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Secondary signal detection algorithm for high-speed mobile environments
Huahua WANG, Xu ZHANG, Feng LI
Journal of Computer Applications    2024, 44 (4): 1236-1241.   DOI: 10.11772/j.issn.1001-9081.2023050580
Abstract83)   HTML0)    PDF (2710KB)(55)       Save

Orthogonal Time Sequency Multiplexing (OTSM) achieves transmission performance similar to Orthogonal Time Frequency Space (OTFS) modulation with lower complexity, providing a promising solution for future high-speed mobile communication systems that require low complexity transceivers. To address the issue of insufficient efficiency in existing time-domain based Gauss-Seidel (GS) iterative equalization, a secondary signal detection algorithm was proposed. First, Linear Minimum Mean Square Error (LMMSE) detection with low complexity was performed in the time domain, and then Successive Over Relaxation (SOR) iterative algorithm was used to further eliminate residual symbol interference. To further optimize convergence efficiency and detection performance, the SOR algorithm was linearly optimized to obtain an Improved SOR (ISOR) algorithm. The simulation experimental results show that compared with SOR algorithm, ISOR algorithm improves detection performance and accelerates convergence while increasing lower complexity. Compared with GS iterative algorithm, ISOR algorithm has a gain of 1.61 dB when using 16 QAM modulation with a bit error rate of 10 - 4 .

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Feature extraction model based on neighbor supervised locally invariant robust principal component analysis
Mengting GE, Minghua WAN
Journal of Computer Applications    2023, 43 (4): 1013-1020.   DOI: 10.11772/j.issn.1001-9081.2022030329
Abstract260)   HTML24)    PDF (1981KB)(155)       Save

Focused on the issue that the category relationship between samples is not considered in the unsupervised Locally Invariant Robust Principal Component Analysis (LIRPCA) algorithm, a feature extraction model based on Neighbor Supervised LIRPCA (NSLIRPCA) was proposed. The category information between samples was considered by the proposed model, and a relationship matrix was constructed based on this information. The formulas of the model were solved and the convergences of the formulas were proved. At the same time, the proposed model was applied to various occlusion datasets. Experimental results show that compared with Principal Component Analysis (PCA), PCA based on L1-norm (PCA-L1), Non-negative Matrix Factorization (NMF), Locality Preserving Projection (LPP) and LIRPCA algorithms on ORL, Yale, COIL-Processed and PolyU datasets, the proposed model has the recognition rate improved by 8.80%, 7.76%, 20.37%, 4.72% and 4.61% at most respectively on the original image datasets, and the recognition rate improved by 30.79%, 30.73%, 36.02%, 19.65% and 17.31% at most respectively on the occluded image datasets. It can be seen that with the proposed model, the recognition performance of the algorithm is improved, and the complexity of the model is reduced, verifying that the model is obviously better than the comparison algorithms.

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Anomaly detection in video via independently recurrent neural network and variational autoencoder network
Qing JIA, Laihua WANG, Weisheng WANG
Journal of Computer Applications    2023, 43 (2): 507-513.   DOI: 10.11772/j.issn.1001-9081.2021122081
Abstract312)   HTML17)    PDF (2994KB)(111)       Save

To effectively extract the temporal information between consecutive video frames, a prediction network IndRNN-VAE (Independently Recurrent Neural Network-Variational AutoEncoder) that fuses Independently Recurrent Neural Network (IndRNN) and Variational AutoEncoder (VAE) network was proposed. Firstly, the spatial information of video frames was extracted through VAE network, and the latent features of video frames were obtained by a linear transformation. Secondly, the latent features were used as the input of IndRNN to obtain the temporal information of the sequence of video frames. Finally, the obtained latent features and temporal information were fused through residual block and input to the decoding network to generate the prediction frame. By testing on UCSD Ped1, UCSD Ped2 and Avenue public datasets, experimental results show that compared with the existing anomaly detection methods, the method based on IndRNN-VAE has the performance significantly improved, and has the Area Under Curve (AUC) values reached 84.3%, 96.2%, and 86.6% respectively, the Equal Error Rate (EER) values reached 22.7%, 8.8%, and 19.0% respectively, the difference values in the mean anomaly scores reached 0.263, 0.497, and 0.293 respectively. Besides, the running speed of this method reaches 28 FPS (Frames Per Socond).

