期刊文献+
共找到42,180篇文章
< 1 2 250 >
每页显示 20 50 100
Unusual recurrence of colon cancer with isolated axillary lymph node metastasis:A case report
1
作者 Ali Toffaha Mahmood Al-Dhaheri +5 位作者 Mohammad AL.Zoubi Arwa Abdelrahim Mahir Petkar Ahmed Badr Mohamed Abunada Ayman Ahmed 《Laparoscopic, Endoscopic and Robotic Surgery》 2026年第1期58-61,共4页
The metastatic pattern of colon cancer is typically well characterized,with initial dissemination occurring through regional lymphatics,followed by hematogenous spread.The most frequent sites of metastasis in colorect... The metastatic pattern of colon cancer is typically well characterized,with initial dissemination occurring through regional lymphatics,followed by hematogenous spread.The most frequent sites of metastasis in colorectal cancer(CRC)include regional lymph nodes(50%–70%),liver(35%–50%),lungs(21%),peritoneum(15%),and ovaries(13%).1 Isolated distant lymph node metastasis,particularly in the absence of concurrent systemic disease,is exceedingly rare in CRC.To date,only six cases of isolated axillary lymph node metastasis(ALNM)from colorectal primaries have been documented in the literature.1–6 Even more uncommon is the incidental discovery of malignant cells in anastomotic doughnuts following stoma reversal procedures.Herein,we report a rare case involving both the incidental histopathological detection of tumor cells within doughnuts during stoma closure and the subsequent development of isolated ALNM after curative resection of sigmoid colon carcinoma. 展开更多
关键词 axillary lymph node hematogenous spreadthe axillary lymph node metastasis distant lymph node metastasisparticularly colon cancer regional lymph nodes liver lungs peritoneum colorectal cancer crc include regional lymphaticsfollowed
原文传递
PSMA PET/CT-guided pelvic lymph node dissection in patients with unfavorable intermediate-or high-risk prostate cancer
2
作者 Eva Donck Sofie Verbeke +4 位作者 Pieter De Visschere Valérie Fonteyne Charles Van Praet Kathia De Man Nicolaas Lumen 《The Canadian Journal of Urology》 2026年第1期83-92,共10页
Objectives:PSMA PET/CT(Prostate-Specific MembraneAntigen Positron Emission Tomography/Computed Tomography)offers improved accuracy in detecting lymph node invasion(LNI)in prostate cancer(PC)patients,potentially reduci... Objectives:PSMA PET/CT(Prostate-Specific MembraneAntigen Positron Emission Tomography/Computed Tomography)offers improved accuracy in detecting lymph node invasion(LNI)in prostate cancer(PC)patients,potentially reducing the need for extended pelvic lymph node dissection(ePLND).This study aims to evaluate a patient-tailored care pathway in which ePLND is performed only in patients with unfavorable intermediate-or high-risk PC who are deemed at risk for LNI based on PSMA PET/CT findings.Methods:In this interventional cohort study,81 patients were managed according to the new care pathway.ePLND was omitted in cases of negative PSMA PET/CT findings(N0M0),while those with positive PSMA PET/CT findings(N1M0)underwent ePLND.A comparator group of 81 patients was selected from a prospectively generated database for comparison.Results:The intervention group experienced a 75% reduction in the number of ePLNDs performed compared to the comparator group(p<0.001).ePLND-related complications were significantly lower in the intervention group(p=0.008).No significant difference was observed in 3-year biochemical-recurrence free survival(BRFS)between the two groups(p=0.958).Conclusion:Omitting ePLND in patients with negative PSMA PET/CT findings(N0M0)leads to a substantial reduction in the number of ePLNDs performed,resulting in a decrease in morbidity,without compromising early oncological outcomes. 展开更多
关键词 prostate cancer PSMA PET/CT radical prostatectomy pelvic lymph node dissection lymph node invasion STAGING
暂未订购
ISTIRDA:An Efficient Data Availability Sampling Scheme for Lightweight Nodes in Blockchain
3
作者 Jiaxi Wang Wenbo Sun +3 位作者 Ziyuan Zhou Shihua Wu Jiang Xu Shan Ji 《Computers, Materials & Continua》 2026年第4期685-700,共16页
