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Local community detection algorithm based on Monte-Carlo iterative solving strategy
LI Zhanli, LI Ying, LUO Xiangyu, LUO Yingxiao
Journal of Computer Applications    2023, 43 (1): 104-110.   DOI: 10.11772/j.issn.1001-9081.2021111942
Abstract223)   HTML10)    PDF (1690KB)(97)       Save
Aiming at the problems of premature convergence and low recall caused by using greedy strategy for community expansion in the existing local community detection algorithms, a local community detection algorithm based on Monte-Carlo iterative solving strategy was proposed. Firstly, in the community expansion stage of each iteration, the selection probabilities were given to all adjacent candidate nodes according to the contribution ratio of each node to the community tightness gain, and one node was randomly selected to join the community according to these probabilities. Then, in order to avoid random selection causing the expansion direction to deviate from the target community, it was determined whether the node elimination mechanism was triggered in this round of iteration according to the changes in community quality. If it was triggered, the similarity sum of each node joining the community and other nodes in the community was calculated, the elimination probabilities were assigned according to the reciprocal of the similarity sum, a node was randomly eliminated according to these probabilities. Finally, whether to continue the iteration was judged on the basis of whether the community size increased in a given number of recent iteration rounds. Experimental results show that, on three real network datasets, compared to Local Tightness Expansion (LTE) algorithm, Clauset algorithm, Common Neighbors with Weighted Neighbor Nodes (CNWNN) algorithm and Fuzzy Similarity Relation (FSR) algorithm, the proposed algorithm has the F-score value of local community detection results increased by 32.75 percentage points, 17.31 percentage points, 20.66 percentage points and 25.51 percentage points respectively, and can effectively avoid the influence of the location of the query node in the community on the local community detection results.
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Review of spatio-temporal trajectory sequence pattern mining methods
KANG Jun, HUANG Shan, DUAN Zongtao, LI Yixiu
Journal of Computer Applications    2021, 41 (8): 2379-2385.   DOI: 10.11772/j.issn.1001-9081.2020101571
Abstract954)      PDF (1204KB)(1479)       Save
With the rapid development of global positioning technology and mobile communication technology, huge amounts of trajectory data appear. These data are true reflections of the moving patterns and behavior characteristics of moving objects in the spatio-temporal environment, and they contain a wealth of information which carries important application values for the fields such as urban planning, traffic management, service recommendation, and location prediction. And the applications of spatio-temporal trajectory data in these fields usually need to be achieved by sequence pattern mining of spatio-temporal trajectory data. Spatio-temporal trajectory sequence pattern mining aims to find frequently occurring sequence patterns from the spatio-temporal trajectory dataset, such as location patterns (frequent trajectories, hot spots), activity periodic patterns, and semantic behavior patterns, so as to mine hidden information in the spatio-temporal data. The research progress of spatial-temporal trajectory sequence pattern mining in recent years was summarized. Firstly, the data characteristics and applications of spatial-temporal trajectory sequence were introduced. Then, the mining process of spatial-temporal trajectory patterns was described:the research situation in this field was introduced from the perspectives of mining location patterns, periodic patterns and semantic patterns based on spatial-temporal trajectory sequence. Finally, the problems existing in the current spatio-temporal trajectory sequence pattern mining methods were elaborated, and the future development trends of spatio-temporal trajectory sequence pattern mining method were prospected.
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Robust multi-view clustering algorithm based on adaptive neighborhood
LI Xingfeng, HUANG Yuqing, REN Zhenwen, LI Yihong
Journal of Computer Applications    2021, 41 (4): 1093-1099.   DOI: 10.11772/j.issn.1001-9081.2020060828
Abstract376)      PDF (1021KB)(717)       Save
Since the existing adaptive neighborhood based multi-view clustering algorithms do not consider the noise and the loss of consensus graph information, a Robust Multi-View Graph Clustering(RMVGC) algorithm based on adaptive neighborhood was proposed. Firstly, to avoid the influence of noise and outliers on the data, the Robust Principal Component Analysis(RPCA) model was used to learn multiple clean low-rank data from the original data. Secondly, the adaptive neighborhood learning was employed to directly fuse multiple clean low-rank data to obtain a clean consensus affinity graph, thus reducing the information loss in the process of graph fusion. Experimental results demonstrate that the Normalized Mutual Informations(NMI) of the proposed algorithm RMVGC is improved by 5.2, 1.36, 27.2, 4.66 and 5.85 percentage points, respectively, compared to the current popular multi-view clustering algorithms on MRSCV1, BBCSport, COIL20, ORL and UCI digits datasets. Meanwhile, in the proposed algorithm, the local structure of data is maintained, the robustness against the original data is enhanced, the quality of affinity graph is improved, and such that the proposed algorithm has great clustering performance on multi-view datasets.
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3D virtual human animation generation based on dual-camera capture of facial expression and human pose
LIU Jie, LI Yi, ZHU Jiangping
Journal of Computer Applications    2021, 41 (3): 839-844.   DOI: 10.11772/j.issn.1001-9081.2020060993
Abstract709)      PDF (1377KB)(580)       Save
In order to generate a three-dimensional virtual human animation with rich expression and smooth movement, a method for generating three-dimensional virtual human animation based on synchronous capture of facial expression and human pose with two cameras was proposed. Firstly, the Transmission Control Protocol (TCP) network timestamp method was used to realize the time synchronization of the two cameras, and the ZHANG Zhengyou's calibration method was used to realize the spatial synchronization of the two cameras. Then, the two cameras were used to collect facial expressions and human poses respectively. When collecting facial expressions, the 2D feature points of the image were extracted and the regression of these 2D points was used to calculate the Facial Action Coding System (FACS) facial action unit in order to prepare for the realization of expression animation. Based on the standard head 3D coordinate, according to the camera internal parameters, the Efficient Perspective- n-Point (EP nP) algorithm was used to realize the head pose estimation. After that, the facial expression information was matched with the head pose estimation information. When collecting human poses, the Occlusion-Robust Pose-Map (ORPM) method was used to calculate the human poses and output data such as the position and rotation angle of each bone point. Finally, the established 3D virtual human model was used to show the effect of data-driven animation in the Unreal Engine 4 (UE4). Experimental results show that this method can simultaneously capture facial expressions and human poses and has the frame rate reached 20 fps in the experimental test, so it can generate natural and realistic three-dimensional animation in real time.
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Relationship reasoning method combining multi-hop relationship path information