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Doubly feature-weighted fuzzy support vector machine
Yunzhi QIU, Tinghua WANG, Xiaolu DAI
Journal of Computer Applications    2022, 42 (3): 683-687.   DOI: 10.11772/j.issn.1001-9081.2021040760
Abstract329)   HTML15)    PDF (434KB)(102)       Save

Concerning the shortcoming that the current feature-weighted Fuzzy Support Vector Machines (FSVM) only consider the influence of feature weights on the membership functions but ignore the application of feature weights to the kernel functions calculation during sample training, a new FSVM algorithm that considers the influence of feature weights on the membership function and the kernel function calculation simultaneously was proposed, namely Doubly Feature-Weighted FSVM (DFW-FSVM). Firstly, relative weight of each feature was calculated by using Information Gain (IG). Secondly, the weighted Euclidean distance between the sample and the class center was calculated in the original space based on the feature weights, and then the membership function was constructed by applying the weighted Euclidean distance; at the same time, the feature weights were applied to the calculation of the kernel function in the sample training process. Finally, DFW-FSVM algorithm was constructed according to the weighted membership functions and kernel functions. In this way, DFW-FSVM is able to avoid being dominated by trivial relevant or irrelevant features. The comparative experiments were carried out on eight UCI datasets, and the results show that compared with the best results of SVM, FSVM, Feature-Weighted SVM (FWSVM), Feature-Weighted FSVM (FWFSVM) and FSVM based on Centered Kernel Alignment (CKA-FSVM) , the accuracy and F1 value of the DFW-FSVM algorithm increase by 2.33 and 5.07 percentage points, respectively, indicating that the proposed DFW-FSVM has good classification performance.

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Technical review and case study on classification of Chinese herbal slices based on computer vision
Yi ZHANG, Hua WAN, Shuqin TU
Journal of Computer Applications    2022, 42 (10): 3224-3234.   DOI: 10.11772/j.issn.1001-9081.2021081498
Abstract516)   HTML12)    PDF (4058KB)(192)       Save

Classifying similar, counterfeit and deteriorated slices in Chinese herbal slices plays a vital role in clinical application of Chinese medicine. Traditional manual identification methods are subjective and fallible. And the classification of traditional Chinese herbal slices based on computer vision is superior in speed and accuracy, which makes Chinese herbal slice screening intelligent. Firstly, general steps of Chinese medicine recognition algorithm based on computer vision were introduced, and technical development status of preprocessing, feature extraction and recognition model of Chinese medicine images were reviewed separately. Then, 12 classes of similar and easily confused Chinese herbal slices were selected as a case to study. By constructing a dataset with 9 156 pictures of Chinese herbal slices, the recognition performance differences of traditional recognition algorithms and various deep learning models were analyzed and compared. Finally, the difficulties and future development trends of computer vision in Chinese herbal slices were summarized and prospected.

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Waterweed image segmentation method based on improved U-Net
Qiwen WU, Jianhua WANG, Xiang ZHENG, Ju FENG, Hongyan JIANG, Yubo WANG
Journal of Computer Applications    2022, 42 (10): 3177-3183.   DOI: 10.11772/j.issn.1001-9081.2021091614
Abstract349)   HTML17)    PDF (2407KB)(93)       Save

During the operation of the Unmanned Surface Vehicles (USVs), the propellers are easily gotten entangled by waterweeds, which is a problem encountered by the whole industry. Concerning the global distribution, dispersivity, and complexity of the edge and texture of waterweeds in the water surface images, the U-Net was improved and used to classify all pixels in the image, in order to reduce the feature loss of the network, and enhance the extraction of both global and local features, thereby improving the overall segmentation performance. Firstly, the image data of waterweeds in multiple locations and multiple periods were collected, and a comprehensive dataset of waterweeds for semantic segmentation was built. Secondly, three scales of input images were introduced into the network to enable full extraction of the features via the network, and three loss functions for the upsampled images were introduced to balance the overall loss brought by the three different scales of input images. In addition, a hybrid attention module, including the dilated convolution branch and the channel attention enhancement branch, was proposed and introduced to the network. Finally, the proposed network was verified on the newly built waterweed dataset. Experimental results show that the accuracy, mean Intersection over Union (mIoU) and mean Pixel Accuracy (mPA) values of the proposed method can reach 96.8%, 91.22% and 95.29%, respectively, which are improved by 4.62 percentage points, 3.87 percentage points and 3.12 percentage points compared with those of U-Net (VGG16) segmentation method. The proposed method can be applied to unmanned surface vehicles for detection of waterweeds, and perform the corresponding path planning to realize waterweed avoidance.

