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Improved butterfly optimization algorithm based on cosine similarity
CHEN Jun, HE Qing
Journal of Computer Applications    2021, 41 (9): 2668-2677.   DOI: 10.11772/j.issn.1001-9081.2020111776
Abstract502)      PDF (1469KB)(411)       Save
Aiming at the problems that Butterfly Optimization Algorithm (BOA) tends to fall into local optimum and has poor convergence, a Multi-Strategy Improved BOA (MSBOA) was proposed. Firstly, the cosine similarity position adjustment strategy was introduced to the algorithm, rotation transformation operator and scaling transformation operator were used to update the positions, so as to effectively maintain the population diversity of the algorithm. Secondly, dynamic switching probability was introduced to balance the transformation between the local phase and the global phase of the algorithm. Finally, a hybrid inertia weight strategy was added to accelerate convergence. Solving 16 benchmark test functions, as well as the Wilcoxon rank-sum test and CEC2014 test functions were to verify, the effectiveness and robustness of the proposed algorithm. Experimental results show that compared with BOA, some BOAs with different improvement strategies and some swarm intelligence algorithms, MSBOA has significant improvement in convergence accuracy and convergence speed.
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Malicious code detection based on multi-channel image deep learning
JIANG Kaolin, BAI Wei, ZHANG Lei, CHEN Jun, PAN Zhisong, GUO Shize
Journal of Computer Applications    2021, 41 (4): 1142-1147.   DOI: 10.11772/j.issn.1001-9081.2020081224
Abstract475)      PDF (2386KB)(601)       Save
Existing deep learning-based malicious code detection methods have problems such as weak deep-level feature extraction capability, relatively complex model and insufficient model generalization capability. At the same time, code reuse phenomenon occurred in large number of malicious samples of the same type, resulting in similar visual features of the code. This similarity can be used for malicious code detection. Therefore, a malicious code detection method based on multi-channel image visual features and AlexNet was proposed. In the method, the codes to be detected were converted into multi-channel images at first. After that, AlexNet was used to extract and classify the color texture features of the images, so as to detect the possible malicious codes. Meanwhile, the multi-channel image feature extraction, the Local Response Normalization(LRN) and other technologies were used comprehensively, which effectively improved the generalization ability of the model with effective reduction of the complexity of the model. The Malimg dataset after equalization was used for testing, the results showed that the average classification accuracy of the proposed method was 97.8%, and the method had the accuracy increased by 1.8% and the detection efficiency increased by 60.2% compared with the VGGNet method. Experimental results show that the color texture features of multi-channel images can better reflect the type information of malicious codes, the simple network structure of AlexNet can effectively improve the detection efficiency, and the local response normalization can improve the generalization ability and detection effect of the model.
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Construction of brain functional hypernetwork and feature fusion analysis based on sparse group Lasso method
LI Yao, ZHAO Yunpeng, LI Xinyun, LIU Zhifen, CHEN Junjie, GUO Hao
Journal of Computer Applications    2020, 40 (1): 62-70.   DOI: 10.11772/j.issn.1001-9081.2019061026
Abstract506)      PDF (1501KB)(404)       Save
Functional hyper-networks are widely used in brain disease diagnosis and classification studies. However, the existing research on hyper-network construction lacks the ability to interpret the grouping effect or only considers the information of group level information of brain regions, the hyper-network constructed in this way may lose some useful connections or contain some false information. Therefore, considering the group structure problem of brain regions, the sparse group Lasso (Least absolute shrinkage and selection operator) (sgLasso) method was introduced to further improve the construction of hyper-network. Firstly, the hyper-network was constructed by using the sgLasso method. Then, two groups of attribute indicators specific to the hyper-network were introduced for feature extraction and feature selection. The indictors are the clustering coefficient based on single node and the clustering coefficient based on a pair of nodes. Finally, the two groups of features with significant difference obtained after feature selection were subjected to multi-kernel learning for feature fusion and classification. The experimental results show that the proposed method achieves 87.88% classification accuracy by using the multi-feature fusion, which indicates that in order to improve the construction of hyper-network of brain function, the group information should be considered, but the whole group information cannot be forced to be used, and the group structure can be appropriately expanded.
