排序方式: 共有39条查询结果,搜索用时 78 毫秒
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The paper discusses six case studies of sleeping bag design, one used by astronauts onboard the Space Shuttle and another currently being used on the ISS, which was developed by a Russian company. Two inflatable designs, one by Wubbo Ockels for ESA and one by the University of Technology in Munich in cooperation with NASA are chosen as case studies as well. Two recent designs set a new paradigm and option of sleeping in zero-g. The cut of the sleeping bag of these two design case studies allows the person to relax and sleep in the neutral body position. They were developed by Toshiroh Ikegami from Kyoto City University of Arts and astronaut Chiaki Mukai for JAXA, and by the Vienna based team LIQUIFER Systems Group in cooperation with ESA-astronaut Gerhard Thiele.Currently there is an increased interest in astronauts' and cosmonauts' sleep quality and related comfort because analysis of their sleep quality showed that sleep during long exposure to microgravity does not always ensure good recovery of cognitive and functional capabilities. Present research in the area of sleep and performance preservation include studies by the Institute of Biomedical Problems (IBMP) in Moscow and the NASA-JSC study from the Behavioral Health and Performance Element Human Research Program about improving sleep quality on ISS.In the context of the paper the operational medical challenges of sleep quality will be described in order to establish the relevance of effective sleeping bag designs to support spaceflight crewmembers' well-being. 相似文献
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为了验证多影响因素作用下的数控XY工作台误差补偿效果,必须设计能够实现温度、运动速度、X/Y坐标位置、标准量实时采集与同步触发的测控系统,用于补偿实验验证。介绍了能够实现工作台运动速度、温度、光栅尺与电感测微仪同步触发并实时采集的测控系统。以数控XY工作台为研究对象,采用电感测微仪为工作台位移标准量,DSP为主控芯片,搭建了实验装置进行了实时采集、同步触发和比对实验,以及测控系统测量误差和重复性误差实验。实验结果表明,所设计的测控系统可以实现预设目标,可以用于不同影响因素下的数控XY工作台位移量与标准量的实时比对,验证工作台误差补偿效果,也为后续数控机床在机测量系统误差补偿器的研制打下基础。 相似文献
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图像增强技术的分析和比较 总被引:1,自引:0,他引:1
对经典的全图像增强枝术和比较先进的局域图像增强技术进行了归纳分析,总结了每种技术适于处理图像的特征和优缺点,并对一些算法进行了描述。 相似文献
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数字IC的检测方法与技术 总被引:1,自引:0,他引:1
数字电路的各种仪器设备中,数字IC的应用较广.那么,如何正确检测数字片的性能,判断故障所在,文中提出了静态检测、逻辑功能检测、逻辑比较等几种常用的方法. 相似文献
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Umut G. Sefercik Mustafa Ozendi 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
With the launch of very high resolution (VHR) optical and synthetic aperture radar (SAR) remote sensing satellites such as IKONOS and TerraSAR-X, a new era has begun in 3D spatial data acquirement. IKONOS provided the first VHR data is still being preferred for many remote sensing applications. TerraSAR-X is considered as a revolution in SAR imaging as a result of 1 m resolution imaging capability. The imaging principles of these satellites are quite different and include advantages and disadvantages that have considerable effects on the quality of acquired 3D spatial data. 相似文献
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Hanqiu Xu Shaolin Huang Tiejun Zhang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
Worldwide urbanization has accelerated expansion of urban built-up lands and resulted in substantial negative impacts on the global environments. Precisely measuring the urban sprawl is becoming an increasing need. Among the satellite-based earth observation systems, the Landsat and ASTER data are most suitable for mesoscale measurements of urban changes. Nevertheless, to date the difference in the capability of mapping built-up land between the two sensors is not clear. Therefore, this study compared the performances of the Landsat-7 ETM+ and ASTER sensors for built-up land mapping in the coastal areas of southeastern China. The comparison was implemented on three date-coincident image pairs and achieved by using three approaches, including per-band-based, index-based, and classification-based comparisons. The index used is the Index-based Built-up Index (IBI), while the classification algorithm employed is the Support Vector Machine (SVM). Results show that in the study areas, ETM+ and ASTER have an overall similar performance in built-up land mapping but also differ in several aspects. The IBI values determined from ASTER were consistently higher than from ETM+ by up to 45.54% according to percentage difference. The ASTER also estimates more built-up land area than ETM+ by 5.9–6.3% estimated with the IBI-based approach or 3.9–6.1% with the SVM classification. The differences in the spectral response functions and spatial resolution between relative spectral bands of the two sensors are attributed to these different performances. 相似文献
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主要介绍采用比对法检定真空计的装置。该装置的原理是将一支或几支需要检定的真空计与副标准真空计一起接到标准容器上,用副标准真空计和被检真空计同时测量标准容器内的同一压强,将所测的结果直接比对。该装置结构简单,操作方便,检定范围宽,效率高,主要技术指标符合国际标准化组织(ISO)和国家有关真空标准的具体现定,可适用于真空计量二级站和基层计量单位大量常规检定。对标准装置的要求以及使用中应注意的问题和结果表示进行了讨论。 相似文献
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详细介绍了国军标电磁兼容检测实验室进行实验室间比对的方案,比对器具的选择和比对数据的处理方法,分析了国军标电磁兼容实验室比对的特点,用平均值、数据偏差等参数对国防系统实验室4个比对项目的数据进行了分析,研究实验室间测试结果存在差异的原因,并给出改进建议。 相似文献