DONG Yongfeng, LIU Chao, WANG Liqin, LI Yingshuang
Journal of Computer Applications    2021, 41 (10): 2799-2805.   DOI: 10.11772/j.issn.1001-9081.2020121905
Abstract326)      PDF (763KB)(330)       Save
Concerning the problems of the lack of a large number of relationships in the current Knowledge Graph (KG), and the lack of full consideration of the hidden information in the multi-hop path between two entities when performing relationship reasoning, a relationship reasoning method combining multi-hop relationship path information was proposed. Firstly, for the given candidate relationships and two entities, the convolution operation was used to encode the multi-hop relationship path connecting the two entities into a low-dimensional space and extract the information. Secondly, the Bidirectional Long Short-Term Memory (BiLSTM) network was used for modeling to generate the relationship path representation vector, and the attention mechanism was used to combine it with the candidate relationship representation vector. Finally, a multi-step reasoning method was used to find the relationship with the highest matching degree as the reasoning result and judge its precision. Compared with the current popular Path Ranking Algorithm (PRA), the neural network model named Path-RNN and reinforcement learning model named MINERVA, the proposed algorithm had the Mean Average Precision (MAP) increased by 1.96,8.6 and 1.6 percentage points respectively when using the large-scale knowledge graph dataset NELL995 for experiments. And when using the small-scale knowledge graph dataset Kinship for experiments, the proposed algorithm had the MAP improved by 21.3,13 and 12.1 percentage points respectively compared to PRA and MINERVA. The experimental results show that the proposed method can infer the relationship links between entities more accurately.
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Sentiment analysis using embedding from language model and multi-scale convolutional neural network
ZHAO Ya'ou, ZHANG Jiachong, LI Yibin, FU Xianrui, SHENG Wei
Journal of Computer Applications    2020, 40 (3): 651-657.   DOI: 10.11772/j.issn.1001-9081.2019071210
Abstract496)      PDF (866KB)(526)       Save
Only one semantic vector can be generated by word-embedding technologies such as Word2vec or GloVe for polysemous word. In order to solve the problem, a sentiment analysis model based on ELMo (Embedding from Language Model) and Multi-Scale Convolutional Neural Network (MSCNN) was proposed. Firstly, ELMo model was used to learn the pre-training corpus and generate the context-related word vectors. Compared with the traditional word embedding technology, in ELMo model, word features and context features were combined by bidirectional LSTM (Long Short-Term Memory) network to accurately express different semantics of polysemous word. Besides, due to the number of Chinese characters is much more than English characters, ELMo model is difficult to train for Chinese corpus. So the pre-trained Chinese characters were used to initialize the embedding layer of ELMo model. Compared with random initialization, the model training was able to be faster and more accurate by this method. Then, the multi-scale convolutional neural network was applied to secondly extract and fuse the features of word vectors, and generate the semantic representation for the whole sentence. Experiments were carried out on the hotel review dataset and NLPCC2014 task2 dataset. The results show that compared with the attention based bidirectional LSTM model, the proposed model obtain 1.08 percentage points improvement of the accuracy on hotel review dataset, and on NLPCC2014 task2 dataset, the proposed model gain 2.16 percentage points improvement of the accuracy compared with the hybrid model based on LSTM and CNN.
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Security-risk-oriented distributed resource allocation method in power wireless private network
HUANG Xiuli, HUANG Jin, YU Pengfei, MIAO Weiwei, YANG Ruxia, LI Yijing, YU Peng
Journal of Computer Applications    2020, 40 (12): 3586-3593.   DOI: 10.11772/j.issn.1001-9081.2020040488
Abstract321)      PDF (2051KB)(350)       Save
Aiming at the problem of ensuring terminal communication in the scenarios of strong interference and high failure risk in the power wireless private network, a security-risk-oriented energy-efficient distributed resource allocation method was proposed. Firstly, the energy consumption compositions of the base stations were analyzed, and the resource allocation model of system energy efficiency maximization was established. Then, K-means++ algorithm was adopted to cluster the base stations in the network, so as to divide the whole network into several independent areas, and the high-risk base stations were separately processed in each cluster. Then, in each cluster, the high-risk base stations were turned into the sleep mode based on the risk values of the base stations, and the users under the high-risk base stations were transferred to other base stations in the same cluster. Finally, the transmission powers of normal base stations in clusters were optimized. Theoretical analysis and simulation experimental results show that, the clustering of base stations greatly reduces the complexity of base station sleeping as well as power optimization and allocation, and the overall network energy efficiency is increased from 0.158 9 Mb/J to 0.195 4 Mb/J after turning off the high-risk base stations. The proposed distributed resource allocation method can effectively improve the energy efficiency of system.
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High-speed railway fare adjustment strategy based on passenger flow assignment
YIN Shengnan, LI Yinzhen, ZHANG Changze
Journal of Computer Applications    2020, 40 (1): 278-283.   DOI: 10.11772/j.issn.1001-9081.2019061088
Abstract406)      PDF (1051KB)(415)       Save
Concerning the problems of single fare, low revenue rate of passenger transport and unbalanced passenger flow in different sections of high-speed railway, an adjustment strategy of high-speed railway fare based on passenger flow assignment was proposed. Firstly, the related factors affecting passenger travel choice behavior were analyzed, and a generalized travel cost function including four indicators of economy, rapidity, convenience and comfort was constructed. Secondly, a bilevel programming model considering the maximization of revenue of railway passenger transport management department and the minimization of passenger travel cost was established, in which the upper level programming achieved the maximum revenue of high-speed railway passenger transport by formulating fare adjustment strategy, the lower-level programming took the minimum passenger generalized travel cost as the goal, and used the competition and cooperation relationship between different trains of section to construct Stochastic User Equilibrium (SUE) model, and the model was solved by Method of Successive Averages (MSA) based on the improved Logit assignment model. Finally, the case study shows that the proposed fare adjustment strategy can effectively balance the section passenger flow, reduce passenger travel cost and improve passenger transport revenue to a certain extent. The experimental results show that the fare adjustment strategy can provide decision support and methodological guidance for railway passenger transport management departments to optimize fare system and formulate fare adjustment schemes.
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Multi-objective optimization model and solution algorithm for emergency material transportation path
LI Zhuo, LI Yinzhen, LI Wenxia
Journal of Computer Applications    2019, 39 (9): 2765-2771.   DOI: 10.11772/j.issn.1001-9081.2019020270
Abstract1013)      PDF (983KB)(431)       Save

