces of the tooth), single-rooted upper first premolars and triple-rooted lower first molars.According to Turner, this ties in with the idea of a single Paleo-lndianmigration out of North Asia, which he sets at before 14,000 years ago by calibrating rates of dental micro-evolution. Tooth analyses also suggest that there were two later migrations of Na-Denes and Eskimo- Aleut.G The linguist Joseph Greenberg has, since the 1950s, argued that all Native American languages belong to a single 'Amerind' family, except for Na-Dene and Eskimo-Aleut - a view that givescredence to the idea of three main migrations. Greenberg is in a minority among fellow linguists, most of whom favour the notion of a great many waves of migration to account for the more than 1,000 languages spoken at one time by American Indians. But there is no doubt that the new genetic and dental evidence provides strong backing for Greenberg's view. Dates given for the migrations should nevertheless be treated with caution, except where supported by hard archaeological evidence.……Passage2Population Movements and Genetics人口迁移与遗传学A Study of the origins and distribution of human populations used to be based on archaeological and fossil evidence. A number of techniques developed since the 1950s, however, have placed the study of these subjects on a sounder and more objective footing.The best information on early population movements is now being obtained from the 'archaeology of the living body', the clues to be found in genetic material.A 过去人们对人类起源与人口分布的研究一直是在考古发现和化石证据的基础上进行的。
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TestOn the Problem of Selecting InteractionObjectsFran¸c ois Bodart&Jean VanderdoncktInstitut d’Informatique,Facult´e s Universitaires Notre-Dame de la Paix,Rue Grandgagnage21,B-5000Namur,Belgium.Tel:+32(0)8172.50.06/72.49.75Fax:+32(0)8172.49.67EMail:fbodart,jvanderdonckt@info.fundp.ac.beThis paper surveys and critically examines the literature dealing with selectionrules for interaction objects.This analysis permits the definition of:i.the premises of selection rules in terms of attributes from an object-oriented data model;ii.the conclusions in terms of abstract interaction objects from an object-oriented model;andiii.a generalized definition of selection rules.Finally,it endeavours to provide a more complete set of selection rules forelementary,composite,and specific data.Keywords:interaction tools and techniques,interaction objects,design process,model-based interface tools,selection,object-oriented programming,user interface management systems.1.IntroductionThe problem of selecting interaction objects arises when all the application data already defined by a designer needs to befitted to a counterpart in the future user interface.The problem involves the selection of interaction objects(e.g.edit box,slider,dial,list box) that are appropriate to the users specifications,the specifications of application data,and the character of the physical environment.The purposes of this paper are:1.to highlight and examine the results of research conducted on selection rules andtools in order to automate this process(Section2);2.to propose a generalized definition of a selection rule(section3):2Fran¸c ois Bodart&Jean Vanderdonckt the premises are expressed according to an object-oriented data model(Section3.1).This model is made up of a user profile,application datafeatures and physical characteristics;the conclusion is expressed according to an object-oriented model of abstractinteraction objects(Section3.2);the generalized definition of a selection rule is therefore a logicalcombination of these premises and conclusions(Section3.3).3.to provide a complete and detailed series of selection rules that are in turn summarizedin decision tables(Section4).This corpus of decision tables could be incorporated into a graphic user interface styleguide,could be used for teaching and referencing purposes as well as potentially providing a foundation for automatic tools.The conclusion highlights some limits of this body of research which demand closer attention, among other things the need for improved formalization,continuous extension,and user validation(Section5).2.Related WorkMac IDA(Petoud&Pigneur,1990)generates windows according to an entity-relationship model.Its selection rules are fairly straightforward:a window is selected for each entity,a simple edit box is selected for each attribute of an entity,a table is selected for each repetitive aggregate of attributes and a pushbutton is designated for each function.These selection rules are independent of the semantic data since they do not vary.There are also non explicit since they are code embedded,and therefore unmodifiable and invisible.Selectors(Johnson,1992)seem to be a good example of where selection rules are explicitly given in terms of application semantics.It is correctly argued that,“semantic considerations play a role in the categorization and choice ofwidgets(interaction objects):designers work at a higher level than arrangingbuttons,textfields,and relations between them.”(Johnson,1992)DON(Kim&Foley,1990)introduced such selection rules after listing important factors for defining conditions:the data constructor type(e.g.enumerated,subrange),a spatial relationship(i.e.horizontal,vertical,or circular),selectability information(i.e.mutually exclusive,mutually compatible),editability information(i.e.writable or read-only),precision (i.e.high or low).DON’s selection rules are consequently semantic dependent and explicit, but still(apparently)unmodifiable and invisible to the eyes of the designer.In the same class,IBIS(Seligmann&Feiner,1991)applies an Intent Based Illustration System to the area of electronic engineering.It automatically generates front panels of electronic devices by using design rules that map intent to stylistic choice and style rules that map stylistic choices to visual effects.GENIUS(Janssen,Weisbecker&Ziegler,1993;Weisbecker,1993)on the other hand,employs nine selection rules which are detailed in Table1for generating a user interface for database-oriented interactive applications.On the Problem of Selecting Interaction Objects3 Type Selection