Lightweight nodes are crucial for blockchain scalability,but verifying the availability of complete block data puts significant strain on bandwidth and latency.Existing data availability sampling(DAS)schemes either re... Lightweight nodes are crucial for blockchain scalability,but verifying the availability of complete block data puts significant strain on bandwidth and latency.Existing data availability sampling(DAS)schemes either require trusted setups or suffer from high communication overhead and low verification efficiency.This paper presents ISTIRDA,a DAS scheme that lets light clients certify availability by sampling small random codeword symbols.Built on ISTIR,an improved Reed–Solomon interactive oracle proof of proximity,ISTIRDA combines adaptive folding with dynamic code rate adjustment to preserve soundness while lowering communication.This paper formalizes opening consistency and prove security with bounded error in the random oracle model,giving polylogarithmic verifier queries and no trusted setup.In a prototype compared with FRIDA under equal soundness,ISTIRDA reduces communication by 40.65%to 80%.For data larger than 16 MB,ISTIRDA verifies faster and the advantage widens;at 128 MB,proofs are about 60%smaller and verification time is roughly 25%shorter,while prover overhead remains modest.In peer-to-peer emulation under injected latency and loss,ISTIRDA reaches confidence more quickly and is less sensitive to packet loss and load.These results indicate that ISTIRDA is a scalable and provably secure DAS scheme suitable for high-throughput,large-block public blockchains,substantially easing bandwidth and latency pressure on lightweight nodes. 展开更多
关键词 Blockchain scalability data availability sampling lightweight nodes
在线阅读 下载PDF
A systematic review of open versus robotic retroperitoneal lymph node dissection for testicular cancer:Comparative operative and oncological outcomes
4
作者 Daniel Peter McNicholas Freddy Kattakayam +2 位作者 Joshua Hemmant Robin Weston Vishwanath Hanchanale 《Laparoscopic, Endoscopic and Robotic Surgery》 2026年第1期1-7,共7页
Objective:Open retroperitoneal lymph node dissection(RPLND)is the gold-standard surgical approach for the management of metastatic testicular cancer,but robotic RPLND is becoming increasingly popular.There is limited ... Objective:Open retroperitoneal lymph node dissection(RPLND)is the gold-standard surgical approach for the management of metastatic testicular cancer,but robotic RPLND is becoming increasingly popular.There is limited research directly comparing open and robotic RPLND.The objective of this systematic review is to identify all the literature with direct comparisons between the open and robotic techniques for RPLND and to compare the two techniques.The primary outcome was peri-operative outcomes,and the secondary outcomes included oncological outcomes and patient demographics.Methods:This systematic review was prospectively registered and was conducted in accordance with the PRISMA statement.The PubMed,Embase and MEDLINE databases were searched for relevant publication from January 2006 to August 2024.Results:Eight studies,totaling 3995 patients,are included in this systematic review,with 3521 patients who underwent open RPLND and 474 who underwent robotic RPLND.For open RPLND,the mean operative duration,blood loss and length of stay were 267.8 min,475 mL and 7.3 d,respectively.For robotic RPLND,the mean operative duration,blood loss and length of stay were 334.5 min,94.6 mL and 3.7 d,respectively.Teratoma was the most common RPLND specimen pathology from both open and robotic surgeries.For open RPLND,the specimens have 13–23 nodes(26–32 mm),whereas the robotic RPLND specimens have 13–28 nodes(18–20 mm).Conclusion:This systematic review suggests that the benefitsof robotic RPLND may be associated with reduced blood loss,shorter hospitalisation and an overall lower risk of minor and major complications while maintaining oncological safety. 展开更多
关键词 Retroperitoneal lymph node dissection Robotic surgery Testicular cancer
原文传递
Predicting lymph node metastasis in colorectal cancer using caselevel multiple instance learning
5
作者 Ling-Feng Zou Xuan-Bing Wang +4 位作者 Jing-Wen Li Xin Ouyang Yi-Ying Luo Yan Luo Cheng-Long Wang 《World Journal of Gastroenterology》 2026年第1期110-125,共16页
BACKGROUND The accurate prediction of lymph node metastasis(LNM)is crucial for managing locally advanced(T3/T4)colorectal cancer(CRC).However,both traditional histopathology and standard slide-level deep learning ofte... BACKGROUND The accurate prediction of lymph node metastasis(LNM)is crucial for managing locally advanced(T3/T4)colorectal cancer(CRC).However,both traditional histopathology and standard slide-level deep learning often fail to capture the sparse and diagnostically critical features of metastatic potential.AIM To develop and validate a case-level multiple-instance learning(MIL)framework mimicking a pathologist's comprehensive review and improve T3/T4 CRC LNM prediction.METHODS The whole-slide images of 130 patients with T3/T4 CRC were