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LM7805

LM7805

LM78XX / LM78XXA — 3-Terminal 1 A Positive Voltage RegulatorAugust 2013LM78XX / LM78XXA3-Terminal 1 A Positive Voltage RegulatorFeatures•Output Current up to 1 A•Output Voltages: 5, 6, 8, 9, 10, 12, 15, 18, 24 V •Thermal Overload Protection •Short-Circuit Protection•Output Transistor Safe Operating Area ProtectionOrdering Information (1)Note:1. Above output voltage tolerance is available at 25°C.Product NumberOutput Voltage TolerancePackageOperating TemperaturePacking MethodLM7805CT ±4%TO-220(Single Gauge)-40°C to +125°CRailLM7806CT LM7808CT LM7809CT LM7810CT LM7812CT LM7815CT LM7818CT LM7824CT LM7805ACT ±2%0°C to +125°CLM7809ACT LM7810ACT LM7812ACT LM7815ACTDescriptionThe LM78XX series of three-terminal positive regulators is available in the TO-220 package and with several fixed output voltages, making them useful in a wide range of applications. Each type employs internal current limiting,thermal shut-down, and safe operating area protection. If adequate heat sinking is provided, they can deliver over 1 A output current. Although designed primarily as fixed-voltage regulators, these devices can be used with exter-nal components for adjustable voltages and currents.11. Input2. GND3. OutputGNDTO-220(Single Gauge)LM78XX / LM78XXA — 3-Terminal 1 A Positive Voltage RegulatorFigure 1. Block DiagramAbsolute Maximum RatingsStresses exceeding the absolute maximum ratings may damage the device. The device may not function or be opera-ble above the recommended operating conditions and stressing the parts to these levels is not recommended. In addi-tion, extended exposure to stresses above the recommended operating conditions may affect device reliability. The absolute maximum ratings are stress ratings only. Values are at T A = 25°C unless otherwise noted.SymbolParameterValueUnitV I Input VoltageV O = 5 V to 18 V 35V V O = 24 V40R θJC Thermal Resistance, Junction-Case (TO-220)5°C/W R θJA Thermal Resistance, Junction-Air (TO-220)65°C/W T OPR Operating Temperature Range LM78xx -40 to +125°C LM78xxA0 to +125T STGStorage Temperature Range- 65 to +150°CStarting Circuit Reference Voltage Current GeneratorSOA ProtectionThermal ProtectionError AmplifierGND 2must be taken into account separately. Pulse testing with low duty is used.3. These parameters, although guaranteed, are not 100% tested in production.4. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects mustbe taken into account separately. Pulse testing with low duty is used.5. These parameters, although guaranteed, are not 100% tested in production.6. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects mustbe taken into account separately. Pulse testing with low duty is used.7. These parameters, although guaranteed, are not 100% tested in production.8. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects mustbe taken into account separately. Pulse testing with low duty is used.9. These parameters, although guaranteed, are not 100% tested in production.10. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects mustbe taken into account separately. Pulse testing with low duty is used.11. These parameters, although guaranteed, are not 100% tested in production.12. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects mustbe taken into account separately. Pulse testing with low duty is used.13. These parameters, although guaranteed, are not 100% tested in production.14. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects mustbe taken into account separately. Pulse testing with low duty is used.15. These parameters, although guaranteed, are not 100% tested in production.16. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects mustbe taken into account separately. Pulse testing with low duty is used.17. These parameters, although guaranteed, are not 100% tested in production.18. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects mustbe taken into account separately. Pulse testing with low duty is used.19. These parameters, although guaranteed, are not 100% tested in production.SC I JI PK Peak Current(21)T J =+25°C 2.2ANotes:20. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects mustbe taken into account separately. Pulse testing with low duty is used.21. These parameters, although guaranteed, are not 100% tested in production.SC I JI PK Peak Current(23)T J = +25°C 2.2ANotes:22. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects mustbe taken into account separately. Pulse testing with low duty is used.23. These parameters, although guaranteed, are not 100% tested in production.SC I JI PK Peak Current(25)T J =+25°C 2.2ANotes:24. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects mustbe taken into account separately. Pulse testing with low duty is used.25. These parameters, although guaranteed, are not 100% tested in production.SC I JI PK Peak Current(27)T J = +25°C 2.2ANotes:26. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects mustbe taken into account separately. Pulse testing with low duty is used.27. These parameters, although guaranteed, are not 100% tested in production.SC I JI PK Peak Current(29)T J =+25°C 2.2ANotes:28. Load and line regulation are specified at constant junction temperature. Changes in V O due to heating effects mustbe taken into account separately. Pulse testing with low duty is used.29. These parameters, although guaranteed, are not 100% tested in production.Figure 4. Output Voltage Figure 5. Quiescent CurrentFigure 7. Load RegulationLM78XXOutput Input5.1Ω0.33μF231R L470μF120Hz+29. To specify an output voltage, substitute voltage value for “XX”. A common ground is required between the input and the output voltage. The input voltage must remain typically 2.0 V above the output voltage even during the low point on the input ripple voltage.30. C I is required if regulator is located an appreciable distance from power supply filter.31. C O improves stability and transient response.Figure 10.0.1μFC OC I0.33μFOutputInputLM78XX132V XXR1R2I QI RI ≥ 5 I QFigure 13. High-Current Voltage RegulatorI O = I REG + B Q1 (I REG –V BEQ1/R 1)I REG –I Q1 B Q1/LM78XXOutput0.1μF0.33μFR13Ω321Q1InputQ2Q1 = TIP42R SCFigure 16. Split Power Supply (±15 V - 1 A)21320.33μF0.1μF2.2μF1μF ++1N40011N4001+15V-15V+20V-20VMC7915LM78XX1mH3122000μFOutputInputD45H110.33μF470Ω4.7Ω10μF0.5ΩZ1++LM78XX / LM78XXA — 3-Terminal 1 A Positive Voltage RegulatorFigure 19. TO-220, MOLDED, 3-LEAD, JEDEC VARIATION AB (ACTIVE)Package drawings are provided as a service to customers considering Fairchild components. Drawings may change in any manner without notice. Please note the revision and/or date on the drawing and contact a Fairchild Semiconductor representative to verify or obtain the most recent revision. Package specifications do not expand the terms of Fairchild’s worldwide terms and conditions, specifically the warranty therein, which covers Fairchild products.TO-220 (SINGLE GAUGE)TRADEMARKSThe following includes registered and unregistered trademarks and service marks, owned by Fairchild Semiconductor and/or its global subsidiaries, and is not intended to be an exhaustive list of all such trademarks.2Cool¥AccuPower¥AX-CAP®*BitSiC¥Build it Now¥CorePLUS¥CorePOWER¥CROSSVOLT¥CTL¥Current Transfer Logic¥DEUXPEED®Dual Cool™EcoSPARK®EfficientMax¥ESBC¥Fairchild®Fairchild Semiconductor®FACT Quiet Series¥FACT®FAST®FastvCore¥FETBench¥FPS¥F-PFS¥FRFET®Global Power Resource SMGreenBridge¥Green FPS¥Green FPS¥ e-Series¥G max¥GTO¥IntelliMAX¥ISOPLANAR¥Making Small Speakers Sound Louderand Better™MegaBuck¥MICROCOUPLER¥MicroFET¥MicroPak¥MicroPak2¥MillerDrive¥MotionMax¥mWSaver®OptoHiT¥OPTOLOGIC®OPTOPLANAR®®PowerTrench®PowerXS™Programmable Active Droop¥QFET®QS¥Quiet Series¥RapidConfigure¥¥Saving our world, 1mW/W/kW at a time™SignalWise¥SmartMax¥SMART START¥Solutions for Your Success¥SPM®STEALTH¥SuperFET®SuperSOT¥-3SuperSOT¥-6SuperSOT¥-8SupreMOS®SyncFET¥Sync-Lock™®*TinyBoost®TinyBuck®TinyCalc¥TinyLogic®TINYOPTO¥TinyPower¥TinyPWM¥TinyWire¥TranSiC¥TriFault Detect¥TRUECURRENT®*P SerDes¥UHC®Ultra FRFET¥UniFET¥VCX¥VisualMax¥VoltagePlus¥XS™* Trademarks of System General Corporation, used under license by Fairchild Semiconductor.DISCLAIMERFAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION, OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. THESE SPECIFICATIONS DO NOT EXPAND THE TERMS OF FAIRCHILD’S WORLDWIDE TERMS AND CONDITIONS, SPECIFICALLY THE WARRANTY THEREIN, WHICH COVERS THESE PRODUCTS.LIFE SUPPORT POLICYFAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF FAIRCHILD SEMICONDUCTOR CORPORATION.As used herein:1. Life support devices or systems are devices or systems which, (a) areintended for surgical implant into the body or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. 2. A critical component in any component of a life support, device, orsystem whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness.ANTI-COUNTERFEITING POLICYFairchild Semiconductor Corporation's Anti-Counterfeiting Policy. Fairchild's Anti-Counterfeiting Policy is also stated on our external website, , under Sales Support.Counterfeiting of semiconductor parts is a growing problem in the industry. All manufacturers of semiconductor products are experiencing counterfeiting of their parts. Customers who inadvertently purchase counterfeit parts experience many problems such as loss of brand reputation, substandard performance, failed applications, and increased cost of production and manufacturing delays. Fairchild is taking strong measures to protect ourselves and our customers from the proliferation of counterfeit parts. Fairchild strongly encourages customers to purchase Fairchild parts either directly from Fairchild or from Authorized Fairchild Distributors who are listed by country on our web page cited above. Products customers buy either from Fairchild directly or from Authorized Fairchild Distributors are genuine parts, have full traceability, meet Fairchild's quality standards for handling and storage and provide access to Fairchild's full range of up-to-date technical and product information. Fairchild and our Authorized Distributors will stand behind all warranties and will appropriately address any warranty issues that may arise. Fairchild will not provide any warranty coverage or other assistance for parts bought from Unauthorized Sources. Fairchild is committed to combat this global problem and encourage our customers to do their part in stopping this practice by buying direct or from authorized distributors.PRODUCT STATUS DEFINITIONSDefinition of TermsDatasheet Identification Product Status DefinitionAdvance Information Formative / In Design Datasheet contains the design specifications for product development. Specifications may change in any manner without notice.Preliminary FirstProduction Datasheet contains preliminary data; supplementary data will be published at a later date. Fairchild Semiconductor reserves the right to make changes at any time without notice to improve design.No Identification Needed Full Production Datasheet contains final specifications. Fairchild Semiconductor reserves the right to make changes at any time without notice to improve the design.Obsolete Not In Production Datasheet contains specifications on a product that is discontinued by Fairchild Semiconductor. The datasheet is for reference information only.Rev. I65®。

幼儿园区域活动中“教学做合一”的教学实践

幼儿园区域活动中“教学做合一”的教学实践

幼儿园区域活动中“教学做合一”的教学实践摘要:幼儿园是孩子们接受启蒙教学的重要场所,老师的授课方法和一言一行,对于孩子的成长都会起到一定的影响。

在新时代教育工作改革的模式下,老师不仅需要突破当前的授课困境,还需要探究新的授课模式。

“教学做合一”是当前幼儿园中应用范围较为广泛的教学模式,在引导孩子们学习知识的同时,也能够激发他们的探究兴趣。

关键词:幼儿园;区域活动;教学做合一;实践探究引言:区域活动,是幼儿一种重要的自主活动形式,主要根据幼儿发展需求和教学目标创设立活动环境,并充分利用各类教育资源,以此来帮助他们在其中开展合作、探索发现。

