Quality cost optimization and control are key factors in the product design process. How to gain the optimal product quality with limited cost is a practical problem to be solved in enterprises. The process of using t...
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Quality cost optimization and control are key factors in the product design process. How to gain the optimal product quality with limited cost is a practical problem to be solved in enterprises. The process of using the analytical hierarchy process (AHP) method to evaluate the quality-level-weights of a product is given. And a BOM based model for quality cost optimization and control, which meets the demand of engineering to order (ETO) enterprises in the phase of product design, is presented. A branch and bound algorithm is developed to get the solution of the model which is a 0/1 integer linear programming problem. An application example of the model is illustrated.
High quality virtual users are the preconditions to ensure the effect of Web performance testing, and it is required to guarantee that the visiting effect of virtual users is consistent with the fact. Then, the real u...
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High quality virtual users are the preconditions to ensure the effect of Web performance testing, and it is required to guarantee that the visiting effect of virtual users is consistent with the fact. Then, the real users' visiting actions, steps, executing time and during times in the general situations should be analyzed firstly. Based on the obtained results, the visiting actions of every virtual user could be defined in the two-step combinative way, i.e. firstly created a common interesting model, indicating the outline for virtual users' visiting, secondly created a stochastic procedure model, determining the detailed visiting actions of each virtual user. Combined with the common interesting model, stochastic procedure model and the testing parameters, virtual users are generated and put into practice, thus more accurate and authentic testing results are gained based on this research work.
Software testability is the degree to which a system facilitates the establishment of test criteria and the performance of tests to determine whether those criteria have been met. It has been widely used in testing, m...
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Software testability is the degree to which a system facilitates the establishment of test criteria and the performance of tests to determine whether those criteria have been met. It has been widely used in testing, measurement, etc. Since the execution of concurrent programs is non-deterministic, there are many issues to be solved in analyzing testability of concurrent programs. The paper proposes a framework to analyze testability for concurrent programs. In this framework, we analyze the data flow and control flow of the programs and the influence of concurrency and synchronization. Based on such information, we propose the testability measure from four facets: independent concurrent units, concurrency, shared variables and communication factors. This gives a guideline to measure the testability of concurrent programs.
Cohesion represents the tight degree of the comp.nents of a software module. In an OO environment, the cohesion is mainly about the tight degree among the attributes and methods in classes. So it is urgent to fully ex...
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Cohesion represents the tight degree of the comp.nents of a software module. In an OO environment, the cohesion is mainly about the tight degree among the attributes and methods in classes. So it is urgent to fully explore the tight degree among the attributes and methods in classes of the detailed applications in order to make up the deficiency of the existing methods. The relationships between attributes and attributes, attributes and methods, methods and methods of a class, and the properties of these relationships are discussed. According to these properties, a new approach is proposed to measure the cohesion of a class based on a dependence analysis. This method is proved to satisfy the properties that a good measurement should have. The approach overcomes the limitations of the previous class cohesion measures, which consider only one or two of the three relationships in a class. The result of the approach provides a guideline for evaluating the cohesion of a class.
A weighted algorithm is proposed for reducing effectively the error caused by non-synchronous sampling in active power and power factor measurement. A analytic formula about the measuring value of active power and pow...
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A weighted algorithm is proposed for reducing effectively the error caused by non-synchronous sampling in active power and power factor measurement. A analytic formula about the measuring value of active power and power factor of periodic signal as a function of the relative frequency deviation and the sampling initial phase (or time) is derived. Both theory and numerical comp.tation show that the error of active power and power factor measurement is proportional to the relative frequency deviation when the conventional algorithm is used, while it is proportional to square of the relative frequency deviation when the proposed weighted algorithm is used. The algorithm is characterized by easy implementation, high precision. If the relative frequency deviation is not very large, a higher measuring precision still could be achieved even if the synchronous sampling technique was not utilized.
The authors attempt to revisit the behaviour of HITS from a different point of view. Namely, a similarity-based analysis model is proposed to observe the distillation procedure. By defining a generalized similarity, a...
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The authors attempt to revisit the behaviour of HITS from a different point of view. Namely, a similarity-based analysis model is proposed to observe the distillation procedure. By defining a generalized similarity, an algorithm is presented, which can improve the quality of distillation using only hyperlinks. A topic exploration function is also integrated into the algorithm framework, which enables end-users to search less popular topics when multi-topics are involved in queries. The experimental results reveal two benefits from the new algorithm: the improvement of distillation quality without utilizing any content information of pages, and an additional ability to explore the topics emerging in the query results.
