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Optimized inversion method for thermal parameters of concrete dam under the insulated condition

ENGINEERING APPLICATIONS OF ARTIFICIAL INTELLIGENCE 2023年第PartB期126卷

作者： Bo, Chen Qingyi, Wang Weinan, Chen Hao, Gu Hohai Univ Coll Water Conservancy & Hydropower Engn Nanjing 210098 Peoples R China Hohai Univ State Key Lab Hydrol Water Resources & Hydraul En Nanjing 210098 Peoples R China Water Conservancy & Hydroelect Power Co Ltd Zhejiang Design Inst Hangzhou 310000 Peoples R China

It is crucial to study how thermal characteristics of concrete dam change over time, especially in cold regions, in order to guarantee long-term safety of the engineering projects. In this manuscript, an inverse analysis method by coupling the numerical simulation model and dam safety monitoring data, is proposed to solve the problem that true thermal parameters of the whole structure cannot be obtained by laboratory experiments or field tests of single points. Moreover, a numerical equivalence method of the dam and its insulation layer is introduced, in order to overcome the problem that the thickness of the insulation layer is much smaller than that of the concrete dam, resulting in low accuracy of the simulation model. Thirdly, the particle swarm optimization is introduced, in order to solve the ill-posed problems occurring during the solution process of multi-parameter inverse analysis. Considering the problem that the original particle swarm algorithm is easy to fall into local optimum and stuck edge, this study improves particles velocity and inertia weights. Benchmark function tests are applied to show the performance compared to several typical optimized algorithms. Numerical simulation and engineering verifi-cation are used to demonstrate the rationality and feasibility of the proposed method. The cases show that the residual box diagram of two typical measuring points calculated by inversion value is smaller than the median line and mean point calculated by design value. Moreover, the change law of the temperature field of the finite element calculation using the inversion values is closer to the actual measured value than that of the design value. The results indicate that the multi-parameter inverse method is feasible in insulated dam engineering. In addition, the result of the improved PSO optimization converges faster and has a higher fitness value than that of the original algorithm. It suggests that the improved PSO algorithm for thermal parameters i

关键词： Cold region Concrete dam Dam insulation Equivalent heat release coefficient optimization algorithm

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ORIENTATION STUDIES FOR SINGLE-AXIS CONCENTRATING COLLECTORS

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JOURNAL OF ENERGY 1979年第3期3卷 151-155页

作者： JETER, S CRAIG, JI GREMS, EG GEORGIA INST TECHNOL SCH AEROSP ENGNATLANTAGA 30332

The useful heat gain of a linear single-axis concentrating solar collector is significantly affected bY the orientation of the collector. The temporal distribution of the heat output, both diurnally and annually, and the integrated energy output varY with the direction of the collector axis. For a typical insolation sequence, a north to south orientation yields greater annual heat gain while an east to west orientation gives a flatter annual distribution. Selection of the best collector orientation depends on this distribution, the load profile, and the thermal capacitance of the system. The first two factors are considered in the definition of an economic criterion function which is then used to identify the optimum distribution of collectors among all possible orientations.

关键词： Transmittance Solar System Heat Flow Material Properties Solar Energy Systems Newton's Method optimization algorithm Thermal Performance Gradient Method Solar Collectors

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Fuel-Optimal Maneuvers for Constrained Relative Satellite Orbits

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2009年第3期32卷 960-973页

作者： Irvin, David J. Cobb, Richard G. Lovell, T. Alan USAF Inst Technol Dept Aeronaut & Astronaut Dayton OH 45433 USA USAF Res Lab Space Vehicles Directorate Albuquerque NM 87117 USA

This research investigates strategies to enable a deputy satellite to hover within a defined volume fixed in the vicinity of a chief satellite in a circular orbit for an extended period of time. Previous research developed initial methodologies for maintaining restricted teardrop hover orbits that exist in a plane fixed within the chief's local reference frame. These methods use the natural drift of the deputy satellite in the relative frame and impulsive thrust to keep the deputy in a bounded volume relative to the chief, but do not address fuel optimality. This research extends and enhances that work by finding the optimal trajectories produced with discrete thrusts that minimize fuel spent per unit time and stay within the user-defined volume, thus providing a practical hover capability in the vicinity of the chief. The work assumes that the Clohessy-Wiltshire closeness assumption between the deputy and chief is valid. Using the new methodology developed in this work, feasible closed- and nonclosed-relative orbits are found and evaluated based on a fuel criterion and are compared with an easily calculated continuous-thrust baseline. It is shown that in certain scenarios (generally corresponding to a smaller total time of flight) a discrete-thrust solution provides a lower overall fuel cost than a continuous-thrust solution. A simple check is proposed that enables the mission planner to make the correct strategy choice.

