A load identification algorithm for contactless power transmission systems

When contactless power transmission (CPT) systems are operating normally, load variation will cause the system operating frequency to drift and the resonance frequency scope to deviate from the desired level. These fluctuations in turn cause the system to vary substantially and affect its normal operation. Considering the slip road track of the primary circuit and the phase angle change between the front of the sub network rectifier circuit current and the voltage, we employ different circuit models to analyze the nature and size of the load for the two types of anti perceptual situations. An algorithm is derived to calculate the junior circuit parameters with the load on the rails. Simulation analysis for the load identification under two different load conditions is conducted, and the expected results achieved.     

An optimal equivalent subchannel algorithm for low voltage power line communication system

According to the low voltage power line channel features,combined with adaptive bit loading and power allocation algorithm,an optimal equivalent subchannel algorithm is proposed.Under the condition of fixed amount of transmitted bits and the minimum transmitted power model,impact of optimal equivalent subchannel on the system performance is studied.The optimization algorithm sorts subchannels with similar transmission features into groups,thus the signaling load can be reduced,and the spectrum can be better used.The simulation results show that system can get lower bit error rate(BER) by adopting optimal equivalent subchannel algorithm.     

A cooperative localization algorithm for wireless sensor networks

Aiming at the shortcomings of the existing RSS(received signal strength) based localization algorithm for wireless sensor networks (WSN), a cooperative localization algorithm (CLA) is proposed. A reference anchor node is introduced to tolerant some minor error including the node position error. Dixon detection method is applied to remove abnormal RSS values, while the standard deviation threshold of RSS and learning model are introduced to reduce the RSS ranging error and effectively improve the precision. Simulation experiments are performed to evaluate the performance of the proposed algorithm. The results demonstrate that the localization accuracy is improved effectively, while the stability and robustness are better.     

A novel dynamic trust model for network service

A novel dynamic trust model for network service is proposed. The corresponding relationship of trust evaluation and interval-valued intuitionistic fuzzy numbers are introduced in the computations,compounds,and general operations of experience of trust,neighbor recommendation trust and agency recommendation trust,which are based on trust demand attributes. Meanwhile,the trust attributes’ weight factors are determined by precise function proportion,while time series weight factors are defined by the inverse form of exponential distribution. And the trust service is finally distinguished by the result of general trust scoring function and psychological factors. Simulation results show that the model can effectively build trust relationship between entities and restrain attacks from malicious entities.     

A fast segmentation algorithm for images with intensity in-homogeneity

A novel fast method based on local region active contour model is proposed to overcome the difficult and ineffective segmentation of in-homogenous images. A new energy function is defined by combining kernel function and cut metric. On one hand,kernel function is favor of computing the in-homogenous distribution of local regions effectively;on the other hand,better approximation of the curve length by cut metric can help contours to quickly evolve into the object’s boundary. In addition,in the evolving process of contours,a max-flow method is adopted,instead of traditional computational level set method. Experimental results of synthetic and real images show that the proposed method can effectively segment objects with weak boundary in in-homogenous images,as well as the complex structure objects with multi-gray levels. At the same time,it is robust to noise and the initial contours.     

A clustering algorithm based on link availability for MANET

The cluster topology management in the MANET network is studied in. The classic Lin-Gerla clustering algorithm is improved to increase the logical topological stability. By considering the node mobility in the communication systems, the notion of relative motion is introduced, and the nodes more stable are chosen as the cluster-heads, which effectively increases the stability of mobile network with Random Direction Model. Regarding the possible high concentration, a fast cluster splitting method is proposed for cluster maintenance. The simulation and performance analysis for the improved algorithm are given.     

A fuzzy logic multicasting algorithm for ad hoc networks

To increase the multicasting efficiency of Ad hoc networks, a fuzzy logic multicasting algorithm (FLMA) is proposed. FLMA adopts the fuzzy logic to tolerate the imprecise information caused by dynamic network topology. The two input variables of the fuzzy logic system are the relative degree of the additional coverage node number and the relative degree of the residual energy. The deferring time of rebroadcast is the output variable of the fuzzy logic system, which is used to optimize the priority of the nodes to rebroadcast. FLMA reduces the redundant retransmission and the chance of the contention and collision, while balances the energy consumption of the nodes. Simulation results reveal that the FLMA achieves better performance than BCAST in terms of the network lifetime, average end-to-end delay, the average number of drops per node and the throughput.     

A method for evolving the architecture and weights of neural networks via gene expression programming

An algorithm for automatic designation of the architecture and the weights of neural networks using gene expression programming (GEP) was presented. The fundamental ideas and procedures of the algorithm were discussed. The algorithm was improved to solve the problems of prematurity and lower variance rate. An application for neural networks designation was given. The experimental results indicate that the proposed GEP approach may evolve the architecture of neural network, and can obtain the weights more precisely. Compared to other conventional evolutional algorithms, GEP shows faster convergence.     

A combined regularization algorithm for three-dimensional electrical impedance tomography system

By studying the reconstructed algorithms of Tikhonov regularization and the Newtons one-step error reconstructor (NOSER),a combined regularization algorithm is proposed. Two evaluation parameters of reconstructed algorithms,i.e. normalization mean square distance criterion(NMSD)and normalized mean absolute distance criterion(NMAD)are used to evaluate the results precision of inverse problem quantificationally. The comparison among Tikhonov regularization,NOSER and the combined regularization shows that the ill-condition and error of inverse problem are reduced. This new algorithm can decrease the condition number by 97%,NMSD by 51% and NMAD by 41% at least. Simulate results show that the combined regularization algorithm can reconstruct the target image in the depth from 10 mm to 40 mm. The performance of this system and the combined regularization algorithm demonstrate significantly better spatial resolution and less reconstructed error.     

