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1.
The distribution system planning is performed with a loop configuration constraint from scratch.With Evolutionary Algorithm,a sample distribution network is designed with a loop configuration,in which the system is operated as radial configuration.It firstly introduces the mathematical model for distribution network planning,then the application of Evolutionary Algorithm for the planning of distribution network.By using the theory mentioned above, Visual C++ is applied to develop the distribution network optimization software.Finally with the optimization process of 17 nodes system being showed,the presented algorithm's utility and validity is verified.  相似文献   

2.
By analyzing the reason that why the existing routing protocols cannot be applied to the wireless sensor networks for bridge health monitoring, a new routing protocol is proposed. Since the locations of the collecting modules are fixed, the proposed protocol exchanges the routing information between the neighbor nodes by adjusting the exchange cycle according to reliability of the modules. For the low routing security requirement, while to increase the routing efficient, the middle nodes replying the routing requirements with variable thresholds is introduced. In order to make full use of information in route discovering procedure, the backup routes mechanism is adopted. The proposed protocol can efficiently forward data and is suitable for the bridge health monitoring.  相似文献   

3.
The existing security methods cannot be applied to the Internet of Things due to the defects of communication nodes. To solve this problem, an intrusion detection model based on repeated game theory is presented. A repeated game model algorithm for detecting malicious nodes is built, and the algorithm of Quantal Response Equilibrium (QRE) is used for optimizing the model and making results reach the Nash equilibrium. Moreover, a common punishment strategy is introduced to improve the success of transfer data in this model. The results of the simulation represent that this model can restrain malicious nodes attacking effectively and improve the efficiency of network.  相似文献   

4.
TOptimization of regional landscape pattern is significant for improving function and value of ecosystem,and restraining the expansion of urban layout.Taking Chengdu City for example,this paper applied RS and GIS techniques,landscape indexes and ecological service function evaluation to further analyze the temporal and spatial characteristics of landscape pattern and spatial differences of regional ecological functions,and on this basis,identified the spatial distribution of ecological source lands.Based on the long-term objective of building Chengdu into a modem garden city,this paper applied the accumulative cost distance model and introduced garden city theory to construct regional ecological corridors and ecological nodes,and explored the approaches of optimizing landscape pattern of modem garden city.The results showed that a great deal of arable land has been transferred to construction land in the urbanization;intensity of regional ecological functions showed obvious spatial differences;ecological source lands were mainly distributed in the Longmen Mountain,the Qionglai Mountain,the Changqiu Mountain and the Longquan Mountain;according to actual conditions of the study area,the road ecological corridors,river corridors and agricultural corridors in the layout of "four rings and six radial corridors" were constructed;ecological nodes dominated by intersection,wetland and forest park were formed.This research method and results are significant references for building Chengdu into a modem garden city  相似文献   

5.
In order to calculate and analyze the effect of two transmission lines in parallel on the reliability evaluation of bulk power system, a model including independent outage, common mode outage and dependent outage of these lines is deduced and a new algorithm corresponding to the model is presented. Two transmission lines in parallel including common mode outages and dependent outages can be really simulated as a multi-state component. While reliability indices are calculated, the probability and frequency of independent outage, common mode outage and dependent outage of a system failure state can be calculated at the same time, and computation complexity is reduced. The proposed model and algorithm are applied to the RBTS system, IEEE One Area RTS96 system and a real power system for reliability computation and analysis. Results show that the new algorithm is credible and validity.  相似文献   

6.
基于GF-1卫星遥感数据识别京津冀冬小麦面积   总被引:5,自引:1,他引:4  
省级尺度冬小麦面积的精准获取技术是农作物面积遥感监测研究的主要内容之一。为了获取省级尺度的冬小麦种植面积, 该文以北京市(京)、天津市(津)和河北省(冀) 3个省域范围为例, 以国家标准地形图分幅为分类的图幅单元, 利用国产GF-1/WFV数据, 构建冬小麦面积指数, 实现了省级尺度冬小麦面积的识别。本文以冬小麦全部9个月生育期的984景影像作为数据源, 依次经过数据预处理、标准图幅单元的NDVI合成、样本点选择、冬小麦面积指数构建、冬小麦作物类型确认、省域范围制图及精度验证等步骤完成研究区域内冬小麦面积的提取。采用区域网平差和6S大气校正算法对数据源预处理, 以中国1︰10万标准地形图分幅为分类图幅单元构建冬小麦面积指数, 将冬小麦面积指数按照1%的比例等分, 并将面积指数从0到100%分割为101个提取节点, 将提取节点的NDVI值依次与类型确认样本比较, 精度最高的则确认为冬小麦面积提取阈值, 同时将该阈值应用于图幅单元内冬小麦面积指数影像, 获取冬小麦种植分布。最后冬小麦面积识别的精度表明, 以标准地图分幅作为计算单元, 在GF-1影像基础上, 利用冬小麦面积指数能够显著提高冬小麦与其他地物类型的波谱差异, 且冬小麦的总体识别精度达到89.6%, 用户精度达到89.8%, 制图精度96.5%, Kappa系数0.72。在典型区域, 本文算法与监督分类算法精度结果较为一致, 除制图精度相差4.77%外, 总体精度与用户精度差都在1.00%以内, 说明本文算法具有精度高、运行效率高、分类单元识别结果一致性强的特点, 能够满足省级尺度农情遥感业务监测的需要。  相似文献   

