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3661-3680hit(16314hit)

  • Enabling a Uniform OpenCL Device View for Heterogeneous Platforms

    Dafei HUANG  Changqing XUN  Nan WU  Mei WEN  Chunyuan ZHANG  Xing CAI  Qianming YANG  

     
    PAPER-Fundamentals of Information Systems

      Pubricized:
    2015/01/20
      Vol:
    E98-D No:4
      Page(s):
    812-823

    Aiming to ease the parallel programming for heterogeneous architectures, we propose and implement a high-level OpenCL runtime that conceptually merges multiple heterogeneous hardware devices into one virtual heterogeneous compute device (VHCD). Moreover, automated workload distribution among the devices is based on offline profiling, together with new programming directives that define the device-independent data access range per work-group. Therefore, an OpenCL program originally written for a single compute device can, after inserting a small number of programming directives, run efficiently on a platform consisting of heterogeneous compute devices. Performance is ensured by introducing the technique of virtual cache management, which minimizes the amount of host-device data transfer. Our new OpenCL runtime is evaluated by a diverse set of OpenCL benchmarks, demonstrating good performance on various configurations of a heterogeneous system.

  • Excess-Bandwidth Transmit Filtering Based on Minimization of Variance of Instantaneous Transmit Power for Low-PAPR SC-FDE

    Amnart BOONKAJAY  Tatsunori OBARA  Tetsuya YAMAMOTO  Fumiyuki ADACHI  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E98-B No:4
      Page(s):
    673-685

    Square-root Nyquist transmit filtering is typically used in single-carrier (SC) transmission. By changing the filter roll-off factor, the bit-error rate (BER), peak-to-average power ratio (PAPR), and spectrum efficiency (SE) changes, resulting in a tradeoff among these performance indicators. In this paper, assuming SC with frequency-domain equalization (SC-FDE), we design a new transmit filtering based on the minimum variance of instantaneous transmit power (VIP) criterion in order to reduce the PAPR of the transmit signal of SC-FDE. Performance evaluation of SC-FDE using the proposed transmit filtering is done by computer simulation, and shows that the proposed transmit filtering contributes lower transmit PAPR, while there exists only a small degradation in BER performance compared to SC-FDE using square-root Nyquist filtering.

  • Multi-ISP Cooperative Cache Sharing for Saving Inter-ISP Transit Cost in Content Centric Networking

    Kazuhito MATSUDA  Go HASEGAWA  Masayuki MURATA  

     
    PAPER-Internet

      Vol:
    E98-B No:4
      Page(s):
    621-629

    Content-Centric Networking (CCN) has an in-network caching mechanism, which can reduce the traffic volume along the route to the destination host. This traffic volume reduction on the transit link can decrease inter-ISP transit cost. However, the memory space for caching in CCN routers is small relative to content volume. In addition, any initial access to the content requested by a user must use the transit link, even when a nearby CCN router outside the route has the cached content. In this paper, we propose a method of cooperative cache sharing among CCN routers in multiple ISPs. It aims to attain a further reduction in the inter-ISP transit cost by improving the cache hit ratio. In the proposed method, the CCN routers share the memory space for caching of non-overlapping cache content. We evaluate the proposed method by simulation experiments using the IP-level network topology of actual ISP, and show that the inter-ISP transit traffic can be reduced by up to 28% compared with normal caching behavior of CCN.

  • The KDM-CCA Security of the Kurosawa-Desmedt Scheme

    Jinyong CHANG  Rui XUE  Anling ZHANG  

     
    LETTER-Cryptography and Information Security

      Vol:
    E98-A No:4
      Page(s):
    1032-1037

    In this letter, we prove that the Kurosawa-Desmedt (KD) scheme [10], which belongs to the hybrid framework, is KDM-CCA secure w.r.t. an ensemble proposed by Qin et al. in [12] under the decisional Diffie-Hellman assumption. Since our proof does not rely on the random oracle model, we partially answer the question presented by Davies and Stam in [7], where they hope to achieve the KDM-CCA security for hybrid encryption scheme in the standard model (i.e. not random oracle model). Moreover, our result may also make sense in practice since KD-scheme is (almost) the most efficient CCA secure scheme.

