- EI核心期刊
A new subject, the study of the laws of information-knowledge-intelligence transforms, is firstly proposed. The background and implications of the subject are explained. The framework and the fundamental concepts of the subject are then explicated，and the major results achieved so far within the subject are also briefly reported. It is pointed out that the research of the subject may open up a huge room for scientific discoveries and technological innovations and thus present great significance and wide foreground for applications.
Considering the impact of aggregation cost on the performance of aggregation routes in wireless sensor networks, an aggregation-decision-based distributed routing algorithm for data aggregation is proposed. When source nodes arrive or leave, the algorithm can calculate the aggregation benefit according to data correlation, aggregation cost and transmission cost. Then the algorithm will adaptively make aggregation and routing decisions based on aggregation benefit. Therefore, it can jointly optimize the aggregation and transmission costs and reduce the energy consumption for data gathering. This distributed algorithm makes all decisions only relying on the local information; hence, the routing maintenance cost is limited. Simulation results show that the energy consumption difference between this distributed online algorithm and the previous offline one is within 17% under any network conditions.
The traffic optimization under the inaccurate network information was discussed. Defining the virtual capacity, a model was made on the local state information; a distributed real-time and unsupervised learning algorithm was proposed, which can learn the range and frequency of the network traffic variation and then choose adaptively whether or not and how to adjust the traffic distribution between parallel paths. This algorithm can optimize the network traffic efficiently. It need not to make statistics, refresh and keep all kinds of state information and traffic matrix in the network.
To analyze the inter-cell interference of orthogonal frequency division multiple access (OFDMA) based distributed network architecture, with the example of generalized distributed cellular architecture-Group Cell, the interference conditions of Group Cell without power control and with signal-to-interference ratio (SIR) balancing power control, stepwise removal algorithm (SRA) are analyzed respectively. The system outage probability compared to traditional cellular structure is evaluated. Analyses and simulation results indicate that the inter-cell interference of Group Cell will not increase more than traditional cellular structure. Group Cell architecture with centralized resource scheduling and allocating also makes it possible to improve the system performance further. Based on these analyses, the concept of Resource Pooling is proposed.
A novel robust mobility management scheme (RMM) is proposed for Hierarchical MIPv6. In RMM, the period of discovering the mobile anchor point ( MAP) failure is decreased by adopting ICMPv6 protocol. And the procedure of recovering from the MAP failure is accelerated by using the primary and backup binding information. The performance of RMM is theoretically analyzed and compared with that of hierarchical MIPv6. The numeric and simulation results show that the performance of RMM is better than that of hierarchical MIPv6 in terms of MAP’s reliability, packet loss rate and the period of discovery and recovery of the MAP failure.
A new perfect correlation signal was proposed, which can be called as almost perfect punctured binary sequence pairs. Its properties and combinatorial admissibility conditions were studied. By making use of these properties and conditions, the searching efficiency for the almost perfect punctured binary sequence pairs can be improved significantly. A computational algorithm is compiled to find out a set of almost perfect punctured binary sequence pairs. The searching results show that the existent range of almost perfect punctured binary sequence pairs is so wide that they are suitable for engineering applications.
A phase-sweeping space-time bit interleave coded modulation (PS-ST-BICM) is presented. By expanding the dimensions of sweeping matrix, the correlation was achieved between the adjacent code matrices, and thereby the higher time diversity gain was realized which effectively avoided possible burst errors in block fading channels. The optimum design criterion of the rotation matrix was proposed to maximize both diversity and coding gain. Then the Singleton bound and BER performances were theoretically analyzed. The simulation results proved that the performance of the new scheme was improved greatly in the Rayleigh block fading channels.
To improve the service ability under hostile intrusion, intrusion tolerance technology was studied and an improved intrusion tolerance model was built. Intrusion tolerance ability was mainly quantified and discussed by the model. Conceptions of Intrusion Tolerance Degree, Integrity Degree and Security Degree were proposed. Some correlated factors which can influence Intrusion Tolerance Degree were analyzed. And quantizing simulation and solution were carried out. The conclusion showed that it was meaning to design intrusion tolerance system.
