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[Keyword] OMP(3945hit)

2941-2960hit(3945hit)

  • A New Transformed Input-Domain ANFIS for Highly Nonlinear System Modeling and Prediction

    Elsaid Mohamed ABDELRAHIM  Takashi YAHAGI  

     
    LETTER-Nonlinear Signal Processing

      Vol:
    E84-A No:8
      Page(s):
    1981-1985

    In two- or more-dimensional systems where the components of the sample data are strongly correlated, it is not proper to divide the input space into several subspaces without considering the correlation. In this paper, we propose the usage of the method of principal component in order to uncorrelate and remove any redundancy from the input space of the adaptive neuro-fuzzy inference system (ANFIS). This leads to an effective partition of the input space to the fuzzy model and significantly reduces the modeling error. A computer simulation for two frequently used benchmark problems shows that ANFIS with the uncorrelation process performs better than the original ANFIS under the same conditions.

  • Recovering the 3D B-Spline Control Points of the Free Curves for Shape Reforming

    Myint Myint SEIN  Hiromitsu HAMA  

     
    PAPER

      Vol:
    E84-D No:8
      Page(s):
    983-989

    This paper presents an accurate method for finding the 3D control points of the B-Spline curves. This method can automatically fit a set of data points with piecewise geometrically continuous cubic B-Spline curves. Iterating algorithm has been used for finding the 2D control points. And a new approach for shape reconstruction based on the control points of the curves on the object's surface is proposed. B-Spline patch, the extension of the B-Spline curves to surface, provides recovering the shape of the object in 2D approach. The 3D control points of the cubic B-Spline curves are computed from the factor decomposition of the measurement matrix of 2D control points. The multiple object approach is also proposed to reconstruct the 3D shape of each curves of an object. Some experiments are demonstrated to confirm the effectiveness of our proposed method.

  • Embedded Lossless Wavelet-Based Image Coder Based on Successive Partition and Hybrid Bit Scanning

    Sheung-Yeung WANG  Lai-Man PO  

     
    PAPER-Image/Visual Signal Processing

      Vol:
    E84-A No:8
      Page(s):
    1863-1868

    A simple embedded lossless wavelet-based image coding algorithm called Successive Partition Zero Coder (SPZC), which uses hybrid bit scanning and non-causal adaptive context modelling, is proposed. By successive partition the wavelet coefficients in the spatial-frequency domain, the coefficients are ordered based on their absolute range. The prioritized coefficients are quantized in a successive approximation manner to generate a binary sequence, which is divided into subsources and encoded by arithmetic coder with non-causal adaptive context modelling. This method is suited for progressive image transmission (PIT). Experimental results show that SPZC outperforms other state-of-the-art coders such as SPIHT, CREW and LJPEG, but slightly inferior to ECECOW and CALIC in lossless mode. SPZC is simple in both context modelling and implementation.

  • Code Optimization Technique for Indirect Addressing DSPs with Consideration in Local Computational Order and Memory Allocation

    Nobuhiko SUGINO  Akinori NISHIHARA  

     
    PAPER-Implementations of Signal Processing Systems

      Vol:
    E84-A No:8
      Page(s):
    1960-1968

    Digital signal processors (DSPs) usually employ indirect addressing using address registers (ARs) to indicate their memory addresses, which often introduces overhead codes in AR updates for next memory accesses. Reduction of such overhead code is one of the important issues in automatic generation of highly-efficient DSP codes. In this paper, a new automatic address allocation method incorpolated with computational order rearrangement at local commutative parts is proposed. The method formulates a given memory access sequence by a graph representation, where several strategies to handle freedom in memory access orders at the computational commutative parts are introduced and examined. A compiler scheme is also extended such that computational order at the commutative parts is rearranged according to the derived memory allocation. The proposed methods are applied to an existing DSP compiler for µPD77230(NEC), and codes generated for several examples are compared with memory allocations by the conventional methods.

