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[Author] Yu WANG(62hit)

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  • Feature Location in Source Code by Trace-Based Impact Analysis and Information Retrieval

    Zhengong CAI  Xiaohu YANG  Xinyu WANG  Aleksander J. KAVS  

     
    PAPER-Software System

      Vol:
    E95-D No:1
      Page(s):
    205-214

    Feature location is to identify source code that implements a given feature. It is essential for software maintenance and evolution. A large amount of research, including static analysis, dynamic analysis and the hybrid approaches, has been done on the feature location problems. The existing approaches either need plenty of scenarios or rely on domain experts heavily. This paper proposes a new approach to locate functional feature in source code by combining the change impact analysis and information retrieval. In this approach, the source code is instrumented and executed using a single scenario to obtain the execution trace. The execution trace is extended according to the control flow to cover all the potentially relevant classes. The classes are ranked by trace-based impact analysis and information retrieval. The ranking analysis takes advantages of the semantics and structural characteristics of source code. The identified results are of higher precision than the individual approaches. Finally, two open source cases have been studied and the efficiency of the proposed approach is verified.

  • Multi Feature Fusion Attention Learning for Clothing-Changing Person Re-Identification

    Liwei WANG  Yanduo ZHANG  Tao LU  Wenhua FANG  Yu WANG  

     
    LETTER-Image

      Pubricized:
    2022/01/25
      Vol:
    E105-A No:8
      Page(s):
    1170-1174

    Person re-identification (Re-ID) aims to match the same pedestrain identity images across different camera views. Because pedestrians will change clothes frequently for a relatively long time, while many current methods rely heavily on color appearance information or only focus on the person biometric features, these methods make the performance dropped apparently when it is applied to Clohting-Changing. To relieve this dilemma, we proposed a novel Multi Feature Fusion Attention Network (MFFAN), which learns the fine-grained local features. Then we introduced a Clothing Adaptive Attention (CAA) module, which can integrate multiple granularity features to guide model to learn pedestrain's biometric feature. Meanwhile, in order to fully verify the performance of our method on clothing-changing Re-ID problem, we designed a Clothing Generation Network (CGN), which can generate multiple pictures of the same identity wearing different clothes. Finally, experimental results show that our method exceeds the current best method by over 5% and 6% on the VCcloth and PRCC datasets respectively.

  • Practical Design Methodology of Mode-Conversion-Free Tightly Coupled Asymmetrically Tapered Bend for High-Density Differential Wiring Open Access

    Chenyu WANG  Kengo IOKIBE  Yoshitaka TOYOTA  

     
    PAPER-Electromagnetic Compatibility(EMC)

      Pubricized:
    2020/09/15
      Vol:
    E104-B No:3
      Page(s):
    304-311

    The plain bend in a pair of differential transmission lines causes a path difference, which leads to differential-to-common mode conversion due to the phase difference. This conversion can cause serious common-mode noise issues. We previously proposed a tightly coupled asymmetrically tapered bend to suppress forward differential-to-common mode conversion and derived the constraint conditions for high-density wiring. To provide sufficient suppression of mode conversion, however, the additional correction was required to make the effective path difference vanish. This paper proposes a practical and straightforward design methodology by using a very tightly coupled bend (decreasing the line width and the line separation of the tightly coupled bend). Full-wave simulations below 20GHz demonstrated that sufficient suppression of the forward differential-to-common mode conversion is successfully achieved as designed. Measurements showed that our design methodology is effective.

  • Fitness-Distance Balance with Functional Weights: A New Selection Method for Evolutionary Algorithms

    Kaiyu WANG  Sichen TAO  Rong-Long WANG  Yuki TODO  Shangce GAO  

     
    LETTER-Biocybernetics, Neurocomputing

      Pubricized:
    2021/07/21
      Vol:
    E104-D No:10
      Page(s):
    1789-1792

    In 2019, a new selection method, named fitness-distance balance (FDB), was proposed. FDB has been proved to have a significant effect on improving the search capability for evolutionary algorithms. But it still suffers from poor flexibility when encountering various optimization problems. To address this issue, we propose a functional weights-enhanced FDB (FW). These functional weights change the original weights in FDB from fixed values to randomly generated ones by a distribution function, thereby enabling the algorithm to select more suitable individuals during the search. As a case study, FW is incorporated into the spherical search algorithm. Experimental results based on various IEEE CEC2017 benchmark functions demonstrate the effectiveness of FW.

