- EI核心期刊
Making use of the temporal correlations of video frames and human visual characteristics, a new algorithm for video-dynamic evaluation is proposed, which is used to quantify motion information and evaluate video quality. Motion rate, motion area, and visual-interest-feature are integrated to calculate video-dynamic. Experimental results show that the video-dynamic metric is reliable, and is well agreed with perceived quality. It can be utilized in video quality measurement.
MA Min-yao1, LUO Shou-shan1,2, WANG Li-cheng1
Secure multi-party computation protocol allows a set of -parties to evaluate a joint function of their inputs such that the function is calculated correctly and furthermore no information about their inputs is revealed by the output of the function. Based on the determinate-commutative cryptosystem and under the semi-honest model hypothesis, secure two-party computation protocols for determine whether an element is belong to a certain finite set, whether two finite sets are equal, and whether two equivalence relations are equal are considered. A mathematic method, relates to kernel, image and kernel-classes of mapping, to determine whether two mappings are equal is introduced. Furthermore, two-party computation protocol for determine whether two mappings are equal is given. Correctness, security, and efficiency of our protocols are analyzed.
XIAO Yong-kang1, SHAN Lin-wei2, YUAN Jian2, SHAN Xiu-ming2
A new router-aided multicast network tomography method is proposed to estimate the spatial-temporal distribution of network performance. Based on MINC (Multicast-based Inference of Network-internal Characteristics), statistical results of background data flows measured by routers are used to improve the correctness of multicast probe even when the probe speed is low. With combination of the maximum likelihood estimation and the aided measurement results, the estimation error is reduced significantly, and the worse influence on background data flows caused by the increase of probe speed is avoided. Simulation shows the validity of the method.
MA Yinglong1,2,ZHANG Shipeng1,LIU Shaohua2,3,JIN Bei
According to that the traditional keyword based information query cannot satisfy
the users’ needs, a new approach for semantic query is proposed. Semantic subst
itution rules and ranking strategy based on semantic approximation degree
also are exploited. Also a distributed semantic query system (DSQ) is developed
to perform the tasks of semantic queries across multiple ontologisms based on a
multiagent system.
We first formalize the definition and the security model of certificateless strong proxy signatures (CLSPS), and then propose a novel CLSPS scheme from bilinear pairings. It proves that our CLSPS scheme satisfies all the requirements of strong proxy signatures in certificateless public key cryptography. Furthermore, our scheme is more efficient than the existing CLSPS schemes because it requires general cryptographic hash functions instead of MapToPoint function which is inefficient, and the signing algorithm and the verification algorithm online altogether require one scalar multiplication, two exponentiations and one pairing computation.
LI Zhi-min, ZHENG Shi-hui, YANG Yi-xian
Merkle-Damgård construction had been found that it could not preserve all of the properties of the compression function, such as the second preimage resistance property, pseudo random property etc. To improve the security of the iterative Hash function, an enhanced iterative construction, called CMD construction was proposed. This construction can maintain the collision resistance of the compression function. The analysis results show that it can resist the attacks on the Merkle-Damgård construction, including the second preimage attack and the herding attack. In addition, using these known attack methods, the security of the Enveloped Merkle-Damgård construction is showed to be the same as that of the Merkle-Damgård construction.
Probabilistic multivariate cryptosystem is one of the new research themes in multivariate public key cryptography. In order to improve the efficiency of probabilistic multivariate signature, an efficient and random new central map is proposed. Furthermore, a modified Gouget et al’s probabilistic method is presented, which can improve the efficiency of generating public key, and greatly reduce the length of public key. Based on the new proposed central map and the modified probabilistic method，an efficient probabilistic multivariate signature scheme is constructed. Through security analysis, this scheme can resist the currently four attacks for multivariate public key cryptosystems.
For the problems of multiple narrowband interferences and interferences with relatively large band in wide-band communication systems, an adaptive interference suppression algorithm based on the model of the generalized sidelobe canceler（GSC）is proposed. Constraining the detector to present a unit response to the desired user’s signature sequence, the detector is decomposed into corresponding constrained and unconstrained components. The unconstrained item is the desired user’s signature sequence and the constrained item is the linear combination of the null space of the signature sequence of the desired user. In the principle of the MOE, the algorithm adaptively adjusts the linear combination weights of the constrained item in order to suppress the interferences and detect the desired signal. Analysis and simulation show that the algorithm is less sensitive to the interference models.