将区域活动与教学做合一的模式相结合,既能够优化区域活动,还有利于帮助老师提高授课质量。

本文将结合实践现状进行深入分析,希望能够帮助老师探究到二者结合的具体措施。

1.在幼儿园区域活动中引入“教学做合一”的重要意义区域活动本身就具有活动范围广、组织形式多的特点,在尊重孩子们个体差异的同时,也能够满足个体发展需要,因此这种活动形式在实践中受到了广泛应用。

但是从现状来看,目前部分老师只注意到了区域活动的形式,却忽略了其中的教育内容,这会在潜移默化中放大孩子们的自主权利,甚至会导致活动的秩序混乱[1]。

因此在区域活动中引入“教学做合一”的模式,在实践中具有重要意义。

对于老师来说,这种模式有利于帮助他们突破现阶段的问题,在树立活动规范、活动标准的同时,也能够使区域活动发挥其本身的教育作用,从而达到最终的教学目标。

对于孩子们来说,这种模式在帮助他们明确行为规范、建立规则意识的同时,更能够提高他们的个人学习能力,从而为他们接下来的学习生活打下坚实的基础。

1.在幼儿园区域活动中引入“教学做合一”的具体途径(一)前期准备工作在开展活动前,为了明确教学目标,也为了提高幼儿的个人能力,教师需要先确定活动主题,并选择恰当的活动材料。

从活动主题这方面来看,教师在选择的过程中需要注意主题与幼儿生活的契合性,以及具体的难易程度。

机电实务如何把书读薄之常用材料总结

机电实务如何把书读薄之常用材料总结

机电实务如何把书读薄之常用材料总结下载提示:该文档是本店铺精心编制而成的,希望大家下载后,能够帮助大家解决实际问题。

文档下载后可定制修改,请根据实际需要进行调整和使用,谢谢!本店铺为大家提供各种类型的实用资料,如教育随笔、日记赏析、句子摘抄、古诗大全、经典美文、话题作文、工作总结、词语解析、文案摘录、其他资料等等,想了解不同资料格式和写法,敬请关注!Download tips: This document is carefully compiled by this editor. I hope that after you download it, it can help you solve practical problems. The document can be customized and modified after downloading, please adjust and use it according to actual needs, thank you! In addition, this shop provides you with various types of practical materials, such as educational essays, diary appreciation, sentence excerpts, ancient poems, classic articles, topic composition, work summary, word parsing, copy excerpts, other materials and so on, want to know different data formats and writing methods, please pay attention!一、金属材料。