  • BEM Channel Estimation for OFDM System in Fast Time-Varying Channel

    Fei LI  Zhizhong DING  Yu WANG  Jie LI  Zhi LIU  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2017/02/09
      Vol:
    E100-B No:8
      Page(s):
    1462-1471

    In this paper, the problem of channel estimation in orthogonal frequency-division multiplexing systems over fast time-varying channel is investigated by using a Basis Expansion Model (BEM). Regarding the effects of the Gibbs phenomenon in the BEM, we propose a new method to alleviate it and reduce the modeling error. Theoretical analysis and detail comparison results show that the proposed BEM method can provide improved modeling error compared with other BEMs such as CE-BEM and GCE-BEM. In addition, instead of using the frequency-domain Kronecker delta structure, a new clustered pilot structure is proposed to enhance the estimation performance further. The new clustered pilot structure can effectively reduce the inter-carrier interference especially in the case of high Doppler spreads.

  • Finding Frequent Closed Itemsets in Sliding Window in Linear Time

    Junbo CHEN  Bo ZHOU  Lu CHEN  Xinyu WANG  Yiqun DING  

     
    PAPER-Data Mining

      Vol:
    E91-D No:10
      Page(s):
    2406-2418

    One of the most well-studied problems in data mining is computing the collection of frequent itemsets in large transactional databases. Since the introduction of the famous Apriori algorithm [14], many others have been proposed to find the frequent itemsets. Among such algorithms, the approach of mining closed itemsets has raised much interest in data mining community. The algorithms taking this approach include TITANIC [8], CLOSET+ [6], DCI-Closed [4], FCI-Stream [3], GC-Tree [5], TGC-Tree [16] etc. Among these algorithms, FCI-Stream, GC-Tree and TGC-Tree are online algorithms work under sliding window environments. By the performance evaluation in [16], GC-Tree [15] is the fastest one. In this paper, an improved algorithm based on GC-Tree is proposed, the computational complexity of which is proved to be a linear combination of the average transaction size and the average closed itemset size. The algorithm is based on the essential theorem presented in Sect. 4.2. Empirically, the new algorithm is several orders of magnitude faster than the state of art algorithm, GC-Tree.

  • Generalized Modeling of Bias Voltage Compensation with Current Control for Full-Color LED Display Based on Load-Line Regulation

    Jian-Long KUO  Tsung-Yu WANG  Tzu-Shuang FANG  

     
    PAPER

      Vol:
    E89-C No:10
      Page(s):
    1418-1426

    To give comprehensive and consecutive understanding about load line regulation in the previous companion paper [1], more generalized expansion and theoretical derivation will be proposed in this paper. The paper provides an alternative current control approach to control the bias voltage compensation for full-color LED display based on the load-line approach. Modeling and formulation of the driver circuit system will be discussed in detail. Bias voltage compensation based on three load-lines regulation will keep the operating point fixed for the three color cells. Many properties can be observed based on the proposed model. Parasite effect such as the stray resistor and the stray capacitor will be considered in this paper. The associated standard RGB color testing for color cells and white color testing will be illustrated to verify the proposed compensation for the display driver circuit. The objectives of the luminance uniformity and the gray scale control can be achieved by using circuit approach. It is believed that this paper will be helpful to the driver circuit technology for the full-color LED display.