To improve the performance of detecting the transmitted sequence, the Viterbi algorithm (VA ) used in the multi-path channels was modified. The recursive metric equation was built and the renewed branch transition metric was given. The modified VA can estimate the channel information and detect the transmitted sequence simultaneously. Meanwhile, the channel information can be estimated by adaptive filter. The simulation results showed that the modified VA is near to the optimal algorithm, however, the its computational speed was faster than the optimal algorithm.
A novel quantum secret sharing (QSS) scheme is proposed by using entanglement swapping on GHZ states. In the scheme, the sender Alice enables the two receivers, Bob and Charlie, to share her secret messages directly via GHZ states entanglement swapping and local unitary operations. This scheme is high efficient in that all the GHZ states can be used to transmit messages except those chosen for checking eavesdroppers, two bits classical messages can be shared by using two GHZ states entanglement swapping. The eavesdropping analysis shows explicitly that the scheme is secure. It is proper to generalize the triple-party QSS protocol to the multiparty situation.
It was claimed that the construction and enumeration of symmetric correlation immune functions with order one was equivalent to the solutions in the binary field and their enumeration for a certain equation. It was also shown that the construction of symmetric correlation immune functions with order m was also related to the solutions in the binary field of the above equation. The equivalent equation was obtained. By solving the equivalent equation, the methods to construct symmetric correlation immune functions with higher order and to enumerate symmetric correlation immune functions with order one were presented. The lower bound of enumeration of symmetric correlation immune functions with order one was also given in two cases.
For maximum Doppler shift estimation in multi-input multi-output (MIMO) systems, the single-factor analysis of variance was applied to establish mathematical model and perform hypotheses testing for estimated values. Furthermore, a novel scheme for illegal data elimination was proposed based on the principle of maximum distance judgment and mean value replacement. Theoretical analysis and simulation results proved that the proposed scheme could detect and eliminate illegal data effectively and improve the accuracy of maximum Doppler shift estimation in MIMO systems.
The path selection for members of virtual concatenation group is non-deterministic polynomial（NP） complete problem in synchronous digital hierarchy(SDH) networks applying virtual concatenation technology. Two-sided constrained optimal path (TSOP) algorithm was proposed to maintain high utilization of network resources and ensure the new adding VC-n to satisfy the differential delay constraints. Simulations results showed the performance of TSOP algorithm is superior to those of k-shortest path algorithm and modified-link-weight k-shortest path algorithm.
The strand space model to analyze guessing attack on the authenticated protocol based on passwords was proposed. The penetrator’s strands were extended through adding guessing traces and the types of cryptographical operation. A new notion of ideal was defined and relative theorems were therefore modified and proved. The extended honest ideal model not only inherits its original characters, but also is adaptive for the analysis of guessing attack. The GLNS protocol was utilized to illuminate how to analyze a protocol formally and effectively by the use of this extended strand spaces.
Currently those algorithms to mine the alarm association rules are limited to the minimal support, so that they can only obtain the association rules among the frequently occurring alarm events, To address this problem, a new mining algorithm based on the statistical correlation was proposed, which firstly acquired the alarm net units with the same character by clustering; and then discovered the association rules from both high-frequency and low-frequency alarm events with the high correlativity and the high confidence. Experimental results demonstrated that this algorithm was efficient and accurate to mine the association rules among alarm events with both high-frequency and low-frequency.
A two-dimensional rate equation model of vertical-cavity surface-emitting lasers (VCSELs) was built up based on the multimode rate equations. The influences of the shape and position of injection contact electrode and intensity of the injection current on the transverse-mode characteristics of VCSELs were investigated by numerical simulation, and the azimuthally non-uniformity of the injection current was taken into account, the dependency of laser modes on different kinds of spatially periodical current was investigated. Numerical results show showed that the intensity and profile of injection current play played important roles in determining the mode behaviors of VCSELs.