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Correlation delay-DCSK chaotic communication scheme without inter-signal interference
HE Lifang, CHEN Jun, ZHANG Tianqi
Journal of Computer Applications    2019, 39 (7): 2014-2018.   DOI: 10.11772/j.issn.1001-9081.2019010036
Abstract475)      PDF (752KB)(238)       Save

The major drawback of existing Differential Chaos Shift Keying (DCSK) communication system is low transmission rate. To solve the problem, a Correlation Delay-Differential Chaos Shift Keying (CD-DCSK) communication scheme without inter-signal interference was proposed. At the transmitting side, two orthogonal chaotic signals were generated by an orthogonal signal generator and normalized by the sign function to keep the energy of the transmitted signal constant. Then, two chaotic signals and their chaotic signals with different delay time intervals were respectively modulated by 1 bit data information to form a frame of transmission signal. At the demodulation side, correlation demodulation was used to extract data information and the information bits were recovered by detecting the sign of correlator output. The theoretical Bit Error Rate (BER) performance of system under Additive White Gaussian Noise (AWGN) channel was analyzed by using Gaussian Approximation (GA) method, and was compared with classical chaotic communication systems. The performance analysis and experimental results indicate that, compared with DCSK system, the transmission rate of CD-DCSK system without inter-signal interference increases by 50 percentage points, and the BER performance of the proposed system is better than that of Correlation Delay Shift Keying (CDSK) system.

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Brain function network feature selection and classification based on multi-level template
WU Hao, WANG Xincan, LI Xinyun, LIU Zhifen, CHEN Junjie, GUO Hao
Journal of Computer Applications    2019, 39 (7): 1948-1953.   DOI: 10.11772/j.issn.1001-9081.2018112421
Abstract352)      PDF (1024KB)(242)       Save

The feature representation extracted from the functional connection network based on single brain map template is not sufficient to reveal complex topological differences between patient group and Normal Control (NC) group. However, the traditional multi-template-based functional brain network definitions mostly use independent templates, ignoring the potential topological association information in functional brain networks built with each template. Aiming at the above problems, a multi-level brain map template and a method of Relationship Induced Sparse (RIS) feature selection model were proposed. Firstly, an associated multi-level brain map template was defined, and the potential relationship between templates and network structure differences between groups were mined. Then, the RIS feature selection model was used to optimize the parameters and extract the differences between groups. Finally, the Support Vector Machine (SVM) method was used to construct classification model and was applied to the diagnosis of patients with depression. The experimental results on the clinical diagnosis database of depression in the First Hospital of Shanxi University show that the functional brain network based on multi-level template achieves 91.7% classification accuracy by using the RIS feature selection method, which is 3 percentage points higher than that of traditional multi-template method.

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Liver CT images segmentation based on fuzzy C-means clustering with spatial constraints
WANG Rongmiao, ZHANG Fengfeng, ZHAN Wei, CHEN Jun, WU Hao
Journal of Computer Applications    2019, 39 (11): 3366-3369.   DOI: 10.11772/j.issn.1001-9081.2019040611
Abstract506)      PDF (693KB)(258)       Save
Traditional Fuzzy C-Means (FCM) clustering algorithm only considers the characteristics of a single pixel when applied to liver CT image segmentation, and it can not overcome the influence of uneven gray scale and the problem of boundary leakage caused by blurred liver boundary. In order to solve the problems, a Spatial Fuzzy C-Means (SFCM) clustering segmentation algorithm combined with spatial constraints was proposed. Firstly, the convolution kernel was constructed by using two-dimensional Gauss distribution function, and the feature matrix could be obtained by using the convolution kernel to extract the spatial information of the source image. Then, the penalty term of spatial constraint was introduced to update and optimize the objective function to obtain a new iteration equation. Finally, the liver CT image was segmented by using the new algorithm. As shown in results, the shape of liver contour splited by SFCM is more regular when segmenting liver CT images with gray unevenness and boundary leakage. The accuracy of SFCM reaches 92.8%, which is 2.3 and 4.3 percentage points higher than that of FCM and Intuitionistic Fuzzy C-Means (IFCM). Also, over-segmentation rate of SFCM is 4.9 and 5.3 percentage points lower than that of FCM and IFCM.
