- Yi Wang;Qixin Chen;Chongqing Kang;Mingming Zhang;Ke Wang;Yun Zhao;
The smart grid has been revolutionizing electrical generation and consumption through a two-way flow of power and information. As an important information source from the demand side, Advanced Metering Infrastructure(AMI) has gained increasing popularity all over the world. By making full use of the data gathered by AMI, stakeholders of the electrical industry can have a better understanding of electrical consumption behavior. This is a significant strategy to improve operation efficiency and enhance power grid reliability. To implement this strategy,researchers have explored many data mining techniques for load profiling. This paper performs a state-of-the-art,comprehensive review of these data mining techniques from the perspectives of different technical approaches including direct clustering, indirect clustering, clustering evaluation criteria, and customer segmentation. On this basis, the prospects for implementing load profiling to demand response applications, price-based and incentivebased, are further summarized. Finally, challenges and opportunities of load profiling techniques in future power industry, especially in a demand response world, are discussed.
2015年02期 v.20 117-129页 [查看摘要][在线阅读][下载 560K] [下载次数：187 ] |[网刊下载次数：0 ] |[引用频次：56 ] |[阅读次数：0 ] - Paul Soulier;Depeng Li;John R. Williams;
As computers continue to advance, they are becoming more capable of sensing, interacting, and communicating with the physical and cyber world. Medical devices, electronic braking systems in automotive applications, and industrial control systems are examples of the many Cyber-Physical Systems(CPS) that utilize these computing capabilities. Given the potential consequences of software related failures in such systems, a high degree of safety, security, and reliability is often required. Programming languages are important tools used by programmers to develop CPS. They provide a programmer with the ability to transform designs into machine code. Of equal importance is their ability to detect and avoid programming mistakes. The development of CPS has predominantly been accomplished using the C programming language. Although C is a powerful language, it lacks features present in other languages that facilitate the development of reliable systems. This has prompted research into language-based alternatives for improving program quality through the use of programming languages. This paper presents an overview of the characteristics of embedded and cyber-physical systems and the associated requirements imposed on programming languages. This is followed by a survey of relevant research into languagebased methods for creating safe, reliable, and robust software for CPS.
2015年02期 v.20 130-141页 [查看摘要][在线阅读][下载 519K] [下载次数：145 ] |[网刊下载次数：0 ] |[引用频次：4 ] |[阅读次数：0 ] - Jiapeng Zhang;Yingfei Dong;
While remote zone 3 protection relays are essential to power systems, their false trips are also one of main causes related to cascading blackouts. Although many methods have been developed on traditional power systems to address this issue, the past cascading failure events showed the ineffectiveness of these methods.With the development of Smart Grid(SG), new agent-based methods have been proposed to address this issue by utilizing SG real-time communications. We found that these solutions simply assume ideal communication networks and do not consider the effect of practical network constraints and resource management. In this paper,we propose several solutions to address practical network resource management and constraints, and further improve the agent-based solutions in order to prevent the false tripping of zone 3 relays in various conditions. We also analyze the potential issues of these solutions, and point out the future investigation in this direction.
2015年02期 v.20 142-154页 [查看摘要][在线阅读][下载 579K] [下载次数：55 ] |[网刊下载次数：0 ] |[引用频次：2 ] |[阅读次数：0 ] - Jisheng Peng;
In this paper, we consider the design of linear precoding in Multiple Input Multiple Output(MIMO) Power Line Communication(PLC) systems with finite-alphabet input. First, we derive mutual information of MIMO-PLC systems with impulsive noise. Considering the non-concavity of the objective function and the low-cost requirement of PLC systems, we choose the lower bound of the mutual information as the objective function. Subsequently,we propose a novel approach to design the precoding scheme to reduce computational complexity. Specifically,our work primarily includes the following two contributions:(1) We design the right unitary matrix that is a product of two fixed unitary matrices, which only depends on the modulation mode. Hence, the results can be saved and require less computations.(2) For the power allocation matrix, we first reduce the space of power allocation using constraints of the optimal power allocation policy. Consequently, we propose a non-linear search method to obtain the optimal power allocation in small space. In regards to the computational complexity of the analysis, we conclude that the proposed precoding matrix design scheme has low complexity and is easy to implement. Moreover, the numerical results are proven to demonstrate the performance of the proposed precoding design scheme.
