Applied Mechanics and Materials Vols. 63-64

Abstract: The major content in FCA is to extract formal concepts and connections between them from data in form of formal context so as to form a lattice structure of formal concepts. Fuzzy set theory and fuzzy logic are acknowledged as an appropriate formalism for capturing imprecise and vague knowledge. The paper offers a methodology for building ontology for knowledge sharing and reusing based on fuzzy concept lattices union. This paper makes up these defects by applying formal concept analysis theory and fuzzy sets to construct concept hierarchies of ontology, and the experiments shows the CPU Time in the attribute numbers, indicating that FFCA is superior to FCA in building the ontology of semantic web.

Abstract: This paper took the grinding force in the heavy load honing as the object to research, it mainly analyzed the influence of the grinding force to the material removal rate. First the mathematical model of grinding force was established from starting with the honing pressure. Then the mathematical model of material removal rate was established according to the relationship between material removal volume and honing pressure. Finally the influence of the honing pressure to the material removal rate was analyzed with the aid of software. The results of this paper have important theoretical significance to optimize the processing technology of heavy load honing and further enhance the machining precision and the honing efficiency.

Abstract: In view of the defect that TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) can not deal with imprecise data properly in multiple criteria decision making. And the weights are often hard to reflect the fact because of subjective preference of decision makers. We proposed a hybrid model combines TOPSIS and imprecise DEA model to improve the disadvantages. Ideal DMU and anti-ideal DMU were built, and the corresponding positive ideal point and negative ideal point were established. Imprecise DEA was set up and an upper-lower limit method is utilized to formulate the imprecise efficiency scores of the two hypothetical DMUs. Based on the distances between DMU₀ and the two hypothetical DMUs respectively, imprecise relative closeness was formulated to rank the superiority of all DMUs. The imprecise DEA model based on TOPSIS can avoid too subjective weights and make the evaluation more rational. A numerical example indicated the efficiency of the hybrid measure.

Abstract: The coal mine gas can cause gas explosion and gas outburst, which is a direct threat to the safety of coal mine production. The gas drainage technology is the highlights in the research of highly gassy mine and coal and gas outburst. Coal gas drainage in the coal mine area includes ground gas development and underground gas drainage. Therefore, the evaluation to the draining feasibility of the coal gas should also be divided into ground coal gas development and underground gas drainage. Draining feasibility of the gas refers to the draining extent in a certain area and the possibility of the development under existing economical situations. By general analysis to the geological parameter that influences the draining feasibility, the drainage area will be optimized in this paper. With the reservoir bed data analog technology, the draining feasibility of the coal gas in the DaFosi field and its draining protential will the evaluated in this paper.

Abstract: According to the Bragging equation, the general mathematical formulas of the temperature change error and the strain error are got under the consideration of the second-order temperature sensitivity and the second-order strain sensitivity. The two error curves are given in the conditions of T = 20°C and e = 1000me.

Abstract: Classroom discipline is a complex and variable dynamic process, classroom problem behavior always leads classroom discipline problem that will affect teaching quality. The simulation on classroom discipline of multiagent system based on complex system theory uses dynamic simulation platform NetLogo. The result of simulation shows that this method can reproduce the dynamics of discipline behavior’s three stages in ecological classroom. This simulation provides forceful support for the classroom discipline management of teachers.

Abstract: In order to improve the cutting efficiency of abrasive waterjet (AWJ), the relationship between pre-mixed AWJ cutting depth and pressure was experimentally studied. Then, through analysis of the cutting results, the topographic characteristics and formation mechanism of the cut trough faces were investigated. Moreover, through comparing the effects of different jet pressures on the topographic characteristics of AWJ cut trough faces and the SEM analysis of the cut trough faces at different pressures and depths, the effects of pre-mixed AWJ cutting mechanism on the characteristics of cut trough faces were investigated, and the characteristics of the trough faces of metals cut by pre-mixed AWJ were analyzed.

Abstract: Safety is the most important thing in coal mine production. There are many kinds of hidden dangers. In order to discover and eliminate the hidden dangers, the safety supervision becomes one of the most popular methods in current coal mine safety management, but there is not an unitive and normalized flow of collection, transmission, and processing and so on links of safety supervision information. Through applying the thought of business optimization, this paper formed a set of safety supervision information flow, supplied method and technical support for the coal mine management.

Abstract: This paper applied stopwatch to measure the work time of workstations on lamp assembling line. It studied issues effecting line production capability such as bottleneck workstations and superfluous capability. To overcome these shortcomings this paper suggests new line balancing schema. The schema includes reallocation of the work content, adjustment of the equipment and workers of each workstation. This improvement saves extra work shifts and reduces labor cost.

Abstract: As one of three civil aviation systems, the Air Traffic Management (ATM) system plays a very important role in security of civil aviation. This paper established the safety risk evaluation index system for ATM. According to the Gray Relational Analysis (GRA), the paper calculated the correlation coefficients and correlation degree between the safety risk in ATM and the first level factors, and the correlation coefficients and correlation degree between the first level factors and corresponding second level factors. The results show that human factor which has been greatly impacted by poor safety awareness contributes main reason to safety risk in ATM. This paper provides ATM units with recommendations to establish risk management programs.