金属材料在机电实务中应用广泛,常用的金属材料包括钢铁、铜、铝和合金等。

Editors

Editors

Linköping Electronic Conference ProceedingsNo. 23Proceedings of the Resilience Engineering Workshop25–27 June, 2007Vadstena, SwedenEditorsRogier Woltjer, Björn Johansson and Jonas LundbergCognitive Systems Engineering LaboratoryDivision of Human-Centered SystemsDepartment of Computer and Information ScienceLinköpings universitetSE-58183 Linköping, SwedenCopyrightThe publishers will keep this document online on the Internet – or its possible replacement –starting from the date of publication barring exceptional circumstances.The online availability of the document implies permanent permission for anyone to read, to download, or to print out single copies for his/her own use and to use it unchanged for non-commercial research and educational purposes. Subsequent transfers of copyright cannot revoke this permission. All other uses of the document are conditional upon the consent of the copyright owner. The publisher has taken technical and administrative measures to assure authenticity, security and accessibility.According to intellectual property law, the author has the right to be mentioned when his/her work is accessed as described above and to be protected against infringement.For additional information about Linköping University Electronic Press and its procedures for publication and for assurance of document integrity, please refer to its www home page: http://www.ep.liu.se/.Linköping Electronic Conference Proceedings, No. 23Linköping University Electronic PressLinköping, Sweden, 2007ISBN 978-91-85831-37-1ISSN 1650-3740 (online)http://www.ep.liu.se/ecp/023/ISSN 1650-3686 (print)© 2007, The AuthorsTable of ContentsPreface v Cognitive Resilience: Reflection-In-Action and On-Action 1 Back, J., Furniss, D. & Blandford, A.Barriers to Regulating Resilience: Example of Pilots’ Crew ResourceManagement Training 7 Deharvengt, S.Contribution of Resilience to the Analysis of Flight Crew Decision-Making:Example of a Near-CFIT in Public Transport13 Delaitre, D., Nouvel, D., Pouliquen, Y. & Travadel, S.Cybernetics and Resilience Engineering: Can Cybernetics and the ViableSystem Model Advance Resilience Engineering? 23 Dijkstra, A.Resilience in Usability Consultancy Practice: The Case for a PositiveResonance Model31 Furniss, D., Blandford A. & Curzon, P.Pragmatic Resilience 37 Lundberg, J. & Johansson, B.Trials and Tribulations: The Building of a Resilient Organization43 Skriver, J.PrefaceThe field of Resilience Engineering is comparatively young. The term was coined a few years ago, reflecting dissatisfaction with the then prevailing view of how safety in complex systems should be achieved. The idea was to view safety as an emergent system property rather than something that can be achieved by having reliable components. A core issue for Resilience Engineering was to achieve systems that are able to recover from disturbances. The agenda for the new field was to achieve engineering tools and methods of monitoring and improving resilience, as well as predicting the effects of change.The new field took off after the first symposium on Resilience Engineering, held in Söderköping, Sweden, in 2005. A group of distinguished researchers from various fields attended that symposium, and the outcome of the symposium was the book “Resilience Engi-neering: Concepts and Precepts” (Hollnagel, E., Woods, D.D., & Leveson, N. (Eds.), Alder-shot: Ashgate, 2006). In that book, the authors presented a variety of perspectives on Resil-ience Engineering that caught the attention of many others. This was evident at the second Symposium on Resilience Engineering which was held in Juan-Les-Pins, France, in 2006. The number of submitted contributions to the event was so large that the symposium had to be extended by a day.It was after this event that the idea of having a workshop on Resilience Engineering in Swe-den came up. At first, the workshop was intended to be a Swedish happening. However, we, the organizers, felt that it would be appropriate to write the call in English in case someone from outside Sweden would like to participate. This turned out to be a wise decision: of a total of seven presentations, all but two are presented by non-Swedes. During mid-spring, we were also quite worried that there would be too few participants. Luckily, this also turned out to be wrong. The beautiful location, in combination with a number of excellent contributions and two distinguished key-note speakers, attracted many national and international participants: a promising formula for a fruitful workshop filled with stimulating discussions.Our first key-note speaker is Professor Sidney Dekker of Lunds universitet. Professor Dekker is a specialist in system safety, human error, reactions to failure and criminalization, and organizational resilience. In addition to this, he is an experienced pilot. He is also a member of the ’core group’ that met at the first Resilience Engineering Symposium in Söderköping. Our second key-note speaker is Professor Erik Hollnagel of Linköpings universitet and École des Mines de Paris. Professor Hollnagel has spent most of his life working with safety, human performance modelling, and cognitive systems engineering, in industry and academia. He is a leading person within the Resilience Engineering community, co-organizer of both previous Resilience Engineering Symposia, and founder of the Resilience Engineering Network.The workshop has been organized into four main themes: Resilience in Aviation, Design and Resilience, Resilience Theory, and Pragmatic Resilience. The individual presentations within the themes have been given a generous amount of time to make room for discussion, empha-sizing the fact that it is a workshop where each participant is given good opportunity to clarify their points and exchange ideas. Finally, we hope that the environment and the cuisine of Vadstena Klosterhotell will encourage discussion also in the “spare time” of the workshop, and perhaps provide opportunities for new forms of cooperation between the workshop par-ticipants.There are a number of people who made this workshop possible. We would like to thank: Anette Larsson, our administrator, for helping us in finding a pleasant venue for the work-shop. Karin Lundblad and Josephine Speziali for handling the registration and other tasks at the workshop. The reviewers, who remain anonymous, for reading the submitted papers and providing good comments. And finally, Erik Hollnagel for coming up with the idea of having a Resilience Engineering workshop in Sweden. Obviously we would not be here without him.Linköping, June 2007Björn Johansson, Jonas Lundberg, and Rogier WoltjerCognitive Resilience: Reflection-In-Action and On-ActionJonathan Back, Dominic Furniss, Ann BlandfordUniversity College London Interaction Centre, United Kingdom{j.back, d.furniss, a.blandford}@Abstract. Identifying cognitive strategies that people use to support resilient performancehas rarely been the focus of experimental work. Our experiments have found that the per-vasiveness of failures during human computer interaction can be recognized by individuals,but underlying cognitive and attentional causes cannot. Understanding how individuals re-cover from failure and adapt to new environmental demands can be studied in the labora-tory, however, this requires a paradigmatic shift away from developing traditional ‘singlecause’ explanations. Previous research has strongly suggested that individuals are relianton ‘bottom-up’ cues from the environment when planning future actions. By systematicallymanipulating factors that influence an individual’s awareness of environmental cues, workreported in this paper has revealed some novel insights. Resilient individuals are able tospontaneously generate new strategies in-action that support response to regular distur-bances. Furthermore when provided with a ‘window of opportunity’ to reflect-on-action,individuals can rehearse future actions so that the influence of any residual strain (or load)can be mitigated against (feedforward strategy). Further work on understanding strategiesadopted by resilient individuals may facilitate the development of systems that explicitlysupport cognitive resilience.1 INTRODUCTIONCognitive psychologists have found that ‘human error’ can be provoked within a labora-tory environment and that the development of causal accounts enables the frequency of certain types of errors to be predicted (e.g., Byrne and Bovair, 1997; Gray, 2000). Dem-onstrating that ‘human error’ is not the product of some stochastic process has led to a better understanding of human cognition but has had little impact on research and prac-tice in safety, risk analysis, and accident analysis. Laboratory studies have focused on errors that occur during practiced routine performance, where a participant performs an incorrect sequence of actions. Outside the laboratory, identifying incorrect action se-quences is not possible since the context in which those sequences took place cannot be easily understood. Dekker (2005) suggested that error classification disembodies data: it removes the context that helped to produce the behavior in its particular manifestation. “Without context, there is no way to re-establish local rationality. And without local rationality, there is no way to understand human error” (Dekker, 2005, p 60). We argue that ‘cognitive resilience’ is an intrinsic component of local rationality. Identifying cog-nitive strategies that people use to support resilient performance might help to account for behavior. Individuals are resilient if they are able to recognize, adapt to and absorb variants, changes, disturbances, disruptions, and surprises (Woods & Hollnagel, 2006). This paper will discuss the extent to which cognitive strategies that support resilience are identifiable in the laboratory.One of the first attempts to demonstrate the non-stochastic nature of errors was sug-gested by Rasmussen and Jensen (1974). The idea that errors can be categorized as be-ing skill-based, rule-based, or knowledge-based allows errors to be attributed to differ-ent cognitive factors. However, whether an error is classified as skill-based, rule-based, or knowledge-based may depend more on the level of analysis than on its ontogeny (Hollnagel, Mancini, & Woods, 1988). For example Gray (2000) argued that the same behavior, e.g. "taking the wrong route during rush hour", can result from lack of knowl-edge (not knowing about a faster route) or misapplication of a rule (knowing that one route is the fastest during rush hour and the other is fastest on the off hours but applying the ‘off hours’ rule in the rush hour). In addition, this behavior could be caused by a slip (taking the more familiar route when the intention was to take the less familiar but faster one) or be intentionally wrong (too much traffic to get into the correct lane).The focus of laboratory work on human error has been to develop 'single cause' ac-counts of slip errors. Slip errors can occur systematically even when individuals have the required ‘expert’ procedural knowledge to perform a task correctly. For example, Byrne and Bovair (1997) showed that post-completion error (a type of slip) is sensitive to working memory demands. If the environment imposes high working memory de-mands then this type of error is more likely. Therefore, an individual who has an in-creased capacity to process information is less likely to make a slip error. This type of finding is of interest to cognitive scientists but is of little use to researchers and practi-tioners in safety, risk analysis, and accident analysis. An understanding of human per-formance is only useful when the context (local rationality) that helped to produce the behavior is understood. Elucidating this context may be possible if cognitive strategies that people use to support resilient performance can be identified.This paper reports on a series of experiments that aimed to reveal some of the strategies that individuals use during human computer interaction. These strategies help individu-als to detect, recover from and mitigate against failure. Previous research has strongly suggested that users are reliant on ‘bottom-up’ cues from the environment when plan-ning future actions (Payne, 1991).It is hypothesized that the development of cognitive strategies is dependent on an individual’s awareness of environmental cues. By system-atically manipulating factors that influence an individual’s awareness of cues, different strategies that support resilient performance may emerge.2 SELF-REPORTING AND RECOGNIZING FAILURESErrors are one measure of the quality of human performance. For example, Miller (1956) identified an important property of working memory by discovering that indi-viduals make errors when recalling more than 7 (+/-2) elements of information. How-ever, the everyday concept of error presupposes a goal. This can make the classification of errors difficult if an individual is interacting in an exploratory way to satisfy a learn-ing goal, especially when a user is adopting a trial-and-error approach. A better under-standing of error is only possible if a way of differentiating between errors and explora-tory interactions (where errors or sub-optimal moves can be an expected or even a de-sired outcome) is possible. However, humans are not always able to describe their goalsor able to recognize the extent to which a goal has been addressed. In an attempt to in-vestigate this issue, a problem solving game was designed that allowed participants to verbally self-report erroneous and exploratory interactions (see Back, Blandford, & Curzon, 2007a). Twenty participants were encouraged to develop their own distinctions between what should be considered erroneous or exploratory. The game specified a se-ries of locations (rooms) and placed objects within rooms or within the player's inven-tory (possessions). Objects such as a locked door were not designed as permanent ob-stacles, but merely as problems to be tackled. Solving problems frequently involved finding objects and then using them in the appropriate way. One aim was to discover whether self-reports provide useful information about the strategies individuals use to mitigate against error. Two types of report were possible: 1) An 'Elective Report' made at any time during interaction; 2) A 'Debrief Report' which required a participant to re-view a trace of their own behavior immediately after a task was completed.When comparing the elective reports with the debrief reports no significant differences were associated with the frequency of erroneous reports. However, exploratory interac-tions were significantly more frequently reported using the elective self-report mecha-nism. Woods, Johannesen, Cook, and Sarter (1994) argued that self-reports