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[Keyword] AME(1195hit)

141-160hit(1195hit)

  • A Fast Cross-Validation Algorithm for Kernel Ridge Regression by Eigenvalue Decomposition

    Akira TANAKA  Hideyuki IMAI  

     
    LETTER-Numerical Analysis and Optimization

      Vol:
    E102-A No:9
      Page(s):
    1317-1320

    A fast cross-validation algorithm for model selection in kernel ridge regression problems is proposed, which is aiming to further reduce the computational cost of the algorithm proposed by An et al. by eigenvalue decomposition of a Gram matrix.

  • Parameter Identification and State-of-Charge Estimation for Li-Ion Batteries Using an Improved Tree Seed Algorithm

    Weijie CHEN  Ming CAI  Xiaojun TAN  Bo WEI  

     
    PAPER-Fundamentals of Information Systems

      Pubricized:
    2019/05/17
      Vol:
    E102-D No:8
      Page(s):
    1489-1497

    Accurate estimation of the state-of-charge is a crucial need for the battery, which is the most important power source in electric vehicles. To achieve better estimation result, an accurate battery model with optimum parameters is required. In this paper, a gradient-free optimization technique, namely tree seed algorithm (TSA), is utilized to identify specific parameters of the battery model. In order to strengthen the search ability of TSA and obtain more quality results, the original algorithm is improved. On one hand, the DE/rand/2/bin mechanism is employed to maintain the colony diversity, by generating mutant individuals in each time step. On the other hand, the control parameter in the algorithm is adaptively updated during the searching process, to achieve a better balance between the exploitation and exploration capabilities. The battery state-of-charge can be estimated simultaneously by regarding it as one of the parameters. Experiments under different dynamic profiles show that the proposed method can provide reliable and accurate estimation results. The performance of conventional algorithms, such as genetic algorithm and extended Kalman filter, are also compared to demonstrate the superiority of the proposed method in terms of accuracy and robustness.

  • Dynamic Performance Adjustment of CPU and GPU in a Gaming Notebook at the Battery Mode

    Chun-Hung CHENG  Ying-Wen BAI  

     
    PAPER-Computer System

      Pubricized:
    2019/03/27
      Vol:
    E102-D No:7
      Page(s):
    1257-1270

    This new design uses a low power embedded controller (EC) in cooperation with the BIOS of a notebook (NB) computer, both to accomplish dynamic adjustment and to maintain a required performance level of the battery mode of the notebook. In order to extend the operation time at the battery mode, in general, the notebook computer will directly reduce the clock rate and then reduce the performance. This design can obtain the necessary balance of the performance and the power consumption by using both the EC and the BIOS cooperatively to implement the dynamic control of both the CPU and the GPU frequency to maintain the system performance at a sufficient level for a high speed and high resolution video game. In contrast, in order to maintain a certain notebook performance, in terms of battery life it will be necessary to make some trade-offs.

  • A Fast Non-Overlapping Multi-Camera People Re-Identification Algorithm and Tracking Based on Visual Channel Model

    Chi-Chia SUN  Ming-Hwa SHEU  Jui-Yang CHI  Yan-Kai HUANG  

     
    PAPER-Image Processing and Video Processing

      Pubricized:
    2019/04/18
      Vol:
    E102-D No:7
      Page(s):
    1342-1348

    In this paper, a nonoverlapping multi-camera and people re-identification algorithm is proposed. It applies inflated major color features for re-identification to reduce computation time. The inflated major color features can dramatically improve efficiency while retaining high accuracy of object re-identification. The proposed method is evaluated over a wide range of experimental databases. The accuracy attains upwards of 40.7% in Rank 1 and 84% in Rank 10 on average, while it obtains three to 15 times faster than algorithms reported in the literature. The proposed algorithm has been implemented on a SOC-FPGA platform to reach 50 FPS with 1280×720 HD resolution and 25 FPS with 1920×1080 FHD resolution for real-time processing. The results show a performance improvement and reduction in computation complexity, which is especially ideal for embedded platform.

