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Local Hybrid Linear State Estimation for Electric Power Systems Using Stream Processing
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作者 Kang Sun Manyun Huang +2 位作者 Zhinong Wei Yuzhang Lin Guoqiang Sun 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2024年第3期1259-1268,共10页
The increasing penetration of renewable energy resources with highly fluctuating outputs has placed increasing concern on the accuracy and timeliness of electric power system state estimation(SE).Meanwhile,we note tha... The increasing penetration of renewable energy resources with highly fluctuating outputs has placed increasing concern on the accuracy and timeliness of electric power system state estimation(SE).Meanwhile,we note that only a fraction of system states fluctuate at the millisecond level and require to be updated.As such,refreshing only those states with significant variation would enhance the computational efficiency of SE and make fast-continuous update of states possible.However,this is difficult to achieve with conventional SE methods,which generally refresh states of the entire system every 4–5 s.In this context,we propose a local hybrid linear SE framework using stream processing,in which synchronized measurements received from phasor measurement units(PMUs),and trigger/timingmode measurements received from remote terminal units(RTUs)are used to update the associated local states.Moreover,the measurement update process efficiency and timeliness are enhanced by proposing a trigger measurement-based fast dynamic partitioning algorithm for determining the areas of the system with states requiring recalculation.In particular,non-iterative hybrid linear formulations with both RTUs and PMUs are employed to solve the local SE problem.The timeliness,accuracy,and computational efficiency of the proposed method are demonstrated by extensive simulations based on IEEE 118-,300-,and 2383-bus systems. 展开更多
关键词 Fast dynamic partitioning local hybrid linear state estimation phasor measurement units stream processing TIMELINESS trigger/timing-mode measurements
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RSSI-Based 3D Wireless Sensor Node Localization Using Hybrid T Cell Immune and Lotus Optimization
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作者 Weiwei Hu Kiran Sree Pokkuluri +3 位作者 Rajesh Arunachalam Bander A.Jabr Yasser A.Ali Preethi Palanisamy 《Computers, Materials & Continua》 SCIE EI 2024年第12期4833-4851,共19页
Wireless Sensor Network(WSNs)consists of a group of nodes that analyze the information from surrounding regions.The sensor nodes are responsible for accumulating and exchanging information.Generally,node local-ization... Wireless Sensor Network(WSNs)consists of a group of nodes that analyze the information from surrounding regions.The sensor nodes are responsible for accumulating and exchanging information.Generally,node local-ization is the process of identifying the target node’s location.In this research work,a Received Signal Strength Indicator(RSSI)-based optimal node localization approach is proposed to solve the complexities in the conventional node localization models.Initially,the RSSI value is identified using the Deep Neural Network(DNN).The RSSI is conceded as the range-based method and it does not require special hardware for the node localization process,also it consumes a very minimal amount of cost for localizing the nodes in 3D WSN.The position of the anchor nodes is fixed for detecting the location of the target.Further,the optimal position of the target node is identified using Hybrid T cell Immune with Lotus Effect Optimization algorithm(HTCI-LEO).During the node localization process,the average localization error is minimized,which is the objective of the optimal node localization.In the regular and irregular surfaces,this hybrid algorithm effectively performs the localization process.The suggested hybrid algorithm converges very fast in the three-dimensional(3D)environment.The accuracy of the proposed node localization process is 94.25%. 展开更多
关键词 Sensor node localization received signal strength indicator 3D wireless sensor network deep neural network average localization error and hybrid T cell immune with lotus effect optimization algorithm
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Robust TDOA/FDOA estimation from emitter signals for hybrid localization using UAVs 被引量:3