For the actual background of the shortage of self-owned vehicles of the transporters in the early stage of emergency, the combinatorial optimization problem of hybrid vehicle paths with transportation mode of joint distribution of self-owned vehicles and vehicles rented by third-party was studied. Firstly, with the different interests between demand points and transporters considered, a multi-objective hybrid vehicle routing optimization model with soft time windows was established with the goal of maximizing system satisfaction and minimizing system delivery time and total cost. Secondly, the shortcomings of NSGA-Ⅱ algorithm in solving this kind of problems such as poor convergence and uneven distribution of Pareto frontiers were considered, the heuristic strategy and pheromone positive feedback mechanism of ant colony algorithm were used to generate offspring population, non-dominated sorting strategy model was used to guide the multi-objective optimization process, and the variable neighborhood descent search was introduced to expand the search space. A multi-objective non-dominated sorting ant colony algorithm was proposed to break through the bottleneck of the original algorithm. The example shows that the proposed model can provide reference for decision makers to choose reasonable paths according to different optimization objectives in different situations, and the proposed algorithm shows better performance in solving different scale problems and different distribution type problems.

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Methods of training data augmentation for medical image artificial intelligence aided diagnosis
WEI Xiaona, LI Yinghao, WANG Zhenyu, LI Haozun, WANG Hongzhi
Journal of Computer Applications    2019, 39 (9): 2558-2567.   DOI: 10.11772/j.issn.1001-9081.2019030450
Abstract464)      PDF (1697KB)(631)       Save

For the problem of time, effort and money consuming to obtain a large number of samples by conventional means faced by Artificial Intelligence (AI) application research in different fields, a variety of sample augmentation methods have been proposed in many AI research fields. Firstly, the research background and significance of data augmentation were introduced. Then, the methods of data augmentation in several common fields (including natural image recognition, character recognition and discourse parsing) were summarized, and on this basis, a detailed overview of sample acquisition or augmentation methods in the field of medical image assisted diagnosis was provided, including X-ray, Computed Tomography (CT), Magnetic Resonance Imaging (MRI) images. Finally, the key issues of data augmentation methods in AI application fields were summarized and the future development trends were prospected. It can be concluded that obtaining a sufficient number of broadly representative training samples is the key to the research and development of all AI fields. Both the common fields and the professional fields have conducted sample augmentation, and different fields or even different research directions in the same field have different sample acquisition or augmentation methods. In addition, sample augmentation is not simply to increase the number of samples, but to reproduce the existence of real samples that cannot be completely covered by small sample size as far as possible, so as to improve sample diversity and enhance AI system performance.

