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131.
132.
The development of autonomous mobile machines to perform useful tasks in real work environments is currently being impeded
by concerns over effectiveness, commercial viability and, above all, safety. This paper introduces a case study of a robotic
excavator to explore a series of issues around system development, navigation in unstructured environments, autonomous decision
making and changing the behaviour of autonomous machines to suit the prevailing demands of users. The adoption of the Real-Time
Control Systems (RCS) architecture (Albus, 1991) is proposed as a universal framework for the development of intelligent systems. In addition it is explained how the use
of Partially Observable Markov Decision Processes (POMDP) (Kaelbling et al., 1998) can form the basis of decision making in the face of uncertainty and how the technique can be effectively incorporated into
the RCS architecture. Particular emphasis is placed on ensuring that the resulting behaviour is both task effective and adequately
safe, and it is recognised that these two objectives may be in opposition and that the desired relative balance between them
may change. The concept of an autonomous system having “values” is introduced through the use of utility theory. Limited simulation
results of experiments are reported which demonstrate that these techniques can create intelligent systems capable of modifying
their behaviour to exhibit either ‘safety conscious’ or ‘task achieving’ personalities. 相似文献
133.
Kensinger Elizabeth A.; Shearer Deirdre K.; Locascio Joseph J.; Growdon John H.; Corkin Suzanne 《Canadian Metallurgical Quarterly》2003,17(2):230
Alzheimer's disease (AD) and Parkinson's disease (PD) impair working memory (WM). It is unclear, however, whether the deficits seen early in the course of these diseases are similar. To address this issue, the authors compared the performance of 22 patients with mild AD, 20 patients with early PD and without dementia, and 112 control participants on tests of inhibition, short-term memory, and 2 commonly administered tests of WM. The results suggest that although mild AD and early PD both impair WM, the deficits may be related to the interruption of different processes that contribute to WM performance. Early PD disrupted inhibitory processes, whereas mild AD did not. The WM deficits seen in patients with AD may be secondary to deficits in other cognitive capacities, including semantic memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
134.
Working with survivors of political torture and war trauma can trigger strong emotional responses in the therapist. As more survivors seek treatment, it is essential to identify and develop robust support systems for therapists who help their clients confront nearly unspeakable experiences. The emotional reactions of 6 psychotherapists who worked with traumatized survivors in a refugee treatment center were explored. The psychotherapists' reactions were compared with those of therapists who worked in different treatment settings with other presenting problems. The results of the study show that the strong level of responsibility therapists feel for their traumatized clients may hide an emotional strain and may lead to burnout. Suggestions are offered for supporting therapists in this difficult but important work. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
135.
Seeing a talker's face influences auditory speech recognition, but the visible input essential for this influence has yet to be established. Using a new seamless editing technique, the authors examined effects of restricting visible movement to oral or extraoral areas of a talking face. In Experiment 1, visual speech identification and visual influences on identifying auditory speech were compared across displays in which the whole face moved, the oral area moved, or the extraoral area moved. Visual speech influences on auditory speech recognition were substantial and unchanging across whole-face and oral-movement displays. However, extraoral movement also influenced identification of visual and audiovisual speech. Experiments 2 and 3 demonstrated that these results are dependent on intact and upright facial contexts, but only with extraoral movement displays. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
136.
137.
To clarify whether motion information per se has a separable influence on action control, the authors investigated whether irrelevant direction of motion of stimuli whose overall position was constant over time would affect manual left-right responses (i.e., reveal a motion-based Simon effect). In Experiments 1 and 2, significant Simon effects were obtained for sine-wave gratings moving in a stationary Gaussian window. In Experiment 3, a direction-based Simon effect with random-dot patterns was replicated, except that the perceived direction of motion was based on the displacement of single elements. Experiments 4 and 5 studied motion-based Simon effects to point-light figures that walked in place--displays requiring high-level analysis of global shape and local motion. Motion-based Simon effects occurred when the displays could be interpreted as an upright human walker, showing that a high-level representation of motion direction mediated the effects. Thus, the present study establishes links between high-level motion perception and action. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
138.
变压器有载合闸过程中故障分闸后铁心剩磁分析 总被引:3,自引:0,他引:3
通过有载合闸变压器模型,分析了变压器有载合闸过程中由于副边突然短路导致主保护动作时电流和磁通的暂态过程,并对变压器铁心内的剩磁作了定性的分析。 相似文献
139.
Cost estimates to guide pre-selection of processes 总被引:2,自引:0,他引:2
A process is a method of shaping, joining or surface-treating a material. Process selection has three steps. The first is to identify from the ‘menu’ of all available processes, the subset, which can give a chosen material the desired shape with the desired detail, precision and finish. The second is to choose, from among these, the ones that will do so at the lowest cost. The final step is to investigate the most promising processes in depth, exploring considerations such as availability, in-house experience, safety and environmental issues. The first two steps can be thought of as process pre-selection. Components have to be assembled and finished to create products. Here too, the ability to rank by cost, however crudely, helps guide pre-selection. Cost models are reviewed from the perspective of material and process selection. An approximate model is useful provided it has generality—that is, it must allow comparison of very different processes. Many approaches fail in this. One that works, based on resource consumption, is developed here and its use for selection is illustrated. It has been implemented as part of a tool that allows rapid pre-selection from a database of 112 processes. 相似文献
140.
总结了开发生产低熔融指数聚丙烯的试验过程与结果,通过优选催化剂、优化操作过程、控制加氢量,生产出质量稳定可靠的熔融指数在0.2~0.5g/l0min之间的低熔融指数聚丙烯. 相似文献