can be bi-ased by hindsight which prevents them from being a useful tool for understanding inter-action. Our analyses showed that the elective mechanism was able to elicit a signifi-cantly wider range of exploratory move types than the debrief mechanism. This sup-ports the notion that outcome knowledge (knowing how things turned out) biases self-reporting processes, especially when reporting exploratory moves. A qualitative analy-sis revealed that exploratory self-reports provided useful information about problem solving strategies that participants were trying out. Crucially, many exploratory reports (65%) outlined strategies that participants used to avoid making persistent errors. During interaction, the pervasiveness of errors was recognizable but underlying cogni-tive and attentional causes were not. Only 20% of elective error reports associated were reasoned accounts of error. During debrief reporting, participants were more able to provide a reasoned accounts (72% of these reports were reasoned). Based on these find-ings we argue that the error recognition process is dependent on cognitive context and the availability of environmental cues. Reasoning about errors during interaction is harder than when performing a debrief report because different environmental cues are 'salient'. During the debriefing session participants were required to debug their task performance. Critically, participants were not reminded of task objectives. Therefore, the only way of detecting erroneous moves was to recall intentions based on the avail-ability of environmental cues. When performing a debrief report immediately after in-teraction, participants were able to reconstruct intentions and were actively looking for environmental cues that could be used to execute those intentions.In summary, an opportunity to reflect-on-action is essential for an individual to reason about why failures occurred, enabling future strategies to be formulated. However, an understanding of the exploratory strategies that individuals actually use can only be elicited during interaction (reflection-in-action).3 REFLECTION-IN-ACTION AND ON-ACTIONSchön (1987) describes two types of reflection: reflection-in-action and reflection-on-action. The former takes place as events unfold, where the participant will perceive the situation as new but implicitly compare it to prior experience, situate possibilities for new actions and carry out experiments to decide a course of action. The latter happens further away from the event temporally, where the participant will formalize the situa-tion and actions so they can evaluate and think about the situation. For example, a foot-baller will be reflecting-in-action during the game by responding to opportunities pre-sented to him by his team mates and the opposition; during the half time break the team‘s coach will facilitate reflection-on-action by describing what was good, what could be improved, and how to change their tactics.The Repetitions-Distinctions-Descriptions (RDD) Model (Nathanael & Marmas, 2006) provides a graphical illustration of how reflection-in-action is distinguished from reflec-tion-on-action. Figure 1 shows an abstracted version of the RDD model presented by Nathanael and Marmas (2006, p. 233). Here repetitions account for the normal routine actions of individuals, where these are abnormal or there is opportunity to try something different then a ‘distinction’ in the normal routine can be made and the participant re-flects-in-action (RIA) to alter their practice, this altered practice can then be absorbed in normal routine if appropriate. Reflection-on-action (ROA) occurs in detached moments where participants may formalise new understandings of their situation for action i.e. the situation is not only distinguished but described and reflected upon away from the event.Fig. 1. The Repetitions, Distinction and Descriptions (RDD) Model adapted from Nathanael and Marmas (2006, p. 233). RIA = Reflection-in-action; ROA = Reflection-on-action4 STRATEGIES FOR REFLECTING-IN-ACTION AND ON-ACTIONBy systematically manipulating factors that influence an individual’s awareness of envi-ronmental cues, some novel insights into the nature of cognitive strategies people use to support resilient performance can be revealed. A simulation of a ‘Fire Engine Dispatch Center’ was developed. Two experiments using 24 participants each were run (see Back, Blandford, & Curzon, 2007b). Experiment 1 investigated the frequency of two classes of slip error under different cognitive and perceptual load scenarios. Experiment 2 investigated if a ‘window of opportunity’, used to rehearse procedural steps, reduced error rates. Results from both of these experiments demonstrate that individuals can de-velop cognitive strategies to maintain resilient performance when reflecting in-action and on-action. Two systematic error manifestations are briefly outlined below.Mode Error - A visual display that informed participants of GPS signal status was pro-vided. Participants were required to attend to this signal so that they could determine what type of route information had to be sent to a particular fire engine. Analysis re-vealed that if participants placed the mouse cursor close to the signal status display, they were significantly less likely to forget to attend to the display before selecting an appropriate route construction method. Avoiding this type of error can be considered a cognitive skill since it involves spontaneous personalized cue creation by reflecting-in action.Initialization Error - When commencing a new trial an individual had to decide which call to prioritise before clicking on the 'Start next call' button. Forgetting to perform this call prioritisation procedure resulted in an initialization error. In Experiment 2 partici-pants were given 4 seconds to reflect on requirements before commencing a trial: Within-subjects Conditions - A) call prioritisation always visible; B) call prioritisation not visible during reflection time. In Condition A participants were significantly better able to avoid initialization errors. Condition A allowed participants to reflect-on-action.5 CONCLUSIONSRehearsal (reflecting-on-action) and personalized cue creation (reflecting-in-action) are examples of cognitive strategies that people can use to support resilient behavior. When a 'window of opportunity' for reflection exists then any residual strain (or load) can be mitigated against (feedforward strategy). Resilient individuals are able to spontaneously generate new strategies in-action that support response to regular disturbances (e.g., learning to use the mouse cursor as an environmental cue). Understanding how indi-viduals recover from failure and adapt to new environmental demands can be studied in the laboratory, however, this requires a paradigmatic shift away from developing tradi-tional ‘single cause’ explanations. An understanding of human performance is only use-ful when the context that helped to produce the behavior is understood. REFERENCESBack, J., Blandford, A. & Curzon, P. (2007a). Recognising erroneous and exploratory interactions. To appear in Proceedings of INTERACT 2007.Back, J., Blandford, A. & Curzon, P. (2007b). Slip errors and cue salience. To appear in Proceedings of ECCE2007.Byrne, M. & Bovair, S. (1997). A working memory model of a common procedural er-ror. Cognitive Science,21 (1), 31-69.Dekker, S. (2005). Ten questions about human error: a new view of human factors and system safety. Lawrence Erlbaum Associates.Gray, W. D. (2000) The nature and processing of errors in interactive behavior. Cogni-tive Science, 24 (2), 205-248.Hollnagel, E., Mancini, G. & Woods, D. (1988). Cognitive engineering in complex dy-namic worlds. Academic Press.Nathanael, D. & Marmas, N. (2006). The interplay between work practices and pre-scription: a key issue for organisational resilience. In E. Hollnagel & E. Rigaud (Eds.) Proceedings of the Second Resilience Engineering Symposium (pp. 229-237), 8-11 No-vember 2006, Juan-Les-Pins, France.Miller, G. (1956). Human memory and the storage of information. Transactions on Info Theory, IT-2 (3), 128-137.Payne, S. J. (1991). Display-based action at the user interface. International Journal of Man-Machine Studies, 35, 275-289.Rasmussen, J., Jensen, A. (1974). Mental procedures in real-life tasks. Ergonomics, 17, 293-307.Schön, D. (1987). Educating the reflective practitioner. San Francisco: Jossey-Bass. Woods, D. D., Johannesen, L. J., Cook, R. I. & Sarter, N. B. (1994). Behind human er-ror: Cognitive systems, computers, complexity and hindsight. CSERIAC, 94-01. Woods, D. D. & Hollnagel, E. (2006). Prologue. In: Hollnagel, E., Woods, D. D. & Leveson, N. Resilience engineering: Concepts and precepts (pp. 1-7). Aldershot, UK: Ashgate.Barriers to Regulating Resilience: Example of Pilots’Crew Resource Management TrainingStéphane DeharvengtDirection Générale de l’Aviation Civile, 50 rue Farman, 75720 Paris cedex 15, Francestephane.deharvengt@aviation-civile.gouv.frAbstract. Regulation in high risk industry is not considered as a characteristic for resil-ience. This article identifies issues surrounding the introduction of a new regulation in anultra safe system that is designed to build more resilience into the system. The developmentand implementation of Pilots’ Crew Resource Management regulation within the FrenchCivil Aviation Authority is reviewed. Interviews and questionnaires form the basis for theanalysis of the intent and practices of those in charge of high level decisions, those havingthe knowledge of human factors discipline, and those whose job it is to implement thisregulation. However the gap between the regulation as imagined, and the regulation as im-plemented, illustrates the resistance of the system towards this approach to regulation andthe potential drifts. The article presents the findings as characteristics of the regulatoryprocess concerning the introduction of resilience. The lack of internal expertise and lack ofimplementation monitoring explain the present shortcomings of regulatory authorities andultimately questions the role of regulation regarding the engineering of resilience. At a timewhen high profile regulations are enacted that aim for adaptive solutions in aviation, thepresented retrospective offers insights into present and future issues.1 RESEARCH CONTEXTThe resilience concept is discussed for high risk activities like medicine, aviation, or power production (Woods, Hollnagel & Leveson, 2006). However it is also informative to look at how those systems are regulated since they cannot thrive and reach a very high safety level without the constraints of regulation by national or international agen-cies (Amalberti, 2001). The safer the system, the less resilient it becomes because of the rigidity of the normative strategy. The central question of this article is to evaluate the potential of regulation to be used as a tool to introduce more resilience. The introduc-tion of pilots’ CRM training regulation by French Civil Aviation Authority (DGAC) is used to illustrate some barriers to building resilience via a regulatory process.The onset of this research stems from formal and informal feedback received concern-ing Crew Resource Management (CRM) training of poor quality being delivered. The research question states as a formal hypothesis that CRM training is stabilizing the training at a low quality level, which is satisfactory for all interested parties (Dehar-vengt, 2007). Different viewpoints of individuals involved in the regulatory process are examined, both from an historical perspective and at the relevant levels of DGAC hier-archy. The initial intentions of those in charge of regulating CRM at the early stages are examined: on one hand the successive heads of the Direction du Contrôle de la Sécurité (Safety Oversight Authority) in charge of decision making in the rulemaking processare interviewed, and on the other hand a human factors perspective is sought from the only people that actually possessed high level knowledge of the discipline within DGAC during the 90s. Consideration is then given to the implementation conditions from the perspective of the inspectors in charge of monitoring the airlines’ Air Operator Certificate. Comparative research is conducted in parallel to investigate the airline in-dustry and their perception of CRM delivery (Pariès & Mourey, 2006).2 RESILIENCE THROUGH CRM REGULATION: LESSONS LEARNED2.1 A Promising Regulatory InitiativeIn the 90s, French civil aviation was under great stress. The context is that of an eco-nomical downturn for airlines as well as fear of increased competition European wide with the implementation of a European license (JAR FCL, Flight Crew Licensing) and common airlines’ operating rules (JAR OPS1). The implementation of ICAO require-ments for human factors threatened the validity of French pilots’ licenses. Concur-rently, the advent of glass cockpit and its early dramatic accidents (e.g. crash of A320 at the Mont St Odile in early 1992) brought into question the transforming role of the pi-lots in the cockpit.International networking between leading human factor experts and the exchange of ideas enabled the importation of the CRM concept into Europe, as well as its subse-quent adaptation to answer the airlines’ needs of the day. Those experts offered a par-ticularly welcome solution to the pressing issues that were confronting the DGAC man-agement and industry (airlines and unions) (Pariès, Amalberti, 2000). Together they formulated the outlines of the CRM regulation as a human factors’ response to airlines’ safety needs and local issues. This regulation is therefore original in the sense that it does not set rigid requirements, but tries to provide flexibility or adaptive capacities for airlines to train their crews.2.2 A Poor Lonesome RegulationFor DGAC management this new training methodology is useful in the sense that, con-trary to normal “individual” pilot training, CRM offers the pilots an opportunity to in-teract inside a group of professionals and discuss operational issues. The rationale is that this interaction leads to a positive change in operational behavior. Achieving this change and controlling it is perceived as particularly suited for monitoring airlines. CRM training is considered to be a tool to control individual behaviors acts, and as a leverage to control the behavior of the airline, hence improving visibility of the safety of the airline. This logic coincides with the changing way that the authorities monitor the activity of the airline, from a former field approach towards requiring, certifying, and monitoring airlines’ organizational systems. This has resulted in a gain in resources and efforts. The first finding is that regulation that tries to regulate resilience corre-。

