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1.
The locally twisted cube is a newly topological structure of network. The authors we design a unicast fault-tolerant routing algorithm on the locally twisted cube by utilizing safety levels and the feature of the network. The performance of the proposed algorithm is evaluated through simulation experiments. When the number of faulty nodes reaches or exceeds half of the total, it can still achieve a quite high percentage of successful routing. An additional advantage of the routing algorithm is that it is highly probable that the selected route be a shortest route between the associated nodes. 相似文献
2.
To expand network coverage and enhance the reliability of wireless personal area network (WPAN), the problem of address overflow resulting from applying the meshed adaptive tree algorithm in large scale mesh network wis studied. By dividing the entire network into smaller sub networks, the subarea meshed adaptive tree wis constructed. An improved meshed adaptive tree routing algorithm wis proposed employing the hierarchical topology structure of the subarea meshed adaptive tree. Experimental results show that the algorithm expands the network coverage without increasing the routing overhead and the network load. It also effectively reduces the end to end delay and increases the packet delivery ratio and communication efficiency. It maintains a good performance in the networks with different scales and provides a theoretical basis for enhancing the coverage and reliability of WPAN. 相似文献
3.
The interconnection network used in a multiprocessor system provides an effective mechanism for the data exchange between the processors and is one of the dominating factors of performance of the system. The fault tolerance of an interconnection network can be measured by the probability that the network keeps functional in the presence of failures. The authors examine the fault tolerance of four regular interconnection networks (i.e. hypercube, crossed cube, Moius cube, and locally twisted cube) with the probabilistic approach. Experimental results show that all these interconnection networks display excellent fault tolerance. Moreover, the crossed cube enjoys the highest probabilistic of connectivity among them. 相似文献
4.
无线移动自组网是仅由移动节点所组成的网络,具有分布式控制、自组织、多跳等特点,由于该网络具有抗毁性能高、易铺设等性质,越来越受到业界的广泛关注。原始的路由协议已经满足不了现有网络不可预测、频繁变化的拓扑结构的需要,因此,在之前研究的基础上,对现有Ad Hoc网络AODV路由协议进行了研究,并设计出一种基于AODV协议的改进路由协议——基于认知的AODV协议(Cognitive-based AODV,CAODV)。通过NS2进行试验仿真,结果表明,CAODV协议具有比AODV协议更加优良的性质,可以有效降低重启路由发现频率,增加断裂链路的修复成功率,降低协议的控制负载,对现有网络的动态变化具有很强的适应能力。 相似文献
5.
Aiming at the problem of link fault restoration in ASON, an improved equalizing routing algorithm (ERA) is introduced to proportion the load at the routing phase. In order to solve the easy blocking problem for the network without wavelength converter because of the wavelength continuity constraint, the algorithm WRCA is proposed at the wavelength assignment phase. This algorithm is realized by adding collision detection object (CDO) in the path message of the resource reservation protocol with traffic engineering extension (RSVP TE). Depending on the value of the CD flag, different wavelength selection strategies are applied at the destination node, and the blocks resulting from wavelength reservation collision are reduced. The simulation experiments compare four wavelength assignment algorithms with the same routing algorithm ERA. The results show that compared with the traditional first fit algorithm (FF) and random fit algorithm (RD), the FF and RD employing CD scheme can effectively reduce the blocking ratio of the whole network, and enhance the practical applicability of the restoration algorithms. 相似文献
6.
The traditional routing protocol for wireless mobile ad hoc networks is unable to achieve balanced energy consumption and could not adapt to the dynamic topology changes well.A novel on-demand rooting algorithm is proposed based on load balancing and mobility prediction.The proposed rooting algorithm excludes the unstable links in routing discovery,and allows the node with more energy forward the routing request packet preferentially.In addition,it adopts the active local routing recovery strategy by predicting the link connection time,and finishes the repair work before the link being actually failure.The simulation experiments demonstrate that,comparing with the traditional AODV protocol,with slight increase of the rooting control overhead,the proposed algorithm increases the average packet delivery ratio,decreases the average end-to-end delay of the data packets,and achieves load balancing in the network and prolong the life-span of the network,which shows the proposed algorithm is highly practical. 相似文献
7.