Interaction objectvaluesalphanumeric unlimited reador writenumeric[1,6]selectionselectionsimple list boxnumeric[1,60]>60readwriteTable1:Decision table of selection rules in GENIUS.4Fran¸c ois Bodart&Jean VanderdoncktCircumstancesin dialog boxes,4choices,choose one,attributesin dialog boxes,4choices,choose many,attributesin dialog boxes,>4choices or dynamically changingdrop down list boxesnumber offixed choices,attributesin dialog boxes,dialog control actionsin application windows,data attributes3.A Generalized Definition of Selection Rules3.1.A Data ModelThe data model consists of an object-oriented model(Figure1)where application data can be divided into seven data types(i.e.hour,calendar,boolean,graphical,integer,real, and alphanumeric).These data types are considered to be the most frequent in business-oriented applications(Bodart et al.,1993)(e.g.office automation,administration,database applications).However,they are also considered to be incomplete when working with other dedicated applications(e.g.graphical editors,engineering laboratories).Each piece of general data is composed of several attributes:a data name:this is an identifier(e.g.PersonSize);the data length:the number of characters,if relevant(e.g.2);an identification label:this unique label identify the data to input/output and its nature(e.g.Size of the person:);a description label:this label specifies some constraints that must be verified by thedata in order to be valid,such as a unit measure,a valid domain or interval;the type of domain(as the limits in UIDE):whether the domain of the data is unknown, known,or mixed(that is a known domain with some unknown values the user can supply);the mandatory status:whether the data is required or not;the interaction(as introduction in GENIUS and content in UIDE):whether data is to be used as input,as display or used in both ways;the number of possible values(Npo for short)(as the range of values in GENIUS): this number can be1,2,or N if infinite(V anderdonckt&Bodart,1993);the number of principal values(Npv for short):the number of values which are most frequently used(V anderdonckt&Bodart,1993);the number of secondary values(Nsv for short):the number of values which are less frequently used such that the sum of principal values and secondary values is equal to the number of possible values(Npo=Npv+Nsv);On the Problem of Selecting Interaction Objects5Figure1:The object-oriented data model.6Fran¸c ois Bodart&Jean Vanderdonckt the number of values to be chosen—as in(Mayhew,1992),GENIUS and UIDE: this can be1,2,or N if infinite.If this number is equal to1,the data followsa simple course:after having chosen a piece of data,the user can only select onevalue at a time to manipulate that data.If the number is greater than1,the data follows a multiple path course:the user may wish to select two or more two values simultaneously;the selected interaction object:a pointer to a suggested entry in the abstract interaction model(see below).Different data types inherit the above mentioned attributes either by specialization(for example,the AlphanumericData object add the ExpandableDomain slot)or redefinition(for example,the domain is known for the GraphicalData objects,Npo=Npv=2,Nsv=0, Nvc=1for the BooleanData object).Specialization attributes include:domain expandability(Exp for short):whether the user can add own values;the precision(as in UIDE):whether the number of digits,or decimals is important;the continuity of the domain(Cont for short):whether all values are spread in a continuous range of values(e.g.x>7,[110]);the data orientation(as in DON):whether the data is more conveniently represented horizontally,vertically,circularly or in an undefined way;the screen density:whether the amount of data measured by presentation unit is high,low;the user level:whether the user experience level is beginner,novice,intermediate, expert or master;the selection preference:whether the user has a preference(or physical skill)for typing in data rather than selecting it.The last three attributes normally do not belong to the specification of application data,but they are provided apart.They are still inserted in the case of hour and calendar data types because the semantics of these cases are better known than the others.Some attributes(e.g. the identification label,the mandatory characteristic)will not serve for selection.They are introduced here for specifying the data model and forfinal generation of user interface.3.2.An Abstract Interaction Object ModelAn Abstract Interaction Object(AIO)Model(V anderdonckt&Bodart,1993)rather than a Concrete Interaction(CIO)Model is introduced to address three problems:1.different AIO can be used for input/display a same class of application data;2.several presentations(or CIO)can be found for one particular AIO:for instance,asame check box can have a lot of different presentations(Figure2);3.the AIO classification should be free of presentation considerations:behaviouralconsiderations should be abstract across different platforms(Johnson,1992).Defining an AIO involves abstracting the behaviours of CIO in order to be independent of a particular physical toolkit or library of interaction objects.Six sets of AIO have been identified:action objects,scrolling objects,static objects,control objects,dialog objects and feedback objects(V anderdonckt&Bodart,1993).These sets have been arranged in a hierarchical object-oriented model where each AIO is identified by a name,by general andOn the Problem of Selecting Interaction Objects7Figure2:Different CIO for one AIO.AIOname]Attribute=V alue AIO=[AIOname is the the designation for any AIO in the AIO model.4.A Corpus of Decision TablesA corpus of decision tables has been developed according to a hierarchy of types of selection rules(Figure3).Selection rules fall into two categories:rules for input data and rules for displaying data.Similar types of selection rules are found in both categories:rules for input/displaying elementary data(7supported data types),rules for taking into account the physical environment,rules for input/displaying specific kinds of data,group of data,and list of data(elementary and composite).Selection rules