  • People Re-Identification with Local Distance Comparison Using Learned Metric

    Guanwen ZHANG  Jien KATO  Yu WANG  Kenji MASE  

     
    PAPER-Image Processing and Video Processing

      Vol:
    E97-D No:9
      Page(s):
    2461-2472

    In this paper, we propose a novel approach for multiple-shot people re-identification. Due to high variance in camera view, light illumination, non-rigid deformation of posture and so on, there exists a crucial inter-/intra- variance issue, i.e., the same people may look considerably different, whereas different people may look extremely similar. This issue leads to an intractable, multimodal distribution of people appearance in feature space. To deal with such multimodal properties of data, we solve the re-identification problem under a local distance comparison framework, which significantly alleviates the difficulty induced by varying appearance of each individual. Furthermore, we build an energy-based loss function to measure the similarity between appearance instances, by calculating the distance between corresponding subsets in feature space. This loss function not only favors small distances that indicate high similarity between appearances of the same people, but also penalizes small distances or undesirable overlaps between subsets, which reflect high similarity between appearances of different people. In this way, effective people re-identification can be achieved in a robust manner against the inter-/intra- variance issue. The performance of our approach has been evaluated by applying it to the public benchmark datasets ETHZ and CAVIAR4REID. Experimental results show significant improvements over previous reports.

  • A Novel User Scheduling Algorithm in Inhomogeneous Networks

    Huan SUN  Xinyu WANG  Xiaohu YOU  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E91-B No:3
      Page(s):
    918-921

    In this paper, a novel user scheduling algorithm for maximizing the sum-rate capacity of inhomogeneous network is investigated. In order to extract the multi-user diversity order and reduce the feedback quantity, selective feedback scheme is adopted. An algorithm of key parameter, the prescribed threshold, is proposed. Numerical simulations show that when adopted the proposed threshold in the inhomogeneous networks, selective feedback scheme can still preserve the majority of the sum-rate capacity of the full back scheme, while the feedback load is significantly reduced.

  • Incentive-Stable Matching Protocol for Service Chain Placement in Multi-Operator Edge System

    Jen-Yu WANG  Li-Hsing YEN  Juliana LIMAN  

     
    PAPER

      Pubricized:
    2022/05/27
      Vol:
    E105-B No:11
      Page(s):
    1353-1360

    Network Function Virtualization (NFV) enables the embedding of Virtualized Network Function (VNF) into commodity servers. A sequence of VNFs can be chained in a particular order to form a service chain (SC). This paper considers placing multiple SCs in a geo-distributed edge system owned by multiple service providers (SPs). For a pair of SC and SP, minimizing the placement cost while meeting a latency constraint is formulated as an integer programming problem. As SC clients and SPs are self-interested, we study the matching between SCs and SPs that respects individual's interests yet maximizes social welfare. The proposed matching approach excludes any blocking individual and block pair which may jeopardize the stability of the result. Simulation results show that the proposed approach performs well in terms of social welfare but is suboptimal concerning the number of placed SCs.

  • Mining Noise-Tolerant Frequent Closed Itemsets in Very Large Database

    Junbo CHEN  Bo ZHOU  Xinyu WANG  Yiqun DING  Lu CHEN  

     
    PAPER-Data Mining

      Vol:
    E92-D No:8
      Page(s):
    1523-1533

    Frequent Itemsets(FI) mining is a popular and important first step in analyzing datasets across a broad range of applications. There are two main problems with the traditional approach for finding frequent itemsets. Firstly, it may often derive an undesirably huge set of frequent itemsets and association rules. Secondly, it is vulnerable to noise. There are two approaches which have been proposed to address these problems individually. The first problem is addressed by the approach Frequent Closed Itemsets(FCI), FCI removes all the redundant information from the result and makes sure there is no information loss. The second problem is addressed by the approach Approximate Frequent Itemsets(AFI), AFI could identify and fix the noises in the datasets. Each of these two concepts has its own limitations, however, the authors find that if FCI and AFI are put together, they could help each other to overcome the limitations and amplify the advantages. The new integrated approach is termed Noise-tolerant Frequent Closed Itemset(NFCI). The results of the experiments demonstrate the advantages of the new approach: (1) It is noise tolerant. (2) The number of itemsets generated would be dramatically reduced with almost no information loss except for the noise and the infrequent patterns. (3) Hence, it is both time and space efficient. (4) No redundant information is in the result.

