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2221-2240hit(4570hit)

  • A Voltage Scalable Advanced DFM RAM with Accelerated Screening for Low Power SoC Platform

    Hiroki SHIMANO  Fukashi MORISHITA  Katsumi DOSAKA  Kazutami ARIMOTO  

     
    PAPER-Next-Generation Memory for SoC

      Vol:
    E90-C No:10
      Page(s):
    1927-1935

    The advanced-DFM (Design For Manufacturability) RAM provides the solution for the limitation of SRAM voltage scaling down and the countermeasure of the process fluctuations. The characteristics of this RAM are the voltage scalability (@0.6 V operation) with wide operating margin and the reliability of long data retention time. The memory cell consists of 2 Cell/bit with the complementary dynamic memory operation and has the 1 Cell/bit test mode for the accelerated screening against the marginal cells. The GND bitline pre-charge sensing scheme and SSW (Sense Synchronized Write) peripheral circuit technologies are also adopted for the low voltage and DFV (Dynamic Frequency and Voltage) controllable SoC which will be strongly required from the many kinds of applications. This RAM supports the DFM functions with both good cell/bit for advanced process technologies and the voltage scalable SoC memory platform.

  • A Model of Discourse Segmentation and Segment Title Assignment for Lecture Speech Indexing

    Kazuhiro TAKEUCHI  Yukie NAKAO  Hitoshi ISAHARA  

     
    PAPER

      Vol:
    E90-D No:10
      Page(s):
    1601-1610

    Dividing a lecture speech into segments and providing those segments as learning objects are quite general and convenient way to construct e-learning resources. However it is difficult to assign an appropriate title to each object that reflects its content. Since there are various aspects of analyzing discourse segments, it is inevitable that researchers will face the diversity when describing the "meanings" of discourse segments. In this paper, we propose the assignment of discourse segment titles from the representation of their "meanings." In this assigning procedure, we focus on the speaker's evaluation for the event or the speech object. To verify the effectiveness of our idea, we examined identification of the segment boundaries from the titles that were described in our procedure. We confirmed that the result of the identification was more accurate than that of intuitive identification.

  • OWL/XDD Application Profiles

    Photchanan RATANAJAIPAN  Ekawit NANTAJEEWARAWAT  Vilas WUWONGSE  

     
    PAPER

      Vol:
    E90-D No:10
      Page(s):
    1611-1620

    An application profile specifies a set of terms, drawn from one or more standard namespaces, for annotation of data, and constrains their usage and interpretations in a particular local application. An approach to representation of and reasoning with application profiles based on the OWL and OWL/XDD languages is proposed. The former is a standard Web ontology language, while the latter is a definite-clause-style rule language that employs XML expressions as its underlying data structure. Semantic constraints are defined in terms of rules, which are represented as XDD clauses. Application of the approach to defining application profiles with fine-grained semantic constraints, involving implicit properties of metadata elements, is illustrated. A prototype application profile development environment equipped with metadata validation features has been implemented based on the proposed framework.

  • Improvement of Inter-Layer Motion Prediction in Scalable Video Coding

    Tae Meon BAE  Truong Cong THANG  Yong Man RO  

     
    LETTER-Image Processing and Video Processing

      Vol:
    E90-D No:10
      Page(s):
    1712-1715

    In this letter, we propose an enhanced method for inter-layer motion prediction in scalable video coding (SVC). For inter-layer motion prediction, the use of refined motion data in the Fine Granular Scalability (FGS) layer is proposed instead of the conventional use of motion data in the base quality layer to reduce the inter-layer redundancy efficiently. Experimental results show that the proposed method enhances coding efficiency without increasing the computational complexity of the decoder.

  • A Basic Theory for Available Operation of Extremely Complicated Large-Scale Network Systems

    Kazuo HORIUCHI  

     
    PAPER-Systems Theory and Control

      Vol:
    E90-A No:10
      Page(s):
    2232-2238

    In this paper, we shall describe about a basic theory based on the concept of set-valued operators, suitable for available operation of extremely complicated large-scale network systems. Fundamental conditions for availability of system behaviors of such network systems are clarified in a form of fixed point theorem for system of set-valued operators. Here, the proof of this theorem is accomplished by the concept of Hausdorff's ball measure of non-compactness.

