期刊文献+
共找到230篇文章
< 1 2 12 >
每页显示 20 50 100
Feature Selection for Image Classification Based on a New Ranking Criterion 被引量:1
1
作者 Xuan Zhou Jiajun Wang 《Journal of Computer and Communications》 2015年第3期74-79,共6页
In this paper, a feature selection method combining the reliefF and SVM-RFE algorithm is proposed. This algorithm integrates the weight vector from the reliefF into SVM-RFE method. In this method, the reliefF filters ... In this paper, a feature selection method combining the reliefF and SVM-RFE algorithm is proposed. This algorithm integrates the weight vector from the reliefF into SVM-RFE method. In this method, the reliefF filters out many noisy features in the first stage. Then the new ranking criterion based on SVM-RFE method is applied to obtain the final feature subset. The SVM classifier is used to evaluate the final image classification accuracy. Experimental results show that our proposed relief- SVM-RFE algorithm can achieve significant improvements for feature selection in image classification. 展开更多
关键词 FEATURE SELECTION for IMAGE Classification based on a New RANKING criterion
下载PDF
uCOS实时响应问题的解决方法 被引量:8
2
作者 戴琪华 戴曙光 穆平安 《上海理工大学学报》 CAS 北大核心 2002年第1期73-75,共3页
阐述了在实际应用开发中uCOS实时响应问题的解决方法. 围绕快速中断服务、上下文切换速度以及特高速系统中精确响应时间三个方面进行了探讨,并给出了相应的解决办法.
关键词 ucos 实时 多任务 中断服务程序 上下文切换 时基 操作系统
下载PDF
快衰落Rayleigh信道下短LDPC码两类BP-Based译码的优化设计 被引量:1
3
作者 郑贺 胡捍英 陆佩忠 《电子与信息学报》 EI CSCD 北大核心 2007年第7期1588-1591,共4页
该文基于最小均方误差(MMSE)准则,对快衰落瑞利(Rayleigh)信道下短码长低密度校验(LDPC)码的ScaledBP-Based和OffsetBP-Based两类改进译码算法进行了优化设计。利用该准则,得出了两类改进算法的最优校正因子,并给出了相应的数值计算。... 该文基于最小均方误差(MMSE)准则,对快衰落瑞利(Rayleigh)信道下短码长低密度校验(LDPC)码的ScaledBP-Based和OffsetBP-Based两类改进译码算法进行了优化设计。利用该准则,得出了两类改进算法的最优校正因子,并给出了相应的数值计算。对码长为504和1008的1/2码率(3,6)规则LDPC码实验仿真显示,使用该准则设计的两类算法能够取得优于置信传播(BP)算法的译码性能。 展开更多
关键词 置信传播 改进的BP-based算法 MMSE准则 短码长LDPC码
下载PDF
Feedback Scheduling of Model-based Networked Control Systems with Flexible Workload 被引量:4
4
作者 Xian-Ming Tang Jin-Shou Yu 《International Journal of Automation and computing》 EI 2008年第4期389-394,共6页
In this paper,a novel control structure called feedback scheduling of model-based networked control systems is proposed to cope with a flexible network load and resource constraints.The state update time is adjusted a... In this paper,a novel control structure called feedback scheduling of model-based networked control systems is proposed to cope with a flexible network load and resource constraints.The state update time is adjusted according to the real-time network congestion situation.State observer is used under the situation where the state of the controlled plant could not be acquired.The stability criterion of the proposed structure is proved with time-varying state update time.On the basis of the stability of the novel system structure,the compromise between the control performance and the network utilization is realized by using feedback scheduler. Examples are provided to show the advantage of the proposed control structure. 展开更多
关键词 Model-based networked control system state update time stability criterion feedback scheduling.
