Publications (18)6.99 Total impact
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Article: Cooperative diversity based on rotation code
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ABSTRACT: In order to obtain coding gain along with diversity gain, rotation code was applied to cooperative diversity employing decoded-and-forward cooperative protocol. Different from the same two symbols transmitted in conventional repetition-coded scheme, two different symbols were transmitted separately in two successive timeslots in the proposed rotation-coded cooperative diversity. In this way, constellation spread in the available two-dimensional signal space rather than on a single-dimensional line in repetition-coded scheme, which was supposed to be responsible for the additional coding gain. Under the proposed cooperative transmission model, upper bounds for the symbol-error-rate (SER) of cooperative diversity based on repetition code and rotation code were derived respectively. Both analytical and simulated results show that cooperative diversity based on rotation code can obtain an improved coding gain (by about 2 dB) than repetition-coded scheme without the expense of power or bandwidth.Journal of Central South University of Technology 04/2012; 16(2):280-284. · 0.36 Impact Factor -
Article: Resource allocation for cooperative diversity systems based on quadrature modulation
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ABSTRACT: To improve the error performance and the resource utilization of cooperative systems, the optimum resource alloca-tion, i.e., power allocation and partner choice, for an adaptive decode-and-forward (DF) cooperative diversity system based on quadrature modulation is investigated. The closed-form expression of the bit error rate (BER) system performance is derived and an optimal power allocation (OPA) algorithm is proposed to optimize the power allocation between the local and relayed signals under the minimum BER criterion. Based on the OPA algorithm, a part-ner choice strategy is proposed to determine the partner locations specified by various cooperation gains. Simulation results show that the proposed resource optimization algorithms are superior to the unoptimized algorithms by significantly reducing the BER and improving the cooperative gain, which is useful to simplify the practical partner choice process.Journal of Systems Engineering and Electronics 05/2011; 22:327-333. · 0.28 Impact Factor -
Chapter: Research on Multi-Dimensional Cellular Automation Pseudorandom Generator of LFSR Architecture
04/2011; , ISBN: 978-953-307-172-5 -
Article: Peak-to-Average Power Ratio Reduction of OFDM Signals Using PTS Scheme With Low Computational Complexity
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ABSTRACT: Partial transmit sequences (PTS) is one of the most attractive schemes to reduce the peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. However, the conventional PTS scheme requires an exhaustive searching over all combinations of allowed phase factors. Consequently, the computational complexity increases exponentially with the number of the subblocks. By utilizing the correlation among the candidate signals generated in PTS, a novel scheme is proposed to decrease the computational complexity. The performance analysis shows that the proposed scheme can reduce the computational complexity dramatically while achieving the same PAPR reduction compared to the conventional PTS scheme.IEEE Transactions on Broadcasting 04/2011; · 1.70 Impact Factor -
Article: Peak-to-Average Power Ratio Reduction of OFDM Signals With Nonlinear Companding Scheme
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ABSTRACT: Companding transform is a simple and efficient method in reducing the Peak-to-Average Power Ratio (PAPR) of Orthogonal Frequency Division Multiplexing (OFDM) systems. In this paper, a novel nonlinear companding scheme is proposed to reduce the PAPR and improve Bit Error Rate (BER) for OFDM systems. This proposed scheme mainly focuses on compressing the large signals, while maintaining the average power constant by properly choosing transform parameters. Moreover, analysis shows that the proposed scheme without de-companding at the receiver can also offer a good BER performance. Finally, simulation results show that the proposed scheme outperforms other companding scheme in terms of spectrum side-lobes, PAPR reduction and BER performance.IEEE Transactions on Broadcasting 07/2010; · 1.70 Impact Factor -
Article: Performance analysis and partner selection for cooperative diversity based on MQAM modulation.