  • A Novel Frame Aggregation Scheduler to Solve the Head-of-Line Blocking Problem for Real-Time UDP Traffic in Aggregation-Enabled WLANs

    Linjie ZHU  Bin WU  Zhiwei WEI  Yu TANG  

     
    LETTER-Information Network

      Pubricized:
    2019/03/29
      Vol:
    E102-D No:7
      Page(s):
    1408-1411

    In this letter, a novel frame aggregation scheduler is proposed to solve the head-of-line blocking problem for real-time user datagram protocol (UDP) traffic in error-prone and aggregation-enabled wireless local area networks (WLANs). The key to the proposed scheduler is to break the restriction of in-order delivery over the WLAN. The simulation results show that the proposed scheduler can achieve high UDP goodput and low delay compared to the conventional scheduler.

  • A Game-Theoretic Approach for Community Detection in Signed Networks

    Shuaihui WANG  Guyu HU  Zhisong PAN  Jin ZHANG  Dong LI  

     
    PAPER-Graphs and Networks

      Vol:
    E102-A No:6
      Page(s):
    796-807

    Signed networks are ubiquitous in the real world. It is of great significance to study the problem of community detection in signed networks. In general, the behaviors of nodes in a signed network are rational, which coincide with the players in the theory of game that can be used to model the process of the community formation. Unlike unsigned networks, signed networks include both positive and negative edges, representing the relationship of friends and foes respectively. In the process of community formation, nodes usually choose to be in the same community with friends and between different communities with enemies. Based on this idea, we proposed a game theory model to address the problem of community detection in signed networks. Taking nodes as players, we build a gain function based on the numbers of positive edges and negative edges inside and outside a community, and prove the existence of Nash equilibrium point. In this way, when the game reaches the Nash equilibrium state, the optimal strategy space for all nodes is the result of the final community division. To systematically investigate the performance of our method, elaborated experiments on both synthetic networks and real-world networks are conducted. Experimental results demonstrate that our method is not only more accurate than other existing algorithms, but also more robust to noise.

  • A Unified Statistical Rating Method for Team Ball Games and Its Application to Predictions in the Olympic Games Open Access

    Eiji KONAKA  

     
    PAPER-Artificial Intelligence, Data Mining

      Pubricized:
    2019/03/11
      Vol:
    E102-D No:6
      Page(s):
    1145-1153

    This study tries to construct an accurate ranking method for five team ball games at the Olympic Games. First, the study uses a statistical rating method for team ball games. A single parameter, called a rating, shows the strength and skill of each team. We assume that the difference between the rating values explains the scoring ratio in a match based on a logistic regression model. The rating values are estimated from the scores of major international competitions that are held before the Rio Olympic Games. The predictions at the Rio Olympic Games demonstrate that the proposed method can more accurately predict the match results than the official world rankings or world ranking points. The proposed method enabled 262 correct predictions out of 370 matches, whereas using the official world rankings resulted in only 238 correct predictions. This result shows a significant difference between the two criteria.

  • A 3Gbps/Lane MIPI D-PHY Transmission Buffer Chip

    Pil-Ho LEE  Young-Chan JANG  

     
    LETTER

      Vol:
    E102-A No:6
      Page(s):
    783-787

    A 3Gbps/lane transmission buffer chip including a high-speed mode detector is proposed for a field-programmable gate array (FPGA)-based frame generator supporting the mobile industry processor interface (MIPI) D-PHY version 1.2. It performs 1-to-3 repeat while buffering low voltage differential signaling (LVDS) or scalable low voltage signaling (SLVS) to SLVS.

