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This paper takes a 3D high-power microwave module as research object and analyses the law that temperature distribution, thermal-via and design variables influence on internal maximum junction temperature of the module base on the model established with finite element simulation software. In view of limitation of the traditional single varying parameters appraisal method for thermal analysis, the...
Microwave tubes for communication must have high reliability, high power, and a long life of 10 to 15 years. Cathode as the electric source module in microwave vacuum tubes, its reliability and life directly affect the tube's reliability and life. In this paper, electronic gun in short tubes are accelerated to evaluate the lifetime of one kind of microwave vacuum (such as traveling wave tube). In...
To construct multi-stress accelerated life model, the traditional method utilizes the observed value acquired in the process of accelerated life test to build likelihood equations of accelerated model, however, the excessive parameters of multi-stress accelerated model will lead to the difficulty in solving pluralism likelihood equations. Based on the predictability and convergence of genetic algorithm...
Along with the rapid development of data storing and sharing techniques in terms of both hardware and software, multiple data instances scattered across multiple databases may be available to support one single task, and then making choices of data are necessary from time to time. Research has been conducted on quality or reliability evaluation for individual piece of data assisted by domain knowledge...
As audiovisual communications services become the dominant traffic source in the Future Internet, their stable coexistence and their fairness towards background traffic is an active research topic. The Internet implements flow multiplexing in a decentralized fashion via congestion control. Audiovisual media streams, however, are classified as inelastic traffic flows that do not allow rate control...
The demand of kinematic accuracy is increasing for modern mechanical systems, while elastic deformation will lead to the decline in kinematic accuracy. This paper examines the application of finite element analysis (FEA) method to kinematic error analysis of elastic mechanisms based on Kineto-Elastodynamics model. The simulation of limit state equations of link mechanisms is performed with Back Propogation...
Traditional dynamic reliability analyzing methods which are evolved from those methods used in discrete system, are short in dealing with continuous variable and process variable. Using dynamic reliability analyzing methods, this paper proposes a system hybrid dynamic model in which discrete events are included in the continuous system model. Simulation results show that this method can detailed depict...
In order to study the operating life of structural components under the condition of load, the tensile damage experiments of carbon/epoxy composite are done in this paper. Then the mathematic model of the damage development of carbon/epoxy composite is built based on the experimental signal parameters, and then the reliability of carbon/epoxy composite is also discussed in this paper. Finally, the...
Field deployed electronics us often subjected to a combination of thermal aging and thermal cycling. The thermal cycle magnitudes may vary over the lifetime of the product. Long-life systems may be re-deployed several times over the use life of the product. Aging has been previously shown to effect the reliability and constitutive behaviour of second-level leadfree interconnects. Often the equipment...
In this paper, we propose a novel framework WSCRec, in which historical information (i.e., execution logs) are utilized to facilitate the process of Web service composition. According to the execution logs of composite services, appropriate services which have been proved to be more reliable and robust and have higher probability to fulfill users' demands are located.
Aiming at the atrocious storage environment of missile solid rocket motor, especially the higher requirement for structural reliability, based on the modified Arrhenius and GM-BP methods, the solid rocket motor life prediction principle was proposed. Using these methods, the engine life estimate and the propulsion system store life prediction model were founded. The modified Arrhenius method suits...
This work is part of a bigger project which aims to research the potential development of commercial opportunities for the re-use of batteries after their use in low carbon vehicles on an electricity grid or microgrid system. There are three main revenue streams (peak load lopping on the distribution Network to allow for network re-enforcement deferral, National Grid primary/ secondary/ high frequency...
Lifetime is a key parameter for electronic products using, and how to obtain the lifetime by using a short-term aging data has become a challenging issue. In this paper, a new aging data analysis method will be introduced, and three groups of aging data for high power laser diodes will be as a case to expound this method. The aging test time will be greatly decreased by using this method.
This paper addresses the problem of flexible procurement of multiple services with multiple non-functional characteristics, i.e., quality of service attributes. We consider the one-to-many negotiation approach as a flexible method for procuring multiple services by a buyer agent. We address the problem of coordinating multiple concurrent negotiations and propose a novel dynamic negotiation strategy...
A method based on pseudo life distributions of multiple parameters was proposed to evaluate the reliability and life of smart meter. Firstly, distributions were determined on the basis of getting the pseudo life of each parameter on each accelerated stresses. Secondly, reliability functions of each parameter were established integrated with the acceleration model, then the point estimates and covariance...
The Metro system is an important index of a modern city. The quality, performance and safety of Metro systems are highly monitored because of their huge cost, complex engineering and long building time. Signaling (SIG) provides train with the Automatic Train Control (ATC) function in order to satisfy the needs of high transportation, high efficiency, safety and comfort. SIG also supervises train operations...
With the rapid development of the information technology, it is inevitable that the distributed mobile computing will evolve to the pervasive computing gradually whose final goal is fusing the information space composed of computers with the physical space in which the people are working and living in. To achieve this goal, one of the problems is how to continuously monitor/capture and interpret the...
This paper aims to investigate the relationship between back-office employee satisfaction and customer satisfaction. Based on the review of existing related theories, this paper puts forward a conceptual model and some hypotheses. The tests of the hypotheses use data from 359 back-office employees, 412 front-line employees and 723 customers across 90 restaurants. Employing statistics techniques of...
Control of safety critical applications requires using of control systems with defined safety level. It is necessary to fulfil requirements not only on safety but in some cases also on reliability of the control system, too. Achievement of these properties depends on the choice of an appropriate structure of the control system. Safety programmable logic controllers (PLC) are modular systems and allow...
Over last two decades, solar and wind energies have become an alternative to traditional energy sources. These alternative energy sources are non-polluting, free in their availability and are renewable. Another alternative is tidal energy, which is related to falling and rising ocean water levels. Tidal behavior can be predicted easily and this means that if it is enabling to harness tidal energy,...
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