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Polynomial ranking function detection method based on Dixon resultant and successive difference substitution
YUAN Yue, LI Yi
Journal of Computer Applications    2019, 39 (7): 2065-2073.   DOI: 10.11772/j.issn.1001-9081.2019010199
Abstract328)      PDF (1216KB)(204)       Save

Ranking function detection is one of the most important methods to analyze the termination of loop program. Some tools have been developed to detect linear ranking functions corresponding to linear loop programs. However, for polynomial loops with polynomial loop conditions and polynomial assignments, existing methods for detecting their ranking functions are mostly incomplete or with high time complexity. To deal with these weaknesses of existing work, a method was proposed for detecting polynomial ranking functions for polynomial loop programs, which was based on extended Dixon resultants (the KSY (Kapur-Saxena-Yang) method) and Successive Difference Substitution (SDS) method. Firstly, the ranking functions to be detected were seen as polynomials with parametric coefficients. Then the detection of ranking functions was transformed to the problem of finding parametric coefficients satisfying the conditions. Secondly, this problem was further transformed to the problem of determining whether the corresponding equations have solutions or not. Based on extended Dixon resultants in KSY method, the problem was reduced to the decision problem whether the polynomials with symbolic coefficients (resultants) were strictly positive or not. Thirdly, a sufficient condition making the resultants obtained strictly positive were found by SDS method. In this way, the coefficients satisfying the conditions were able to be obtained and thus a ranking function satisfying the conditions was found. The effectiveness of the method was proved by experiments. The experimental results show that polynomial ranking functions including d-depth multi-stage polynomial ranking functions are able to be detected for polynomial loop programs. This method is more efficient to find polynomial ranking functions compared with the existing methods. For loops whose ranking functions cannot be detected by the method based on Cylindrical Algebraic Decomposition (CAD) due to high time complexity, their ranking functions are able be found within a few seconds with the proposed method.

