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Application of fuzzy optimal selection of similar slopes to the evaluation of slope stability 被引量:8
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作者 王旭华 陈守煜 +1 位作者 唐列宪 张厚全 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2007年第3期415-418,共4页
The numerical calculation method is widely used in the evaluation of slope stability,but it cannot take the randomness and fuzziness into account that exist in rock and soil engineering objectively.The fuzzy optimizat... The numerical calculation method is widely used in the evaluation of slope stability,but it cannot take the randomness and fuzziness into account that exist in rock and soil engineering objectively.The fuzzy optimization theory is thus introduced to the evaluation of slope stability by this paper and a method of fuzzy optimal selection of similar slopes is put forward to analyze slope stability.By comparing the relative membership degrees that the evaluated object sample of slope is similar to the source samples of which the stabilities are detected clearly,the source sample with the maximal relative membership degree will be chosen as the best similar one to the object sample,and the stability of the object sample can be evaluated by that of the best similar source sample.In the process many uncertain influential factors are considered and characteristics and knowledge of the source samples are obtained.The practical calculation indicates that it can achieve good results to evaluate slope stability by using this method. 展开更多
关键词 fuzzy optimal selection of similar slopes relative membership degree object sample source sample
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AHP-Based Optimal Selection of Garment Sizes for Online Shopping 被引量:2
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作者 许轶超 齐洁 丁永生 《Journal of Donghua University(English Edition)》 EI CAS 2007年第2期222-225,共4页
Garment online shopping has been accepted by more and more consumers in recent years. In online shopping, a buyer only chooses the garment size judged by his own experience without trying-on, so the selected garment m... Garment online shopping has been accepted by more and more consumers in recent years. In online shopping, a buyer only chooses the garment size judged by his own experience without trying-on, so the selected garment may not be the fittest one for the buyer due to the variety of body's figures. Thus, we propose a method of optimal selection of garment sizes for online shopping based on Analytic Hierarchy Process (AHP). The hierarchical structure model for optimal selection of garment sizes is structured and the fittest garment for a buyer is found by calculating the matching degrees between individual's measurements and the corresponding key-part values of ready-to-wear clothing sizes. In order to demonstrate its feasibility, we provide an example of selecting the fittest sizes of men's bottom. The result shows that the proposed method is useful in online clothing sales application. 展开更多
关键词 optimal selection of garment sizes analytichierarchy process apparel online shopping
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Optimal Selection Model of Equipment Design Scheme Based on Set Pair Analysis
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作者 赵劲松 康建设 +1 位作者 张春润 贺宇 《Journal of Donghua University(English Edition)》 EI CAS 2015年第6期982-985,共4页
Selecting the optimal one from similar schemes is a paramount work in equipment design.In consideration of similarity of schemes and repetition of characteristic indices,the theory of set pair analysis(SPA)is proposed... Selecting the optimal one from similar schemes is a paramount work in equipment design.In consideration of similarity of schemes and repetition of characteristic indices,the theory of set pair analysis(SPA)is proposed,and then an optimal selection model is established.In order to improve the accuracy and flexibility,the model is modified by the contribution degree.At last,this model has been validated by an example,and the result demonstrates the method is feasible and valuable for practical usage. 展开更多
关键词 set pair analysis(SPA) equipment design scheme optimal selection model nearness degree
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Digital twin-driven green material optimal selection and evolution in product iterative design
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作者 Feng Xiang Ya-Dong Zhou +3 位作者 Zhi Zhang Xiao-Fu Zou Fei Tao Ying Zuo 《Advances in Manufacturing》 SCIE EI CAS CSCD 2023年第4期647-662,共16页
