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[Keyword] PD(276hit)

141-160hit(276hit)

  • Traitor Tracing Scheme Secure against Adaptive Key Exposure and its Application to Anywhere TV Service

    Kazuto OGAWA  Goichiro HANAOKA  Hideki IMAI  

     
    PAPER

      Vol:
    E90-A No:5
      Page(s):
    1000-1011

    Copyright protection is a major issue in distributing content on Internet or broadcasting service. One well-known method of protecting copyright is a traitor tracing scheme. With this scheme, if a pirate decoder is made, the content provider can check the secret key contained in it and trace the authorized user/subscriber (traitor). Furthermore, users require that they could obtain services anywhere they want (Anywhere TV). For this purpose, they would need to take along their secret keys and therefore key exposure has to be kept in mind. As one of countermeasures against key exposure, a forward secure public key cryptosystem has been developed. In this system, the user secret key remains valid for a limited period of time. It means that even if it is exposed, the user would be affected only for the limited time period. In this paper, we propose a traitor tracing scheme secure against adaptive key exposure (TTaKE) which contains the properties of both a traitor tracing scheme and a forward secure public key cryptosystem. It is constructed by using two polynomials with two variables to generate user secret keys. Its security proof is constructed from scratch. Moreover we confirmed its efficiency through comparisons. Finally, we show the way how its building blocks can be applied to anywhere TV service. Its structure fits current broadcasting systems.

  • Implementation of Local Boundary Conditions in Two ADI-FDTD Updating Schemes

    Saehoon JU  Kyung-Hoon LEE  In-Ho HWANG  Hyung-Hoon KIM  Hyeongdong KIM  

     
    LETTER-Antennas and Propagation

      Vol:
    E90-B No:5
      Page(s):
    1286-1289

    In numerical simulations of microwave structures using the alternating-direction implicit finite-difference time-domain (ADI-FDTD) method, the time marching scheme comprises two sub-iterations, where different updating schemes for evaluating E and H fields at each sub-iteration can be adopted. In this paper, the E-field implicit-updating (EFIU) and H-field implicit-updating (HFIU) schemes are compared with each other especially with regard to the implementation of local boundary conditions.

  • Extended Ticket-Based Binding Update (ETBU) Protocol for Mobile IPv6 (MIPv6) Networks

    Jung-Doo KOO  Dong-Chun LEE  

     
    PAPER

      Vol:
    E90-B No:4
      Page(s):
    777-787

    Currently, Mobile IPv6 (MIPv6) working group of Internet Engineering Task Force (IETF) recommends to execute the Binding Update (BU) using Return Routability (RR) procedure. However, the RR procedure doesn't entirely satisfy the security requirements of MIPv6. The previous BU protocols are also likely to reduce the efficiency since they iterate entirely BU protocol courses in Pico/Micro cellular environment in which it occurs frequently handoff or handover and some protocols don't consider that the Correspondent Node (CN) is movable node and has the limited resources. In this paper we propose the ETBU protocol, which is based on Cryptographically Generated Address (CGA) to provide mutual authentication between nodes; it considers that the CN is a movable node. This protocol doesn't require a Mobile Node (MN) to create a signature each time it obtains a new Care-of Address (CoA) unlike the previous CGA-based BU protocol. An MN and its CN issue the ticket to minimize the computing costs that need to calculate CGA. Also, the ETBU protocol minimizes the loss of traffic using smooth handoff or handover. A performance analysis shows that the scheme provides the security as much as the previous BU protocols and more efficiency than them in case that each node obtains the ticket. Therefore, the proposed ETBU protocol can be applied easily to the mobile network environments.

  • Boosted Voltage Scheme with Active Body-Biasing Control on PD-SOI for Ultra Low Voltage Operation

    Masaaki IIJIMA  Masayuki KITAMURA  Masahiro NUMA  Akira TADA  Takashi IPPOSHI  Shigeto MAEGAWA  

     
    PAPER-Digital

      Vol:
    E90-C No:4
      Page(s):
    666-674

    In this paper, we propose an Active Body-biasing Controlled (ABC)-Bootstrap PTL (Pass-Transistor Logic) on PD-SOI for ultra low power design. Although simply lowering the supply voltage (VDD) causes a lack of driving power, our boosted voltage scheme employing a strong capacitive coupling with ABC-SOI improves a driving power and allows lower voltage operation. We also present an SOI-SRAM design boosting the word line (WL) voltage higher than VDD in short transition time without dual power supply rails. Simulation results have shown improvement in both the delay time and power consumption.