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Research on dynamic stability of badminton
ZHANG Jinghua WANG Renhuang YUE Hongwei
Journal of Computer Applications    2014, 34 (3): 902-906.   DOI: 10.11772/j.issn.1001-9081.2014.03.0902
Abstract397)      PDF (754KB)(345)       Save

To solve the problem of the regulation of badminton dynamic stable equilibrium, the particle influence coefficient method of feather piece was put forward. The method combined badminton quality models and quality feather piece, bending camber degree, angle of attack, and other related factors. The feather piece of particle influence coefficient was obtained by adjusting the height centroid which satisfied badminton dynamic stability requirements got by striking tilt minimum square. Compared with the traditional badminton dynamic stabilization which must depend on the experience accumulated for a long time, the badminton particle influence coefficient method of feather piece that was put forward by this paper formed a theoretical system. And it had less time consumption, high efficiency, etc. The numerical results show that the proposed method is correct and effective.

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Pedestrian segmentation based on Graph Cut with shape prior
HU Jianghua WANG Wenzhong LUO Bin TANG Jin
Journal of Computer Applications    2014, 34 (3): 837-840.   DOI: 10.11772/j.issn.1001-9081.2014.03.0837
Abstract639)      PDF (640KB)(366)       Save

Most of the variants of Graph Cut algorithm do not impose any shape constraints on the segmentations, rendering it difficult to obtain semantic valid segmentation results. As for pedestrian segmentation, this difficulty leads to the non-human shape of the segmented object. An improved Graph Cut algorithm combining shape priors and discriminatively learned appearance model was proposed in this paper to segment pedestrians in static images. In this approach, a large number of real pedestrian silhouettes were used to encode the a'priori shape of pedestrians, and a hierarchical model of pedestrian template was built to reduce the matching time, which would hopefully bias the segmentation results to be humanlike. A discriminative appearance model of the pedestrian was also proposed in this paper to better distinguish persons from the background. The experimental results verify the improved performance of this approach.

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Diversity feedback and control particle swarm optimization algorithm
RAO Xinghua WANG Wenge HU Xu
Journal of Computer Applications    2014, 34 (2): 506-509.  
Abstract439)      PDF (712KB)(428)       Save
Concerning the premature convergence problem in Particle Swarm Optimization (PSO) algorithm, a Diversity Feedback and Control PSO (DFCPSO) algorithm was proposed. In the process of search, the algorithm dynamically adjusted the algorithm parameters according to the feedback information of diversity; as a result, the distribution of iterations in the diversity curve was improved. When the population diversity or the variance of the population's fitness dropped to the given thresholds, the proposed algorithm would let the particle swarm initialize based on the repulsion of the global best position and fly away from the gathering area efficiently to search again, hence the diversity was controlled in a reasonable range, which avoided premature convergence. The experimental results on several well-known benchmark functions show that DFCPSO has stronger global optimization ability in the complicated problems and multi-modal optimization when being compared with the existing Diversity-Controlled PSO (DCPSO).
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Novel sliding mode control with power reaching law based on frequency domain identification models
ZHONG Hua WANG Yong SHAO Changxing
Journal of Computer Applications    2014, 34 (12): 3637-3640.  
Abstract148)      PDF (680KB)(595)       Save

Considering the complexity and inaccuracy of traditional theoretical modeling for rigid-flexible couple system, the frequency domain subspace method was used to identify the motor's model and piezoelectric ceramic piece's model in the experimental system. Due to the problem of chattering and long reaching time of traditional reaching law, a novel sliding mode control with power reaching law was proposed. Theoretical analysis shows that the reaching time can be shortened and the range of traditional power reaching law's parameter α can be expanded, which will not affect the chattering. Considering the effect of vibration characteristics of flexible beam on system performance, the method of sub-sliding surface was used to design the sliding mode controller. Lastly, experimental results show that the designed controller can track the angle of the center of the rigid body rapidly and suppress the vibration of the flexible beam quickly.