关键词： Satellites Fuels optimization algorithm Nonlinear Programming Linear Time Invariant Elliptical Cylinders MATLAB Clohessy Wiltshire Equation Flight Trajectory Harmonic Oscillator

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A 3-D Kinematic Model For The Biomechanical Analysis Of The Lower Limb While Cycling

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International Journal of Modelling and Simulation 1990年第2期10卷 36-42页

作者： R. Radharamanan H. Shen Department of Mechanical and Industrial Engineering Marquette University Milwaukee WI 53233 Graduate Student Department of Mechanical Engineering The Pennsylvania State University University Park PA 16802

In this paper, a ten-joint 3-D kinematic model has been developed by carefully *** the anatomy of the lower limb during bicycling for understandmg and analyzmg the complex motions of the joints. An optimization algorithm has also been developed and used to compute the Joint vanables and find the numerical solution. In order to simulate the indeterminate kinematic system, random vectors of multinormal distribution have been generated and statistical means and variances have been obtained from these random vector samples. The validity of the developed model has been checked by comparing the results with that of *** measurements. The model developed has good desirability to descnbe the hmb and IS more accurate than 2-D models to predict the motion of lower extremities.

关键词： Kinematic Model Biomechanical Analysis Lower Limb Multinormal Distribution optimization algorithm Bicycling

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Parameter extraction of photovoltaic cell and module: Analysis and discussion of various combinations and test cases

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SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS 2020年 40卷

作者： Oulcaid, Mostapha El Fadil, Hassan Ammeh, Leila Yahya, Abdelhafid Giri, Fouad Ibn Tofail Univ LGS Lab Kenitra 14000 Morocco Univ Caen Lab Automat Caen Bd Marechal JuinBP 8156 F-14032 Caen France

A reliable model for photovoltaic (PV) cell/panel is of great interest;it helps to simulate and better understand the behavior of PV systems. Consequently, better control and optimization of the system can be achieved. The most used models of PV cell/panel in literature are the one-diode (ODM) and double-diode (DDM) models. Their accuracy strongly depends on their parameters which must be obtained carefully. optimization-based approaches are widely adopted for this purpose. In this context, this paper presents two main references studies: The first one focuses on optimization methods and their three basic elements: model, objective function and algorithm. The study highlights the improvement that can be made to the accuracy of the final I-V curve and to the CPU-time required for the extraction by choosing the right combination of the three elements. This is done through the analysis of more than 50 results obtained by different combinations of algorithms, objective functions and models applied to benchmark PV cells and panels widely used in literature. The best combinations are identified and recommended. The second is a detailed comparison and classification of 47 I-V curve estimation methods based on three different approaches: optimization techniques, analytical methods and explicit models of PV cells/panels.

关键词： Photovoltaic cell model optimization algorithm Parameter extraction Analytical approach Explicit models

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Reviewer assignment algorithms for peer review automation: A survey

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INFORMATION PROCESSING & MANAGEMENT 2022年第5期59卷

作者： Zhao, Xiquan Zhang, Yangsen Beijing Informat Sci & Technol Univ 12 Xiaoying East Rd Beijing 100192 Peoples R China

Assigning paper to suitable reviewers is of great significance to ensure the accuracy and fairness of peer review results. In the past three decades, many researchers have made a wealth of achievements on the reviewer assignment problem (RAP). In this survey, we provide a comprehensive review of the primary research achievements on reviewer assignment algorithm from 1992 to 2022. Specially, this survey first discusses the background and necessity of automatic reviewer assignment, and then systematically summarize the existing research work from three aspects, i.e., construction of candidate reviewer database, computation of matching degree between reviewers and papers, and reviewer assignment optimization algorithm, with objective comments on the advantages and disadvantages of the current algorithms. Afterwards, the evaluation metrics and datasets of reviewer assignment algorithm are summarized. To conclude, we prospect the potential research directions of RAP. Since there are few comprehensive survey papers on reviewer assignment algorithm in the past ten years, this survey can serve as a valuable reference for the related researchers and peer review organizers.