  • UTC-PD-Based Optoelectronic Components for High-Frequency and High-Speed Applications

    Satoshi KODAMA  Hiroshi ITO  

     
    INVITED PAPER

      Vol:
    E90-C No:2
      Page(s):
    429-435

    The uni-traveling-carrier photodiode (UTC-PD) is an innovative PD that has a unique operation mode in which only electrons act as the active carriers, resulting in ultrafast response and high electrical output power at the same time. This paper describes the features of the UTC-PD and its excellent performance. In addition, UTC-PD-based optoelectronic devices integrated with various elements, such as passive and active devices, are presented. These devices are promising for various applications, such as millimeter- and submillimeter-wave generation up to the terahertz range and ultrafast optical signal processing at data rates of up to 320 Gbit/s.

  • Characteristics of 60 GHz Analog RF-Optic Transceiver Module

    Jeha KIM  Yong-Duck CHUNG  Kwang-Seong CHOI  Young-Shik KANG  Kyoung-Ik CHO  

     
    INVITED PAPER

      Vol:
    E90-C No:2
      Page(s):
    359-364

    Using an electro-absorption duplexer (EAD) we presented a transceiver (TRx) module for dual function of both electrical-to-optical (E/O) and optical-to-electrical (E/O) conversion at 60 GHz band. The EAD chip was fabricated by monolithically integrating both a waveguide photodiode (PD) and an electro-absorption modulator (EAM) in association with traveling wave electrodes. We also investigated the issues of RF packaging in which the optoelectronic and electronic amplifier devices were co-packaged in a single housing. The RF impedance matching was accomplished in assistance with a microstrip bandpass filter.

  • Low-Power Partial Distortion Sorting Fast Motion Estimation Algorithms and VLSI Implementations

    Yang SONG  Zhenyu LIU  Takeshi IKENAGA  Satoshi GOTO  

     
    PAPER

      Vol:
    E90-D No:1
      Page(s):
    108-117

    This paper presents two hardware-friendly low-power oriented fast motion estimation (ME) algorithms and their VLSI implementations. The basic idea of the proposed partial distortion sorting (PDS) algorithm is to disable the search points which have larger partial distortions during the ME process, and only keep those search points with smaller ones. To further reduce the computation overhead, a simplified local PDS (LPDS) algorithm is also presented. Experiments show that the PDS and LPDS algorithms can provide almost the same image quality as full search only with 36.7% computation complexity. The proposed two algorithms can be integrated into different FSBMA architectures to save power consumption. In this paper, the 1-D inter ME architecture [12] is used as an detailed example. Under the worst working conditions (1.62 V, 125) and 166 MHz clock frequency, the PDS algorithm can reduce 33.3% power consumption with 4.05 K gates extra hardware cost, and the LPDS can reduce 37.8% power consumption with 1.73 K gates overhead.

  • Binary Self-Organizing Map with Modified Updating Rule and Its Application to Reproduction of Genetic Algorithm

    Ryosuke KUBOTA  Keiichi HORIO  Takeshi YAMAKAWA  

     
    LETTER-Biocybernetics, Neurocomputing

      Vol:
    E90-D No:1
      Page(s):
    382-383

    In this paper, we propose a modified reproduction strategy of a Genetic Algorithm (GA) utilizing a Self-Organizing Map (SOM) with a novel updating rule of binary weight vectors based on a significance of elements of inputs. In this rule, an updating order of elements is decided by considering fitness values of individuals in a population. The SOM with the proposed updating rule can realize an effective reproduction.

