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Robotic grasp detection in low-light environment by incorporating visual feature enhancement mechanism
Gan LI, Mingdi NIU, Lu CHEN, Jing YANG, Tao YAN, Bin CHEN
Journal of Computer Applications    2023, 43 (8): 2564-2571.   DOI: 10.11772/j.issn.1001-9081.2023050586
Abstract275)   HTML26)    PDF (2821KB)(643)       Save

Existing robotic grasping operations are usually performed under well-illuminated conditions with clear object details and high regional contrast. At the same time, for low-light conditions caused by night and occlusion, where the objects’ visual features are weak, the detection accuracies of existing robotic grasp detection models decrease dramatically. In order to improve the representation ability of sparse and weak grasp features in low-light scenarios, a grasp detection model incorporating visual feature enhancement mechanism was proposed to use the visual enhancement sub-task to impose feature enhancement constraints on grasp detection. In grasp detection module, the U-Net like encoder-decoder structure was adopted to achieve efficient feature fusion. In low-light enhancement module, the texture and color information was respectively extracted from local and global level, thereby balancing the object details and visual effect in feature enhancement. In addition, two low-light grasp datasets called low-light Cornell dataset and low-light Jacquard dataset were constructed as new benchmark dataset of low-light grasp and used to conduct the comparative experiments. Experimental results show that the accuracies of the proposed low-light grasp detection model are 95.5% and 87.4% on the benchmark datasets respectively, which are 11.1, 1.2 percentage points higher on low-light Cornell dataset and 5.5, 5.0 percentage points higher on low-light Jacquard dataset than those of the existing grasp detection models, including Generative Grasping Convolutional Neural Network (GG-CNN), and Generative Residual Convolutional Neural Network (GR-ConvNet), indicating that the proposed model has good grasp detection performance.

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Cross-corpus speech emotion recognition based on decision boundary optimized domain adaptation
Yang WANG, Hongliang FU, Huawei TAO, Jing YANG, Yue XIE, Li ZHAO
Journal of Computer Applications    2023, 43 (2): 374-379.   DOI: 10.11772/j.issn.1001-9081.2021122043
Abstract302)   HTML16)    PDF (3084KB)(123)       Save

Domain adaptation algorithms are widely used for cross-corpus speech emotion recognition. However, many domain adaptation algorithms lose the discrimination of target domain samples while pursuing the minimization of domain discrepancy, resulting in their presence at the decision boundary of the model in a high-density form, which degrades the performance of the model. Based on the above problem, a Decision Boundary Optimized Domain Adaptation (DBODA) method based cross-corpus speech emotion recognition was proposed. Firstly, the features were processed by using convolutional neural networks. Then, the features were fed into the Maximum Nuclear-norm and Mean Discrepancy (MNMD) module to maximize the nuclear norm of the sentiment prediction probability matrix of the target domain while reducing the inter-domain discrepancy, thereby enhancing the discrimination of the target domain samples and optimize the decision boundary. In six sets of cross-corpus experiments set up on the basis of Berlin, eNTERFACE and CASIA speech databases, the average recognition accuracy of the proposed method is 1.68 to 11.01 percentage points ahead of those of the other algorithms, indicating that the proposed model effectively reduces the sample density around the decision boundary and improves the prediction accuracy.

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Several novel intelligent optimization algorithms for solving constrained engineering problems and their prospects
Mengjian ZHANG, Deguang WANG, Min WANG, Jing YANG
Journal of Computer Applications    2022, 42 (2): 534-541.   DOI: 10.11772/j.issn.1001-9081.2021020265
Abstract476)   HTML32)    PDF (849KB)(294)       Save

To study the performance and application prospects of novel intelligent optimization algorithms, six bionic intelligent optimization algorithms proposed in the past few years were analyzed, concluding Harris Hawks Optimization (HHO) algorithm, Equilibrium Optimizer (EO), Marine Predators Algorithm (MPA), Political Optimizer (PO), Slime Mould Algorithm (SMA), and Heap-Based Optimizer (HBO). Their performance and applications in different constrained engineering optimization problems were compared and analyzed. Firstly, the basic principles of six optimization algorithms were introduced. Secondly, the optimization tests were performed on ten standard benchmark functions for six optimization algorithms. Thirdly, six optimization algorithms were applied to solve three engineering optimization problems with constraints. Experimental results show that the convergence accuracy of PO is the best for the optimization of unimodal and multimodal test functions and can reach the theoretical optimal value zero many times. The EO and MPA are better for solving constrained engineering problems with fast optimization speed, high stability and standard deviation of a small order of magnitude. Finally, the improvement methods and development potentials of six optimization algorithms were analyzed.

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Image super-resolution restoration algorithm based on information distillation network with dual attention mechanism
Suyu WANG, Jing YANG, Yue LI
Journal of Computer Applications    2022, 42 (1): 239-244.   DOI: 10.11772/j.issn.1001-9081.2021010134
Abstract444)   HTML13)    PDF (632KB)(131)       Save

Aiming at the problems of network training difficulty and low utilization rate of feature information caused by increasing network layers in super-resolution restoration technology, an image super-resolution restoration algorithm based on dual attention Information Distillation Network (IDN) was designed and implemented. Firstly, by taking the advantage of the low computational complexity of IDN and the advantage of the information distillation module by which more features were extracted, the weights of the features were readjust adaptively by introducing the Residual Attention Module (RAM) and considering the interdependence of image channels, so as to further improve the reconstruction ability of high-resolution details of images. Then, a new mixed loss function sensitive to edge information was designed to refine the image and accelerate the convergence of the network. Test results on Set5, Set14, BSD100 and Urban100 public datasets show that the visual effect and Peak Signal-to-Noise Ratio (PSNR) of the proposed method are superior to those of the current mainstream algorithms.

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Teaching resources recommendation system for K12 education
ZHANG Haidong NI Wancheng ZHAO Meijing YANG Yiping
Journal of Computer Applications    2014, 34 (11): 3353-3356.   DOI: 10.11772/j.issn.1001-9081.2014.11.3353
Abstract395)      PDF (767KB)(653)       Save

In data layer, the course model and resource model were built based on Markov chain and vector space model, and the teacher model was built based on teachers' personal registration information and nodes of course model. In off-line layer, the content features of course model and resource model were extracted via Term Frequency-Inverse Document Frequency (TF-IDF) algorithm, and the course model and resource model of data layer were initialized and optimized. Then relations between any two resources or recourse and course were calculated using association rules mining and similarity measure, and intermediate recommendation results were given using teacher model and course model. A weighted hybrid recommendation algorithm was proposed to generate recommendation list in on-line layer. The proposed system has been successfully applied in a real education resources sharing platform which consists of 600 thousand teaching resources.

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New method of pattern-matching for network intrusion detection
FAN Ai-jing YANG Zhao-feng
Journal of Computer Applications    2011, 31 (11): 2961-2964.   DOI: 10.3724/SP.J.1087.2011.02961
Abstract1439)      PDF (740KB)(425)       Save
New generations of Network Intrusion Detection Systems (NIDS) create the need for advanced pattern-matching engines. This paper presented a new scheme for pattern-matching, which adopted a hardware-based programmable state machine technology to achieve deterministic processing rates. A lot of patterns can be obtained in one input stream by Balanced Routing Table-based FSM (B-FSM), and transition rules can be mapped effectively. Experiments had been done with Snort used widely in network intrusion detection systems. The experimental results show that the method is effective in storage, fast in operation, and renewable dynamically. The method proposed in this paper can satisfy the requirement of NIDS.
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