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[Keyword] PU(3318hit)

841-860hit(3318hit)

  • A Performance Fluctuation-Aware Stochastic Scheduling Mechanism for Workflow Applications in Cloud Environment

    Fang DONG  Junzhou LUO  Bo LIU  

     
    PAPER

      Vol:
    E97-D No:10
      Page(s):
    2641-2651

    Cloud computing, a novel distributed paradigm to provide powerful computing capabilities, is usually adopted by developers and researchers to execute complicated IoT applications such as complex workflows. In this scenario, it is fundamentally important to make an effective and efficient workflow application scheduling and execution by fully utilizing the advantages of the cloud (as virtualization and elastic services). However, in the current stage, there is relatively few research for workflow scheduling in cloud environment, where they usually just bring the traditional methods directly into cloud. Without considering the features of cloud, it may raise two kinds of problems: (1) The traditional methods mainly focus on static resource provision, which will cause the waste of resources; (2) They usually ignore the performance fluctuation of virtual machines on the physical machines, therefore it will lead to the estimation error of task execution time. To address these problems, a novel mechanism which can estimate the probability distribution of subtask execution time based on background VM load series over physical machines is proposed. An elastic performance fluctuations-aware stochastic scheduling algorithm is introduced in this paper. The experiments show that our proposed algorithm can outperform the existing algorithms in several metrics and can relieve the influence of performance fluctuations brought by the dynamic nature of cloud.

  • Coherent Combining-Based Initial Ranging Scheme for MIMO-OFDMA Systems

    Yujie XIA  Guangliang REN  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E97-B No:10
      Page(s):
    2203-2211

    A coherent combining-based initial ranging scheme is proposed for multiple-input multiple-output and orthogonal frequency division multiple access systems. The proposed algorithm utilizes the correlation properties of the ranging codes to resolve the multipath components, coherently combines the initial ranging signal of resolved path on each receiving antenna to maximize the output signal-to-interference-and-noise ratio, and then collects the power of the multipath signals to detect the states of the ranging codes. Simulation results show that the proposed scheme has much better performance than the available noncoherent combining method, and can accommodate more active ranging users simultaneously in each cell.

  • Versatile Radio Channel Sounder for Double Directional and Multi-link MIMO Channel Measurements at 11 GHz

    Yohei KONISHI  Yuyuan CHANG  Minseok KIM  Jun-ichi TAKADA  

     
    PAPER

      Vol:
    E97-C No:10
      Page(s):
    994-1004

    This paper presents a $24 imes24$ MIMO channel sounder that has been developed based on a scalable fully parallel MIMO architecture. It can be flexibly configured with 3 sub-transmitters and 3 sub-receivers, each of which consists of 8 RF ports. This flexibility allows the measurement for both purposes of double directional and multi-link MIMO channel measurements. Implementation issues related to the multi-link operation on the fully parallel architecture were successfully solved by appropriate system design and applying several calibration techniques. The performance of the developed system was validated by extensive test experiments. Finally, a multi-link channel measurement example in an indoor environment was presented demonstrating the capability of the proposed system.

  • An Online Framework for Flow Round Trip Time Measurement

    Xinjie GUAN  Xili WAN  Ryoichi KAWAHARA  Hiroshi SAITO  

     
    PAPER-Network

      Vol:
    E97-B No:10
      Page(s):
    2145-2156

    With the advent of high speed links, online flow measurement for, e.g., flow round trip time (RTT), has become difficult due to the enormous demands placed on computational resources. Most existing measurement methods are designed to count the numbers of flows or sizes of flows, but we address the flow RTT measurement, which is an important QoS metric for network management and cannot be measured with existing measurement methods. We first adapt a standard Bloom Filter (BF) for the flow RTT distribution estimation. However, due to the existence of multipath routing and Syn flooding attacks, the standard BF does not perform well. We further design the double-deletion bloom filter (DDBF) scheme, which alleviates potential hash collisions of the standard BF by explicitly deleting used records and implicitly deleting out-of-date records. Because of these double deletion operations, the DDBF accurately estimates the RTT distribution of TCP flows with limited memory space, even with the appearance of multipath routing and Syn flooding attacks. Theoretical analysis indicates that the DDBF scheme achieves a higher accuracy with a constant and smaller amount of memory compared with the standard BF. In addition, we validate our scheme using real traces and demonstrate significant memory-savings without degrading accuracy.