In recent years,green concepts have been integrated into the product iterative design in the manufacturing field to address global competition and sustainability issues.However,previous efforts for green material opti... In recent years,green concepts have been integrated into the product iterative design in the manufacturing field to address global competition and sustainability issues.However,previous efforts for green material optimal selection disregarded the interaction and fusion among physical entities,virtual models,and users,resulting in distortions and inaccuracies among user,physical entity,and virtual model such as inconsistency among the expected value,predicted simulation value,and actual performance value of evaluation indices.Therefore,this study proposes a digital twin-driven green material optimal selection and evolution method for product iterative design.Firstly,a novel framework is proposed.Subsequently,an analysis is carried out from six perspectives:the digital twin model construction for green material optimal selection,evolution mechanism of the digital twin model,multi-objective prediction and optimization,algorithm design,decision-making,and product function verification.Finally,taking the material selection of a shared bicycle frame as an example,the proposed method was verified by the prediction and iterative optimization of the carbon emission index. 展开更多
关键词 Product iterative design Digital twin(DT) Green material optimal selection Evolution mechanism Iterative optimization
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Sensitivity of solar greenhouse envelopes to the thermal disfigurements and optimal selection of the thermal insulation quilt 被引量:1
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作者 Yachen Sun Yao Zhang +7 位作者 Chenmeng Zhu Shaonan Xu Bowen Liu Yanfei Cao Changji Zhou Yaqi Zhou Zhirong Zou Encai Bao 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2021年第5期50-55,共6页
The objectives of the present work are focused on exploration of the reasons for temperature difference in different envelopes,the sensitivity of envelopes of solar greenhouse to thermal disfigurements and optimal sel... The objectives of the present work are focused on exploration of the reasons for temperature difference in different envelopes,the sensitivity of envelopes of solar greenhouse to thermal disfigurements and optimal selection of the thermal insulation quilt.Theoretical analysis and derivation are conducted according to the experimental results of surface temperature,convective heat transfer,and heat flux density in different envelopes which with thermal disfigurements of solar greenhouse using heat transfer theory.The results revealed that the difference of intrinsic thermal conductivity and thickness of the envelopes leads to difference in the thermal flux and thus in the surface temperature of different envelopes.Compared with the front roof and back roof,the wall is more sensitive to thermal disfigurements.According to the influence of thermal disfigurements on solar greenhouse temperature,the allowable thermal disfigurements area fraction of front roof and back roof are given.Based on the analysis of heat transfer theory and test results,the work given the expression of the thickness and thermal conductivity of thermal insulation quilt under different outdoor minimum temperatures for optimal selection of thermal insulation quilt based on comprehensive considering factors of the solar greenhouse structure,crop demand,outdoor minimum temperature,and insulation quilt properties.The results of this work give technical criterion for whether the envelopes with thermal disfigurements needs to be repaired or replaced,and it also provides theoretical and technical support for design the solar greenhouse as well as methodological guidance for the optimal selection of the thermal insulation quilt. 展开更多
关键词 solar greenhouse thermal disfigurements optimal selection thermal insulation quilt
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Cooperative Channel and Optimized Route Selection in Adhoc Network 被引量:1
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作者 D.Manohari M.S.Kavitha +1 位作者 K.Periyakaruppan B.Chellapraba 《Intelligent Automation & Soft Computing》 SCIE 2023年第5期1547-1560,共14页
Over the last decade,mobile Adhoc networks have expanded dramati-cally in popularity,and their impact on the communication sector on a variety of levels is enormous.Its uses have expanded in lockstep with its growth.D... Over the last decade,mobile Adhoc networks have expanded dramati-cally in popularity,and their impact on the communication sector on a variety of levels is enormous.Its uses have expanded in lockstep with its growth.Due to its instability in usage and the fact that numerous nodes communicate data concur-rently,adequate channel and forwarder selection is essential.In this proposed design for a Cognitive Radio Cognitive Network(CRCN),we gain the confidence of each forwarding node by contacting one-hop and second level nodes,obtaining reports from them,and selecting the forwarder appropriately with the use of an optimization technique.At that point,we concentrate our efforts on their channel,selection,and lastly,the transmission of data packets via the designated forwarder.The simulation work is validated in this section using the MATLAB program.Additionally,steps show how the node acts as a confident forwarder and shares the channel in a compatible method to communicate,allowing for more packet bits to be transmitted by conveniently picking the channel between them.We cal-culate the confidence of the node at the start of the network by combining the reliability report for thefirst hop and the reliability report for the secondary hop.We then refer to the same node as the confident node in order to operate as a forwarder.As a result,we witness an increase in the leftover energy in the output.The percentage of data packets delivered has also increased. 展开更多