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Quantum-inspired migrating birds co-optimization algorithm for lot-streaming flow shop scheduling problem
CHEN Linfeng, QI Xuemei, CHEN Junwen, HUANG Cheng, CHEN Fulong
Journal of Computer Applications    2019, 39 (11): 3250-3256.   DOI: 10.11772/j.issn.1001-9081.2019040700
Abstract537)      PDF (949KB)(244)       Save
A Quantum-inspired Migrating Birds Co-Optimization (QMBCO) algorithm was proposed for minimizing the makespan in Lot-streaming Flow shop Scheduling Problem (LFSP). Firstly, the quantum coding based on Bloch coordinates was applied to expand the solution space. Secondly, an initial solution improvement scheme based on Framinan-Leisten (FL) algorithm was used to makeup the shortage of traditional initial solution and construct the random initial population with high quality. Finally, Migrating Birds Optimization (MBO) and Variable Neighborhood Search (VNS) algorithm were applied for iteration to achieve the information exchange between the worse individuals and superior individuals in proposed algorithm to improve the global search ability. A set of instances with different scales were generated randomly, and QMBCO was compared with Discrete Particle Swarm Optimization (DPSO), MBO and Quantum-inspired Cuckoo Co-Search (QCCS) algorithms on them. Experimental results show that compared with DPSO, MBO and QCCS, QMBCO has the Average Relative Percentage Deviation (ARPD) averagely reduced by 65%, 34% and 24% respectively under two types of running time, verifying the effectiveness and efficiency of the proposed QMBCO algorithm.
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Uncertainty measurement and attribute reduction in incomplete neighborhood rough set
YAO Sheng, WANG Jie, XU Feng, CHEN Ju
Journal of Computer Applications    2018, 38 (1): 97-103.   DOI: 10.11772/j.issn.1001-9081.2017061372
Abstract491)      PDF (1056KB)(420)       Save
Focusing on that the existing attribute reduction algorithms are not suitable for dealing with the incomplete data with both numerical attributes and symbolic attributes, an extented incomplete neighborhood rough set model was proposed. Firstly, the distance between the missing attribute values was defined to deal with incomplete data with mixed attributes by considering the probability distribution of the attribute values. Secondly, the concept of neighborhood mixed entropy was defined to evaluate the quality of attribute reduction and the relevant property theorem was proved. An attribute reduction algorithm for incomplete neighborhood rough set based on neighborhood mixed entropy was constructed. Finally, seven sets of data were selected from the UCI dataset for experimentation, and the algorithms was compared with the Attribute Reduction of Dependency (ARD), the Attribute Reduction of neighborhood Conditional Entropy (ARCE) and the Attribute Reduction of Neighborhood Combination Measure (ARNCM) algorithm respectively. The theoretical analysis and the experimental results show that compared to ARD, ARCE, ARNCM algorithms, the proposed algorithm reduces the attributes by about 1, 7, 0 respectively, and improves the classification accuracy by about 2.5 percentage points, 2.1 percentage points, 0.8 percentage points respectively. The proposed algorithm not only has less reducted attributes, but also has higher classification accuracy.
