This paper presents the results obtained testing a tool designed to characterize and simulate the behavior of a Photovoltaic (PV) panel under real and/or simulated working conditions. The presented tool permits the co...
详细信息
ISBN:
(纸本)9781424428335
This paper presents the results obtained testing a tool designed to characterize and simulate the behavior of a Photovoltaic (PV) panel under real and/or simulated working conditions. The presented tool permits the continuous monitoring of the I-V (Current-Voltage) and P-V (Power-Voltage) characteristics of the panel and the comparison between actual and expected performance;in this way it is possible to prevent any possible decrease of the output power and to replace the monitored module before it goes out of order or its efficiency falls under a given threshold. The well known two-diode model is used to estimate the parameters of the electrical equivalent circuit of the PV panel and to simulate both the I-V and P-V characteristic curves in any given environmental condition of irradiation and/or temperature. The model and the estimation algorithm are implemented as a MATLAB (R) script while the user interface is designed with LabVIEW (TM). The presented tool has been validated against an experimentally characterized PV panel. The environmental parameters of the model such as irradiance and temperature have been measured directly, whereas the others parameters have been evaluated using a best-fit algorithm on the measured data.
Computational optimization forms an integrated part of modern computational science. Any good design should intend to achieve certain optimality, though optimal solutions are often difficult to find in practice since ...
详细信息
Computational optimization forms an integrated part of modern computational science. Any good design should intend to achieve certain optimality, though optimal solutions are often difficult to find in practice since uncertainty and nonlinearity always present in almost all real-world problems. As resources, time and money are always limited, optimization becomes even more important in practice. This workshop on Computational optimization, Modelling and Simulation (COMS 2010) at ICCS 2010 will summarize the latest developments of optimization and modelling and their applications in science, engineering and industry
Band-gap grading in a CIGS absorber and a conduction band offset at n/p hetero-interface are two important parameters of band-gap engineering aiming at high efficient CIGS solar cells. To obtain optimal CIGS absorber&...
详细信息
Band-gap grading in a CIGS absorber and a conduction band offset at n/p hetero-interface are two important parameters of band-gap engineering aiming at high efficient CIGS solar cells. To obtain optimal CIGS absorber's band-gap grading profile an automatic optimization loop based on Nelder-Mead simplex optimization algorithm has been implemented. The optimization problem is described with an objective function, which-by varying the input parameters-is minimized or maximized. In our study two types of objective functions are used;optical and electrical. As the most optimal profile a parabolic, double graded band-gap profile with a positive or nearly zero conduction band offset at n/p hetero-interface is calculated. Structures with different CIGS absorber thicknesses and bulk and/or hetero-interface recombination lifetimes are examined and their optimized parameters are discussed in the light of experimental achievements. (c) 2005 Elsevier B.V All rights reserved.
In this paper, an improvement of the quantization optimization algorithm for the MPEG-Advanced Audio Coder (AAC) is presented. This algorithm, given a bit-rate constraint, minimizes the perceived distortion generated ...
详细信息
In this paper, an improvement of the quantization optimization algorithm for the MPEG-Advanced Audio Coder (AAC) is presented. This algorithm, given a bit-rate constraint, minimizes the perceived distortion generated by the signal compression. The distortion can be related to the quantization error level over frequency subbands through an auditory model. Thus, optimizing the quantization requires knowledge of the rate-distortion function for each subband. When this function can be modeled in a simple way, the algorithm can take a one-loop recursive structure. However, in the MPEG AAC, the rate-distortion function is hard to characterize, since AAC makes use of nonlinear quantizers and variable length entropy coders. As a result, the standard algorithm makes use of two nested loops with a local decoder, in order to measure the error level rather than predicting its value. We first describe a partial subband modeling of the rate-distortion function of interest in the MPEG AAC. Then, using a statistical approach, we find a relationship between the error level and the so-called quantization "scale-factor" and propose a new algorithm that is basically similar to a classical one loop "bit allocation" process. Finally, we describe the complete algorithm and show that it is more efficient than the standard one.
Being versatile and fast, a co-ordinate measuring machine is used for the measurement of worm. A best-fit surface is obtained from the measured points by a surface fitting method, which minimizes the root mean square ...