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作者 Yu-bing Wang Xiao-long Liang +2 位作者 Jia-qiang Zhang Bao-xiang Ren Ke Jin 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2022年第1期81-93,共13页
This paper considers the time difference of arrival(TDOA)and frequency difference of arrival(FDOA)estimation problem for joint localization using unmanned aerial vehicles(UAVs),involving range migration(RM)and Doppler... This paper considers the time difference of arrival(TDOA)and frequency difference of arrival(FDOA)estimation problem for joint localization using unmanned aerial vehicles(UAVs),involving range migration(RM)and Doppler ambiguity within observation interval.A robust estimation method based on interpolation and resampling is proposed.Specifically,the interpolation artificially increases the pulse repetition frequency(PRF).After that,the resampling eliminates the coupling between range frequency and slow time.Finally,a coherent integration step based on inverse discrete Fourier transform(IDFT)is used to achieve parameter estimation and suppress the grating lobes caused by interpolation.The proposed method could be efficiently implemented by fast Fourier transform(FFT),inverse FFT(IFFT)and non-uniform FFT(NUFFT)without parameter searching procedures.Numerical experiments indicate that the proposed method has nearly optimal anti-noise performance but much lower computational complexity than the maximum likelihood estimator,which makes it more competitive in practical applications. 展开更多
关键词 TDOA FDOA Parameter estimation Doppler ambiguity hybrid localization
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Bi-level hybrid local search approach for three-dimensional loading problem with balancing constraints 被引量:3
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作者 ZHU Xiang LEI Ding-you 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第4期903-918,共16页
This paper presents a bi-level hybrid local search(BHLS)algorithm for the three-dimensional loading problem with balancing constraints(3DLP-B),where several rectangular boxes with even densities but different sizes ar... This paper presents a bi-level hybrid local search(BHLS)algorithm for the three-dimensional loading problem with balancing constraints(3DLP-B),where several rectangular boxes with even densities but different sizes are loaded into a single cubic bin to meet the requirements of the space or capacity utilization and the balance of the center of gravity.The proposed algorithm hybridizes a novel framed-layout procedure in which the concept of the core block and its generation strategy are introduced.Once the block-loading sequence has been determined,we can load one block at a time by the designed construction heuristic.Then,the double-search is introduced;its external search procedure generates a list of compact packing patterns while its internal search procedure is used to search the core-block frames and their best distribution locations.The approach is extensively tested on weakly to strongly heterogeneous benchmark data.The results show that it has better performance in improving space utilization rate and balanced condition of the placement than existed techniques:the overall averages from 79.85%to 86.45%were obtained for the balanced cases and relatively high space-usage rate of 89.44%was achieved for the unbalanced ones. 展开更多
关键词 3D loading balancing constraints framed layout bi-level hybrid local search core block
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Heterosis in locally adapted sorghum genotypes and potential of hybrids for increased productivity in contrasting environments in Ethiopia 被引量:3
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作者 Taye T.Mindaye Emma S.Mace +1 位作者 Ian D.Godwin David R.Jordan 《The Crop Journal》 SCIE CAS CSCD 2016年第6期479-489,共11页
