Space-time interest points
Space exploration 太空探索的花销是否合理 英语作文
Space exploration requires vast sums of money. Is the amount of money spent on space research justifiable？Could the money be better spent？Model Essay 1What is your viewpoint on this issue? Give reasons for your answer. You should write at least 250 words.Model Essay 1:We all know that there is no perfect country in this world of ours. People face death through starvation every day due to the lack of money to buy food and other necessities, such as medication. Sometimes, there is a scarcity of these resources even if money is available. Inmy view, it is wrong for governments to spend enormous funds on their space exploration and astrophysics programs when there are poor people who are hungry and sick in their various countries.I believe that governments should make it a priority to spend money on providing the basic needs of people here on Earth before they use it for research towards exploring other planets. First of all, regardless of what country they may happen to live in - all people require food, clean water/sanitation, shelter and medication to protect themselves from viruses and bacterialinfections. Apart from these most basic and fundamental requirements, people also need a good education so that they can find stable jobs in order to support themselves and their families. Instead of allocating additional funding for space exploration, governments should realise the importance of maintaining a healthy populace. For example, the USA has spent more than 23 billion dollars in the last 30 years on research, rather than spending it on the basic needs of its citizens.Moreover, in America, there are over 6 million homeless people and more than 2 million otherswho have lost their houses because of foreclosure. Also, there are more than 5 million people who are HIV-positive and in need of treatment. If the U.S. Government would decide to spend an equal amount of money on medical research as it does on its space program, then scientists might be able to find better treatments for this devastating disease so that many lives could be saved.Secondly, many people in Africa have a lack of food, clean water and electricity. I believe that we have a moral and ethical duty to help Africa and other poor countries around the world. It isworthier to help those who share our own planet before we travel to the moon. As for myself, I did my pharmacy internship in Egypt, where I witnessed many examples of why it would be wise for the government to spend more money in the area of medical / pharmaceutical research. Many people there face pain and death every day because of the Hepatitis C Virus. This insidious virus is responsible for causing the deaths of more than 1 million people in Africa each year. The cost of medication to treat it is very high -- approximately 20,000 dollars per patient. On the other hand, Egypt has spent more than 200 million dollars on spaceexploration and researching other planets. I think that it would have been a much smarter choice for them to have used the money to provide medication for those who could not afford it.In summary, it is my viewpoint that governments should concentrate on solving their own internal problems by offering their citizens the basic requirements of life such as food, clean water/sanitation, shelter and medication. They should use any excess money for improving the lives of their inhabitants by providing them with educational opportunities sothat they can find decent jobs in order to become independent. It is important to fund academic pursuits such as space exploration and research in the field of Astrophysics, of course, but not at the expense of the lives of human beings who live on this planet.Model Answer 2:There has always been considerable discussion and debate about whether governments in many countries should spend taxpayers’ money on space research. In my view, it is impossible to justify the amount of money spent on space research. Generally speaking, the main reasonfor this position is that there are several areas in which the money could be invested better. When we have so many problems and hungry people in the Earth, spending money on space is not a good choice at all.The first point to make is that governments have a responsibility to spend public money on projects that bring a benefit to the citizens. This has not been the case with space research as most developments have been limited to helping astronauts in space or have been very specialised. For example, it is not of great value to the general public that we now have pens andbiros that can write upside down. This does not merit the huge amount of money spent. Little success has been made so far on space exploration except landing on the Moon or knowing that Mars had once been a place for living being. What good that can bring to people who are starving in many countries?The second point to make is that there are many much more urgent projects on Earth that require investment. If governments spent less money on space research, then they would be able to help solve some of these problems such as population control, elimination of diseaseslike cholera, global warming and food shortages. It seems to me that all of these issues are more important because they affect the lives of millions of ordinary people. An illustration of this is that the US government could provide food for all the starving people in the world if they did not spend so much on NASA.My conclusion is that politicians should not fund space research. The grounds for saying this are that it is very costly and provides little real benefits. Furthermore, there are several more urgent issues that need to be funded.。
莱埃尔电子有限公司产品说明：拉瓦雷特时间间隔计数器说明书
LAUREL ELECTRONICS, INC.Laureate™ Time Interval Meter Resolution to 0.2 µs for time of periodic events. Displays highly accurate rate based on 1 / time.Features•Times periodic events with width from 1 µs to 199.999 s•Display resolution to 0.2 µs•Rep rates to 250 kHz•Inputs from NPN or PNP proximity switches, contact closures, digital logic,magnetic pickups down to 12 mV, or AC inputs up to 250 Vac•Triggers on positive or negative pulse edges•Universal AC power, 85-264 Vac•Isolated 5, 10 or 24 Vdc excitation supply to power sensors•NEMA 4X, 1/8 DIN case•Optional serial I/O: Ethernet, USB, RS232, RS485, Ethernet-to-RS485 converter•Optional relay outputs: dual or quad relays, contact or solid state•Optional isolated analog output: 4-20 mA, 0-20 mA, 0-10V, -10 to +10V•Optional low voltage power: 10-48 Vdc or 12-32 Vac•Optional Extended Timer: features of standard timer plus rate based on 1/time DescriptionThe Laureate A-to-B Time Interval Meter can display pulsewidth or time delay between individual pulses to a resolution of0.2 µs. It can also display average pulse width or average timedelay between multiple pulses.Time interval is measured between inputs on channels A andB. Timing starts when a pulse is applied to Channel A (selectablepositive or negative edge), and ends when a pulse is applied toChannel B (selectable positive or negative edge). In case of asingle pulsed signal, the A and B inputs can be tied together. Apositive or negative slope may be selected to start timing, andthe opposite slope must be selected to stop timing. Timing isachieved by counting 5.5 MHz clock pulses. Multiple integral timeintervals are averaged over a gate time which is selectable from10 ms to 199.99 s and also controls the display update time.Time interval can be displayed in seconds, milliseconds, ormicroseconds with 6-digit resolution. In the typical application,time is displayed in milliseconds with 1 µs resolution. For timesless than 100 ms, display resolution down to 0.2 µs can beachieved by applying a multiplier of 10, moving the decimal pointby one position, and averaging many time intervals.Highly accurate rate can be displayed by taking the inverse oftime. Extensive arithmetic capabilities allow display inengineering units, such as meters/sec. Rate based on timerequires use of the Extended counter main board.The FR dual-channel signal conditioner board accepts inputsfrom proximity switches with PNP or NPN output, TTL or CMOSlogic, magnetic pickups, contact closures, and other signals from12 mV to 250 Vac. Jumper selections provide optimum operationfor different sensor types and noise conditions. A built-in isolated5, 10, or 24 Vdc excitation supply can power proximity switchesand other sensors, and eliminate the need for an external powersupply.Designed for system use. Optional plug-in boards includeEthernet and other serial communication boards, dual or quadrelay boards, and an isolated analog output board. Laureatesmay be powered from 85-264 Vac or optionally from 12-32 Vacor 10-48 Vdc. The display is available with red or green LEDs.The 1/8 DIN case meets NEMA 4X (IP65) specifications from thefront when panel mounted. Any setup functions and front panelkeys can be locked out for simplified usage and security. A built-in isolated 5, 10, or 24 Vdc excitation supply can power trans-ducers and eliminate the need for an external power supply.All power and signal connections are via UL / VDE / CSA ratedscrew clamp plugs.SpecificationsDisplayReadoutRangeIndicators6 LED digits, 7-segment, 14.2 mm (.56"), red or green-999999 to +999999Four LED lampsInputsTypes Grounding Minimum Signal Maximum Signal Noise Filter Contact Debounce AC, pulses from NPN, PNP transistors, contact closures, magnetic pickups. Common ground for channels A & BNine ranges from (-12 to +12 mV) to (+1.25 to +2.1V).250 Vac1 MHz, 30 kHz, 250 Hz (selectable)0, 3, 50 ms (selectable)Time Interval ModeTiming StartTiming StopPeriodic Timing Interval Gate TimeTime Before Zero Output Channel A pulse, + or - edges Channel B pulse, + or - edgesGate time + 30 ms + 0-2 time intervals Selectable 10 ms to 199.99 s Selectable 10 ms to 199.99 sResolution0 - 199.999 s 0 - 99.9999 s 0 - 9.99999 s 0 - .999999 s 0 - .099999 s 1 ms 100µs 10 µs 1 µs 0.2 µsAccuracyTime Base Span Tempco Long-term Drift Crystal calibrated to ±2 ppm ±1 ppm/°C (typ)±5 ppm/yearPowerVoltage, standard Voltage, optional Power frequency Power consumption (typical, base meter) Power isolation 85-264 Vac or 90-300 Vdc12-32 Vac or 10-48 VdcDC or 47-63 Hz1.2W @ 120 Vac, 1.5W @ 240 Vac, 1.3W @ 10 Vdc, 1.4W @ 20 Vdc, 1.55W @ 30 Vdc, 1.8W @ 40 Vdc,2.15W @ 48 Vdc250V rms working, 2.3 kV rms per 1 min testExcitation Output (standard)5 Vdc10 Vdc24 VdcOutput Isolation 5 Vdc ± 5%, 100 mA 10 Vdc ± 5%, 120 mA 24 Vdc ± 5%, 50 mA 50 Vdc to meter groundAnalog Output (optional)Output Levels Current compliance Voltage compliance Scaling Resolution Isolation 4-20 mA, 0-20 mA, 0-10V, -10 to +10V (single-output option) 4-20 mA, 0-20 mA, 0-10V (dual-output option)2 mA at 10V ( > 5 kΩ load)12V at 20 mA ( < 600Ω load)Zero and full scale adjustable from -99999 to +9999916 bits (0.0015% of full scale)250V rms working, 2.3 kV rms per 1 min test(dual analog outputs share the same ground)Relay Outputs (optional)Relay Types Current Ratings Output common Isolation 2 Form C contact relays or 4 Form A contact relays (NO)2 or 4 Form A, AC/DC solid state relays (NO)8A at 250 Vac or 24 Vdc for contact relays120 mA at 140 Vac or 180 Vdc for solid state relays Isolated commons for dual relays or each pair of quad relays 250V rms working, 2.3 kV rms per 1 min testSerial Data I/O (optional)Board SelectionsProtocols Data RatesDigital Addresses Isolation Ethernet, Ethernet-to-RS485 server, USB, USB-to-RS485 server, RS485 (dual RJ11), RS485 Modbus (dual RJ45), RS232 Modbus RTU, Modbus ASCII, Laurel ASCII protocol 300 to 19200 baud247 (Modbus), 31 (Laurel ASCII),250V rms working, 2.3 kV rms per 1 min testEnvironmental Operating Temperature Storage Temperature Relative Humidity Protection0°C to 55°C -40°C to 85°C95% at 40°C, non-condensingNEMA-4X (IP-65) when panel mountedElectrical ConnectionsMechanicalApplication ExamplesTime Interval Mode for Time DelayFor periodic pulses applied to A and B channels, time delays can be measured down to 0.2 µs resolution from the rising or falling edge of A to the rising or falling edge of B (selectable). Time Interval Mode for Pulse WidthThe width of periodic pulses (t1 or t2) can be measured by tying the A and B channels together. As for time delay, readings are averaged over a user-selectable gate time. Timing Process DynamicsThe start and stop pulses used for timing can be generated by the dual relay board in a Laureate panel meter or digital counter. For instance, the start and stop pulse edges can be created as temperature passes two alarm setpoints, or temperature cycles in a hysteresis control mode. Rate Based on 1 / TimeThe start and stop pulses used for timing can be generated by the dual relay board in a Laureate panel meter or digital counter. For instance, the start and stop pulse edges can be created as temperature passes two alarm setpoints, or temperature cycles in a hysteresis control mode.Replacing an Oscilloscope with a Laureate Time Interval MeterAn oscilloscope is great for viewing and timing pulses in a lab. However, in fixed installations where digital timing accuracy and control outputs are required, a low-cost Laureate time interval meter will be the instrument of choice. Resolution to 0.2 µs is feasible.Instrumenting a Pulsed Laser SystemSome of the many possibilities in instrumenting a pulsed laser system with Laureate dual-channelcounters: elapsed time, number of pulses, pulse width, pulse separation, duty cycle, and pulse rep rate.Ordering GuideCreate a model number in this format: L50000FR, IPCMain Board L5 Standard Main Board, Green LEDsL6 Standard Main Board, Red LEDsL7 Extended Main Board, Green LEDsL8 Extended Main Board, Red LEDsNote: Use of the Extended Main Board makes this counter also suitable for A-B time interval,frequency, rate, period, square root of rate, up or down total, arithmetic functions, simultaneousrate and total, phase, duty cycle, batching, and custom curve linearization.Power0 Isolated 85-264 Vac1 Isolated 12-32 Vac or 10-48 VdcRelay Output (isolated) 0 None1 Two 8A Contact Relays2 Two 120 mA Solid State Relays3 Four 8A Contact Relays4 Four 120 mA Solid State RelaysAnalog Output (isolated) 0 None1 Single isolated 4-20 mA, 0-20 mA, 0-10V, -10 to +10V2 Dual isolated 4-20 mA, 0-20 mA, 0-10VDigital Interface (isolated) 0 None1 RS2322 RS485 (dual RJ11 connectors)4 RS485 Modbus (dual RJ45 connectors)5 USB6 USB-to-RS485 converter7 Ethernet8 Ethernet-to-RS485 converterInput Type FR Dual-Channel Pulse Input Signal ConditionerAdd-on Options CBL01RJ11-to-DB9 cable. RJ11 to DB9. Connects RS232 ports of meter and PC.CBL02USB-to-DB9 adapter cable. Combination of CBL02 and CBL01 connects meter RS232port to PC USB port.CBL03-16-wire data cable, RJ11 to RJ11, 1 ft. Used to daisy chain meters via RS485.CBL03-76-wire data cable, RJ11 to RJ11, 7 ft. Used to daisy chain meters via RS485.CBL05USB cable, A-B. Connects USB ports of meter and PC.CBL06USB to RS485 adapter cable, half duplex, RJ11 to USB. Connects meter RS485 portto PC USB port.CASE1Benchtop laboratory case for one 1/8 DIN meterCASE2Benchtop laboratory case for two 1/8 DIN metersIPC Splash-proof coverBOX1NEMA-4 EnclosureBOX2NEMA-4 enclosure plus IPCBL Blank Lens without button padsNL Meter lens without button pads or Laurel logo。
