Monitoring human or robot activities is critical for health care, artificial intelligence and manufacture, etc., whereas the broad range of the pressure stimuli generated by human or robot activities is...

The relationship between the change of a local gravity field and the mass migration underground is discussed by means of using a point-source disturbed body as a substitute for the mass migration underground. Some significant local gravity field changes in Beijing area have been found, from which the three parameters of the disturbed bodies, location, depth and mass, have been derived successfully from the observations of a gravimetric network. In order to determine the depth of a body, a new approach is suggested in which the gravity change difference is used instead of the gravity change itself. The mass of a disturbing body has been estimated properly. Astronomical PZT is suggested for this kind of survey. The results provide us a picture of the underground mass migration with which the gravity changes on the ground surface may be interpreted in a better way. This additional information may be useful in seismological studies.

The multistage goal programming model is popular to model the defense projects portfolio optimization problem in recent years. However, as its high-dimensional variables and large-scale solution space, the addressed model is hard to be solved in an acceptable time. To deal with this challenge, we propose an improved differential evolution algorithm which combines three novel strategies i.e. the variables clustering based evolution, the whole randomized parameters, and the child-individual based selection. The simulation results show that this algorithm has the fastest convergence and the best global searching capability in 6 test instances with different scales of solution space, compared with classical differential evolution algorithm (CDE), genetic algorithm (GA) and particle swarm optimization (PSO) algorithm.

This paper first analyzes the characteristics of holding strength of ceramic adhesive to diamond grains within vitrified abrasives grinding wheel, subsequently put forwards a calculating method of holding strength based on the data of the samples tensile strength test and fractography analysis. The holding strength mechanical model and the mathematic model are presented in this paper, which is figured out by load strength analyzing and idealized assumptions. Considering the holding strength computational complexity a set of software was designed to calculate the strength with the Excel data sheets exported from the tensile strength test and micro image analysis. Its flow diagram was shown in this paper.

Cu-based metal matrix, Ti coated and uncoated diamond composite were prepared by hot-press sintering in vacuum. The effects of the mixing time and the sintering temperature on the relative density, hardness and transverse rupture strength (TRS) of the matrix were studied. Structures of specimens sintered at different temperatures were studied by XRD. The TRS and wear resistant of coated and uncoated diamond segment were compared. The results show that the optimum mixing time is 20 hours; with the increase of sintering temperature, the relative density, hardness and TRS of the matrix firstly increase and then decrease; the TRS of diamond segment is lower than the matrix sintered at the same temperature and TRS of Ti coated diamond segment increased by 6.18% as compared with uncoated diamond segment; moreover the wear resistance of Ti coated diamond segment is better than that of uncoated diamond segment.