关键词 Adhoc Network confident FORWARDER one-hop optimized route selection secondary report channel selection
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Optimal Route Selection Method Based on Vague Sets
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作者 郭瑞 杜利敏 王淳 《Chinese Quarterly Journal of Mathematics》 2015年第1期130-136,共7页
Optimal route selection is an important function of vehicle trac flow guidance system. Its core is to determine the index weight for measuring the route merits and to determine the evaluation method for selecting rout... Optimal route selection is an important function of vehicle trac flow guidance system. Its core is to determine the index weight for measuring the route merits and to determine the evaluation method for selecting route. In this paper, subjective weighting method which relies on driver preference is used to determine the weight and the paper proposes the multi-criteria weighted decision method based on vague sets for selecting the optimal route. Examples show that, the usage of vague sets to describe route index value can provide more decision-making information for route selection. 展开更多
关键词 trafflc guidance optimal route selection vague sets multi-criteria fuzzy decision-making
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A Novel Hybrid Optimization Algorithm for Materialized View Selection from Data Warehouse Environments
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作者 Popuri Srinivasarao Aravapalli Rama Satish 《Computer Systems Science & Engineering》 SCIE EI 2023年第11期1527-1547,共21页
Responding to complex analytical queries in the data warehouse(DW)is one of the most challenging tasks that require prompt attention.The problem of materialized view(MV)selection relies on selecting the most optimal v... Responding to complex analytical queries in the data warehouse(DW)is one of the most challenging tasks that require prompt attention.The problem of materialized view(MV)selection relies on selecting the most optimal views that can respond to more queries simultaneously.This work introduces a combined approach in which the constraint handling process is combined with metaheuristics to select the most optimal subset of DW views from DWs.The proposed work initially refines the solution to enable a feasible selection of views using the ensemble constraint handling technique(ECHT).The constraints such as self-adaptive penalty,epsilon(ε)-parameter and stochastic ranking(SR)are considered for constraint handling.These two constraints helped the proposed model select the finest views that minimize the objective function.Further,a novel and effective combination of Ebola and coot optimization algorithms named hybrid Ebola with coot optimization(CHECO)is introduced to choose the optimal MVs.Ebola and Coot have recently introduced metaheuristics that identify the global optimal set of views from the given population.By combining these two algorithms,the proposed framework resulted in a highly optimized set of views with minimized costs.Several cost functions are described to enable the algorithm to choose the finest solution from the problem space.Finally,extensive evaluations are conducted to prove the performance of the proposed approach compared to existing algorithms.The proposed framework resulted in a view maintenance cost of 6,329,354,613,784,query processing cost of 3,522,857,483,566 and execution time of 226 s when analyzed using the TPC-H benchmark dataset. 展开更多
关键词 MATERIALIZATION ensemble approach stochastic ranking optimization optimal view selection
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Towards complex scenes: A deep learning-based camouflaged people detection method for snapshot multispectral images
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作者 Shu Wang Dawei Zeng +3 位作者 Yixuan Xu Gonghan Yang Feng Huang Liqiong Chen 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第4期269-281,共13页