Increased productivity in sorghum has been achieved in the developed world using hybrids.Despite their yield advantage,introduced hybrids have not been adopted in Ethiopia due to the lack of adaptive traits,their shor... Increased productivity in sorghum has been achieved in the developed world using hybrids.Despite their yield advantage,introduced hybrids have not been adopted in Ethiopia due to the lack of adaptive traits,their short plant stature and small grain size.This study was conducted to investigate hybrid performance and the magnitude of heterosis of locally adapted genotypes in addition to introduced hybrids in three contrasting environments in Ethiopia.In total,139 hybrids,derived from introduced seed parents crossed with locally adapted genotypes and introduced R lines,were evaluated.Overall,the hybrids matured earlier than the adapted parents,but had higher grain yield,plant height,grain number and grain weight in all environments.The lowland adapted hybrids displayed a mean better parent heterosis(BPH) of19%,equating to 1160 kg ha-1and a 29% mean increase in grain yield,in addition to increased plant height and grain weight,in comparison to the hybrids derived from the introduced R lines.The mean BPH for grain yield for the highland adapted hybrids was 16% in the highland and 52%in the intermediate environment equating to 698 kg ha-1and 2031 kg ha-1,respectively,in addition to increased grain weight.The magnitude of heterosis observed for each hybrid group was related to the genetic distance between the parental lines.The majority of hybrids also showed superiority over the standard check varieties.In general,hybrids from locally adapted genotypes were superior in grain yield,plant height and grain weight compared to the high parents and introduced hybrids indicating the potential for hybrids to increase productivity while addressing farmers' required traits. 展开更多
关键词 Farmers preferred traits High parent heterosis locally adapted genotypes Sorghum hybrids
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Research of Rhine Goose and Heilongjiang Local Goose Hybrid Result
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作者 LIU Guo-jun 《Animal Husbandry and Feed Science》 CAS 2013年第3期115-116,124,共3页
[Objective]The aim is to improve the local goose in Heilongjiang Province( Zi goose,Huo goose,Heilongjiang white sticky goose) growth rate and production performance,increase the goose economic benefits and change t... [Objective]The aim is to improve the local goose in Heilongjiang Province( Zi goose,Huo goose,Heilongjiang white sticky goose) growth rate and production performance,increase the goose economic benefits and change the resource advantage of local into commercial and economic advantages. [Methods]Rhine goose of large size,fast growth,high wool and cashmere was introduced on hybrid improvement. [Results] Improved goose 60 days of age weight was 3. 240 kg,1. 40 kg higher than that of local goose weight; Improved adult male goose weight were 4. 661 kg,female goose 4. 150 kg,0. 50 kg or 0. 80 kg higher than the local goose weight respectively; Improved goose fleece production was 110. 03 g,fleece rate 29. 17%,33. 15 g higher than the local goose prolific wool,fleece rate increased by 12. 71%. [Conclusion] Effect of using Rhine goose to improve Heilongjiang local goose obvious and economic benefit is improved. 展开更多
关键词 Rhine goos Heilongjiang local goose hybridization
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Local Search Algorithm with Hybrid Neighborhood and Its Application to Job Shop Scheduling Problem
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作者 黄文奇 曾立平 《Journal of Southwest Jiaotong University(English Edition)》 2004年第2期95-100,共6页
A new local search method with hybrid neighborhood for Job shop scheduling problem is developed. The proposed hybrid neighborhood is not only efficient in local search, but also can help overcome entrapments while sea... A new local search method with hybrid neighborhood for Job shop scheduling problem is developed. The proposed hybrid neighborhood is not only efficient in local search, but also can help overcome entrapments while search procedure get trapped at local optima and carry the search to areas of the feasible set with better prospect. New strategies used for breaking out of entrapments are presented and they are helpful for the procedure to improve local optima. A performance comparison of the proposed method with some best-performing algorithms on all 10-job, 10-machine benchmark problems and the other two problems generated by Fisher and Thompson (ie., FT6 and FT20)is made. The experiment results show the better optimal performance of the proposed algorithm. 展开更多
关键词 Job shop scheduling local search hybrid neighborhood Off-trap strategy
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GRAPES Hybrid-3DVar对台风苏迪罗的数值试验 被引量:4
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作者 庄照荣 李兴良 +1 位作者 陈静 孙健 《大气科学》 CSCD 北大核心 2020年第5期1076-1092,共17页
