We show that, when a mixture of small and large grains is simply poured in a g̀ranular Hele± Shaw cell’ (two transparent slabs separated by a gap of about 5mm), the grains spontaneously stratify in alternating layers of small and large grains parallel to the surface of the pile. The spontaneous self-strati® cation occurs only when the large grains have a larger angle of repose than the small gra...

A new health impact index, excess cost, is advocated for identifying jobs in need of further study regarding ergonomic problems. The excess cost index is compared with incidence rate, excess count, and severity rate indices in terms of concept and appropriateness to the purpose. The four indices are illustrated with data regarding medical leave from an automobile assembly plant and evaluated in...

A visual programming facility is described which is based on a visual rule formalism. It permits programmers to specify the behaviors of agents in the class of program objects in the Agentsheets system of Repen-ning. The resulting agents can be used in designing simulations for two-dimensional cellular worlds such as in automobile traac ow situations, video games, and cellular automata studies....

Non-motorized travel in terms of walking or bicycling plays a critical role in promoting healthy living style, offering sustainable alternatives to environmental impacts, energy consumption, and societal costs of motorized travel modes, and allocating limited resources for constructing pedestrian-orientated transportation infrastructure facilities. Historically, much research has been focused o...

Virtual assembly has been widely used in product development. However, virtual operation and actual operation are different in time and space, the simulation of interactive virtual assembly cannot support the assembly operation’s process planning directly. In this paper, the solution for assembly operation’s process planning is developed based on interactive virtual assembly. According to the s...

Compressed air is a widespread but costly energy carrier. Leaks account for 10 compressed air consumption in production facilities and their removal offers high potential for cost reduction. The turbulent flow from a leak causes broadband acoustic emissions. These are exploited for leak detection using a narrowband ultrasonic microphone that is insensitive to audible noise. A parabolic mirror o...