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Brain network analysis and classification for patients of Alzheimer's disease based on high-order minimum spanning tree
GUO Hao, LIU Lei, CHEN Junjie
Journal of Computer Applications    2017, 37 (11): 3339-3344.   DOI: 10.11772/j.issn.1001-9081.2017.11.3339
Abstract476)      PDF (1091KB)(508)       Save
The use of resting-state functional magnetic resonance imaging to study the functional connectivity network of the brain is one of the important methods of current brain disease research. This method can accurately detect a variety of brain diseases, including Alzheimer's disease. However, the traditional network only studies the correlation between the two brain regions, and lacks a deeper interaction between the brain regions and the association between functional connections. In order to solve these problems, a method was proposed to construct a functional connectivity network of high-order minimum spanning tree, which not only ensured the physiological significance of functional connectivity network, but also studied more complex interactive information in the network and improves the accuracy of classification. The classification results show that the resting-state functional magnetic resonance imaging classification method based on the functional connectivity network of high-order minimum spanning tree greatly improves the accuracy of Alzheimer's disease detection.
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Cow recognition algorithm based on improved bag of feature model
CHEN Juanjuan, LIU Caixing, GAO Yuefang, LIANG Yun
Journal of Computer Applications    2016, 36 (8): 2346-2351.   DOI: 10.11772/j.issn.1001-9081.2016.08.2346
Abstract379)      PDF (1056KB)(401)       Save
Concerning the high time-consuming and low recognition accuracy of Bag of Feature (BOF) model, a new improved BOF model was proposed to improve the accuracy and efficiency of target recognition, and it was also applied to cow recognition. The optimized Histogram of Oriented Gradient (HOG) feature was introduced to feature extraction and description of the images; then the Spatial Pyramid Matching (SPM) principle was used to generate the histogram representation of images based on visual dictionary; finally, the histogram intersection kernel defined in this paper was used as the kernel function of the classifier. The experimental results on the data set in this paper (including 15 kinds of cows with 7500 images of cow heads) showed that the recognition rate of the algorithm was improved by an average of 2 percentage points by using the BOF model based on SPM; compared with Gauss kernel, the recognition rate of the algorithm was increased by an average of 2.5 percentage points by using the histogram intersection kernel; compared with traditional HOG feature, the recognition rate of the algorithm was improved by an average of 21.3 percentage points by using optimized HOG feature, and the computation efficiency of the algorithm was improved by an average of 1.68 times; compared with Scale Invariant Feature Transform (SIFT) feature, the computation efficiency of the algorithm was improved by an average of nearly 7.10 times as well as ensuring the average recognition accuracy reached 95.3%. Analysis results indicate that this algorithm has good robustness and practicability in cow individual recognition.
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Multisensor information fusion algorithm based on intelligent particle filtering
CHEN Weiqiang, CHEN Jun, ZHANG Chuang, SONG Liguo, TAN Zhuoli
Journal of Computer Applications    2016, 36 (12): 3358-3362.   DOI: 10.11772/j.issn.1001-9081.2016.12.3358
Abstract559)      PDF (733KB)(503)       Save
In order to solve the low-quality and degeneration problem of particles in the process of particle filtering, a multisensor information fusion algorithm based on intelligent particle filtering was proposed. The process of the proposed algorithm was divided into two steps. Firstly, the multisensor data was sent to the appropriate particle filtering calculation module, and the proposal distribution density was updated for the purpose of optimizing the particle distribution. Then, the integrated likelihood function model was structured by using the multisensor data in intelligent particle filtering module, meanwhile, the small-weight particles were modified into large-weight ones according to the designed genetic operators. The posterior distribution was more sufficiently approximated, thus large-weight particles were reserved in the process of resampling, which avoided the problem of exhausting particles, further maintained the diversity of the particles and improved the filtering precision. Finally, the optimal accurate estimated value was obtained. The proposed algorithm was applied to the GPS/SINS/LOG integrated navigation system according to the prototype testing data, and its effectiveness was verified by the simulation calculation. The simulation results show that, the proposed algorithm can get accurate informations of location, speed and heading, and effectively improve the filtering performance, which can improve the calculating precision of the integrated navigation system and meet the requirement of high precision navigation and positioning of the ship.