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Optimization of fractional PID controller parameters based on improved PSO algorithm
JIN Tao, DONG Xiucheng, LI Yining, REN Lei, FAN Peipei
Journal of Computer Applications    2019, 39 (3): 796-801.   DOI: 10.11772/j.issn.1001-9081.2018081698
Abstract645)      PDF (931KB)(495)       Save
Aiming at poor control effect of Fractional Order Proportional-Integral-Derivative (FOPID) controller and the characteristics of wide range and high complexity of parameter tuning for FOPID controller, an improved Particle Swarm Optimization (PSO) method was proposed to optimize the parameters of FOPID controller. In the proposed algorithm, the upper and lower limits of inertial weight coefficients in PSO were defined and decreased nonlinearly with the iteration times in form of Gamma function, meanwhile, the inertia weight coefficients and learning factors of particles were dynamically adjusted according to the fitness value of particles, making the particles keep reasonable motion inertia and learning ability, and improving self-adaptive ability of the particles. Simulation experiments show that the improved PSO algorithm has faster convergence rate and higher convergence accuracy than the standard PSO algorithm in optimizing the parameters of FOPID controller, which makes the FOPID controller obtain better comprehensive performance.
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Application protocol recognition method based on convolutional neural network
FENG Wenbo, HONG Zheng, WU Lifa, LI Yihao, LIN Peihong
Journal of Computer Applications    2019, 39 (12): 3615-3621.   DOI: 10.11772/j.issn.1001-9081.2019060977
Abstract381)      PDF (1254KB)(418)       Save
To solve the problems in traditional network protocol recognition methods, such as difficulty of manual feature extraction and low recognition accuracy, an application protocol recognition method based on Convolutional Neural Network (CNN) was proposed. Firstly, the raw network data was divided according to Transmission Control Protocol (TCP) connection or User Datagram Protocol (UDP) interaction, and the network flow was extracted. Secondly, the network flow was converted into a two-dimensional matrix through data prepocessing to facilitate the CNN analysis. Then, a CNN model was trained using the training set to extract protocol features automatically. Finally, the trained CNN model was used to recognize the application network protocols. The experimental results show that, the overall recognition accuracy of the proposed method is about 99.70%, which can effectively recognize the application protocols.
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Urban traffic networks collaborative optimization method based on two-layered complex networks
CHEN Xiaoming, LI Yinzhen, SHEN Qiang, JU Yuxiang
Journal of Computer Applications    2019, 39 (10): 3079-3087.   DOI: 10.11772/j.issn.1001-9081.2019030538
Abstract521)      PDF (1344KB)(349)       Save
In order to solve the problems in the transfer process connection and collaboration of metro-bus two-layered network faced by the passengers making route selection in the urban transportation network, such as the far distance between some transfer stations, the unclear connection orientation and the imbalance between supply and demand in local transfer, a collaborative optimization method for urban traffic networks based on two-layered complex networks was presented. Firstly, the logical network topology method was applied to the topology of the urban transportation network, and the metro-bus two-layered network model was established by the complex network theory. Secondly, with the transfer station as research object, a node importance evaluation method based on K-shell decomposition method and central weight distribution was presented. This method was able to realize coarse and fine-grained divison and identification of metro and bus stations in large-scale networks. And a collaborative optimization method for two-layered urban traffic network with mutual encouragement was presented, that is to say the method in the complex network theory to identify and filter the node importance in network topology was introduced to the two-layered network structure optimization. The two-layered network structure was updated by identifying high-aggregation effects and locating favorable nodes in the route selection to optimize the layout and connection of stations in the existing network. Finally, the method was applied to the Chengdu metro-bus network, the existing network structure was optimized to obtain the optimal optimized node location and number of existing network, and the effectiveness of the method was verified by the relevant index system. The results show that the global efficiency of the network is optimized after 32 optimizations, and the optimization effect of the average shortest path is 15.89% and 16.97%, respectively, and the passenger transfer behavior is increased by 57.44 percentage points, the impact on the accessibility is the most obvious when the travel cost is 8000-12000 m with the optimization effect of 23.44% on average. At the same time, with the two-layered network speed ratio and unit transportation cost introduced, the response and sensitivity difference of the traffic network to the collaborative optimization process under different operational conditions are highlighted.
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Long text classification combined with attention mechanism
LU Ling, YANG Wu, WANG Yuanlun, LEI Zijian, LI Ying
Journal of Computer Applications    2018, 38 (5): 1272-1277.   DOI: 10.11772/j.issn.1001-9081.2017112652
Abstract2588)      PDF (946KB)(1133)       Save
News text usually consists of tens to hundreds of sentences, which has a large number of characters and contains more information that is not relevant to the topic, affecting the classification performance. In view of the problem, a long text classification method combined with attention mechanism was proposed. Firstly, a sentence was represented by a paragraph vector, and then a neural network attention model of paragraph vectors and text categories was constructed to calculate the sentence's attention. Then the sentence was filtered according to its contribution to the category, which value was mean square error of sentence attention vector. Finally, a classifier base on Convolutional Neural Network (CNN) was constructed. The filtered text and the attention matrix were respectively taken as the network input. Max pooling was used for feature filtering. Random dropout was used to reduce over-fitting. Experiments were conducted on data set of Chinese news text classification task, which was one of the shared tasks in Natural Language Processing and Chinese Computing (NLP&CC) 2014. The proposed method achieved 80.39% in terms of accuracy for the filtered text, which length was 82.74% of the text before filtering, yielded an accuracy improvement of considerable 2.1% compared to text before filtering. The emperimental results show that combining with attention mechanism, the proposed method can improve accuracy of long text classification while achieving sentence level information filtering.
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Optimization model of green multi-type vehicles routing problem
HE Dongdong, LI Yinzhen
Journal of Computer Applications    2018, 38 (12): 3618-3624.   DOI: 10.11772/j.issn.1001-9081.2018051085
Abstract441)      PDF (1146KB)(377)       Save
In order to reduce the waste gas pollution generated by vehicles in the process of logistics distribution, on the basis of traditional Vehicle Routing Problem with Time Windows (VRPTW) model, an approximate calculation method for fuel consumption and carbon emission was introduced from the perspective of energy saving and emission reduction, then a Green Multi-type Vehicles Routing Problem with Time Windows (G-MVRPTW) model was established. The minimum total cost was taken as an optimization objective to find environment-friendly green paths, and an improved tabu search algorithm was designed to solve the problem. When the initial solution and the neighborhood solution were generated, the order of customer sequence in the subpath was set according to the ascending order of the latest service time and the time window size of each customer point. At the same time, through three indexes of the minimum subpath, the total cost of subpaths and the overload, the evaluation function of solution was improved, and a mechanism of reducing the possibility of precocious maturing was adopted. Finally, the effectiveness and feasibility of the proposed model and algorithm were verified by numerical experiments. The experimental results show that, the ton-kilometer index can better measure the fuel consumption and carbon emission cost, and it is a new trend for new energy vehicles to enter the transportation market. It can provide decision support and methodological guidance for low-carbon transportation and management.
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Method for exploiting function level vectorization on simple instruction multiple data extensions
LI Yingying, GAO Wei, GAO Yuchen, ZHAI Shengwei, LI Pengyuan
Journal of Computer Applications    2017, 37 (8): 2200-2208.   DOI: 10.11772/j.issn.1001-9081.2017.08.2200
Abstract645)      PDF (1353KB)(438)       Save
Currently, two vectorization methods which exploit Simple Instruction Multiple Data (SIMD) parallelism are loop-based method and Superword Level Parallel (SLP) method. Focusing on the problem that the current compiler cannot realize function level vectorization, a method of function level vectorization based on static single assignment was proposed. Firstly, the variable properties of program were analysed, and then a set of compiling directives including SIMD function annotations, uniform clauses, linear clauses were used to realize function level vectorization. Finally, the vectorized code was optimized by using the variable attribute result. Some test cases from the field of multimedia and image processing were selected to test the function and performance of the proposed function level vectorization on Sunway platform. Compared with the scalar program execution results, the execution of the program after the function level vectorization is more efficient. The experimental results show that the function level vectorization can achieve the same effect of task level parallelism, which is instructive to realize the automatic function level vectorization.