SCIENCE CHINA Information Sciences. 01/2010; 53:1044-1055. -
Conference Proceeding: Genetic Algorithm Rule Definition for Denial of Services Network Intrusion Detection
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ABSTRACT: Many previous genetic algorithm methods can get much better example results in KDD cup 99 dataset. In the real intrusion detection system, the software needs update the rule even everyday. In this paper, we expand previous work and present a fitness function, propose an efficient rule generator for denial of services of network intrusion detection. We use more chromosomes with relevant features and more rule generator. As such, the rules generated by our algorithm are suitable to continuously changing misuse detection. In order to verify our approach, we tested our proposal with KDD Cup99 dataset, The experimental results show that the proposed approach is an efficient way in network intrusion detection.Computational Intelligence and Natural Computing, 2009. CINC '09. International Conference on; 07/2009 -
Conference Proceeding: Back Propagation Neural Network for Short-term Electricity Load Forecasting with Weather Features
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ABSTRACT: In this paper, we expand previous work and present an accurate electricity load forecasting algorithm with back propagation neural networks. It contributes to short-term electricity load forecast methodology with neural network with weather feature such as max centigrade, min centigrade and weather types. The original electricity load is from shanghai district, which is composed of original every 5 minutes load records. Through the data transform the every hour data average 12 original records and weather feature become double value. After training and simulation, the prediction errors fit for the application needs. The algorithm besides other algorithms has been used in electricity load forecasting software. Many results confirm that the proposed method is capable of forecasting load efficiently.Computational Intelligence and Natural Computing, 2009. CINC '09. International Conference on; 07/2009 -
Conference Proceeding: Virus Analysis on IDT Hooks of Rootkits Trojan
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ABSTRACT: Rootkits Trojan virus, which can control attacked computers, delete import files and even steal password, are much popular now. Interrupt Descriptor Table (IDT) hook is rootkit technology in kernel level of Trojan. The paper makes deeply analysis on the IDT hooks handle procedure of rootkit Trojan according to previous other researchers methods. We compare its IDT structure and programs to find how Trojan interrupt handler code can respond the interrupt vector request in both real address mode and protected address mode. Finally, we analyze the IDT hook detection methods of rootkits Trojan by Windbg or other professional tools.Information Engineering and Electronic Commerce, 2009. IEEC '09. International Symposium on; 06/2009 -
Conference Proceeding: Research on Multi-dimensional Cellular Automation Pseudorandom Generator of LFSR Architecture
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ABSTRACT: Cellular automata (CA) or linear feedback shift register (LFSR) architecture is widely used in pseudorandom generator of applied cryptography. The paper proposes a multi-dimensional and multi-rank pseudorandom generator combined the CA algorithm and LFSR architecture. In order to test the feasibility of the design, we research on feasibility and efficient of the algorithm by using three bit tests such as mono bit test, poker test and run test according to FIPS 140-1 standard. The final result can pass three FIPS 140-1 standard pseudorandom stream bit tests and provide better pseudorandom key stream. The results illustrate the algorithm is feasible and efficient.Information Engineering and Electronic Commerce, 2009. IEEC '09. International Symposium on; 06/2009 -
Conference Proceeding: Network Intrusion Detection with Workflow Feature Definition Using BP Neural Network.
Advances in Neural Networks - ISNN 2009, 6th International Symposium on Neural Networks, ISNN 2009, Wuhan, China, May 26-29, 2009, Proceedings, Part I; 01/2009 -
Article: A bandwidth efficient two-user cooperative diversity system with limited feedback.