  • Experimental Performance Evaluations of Reflect-Transmission Control Schemes for Vehicle-PEdestrian Communications (VPEC)

    Yoshihisa OKADA  Tomotaka WADA  Masato HORIE  Fumio NAKASE  Hiromi OKADA  

     
    PAPER-Integrated Systems for Communications

      Vol:
    E90-B No:10
      Page(s):
    2931-2939

    Inter-Vehicle Communication (IVC) is one of the most important technologies to realize advanced Intelligent Transport Systems (ITS). We extensively apply the IVC technology to the communications between pedestrians and vehicles. We call this kind of communications VPEC (Vehicle-PEdestrian Communications). The objective of this paper is to present an effective control scheme for VPEC and to evaluate the performance of proposed scheme by experiments. We deal with direct communications between pedestrians and vehicles. Due to the battery shortage of pedestrians' terminals (p-node), we have presented a reflect-transmission scheme. In this paper, we propose a new access protocol for reflect-transmission scheme, and show its validity by various experiments with several vehicles.

  • A Visual Inpainting Method Based on the Compressed Domain

    Yi-Wei JIANG  De XU  Moon-Ho LEE  Cong-Yan LANG  

     
    LETTER-Image Processing and Video Processing

      Vol:
    E90-D No:10
      Page(s):
    1716-1719

    Visual inpainting is an interpolation problem that restores an image or a frame with missing or damaged parts. Over the past decades, a number of computable models of visual inpainting have been developed, but most of these models are based on the pixel domain. Little theoretical and computational work of visual inpainting is based on the compressed domain. In this paper, a visual inpainting model in the discrete cosine transform (DCT) domain is proposed. DCT coefficients of the non-inpainting blocks are utilized to get block features, and those block features are propagated to the inpainting region iteratively. The experimental results with I frames of MPEG4 are presented to demonstrate the efficiency and accuracy of the proposed algorithm.

  • Evaluation of Reliable Multicast Applications for Large-Scale Contents Delivery

    Teruji SHIROSHITA  Shingo KINOSHITA  Takahiko NAGATA  Tetsuo SANO  Yukihiro NAKAMURA  

     
    PAPER

      Vol:
    E90-B No:10
      Page(s):
    2738-2745

    Reliable Multicast has been applied to large-scale contents delivery systems for distributing digital contents to a large number of users without data loss. Reliable contents distribution is indispensable for software updates and management data sharing in actual delivery services. This paper evaluates the implementation and performance of RMTP; a reliable multicast protocol for bulk-data transfer, through the developments of contents delivery systems. Software configuration is also examined including operation functions such as delivery scheduling. Furthermore, applicability of reliable multicast to emerging broadband networks is also discussed based on the experimentation results. Through the deployment of the protocol and the software, performance estimation has played a key role for constructing the delivery systems as well as for designing the communication protocol.

  • Relaxed Monotonic Conditions for Schur Stability of Real Polynomials

    Thang V. NGUYEN  Yoshihiro MORI  Takehiro MORI  

     
    LETTER-Systems and Control

      Vol:
    E90-A No:10
      Page(s):
    2326-2328

    Monotonic condition, a well-known sufficient condition for Schur stability of real polynomials, is relaxed. The condition reads that a series of strictly and monotonically decreasing positive coefficients of the polynomials yields Schur stability. It is shown by inspecting the original proof that equalities are allowed in all the inequalities but two which are located at appropriate positions.

