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Well placement optimization using an analytical formula-based objective function and cat swarm optimization algorithm

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JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING 2017年 157卷 1054-1070页

作者： Chen, Hongwei Feng, Qihong Zhang, Xianmin Wang, Sen Zhou, Wensheng Geng, Yanhong China Univ Petr East China Sch Petr Engn Qingdao 266580 Shandong Peoples R China CNOOC Res Inst Beijing 100027 Peoples R China

Well placement optimization is a crucial and complex task in oil field development. Well placement is usually optimized by coupling reservoir numerical simulator with optimization algorithm. This method spends most of computing time in objective function evaluation by reservoir numerical simulator which limits its optimization efficiency. In this work, a well placement optimization method using an analytical formula-based objective function and cat swarm optimization (CSO) algorithm is established. The objective function, derived from fluid flow in porous media and material balance principle, can be calculated by the analytical formula to avoid running reservoir numerical simulator. Then the well placement optimization model is built and solved by CSO algorithm. Three examples are applied to justify the feasibility of the new objective function and the efficiency of this optimization method. Results demonstrate this method can significantly accelerate the speed of well placement optimization process. It can help to determine the optimal well placement more efficiently for actual oilfield development.

关键词： Well placement Optimization efficiency Analytical formula objective function Cat swarm optimization algorithm

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A New Design of the objective function for the Optimal Allocation of Distributed Generation with Short-Circuit Currents

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JOURNAL OF ELECTRICAL ENGINEERING & TECHNOLOGY 2022年第3期17卷 1487-1497页

作者： Son, Seung-Wan Lee, Dong-Hyeon Kim, Insu Jung, Chang-Hyeon Kim, Hyoungkwon Yoon, Dong-Jin Lee, Joohan InhaUniversity Dept Elect Engn Incheon South Korea Korea Polar Res Inst Off Technol Dev & Serv Incheon South Korea Korea Polar Res Inst Dept Future Technol Convergence Incheon South Korea

Renewable energy sources reduce irresponsible carbon emissions and have the advantage of being located close to the load as a distributed generation (DG). Thus, various studies have examined the optimal placement and capacity of DG to maximize their effect on power grids. However, there was no paper that considered the normalized cost including the fault current in the process of the optimal allocation of DG. The reason that the normalized fault current cost should be included in objective function is that the more DG is connected to the network, the higher fault current will flow. Thus, this paper presents a method of optimizing the DG placement and capacity from a novel perspective using normalized costs that minimize the fault current. For this purpose, this study incorporates the particle swarm optimization method to the Newton-Raphson power-flow calculation and the sequence network decomposition methods. The proposed normalized cost function includes not only voltage variations determined by the power-flow method, installation costs, and power losses but also fault current determined by the sequence method. As a result, the objective function of the new design, adding the normalized fault current cost, enables the solution set to be more optimal than the previous solution set.

关键词： Distributed generation Fault current objective function Optimal allocation Particle swarm optimization

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Utilizing the Correlation Between Constraints and objective function for Constrained Evolutionary Optimization

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IEEE TRANSACTIONS ON EVOLUTIONARY COMPUTATION 2020年第1期24卷 29-43页

作者： Wang, Yong Li, Jia-Peng Xue, Xihui Wang, Bing-Chuan Cent South Univ Sch Automat Changsha 410083 Peoples R China City Univ Hong Kong Dept Syst Engn & Engn Management Hong Kong Peoples R China

When solving constrained optimization problems by evolutionary algorithms, the core issue is to balance constraints and objective function. This paper is the first attempt to utilize the correlation between constraints and objective function to keep this balance. First of all, the correlation between constraints and objective function is mined and represented by a correlation index. Afterward, a weighted sum updating approach and an archiving and replacement mechanism are proposed to make use of this correlation index to guide the evolution. By the above process, a novel constrained optimization evolutionary algorithm is presented. Experiments on a broad range of benchmark test functions indicate that the proposed method shows better or at least competitive performance against other state-of-the-art methods. Moreover, the proposed method is applied to the gait optimization of humanoid robots.