Science in China Series F: Information Sciences. 01/2009; 52:1055-1066. -
Conference Proceeding: Cooperative transmit diversity in wireless networks: Performance analysis and optimum power allocation
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ABSTRACT: Cooperative diversity is an emerging technique that enables single-antenna terminals to share their resources (bandwidth and power) and achieve transmit diversity in a distributed fashion. In this work, an adaptive decode-and-forward(DF) cooperative diversity system based on quadrature signaling is proposed. Then a tight closed-form approximate bit error rate(BER) expression is derived in terms of the average received inter-user and uplink channel signal-to-noise ratios (SNRs) and power allocation factor. The derived BER performance is validated by simulations, which makes it possible to optimize the power allocation between the local and relay signals numerically under the channel scenarios of interest. Simulations show that equal power allocation strategy outperforms noncooperative system and the full diversity order of two is achieved at high inter-user channel SNRs, moreover, it is optimum in ideal cooperation scenario. In general scenarios, optimum power allocation strategy can be exploited to achieve additional performance benefits.Communication Systems, 2008. ICCS 2008. 11th IEEE Singapore International Conference on; 12/2008 -
Article: Ore Geology, Fluid Geochemistry and Genesis of the Shanggong Gold Deposit, Eastern Qinling Orogen, China
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ABSTRACT: The Shanggong Au deposit in the Xiong'er Terrane, East Qinling, has reserves of about 30 t Au, making it one of the largest orogenic-type Au deposits hosted in volcanic rocks in China. The deposit is hosted in the andesitic assemblage of the Xiong'er Group of 1.85˜1.4 Ga. Three stages of hydrothermal ore-forming processes are recognized, Early (E), Middle (M) and Late (L), characterised by quartz-pyrite, polymetallic sulfides and carbonate-quartz, respectively. Homogenization temperatures of fluid inclusions are between 380-320d̀C for the E-stage, 300-220d̀C for the M-stage and 200-120d̀C for the L-stage. The composition of fluid inclusions changed from CO2-rich in the E-stage to CO2-poor L-stage. The M-stage fluid has the highest contents of cations and anions (e.g., SO42-, Cl1, K+), the highest (K+Na)/(Mg+Ca) and lowest CO2/H2O ratios, which probably resulted from CO2 phase separation. This, together with the alkaline and reducing conditions, as indicated by highest pH and lowest Eh values, is most conducive to the deposition of polymetallic sulfides and native elements such as Au, Ag and Te.H-O isotope systematics indicate that ore fluids evolved from deep-sourced through to shallow-sourced, with the M-stage being a mixing phase of these two fluid-systems. Nineteen δ18OW values, from 4.2 to 13.4 %o, averaging 8.1 %o, suggest that the E-stage fluids derived from metamorphic devolatilization of sedimentary rocks at depth. Comparison of the H-O isotope systematics between the Shanggong deposit and the main lithologies in the Xiong'er Terrane, shows that neither these nor the underlying lower crust and mantle, or combinations thereof, could be considered as the source of ore fluids and metals for the Shanggong Au deposit. Instead, a source which meets the isotopic constraints, is a carbonaceous carbonate-sandstone-shale-chert (CSC) sequence, which is present in the Guandaokou and Luanchuan Groups in the south of the Xiong'er Terrane. This conclusion is supported by thirteen high δ18O values of the Meso-Neoproterozoic strata south of the Machaoying fault, and the high δ18OW values calculated for their possibly metamorphic fluids. It can be also supported by previous observation that the Guandaokou and Luanchuan Groups were underthrust beneath the Xiong'er Terrane, during the Mesozoic collision between the Yangtze and Sinokorean continents.Available isotope ages, together with geological field data, constrain the timing of the Au metallogenesis between 250˜110 Ma. This metallogenesis and associated granitic magmatism, can be related to the Yangtze-Sinokorean continental collision that resulted in the formation of the Qinling Orogen. This collision event progressed from early compression (Triassic to Early Jurassic), through middle compression-to-extension transition (Late Jurassic to Early Cretaceous), to late extension (Cretaceous). These three stages in the evolution of the Qinling Orogen form the basis of an ore genesis model that combines collisional orogeny, metallogeny and fluid flow (CMF model). These three evolutionary stages correspond to the three-stages of ore-forming fluids of the Shanggong Au deposit. We conclude that the formation of the Shanggong Au deposit is a result of the Mesozoic northward intracontinental A-type subduction along the Machaoying fault during Yangtze-Sinokorean continental collision, which led to the metamorphic devolatilization of the CSC sequence, thereby providing both fluids and metals.Resource Geology 11/2008; 56(2):99 - 116. · 0.67 Impact Factor -