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Heuristic anti-monitoring path finding algorithm based on local Voronoi tessellation in sensory field
CHEN Juan
Journal of Computer Applications    2015, 35 (1): 15-18.   DOI: 10.11772/j.issn.1001-9081.2015.01.0015
Abstract584)      PDF (728KB)(445)       Save

Considering the safety problem of mobile objects while traversing through a sensory field, a novel heuristic anti-monitoring path finding algorithm based on local Voronoi Tessellation (VT) was proposed in this paper. First, an approximate estimation model of path exposure based on local Voronoi tessellation was presented, in which, the mobile object could generate the local Voronoi tessellation dynamically based on currently detected sensor nodes information, and approximately estimated the exposure risk of each path corresponding to an edge of the local Voronoi tessellation based on the newly defined exposure risk computation formula. And then, based on the newly given exposure model, a novel heuristic anti-monitoring path finding algorithm was designed, in which, the mobile object could firstly determine its candidate set of next hop location points based on the local Voronoi tessellation, and then selected a location point with the minimum risk cost from its candidate set as its actual next hop location based on the newly defined heuristic cost function, and therefore, moved along the corresponding path with the minimum exposure risk in the local Voronoi tessellation to the selected next hop location. The theoretical analysis and simulation results show that the proposed algorithm has good anti-monitoring performance, and as for a sensory field with total n sensor nodes, the mobile object can select a path with relatively small risk to get to the destination within the time no more than O(n log n).

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Pedestrian detection based on improved color self-similarity feature
GU Huijian CHEN Junzhou
Journal of Computer Applications    2014, 34 (7): 2033-2035.   DOI: 10.11772/j.issn.1001-9081.2014.07.2033
Abstract205)      PDF (594KB)(669)       Save

In recent years, multiscale pedestrian detection received extensive attentions in the field of computer vision. In traditional methods, the input image must be resized with different scales to compute the features, which significantly reduces the detection speed. Color Self-Similarity Feature (CSSF) was presented to overcome this problem. An improved CSSF with lower dimension was proposed for the CSSF whose dimension is too high and time-consuming in the training process of the classifiers. Combined with pedestrian structural similarity, a fixed-size window was defined at first, and then the improved CSSF was extracted by sliding the fixed-size window in different color space. Finally, the pedestrian detection classifier was constructed by combining with AdaBoost algorithm. Test shows that compared with the traditional CSSF whose dimension is ten millions, new feature dimension is only a few thousand, and it can be extracted and trained faster, but detection effect decreases slightly; compared with the Histogram of Oriented Gradient (HOG), feature extraction speed improves 5 times, detection effect is essentially the same. The new method has a good application value in real-time pedestrian detection and monitoring systems.

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Encryption algorithm based on 2D X-type reversible cellular automata
YUAN Ye LI Jingyi CHEN Juhua
Journal of Computer Applications    2014, 34 (12): 3466-3469.  
Abstract222)      PDF (570KB)(669)       Save

Concerning the problems of complicated structure and revolution of 2D traditional neighborhood cellular automata, low encrypting efficiency, little key space of 1D cellular automata, low diffusion speed and needing multiple rounds iteration to produce avalanche effect, a new encryption algorithm based on 2D X-type reversible cellular automata and Arnold transformation was proposed. Firstly, the plaintext was evolved by the proposed cellular automata, then it was transformed by Arnold transformation and cyclic shift transformation after every evolution, until the ciphertext was encrypted well enough. The experimental result shows that the key space is increased by 16.8% and has perfect robustness in resisting brute force attack. In addition the diffusion and confusion is so excellent that it can produce higher avalanche effect and resist chosen plaintext attack.

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Parallel recognition of illegal Web pages based on improved KNN classification algorithm
XU Yabin LI Zhuo CHEN Junyi
Journal of Computer Applications    2013, 33 (12): 3368-3371.  