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Index structure with self-adaptive mechanism in flash-based database system
FANG Junhua WANG Hanhu CHEN Mei MA Dan
Journal of Computer Applications    2013, 33 (02): 563-566.   DOI: 10.3724/SP.J.1087.2013.00563
Abstract846)      PDF (591KB)(445)       Save
The log-based index update mechanism in flash-based database system has following shortage: low query efficiency, expensive update cost, unreasonable space allocation and merge for the log. In order to solve these problems, a new adaptive index structure named LM-B+TREE was proposed. LM-B+TREE can map the page for index update buffer into corresponding node of traditional B+ TREE. Furthermore, according to the read/write workload and read/write overhead, LM-B+TREE can dynamically maintain the update buffer and adjust the index frame adaptively. The experimental results show that LM-B+ TREE can dynamically adjust the index structure to adapt to the read-write workload, significantly reduce the overhead of index update and improve the query performance.
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Improvement of the adversarial optimization approach for outlier removal in image matching
XUE Zhen-hua WANG Ping ZHANG Chu-han CAI Si-jia
Journal of Computer Applications    2012, 32 (11): 3157-3160.   DOI: 10.3724/SP.J.1087.2012.03157
Abstract1106)      PDF (638KB)(545)       Save
Applying the adversarial optimization approach to remove the error matches in image matching usually causes the removal of correct matches,especially when multiple iterations are run.Concerning this drawback,a limit was put on the number of iterations,and a subsequent processing was added,which reestimated the homography matrix using a Random Sample Consensus (RANSAC)like method.The experiments show that the improved method can preserve almost all the correct matches with smaller root mean square error.And in the aspect of computing speed,the time the improved method needs is less than half the time the original method needs.
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Three dimensional reconstruction algorithm based on uncalibrated multiple images
ZHAO Lu-lu GENG Guo-hua WANG Xiao-feng LIU Qian
Journal of Computer Applications    2012, 32 (10): 2802-2805.   DOI: 10.3724/SP.J.1087.2012.02802
Abstract977)      PDF (636KB)(439)       Save
This paper proposed an algorithm for 3D reconstruction based on uncalibrated images. First, this algorithm detected the feature points by using Harris corners, and presented an improved bidirectional matching to match these feature points. Under the condition of the known camera parameters, the authors carried out 3D reconstruction of two images. Then the quaternion algorithm was adopted to transform coordinate. The results coming from different subsets were brought into a common coordinate frame, achieving 3D reconstruction of multiple images. Finally, bundle adjustment was used to optimize the results. The experimental results show that object structure can be well reconstructed by using this algorithm.
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Visual saliency detection algorithm based on Bayes theorem and statistical learning
DAI Hua WANG Jian-ping
Journal of Computer Applications    2012, 32 (08): 2288-2290.   DOI: 10.3724/SP.J.1087.2012.02288
Abstract1235)      PDF (510KB)(436)       Save
Image processing technology depends on the quality of the visual saliency map to obtain better results. The existing visual saliency detection method usually can only detect and get rough visual saliency attribute graph, seriously affecting the image processing results. This paper put forward a method of using Bayes theorem and statistical learning of visual saliency detection to detect the visual saliency property of image. The method was based on Bayes theorem of static image top-down significant and overall significance, and combined the top-down knowledge and the down-top significance. For the synthetic integration of characteristics, all the factors related to the weight parameter were studied by using linear model with the linear weighting combination method and regularized neural network combined with nonlinear weighting method. The ROC curves of the bottom-up visual saliency model in two fixed data set for quantitative evaluation, show that the effect of non-linear combination is better than that of linear combination.
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Dynamic trusted measurement model of operating system kernel
XIN Si-yuan ZHAO Yong LIAO Jian-hua WANG Ting
Journal of Computer Applications    2012, 32 (04): 953-956.   DOI: 10.3724/SP.J.1087.2012.00953
Abstract1451)      PDF (839KB)(441)       Save
Dynamic trusted measurement is a hot and difficult research topic in trusted computing. Concerning the measurement difficulty invoked by the dynamic nature of operating system kernel, a Dynamic Trusted Kernel Measurement (DTKM) model was proposed. Dynamic Measurement Variable (DMV) was presented to describe and construct dynamic data objects and their relations, and the method of semantic constraint was proposed to measure the dynamic integrity of kernel components. In DTKM, the collection of memory data was implemented in real-time, and the dynamic integrity was verified by checking whether the constructed DMV was consistent with semantic constraints which were defined based on the security semantics. The nature analysis and application examples show that DTKM can effectively implement dynamic measurement of the kernel and detect the illegal modification of the kernel dynamic data.
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Routing scheme for vehicle Ad Hoc network
LIU Jing WANG Xin-hua WANG Zhen WANG Shuo
Journal of Computer Applications    2012, 32 (02): 359-366.   DOI: 10.3724/SP.J.1087.2012.00359
Abstract787)      PDF (763KB)(427)       Save