  • Investigation of Time Evolution of Length of Break Arcs Occurring in a 48VDC/50-300A Resistive Circuit

    Kenshi HAMAMOTO  Junya SEKIKAWA  

     
    BRIEF PAPER-Electromechanical Devices and Components

      Vol:
    E102-C No:5
      Page(s):
    424-427

    Break arcs are generated in a 48VDC resistive circuit. Circuit current I0 when electrical contacts are closed is changed from 50A to 300A. The break arcs are observed by a high-speed camera with appropriate settings of exposure from horizontal direction. Length of the break arcs L is measured from images of the break arcs. Time evolutions of the length L and gap voltage Vg are investigated. The following results are obtained. By appropriate settings of the high-speed camera, the time evolution of the length L is obtained from just after ignition to before arc extinction. Tendency of increase of the length L is similar to that of increase of the voltage Vg for each current I0.

  • The Combination Effect of Cache Decision and Off-Path Cache Routing in Content Oriented Networks

    Yusaku HAYAMIZU  Akihisa SHIBUYA  Miki YAMAMOTO  

     
    PAPER-Network

      Pubricized:
    2018/10/29
      Vol:
    E102-B No:5
      Page(s):
    1010-1018

    In content oriented networks (CON), routers in a network are generally equipped with local cache storages and store incoming contents temporarily. Efficient utilization of total cache storage in networks is one of the most important technical issues in CON, as it can reduce content server load, content download latency and network traffic. Performance of networked cache is reported to strongly depend on both cache decision and content request routing. In this paper, we evaluate several combinations of these two strategies. Especially for routing, we take up off-path cache routing, Breadcrumbs, as one of the content request routing proposals. Our performance evaluation results show that off-path cache routing, Breadcrumbs, suffers low performance with cache decisions which generally has high performance with shortest path routing (SPR), and obtains excellent performance with TERC (Transparent En-Route Cache) which is well-known to have low performance with widely used SPR. Our detailed evaluation results in two network environments, emerging CONs and conventional IP, show these insights hold in both of these two network environments.

  • Content-Oriented Disaster Network Utilizing Named Node Routing and Field Experiment Evaluation

    Xin QI  Zheng WEN  Keping YU  Kazunori MURATA  Kouichi SHIBATA  Takuro SATO  

     
    PAPER

      Pubricized:
    2019/02/15
      Vol:
    E102-D No:5
      Page(s):
    988-997

    Low Power Wide Area Network (LPWAN) is designed for low-bandwidth, low-power, long-distance, large-scale connected IoT applications and realistic for networking in an emergency or restricted situation, so it has been proposed as an attractive communication technology to handle unexpected situations that occur during and/or after a disaster. However, the traditional LPWAN with its default protocol will reduce the communication efficiency in disaster situation because a large number of users will send and receive emergency information result in communication jams and soaring error rates. In this paper, we proposed a LPWAN based decentralized network structure as an extension of our previous Disaster Information Sharing System (DISS). Our network structure is powered by Named Node Networking (3N) which is based on the Information-Centric Networking (ICN). This network structure optimizes the excessive useless packet forwarding and path optimization problems with node name routing (NNR). To verify our proposal, we conduct a field experiment to evaluate the efficiency of packet path forwarding between 3N+LPWA structure and ICN+LPWA structure. Experimental results confirm that the load of the entire data transmission network is significantly reduced after NNR optimized the transmission path.

  • Power Efficient Object Detector with an Event-Driven Camera for Moving Object Surveillance on an FPGA

    Masayuki SHIMODA  Shimpei SATO  Hiroki NAKAHARA  

     
    PAPER-Applications

      Pubricized:
    2019/02/27
      Vol:
    E102-D No:5
      Page(s):
    1020-1028

    We propose an object detector using a sliding window method for an event-driven camera which outputs a subtracted frame (usually a binary value) when changes are detected in captured images. Since sliding window skips unchanged portions of the output, the number of target object area candidates decreases dramatically, which means that our system operates faster and with lower power consumption than a system using a straightforward sliding window approach. Since the event-driven camera output consists of binary precision frames, an all binarized convolutional neural network (ABCNN) can be available, which means that it allows all convolutional layers to share the same binarized convolutional circuit, thereby reducing the area requirement. We implemented our proposed method on the Xilinx Inc. Zedboard and then evaluated it using the PETS 2009 dataset. The results showed that our system outperformed BCNN system from the viewpoint of detection performance, hardware requirement, and computation time. Also, we showed that FPGA is an ideal method for our system than mobile GPU. From these results, our proposed system is more suitable for the embedded systems based on stationary cameras (such as security cameras).