对比尔盖茨的评价英文
对比尔盖茨的评价英文对比尔盖茨的评价英文----WORD文档，下载后可编辑修改----下面是小编收集整理的范本，欢迎您借鉴参考阅读和下载，侵删。
您的努力学习是为了更美好的未来！对比尔盖茨的评价英文篇一Bill Gates biography, a record of great people legendary experience of the book, is really worth seeing, a computer genius, a studious but not abide by the rules of the game characters, a dare to dare, consciousness ahead of the guy, one to one To help the elite can be united in one, to the hearts of the Microsoft Empire dominated the world occupation of the high-end market business leaders, a successful business owners, one of the world's richest but most generous people, this is my mind For Bill Gates, the world's richest man's impression.Bill Gates was born in a family of lawyers and teachers, so childhood was a very good education, his partners are very admire his childhood talent and the wisdom of speaking, they say Bill Gates as an adult people. Bill Gates was so interested in computers that he later decided to set up a company with his friend Paul.The turning point of his life is after graduating from primary school, came to Seattle private school Lakeside Middle School, of course, Lakeside high school, tuition is very expensive, $ 5,000 per semester, the school also attaches great importance to students with special abilities to encourage students to develop their hobbies and interests, The school is only 300 students, but this school is the first computer school courses in the United States, when the United States committed to the spacecraft on the moon, the community there is a surge in technology,Lakeside Middle School was the first to make wise decisions to introduce computer. It is this decision that has made this development in society now. Bill Gatesin the lake middle school shows his talent with the computer, although the class will doze, usually do not have top-notch academic, but this does not stop him to explore the mysteries of the computer, where he laid the foundation for aspirations to the world, also led to Microsoft The ultimate birth of the empire. After graduating from high school, entered the Harvard legal profession, but not interested in it, still a soft spot for the computer, and dissatisfaction with the Harvard system, two years later, with the support of friends, he fired the Harvard squid.Bill Gates succeeded in persuading his father and mother, and in the United States more desolate New Mexico established the Microsoft Corporation. Here, they have compiled a microcomputer with the real useless BASIC software. BASIC software has brought a lot of wealth to Microsoft, but the software industry is a fast-growing industry, Microsoft has gradually fallen behind, at this time, Bill and his team did not flinch, they moved the company to the research environment Good Seattle. In 1980, Microsoft was the largest computer hardware company IBM's praise, and IBM's cooperation, so that Microsoft's rapid, defeated Apple. Later, Microsoft also developed WINDOWS Windows and the Internet, Bill became the software market emperor. Microsoft's revenue in 2007 reached 51.12 billion US dollars, Bill changed the world, has become synonymous with the world's richest man.Gates can become a software overlord, smart is not the first, he did not want to put the second ambition is the real driving force for success, imagine there is such domineering, the worldwho can compete with it?A good business unit, is everyone wants to enter, because it can give you is a rich salary of materials, to give you a better life protection.But all the material is accumulated and created by the predecessors, you do not haveGates's "Ten Principles of Good Employee", Bill Gates answered us with his experience. First of all, you must love the enterprise, andself-enterprise products of interest, if even its people are not interested, you expect your products will produce a sensation in the market? Only you actively love it, you can find it Advantages, keep the missionary-like enthusiasm to promote your product, impress your customers, you can find it's shortcomings, you can make improvements to the views of the relevant departments, so that products will continue to improve, enterprises willMore thriving!In the book also illustrates the importance of responsibility. "People can not great, but not without responsibility", a responsible staff can be regarded as truly excellent staff!Bill Gates is the world's richest man, is a well-known legendary figure, his success has attracted worldwide attention, as teen idols. Bill Gates is not only of concern to his wealth, more importantly, his achievements in the cause of his legendary entrepreneurial experience and process. The author from the success of the perspective of the analysis of Bill Gates's success, the introduction of 11 guidelines to guide us to learn, to think. In this book is to succeed in the end, there are many incisive expositions and aphorisms, aphorisms, I learn from the following points:First, adhere to the only way to success."Success is a measure of the value of life ruler, it is the needfor human self-realization" Success is a state of life. So the success of all people to pursue and longing for the goal; However, to determine the goal is not easy, easy to achieve. Bill Gates also said, "fate is always full of elusive variables," to achieve the goal of success is a process, in this process to encounter frustrations and failures, to pay the price. So whether the difficulties and progress, and win the war, to determine the direction of Qierbushe, adhere to the established goal is an important part, there is no contract and do not insist in the end the spirit, easily halfway.Third, we must never insist on continuous progress."Winners are busy with hard work, never rely on the advent of luck," easy to meet, by luck to meet the desire is also one of the performance of the character of vulnerability. "Looking up at the ideal of self, not satisfied with the present self" "Success comes from the positive efforts, hard work and good at thinking" "by the desire and prayer is not enough, must be hands-on to achieve the ideal.For those tasted, Can not adhere to, adhere to, and then adhere to the attitude to complete their studies, to achieve the ideal of the young people, is inspiration is spur.Fourth, insist on success must restrict themselves.Success must start from the action, to choose their own do not give up the choice to do, and insist on seeking extraordinary from the ordinary, from small things, make a little money to start and so on, all of these arguments, such as: "Do not ignore the little things" "Do not want to get something for nothing" and so full of educating young people's philosophy.Everyone's success is not just standing in the spotlight smile when the brilliant so simple, it is through the back of the base of the drops of effort and sweat cast.1. Anti-piracy measures: bundled sales2. Maximize the potential of working in teams3. Do not fear failure, to correctly deal with failure, respect for failure, failure to be "cruel" analysis process.4. Work for successful people first, then with successful people, and finally let the successful people work for you.5. Through social relations to carry out business, which is attached importance to the development of a network of purposes.6. Start with hard work, master time, immediate action.7. Google browser competition in the use of the image of Google to。
基于粒子群算法优化最小二乘支持向量机在基坑施工过程中周围环境沉降预测研究
———————————————————————作者简介:任海龙（1989-），男，黑龙江齐齐哈尔人，本科，讲师，从事工程造价专业教学；张洁（通讯作者）（1989-），女，山东滨州人，硕士研究生，中级工程师，从事工程造价工作；马征（1991-），男，黑龙江鸡西人，助理工程师，硕士研究生，研究方向为岩土工程。
0引言由基坑施工引发周围环境的沉降是极为复杂且常见的现象，但基坑工程具有时间短、工序复杂、临空面暴露时间长的特点，这样会造成周围环境的沉降数据收集的时间少、样本数据不足等特性，因此，周围环境的沉降数据是一个小样本数据。
现有研究表明[1]基坑施工对周围环境沉降研究的方式、方法对观测数据依赖数据的依赖性较大，但现实情况往往不满足研究条件[2、3]，这就造成因预测精度不高导致的工程事故发生。
基于上述原因，如何在有限的样本数据中寻求内在规律对周围环境沉降量的快速、精准预测是十分必要的。
对现有研究总结发现[4、5]，LSSVM 模型在小样本数据的预测方面具有其优越性，但该模型对参数选择的依赖性较大，参数选择的优劣直接影响了该模型的预测精度[6、7]，因此，本文提出了由PSO （粒子群优化算法）优化LSSVM 模型（最小二乘支持向量机）参数选择的一种预测模型。
为了验证模型的可靠性，本文采用某市实测沉降量数据对比分析了PSO 算法，遗传算法等对预测精度进行定量分析。
1最小二乘支持向量机原理(LSSVM )训练数据的样本可以表示为，，。
其中x i 是输入向量，y i是目标值，在特征空间（R nf）中LSSVM 模型可表示为：（1）式中，ω∈R nf 为超平面的权值向量，φ（·）为非线性变换映射函数，将输入样本一维数据映射到高维特征空间（R n →R nf ）；b 为偏置量。
根据结构风险最小化原则，寻找ω和b 使（2）式最小化，即有：（2）式中，控制模型的复杂度，γ为误差惩罚因子，R emp 为误差控制函数。
expiration points gating
expiration points gatingExpiration Points Gating: Unlocking the Power of TimeIntroduction:Expiration points gating, also known as time gating, is a popular game design mechanic in which content or features are locked behind a time-based restriction. This technique has gained popularity in recent years due to its ability to create a sense of anticipation and urgency among players. In this article, we will explore the concept of expiration points gating, its benefits, drawbacks, and its impact on the gaming industry.What is Expiration Points Gating?Expiration points gating is a game design strategy in which players are required to wait for a certain amount of time before they can access new content or features in a game. This can be in the form of waiting for a cooldown period to expire, daily resets, or specific time-based events. It is a method employed by game developers to retain players and encourage them to log in regularly.Benefits of Expiration Points Gating:1. Player Engagement: Expiration points gating compels players toreturn to the game regularly, as they do not want to miss out on any valuable rewards or limited-time events. This creates a strong sense of engagement and investment in the game.2. Monetization Opportunities: The time restriction imposed by expiration points gating can be monetized through microtransactions. Players who do not want to wait can choose to pay to bypass the waiting period, providing developers with an additional revenue stream.3. Social Interaction: Time restrictions can be used to foster social interaction among players. By coordinating their schedules and activities, players can maximize the benefits of limited-time events or increase their chances of success.Drawbacks of Expiration Points Gating:1. Player Frustration: Expiration points gating can be frustrating for players who are unable to access content due to real-life commitments or time zone differences. This frustration can lead to player dissatisfaction and retention issues.2. Inequality Among Players: Players who have more time to spendon the game have a significant advantage over those who cannot invest as much time. This can create an imbalance among players and discourage casual gamers from continuing to play.3. Game Design Limitations: The implementation of expiration points gating may impact the design of other gameplay features. Developers may be forced to create additional content to fill the gaps in game progression, leading to a potential dilution of the overall gameplay experience.The Impact on the Gaming Industry:1. Evolution of Game Monetization: Expiration points gating has contributed to the evolution of game monetization models. Developers have moved away from traditional one-time purchases towards free-to-play with in-app purchases. This shift has allowed for continuous revenue generation and increased profitability.2. Changing Player Expectations: With the widespread use of expiration points gating in popular games, players have come to expect regular, time-restricted events and rewards. This has influenced game design across multiple genres and led to an emphasis on daily log-ins and engagement.3. Balance Between Engagement and Retention: Game developers must strike a balance between engaging players and retaining them. Excessive reliance on expiration points gating may lead to burnout or player fatigue, negatively impacting player retention in the long run.Conclusion:Expiration points gating is a game design technique that has both benefits and drawbacks. While it boosts player engagement, provides monetization opportunities, and encourages social interaction, it can also frustrate players, create inequalities, and limit game design flexibility. As the gaming industry continues to evolve, finding the right balance between engaging gameplay and respecting players' time will be crucial for sustainable success.。
2022-2023学年广东省揭阳市揭东区光正实验学校高三上学期第二次月考英语考试
2022-2023学年广东省揭阳市揭东区光正实验学校高三上学期第二次月考英语考试1. ASTRONAUT CAMP- FLORIDAHave you ever wanted to step into the shoes of an astronaut and experience rocket flight and cosmic(宇宙的)exploration? On this journey to Florida you will come as close as possible to this experience without actually traveling into space.Part 1-Visit the Planetarium(天文馆)From traditional star displays and cultural shows that detail the importance of astronomy around the world, to feature presentations that show the depths of outer space, the planetarium has something for curious stargazers of all ages.Part 2-Take Part in Mission SpaceWhat’s it like to be an astronaut? You’ll find out on Mission SPACE! Before you board,you’ll train for your mission on the X-2 Deep Space Shuttle at the International Space TrainingCenter(ISTC).Each member of your 4-cadet(学员)crew will assume an important role: navigator, pilot, commander or engineer.Part 3-Lunch with an AstronautThis 90-minute encounter at the Space Center in Cape features a buffet-style lunch along with a personalized presentation from one of celebrated astronauts. At the end of the event, there’s a brief question-and-answer session, plus time for family photos with the astronaut. Astronauts describe what it's like to live in space-eating, exercising, sleeping and training. No topic is off-limits.Part 4-Experience Rocket FlightEnter the Shuttle Launch Experience, and recreate the feeling of a space shot in real time, from the launch pad(发射台)to orbit. Adjust before six seconds, the main engines fire up, and as the speakers say“3, 2, 1….” the rocket launches.1. What does Mission Space include?A．Experiencing a space shot. B．Preparing for a space mission.C．Learning how to train your crew. D．Seeing the depth of outer space.2. In which part can you ask astronauts questions?A．At the Planetarium. B．On Mission SPACE.C．At Lunch with an Astronaut. D．In the Shuttle Launch Experience.3. What is the purpose of this journey?A．To show people modern star displays. B．To train people to be future astronautsC．To provide some knowledge of planetarium. D．