Through analyzing the application status of Vehicle Ad Hoc NETwork (VANET) in road transportation field, according to the characteristics of VANET and challenges in news transmission process, concerning the problems of previous algorithms being difficult to establish spatial model accurately and hardly considering the regularity characteristics of social behavior, a routing scheme named HBSR was proposed based on the historical behavior statistics of vehicles, including nodes connected algorithm calculating the connectivity between vehicles, topological overlap algorithm calculating the number of periods between the source node and destination node, paths selected algorithm selecting messages forwarding paths and loss strategy. Compared with several typical routing algorithms on ONE simulation platform, the simulation results prove that HBSR can find news forwarding paths more effectively, and reduces message delivery delay obviously while delivery rate increases significantly, and performance is relatively stable in VANET.
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Embedded face recognition system based on Gabor uncertainty
YE Ji-hua WANG Shi-min GUO Fan YU Min
Journal of Computer Applications    2011, 31 (09): 2502-2505.   DOI: 10.3724/SP.J.1087.2011.02502
Abstract1387)      PDF (801KB)(435)       Save
Gabor uncertainty features fusion can solve the problem that multiscale Gabor features are unsuitable for ARM because of huge data and dimensions in the embedded face recognition system. Multiscale Gabor features were first extracted, and then the uncertain weight was calculated, at last multiscale Gabor features were integrated into one. The embedded face recognition system detected face by using Haar-like features of face, and reduced dimensions by using 2-Dimensional Principal Component Analysis (2DPCA) algorithm. Based on EELiod 270 development board, the performance of face recognition was tested on ORL and Yale. Comparative results with other face recognition algorithms show that a significant decline is got in the amount of arithmetic operations, and a good real-time recognition is obtained while ensuring the recognition rate.
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Selection scheme of message carried vehicles in vehicle network environment
LIU Jing WANG Xin-hua WANG Shuo
Journal of Computer Applications    2011, 31 (09): 2349-2351.   DOI: 10.3724/SP.J.1087.2011.02349
Abstract960)      PDF (703KB)(383)       Save
For the dynamic characteristic of vehicle Ad-Hoc network's topology, the file is difficult to completely downloaded within the communication of a single vehicle road Access Point (AP) using the existing schemes of information dissemination, having the long time delay limitation of waiting for the next AP to document communication. A method that downloaded and spread the file fragmentation using multiple vehicles within the range of some free APs was proposed, the message delivery delay was divided into direct and indirect encounter delays, and discussion was made on them respectively, and a specific option was given to choose message carried vehicles. The experimental results of the message loss rate and delay show that the environment joined with the proposed scheme can effectively improve the reliability of message downloading, shorten the delay of downloading message to the purpose vehicle, without significant additional load to the network.
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Touched human object segmentation based on Mean-shift algorithm
Sen Guo Wei Liu JiangHua Wang
Journal of Computer Applications   
Abstract1692)      PDF (425KB)(1335)       Save
Human objects Segmentation is one of the key problems of Visual Analysis. In this paper, a novel touched human objects segmentation based on Mean-shift algorithm was proposed. At first, Video Images was preprocessed and motion regions were obtained, and model of human object was built according to statistical characteristics of body surface. Then, a few of points of motion region picked equably were taken as seeds, and local mode centroids were calculated by Mean-shift iterative process. At last, the number of categories was automatically acqured based on the clustering algorithm, and human objects were segmented according to the result of clustering. The experiment based on PETS 2006 Database proves this method is feasible.
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Research of GPS vehicle terminal communication technology based on GPRS
Xiao-wei HE Ai-hua WANG Yue MA
Journal of Computer Applications   
Abstract1827)      PDF (629KB)(1552)       Save
The software design of Global Positioning System (GPS) vehicle terminal was discussed, which was based on General Packet Radio Service (GPRS) wireless communication, including the definition of communication protocol between vehicle terminal and monitor center, the design of efficient strategy of GPS information receiving and unpacking, and GPRS communication flow design. The work provides a useful reference for developing GPRS communication equipment and GPS location equipment.
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Multi-objective optimization algorithm based on the combination of NSGA-Ⅱ and MOPSO
Jin-Hua WANG Ze-Yong Yin
Journal of Computer Applications   
Abstract2037)            Save
A new algorithm was developed through replacing the crossover operation in NSGA-Ⅱ with the mode of position updating in multiobjective particle swarm optimizer (MOPSO). In order to seamlessly combine NSGAⅡand the greatly different MOPSO, the special concepts (particle and its velocity, Pbest and leader) for MOPSO were dealt with within the scope of NSGA-Ⅱ: 1) particle in MOPSO was considered to be equivalent to offspring individual in NSGA-Ⅱ; 2) the concept of velocity fell into disuse; 3) the concept of Pbest also came into disuse. Instead of that, for each dimension of a particle, the nearest one among its nondominated individuals in parent population was used; 4) the leader of a particle was the individual with largest sparse degree among parent population or selected from parent population by binary tournament selection method, which of them taking effect lies on the predefined probability. In addition, a new concept, i.e., sparse degree, was introduced to evaluate the distribution of particles in objective function space. Experiments on six benchmark problems indicate that the new algorithm is an effective and stable one when compared with NSGA-Ⅱ and two of the latest MOPSOs (CLMOPSO and EM-MOPSO).
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