为了把反映天气形势变化的背景误差协方差引入到变分分析系统中来提高分析质量,本文在GRAPES区域三维变分框架的基础上通过扩展控制变量方法实现动态与静态背景误差协方差耦合,建立混合三维变分分析系统(GRAPES Hybrid-3DVar)。通过控... 为了把反映天气形势变化的背景误差协方差引入到变分分析系统中来提高分析质量,本文在GRAPES区域三维变分框架的基础上通过扩展控制变量方法实现动态与静态背景误差协方差耦合,建立混合三维变分分析系统(GRAPES Hybrid-3DVar)。通过控制变量扰动产生的集合样本进行单点观测分析试验验证Hybrid-3DVar及其局地化方案的合理性,并针对台风苏迪罗进行实际观测资料同化和数值预报试验,结果表明:用集合样本描述的背景误差协方差是随着天气流型变化的,动力场和质量场的离散度在台风中心处最大,因而混合同化的分析增量包含更多细微结构和中小尺度信息;其分析和24 h内预报要素质量优于3DVar,24 h内降水强度和落区预报也更准确,混合同化分析改善了3DVar分析的降水空报问题;同时混合同化分析的24 h内台风路径预报也最接近实况,台风强度预报在48 h之内都比3DVar更接近观测。 展开更多
关键词 hybrid-3DVar 3DVAR GRAPES 局地化 台风苏迪罗
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Solving Travelling Salesman Problem with an Improved Hybrid Genetic Algorithm 被引量:4
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作者 Bao Lin Xiaoyan Sun Sana Salous 《Journal of Computer and Communications》 2016年第15期98-106,共10页
We present an improved hybrid genetic algorithm to solve the two-dimensional Eucli-dean traveling salesman problem (TSP), in which the crossover operator is enhanced with a local search. The proposed algorithm is expe... We present an improved hybrid genetic algorithm to solve the two-dimensional Eucli-dean traveling salesman problem (TSP), in which the crossover operator is enhanced with a local search. The proposed algorithm is expected to obtain higher quality solutions within a reasonable computational time for TSP by perfectly integrating GA and the local search. The elitist choice strategy, the local search crossover operator and the double-bridge random mutation are highlighted, to enhance the convergence and the possibility of escaping from the local optima. The experimental results illustrate that the novel hybrid genetic algorithm outperforms other genetic algorithms by providing higher accuracy and satisfactory efficiency in real optimization processing. 展开更多
关键词 Genetic Algorithm hybrid local Search TSP
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A nuclear localized protein ZCCHC9 is expressed in cerebral cortex and suppresses the MAPK signal pathway 被引量:1
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作者 Aidong Zhou Jianlin Zhou Liping Yang Mingjun Liu Hong Li Su Xu Mei Han Jian Zhang 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2008年第8期467-472,共6页
The CCHC-type zinc finger motif has numerous biological activities (such as DNA binding and RNA binding) and can also mediate protein-protein interaction. This article gives a primary report about the human ZCCHC9 g... The CCHC-type zinc finger motif has numerous biological activities (such as DNA binding and RNA binding) and can also mediate protein-protein interaction. This article gives a primary report about the human ZCCHC9 gene. Protein ZCCHC9 contains four CCHC motifs and is highly conserved in humans, mice, and rats. The whole eDNA sequence of the ZCCHC9 gene has been amplified by PCR and a number of plasmids have been constructed for further study. The results show that ZCCHC9 is localized in the nucleus, and especially concentrated in the nueleolus. It is highly expressed in the brain and testicles of the mouse. This has been confirmed by real-time reverse transcription polymerase chain reaction (RT-PCR). In situ hybridization of the mouse brain indicates that ZCCHC9 is mainly expressed in the cerebral cortex. Reporter gene assay shows that ZCCHC9 suppresses the transcription activities of NF-kappa B and SRE, and may play roles in the Mitogen-Aetivated Protein Kinase (MAPK) signaling transduetion pathway. 展开更多
关键词 ZCCHC9 gene real-time RT-PCR subcellular localization in situ hybridization NF-kappa B SRE
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A Vision-aided Localization and Geo-registration Method for Urban ARGIS Based on 2D Maps
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作者 Chen DENG Xiong YOU +3 位作者 Weiwei ZHANG Meixia ZHI Diao LIN Wang XU 《Journal of Geodesy and Geoinformation Science》 2022年第3期93-110,共18页
Augmented Reality Geographic Information System(ARGIS) applications can only provide users accurate content services with a highly precise geo-registration.However,the absolute 6DOF(Degree of Freedom) pose provided by... Augmented Reality Geographic Information System(ARGIS) applications can only provide users accurate content services with a highly precise geo-registration.However,the absolute 6DOF(Degree of Freedom) pose provided by the portable sensors is usually inaccurate in urban outdoors,resulting in poorly geo-registration accuracy for ARGIS applications.Aiming at this issue,an automatic vision-aided localization method based on the 2D map is proposed to improve the initial localization accuracy of the portable sensors,and an overall geo-registration optimization framework for outdoor ARGIS is proposed.Based on the initial pose provided by the sensors,the basic principles of the vision-aided localization method are expounded in detail.The experimental results show that the proposed method can effectively correct the initial pose obtained by the pose sensors,and improve the geo-registration accuracy of outdoor ARGIS applications ultimately. 展开更多