  • 3D Error Diffusion Method Based on Edge Detection for Flat Panel Display

    Zujun LIU  Chunliang LIU  Shengli WU  

     
    LETTER-Electronic Displays

      Vol:
    E89-C No:10
      Page(s):
    1485-1486

    A 3 dimensional (3D) error diffusion method based on edge detection for flat panel display (FPD) is presented. The new method diffuses errors to the neighbor pixels in current frame and the neighbor pixel in the next frame. And the weights of error filters are dynamically adjusted based on the results of edge detection in each pixel's processing, which makes the weights coincide with the local edge feathers of input image. The proposed method can reduce worm artifacts and improve reproduction precision of image details.

  • An Efficient User Selection Algorithm for Zero-Forcing Beamforming in Downlink Multiuser MIMO Systems

    Haibo ZHENG  Xiang CHEN  Shidong ZHOU  Jing WANG  Yongxing ZHOU  James Sungjin KIM  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E89-B No:9
      Page(s):
    2641-2645

    In this letter, we propose an efficient user selection algorithm aiming to select users with less spatially correlation and meet the user number limit of zero-forcing beamforming in downlink multiuser MIMO systems. This algorithm yields a considerable complexity reduction with only a small loss in performance and it only needs partial users' CSI feedback. Coupled with the algorithm, a null space updating method in O(K2) time and a modified proportional fair scheduling algorithm are also proposed.

  • Fast and Accurate Power Bus Designer for Multi-Layers High-Speed Digital Boards

    Yong-Ju KIM  Won-Young JUNG  Jae-Kyung WEE  

     
    PAPER-Integrated Electronics

      Vol:
    E89-C No:7
      Page(s):
    1097-1105

    Fast and accurate power bus designer (FAPUD) for multi-layers high-speed digital boards is the power supply network design tool for accurate and precise high speed board. FAPUD is constructed based on two main algorithms of the PBEC (Path Based Equivalent Circuit) model and the network synthesis method. The PBEC model exploits simple arithmetic expressions of the lumped 1-D circuit model from the electrical parameters of a 2-D power distribution network. The circuit level design based on PBEC is carried with the proposed regional approach. The circuit level design directly calculates and determines the size of on-chip decoupling capacitors, the size and the location of off-chip decoupling capacitors, and the effective inductances of the package power bus. As a design output, a lumped circuit model and a pre-layout of the power bus including a whole decoupling capacitors are obtained after processing FAPUD. In the tuning procedure, the board re-optimization considering simultaneous switching noise (SSN) added by I/O switching in can be carried out because the I/O switching effect on a power supply noise can estimate for the operation frequency range with the lumped circuit model. Furthermore, if a design changes or needs to be tuned, FAPUD can modify design by replacing decoupling capacitors without consuming other design resources. Finally, FAPUD is accurate compared with conventional PEEC-based design tools, and its design time is 10 times faster than that of conventional PEEC-based design tools.

  • Approximations for Detection Probability and Measurement Accuracy Taking into Account Antenna Beam-Pointing Losses

    Sun-Mog HONG  Young K. KWAG  

     
    LETTER-Sensing

      Vol:
    E89-B No:7
      Page(s):
    2106-2110

    Expressions are presented for the probability of target detection and the measurement accuracy of the detection, taking into account the effects of antenna beam-pointing error. Evaluation of these expressions requires numerical integration, which is computationally expensive. Approximate but analytic and efficient expressions are also presented. Numerical examples are given to present the relative accuracy of our analytic approximations.

  • Mobility-Awareness: An Efficient Approach to Improve Energy Efficiency in Location-Aware Computing

    MoonBae SONG  KwangJin PARK  Ki-Sik KONG  

     
    PAPER

      Vol:
    E89-D No:5
      Page(s):
    1662-1671

    There are two principal aspects of "mobility" in location-aware computing: (1) how to support mobility and (2) how to exploit it. This paper considers the latter, while many existing works only concentrate on the former. This work is trying to prove that the performance of location-aware systems will be greatly improved by understanding the user's movement. In this paper, we propose a novel location update protocol called state-based location update protocol (SLUP), which significantly minimizes the energy consumption of mobile client by exploiting a syntactic information of a user's movement. This concept is called mobility-awareness which is a kind of context-awareness. Moreover, there are three variations of the proposed protocol in terms of how to choose the optimal state: SLUP/BS, SLUP/UITR, and SLUP/IUT. Experimental results show that the proposed protocol outperforms the well-known existing protocols such as dead-reckoning and distance-based protocol, and that the SLUP/IUT approach can achieve different performance tradeoffs between energy efficiency and location accuracy by fine-tuning its algorithmic parameter Tiut.