Nowadays the network of high-speed and broadband is required in the application of multimedia technology and information community. Many methods, such as network layering design, address design and routing are introduced to design Enterprise Backbone Network VPN's interrelation protocol is disposed and VPN tunnel is cut to establish virtual private network. Server and run plane design, bowels IP address distribution and network security advisement to design Intelligent Residential Area Network are given. It is pointed out that the method of modern network designs satisfies high-speed, intelligent and broadband for the developments of network technology. 相似文献
8.
In wireless sensor networks that consist of a large number of low-power sensors.Because the sensor's energy is limited,one of the main design is to obtain long system lifetime.The authors firstly analyse LEACH and LEACH-C clustering routing for wireless sensor networks.Aimming at their shortcoming,they present a new routing LEACH-NEW.This routing uses multi ho Pinstead of one hop.At last,they use NS2 to simulate them.Simulation show results that new routing exhibits noticeably longer system lifetime than rouing LEACH and LEACH-C. 相似文献
9.
Zhang Changcai 《保鲜与加工》1993,(4)
This paper uses n nature numbers from 1 to n to form a numerical table of twofold maoic square' s necessary condition. It also proves that x>n(n-1) and the numerical table is the sufficient condition of the basic solution. 相似文献
10.
Honeycomb meshes are topological structures for connecting processors within parallel computers. The unicast routing strategy on honeycomb meshes are studied. It is indicated that a previous known routing algorithm may suffer from deadlock. A deadlock-free routing algorithm known as the XYZ-ROUTE algorithm is presented by employing the classical virtual channel technique. This algorithm is improved to make it work properly in the presence of convex faults. 相似文献
11.
On current network actuality and development trend, it is necessary to put traffic engineering in practice in IP backbone network on IP/MPLS. The essential demand in actualizing traffic engineering is traffic matrix measurement. After analyzing the defect of current measurement method, traffic engineering model and traffic matrix on LSP in IP backbone network based on MPLS, or relevant routing algorithm are researched. The merit of the traffic matrix's measurement method is that implement of measurement is only located in the edge node; therefore, network resource's cost is lower and it offers a new train of thoughts for resolving the flaw of current main measurement methods, moreover, and condition for actualizing traffic engineering. 相似文献
12.
The authors introduce a sort of novel adaptive penalty gene, transform the constrained problem into unconstrained problems. An solution is given for this unconstrained problem with genetic algorithm, and then it is used as initial values for the constrained variable metric method to get precise solution. The numerical experiments illustrate that this hybrid genetic algorithm is more efficient than the genetic algorithm, and at most situations globally optimal solution can be gotten. 相似文献
13.
A low-complexity blind adaptive receiver for ultra-wideband (UWB) systems in the presence of both multiple access interference (MAI) and inter symbol interference (ISI) is proposed, which is composed of two stages. In the first stage, a reduced-rank algorithm based on the multi-stage Wiener filter (MSWF) is considered to suppress the MAI and extract multi-path components. Channel estimation using the projection approximation subspace tracking with deflation (PASTd) algorithm and multi-path combining are then performed to further enhance the signal to interference plus noise ratio (SINR) of the desired user in the second stage. The simulation results show that the proposed receiver exhibits reasonably good bit error ratio (BER) performance compared with those of matched filter, conventional Rake receiver, decorrelating Rake receiver and adaptive receiver based on constant modulus algorithm (CMA). Moreover, it has faster convergence speed and less complexity. 相似文献
14.
15.