  • Predicting Violence Rating Based on Pairwise Comparison

    Ying JI  Yu WANG  Jien KATO  Kensaku MORI  

     
    PAPER-Data Engineering, Web Information Systems

      Pubricized:
    2020/08/28
      Vol:
    E103-D No:12
      Page(s):
    2578-2589

    With the rapid development of multimedia, violent video can be easily accessed in games, movies, websites, and so on. Identifying violent videos and rating violence extent is of great importance to media filtering and children protection. Many previous studies only address the problems of violence scene detection and violent action recognition, yet violence rating problem is still not solved. In this paper, we present a novel video-level rating prediction method to estimate violence extent automatically. It has two main characteristics: (1) a two-stream network is fine-tuned to construct effective representations of violent videos; (2) a violence rating prediction machine is designed to learn the strength relationship among different videos. Furthermore, we present a novel violent video dataset with a total of 1,930 human-involved violent videos designed for violence rating analysis. Each video is annotated with 6 fine-grained objective attributes, which are considered to be closely related to violence extent. The ground-truth of violence rating is given by pairwise comparison method. The dataset is evaluated in both stability and convergence. Experiment results on this dataset demonstrate the effectiveness of our method compared with the state-of-art classification methods.

  • Face Hallucination via Multi-Scale Structure Prior Learning

    Yuexi YAO  Tao LU  Kanghui ZHAO  Yanduo ZHANG  Yu WANG  

     
    LETTER-Image

      Pubricized:
    2022/07/19
      Vol:
    E106-A No:1
      Page(s):
    92-96

    Recently, the face hallucination method based on deep learning understands the mapping between low-resolution (LR) and high-resolution (HR) facial patterns by exploring the priors of facial structure. However, how to maintain the face structure consistency after the reconstruction of face images at different scales is still a challenging problem. In this letter, we propose a novel multi-scale structure prior learning (MSPL) for face hallucination. First, we propose a multi-scale structure prior block (MSPB). Considering the loss of high-frequency information in the LR space, we mainly process the input image in three different scale ascending dimensional spaces, and map the image to the high dimensional space to extract multi-scale structural prior information. Then the size of feature maps is recovered by downsampling, and finally the multi-scale information is fused to restore the feature channels. On this basis, we propose a local detail attention module (LDAM) to focus on the local texture information of faces. We conduct extensive face hallucination reconstruction experiments on a public face dataset (LFW) to verify the effectiveness of our method.

  • Leakage-Aware TSV-Planning with Power-Temperature-Delay Dependence in 3D ICs

    Kan WANG  Sheqin DONG  Yuchun MA  Yu WANG  Xianlong HONG  Jason CONG  

     
    PAPER-Physical Level Design

      Vol:
    E94-A No:12
      Page(s):
    2490-2498

    Due to the increased power density and lower thermal conductivity, 3D ICs are faced with heat dissipation and temperature problem seriously. TSV (Through-Silicon-Via) has been shown as an effective way to help heat removal, but they introduce several issues related with cost and reliability as well. Previous researches of TSV planning didn't pay much attention to the impact of leakage power, which will bring in error on estimation of temperature, TSV number and also critical path delay. The leakage-temperature-delay dependence can potentially negate the performance improvement of 3D designs. In this paper, we analyze the impact of leakage power on TSV planning and integrate leakage-temperature-delay dependence into thermal via planning of 3D ICs. A weighted via insertion approach, considering the influence on both module delay and wire delay, is proposed to achieve the best balance among temperature, via number and performance. Experiment results show that, with leakage power and resource constraint considered, temperature and the required via number can be quite different, and the weighted TSV insertion approach with iterative process can obtain the trade-off between different factors including thermal, power consumption, via number and performance.