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Scale adaptive improvement of kernel correlation filter tracking algorithm
QIAN Tanghui, LUO Zhiqing, LI Guojia, LI Yingyun, LI Xiankai
Journal of Computer Applications    2017, 37 (3): 811-816.   DOI: 10.11772/j.issn.1001-9081.2017.03.811
Abstract559)      PDF (961KB)(591)       Save
To solve the problem that Circulant Structure of tracking-by-detection with Kernels (CSK) is difficult to adapt to the target scale change, a multi-scale kernel correlation filter classifier was proposed to realize the scale adaptive target tracking. Firstly, the multi-scale image was used to construct the sample set, the multi-scale kernel correlation filtering classifier was trained by the sample set, for target size estimation to achieve the goal of the optimal scale detection, and then the samples collected on the optimal target scale were used to update the classifier on-line to achieve the scale-adaptive target tracking. The comparative experiments and analysis illustrate that the proposed algorithm can adapt to the scale change of the target in the tracking process, the error of the eccentricity is reduced to 1/5 to 1/3 that of CSK algorithm, which can meet the needs of long time tracking in complex scenes.
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Sound recognition based on optimized orthogonal matching pursuit and deep belief network
CHEN Qiuju, LI Ying
Journal of Computer Applications    2017, 37 (2): 505-511.   DOI: 10.11772/j.issn.1001-9081.2017.02.0505
Abstract611)      PDF (1251KB)(516)       Save
Concerning the influence of various environmental ambiances on sound event recognition, a sound event recognition method based on Optimized Orthogonal Matching Pursuit (OOMP) and Deep Belief Network (DBN) was proposed. Firstly, Particle Swarm Optimization (PSO) algorithm was used to optimize Orthogonal Matching Pursuit (OMP) sparse decomposition of sound signal, which realized fast sparse decomposition of OMP and reserved the main body of sound signal and reduced the influence of noise. Then, an optimized composited feature was composed by Mel-Frequency Cepstral Coefficient (MFCC), time-frequency OMP feature and Pitch feature extracted from the reconstructed sound signal, which was called OOMP feature. Finally, the DBN was employed to learn the OOMP feature and recognize 40 classes of sound events in different environments and Signal-to-Noise Ratio (SNR). The experimental results show that the proposed method which combined OOMP and BDN is suitable for sound event recognition in various environments, and can effectively recognize sound events in various environments; it can still maitain an average accuracy rate of 60% even when the SNR is 0 dB.
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Delaunay triangulation subdivision algorithm of spherical convex graph and its convergence analysis
XIA Jun, LI Yinghua
Journal of Computer Applications    2017, 37 (12): 3558-3562.   DOI: 10.11772/j.issn.1001-9081.2017.12.3558
Abstract419)      PDF (738KB)(510)       Save
When calculating curved Ricci Flow, non-convergence emerges due to the existence of undersized angles in triangular meshes. Concerning the problem of non-convergence, a Delaunay triangulation subdivision algorithm of spherical convex graph of enhancing the minimum angle was proposed. First of all, the Delaunay triangulation subdivision algorithm of spherical convex graph was given. The proposed algorithm had two key operations:1) if a Delaunay minor arc was "encroached upon", a midpoint of the Delaunay minor arc was added to segment the Delaunay minor arc; 2) if there was a "skinny" spherical triangle, it was disassembled by adding the center of minor circle of its circumscribed sphere. Then, the convergence criteria of the proposed algorithm was explored on local feature scale and an upper-bound formula of the output vertex was given. The grids based on the output of experiment show that the spherical triangle generated by the grids of the proposed algorithm has no narrow angle, so it is suitable for calculating Ricci Flow.
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Aspect rating prediction based on heterogeneous network and topic model
JI Yugang, LI Yitong, SHI Chuan
Journal of Computer Applications    2017, 37 (11): 3201-3206.   DOI: 10.11772/j.issn.1001-9081.2017.11.3201
Abstract624)      PDF (863KB)(486)       Save
Concerning the problem that traditional aspect rating prediction methods just pay attention to textual information while ignoring the structural information in the review network, a novel Aspect rating prediction method based on Heterogeneous Information Network and Topic model (HINToAsp) was proposed for effectively integering textual information and structural information. Firstly, a new review topic model of opinion phrases called Phrase-PLSA (Phrase-based Probabilistic Latent Semantic Analysis) was put forward to integrate textual information of reviews and ratings for mining aspect topics. And then, considering the rich structural information among users, reviews, and items, a topic propagation model was designed by the aid of constructing "User-Review-Item" heterogeneous information network. Finally, a random walk framework was used to combine textual information and structural information effectively, which insured an accurate aspect rating prediction. The experimental results on both Dianping corpora and TripAdvisor corpora demonstrate that HINToAsp is more effective than recent methods like the Quad-tuples PLSA (QPLSA) model, the Gaussian distribution for RAting Over Sentiments (GRAOS) model and the Sentiment-Aligned Topic Model (SATM), and has better performance on recommendation system.
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Application of symbiotic system-based artificial fish school algorithm in feed formulation optimization
LIU Qing, LI Ying, QING Maiyu, ODAKA Tomohiro
Journal of Computer Applications    2016, 36 (12): 3303-3310.   DOI: 10.11772/j.issn.1001-9081.2016.12.3303
Abstract445)      PDF (1134KB)(428)       Save
In consideration of intelligence algorithms' extensive applicability to various types of feed formulation optimization models, the Artificial Fish Swarm Algorithm (AFSA) was firstly applied in feed formulation optimization. For meeting the required precision of feed formulation optimization, a symbiotic system-based AFSA was employed. which significantly improved the convergence accuracy and speed compared with the original AFSA. In the process of optimization, the positions of Artificial Fish (AF) individuals in solution space were directly coded as the form of solution vector to the problem via the feed ratio, a penalty-based objective function was employed to evaluate AF individuals' fitness. AF individuals performed several behavior operators to explore the solution space according to a predefined behavioral strategy. The validity of the proposed algorithm was verified on three practical instances. The verification results show that, the proposed algorithm has worked out the optimal feed formulation, which can not only remarkably reduce the fodder cost, but also satisfy various nutrition constraints. The optimal performance of the proposed algorithm is superior to the other existing algorithms.
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Aircraft stands assignment optimization based on variable tabu length
LI Yaling, LI Yi
Journal of Computer Applications    2016, 36 (10): 2940-2944.   DOI: 10.11772/j.issn.1001-9081.2016.10.2940
Abstract432)      PDF (720KB)(419)       Save
Aiming at the problem of maximizing the utilization of aircraft stands and minimizing the passengers' total walking distance in air transport, a new dynamic and flexible algorithm was proposed. Firstly, a simple and basic tabu search algorithm was introduced; then a modified method called Dynamic Tabu Search (DTS) was recommended; finally, comparison of several groups of data was given to verify that the variable length of tabu can reduce cycle times of global optimization. Moreover, the comparison with algorithms from references showed that the total walking time was decreased by 15.75% under sufficient resources and 22.84% under limited resources respectively. Experimental results indicate that the dynamic tabu search algorithm can get distribution solutions with smaller passenger walking distance.
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Indoor positioning algorithm with dynamic environment attenuation based on particle filtering
LI Yinuo, XIAO Ruliang, NI Youcong, SU Xiaomin, DU Xin, CAI Shengzhen
Journal of Computer Applications    2015, 35 (9): 2465-2469.   DOI: 10.11772/j.issn.1001-9081.2015.09.2465
Abstract677)      PDF (796KB)(343)       Save
Due to the problem that the nodes having the same distance but different position in the complex environment, brings shortage to accuracy and stability of indoor positioning, a new indoor positioning algorithm with Dynamic Environment Attenuation Factor (DEAF) was proposed. This algorithm built a DEAF model and redefined the way to assume the value. In this algorithm, particle filtering method was firstly used to smooth the Received Signal Strength Indication (RSSI); then, the DEAF model was used to calculate the estimation distance of the node; finally, the trilateration was used to get the position of the target node. Comparative experiments had been done using several filtering models, and the results show that this dynamic environment attenuation factor model combined with particle filtering can resolve the problem of the environment difference very well. This algorithm reduces the mean error to about 0.68 m, and the result has higher positioning accuracy and good stability.
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Improved ant colony optimization for QoS-based Web service composition optimization
NI Zhiwei, FANG Qinghua, LI Rongrong, LI Yiming
Journal of Computer Applications    2015, 35 (8): 2238-2243.   DOI: 10.11772/j.issn.1001-9081.2015.08.2238
Abstract488)      PDF (1051KB)(445)       Save