ken_da_18

ken_da_18

−2−
他 *埼玉県医師会産業医会理事会・講演会(2008年11月 13日 さいたま) 講演 宮谷博幸 「ストレスと消化器疾患」 *第22回埼玉胆膵懇話会(2008年11月14日 さいた ま) 当番世話人 宮谷博幸 演題 岩城孝明:副乳頭切開を行った急性膵炎合併 膵管非癒合の一例 *第13回東京膵臓研究会(2008年11月22日 東京) ・池谷敬、岩城孝明、宮谷博幸、山中健一、池田正 俊、牛丸信也、本田英明、松本吏弘、高松徹、福西 昌徳、中島嘉之、鷺原規喜、吉田行雄:MCN 様外 観を呈した IPMN の1例 2)原著およびその他論文(2008年9月~11月) ・福田重信、宮谷博幸、本田英明、高松徹、福西昌徳、 岩城孝明、宇賀神卓広、中島嘉之、鷺原規喜、吉田 行雄:メシル酸カモスタット増量により高アミラー ゼ血症の改善が得られた潰瘍性大腸炎合併慢性膵炎 の1例.膵臓 23: 533-540, 2008. ・岩城孝明、宮谷博幸、池谷敬、山中健一、池田正俊、 牛丸信也、松本吏弘、本田英明、高松徹、福西昌徳、 宇賀神卓広、中島嘉之、鷺原規喜、吉田行雄:当院 における Helicobacter pylori 除菌治療の現状.消化 器の臨床 11:592-586, 2008. ・宮谷博幸、吉田行雄:GIST(消化管間質腫瘍) . BIO Clinica 23: 1056-1060, 2008. ・宮谷博幸、中島嘉之、岩城孝明、池谷敬、山中健 一、池田正俊、牛丸信也、本田英明、松本吏弘、高 松徹、澤田幸久、福西昌徳、鷺原規喜、吉田行雄: 高齢者胆膵内視鏡治療の問題点.月刊地域医学 22: 1136-1141, 2008.
ቤተ መጻሕፍቲ ባይዱ
でも世界に知らしめ、その研究の initiative をとる必 要がある。そこでこのところ、台湾、韓国、トルコ、 米国での国際学会で積極的に発表しているが、必ず質 問が来るようになった。 “自分もこのような中耳炎患 者を診ているがどのように治療するのか?”etc, etc …。な〜んだ、やはり同様の患者がいるのだ。日本に 特有の病気ではないのだ。日本発信の中耳炎としてな んとか世界中に認めさせることが現在の私の夢であ る。そのためにはさらに病態に迫った研究が必要と、 いろいろ暗中模索をしているのが現況である。 研究は楽しい、そして認めてもらうともっと楽し い。ノーベル賞にはほど遠いささやかな臨床研究で あっても、自己満足だけでは終わらないように、発表 する、論文を書く努力を惜しまないようにしたいもの だ。

Amos Fiat

Amos Fiat

Haim Kaplan
School of Computer Science Tel Aviv University Tel Aviv 69978, Israel
edith@
fiat@cs.tau.ac.il
haimk@cs.tau.ac.il
The success of a P2P le-sharing network highly depends on the scalability and versatility of its search mechanism. Two particularly desirable search features are scope (ability to nd infrequent items) and support for partial-match queries (queries that contain typos or include a subset of keywords). While centralized-index architectures (such as Napster) can support both these features, existing decentralized architectures seem to support at most one: prevailing protocols (such as Gnutella and FastTrack) support partial-match queries, but since search is unrelated to the query, they have limited scope. Distributed Hash Tables (such as CAN and CHORD) constitute another class of P2P architectures promoted by the research community. DHTs couple index location with the item's hash value and are able to provide scope but can not e ectively support partialmatch queries; another hurdle in DHT deployment is their tight control the overlay structure and data placement which makes them more sensitive to failures. Associative overlays are a new class of decentralized P2P architectures. They are designed as a collection of unstructured P2P networks (based on popular architectures such as gnutella or FastTrack), and the design retains many of their appealing properties including support for partial match queries, and relative resilience to peer failures. Yet, the search process is orders of magnitude more e ective in locating rare items. Our design exploits associations inherent in human selections to steer the search process to peers that are more likely to have an answer to the query. Peer-to-peer (P2P) networks have become, in a short period of time, one of the fastest growing and most popular Internet applications. As for any heavily used large distributed source of data, the e ectiveness of a P2P network is largely a function of the versatility and scalability of its search mechanism. Peer-to-peer networks came to fame with the advent of Napster 23], a centralized architecture, where the shared items of all peers are indexed in a single location. Queries were sent to the Napster Web site and results were returned after locally searching the central index; subsequent downloads were performed directly from peers. The legal issues which led to Napster's demise exposed all centralized architectures to a similar fate. Internet users and the research community subsequently turned to decentralized P2P architectures, where the search index and query processing, as well as the downloads, are distributed among peers.

18年考研英语精选必背真题范文

18年考研英语精选必背真题范文

2009考研英语18年满分范文修订背诵版序大家好,我是风中劲草,很高兴又和大家见面了。

2007年我曾经在沪江论坛发了《07考研英语精选必背10年真题范文》这个帖子和资料(原贴地址/dispbbs.asp?boardID=20&ID=365692)一直受到沪友的追捧和支持。

我曾经发给我的一些考研的朋友他们也相当喜欢,而且他们把里面的每一篇范文都背得很熟练,在08年考研英语中取的不错的成绩。

一直以来,沪友都通过回帖或者发短信的方式,希望我制作新的版本。

特别是我几个懒惰的狐朋狗友极力要求制作新的版本。

想想现在考研作文的书漫天飞舞但是真正一些值得背的范文确实凤毛麟角,很多甚至把本身考试虽然得了高分但是存在很多问题的文章也作为范文,这个是很不负责任的。

为此,我抽出自己的休息时间,制作了这个《2009考研英语18年满分范文修订背诵版》。

考虑到大家都有作文的题目,这里我不再提供题目,也不给出翻译的中文,为大家省出打印的纸张,这样打印的时候可以少花一点钱。

这个《2009考研英语18年满分范文修订背诵版》大部分是在原来07十年真题必背范文的基础上修订而成。

去掉了原来的题目和翻译,增加了范文的年份,特别是加上07、08两年的范文。

所有这些范文都是经过劲草精心挑选,很多范文都是新东方老师千锤百炼在课堂上讲过的,其中有何钢老师讲解过的、有汪海涛老师讲解过的、有王江涛老师讲解过的还有胡敏老师讲解过的,还有一些是来自张剑老师的黄宝书,当然也有个别是其他老师润色的。

所以你别小看这个18年范文只有仅仅的13页,但是却是我从各个精华中课件和书籍中精选出来的。

可以说是精华中的精华,他是站在巨人肩膀上的巨人。

大家可以放心使用,大家可以随便把自己手头上作文书的范文拿来和这里面的比较,你自己就可以作出鉴别了。

当然,尽管劲草努力的去做一份完美的范文提供给大家背诵,但是毕竟劲草一个人的力量比较单薄,而且可能还有不尽人意的地方。

我希望大家发现有问题的地方给劲草回帖指出,这样也可以方便后人。

opa333

opa333
)
PRODUCT OPA333 PACKAGE-LEAD SOT23-5 SC70-5 SO-8 SO-8 OPA2333 DFN-8 MSOP-8 (1) PACKAGE DESIGNATOR DBV DCK D D DRB DGK PACKAGE MARKING OAXQ BQY O333A O2333A BQZ OBAQ
BurrĆBrown Products from Texas Instruments
OPA333 OPA2333
SBOS351C – MARCH 2006 – REVISED MAY 2007
1.8V, microPOWER CMOS OPERATIONAL AMPLIFIERS Zerø-Drift Series
(2)
UNIT V V mA °C °C °C
+7 –0.3 to (V+) + 0.3 ±10 Continuous –40 to +150 –65 to +150 +150
Stresses above these ratings may cause permanent damage. Exposure to absolute maximum conditions for extended periods may degrade device reliability. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those specified is not supported. Input terminals are diode-clamped to the power-supply rails. Input signals that can swing more than 0.3V beyond the supply rails should be current limited to 10mA or less. Short-circuit to ground, one amplifier per package.