Abstract694)      PDF (828KB)(445)       Save
There are many illegal Web pages on the Internet, which may have pornographic, violent, gambling or reactionary content. Without being filtered effectively, they will exercise a malign influence on the searching services. An improved K-Nearest Neighbors (KNN) classification algorithm to promote the recognition accuracy was proposed and implemented on a virtualized platform following the MapReduce model provided by the open source software Hadoop, which made it distributed and parallel. Through experiments and comparison with the existing work, it is proved that the proposed recognition method improves the accuracy and efficiency greatly. The algorithm is implemented on a virtualized platform following the MapReduce model provided by the open source software Hadoop, which makes it distributed and parallel. Through experiments and comparison with existing work, it is proved that the recognition method we propose improves the accuracy and efficiency greatly.
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Fleet elastic load balancing mechanism in cloud environment
DU Yao GUO Tao CHEN Junjie
Journal of Computer Applications    2013, 33 (03): 830-833.   DOI: 10.3724/SP.J.1087.2013.00830
Abstract1301)      PDF (641KB)(517)       Save
In order to overcome the defects of traditional rigid load balancing mechanism that it can not adapt to changing network environment, and to solve the problem of load balancing mechanisms in cloud environment that it can not take full advantage of elastic characteristics and Quality of Service (QoS) would be unstable, this paper proposed a new load balancing mechanism in cloud environment based on green computing resource pool strategy. It quantified the load according to the utilization rate of system resources and the quantization decided distribution of virtual machines. On the basis of the use of the virtual machines, resources would be recycled to improve resource utilization. The experimental results show that the response time stablizes around 2.5 seconds, the overall QoS has been obviously improved with the power consumption reduced, and the effectiveness of the mechanisms has been verified.
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Unipolar Sigmoid neural network classifier based on weights and structure determination method
ZHANG Yunong CHEN Junwei LIU Jinrong QU Lu LI Weibing
Journal of Computer Applications    2013, 33 (03): 766-770.   DOI: 10.3724/SP.J.1087.2013.00766
Abstract820)      PDF (847KB)(486)       Save
A neural network classifier with the hidden neurons activated by unipolar Sigmoid function was constructed and investigated in this paper. The thresholds of hidden neurons and weights between the input layer and the hidden layer of the neural network were randomly generated. The psedoinverse-type Weights Direct Determination (WDD) method was applied to determining the weights between the hidden layer and the output layer. Moreover, a Structure Automatic Determination (SAD) algorithm with pruning-while-growing and twice-pruning policies was proposed to determine the optimal structure of the neural network. The numerical experimental results demonstrate that the SAD algorithm can determine the optimal structure of the neural network quickly and effectively and the neural network classifier has a satisfactory performance.
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Node scheduling algorithm based on combinatorial assignment code model for heterogeneous sensor network
CHEN Juan
Journal of Computer Applications    2013, 33 (01): 96-100.   DOI: 10.3724/SP.J.1087.2013.00096
Abstract723)      PDF (970KB)(549)       Save
For node scheduling problem in Wireless Sensor Network (WSN) with heterogeneous sensing radius, a new distributed node scheduling scheme based on combinatorial assignment code model was proposed, in which the very possible biggest group number was decided first, and then nodes were divided into clusters in a distributed way based on the concept of two-hop cluster, finally, the nodes in each cluster were scheduled into different groups based on combinatorial assignment code model. The theoretical analysis and experimental results show that the proposed algorithm can prolong the network lifecycle better than the existing methods, such as random-based and two-hop cluster based methods. Therefore, it is more suitable for the environment of WSN with heterogeneous sensing radius.
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Research into community structure of resting-state brain functional network
WANG Yan-qun LI Hai-fang GUO Hao CHEN Jun-jie
Journal of Computer Applications    2012, 32 (07): 2044-2048.   DOI: 10.3724/SP.J.1087.2012.02044
Abstract1046)      PDF (815KB)(726)       Save
The community detecting algorithm was applied to human functional network to explore the mechanism of human brain. The brain functional data of 28 healthy subjects were collected by functional Magnetic Resonance Imaging (fMRI), and the brain functional network of human beings based on time series was constructed. A threshold range of vertices in the network was designated according to modularity and full connected network theory. The community structures were detected by using the hierarchical clustering algorithm and the greedy algorithm respectively, and the experimental results show that similar community structures have been obtained. Then different performances can be explored across the threshold by analyzing the modularity. An effective threshold range of vertices between 180 to 320 in brain network was proposed. Exploring the community structure is helpful to comprehend the mechanism of brain lesions, which provides a tool for diagnosis and treatment of brain diseases.