The basic Ant Colony Optimization (ACO) has slow searching speed at prior period and being easy to fall into local optimum at later period. To overcome these shortcomings, the initial pheromone distribution strategy and local optimization strategy were proposed, and a new pheromone updating rule was put forward to strengthen the effective accumulation of pheromone. The improved ACO was used in QoS-based Web service composition optimization problem, and the feasibility and effectiveness of it was verified on QWS2.0 dataset. The experimental results show that, compared with the basic ACO, the improved ACO which updates the pheromone with the distance of the solution and the ideal solution, and the improved genetic algorithm which introduces individual domination strength into the environment selection, the proposed ACO can find more Pareto solutions, and has stronger optimizing capacity and stable performance.

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Target tracking algorithm for underwater bearings-only system with incomplete measurements
DING Wei, LI Yinya
Journal of Computer Applications    2015, 35 (4): 1106-1109.   DOI: 10.11772/j.issn.1001-9081.2015.04.1106
Abstract614)      PDF (545KB)(545)       Save

Concerning the problem of underwater bearings-only system target tracking with incomplete measurements when the probability of sensor detection is less than 1,an improved extended Kalman filtering algorithm for target state estimation was presented. First, the mathematical model of underwater bearings-only system for target tracking with incomplete measurements was established. Second, based on the sensor's incomplete measurement data, the previous update data was used to compensate for the incomplete date and then to perform the filtering. Finally, two evaluation criteria including Cramer-Rao Low Bound (CRLB) and Root Mean Square Errors (RMSE) were used to evaluate the proposed algorithm. The simulation results show that the proposed extended Kalman filtering algorithm for target tracking has higher real-time property with desired tracking precision in the problem of underwater bearings-only system target tracking with incomplete measurements.