Camouflaged people are extremely expert in actively concealing themselves by effectively utilizing cover and the surrounding environment. Despite advancements in optical detection capabilities through imaging systems,... Camouflaged people are extremely expert in actively concealing themselves by effectively utilizing cover and the surrounding environment. Despite advancements in optical detection capabilities through imaging systems, including spectral, polarization, and infrared technologies, there is still a lack of effective real-time method for accurately detecting small-size and high-efficient camouflaged people in complex real-world scenes. Here, this study proposes a snapshot multispectral image-based camouflaged detection model, multispectral YOLO(MS-YOLO), which utilizes the SPD-Conv and Sim AM modules to effectively represent targets and suppress background interference by exploiting the spatial-spectral target information. Besides, the study constructs the first real-shot multispectral camouflaged people dataset(MSCPD), which encompasses diverse scenes, target scales, and attitudes. To minimize information redundancy, MS-YOLO selects an optimal subset of 12 bands with strong feature representation and minimal inter-band correlation as input. Through experiments on the MSCPD, MS-YOLO achieves a mean Average Precision of 94.31% and real-time detection at 65 frames per second, which confirms the effectiveness and efficiency of our method in detecting camouflaged people in various typical desert and forest scenes. Our approach offers valuable support to improve the perception capabilities of unmanned aerial vehicles in detecting enemy forces and rescuing personnel in battlefield. 展开更多
关键词 Camouflaged people detection Snapshot multispectral imaging optimal band selection MS-YOLO Complex remote sensing scenes
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Dynamic services selection algorithm in Web services composition supporting cross-enterprises collaboration 被引量:7
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作者 胡春华 陈晓红 梁昔明 《Journal of Central South University》 SCIE EI CAS 2009年第2期269-274,共6页
Based on the deficiency of time convergence and variability of Web services selection for services composition supporting cross-enterprises collaboration,an algorithm QCDSS(QoS constraints of dynamic Web services sele... Based on the deficiency of time convergence and variability of Web services selection for services composition supporting cross-enterprises collaboration,an algorithm QCDSS(QoS constraints of dynamic Web services selection)to resolve dynamic Web services selection with QoS global optimal path,was proposed.The essence of the algorithm was that the problem of dynamic Web services selection with QoS global optimal path was transformed into a multi-objective services composition optimization problem with QoS constraints.The operations of the cross and mutation in genetic algorithm were brought into PSOA(particle swarm optimization algorithm),forming an improved algorithm(IPSOA)to solve the QoS global optimal problem.Theoretical analysis and experimental results indicate that the algorithm can better satisfy the time convergence requirement for Web services composition supporting cross-enterprises collaboration than the traditional algorithms. 展开更多
关键词 Web services composition optimal service selection improved particle swarm optimization algorithm (IPSOA) cross-enterprises collaboration
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Test selection and optimization for PHM based on failure evolution mechanism model 被引量:8
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作者 Jing Qiu Xiaodong Tan +1 位作者 Guanjun Liu Kehong L 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2013年第5期780-792,共13页
The test selection and optimization (TSO) can improve the abilities of fault diagnosis, prognosis and health-state evalua- tion for prognostics and health management (PHM) systems. Traditionally, TSO mainly focuse... The test selection and optimization (TSO) can improve the abilities of fault diagnosis, prognosis and health-state evalua- tion for prognostics and health management (PHM) systems. Traditionally, TSO mainly focuses on fault detection and isolation, but they cannot provide an effective guide for the design for testability (DFT) to improve the PHM performance level. To solve the problem, a model of TSO for PHM systems is proposed. Firstly, through integrating the characteristics of fault severity and propa- gation time, and analyzing the test timing and sensitivity, a testability model based on failure evolution mechanism model (FEMM) for PHM systems is built up. This model describes the fault evolution- test dependency using the fault-symptom parameter matrix and symptom parameter-test matrix. Secondly, a novel method of in- herent testability analysis for PHM systems is developed based on the above information. Having completed the analysis, a TSO model, whose objective is to maximize fault trackability and mini- mize the test cost, is proposed through inherent testability analysis results, and an adaptive simulated annealing genetic algorithm (ASAGA) is introduced to solve the TSO problem. Finally, a case of a centrifugal pump system is used to verify the feasibility and effectiveness of the proposed models and methods. The results show that the proposed technology is important for PHM systems to select and optimize the test set in order to improve their performance level. 展开更多
关键词 test selection and optimization (TSO) prognostics and health management (PHM) failure evolution mechanism model (FEMM) adaptive simulated annealing genetic algorithm (ASAGA).