  • Rethinking the Rotation Invariance of Local Convolutional Features for Content-Based Image Retrieval

    Longjiao ZHAO  Yu WANG  Jien KATO  

     
    PAPER-Image Processing and Video Processing

      Pubricized:
    2020/10/14
      Vol:
    E104-D No:1
      Page(s):
    174-182

    Recently, local features computed using convolutional neural networks (CNNs) show good performance to image retrieval. The local convolutional features obtained by the CNNs (LC features) are designed to be translation invariant, however, they are inherently sensitive to rotation perturbations. This leads to miss-judgements in retrieval tasks. In this work, our objective is to enhance the robustness of LC features against image rotation. To do this, we conduct a thorough experimental evaluation of three candidate anti-rotation strategies (in-model data augmentation, in-model feature augmentation, and post-model feature augmentation), over two kinds of rotation attack (dataset attack and query attack). In the training procedure, we implement a data augmentation protocol and network augmentation method. In the test procedure, we develop a local transformed convolutional (LTC) feature extraction method, and evaluate it over different network configurations. We end up a series of good practices with steady quantitative supports, which lead to the best strategy for computing LC features with high rotation invariance in image retrieval.

  • Interference Coordination Mechanisms for Device-to-Device Multicast Uplink Underlaying Cellular Networks

    Dongyu WANG  Xiaoxiang WANG  Bo GU  

     
    PAPER-Network

      Vol:
    E97-B No:1
      Page(s):
    56-65

    In this paper, a multicast concept for Device-to-Device (D2D) communication underlaying a cellular infrastructure is investigated. To increase the overall capacity and improve resource utilization, a novel interference coordination scheme is proposed. The proposed scheme includes three steps. First, in order to mitigate the interference from D2D multicast transmission to cellular networks (CNs), a dynamic power control scheme is proposed that can determine the upper bound of D2D transmitter power based on the location of Base Station (BS) and areas of adjacent cells from the coverage area of D2D multicast group. Next, an interference limited area control scheme that reduces the interference from CNs to each D2D multicast receiver is proposed. The proposed scheme does not allow cellular equipment (CUE) located in the interference limited area to reuse the same resources as the D2D multicast group. Then two resource block (RB) allocation rules are proposed to select the appropriate RBs from a candidate RB set for D2D multicast group. From the simulation results, it is confirmed that the proposed schemes improve the performance of the hybrid system compared to the conventional ways.

  • Multi-View Texture Learning for Face Super-Resolution

    Yu WANG  Tao LU  Feng YAO  Yuntao WU  Yanduo ZHANG  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2021/03/24
      Vol:
    E104-D No:7
      Page(s):
    1028-1038

    In recent years, single face image super-resolution (SR) using deep neural networks have been well developed. However, most of the face images captured by the camera in a real scene are from different views of the same person, and the existing traditional multi-frame image SR requires alignment between images. Due to multi-view face images contain texture information from different views, which can be used as effective prior information, how to use this prior information from multi-views to reconstruct frontal face images is challenging. In order to effectively solve the above problems, we propose a novel face SR network based on multi-view face images, which focus on obtaining more texture information from multi-view face images to help the reconstruction of frontal face images. And in this network, we also propose a texture attention mechanism to transfer high-precision texture compensation information to the frontal face image to obtain better visual effects. We conduct subjective and objective evaluations, and the experimental results show the great potential of using multi-view face images SR. The comparison with other state-of-the-art deep learning SR methods proves that the proposed method has excellent performance.