A virtual wavelet transform analyzer for the signal analysis based on the direct algorithm is introduced so that the discrete wavelet transform and continuous wavelet transform is maken to signal in the direct algorithm. The authors first introduce the direct algorithm of the WT, which is numerical algorithm obtained from the original formula of the wavelet transform by directly numericalizing. Then some conclusions are drawn on the direct algorithm. The examples are the sampling principle and technology for the wavelets, the limitation of the scale range of the wavelets and the measures to solve the edge phenomenal in the direct algorithm of the discrete wavelet transform, and some conclusions in the direct algorithm of the continuous wavelet transform. The virtual wavelet transform analyzer for the signal analysis based on the direct algorithm explored based on these studies and combined with virtual instrument technique can make the discrete wavelet transform and continuous wavelet transform to signal with any basic wavelet. It can be applied in studying the property of any basic wavelet and learning the theory on the wavelet transform, and also in making some engineering signal analysis. In the end, the authors give some typical examples for the application of the virtual analyzer. These examples show that the analyzer can be applied in many situations. 相似文献
16.
In wireless sensor network, routing protocols which based on clustering have the advantages of energy consumption, topology management and data fusion. The HEED protocol, which generates cluster heads based on distributed algorithm, drives up the rate of clustering and creates well distributed cluster heads. However, it does not consider the mobility of nodes in the network. When the distance between neighbor nodes has changed, the AMRP method which decides the node belongs to different cluster heads would cause problems such as high energy consumption, short lifetime of network and so on. Responding to these problems, the paper proposes the S HEED, a clustering algorithm based on stability, which chooses the stability as a parameter of nodes when choosing a cluster head. With S HEED algorithm, the high energy consumption problem among cluster nodes and cluster heads caused by the mobility is tackled. The simulation experiment demonstrates that the S HEED algorithm lower the energy consumption of cluster heads and prolongs the network lifetime. 相似文献
17.
Yang Yongzhen Ton Jun 《保鲜与加工》1993,(5):1-6
An adaptive robust control based on synthetical algorithm was presented in this paper. The main character is to put the expert knowledge into parameter identification to realize the robust estimation, and combine the generalised minimum variance control with the pole assignment control for improving the robustness of the controller. Numerical simulation has proved that the control scheme suggested by authors quite prevailed over the general adaptive controller in control effects. 相似文献
18.
In this paper, a simple genetic algorithm (GA) is presented for optimizing the structural systems with discrete design variable. First, the origin, basic process of GA was discussed. In order to improve the convergence of GA, considering the difficulty in choosing the probability of crossover and mutation, an adaptive GA, in which the probability of crossover and mutation were varied depending on the fitness values of the solutions, was introduced. Finally, the availability of the adaptive GA was shown by an example. 相似文献
19.
The distribution properties of the normally data and anomaly data in the network connectivity features have huge differences ; therefore, there exist the low rate of detection and false positive rate problem for the traditional classifier which is applied to the network intrusion detection. An adaptive classifier based on the artificial immune cluster is presented. The new classifier adopts multi -granularities idea and it effectively eliminates the inconsistency between the classification algorithm and the clustering algorithm. Through the classification of the data sets in real variety of network intrusion data sets, experimental results show that the classifier has high detection rate and low false positive rate; it has better classification performance and generalization ability than RBF and BP classifiers. 相似文献
20.
Rating cultivars and trials in applied plant breeding 总被引：8，自引：0，他引：8
A. C. Fasoulas 《Euphytica》1983,32(3):939-943
Summary The number of means m, from which a particular cultivar differs significantly, is used to arrange cultivars in order of descending superiority. For n cultivars under study, the maximum m value corresponding to the best cultivar is n-1, indicating that it exceeds significantly the n-1 other cultivars, and the minimum zero. Because m represents an objective and reliable statistical measure of cultivar performance, it has been used to calculate two indexes: (1) performance index, P=100 m/(n-1), giving the percentage of means which a particular cultivar exceeds significantly, and (2) differentiation index, D=200 m/n (n-1), giving the percentage of paired comparisons between cultivars that show significant differences. Rating cultivars according to P across years (Py), sites (Ps), and years plus sites (Pys), gives an overall picture of the relative superiority of the entries. Rating trials according to D allows comparisons between trials and offers the possibility when the same sets of entries are compared each year across sites, to identify sites that give maximum differentiation. 相似文献