  • Performance Analysis of Large-Scale IP Networks Considering TCP Traffic

    Hiroyuki HISAMATSU  Go HASEGAWA  Masayuki MURATA  

     
    PAPER-Network Management/Operation

      Vol:
    E90-B No:10
      Page(s):
    2845-2853

    In this paper, we propose a novel analysis method for large-scale networks with consideration of the behavior of the congestion control mechanism of TCP. In the analysis, we model the behavior of TCP at end-host and network link as independent systems, and combine them into a single system in order to analyze the entire network. Using this analysis, we can analyze a large-scale network, i.e. with over 100/1,000/10,000 routers/hosts/links and 100,000 TCP connections very rapidly. Especially, a calculation time of our analysis, it is different from that of ns-2, is independent of a network bandwidth and/or propagation delay. Specifically, we can derive the utilization of the network links, the packet loss ratio of the link buffer, the round-trip time (RTT) and the throughput of TCP connections, and the location and degree of the network congestion. We validate our approximate analysis by comparing analytic results with simulation ones. We also show that our analysis method treats the behavior of TCP connection in a large-scale network appropriately.

  • Averaging Method Analysis of Synchronization Characteristics of a Large Number of Nonlinearly Coupled van der Pol Oscillators

    Kuniyasu SHIMIZU  Tetsuro ENDO  Hisa-Aki TANAKA  

     
    PAPER-Nonlinear Phenomena and Analysis

      Vol:
    E90-A No:10
      Page(s):
    2162-2169

    The averaged equation for an arbitrary number of oscillators coupled by nonlinear coupling scheme invented by S. Nagano, is derived. This system is invented as a model of uni-cellular slime amoeba. By using the averaged equation, we investigate the synchronization characteristics of five coupled oscillators and a large number of coupled oscillators. In particular, we present the statistical property of coupled oscillators in terms of coupling factor γ. We also investigate the effect of linear and nonlinear coupling terms for achieving synchronization, and confirm that the nonlinear coupling term plays an important role for strong synchronization than linear coupling term does.

  • Adaptive Transform Coefficient Scan for H.264 Intra Coding

    Jie JIA  Eun-Ku JUNG  Hae-Kwang KIM  

     
    LETTER-Image Processing and Video Processing

      Vol:
    E90-D No:10
      Page(s):
    1709-1711

    This paper presents an adaptive transform coefficient scan method that effectively improves intra coding efficiency of H.264. Instead of applying one zig-zag scan to all transform blocks, the proposed method applies a field scan to a horizontally predicted block, a horizontal scan to a vertically predicted block, and a zig-zag scan to blocks predicted in other prediction modes. Experiments based on JM9.6 were performed using only intra coding. Results of the experiments show that the proposed method yields an average PSNR enhancement of 0.16 dB and a maximum PSNR enhancement of 0.31 dB over the current H.264 using zig-zag scan.

  • Performance Enhancement of Transport Layer Handover on Single-Homed Mobile Nodes

    Michio HONDA  Yoshifumi NISHIDA  Jin NAKAZAWA  Hideyuki TOKUDA  

     
    PAPER

      Vol:
    E90-B No:10
      Page(s):
    2683-2692

    Many handover techniques in the Internet have been introduced with the development of mobile computing technologies. Although many proposed handover schemes utilize multiple wireless interfaces, having multiple wireless interfaces in a mobile device increases its power consumption, device installation space, and hardware costs. We have been studying handover schemes for mobile nodes with a single wireless interface. To achieve seamless and efficient handover, we focus on Stream Control Transmission Protocol (SCTP) that offers a message-oriented, reliable and connection-oriented delivery transport service. Unlike other transport protocols like TCP, SCTP can provide an end-to-end handover mechanism with multi-homing feature. However, the handover mechanism in the current SCTP causes large handover latency particularly when a mobile node has only one single wireless interface. This paper investigates the current issues of the SCTP handover mechanism, and proposes a new efficient handover scheme based on SCTP, which identifies a communication path as a pair of source and destination address. Additionally, we modified SCTP behavior when an SCTP endpoint received a SET PRIMARY message to change primary destination of peer endpoint. This paper shows that our scheme can reduce the handover latency by two to thirty seconds.