To help people learn more about space travel.2. Tired of working in IT and staying the same in Australia, Paulo Cattaneo decided to make a change. In 2015 he started a strict budget so he could save up enough money to buy his dream KTM 1190 motorbike, a camera, and enough funds to support himself for a few years.Then he gave up his job, packed his things, and set off on an adventure, travelling the world on his motorbike. Paulo, 39, has spent the last four years biking through Australia, South America, North America, and Europe, riding up to 12 hours a day and spending his nights in his tent under the stars.“Australia for me was my first experience riding long distance and I was mind-blown by the beauty of the old continent.” Paulo wrote on his travel journal, “Traveling through Latin America, I explored the rainforest and learned Spanish and Portuguese. Mexico has some of the best food I ever had and Peru is an interesting place where I can enjoy the unique local Indian culture, also called Inca civilization.”Paulo has managed to keep his travels going by keeping his budget tight, so he hasn’t had to get a job for his travels. To keep costs low, he seldom looked for accommodation in hotels and went camping instead. Thankfully, the motorbike, which Paulo bought secondhand in Australia, has not required any major repairs since he set off. The journey isn’t always easy, but Paulo has never looked back.Sadly, the Covid-19 pandemic put a stop to his travels in Greece when he traveled around Europe, and Paulo has had to spend the last few months in Italy, his homeland. Once the world is back up and running, he plans to return to life on the road and explore Asia and Africa.1. What did Paulo begin to do in 2015?A．Change his job to live a better life.B．Collect enough money to buy a car.C．Travel the world on his motorbike.D．Prepare for his trip around the world.2. What is not mentioned in paragraph 2?A．The way to travel. B．The last destination of travel.C．The places he’d been to.D．The travel daily schedule of travel.3. What happened to him during Paulo’s trip?A．He enjoyed the best food in Peru.B．He got a job to support his travel.C．The motorbike often troubled him.D．The view in Australia attracted him.4. What can we learn from the last paragraph?A．Paulo was glad to return to his homeland.B．Paulo had to find accommodation in hotel.C．The Covid-19 couldn’t stop Paulo’s dream.D．Being alone was a challenge during Paulo’s trip .3. Human activity has shrunk (缩小) the size of wild animals worldwide, and yet recent research has found many mammals (哺乳动物) living near cities have gradually become larger, both in length and in weight. The findings are unexpected. Spreading urban environments can grow much hotter than natural habitats, and warmer temperatures usually benefit mammals that have a smaller, more energy-saving figure—a principle of biology known as Bergmann’s rule.As the world grows warmer, scientists have worried that mammals living near cities are going to grow smaller, possibly reducing their fitness and the fitness of their predators (捕食者). Even with climate change that might not happen. As it turns out, there is another factor affecting a mammal’s size that might exceed temperature, and that is food. In and around places with dense populations, where high-calorie human foods are more widely available and predators are fewer and farther in between, new research discovered that most of the mammal species studied appear to be growing in size, not shrinking. According to careful measurements of more than 100 species from North America, gathered from museum collections over the past 80 years, the main reason is not a city’s temperature. Instead, the greatest increases in weight and body length appear to lie among those mammals that live near humans, regardless of how hot their surroundings are.As climate change grows worse, there is, of course, the possibility that that might change, but at least for now, it seems wolves, deer, bats, and other mammals in North America could be affected more by city populations than city climates.If we want to protect mammals that exist today for the future, it’s important we kn ow how human civilization is influencing their size, behavior, and well-being. In a rapidly changing world, that knowledge could mean the difference between ongoing life and dying out.1. Why are the findings unexpected according to Paragraph 1?A．The temperature in cities is hotter than that in nature.B．Mammals around cities grow against Bergmann’s rule.C．The animals living in nature become bigger in size.D．The city temperature makes animals become smaller.2. What does the underlined word “dense” in Paragraph 2 mean?A．Large. B．Young. C．Working. D．Educated.3. Which of the following best supports the main idea of the text?A．Human activity has shrunk the size of wild animals.B．Climate matters most in determining the size of mammals.C．Mammals become larger with more food near cities.D．Living in hot surroundings shapes the size of mammals.4. What will the passage most probably talk about next?A．Human’s impact on the mammals’ development.B．Different ways to rescue the endangered city animals.C．How to help mammals adjust to the climate change.D．What healthy food can be given to city mammals.4. Researchers have long sought ways to design air conditioning systems that can work without such greenhouse gases as HFCS, but none has come close to being a direct replacement. A small Irish company, however, now states to have come up with an answer.Exergyn, based in Dublin, has been working on a 60kw prototype(原型机)which not only avoids HFCS, but also has the benefit of having few moving parts. The system uses a material called a shape-memory alloy(合金). SMAS, as they are known for short, have the unusual ability to return to a predetermined shape when heated. The SMAS produce heat when their shapes are changed by compression(压缩), and then absorb it when the pressure is gone and they return to their original shapes.Tony Ennis, Exergyn’s chairman, says this method of cooling is not only more environmentally friendly than an HFCS system, but will also be less expensive to buy and 30%～40% cheaper to run. It will be lighter and smaller, too. As for reliability, he says the prototype’s performance suggests the unit could operate for more than 40 years without a problem.When Dr. O’Toole, an expert in memory materials, cofounded Exergyn in 2012, his intention was to use the SMAS to create a system that would turn low grade waste heat into electricity. But the challenges presented by HFCS persuaded him that air conditioning would be a quicker way to bring the technology to market. Development is still continuing, but products may be only a few years away.He has not given up thoughts of producing electricity. He even wants to expand its application to other products, such as refrigerators and heat pumps to absorb heat from the ground for homeheat ing. When time allows, Dr. O’Toole and his colleagues hope to get to work on those ideas, too.1. What does the underlined word “predetermined” in paragraph 2 probably mean?A．Original. B．Different. C．Strange. D．Perfect.2. Exergyn’s air conditioner will be ________ than the HFCS system.A．more expensive B．more reliable C．bigger D．heavier3. Which product did Exergyn want to apply the SMAS to in 2012?A．Heat pumps. B．Air conditioning systems.C．Refrigerators. D．Waste-to-energy systems.4. Which of the following is a suitable title for the text?A．Challenges Presented by HFCSB．Potential Uses of Shape memory AlloysC．A NewHeat Pump With Few Moving PartsD．A New Air-conditioner Without Greenhouse Gases5. The 24 solar terms were created thousands of years ago in China to guide agricultural production. They also reflect China’s rich history through the seasonal festivals, special foods, cultural ceremonies, family gatherings and even healthy living tips that correspond with each solar term. 1Rain Water signals the increase in rainfall and rise in temperature. With its arrival, lively spring-like scenery starts blossoming: the river water defreezes, wild geese move from south to north and trees and grass turn green again.2 In northern China, the spring drought is common and the precipitation of this season accounts for only 10 to 15 percent of annual average rainfall. At this time of year, farmers begin to plough their fields. It’s the right time to prepare for spring sowing when the day gets warmer. 3During Rain Water period, extra care is needed to deal with a returning cold spell and humidity, which is the amount of water in the air. 4 It is strongly advised not to take off the thick coats too early and to keep warm, especially the elderly and children.The wet and humid weather during Rain Water period is considered harmful for people’s spleen and stomach according to Chinese medical practice. 5 People in Beijing often eat porridge (粥) cooked with a kind of Chinese herb medicine to resist cold and wet weather. Honey, dates and Chinese yam are also very good nourishment (营养) to put in the porridge6. Five years ago, when it was time for my cousin to start college, my 75-year-old grandfather, Rex, decided to do the same. He went to ______, taking classes twice a week until his death last summer.As a student, my grandfather spent countless hours in his office ______ and completing assignments. Although he was twice as ______ as his professors, he loved going. He said,“You can never ______ too much, no matter how old you are.” He loved everything about school. Learning new things was truly his passion.My grandfather’s will to learn was a great ______ for me to do my best in school. We were always ______ with each other, trying to bring home the better grade. When he turned 80 and still had a full head of hair, my grandfather even felt like he could take on the ______. He felt like he could beat the unstoppable no matter what came in his way---whether it was his continuing with cancer ______ a tough professor.Some people look to Superman or Batman as their ______, but my grandfather will forever be my hero, the ______ who always came to my rescue. My grandfather was made the hall of fame（名人堂） at his high school as one of the school’s most successful football players. When I did some research I _______that his nickname was Atlas. In Greek mythology（神话）, Atlas held the heavens on his shoulders. For my grandfather’s football team, he was ______ Atlas, holding the team together. He was my Atlas too, as the foundation of our family.In my times of need he was always there to ______ me and celebrate my success. I could count on him to help me out and stand by me. The strength he ______ with me will continue to hold me up asI forever keep his memory ______ in my heart and mind.1.A．college B．party C．hospital D．cinema2.A．teaching B．talking C．studying D．playing3.A．tall B．new C．thin D．old4.A．pay B．know C．think D．work5.A．example B．exercise C．method D．friend6.A．fighting B．working C．competing D．arguing7.A．world B．country C．city D．class8.A．and B．or C．so D．but9.A．grandfather B．student C．professor D．hero10.A．other B．only C．one D．same11.A．realized B．remembered C．discovered D．guessed12.A．my B．their C．his D．our13.A．surprise B．supply C．warm D．support14.A．enjoyed B．shared C．afforded D．kept15.A．alive B．awake C．alone D．asleep7. 阅读下面材料，在空白处填入1个适当的单词或括号内单词的正确形式。
ViewSonic PJD6383 短焦多imedia DLP 项目器说明说明书
ViewSonic’s PJD6383 multimedia DLP ® short-throw projector is ideal for education purposes showing images with high brightness and a defined resolution. It is compatible with the Crestron RoomView ® network management software that facilitates processes by acentralized monitor and allows management of multiple projectors monitoring over LAN or WLAN. DynamicEco ™ mode reduces power consumption and extends the projector’s lifespan where Dynamic Movie mode automatically adjusts the image brightness and contrast with the changing environments.Its exclusive technologies help teachers to provide a better teaching experience and save on total cost of ownership. Moreover, theprojector can be easily and efficiently managed by IT persons and is optimal for educational campuses or libraries. Versatile connectivity and an HDMI interface allow for connection with multimedia devices and increases content attractiveness for classrooms.Outstanding projection qualityWith its XGA resolution and 3,000 ANSI lumens, the PJD6383 delivers a sharp projection image and displays video contents with quality making it the first choice projector for the classroom.Planet-friendly DynamicEco ™ modeViewSonic’s exclusive DynamicEco™ mode reduces powerconsumption of the lamp up to 70% which extends lamp life as well as the projector’s lifespan. DynamicEco™ mode automatically kicks in when no signal is present or it can be manually enabled through a button on the remote. This feature also reduces fan noise and ultimately eliminates distractions. It also improves contrast ratio to 15,000:1 to tailor for professional projection performance.No space limitations with short throw functionWith its high quality short throw zoom lens, the PJD6383s delivers a 80-inch projected image at a distance of only 1.2 metres. Such a short distance allows users to share projected contents in limited space and enjoy larger presentations without interruption.Versatile connectivityVersatile connectivity including HDMI and RGB interfaces offerdiversity and high efficiency when displaying multi-media contents to enhance presentation.Crestron RoomView ® Network managementCrestron RoomView® provides an advanced, real-time alert system that sends status updates regarding power to the PC, lamp life and unit to simplify maintenance efforts. It also automates device scheduling, such as power on/off, and broadcast urgent messages via closed captioning. With smart network management, you’ll be able to save time, save money and save maintenance effort.Dynamic Movie mode for auto brightness and contrast detection With Dynamic Movie mode, the projector’s lamp automatically dims to strengthen and reveal fine details when displaying darker images. Dynamic Movie mode enhances image clarity, increases lamp life, reduces power consumption and noise.Enhanced audio quality with 10W speakerViewSonic’s PJD6383 DLP® projectors integrate a 10W speaker to provide high volume audio for classroom presentation without the need for external speakers.>>>>>>>XGA Short Throw with Network Management Projector for Education ApplicationModel No.VS14553*Running DynamicECO exclusively can extend lamp life. DLP and the DLP logo are registered trademarks of Texas Instruments and BrilliantColor is a trademark of Texas Instruments. All rights reserved b y ViewSonic Corporation. All other Corporate names and trademarks are the property of their respective companies. E&EO. Specifications are subject to change without notice. Images are for illustrative purpose only.Copyright © 2012 ViewSonic Corporation. All rights reserved. [VSE08/08/2012] PJD6383.HIGH RESOLUTION PROJECTOR FOR PERFECT CLASSROOM PRESENTATIONSPJD6383ViewSonic Corporation’s QMS & EMS have been registered to ISO 9001 & ISO 14001, respectively,by the British Standards Institution.Soft Carry CasePJ-CASE-0013D Active Shutter Glasses PGD-2503D Processor BoxVP3D1Projection Distance Screen Size (aspect ratio4:3)Meters Inches 0.5400.6500.7600.9701801.1901.2100Focus AdjustmentMini USB RS-232LAN HDMIS-Video Audio InAudio Out PowerMonitor Out。