ADXL103

ADXL103

Precision ±1.7 gSingle/Dual Axis AccelerometerADXL103/ADXL203Rev. 0Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. FEATURESHigh performance, single/dual axis accelerometer on a single IC chip5 mm × 5 mm × 2 mm LCC package 1 m g resolution at 60 HzLow power: 700 µA at V S = 5 V (typical) High zero g bias stability High sensitivity accuracy–40°C to +125°C temperature rangeX and Y axes aligned to within 0.1° (typical) BW adjustment with a single capacitor Single-supply operation 3500 g shock survivalAPPLICATIONSVehicle Dynamic Control (VDC)/Electronic Stability Program (ESP) systemsElectronic chassis control Electronic brakingPlatform stabilization/leveling NavigationAlarms and motion detectors. High accuracy, 2-axis tilt sensingGENERAL DESCRIPTIONThe ADXL103/ADXL203 are high precision, low power, complete single and dual axis accelerometers with signalconditioned voltage outputs, all on a single monolithic IC. The ADXL103/ADXL203 measures acceleration with a full-scale range of ±1.7 g . The ADXL103/ADXL203 can measure both dynamic acceleration (e.g., vibration) and static acceleration (e.g., gravity).The typical noise floor is 110 μg /√Hz, allowing signals below 1 m g (0.06° of inclination) to be resolved in tilt sensing applications using narrow bandwidths (<60 Hz).The user selects the bandwidth of the accelerometer using capacitors C X and C Y at the X OUT and Y OUT pins. Bandwidths of 0.5 Hz to 2.5 kHz may be selected to suit the application. The ADXL103 and ADXL203 are available in 5 mm × 5 mm × 2 mm, 8-pad hermetic LCC packages.FUNCTIONAL BLOCK DIAGRAM03757-0-001C CFigure 1. ADXL103/ADXL203 Functional Block DiagramADXL103/ADXL203 TABLE OF CONTENTSSpecifications (3)Absolute Maximum Ratings (4)Typical Performance Characteristics (5)Theory of Operation (8)Performance (8)Applications (9)Power Supply Decoupling (9)Setting the Bandwidth Using C X and C Y (9)Self Test (9)Design Trade-Offs for Selecting Filter Characteristics: The Noise/BW Trade-Off (9)Using the ADXL103/ADXL203 with Operating Voltages Other than 5 V (10)Using the ADXL203 as a Dual-Axis Tilt Sensor (10)Pin Configurations and Functional Descriptions (11)Outline Dimensions (12)Ordering Guide (12)REVISION HISTORY Revision 0: Initial VersionADXL103/ADXL203SPECIFICATIONSTable 1. T A = –40°C to +125°C, V S = 5 V, C X = C Y = 0.1 μF, Acceleration = 0 g , unless otherwise noted.Parameter Conditions Min Typ Max Unit SENSOR INPUT Each AxisMeasurement Range 1±1.7g Nonlinearity % of Full Scale ±0.5 ±2.5 % Package Alignment Error ±1 Degrees Alignment Error (ADXL203) X Sensor to Y Sensor ±0.1 Degrees Cross Axis Sensitivity ±2 ±5 %SENSITIVITY (Ratiometric)2Each Axis Sensitivity at X OUT , Y OUT V S = 5 V 940 1000 1060 mV/gSensitivity Change due to Temperature 3V S = 5 V ±0.3 % ZERO g BIAS LEVEL (Ratiometric) Each Axis 0 g Voltage at X OUT , Y OUT V S = 5 V 2.4 2.5 2.6 V Initial 0 g Output Deviation from Ideal V S = 5 V, 25°C ±25 m g 0 g Offset vs. Temperature ±0.1 m g /°C NOISE PERFORMANCE Output Noise < 4 kHz, V S = 5 V, 25°C 1 6 mV rms Noise Density @25°C 110 µg /√Hz rmsFREQUENCY RESPONSE 4C X , C Y Range 5 0.002 10 µF R FILT Tolerance 24 32 40 kΩ Sensor Resonant Frequency 5.5 kHz SELF TEST 6 Logic Input Low 1 V Logic Input High 4 V ST Input Resistance to Ground 30 50 kΩ Output Change at X OUT , Y OUT Self Test 0 to 1 400 750 1100 mV OUTPUT AMP LIFIER Output Swing Low No Load 0.3 V Output Swing High No Load 4.5 V POWER SUPP LY Operating Voltage Range 3 6 V Quiescent Supply Current 0.7 1.1 mATurn-On Time 720 ms1 Guaranteed by measurement of initial offset and sensitivity.2Sensitivity is essentially ratiometric to V S . For V S = 4.75 V to 5.25 V, sensitivity is 186 mV/V/g to 215 mV/V/g . 3Defined as the output change from ambient-to-maximum temperature or ambient-to-minimum temperature. 4Actual frequency response controlled by user-supplied external capacitor (C X , C Y ). 5Bandwidth = 1/(2 × π × 32 kΩ × C). For C X , C Y = 0.002 µF, Bandwidth = 2500 Hz. For C X , C Y = 10 µF, Bandwidth = 0.5 Hz. Minimum/maximum values are not tested. 6Self-test response changes cubically with V S . 7Larger values of C X , C Y will increase turn-on time. Turn-on time is approximately 160 × C X or C Y + 4 ms, where C X , C Y are in µF.All minimum and maximum specifications are guaranteed. Typical specifications are not guaranteed.ADXL103/ADXL203ABSOLUTE MAXIMUM RATINGSTable 2. ADXL103/ADXL203 Stress RatingsParameter Rating Acceleration (Any Axis, Unpowered) 3,500 g Acceleration (Any Axis, Powered) 3,500 g Drop Test (Concrete Surface) 1.2 m V S –0.3 V to +7.0 V All Other Pins (COM – 0.3 V) to(V S + 0.3 V)Output Short-Circuit Duration (Any Pin to Common) Indefinite Operating Temperature Range –55°C to +125°C Storage Temperature –65°C to +150°CStresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operationalsection of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.Table 3. Package CharacteristicsPackage Type θJAθJCDevice Weight 8-Lead CLCC 120°C/W20°C/W <1.0 gramT E M P E R A T U R ETIMET TConditionProfile Feature Sn63/Pb37 Pb FreeAverage Ramp Rate (T L to T P ) 3°C/second Max Preheat• Minimum Temperature (T SMIN ) 100°C 150°C •Minimum Temperature (T SMAX )150°C 200°C • Time (T SMIN to T SMAX ) (t S )60–120 seconds60–150 secondsT SMAX to T L• Ramp-Up Rate3°C/second Time Maintained above Liquidous (T L )• Liquidous Temperature (T L ) 183°C 217°C • Time (t L )60–150 seconds60–150 secondsPeak Temperature (T P )240°C +0°C/–5°C 260°C +0°C/–5°C Time within 5°C of Actual Peak Temperature (t P ) 10–30 seconds 20–40 secondsRamp-Down Rate6°C/second MaxTime 25°C to Peak Temperature6 minutes Max 8 minutes MaxFigure 2. Recommended Soldering ProfileADXL103/ADXL203TYPICAL PERFORMANCE CHARACTERISTICS(V S = 5 V for all graphs, unless otherwise noted.)P E R C E N T O F P O P U L A T I O N (%)025201510503757-0-010VOLTS–0.10–0.08–0.06–0.04–0.020.020.040.060.080.1Figure 3. X Axis Zero g Bias Deviation from Ideal at 25°CP E R C E N T O F P O P U L A T I O N (%)02530201510503757-0-011m g /°C–0.80–0.70–0.60–0.50–0.40–0.30–0.20–0.1000.100.200.300.400.500.600.700.8Figure 4. X Axis Zero g Bias TempcoP E R C E N T O F P O P U L A T I O N (%)35402025301510503757-0-012VOLTS/g0.940.950.960.970.980.991.001.011.021.031.041.051.06Figure 5. X Axis Sensitivity at 25°CP E R C E N T O F P O P U L A T I O N (%)03757-0-013VOLTS–0.10–0.08–0.06–0.04–0.020.020.040.060.080.10Figure 6. Y Axis Zero g Bias Deviation from Ideal at 25°CP E R C E N T O F P O P U L A T I O N (%)03757-0-014m g /°C–0.8–0.7–0.6–0.50–0.4–0.3–0.2–0.10.10.20.30.40.50.60.70.8Figure 7. Y Axis Zero g Bias TempcoP E R C E N T O F P O P U L A T I O N (%)03757-0-015VOLTS/g0.940.950.960.970.980.991.001.011.021.031.041.051.06Figure 8. Y Axis Sensitivity at 25°CADXL103/ADXL203TEMPERATURE (°C)V O L T A G E (1V /g )–502.402.602.582.562.542.522.502.482.462.442.42–40–30–20–1010203050406070809010011012013003757-0-004Figure 9. Zero g Bias vs. Temperature – Parts Soldered to PCBX AXIS NOISE DENSITY (µg /√Hz)P E R C E N T O F P O P U L A T I O N (%)403530252015105455003757-0-007Figure 10. X Axis Noise Density at 25°CPERCENT SENSITIVITY (%)P E R C E N T O F P O P U L A T I O N (%)–5.0302520151053540–4.0–3.0–2.0–1.01.02.03.04.05.003757-0-005Figure 11. Z vs. X Cross-Axis Sensitivity TEMPERATURE (°C)S E N S I T I V I T Y (V /g )–500.971.000.990.981.021.011.03–40–30–20–1010203050406070809010011012013003757-0-016Figure 12. Sensitivity vs. Temperature – Parts Soldered to PCBX AXIS NOISE DENSITY (µg /√Hz)P E R C E N T O F P O P U L A T I O N (%)03757-0-008Figure 13. Y Axis Noise Density at 25°CPERCENT SENSITIVITY (%)P E R C E N T O F P O P U L A T I O N (%)–5.0–4.0–3.0–2.0–1.01.02.03.04.05.003757-0-006Figure 14. Z vs. Y Cross-Axis SensitivityADXL103/ADXL203TEMPERATURE (°C)C U R R E N T (m A )0.30.80.70.60.50.40.903757-0-020Figure 15. Supply Current vs. TemperatureP E R C E N T O F P O P U L A T I O N (%)4520253035401510503757-0-017VOLTS0.400.450.500.550.650.600.700.750.800.850.900.951.00Figure 16. X Axis Self Test Response at 25°CTEMPERATURE (°C)V O L T A G E (1V /g )–500.500.800.750.700.650.600.550.850.90–40–30–20–1010203050406070809010011012013003757-0-003Figure 17. Self Test Response vs. TemperatureP E R C E N T O F P O P U L A T I O N (%)03757-0-018µA2003004005006007008009001000Figure 18. Supply Current at 25°CP E R C E N T O F P O P U L A T I O N (%)03757-0-019VOLTS0.400.450.500.550.650.600.700.750.800.850.900.951.00Figure 19. Y Axis Self Test Response at 25°C03757-0-009Figure 20. Turn-On Time – C X , C Y = 0.1 µF, Time Scale = 2 ms/divADXL103/ADXL203THEORY OF OPERATIONEARTH'S SURFACE03757-0-021TOP VIEW (Not to Scale)OUT = 2.5V OUT = 1.5VX OUT = 2.5V Y OUT = 2.5VPIN 8X OUT = 2.5V Y OUT = 3.5VPIN 8X OUT = 1.5V Y OUT = 2.5VPIN 8X OUT = 3.5V Y OUT = 2.5VFigure 21. Output Response vs. OrientationThe ADXL103/ADXL203 are complete acceleration measure-ment systems on a single monolithic IC. The ADXL103 is a single axis accelerometer, while the ADXL203 is a dual axis accelerometer. Both parts contain a polysilicon surface-micromachined sensor and signal conditioning circuitry to implement an open-loop acceleration measurement architec-ture. The output signals are analog voltages proportional toacceleration. The ADXL103/ADXL203 are capable of measuring both positive and negative accelerations to at least ±1.7 g . The accelerometer can measure static acceleration forces such as gravity, allowing it to be used as a tilt sensor.The sensor is a surface-micromachined polysilicon structure built on top of the silicon wafer. Polysilicon springs suspend the structure over the surface of the wafer and provide a resistance against acceleration forces. Deflection of the structure is mea-sured using a differential capacitor that consists of independent fixed plates and plates attached to the moving mass. The fixed plates are driven by 180° out-of-phase square waves. Accelera-tion will deflect the beam and unbalance the differentialcapacitor, resulting in an output square wave whose amplitude is proportional to acceleration. Phase sensitive demodulation techniques are then used to rectify the signal and determine the direction of the acceleration. The output of the demodulator is amplified and brought off-chip through a 32 kΩ resistor. At this point, the user can set the signal bandwidth of the device by adding a capacitor. This filtering improves measurement resolution and helps prevent aliasing.PERFORMANCERather than using additional temperature compensationcircuitry, innovative design techniques have been used to ensure high performance is built in. As a result, there is essentially no quantization error or non-monotonic behavior, andtemperature hysteresis is very low (typically less than 10 m g over the –40°C to +125°C temperature range).Figure 9 shows the zero g output performance of eight parts (X and Y axis) over a –40°C to +125°C temperature range. Figure 12 demonstrates the typical sensitivity shift overtemperature for V S = 5 V . Sensitivity stability is optimized for V S = 5 V , but is still very good over the specified range; it is typically better than ±1% over temperature at V S = 3 V .ADXL103/ADXL203 APPLICATIONSPOWER SUPPLY DECOUPLINGFor most applications, a single 0.1 µF capacitor, C DC, will adequately decouple the accelerometer from noise on the power supply. However in some cases, particularly where noise is pre-sent at the 140 kHz internal clock frequency (or any harmonic thereof), noise on the supply may cause interference on theADXL103/ADXL203 output. If additional decoupling is needed,a 100 Ω (or smaller) resistor or ferrite beads may be inserted inthe supply line of the ADXL103/ADXL203. Additionally, alarger bulk bypass capacitor (in the 1 µF to 22 µF range) may be added in parallel to C DC.SETTING THE BANDWIDTH USING C X AND C YThe ADXL103/ADXL203 has provisions for bandlimiting theX OUT and Y OUT pins. Capacitors must be added at these pins to implement low-pass filtering for antialiasing and noisereduction. The equation for the 3 dB bandwidth isF–3 dB = 1/(2π(32 kΩ) × C(X, Y))or more simply,F–3 dB = 5 µF/C(X, Y)The tolerance of the internal resistor (R FILT) can vary typically as much as ±25% of its nominal value (32 kΩ); thus, the band-width will vary accordingly. A minimum capacitance of 2000 pFfor C X and C Y is required in all cases.Table 4. Filter Capacitor Selection, C X and C YBandwidth (Hz) Capacitor (µF)1 4.7 10 0.47 50 0.10 100 0.05 200 0.027 500 0.01SELF TESTThe ST pin controls the self-test feature. When this pin is set toV S, an electrostatic force is exerted on the beam of the accelero-meter. The resulting movement of the beam allows the user totest if the accelerometer is functional. The typical change inoutput will be 750 m g (corresponding to 750 mV). This pin maybe left open-circuit or connected to common in normal use.The ST pin should never be exposed to voltage greater thanV S + 0.3 V. If the system design is such that this conditioncannot be guaranteed (i.e., multiple supply voltages present), alow V F clamping diode between ST and V S is recommended. DESIGN TRADE-OFFS FOR SELECTING FILTER CHARACTERISTICS: THE NOISE/BW TRADE-OFF The accelerometer bandwidth selected will ultimately determine the measurement resolution (smallest detectable acceleration). Filtering can be used to lower the noise floor, which improves the resolution of the accelerometer. Resolution is dependent on the analog filter bandwidth at X OUT and Y OUT. The output of the ADXL103/ADXL203 has a typical bandwidth of 2.5 kHz. The user must filter the signal at this point to limit aliasing errors. The analog bandwidth must be no more than half the A/D sampling frequency to minimize aliasing. The analog bandwidth may be further decreased to reduce noise and improve resolution.The ADXL103/ADXL203 noise has the characteristics of white Gaussian noise, which contributes equally at all frequencies and is described in terms of µg/√Hz (i.e., the noise is proportional to the square root of the accelerometer’s bandwidth). The user should limit bandwidth to the lowest frequency needed by the application in order to maximize the resolution and dynamic range of the accelerometer.With the single pole roll-off characteristic, the typical noise of the ADXL103/ADXL203 is determined by)6.1()/µg110(××=BWHzrmsNoiseAt 100 Hz, the noise isg4.1)6.1100()/µg110(mHzrmsNoise=××=Often, the peak value of the noise is desired. Peak-to-peak noise can only be estimated by statistical methods. Table 5 is useful for estimating the probabilities of exceeding various peak values, given the rms value.Table 5. Estimation of Peak-to-Peak NoisePeak-to-Peak Value% of Time That Noise Will ExceedNominal Peak-to-Peak Value2 × RMS 324 × RMS 4.66 × RMS 0.278 × RMS 0.006ADXL103/ADXL203Peak-to-peak noise values give the best estimate of the uncertainty in a single measurement. Table 6 gives the typical noise output of the ADXL103/ADXL203 for various C X and C Y values.Table 6. Filter Capacitor Selection (C X, C Y)Bandwidth(Hz) C X, C Y(µF)RMS Noise(m g)Peak-to-Peak NoiseEstimate (m g)10 0.470.42.6 50 0.11.06 100 0.0471.48.4 500 0.013.118.7 USING THE ADXL103/ADXL203 WITH OPERATING VOLTAGES OTHER THAN 5 VThe ADXL103/ADXL203 is tested and specified at V S = 5 V; however, it can be powered with V S as low as 3 V or as high as 6 V. Some performance parameters will change as the supply voltage is varied.The ADXL103/ADXL203 output is ratiometric, so the output sensitivity (or scale factor) will vary proportionally to supply voltage. At V S = 3 V the output sensitivity is typically 560 mV/g. The zero g bias output is also ratiometric, so the zero g output is nominally equal to V S/2 at all supply voltages.The output noise is not ratiometric but is absolute in volts; therefore, the noise density decreases as the supply voltage increases. This is because the scale factor (mV/g) increases while the noise voltage remains constant. At V S = 3 V, the noise density is typically 190 µg/√Hz.Self-test response in g is roughly proportional to the square of the supply voltage. However, when ratiometricity of sensitivity is factored in with supply voltage, self-test response in volts is roughly proportional to the cube of the supply voltage. So atV S = 3 V, the self-test response will be approximately equivalent to 150 mV, or equivalent to 270 m g (typical).The supply current decreases as the supply voltage decreases. Typical current consumption at V DD = 3 V is 450 µA. USING THE ADXL203 AS A DUAL-AXIS TILT SENSOROne of the most popular applications of the ADXL203 is tilt measurement. An accelerometer uses the force of gravity as an input vector to determine the orientation of an object in space. An accelerometer is most sensitive to tilt when its sensitive axis is perpendicular to the force of gravity, i.e., parallel to the earth’s surface. At this orientation, its sensitivity to changes in tilt is highest. When the accelerometer is oriented on axis to gravity, i.e., near its +1 g or –1 g reading, the change in output acceleration per degree of tilt is negligible. When the accelerometer is perpendicular to gravity, its output will change nearly 17.5 m g per degree of tilt. At 45°, its output changes at only 12.2 m g per degree and resolution declines.Dual-Axis Tilt Sensor: Converting Acceleration to Tilt When the accelerometer is oriented so both its X axis and Y axis are parallel to the earth’s surface, it can be used as a 2-axis tilt sensor with a roll axis and a pitch axis. Once the output signal from the accelerometer has been converted to an acceleration that varies between –1 g and +1 g, the output tilt in degrees is calculated as follows:PITCH = ASIN(A X/1 g)ROLL = ASIN(A Y/1 g)Be sure to account for overranges. It is possible for the accelerometers to output a signal greater than ±1 g due to vibration, shock, or other accelerations.ADXL103/ADXL203 PIN CONFIGURATIONS AND FUNCTIONAL DESCRIPTIONSADXL103ETOP VIEW(Not to Scale)STDNC COM X OUT DNC DNC3757--22Figure 22. ADXL103 8-Lead CLCCTable 7. ADXL103 8-Lead CLCC Pin Function Descriptions Pin No. Mnemonic Description1 ST SelfTest2 DNC Do Not Connect3 COM Common4 DNC Do Not Connect5 DNC Do Not Connect6 DNC Do Not Connect7 XOUT X Channel Output 8 V S 3 V to 6 VADXL203ETOP VIEW(Not to Scale)STDNCCOMX OUTY OUTDNC3757--23Figure 23. ADXL203 8-Lead CLCCTable 8. ADXL203 8-Lead CLCC Pin Function Descriptions Pin No. Mnemonic Description1 ST SelfTest2 DNC Do Not Connect3 COM Common4 DNC Do Not Connect5 DNC Do Not Connect6 Y OUT Y Channel Output7 X OUT X Channel Output8 V S 3 V to 6 VADXL103/ADXL203OUTLINE DIMENSIONSBOTTOM VIEWFigure 24. 8-Terminal Ceramic Leadless Chip Carrier [LCC](E-8)Dimensions shown in millimetersESD CAUTIONESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although this product features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performancedegradation or loss of functionality.ORDERING GUIDEADXL103/ADXL203 Products Number of Axes Specified Voltage (V) Temperature RangePackage DescriptionPackage Option ADXL103CE 11 5 –40°C to +125°C 8-Lead Ceramic Leadless Chip Carrier E-8 ADXL103CE–REEL 1 1 5 –40°C to +125°C 8-Lead Ceramic Leadless Chip Carrier E-8 ADXL203CE 12 5 –40°C to +125°C 8-Lead Ceramic Leadless Chip Carrier E-8 ADXL203CE–REEL 12 5 –40°C to +125°C 8-Lead Ceramic Leadless Chip Carrier E-8 ADXL203EB Evaluation BoardEvaluation Board1Lead finish—Gold over Nickel over Tungsten.© 2004 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D03757–0–4/04(0)。