7.
The follow-up application of underwater wireless sensor network is influenced by accuracy of self-localization of nodes. The self-localization of nodes is discussed in this paper. First of all, nodes of underwater wireless sensor network are classified into several levels according to the accuracy of position of nodes and the levels are from the first to the fifth in accordance with accuracy of nodes from high to low respectively. Secondly, the level of anchor nodes can be known by those unknown nodes from the information given by the anchor nodes themselves, At the same time the unknown nodes are able to be located in the area controlled by the first level of anchor nodes that are as the aggregation. Then the positioning algorithm is designed correspondingly in accordance with the accuracy level of nodes. Finally, the positioning algorithm is simulated and analyzed. The result shows that the unknown nodes can be located effectively by hierarchical control.  相似文献   

8.
A novel shuffled frog leaping algorithm for ICPT power programming   总被引:1,自引:0,他引:1  
A new mode of inductively coupled power transfer (ICPT) is presented to city electrization traffic vehicle power supply optimization. The power supply distribution plan and ICPT technology are investigated. To avoid the local optimal of shuffled frog leaping algorithm (SFLA),a novel algorithm based on mutative scale chaos search and SFLA is presented. It is applied to inductively coupled power transfer substation optimal planning. The advantages of global and local search strategies for SFLA are combined with the proposed algorithm. In order to implement local refined search to improve local chaotic search ability and to enhance the solution accuracy, mutative scale chaos search is introduced to the proposed algorithm. The minimum annual expense of the proposed algorithm is 2.39% less than that of SFLA, which shows its advantage.  相似文献   

9.
大豆产量潜力受到基因型和环境条件的制约。一种基因型的密度、植株分布决定其对太阳辐射、水分和养分的利用,进而高产的形成。当群体生长所需外界要素之一不能满足时,植株间形成竞争。产量的区域间及年际间差异与这种株间竞争关系密切,最终表现为单位面积内一个或多个产量构成因子的差异,如株荚数、荚粒数、或单粒重(籽粒大小)。本研究探讨籽粒大小在调节不同密度、行距条件下产量差异及年际间产量差异的作用。多点试验表明,籽粒大小在不同节位上及不同籽粒数的荚间差异不大。然而在2粒或3粒荚内,荚基部粒比中部及顶部粒小10%,而且子叶细胞体积差异不大。在改变源库、增强光照或遮阴条件下,籽粒大小发生变化。籽粒大小与子叶细胞数相关。籽粒大小是可塑的,但即使底部节位荚较顶部节位提前15~20 d鼓粒,籽粒大小在所有节位间差异不大,所以籽粒大小与子叶细胞数的关系仍值得探讨。  相似文献   

10.
Melting processes are calculated using the molecular dynamics simulation method. Melting points are obtained using the radial distribution function, potential energy temperature, and bond pair analysis. The characteristics of these different methods are analyzed by comparing calculated and experimental results. Tracing clusters from order to disorder can be determined easily by the radial distribution function method, but the melting point can not be obtained accurately. The potential energy temperature method is based on the principle that the distance between atoms near the melting point will have a step change, which can determine the melting points accurately. When a cluster changes from a solid to a liquid state, the microscopic structure will change significantly, providing the basis for the bond pair analysis method of determining the melting point.  相似文献   

11.
民族地区的农村居民点因受国家政策及人类活动的影响而亟待转型,探索此区域农村居民点的布局优化模式有利于推进该区域国土空间治理和全面实现乡村振兴。以民族地区典型代表区贵州省黎平县为研究区,采用AHP法、GIS空间分析法、复杂网络、Python语言编程等方法集成分析研究区农村居民点的优化布局模式。结果表明:(1)研究区农村居民点综合影响力在22.30~76.09之间,中高等水平的农村居民点居多,农村居民点综合影响大小分布不均。(2)以农村居民点综合影响力为切入点构建农村居民点复杂网络,网络的联系性、集中性强但中心性一般。在空间上,网络节点分布不均且差异明显,中心性强的节点集聚分布。将复杂网络的5个指标加权求和后,依据分析结果将黎平县农村居民点优化布局模式归纳为集聚发展型、重点发展型、潜力优化型、规模控制型、迁村撤并型。  相似文献   