  • Privacy-Aware Human-Detection and Tracking System Using Biological Signals Open Access

    Toshihiro KITAJIMA  Edwardo Arata Y. MURAKAMI  Shunsuke YOSHIMOTO  Yoshihiro KURODA  Osamu OSHIRO  

     
    PAPER

      Pubricized:
    2018/10/15
      Vol:
    E102-B No:4
      Page(s):
    708-721

    The arrival of the era of the Internet of Things (IoT) has ensured the ubiquity of human-sensing technologies. Cameras have become inexpensive instruments for human sensing and have been increasingly used for this purpose. Because cameras produce large quantities of information, they are powerful tools for sensing; however, because camera images contain information allowing individuals to be personally identified, their use poses risks of personal privacy violations. In addition, because IoT-ready home appliances are connected to the Internet, camera-captured images of individual users may be unintentionally leaked. In developing our human-detection method [33], [34], we proposed techniques for detecting humans from unclear images in which individuals cannot be identified; however, a drawback of this method was its inability to detect moving humans. Thus, to enable tracking of humans even through the images are blurred to protect privacy, we introduce a particle-filter framework and propose a human-tracking method based on motion detection and heart-rate detection. We also show how the use of integral images [32] can accelerate the execution of our algorithms. In performance tests involving unclear images, the proposed method yields results superior to those obtained with the existing mean-shift method or with a face-detection method based on Haar-like features. We confirm the acceleration afforded by the use of integral images and show that the speed of our method is sufficient to enable real-time operation. Moreover, we demonstrate that the proposed method allows successful tracking even in cases where the posture of the individual changes, such as when the person lies down, a situation that arises in real-world usage environments. We discuss the reasons behind the superior behavior of our method in performance tests compared to those of other methods.

  • Learning in Two-Player Matrix Games by Policy Gradient Lagging Anchor

    Shiyao DING  Toshimitsu USHIO  

     
    LETTER-Mathematical Systems Science

      Vol:
    E102-A No:4
      Page(s):
    708-711

    It is known that policy gradient algorithm can not guarantee the convergence to a Nash equilibrium in mixed policies when it is applied in matrix games. To overcome this problem, we propose a novel multi-agent reinforcement learning (MARL) algorithm called a policy gradient lagging anchor (PGLA) algorithm. And we prove that the agents' policies can converge to a Nash equilibrium in mixed policies by using the PGLA algorithm in two-player two-action matrix games. By simulation, we confirm the convergence and also show that the PGLA algorithm has a better convergence than the LR-I lagging anchor algorithm.

  • High-Quality Multi-View Image Extraction from a Light Field Camera Considering Its Physical Pixel Arrangement

    Shu FUJITA  Keita TAKAHASHI  Toshiaki FUJII  

     
    INVITED PAPER

      Pubricized:
    2019/01/28
      Vol:
    E102-D No:4
      Page(s):
    702-714

    We propose a method for extracting multi-view images from a light field (plenoptic) camera that accurately handles the physical pixel arrangement of this camera. We use a Lytro Illum camera to obtain 4D light field data (a set of multi-viewpoint images) through a micro-lens array. The light field data are multiplexed on a single image sensor, and thus, the data is first demultiplexed into a set of multi-viewpoint (sub-aperture) images. However, the demultiplexing process usually includes interpolation of the original data such as demosaicing for a color filter array and pixel resampling for the hexagonal pixel arrangement of the original sub-aperture images. If this interpolation is performed, some information is added or lost to/from the original data. In contrast, we preserve the original data as faithfully as possible, and use them directly for the super resolution reconstruction, where the super-resolved image and the corresponding depth map are alternatively refined. We experimentally demonstrate the effectiveness of our method in resolution enhancement through comparisons with Light Field Toolbox and Lytro Desktop Application. Moreover, we also mention another type of light field cameras, a Raytrix camera, and describe how it can be handled to extract high-quality multi-view images.