时空手表的英语作文
时空手表的英语作文The time and space watch is an incredible invention that has revolutionized the way we perceive and interact with time. This remarkable piece of technology allows its wearer to not only tell time, but also to navigate through different points in time and space.The watch's sleek and stylish design is complemented byits advanced features, including a time-travel module that enables the user to explore different moments in history. Whether it's visiting ancient civilizations or witnessing key moments in world history, the time and space watch offers an unparalleled experience.In addition to its time-travel capabilities, the watchalso serves as a reliable timepiece, ensuring that its wearer is always punctual and on schedule. Its precision engineeringand state-of-the-art technology make it a must-have accessory for anyone with a keen interest in time and space.Furthermore, the watch's ability to transcend the constraints of time and space has significant implicationsfor scientific research and exploration. By providing scientists and researchers with the means to observedifferent periods in history, the watch has the potential to unlock countless mysteries and contribute to our understanding of the universe.From a practical standpoint, the time and space watch has also proven to be invaluable in various fields, such as archaeology, history, and space exploration. Its ability to provide firsthand access to historical events and distant planets is unprecedented, making it an indispensable tool for professionals in these fields.In conclusion, the time and space watch is a groundbreaking innovation that has redefined our relationshipwith time and space. Its extraordinary capabilities and potential applications make it a true marvel of modern technology, with far-reaching implications for science, exploration, and our understanding of the world around us.。
Unit4SpaceExplorationLanguagePoints2知识点讲义高中英语人教版
B3U4 Language Points 2Period 3 Discovering Useful Structures & Listening and Talking4.beyond(prep.)在更远处on or to the further side of sth; 超出Sending people to other planets or even beyond the solar system is not an easy goal to achieve.把人类送到其他行星甚至太阳系以外的地方不是一个容易实现的目标。
I watched him dive into the waves just beyond the horizon.我看见他一头扎进海浪里，消失在地平线处。
Potter trusted Black beyond all his other friend.波特信任布莱克，这种信任超过对其他所有朋友的信任。
(超出；除...之外more than tha t)What Joke had done was beyond my prehension.我无法理解Joke的所作所为。
(无法（理解、相信等）) The situation was beyond her control.局势并非她能控制。
(非...能力所及；超出...的能力)back.例如，使用当前的技术，到达（离地球）最近的行星火星并且返回，需要两年多的时间。
current prices时价 a budget for the current year今天的预算(当前的；现在的)words that are no longer current已不再通用的词(通用的；流通的；流行)cold/warm currents 寒流/暖流 a 15 amp electrical current 15安培的电流a strong current of nationalism一股强烈的民族主义思潮Twelve potential vaccines are currently being tested on human volunteers.目前正在人类志愿者身上试验12种试用疫苗。
State Space Reconstruction for Multivariate Time Series Prediction
a r X i v :0809.2220v 1 [n l i n .C D ] 12 S e p 2008APS/123-QEDState Space Reconstruction for Multivariate Time Series PredictionI.Vlachos ∗and D.Kugiumtzis †Department of Mathematical,Physical and Computational Sciences,Faculty of Technology,Aristotle University of Thessaloniki,Greece(Dated:September 12,2008)In the nonlinear prediction of scalar time series,the common practice is to reconstruct the state space using time-delay embedding and apply a local model on neighborhoods of the reconstructed space.The method of false nearest neighbors is often used to estimate the embedding dimension.For prediction purposes,the optimal embedding dimension can also be estimated by some prediction error minimization criterion.We investigate the proper state space reconstruction for multivariate time series and modify the two abovementioned criteria to search for optimal embedding in the set of the variables and their delays.We pinpoint the problems that can arise in each case and compare the state space reconstructions (suggested by each of the two methods)on the predictive ability of the local model that uses each of them.Results obtained from Monte Carlo simulations on known chaotic maps revealed the non-uniqueness of optimum reconstruction in the multivariate case and showed that prediction criteria perform better when the task is prediction.PACS numbers:05.45.Tp,02.50.Sk,05.45.aKeywords:nonlinear analysis,multivariate analysis,time series,local prediction,state space reconstructionI.INTRODUCTIONSince its publication Takens’Embedding Theorem [1](and its extension,the Fractal Delay Embedding Preva-lence Theorem by Sauer et al.[2])has been used in time series analysis in many different settings ranging from system characterization and approximation of invariant quantities,such as correlation dimension and Lyapunov exponents,to prediction and noise-filtering [3].The Em-bedding Theorem implies that although the true dynam-ics of a system may not be known,equivalent dynamics can be obtained under suitable conditions using time de-lays of a single time series,treated as an one-dimensional projection of the system trajectory.Most applications of the Embedding Theorem deal with univariate time series,but often measurements of more than one quantities related to the same dynamical system are available.One of the first uses of multivari-ate embedding was in the context of spatially extended systems where embedding vectors were constructed from data representing the same quantity measured simulta-neously at different locations [4,5].Multivariate em-bedding was used for noise reduction [6]and for surro-gate data generation with equal individual delay times and equal embedding dimensions for each time series [7].In nonlinear multivariate prediction,the prediction with local models on a space reconstructed from a different time series of the same system was studied in [8].This study was extended in [9]by having the reconstruction utilize all of the observed time series.Multivariate em-bedding with the use of independent components analysis was considered in [10]and more recently multivariate em-2as x n=h(y n).Despite the apparent loss of information of the system dynamics by the projection,the system dynamics may be recovered through suitable state space reconstruction from the scalar time series.A.Reconstruction of the state space According to Taken’s embedding theorem a trajectory formed by the points x n of time-delayed components from the time series{x n}N n=1asx n=(x n−(m−1)τ,x n−(m−2)τ,...,x n),(1)under certain genericity assumptions,is an one-to-one mapping of the original trajectory of y n provided that m is large enough.Given that the dynamical system“lives”on an attrac-tor A⊂Γ,the reconstructed attractor˜A through the use of the time-delay vectors is topologically equivalent to A.A sufficient condition for an appropriate unfolding of the attractor is m≥2d+1where d is the box-counting dimension of A.The embedding process is visualized in the following graphy n∈A⊂ΓF→y n+1∈A⊂Γ↓h↓hx n∈R x n+1∈R↓e↓ex n∈˜A⊂R m G→x n+1∈˜A⊂R mwhere e is the embedding procedure creating the delay vectors from the time series and G is the reconstructed dynamical system on˜A.G preserves properties of the unknown F on the unknown attractor A that do not change under smooth coordinate transformations.B.Univariate local predictionFor a given state space reconstruction,the local predic-tion at a target point x n is made with a model estimated on the K nearest neighboring points to x n.The local model can have a simple form,such as the zeroth order model(the average of the images of the nearest neigh-bors),but here we consider the linear modelˆx n+1=a(n)x n+b(n),where the superscript(n)denotes the dependence of the model parameters(a(n)and b(n))on the neighborhood of x n.The neighborhood at each target point is defined either by afixed number K of nearest neighbors or by a distance determining the borders of the neighborhood giving a varying K with x n.C.Selection of embedding parametersThe two parameters of the delay embedding in(1)are the embedding dimension m,i.e.the number of compo-nents in x n and the delay timeτ.We skip the discussion on the selection ofτas it is typically set to1in the case of discrete systems that we focus on.Among the ap-proaches for the selection of m we choose the most popu-lar method of false nearest neighbors(FNN)and present it briefly below[13].The measurement function h projects distant points {y n}of the original attractor to close values of{x n}.A small m may still give badly projected points and we seek the reconstructed state space of the smallest embed-ding dimension m that unfolds the attractor.This idea is implemented as follows.For each point x m n in the m-dimensional reconstructed state space,the distance from its nearest neighbor x mn(1)is calculated,d(x m n,x mn(1))=x m n−x mn(1).The dimension of the reconstructed state space is augmented by1and the new distance of thesevectors is calculated,d(x m+1n,x m+1n(1))= x m+1n−x m+1n(1). If the ratio of the two distances exceeds a predefined tol-erance threshold r the two neighbors are classified as false neighbors,i.e.r n(m)=d(x m+1n,x m+1n(1))3 III.MULTIV ARIATE EMBEDDINGIn Section II we gave a summary of the reconstructiontechnique for a deterministic dynamical system from ascalar time series generated by the system.However,it ispossible that more than one time series are observed thatare possibly related to the system under investigation.For p time series measured simultaneously from the samedynamical system,a measurement function H:Γ→R pis decomposed to h i,i=1,...,p,defined as in Section II,giving each a time series{x i,n}N n=1.According to the dis-cussion on univariate embedding any of the p time seriescan be used for reconstruction of the system dynamics,or better,the most suitable time series could be selectedafter proper investigation.In a different approach all theavailable time series are considered and the analysis ofthe univariate time series is adjusted to the multivariatetime series.A.From univariate to multivariate embeddingGiven that there are p time series{x i,n}N n=1,i=1,...,p,the equivalent to the reconstructed state vec-tor in(1)for the case of multivariate embedding is of theformx n=(x1,n−(m1−1)τ1,x1,n−(m1−2)τ1,...,x1,n,x2,n−(m2−1)τ2,...,x2,n,...,x p,n)(3)and are defined by an embedding dimension vector m= (m1,...,m p)that indicates the number of components used from each time series and a time delay vector τ=(τ1,...,τp)that gives the delays for each time series. The corresponding graph for the multivariate embedding process is shown below.y n∈A⊂ΓF→y n+1∈A⊂Γւh1↓h2...ցhpւh1↓h2...ցhpx1,n x2,n...x p,n x1,n+1x2,n+1...x p,n+1ցe↓e...ւeցe↓e...ւex n∈˜A⊂R M G→x n+1∈˜A⊂R MThe total embedding dimension M is the sum of the individual embedding dimensions for each time seriesM= p i=1m i.Note that if redundant or irrelevant information is present in the p time series,only a sub-set of them may be represented in the optimal recon-structed points x n.The selection of m andτfollows the same principles as for the univariate case:the attrac-tor should be fully unfolded and the components of the embedding vectors should be uncorrelated.A simple se-lection rule suggests that all individual delay times and embedding dimensions are the same,i.e.m=m1and τ=τ1with1a p-vector of ones[6,7].Here,we set againτi=1,i=1,...,p,but we consider bothfixed and varying m i in the implementation of the FNN method (see Section III D).B.Multivariate local predictionThe prediction for each time series x i,n,i=1,...,p,is performed separately by p local models,estimated as in the case of univariate time series,but for reconstructed points formed potentially from all p time series as given in(3)(e.g.see[9]).We propose an extension of the NRMSE for the pre-diction of one time series to account for the error vec-tors comprised of the individual prediction errors for each of the predicted time series.If we have one step ahead predictions for the p available time series,i.e.ˆx i,n, i=1,...,p(for a range of current times n−1),we define the multivariate NRMSENRMSE=n (x1,n−¯x1,...,x p,n−¯x p) 2(4)where¯x i is the mean of the actual values of x i,n over all target times n.C.Problems and restrictions of multivariatereconstructionsA major problem in the multivariate case is the prob-lem of identification.There are often not unique m and τembedding parameters that unfold fully the attractor.A trivial example is the Henon map[17]x n+1=1.4−x2n+y ny n+1=0.3x n(5) It is known that for the state space reconstruction from the observable x n the appropriate embedding parame-ters are m=2andτ=1.Due to the fact that y n is a lagged multiple of x n the attractor can obviously be reconstructed from the bivariate time series{x n,y n} equally well with any of the following two-dimensional embedding schemesx n=(x n,x n−1)x n=(x n,y n)x n=(y n,y n−1) since they are essentially the same.This example shows also the problem of redundant information,e.g.the state space reconstruction would not improve by augmenting the delay vector x n=(x n,x n−1)with the component y n that actually duplicates x n−1.Redundancy is inevitable in multivariate time series as synchronous observations of the different time series are generally correlated and the fact that these observations are used as components in the same embedding vector adds redundant information in them.We note here that in the case of continuous dynamical systems,the delay parameterτi may be se-lected so that the components of the i time series are not correlated with each other,but this does not imply that they are not correlated to components from another time series.4 A different problem is that of irrelevance,whenseries that are not generated by the same dynamicaltem are included in the reconstruction procedure.may be the case even when a time series is connectedtime series generated by the system underAn issue of concern is also the fact thatdata don’t always have the same data ranges andtances calculated on delay vectors withdifferent ranges may depend highly on only some ofcomponents.So it is often preferred to scale all theto have either the same variance or be in the samerange.For our study we choose to scale the data torange[0,1].D.Selection of the embedding dimension vector Taking into account the problems in the state space reconstruction from multivariate time series,we present three methods for determining m,two based on the false nearest neighbor algorithm,which we name FNN1and FNN2,and one based on local models which we call pre-diction error minimization criterion(PEM).The main idea of the FNN algorithms is as for the univariate case.Starting from a small value the embed-ding dimension is increased by including delay compo-nents from the p time series and the percentage of the false nearest neighbors is calculated until it falls to the zero level.The difference of the two FNN methods is on the way that m is increased.For FNN1we restrict the state space reconstruction to use the same embedding dimension for each of the p time series,i.e.m=(m,m,...,m)for a given m.To assess whether m is sufficient,we consider all delay embeddings derived by augmenting the state vector of embedding di-mension vector(m,m,...,m)with a single delayed vari-able from any of the p time series.Thus the check for false nearest neighbors in(2)yields the increase from the embedding dimension vector(m,m,...,m)to each of the embedding dimension vectors(m+1,m,...,m), (m,m+1,...,m),...,(m,m,...,m+1).Then the algo-rithm stops at the optimal m=(m,m,...,m)if the zero level percentage of false nearest neighbors is obtained for all p cases.A sketch of thefirst two steps for a bivariate time series is shown in Figure1(a).This method has been commonly used in multivariate reconstruction and is more appropriate for spatiotem-porally distributed data(e.g.see the software package TISEAN[18]).A potential drawback of FNN1is that the selected total embedding dimension M is always a multiple of p,possibly introducing redundant informa-tion in the embedding vectors.We modify the algorithm of FNN1to account for any form of the embedding dimension vector m and the total embedding dimension M is increased by one at each step of the algorithm.Let us suppose that the algorithm has reached at some step the total embedding dimension M. For this M all the combinations of the components of the embedding dimension vector m=(m1,m2,...,m p)are considered under the condition M= p i=1m i.Then for each such m=(m1,m2,...,m p)all the possible augmen-tations with one dimension are checked for false nearest neighbors,i.e.