  • A Spatially Correlated Mixture Model for Image Segmentation

    Kosei KURISU  Nobuo SUEMATSU  Kazunori IWATA  Akira HAYASHI  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2015/01/06
      Vol:
    E98-D No:4
      Page(s):
    930-937

    In image segmentation, finite mixture modeling has been widely used. In its simplest form, the spatial correlation among neighboring pixels is not taken into account, and its segmentation results can be largely deteriorated by noise in images. We propose a spatially correlated mixture model in which the mixing proportions of finite mixture models are governed by a set of underlying functions defined on the image space. The spatial correlation among pixels is introduced by putting a Gaussian process prior on the underlying functions. We can set the spatial correlation rather directly and flexibly by choosing the covariance function of the Gaussian process prior. The effectiveness of our model is demonstrated by experiments with synthetic and real images.

  • Supporting Jogging at an Even Pace by Synchronizing Music Playback Speed with Runner's Pace

    Tetsuro KITAHARA  Shunsuke HOKARI  Tatsuya NAGAYASU  

     
    LETTER-Human-computer Interaction

      Pubricized:
    2015/01/09
      Vol:
    E98-D No:4
      Page(s):
    968-971

    In this paper, we propose a jogging support system that plays back background music while synchronizing its tempo with the user's jogging pace. Keeping an even pace is important in jogging but it is not easy due to tiredness. Our system indicates the variation of the runner's pace by changing the playback speed of music according to the user's pace variation. Because this requires the runner to keep an even pace in order to enjoy the music at its normal speed, the runner will be spontaneously influenced to keep an even pace. Experimental results show that our system reduced the variation of jogging pace.

  • Transponder Array System with Universal On-Sheet Reference Scheme for Wireless Mobile Sensor Networks without Battery or Oscillator

    Takahide TERADA  Haruki FUKUDA  Tadahiro KURODA  

     
    PAPER-Analog Signal Processing

      Vol:
    E98-A No:4
      Page(s):
    932-941

    A rotating shaft with attached sensors is wrapped in a two-dimensional waveguide sheet through which the data and power are wirelessly transmitted. A retrodirective transponder array affixed to the sheet beamforms power to the moving sensor to eliminate the need for a battery. A universal on-sheet reference scheme is proposed for calibrating the transponder circuit delay variation and eliminating a crystal oscillator from the sensor. A base signal transmitted from the on-sheet reference device is used for generating the pilot signal transmitted from the sensor and the power signal transmitted from the transponder. A 0.18-µm CMOS transponder chip and the sheet with couplers were fabricated. The coupler has three resonant frequencies used for the proposed system. The measured propagation gain of the electric field changes to less than ±1.5dB within a 2.0-mm distance between the coupler and the sheet. The measured power transmission efficiency with beamforming is 23 times higher than that without it. Each transponder outputs 1W or less for providing 3mW to the sensor.

  • Techniques for Measuring Business Process Based on Business Values

    Jihyun LEE  Sungwon KANG  

     
    PAPER-Office Information Systems, e-Business Modeling

      Pubricized:
    2014/12/26
      Vol:
    E98-D No:4
      Page(s):
    911-921

    The ultimate purpose of a business process is to promote business values. Thus, any process that fails to enhance or promote business values should be improved or adjusted so that business values can be achieved. Therefore an organization should have the capability of confirming whether a business value is achieved; furthermore, in order to cope with the changes of business environment, it should be able to define the necessary measures on the basis of business values. This paper proposes techniques for measuring a business process based on business values, which can be used to monitor and control business activities focusing on the attainment of business values. To show the feasibility of the techniques, we compare their monitoring and controlling capabilities with those of the current fulfillment process of a company. The results show that the proposed techniques are effective in linking business values to relevant processes and integrating each measurement result in accordance with the management level.

