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1.
在信息时代如何提高课堂教学的信息量?如何满足学生的求知欲?本结合作的教学经验,从词汇、听力及阅读三个方面提出了有关英语教学的几点实践性见解。  相似文献   

2.
探析信息技术的伦理问题   总被引:1,自引:0,他引:1  
信息技术的广泛使用引发了诸多的伦理问题,如知识产权的侵犯、个人隐私的失控、信息安全的破坏、信息垃圾的传播等。通过对这些问题的探究,分析了伦理失范原因,指出建立信息技术伦理道德体系的必要性与迫切性,并从法律、道德、信息伦理学三个方面提出了建构信息伦理道德体系的构想。  相似文献   

3.
虚拟现实技术及其应用   总被引:10,自引:0,他引:10  
虚拟现实技术是当今最为流行的计算机技术之一 ,本文对虚拟现实的历史、发展、概况进行了必要的介绍 ,同时讲述了虚拟现实技术的基本特点。介绍了虚拟现实系统的构成及其基本的应用与今后发展的趋势。最后针对当前的实际情况 ,提出了今后应该做的工作。  相似文献   

4.
《Air & Space Europe》1999,1(1):48-50
As automation becomes more sophisticated and complex, there is increasing concern about the time and cost of training pilots to use it, and the possibility of pilot errors. In this sense, the evolution of avionics systems is emulating the evolution of personal computers in the 1980s. In the early days of personal computing, users had to learn some basic computer science concepts and an obscure command language with only passing resemblance to natural language. Because the command language was highly codified and condensed, the user had to commit apparently arbitrary syntax rules to memory, and if the user made an error, such as reversing the source and destination drives in the “copy” command, the results could be catastrophic (in this case, erasing the file that was intended to be saved and saving the one that was intended to be erased).The personal computer industry responded to the widespread perception that computers were difficult to use by developing graphic user interfaces. Today, most users can perform rudimentary operations on a personal computer with little or no training or reference to the manual. It is possible that the same type of advance could be achieved with avionics systems, so that almost any trained pilot could operate a new piece of avionics with little or no training in its specific operation.  相似文献   

5.
在多属性群决策分析中,由于涉及到各属性评价值的综合和专家个体评判的集结,所以决策群体很难对方案直接评优,针对多属性群决策方法问题,给出了一种分析方法.首先,给出了每位专家多属性数值决策矩阵和理想点的定义;然后通过定义专家群体贴近度矩阵和专家群体理想点,给出了基于多属性数值决策矩阵形式偏好信息的群决策方法;最后,通过一个算例对该方法的合理性和有效性进行了说明。  相似文献   

6.
This paper describes the latest trends in the IEEE 1394 (“firewireTM” or “iLinkTM”) standards and why it is becoming the connectivity standard of choice for automatic test applications. Why move to IEEE 1394, what are the possible risks with doing so, what are some of the myths associated with IEEE 1394 and a practical example of an automatic test application will all be presented with the prime emphasis on giving the latest information that will help you get IEEE 1394 integrated into your automatic test system  相似文献   

7.
Annie 《航空港》2012,(8):78-83
威士忌是真正属于男人的酒,尘世的烟火气味掩饰不了它的天生神韵,如果你从心里接受了它,一生都会是它的信徒,因为它能渗透到你的生命里去。如何鉴别优质威士忌1色泽:拿酒杯时应该捏住杯子的下方杯脚,而不能托着杯壁。因为手指的温度会让杯中的酒发生微妙的变化。在灯光下仔细观察,可以在酒杯的背后衬上一张白纸作为背景。威士忌的颜色有很多种,从深琥珀色到浅琥珀色都有。酒的色泽和威士忌在橡木桶里存放时间的长短密切相关。一般来说,存放时间越长,威士忌的色泽就  相似文献   