(m1+1,m2,...,m p),(m1,m2+1,...,m p), ...,(m1,m2,...,m p+1).A sketch of thefirst two steps of the extended FNN algorithm,denoted as FNN2,for a bivariate time series is shown in Figure1(b).The termination criterion is the drop of the percent-age of false nearest neighbors to the zero level at every increase of M by one for at least one embedding dimen-sion vector(m1,m2,...,m p).If more than one embedding dimension vectors fulfill this criterion,the one with the smallest cumulative FNN percentage is selected,where the cumulative FNN percentage is the sum of the p FNN percentages for the increase by one of the respective com-ponent of the embedding dimension vector.The PEM criterion for the selection of m= (m1,m2,...,m p)is simply the extension of the goodness-of-fit or prediction criterion in the univariate case to account for the multiple ways the delay vector can be formed from the multivariate time series.Thus for all possible p-plets of(m1,m2,...,m p)from(1,0,...,0), (0,1,...,0),etc up to some vector of maximum embed-ding dimensions(m max,m max,...,m max),the respective reconstructed state spaces are created,local linear mod-els are applied and out-of-sample prediction errors are computed.So,totally p m max−1embedding dimension vectors are compared and the optimal is the one that gives the smallest multivariate NRMSE as defined in(4).IV.MONTE CARLO SIMULATIONS ANDRESULTSA.Monte Carlo setupWe test the three methods by performing Monte Carlo simulations on a variety of known nonlinear dynamical systems.The embedding dimension vectors are selected using the three methods on100different realizations of each system and the most frequently selected embedding dimension vectors for each method are tracked.Also,for each realization and selected embedding dimension vec-5ate NRMSE over the100realizations for each method is then used as an indicator of the performance of each method in prediction.The selection of the embedding dimension vector by FNN1,FNN2and PEM is done on thefirst three quarters of the data,N1=3N/4,and the multivariate NRMSE is computed on the last quarter of the data(N−N1).For PEM,the same split is used on the N1data,so that N2= 3N1/4data are used tofind the neighbors(training set) and the rest N1−N2are used to compute the multivariate NRMSE(test set)and decide for the optimal embedding dimension vector.A sketch of the split of the data is shown in Figure2.The number of neighbors for the local models in PEM varies with N and we set K N=10,25,50 for time series lengths N=512,2048,8192,respectively. The parameters of the local linear model are estimated by ordinary least squares.For all methods the investigation is restricted to m max=5.The multivariate time series are derived from nonlin-ear maps of varying dimension and complexity as well as spatially extended maps.The results are given below for each system.B.One and two Ikeda mapsThe Ikeda map is an example of a discrete low-dimensional chaotic system in two variables(x n,y n)de-fined by the equations[19]z n+1=1+0.9exp(0.4i−6i/(1+|z n|2)),x n=Re(z n),y n=Im(z n),where Re and Im denote the real and imaginary part,re-spectively,of the complex variable z n.Given the bivari-ate time series of(x n,y n),both FNN methods identify the original vector x n=(x n,y n)andfind m=(1,1)as optimal at all realizations,as shown in Table I.On the other hand,the PEM criterionfinds over-embedding as optimal,but this improves slightly the pre-diction,which as expected improves with the increase of N.Next we consider the sum of two Ikeda maps as a more complex and higher dimensional system.The bivariateI:Dimension vectors and NRMSE for the Ikeda map.2,3and4contain the embedding dimension vectorsby their respective frequency of occurrenceNRMSEFNN1PEM FNN2 512(1,1)1000.0510.032 (1,1)100(2,2)1000.028 8192(1,1)1000.0130.003II:Dimension vectors and NRMSE for the sum ofmapsNRMSEFNN1PEM FNN2 512(2,2)650.4560.447(1,3)26(3,3)95(2,3)540.365(2,2)3(2,2)448192(2,3)430.2600.251(1,4)37time series are generated asx n=Re(z1,n+z2,n),y n=Im(z1,n+z2,n).The results of the Monte Carlo simulations shown in Ta-ble II suggest that the prediction worsens dramatically from that in Table I and the total embedding dimension M increases with N.The FNN2criterion generally gives multiple optimal m structures across realizations and PEM does the same but only for small N.This indicates that high complex-ity degrades the performance of the algorithms for small sample sizes.PEM is again best for predictions but over-all we do not observe large differences in the three meth-ods.An interesting observation is that although FNN2finds two optimal m with high frequencies they both give the same M.This reflects the problem of identification, where different m unfold the attractor equally well.This feature cannot be observed in FNN1because the FNN1 algorithm inspects fewer possible vectors and only one for each M,where M can only be multiple of p(in this case(1,1)for M=2,(2,2)for M=4,etc).On the other hand,PEM criterion seems to converge to a single m for large N,which means that for the sum of the two Ikeda maps this particular structure gives best prediction re-sults.Note that there is no reason that the embedding dimension vectors derived from FNN2and PEM should match as they are selected under different conditions. Moreover,it is expected that the m selected by PEM gives always the lowest average of multivariate NRMSE as it is selected to optimize prediction.TABLE III:Dimension vectors and NRMSE for the KDR mapNRMSE FNN1PEM FNN2512(0,0,2,2)30(1,1,1,1)160.7760.629 (1,1,1,1)55(2,2,2,2)39(0,2,1,1)79(0,1,0,1)130.6598192(2,1,1,1)40(1,1,1,1)140.5580.373TABLE IV:Dimension vectors and NRMSE for system of Driver-Response Henon systemEmbedding dimensionsN FNN1PEM FNN2512(2,2)100(2,2)75(2,1)100.196(2,2)100(3,2)33(2,2)250.127(2,2)100(3,0)31(0,3)270.0122048(2,2)100(2,2)1000.093(2,2)100(3,3)45(4,3)450.084(2,2)100(0,3)20(3,0)190.0068192(2,2)100(2,2)1000.051(2,2)100(3,3)72(4,3)250.027(2,2)100(0,4)31(4,0)300.002TABLE V:Dimension vectors and NRMSE for Lattice of3coupled Henon mapsEmbedding dimensionsN FNN1PEM FNN2512(2,2,2)94(1,1,1)6(1,2,1)29(1,1,2)230.298(2,2,2)98(1,1,1)2(2,0,2)44(2,1,1)220.2282048(2,2,2)100(1,2,2)34(2,2,1)300.203(2,2,2)100(2,1,2)48(2,0,2)410.1318192(2,2,2)100(2,2,2)97(3,2,3)30.174(2,2,2)100(2,1,2)79(3,2,3)190.084NRMSEC FNN2FNN1PEM0.4(1,1,1,1)42(1,0,2,1)170.2850.2880.8(1,1,1,1)40(1,0,1,2)170.3140.2910.4(1,1,1,1)88(1,1,1,2)70.2290.1900.8(1,1,1,1)36(1,0,2,1)330.2250.1630.4(1,1,1,1)85(1,2,1,1)80.1970.1370.8(1,2,0,1)31(1,0,2,1)220.1310.072 PEM cannot distinguish the two time series and selectswith almost equal frequencies vectors of the form(m,0)and(0,m)giving again over-embedding as N increases.Thus PEM does not reveal the coupling structure of theunderlying system and picks any embedding dimensionstructure among a range of structures that give essen-tially equivalent predictions.Here FNN2seems to de-tect sufficiently the underlying coupling structure in thesystem resulting in a smaller total embedding dimensionthat gives however the same level of prediction as thelarger M suggested by FNN1and slightly smaller thanthe even larger M found by PEM.ttices of coupled Henon mapsThe last system is an example of spatiotemporal chaosand is defined as a lattice of k coupled Henon maps{x i,n,y i,n}k i=1[22]specified by the equationsx i,n+1=1.4−((1−C)x i,n+C(x i−1,n+x i+1,n)ple size,at least for the sizes we used in the simulations. Such a feature shows lack of consistency of the PEM cri-terion and suggests that the selection is led from factors inherent in the prediction process rather than the quality of the reconstructed attractor.For example the increase of embedding dimension with the sample size can be ex-plained by the fact that more data lead to abundance of close neighbors used in local prediction models and this in turn suggests that augmenting the embedding vectors would allow to locate the K neighbors used in the model. On the other hand,the two schemes used here that ex-tend the method of false nearest neighbors(FNN)to mul-tivariate time series aim atfinding minimum embedding that unfolds the attractor,but often a higher embedding gives better prediction results.In particular,the sec-ond scheme(FNN2)that explores all possible embedding structures gives consistent selection of an embedding of smaller dimension than that selected by PEM.Moreover, this embedding could be justified by the underlying dy-namics of the known systems we tested.However,lack of consistency of the selected embedding was observed with all methods for small sample sizes(somehow expected due to large variance of any estimate)and for the cou-pled maps(probably due to the presence of more than one optimal embeddings).In this work,we used only a prediction performance criterion to assess the quality of state space reconstruc-tion,mainly because it has the most practical relevance. There is no reason to expect that PEM would be found best if the assessment was done using another criterion not based on prediction.However,the reference(true)value of other measures,such as the correlation dimen-sion,are not known for all systems used in this study.An-other constraint of this work is that only noise-free multi-variate time series from discrete systems are encountered, so that the delay parameter is not involved in the state space reconstruction and the effect of noise is not studied. It is expected that the addition of noise would perplex further the process of selecting optimal embedding di-mension and degrade the performance of the algorithms. For example,we found that in the case of the Henon map the addition of noise of equal magnitude to the two time series of the system makes the criteria to select any of the three equivalent embeddings((2,0),(0,2),(1,1))at random.It is in the purpose of the authors to extent this work and include noisy multivariate time series,also fromflows,and search for other measures to assess the performance of the embedding selection methods.AcknowledgmentsThis paper is part of the03ED748research project,im-plemented within the framework of the”Reinforcement Programme of Human Research Manpower”(PENED) and co-financed at90%by National and Community Funds(25%from the Greek Ministry of Development-General Secretariat of Research and Technology and75% from E.U.-European Social Fund)and at10%by Rik-shospitalet,Norway.[1]F.Takens,Lecture Notes in Mathematics898,365(1981).[2]T.Sauer,J.A.Yorke,and M.Casdagli,Journal of Sta-tistical Physics65,579(1991).[3]H.Kantz and T.Schreiber,Nonlinear Time Series Anal-ysis(Cambridge University Press,1997).[4]J.Guckenheimer and G.Buzyna,Physical Review Let-ters51,1438(1983).[5]M.Paluˇs,I.Dvoˇr ak,and I.David,Physica A StatisticalMechanics and its Applications185,433(1992).[6]R.Hegger and T.Schreiber,Physics Letters A170,305(1992).[7]D.Prichard and J.Theiler,Physical Review Letters73,951(1994).[8]H.D.I.Abarbanel,T.A.Carroll,,L.M.Pecora,J.J.Sidorowich,and L.S.Tsimring,Physical Review E49, 1840(1994).[9]L.Cao,A.Mees,and K.Judd,Physica D121,75(1998),ISSN0167-2789.[10]J.P.Barnard,C.Aldrich,and M.Gerber,Physical Re-view E64,046201(2001).[11]S.P.Garcia and J.S.Almeida,Physical Review E(Sta-tistical,Nonlinear,and Soft Matter Physics)72,027205 (2005).[12]Y.Hirata,H.Suzuki,and K.Aihara,Physical ReviewE(Statistical,Nonlinear,and Soft Matter Physics)74, 026202(2006).[13]M.B.Kennel,R.Brown,and H.D.I.Abarbanel,Phys-ical Review A45,3403(1992).[14]D.T.Kaplan,in Chaos in Communications,edited byL.M.Pecora(SPIE-The International Society for Optical Engineering,Bellingham,Washington,98227-0010,USA, 1993),pp.236–240.[15]B.Chun-Hua and N.Xin-Bao,Chinese Physics13,633(2004).[16]R.Hegger and H.Kantz,Physical Review E60,4970(1999).[17]M.H´e non,Communications in Mathematical Physics50,69(1976).[18]R.Hegger,H.Kantz,and T.Schreiber,Chaos:An Inter-disciplinary Journal of Nonlinear Science9,413(1999).[19]K.Ikeda,Optics Communications30,257(1979).[20]C.Grebogi,E.Kostelich,E.O.Ott,and J.A.Yorke,Physica D25(1987).[21]S.J.Schiff,P.So,T.Chang,R.E.Burke,and T.Sauer,Physical Review E54,6708(1996).[22]A.Politi and A.Torcini,Chaos:An InterdisciplinaryJournal of Nonlinear Science2,293(1992).。
学科交叉背景下的大学校园设计
1引言学科交叉,又称跨学科,指的是不同学科之间相互交叉、融合、渗透而出现新兴学科的过程。
大学校园是一个教育、学习、科研、创新的地方,其形态一直在演变,以反映不断变化的社会需求和理念。
传统的校园规划侧重于对称性、纪念性和功能性,而现今的理念强调可持续性、创新性和协同发展。
学科交叉融合的学科发展趋势在这一演变过程中发挥了重要作用,重塑了大学校园空间,以反映一种更具合作性、包容性和创新性的教育方式。
2大学校园的发展趋势校园规划和设计的根源可以追溯到中世纪的欧洲。
成立于1088年的博洛尼亚大学、1096年成立的牛津大学以及1150年成立的巴黎大学一起构成了欧洲大学的原型[1]。
这个时期的大学只是一些分散的建筑物,充当教学、住宿等用途。
自13世纪起,四方院式建筑逐渐成为欧洲大学的建筑原型,牛津大学和剑桥大学是这种建筑风格的代表。
17~18世纪,美国的建筑师吸取英国学院建筑的风格和特点,但摒弃了四方院的封闭性,把建筑置于开阔的景观当中,强调校园的开放性以及与社区的联系。
19世纪的美国大学强调美学、功能和秩序的重要性,这时候的校园建设方向是开放绿地,轴向路径,以及由建筑物半围合的方院。
第二次世界大战后,校园设计受到现代建筑原则的影响,更注重功能和效率,强调灵活空间、功能设计和合理规划的重要性。
如加州大学伯克利分校就采用了这种方法来创建大型开放空间,以适应不断变化的需求。
在21世纪,校园规划设计已经转向更多的跨学科和协作空间。
这种方法强调开放的、灵活的学习空间,多功能混合的建筑和可持续设计原则。
大学校园正在将这些原则纳入校园总体规划,以创造更具活力和包容性的校园环境,鼓励创造力、创新和可持续发展。
3学科交叉与校园空间交互的关键因素学科是个相对现代的概念。
早期的科学家都是百科全书式的人物,他们的研究涵盖了数学、哲学、解剖学。
但进入19世纪,科学迅速发展,人们对于科学的研究变得更加深入和专业化,导致了学科的细分,自那时起,学科的划分便深刻影响【作者简介】胡创欢（1996~），女，广东清远人，从事建筑与城市设计研究。
拉格朗日点的英语