  • Progressive Transform-Based Phase Unwrapping Utilizing a Recursive Structure

    Andriyan Bayu SUKSMONO  Akira HIROSE  

     
    PAPER-Sensing

      Vol:
    E89-B No:3
      Page(s):
    929-936

    We propose a progressive transform-based phase unwrapping (PU) technique that employs a recursive structure. Each stage, which is identical with others in the construction, performs PU by FFT method that yields a solution and a residual phase error as well. The residual phase error is then reprocessed by the following stages. This scheme effectively improves the gradient estimate of the noisy wrapped phase image, which is unrecoverable by conventional global PU methods. Additionally, by incorporating computational strength of the transform PU method in a recursive system, we can realize a progressive PU system for prospective near real-time topographic-mapping radar and near real-time medical imaging system (such as MRI thermometry and MRI flow imager). PU performance of the proposed system and the conventional PU methods are evaluated by comparing their residual error quantitatively with a fringe-density-related error metric called FZX (fringe's zero-crossing) number. Experimental results for simulated and real InSAR phase images show significant, progressive improvement over conventional ones of a single-stage system, which demonstrates the high applicability of the proposed method.

  • Distributing Requests by (around k)-Bounded Load-Balancing in Web Server Cluster with High Scalability

    MinHwan OK  Myong-soon PARK  

     
    PAPER-Parallel/Distributed Algorithms

      Vol:
    E89-D No:2
      Page(s):
    663-672

    Popular Web sites form their Web servers into Web server clusters. The Web server cluster operates with a load-balancing algorithm to distribute Web requests evenly among Web servers. The load-balancing algorithms founded on conventional periodic load-information update mechanism are not scalable due to the synchronized update of load-information. We propose a load-balancing algorithm that the load-information update is not synchronized by exploiting variant execution times of executing scripts in dynamic Web pages. The load-information of each server is updated 'individually' by a new load-information update mechanism, and the proposed algorithm supports high scalability based on this individual update. Simulation results have proven the improvement in system performance through another aspect of high scalability. Furthermore, the proposed algorithm guarantees some level of QoS for Web clients by fairly distributing requests. A fundamental merit of the proposed algorithm is its simplicity, which supports higher throughput of the Web switch.

  • A Cooperative Algorithm for Autonomous Distributed Vehicle Systems with Finite Buffer Capacity

    Toshiyuki MIYAMOTO  Norihiro TSUJIMOTO  Sadatoshi KUMAGAI  

     
    PAPER

      Vol:
    E88-A No:11
      Page(s):
    3036-3044

    Recently, there are so many researches on Autonomous Distributed Manufacturing Systems (ADMSs), where cooperation among agents is used to solve problems, such as the scheduling problem and the vehicle routing problem. We target ADMSs where an ADMS consists of two sub-systems: a Production System (PS) and an Autonomous Transportation System (ATS). This paper discusses an on-line Tasks Assignment and Routing Problem (TARP) for ATSs under conditions of given production schedule and finite buffer capacity. The TARP results in a constrained version of the Pickup and Delivery Problem with Time Windows (PDPTW), and this paper gives a mathematical formulation of the problem. This paper, also, proposes a cooperative algorithm to obtain suboptimal solutions in which no deadlocks and buffer overflows occur. By computational experiments, we will examine the effectiveness of the proposed algorithm. Computational experiments show that the proposed algorithm is able to obtain efficient and deadlock-free routes even though the buffer capacity is less.