2015年02期 v.20 155-163页 [查看摘要][在线阅读][下载 405K] [下载次数：128 ] |[网刊下载次数：0 ] |[引用频次：9 ] |[阅读次数：0 ]
- Mingchui Dong;Chinwang Lou;
In this paper, a methodology, Self-Developing and Self-Adaptive Fuzzy Neural Networks using Type-2Fuzzy Bayesian Ying-Yang Learning(SDSA-FNN-T2FBYYL) algorithm and multi-objective optimization is proposed.The features of this methodology are as follows:(1) A Bayesian Ying-Yang Learning(BYYL) algorithm is used to construct a compact but high-performance system automatically.(2) A novel multi-objective T2 FBYYL is presented that integrates the T2 fuzzy theory with BYYL to automatically construct its best structure and better tackle various data uncertainty problems simultaneously.(3) The weighted sum multi-objective optimization technique with combinations of different weightings is implemented to achieve the best trade-off among multiple objectives in the T2 FBYYL. The proposed methods are applied to electric load forecast using a real operational dataset collected from Macao electric utility. The test results reveal that the proposed method is superior to other existing relevant techniques.
2015年02期 v.20 164-174页 [查看摘要][在线阅读][下载 533K] [下载次数：45 ] |[网刊下载次数：0 ] |[引用频次：3 ] |[阅读次数：0 ] - Keqian Yan;Kewu Peng;Fang Yang;Jian Song;
Traditional Amplitude Phase Shift Keying(APSK) consists of rings with points uniformly spaced. By giving up this uniform-spacing feature, we propose an APSK optimization method based on the uniform APSK with Gray labeling(Gray-APSK). The aim of the optimization is to maximize the Generalized Mutual Information(GMI)of Bit-Interleaved Coded Modulation(BICM) for the targeted code rate and channel. We show that our optimized non-uniform APSK could offer further performance gain compared with the conventional uniform Gray-APSK and considerably outperforms the traditional quadrature amplitude modulation at the targeted SNR and channel.
2015年02期 v.20 175-181页 [查看摘要][在线阅读][下载 410K] [下载次数：48 ] |[网刊下载次数：0 ] |[引用频次：3 ] |[阅读次数：0 ] - Zhiqing Xiao;Yunzhou Li;Jing Wang;
The diversity provided by disjoint paths can increase the survivability of communication networks. This paper considers the allocation of network error correction flow on a network that consists of disjoint paths from the source node to the destination node. Specifically, we propose an algorithm of allocating the path-flows to support the given rate with minimum cost. Our analysis shows that the asymptotic time complexity of this algorithm is linearithmic, and this algorithm is optimal in general.
2015年02期 v.20 182-187页 [查看摘要][在线阅读][下载 239K] [下载次数：22 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：0 ] - Hui Li;Linxuan Zhang;Tianyuan Xiao;Jietao Dong;
Motion planning issues encountered in assembling airplanes by employing the 6PURU parallel mechanism are analyzed in this paper. A sine curve of the change rate of acceleration, which is called as jerk in the following text, is proposed for uniaxial flexible acceleration and deceleration planning based on the optimal time and velocity and acceleration constraints. Compared with other curves, the proposed curve can realize a continuous n-order derivative and the smooth change of the speed and acceleration. The method is computationally simple and suitable for programming. In addition, a multiaxial coordinated movement scheme is proposed. The motion trajectory is no longer simply split into many single-direction trajectories nor are all single-direction planning trajectories combined directly. The multiaxial coordinated movement scheme aims to achieve synergic movement in multiple directions to ensure smoothness of the movement in the event of a kinematic error when maintaining a stable value. If the movement fails to achieve this goal, driving force mutations will deteriorate the effect of synergic movement. A physical model of the parallel mechanism is developed in sim Mechanics, and a holistic system model is completed in SIMULINK. The feasibility of the new planning algorithm is simulated and tested, and then, the multiaxial synergic movement planning method is proposed and verified.
2015年02期 v.20 188-199页 [查看摘要][在线阅读][下载 824K] [下载次数：56 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：0 ] - Xin Wen;Xingwang Zhang;Yaping Zhu;
In this paper, we propose the Hyper Basis Function(HBF) neural network on the basis of Radial Basis Function(RBF) neural network. Compared with RBF, HBF neural networks have a more generalized ability with different activation functions. A decision tree algorithm is used to determine the network center. Subsequently, we design an adaptive observer based on HBF neural networks and propose a fault detection and diagnosis method based on the observer for the nonlinear modeling ability of the neural network. Finally, we apply this method to nonlinear systems. The sensitivity and stability of the observer for the failure of the nonlinear systems are proved by simulation, which is beneficial for real-time online fault detection and diagnosis.