8.
This discusses the implementation issues of installing a commercially available hand geometry system in the current infrastructure of Purdue University's Recreational Sports Center. In addition to a performance analysis of the system, a pre- and post-data collection survey was distributed to the 129 test subjects gathering information on perceptions of biometrics, in particular hand geometry, as well as participants' thoughts and feelings during their interaction with the hand geometry device. The results of the survey suggest that participants were accepting of hand geometry. Additionally, analyses of the participants' survey responses revealed that 93% liked using hand geometry, 98% thought it was easy to use, and 87% preferred it to the existing card-based system, while nobody thought the device invaded their personal privacy. System performance achieved a 3-try match rate of 99.02% (FRR 0.98%) when "gaming"/potential impostor attempts were removed from analysis. The failure to enroll rate was zero. Statistical analyses exposed a significant difference in the scores of attempts made by users with prior hand geometry usage, and subjects that could not straighten out their hand on the device. However, there were no statistical difference in the effects of rings/no rings, improper hand placements/proper hand placements, or gender on hand geometry score.  相似文献   

9.
傅百先 《航空学报》1988,9(6):259-264
 本文介绍远洋航途中和南极地区的海情、地理环境和气象特点及其给直升机使用和维修带来的主要问题,并提出为适应远洋、极地使用要求,我国远洋舰载直升机应具备的性能。  相似文献   

10.
本文对用结构信息二次加权问题进行了分析讨论,结论是当在各准则(子准则或指标)下支配的方案数不同,并且这个数目确实反映了准则(子准则或指标)的某种量的信息,从而对准则(子准则或指标)的权值有影响时,而且仅当上述条件成立时,才应使用结构信息二次加权。此外,本文也导出了使用结构信息二次加权时计算一致性比例的公式。  相似文献   

11.
Shea  M.A.  Smart  D.F. 《Space Science Reviews》2000,93(1-2):187-205
There appears to be concern among some people about the possible effects of cosmic radiation on everyday life. The amount of cosmic radiation that reaches the Earth and its environment is a function of solar cycle, altitude and latitude. The possible effect of naturally occurring cosmic radiation on airplane crews and space flight personal is a subject of current study. This paper discusses the variables controlling the cosmic ray flux in the atmosphere and describes models and software that have been developed that provide quantitative information about the cosmic radiation exposure at flight altitudes. The discussion is extended to include the cosmic radiation exposure to manned spacecraft. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

12.
This paper is about the disparity between what is known and what is being learned in academia and what is being used in industry. The author believes there are many reasons. Some of these represent accidental and some essential problems. Most are part of a general issue of quality in the software products. Most problems that make it more difficult to apply testing techniques are part of a larger problem which make them more cost-effective to produce high quality software. The author presents a list of reasons industry does not use the highly advanced, and in some cases, highly developed software testing techniques that are available. The problems are divided into three broad categories: problems in industry; problems in academic research and education; and problems in the interface between the two  相似文献   

13.
某型发动机性能衰退的统计分析和预测   总被引:3,自引:2,他引:3  
李珈  陶增元 《航空动力学报》1992,7(2):173-176,197
本文根据500多台次经过0~3次翻修的同一型号发动机的台架性能,运用统计和综合分析的方法对发动机性能衰退进行了分析。提出了反映发动机整体性能的总体性能指数的概念。建立了翻修性能衰退的数学模型,并对性能衰退的发展趋势进行了预测。其结果与实际情况较为吻合,从而为发动机的使用和寿命研究提供了依据。   相似文献   

14.
The computerized model permits a mixed fleet of aircraft to ?fly? over a route structure for a given time period. By doing so, the detailed operational and economic factors are evaluated. In the past, the above-mentioned information was available after the purchase of the aircraft, and the selection of the airplane was done by little-known parameters. This program will furnish the data before the aircraft is purchased, thus taking the guessing from the selection. The high investment makes it mandatory for airline management to examine and to know ahead what to expect from the airplane and what is the acceptable return on this investment. On the other hand, an existing fleet with a given route structure can be analyzed by varying the schedule.  相似文献   