关键词： Linear programming Optimization Correlation Sociology Humanoid robots Indexes Constrained optimization constraints correlation evolutionary algorithms (EAs) humanoid robots objective function

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Artificial neural networks with a signed-rank objective function and applications

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COMMUNICATIONS IN STATISTICS-SIMULATION AND COMPUTATION 2022年第6期51卷 3363-3388页

作者： Kwessi, Eddy Edwards, Lloyd J. Trinity Univ Dept Math San Antonio TX 78212 USA Univ Alabama Birmingham Dept Biostat 327D Ryals Publ Hlth Bldg1665 Univ Blvd Birmingham AL 35294 USA

In this paper, we propose to analyze artificial neural networks using a signed-rank objective function as the error function. We prove that the variance of the gradient of the learning process is bounded as a function of the number of patterns and/or outputs, therefore preventing the gradient explosion phenomenon. Simulations show that the method is particularly efficient at reproducing chaotic behaviors from biological models such as the Logistic and Ricker models. In particular, the accuracy of the learning process is improved relatively to the least squares objective function in these cases. Applications in regression settings on two real datasets, one small and the other relatively large are also considered.

关键词： Artificial neural network objective function Signed-rank Ricker Logistic

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Full waveform inversion method using envelope objective function without low frequency data

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JOURNAL OF APPLIED GEOPHYSICS 2014年 109卷 36-46页

作者： Chi, Benxin Dong, Liangguo Liu, Yuzhu Tongji Univ State Key Lab Marine Geol Shanghai 20092 Peoples R China

Full waveform inversion (FWI) has been a successful tool to build high resolution velocity models, but it is affected by a local minima problem. The conventional multi-scale strategy to tackle this severe problem may not work for real seismic data without long offsets and low frequency data. We use an envelope-based objective function FWI method to provide the long wavelength components of the velocity model for the traditional FWI. The gradient can be computed efficiently with the adjoint state method without any additional computational cost Simple models are used to prove that the envelope-based objective function is more convex than the traditional misfit function, thus the cycle-skipping problem can be mitigated. Due to the envelope demodulation effect, the adjoint source of the envelope-based FWI contains abundant low frequency information, therefore the gradient tends to sense the low wavenumber model update. A Marmousi synthetic data example illustrates that the envelope-based FWI method can provide an adequately accurate initial model for the traditional FWI approach even when the initial model is far from the true model and low-frequency data are missing. (C) 2014 Elsevier B.V. All rights reserved.

关键词： Full waveform inversion objective function Nonlinearity Envelope Adjoint-state method

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Class of high step-up switched Z-source inverters: steady state analysis and objective function

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IET POWER ELECTRONICS 2019年第6期12卷 1329-1340页

作者： Nozadian, Mohsen Hasan Babayi Babaei, Ebrahim Hosseini, Seyed Hossein Univ Tabriz Fac Elect & Comp Engn Tabriz Iran Near East Univ Engn Fac Mersin 10 TR-99138 Nicosia North Cyprus Turkey

In this study, high step-up switched Z-source inverters (HSZSIs) with two main groups namely types I and II are proposed. Each of these groups includes several proposed structures. Owing to the features of the proposed structures such as high boost factor $\lpar \beta \rpar $(beta), continuous input current, and low voltage stress;they can be used in different applications such as renewable power systems. By using the same numbers of the passive elements in comparison with a conventional Z-source inverter (ZSI), quasi-ZSI, and series ZSI (SZSI), the proposed structures produce a higher boost factor. A new objective function is defined so that all compared parameters can be investigated with each other simultaneously. The power losses and efficiency analyses for all of the proposed structures are done and compared with the conventional structures. It is shown that for $P_{{\rm out}} \simeq 200\, {\rm W}$Pout similar or equal to 200W, the measured efficiencies for basic HSZSI type I, quasi-HSZSI type I, basic HSZSI type II and quasi-HSZSI type II are 91, 85, 96, and 92%, respectively. In addition, the total harmonic distortion calculation, dynamic performance and designing a closed-loop control method for the proposed structures are shown. Finally, the experimental results are indicated for a 500 W prototype.

关键词： harmonic distortion closed loop systems invertors voltage control electric current control high step-up switched Z-source inverters steady state analysis objective function renewable power systems basic HSZSI type II boost factor continuous input current quasi-HSZSI type II total harmonic distortion calculation closed-loop control method series ZSI power 200 0 W power 500 0 W efficiency 91 percent efficiency 85 percent efficiency 96 percent efficiency 92 percent

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Micro-seismic source location determined by a modified objective function

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ENGINEERING WITH COMPUTERS 2020年第4期36卷 1849-1856页

作者： Wu, L. Z. Li, S. H. Huang, R. Q. Wang, S. Y. Chengdu Univ Technol State Key Lab Geohazard Prevent & Geoenvironm Chengdu 610059 Sichuan Peoples R China Univ Newcastle ARC Ctr Excellence Geotech Sci & Engn Dept Civil Surveying & Environm Engn Callaghan NSW 2308 Australia

The exact localization of micro-seismic sources is of significant importance in micro-seismic monitoring technology. The methods determining arrival time and time difference of micro-seismic source locations in engineering are introduced. The factors affecting the accuracy of the micro-seismic source location are analysed. To improve the accuracy of micro-seismic source localization, an objective function is used to examine the source, and a new method for locating micro-seismic sources is proposed. To make full use of the monitoring data of each geophone, the L2-norm and variance function are combined to improve the overall accuracy of the positioning and the stationarity of the objective function of each geophone equation. Finally, a particle swarm optimization is employed to search for the source location. The effectiveness of the improved method is verified by two case studies, and the results indicate that the proposed method is better than conventional approaches. The proposed method is simple and easy to perform.