2015年02期 v.20 200-204页 [查看摘要][在线阅读][下载 454K] [下载次数：42 ] |[网刊下载次数：0 ] |[引用频次：9 ] |[阅读次数：0 ] - Bo Hou;Fuchun Sun;Hongbo Li;Guangbin Liu;
This study investigates the consensus problem of second-order multi-agent systems subject to timevarying interval-like delays. The notion of consensus is extended to networks containing antagonistic interactions modeled by negative weights on the communication graph. A unified framework is established to address both the stationary and dynamic consensus issues in sampled-data settings. Using the reciprocally convex approach,a sufficient condition for consensus is derived in terms of matrix inequalities. Numerical examples are provided to illustrate the effectiveness of the proposed result.
2015年02期 v.20 205-211页 [查看摘要][在线阅读][下载 756K] [下载次数：49 ] |[网刊下载次数：0 ] |[引用频次：8 ] |[阅读次数：0 ] - Dexi Wang;Fei He;Yangdong Deng;Chao Su;Ming Gu;Jiaguang Sun;
Formal verification of VHSIC Hardware Description Language(VHDL) in Field-Programmable Gate Array(FPGA) design has been discussed for many years. In this paper we provide a practical approach to do so. We present a semi-automatic way to verify FPGA VHDL software deadlocks, especially those that reside in automata.A domain is defined to represent the VHDL modules that will be verified; these modules will be transformed into Verilog models and be verified by SMV tools. By analyzing the verification results of SMV, deadlocks can be found;after looking back to the VHDL code, the deadlocking code is located and the problem is solved. VHDL verification is particularly important in safety-critical software. As an example, our solution is applied to a Multifunction Vehicle Bus Controller(MVBC) system for a train. The safety properties were tested well in the development stage, but experienced a breakdown during the long-term software testing stage, which was mainly caused by deadlocks in the VHDL software. In this special case, we managed to locate the VHDL deadlocks and solve the problem by the FPGA deadlock detection approach provided in this paper, which demonstrates that our solution works well.
2015年02期 v.20 212-218页 [查看摘要][在线阅读][下载 189K] [下载次数：62 ] |[网刊下载次数：0 ] |[引用频次：2 ] |[阅读次数：0 ]
<正>Tsinghua Science and Technology was started publication in 1996.It is an international academic journal sponsored by Tsinghua University and is published bimonthly.This journal aims at presenting the up-to-date scientific achievements in computer science,electronic engineering,and other IT fields.It is indexed by EI and other abstracting indexes.From 2012,the journal enters into IEEE Xplore Digital Library and all papers published there are freely downloadable.This special issue is devoted to new research addressing the challenges in the areas of bioinformatics and computational biology.Biological and medical science is one of the fastest developing research fields in the last two decades.High throughput biological data that are used to provide information at molecular and genetic level are
2015年02期 v.20 219页 [查看摘要][在线阅读][下载 52K] [下载次数：12 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：0 ] -
<正>Tsinghua Science and Technology was started publication in 1996.It is an international academic journal sponsored by Tsinghua University and is published bimonthly.This journal aims at presenting the up-to-date scientific achievements in computer science,electronic engineering,and other IT fields.It is indexed by EI and other abstracting indexes.From 2012,the journal enters into IEEE Xplore Digital Library and all papers published there are freely downloadable.This special issue is devoted to addressing new challenges in Big Data computation and communications(Big Com).We intend to bring together researchers,developers,and practitioners interested in Big Data analytics,management,security and privacy,communication and high performance computing from academia,industry,and service providers,to share ideas,experiences,and practical implementations related to Big Com.Both theoreticians
2015年02期 v.20 220页 [查看摘要][在线阅读][下载 52K] [下载次数：33 ] |[网刊下载次数：0 ] |[引用频次：1 ] |[阅读次数：0 ] <正>Tsiiig/um Science and Technology(Tsumhiia Sci Techno/),an academic journal sponsored by Tsinghua University,is published bimonihly.This journal aims al prcsenling llic up-lo-date scientific achievements with high crealivily and great significance in computer and electronic engineering.C'onlributions all over the world are wclcomc.Tsinghua Sci Technol is indexed by IEEE Xplore,Engineering index(Ei,USA),I NSPEC,S A,C ambridge Abstract and other abstracting indexes.Manuscripts are selected for publication according to the editorial assessment of their suitability and evalualion from independent reviewers.Papers are usually sent to two or more reviewers including one reviewer out of China.Editorial stall will edit acccplcd papers to improve accuracy and clarity and shorten,if necessary.
2015年02期 v.20 221页 [查看摘要][在线阅读][下载 527K] [下载次数：10 ] |[网刊下载次数：0 ] |[引用频次：0 ] |[阅读次数：0 ]