关键词 augmented reality ARGIS geo-registration vision-aided localization hybrid localization portable sensors
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A FULLY-HYBRID MAC PROTOCOL IN LANS
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作者 陈家训 朱国进 《Journal of China Textile University(English Edition)》 EI CAS 1993年第1期16-24,共9页
In announced hybrid protocols,there are two mechanisms usually employed.One operates in aCSMA family manner and the other follows a token passing family way.However,only one ofthem works efficiently when traffic is li... In announced hybrid protocols,there are two mechanisms usually employed.One operates in aCSMA family manner and the other follows a token passing family way.However,only one ofthem works efficiently when traffic is light or heavy.This results in an inefficient redundance and aburden to the protocol implementation.In this paper,we present a new hybrid concept and its idealmodel in which risky transmissions alternate with safe transmissions in response to the dynamicchange in traffic.Being similar to virtual time CSMA in the abstract,a single control mechanism isproposed to approach this ideal model.The mechanism is rather compact,and its implementationcan be designed to be simple,efficient,reliable,robust,and fully distributed without any centralizedelement at any instant.Simulation results show that the proposed mechanism performs well overthe entire range of the traffic load from light to heavy. 展开更多
关键词 hybrid local area NETWORKS PROTOCOL MEDIUM ACCESS control
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An Evolutionary Algorithm with Multi-Local Search for the Resource-Constrained Project Scheduling Problem
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作者 Zhi-Jie Chen Chiuh-Cheng Chyu 《Intelligent Information Management》 2010年第3期220-226,共7页
This paper introduces a hybrid evolutionary algorithm for the resource-constrained project scheduling problem (RCPSP). Given an RCPSP instance, the algorithm identifies the problem structure and selects a suitable dec... This paper introduces a hybrid evolutionary algorithm for the resource-constrained project scheduling problem (RCPSP). Given an RCPSP instance, the algorithm identifies the problem structure and selects a suitable decoding scheme. Then a multi-pass biased sampling method followed up by a multi-local search is used to generate a diverse and good quality initial population. The population then evolves through modified order-based recombination and mutation operators to perform exploration for promising solutions within the entire region. Mutation is performed only if the current population has converged or the produced offspring by recombination operator is too similar to one of his parents. Finally the algorithm performs an intensified local search on the best solution found in the evolutionary stage. Computational experiments using standard instances indicate that the proposed algorithm works well in both computational time and solution quality. 展开更多
关键词 RESOURCE-CONSTRAINED Project SCHEDULING EVOLUTIONARY ALGORITHMS local SEARCH hybridIZATION
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Investigation of lower hybrid current drive during H-mode in EAST tokamak
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作者 李妙辉 丁伯江 +10 位作者 孔二华 张磊 张新军 钱金平 颜宁 韩效锋 单家方 刘甫坤 王茂 徐旵东 万宝年 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第12期298-304,共7页
H-mode discharges with lower hybrid current drive (LHCD) alone are achieved in EAST divertor plasma over a wide parameter range. These H-mode discharges are characterized by a sudden drop in Da emission and a sponta... H-mode discharges with lower hybrid current drive (LHCD) alone are achieved in EAST divertor plasma over a wide parameter range. These H-mode discharges are characterized by a sudden drop in Da emission and a spontaneous rise in main plasma density. Good lower hybrid (LH) coupling during H-mode is obtained by putting the plasma close to the antenna and by injecting D2 gas from a pipe near the grill mouse. The analysis of lower hybrid current drive properties shows that the LH deposition profile shifts off axis during H-mode, and current drive (CD) efficiency decreases due to the increase in density. Modeling results of H-mode discharges with a general ray trueing code GENRAY are reported. 展开更多