  • Comparing the Performance of MMIC Matrix and Distributed Amplifiers

    Emad HAMIDI  Mahmoud MOHAMMAD-TAHERI  

     
    LETTER-Microwaves, Millimeter-Waves

      Vol:
    E90-C No:10
      Page(s):
    2057-2061

    A comparison is made between the performance of the MMIC matrix and distributed amplifiers. It has been shown that based on the analytical formulations, in most typical cases a cascaded dual stage distributed amplifier has more gain than that of a two-tier matrix amplifier with the same number of transistors; however the difference is not significant. Results of the analytical approach are then compared with the simulated and the measured results and a good agreement between the results has been obtained. Then other scattering parameters of the matrix and distributed amplifiers have been compared.

  • Analysis of Symmetric Cancellation Coding for OFDM over a Multi-Path Rayleigh Fading Channel

    Abdullah S. ALARAIMI  Takeshi HASHIMOTO  

     
    PAPER-Communication Theory and Signals

      Vol:
    E90-A No:9
      Page(s):
    1956-1964

    Orthogonal frequency division multiplexing (OFDM) systems for mobile applications suffer from inter-carrier-interference (ICI) due to frequency offset and to time-variation of the channels and from high peak-to-average-power ratio (PAPR). In this paper, we revisit symmetric cancellation coding (SCC) proposed by Sathananthan et al. and compare the effectiveness of SCC with a fixed subtraction combining and the well-known polynomial cancellation coding (PCC) over Rayleigh fading channels with Doppler spread in terms of the signal-to-interference plus noise power ratio (SINR) and bit-error-rate (BER). We also compare SCC with subtraction combining and SCC of Sathananthan et al. with maximum ratio combining (MRC). Our results show that SCC-OFDM with subtraction combining gives higher SINR than PCC-OFDM over the flat Rayleigh fading channel and that this superiority is not maintained under multi-path induced frequency-selective fading unless diversity combining is used. A simulation result shows, however, that SCC-OFDM with subtraction combining may perform better than PCC-OFDM for a certain range of Doppler spread when differential modulation is employed. Finally, we also demonstrate that the SCC-OFDM signal has less PAPR compared to the normal OFDM and PCC-OFDM and hence may be more practical.

  • Beam Scanning Comb-Line Antenna Loading Movable Dielectric Plate

    Kazuhiro KITATANI  Takahiko TERADA  Yasuyuki OKAMURA  

     
    PAPER-Antennas

      Vol:
    E90-B No:9
      Page(s):
    2213-2218

    This paper describes a beam scanning antenna that consists of a movable dielectric plate loaded onto a microstrip comb-line antenna. This type of antenna uses a mechanical system and so offers a simple structure and low cost. The main beam direction of the proposed antenna is changed by moving the dielectric plate. The guide wavelength of the microstrip line was measured at the quasi-millimeter wave band (20 GHz) when moving the dielectric plate to investigate the possibility of beam scanning. The proposed antenna was fabricated to experimentally demonstrate its principle operation. A possible beam scanning angle of 20 degrees was confirmed.

  • A Study on Miniaturization of Printed Disc Monopole Antenna for UWB Applications Using Notched Ground Plane

    Hiroyuki KOBAYASHI  Takayuki SASAMORI  Teruo TOBANA  Kohshi ABE  

     
    PAPER-Antennas

      Vol:
    E90-B No:9
      Page(s):
    2239-2245

    In this paper, we report the detailed investigation of novel printed disc monopole antennas for ultra-wideband (UWB) applications focusing on miniaturization of the disc radiator. First, the basic property was examined for the case of a circular disc with diameter of 50 mm, and it was found that the VSWR is less than 2 in the UWB band of 3.1-10.6 GHz when the feed gap length is between about -0.1 and 0.2 mm. Next, in order to reduce the size of the disc radiator, various dimensions of elliptical discs were investigated. It is shown that if the dimensions of the elliptical disc are chosen appropriately, a smaller disc size antenna can be achieved. To decrease the antenna size further, a triangular notch and an exponentially curved notch on the ground plane of the antenna were examined. It is observed that the use of the notched ground is very effective and that the diameter of the circular radiator can be reduced to 17 mm. The proposed antenna has an omnidirectional pattern in the x-y plane. The influence of the notch on the radiation pattern is very small. Details of the simulation results using the FDTD method and experimental results for the proposed antenna are presented and analyzed. These features are very attractive for UWB applications.