详细信息
Being versatile and fast, a co-ordinate measuring machine is used for the measurement of worm. A best-fit surface is obtained from the measured points by a surface fitting method, which minimizes the root mean square of normal deviations. For this problem in discrete space, an iterative optimization algorithm based on an orthogonal array is developed. On minimizing the objective function, the deviations of worm parameters from the specified values are obtained. The algorithm is validated using input data points generated from a straight-sided in axial section worm (ZA worm) with known errors. The proposed algorithm requires fewer objective function evaluations and the result is highly repeatable as there are no random operations involved.
Service composition is a promising technique for developing applications especially for those across multiple organizations. The dependability of composite services, however, is difficult to be guaranteed due to the d...
详细信息
Service composition is a promising technique for developing applications especially for those across multiple organizations. The dependability of composite services, however, is difficult to be guaranteed due to the distributed, dynamic and autonomous characteristics of service domains. In this paper, we address this problem by proposing a novel approach—PASCAL (Protocol-based Approach for Web Service Composition And DependabLe optimization). We initially propose a protocol based service composition system architecture supporting online monitoring of services interaction and dynamic replacing of service. Then, we design the dependable optimization mechanism based on the service and dependencies monitoring. Furthermore, we design an algorithm to adjust the configuration adaptively base on policies and protocols to keep the composite service dependable while service failure appears. Finally we implement the PASCAL approach based on XService suit and evaluate the proposed mechanism through comprehensive experiments and achieve improved results.
Target's spectral emissivity changes variously, and how to obtain target's continuous spectral emissivity is a difficult problem to be well solved nowadays. In this letter, an activation-function-tunable neura...
详细信息
Target's spectral emissivity changes variously, and how to obtain target's continuous spectral emissivity is a difficult problem to be well solved nowadays. In this letter, an activation-function-tunable neural network is established, and a multistep searching method which can be used to train the model is proposed. The proposed method can effectively calculate the object's continuous spectral emissivity from the multispectral radiation information. It is a universal method, which can be used to realize on-line emissivity demarcation.
The present research, based on system engineering, information engineering technology, applied mathematics, and the theories and methodology of safety predicative assessment, carried out a thorough and in-depth resear...
详细信息
The present research, based on system engineering, information engineering technology, applied mathematics, and the theories and methodology of safety predicative assessment, carried out a thorough and in-depth research into the intelligence decision-making and analysis for optimization design development of road surface maintenance system from the aspects of data support, road performance assessment and optimization and selection scheme for maintenance decision-making and strategies. In addition, the optimization algorithm is provided for data categorization and sifting as well as the division of storage units. Then, an optimization model is constructed based on the load bearing capacity of road structures, road quality for driving, road safety for driving together with road surface damage. At last, based on multi-model predications and the correlation analysis for predicative concepts of decision-making flow for road surface performance, the PPM optimization model is constructed for protective maintenance modules for road surface and the mathematical model and method are offered for the optimization and selection of strategic schemes.
This paper presents a differential evolution optimized fuzzy clustering algorithm (DEOFCA), which combines differential evolution (DE) algorithm and fuzzy clustering theory. Since DE algorithm has strong global search...
详细信息
This paper presents a differential evolution optimized fuzzy clustering algorithm (DEOFCA), which combines differential evolution (DE) algorithm and fuzzy clustering theory. Since DE algorithm has strong global search ability and good robustness, DEOFCA uses DE to replace the iteration process of fuzzy C means clustering algorithm, by which the global optimization capability is greatly improved. An adaptive adjusting strategy for control parameters is integrated with the algorithm to eliminate negative effects of the control parameters setting to algorithm performance and efficiency. The proposed algorithm is applied to a case of power system, and the results demonstrate the feasibility and efficiency of this novel method.
Ecology evolutionary algorithm of food chain(EEAFC) as a new power transmission network planning approach is applied to power transmission network expansion planning,the objective function is selected as achieving min...
详细信息
Ecology evolutionary algorithm of food chain(EEAFC) as a new power transmission network planning approach is applied to power transmission network expansion planning,the objective function is selected as achieving minimal investment sum of transmission *** at the different characteristics of the scale and the quality of various populations in ecology evolutionary algorithm of food chain,selection methods such as proportional model and deterministic sampling are used in low population and intermediate population separately,senior population uses optimal reserved strategy but dose not use reproduction operator,which gives further consideration to both the overall search and the local search *** expansion transmission corridor as decision variable,a real number encoding method is proposed for reducing the dimension numbers of *** test was performed on the 18-bus system,the calculation results verify the feasibility and superiority of the proposed algorithm.
暂无评论