15.
In this paper we offer an overview of a number of algorithms suitable for 3D characterization of an urban environment from interferometric SAR data. By means of these algorithms we compare fine resolution C- and X-band SAR measurements over the same area to understand what useful information can be derived from these measurements. In addition we examine the similarities and differences of these data sets that are acquired with different frequency bands, bandwidths, and radar look direction. These data sets are recorded over Los Angeles, California, by the C-band NASA/JPL AIRSAR system, and by X-band Intermap Star-3i system. We analyze the original range measurements as reconstructed after the phase unwrapping procedure, the bald earth topography that we were able to retrieve, and the 3D shapes of some of the buildings in the UCLA area. Our results show that both data sets provide useful information of urban 3D characteristics. The better ground resolution of the X-band system results in better building shape extraction. Lower resolution of the C-band data, surprisingly, was not a limiting factor for extraction of large building structures. We demonstrate that it is possible to extract the terrain elevation model (bald earth topography), and the heights of large building structures by means of our algorithms  相似文献   

16.
In this introductory presentation, material is categorized according to our state of knowledge: What do we know, what do we think we know but don’t know certainly, and what do we not know but often describe it as if it were a well-established fact about comets, their nuclei, their composition, and processes within comets and their nuclei. The material is presented not with the intend to criticize laboratory work simulating condition in comet nuclei, or observers analyzing their observations, nor modelers using data from both these sources to improve our understanding and make predictions. The intent is to provoke discussion and dialog between these groups to avoid overstating the results. What is a Comet? A comet is a diffuse appearing celestial phenomenon moving in an orbit about the Sun. The central body, the nucleus, is composed of ice and dust. It is the source of all cometary activity, including comae and tails. We distinguish between molecular (including atoms and ions) and dust comae. At heliocentric distances of about 1 AU and less, the hydrogen coma typically has dimensions larger than the Sun. The tails are composed of dust, neutral atoms and molecules, and plasma.  相似文献   

17.
构建直升机交互式电子技术手册(IETM)框架,将重要的技术资料有效地结合到IETM系统中,给维护人员提供最直接、最全面、最新版的信息支持,对确保直升机维修的科学性和高效性有着重要的意义。针对直升机IETM的发展趋势,在详细研究了S1000D标准的思想及特点的基础上,提出了信息数据“一次存储,多次使用”的理念,探讨了有关信息产生的基本规则和数据模块的优化原则。在此基础上,提出了直升机IETM信息组织的基本原则和整体架构,对通用资源数据库(CSDB)中的相关信息对象涉及的范围及内容进行了详细说明,并提出了IETM系统的开发、发布及管理流程。  相似文献   

18.
报刊新闻及时准确地向广大受众传递国内外最新信息,是一种重要的信息传播手段,通过对严复的“信、达、雅”三字标准、奈达的“动态对等论”的分析,认为英语报刊新闻的翻译要忠实于原文信息,照顾中文读者阅读习惯,并对此提出了7种不同的翻译策略,为英语报刊新闻翻译策略提供有价值的参考意见。  相似文献   

19.
张立民  钟兆根  武恒州 《航空学报》2013,34(5):1191-1203
 针对长码直接序列扩频码分多址(DS-CDMA)信号的盲解扩,在信号模型分析的基础上,提出了一种基于可逆跳跃的马尔可夫链蒙特卡罗(RJ-MCMC)扩频码和信息序列联合估计算法。该算法分别对建立的联合后验分布模型进行迭代抽样,并有效地在不同维数的子空间中跳转,从而构造一条马尔可夫链,使其平稳分布为待估参数的后验分布,最终拼接得到每个用户的完整扩频序列和信息序列估计。仿真结果表明:该方法在迭代二十几步时达到收敛;并且在功率相同和不同条件下,当信噪比(SNR)大于-9 dB时,估计序列与真实序列的相似度均超过0.95,信息序列的误码率低于0.01;同时算法对不同用户个数和不同调制样式具有较强的适应性,与Fast-ICA算法相比,估计性能平均提高了约3 dB。  相似文献   

20.
在应用CATIA进行飞机三维建模过程中会经常性地重复用到航空标准件,为提高工作效率,简要介绍通过Visual Basic软件设计的参数化航空标准件库工作界面,该界面实现了在CATIA软件中生成、调用航空标准件三维模型和标准件材料、尺寸以及使用说明等相关信息的查询功能。  相似文献   

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