Based on analysis of service blocking rate and traffic intensity of interactive
video services, a new hybrid fibercoaxial (HFC) access network design for inte
ractive video multiservice was presented with extended Erlang B model under no
nsharing edge bandwidth circumstances and with KaufmanRoberts recursive algo
rithm under sharing circumstances. Formulas were provided to calculate the optim
al Internet protocol quadrature amplitude modulation radio frequency numbers of
timeshifted television video and videoondemand services to achieve
an economical deployment of interactive video services.
A hybrid formation control of multi-robot system, combined with behavior-based method and feedback-based method, is presented. The multi-robot formation control is implement by the dead-zone and dynamic equations. The method overcomes the problems of fluctuation in behavior-based control. It is also proved that the method can meet the wide-angle transformation which can not be achieved by the following leader’s method based on feedback control. Experiments based on the AmigoBot robot platform shows it has better results comparing with several different methods.
HUANG Jiang-chun1, 2, ZHANG Jian-hua1, ZHANG Yan-yan1, ZHANG Ping1
In order to reduce computational complexity of selecting beamforming vectors and feedback in multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) systems, a nonlinear interpolation based beamforming scheme is proposed, the principle of which is to interpolate beamforming vectors of the non-pilot subcarriers via that of the pilot subcarriers. Analysis and simulation results illustrate that the proposed scheme outperforms the optimal beamforming with quantization as well as significant feedback and computational complexity reduction in the case of small size of codebook, while provides better performance than the existing linear interpolation and geodesic interpolation based beamforming methods with the same feedback.
Traveling agent problem is a complex and combinatorial optimization problem, which solves the problem of finding an optimal path when an agent migrates to several hosts. An improved ant colony algorithm is presented. A mutation operator is introduced. The local and global updating rules of pheromone are modified on the basis of ant colony algorithm with which the possibility of halting the ant system becomes much lower than the ever in the time arriving at local minimum. Experiment shows that the mobile agents can accomplish the computing tasks with much higher efficiency and in a shorter time.
ZHANG Hua1, WEN Qiao-yan1, YUAN Zheng1,2
Remote Desktop Protocol can make clients to access the remote servers, but it is vulnerable to man-in-middle attacks. A new password-based ciphersuite was proposed for the remote desktop protocol in this paper. It devised a key agreement protocol with the original password of RDP. The new ciphersuite can offer strong authentication. It doesn’t change the computation of keys. This ciphersuite is provably secure in random oracle model. The handshake of RDP that adopts this ciphersuite can avoid man-in-middle attacks. It is the first attempt at drafting provably secure key agreement ciphersuites for RDP.
LIU Da-liang, SUN Han-xu, JIA Qing-xuan, ZHENG Yi-li
A dynamic balance control method for a spherical inspection robot was presented. A cascade nonlinear system model was derived using input transformation and diffeomeorphism. Based on sigmoidal function, a state feedback controller was designed. This method guarantees globally asymptotic convergence of the state to the desired small neighborhood. Simulation results and experiments are carried out to verify the feasibility of this method.
TAN Jihong1,2,LI Wei3，WANG Cong3
On the basis of constructing index system of general quality evaluation of scien
ce and technology manuscrippt，a kind of contribution evaluation model based on
domai
n knowledge base is put forward，which is mainly used for the quantified quality
evaluation of science and technology periodical papers. In the first checkup of
total 2?365 contribution manuscrippt for computer science and technology，the
proto
type system can help the editors eliminate lowquality contributions about 35 p
ercent，which improves the first checkup efficiency of the editors effectively.