  • Stochastic Channel Selection for UAV-Aided Data Collection

    Tianyu LU  Haibo DAI  Juan ZHAO  Baoyun WANG  

     
    LETTER-Communication Theory and Signals

      Vol:
    E102-A No:3
      Page(s):
    598-603

    We investigate the uplink channel selection problem of unmanned aerial vehicle (UAV)-aided data collection system in delay-sensitive sensor networks. In the studied model, the fixed-wing UAV is dispatched to gather sensing information from terrestrial sensor nodes (SNs) and they contend for uplink channels for transmission. With the goal of minimizing the system-wide delay, we formulate a resource allocation problem. Encountered with the challenge that the flight trajectory of UAV is unknown to SNs and the wireless channel is time-varying, we solve the problem by stochastic game approach and further propose a fully distributed channel selection algorithm which is proved to converge to a pure strategy Nash Equilibrium (NE). Simulation results are presented to show that our proposed algorithm has good performance.

  • Software Engineering Data Analytics: A Framework Based on a Multi-Layered Abstraction Mechanism

    Chaman WIJESIRIWARDANA  Prasad WIMALARATNE  

     
    LETTER-Software Engineering

      Pubricized:
    2018/12/04
      Vol:
    E102-D No:3
      Page(s):
    637-639

    This paper presents a concept of a domain-specific framework for software analytics by enabling querying, modeling, and integration of heterogeneous software repositories. The framework adheres to a multi-layered abstraction mechanism that consists of domain-specific operators. We showcased the potential of this approach by employing a case study.

  • Price-Based Power Control Algorithm in Cognitive Radio Networks via Branch and Bound

    Zhengqiang WANG  Wenrui XIAO  Xiaoyu WAN  Zifu FAN  

     
    PAPER-Fundamentals of Information Systems

      Pubricized:
    2018/12/26
      Vol:
    E102-D No:3
      Page(s):
    505-511

    Price-based power control problem is investigated in the spectrum sharing cognitive radio networks (CRNs) by Stackelberg game. Using backward induction, the revenue function of the primary user (PU) is expressed as a non-convex function of the transmit power of the secondary users (SUs). To solve the non-convex problem of the PU, a branch and bound based price-based power control algorithm is proposed. The proposed algorithm can be used to provide performance benchmarks for any other low complexity sub-optimal price-based power control algorithms based on Stackelberg game in CRNs.

  • Superconducting Digital Electronics for Controlling Quantum Computing Systems Open Access

    Nobuyuki YOSHIKAWA  

     
    INVITED PAPER

      Vol:
    E102-C No:3
      Page(s):
    217-223

    The recent rapid increase in the scale of superconducting quantum computing systems greatly increases the demand for qubit control by digital circuits operating at qubit temperatures. In this paper, superconducting digital circuits, such as single-flux quantum and adiabatic quantum flux parametron circuits are described, that are promising candidates for this purpose. After estimating their energy consumption and speed, a conceptual overview of the superconducting electronics for controlling a multiple-qubit system is provided, as well as some of its component circuits.

  • The Explicit Formula of the Presumed Optimal Recurrence Relation for the Star Tower of Hanoi Open Access

    Akihiro MATSUURA  Yoshiaki SHOJI  

     
    PAPER

      Pubricized:
    2018/10/30
      Vol:
    E102-D No:3
      Page(s):
    492-498

    In this paper, we show the explicit formula of the recurrence relation for the Tower of Hanoi on the star graph with four vertices, where the perfect tower of disks on a leaf vertex is transferred to the central vertex. This gives the solution to the problem posed at the 17th International Conference on Fibonacci Numbers and Their Applications[11]. Then, the recurrence relation are generalized to include the ones for the original 4-peg Tower of Hanoi and the Star Tower of Hanoi of transferring the tower from a leaf to another.

141-160hit(1195hit)