  • A Local Resource Sharing Platform in Mobile Cloud Computing

    Wei LIU  Ryoichi SHINKUMA  Tatsuro TAKAHASHI  

     
    PAPER-Network

      Vol:
    E97-B No:9
      Page(s):
    1865-1874

    Despite the increasing use of mobile computing, exploiting its full potential is difficult due to its inherent characteristics such as error-prone transmission channels, diverse node capabilities, frequent disconnections and mobility. Mobile Cloud Computing (MCC) is a paradigm that is aimed at overcoming previous problems through integrating mobile devices with cloud computing. Mobile devices, in the traditional client-server architecture of MCC, offload their tasks to the cloud to utilize the computation and storage resources of data centers. However, along with the development of hardware and software technologies in mobile devices, researchers have begun to take into consideration local resource sharing among mobile devices themselves. This is defined as the cooperation based architecture of MCC. Analogous to the conventional terminology, the resource platforms that are comprised of surrounding surrogate mobile devices are called local resource clouds. Some researchers have recently verified the feasibility and benefits of this strategy. However, existing work has neglected an important issue with this approach, i.e., how to construct local resource clouds in dynamic mobile wireless networks. This paper presents the concept and design of a local resource cloud that is both energy and time efficient. Along with theoretical models and formal definitions of problems, an efficient heuristic algorithm with low computational complexity is also presented. The results from simulations demonstrate the effectiveness of the proposed models and method.

  • Formal Design of Arithmetic Circuits over Galois Fields Based on Normal Basis Representations

    Kotaro OKAMOTO  Naofumi HOMMA  Takafumi AOKI  

     
    PAPER-VLSI Architecture

      Vol:
    E97-D No:9
      Page(s):
    2270-2277

    This paper presents a graph-based approach to designing arithmetic circuits over Galois fields (GFs) using normal basis representations. The proposed method is based on a graph-based circuit description called Galois-field Arithmetic Circuit Graph (GF-ACG). First, we extend GF-ACG representation to describe GFs defined by normal basis in addition to polynomial basis. We then apply the extended design method to Massey-Omura parallel multipliers which are well known as typical multipliers based on normal basis. We present the formal description of the multipliers in a hierarchical manner and show that the verification time can be greatly reduced in comparison with those of the conventional techniques. In addition, we design GF exponentiation circuits consisting of the Massey-Omura parallel multipliers and an inversion circuit over composite field GF(((22)2)2) in order to demonstrate the advantages of normal-basis circuits over polynomial-basis ones.

  • A Survey of Intelligent Computing in Medical and Health Care System Open Access

    Yutaka HATA  Hiroshi NAKAJIMA  

     
    INVITED PAPER

      Vol:
    E97-D No:9
      Page(s):
    2218-2225

    This paper gives a survey of intelligent computational techniques in medical and health care system. First, we briefly describe diagnosable techniques in medical image processing. Next, we demonstrate two ultrasonic surgery support systems for orthopedic and rectum cancer surgeons. In them, intelligent computational technique plays a primary role. Third, computational techniques are introduced in human health care system. Usually, this goal is not to apply clinical treatment but to home use to pay consciousness to health. In it, a simple ECG and respiration meter are introduced with a mat sheet which detects heart rate and respiration. Finally, a medical big data application is introduced, that is, body weight prediction is shown based on autoregressive model. Thus, we show that intelligent computing is effective and essential in modern medical and health care system.