关键词 H-MODE edge localized mode lower hybrid current drive
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Differential evolution algorithm for hybrid flow-shop scheduling problems 被引量:9
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作者 Ye Xu Ling Wang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第5期794-798,共5页
Aiming at the hybrid flow-shop (HFS) scheduling that is a complex NP-hard combinatorial problem with wide engineering background, an effective algorithm based on differential evolution (DE) is proposed. By using a... Aiming at the hybrid flow-shop (HFS) scheduling that is a complex NP-hard combinatorial problem with wide engineering background, an effective algorithm based on differential evolution (DE) is proposed. By using a special encoding scheme and combining DE based evolutionary search and local search, the exploration and exploitation abilities are enhanced and well balanced for solving the HFS problems. Simulation results based on some typical problems and comparisons with some existing genetic algorithms demonstrate the proposed algorithm is effective, efficient and robust for solving the HFS problems. 展开更多
关键词 hybrid flow-shop (HFS) scheduling differential evolution (DE) local search.
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Application of hybrid operating rooms for treating spinal dural arteriovenous fistula 被引量:8
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作者 Nai Zhang Wen-Qiang Xin 《World Journal of Clinical Cases》 SCIE 2020年第6期1056-1064,共9页
BACKGROUND A hybrid operating room(hybrid-OR)is a surgical space that combines a conventional operating room with advanced medical imaging devices.AIM To explore and summarize the technical features and effectiveness ... BACKGROUND A hybrid operating room(hybrid-OR)is a surgical space that combines a conventional operating room with advanced medical imaging devices.AIM To explore and summarize the technical features and effectiveness of the application of a hybrid-OR in dealing with spinal dural arteriovenous fistulas(SDAVFs).METHODS Eleven patients with SDAVFs were treated with the use of a hybrid-OR at the Department of Neurosurgery of our hospital between January 2015 and December 2018.The dual-marker localization technique was used in the hybrid-OR to locate the SDAVFs and skin incision,and the interoperative digital subtraction angiography(DSA)technique was used before and after microsurgical ligation of the fistulae in the hybrid-OR to verify the accuracy of obliteration.The patients were followed for an average of 2 years after the operation,and the preoperative American Spinal Cord Injury Association(ASIA)score and postoperative ASIA score at 6 mo after the operation were compared.RESULTS The location and skin incision of the SDAVFs were accurately obtained by using the dual-marker localization technique in the hybrid-OR in all patients,and there were no cases that required expansion of the range of the bone window in order to expose the lesions.Intraoperative error obliteration occurred and was identified in two patients by using the intraoperative DSA technique;therefore,the findings provided by the intraoperative DSA system significantly changed the surgical procedure in these two patients.With the assistance of the hybrid-OR,the feeding artery was correctly ligated in all cases,and the intraoperative error obliteration rate decreased from 18.2%(2/11)to 0%.All 11 patients were followed for an average of 2 years.The ASIA score at 6 mo after the operation was significantly improved compared with the preoperative ASIA score,and there were no patients with late recurrence during the follow-up.CONCLUSION Compared with intra-arterial embolization for the treatment of SDAVFs,hybrid-ORs can solve the problem of a higher incidence of initial failure and late recurrence.Compared with direct occlusion of SDAVFs in microsurgery,hybrid-ORs can take advantage of the intraoperative DSA system for locating the shunt and verifying the obliteration of fistulae in order to reduce the error obliteration rate.At this point,our experience suggests that the safety and ease of use make hybrid-ORs combined with microsurgery and intraoperative DSA systems an attractive modality for dealing with SDAVFs. 展开更多