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Research of digital time-stamping service in unreliable networks
CHANG Chao-wen CHEN Jun-feng QIN Xi
Journal of Computer Applications    2012, 32 (01): 60-65.   DOI: 10.3724/SP.J.1087.2012.00060
Abstract1043)      PDF (955KB)(639)       Save
The technology of Digital Time-Stamping (DTS) is widely used in digital signature, electronic commerce and patents and property right protection of various software and hardware. For some unreliable networks, of which the network situation is poor, the net speed changes greatly and the net links are usually intermittent, there is no necessary technological means to guarantee the normal and effective operation of DTS service. According to the characteristics of the unreliable networks, a new time-stamping scheme was proposed. In the scheme, it did not need to communicate with Time Stamp Authority (TSA) each time when a time-stamping service was required. The local trusted platform would offer the time-stamping service itself. A new DTS service protocol based on Trusted Platform Module (TPM) was also proposed under the circumstances of unreliable networks. The results of the security analysis of the protocol show that the protocol is secure and the time error in the protocol can be kept under control. The adaptability of the protocol for the unreliable network is excellent.
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Harris corner detection algorithm based on adaptive fractional differential
WANG Cheng-liang QIAO He-song CHEN Juan-juan
Journal of Computer Applications    2011, 31 (10): 2702-2704.   DOI: 10.3724/SP.J.1087.2011.02702
Abstract1214)      PDF (746KB)(592)       Save
False corners will emerge in the corner detection of the image with high texture complexity by Harris algorithm, and when fractional differential is applied to image processing, the order needs to be specified by human. This paper analyzed the reason that caused the false corners and suggested to replace the integral order in the algorithm with fractional order to operate differential coefficient so as to improve the algorithm. The paper also brought forward an approach regarding fractal dimension as a parameter which came from the order in choosing differential coefficient. So the marginal information of image can be saved when operating the differential coefficient of the image, and this approach makes the fractional differential be applied in occasions with high real-time requirements such as video target tracing and video image stabilization. The tests show that the modified algorithm has higher precision in the corner detection.
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Group argumentation model based on IBIS and Toulmin's argument schema
CHEN Jun-liang CHEN Chao JIANG Xin ZHANG Zhen
Journal of Computer Applications    2011, 31 (09): 2526-2529.   DOI: 10.3724/SP.J.1087.2011.02526
Abstract1351)      PDF (644KB)(432)       Save
Argumentation model is the theoretical basis to establish group argumentation environment. Based on Issue-Based Information System (IBIS) model and Toulmin' argument schema, a group argumentation model was proposed, which was able to evaluate the argumentative utterance. With this model, the group argumentative information could be structured as a graph which consisted of utterance nodes and semantic links. A method of evaluating utterance nodes based on Language Weighted Aggregation (LWA) operator and node reduction was proposed. A group argumentation on the issue of system architecture design was illustrated as an example to show the usability and effectiveness of the proposed model.
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Research of Web Services attack detection based on ontology
CHEN Jun WU Lifa XU Guanghui HE Zhengqiu HUNAG Kangyu
Journal of Computer Applications    2011, 31 (06): 1515-1520.   DOI: 10.3724/SP.J.1087.2011.01515
Abstract1455)      PDF (972KB)(446)       Save
Web service greatly facilitates the application-to-application integration based on heterogeneous platform, but its core components are faced with threats of malicious attacks. Currently, the Intrusion Detection System (IDS) is usually used to prevent these attacks. However, the IDSs distributed throughout the network may be developed by different vendors and there is not a common vocabulary understandable among them. Therefore, the IDSs stopped people from cooperatively preventing the multi-phased and distributed attacks easily. In this paper, a new method based on ontology and OWL to classify and describe the Web services attack was presented. Through constructing a Web services attack ontology, the common understandable vocabulary could be provided for different IDSs. Then, an intrusion detection system based on the Web Service Attack ontology (called O-IDS) was presented as well, which could efficiently overcome the shortage of the existed IDS and enhance the ability to detect the multi-phased and distributed attacks.