  • Asynchronous Stochastic Decoding of LDPC Codes: Algorithm and Simulation Model

    Naoya ONIZAWA  Warren J. GROSS  Takahiro HANYU  Vincent C. GAUDET  

     
    PAPER-VLSI Architecture

      Vol:
    E97-D No:9
      Page(s):
    2286-2295

    Stochastic decoding provides ultra-low-complexity hardware for high-throughput parallel low-density parity-check (LDPC) decoders. Asynchronous stochastic decoding was proposed to demonstrate the possibility of low power dissipation and high throughput in stochastic decoders, but decoding might stop before convergence due to “lock-up”, causing error floors that also occur in synchronous stochastic decoding. In this paper, we introduce a wire-delay dependent (WDD) scheduling algorithm for asynchronous stochastic decoding in order to reduce the error floors. Instead of assigning the same delay to all computation nodes in the previous work, different computation delay is assigned to each computation node depending on its wire length. The variation of update timing increases switching activities to decrease the possibility of the “lock-up”, lowering the error floors. In addition, the WDD scheduling algorithm is simplified for the hardware implementation in order to eliminate time-averaging and multiplication functions used in the original WDD scheduling algorithm. BER performance using a regular (1024, 512) (3,6) LDPC code is simulated based on our timing model that has computation and wire delay estimated under ASPLA 90nm CMOS technology. It is demonstrated that the proposed asynchronous decoder achieves a 6.4-9.8× smaller latency than that of the synchronous decoder with a 0.25-0.3 dB coding gain.

  • Speech Emotion Recognition Using Transfer Learning

    Peng SONG  Yun JIN  Li ZHAO  Minghai XIN  

     
    LETTER-Speech and Hearing

      Vol:
    E97-D No:9
      Page(s):
    2530-2532

    A major challenge for speech emotion recognition is that when the training and deployment conditions do not use the same speech corpus, the recognition rates will obviously drop. Transfer learning, which has successfully addressed the cross-domain classification or recognition problem, is presented for cross-corpus speech emotion recognition. First, by using the maximum mean discrepancy embedding (MMDE) optimization and dimension reduction algorithms, two close low-dimensional feature spaces are obtained for source and target speech corpora, respectively. Then, a classifier function is trained using the learned low-dimensional features in the labeled source corpus, and directly applied to the unlabeled target corpus for emotion label recognition. Experimental results demonstrate that the transfer learning method can significantly outperform the traditional automatic recognition technique for cross-corpus speech emotion recognition.

  • A Survey on Thai Input Methods on Smartphones Open Access

    Cholwich NATTEE  

     
    SURVEY PAPER-Artificial Intelligence, Data Mining

      Vol:
    E97-D No:9
      Page(s):
    2338-2345

    Smartphones have become vital devices in the current on-the-go Thai culture. Typically, virtual keyboards serve as tools for text input on smartphones. Due to the limited screen area and the large number of Thai characters, the size of each button on the keyboard is quite small. This leads to character mistyping and low typing speed. In this paper, we present a typical framework of a Thai Input Method on smartphones which includes four processes; Character Candidate Generation, Word Candidate Generation, Word Candidate Display, and Model Update. This framework not only works with Thai, it works with other letter-based languages as well. We also review virtual keyboards and techniques currently used and available for Thai text input.

  • Full-Order Observer for Discrete-Time Linear Time-Invariant Systems with Output Delays

    Joon-Young CHOI  

     
    LETTER-Systems and Control

      Vol:
    E97-A No:9
      Page(s):
    1975-1978

    We design a full-order observer for discrete-time linear time-invariant systems with constant output delays. The observer design is based on the output delay model expressed by a two-dimensional state variable, with discrete-time and space independent variables. Employing a discrete-time state transformation, we construct an explicit strict Lyapunov function that enables us to prove the global exponential stability of the full-order observer error system with an explicit estimate of the exponential decay rate. The numerical example demonstrates the design of the full-order observer and illustrates the validity of the exponential stability.