  • Material and Manufacturing Process Technologies of Discharge Deactivation Film for Stripe Rib PDPs

    Shinichiro NAGANO  Shigeki HARADA  Keisuke JO  Ko SANO  

     
    PAPER

      Vol:
    E88-C No:11
      Page(s):
    2070-2077

    We developed material and process technologies concerned to DDF, which is formed on MgO surface around the inter-pixel gap to prevent vertical crosstalk discharge in stripe rib structure. First we tried with thin film deposition and lift-off patterning to find Al2O3 and TiO2 are both available for DDF material. Next we tried with thick film printing in favor of mass productivity for large size PDPs. In case DDF included PbO glass, we met serious hardship in generating discharge. The problem was perfectly solved by having thick film DDF composed of 100 nm sized Al2O3 grains without glass component. Its γi was about 1/5 that of MgO, suggesting that the thick film DDF is almost compatible with thin film Al2O3 in electron emission characteristics. Such very small grain size contributes to DDF transparency, which is excellently high. In addition to it, such DDF is equipped with cushioning effect to prevent dot defects caused by rib breakage. Furthermore the DDF functions as getter during panel exhaustion to bring deep blue color by promoting deoxidization of blue phosphor provided that its volume is small enough. Transparent DDF may be rather better than black one with respect to bright room contrast ratio, not to mention to avoiding terrible sparking discharge. Thus material and process technologies for DDF have been almost fixed in success.

  • Correlation between Contact Resistance Characteristics and Scanning Tunneling Microscopy Images for Ag-Pd Alloy with Some Example Additives

    Terutaka TAMAI  

     
    PAPER-Contact Phenomena

      Vol:
    E88-C No:8
      Page(s):
    1559-1565

    Scanning tunneling microscopy (STM) images indicate a change in tunnel current. The tunnel current strongly depends on the applied voltage between the specimen surface and a probe tip, and also on the work function of the specimen surface. Therefore, STM images are different from optical images. Under a certain applied voltage, the distribution of the work function on the surface is directly related to the image. In the present study, in order to understand the STM images obtained from the contact surface, example surfaces of Ag-Pd alloys with Mg and Cr additives were investigated by STM. The additives are easily oxidized, and their oxides distribute over the surface. Therefore, the effect of the additives on the STM images could be observed. For Ag-Pd-Cr, in the case of both clean and oxidized surfaces, the Cr oxides CrO and Cr2O3 formed on the surface are typical insulators, and sharp projections, such as needles, can be seen in the images which are very different from optical microscopy image. In addition, a high contact resistance was measured. On the other hand, for Ag-Pd-Mg, MgO formed on the surface was conductive, and a smooth surface was obtained, as evidenced by the STM image. Contact resistance was very low. Even if the oxides grew under heating, the same tendencies were observed. The conductivity of oxides on the surface had a great effect on the images obtained. A correlation between the contact resistance and the STM images was found.

  • An Experimental Study on Re-interpretation of Minimum Arc Current of Electrical Contact Materials

    Makoto HASEGAWA  Yusuke KAMADA  

     
    LETTER-Arc Discharge & Related Phenomena

      Vol:
    E88-C No:8
      Page(s):
    1616-1619

    Arc occurrence rates are measured for Ag and Pd contacts operated in a DC resistive load circuit. Based on the obtained results, it is confirmed that arc certainly occurs at current levels lower than the conventional minimum arc current value for each of the tested contact materials. Arc occurrence rate in general comes close to 100% at the conventional minimum arc current level. Accordingly, careful attention should be paid to use of the term "minimum arc current" in order to avoid misinterpretation thereof.

  • APD Measurement for Evaluating Disturbances Related to the Performance of Digital Communication Systems

    Kaoru GOTOH  Yasushi MATSUMOTO  Yukio YAMANAKA  Takashi SHINOZUKA  

     
    PAPER-Communications

      Vol:
    E88-B No:8
      Page(s):
    3235-3241

    The measured values of electromagnetic disturbances should strongly correlate with degradation in the communication quality of digital wireless communication systems. The Amplitude Probability Distribution (APD) of a disturbance represents statistical information as applicable measurement readings that meet the above requirement. In this paper, correlations between APD measurements of disturbances and the bit error rate (BER) as a quality degradation index for victim systems are quantitatively investigated. Disturbance regulation by APD measurements is discussed from the viewpoint of protecting systems from disturbances. This investigation specifically considers the situation in which a repetition pulse disturbance impacts PHS and W-CDMA systems assumed as victims. The results confirm high correlations between the APD and BER not only experimentally but also theoretically under some conditions. A disturbance regulation criterion based on APD measurements is thus proposed for compliance testing of electronic appliances with the potential to act as disturbance noise sources.

141-160hit(276hit)