WU Bin, ZHENG Kang-feng, YANG Yi-xian
A honeynet architecture with the analysis model of alerts is proposed. The new design of honeynet combines alerts of network intrusion detection system NIDS and HIDS to find out the correlations among them. The alerts are filtered and merged using the network information and similarity membership function. An improved Apriori algorithm is applied to discover the alert correlation knowledge which is matched to construct attack scenarios. Experiments demonstrate that with the analysis model of IDS alerts the redundant IDS alerts decrease efficiently and the correlation relationships of different attacks are constructed accurately
LI Jian1,2, JING Bo2, YANG Yi-xian1
To make the negotiation agents gain optimal result and more efficiently to negotiate in multi-agent based e-commerce, an adaptive genetic algorithm is presented and applied in multi-lateral multi-issue simultaneous bidding negotiations. 1000 times of experiments show that, for satisfying results, the adaptive genetic algorithm averagely needs 210 times run with contrast to 187 times run of the standard genetic algorithm. So it also shows that the adaptive genetic algorithm can gain the optimal negotiation result more efficiently in multi-literal multi-issue negotiation.
SHEN Zhen-hui, WANG Xiao-xiang
The achievable rates of coded cooperative OFDMA systems were analyzed and their upper bound expressions were derived. Based on the expressions, an adaptive subcarrier searching allocation algorithm was proposed on the principle of maximization the minimum of users’ achievable rates. This algorithm starts with the greedy algorithm and optimizes subcarrier allocation by iterating. Simulation results show that the proposed searching algorithm can improve greatly the achievable rates, balance the performance of users and run quickly which could satisfy the real time application.
GENG Shu-qin, GAO Da-ming, WANG Jin-hui, ZUO Lei, WU Wu-chen
An improved dynamic framed slotted Aloha algorithm (IDFSA) based on the radio frequency identification system is presented. IDFSA divides the tags into different frequency channels in the design period and saves the communication time. In the meantime, and IDFSA optimizes the real-time slots accounts obtained after frequency division, reducing the colliding efficiency up to 2.67 times, and improves the system efficiency. IDFSA dissolves the problem that the slots amount increases exponentially with an increasing of the identified tags amount. IDFSA has been used in the 433/868/915MHz system, verifying this method easy and efficiency.
A distributed resource allocation scheme was proposed for relaying networks utilized orthogonal frequency division multiple access (OFDMA) technique. The problem was described as a relaying non- cooperative power allocation game (RNCPAG) between the node B and the relay node, and two utilities functions were exploited taking the maximum utility function as the optimization criterion. Moreover, on the constraints of the limited total transmission power, the existence of Nash equilibrium was investigated, while the proposed algorithm converged to a unique Nash equilibrium. Compared with the traditional uniform power allocation scheme, the study shows that the proposed scheme can significantly improve the performance in terms of system capacity and resource utilization within a few steps of iteration.
An Adaptive STBC-Beamforming cross-layer design scheme is proposed to improve wireless communication network’s spectral efficiencies. The scheme is scheduled through combining multi-level adaptive modulation and coding with hybrid automatic repeat request protocol. The transmitter updates the modulation mode, chooses the optimal transmission vector adaptively and retransmits data automatically by outdated feedback information. The close-form expressions of cross-layer system for spectral efficiencies and the probability of outage under outdated feedback are obtained. Effects of outdated feedback on system’s performance are analyzed. Simulations show that, compared to SISO cross-layer system and Alamouti’s cross-layer system, the performance of the adaptive STBC-Beamforming cross-layer system is observably enhanced.
XU Guo-ai1, ZHANG Miao1, CHEN Ai-guo1, LI Zhong-xian2
Through analyzing the principium of integer overflow, an integer overflow detection method on software source code is proposed which is based on integer variable unification. We presented the integer variable unification method and defined three unified actions which were used in three given cases. Then the detection process was described, it simplified integer overflow flaw into mathematic inequalities, and removed the influence of context to the objective variable. Finally, instances were provided to demonstrate the effectiveness and practicability of the presented method.
Model-driven service creation technology allows the reuse of application-level and enhances portability and development efficiency in telecommunication services. After analyzing the key concepts involved in telecommunication service process, a new event-driven approach for telecommunication service process modeling is proposed. This approach uses event-driven mechanism to combine actions and events to describe a service logic based on UML activity diagram extension, so that the service logic can make correct response to asynchronous events from network. This approach also meets the requirement of telecommunication service process modeling. UML activity diagram extension, model description of event-driven mechanism and executing mechanism of service process model are studied as well.