Article: Extraction of Misorientation Components from the Total Misorientation at Grain Boundaries using Electron Diffraction in a Y0.9Sm0.1Ba2Cu3O7 Film
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ABSTRACT: Grain boundary (GB) misorientation determines the transport properties of REBa2Cu3O7 (REBCO) superconducting films (rare earth (RE)). In this study, the misorientation angles between the adjacent grains in a Y0.9Sm0.1Ba2Cu3O7 (YSBCO) epitaxial superconducting film on buffers performed via ion-beam-assisted deposition have been characterized using transmission electron microscopy. The in-plane and out-of-plane misorientation at GBs and sub-GBs has been separated from the total misorientation. Most of the GB misorientation angles are smaller than 5°, with the in-plane component γ<3° and out-of-plane components α≤1° and β<2°. This study provided a relatively simplified, practical, and useful method for determination of GB misorientation angles and separation of the in-plane and out-of-plane misorientation from the total misorientation for epitaxial REBCO superconducting films.Journal of the American Ceramic Society 07/2008; 91(9):3045 - 3051. · 2.27 Impact Factor -
Article: Surface pressure solution for boundary‐element analysis of stokes flow
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ABSTRACT: Analysis of creeping flow problems using the boundary-element method is now well established. The method is based on the transformation of the governing partial differential equations into a boundary integral equation for the velocity at arbitrary field points in terms of the surface velocities and tractions. Associated with the velocity boundary integral equation is a pressure boundary integral equation. The singularities contained in the kernel functions for the pressure boundary integral equation are an order higher than for the velocity boundary integral equation. Hence, for field points along the boundary of the domain, the pressure boundary integral equation is hypersingular, causing difficulties in evaluating the surface pressure. A method of regularization for the pressure boundary integral equation in which the hypersingular integral is converted into a Cauchy principal value integral is discussed. Some example applications are presented.Communications in Applied Numerical Methods 06/2005; 7(5):367 - 376. -
Chapter: Acupuncture for children with cerebral palsy
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Conference Proceeding: Cooperative Diversity Based on Alamouti Space-Time Code
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ABSTRACT: Cooperative diversity enables single-antenna terminals in a multi-user environment to share their antennas so as to form a virtual antenna array and achieve spatial diversity in a distributed fashion. To improve the bandwidth efficiency of classical scheme, a novel cooperative diversity scheme based on space-time coding is proposed in this work. With the selection decode-and-forward (SDF) relaying protocol, a tight closed form approximate bit error rate(BER) for BPSK constellation is derived, and the effect of symmetric and asymmetric inter-user channels of various qualities on system performance is studied. Theoretical and simulation results show that the proposed scheme offers substantial performance gain over non-cooperative scheme under the scenarios of interest and the full diversity order of two is achieved at high inter-user channel signal-to-noise ratio(SNR). Compared with the classical cooperative diversity scheme, the proposed scheme provides better bandwidth efficiency with acceptable performance loss.Computer Science and Information Technology, 2008. ICCSIT '08. International Conference on;
Top co-authors
Top Journals
Institutions
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2008–2011
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Xidian University
Xi’an, Shaanxi Sheng, China -
Oak Ridge National Laboratory
- Materials Science and Technology Division
Oak Ridge, FL, USA -
Chinese Academy of Sciences
- Key Laboratory for Metallogenic Dynamics
Beijing, Beijing Shi, China
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2009
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Shanghai Jiao Tong University
- Department of Computer Science and Engineering
Shanghai, Shanghai Shi, China
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2005
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University of New Mexico
- Department of Mechanical Engineering
Albuquerque, NM, USA
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