关键词： Micro-seismic source localization objective function Particle swarm optimization Mathematical model

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Modularity-like objective function in annotated networks

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Frontiers of physics 2017年第6期12卷 109-113页

作者： Jia-Rong Xie Bing-Hong Wang Department of Modern Physics University of Science and Technology of China Hefei 230026 China

We ascertain the modularity-like objective function whose optimization is equivalent to the maximum likelihood in annotated networks. We demonstrate that the modularity-like objective function is a lin- ear combination of modularity and conditional entropy. In contrast with statistical inference methods, in our method, the influence of the metadata is adjustable; when its influence is strong enough, the metadata can be recovered. Conversely, when it is weak, the detection may correspond to another partition. Between the two, there is a transition. This paper provides a concept for expanding the scope of modularity methods.

关键词： community structure annotated networks modularity objective function

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Non-Rigid Point Set Registration via Adaptive Weighted objective function

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IEEE ACCESS 2018年 6卷 75947-75960页

作者： Yang, Changcai Liu, Yizhang Jiang, Xingyu Zhang, Zejun Wei, Lifang Lai, Taotao Chen, Riqing Fujian Agr & Forestry Univ Coll Comp & Informat Sci Digital Fujian Res Inst Big Data Agr & Forestry Fuzhou 350002 Fujian Peoples R China Fujian Agr & Forestry Univ Fujian Prov Univ Key Lab Smart Agr & Forestry Fuzhou 350002 Fujian Peoples R China Wuhan Univ Elect Informat Sch Wuhan 430072 Hubei Peoples R China

Non-rigid point set registration is a fundamental problem in many fields related to computer vision, medical image processing, and pattern recognition. In this paper, we develop a new point set registration method by using an adaptive weighted objective function, which formulates the alignment of two point sets as a mixture model estimation problem. The correspondences and the transformation are jointly recovered by using the expectation-maximization algorithm to obtain the promising results. First, the correspondences are established using local feature descriptors, and the adaptation parameters for the mixture model are computed from these correspondences. Then, the underlying transformation is recovered by minimizing the adaptive weighted objective function deduced from the mixture model. We demonstrate the advantages of the proposed method on various types of synthetic and real data and compare the results against those obtained using the state-of-the-art methods. The experimental results show that the proposed method is robust and outperforms the other registration approaches.

关键词： Registration expectation-maximization (EM) algorithm thin-plate spline (TPS) objective function mixture model point set

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IRH-OF: A New objective function for RPL Routing Protocol in IoT Applications

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WIRELESS PERSONAL COMMUNICATIONS 2021年第1期119卷 673-689页

作者： Eloudrhiri Hassani, Abdelhadi Sahel, Aicha Badri, Abdelmajid Hassan II Univ Casablanca FSTM Elect Energy Automat & Informat Proc Lab Mohammadia Morocco

Faced to challenges of low power and lossy networks (LLN's) as well as the nature of these networks without infrastructure, it remains the subject of several researches to deal with routing constraints and thus propose adapted routing protocols according to different applications. In this context, a protocol based on Ipv6 RPL has been standardized to meet the requirements of low power and lossy networks. RPL centralizes traffic to one or more nodes through the construction of a Destination Oriented Directed Acyclic Graph (DODAG) based on a specific objective function. Nevertheless, the objective function influences the behavior of the routing protocol, so that the design must follow the prerequisites of each application. The problem of standardized objective functions is found in their routing paths selection, they are not based on different criteria which leads to unoptimized choices of routes which affects the network quality of services . Thus, we propose in this paper a new objective function IRH-OF based on designed combined metric cmIRH for rank calculation. Our proposed method, injected on the core of Contiki Operating System, ensures a better quality of services compared to other objective functions. The results showed that the new objective function can maintain a packet delivery ratio higher than 98% regardless of density, decreases approximately with 45% the average power consumption of the network, achieves a less convergence time and latency.

关键词： WSN LLN IoT RPL objective function RSSI Hop count Combined metrics

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