Applied Mechanics and Materials Vols. 58-60

Abstract: This paper considers the issue of robust H_∞ control for a class of nonlinear uncertain systems with delayed states and control, and the feedback controller is designed. By constructing proper Lyapunov-krasovskii function, the resulting closed-loop system is stochastically stable for all admissible uncertainties, time-delays and nonlinearities, and satisfies a prescribed H_∞ performance. Sufficient conditions for the system to be robustly stochastically asymptotically stable are derived, by using linear matrix inequalities and Lyapunov-krasovskii stability theory. The feedback controller is obtained by solving the linear matrix inequalities. Numerical example is provided to show the validity of the proposed approaches.

Abstract: This paper investigates the problems of delay-dependent passive analysis and control for uncertain stochastic systems with time-varying delay and norm-bounded parameters uncertainties. Delay-dependent stochastic passive condition for the uncertain stochastic time-delay systems is obtained based on Laypunov-Krasovkii functional approach. On the basis of this condition, a delay-dependent passive controller is presented. Sufficient condition for the existence of desired controller is formulated in terms of linear matrix inequality. Finally, a numerical example is given to illustrate the effectiveness of the proposed method.

Abstract: Manufacturing Grid aims at looking for an innovative next generation inter-organizational collaborative environment. A new architecture named P2P Semantic Manufacturing Grid (P2PSMG) was introduced in this research, which adopts ontology as a common language to help different participants to understand each other, and works in a semantic grid service oriented Napster style. The means of resource integration under this architecture was emphatically studied, by which service providers virtualize their manufacturing resources, encapsulate them into multi-granularity services based on resource ontology, and then submit their semantic descriptions to a third party registry for integration and discovery. A prototype system was developed, by which the feasibility of the means of resource integration introduced in this research is validated.

Abstract: In order to study the comprehensive effect of material flow and energy flow on energy consumption of steel manufacturing process, firstly, the using energy peculiarity and energy saving technology of energy process of steel enterprise were analyzed. Secondly, the evaluation index of energy saving for steel enterprises was put forward based on analytic hierarchy process. The rule layer includes process energy consumption, steel ratio and application of energy saving technology. The variable layer includes 22 indexes. Indexes’ weight of rule layer, steel ratio and application of energy saving technology was determined by analytic hierarchy process and Delphi method. Indexes’ weight of process energy consumption was determined according to the average process energy consumption value of key steel enterprises in china. Finally, the evaluation index system of energy saving for steel enterprises was established. With the index system, the energy saving level of one steel enterprise can be evaluated according to its actual production data. The index system is practical and easy to apply.

Abstract: Evaluation on energy consumption is a key point for research of energy-saving work, and the current research mainly focuses on the energy consumption of individual processes. In order to solve the problem of energy consumption for the whole process of steel enterprise, three types of energy consumption indicators are proposed: comprehensive indicator, process energy consumption indicator and energy recovery indicator. A TOPSIS model has been established for energy consumption of steel enterprise. In order to avoid the tolerance caused by experts’ subjective consciousness, in the model, the indicator weight will be confirmed by entropy weight. Five steel enterprises were evaluated using this model. The result of evaluation is almost the same as the result of benchmarking analysis method, which has verified the availability of the model. The model has primarily solved the energy consumption problem for the whole process of steel enterprise.

Abstract: Since commercial aviation started, fatigue among pilots and aircrew has been acknowledged as a human factor safety issue. This survey was conducted between September and December 2009 among airlines pilots. The three main objectives of this study are: to identify sleep patterns, their promoting and interfering factors of airlines pilots. This survey results revealed that most of the pilots do not have any problem to get to sleep and majority of them had never taken any sleeping aids, such as: alcohol or medication. The five sleep interfering factors, which include environmental (i.e. heat, noise and lighting) and physiological (i.e. nature’s call and personal worries) were investigated in this survey. It was found out that personal worries top the list. From this study, it can be concluded that fatigue issue is significant among South East Asian airlines pilot.

Abstract: With the development of information and network technology, the channel of enterprises product sales and customers shopping are being more and more diversification. The realization of unified multi-channel integrated sales necessarily will be a trend of future development. This thesis launches a platform research on multi-channel integrated sales, analyzes the difficulties of the architecture construction and designs a dynamic e-commerce system architecture basing on the Service-Oriented- Architecture (SOA) of Web Services.

Abstract: In order to decrease output micro-flux ripple wave characteristics of the piezoelectric driven micro-flux valve, it carried out research on piezoelectric ceramics driving power supply. In the research, it especially designed the low-voltage and high-voltage stabilizing circuit, small signal amplifying circuit and power amplifying circuit. By applying the power supply, the function signal would be amplified to a high-voltage output to drive the piezoelectric ceramics stack (PZT) to control displacement of the micro-flux valve’s spool, and then realize precise control the micro-flux of the valve. At last, it carried out experimentations on the output characteristics of the power supply, and the experimental results proved the output signal of the power supply have excellent input-output linearity and small ripple wave characteristics, and the high-voltage output ripple wave error is less than 10mV. More over, it used the power supply to drive an 8×8×20mm PZT with capacitance 2.3, and measured the quickly discharging characteristics. The results prove the quickly discharging time is only 10.10ms when the driving voltage is 180V, which means the power supply has excellent quickly discharging characteristics.

Abstract: By analysis on every construction phase, an optimization method is presented for choosing construction schemes with multi objects which can be used to compare the schemes. An example shows that the method is simple and feasible, and the results are reasonable.

Abstract: To resolve the water resource shortage, the water reuse technologies are of key importance. But in nowadays, the water reuse is only limited in large cities and industry fields. Many residential communities and constructions have not build water reuse systems. The article briefly describes the features and utilizations of domestic and foreign water, analysis the profits and disservices and scale of large and small recycled water. For the current domestic situation and water resources and promote water reuse status and problems considering the urban size, economic status, urban planning and norm-setting and other factors, it advocate that the development of water should start from small to large, from micro to macro, researched the precedent of the scaled provision about small water in Japan and Beijing and proposed the conclusion that to prompt reasonable division of small recycled water and achieve the optimal balance of large and small recycled water in order to promote better water utilization, and thus weaken the limits of water shortage in the development of urbanization.