下载PDF
Reliability-based design in rock engineering: Application of Bayesian regression methods to rock strength data 被引量:1
5
作者 Nezam Bozorgzadeh John P.Harrison 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2019年第3期612-627,共16页
Reliability-based design (RBD) is being adopted by geotechnical design codes worldwide, and it is therefore necessary that rock engineering practice evolves to embrace RBD. This paper examines the Hoek-Brown (H-B) str... Reliability-based design (RBD) is being adopted by geotechnical design codes worldwide, and it is therefore necessary that rock engineering practice evolves to embrace RBD. This paper examines the Hoek-Brown (H-B) strength criterion within the RBD framework, and presents three distinct analyses using a Bayesian approach. Firstly, a compilation of intact compressive strength test data for six rock types is used to examine uncertainty and variability in the estimated H-B parameters m and σc, and corresponding predicted axial strength. The results suggest that within- and between-rock type variabilities are so large that these parameters need to be determined from rock testing campaigns, rather than reference values being used. The second analysis uses an extensive set of compressive and tensile (both direct and indirect) strength data for a granodiorite, together with a new Bayesian regression model, to develop joint probability distributions of m and σc suitable for use in RBD. This analysis also shows how compressive and indirect tensile strength data may be robustly used to fit an H-B criterion. The third analysis uses the granodiorite data to investigate the important matter of developing characteristic strength criteria. Using definitions from Eurocode 7, a formal Bayesian interpretation of characteristic strength is proposed and used to analyse strength data to generate a characteristic criterion. These criteria are presented in terms of characteristic parameters mk and σck, the values of which are shown to depend on the testing regime used to obtain the strength data. The paper confirms that careful use of appropriate Bayesian statistical analysis allows the H-B criterion to be brought within the framework of RBD. It also reveals that testing guidelines such as the International Society for Rock Mechanics and Rock Engineering (ISRM) suggested methods will require modification in order to support RBD. Importantly, the need to fully understand the implications of uncertainty in nonlinear strength criteria is identified. 展开更多
关键词 Reliability-based design(RBD) Hoek-Brown(HeB)criterion BAYESIAN regression Indirect TENSILE STRENGTH Characteristic STRENGTH criterion
下载PDF
WORST SUBCARRIER AVOIDING WATER-FILLING SUBCARRIER ALLOCATION SCHEME FOR OFDM-BASED CRN 被引量:3
6
作者 Zhang Jianwu Chi Jingxiu Xu Xiaorong 《Journal of Electronics(China)》 2012年第3期204-210,共7页