拉格朗日点的英语Lagrange points, also known as Lagrangian points or libration points, are five positions in space where the gravitational forces of a two-body system, such as the Earth and the Moon or the Earth and the Sun, produce enhanced regions of attraction and repulsion. These points were discovered by Italian-French mathematician Joseph-Louis Lagrange in 1772 while he was studying the three-body problem in celestial mechanics.The Lagrange points are labeled L1 through L5, and each point has unique characteristics and applications in space exploration and satellite missions.L1, the first Lagrange point, is located between the two larger masses, closer to the smaller mass. It lies along the line connecting the two bodies and remains relatively stable with respect to them. Satellites placed at this point can maintain a fixed position relative to both bodies, making it an ideal location for space telescopes like the James Webb Space Telescope.L2, the second Lagrange point, is also situated along the line connecting the two masses but on the opposite side of the smaller mass. This point is particularly useful for space observatories and communications satellites, as it provides an unobstructed view of the side of the larger mass facing away from the smaller mass.L3, the third Lagrange point, lies on the opposite side of the system from L2, forming an equilateral triangle with the two masses. While this point has been proposed for space colonies or future exploration missions, it is less stable than L1 or L2 due to the gravitational influences of other celestial bodies.L4 and L5, the fourth and fifth Lagrange points, are located at the vertices of equilateral triangles formed by the three masses. These points are stable and have been observed to collect small celestial bodies such as asteroids and dust particles. Some of the most well-known examples of objects located at these points are the Trojan asteroids, which share Jupiter's orbit around the Sun.In addition to their scientific significance, Lagrange points play a crucial role in space mission planning and satellite deployment. By utilizing the gravitational equilibrium at these points, spacecraft can conserve fuel and maintain their positions with minimal energy expenditure. This efficiency is particularly valuable for long-duration missions or missions requiring precise positioning, such as satellite constellations for global communications or Earth observation.Furthermore, Lagrange points serve as natural gateways for exploring the solar system and beyond. By establishing infrastructure at these points, such as refueling stations or staging areas, future space missions could leverage the gravitational dynamics to travel deeper into space with greater efficiency and reliability.In conclusion, Lagrange points represent fascinating intersections of celestial mechanics and practical space exploration. Their unique gravitational properties offer valuable opportunities for scientific research, satellite operations, and future space missions. As humanity continues to venture into the cosmos, these points will undoubtedly remain key waypoints in our journey to understand and explore the universe.。
新人教高中英语必修三Unit4SpaceexplorationReadingforwriting教案
2019新人教高中英语必修三Unit4 Space explorationReading for writing公开课教案Teaching aims:1.Enable students to distinguish the thesis statement and the related arguments while reading the argumentative essay about space exploration.2.Enable students to reflect on the question of whether exploring space is worth the money and effort.3.Help students to analyse the structure and language features of an argumentative essay.4.Guide students to write an argumentative essay about space exploration.Teaching key points:1.Lead students to reflect on the question of whether exploring space is worth the money and effort.2.Lead students to write an argumentative essay about space exploration.Teaching difficult points:1.Enable students to distinguish the thesis statement and the related arguments while reading an argumentative essay.2.Enable students to analyse the organisation and language features of an argumentative essay.StepⅠLead-inActivity 1 Look at the picture and answer the following questions.NASA satellite image of Typhoon Goni1.What can you see in the picture?2.Where do you think the picture was taken?3.Why do people take such pictures from space?4.Do you think it’s worth the money and effort?Suggested answers:1.There is a powerful cyclone called Typhoon Goni.2.It was taken from the space by NASA satellite.3.It can help predict the weather,protect lives and reduce losses.4.The answer may vary.Activity 2 Look at the title and answer the questions.1.What do you think will be included in the passage?2.What kind of the text is it?Suggested answers:1.It talks about the question of whether exploring space is worth the money and effort.2.It’s an argumentative essay.StepⅠ Reading for the main ideaRead the passage and answer the questions.1.What’s the author’s point of view on this issue?2.Why are some people against space exploration?3.What has space exploration done for food production?4.What did the pictures of Earth from space make people realise?5.How does space exploration benefit the products that people use nowadays?Suggested answers:1.The author doesn’t think exploring space is a waste of time and money.2.Because they think that we should feed the world’s poor and find immediate solutions to other problems,such as pollution and fatal diseases,instead.3.A number of the satellites record data on land and weather patterns.These studies help farmers grow more crops and warn them about natural disasters before they occur.4.They made people realise that our planet’s resources are limited.5.Advanced technology developed for space exploration has promoted technological improvements that benefit us all by allowing products to be made to ahigher standard.Step Ⅰ Reading for the detailsActivity 1 Read paragraphs 2,3 and 4 again to find out the arguments and supporting details.Paragraph 2:The argument:_____________________________Supporting details:________________________Paragraph 3:The argument:_____________________________Supporting details:________________________Paragraph 4:The argument:_____________________________Supporting details:________________________Suggested answers:Paragraph 2:The argument:Firstly,exploring space has already made a difference in the fight against world hunger.Supporting details:recording data on land and weather patterns;transmitting data to Earth;analysing data;providing recommendations sand adviceParagraph 3:The argument:Secondly,space exploration has already promoted technological improvements that benefit us all.Supporting details:new material;better heart monitors and other machines;GPS;memory foam pillows;smartphone camerasParagraph 4:The argument:Finally,sending astronauts into space has helped people to think about the world’s problems and even to find ways to solve them.Supporting details:limited resources;finding other planets to live on.Activity 2 Underline the sentence that repeats the writer’s opinion in the last paragraph.Suggested answers:In closing,exploring space provides the world with many different benefits.StepⅠ Reading for the structure and language featuresActivity 1 Analyse the topic sentence and get to know the organisation of an argumentative writing.Organisation of an argumentative writingParagr aph 1Some people arguethat we should...introduction paragraph However,othersfeel...Paragr aphs 2-4Firstly,...made a difference...body paragraph Secondly,...promoted...Finally,...hashelped...Paragr aph 5In closing,...differentbenefits.closing paragraphActivity 2 Further analyse the features of an argumentative writing. Para. 1 introduction paragraphThe author intends to________________.Paras. 2—4 body paragraphWhere is the argument in each paragraph?supporting evidence:___________________.language features:___________________.The author intends to_________________________.Para. 5 closing paragraphThe author intends to________________.Suggested answers:Para. 1give background information,stimulate the readers’ interest and state the point of viewParas. 2—4The topic sentence is usually at the beginning in each paragraph.supporting evidence:data,facts,case studies,authority,etc.language feature:concise,essential,objective,calm,detailed,etc.The author intends to show main arguments and to persuade the readersPara. 5summarise the argument and to rephrase the pointStepⅠWrite an argumentative essay about space explorationActivity 1 Decide upon a topicTopic:_____________________________Suggested answers:Is exploring space a waste of time and money?Activity 2 Structure the essayAre these arguments for or against exploring space? Choose your own ideas and write your supporting arguments on your worksheet.A:There are a lot of unsolved mysteries on Earth.So why are we going into space to explore?B:It is necessary to find a new home for people in space,as the resources on Earth will run out.C:I cannot understand spending all this money on expensive research and experiments when so many people need food.D:Exploring space encourages scientists to improve technology that can help people in other ways,too.For space exploration:__________________________________Against space exploration:_______________________________Introduction paragraph_____________________________________________________Body paragraph_____________________________________________________Closing paragraph_____________________________________________________Suggested answers:B D;A CIntroduction paragraph:different opinions and the thesis statementBody paragraph:arguments and supporting details/evidence/examplesClosing paragraph:restatement of the writer’s opinionActivity 3 Use the checklist to check and improve your draft.Activity 4 Your revised composition.Is exploring space a waste of time and money?Suggested answers:Space Exploration is a Waste of Time and Money Everyone gets excited by the news of the most recent space flights,and I too share in people’s sense of awe and wonder at the photos from space that we see.Having said that,it is hard to believe that the high cost of space flight is justified so that we can get some lovely pictures.We should be spending our money more wisely,on what people need.I cannot understand spending all money on expensive research and experiments when so many people need food.Around the world,millions of people are hungry and dying of starvation.On the other hand,we hear on TV that for as little as a dollar a day,a child in Africa can be saved.Considering the billions spent on space travel,it just seems a better investment to feed the hungry.Some people argue that someday we will have to go live in space because the world will be made impossible to live in through pollution.This seems silly.When your house gets dirty,you spend the time and money to clean it up.You don’t move house simply because you need to wash your windows or vacuum the floor.In the same way,it makes more sense to use our time and money to take care of our planet,rather than look for a new home.Finally,there are a lot of unsolved mysteries on the earth.So why are we going into space to explore? There are still many things to discover in the ocean depths and the Antarctic.But we do not even have to go that far:Science has yet to unlock all the mysteries of the atom,and there are many realms of technology that we are justbeginning to understand and explore.In the end,it just does not seem a very wise investment to go to space.We have too many needs here on the earth to be wasting our effort on space exploration.StepⅠ Homework假定你是李华,你班最近一次班会的主题是“太空探险的意义”。
6dof average distance of model points
6dof average distance of model pointsThe average distance of model points is an important metric in 6 Degrees of Freedom (6DoF) motion tracking. It helps us understand the accuracy and precision of the trackingsystem in reproducing the motion of a real-world object ina virtual environment. In this context, 6DoF refers to the ability to accurately track and measure six different types of motions: three rotational (pitch, yaw, and roll) andthree translational (surge, sway, and heave). This meansthat for each point on the model being tracked, we are considering its 3D movement in space.模型点的平均距离是6自由度运动跟踪中的一个重要指标。
它帮助我们了解跟踪系统在虚拟环境中还原真实世界物体运动时的准确性和精度。
在这个背景下，6DoF指的是能够准确跟踪和测量六种不同类型的运动：三种旋转（俯仰、偏航和横滚）和三种平移（前后、左右和上下）。
这意味着对于被跟踪模型上的每个点，我们考虑它在空间中的三维运动。
To calculate the average distance of model points in 6DoF tracking, we first need to have an accurate reference model.The reference model represents the ideal or original position and orientation of the object being tracked. The actual tracked data from the motion tracking system is compared with this reference model to determine how closely it matches.为了计算6自由度跟踪中模型点的平均距离，我们首先需要一个准确的参考模型。
职业规划讲座英语作文通知
Attention all students,We are excited to announce an upcoming lecture on Career Planning that is set to take place on the 15th of this month. This event is designed to provide valuable insights and guidance for students who are looking to map out their professional futures.Date: Saturday, 15th of this monthTime: 2:00 PM 4:00 PMLocation: Main Auditorium, Campus CentralThe lecture will be conducted by Ms. Emily Thompson, a renowned career counselor with over a decade of experience in the field. She has helped numerous individuals find their career paths and achieve their professional goals.During the session, Ms. Thompson will cover several key topics, including:Understanding your strengths and interestsExploring various career optionsSetting achievable career goalsCrafting a winning resume and cover letterPreparing for job interviewsThis is a fantastic opportunity for students of all years to gain a clearer perspective on their career aspirations and the steps needed to achieve them. Whether you are just starting to think about your future career or are in the midst of job hunting, this lecture promises to be both informative and inspiring.Please make sure to RSVP by the 10th of this month to secure your spot. Space is limited, and we anticipate a high level of interest in this event.We look forward to seeing you there!Best regards,Your NameCareer Services Coordinator。
散射特性分析
4．5 接收机
到目前为止，我们只模拟了直接探测。在仿真过程中不只有光-电能转化，接收机还引入了噪声的模拟。为了确切的知道我们接收到的是哪一种噪声，以及他的振幅，全电子化设计的重要性已经很明确，事实却并非如此，不过，虽然有一些标准的结构体，我们有一个简化的模型是一个很好的设想并且在许多模拟中是可行的。这个设想最初是由Der et.al提出的，并建立于一个RC滤波器的结构体上。
图13：两种不同的反射参数设置。左面的镜面反射较多，右面的只有漫反射。
5．3大气的衰减
当距离目标较远的时候，信号由于穿越大气层会产生衰减并淹没在噪声之中，来看图14的例子，目标被安置在10公里远的距离上，不断改变能见度（从左到右能见度分别为6、8、10 、15公里），很明显当能见度变大时目标也更容易被监测到。这个方针用到的参数都是常数（除能见度外）比如说激光脉冲能量Ep=1 mJ，脉冲宽度为 =5 ns，波长λ=1060 nm，扫描阵列的像素数为32X32,噪声等效功率（NEP噪声的标准差）保持在15 nW左右的范围，而激光雷达到目标的峰值功率从10nw,6公里能见度到550nw，15公里能见度。
3原理
3．1 激光雷达目标截面的一般公式
我们不考虑相位和多普勒效应，并只关注单脉冲单站雷达系统。在不考虑大气的情况下，接收机在Z方向接收到的反射光强可表示为：
在本式中I(x,y,z)是发射光强，ρb是目标面积元的双向反射函数（BRDF）,他所计算的是目标被激光所照到的部分。距离z=R是指到目标的平均距离并假定其远大于目标尺寸。由此我们可得出发射光强为：