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An optimizing selection model in preparation of powdery emulsion explosives 被引量:2
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作者 BaofuDuan XuguangWang JinquanSong 《Journal of University of Science and Technology Beijing》 CSCD 2004年第1期1-4,共4页
In order to get cheap and excellent PEE (Powdery Emulsion Explosives), themodel of optimizing selection on preparation of PEE was established by the Neural Net Theory (NNT).On the basis of some data in the study of PE... In order to get cheap and excellent PEE (Powdery Emulsion Explosives), themodel of optimizing selection on preparation of PEE was established by the Neural Net Theory (NNT).On the basis of some data in the study of PEE, the training, prediction and optimizing selection ofthe Neural Net (NN) model were finished by compiling procedures. The results indicate that the modelis helpful to the preparation of PEE and worthy to extend and apply broadly. 展开更多
关键词 neural net powdery emulsion explosives PREPARATION optimizing selection
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Directional Filter for SAR Images Based on Nonsubsampled Contourlet Transform and Immune Clonal Selection 被引量:3
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作者 Xiao-Hui Yang Li-Cheng Jiao Deng-Feng Li 《International Journal of Automation and computing》 EI 2009年第3期245-253,共9页
A directional filter algorithm for intensity synthetic aperture radar (SAR) image based on nonsubsampled contourlet transform (NSCT) and immune clonal selection (ICS) is presented. The proposed filter mainly foc... A directional filter algorithm for intensity synthetic aperture radar (SAR) image based on nonsubsampled contourlet transform (NSCT) and immune clonal selection (ICS) is presented. The proposed filter mainly focuses on exploiting different features of edges and noises by NSCT. Furthermore, ICS strategy is introduced to optimize threshold parameter and amplify parameter adaptively. Numerical experiments on real SAR images show that there are improvements in both visual effects and objective indexes. 展开更多
关键词 Directional filter nonsubsampled contourlet transform (NSCT) immune clonal selection optimization (ICSO) syntheticaperture radar (SAR).
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Multi-Source Adaptive Selection and Fusion for Pedestrian Dead Reckoning 被引量:1
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作者 Yuanxun Zheng Qinghua Li +2 位作者 Changhong Wang Xiaoguang Wang Lifeng Hu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2022年第12期2174-2185,共12页
Accurate multi-source fusion is based on the reliability, quantity, and fusion mode of the sources. The problem of selecting the optimal set for participating in the fusion process is nondeterministic-polynomial-time-... Accurate multi-source fusion is based on the reliability, quantity, and fusion mode of the sources. The problem of selecting the optimal set for participating in the fusion process is nondeterministic-polynomial-time-hard and is neither sub-modular nor super-modular. Furthermore, in the case of the Kalman filter(KF) fusion algorithm, accurate statistical characteristics of noise are difficult to obtain, and this leads to an unsatisfactory fusion result. To settle the referred cases, a distributed and adaptive weighted fusion algorithm based on KF has been proposed in this paper. In this method, on the basis of the pseudo prior probability of the estimated state of each source, the reliability of the sources is evaluated and the optimal set is selected on a certain threshold. Experiments were performed on multi-source pedestrian dead reckoning for verifying the proposed algorithm. The results obtained from these experiments indicate that the optimal set can be selected accurately with minimal computation, and the fusion error is reduced by 16.6% as compared to the corresponding value resulting from the algorithm without improvements.The proposed adaptive source reliability and fusion weight evaluation is effective against the varied-noise multi-source fusion system, and the fusion error caused by inaccurate statistical characteristics of the noise is reduced by the adaptive weight evaluation.The proposed algorithm exhibits good robustness, adaptability,and value on applications. 展开更多
关键词 Adaptive reliability evaluation adaptive weight evaluation Kalman filter(KF) multi-source fusion optimal set selection
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Strategy Selection for Moving Target Defense in Incomplete Information Game 被引量:1
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作者 Huan Zhang Kangfeng Zheng +2 位作者 Xiujuan Wang Shoushan Luo Bin Wu 《Computers, Materials & Continua》 SCIE EI 2020年第2期763-786,共24页