WANG Hai-ying , ZHANG Xin-fa
A new QP setting algorithm of I frame based on H.264 is proposed. The improved method establishes a rate-quantization(R-Q) model by using gradient-based picture complexity measure. Simulation shows that by using the proposed scheme, a better rate control accuracy and a higher PSNR gain will be achieved. When applied to scene change, the number of skipped frames will be significantly reduced and the overall subjective quality of the reconstructed video will be provided.
ZHANG Lu1, 2, CHUAI Gang1, 2, LIN Li-fan1, 2, WEN Xiao-jun1, 2
An analytical model based on multiple cooperative relays and multiple antennas at the destination in cooperative communication is presented. An approximate method is derived for analysis of the power allocation between the multiple relay nodes and the source node, so the transforming logarithmic operation into linear operation becomes very. Analysis and simulation demonstrate that there exists an optimal power allocation (OPA) parameter when the system model is determined. The effect signal-to-noise ratio (SNR) on the OPA parameter is also shown.
Aimed at data integration in a larger extent，an ontologybased description mod el of data query is put forward. By depicting informationproviding web service s as data views with limited access pattern，the model enables them to answer da ta queries as ordinary resource description framework (RDF) data sources do. The matching algorithm of corresponding querydata sources is presented. Based on the dynamic invocation technology of web services，a data integration system is designed which combines such two kinds of data sources. And a prototype is imple mented successfully through which the feasibility is validated.
Optical soliton amplitude squeezed state caused by intensity correlation self-phase modulation effect was generated experimentally. The main part of experiment system was asymmetric Sagnac interferometer. Pulsed laser was connected to a coupler with splitting ratio of 90:10 by PC/FC connector. The coupler and 40-meter photonic crystal fiber composed interference loop. At proper input power, optical soliton amplitude squeezed state could be observed at output terminal of the interferometer. Balanced homodyne detection system composed of 50/50 beam splitter, two low-noise photo detectors, adder/subtracter, and spectrum analyzer was used to detect the squeezed state. Intensity distribution curves of input and output of the Sagnac loop were drawn, and the signal noise curve using shot noise as reference was obtained. The compressibility was 1.6 dB. Analysis on experimental data shows that it’s possible to improve compressibility further by choosing proper photonic crystal fiber.
XIAO Li-hua, LI Li, WANG Hua-zhi
The effect of antenna directivity on both spatial fading correlation and signal-to-noise ratio based on Kronecker channel model is investigated in three dimensional scattering environments. The channel capacity of multiple-in multiple-out system for uniform circular array, line array, and rectangle array is studied. The contribution of antenna directivity to channel capacity is concluded that, when the main lobe of directive antenna points at the coming wave, the improved signal to noise ratio resulting from the antenna directivity will exceed the negative impact caused by increased spatial fading correlation, leading to a better channel capacity than that of isotropic antenna. The stronger antenna directivity is, the greater the channel capacity.
The polynomial representation of a quantum state is defined. Based on the Calderbank-Shor-Steane(CSS)- type construction of quantum codes, a new method for encoding and decoding of CSS-type quantum convolution codes is presented. Its corresponding networks are also described. The basis state of the code is transformed into the multiplication of an information polynomial by the generator polynomial. Then networks can be realized with operations of polynomial multiplication. The simple method possesses a highly regular structure, and the networks are easy to realize.
To analyze the channel capacity of multiple input multiple output-distributed antenna systems (MIMO-DAS) , a multiple cell channel model is proposed, and the closed-form expression for the ergodic capacity of downlink transmission in MIMO-DAS is also derived. Based on this expression, the channel capacities of distributed systems and centralized systems are compared. Simulation results show that compared with centralized systems, distributed systems improve channel capacity in the over 80% area of the cell, it is also shown that fewer optimal antennas are selected for transmission can get capacity gains greatly, when one optimal antenna is chosen, the channel capacity reaches the peak.