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排序方式: 共有1301条查询结果,搜索用时 15 毫秒
91.
92.
This contribution deals with the impact of human error on the overall system reliability in flexible manufacturing systems (FMS). Autonomous production cells are used to illustrate an error-compensating system design on the basis of Sheridan's (1997) paradigm of supervisory control. In order to specify human errors and their effects in terms of system disturbances, a taxonomy of system disturbances is recommended. This taxonomic approach was derived by a value benefit analysis and is based on HEDOMS (Human Error and Disturbance Occurrence in Manufacturing Systems) with slight modifications and Reason's GEMS (Generic Error Modelling System). The taxonomy is used for data acquisition. Next, a risk priority equivalent to FMEA (Failure Mode and Effect Analysis) is introduced to structure the data according to their relevance. Then, Vicente's and Rasmussen's guidelines (1987) for an ecological interface design are related to the paradigm of supervisory control. On the basis of these guidelines four case studies are presented to show their successful applicability for interface design in FMS. 相似文献
93.
Holger Petersen 《Information Processing Letters》2007,105(1):32-34
With the help of a general simulation technique of deterministic finite two-way multi-head automata by automata with blind heads we show O(n2/logn) to be an upper time bound on string matching. This result is tight by a previously known lower bound. 相似文献
94.
Anja Wessels Stefan Fries Holger Horz Nicolai Scheele Wolfgang Effelsberg 《Computers in human behavior》2007
Among the severe instructional shortcomings of lectures is their lack of interactivity. To overcome these problems, the learning environment of the interactive lecture is introduced, in which students and lecturer interact by using mobile computers in a wireless network. In an experimental study, 44 students participated in interactive and in conventional lecture meetings. A quiz service that allowed question to be posted, students’ answers to be evaluated, and the results to be presented graphically, was implemented on mobile computers. The participants rated the interactive condition better, also reporting higher levels of attention, activity and perceived learning success for this condition. Objective measures indicated a slight but insignificant difference toward better learning results in the interactive condition. 相似文献
95.
96.
Gunther?HeidemannEmail author Robert?Rae Holger?Bekel Ingo?Bax Helge?Ritter 《Machine Vision and Applications》2004,16(1):64-73
We present a vision system for human-machine interaction based on a small wearable camera mounted on glasses. The camera views the area in front of the user, especially the hands. To evaluate hand movements for pointing gestures and to recognise object references, an approach to integrating bottom-up generated feature maps and top-down propagated recognition results is introduced. Modules for context-free focus of attention work in parallel with the hand gesture recognition. In contrast to other approaches, the fusion of the two branches is on the sub-symbolic level. This method facilitates both the integration of different modalities and the generation of auditory feedback.Published online: 5 October 2004Robert Rae: Now at PerFact Innovation, Lampingstr. 8, 33615 Bielefeld, Germany 相似文献
97.
Clausnitzer T Limpert J Zöllner K Zellmer H Fuchs HJ Kley EB Tünnermann A Jupé M Ristau D 《Applied optics》2003,42(34):6934-6938
We report on highly efficient transmission gratings in fused silica with a grating period of 800 nm generated by electron-beam lithography. At a wavelength of 1060 nm, 95% diffraction efficiency is achieved under Littrow conditions. The damage threshold, extremely enhanced compared with conventional gold-coated diffraction gratings, makes these gratings the key elements in high average power (>100 W) femtosecond fiber chirped-pulse amplification systems. 相似文献
98.
99.
Dr. Bettina Sommer Dr. Holger von Moeller Martina Haack Dr. Farah Qoura Clemens Langner Dr. Gleb Bourenkov Dr. Daniel Garbe Dr. Bernhard Loll Prof. Dr. Thomas Brück 《Chembiochem : a European journal of chemical biology》2015,16(1):110-118
Isobutanol is deemed to be a next‐generation biofuel and a renewable platform chemical. 1 Non‐natural biosynthetic pathways for isobutanol production have been implemented in cell‐based and in vitro systems with Bacillus subtilis acetolactate synthase (AlsS) as key biocatalyst. 2 – 6 AlsS catalyzes the condensation of two pyruvate molecules to acetolactate with thiamine diphosphate and Mg2+ as cofactors. AlsS also catalyzes the conversion of 2‐ketoisovalerate into isobutyraldehyde, the immediate precursor of isobutanol. Our phylogenetic analysis suggests that the ALS enzyme family forms a distinct subgroup of ThDP‐dependent enzymes. To unravel catalytically relevant structure‐function relationships, we solved the AlsS crystal structure at 2.3 Å in the presence of ThDP, Mg2+ and in a transition state with a 2‐lactyl moiety bound to ThDP. We supplemented our structural data by point mutations in the active site to identify catalytically important residues. 相似文献
100.
We review fabrication methods and common structures for optofluidic waveguides, defined as structures capable of optical confinement
and transmission through fluid filled cores. Cited structures include those based on total internal reflection, metallic coatings,
and interference based confinement. Configurations include optical fibers and waveguides fabricated on flat substrates (integrated
waveguides). Some examples of optofluidic waveguides that are included in this review are Photonic Crystal Fibers (PCFs) and
two-dimensional photonic crystal arrays, Bragg fibers and waveguides, and Anti Resonant Reflecting Optical Waveguides (ARROWs).
An emphasis is placed on integrated ARROWs fabricated using a thin-film deposition process, which illustrates how optofluidic
waveguides can be combined with other microfluidic elements in the creation of lab-on-a-chip devices. 相似文献