As a core component of the network,web applications have become one of the preferred targets for attackers because the static configuration of web applications simplifies the exploitation of vulnerabilities by attacke... As a core component of the network,web applications have become one of the preferred targets for attackers because the static configuration of web applications simplifies the exploitation of vulnerabilities by attackers.Although the moving target defense(MTD)has been proposed to increase the attack difficulty for the attackers,there is no solo approach can cope with different attacks;in addition,it is impossible to implement all these approaches simultaneously due to the resource limitation.Thus,the selection of an optimal defense strategy based on MTD has become the focus of research.In general,the confrontation of two players in the security domain is viewed as a stochastic game,and the reward matrices are known to both players.However,in a real security confrontation,this scenario represents an incomplete information game.Each player can only observe the actions performed by the opponent,and the observed actions are not completely accurate.To accurately describe the attacker’s reward function to reach the Nash equilibrium,this work simulated and updated the strategy selection distribution of the attacker by observing and investigating the strategy selection history of the attacker.Next,the possible rewards of the attacker in each confrontation via the observation matrix were corrected.On this basis,the Nash-Q learning algorithm with reward quantification was proposed to select the optimal strategy.Moreover,the performances of the Minimax-Q learning algorithm and Naive-Q learning algorithm were compared and analyzed in the MTD environment.Finally,the experimental results showed that the strategy selection algorithm can enable defenders to select a more reasonable defensive strategy and achieve the maximum possible reward. 展开更多
关键词 Moving target defense Nash-Q learning algorithm optimal strategy selection incomplete information game web service
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Using Extension Theory and Fuzzy Analytic Hierarchy Process on Heterogeneous Wireless Network Selection Algorithm 被引量:1
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作者 张裕 郑正奇 陈丽娜 《Journal of Donghua University(English Edition)》 EI CAS 2012年第5期417-422,共6页
In order to solve the problem that determining decision factors weights is of subjectivity in heterogeneous wireless network selection algorithm, a network selection algorithm based on extension theory and fuzzy analy... In order to solve the problem that determining decision factors weights is of subjectivity in heterogeneous wireless network selection algorithm, a network selection algorithm based on extension theory and fuzzy analytic hierarchy process (FAHP) is proposed in this paper. In addition, user and operator codetermine the optimal network using the proposed algorithm, which can give consideration to user and operator benefits. The fuzzy judgment matrix is coustructed by membership degree of decision factors which is calculated according to extension theory. The comprehensive weight of each decision factor is obtained using FAHP. Finally, the optimal network is selected through total property value ranldng of each candidate network under user preference and operator preference. The simulation results show that the proposed algorithm can select the optimal network efficiently and accurately, satisfy user preference, and implement load balance between networks. 展开更多
关键词 heterogeneous wireless network optimal network selection extension theory fuzzy analytic hierarchy process (FAHP) load balancing
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Optimal ship imaging for shore-based ISAR using DCF estimation 被引量:1
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作者 Ling Wang Zhenxiao Cao +2 位作者 Ning Li Teng Jing Daiyin Zhu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第4期739-745,共7页
The optimal imaging time selection of ship targets for shore-based inverse synthetic aperture radar (ISAR) in high sea conditions is investigated. The optimal imaging time includes opti- mal imaging instants and opt... The optimal imaging time selection of ship targets for shore-based inverse synthetic aperture radar (ISAR) in high sea conditions is investigated. The optimal imaging time includes opti- mal imaging instants and optimal imaging duration. A novel method for optimal imaging instants selection based on the estimation of the Doppler centroid frequencies (DCFs) of a series of images obtained over continuous short durations is proposed. Combined with the optimal imaging duration selection scheme using the image contrast maximization criteria, this method can provide the ship images with the highest focus. Simulated and real data pro- cessing results verify the effectiveness of the proposed imaging method. 展开更多
关键词 inverse synthetic aperture radar (ISAR) ship target optimal imaging time selection Doppler centroid frequency (DCF).
