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81.
Branton P 《Applied ergonomics》1984,15(2):105-107
The backshapes of 114 seated persons were measured. The horizontal and vertical positions of various spinal landmarks are given for male and female subjects and for those with lordotic, straight and kyphotic backs. 相似文献
82.
《Behaviour & Information Technology》2012,31(6):457-473
User involvement has been shown to be beneficial in the development of useful and usable systems. The trend of software development becoming a product-oriented activity creates challenges to user involvement. Field studies appear a promising approach, but the analysis of the gathered user needs has been shown to be demanding. This study presents, on the basis of seven case studies, an early user-involvement process showing how user needs can be analysed and how the input to product development can be identified. In addition, the process is evaluated in two industrial cases with interviews and a questionnaire. The results show that the process supports effective early user involvement; the resulted requirements were evaluated as being more successful and their quality as better than average in a company. However, the case studies show that user involvement not only provides useful information about users' needs but also increases the understanding of users' values. 相似文献
83.
在开展宁夏节水型灌区建设现状调研的基础上,对灌区节水技术推广应用情况、水资源利用现状、节水成效进行总结,对节水型灌区建设中存在的问题进行分析,结合灌区特点,研究提出了宁夏节水型灌区建设的对策. 相似文献
84.
2010-2011年枯季珠江来水偏枯,珠江三角洲地区咸潮上溯加剧,珠江防总组织实施了枯季水量调度,确保了珠海、澳门等地供水安全,有效改善了广州亚运期间珠江三角洲地区的水环境,实现了供水、水环境、电力、航运等多方共赢,充分体现了流域水资源统一管理的重要性和迫切性,彰显了新形势下水利的战略地位.同时,分析结果表明,珠江水资源调控能力不足,应尽早建设西江大藤峡水利枢纽工程,以实现珠江水资源效益最大化. 相似文献
85.
利用Ansoft HFSS软件研究了电磁兼容设计中的孔缝耦合问题,介绍了有限元法的基本原理,对比仿真结果与对数周期天线的测量值,验证了此有限元法的可靠性.通过对带孔缝机箱建模,改变其孔缝的形状、面积等因素进行机箱的屏蔽效能仿真分析,获得了不同情况下的屏蔽效能仿真结果,并指导机箱内电路板的布置. 相似文献
86.
23 highly hypnotizable undergraduates (Harvard Group Scale of Hypnotic Susceptibility) underwent 2 specially constructed 7-item hypnotic inductions. Over the 14 items, the main finding was of a relationship between E. R. Hilgard's (1973, 1977, 1979) "hidden observer" effect and 2 aspects of hypnotic age regression. Ss reporting a hidden observer experienced duality during regression to age 5, in which they were aware of being both adult and child. When asked to write a complex sentence, most did so, usually without spelling errors. The Ss not reporting this effect experienced quasi-lateral age regression in which they had the exclusive feeling of being 5 yrs old, with no sense of an adult identity. Most of these Ss were unable to write the same complex sentence when requested to during age regression. The study replicated Hilgard's finding of the hidden observer phenomenon in terms of its incidence and obtained similar verbal reports from Ss experiencing it. At the same time, the results suggest that a neodissociation account of hypnosis may need some modifications to accommodate these additional findings. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
87.
文章对电力系统稳定性研究内涵进行了评述,然后从认识论和方法论上加以分析,讨论了认识过程从功角稳定到电压稳定的转变、从线性向非线性的转变、从简单系统到复杂系统的转变、从重视解析方法到重视非解析方法的转变过程,为电力系统稳定性研究提供方法论指导。 相似文献
88.
基于DRFM的脉冲多普勒雷达组合干扰及其效能评估 总被引:2,自引:0,他引:2
脉冲多普勒雷达具有较强的抗干扰能力,对其实施有效干扰有一定的困难。本文仿真研究了两种基于数字射频存储器的脉冲多普勒雷达组合干扰技术,并分别提出了脉冲多普勒雷达压制性干扰和欺骗性干扰的干扰效果度量方法,该方法在具体应用场合更贴近于干扰抗干扰的动态对抗过程。 相似文献
89.
James G. Berryman 《Canadian Metallurgical Quarterly》2005,131(9):928-936
Four methods of upscaling coupled equations at the microscale to equations valid at the mesoscale and/or macroscale for fluid-saturated and partially saturated porous media will be discussed, compared, and contrasted. The four methods are: (1) effective medium theory, (2) mixture theory, (3) two-scale and multiscale homogenization, and (4) volume averaging. All these methods have advantages for some applications and disadvantages for others. For example, effective medium theory, mixture theory, and homogenization methods can all give formulas for coefficients in the up-scaled equations, whereas volume averaging methods give the form of the up-scaled equations but generally must be supplemented with physical arguments and/or data in order to determine the coefficients. Homogenization theory requires a great deal of mathematical insight from the user in order to choose appropriate scalings for use in the resulting power-law expansions, while volume averaging requires more physical insight to motivate the steps needed to find coefficients. Homogenization often is performed on periodic models, while volume averaging does not require any assumption of periodicity and can therefore be related very directly to laboratory and/or field measurements. Validity of the homogenization process is often limited to specific ranges of frequency—in order to justify the scaling hypotheses that must be made—and therefore cannot be used easily over wide ranges of frequency. However, volume averaging methods can quite easily be used for wide band data analysis. So, we learn from these comparisons that a researcher in the theory of poroelasticity and its generalizations needs to be conversant with two or more of these methods to solve problems generally. 相似文献
90.
Frey Karin S.; Hirschstein Miriam K.; Snell Jennie L.; Edstrom Leihua Van Schoiack; MacKenzie Elizabeth P.; Broderick Carole J. 《Canadian Metallurgical Quarterly》2005,41(3):479
Six schools were randomly assigned to a multilevel bullying intervention or a control condition. Children in Grades 3-6 (N=1,023) completed pre- and posttest surveys of behaviors and beliefs and were rated by teachers. Observers coded playground behavior of a random subsample (n=544). Hierarchical analyses of changes in playground behavior revealed declines in bullying and argumentative behavior among intervention-group children relative to control-group children, increases in agreeable interactions, and a trend toward reduced destructive bystander behavior. Those in the intervention group reported enhanced bystander responsibility, greater perceived adult responsiveness, and less acceptance of bullying/aggression than those in the control group. Self-reported aggression did not differ between the groups. Implications for future research on the development and prevention of bullying are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献