Applied Mechanics and Materials Vols. 713-715

Abstract: The driver's reaction time (DRT) is an important parameter of driving safety. In the current study, a new method based on the combined use of cross-correlation analysis and the gray correlation analysis was developed to calculate DRT during car following. Furthermore, an assumed model of normal distribution with simple reaction time and complex reaction time as variables was verified by DRT values calculated from data experimentally collected from a road test. The current study provides useful information about calculation of DRT during car following, and is very meaningful and important in terms of the enhancement of driving safety.

Abstract: Transport infrastructure has been playing an increasingly important role to the world economy. Intersections have been widely accepted as the bottlenecks for an urban transport system. As such, the intersection design has been of great importance for transport agencies. Saturation flow is the most important design parameter for traffic signal timing. In this study, we aim to calibrate saturation flows for signalized intersections. Based on calibrated saturation flows, we thus intend to examine whether headways between consecutive vehicles during a queue are affected by intersection shapes and speed limit. To this end, five signalized intersections are observed to collect time headways. According to collected time headways, saturation headways in various cycles are calibrated using linear regression models. Finally, according to analysis of variance (referred to as ANOVA hereafter), we reveal that there is no direct relationship among speed limit, intersection shape, and saturation headways.

Abstract: In order to have more accurate analysis about the eruption period of gas eruption under a coal mine system, fractal geometry theory was introduced. Based on field test data, a novel R / S analysis method was used to calculate the Hurst parameter, which determined the persistence correlation of the gas system, and eruption period was calculated subsequently. The period was used by the coal mine factory to arrange the manufacturing process and for three years no accident about gas eruption under the coal mine was reported.

Abstract: The key of real-time obstacle avoidance for AUV is to accurately and fast identify underwater obstacle. In this paper, according to the characteristics of the multi-beam forward-looking sonar of AUV, we extracted the obstacle information from sonar image with the image filtering, fuzzy clustering and morphological methods. Finally, it can be proved that the real-time image processing method is feasible and effective by the lake trial.

Abstract: The work is devoted to solve allocation task problem in multi agents systems using multi-objective genetic algorithms and comparing the technique with methods used in game theories. The paper shows the main advantages of genetic algorithms and the way to apply a parallel approach dividing the population in sub-populations saving time in the search and expanding the coverage of the solution in the Pareto optimal space.

Abstract: According to the characteristics of inspection and search submarines, combining anti-submarine patrol aircraft method of searching with magnetic finder, this paper first established submarine motor model, and on this basis, respectively, set up a single and double machine mathematical model using magnetic finder inspection and search. Through simulation calculation, the influence of the range change of search area and magnetic detection finder on search probability was analyzed, and the effective suggestions for magnetic finder optimization are put forward.

Abstract: The research objectives were to investigate non-motor vehicle violation in signal intersection by studying behavior analysis. Non-motor vehicles’ street-crossing behavior was examined by modeling the non-motor vehicles waiting time survival function at signalized crosswalk through survival analysis method. Statistical and analysis of the filtered traffic parameters such as drivers, road conditions and other factors on the age obtained regularities of non-motor vehicles violation and a contrast and reference value with pedestrians’ violation serving as evaluation of the crowd and traffic characteristics for non-motor vehicles violation which can be used on other similar traffic behavior analysis and has some reference value.

Abstract: According to the geometric optics, off-axis parabolic mirrors are used in terahertz time domain system for focusing the terahertz pulse. Theoretically, the focus of the parabolic reflector to eliminate the effects of spherical aberration, but a very high sensitivity to its optical axis misalignment, subtle misalignment will reduce the focal spot quality and therefore the need for precision optical axis adjustment is important. This article discusses terahertz time-domain spectroscopy system adjustment method in four off-axis parabolic mirror, after many experiments have proved feasible. In this work, two optical path adjustment methods were analyzed. The first approach is based on adjustment of spot shape from collimation and focus. In the second method, depend on the principle that the incident light path is different from reflected light path in parabolic cross section. Through testing this two methods have been proved feasible.

Abstract: In order to enhance the self-care ability of persons with disabilities and satisfy people's demand for intelligent control home appliance, a smart home system based on Microsoft speech synthesis and speech recognition technology is proposed. After the initialization of the system, it receive voice commands which send by users, while the system distinguish the voice signal, the system will call voice feedback module and request users to confirm the voice instructions, after users’ confirmation, the system will record the voice command and convert it to electrical control code which can be recognized by the general household appliances’ control system. One voice command recognition time was within 30 ms and one speech interaction process was within 3 second which shows the simply and efficiently control for appliances based on speech recognition technology.

Abstract: A study on the navigation behavior for ships in shallow water had been carried out on CFD. The problem of surface ship hulls free of sinkage and trim in shallow water is analyzed numerically by simultaneously solving equations of the Reynolds averaged Navier-Stokes (RANS). The computations, based on the single-phase level set and overset grid, are discretized by finite volume method (FVM). An earth-based reference system is used for the solution to the fluid flow, while a ship-based reference is used to compute the rigid-body equations of motion. A S60 C_B=0.6 ship model is taken as an example to the numerical simulation. Numerical results of the sinkage and trim of the seven Froude Numbers (F_n=0.5~0.8) are compared against experimental data, which have a good agreement.