  • Simultaneous Halftone Image Generation with Improved Multiobjective Genetic Algorithm

    Hernan AGUIRRE  Kiyoshi TANAKA  Tatsuo SUGIMURA  Shinjiro OSHITA  

     
    PAPER-Image/Visual Signal Processing

      Vol:
    E84-A No:8
      Page(s):
    1869-1882

    A halftoning technique that uses a simple GA has proven to be very effective to generate high quality halftone images. Recently, the two major drawbacks of this conventional halftoning technique with GAs, i.e. it uses a substantial amount of computer memory and processing time, have been overcome by using an improved GA (GA-SRM) that applies genetic operators in parallel putting them in a cooperative-competitive stand with each other. The halftoning problem is a true multiobjective optimization problem. However, so far, the GA based halftoning techniques have treated the problem as a single objective optimization problem. In this work, the improved GA-SRM is extended to a multiobjective optimization GA to simultaneously generate halftone images with various combinations of gray level precision and spatial resolution. Simulation results verify that the proposed scheme can effectively generate several high quality images simultaneously in a single run reducing even further the overall processing time.

  • LINA: A New Approach to Mobility Support in Wide Area Networks

    Masahiro ISHIYAMA  Mitsunobu KUNISHI  Keisuke UEHARA  Hiroshi ESAKI  Fumio TERAOKA  

     
    PAPER-Mobile Internet

      Vol:
    E84-B No:8
      Page(s):
    2076-2086

    This paper presents a new network architecture called LINA that provides node mobility. The basic concept of LINA is separation of the node identifier and the interface locator. Although there are several protocols based on such a concept, they do not address issues that arise when dealing with an entire network architecture. LINA is a holistic architecture covering the network layer to the application layer in order to support node mobility. Overhead incurred by separation of the node identifier and the interface locator is minimized in LINA by introducing the embedded addressing model. This paper also presents a new protocol called LIN6 that supports IPv6 mobility. LIN6 is an application of LINA to IPv6 and is fully compatible with IPv6. It has several advantages in comparison to Mobile IPv6, e.g. less protocol overhead. Our prototype implementation of LIN6 shows minimal overhead compared to a conventional IPv6 implementation.

  • Validation of Rain/No-Rain Discrimination in the Standard TRMM Data Products 1B21 and 1C21

    Yuji OHSAKI  

     
    LETTER-Sensing

      Vol:
    E84-B No:8
      Page(s):
    2321-2325

    The Tropical Rainfall Measuring Mission (TRMM) is a United States-Japan joint project to measure rainfall from space. The first spaceborne rain radar is aboard the TRMM satellite. Rain/no-rain discrimination for the TRMM provides useful information for on-line data processing, storage, and post-processing analysis. In this paper, rain/no-rain discrimination for the TRMM has been validated through simulation and theory for the no-rain condition and by comparison with the ground-based radar data for rain conditions.

  • An Efficient Algorithm for Decomposition and Reconstruction of Images by Box Splines

    Takeshi ASAHI  Koichi ICHIGE  Rokuya ISHII  

     
    PAPER-Image/Visual Signal Processing

      Vol:
    E84-A No:8
      Page(s):
    1883-1891

    This paper proposes a novel fast algorithm for the decomposition and reconstruction of two-dimensional (2-D) signals by box splines. The authors have already proposed an algorithm to calculate the discrete box splines which enables the fast reconstruction of 2-D signals (images) from box spline coefficients. The problem still remains in the decomposition process to derive the box spline coefficients from an input image. This paper first investigates the decomposition algorithm which consists of the truncated geometric series of the inverse filter and the steepest descent method with momentum (SDM). The reconstruction process is also developed to correspond to the enlargement of images. The proposed algorithm is tested for the expansion of several natural images. As a result, the peak signal-to-noise ratio (PSNR) of the reconstructed images became more than 50 dB, which can be considered as enough high level. Moreover, the property of box splines are discussed in comparison with 2-D (the tensor product of) B-splines.