retrospectively collected.A case-level MIL framework utilising the CONCH v1.5 and UNI2-h deep learning models was trained on features from all haematoxylin and eosinstained primary tumour slides for each patient.These pathological features were subsequently integrated with clinical data,and model performance was evaluated using the area under the curve(AUC).RESULTS The case-level framework demonstrated superior LNM prediction over slide-level training,with the CONCH v1.5 model achieving a mean AUC(±SD)of 0.899±0.033 vs 0.814±0.083,respectively.Integrating pathology features with clinical data further enhanced performance,yielding a top model with a mean AUC of 0.904±0.047,in sharp contrast to a clinical-only model(mean AUC 0.584±0.084).Crucially,a pathologist’s review confirmed that the model-identified high-attention regions correspond to known high-risk histopathological features.CONCLUSION A case-level MIL framework provides a superior approach for predicting LNM in advanced CRC.This method shows promise for risk stratification and therapy decisions,requiring further validation. 展开更多
关键词 Colorectal cancer Lymph node metastasis Deep learning Multiple instance learning HISTOPATHOLOGY
暂未订购
Multi-Label Classification Model Using Graph Convolutional Neural Network for Social Network Nodes
6
作者 Junmin Lyu Guangyu Xu +4 位作者 Feng Bao Yu Zhou Yuxin Liu Siyu Lu Wenfeng Zheng 《Computer Modeling in Engineering & Sciences》 2026年第2期1235-1256,共22页
Graph neural networks(GNN)have shown strong performance in node classification tasks,yet most existing models rely on uniform or shared weight aggregation,lacking flexibility in modeling the varying strength of relati... Graph neural networks(GNN)have shown strong performance in node classification tasks,yet most existing models rely on uniform or shared weight aggregation,lacking flexibility in modeling the varying strength of relationships among nodes.This paper proposes a novel graph coupling convolutional model that introduces an adaptive weighting mechanism to assign distinct importance to neighboring nodes based on their similarity to the central node.Unlike traditional methods,the proposed coupling strategy enhances the interpretability of node interactions while maintaining competitive classification performance.The model operates in the spatial domain,utilizing adjacency list structures for efficient convolution and addressing the limitations of weight sharing through a coupling-based similarity computation.Extensive experiments are conducted on five graph-structured datasets,including Cora,Citeseer,PubMed,Reddit,and BlogCatalog,as well as a custom topology dataset constructed from the Open University Learning Analytics Dataset(OULAD)educational platform.Results demonstrate that the proposed model achieves good classification accuracy,while significantly reducing training time through direct second-order neighbor fusion and data preprocessing.Moreover,analysis of neighborhood order reveals that considering third-order neighbors offers limited accuracy gains but introduces considerable computational overhead,confirming the efficiency of first-and second-order convolution in practical applications.Overall,the proposed graph coupling model offers a lightweight,interpretable,and effective framework for multi-label node classification in complex networks. 展开更多
关键词 GNN social networks nodes multi-label classification model graphic convolution neural network coupling principle
在线阅读 下载PDF
Combined multidetector computed tomography and gastrointestinal endoscopy for gastric cancer screening,preoperative staging,and lymph node metastasis detection
7
作者 Le-Ping Ye Yan-Ping Zhang +4 位作者 Gang Chen Yi-Xian Wu Cheng-Long He Dong Wang Qiao Mei 《World Journal of Gastrointestinal Oncology》 2026年第1期200-210,共11页
BACKGROUND Early screening,preoperative staging,and diagnosis of lymph node metastasis are crucial for improving the prognosis of gastric cancer(GC).AIM To evaluate the diagnostic value of combined multidetector compu... BACKGROUND Early screening,preoperative staging,and diagnosis of lymph node metastasis are crucial for improving the prognosis of gastric cancer(GC).AIM To evaluate the diagnostic value of combined multidetector computed tomography(MDCT)and gastrointestinal endoscopy for GC screening,preoperative staging,and lymph node metastasis detection,thereby providing a reference for clinical diagnosis and treatment.METHODS In this retrospective study clinical and imaging data of 134 patients with suspected GC who were admitted between