NASHAPP

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54
Chapter 3. Nash Equilibrium: Illustrations
is qi , then the price is P (q1 + · · · + qn ), so that firm i’s revenue is qi P (q1 + · · · + qn ). Thus its profit is πi (q1 , . . . , qn ) = qi P (q1 + · · · + qn ) − Ci (qi ). (54.1)
To find firm 1’s best response to any given output q2 of firm 2, we need to study firm 1’s profit as a function of its output q1 for given values of q2 . If q2 = 0 then firm 1’s profit is π1 (q1 , 0) = q1 (α − c − q1 ) for q1 ≤ α, a quadratic function that is zero when q1 = 0 and when q1 = α − c. This function is the black curve in Figure 55.1. Given the symmetry of quadratic functions (Section 17.4), the output q1 of firm 1 that maximizes its profit is q1 = 1 2 (α − c). (If you know calculus, you can reach the same conclusion by setting the derivative of firm 1’s profit with respect to q1 equal to zero and solving for q1 .) Thus firm 1’s best response to an output of zero for firm 2 is b1 (0) = 1 2 (α − c). As the output q2 of firm 2 increases, the profit firm 1 can obtain at any given output decreases, because more output of firm 2 means a lower price. The gray curve in Figure 55.1 is an example of π1 (q1 , q2 ) for q2 > 0 and q2 < α − c. Again this function is a quadratic up to the output q1 = α − q2 that leads to a price of zero. Specifically, the quadratic is π1 (q1 , q2 ) = q1 (α − c − q2 − q1 ), which is zero when q1 = 0 and when q1 = α − c − q2 . From the symmetry of quadratic functions (or some calculus) we conclude that the output that maximizes π1 (q1 , q2 ) 1 is q1 = 1 2 (α − c − q2 ). (When q2 = 0, this is equal to 2 (α − c), the best response to an output of zero that we found in the previous paragraph.) ↑ π1 (q1 , q2 ) q2 = 0 q2 > 0

Contents

Contents
M be a finite module over a commutative noetherian local ring R. There always exists a minimal free resolution F of M over R, that is unique up to isomorphism, and defines the Betti numbers bR n (M ) = rankR Fn . The structure of finite resolutions is very rigid, but little is known in the infinite case. To some extent, this is due to intrinsic numerical difficulties: Anick [2] shows that the Betti sequence of the residue field k of R may be non-recurrent, and Avramov [6] that it has exponential growth, unless R is a complete intersection . In contrast, the behavior at infinity of Betti sequences over complete intersections is not so daunting: Tate [36] proves R that bR n (k ) is eventually given by a polynomial, and Gulliksen [23] that each b n (M ) is a quasi-polynomial of period 2 and degree smaller than the codimension. The point of view of this paper, expanding on that of Eisenbud [18] and Avramov [8], [9], is that the beginning of a minimal free resolution is usually unstructured and (therefore) complicated, remarkable patterns emerge at infinity. Our objective is the introduction and study of a class of modules that afford a highly non-trivial, yet tractable, theory of minimal free resolutions. As necessary ingredients for such a study, we develop a conceptual

菜鸟记之电子文档汇总与分享专题合集—制作电子书,看这篇就够了!

菜鸟记之电子文档汇总与分享专题合集—制作电子书,看这篇就够了!

菜鸟记之电子文档汇总与分享专题合集—制作电子书,看这篇就够了!万一您身边的朋友用得着呢?免费咨询热线:如果您有工作中的困惑要和小菜分享或探讨,欢迎您发送邮件至**************,咱们一起研究提高。

截止今日小菜已分享300+篇经验之谈,可以文章编号或关键词进行搜索以下才是今天的正式内容……电子资料汇总和分享是教学管理人员日常工作的典型场景,如何将WORD、EXCEL、PPT、图片等多种类型的素材进行整合,并形成格式美观、可分享、浏览界面友好的文件,即制的电子书。

要实现这个目的,根据不同的情况咱们可以有不同的处理方式:图 1:电子文档汇总分享思路1相同格式素材的电子资料汇总1.1WORD格式文件一定要用样式来规范文档,建议通过样式区分标题和正文,同时生成封面和自动目录。

具体操作方法请阅读以下公众号文章:《菜鸟记11~规范化Word文档模板》《菜鸟记12—制作WORD格式电子书》《菜鸟记152-私人定制属于自己的文档模板之WORD篇》《菜鸟记190-每章节标题上页眉,校本教材也可以很专业!》《菜鸟记194-三分钟搞定论文里的标题编号》《菜鸟记235-WORD文件怎么批量合并和分拆?》《菜鸟记275-word文件标题样式批量升降级,原来这样简单!》《菜鸟记295-自定义模板随身携带,新建模块化文档更便捷!》《菜鸟记320-如何批量修改多个WORD文档的格式?》《菜鸟记331-制作一份带提醒的WORD模板》1.2EXCEL格式文件关于该部分的汇总相对复杂,基本可以分为两种情况:一是工作簿内工作表的汇总或拆分;二是工作簿之间的汇总。

我们可以借助的工具包括数据透视表、WPS、EXCEL插件或相应的函数等等。

关于汇总工作表或工作簿,可以看看这些:《菜鸟记61-从工作表中提取所需数据之下中集》《菜鸟记63-选择性粘贴巧妙汇总分发的工作簿》《菜鸟记123-ACCESS数据库简单应用1-两数据表简单查询应用》《菜鸟记124-ACCESS数据库简单应用2-多数据表简单查询应用》《菜鸟记131- Power Query,让数据查询更简单-两数据表简单查询应用》《菜鸟记133- Power Query,让数据查询更简单-多数据表简单查询应用》《菜鸟记142-制作多工作表的目录的三种方法,您喜欢用哪个?》《菜鸟记145-Power Query,没有唯一识别字段也能查询》《菜鸟记173-合并相同数据结构的多个工作簿,您属于几级菜鸟?》《菜鸟记176-汇总多个不规则的数据表,原来还可以这样玩!》《菜鸟记181-小菜如何偷懒系列之EXCEL插件KUTOOLS推荐》《菜鸟记284—厉害了我的WPS,合并表格再也不用复制粘贴!》《菜鸟记322-拒绝复制粘贴,相对引用制作模式化报表》《菜鸟记376-如何快速统计保送学生名单?》《菜鸟记377-EXCEL居然有自带的合并工作簿功能?》关于拆分工作表或工作簿,可以看看这些:《菜鸟记8-独孤九剑之数据透视表中集》《菜鸟记61-从工作表中提取所需数据之下中集》1.3PPT格式文件建议转换为PDF或网页格式文件,请参阅2.1和2.2关于PPT文件管理的内容请可阅读以下公众号文章:《菜鸟记90-文档保密之PPT篇》《菜鸟记104-精确控制自动播放的PPT时间》《菜鸟记154-私人订制属于自己的文档模板之PPT篇》《菜鸟记180-领导对PPT做了哪些改动?三分钟我就知晓》《菜鸟记243-一分钟快速制作文字型PPT的方法》《菜鸟记326-如何去掉PPT保存为PDF后烦人的日期?》《菜鸟记328-多页PPT转为一页PDF,节约一点是一点》2不同格式素材的电子资料汇总2.1转换为PDF格式建议采用All Office Converter Platinum、PDF Binder或在线网站等工具,将不同格式文件转换为PDF文件,进行合并添加页码,再制作人工目录和封面,再合并成一个文件。

笔记版黄简讲书法:329裹束29-技法总结1

笔记版黄简讲书法:329裹束29-技法总结1

笔记版黄简讲书法:329裹束29-技法总结1329:技法总结1一、两条路追踪王羲之 书法有哪些“法”?关键就是寻找王羲之笔法。

你看很多人买字帖学书法,选颜真卿、柳公权、赵孟頫,甚至更近一些的,如学赵子谦、黄自元等等。

你买一本字帖等于投入这一家,这些路径未免太远。

唐太宗说“取法于上,仅得为中;取法于中,故为其下”。

王羲之是公认的书圣,我在一级课程第四课中指出,学书法应当聚焦王羲之,目标要非常明确。

1963年9月,沈尹默先生发表《二王法书管窥》一文,专谈学王羲之的问题,虽然没有具体结论,但他提出的一些观点值得注意。

沈先生说:“自唐以来学书的人,无一不首推右军……。

”这是经过时间淘汰和历史考验后得出来的结论,成就最高、用笔最精就是王羲之。

跟研究中国的儒家学派一样,儒家的代表人物是孔子。

研究儒家当然要读读孔子的六经,熟悉《论语》。

后代对儒家的解释往往加点私货,偏离孔子的原意。

如果你说研究孔子主要靠看电视剧,那实在不敢恭维。

就书法这一门艺术而言,王羲之的地位等于孔子。

但王羲之没有专谈用笔的文章传世,作品也只有钩摹本和刻本。

那怎样去寻找王羲之的笔法呢?这跟警察破案一样,先要整理出一个思路。

沈尹默先生设想破案的方案是:“好在陈隋以来,号称传授王氏笔法的诸名家遗留下来的手迹未经摹拓者尚可看见,通过他们从王迹认真学得的笔法,就有窍门可找。

不可株守一家,应该从各人用笔处,比较来看,求其同者,存其异者,这样一来,对于王氏笔法,就有了几分体会了。

”也就是说,沈先生设想拿王羲之系统的书法家作品,加以比对,从而找出共同的用笔特征。

王羲之生卒年月大约是303-361,享年59岁。

东晋前后一共103年,王羲之是生活在东晋前半期。

沈尹默先生说陈隋时期的书法家,多见王羲之真迹。

这时期离开王羲之只有二百多年,等于我们现在看乾隆时期的书迹,当然可以看到很多。

智永就是陈隋间人,他是王羲之七世孙,智永寿命很长,大致一算,离王羲之也就是250年左右。

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我与智慧课堂共成长——电子书包教学经验分享德保县城关镇鉴河小学黄练尊敬的各位领导、老师们:大家好!我叫黄练,是鉴河小学的一名语文老师,2015年上半年,我们学校启动“智慧课堂”教学,我和所任教的2013级8班的同学们有幸成为我校第一批智慧课堂的感受者,成为了“第一个吃螃蟹的人”。