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Distributed discrete event simulation model based on RPC and barrier synchronization mechanism
CHEN You-zi CHEN Jun-yan WANG Tong
Journal of Computer Applications    2011, 31 (05): 1413-1416.   DOI: 10.3724/SP.J.1087.2011.01413
Abstract1346)      PDF (591KB)(824)       Save
A distributed simulation approach was proposed for discrete-events simulation with considerable amounts of events between logical processes. The proposed approach employed a time-driven method to simulate occurrence of discrete-events, using Remote Procedure Call (RPC) to describe the interaction between simulation members. In this approach, barrier synchronization objects were deployed for time synchronization in simulation advancement, in order to ensure the correctness of the causal ordering. Results obtained from the experiments show that the proposed approach can correctly and promptly handle large number of events, providing accuracy guarantee and efficiency improvement of the simulation model.
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Live migration transition framework of mobile IPv4/IPv6 virtual machine
CHEN Jun CHEN Xiao-wei
Journal of Computer Applications    2011, 31 (05): 1180-1183.   DOI: 10.3724/SP.J.1087.2011.01180
Abstract1149)      PDF (641KB)(863)       Save
In order to fully use IPv4/IPv6 heterogeneous network resources and provide resource requirement for cloud computation platform, the authors designed an IPv4/IPv6 virtual machine migration transition framework for cloud computation based on tunnel technology, prefix management, address pool management and mobile IP. The framework used the designed cloud computation control engine as a core to translate and link heterogeneous network, and needed Network Address Translation-Protocol Translation (NAT-PT) and tunnel technology collaboration. The framework was established for IPv4/IPv6 virtual machine seamless live migration in the early, middle, late period of IPv4 to IPv6 transition, and IPv4/IPv6 cloud computation service was provided for client. The framework could be applied to construct cloud computation platform in the IPv4/IPv6 transition period.
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Particle swarm optimization algorithm with multidimensional asynchronism and stochastic disturbance
Chen Junyan
Journal of Computer Applications    2009, 29 (12): 3267-3269.  
Abstract1487)      PDF (428KB)(1355)       Save
Particle swarm optimization has the disadvantages of being easily trapped into a local optimal solution and searching with lower efficiency in multi-dimensional space. With reference to the strategy of concave function to the inertia weight, the authors proposed a method of multidimensional asynchronism and stochastic disturbance to improve the ability to search for global optimum as well as solve the limitation of dimensionality problem. The experimental results of four classic benchmark functions show that the algorithm can keep the balance between the global search and local search, which effectively improves the success probability of searching with higher precision.
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Solving frequency assignment problem using an adaptive multiple-colony ant algorithm
ZHANG Chun-fang,CHEN Ling,CHEN Juan
Journal of Computer Applications    2005, 25 (07): 1641-1644.   DOI: 10.3724/SP.J.1087.2005.01641
Abstract1501)      PDF (662KB)(12923)       Save

An adaptive multiple colony ant algorithm was presented to solve frenquency assignment problem of mobile communicaiton. Unlike the traditional ant colony algorithm which used only one ant colony, our algorithm used multiple ant colonies. For each ant colony, a coefficient of convergence was defined by which the ants adaptively could choose the path, update their local pheromone and exchange information between colonies. By using the adaptive strategy to update the pheromone, the balance between the diversity and convergence of every ant colony was kept. The simulation results on the fixed frequency assignment problem and minimal span frequency assignment problem show that our algorithm has global convergence and higher speed of optimization.

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Multi-key page-level encryption system for SQLite
LI Xudong, FENG Yukang, CHEN Junsheng
Journal of Computer Applications    DOI: 10.11772/j.issn.1001-9081.2023091362
Online available: 21 March 2024