January 2023 and October 2024 were initially reviewed.According to the inclusion and exclusion criteria,102 patients were finally enrolled in the analysis.All enrolled patients had undergone both MDCT and gastrointestinal endoscopy examinations prior to surgical intervention.Preoperative clinical staging and lymph node metastasis findings were compared with pathological results.RESULTS The combined use of MDCT and gastrointestinal endoscopy demonstrated a sensitivity of 98.53%,specificity of 97.06%,accuracy of 98.04%,positive predictive value of 98.53%,and negative predictive value of 97.06%for diagnosing GC.These factors were all significantly higher than those of MDCT or endoscopy alone(P<0.05).The accuracy rates of the combined approach for detecting clinical T and N stages were 97.06%and 92.65%,respectively,outperforming MDCT alone(86.76% and 79.41%)and endoscopy alone(85.29% and 70.59%)(P<0.05).Among 68 patients with confirmed GC,50(73.53%)were pathologically diagnosed with lymph node metastasis.The accuracy for detecting lymph node metastasis was 66.00%with endoscopy,76.00%with MDCT,and 92.00% with the combined approach,all with statistically significant differences(P<0.05).CONCLUSION The combined application of MDCT and gastrointestinal endoscopy enhanced diagnostic accuracy for GC,provided greater consistency in preoperative staging,and improved the detection of lymph node metastasis,thereby demonstrating significant clinical utility. 展开更多
关键词 Multidetector computed tomography Gastrointestinal endoscopy Gastric cancer Preoperative staging Lymph node metastasis
暂未订购
Analysis of Long-term Prognosis and Cosmetic Outcomes of Breast-conserving Surgery Combined with Sentinel Lymph Node Biopsy for Early-stage Breast Cancer
8
作者 Yuedong Zhang 《Proceedings of Anticancer Research》 2026年第1期101-108,共8页
Objective:To investigate the long-term prognosis and postoperative cosmetic outcomes of breast-conserving surgery combined with sentinel lymph node biopsy in patients with early-stage breast cancer,providing a referen... Objective:To investigate the long-term prognosis and postoperative cosmetic outcomes of breast-conserving surgery combined with sentinel lymph node biopsy in patients with early-stage breast cancer,providing a reference for the selection of clinical treatment plans.Methods:A retrospective analysis was conducted on the clinical data of 68 patients with early-stage breast cancer admitted from January 2022 to December 2025.Based on the surgical approach,patients were divided into an observation group(breast-conserving surgery+sentinel lymph node biopsy)and a control group(other surgical methods such as modified radical mastectomy/total mastectomy).Clinical and pathological characteristics,incidence of postoperative complications,follow-up prognosis,and satisfaction with cosmetic outcomes were compared between the two groups.Results:Among the 68 patients,41 were in the observation group and 27 in the control group.The average age of patients in the observation group was(54.32±8.15)years,while that in the control group was(62.45±9.76)years.The average tumor size in the observation group was(1.86±0.72)cm,compared to(3.21±1.45)cm in the control group.The incidence of postoperative complications in the observation group was 9.76%,significantly lower than that in the control group at 33.33%(P<0.05).The 6-month disease-free survival rate was 95.12%in the observation group and 88.89%in the control group,with no statistically significant difference between the two groups(P>0.05).The excellent and good rate of cosmetic outcomes in the observation group was 87.80%,significantly higher than that in the control group at 29.63%(P<0.05).Conclusion:Breast-conserving surgery combined with sentinel lymph node biopsy for early-stage breast cancer can achieve long-term prognostic outcomes comparable to those of traditional radical surgery,with the advantages of fewer postoperative complications and superior cosmetic results.This approach is worthy of clinical promotion and application,particularly for early-stage breast cancer patients who have a demand for preserving breast morphology. 展开更多
关键词 Early-stage breast cancer Breast-conserving surgery Sentinel lymph node biopsy Long-term prognosis Cosmetic results
暂未订购
Research on the Impact of Different Lymph Node Dissection Scopes on Postoperative Recurrence and Survival Rates in Patients with Early Gastric Cancer
9
作者 Zhijun Mao Yingdi Wei +2 位作者 Ganjie Yang Pan Gao Tong Hui 《Proceedings of Anticancer Research》 2026年第1期130-137,共8页
