Papers by Keyword: Decomposition

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Authors: Xia Yan, Jun Li, Hui Zhao
Abstract: A novel and simple parameterization method using an ensemble of unconditional model realizations is applied to decrease the dimension of the misfit objective function in large-scale history matching problems. The major advantage of this parameterization method is that the singular value decomposition (SVD) calculation is completely avoided, which saves time and cost for huge matrix decomposition and the eigenvectors computations in parameterization process. After objective function transforms from a higher dimension to a lower dimension by parameterization, a Monte Carlo approach is introduced to evaluate the gradient information in the lower domain. Unlike the adjoint-gradient algorithms, the gradient in our method is estimated by Monte Carlo stochastic method, which can be easily coupled with different numerical simulator and avoid complicated adjoint code. When the estimated gradient information is obtained, any gradient-based algorithm can be implemented for optimizing the objective function. The Monte Carlo algorithm combined with the parameterization method is applied to Brugge reservoir field. The result shows that our present method gives a good estimation of reservoir properties and decreases the geological uncertainty without SVD but with a lower final objective function value, which provides a more efficient and useful way for history matching in large scale field.
Authors: G. Dlubek, R. Unger, K. Pawelzyk, U.H. Gläser, G. Wendrock
Authors: Shan Shan Wu, Bei Zhi Li, Jian Guo Yang
Abstract: This paper aims to propose a novel three-fold approach to solve dynamic job-shop scheduling problems by artificial immune algorithm. The proposed approach works in three phases. Firstly, priority rules are deployed to decrease problem scale instead of using scheduling algorithms directly. Secondly, immune algorithm is applied to optimize the individual scheduling modules. Finally, integration schema is employed to reschedule operations and minimize makespan of gross schedule. The integration schema is carried out in a dynamic manner that the previous modules’ machine idle time is searched continuously. In this way, the machine utilization is increased while the objective of makespan minimization is maintained. Efficacy of the proposed approach has been tested with test instances of job-shop scheduling problems. The experimentation results clearly show effectiveness of the proposed approach.
Authors: Yi Gong, Quan Huan Huangfu
Abstract: The mathematical model of optimal daily operation for multiple pump units with adjustable-blade in single pumping station was solved by means of decomposition-dynamic programming aggregation method and experimental optimization method while the peak-valley electricity price was taken into consideration. After taking No.4 Huaian Pumping Station as a study case, a series of optimal operation schemes under different average daily heads and water pumping loads were obtained. Based on the analysis of optimization benefits, the applicability comparison of two optimal algorithms have been carried out, by which the application scope of each algorithm was proposed.
Authors: Hui Xuan Shi, Jin Qian, Xiao Bo Liu, Xiao Li Liu
Abstract: This work is dedicated to the development of an on-line monitoring system of SF6 decomposition in electrical devices (SF6DcpMS) in order to evaluate the health condition of the devices in real time. The feature decomposition, SO2, and SF6 purity are continuously monitored. Considering the oxidation-reduction reactions of SO2 electrochemical sensor during detection, the methodology of utilizing the air in the electrical device is proposed based on the tests of serving devices. And it is proved via tests that electrochemical sensors can be applied into SF6DcpMS. Besides, infrared detector is employed to detect SF6 purity. Sampling method of SF6 in electrical devices is described. There are three keys in the sampling device design for the on-line monitoring system: -- Sensor working environment: The rating pressure is one atmospheric pressure for sensor working. Therefore, a gas chamber is constructed, in which the suitable environment for sensor is completed via a pressure regulator and a pressure sensor. At the same time, an appropriate control method is scheduled. Gas in the chamber is continuously replaced with that in the electrical device to ensure detection accuracy within an acceptable range. -- SO2 adsorption feature: The monitoring accuracy is seriously influenced by the adsorption feature of SO2. As we known, flowing gas can decrease SO2 adsorption feature. So, a micro bump is designed in the gas chamber, which can ensure the gas flowing at the speed of 200ml/min. -- Sample gas back into electrical devices: In order to avoid the gas cause harm to humans, the gas leakage is not allowed in the on-line monitoring system, and the sample gas must be sent back to the electrical device after detection is accomplished. Sample gas back into electrical devices is realized via a bump and a check valve with adjustable cracking pressure. The first SF6DcpMS in China has been successfully put into service in Zunyi substation, and its performance has been proved out.
Authors: Li Yu, Jia Quan Wang
Abstract: The main pollutants in Huaihe river city average concentration time series, for example, according to the basic principles of the wavelet analysis, the application of wavelet decomposition and reconstruction of Huaihe river main pollutant concentration changes of time sequence is analyzed by the major pollutants of Huaihe river in changing trends and mutation characteristics. The results of the study show that, wavelet analysis is applied to the analysis of the concentration of pollutant time series is feasible.
Authors: Lin Yang
Abstract: Health monitoring of the bridge structure has gradually become one of the hot topics. The signal decomposition technology is the key technique of the bridge structural health monitoring. The traditional data analysis and processing methods, which can only be applied to stationary or linear signal processing, have significant limitations. However, the structural response signals tested are mostly non-stationary and nonlinear. So methods that can effectively analyze non-stationary and nonlinear signal are urgently needed. Based on the summarization and analysis of the shortage of wavelet analysis method, the application of local wave method for data processing and analysis in structural health monitoring is put forward. The feasibility and superiority of local wave method is discussed. Experimental simulation results show that the application of local wave method in bridge health monitoring signal decomposition is feasible.
Authors: Ye Xia Tu, Yu Gao
Abstract: There are many thinking method, the thinking method of decomposition and combination is important and widely used. In the category of scholars, "decomposition and combination" belong to "analysis and synthesis". Developing software is a complex mental activity, so it requires the use of a variety of thinking method. Thinking method of decomposition and combination is the use of the most frequent in developing software. Content of thinking method of decomposition and combination is analyzed. Application of thinking method of decomposition and combination has been analyzed from four aspects. Four aspects are the development trend of software, the main content of the structured software development method, the main content of the object-oriented software development method, several commonly used software development tools.
Authors: Jian Wei Leng, Ya Ni Guo
Abstract: Radar Level Meter is being more and more widely used in the industry field. However, due to the complex radar system, the noise contained in the clutter echo signal, and the interference within the system and hardware, it is quietly significant to study the research of radar echo reduction technology. Based on the introduction of radar level meter ‘working theory, This paper presents a wavelet transform analysis of the echo signal de-noising method. Studies have shown that the radar echo signal processing method of using wavelet transform can effectively suppress noise, remove interference and achieve echo signal de-noising processing.
Authors: Hai Qian Zhao, Ji Hui Gao, Zhong Hua Wang, Shao Hua Wu
Abstract: There are variety of active substances in Fenton system, such as H2O2, HO2-, O2-·, ·OH and HO2·. In this paper, the oxidation of H2O2, HO2-, O2-·, ·OH and HO2· on NO gas was determined respectively with experimental methods. The results showed that direct oxidation of gaseous NO by H2O2, HO2- and O2-·was weak. ·OH and HO2· had strong oxidizing capacity on gaseous NO, especially ·OH. With the acceleration of ·OH and HO2· generation rate, the oxidizability of Fenton system on NO gas was stronger, but O2 generation rate also accelerated. Rapid decomposition of H2O2 is the premise to realize high NO oxidation efficiency using H2O2, but how to avoid the invalid decomposition of H2O2 is the key to increase use ratio of H2O2.
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