关键词 Spinal DURAL ARTERIOVENOUS FISTULA hybrid operating room Dual-marker localization TECHNIQUE Interoperative DSA TECHNIQUE RETROSPECTIVE study
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Decentralized PD Control for Non-uniform Motion of a Hamiltonian Hybrid System 被引量:1
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作者 Mingcong Deng Hongnian Yu Akira Inoue 《International Journal of Automation and computing》 EI 2008年第2期119-124,共6页
In this paper, a decentralized proportional-derivative (PD) controller design for non-uniform motion of a Hamiltonian hybrid system is considered. A Hamiltonian hybrid system with the capability of producing a non-u... In this paper, a decentralized proportional-derivative (PD) controller design for non-uniform motion of a Hamiltonian hybrid system is considered. A Hamiltonian hybrid system with the capability of producing a non-uniform motion is developed. The structural properties of the system are investigated by means of the theory of Hamiltonian systems. A relationship between the parameters of the system and the parameters of the proposed decentralized PD controller is shown to ensure local stability and tracking performance. Simulation results are included to show the obtained non-uniform motion. 展开更多
关键词 Decentralized proportional-derivative (PD) control hybrid system non-uniform motion local stability tracking performance
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New Hybrid Genetic Algorithm for Vertex Cover Problems
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作者 HuoHongwei XuJin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2003年第4期90-94,共5页
This paper presents a new hybrid genetic algorithm for the vertex cover problems in which scan-repair and local improvement techniques are used for local optimization. With the hybrid approach, genetic algorithms are ... This paper presents a new hybrid genetic algorithm for the vertex cover problems in which scan-repair and local improvement techniques are used for local optimization. With the hybrid approach, genetic algorithms are used to perform global exploration in a population, while neighborhood search methods are used to perform local exploitation around the chromosomes. The experimental results indicate that hybrid genetic algorithms can obtain solutions of excellent quality to the problem instances with different sizes. The pure genetic algorithms are outperformed by the neighborhood search heuristics procedures combined with genetic algorithms. 展开更多
关键词 vertex cover hybrid genetic algorithm scan-repair local improvement.
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多水源灌溉系统的管网布置与管径协同优化研究
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作者 李妍峰 陈赛玥 《工业工程》 2024年第4期141-149,共9页
基于多水源灌溉系统,考虑系统水资源分配并确定管网拓扑结构与连接管道尺寸,以最小化系统流量分配成本和管道安装成本之和为目标函数建立混合整数规划模型。设计一种混合启发式算法将局部搜索与精确算法结合,协同优化管网布置与管网设... 基于多水源灌溉系统,考虑系统水资源分配并确定管网拓扑结构与连接管道尺寸,以最小化系统流量分配成本和管道安装成本之和为目标函数建立混合整数规划模型。设计一种混合启发式算法将局部搜索与精确算法结合,协同优化管网布置与管网设计两个阶段,分析各节点之间的连接情况与连接管径,并为需水节点分配流量。通过不同规模的测试算例验证协同优化算法能有效降低多水源灌溉系统的建设成本。 展开更多
关键词 多水源灌溉系统 局部搜索 混合启发式算法
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An Obliquely Propagating Electromagnetic Lower-Hybrid-Drift Instability in Plasmas with Negative Ions
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作者 王飞虎 张宙 +1 位作者 陈银华 黄凤 《Plasma Science and Technology》 SCIE EI CAS CSCD 2007年第4期388-393,共6页
In this study, by employing a local fluid theory for warm plasma containing negative ions, an obliquely propagating electromagnetic instability in the lower hybrid frequency range driven by cross-field currents or rel... In this study, by employing a local fluid theory for warm plasma containing negative ions, an obliquely propagating electromagnetic instability in the lower hybrid frequency range driven by cross-field currents or relative drifts between electrons and ions was investigated. It is found that the growth rate of the lower-hybrid-drift instability (LHDI) can be controlled by appropriate selection of the propagation direction, the wave number and the relative population of the negative ions. 展开更多
关键词 lower-hybrid-drift frequency INSTABILITY negative ions local fluid theory
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