Early-stage gastric cancer;Extent of lymph node dissection;D1 dissection;D2 dissection;Recurrence rate;Survival rateObjective:To investigate the impact of different lymph node dissection scopes on postoperative recurr... Early-stage gastric cancer;Extent of lymph node dissection;D1 dissection;D2 dissection;Recurrence rate;Survival rateObjective:To investigate the impact of different lymph node dissection scopes on postoperative recurrence and survival rates in patients with early gastric cancer,providing evidence-based support for optimizing clinical surgical plans.Methods:A retrospective analysis was conducted on the clinical data of 100 patients with early gastric cancer who underwent surgical treatment at our hospital from October 2021 to October 2023.Patients were divided into Group D1(n=50)and Group D2(n=50)based on the extent of lymph node dissection.Group D1 underwent limited lymph node dissection(dissection of the first station of lymph nodes around the stomach),while Group D2 underwent standard lymph node dissection(dissection of the first and second stations of lymph nodes around the stomach).Surgical-related indicators,the incidence of postoperative complications,the 2-year recurrence rate,and the 2-year survival rate were compared between the two groups of patients.Results:The operative time,intraoperative blood loss,postoperative hospital stay,and the number of lymph nodes dissected were significantly higher in the D2 group than in the D1 group(all P<0.001).The overall incidence of postoperative complications was higher in the D1 group than in the D2 group,but the difference was not statistically significant(χ^(2)=0.884,P=0.766).After a 2-year follow-up,the recurrence rate was significantly higher in the D1 group than in the D2 group(χ^(2)=4.000,P=0.046).The 2-year survival rate was significantly lower in the D1 group than in the D2 group(χ^(2)=5.005,P=0.025).A total of 100 patients with early-stage gastric cancer were grouped according to the depth of invasion,degree of differentiation,and lymph node metastasis status,and the recurrence rates of different subgroups were compared.The results showed that the recurrence rate was higher in patients with T1b stage than in those with T1a stage(χ^(2)=5.005,P=0.025),higher in poorly differentiated patients than in moderately and well-differentiated patients(χ^(2)=4.155,P=0.042),and higher in patients with lymph node metastasis than in those without lymph node metastasis(χ^(2)=4.512,P=0.034).Conclusion:Compared with D1 limited lymph node dissection,D2 standard lymph node dissection can significantly reduce the postoperative recurrence rate and improve the 2-year survival rate in patients with early-stage gastric cancer without significantly increasing the risk of postoperative complications.Although the surgical trauma is slightly greater,the overall prognosis is better,making it a preferred surgical treatment option for patients with early-stage gastric cancer. 展开更多
关键词 Early-stage gastric cancer Extent of lymph node dissection D1 dissection D2 dissection Recurrence rate Survival rate
暂未订购
基于Nodejs的智能实验室管理系统设计与实现
10
作者 高敏节 黎坤坤 张美春 《信息记录材料》 2026年第1期127-129,共3页
针对高校实验室管理效率低下的现状,本研究开发了一套智能实验室管理系统。该系统前端基于Vue.js框架,后端使用Node.js提供高性能支持,并结合MySQL数据库实现高效的数据存储与管理。结果表明:该系统在高效稳定的运行状态下,为用户提供... 针对高校实验室管理效率低下的现状,本研究开发了一套智能实验室管理系统。该系统前端基于Vue.js框架,后端使用Node.js提供高性能支持,并结合MySQL数据库实现高效的数据存储与管理。结果表明:该系统在高效稳定的运行状态下,为用户提供了流畅且直观的操作界面,极大地提高了实验室管理的便捷性和效率。 展开更多
关键词 智能实验室管理系统 Vue.js框架 node.js MYSQL数据库
在线阅读 下载PDF
基于Node-RED的SMT贴片车间多传感智能环境监控平台
11
作者 姚莉娟 刘思远 王栋 《化工自动化及仪表》 2026年第1期119-124,共6页
为满足SMT贴片车间环境的智能监控,设计了基于Node-RED的多传感智能环境监控平台,S7-1200 PLC为系统的主控单元,通过现场总线与多传感器连接,实现温湿度、PM2.5/PM10、光照度及噪声等核心参数的动态感知,采用S7协议与Node-RED平台通信,... 为满足SMT贴片车间环境的智能监控,设计了基于Node-RED的多传感智能环境监控平台,S7-1200 PLC为系统的主控单元,通过现场总线与多传感器连接,实现温湿度、PM2.5/PM10、光照度及噪声等核心参数的动态感知,采用S7协议与Node-RED平台通信,实现数据双向传输、自动控制与智能响应,通过Things Board云平台实现远程监控、历史数据回溯和参数调节。系统联调应用测试结果表明:该监控平台运行稳定,实现了工业环境的实时监控和快速响应,具有高度的智能化和灵活性。 展开更多
关键词 node-RED SMT贴片车间 多源传感器 S7-1200 PLC 工业环境监控
在线阅读 下载PDF
Capacitated stochastic coloured Petri net-based approach for computing two-terminal reliability of multi-state network 被引量:3
12
作者 Tao Zhang Bo Guo 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第2期304-313,共10页