for window and dialog box are included in the‘display’division.Discussing every decision table that might be applied would be impossible.Therefore we refer to the technical report where all tables are explained(V anderdonckt,1993).We would rather focus on some decision tables and examples in order to illustrate the main ideas which prevail in the creation of the tables.These ideas are expressed in the form of underlying principles for selection rules.In order to introduce,to define and to illustrate these principles, we propose to show decision tables for input of integer data(elementary).8Fran¸c ois Bodart&Jean VanderdoncktFigure3:Hierarchy of selection rules.Nsv Cont Precision AIO>0list boxyesno[2,3][4,7][8,Tm][Tm+1,2Tm]>2Tmyes low scroll barscalepie diagramscaleverticalhorizontalcircularundefined[11,Tm]low scalehigh spin buttonverticalhorizontalcircularundefinedpropose to select a radio button if the number of possible values(Npo)is bounded by2and3 (Table3,Row3).A group box is then added if Npo is between4and7in order to clearly build a visual group(Table3,Row4).If the domain is expandable,an edit box is placed beneath the known values(Figure5)(Table6,Row2).Beyond the limit of8items,a list boxExp AIOno check boxescheck boxes+group boxlist boxScrolling list boxScrolling drop-down list box>0Table4:Selection rules for the input of an integer where domain is known and the choiceis multiple.DomainunknownTable5:Selection rule for the input of an integer where domain is unknown.Npo[2,3][4,7][8,Tm][Tm+1,2Tm]>2TmTable6:Selection rule for input an integer if domain is mixed.is recommended.The use of list box is also limited by Tullis’constant Tm=50so that if the Npo exceeds this constant,a scrolling list will be preferred instead.Figure5:A group box surrounding a radio button and an edit box.Figure7:(a)A dial;(b)A spin button.Figure8:A list box replaced with a drop-down list box.Figure9:Some scrolling cursors.4.2.8.Principle of Data GroupingThe goal of data grouping is to define selection rules when considering the input/display of data groups.This is often the case where semantically related data have to be grouped in an appropriate AIO whose definition support aggregation of data.For example,multiple group boxes can be selected for surrounding all AIO selected for elementary data.Figure10depicts a user interface where group boxes group data about the person,about his/her job,about his/her skills/orientation.4.2.9.Principle of Data ListingThe goal of this principle is to define selection rules used in the consideration of data list input/display.A common applicable case arises when the user provides multiple instances of a same aggregation of data.For example,a repetitive dialog box can be selected to enter a data-series whose type and definition are the same(Figure11).A normal table can be selected to input/display aggregates of data arranged in rows and columns on the condition that all data are elementary and can be expressed in simple edit boxes(Figure12).5.ConclusionDespite extensive research activity and experience in the selection of AIO,this work still suffers from several intrinsic drawbacks:Figure11:A repetitive dialog box for a list of data.a great number of selection rules(257for input and63for display)have been defined and detailed to increase the precision and the appropriateness of selection rules. However,this number becomes so high that the range of values become cumbersome to manipulate and master;the ergonomic richness of the selected AIO only becomes to be realized in cases where data are sufficiently specific.Given precisely limited circumstances,the most appropriate AIO can in such cases be deduced.Thus,the power of semantic formalization of the data model stops where selection rules for specific data begin. Therefore,the significance of these rules is not maximized.We believe that human perception of real world and these limits constrain the efficiency of the selection rules.On the other hand,a human actor who is an expert in a givenfield and thus is conversant with thefields’difficult-to-formulate tacit knowledge,this expert might be able to recommend the AIO that is most appropriate to specific circumstance. In other words,the time and effort to formalize this knowledge into selection rules would outweigh the benefits;our corpus of selection rules was mainly based on results,conventions and assumptions gathered from the experimental study mentioned in our different references(Mayhew,1992).The consistency between these selection rules is not always clear.A trade-off has been chosen when necessary;the selection rules have been expressed according to a strict production scheme: applying the set of selection rules therefore leads to one particular AIO.Sometimesalternative AIO should be considered equally.Fuzzy thinking should be added to express the likelihood of selecting a particular AIO rather than another one under particular circumstances;selection rules will always remain incomplete since they are based on existing AIO.If new AIO are born,new selection rules have to be defined;selection rules heavily depends on user habits and preferences:selecting the most appropriate AIO according to experimental criteria sometimes does not lead to a rational result.Experimental criteria are formal,but psychological preferences are not.It is not always explicit about the criteria used to judge how well the selection rules meet users’needs at different points in the interaction dialog;selection rules really need afinal user validation even though they are basically founded on proven theoretical and experimental results;selection rules strictly for business-oriented application have been studied.If they are to be extended to otherfields,recent research in the visualization of information according to the complex information types and structures should be considered. For our limited purposes,we can say that those selection rules have in most cases been proved sufficient.We do not get the impression that new rules would substantially improve the usability of a selected AIO,except under particular circumstances(e.g.for multimedia data). 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