图1 ：举例说明目标几何特征对激光雷达检测信号（波形）的影响。
图2：对于目标识别者来说不同方向的坦克对应着激光器与目标之间的不同角度。但问题是需要多少个目标像素数和什么程度的精度与分辨率才能很好的识别目标。
ACU-RITE 精密玻璃尺度说明书
V i s i t u s a t ...ww w .a c u -r i t e .c o mP .N. 9951-0220 Rev. 5/07Made in USAPrecision Glass ScalesWith more than one million scales in use today, ACU-RITE precision glass scales withstand the elements of contamination found in even the harshest machine shop environments. As a result, our precision glass scales resist changes in size, shape or density due to temperature and humidity variations. This stability provides exceptional accuracy down to ±1.5µm (.00006"), resulting in tighter workpiece tolerances.ACU-RITE scales are available in travel lengths from 1"–773" and in resolutions from 0.5µm (.00002") to 5µm (.0002").Worldwide Office LocationsAcu-Rite Companies Inc. USAOne Precision Way, Jamestown, NY 14701 Tel: 800.344.2311 Fax: 716.661.1888 Web:/E-mail:******************Acu-Rite Companies Inc. USA - West Coast Office16312 Garfield Avenue, Unit B, Paramount, CA 90723 Tel: 562.634.5421 Fax: 562.634.5459 Web:/E-mail:******************ACI (Shanghai Rep. Office), ChinaRoom 1986, Tower B, City Center of Shanghai No. 100 Zunyi Lu Road, Chang Ning District 200051 Shanghai P .R.C Tel: 011.86.21.62370398 Fax: 011.86.21.62372320E-mail:******************ACU-RITE GmbH, GermanyFraunhoferstrasse 1, D-83301, Traunreut, Germany Tel: 011.49.8669.856110 Fax: 011.49.8669.850930 Web:www.acu-rite.de/E-mail:****************ANILAM srl, Acu-Rite Products, ItalyStrada Borgaretto, 38, 10043 Orbassano, Torino, Italy Tel: 011.39.011.900.2606 Fax: 011.39.011.900.2466 Web:www.acu-rite.it/E-mail:************ANILAM TW, Acu-Rite Products, TaiwanNo. 246 Chau-Fu Road, Taichung City 407, Taiwan, ROC Tel: 011.886.4.225.87222 Fax: 011.886.4.225.87260 E-mail:*******************ACI (UK) Limited, United Kingdom16 Plover Close, Interchange Park, Newport Pagnell Buckinghamshire, MK16 9PS United Kingdom Tel: 011.44.0.1908.514.500 Fax: 011.44.0.1908.610.111 Web:/E-mail:**************.ukVUE Technical DataDisplay 1-,2- or 3-axes 5.7”transmissive LCD displayCommon Functions• Job clock • Feed rate display • Multiple language supports • Absolute/incremental • Near-zero warning • Help function • 16 tool offsets / diameter • Preset and zero reset • 4 function calculator / Trig calculator • Instant inch/mm conversion • 200mm fixed reference marksMilling Specific Functions • Bolthole pattern calculations with graphics (full and partial circles/linear patterns)• Centerline calculation enables you to establish workpiece zero and midpointsTurning Specific Functions • Lock axis feature - used in conjunction with tool offsetting,lets you establish tool offsets with the tool under load,resulting in reduced tool deflection.• Instant radius / diameter conversion Error Compensation Linear and non-linear compensation up to +/-9,999 ppmConstruction Die-cast metalData Interface Serial communication via USB for software downloadsElectrical Requirements Voltage of 100-240 Vac Power of 25 VA max Frequency of 50/60 Hz (+/-3Hz)Operating Temperature0 degrees to 45 degrees C (32 degrees to 113 degrees F)Storage Temperature-20 degrees to 70 degrees C (-22 degrees to 158 degrees F)Weight5.20 lbs.CertificationsISO-9001:2001,UL,CSA,CEVUE for MillingThe world’s first choice for readout systems.Visit today for more information.VUE for Turning VUE for GrindingThe ACU-RITE VUE is a simple, cost-effectiveentry level solution for manual machine toolapplications.The ACU-RITE VUE features exclusive LCD display screentechnology and versatile software to accommodatemilling, turning or grinding applications. The ACU-RITEVUE is the first readout in the industry to display full texton a crystal clear LCD display. Plus, a content-sensitivehelp function assists you right on screen.The ACU-RITE VUE is designed and manufactured inACU-RITE’s ISO 9001:2001 certified facility. They aredesigned to UL/CSA/CE specifications and are backed by a3-year Hassle-Free Warranty.ACU-RITE maintains a strong worldwide authorizeddistribution network of fully trained and qualifiedpersonnel to provide quality sales and service support.ACU-RITE’s authorized distribution network is readilyavailable to provide prompt delivery, thorough producttraining and skilled technical service.VUE LCD Digital ReadoutsV ersatile, User-Friendly, Easy.SALES & SERVICE: A Tech Authority, Inc. 13745 Stockton Ave. Chino CA 91710 909-614-4522 ************************SALES & SERVICE: A Tech Authority, Inc. 13745 Stockton Ave. Chino CA 91710 909-614-4522 ************************。
卫星轨道外推：第一部分(英文批注)
Orbital Propagation: Part I轨道外推：第一部分By Dr. T.S. KelsoWelcome to the Computers and Satellites column of Satellite Times. We are about to embark on an adventure of discovery—an adventure I have been looking forward to for quite some time. I only hope you will enjoy the experience as much as I and want to follow along with each new episode.欢迎来到《卫星时刻》计算机与卫星专栏，我们即将踏上我期待已久的探索之旅。
我谨希望你能和我一同享受这份经历并追随每一段新的旅程。
Along the way, I hope to enlighten you, the reader—whether novice or expert—on the subtleties involved in the theory and practical application of computers to the process of tracking satellites in earth orbit. Whether you simply want to be able to know where to point your TVRO antenna to pick up your favorite television shows, are curious as to where to look to see the Mir space station on a twilight pass, or want to know when you will be able to DX with the space shuttle on the next SAREX mission, we'll cover it all.一路上，我希望无论新手还是专家的每一位读者在卫星地球轨道计算的详细理论和实际应用方面能有所启迪。
初中英语说课稿
Part 2______________________________________
Part 3______________________________________
III.Careful reading: To let students find out the detailed information and understand it correctly and fully)
4. What did Yang do when he was orbiting in the capsule?
5. Yang said: “Our planet is so beautiful.” In your opinion, what does our planet look like in space? (within 30 words)
Aids:
a projector, a tape recorder, multimedia, the blackboard and studying plan which will be carried out during the whole lesson.
Part 6. Teaching procedures
3. Emotional aim: to instruct Ss to be proud of the achievements our motherland made on space flight.
Part 3 Important and difficult points:
1. Help students understand some difficult words and grasp the usage of adverbial clauses of time.
2021年专升本《英语》培训模拟试卷八
2021年专升本《英语》培训模拟试卷八Part Ⅰ. Vocabulary and Structure (1×40 points)Directions: There are 40 incomplete sentences in this part. For each sentence there are four choices marked A, B, C and D. Choose the ONE that best completes the sentence，and then mark the corresponding letter on the Answer Sheet.1. Don’t ______ to let me know if there is anything I can do for you.A. rejectB. preventC. hesitateD. refuse2. Let’s hang up some paintings on these ______ walls.A. bareB. emptyC. blankD. free3. At the conference he expressed some personal views which later brought him into ______ with the Party leadership.A. actionB. crisisC. conflictD. power4. They have developed techniques which are ______ to those used in most factories.A. more talentedB. betterC. greaterD. superior5. Man must stop ______ the earth’s atmosphere.A. fillingB. emittingC. pollutingD. wasting6. No one has yet succeeded in explaining the ______ of how life began.A. problemB. causeC. puzzleD. logic7. Unfortunately, very few sheep ______ the severe winter last year.A. survivedB. enduredC. spentD. remained alive8. They discussed the problem three or four times, but could come to no ______.A. endB. conclusionC. resultD. judgment9. Well, Let’s put our heads together and find ______ to the problem.A. an answerB. a wayC. a solutionD. a method10. The old couple decided to move out of town to a quiet ______, where they had spent several years immediately after their marriage.A. paceB. suburbC. neighborhoodD. area11. It was wise of him to ______ your advice or he might have lost the game.A. followB. listenC. carryD.hear12. I didn’t go to his party because I had to attend an ______ lecture. If we do not hurry up, we may be late for class.A. importantB. impatientC. impressiveD. impossible13. The front door is the main ______ to the house.A. solutionB. wayC. entranceD. path14. I strongly ______ to the proposals they had put forward at the meeting.A. adjustedB. pointedC. aimedD. objected15. If you ______ Bob, please tell him that I am looking for him.A. take inB. run intoC. get overD. break down16. Robert is said ______ in a Japanese company as a salesman for many years.A. have been workingB. to have workedC. be workingD. to work17. It’s a waste of time ______ to make the man give up his own idea.A. tryB. have triedC. tryingD. tried18. It’s very kind ______ you to help us when we are in such a trouble.A. toB. ofC. forD. by19. He was looking forward to the time ______ he would have to attend the interview.A. whereB. thatC. whyD. when20. It is relatively easy to understand how and why nations ______ in international trade.A. engageB. existC. emergeD. exceed21. ______ born in China, the boy was brought up in the USA.A. AlthoughB. SinceC. AsD. When22. ______ is known to all, haste makes waste.A. WhatB. ThatC. AsD. Which23. That is the very old woman ______ house was burned down last night.A. whichB. herC. of whomD. whose24. Hardly had he finished his speech ______ the audience started cheering.A. thanB. thenC. whenD. as soon as25. ______ the book, he found out some answers to this question.A. As he readingB. At his readingC. As readingD. On reading26. The spacecraft will send back ______ on surface winds and temperatures.A. many new informationB. some new informationC. a new informationD. a few new information27. The reason for my refusal is ______ you’re unreliable.A. becauseB. thatC. due toD. for28. He came all the way to China for promoting friendship ______ for making money.A. other thanB. insteadC. apart fromD. rather than29. If you don’t mind, I ______ do my homework than play cards with you.A. had betterB. would ratherC. preferD. would like30. No one, except his two best friends, ______ where he is.A. knowB. to knowC. knowsD. knowing31. What he said on the press conference sounded convincing, but I ______ it to be a lie.A. doubtedB. suspectedC. expectedD. predicted32. My sister ______ my e-mail. Otherwise, she would have replied.A. mustn’t have receivedB. can’t have receivedC. shouldn’t have receivedD. needn’t have received33. I think you are supposed ______ your assignment last night.A. to be finishingB. to have finishedC. to finishD. to have been finished34. In his time, he enjoyed a reputation .A. as great as Mozart, if not greater thanB. as great as, if not greater than, MozartC. as great, if not greater, as MozartD. greater, if not as great as Mozart35. We will go to Mount. Huang for our holidays, ______ it isn’t too expensive.A. exceptB. unlessC. as soon asD. provided36. Nobody should ______ the authority that people have placed on him.A. abuseB. accuseC. amuseD. arouse37. Whenever I ask a question in class, I expect a ______ answer from my students.A. punctualB. promptC. rapidD. fast38. ______ with that of the developed countries, people’s living standard of this African country is extremely low.A. CompareB. While comparingC. When comparedD. Comparing39. More and more automatic machines ______, the output of the factory that manufactured electronic equipment increased tremendously.A. usingB. having usedC. having been usedD. to have been used40. When several graduates apply for the same job, ______ is often given to whoever is better qualified for it.A. superiorityB. privilegeC. majorityD. priorityPart Ⅱ. Cloze (1×20 points)Directions: There are 20 blanks in the following passage. For each blank there are four choices marked A, B,C and D. You should choose the ONE that best fits into the passage and mark the corresponding letter on the Answer Sheet.The best time to buy is often during a “sale”, when a store (41) prices on certain items. Sales are (42) on television, radio, and in newspapers, or the store itself may have (43) showing which items are “on sale”. Just because an item is “on sale”, (44), it does not (45) that it is indeed a good (46). Another store may have the same item at a (47) price, or the sale item may be of poor (48). Comparing prices and quality at (49) stores is a good way to find the (50) value.Household and food items can (51) be found on sale. In many (52), however, coupons（优惠券） (53) the best savings for these items. Coupons are small pieces of paper on advertisements that can be (54) in newspapers, in the mail, in magazines, and even at food stores. If you have coupons for items you’re (55), you can (56) them to the store before (57) for your purchase. The amount (58) on the coupon is then taken (59) form the purchase price of that item. When using coupons, make sure the coupon is for the (60) item you are purchasing, and that the coupon has not expired （过期）.41. A. sets B. keeps C. lowers D. raises42. A. increased B. expected C. organized D. advertised43. A. signs B. problems C. time D. interest44. A. thus B. however C. consequently D. therefore45. A. order B. report C. mean D. request46. A. place B. time C. way D. value47. A. cheaper B. fixed C. higher D. retail48. A. appearance B. service C. quality D. performance49. A. chain B. local C. international D. several50. A. best B. total C. different D. equal51. A. never B. seldom C. also D. either52. A. occasions B. moments C. conditions D. cases53. A. take B. put C. provide D. make54. A. found B. bought C. promoted D. asked55. A. producing B. selling C. developing D. purchasing56. A. present B. return C. put D. add57. A. asking B. paying C. leaving D. applying58. A. reduced B. increased C. listed D. expressed59. A. away B. in C. up D. over60. A. various B. major C. small D. exactPart Ⅲ. Reading Comprehension (2×20 points)Directions: There are 4 passages in this part. Each passage is followed by some questions or incomplete statements. For each of them there are 4 choices marked A,B,C and D. You should decide on the best choice, and mark the corresponding letter on the Answer Sheet.Passage 1Maybe ten-year-old Elizabeth put it best when she said to her father, “But, Dad, you can’t be healthy if you’re dead.”Dad, in a hurry to get home before dark so he could go for a run, had forgotten to wear his safety belt—a mistake 75% of the US population make every day. The big question is why.There have been many myths about safety belts ever since their first appearance in cars some forty years ago. The following are three of the most common.Myth Number One: Safety belts “trap” people in cars that are burning or sinking in water.Truth: Sorry, but studies show that people knocked unconscious due to not wearing safety belts have a greater chance of dying in these accidents. People wearing safety belts are usually protected to the point of having a clear head to free themselves from such dangerous situation, not to be trapped in