  • Synthesis of Quantum Arrays from Kronecker Functional Lattice Diagrams

    Martin LUKAC  Dipal SHAH  Marek PERKOWSKI  Michitaka KAMEYAMA  

     
    PAPER-Reversible/Quantum Computing

      Vol:
    E97-D No:9
      Page(s):
    2262-2269

    Reversible logic is becoming more and more popular due to the fact that many novel technologies such as quantum computing, low power CMOS circuit design or quantum optical computing are becoming more and more realistic. In quantum computing, reversible computing is the main venue for the realization and design of classical functions and circuits. We present a new approach to synthesis of reversible circuits using Kronecker Functional Lattice Diagrams (KFLD). Unlike many of contemporary algorithms for synthesis of reversible functions that use n×n Toffoli gates, our method synthesizes functions using 3×3 Toffoli gates, Feynman gates and NOT gates. This reduces the quantum cost of the designed circuit but adds additional ancilla bits. The resulting circuits are always regular in a 4-neighbor model and all connections are predictable. Consequently resulting circuits can be directly mapped in to a quantum device such as quantum FPGA [14]. This is a significant advantage of our method, as it allows us to design optimum circuits for a given quantum technology.

  • A Personality Model Based on NEO PI-R for Emotion Simulation

    Yi ZHANG  Ling LI  

     
    PAPER-Affective Computing

      Vol:
    E97-D No:8
      Page(s):
    2000-2007

    The last decade has witnessed an explosion of interest in research on human emotion modeling for generating intelligent virtual agents. This paper proposes a novel personality model based on the Revised NEO Personality Inventory (NEO PI-R). Compared to the popular Big-Five-Personality Factors (Big5) model, our proposed model is more capable than Big5 on describing a variety of personalities. Combining with emotion models it helps to produce more reasonable emotional reactions to external stimuli. A novel Resistant formulation is also proposed to effectively simulate the complicated negative emotions. Emotional reactions towards multiple stimuli are also effectively simulated with the proposed personality model.

  • Mood-Learning Public Display: Adapting Content Design Evolutionarily through Viewers' Involuntary Gestures and Movements

    Ken NAGAO  Issei FUJISHIRO  

     
    PAPER-Interaction

      Vol:
    E97-D No:8
      Page(s):
    1991-1999

    Due to the recent development of underlying hardware technology and improvement in installing environments, public display has been becoming more common and attracting more attention as a new type of signage. Any signage is required to make its content more attractive to its viewers by evaluating the current attractiveness on the fly, in order to deliver the message from the sender more effectively. However, most previous methods for public display require time to reflect the viewers' evaluations. In this paper, we present a novel system, called Mood-Learning Public Display, which automatically adapts its content design. This system utilizes viewers' involuntary behaviors as a sign of evaluation to make the content design more adapted to local viewers' tastes evolutionarily on site. The system removes the current gap between viewers' expectations and the content actually displayed on the display, and makes efficient mutual transmission of information between the cyberworld and the reality.

  • Efficient Screen Space Anisotropic Blurred Soft Shadows

    Zhongxiang ZHENG  Suguru SAITO  

     
    PAPER-Rendering

      Vol:
    E97-D No:8
      Page(s):
    2038-2045

    Shadow mapping is an efficient method to generate shadows in real time computer graphics and has broad variations from hard to soft shadow synthesis. Soft shadowing based on shadow mapping is a blurring technique on a shadow map or on screen space. Blurring on screen space has an advantage for efficient sampling on a shadow map, since the blurred target array has exactly the same coordinates as the screen. However, a previous blurring method on screen space has a drawback: the generated shadow is not correct when a view direction has a large angle to the normal of the shadowed plane. In this paper, we introduce a new screen space based method for soft shadowing that is fast and generates soft shadows more accurately than the previous screen space soft shadow mapping method. The resultant images show shadows produced by our method just stand in the same place, while shadows by the previous method change in terms of penumbra while the view moves. Surprisingly, although our method is more complex than the previous method, the measurement results of the calculation time show our method is almost the same performance. This is because it controls the blurring area more accurately and thus successfully reduces multiplications for blurring.