An admission control scheme with multi-priority delay reservation is proposed for multi-priority multimedia network. In the scheme, different delay threshold was adopted for different priority traffic so as to guarantee network QoS. Numerical results showed that the service of both high priority traffic and low priority traffic was guaranteed by the new scheme, and moreover, the network utilization was promoted.
A kind of dynamic model of bicycle robot was built based on the lagrange method. To keep bicycle self-balance, the steering angle, the roll-angle and the rear wheel velocity were taken as system outputs; the steering, mass balancing and rear-wheel toque were taken as inputs. Therefore, a multi-input and multi-output (MIMO) affine nonlinear system was constructed. Then input-output linearization control theory was applied to analyze the affine nonlinear system, so that the equal linear system was achieved by exact linearization. By analysis of the equal linear system and state feedback method, the desired pole locations were realized. Computer simulations verified the validity of the control algorithm.
An efficient algorithm to calculate the probability distribution of XOR difference between single mod2n sum and XOR is presented. The complexity of this algorithm is O((n-1)/2), which is lower than that of Maximov’s result. For the case of multi-mod2n sum, a recursive formula to calculate the XOR difference between multi-mod2n sum and XOR is given.
By analyzing the present dominating prefetch algorithms’ advantages and disadvantages, according to the difference between VoiceXML-based voice platform and HTML-based World Wide Web, it is proposed that the cited voice resource should be prefetched in VoiceXML-based voice platform. At the same time of adopting the hot-spot-based prefetch technology, an adaptive multi-user shared Markov prediction model is presented, which can predict the forthcoming required resource of all the online users and its probability to improve the accuracy of the prediction. The simulation research showed that this multi-user shared Markov prediction model could get a higher hit ratio, reduce delay of a user’s request and improve response speed comparing with the single-user Markov prediction model with the same consumed bandwidth.
The acquisition probability of two popular algorithms are investigated, which are based on general cross correlation (GCC) algorithm and widely used to evaluate time difference of arrival (TDOA) coefficients. A numerical algorithm is proposed to calculate the acquisition probability of GCC, which lays a basis for the comparison between these two algorithms. In order to evaluate the TDOA，one of these algorithms is correlating the input signals directly while the other correlates the two input signals with a noiseless m-sequence separately. The simulation result proves that the later has higher algorithm efficiency.
A novel channel estimation and pilot structure are proposed for multi-input multi-output orthogonal frequency division multiplex (MIMO-OFDM) structure. When the number of OFDM symbols, whose channels keep invariant, equals the number of transmit antennas, the frequency and time domain channel estimation solutions based on superposition-pilot and orthogonal-pilot structure are deduced theoretically. The algorithm loosens greatly the condition for optimal pilot signals and has very low complex-ity and flexible antenna structure, where the design of pilot signals can be easily implemented to obtain the optimal mean square error （MSE） performance. The algorithm has a very big practical value when the number of transmit antennas is 2，3 and 4. Simulation results verified the validity of channel estimation algorithm and pilot structure.
To improve performance of distributed control wavelength-routed optical burst switching(WR-OBS) network, a novel parallel burst assembly algorithm based on Internet traffic estimation is proposed. In this algorithm burst assembly and resource reservation are implemented simultaneously. With this mechanism end-to-end delay introduced by burst assembly can be reduced with the time scale of several milliseconds to tens of milliseconds. Simulation result also shows that under light traffic load burst blocking probability can be reduced by 20%. Furthermore, transmission control protocol performance with this algorithm is studied, and simulation result shows that a much better transmission control protocol performance can be achieved compared with traditional wavelength routed optical burst switching network.