  • A Weighted Voronoi Diagram-Based Self-Deployment Algorithm for Heterogeneous Directional Mobile Sensor Networks in Three-Dimensional Space

    Li TAN  Xiaojiang TANG  Anbar HUSSAIN  Haoyu WANG  

     
    PAPER-Network

      Pubricized:
    2019/11/21
      Vol:
    E103-B No:5
      Page(s):
    545-558

    To solve the problem of the self-deployment of heterogeneous directional wireless sensor networks in 3D space, this paper proposes a weighted Voronoi diagram-based self-deployment algorithm (3DV-HDDA) in 3D space. To improve the network coverage ratio of the monitoring area, the 3DV-HDDA algorithm uses the weighted Voronoi diagram to move the sensor nodes and introduces virtual boundary torque to rotate the sensor nodes, so that the sensor nodes can reach the optimal position. This work also includes an improvement algorithm (3DV-HDDA-I) based on the positions of the centralized sensor nodes. The difference between the 3DV-HDDA and the 3DV-HDDA-I algorithms is that in the latter the movement of the node is determined by both the weighted Voronoi graph and virtual force. Simulations show that compared to the virtual force algorithm and the unweighted Voronoi graph-based algorithm, the 3DV-HDDA and 3DV-HDDA-I algorithms effectively improve the network coverage ratio of the monitoring area. Compared to the virtual force algorithm, the 3DV-HDDA algorithm increases the coverage from 75.93% to 91.46% while the 3DV-HDDA-I algorithm increases coverage from 76.27% to 91.31%. When compared to the unweighted Voronoi graph-based algorithm, the 3DV-HDDA algorithm improves the coverage from 80.19% to 91.46% while the 3DV-HDDA-I algorithm improves the coverage from 72.25% to 91.31%. Further, the energy consumption of the proposed algorithms after 60 iterations is smaller than the energy consumption using a virtual force algorithm. Experimental results demonstrate the accuracy and effectiveness of the 3DV-HDDA and the 3DV-HDDA-I algorithms.

  • 3D-HEVC Virtual View Synthesis Based on a Reconfigurable Architecture

    Lin JIANG  Xin WU  Yun ZHU  Yu WANG  

     
    PAPER-Multimedia Systems for Communications

      Pubricized:
    2019/11/12
      Vol:
    E103-B No:5
      Page(s):
    618-626

    For high definition (HD) videos, the 3D-High Efficiency Video Coding (3D-HEVC) reference algorithm incurs dramatically highly computation loads. Therefore, with the demands for the real-time processing of HD video, a hardware implementation is necessary. In this paper, a reconfigurable architecture is proposed that can support both median filtering preprocessing and mean filtering preprocessing to satisfy different scene depth maps. The architecture sends different instructions to the corresponding processing elements according to different scenarios. Mean filter is used to process near-range images, and median filter is used to process long-range images. The simulation results show that the designed architecture achieves an averaged PSNR of 34.55dB for the tested images. The hardware design for the proposed virtual view synthesis system operates at a maximum clock frequency of 160MHz on the BEE4 platform which is equipped with four Virtex-6 FF1759 LX550T Field-Programmable Gate Array (FPGA) for outputting 720p (1024×768) video at 124fps.

  • Discriminative Part CNN for Pedestrian Detection

    Yu WANG  Cong CAO  Jien KATO  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2021/12/06
      Vol:
    E105-D No:3
      Page(s):
    700-712

    Pedestrian detection is a significant task in computer vision. In recent years, it is widely used in applications such as intelligent surveillance systems and automated driving systems. Although it has been exhaustively studied in the last decade, the occlusion handling issue still remains unsolved. One convincing idea is to first detect human body parts, and then utilize the parts information to estimate the pedestrians' existence. Many parts-based pedestrian detection approaches have been proposed based on this idea. However, in most of these approaches, the low-quality parts mining and the clumsy part detector combination is a bottleneck that limits the detection performance. To eliminate the bottleneck, we propose Discriminative Part CNN (DP-CNN). Our approach has two main contributions: (1) We propose a high-quality body parts mining method based on both convolutional layer features and body part subclasses. The mined part clusters are not only discriminative but also representative, and can help to construct powerful pedestrian detectors. (2) We propose a novel method to combine multiple part detectors. We convert the part detectors to a middle layer of a CNN and optimize the whole detection pipeline by fine-tuning that CNN. In experiments, it shows astonishing effectiveness of optimization and robustness of occlusion handling.

1-20hit(62hit)