  • Investigation on Seasonal Water Area Change in Lake Sakata Based on POLSAR Image Analysis

    Ryoichi SATO  Yuki YAJIMA  Yoshio YAMAGUCHI  Hiroyoshi YAMADA  

     
    PAPER-Sensing

      Vol:
    E90-B No:9
      Page(s):
    2369-2375

    This paper examines seasonal change of the true water area of Lake "Sakata" by using Polarimetric Synthetic Aperture Radar (POLSAR) image analysis. The true water area includes not only the body of water but also the water area under emerged-plants and/or floating-leave plants in the lake. Statistical POLSAR image analysis is carried out for both X- and L-band data, based on the three-component scattering power decomposition method, where the decomposed components are surface scattering, double-bounce scattering and volume scattering components. From the results of the image analysis for the L-band POLSAR data acquired by Pi-SAR system, it is found that strong double-bounce scattering can be observed at the vicinity of the boundary region between water area and the surrounding emerged-plants area in early and middle summer. This phenomenon is an important factor for environmental monitoring. To verify the generating mechanism of the double-bounce scattering, the Finite-Difference Time-Domain (FDTD) polarimetric scattering analysis is also executed for a simplified boundary model, which simulates the local boundary region around the lake and consists of lots of vertical thin dielectric pillars on a perfect electric conductor (PEC) plate or on a PEC and dielectric hybrid plate. Taking into account the polarimetric feature of the double-bounce scattering obtained by both the FDTD and POLSAR image analyses, one can distinguish the actual water area from the bush of the emerged-plants around the lake, even when the water area is concealed by emerged-plants and/or floating-leave plants. Consequently, it is found that by using the proposed approach, one can estimate the true water area seasonal change for the lake and the surrounding wetland.

  • Contention-Free λ-Planes in Optically Burst-Switched WDM Networks

    Kouji HIRATA  Takahiro MATSUDA  Hiroshi NAGAMOCHI  Tetsuya TAKINE  

     
    PAPER-Internet

      Vol:
    E90-B No:9
      Page(s):
    2524-2531

    This paper proposes a contention-free burst scheduling scheme for optically burst-switched WDM networks. We construct contention-free wavelength planes (λ-planes) by assigning dedicated wavelengths to each ingress node. Bursts are transmitted to their egress nodes on λ-planes, along routes forming a spanning tree. As a result, contention at intermediate core nodes is completely eliminated, and contention at ingress nodes is resolved by means of electric buffers. This paper develops a spanning tree construction algorithm, aiming at balancing input loads among output ports at each ingress node. Furthermore, a wavelength assignment algorithm is proposed, which is based on the amount of traffic lost at ingress nodes. We show that the proposed scheme can decrease the burst loss probability drastically, even if traffic intensities at ingress nodes are different.

  • Characteristics of Nano-Grating N-Channel MOSFETs for Improved Current Drivability

    Xiaoli ZHU  Shin-Ichiro KUROKI  Koji KOTANI  Hideharu SHIDO  Masatoshi FUKUDA  Yasuyoshi MISHIMA  Takashi ITO  

     
    PAPER-Semiconductor Materials and Devices

      Vol:
    E90-C No:9
      Page(s):
    1830-1836

    Drivability-improved MOSFETs were successfully fabricated by using nano-grating silicon wafers. There was almost no additional process change in device fabrication when the height of the gratings was less than the conventional macroscopic wafer surface roughness. The MOSFETs with the grating height of 35 nm showed 21% improvement in current drivability compared to the conventional one with the same device occupancy area. And the roll-off characteristic of threshold voltage of nano-grating device held the line of conventional one in despite of the 3-D channel structure. The technology provides great advantages for drivability improvement without paying much tradeoff of process cost. This proposal will be useful to CMOS-LSIs with high performance in general.

2221-2240hit(4570hit)