In this paper, we present three-grid Fourier analysis for multigrid methods. Due to the recursive structure of a multigrid iteration, this analysis can be deduced from the well-known two-grid Fourier analysis. The coa...
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In this paper, we present three-grid Fourier analysis for multigrid methods. Due to the recursive structure of a multigrid iteration, this analysis can be deduced from the well-known two-grid Fourier analysis. The coarse grid correction part of multigrid algorithms can be more accurately evaluated with the three-grid analysis. We apply the analysis to several scalar equations and discretizations with an emphasis on problems with a multigrid coarse grid correction difficulty like upwind discretizations of the convection diffusion equation. The main focus lies on possible improvements by carefully chosen Galerkin operators and/or by an additional acceleration with restarted GMRES, GMRES(m). Numerical test calculations validate the theoretical predictions.
The critical materials and critical parts are keys to the production at Engineer to Order (ETO) enterprises implies that the control of plans for critical materials and critical parts is essential to the control of al...
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The critical materials and critical parts are keys to the production at Engineer to Order (ETO) enterprises implies that the control of plans for critical materials and critical parts is essential to the control of all plans at ETO enterprises. A mixed mode of hierarchical network planning/MRP (NP/MRP) is proposed to generate network plans for critical materials or critical parts from project networks and the plans for non critical parts produced by MRP are constrained by the related project networks. The multilevel hierarchical network planning/MRP mixed planning (MHNM) architecture proposed is the extension of the hierarchical NP/MRP to the supply chain based on the temporal constraints of multilevel project networks for critical materials or critical parts. A general model is formulated for scheduling tasks on machines at work centers as well.
Customers of Virtual Private Networks (VPNs) over Differentiated Services (DiffServ) infrastructure are most likely to demand not only security but also guaranteed Quality-of-Service (QoS) in pursuance of their desire...
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Customers of Virtual Private Networks (VPNs) over Differentiated Services (DiffServ) infrastructure are most likely to demand not only security but also guaranteed Quality-of-Service (QoS) in pursuance of their desire to have leased-line-like services. However, expectedly they will be unable or unwilling to predict the load between VPN endpoints. This paper proposes that customers specify their requirements as a range of quantitative services in the Service Level Agreements (SLAs). To support such services Internet Service Providers (ISPs) would need an automated provisioning system that can logically partition the capacity at the edges to various classes (or groups) of VPN connections and manage them efficiently to allow resource sharing among the groups in a dynamic and fair manner. While with edge provisioning a certain amount of resources based on SLAs (traffic contract at edge) are allocated to VPN connections, we also need to provision the interior nodes of a transit network to meet the assurances offered at the boundaries of the network. We, therefore, propose a two-layered model to provision such VPN-DiffServ networks where the top layer is responsible for edge provisioning, and drives the lower layer in charge of interior resource provisioning with the help of a Bandwidth Broker (BB). Various algorithms with examples and analyses are presented to provision and allocate resources dynamically at the edges for VPN connections. We have developed a prototype BB performing the required provisioning and connection admission.
A new and efficient class of nonlinear receivers is introduced for digital communication systems. These "iterated-decision" receivers use optimized multipass algorithms to successively cancel interference fr...
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A new and efficient class of nonlinear receivers is introduced for digital communication systems. These "iterated-decision" receivers use optimized multipass algorithms to successively cancel interference from a block of received data and generate symbol decisions whose reliability increases monotonically with each iteration. Two variants of such receivers are discussed: the iterated-decision equalizer and the iterated-decision multiuser detector. Iterated-decision equalizers, designed to equalize intersymbol interference (ISI) channels, asymptotically achieve the performance of maximum-likelihood sequence detection (MLSD), but only have a comp.tational comp.exity on the order of a linear equalizer (LE). Even more importantly, unlike the decision-feedback equalizer (DFE), iterated-decision equalizers can be readily used in conjunction with error-control coding. Similarly, iterated-decision multiuser detectors, designed to cancel multiple-access interference (MAI) in typical wireless environments, approach the performance of the optimum multiuser detector in uncoded systems with a comp.tational comp.exity comp.rable to a decorrelating detector or a linear minimum mean-square error (MMSE) multiuser detector.
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