Advanced Materials Research Vols. 143-144

Abstract: This paper statistically analyzes the large coal mine gas accidents in China since 2006, and points out that explosion and gas outburst are the main reasons of gas accident, and focus in the future should be put on those serious accidents caused by gas explosion. Death toll of large gas accidents in 2009 is equal to that in 2008, which illustrates the importance of safety input in order to further improve the coal mine safety situation in China. In order to raise consciousness of enterprises on safety input, this paper puts forward the idea of integrating the value of life casualties’ loss into the analysis of loss in coal mine accidents and builds an optimization model of optimization of safety input based on maximization of economic benefit and thorough analysis of safety input, economic losses caused by coal mine accidents and loss of human life. With reference to foreign practices and related research, the value of life for each person is finally set from 5 million to 30 million. Finally it is proved through case study that the consideration of value of life is vital to improve the level of safety input and reduce mortality. Since 2005, the number of deaths caused by gas accident many years occupied the first coal mine accident in major categories. Therefore, the gas accident occurred in recent year statistical analysis, to take specific measures for improving the level of China's coal mine safety is important.

Abstract: A humidification approach was employed by using spraying mist on the roving before the back rollers of the spinning frame to improve the quality of the hemp/cotton blended yarn. The yarn performance after was investigated. The investigation showed that the evenness, hairiness, tenacity of the yarn was improved by using the humidification technique. When the humidification reached 250mL/h, the spinning process was adversely affected and quality of yarn decreased.

Abstract: The least squares method is very sensitive to outliers, one of the simple alternative is the least absolute deviation, i.e. L1 regression, which is less sensitive to outliers, so which is more suitable the small sample and much noise situation. In this paper, the L1 problem of linear model is discussed, the previous work is reviewed systematically, different algorithms is compared, it is proved that the dual forms of different algorithms are the same.

Abstract: In Section 1, we describe process of ball-bat collision using kinetic model, and derive the post-collision ball speed as a function of the hitting location. Then we differentiate the function and find out where the sweet spot is. The result successfully explains the best location is not at the end of the bat in consistent with our practical experience. In Section 2, based on the model in Section 1, we add two assumptions, supposing corking only influences mass and moment of inertia of bat. Then the maximum outgoing ball speed is only depended on mass of bat. The result shows properly corking will enhance the bat performance. In Section 3, we explain “trampoline effect” in dynamic model and throw light on energy transformation in collision process. We conclude that COR is related to materials, and aluminum bats perform better than wood bats.

Abstract: As only using Euclidean distance KNN algorithm has its limits, many researchers use other distance calculation methods as the replacement it to improve the accuracy of Data Classification. While combining the DS evidence theory with a series of KNN algorithm which discussed in this paper, we found that every algorithm has their merits. All of them ignore the analysis of the data set, through deeply analysis we found that the actual distance is determined by the larger value when two attribute values are in great difference. Therefore, what we do next is to compress the large-dimensional numerical data values. By this way, the accuracy of KNN, VSMKNN, KERKNN algorithm are obviously improved after experiment and then these new methods are called CDSKNN, CDSVSMKNN, CDSKERKNN.

Abstract: With safety, comfort, convenience, fast, economy, punctuality advantages and high service effectiveness, the introduction of passenger-dedicated line (PDL) will attract passenger volume assumed by other modes of long-short distance passenger transportation in terminal transportation system as part of its traffic component, named the transferred volume. Meanwhile, PDL will stimulate the potential travel demand to generate induced passenger volume. The volume of terminal passenger flow is of great significance in building PDLs, passenger railway stations, and transportation terminals. From the perspective of transportation mode service, by employing passenger-sharing rate model, Xi'an terminal is presented to estimate and analyze the long and short distance passenger transferred volume and the induced volume which it undertakes after introducing PDL.

Abstract: Fire is one of the major hazards in coal mines. After the fire broke out.the primary task of disaster rescue is to judge the location of fire and it is the prerequisite of analyzing the combustion state, the base of fire prediction. In this paper, the method of tunnel fire location judgment combining with qualitative and quantitative analysis is used, it includes the qualitative analysis basing on sets theory and quantitative analysis on fuzzy clustering. The potential location can be conversely reasoned by the warning sensors and the scope can be narrowed down widely. On this basis, the distance and similarity between the veritable time difference and the numerical simulation difference are calculated and by the value we can know the site of the fire.

Abstract: To improve the trajectory planning control accuracy of the working device of excavator robot when working for excavation, reduce working device of excavator robot to be the two joints two dimension robot arm composed of arm and bucket when analyses. Creating inverse kinematics model, need to relate to terminal position and orientation space of bucket and joint space and cylinder space of working devices to plan trace, so that to control excavator robot in each space. Because of the geometry complexity of inverse kinematics, the nonlinear of electro-hydraulic system, the uncertainty and non-uniqueness for inverse mapping, lead to the difficulty of trajectory planning. To improve the precision for tracking desired trace, obtaining inverse kinematics mapping between terminal trace and joint angle, use two adaptive neural-fuzzy inference system(ANFIS) to learn inverse mapping relations between (x, y) two joint coordinate and joint angle, create ANFIS inverse mapping model. Select I/O curve data of inverse mapping to train ANFIS structure, obtain I/O mapping curve of fuzzy model, realize the aim of obtaining corresponding joint angle based on given desired excavation trace. Use the model to trace expected motion trace finally, indicate by simulation that trace precision can meet the actual demands.

Abstract: In this paper, we investigate a delayed stage-structured predator-prey model with continuous harvesting on prey. Positivity and boundness of solutions and sufficient conditions of the stability of equilibria are obtained. Using and as bifurcation parameters, the existence of Hopf bifurcations at equilibria is established by analyzing the distribution of the characteristic values.

Abstract: In this paper, the operation optimization problem for utility systems is formulated and a mixed integer linear program (MILP) model is presented. The objective function of the model is to minimize the operational cost of utility systems during the whole operational period. In order to obtain the optimal solution of the foregoing model, an improved particle swarm optimization is proposed. Finally, a case with quantitive results presented is considered for illustrating the advantage of proposed optimization approach. Results show that the new algorithms are much more efficient than some existing particle swarm optimization algorithms.