Efficient and reliable subcarrier power joint allocation is served as a promising problem in cognitive OFDM-based Cognitive Radio Networks (CRN). This paper focuses on optimal subcarrier allocation for OFDM-based CRN.... Efficient and reliable subcarrier power joint allocation is served as a promising problem in cognitive OFDM-based Cognitive Radio Networks (CRN). This paper focuses on optimal subcarrier allocation for OFDM-based CRN. We mainly propose subcarrier allocation scheme denoted as Worst Subcarrier Avoiding Water-filling (WSAW), which is based on Rate Adaptive (RA) criterion and three constraints are considered in CRN. The algorithm divides the assignment procedure into two phases. The first phase is an initial subcarrier allocation based on the idea of avoiding selecting the worst subcarrier in order to maximize the transmission rate; while the second phase is an iterative adjustment process which is realized by swapping pairs of subcarriers between arbitrary users. The proposed scheme could assign subcarriers in accordance with channel coherence time. Hence, real time subcarrier allocation could be implemented. Simulation results show that, comparing with the similar existing algorithms, the proposed scheme could achieve larger capacity and a near-optimal BER performance. 展开更多
关键词 OFDM-based Cognitive Radio Networks (CRN) Subcarrier allocation scheme Worst Subcarrier Avoiding Water-filling (WSAW) Rate Adaptive (RA) criterion
下载PDF
Efficient volume preserving approach for skeleton-based implicit surfaces
7
作者 史红兵 童若锋 董金祥 《Journal of Zhejiang University Science》 EI CSCD 2003年第6期637-642,共6页
This paper presents an efficient way to preserve the volume of implicit surfaces generated by skeletons. Recursive subdivision is used to efficiently calculate the volume. The criterion for subdivision is obtained by ... This paper presents an efficient way to preserve the volume of implicit surfaces generated by skeletons. Recursive subdivision is used to efficiently calculate the volume. The criterion for subdivision is obtained by using the property of density functions and treating different types of skeletons respectively to get accurate minimum and maximum distances from a cube to a skeleton. Compared with the criterion generated by other ways such as using traditional Interval Analysis, Affine Arithmetic, or Lipschitz condition, our approach is much better both in speed and accuracy. 展开更多
关键词 计算机图形学 隐藏表面 区间分析 体积保留 细分规则
下载PDF
Delay-dependent observer-based stabilizing controller design for linear multiple state-delayed systems
8
作者 Dejin WANG(Institute of Electronic Engineering, Heilongjiang University, Harbin Heilongjiang 150080, China) 《控制理论与应用(英文版)》 EI 2003年第1期101-104,共4页