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Efficient Virtual Network Embedding Algorithm Based on Restrictive Selection and Optimization Theory Approach 被引量:2
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作者 Haotong Cao Zhicheng Qu +1 位作者 Yishi Xue Longxiang Yang 《China Communications》 SCIE CSCD 2017年第10期39-60,共22页
Network virtualization(NV) is widely considered as a key component of the future network and promises to allow multiple virtual networks(VNs) with different protocols to coexist on a shared substrate network(SN). One ... Network virtualization(NV) is widely considered as a key component of the future network and promises to allow multiple virtual networks(VNs) with different protocols to coexist on a shared substrate network(SN). One main challenge in NV is virtual network embedding(VNE). VNE is a NPhard problem. Previous VNE algorithms in the literature are mostly heuristic, while the remaining algorithms are exact. Heuristic algorithms aim to find a feasible embedding of each VN, not optimal or sub-optimal, in polynomial time. Though presenting the optimal or sub-optimal embedding per VN, exact algorithms are too time-consuming in smallscaled networks, not to mention moderately sized networks. To make a trade-off between the heuristic and the exact, this paper presents an effective algorithm, labeled as VNE-RSOT(Restrictive Selection and Optimization Theory), to solve the VNE problem. The VNERSOT can embed virtual nodes and links per VN simultaneously. The restrictive selection contributes to selecting candidate substrate nodes and paths and largely cuts down on the number of integer variables, used in the following optimization theory approach. The VNE-RSOT fights to minimize substrate resource consumption and accommodates more VNs. To highlight the efficiency of VNERSOT, a simulation against typical and stateof-art heuristic algorithms and a pure exact algorithm is made. Numerical results reveal that virtual network request(VNR) acceptance ratio of VNE-RSOT is, at least, 10% higher than the best-behaved heuristic. Other metrics, such as the execution time, are also plotted to emphasize and highlight the efficiency of VNE-RSOT. 展开更多
关键词 network virtualization virtual network embedding NP-hard heuristic exact restrictive selection optimization theory
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Tool selection and collision-free in 5-axis numerical control machining of free-form surfaces
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作者 杨长祺 QIN +1 位作者 Datong 《Journal of Chongqing University》 CAS 2002年第2期20-23,共4页
The methodology of 5-axis cutter selection to avert collision for free-form surface machining by flat-end cutters is presented. The combination of different cutters is adopt aiming at short machining time and high pre... The methodology of 5-axis cutter selection to avert collision for free-form surface machining by flat-end cutters is presented. The combination of different cutters is adopt aiming at short machining time and high precision. The optimal small cutter is determined based on the geometric information of the points where a cutter most probably collide with the machined surface. Several larger cutters are selected to machine the surface in order to find the interference-free area. The difference of machining time for this area between the optimal small cutter and the large cutters is calculated. The functional relationship between the machining time and the radius of a cutter is established, by which the optimal number of cutters is obtained. The combination of cutters, which possesses the minimum overall machining time, is selected as the optimal cutter sizes. A case study has demonstrated the validity of the proposed methodology and algorithms. 展开更多
关键词 optimal tool selection collision-free tool path generation free-form surfaces flat-end cutter
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Optimizing selection of bridge raft based on fuzzy matter-element model and combination weighting
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作者 Li Feng Shao Fei +1 位作者 Wang Jianping Li Zhigang 《Engineering Sciences》 EI 2012年第1期61-64,96,共5页
It' s a necessary selection to support the maneuver across Yangtze River by floating bridge constructed by portable steel bridge and civilian ships. It is a comprehensive index for the scheme of bridge raft, containi... It' s a necessary selection to support the maneuver across Yangtze River by floating bridge constructed by portable steel bridge and civilian ships. It is a comprehensive index for the scheme of bridge raft, containing a variety of technical factors and uncertainties. The optimization is the selection in the constructing time, quantity of equipments and man power. Based on the calculation result of bridge rafts, an evaluating system is established, consisting of index of spacing between interior bays, raft length, truss numbers, operation difficulty and maximal bending stress. A fuzzy matter element model of optimizing selection of bridge rafts was built up by combining quantitative analysis with qualitative analysis. The method of combination weighting was used to calculate the value of weights index to reduce the subjective randomness. The sequence of schemes and the optimization resuh were gained finally based on euclid approach degree. The application result shows that it is simple and practical. 展开更多
关键词 bridge raft optimizing selection fuzzy matter-element combination weighting euclid approach degree
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