关键词： Matching degree Information retrieval Reviewer assignment problem optimization algorithm Natural language processing Peer review

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Image Reconstruction for Few-view Computed Tomography Based on ℓ 0 Sparse Regularization

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Procedia Computer Science 2017年 107卷 808-813页

作者： Wei Yu Chengxiang Wang Xiaoying Nie Min Huang Limin Wu School of Biomedical Engineering Hubei University of Science and Technology Xianning 437100 China School of Mathematical Sciences University of Electronic Science and Technology of China Chengdu 611731 China School of Biomedical Engineering South-Central University for Nationalities Wuhan 430074 China Hubei Key Laboratory of Medical Information Analysis & Tumor Diagnosis and Treatment Wuhan 430074 China

Accurate CT images are expected to be obtained from low-dose/limited projection data. In this work, an ℓ 0 sparse regularization based optimization model was investigated for few-view CT. With the aim to effectively solve the optimization model, original optimization problem was transformed following the framework of iterative reconstruction based on alternating direction (ADM) method. Experiments are demonstrated to validate the efficiency of the proposed algorithm.

关键词： computed tomography iterative reconstruction few-view ℓ 0 sparse regularization optimization algorithm

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A Vertical-axis Wind-solar Complementary Power Generation System Optimized based on Adaptive Particle Swarm algorithm

International Core Journal of Engineering

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International Core Journal of Engineering 2021年第5期7卷 492-500页

作者： Gaoyuan Liu Guangyuan Zhong Huayi Sun Jiarui Liang

Wind energy and solar energy are inexhaustible green, clean and renewable energy sources on the earth. Comprehensive utilization of wind and solar resources and the development of wind-solar complementary power generation technology has become a research and development trend in the field of new energy. The wind and solar hybrid power generation system is a power generation system that combines wind power and solar photovoltaic power generation, which is mainly composed of wind turbines, solar photovoltaic battery packs, controllers, batteries, inverters, AC and DC loads and other parts. This paper systematically expounds the composition of the wind-solar hybrid power generation system and the characteristics of each part, proposes a new type of vertical axis wind turbine, and uses a newly proposed improved particle swarm algorithm (YAPSO) to optimize the multi-objective battery in wind-solar hybrid power generation. The simulation experiment proves the feasibility and practicability of the proposed algorithm.

关键词： Vertical-axis Wind and Solar Hybrid Power Generation Microgrid optimization algorithm Self-adaptation Multi-objective optimization

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A Cooperative and Hybrid Network Intrusion Detection Framework in Cloud Computing Based on Snort and Optimized Back Propagation Neural Network

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Procedia Computer Science 2016年 83卷 1200-1206页

作者： Z. Chiba N. Abghour K. Moussaid A. El omri M. Rida Team of Modeling and Optimization of mobile services Faculty of Sciences Hassan II University of Casablanca 20100 Casablanca Morocco

Cloud computing provides a framework for supporting end users easily attaching powerful services and applications through Internet. To give secure and reliable services in cloud computing environment is an important issue. Providing security requires more than user authentication with passwords or digital certificates and confidentiality in data transmission, because it is vulnerable and prone to network intrusions that affect confidentiality, availability and integrity of Cloud resources and offered services. To detect DoS attack and other network level malicious activities in Cloud, use of only traditional firewall is not an efficient solution. In this paper, we propose a cooperative and hybrid network intrusion detection system (CH-NIDS) to detect network attacks in the Cloud environment by monitoring network traffic, while maintaining performance and service quality. In our NIDS framework, we use Snort as a signature based detection to detect known attacks, while for detecting network anomaly, we use Back-Propagation Neural network (BPN). By applying snort prior to the BPN classifier, BPN has to detect only unknown attacks. So, detection time is reduced. To solve the problem of slow convergence of BPN and being easy to fall into local optimum, we propose to optimize the parameters of it by using an optimization algorithm in order to ensure high detection rate, high accuracy, low false positives and low false negatives with affordable computational cost. In addition, in this framework, the IDSs operate in cooperative way to oppose the DoS and DDoS attacks by sharing alerts stored in central log. In this way, unknown attacks that were detected by any IDS can easily be detected by others IDSs. This also helps to reduce computational cost for detecting intrusions at others IDS, and improve detection rate in overall the Cloud environment.

关键词： Cloud computing Network intrusion detection Back-propagation neural network Snort optimization algorithm

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A Review of Research on Vehicle Routing Problem for Electric Vehicles

Frontiers in Economics and Management

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Frontiers in Economics and Management 2022年第10期3卷 96-103页

作者： Fei Peng

In recent years, China's logistics industry has developed rapidly, and the logistics network has become increasingly large. How to optimize the vehicle route is one of the key issues to reduce the cost of logistics and distribution. With the continuous progress of new energy technology, scholars at home and abroad have given a lot of attention to the EVRP problem model and its solution method. With continuous in-depth research, many branch problems with more constraints have been developed, and their solution methods have become more and more diverse. In order to further sort out the research status of EVRP problem at home and abroad, the basic model, variant problem and its solving algorithm type of EVRP problem are firstly introduced.

关键词： Electric Vehicle Routing Problem Literature Review optimization algorithm

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