  • Functional Decomposition with Application to LUT-Based FPGA Synthesis

    Jian QIAO  Kunihiro ASADA  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E84-A No:8
      Page(s):
    2004-2013

    In this paper, we deal with the problem of compatibility class encoding, and propose a novel algorithm for finding a good functional decomposition with application to LUT-based FPGA synthesis. Based on exploration of the design space, we concentrate on extracting a set of components, which can be merged into the minimum number of multiple-output CLBs or LUTs, such that the decomposition constructed from these components is also minimal. In particular, to explore more degrees of freedom, we introduce pliable encoding to take over the conventional rigid encoding when it fails to find a satisfactory decomposition by rigid encoding. Experimental results on a large set of MCNC91 logic synthesis benchmarks show that our method is quite promising.

  • Packet Discarding Scheme Considering Both Instantaneous and Historical Use of Network Resources

    Norio YAMAGAKI  Katsuya MINAMI  Hideki TODE  Koso MURAKAMI  

     
    PAPER-Flow and Congestion Control

      Vol:
    E84-B No:8
      Page(s):
    2115-2123

    In the future Internet, various kinds of services will rapidly increase its volume and require different qualities. Thus, it is main technical problem to guarantee various QoS to each connection. However, in the current IP networks where most applications use TCP as transport protocol, most typical packet discarding scheme, RED (Random Early Detection), causes unfairness such as the difference of bandwidth sharing among flows traversing the same router. To dissolve this problem, we consider that two viewpoints are important associated with flow-base fairness. One is instantaneous flow condition and the other is historical flow condition. In this paper, we propose the packet discarding scheme considering both instantaneous and historical use of network resources for the purpose of dissolving unfairness of each flow and improving the flow-base QoS. We call this proposal method "Random Early Drop with Dual-fairness metrics (DRED). " DRED can improve whole throughput and transfer completion time of information such as a file, etc.

  • Distributed Evolutionary Digital Filters for IIR Adaptive Digital Filters

    Masahide ABE  Masayuki KAWAMATA  

     
    PAPER-Adaptive Signal Processing

      Vol:
    E84-A No:8
      Page(s):
    1848-1855

    This paper proposes distributed evolutionary digital filters (EDFs) as an improved version of the original EDF. The EDF is an adaptive digital filter which is controlled by adaptive algorithm based on evolutionary computation. In the proposed method, a large population of the original EDF is divided into smaller subpopulations. Each sub-EDF has one subpopulation and executes the small-sized main loop of the original EDF. In addition, the distributed algorithm periodically selects promising individuals from each subpopulation. Then, they migrate to different subpopulations. Numerical examples show that the distributed EDF has a higher convergence rate and smaller steady-state value of the square error than the LMS adaptive digital filter, the adaptive digital filter based on the simple genetic algorithm and the original EDF.

  • Improving the Secure Electronic Transaction Protocol by Using Signcryption

    Goichiro HANAOKA  Yuliang ZHENG  Hideki IMAI  

     
    PAPER-Information Security

      Vol:
    E84-A No:8
      Page(s):
    2042-2051

    In the past few years, we have seen the emergence of a large number of proposals for electronic payments over open networks. Among these proposals is the Secure Electronic Transaction (SET) protocol promoted by MasterCard and VISA which is currently being deployed world-widely. While SET has a number of advantages over other proposals in terms of simplicity and openness, there seems to be a consensus regarding the relative inefficiency of the protocol. This paper proposes a light-weight version of the SET protocol, called "LITESET. " For the same level of security as recommended in the latest version of SET specifications, LITESET yields a 56.2/51.4% reduction in the computational time in message generation/verification and a 79.9% reduction in communication overhead. This has been achieved by the use of a new cryptographic primitive called signcryption. We hope that our proposal can contribute to the practical and engineering side of real-world electronic payments.