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Sequence images super-resolution reconstruction based on L 1 and L 2 mixed norm
LI Yinhui, LYU Xiaoqi, YU Hefeng
Journal of Computer Applications    2015, 35 (3): 840-843.   DOI: 10.11772/j.issn.1001-9081.2015.03.840
Abstract555)      PDF (706KB)(348)       Save

In order to filter out Gaussian noise and impulse noise at the same time, and get high resolution image in super-resolution reconstruction, a method with L1 and L2 mixed norm and Bilateral Total Variation (BTV) regularization was proposed for sequence images super-resolution. Firstly, multi-resolution optical flow model was used to register low-resolution sequence images and the registration precision was up to sub-pixel level, then the complementary information was used to raise image resolution. Secondly, taking advantage of L1 and L2 mixed norm, BTV regularization algorithm was used to solve the ill-posed problem. Lastly, the proposed algorithm was used to sequence images super-resolution. Experimental results show that the method can decrease the mean square error and increase Peak Signal-to-Noise Ratio (PSNR) by 1.2 dB to 5.2 dB. The algorithm can smooth Gaussian and impulse noise, protect image edge information and improve image identifiability, which provides good technique basis for license plate recognition, face recognition, video surveillance, etc.

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Resource matching maximum set job scheduling algorithm under Hadoop
ZHU Jie, LI Wenrui, ZHAO Hong, LI Ying
Journal of Computer Applications    2015, 35 (12): 3383-3386.   DOI: 10.11772/j.issn.1001-9081.2015.12.3383
Abstract613)      PDF (725KB)(332)       Save
Concerning the problem that jobs of high proportion of resources execute inefficiently in job scheduling algorithms of the present hierarchical queues structure, the resource matching maximum set algorithm was proposed. The proposed algorithm analysed job characteristics, introduced the percentage of completion, waiting time, priority and rescheduling times as urgent value factors. Jobs with high proportion of resources or long waiting time were preferentially considered to improve jobs fairness. Under the condition of limited amount of available resources, the double queues was applied to preferentially select jobs with high urgent values, select the maximum job set from job sets with different proportion of resources in order to achieve scheduling balance. Compared with the Max-min fairness algorithm, it is shown that the proposed algorithm can decrease average waiting time and improve resource utilization. The experimental results show that by using the proposed algorithm, the running time of the same type job set which consisted of jobs of different proportion of resources is reduced by 18.73%, and the running time of jobs of high proportion of resources is reduced by 27.26%; the corresponding percentages of reduction of the running time of the mixed-type job set are 22.36% and 30.28%. The results indicate that the proposed algorithm can effectively reduce the waiting time of jobs of high proportion of resources and improve the overall jobs execution efficiency.
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PageRank parallel algorithm based on Web link classification
CHEN Cheng, ZHAN Yinwei, LI Ying
Journal of Computer Applications    2015, 35 (1): 48-52.   DOI: 10.11772/j.issn.1001-9081.2015.01.0048
Abstract871)      PDF (740KB)(683)       Save

Concerning the problem that the efficiency of serial PageRank algorithm is low in dealing with mass Web data, a PageRank parallel algorithm based on Web link classification was proposed. Firstly, the Web was classified according to its Web link, and the weights of different Web which was from diverse websites were set variously. Secondly, with the Hadoop parallel computation platform and MapReduce which has the characteristics of dividing and conquering, the Webpage ranks were computed parallel. At last, a data compression method of three layers including data layer, pretreatment layer and computation layer was adopted to optimize the parallel algorithm. The experimental results show that, compared with the serial PageRank algorithm, the accuracy of the proposed algorithm is improved by 12% and the efficiency is improved by 33% in the best case.

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Bird sounds recognition based on Radon and translation invariant discrete wavelet transform
ZHOU Xiaomin LI Ying
Journal of Computer Applications    2014, 34 (5): 1391-1396.   DOI: 10.11772/j.issn.1001-9081.2014.05.1391
Abstract455)      PDF (1071KB)(408)       Save

To improve the accuracy of bird sounds recognition in low Signal-to-Noise Ratio (SNR) environment, a new bird sounds recognition technology based on Radon Transform (RT) and Translation Invariant Discrete Wavelet Transform (TIDWT) from spectrogram after the noise reduction was proposed. First, an improved multi-band spectral subtraction method was presented to reduce the background noise. Second, short-time energy was used to detect silence of clean bird sound, and the silence was removed. Then, the bird sound was translated into spectrogram, RT and TIDWT were used to extract features. Finally, classification was achieved by Support Vector Machine (SVM) classifier. The experimental results show that the method can achieve better recognition effect even the SNR belows 10dB.

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