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51.
J. Giacomin M. S. Shayaa E. Dormegnie L. Richard 《International Journal of Industrial Ergonomics》2004,33(6):56-541
The human perception of rotational hand–arm vibration has been investigated by means of a test rig consisting of a rigid frame, an electrodynamic shaker unit, a rigid steering wheel, a shaft assembly, bearings and an automobile seat. Fifteen subjects were tested while seated in a driving posture. Four equal sensation tests and one annoyance threshold test were performed using sinusoidal excitation at 18 frequencies in the range from 3 to 315 Hz. In order to guarantee the generality of the equal sensation data, the four tests were defined to permit checks of the possible influence of three factors: reference signal amplitude, psychophysical test procedure and temporary threshold shift caused by the test exposure. All equal sensation tests used a reference sinusoid of 63 Hz at either 1.0 or 1.5 m/s2 r.m.s. in amplitude. The four equal sensation curves were similar in shape and suggested a decrease in human sensitivity to hand–arm rotational vibration with increasing frequency. The slopes of the equal sensation curves changed at transition points of approximately 6.3 and 63 Hz. A frequency weighting, called Ws, was developed for the purpose of evaluating steering wheel rotational vibration. The proposed Ws has a slope of 0 dB per octave over the frequency range from 3 to 6.3 Hz, a slope of −6 dB per octave from 6.3 to 50 Hz, a slope of 0 dB per octave from 50 to 160 Hz and a slope of −10 dB per octave from 160 to 315 Hz. Ws provides a possible alternative to the existing Wh frequency weighting defined in International Standards Organisation 5349-1 (2001) and British Standards Institution BS 6842 (1987).
Relevance to industry
For the manufacturers of tyres, steering systems and other vehicular components the proposed Ws frequency weighting provides a more accurate representation of human perception of steering wheel rotational vibration than the Wh weighting of ISO 5349-1 and BS6842. 相似文献
52.
53.
对小型中间下料预焙电解槽技术条件摆布的原则和具体数据进行了探讨,提出了尽可能利用从大型预焙槽上得出的先进经验,并消化吸收,掌握好各种条件的平衡,以取得好经济技术指标的观点。 相似文献
54.
Per Hovstad Liching Sung 《International Journal of Satellite Communications and Networking》2005,23(2):91-110
The 1977 Broadcasting‐Satellite Service (BSS) Plan for Region 1 & 3 had been widely acknowledged to be out‐of‐date by the late 1980s. Development of digital modulation in the early 1990s provided an opportunity to update the technical provisions of the Plan to make it more economically viable. After a decade of work and three World Radiocommunication Conferences (WRCs), the revision of Region 1 & 3 BSS Plan was finally completed in 2003. The new Plan increased channel assignments from 5 to 10 analog‐equivalent channels for each country in Region 1, and from 4 to 12 channels for each country in Region 3. Yet, despite the increase in capacity, the new Plan is surprisingly similar to the original one in terms of the technical parameters. It is still based on national coverage, and the channel plan, orbital location, orbital spacing, and polarization are also the same. As a result, the new Plan is no more economically viable to implement than the old. To create economically viable BSS systems would most likely require modifications to the assignment in the Plan. Yet, modification procedures were made more difficult to apply after replanning. Less future implementation of BSS networks than would otherwise have occurred can be expected, and an inefficient usage of these frequency bands will likely result. On the other hand, less implemented systems will mean more capacity set aside for future use. This is important for countries that currently do not have satellite operations. In the end, BSS replanning reflects the eternal conflict between efficient usage and guaranteed future access. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
55.
李桂敏 《中国材料科技与设备》2007,4(4):92-93
本文介绍了一种作业效率高、省时省力新型的转炉炉底车,其特点是转盘转动灵活,炉底车上项盘径向任意方向均能平稳倾斜一定角度,以保证炉底圆周所受项力均匀可靠,满足炉底安装要求。 相似文献
56.
In many legal proceedings, fact finders scrutinize the demeanor of a defendant or witness, particularly his or her nonverbal behavior, for indicators of deception. This meta-analysis investigated directly observable nonverbal correlates of deception as a function of different moderator variables. Although lay people and professionals alike assume that many nonverbal behaviors are displayed more frequently while lying, of 11 different behaviors observable in the head and body area, only 3 were reliably associated with deception. Nodding, foot and leg movements, and hand movements were negatively related to deception in the overall analyses weighted by sample size. Most people assume that nonverbal behaviors increase while lying; however, these behaviors decreased, whereas others showed no change. There was no evidence that people avoid eye contact while lying, although around the world, gaze aversion is deemed the most important signal of deception. Most effect sizes were found to be heterogeneous. Analyses of moderator variables revealed that many of the observed relationships varied as a function of content, motivation, preparation, sanctioning of the lie, experimental design, and operationalization. Existing theories cannot readily account for the heterogeneity in findings. Thus, practitioners are cautioned against using these indicators in assessing the truthfulness of oral reports. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
57.
Presents a reply by B. Fowers and B. Davidov to Islam's comments (see record 2007-14606-019) regarding their article (see record 2006-11202-002). Islam noted that virtues are often presented as universally valid character strengths, yet formulations of virtues are always embedded in a particular cultural context, a point we took pains to make in our article. We focus our response on Islam's important suggestion that this tension between universal human characteristics and the particulars of cultural context is indissoluble. Whereas he suggested this tension leads to contradiction and paradox, we see it as a fertile dialectic. The virtue of openness to the other is also subject to the same tension of abstract formulation and particular application. Although we formulated this virtue in a very general way, any instantiation of it would be shaped by the particulars of the cultural context and the situation in which it is exercised. We introduced the concept of dialogue because it is constituted not only by differences between individuals or groups but even more fundamentally by the dialectical relationship between those differences in cultural particularities and the universal human capacities for reason, curiosity, and social engagement, among others. Dialogue acknowledges the indissoluble otherness one finds in those culturally different from oneself, and yet real interchange can only occur because participants in dialogue exercise the cognitive flexibility characteristic of human beings and recognize a shared humanity with the other. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
58.
No authorship indicated 《Canadian Metallurgical Quarterly》2007,62(8):786
Presents the citation, biography, and selected bibliography for J?rn Diedrichsen, one of the 2007 recipients of the American Psychological Association's Award for Distinguished Scientific Early Career Contributions to Psychology (perception/motor performance). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
59.
No authorship indicated 《Canadian Metallurgical Quarterly》2007,62(8):796
Presents the citation, biography, and selected bibliography for Patrik O. Vuilleumier, one of the 2007 recipients of the American Psychological Association's Award for Distinguished Scientific Early Career Contributions to Psychology (behavioral and cognitive neuroscience). (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
60.
No authorship indicated 《Canadian Metallurgical Quarterly》2007,62(8):800
Presents the citation, biography, and selected bibliograpy for Larke Nahme Huang, the 2007 recipient of the American Psychological Association's Award for Distinguished Senior Career Contributions to Psychology in the Public Interest. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献