12.
Yang  Youkui 《保鲜与加工》1991,(6):91-96
A procedure of fracture control blasting for achieving directional breaking of rocks by blasting is presented. The criterion for initiating of radial cracks in borehole wall under dynamic load and the method for determining the permissible rang of initial gas pressure (p0) in the charge cavity are developed .and the branching of radial cracks and the effeets of the pressure (p0) and blasthole geometry (R0.a.L3) on final dimensions of directed cracks are studied .with Fracture Mechanics analysis in all three aspects of fracture process including crack initiation .crack propagation and crack arrest.  相似文献   

13.
This paper presents the concept of equivalent-unit and the solution method of state probabilities for short-term reliability evaluation for generation systems. The ideas and methods are applied to evaluate short-term reliability of intercommected power systems,and the models of equivalent assistance,which can be conveniently combined with subsystem models,are propesed. The models and algorithm proposed not only solve the difficult problem of "state explosion" , but also improve the calculating accuracy. A numerical example is given to show that the models and algorithm are feasible and effective.  相似文献   

14.
There are a large number of malicious attack nodes and collusion groups in P2P(peer to peer) network, and the existing trust models improve the P2P network environment to some extent, but the emphasis of the models are different, which are unable to fully solve large-scale malicious attacks and deception. Therefore, a P2P trust model based on equilibrium theory is presented. The model consists of the construction of the trust structure, the malicious node detection and trust speculation. It constructs trust network according to the equilibrium theory, uses the equilibrium theory to define nodes balance factor, detects balance malicious nodes by calculating the impact of malicious behavior on the network, and adopts trust inference algorithm to estimate trust nodes to prevent distrust network nodes being added. Experimental results show that the model is reliable, and the algorithm is efficient and robust.  相似文献   

15.
A method based on radial basis function networks for forecasting chaotic time series is proposed.The nonlinear time series identification problem is formulated with a nonlinear autoregressive moving average(NARMAX)model then a new identification algorithm based on dynamic radial basis function networks is proposed.Then this method is applied to the estimation of embedding dimension for chaotic time series of Henon mapping and the confirmation of the chaotic phenomena in stock markets of China,from which one can get the desired results.Further research directions are also pointed out.  相似文献   

16.
A section algorithm of reliability evaluation for complex medium voltage Electrical Distribution Networks (EDNs) using adjacency multilist (AM) is proposed. The constructing method for AM is introduced. The AM can be used to store the structure data of EDNs and to solve the problem of space & time complexity. A new power flow algorithm of backward / forward sweep is proposed and a fast algorithm of forming sections in distribution network is put forward. The proposed algorithm makes a perfect combination of the power flow algorithm and the section algorithm of reliability evaluation, which makes efforts to decrease the work of programming and saves the computing time. Applying the proposed algorithm in RBTS-BUS6 system and actual EDNs, the reliability assessment results show that the algorithm has an advantage of saving time and possesses efficiency in engineering practicality.  相似文献   

17.
A Prüfer-coded genetic algorithm based on the decimal number of nodes is proposed and it is used to solve collaborative optimization planning of access solution of distributed generation(DG)and structure of distribution network.Using graph theory to generate theoretically feasible topology structureand the access nodes and the installed capacity of distributed generation are coded by the Prüfer number.The coding method makes the distribution network operation structure and the access solution of DG combine into the evolution problem of the same chromosomal gene.The length of the chromosome coding of this method is shorter than binary encoding.This solution takes full advantage of the Prüfer-coded to improve computational efficiency and convergence rateand makes some restrictions and improvements in some key parts of the algorithm to solve the problem illegal solution.Finallyfeasibility and superiority of the algorithm is validated by a case study.  相似文献   

18.
The worst and best-case coverage algorithm is presented based on probability mode of wireless sensor network. The main idea is that choose these lattice points possibly with lowest detection probability by nodes to form the most breach path and choose those lattice points possibly with maximal detection probability by nodes to form the most support path. Simulation experiment validates the algorithm.  相似文献   

19.
This thesis analyzes the factors which lead to the failure of equipment,the type of the failures and the reliability of the equipment.The distribution functions(such as exponential distribution and Weibuill distribution) of the failures are discussed and the reliability of equipment is estimated.Meanwhile,the methods of identifying the types of failures and the degree of the reliability of equipment are described by an actual example.The Failure Distribution and reliability of ZW-17/29 Series Air Compressors in use are obtained.It provides the ways to plan the technical and maintenance management of the equipment.  相似文献   

20.
A fracture-developed carbonate oil field in the east has a complicate oil and gas distribution in facture network at late development stage, which leads to multiplicity of favorable reservoir estimation. In view of problems above, ant colony algorithm is adapted to recognition and predict facture in this field. The ant parameters are optimized on the basis of core and image log data, and the spatial distribution feature of fracture is described, as a reticulate structure with three dominant clusters of fracture (NW, NNE & NE). Drilling leakage, production data and image log are then used for reliability analysis of fracture predict, which presents that ant colony algorithm is a practicable methodology to recognition fracture and provides a support for remaining oil distribution analysis. As a booming bionic algorithm, ant colony algorithm has great potential for quantitative fracture predict with seismic materials.  相似文献   

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