Papers by Keyword: Cost Function

Abstract: The concept of distributed generation (DG) has been developed as a hopeful solution to meet the demand increase in distribution systems. The optimal DG deployment in the distribution system can improve the technical benefits. This study presents a framework to find the optimum location and size for different types of DG units to enhance the voltage stability index (VSI), improve the voltage regulation and reduce the daily energy losses. The emission effect and cost function (environment and economic benefits) are augmented in the multi-objective function. Combinations of DG types are introduced to obtain the best benefits from each one. The daily load variations and dynamic output of each DG type are considered in the problem formulation. The genetic algorithm (GA) technique is used to find the optimal allocation for different cases. The typical IEEE 33-bus system is utilized to evaluate the proposed framework.

Abstract: Belt conveyance belongs to the continual transport systems characteristic with high-level conveying performances. Belt conveyors are of significant importance in the transportation of various types of materials in the industries like engineering, metallurgy and construction. The fundamental and the most expensive component of belt conveyors is the conveyor belt which is, during the operation on the belt conveyor, exposed to number of various loads that evoke the process of conveyor belt wear and damage. Lifetime of conveyor belts, which is the determining parameter for the belt conveyance economy and efficiency, is very important for the practice.Issues regarding the conveyor belt lifetime should be solved applying also the methods of operation analysis, especially the linear programming and the renewal theory that uses the theory of probability and mathematic statistics. The objective of our research was to determine the optimal lifetime (optimal performance duration) of a belt conveyor, applying the renewal theory, whereas the research was based on the cost approach of the renewal process.

Abstract: By analyzing the priority arbitration bit by bit without destroy in can bus rule, the article elicits the conclusion that if static priority based on the affirmatory system model is used, the lower priority’s messages will be much more delayed, even lose some data when the bus’s bandwidth is widely used and scheduling can’t be modified during the system. The dynamic priority promoting method and math model of SQSA and SQMA is achieved in the article, it analyses the model’s rate of taking in and sending out in large quantities, the largest delay, the problems and solutions when using SQMA. In the end, It is validated that the method of improved dynamic in the article has good performances on the network rate of taking in and sending out in large quantities, the average delay and the rate of network usage by emulational experiments.

Abstract: In the next generation of heterogeneous wireless network environment, to meet the network requirements of diverse services ,we propose a vertical handoff decision algorithm based on QoS evaluation that refine the handover unit to services. The proposed algorithm consider the needs of the services、 network conditions、 user preferences and other factors, and makes Analytic Hierarchy Process (AHP) and cost function combine to choose the target network that is best meet the requirements of services . Comparing with the vertical handoff decision based on RSS, simulation results show that the proposed method can take full account of the different QoS requirements of various services types to choose the appropriate network, and would not cause performance degradation.

Abstract: The flux-switching permanent magnet machine (FSPMM) has got great attention by academic researchers during the past couple of years for its merits of strong mechanical robustness, high efficiency, strong thermal dissipation ability, etc. However, for its inherited double salient structure in both stator and rotor, the FSPMM suffers from severe torque and flux ripples at different rotor positions for its variable magnetic resistance, which cannot be solved completely only by electromagnetic optimal design. In order to increase the drive performance of FSPMM, such as dynamic response and stable torque smoothness, an improved model based predictive torque control (MPTC) algorithm is proposed. By using the cost function modulation strategy, the torque and flux ripples of FSPMM are reduced evidently, accompanying with the minimized converter switching frequency and power loss. Comprehensive simulation investigations are finally carried out to validate relevant theoretical analysis.

Abstract: In the process of detecting leak hole in pipeline by intelligent pig with eddy current measuring method, the cut off effect of eddy current field in the closed cross section of leak hole in steel plate is weak due to geometric deformation of eddy current on the edge of the hole produced by destroyed drilling. As a result, the measured signal is very unobvious. Meanwhile, owing to the rough surface of steel plate, the periodic interference generated by movement of the detecting probe cannot be eliminated or be inhibited easily by conventional signal processing methods for its large amplitude and approximate frequency band with the leak hole signals, the signal to noise ratio (SNR) of measured signal is very low and the accurate identification of leak hole cannot be guaranteed. The wavelet transform, with characteristics of time-frequency localization and multiple scales, is a useful and effective method for identifying singularity of the signals and adapts to detect the transient signal or extract non-stationary information in the signals with strong periodic interference and noise. The reconstructing signal SNR will be increased greatly in eddy current detecting of leak hole in the pipeline with wavelet packet analysis of the signal by constructing the self-defined cost function based on maximum SNR to obtain optimal wavelet packet basis function. This ensures good detection and location of leak hole in the pipeline.

Abstract: Suppose the firm's output is influenced by the agent’s effort level observable and the ability unobservable, researching the optimal level of incentives under the two levels of incentives associated. Study found that corporate client based on the first period of corporate performance, the agents ability to judge the case, risk aversion, the variance of the degree of capacity, the degree of attention of the principal agents the ability have an impact on the agents first and second of the optimal incentive level. In addition, of the optimal incentive level in first period is correlated with the contribution of the efforts with the manager of the firm's output, the agent's incentive level in the second period as well as the effort cost associated of the first period; while the second period of the optimal the incentive level is a decreasing function of the current cost of effort.

Abstract: The thermomechanical behavior of Shape Memory Alloys (SMAs) is described by many micromechanical and phenomenological models. The first ones have material parameters whose physical meaning is based on the crystallography of the phase transformation related to the studied alloy. In contrast, phenomenological models often have material parameters whose physical meaning is not obvious and that makes them difficult to identify, some of which are based on mathematical considerations. In this paper, we propose to use the formulation of the phenomenological model of Chemisky et al., and to consider the particular case of a superelastic SMA. In this case, the constitutive equation should be easily expressed analytically through the strain tensor as a function of applied load direction and material parameters. The behavior is then characterized by a complete and proportional loading. This analytical model contains 8 material parameters, 2 related to the elasticity and 6 to the phase transformation. Based on several isothermal tensile tests at various temperatures, material parameters of this model are identified using the Levenberg-Marquardt algorithm and an analytical calculation of the sensitivity matrix. Their physical meaning and their influence on the thermomechanical behavior of the alloy studied are highlighted and discussed.

Abstract: In this paper, cost coefficient is introduced by using the technology of FMECA and FTA, and the DM model is proposed, the parameters of cost function are determined by applying the comprehensive evaluation method, the system reliability correlation model is set up by using copula function. the model is nonlinear programming, and the minimum cost is the goal of the model. The reliability allocation for diesel engine is completed by use of genetic algorithm. Finally, the feasibility and effectiveness of the model are verified through example.

Abstract: A constraint constant module blind equalization algorithm for medical image based on dimension reduction was proposed. The constant modulus cost function applied to medical image was founded. In order to improve the effect of image restoration, a constraint item was introduced to restrict cost function, and it guarantees that the algorithm converge the optimal solution. Compared to the traditional methods, the novel algorithm improves peak signal to noise ratio and restoration effects. Computer simulations demonstrate the effectiveness of the algorithm.