从2015年5月启动直至2019年7月,(8)班的同学们毕业,我们在“智慧课堂”中共同成长,共同经历了人们对电子书包教学从怀疑到肯定的巨大转变。

下面,我想从平台数据、起步艰难、电子书包重点运用,还有学生能力和成绩的提升,这四个视角和大家分享这一路来的点点滴滴。

首先,我想让大家从优学派平台的一些统计数据中感受一下电子书包在我们日常教学中的渗透程度。

作为语文老师,我的个人积分累计7867分,班级学生总积分354,710分,积分最高的农项同学积分总分9746分;在班级空间建设中,累计发布话题150个,创建与学习相关的资料相册360个,创建班级问答1383个,在资源库中创建资源4244个。

电子书包在日常教学中的应用超过了80%。

二、起步艰难。

我们德保是国家级贫困县,当时想要动员家长在义务教育阶段自费购买将近两千八的平板电脑帮助学习,难度是非常大的。

作为班主任,我真真切切感受到学校的宣传工作开展得很艰难,家长们顾虑重重,焦躁迷茫。

曲曲折折之后,我们原本六十几人的班级,有50个同学报名,终于,第一个电子书包实验班成立了!从校园网络建设到教师的专业培训,学校领导高瞻远瞩,为智慧课堂的成功启动做了巨大的投入。

2015年的寒假,春节过后,校长就组织老师们回校学习,我记得当时为了这个学习,我还特地换了新款的性能更好的手机。

就算是我这个平时自觉对电化教学得心应手的80后老师,也觉得一开始的学习很吃力,感觉一头雾水。

可是校长对学校未来智慧课堂的憧憬,她的那份自信,又使我无比兴奋和向往。

于是,我虚心和技术员请教,拿到教师机后,我就努力地体验平板的各种功能,对其中的资源不断地使用、摸索,每天在平台上到处点点点,学习利用平台资源,尝试创建适合自己学生的资源。

让自己更快地熟悉电子书包,并把自己体验到的这些优势分享给家长和同学们。

当时,面对文化水平参差不齐的家长,面对只有老人和孩子的留守家庭,面对家中WiFi还没有开通的情况,重重困难,真是是靠信念的支撑、对智慧课堂的一腔热情和对学生、家长的耐心细心一一化解的。

毫不夸张地说,启动初期,平板电脑是我每天包包里的标配,一有机会就尝试各种操作和改作业,回到家中也总是离不开手机,不厌其烦地在班级微信群里向家长解答各种电子书包的问题。

甚至有几次,晚上和周末,我和家长面对面,手把手教家长解决使用平板遇到的问题。

大到课堂备课、编辑作业题目,小到充电车的布线、充电位置的安排、“轻拿轻放”的提醒标语,我都事无巨细的用心。

课堂上、课后使用的多,出现的状况就多;处理的状况多,我和同学们、家长们成长得就很快。

热烈讨论问题的班群,在四个月之后,逐渐回归原来的样子,因为家长和孩子们已经能操作顺畅了,我们班算是渡过了启动初期最艰难的适应期。

这期间,我注意聆听同学们和家长们的声音,从易到难设计作业,让孩子们一步一步提高自己对电子书包的操作能力。

平时的教学中,注意拍照、拍视频记录孩子们在学习中的点滴成长,并制作成短片,让同学和家长们在图片中回顾自己的每一点进步,增强对电子书包教学这个新鲜方式的信心。

三、电子书包的重点运用我们班启动时是二年级下学期,学生处在低中年级过渡阶段,所以我就从最简单的生字书写和电子朗读作业入手。

利用“优学”中的“汉字听写”功能纠正同学们不规范的书写习惯,即交即出分数即攻克错字的特点还能迅速提升同学们的生字掌握能力。

假期时,我安排同学们学习“优学”中的语文知识点,对已学的内容进行巩固,对即将接触的内容提前进行预习,并定期发布电子作业进行检测。

这样,更合理地利用了寒暑假的时间,更快更全面地了解到了学生的知识薄弱点,就能更有针对性地进行备课。

从而实现“预见方能遇见”。

电子朗读作业解决了面对面检查朗读背诵耗时长的问题,每个同学在家中对着平板朗读、录音提交,闭上眼睛背诵,提交视频,这样给性格内向的学生提供了更舒适的学习空间,使学生的能力更好地展现出来。

让尖子生做学习小组组长帮助老师批改朗读作业,不仅节约了老师的批改时间,也培养了学生的责任心和细心。

三年级,同学们已经能熟练操作平板上课和作业。

这时,针对学习写作文初期遇到的写作素材匮乏,缺少体验等困难,我开始带领孩子们利用平板的拍照、录视频和电子笔记等功能在生活中积累写作素材。

平时孩子们没有自己的记录工具,大部分家长疏于陪伴,学生懒于动笔摘抄和记录。

有了平板,有了电子书包,同学们可以拍、可以录、可以上网查资料、可以截图保存、可以录音保存、可以边录看到的景象变配上自己的语音旁白,合成自己的电子日记。

提交电子作业后同学们可以互评,身临其境地感受到别人的世界;共享到班级空间后,同学们可以在线互动,分享到更多的素材。

作业不再是枯燥乏味的写写写,而是变得立体有趣起来。

孩子们永远是喜欢新鲜事物的,这样的学习和交流方式大大提升了同学们的学习积极性和实践能力。

四年级,我休产假。

五六年级时,我把电子书包的应用重点放在了知识整合、查缺补漏。

注重培养孩子们随堂创建电子笔记,课堂上利用对老师的重点讲解和同学的优秀发言进行录音、对板书进行拍照,课后对错题整理进行拍照、截图或下载图片保存班级空间分享的重要内容等等便捷方式,更快更方便地整理到电子笔记里。

在进行每个单元的检测之前打开电子笔记进行复习,更有针对性,学习更高效,也能更快提升成绩。

每个学期都对本学期的知识点进行梳理、整合,利用“优学”和平台上下载的资源进行强化。

从电子书包在教学应用中的方式和时间。

方式:课堂教学课件、优学派互动课堂工具的辅助、电子作业、电子考试班务管理等。

平台资源库里的课件非常丰富,帮助我更好地备出适合自己班级的课件,课堂上互动课堂工具为课堂增添了活力,有效调动了学生学习的积极性。

一直到六年级,抢答功能都还让同学们乐此不疲,随机抽查功能也更好地帮助学生丢掉了懒惰和侥幸心理。

我们班的电子作业量能达到所有作业量的一半以上。

几年的摸索,让我学会了扬长避短,忙的时候,我更多布置客观题为主的作业,学生一提交系统就能显示批改结果,就能马上进行错题攻克。

对于学生操作时容易出现的系统错误,比如标点输入,我就更改题型或者用填序号代替填标点,这样也同样达到了训练目的,又不至于让学生和家长对电子作业产生焦躁情绪。

每隔一段时间就从学生的错题库中选题再次组卷进行检测,确保更扎实地消灭难题。

即便是到了临近毕业考以纸质作业为主的紧张时期,我们班也坚持每天两三道题的电子作业,我会从资源库里有针对性的查找适合的题目进行发布,并进行难度的分类,同学们可以按自己的能力和时间情况选择性地进行练习,这样不强迫、更注重自觉自愿的“加分作业”,同学们更乐于接受,减轻压力。

从同学们的参与度数据,结合这个班同学的毕业考成绩,我可以得到验证:成绩优秀的同学都很积极完成电子作业,特别是这次毕业考语文成绩最高分98.5的农项同学,大家可以看到,平台数据显示她的积分是最高的。

几乎每个学期,我都会进行电子期末考试,向学生和家长传达一个态度:作为电子书包实验班,电子考试和书面考试同样重要。

这样,无形中,孩子和家长们对电子书包就更重视、对于平板也更爱护。

在电子书包应用的时间上看,我从课前、课堂、到课后、到寒暑假,紧密衔接,不断开。

特别是寒暑假,我觉得电子书包很好地帮助我实现了对学生更科学完成作业的管控。

请大家看图,我会把假期时间进行科学安排,每个阶段安排不同的作业,并定期发布电子检测,循序渐进,在规定时间内完成并攻克,超过期限就删除作业。

很大程度上避免了同学们犯假期作业拖延到开学前几天才加班加点完成的老毛病。

这个方法也得到了家长们的好评。

孩子们在假期里这样认真对待作业,一定程度上减轻了开学后的学习负担,我觉得这也是我们班为什么在很多能力上由于其他班级同学的原因。

另外,我想想用“经典”和“惊喜”这两个词来形容电子书包的几个功能,经典——是电子书包在语文科的应用中,“早晚读”和“高效阅读”不仅是提升语文能力最基本的方法,也是很大的亮点。

这两个功能在二年级到六年级的教学中,一直贯穿始终。

早读晚读周末读,学完一篇课文我会趁热打铁,及时发布一个高效阅读进行巩固。

同学们从最初的看“诺亚优学”里的书到自己下载新书、到上网查阅资料分享到班级空间,建设我们自己的“阅读空间”,在“班级话题”里浏览帖子、回帖,到学会在电子书上进行标注,阅读速度越来越快,素材积累越来越多,阅读题出错率也越来越低。

我真真切切感觉到了孩子们阅读能力的提升。

惊喜——我还很惊喜地发现:电子书包的部分功能有助于班级活动的开展和班务管理。

比如投票功能,让我们的班干竞选变得公平而高效。

策划活动时让我更好地了解学生的喜好,得到活动反馈。

“私信”功能更拉近了老师和学生之间的距离,有些话,孩子们当面说不出来,他们更愿意私信我说。

“班级空间”的建设更好的增强了班级的凝聚力和同学们的友谊。

四、学生能力(成绩)的提升。

在平时的教学中,也许我们感受到更多的是教学时各种操作带来的麻烦,网络不顺畅、系统错误等客观原因带来的不确定,会拖累教学进度,但是,几年下来,这个先进的教学方式所带来的效果越来越明显,作为这个班的语文老师和班主任,我真真切切感受到同学们能力的提升,视野的拓宽,成绩的进步。

这些年来,每年的语文竞赛,我们班总是硕果累累,获奖率占整个年级甚至整个县域的很大比重。

考试成绩也是一直保持在全县前列。

特别是今年7月份的毕业考。

我们班的语文课成绩取得了全县第一的好成绩。

全班平均分89.26,九十分段同学30人,优秀率达到87.3%,全校最高分98.5的就是优学派平台积分最高分9746分的农项同学,最低分为五年级才插班进来,一直到毕业时家中WiFi都没有的留守儿童麻腾彪同学——71.3分。

我没有夸张,电子书包教学是利大于弊还是弊大于利,这是最有力的的说明。

以下,是我搜集的一些平时教学中的图片和数据截图,因为周末拟稿时才发现一部分平台数据随着(8)班同学们的毕业而消失了,昨天技术员才帮我重新把数据调出来,所以图片的筛选比较仓促,不多也不算最典型的,还请大家谅解。

也借此提醒各位授课的老师,在平时的教学中,注意收集和保存有价值的图片和数据,以免出现像我这次的问题。

图片解说(略)今天,这里坐满了我敬佩的领导和各兄弟学校优秀的同仁们,我站在大家面前分享这些做法,实在是诚惶诚恐,班门弄斧。

不敢说是什么经验,只能说我何其幸运,学校给我这样一个平台,能早早踏上了这个探索之路,并且把这个班带到了毕业,让我对小学的智慧课堂有了一个比较完整的感受。

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