  • An Original Entry Point Detection Method with Candidate-Sorting for More Effective Generic Unpacking

    Ryoichi ISAWA  Daisuke INOUE  Koji NAKAO  

     
    PAPER-Information Network

      Pubricized:
    2015/01/06
      Vol:
    E98-D No:4
      Page(s):
    883-893

    Many malware programs emerging from the Internet are compressed and/or encrypted by a wide variety of packers to deter code analysis, thus making it necessary to perform unpacking first. To do this task efficiently, Guo et al. proposed a generic unpacking system named Justin that provides original entry point (OEP) candidates. Justin executes a packed program, and then it extracts written-and-executed points caused by the decryption of the original binary until it determines the OEP has appeared, taking those points as candidates. However, for several types of packers, the system can provide comparatively large sets of candidates or fail to capture the OEP. For more effective generic unpacking, this paper presents a novel OEP detection method featuring two mechanisms. One identifies the decrypting routine by tracking relations between writing instructions and written areas. This is based on the fact that the decrypting routine is the generator for the original binary. In case our method fails to detect the OEP, the other mechanism sorts candidates based on the most likely candidate so that analysts can reach the correct one quickly. With experiments using a dataset of 753 samples packed by 25 packers, we confirm that our method can be more effective than Justin's heuristics, in terms of detecting OEPs and reducing candidates. After that, we also propose a method combining our method with one of Justin's heuristics.

  • Preliminary Study of Electrical Contact Behaviors of Au-plated Material at Super Low Making/Breaking Velocity

    Wanbin REN  Shengjun XUE  Hongxu ZHI  Guofu ZHAI  

     
    PAPER-Electromechanical Devices and Components

      Vol:
    E98-C No:4
      Page(s):
    364-370

    This paper presents the electrical contact behaviors of Au-plated material at super low making and breaking velocity conditions by introducing our new designed test rig. The fundamental phenomena in the contact voltage and contact force versus piezoactuator displacement curves were investigated under the load current of 1A and velocity of 50,nm/s. From the repetitive experimental results, we found that the adhesion phenomena during the unloading process are closely correlative with the initial contact stage in the loading process. Furthermore, a mathematical model which is relative to the variation of contact force in loading is built, thus the physical mechanism of adhesion and principal factors of gold-plated materials are discussed. Finally, the physical process of molten bridge under the no mechanical contact situation is also analyzed in detail.

  • A New Generic Construction of Proxy Signatures under Enhanced Security Models

    Kee Sung KIM  Ik Rae JEONG  

     
    PAPER-Cryptography and Information Security

      Vol:
    E98-A No:4
      Page(s):
    975-981

    A proxy signature scheme allows an entity to delegate his signing capabilities to another. Many schemes have been provided for use in numerous applications such as distributed computing, grid computing, and mobile communications. In 2003, Boldyreva et al. introduced the first formal security model of proxy signatures and also proposed a generic construction secure in their model. However, an adversary can arbitrarily alter the warrants of the proxy signatures because the warrants are not explicitly considered in their model. To solve this problem, Huang et al. provided an enhanced security model of proxy signatures in 2005. Some proxy signatures secure in this security model have been proposed but there is no generic construction yet. In this paper, we redefine and improve the Huang et al.'s security model in terms of multi-user and then provide a new generic construction of proxy signatures secure against our enhanced security model based on ID-based signatures. Moreover, we can make a lattice-based proxy signature scheme in the standard model from our result.

  • Estimating Korean Residence Registration Numbers from Public Information on SNS

    Daeseon CHOI  Younho LEE  Yongsu PARK  Seokhyun KIM  

     
    PAPER-Fundamental Theories for Communications

      Vol:
    E98-B No:4
      Page(s):
    565-574

    People expose their personal information on social network services (SNSs). This paper warns of the dangers of this practice by way of an example. We show that the residence registration numbers (RRNs) of many Koreans, which are very important and confidential personal information analogous to social security numbers in the United States, can be estimated solely from the information that they have made open to the public. In our study, we utilized machine learning algorithms to infer information that was then used to extract a part of the RRNs. Consequently, we were able to extract 45.5% of SNS users' RRNs using a machine learning algorithm and brute-force search that did not consume exorbitant amounts of resources.