This article concerns a coupled LMIs approach to delay-dependent observer-based output feedback stabilizing controller design for linear continuous-time systems with multiple state delays. The advantage of our propose... This article concerns a coupled LMIs approach to delay-dependent observer-based output feedback stabilizing controller design for linear continuous-time systems with multiple state delays. The advantage of our proposed delay-dependent coupled LMIs criterion lies in that: ( 1 ) it can optimize one of multiple time delays with others selected properly, and at the same time, the feedback-gain and observer-gain can be obtained, respectively. (2) it is less conservative than the existing delay-independent ones in the literature. Algorithm to solve the coupled LMIs is also given. Numerical examples illustrate the effectiveness of our method. Keywords Delay-dependent criterion - Time-delay system - Multiple time-delay - Observer-based controller - Linear matrixinequality (LMI) 展开更多
关键词 Delay-dependent criterion Time-delay system Multiple time-delay Observer-based controller Linear matrixinequality (LMI)
下载PDF
Development of Performance-Based Tunnel Evaluation Methodology and Performance Evaluation of Existing Railway Tunnels
9
作者 Sadao Kimura Takashi Kitani Atsushi Koizumi 《Journal of Transportation Technologies》 2012年第2期113-128,共16页
The concept of performance-based design, which mainly focuses on mechanical performance, has become the international standard, as in the case for ISO. The standardization of tunnel design has not been achieved becaus... The concept of performance-based design, which mainly focuses on mechanical performance, has become the international standard, as in the case for ISO. The standardization of tunnel design has not been achieved because it requires integration of separate specialized fields, such as geotechnical engineering, structural engineering and concrete engineering. It is also required to clarify performance-based criteria for tunnel structures to suit specific use purposes (objectives), establish the concept of survey, planning, design, construction and maintenance based on such criteria, and develop proper management systems for operation and maintenance to suit specific tunnel use purposes. To this end, it is vital to develop a methodology for evaluating and verifying the performance of existing tunnels. This paper presents a new concept of performance requirements for tunnel structures and describes the method of quantitatively evaluating the total performance of existing tunnels in relation to the required performance, assuming the total performance to be based on the Analysis Hierarchy Process. 展开更多
关键词 TUNNEL Performance criterion Life CYCLE DESIGN Performance-based DESIGN ASSET Management Maintenance Analysis HIERARCHY Process
下载PDF
A criterion for quantum teleportation of an arbitrary N-particle state via a 2N-particle quantum channel 被引量:3
10
作者 刘大明 王艳伟 +1 位作者 江秀梅 郑亦庄 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第2期53-61,共9页