Classical network reliability problems assume both net- works and components have only binary states, fully working or fully failed states. But many actual networks are multi-state, such as communication networks and ... Classical network reliability problems assume both net- works and components have only binary states, fully working or fully failed states. But many actual networks are multi-state, such as communication networks and transportation networks. The nodes and arcs in the networks may be in intermediate states which are not fully working either fully failed. A simulation ap- proach for computing the two-terminal reliability of a multi-state network is described. Two-terminal reliability is defined as the probability that d units of demand can be supplied from the source to sink nodes under the time threshold T. The capacities of arcs may be in a stochastic state following any discrete or continuous distribution. The transmission time of each arc is also not a fixed number but stochastic according to its current capacity and de- mand. To solve this problem, a capacitated stochastic coloured Petri net is proposed for modelling the system behaviour. Places and transitions respectively stand for the nodes and arcs of a net- work. Capacitated transition and self-modified token colour with route information are defined to describe the multi-state network. By the simulation, the two-terminal reliability and node importance can be estimated and the optimal route whose reliability is highest can also be given. Finally, two examples of different kinds of multi- state networks are given. 展开更多
关键词 two-terminal reliability multi-state network Petri net (PN) simulation node importance.
在线阅读 下载PDF
Reliability Modeling and Evaluation of Complex Multi-State System Based on Bayesian Networks Considering Fuzzy Dynamic of Faults 被引量:5
13
作者 Fangjun Zuo Meiwei Jia +2 位作者 Guang Wen Huijie Zhang Pingping Liu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第11期993-1012,共20页
In the traditional reliability evaluation based on the Bayesian method,the failure probability of nodes is usually expressed by the average failure rate within a period of time.Aiming at the shortcomings of traditiona... In the traditional reliability evaluation based on the Bayesian method,the failure probability of nodes is usually expressed by the average failure rate within a period of time.Aiming at the shortcomings of traditional Bayesian network reliability evaluation methods,this paper proposes a Bayesian network reliability evaluation method considering dynamics and fuzziness.The fuzzy theory and the dynamic of component failure probability are introduced to construct the dynamic fuzzy set function.Based on the solving characteristics of the dynamic fuzzy set and Bayesian network,the fuzzy dynamic probability and fuzzy dynamic importance degree of the fault state of leaf nodes are solved.Finally,through the dynamic fuzzy reliability analysis of CNC machine tool hydraulic system balance circuit,the application of this method in system reliability evaluation is verified,which provides support for fault diagnosis of CNC machine tools. 展开更多
关键词 Bayesian network(BN) dynamics FUZZY multi-state
在线阅读 下载PDF
Importance measure of system reliability upgrade for multi-state consecutive k-out-of-n systems 被引量:3
14
作者 HonQvan Dui Shubin si +2 位作者 Zhiqiang Cai Shudong Sun Yingfeng Zhang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第6期936-942,共7页
Importance measures in reliability systems are used to identify weak components in contributing to a proper function of the system.Traditional importance measures mainly concerned the changing value of the system reli... Importance measures in reliability systems are used to identify weak components in contributing to a proper function of the system.Traditional importance measures mainly concerned the changing value of the system reliability caused by the change of the reliability of the component,and seldom considered the joint effect of the probability distribution,improvement rate of the object component.This paper studies the rate of the system reliability upgrading with an improvement of the component reliability for the multi-state consecutive k-out-of-n system.To verify the multi-state consecutive k-out-of-n system reliability upgrading by improving one component based on its improvement rate,an increasing potential importance(IPI)and its physical meaning are described at first.Secondly,the relationship between the IPI and Birnbaum importance measures are discussed.And the IPI for some different improvement actions of the component is further discussed.Thirdly,the characteristics of the IPI are analyzed.Finally,an application to an oil pipeline system is given. 展开更多
关键词 system reliability multi-state consecutive k-out-of-nsystem IMPROVEMENT Birnbaum importance.