  • Making Joint-Histogram-Based Weighted Median Filter Much Faster

    Hanhoon PARK  

     
    LETTER-Image Processing and Video Processing

      Pubricized:
    2014/12/12
      Vol:
    E98-D No:3
      Page(s):
    721-725

    In this letter, we propose a simple framework for accelerating a state-of-the-art histogram-based weighted median filter at no expense. It is based on a process of determining the filter processing direction. The determination is achieved by measuring the local feature variation of input images. Through experiments with natural images, it is verified that, depending on input images, the filtering speed can be substantially increased by changing the filtering direction.

  • Multiple Impossible Differential Cryptanalysis on Reduced FOX

    Xinran LI  Fang-Wei FU  Xuan GUANG  

     
    LETTER-Cryptography and Information Security

      Vol:
    E98-A No:3
      Page(s):
    906-911

    FOX is a family of block ciphers published in 2004 and is famous for its provable security to cryptanalysis. In this paper, we present multiple 4-round impossible differentials and several new results of impossible differential attacks on 5,6,7-round FOX64 and 5-round FOX128 with the multiple differentials and the new early abort technique which shall reduce the data complexity and the time complexity respectively. In terms of the data complexity and the time complexity, our results are better than any of the previously known attacks.

  • Detection of S1/S2 Components with Extraction of Murmurs from Phonocardiogram

    Xingri QUAN  Jongwon SEOK  Keunsung BAE  

     
    LETTER-Biological Engineering

      Pubricized:
    2014/11/25
      Vol:
    E98-D No:3
      Page(s):
    745-748

    The simplicity is a type of measurement that represents visual simplicity of a signal, regardless of its amplitude and frequency variation. We propose an algorithm that can detect major components of heart sound using Gaussian regression to the smoothed simplicity profile of a heart sound signal. The weight and spread of the Gaussians are used as features to discriminate cardiac murmurs from major components of a heart sound signal. Experimental results show that the proposed method is very promising for robust and accurate detection of major heart sound components as well as cardiac murmurs.

  • Stealthy Mobile Phone Identity Catcher

    Changqing XU  Fan YANG  Jin TENG  Sumxin JIANG  

     
    PAPER-Terrestrial Wireless Communication/Broadcasting Technologies

      Vol:
    E98-B No:3
      Page(s):
    494-501

    In this paper, we design a stealthy GSM phone identity catcher. As the GSM protocols do not mandate the authentication of BSes (Base Stations) to MSes (Mobile Stations), fake BSes can be implemented to lure victims to register with and thereby intercept crucial information of the user, including their identities. However, the straightforward implementation of GSM phone identity catcher can be easily perceived by users employing detection software due to such phenomena as phone interface changes and service interruptions. In this paper, we propose several effective mechanisms, such as smart configuration of the fake BSes, quick attachment/detachment and service relay, to make the catching process invisible to users and software. Real world experiments have been conducted and the results prove the efficiency and stealth of our proposed GSM phone identity catcher. We hope our work could help to enhance the effectiveness of IMSI catching attack and thereby alert the industry to design stronger authentication protocol in communication systems.

  • Efficient Partial Single Relay Selection Scheme for Wireless Communications

    Sung-Bok CHOI  Young-Hwan YOU  Hyoung-Kyu SONG  

     
    LETTER-Communication Theory and Signals

      Vol:
    E98-A No:3
      Page(s):
    923-926

    Many wireless communication systems use a relay station for cooperative diversity or cell coverage extension. In this letter, an efficient partial single relay selection scheme is proposed for wireless communications. The conventional schemes such as the best harmonic mean and the threshold-based relay selection should know channel state informaion (CSI), or noise variance at all stations in advance. But the proposed scheme does not require any priori information. It uses a characteristic of the repeated signal pattern at candidates of the relay station. Simulation results show that the performance of proposed scheme is very close to the best harmonic mean relay selection scheme as one of the optimal relay selection schemes.