A criterion for he tquantum teleportation of an arbitrary N-particle state via a 2N-particle quantum channel is presented by introducing a term of the judgment operator''. Using the criterion, not only the qualitati... A criterion for he tquantum teleportation of an arbitrary N-particle state via a 2N-particle quantum channel is presented by introducing a term of the judgment operator''. Using the criterion, not only the qualitative judgment of the possibility of successful teleportation can be made but also the quantitative calculation of the probability of successful teleportation can be explicitly given. In addition, a new genuine four-qubit entangled state is proposed, which could not belong to the category of previously known states under stochastic local operations and classical communication. 展开更多
关键词 teleportation criterion judgment operator generalized measurement base
下载PDF
Criterion of Quantum Entanglement and the Covariance Correlation Tensor in the Theory of Quantum Network
11
作者 QIANShang-Wu GUZhi-Yu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2003年第1期15-20,共6页
This article discusses the covariance correlation tensor (CCT) in quantum network theory for four Bell bases in detail. Furthermore, it gives the expression of the density operator in terms of CCT for a quantum networ... This article discusses the covariance correlation tensor (CCT) in quantum network theory for four Bell bases in detail. Furthermore, it gives the expression of the density operator in terms of CCT for a quantum network of three nodes, thus gives the criterion of entanglement for this case, i.e. the conditions of complete separability and partial separability for a given quantum state of three bodies. Finally it discusses the general case for the quantum network of m≥3 nodes. 展开更多
关键词 量子力学 量子牵连 协变关联张量
下载PDF
水泥基材料中钢筋脱钝临界氯离子浓度的加速测试装置及方法 被引量:1
12
作者 余波 黄俊铭 +1 位作者 卢金马 杨绿峰 《材料导报》 EI CAS CSCD 北大核心 2023年第3期148-153,共6页
本工作结合氯离子电迁移系统和电化学测试系统,研发了一种新型的水泥基材料中钢筋脱钝临界氯离子浓度的加速测试装置,分别测试了混凝土和砂浆中钢筋脱钝过程的开路电位、极化电阻和腐蚀电流密度的变化规律,提出了水泥基材料中钢筋脱钝... 本工作结合氯离子电迁移系统和电化学测试系统,研发了一种新型的水泥基材料中钢筋脱钝临界氯离子浓度的加速测试装置,分别测试了混凝土和砂浆中钢筋脱钝过程的开路电位、极化电阻和腐蚀电流密度的变化规律,提出了水泥基材料中钢筋脱钝的量化判别方法,并测试了混凝土和砂浆中钢筋脱钝的临界氯离子浓度。分析结果表明,利用所研发的临界氯离子测试装置不仅可以通过电迁移方式加速氯离子在水泥基材料中的传输、缩短试验测试周期,而且能够通过量化判别准则判别试件中钢筋测试端面是否发生脱钝,避免传统测试方法采用钢筋环面作为测试工作面、根据腐蚀电化学参数的特定取值或变化规律定性判断钢筋是否脱钝造成的测试误差。 展开更多
关键词 水泥基材料 钢筋脱钝 临界氯离子浓度 测试装置 量化判别准则
下载PDF
Fermentation process modeling of exopolysaccharide using neural networks and fuzzy systems with entropy criterion
13
作者 Zuo-Ping Tan Shi-Tong Wang +1 位作者 Zhao-Hong Deng Guo-Cheng Du 《Journal of Biomedical Science and Engineering》 2010年第4期430-438,共9页
The prediction accuracy and generalization of fermentation process modeling on exopolysaccharide (EPS) production from Lactobacillus are often deteriorated by noise existing in the corresponding experimental data. In ... The prediction accuracy and generalization of fermentation process modeling on exopolysaccharide (EPS) production from Lactobacillus are often deteriorated by noise existing in the corresponding experimental data. In order to circumvent this problem, a novel entropy-based criterion is proposed as the objective function of several commonly used modeling methods, i.e. Multi-Layer Perceptron (MLP) network, Radial Basis Function (RBF) neural network, Takagi-Sugeno-Kang (TSK) fuzzy system, for fermentation process model in this study. Quite different