  • A Novel Method of Reducing the Decoding Complexity for High-Rate Turbo Codes

    Tadashi MINOWA  Hideki IMAI  

     
    PAPER-Fundamental Theories

      Vol:
    E84-B No:8
      Page(s):
    2151-2160

    This paper considers a high-rate turbo code which employs high-rate convolutional codes as component codes, and presents a novel method of reducing the decoding complexity of the codes. By eliminating some of branches that have the lowest reliabilities among all the branches entering each node, the proposed algorithm reduces the complexity in the process of the add-compare-select (ACS) between the consecutive stages of iterative decoding. That is, the complexity gradually decreases as the number of iterations increases. We compare the unpunctured high-rate turbo code with a classical punctured high-rate turbo code in terms of performance/complexity trade-off under the same code rate. Simulation results show that the proposed approach with a good trade-off provides an alternative coding scheme to the classical punctured high-rate turbo coding for the application to high-data-rate wireless communication systems.

  • MESH: Multi-Eye Spiral-Hopping Routing Protocol in a Wireless Ad Hoc Network

    Yuh-Shyan CHEN  Kuan-Chang LAI  

     
    PAPER-Network

      Vol:
    E84-B No:8
      Page(s):
    2237-2248

    A mobile ad hoc network (MANET) is a characterized by multi-hop wireless links, absence of any cellular infrastructure, and frequent host mobility. Existing MANET routing protocols are divided into location-aware and non-location-aware routing protocols. In a location-aware routing protocol, location information can be exploited to facilitate routing. Our protocol, namely multi-eye spiral-hopping (MESH) routing protocol, is a location-aware routing protocol. Most promising routing protocols are constructed by the route-discovery, route-reply, and route-maintenance phases. Our MESH protocol utilizes the location-information to confine the blind-flooding region in the route-discovery phase, minimize route-reply packets in the route-reply phase, and promote the routing robustness in the route-maintenance phase. Two major contributions of this paper are introduced: (1) a multi-eye scheme is presented to confine route-discovery region for reducing redundant packets, and (2) a special multi-path scheme, called as spiral-hopping scheme, is introduced to provide on-line route-recovery capability. Extensive simulations are conducted to evaluate the protocol.

  • MIBsocket: An Integrated Mechanism to Manipulate General Network Information in Mobile Communications

    Ryuji WAKIKAWA  Keisuke UEHARA  Fumio TERAOKA  Jun MURAI  

     
    PAPER-Internet Architecture

      Vol:
    E84-B No:8
      Page(s):
    2001-2010

    Layering architecture of the Internet Protocol provides independent processing for each layer by concealing state information from each layer. Application Program Interface (API) is based on the idea of layering model. However, the idea disturbs efficient processing of applications requiring adaptation to network environment, such as context-aware applications in mobile computing. To address this need, this paper proposes MIBsocket designed as an integrated control and management system for general network information. Any variable information related to network is shared between each applications and operating system. MIBsocket detects and informs changes in network resources to applications. MIBsocket functions such as Get, Set, and Trap used in the application adapts dynamically to any environments. MIBsocket provides portability and facility for applications: it only requires a few modification to the operating system and its API has the same programmable interfaces as usual API's. MIBsocket does not interfere the current layering architecture, but it achieves remarkable improvement on the current model. We have measured costs of MIBsocket, and applied MIBsocket to the application named interface switching system which enables a mobile host to connect to the Internet anytime by switching interface depending on network environment. As a result, the costs of MIBsocket was found acceptable. The application shows that MIBsocket is useful for movement detection and reconfiguration of network resources in the mobile computing.

  • A Unified View of Heterogeneous Agents' Interaction

    Hiroyuki ONJO  Behrouz H. FAR  

     
    PAPER

      Vol:
    E84-D No:8
      Page(s):
    945-956

    In this paper agents' interactions are defined in terms of cooperation, coordination and competition. As for cooperation and coordination problems, we focus on knowledge sharing of agents, define agencies as organizations of agents, propose a method to extract organizational knowledge for interacting agents. In case of competition, knowledge sharing is impossible. Therefore, modeling and formalization of strategic decision making and uncertainty management is required. We present an incomplete game theoretical based decision making method for competitive agents.