  • SQUID Systems for Geophysical Time Domain Electromagnetics (TEM) at IPHT Jena Open Access

    Andreas CHWALA  Ronny STOLZ  Matthias SCHMELZ  Vyacheslav ZAKOSARENKO  Matthias MEYER  Hans-Georg MEYER  

     
    INVITED PAPER

      Vol:
    E98-C No:3
      Page(s):
    167-173

    Forty years after the first application of Superconducting Quantum Interference Devices (SQUIDs) [1], [2] for geophysical purposes, they have recently become a valued tool for mineral exploration. One of the most common applications is time domain (or transient) electromagnetics (TEM), an active method, where the inductive response from the ground to a changing current (mostly rectangular) in a loop on the surface is measured. After the current in the transmitter coil is switched, eddy currents are excited in the ground, which decay in a manner dependent on the conductivity of the underlying geologic structure. The resulting secondary magnetic field at the surface is measured during the off-time by a receiver coil (induced voltage) or by a magnetometer (e.g. SQUID or fluxgate). The recorded transient signal quality is improved by stacking positive and negative decays. Alternatively, the TEM results can be inverted and give the electric conductivity of the ground over depth. Since SQUIDs measure the magnetic field with high sensitivity and a constant frequency transfer function, they show a superior performance compared to conventional induction coils, especially in the presence of strong conductors. As the primary field, and especially its slew rate, are quite large, SQUID systems need to have a large slew rate and dynamic range. Any flux jump would make the use of standard stacking algorithms impossible. IPHT and Supracon are developing and producing SQUID systems based on low temperature superconductors (LTS, in our case niobium), which are now state-of-the-art. Due to the large demand, we are additionally supplying systems with high temperature superconductors (HTS, in our case YBCO). While the low temperature SQUID systems have a better performance (noise and slew rate), the high temperature SQUID systems are easier to handle in the field. The superior performance of SQUIDs compared to induction coils is the most important factor for the detection of good conductors at large depth or ore bodies underneath conductive overburden.

  • Analysis of Noteworthy Issues in Illumination Processing for Face Recognition

    Min YAO  Hiroshi NAGAHASHI  

     
    PAPER-Image Recognition, Computer Vision

      Vol:
    E98-D No:3
      Page(s):
    681-691

    Face recognition under variable illumination conditions is a challenging task. Numbers of approaches have been developed for solving the illumination problem. In this paper, we summarize and analyze some noteworthy issues in illumination processing for face recognition by reviewing various representative approaches. These issues include a principle that associates various approaches with a commonly used reflectance model and the shared considerations like contribution of basic processing methods, processing domain, feature scale, and a common problem. We also address a more essential question-what to actually normalize. Through the discussion on these issues, we also provide suggestions on potential directions for future research. In addition, we conduct evaluation experiments on 1) contribution of fundamental illumination correction to illumination insensitive face recognition and 2) comparative performance of various approaches. Experimental results show that the approaches with fundamental illumination correction methods are more insensitive to extreme illumination than without them. Tan and Triggs' method (TT) using L1 norm achieves the best results among nine tested approaches.

  • Three-Dimensionally Assembled TES X-ray Microcalorimeter Arrays for a TEM EDS System

    Kenichiro NAGAYOSHI  Kazuhiro SAKAI  Kazuhisa MITSUDA  Noriko Y. YAMASAKI  Yoh TAKEI  Keisuke MAEHATA  Naoko IYOMOTO  Shohei EZAKI  Akira TAKANO  Makoto MAEDA  Toru HARA  

     
    PAPER

      Vol:
    E98-C No:3
      Page(s):
    186-191

    Three-dimensionally assembled TES X-ray microcalorimeter arrays may be utilized for three purposes: (1) to obtain wide X-ray energy coverage of TES microcalorimeters, (2) to distinguish charged particle events from X-ray events, (3) to reconstruct Compton-scattering geometry for hard X-ray Compton cameras. We have designed and fabricated three-dimensionally assembled array of the minimum format i.e. $2 imes 2 imes 2$ array in order to obtain a good energy resolution in a wide energy range of 0.5--20,keV and a high maximum counting rate of 2000,cps for energy dispersive X-ray spectrometer (EDS) system for a transmission electron microscope (TEM). Although we could not obtain required energy resolution because of a problem in the refrigerator system, we confirmed the operation of the three-dimensional array.

3661-3680hit(16314hit)