from the traditional Mean Square Error (MSE) based criterion, the novel entropy-based criterion can be used to train the parameters of the adopted modeling methods from the whole distribution structure of the training data set, which results in the fact that the adopted modeling methods can have global approximation capability. Compared with the MSE- criterion, the advantage of this novel criterion exists in that the parameter learning can effectively avoid the over-fitting phenomenon, therefore the proposed criterion based modeling methods have much better generalization ability and robustness. Our experimental results confirm the above virtues of the proposed entropy-criterion based modeling methods. 展开更多
关键词 RELATIVE ENTROPY MSE-criterion based Modeling ROBUSTNESS Parzen WINDOW TSK Fuzzy System
下载PDF
基于拓展禁区判据的光伏接入牵引供电系统低频稳定性分析 被引量:1
14
作者 赵霞 谢子昀 +3 位作者 王英 陈小强 辛月阳 母秀清 《高电压技术》 EI CAS CSCD 北大核心 2023年第5期1997-2007,共11页
在“双碳”愿景下,光伏通过铁路功率调节器接入牵引供电系统具有良好的发展前景,但光伏接入会对系统的低频稳定性产生影响。针对这一问题,首先建立了光伏-车-网耦合系统小信号阻抗模型,得到了该系统的回比矩阵;然后针对禁区判据进行拓展... 在“双碳”愿景下,光伏通过铁路功率调节器接入牵引供电系统具有良好的发展前景,但光伏接入会对系统的低频稳定性产生影响。针对这一问题,首先建立了光伏-车-网耦合系统小信号阻抗模型,得到了该系统的回比矩阵;然后针对禁区判据进行拓展,提出了拓展禁区判据并给出了判据形式;最后利用拓展禁区判据分析了铁路功率调节器控制器参数等系统参数对低频稳定性的影响,并搭建MATLAB/Simulink测试模型和StarSim半实物实验平台进行了验证。结果表明,与禁区判据相比,拓展禁区判据能更准确地判断光伏-车-网耦合系统低频稳定状态,降低了一定的保守性。 展开更多
关键词 光伏-车-网耦合系统 铁路功率调节器 光伏并网 拓展禁区判据 低频稳定性 StarSim
下载PDF
融入“OBE”教学理念的“动物微生物及免疫”课程评价标准开发
15
作者 杨井坤 《黑龙江水产》 2023年第6期482-486,共5页
“成果导向”教学理念(简称“OBE”)1981年由Spady等人提出后,迅速得到人们的重视和认可,并已成为美国、英国、加拿大等国家教育改革的主流思想与理念。黑龙江职业学院在全面推进“OBE”教育教学改革的基础上,进一步树立科学的人才成长... “成果导向”教学理念(简称“OBE”)1981年由Spady等人提出后,迅速得到人们的重视和认可,并已成为美国、英国、加拿大等国家教育改革的主流思想与理念。黑龙江职业学院在全面推进“OBE”教育教学改革的基础上,进一步树立科学的人才成长观和“评价即学习”的理念,创新“三循环”学生评价机制,构建并实施符合职业教育人才成长规律的“素质基础、能力本位”学生评价体系,边研究、边实践、边完善,持续改进结果评价、强化过程评价、探索增值评价、健全综合评价,实现评价主体、评价内容、评价标准、评价形式、评价方法多元化,借助大数据分析,提高学生评价的科学性、准确性、客观性、全面性,促进学生全面发展和个性化发展,促进人才培养目标的有效达成,不断提高技术技能人才培养水平。“动物微生物及免疫”课程在以上前提下,融入“OBE”教学理念进行课程评价标准的开发与应用,有关课程评价的标准开发与应用的具体办法供参考。 展开更多
关键词 “动物微生物及免疫”课程 “成果导向”教学理念(OBE) 评价标准
下载PDF
浅埋厚松散层薄基岩综采工作面开采覆岩切落体结构分析及应用 被引量:2
16
作者 汪北方 蒋嘉祺 +2 位作者 刘学生 梁冰 张晶 《岩土力学》 EI CAS CSCD 北大核心 2023年第10期3011-3021,共11页
浅埋厚松散层薄基岩综采工作面开采覆岩破断失稳诱发的强压显现问题日益凸显,已对矿井安全及高效生产带来严重威胁。为此,以神东矿区22614工作面为工程背景,采用现场监测、相似试验与力学建模相结合的研究方法,分析其强矿压显现特征,揭... 浅埋厚松散层薄基岩综采工作面开采覆岩破断失稳诱发的强压显现问题日益凸显,已对矿井安全及高效生产带来严重威胁。为此,以神东矿区22614工作面为工程背景,采用现场监测、相似试验与力学建模相结合的研究方法,分析其强矿压显现特征,揭示采动覆岩破断失稳诱因,构建覆岩破断结构力学模型,核定工作面液压支架工作阻力,并开展现场实例应用。结果表明:现场监测的工作面开采顶板平均破断步距为11.2 m,液压支架平均工作阻力为8450.1 kN,最大工作阻力为11857 kN;相似试验中,工作面开采老顶呈短悬臂岩梁剪切破断,断裂面贯通地表,覆岩滞后煤壁整体切落,平均垮落步距为12.5 m;通过建立浅埋厚松散层薄基岩综采工作面覆岩切落体结构平面力学模型,提出了覆岩切落体结构失稳判据,指明不稳定系数与覆岩切落角和液压支架承载力间的正相关关系;并给定了工作面液压支架工作阻力计算公式,算出了液压支架平均承载力为8364.22kN,与现场监测结果具有较好的一致性。该结果可为我国浅埋厚松散层薄基岩综采工作面支架选型和顶板控制提供重要的理论依据。 展开更多
关键词 浅埋综采工作面 厚松散层薄基岩 切落体结构 平面力学模型 失稳判据 液压支架工作阻力
下载PDF
一种多轴向耦合随机激励下缺口试件振动疲劳寿命预测方法
17
作者 骆政波 范鑫 +2 位作者 刘峰 陈怀海 郑荣慧 《振动与冲击》 EI CSCD 北大核心 2023年第17期105-113,共9页