  • Fast Correlation Method for Partial Fourier and Hadamard Sensing Matrices in Matching Pursuit Algorithms

    Kee-Hoon KIM  Hosung PARK  Seokbeom HONG  Jong-Seon NO  

     
    PAPER-Digital Signal Processing

      Vol:
    E97-A No:8
      Page(s):
    1674-1679

    There have been many matching pursuit algorithms (MPAs) which handle the sparse signal recovery problem, called compressed sensing (CS). In the MPAs, the correlation step makes a dominant computational complexity. In this paper, we propose a new fast correlation method for the MPA when we use partial Fourier sensing matrices and partial Hadamard sensing matrices which are widely used as the sensing matrix in CS. The proposed correlation method can be applied to almost all MPAs without causing any degradation of their recovery performance. Also, the proposed correlation method can reduce the computational complexity of the MPAs well even though there are restrictions depending on a used MPA and parameters.

  • Block-Refined Orthogonal Matching Pursuit for Sparse Signal Recovery

    Ying JI  Xiaofu WU  Jun YAN  Wei-ping ZHU  Zhen YANG  

     
    LETTER-Digital Signal Processing

      Vol:
    E97-A No:8
      Page(s):
    1787-1790

    We propose a variant of OMP algorithm named BROMP for sparse solution. In our algorithm, the update rule of MP algorithm is employed to reduce the number of least square calculations and the refining strategy is introduced to further improve its performance. Simulations show that the proposed algorithm performs better than the OMP algorithm with significantly lower complexity.

  • Katakana EdgeWrite: An EdgeWrite Version for Japanese Text Entry

    Kentaro GO  Yuichiro KINOSHITA  

     
    LETTER-Interaction

      Vol:
    E97-D No:8
      Page(s):
    2053-2054

    This paper presents our project of designing EdgeWrite text entry methods for Japanese language. We are developing a version of EdgeWrite text entry method for Japanese language: Katakana EdgeWrite. Katakana EdgeWrite specifies the line stroke directions and writing order of the Japanese Katakana character. The ideal corner sequence pattern of EdgeWrite for each Katakana character is designed based on its line stroke directions and writing order.

  • EDISON Science Gateway: A Cyber-Environment for Domain-Neutral Scientific Computing

    Hoon RYU  Jung-Lok YU  Duseok JIN  Jun-Hyung LEE  Dukyun NAM  Jongsuk LEE  Kumwon CHO  Hee-Jung BYUN  Okhwan BYEON  

     
    PAPER-Scientific Application

      Vol:
    E97-D No:8
      Page(s):
    1953-1964

    We discuss a new high performance computing service (HPCS) platform that has been developed to provide domain-neutral computing service under the governmental support from “EDucation-research Integration through Simulation On the Net” (EDISON) project. With a first focus on technical features, we not only present in-depth explanations of the implementation details, but also describe the strengths of the EDISON platform against the successful nanoHUB.org gateway. To validate the performance and utility of the platform, we provide benchmarking results for the resource virtualization framework, and prove the stability and promptness of the EDISON platform in processing simulation requests by analyzing several statistical datasets obtained from a three-month trial service in the initiative area of computational nanoelectronics. We firmly believe that this work provides a good opportunity for understanding the science gateway project ongoing for the first time in Republic of Korea, and that the technical details presented here can be served as an useful guideline for any potential designs of HPCS platforms.

  • Adaptive Control of a Chain of Integrators under Unknown Time-Varying Input Delay Using Noisy Output Feedback

    Hyun-Wook JO  Ho-Lim CHOI  Jong-Tae LIM  

     
    LETTER-Systems and Control

      Vol:
    E97-A No:8
      Page(s):
    1795-1799

    Sensor noise prevents the exact measurement of output, which makes it difficult to guarantee the ultimate bound of the actual output and states, which is smaller than the sensor noise amplitude. Even worse, the time-varying delay in the input does not guarantee the boundedness of the actual output and states under sensor noise. In this letter, our considered system is a chain of integrators in which time-varying delay exists in the input and there is an additive form of sensor noise in the output measurement. To guarantee the arbitrarily small ultimate bound of the actual output and states, we newly propose an adaptive output feedback controller whose gain is tuned on-line. The merits of our control method over the existing results are clearly shown in the example.

841-860hit(3318hit)