them.Myth Number Two: Safety belts aren’t needed at speeds of less than 30 miles per hour (mph).Truth: When two cars traveling at 30 mph hit each other, an unbelted driver would meet the windshield with a force equal to diving headfirst into the ground from a height of 10 meters.61. Why did Elizabeth say to her father, “But, Dad, you can’t be healthy if you’re dead”?A. He was driving at great speed.B. He was running across the street.C. He didn’t have his safety belt on.D. He didn’t take his medicine on time.62. The reason father was in a hurry to get home was that he ______.A. wasn’t feeling very wellB. hated to drive in the darkC. wanted to take some exerciseD. didn’t want to be caught by the police63. Which of the following statements is supported in this passage?A. 50% of the US population forgot to wear safety belt every day.B. The first safety belts in cars appeared forty years ago.C. Safety belts “trap” people in cars that are burning or sinking in water.D. Not wearing safety belts will be fined.64. Some people prefer to drive without wearing a safety belt because they believe ______.A. the belt prevents them from escaping in an accidentB. they will be unable to think clearly in an accidentC. they will be caught when help comesD. cars catch fire easily65. What is the advice given in the text?A. Never drive faster than 30 miles an hour.B. Try your best to save yourself in a car accident.C. Never forget to wear the safety belt while driving.D. Drive slowly while you’re not wearing a safety belt.Passage 2Borrowing to start a business is not easy. Getting a bank loan, particularly for a new small business, is like going through the eye of a needle.Banks favor established business people with a solid credit rating and a large bank account. They should also have experience in the business they propose to enter, and offer well-prepared business plans that show the ability to repay the loans. If you are not such a person, then you need to double your preparations to convince the banker to lend you that much needed start-up capital. If your business is new and small, bankers will need to know as much as possible about you and your business.However, many small business owners often make the mistake of not being well prepared when going to the bank to apply for the loan. Surprisingly, many loan applicants don’t even have the slightest idea how or when they intend to repay the money they request. Often they don’t even know much money they need. When asked how much money they want to borrow, many people give these two common responses: “How much money can I get?” and “As much as possible.” Is it any wonder that lenders say no?So the most important thing is do your homework before you ask for a loan.66. By saying “Getting a bank loan… is like going through the eye of a needle”, the writer emphasizes ______.A. the ability to borrow from a bankB. the importance of borrowing moneyC. the difficulty of getting a bank loanD. the start-up of a new small business67. Banks prefer to give a loan to those who ______.A. are in need of start-up capitalB. have the ability to pay it backC. own an old and large businessD. haven’t borrowed money before68. What will bankers do before they give a loan to a new and small business?A. Help fill out a special form for getting a loan.B. Request the business to pay a small deposit.C. Get enough information about the business.D. Estimate the size of the loan they will give.69. Some small businesses fail to get a bank loan because ______.A. the form they fill in is incompleteB. their products are not technically advancedC. the amount of money the want to borrow is too bigD. they have no clear idea of how much they need to borrow70. The writer advises that before applying for a bank loan, the applicant should ______.A. thoroughly prepareB. do some market researchC. learn a lot about the bankD. know the upper limit of the loanPassage 3Happiness can be described as a positive mood and a pleasant state of mind. According to recent polls(民意测试), sixty to seventy percent of Americans consider themselves to be moderately happy and one in twenty persons feels very unhappy. Psychologists have been studying the factors that contribute to happiness. It is not predictable nor is a person in an apparently ideal situation necessarily happy. The ideal situation may have little to do with his actual feelings.A good education and income are usually considered necessary for happiness. Though both may contribute, they are only chief factors if the person is seriously undereducated or actually suffering from lack of physical needs.The rich are not likely to be happier than the middle-income group or even those with very low incomes. People with college educations are somewhat happier than those who did not graduate from high school, and it is believed that this is mainly because they have more opportunity to control their lives. Yet people with a high income and a college education may be less happy than those with the same income and no college education.Poor health does not rule out happiness except for the severely disabled or those in pain. Learning to cope with a health problem can contribute to happiness. Those with a good sex life are happier in general, but those who have a loving, affectionate relationship are happier than those who rely on sex alone. Love has a higher correlation with happiness than any other factor.It should be noted that people quickly get used to what they have, and they are happiest when they feel they are increasing their level no matter where it stands at a given time.Children whose parents were happily married have happier childhoods yet theyare not necessarily happier adults when they grow up.The best formula for happiness is to be able to develop the ability to tolerate frustration, to have a personal involvement and commitment, and to develop self-confidence and self-esteem.71. It can be inferred from the passage that ______.A. happiness is predictableB. a person in an apparently ideal situation must be happyC. happiness is not necessarily connected to one’s situation in societyD. the rich are likely to be happier than the middle-income group72. People with college education ______.A. have less opportunity to control their livesB. have more opportunity to control their livesC. are not happier than those who have only an education at high schoolD. are much happier than those who did not graduate from high school73. According to the article, happiness is greatly dependent upon ______.A. a happy childhoodB. great wealthC. a college degreeD. a feeling that conditions are becoming for the better74. Which of the following is most likely to contribute to happiness?A. Being exceptionally good-looking.B. Having a good paying job.C. Having a loving, affectionate relationship.D. Meeting lots of people.75. Which of the following attitudes of feelings is most likely to be found in happy people?A. Having self-esteem.B. Being sure of keeping everything they already have.C. Never being jealous.D. Knowing how to be charming.Passage 4That cold January night, I was growing sick of my life in San Francisco. There I was, walking home at one in the morning after a tiring practice at the theatre. With opening night only a week away, I was still learning my lines. I was having trouble dealing with my part-time job at the bank and my acting at night at the same time. As I walked, I thought seriously about giving up both acting and San Francisco. City life had become too much for me.As I walked down empty streets under tall buildings, I felt very small and cold.I began running, both to keep warm and to keep away from any possible robbers. Very few people were still out except a few sad-looking homeless people under blankets.About a block from my apartment, I heard a sound behind me. I turned quickly, half expecting to see someone with a knife or a gun. The street was empty. All I saw was a shining streetlight. Still, the noise had made me nervous, so I started to run faster. Not until I reached my apartment building and unlocked the door didI realize what the noise had been. It had been my wallet falling to the sidewalk.Suddenly I wasn’t cold or tired anymore. I ran out of the door and back where I’d heard the noise. Although I searched the sidewalk anxiously for fifteen minutes, my wallet was nowhere to be found.Just as I was about to give up the search, I heard the garbage truck pull up to the sidewalk next to me. When a voice called from the inside, “Alisa Camacho?”I thought I was dreaming. How could this man know my name? The door opened, and out jumped a small red-haired man with an amused look in his eye.“Is this what you’re looking for?” he asked, holding up a small square shape.It was nearly 3 A.M. by the time I got into bed. I wouldn’t get much sleep that night, but I had gotten my wallet back. I also had gotten back some enjoyment of city life. I realized that the city couldn’t be a bad place as long as people were willing to help each other.76. How did the writer feel when she was walking home after work?A. Cold and sick.B. Fortunate and helpful.C. Satisfied and cheerful.D. Disappointed and helpless.77. From the first paragraph, we learn that the writer was busy ______.A. solving her problem at the bankB. taking part in various city activitiesC. learning acting in an evening schoolD. preparing for the first night show78. On her way home the writer ______.A. lost her wallet unknowinglyB. was stopped by a garbage truck driverC. was robbed of her wallet by an armed manD. found some homeless people following her79. In the fifth paragraph, why did the writer say she was dreaming?A. Someone offered to take her back home.B. A red-haired man came to see her.C. She heard someone call her name.D. Her wallet was found in a garbage truck.80. From the text, we can infer that the writer ______.A. would stop working at nightB. would stay on in San FranciscoC. would make friends with cleanersD. would give up her job at the bankPart Ⅳ. Translation (2×10 points)Directions: There are 10 sentences in this section. Please translate sentences 81～85 from Chinese into English, and translate sentences 86～90 from English into Chinese. Write your answer on the Answer Sheet.81. 电脑在我们的日常生活中起着非常重要的作用。
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∗ The support from the Swedish Research Council and from the Royal Swedish Academy of Sciences as well as the Knut and Alice Wallenberg Foundation is gratefully acknowledged.
frequently referred to as “interest points” and are attractive due to their high information contents and relative stability with respect to perspective transformations of the data. Highly successful applications of interest points have been presented for image indexing (Schmid and Mohr, 1997), stereo matching (Tuytelaars and Van Gool, 2000; Mikolajczyk and Schmid, 2002; Tell and Carlsson, 2002), optic flow estimation and tracking (Smith and Brady, 1995; Bretzner and Lindeberg, 1998), and object recognition (Lowe, 1999; Hall, de Verdiere and Crowley, 2000; Fergus, Perona and Zisserman, 2003; Wallraven, Caputo and Graf, 2003). In this paper, we extend the notion of interest points into the spatio-temporal domain and show that the resulting local space-time features often correspond to interesting events in video data (see figure 1). In particular, we aim at a direct scheme for event detection and interpretation that does not require feature tracking nor computation of optic flow. In the considered sample application we show that the proposed type of features can be used for sparse coding of video information that in turn can be used for interpreting video scenes such as human motion in situations with complex and non-stationary background. To detect spatio-temporal interest points, we build on the idea of the Harris and F¨ orstner interest point operators (Harris and Stephens, 1988; F¨ orstner and G¨ ulch, 1987) and describe the detection method in section 2. As events often have characteristic extents in both space and time (Koenderink, 1988; Lindeberg and Fagerstr¨ om, 1996; Florack, 1997; Lindeberg, 1997; Chomat, Martin and Crowley, 2000b; Zelnik-Manor and Irani, 2001), we investigate the behavior of interest points in spatio-temporal scale-space and adapt both the spatial and the temporal scales of the detected features in section 3. In section 4, we show how the neighborhoods of interest points can be described in terms of spatio-temporal derivatives and then be used to distinguish different events in video. In section 5, we consider a video representation in terms of classified spatio-temporal interest points and demonstrate how this representation can be efficient for the task of video registration. In particular, we present an approach for detecting walking people in complex scenes with occlusions and dynamic background. Finally, section 6 concludes the paper with the summary aoduction
Analyzing and interpreting video is a growing topic in computer vision and its applications. Video data contains information about changes in the environment and is highly important for many visual tasks including navigation, surveillance and video indexing. Traditional approaches for motion analysis mainly involve the computation of optic flow (Barron, Fleet and Beauchemin, 1994) or feature tracking (Smith and Brady, 1995; Blake and Isard, 1998). Although very effective for many tasks, both of these techniques have limitations. Optic flow approaches mostly capture first-order motion and may fail when the motion has sudden changes. Interesting solutions to this problem have been proposed (Niyogi, 1995; Fleet, Black and Jepson, 1998; Hoey and Little, 2000). Feature trackers often assume a constant appearance of image patches over time and may hence fail when the appearance changes, for example, in situations when two objects in the image merge or split. Model-based solutions for this problem have been presented by (Black and Jepson, 1998). Image structures in video are not restricted to constant velocity and/or constant appearance over time. On the contrary, many interesting events in video are characterized by strong variations in the data along both the spatial and the temporal dimensions. For example, consider a scene with a person entering a room, applauding hand gestures, a car crash or a water splash; see also the illustrations in figure 1. More generally, points with non-constant motion correspond to accelerating local image structures that may correspond to accelerating objects in the world. Hence, such points can be expected to contain information about the forces acting in the physical environment and changing its structure. In the spatial domain, points with a significant local variation of image intensities have been extensively investigated in the past (F¨ orstner and G¨ ulch, 1987; Harris and Stephens, 1988; Lindeberg, 1998; Schmid, Mohr and Bauckhage, 2000). Such image points are