提出了一种多轴向耦合随机激励下缺口结构振动疲劳寿命预测的频域分析方法。实施了缺口试件的双轴向随机振动疲劳试验,研究了两个振动轴向上载荷谱之间的相干性和相位差对缺口试件疲劳损伤的影响规律;通过随机振动分析计算得到试件缺口... 提出了一种多轴向耦合随机激励下缺口结构振动疲劳寿命预测的频域分析方法。实施了缺口试件的双轴向随机振动疲劳试验,研究了两个振动轴向上载荷谱之间的相干性和相位差对缺口试件疲劳损伤的影响规律;通过随机振动分析计算得到试件缺口根部各节点的应力功率谱密度矩阵,并假设缺口试件裂纹萌生点为历经von Mises应力最大均方根值的节点;缺口试件疲劳临界点可由疲劳裂纹初始点和修正临界距离理论确定;在疲劳临界点处通过Carpinteri-Spagnoli频域准则计算缺口试件的振动疲劳寿命,并与试验结果进行了对比。结果表明:该多轴缺口疲劳预测方法具有较高的预测精度,绝大部分预测结果都在3倍误差带内。 展开更多
关键词 振动疲劳 多轴向随机基础激励 相干性 临界距离理论 Carpinteri-Spagnoli准则
下载PDF
低通道依赖的变电站动力电缆漏电流监测方法 被引量:7
18
作者 陈昊 沙浩源 +3 位作者 钱其隆 任旭超 刘怀宇 徐伟伦 《电力自动化设备》 EI CSCD 北大核心 2023年第1期218-224,共7页
为缓解变电站动力电缆漏电状态判断算法对理想通信条件的高度依赖,提出了一种低通道依赖的变电站动力电缆漏电流监测方法。首先,在监测信号同步计算中对传统的参考相量法进行改进,以电源侧为相位差计算的参考基准,消除了负荷波动对信号... 为缓解变电站动力电缆漏电状态判断算法对理想通信条件的高度依赖,提出了一种低通道依赖的变电站动力电缆漏电流监测方法。首先,在监测信号同步计算中对传统的参考相量法进行改进,以电源侧为相位差计算的参考基准,消除了负荷波动对信号同步计算的影响。然后,提出基于电流差动原理的复合漏电流判据,以解决系统在未采集到对比基准时的电缆漏电状态判断问题。同时,针对变电站实际运行中漏电流监测系统可能出现的非理想通信情况,建立了与之相匹配的不同漏电判断模式及相应的判断方法,实现了在信息不全的情况下动力电缆漏电状态的正常监测。最后,通过仿真及江苏某500 kV变电站实际数据对所提方法的有效性与优越性进行验证。结果表明,该方法能够在不同通信条件下灵活切换漏电判断模式,显著提高了对漏电状态判断的准确性与可靠性。 展开更多
关键词 动力电缆 改进参考相量同步法 复合漏电流判据 判断模式 漏电流监测 智能运检
下载PDF
基于系统拓扑动态调整的短路电流抑制措施对系统暂态功角稳定性的影响研究 被引量:5
19
作者 韩奕 陈维江 +7 位作者 韩彬 金玉琪 常乃超 张健 张彦涛 孟祥飞 郄鑫 倪秋龙 《电网技术》 EI CSCD 北大核心 2023年第5期2069-2077,共9页
随着电网的发展,网架结构不断加强,交流系统短路容量逐步提高,短路电流超标问题日渐突出,需要合理控制系统的短路电流水平。基于系统拓扑动态调整的短路电流抑制措施,通过在故障期间快速动态改变系统拓扑结构达到限制短路电流的目的。... 随着电网的发展,网架结构不断加强,交流系统短路容量逐步提高,短路电流超标问题日渐突出,需要合理控制系统的短路电流水平。基于系统拓扑动态调整的短路电流抑制措施,通过在故障期间快速动态改变系统拓扑结构达到限制短路电流的目的。该文以500kV和220kV典型接线为例,研究3/2接线与双母线接线的母线分段开关采用抑制措施后,对系统暂态功角稳定性的影响。根据理论及仿真分析得出,基于系统拓扑动态调整的短路电流抑制措施在有效减少短路电流的同时,对系统的暂态功角稳定性有一定的影响,实施中需要针对实际系统进行具体仿真分析。 展开更多
关键词 基于系统拓扑动态调整的短路电流抑制措施 暂态功角稳定性 等面积定则
下载PDF
A computed tomography reconstruction algorithm based on multipurpose optimal criterion and simulated annealing theory 被引量:4
20
作者 李辉 万雄 +2 位作者 刘桃丽 刘仲寿 朱彦华 《Chinese Optics Letters》 SCIE EI CAS CSCD 2007年第6期340-343,共4页
Although emission spectral tomography (EST) combines emission spectral measurement with optical computed tomography (OCT), it is difficult to gain transient emission data from a large number of views, therefore, h... Although emission spectral tomography (EST) combines emission spectral measurement with optical computed tomography (OCT), it is difficult to gain transient emission data from a large number of views, therefore, high precision OCT algorithms with few views ought to be studied for EST application. To improve the reconstruction precision in the case of few views, a new computed tomography reconstruction algorithm based on multipurpose optimal criterion and simulated annealing theory (multi-criterion simulated annealing reconstruction technique, MCSART) is proposed. This algorithm can suffice criterion of least squares, criterion of most uniformity, and criterion of most smoothness synchronously. We can get global optimal solution by MCSART algorithm with simulated annealing theory. The simulating experiment result shows that this algorithm is superior to the traditional algorithms under various noises. 展开更多
关键词 CCD A computed tomography reconstruction algorithm based on multipurpose optimal criterion and simulated annealing theory VIEW
原文传递
上一页 1 2 12 下一页 到第
使用帮助 返回顶部