To compensate the effect of polarization mode dispersion (PMD) in fiber-optic transmission systems efficiently and automatically, an automatic compensation experimental system is proposed which uses certain electrical frequency component as control signal. On this foundation, the principles and characteristics of the three optimization algorithms, simplex algorithm, genetic algorithm and particle swarm algorithm, were analyzed and compared. Then these control algorithms were separately adopted not only to compensate first-order PMD alone, but also to compensate both first-order PMD and second-order PMD together. Consequently, the distribution of degree of polarization (DOP) and eye graphs were obtained. The experimental results showed that the particle swarm optimization algorithm is preferable in adaptive PMD compensation system.
The routing infrastructure of multi-area and hierarchy in the automatically switched optical network (ASON) was researched. A notification mechanism of topology information based on speaker node is proposed, which realizes topology discovery, synchronization and routing computation in the hierarchical network. The simulation showed that the size of routing load and link state database (LSDB) was rapidly decreased with the increase of routing layers. This mechanism can solve the scalability of the network, save the memory space of the node and improve the routing efficiency.
A constant-degree peer-to-peer network constitution based on d dimension star connected cycles(SCC) graph was presented firstly, namely SCC- distributed Hash table (DHT). It adopts DHT to search and locate resource, and the connection of network nodes are covered and connected according to SCC graph. SCC-DHT achieves a time complexity of logic hop per lookup request by using neighbors per node. The simulation results show that SCC-DHT has better robustness and expansibility.
A fuzzy neural network (FNN) based fault diagnosis model for the code division multiple access (CDMA) network is proposed which focusing on solving the difficult problem that general diagnosis algorithms can hardly build model for the CDMA network fault diagnosis system. For the proposed fault diagnosis model, the numbers of neurons in the output layer are based on the fault types of the CDMA network, and the amount of input variables needed for those fault diagnosis determine the number of neurons in the input layer. Moreover, the synaptic weighting value and fuzzy member function are obtained from training the model with the input/output fault diagnosis data in the expert knowledge base. Computer simulation results show the effectiveness and the applicability of the proposed method.
The P-cycles algorithms in the WDM mesh optical networks was investigated. In order to utilize the free resource adequately and improve the network performance in the WDM network, two evaluation parameters for P-cycles were introduced, and different P-cycles generation algorithms were proposed in terms of three aspects that are elementary cycle-set generation, expansion strategies and expansion times. At last simulation and analysis with these different algorithms will be presented. The simulation results show that the new P-cycles algorithms could be used in the different conditions and the network performance could be improved significantly when implmenting these algorithms.
Based on compressed chirp pulses and the linear superposition of these signals, a novel method to generate ultra wide band (UWB) shaping pulses was proposed. It is flexible and easy to get UWB shaping pulses, which not only can comply with the requirement of a special spectrum mask, but also can suppress the co-channel interference between UWB and the existing narrow band systems. The simulation results show that the power spectral density(PSD) distribution of the UWB shaping pulse is accorded with the federal communications commission(FCC) mask very well, and also has very high spectrum utilization ratio. It needn’t to reduce the transmitted power in the whole UWB frequency band to resolve the co-existence problem between UWB and the narrow band communication systems.
A two-stage implementation strategy based on canonical particle swarm optimization was proposed. With the cost of acceptably additional evaluations, this strategy achieved higher success rate which were demonstrated by a suite of benchmark functions. The simulation showed that two-stage implementation strategy could bring forward relatively higher success rate under different upper limitation of iterations. At the same time the proposed strategy reduced the sensitivity of learning rate and presented a stable performance. It was revealed experimentally that the number of sub-populations should be set at a moderate value to consider both the reliability and the computation cost.
To enhance the reliability and the fault coverage of the test results, a local error diagnostic mechanism was introduced into dynamic protocol conformance test, a new dynamic test method was proposed, whose principle and correctness was analyzed on determinate FSM model. The new method took full advantage of the dynamic information generated during test to avoid the incorrect locating of local error. Also a local error diagnostic method was presented on error sub-sequence, which was not restricted to single error assumption and more practical. The experimental results showed that the method can effectively avoid the descending of the test reliability and give better fault coverage.