在线阅读 下载PDF
Reliability Analysis of Retracting Actuator with Multi-State Based on Goal Oriented Methodology 被引量:3
15
作者 周琳玕 董海平 +2 位作者 伊枭剑 李媛媛 赖岳华 《Journal of Shanghai Jiaotong university(Science)》 EI 2015年第3期307-311,共5页
In order to conduct effective reliability analysis of retracting actuator with multi-state(success state,safety failure state and action failure state), we redefine type-3 operator in goal oriented(GO) method to descr... In order to conduct effective reliability analysis of retracting actuator with multi-state(success state,safety failure state and action failure state), we redefine type-3 operator in goal oriented(GO) method to describe three states of main charge of retracting actuator and improve type-15 operator in GO method to describe the logic relations of multi-state output. The quantitative and qualitative reliability analyses of retracting actuator are made based on GO method in this paper. The system state probability of retracting actuator is obtained through quantitative analysis, and its weakness is found through qualitative analysis. The analysis results show that GO method is effective to improve the reliability of retracting actuator, and this method is also feasible for reliability analysis of other complicated initiating explosive systems. 展开更多
关键词 retracting actuator goal oriented(GO) methodology OPERATOR multi-state reliability analysis
原文传递
Integrated importance measure for multi-state coherent systems of k level 被引量:2
16
作者 Xibin Zhao Shubin Si +2 位作者 Hongyan Dui Zhiqiang Cai Shudong Sun 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2013年第6期1029-1037,共9页
To verify the effectiveness of the integrated importance measure (IIM) for multi-state coherent systems of k level, the definition and physical meaning of IIM are demonstrated. Then, the improvement potential and Δ... To verify the effectiveness of the integrated importance measure (IIM) for multi-state coherent systems of k level, the definition and physical meaning of IIM are demonstrated. Then, the improvement potential and Δ-importance measures are generalized to multi-state coherent systems based on the system performance level, and the relationships between IIM and traditional importance measures are discussed. The characteristics of IIM are demonstrated in both series and parallel systems. Also, an application to an oil transportation system is given. The comparison results show that: (i) IIM has some useful properties that are not possessed by traditional importance measures; (ii) IIM is effective in evaluating the component role in multi-state systems when the component reliability and the failure rate are simultaneously considered. 展开更多
关键词 multi-state coherent system system performance level integrated importance measure system reliability
在线阅读 下载PDF
A voltage support control strategy based on three-port flexible multi-state switch in distribution networks 被引量:1
17
作者 Bo PENG Guorong ZHANG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2020年第8期192-202,共11页
Voltage sags in power system may lead to serious problems such as the off-grid of distributed generation and electrical equipment failures.As a novel type of power electronic equipment,a flexible multi-state switch(FM... Voltage sags in power system may lead to serious problems such as the off-grid of distributed generation and electrical equipment failures.As a novel type of power electronic equipment,a flexible multi-state switch(FMSS)is capable to support the voltage during the grid faults.In this paper,a voltage control strategy to support the voltage in a distribution network is proposed by introducing three-port FMSS.The positive-negative-sequence compensation(PNSC)scheme is adopted to control the active and reactive current.This control scheme eliminates active power oscillations at the port of voltage sags and reduces coupling oscillations of other ports.Based on the characteristics of the voltage support under PNSC scheme,two voltage support strategies are proposed.A proportional-integral controller is introduced to provide the reactive power references,which eliminates the errors when estimating the grid voltage and impedance.A current limiting scheme is adopted to keep the port current in a safe range by adjusting the active and reactive power references.The voltage support strategies in two different voltage sags are simulated,and results show the feasibility and effectiveness of the proposed control strategies. 展开更多
关键词 FLEXIBLE multi-state SWITCH voltage support low-voltage ride-through reactive power control
在线阅读 下载PDF
Optimal transmission lines assignment with maximal reliabilities in multi-source multi-sink multi-state computer network 被引量:1
18
作者 章筠 徐正国 +2 位作者 王文海 卢建刚 孙优贤 《Journal of Central South University》 SCIE EI CAS 2013年第7期1868-1877,共10页