  • An Unwrapping of Signals in Transform Domain and Its Application in Signal Reconstruction

    Pavol ZAVARSKY  Nobuo FUJII  Noriyoshi KAMBAYASHI  Masahiro IWAHASHI  Somchart CHOKCHAITAM  

     
    PAPER-Image

      Vol:
    E84-A No:7
      Page(s):
    1765-1771

    An unwrapping of signal coefficients in transform domain is proposed for applications in which a lossy operation is performed on the coefficients between analysis and synthesis. It is shown that the unwrapping-based modification of signal-to-additive-signal ratio can employ the fact that an implementation of a biorthogonal decomposition is characterized by a mutually orthogonal eigenvectors. An example to illustrate the benefits of the presented approach in lossy image compression applications is shown.

  • On Dynamic Service Integration in VNA Architecture

    Jin NAKAZAWA  Yoshito TOBE  Hideyuki TOKUDA  

     
    PAPER

      Vol:
    E84-A No:7
      Page(s):
    1610-1623

    In forthcoming home network environment, computation capability will be embedded invisibly in home appliances, sensors, walls, ceilings, and floors. People will conduct various tasks using multiple devices simultaneously without consciousness of using computers. In this paper, first, we propose an application model named Virtual Network Appliance (VNA) model which simplify and expand device utilization. In the model, each device has VNA runtime system and function objects, called VNA components, running on it. A user task is defined in an application called VNA which is a logical appliance consisting of abstract function requirements and a message graph among them. Second, we propose Virtual Plug&Play mechanism which is a dynamic service integration mechanism in VNA model implementation. When a user conducts a task, he/she makes a VNA runtime system on a user-side terminal load a VNA definition appropriate for the task. Virtual Plug&Play dynamically discovers required VNA components and establishes the message graph as defined. Since XML documents are used to describe a VNA, users can share and customize it easily. We call the device integration done by Virtual Plug&Play top-down integration, which existing middleware do not aim at. Finally, we show that Virtual Plug&Play affords practical performance for top-down integration by performance evaluation.

  • Concept and Evaluation of a 2-D FDTD Formulation Based on Expanded Wave Equation Approach

    Koichi ICHIGE  Hiroyuki ARAI  

     
    PAPER-Electromagnetic Theory

      Vol:
    E84-C No:7
      Page(s):
    981-993

    This paper presents a novel concept of a Two-Dimensional (2-D) Finite-Difference Time-Domain (FDTD) formulation for the numerical analysis of electromagnetic fields. FDTD method proposed by Yee is widely used for such analysis, although it has an inherent problem that there exist half-cell-length and half-time-step distances between electric and magnetic field components. To dissolve such distances, we begin with the finite-difference approximation of the wave equation, not Maxwell's equations. Employing several approximation techniques, we develop a novel algorithm which can condense all field components to equidistant discrete nodes. The proposed algorithm is evaluated in comparison with several conventional algorithms by computer simulations.

  • Estimation of Complex Permittivity Using Rectangular Waveguide with Flange by FDTD Method

    Kouji SHIBATA  Osamu HASHIMOTO  Kouji WADA  

     
    LETTER

      Vol:
    E84-C No:7
      Page(s):
    977-980

    A method for estimating complex permittivity of a material using a rectangular waveguide with a flange is presented by the finite difference time domain (FDTD) method. An advantage of the present method is that it is not necessary to vary the material structure in order to insert it into the waveguide. Therefore estimation errors related to the dimensions of the material are almost negligible. In this case, fluoridated rubber is chosen as the low-loss material. The comparison of the complex permittivity of the material determined by the present method with FDTD and the conventional waveguide method at 10 GHz is performed. It was confirmed that the present method is effective for estimating the complex permittivity under the condition that the length of the flange is about 50 mm (1.7λ) square.

2941-2960hit(3945hit)