A domain decomposition algorithm in meshless method for discontinuous problem

A domain decomposition algorithm for material and displacement discontinuity problems in meshless method is presented. The domain is decomposed into sub-domains along the discontinuous interface. The continuity of the displacements on the interface is satisfied through the introduction of two transformation matrixes. The partitioned-matrix method is proposed to calculate the transferred stiffness matrix,which is sparse and bandy. By means of coupling meshless method and finite element method, the essential boundary condition can be imposed directly. The computer program based on the presented method is developed and two numerical examples, a beam consisted with two kinds of materials and an edge-cracked plate under uniform tension, are employed to demonstrate the correctness and efficiency of the method.     

A multi-parameter weighted clustering algorithm for mobile ad hoc networks

Network clustering can support resource spatial multiplexing and increase the capacity of the wirless networks. Clusterheads constitute the virtual backbone of the network, which reduces the overhead of routing and makes it simpler and easier for network     

A member selection model and solving algorithm for project owners

To reduce the uncertainty and ambiguity in the owners’ member selection process of mega-construction project,the influence of candidates’ competence,opportunity cost and coordination efficiency is investigated. By introducing the CMM (capability maturity     

A novel control method for controllable reactor of transformer type

Conventional control methods for controllable reactor of transformer type generally depend on the parameters of transformer and cannot control capacitor voltage effectively. A novel control method for controllable reactor of transformer type is proposed. Based on a novel algorithm for fundamental extraction, the proposed approach can control the reactance accurately in real time mode by monitoring the condition of primary voltage and current. It also can control the capacitor voltage effectively and keep the capacitor voltage stable by introducing the feedback of capacitor voltage to control the phase of secondary current. Simulation has been carried out to proof the effectiveness of the method.     

A novel control method for two-phase short current of lines

The tremendous power flow may be transfered when two-phase short line is shut down, which may result in unstable state of the system and large loss of electric power. A novel line fault current controller (LFCC) and control method for the fault current of the two-phase short are presented. LFCC, emdedded at the line terminal, is composed of a series-connection transformer, a shunt-connection transformer,2 controllable inductors and on-line taps and is equivalent to the series of the insertion voltage and the insertion inductor when it works. The insertion voltage at the sending terminal(receiving terminal) is controlled to lead (lag)the fault source voltage by 2π/3 by adjusting on-line taps states. Because the insertion voltage amplitude and the insertion inductance can be controlled independently, the fault current gets zero and the current through the fault line reaches the normal current by the appropriate control of the insertion voltage amplitudes and the insertion inductances. Therefore, the fault line keeps the operation and the current through the line during the two-phase short existing equals that in normal operation, which improves the supply reliability. In addition, the corresponding control strategy for two phase short current is proposed. The experiment results show that the proposed LFCC is able to control the fault current through the line to reach corresponding normal current. The proposed control method suited for the proposed LFCC for the two phase short current is verified with the simulation results.     

K近邻的自适应谱聚类快速算法

利用时域递归展开算法对墙体内热湿耦合传递方程进行求解。以木板为例,应用该算法进行了热湿耦合传递的分析计算,在时间域和空间域上分别运用递归展开法和控制容积法进行离散,从而得到递归形式的线性方程组,运用MATLAB软件对这一过程进行求解。计算结果与有限差分算法、解析解计算结果以及实验数据吻合良好,表明该算法能够用于求解多孔介质热湿耦合传递模型。时间步长的改变对计算结果影响较小,可通过增加时间步长方法来减少工作量。     

A reliability evaluation model for photovoltaic/diesel hybrid power generation system

Photovoltaic power generation is considered to be one of the most promising power generation forms. It is difficult to accurately assess the reliability of the photovoltaic system (PVS) for the volatility and intermittent of the light intensity. By analyzing PVS component failure modes and their impacts on PVS output power, the reliability model of PVS is built. Then the probability model of PVS output power is presented by considering both illumination uncertainty and PVS component random faults. According to the influence of components random faults outside the intentional islands on the reliability of load points inside the intentional islands, the concepts of repair zone, isolation zone and zero zone are defined. Furthermore, by considering the fail-operation of breaker and fuse, the concept for zone hierarchy is proposed, and the analytical formulas to calculate reliability indices of the load points inside the intentional islands are deduced. The application of the presented reliability evaluation model is clarified using a typical example to show the practicality and validity of the proposed approach.     

A method for considering parameter errors in power system harmonic state estimation

Total least squares (TLS) is proposed to complete harmonic state estimation when parameter and measurement errors are both taken into consideration. The buses are partitioned into subsets of non source buses and suspicious buses, thereby reducing the number of unknown state variables. The validity and practicability of this approach is validated using the IEEE 14bus harmonic testing system. The estimation precision is analyzed by random sampling 10 000 times in Matlab when measurement errors and parameter errors followed a Gaussian distribution. The results show that an accurate estimate can be obtained using TLS if parameter and measurement errors are considered.