The optimal transmission lines assignment with maximal reliabilities (OTLAMR) in the multi-source multi-sink multi-state computer network (MMMCN) was investigated. The OTLAMR problem contains two sub-problems: the MMM... The optimal transmission lines assignment with maximal reliabilities (OTLAMR) in the multi-source multi-sink multi-state computer network (MMMCN) was investigated. The OTLAMR problem contains two sub-problems: the MMMCN reliabilities evaluation and multi-objective transmission lines assignment optimization. First, a reliability evaluation with a transmission line assignment (RETLA) algorithm is proposed to calculate the MMMCN reliabilities under the cost constraint for a certain transmission lines configuration. Second, the non-dominated sorting genetic algorithm II (NSGA-II) is adopted to find the non-dominated set of the transmission lines assignments based on the reliabilities obtained from the RETLA algorithm. By combining the RETLA and the NSGA-II algorithms together, the RETLA-NSGA II algorithm is proposed to solve the OTLAMR problem. The experiments result show that the RETLA-NSGA II algorithm can provide efficient solutions in a reasonable time, from which the decision makers can choose the best solution based on their preferences and experiences. 展开更多
关键词 multi-state network reliability evaluation transmission lines assignments multi-objective optimization non-dominatedsorting genetic algorithm II
在线阅读 下载PDF
Importance Analysis of a Multi-state System Based on Direct Partial Logic Derivatives and Multi-valued Decision Diagrams 被引量:1
19
作者 古莹奎 李晶 《Journal of Donghua University(English Edition)》 EI CAS 2014年第6期789-792,共4页
Importance analysis quantifies the critical degree of individual component. Compared with the traditional binary state system,importance analysis of the multi-state system is more aligned with the practice. Because th... Importance analysis quantifies the critical degree of individual component. Compared with the traditional binary state system,importance analysis of the multi-state system is more aligned with the practice. Because the multi-valued decision diagram( MDD) can reflect the relationship between the components and the system state bilaterally, it was introduced into the reliability calculation of the multi-state system( MSS). The building method,simplified criteria,and path search and probability algorithm of MSS structure function MDD were given,and the reliability of the system was calculated. The computing methods of importance based on MDD and direct partial logic derivatives( DPLD) were presented. The diesel engine fuel supply system was taken as an example to illustrate the proposed method. The results show that not only the probability of the system in each state can be easily obtained,but also the influence degree of each component and its state on the system reliability can be obtained,which is conducive to the condition monitoring and structure optimization of the system. 展开更多
关键词 multi-state system(MSS) importance analysis reliability multi-valued decision diagram(MDD) direct partial logic derivative(DPLD) diesel engine fuel supply system
在线阅读 下载PDF
A multi-state weather generator for daily precipitation for the Torne River basin, northern Sweden/western Finland
20
作者 David RAYNER Christine ACHBERGER Deliang CHEN 《Advances in Climate Change Research》 SCIE CSCD 2016年第1期70-81,共12页
This paper describes a new weather generator e the 10-state empirical model e that combines a 10-state, first-order Markov chain with a non-parametric precipitation amounts model. Using a doubly-stochastic transition-... This paper describes a new weather generator e the 10-state empirical model e that combines a 10-state, first-order Markov chain with a non-parametric precipitation amounts model. Using a doubly-stochastic transition-matrix results in a weather generator for which the overall precipitation distribution(including both wet and dry days) and the temporal-correlation can be modified independently for climate change studies. This paper assesses the ability of the 10-state empirical model to simulate daily area-average precipitation in the Torne River catchment in northern Sweden/western Finland in the context of 3 other models: a 10-state model with a parametric(Gamma) amounts model; a wet/dry chain with the empirical amounts model; and a wet/dry chain with the parametric amounts model. The ability to accurately simulate the distribution of multi-day precipitation in the catchment is the primary consideration.Results showed that the 10-state empirical model represented accumulated 2- to 14-day precipitation most realistically. Further, the distribution of precipitation on wet days in the catchment is related to the placement of a wet day within a wet-spell, and the 10-state models represented this realistically, while the wet/dry models did not. Although all four models accurately reproduced the annual and monthly averages in the training data, all models underestimated inter-annual and inter-seasonal variance. Even so, the 10-state empirical model performed best.We conclude that the multi-state model is a promising candidate for hydrological applications, as it simulates multi-day precipitation well, but that further development is required to improve the simulation of interannual variation. 展开更多
关键词 Weather generator multi-state Torne River PRECIPITATION
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部