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  • The Future of EMC Technology

    Shuichi NITTA  

     
    INVITED PAPER

      Vol:
    E83-B No:3
      Page(s):
    435-443

    This paper reviews the present EMC technology level, introduces the problems to be investigated in the near future from the viewpoint of design technology, test and measurement and systems safety, and proposes what is a goal of technology level of EMC to be established for circuits, equipments and systems.

  • Two-Processor Scheduling of General Acyclic SWITCH-less Program Nets via Hybrid Priority Lists

    Qi-Wei GE  

     
    PAPER

      Vol:
    E83-A No:3
      Page(s):
    471-479

    This paper deals with two-processor scheduling for general acyclic SWITCH-less program nets with random node firing times. First, we introduce a hybrid priority list L* that has been shown to generate optimal schedules for the acyclic SWITCH-less program nets with unity node firing times, of which AND-nodes possess at most single input edge. Then considering the factors of existence of the AND-nodes with two input edges as well as random node firing times, we extend L* to design a new dynamic priority list Ld and four static priority lists {Lsii=1,2,3,4}; and then combining Ld and Lsi (i=1,2,3,4) we propose four hybrid priority lists {L*ii=1,2,3,4}. Finally, we apply genetic algorithm to evaluate the schedules generated by the four lists through simulations on 400 program nets. Our simulation results show two of the four lists can generate reasonably good schedules.

  • Design of Integer Wavelet Filters for Image Compression

    Hitoshi KIYA  Hiroyuki KOBAYASHI  Osamu WATANABE  

     
    LETTER

      Vol:
    E83-A No:3
      Page(s):
    487-491

    This paper discusses a method of designing linear phase two-channel filter banks for integer wavelet transform. We show that the designed filter banks are easily structed as the lifting form by leading relationship between designed filters and lifting structure. The designed integer wavelets are applied to image compression to verify the efficiency of our method.

  • Approximation Algorithms for Multiprocessor Scheduling Problem

    Satoshi FUJITA  Masafumi YAMASHITA  

     
    INVITED SURVEY PAPER-Approximate Algorithms for Combinatorial Problems

      Vol:
    E83-D No:3
      Page(s):
    503-509

    In this paper, we consider the static multiprocessor scheduling problem for a class of multiprocessor systems consisting of m ( 1) identical processors connected by a complete network. The objective of this survey is to give a panoramic view of theoretical and/or practical approaches for solving the problem, that have been extensively conducted during the past three decades.

  • Fiber-Optic Low Coherence Velocimetry by Detecting Interference Fluctuations

    Yoh IMAI  Kazuhiro TANAKA  

     
    PAPER-Distributed Sensing

      Vol:
    E83-C No:3
      Page(s):
    423-427

    A new sensing method for measuring directly flow velocity by using low coherence interference techniques is proposed and demonstrated. In this method, a temporally fluctuating signal, not the Doppler frequency shift, is detected. Theoretical analysis shows that a spectrum of light backscattered from a particle takes a Gaussian form whose width is simply proportional to the flow velocity. The measured velocity is in good agreement with the actual flow velocity derived from the flow rate. The dynamic range of this sensing method is governed by the frequency range of the FFT processor used and is estimated to be 1.4 10-4 14 m/s. The depth position can be adjusted with an accuracy of approximately 30 µm which is determined by the coherence length of the light source. The velocity distribution along the depth is easily measured by changing mechanically the length of the reference arm in the low coherence interferometer.

  • A New Efficient Server-Aided RSA Secret Computation Protocol against Active Attacks

    Shin-Jia HWANG  Chin-Chen CHANG  

     
    LETTER-Information Security

      Vol:
    E83-A No:3
      Page(s):
    567-570

    In this paper, we propose a new secure server-aided RSA secret computation protocol which guards against not only the attacks in [1],[2],[15],[18] but also the new powerful active attacks in [3],[4]. The new protocol is also efficient to support high security level.

  • NP-Hardness of Rotation Type Cell-Mazes

    Shiro AOKI  Hiro ITO  Hideyuki UEHARA  Mitsuo YOKOYAMA  Tsuyoshi HORINOUCHI  

     
    LETTER

      Vol:
    E83-A No:3
      Page(s):
    492-496

    In this paper, a puzzle called Cell-Maze is analyzed. In this puzzle, cells are arranged in checker board squares. Each cell is rotated when a player arrives at the cell. Cell-Maze asks whether or not a player started from a start cell can reach a goal cell. The reachability problem for ordinary graphs can be easily solved in linear time, however a reachability problem for the network such as Cell-Maze may be extremely difficult. In this paper, NP-hardness of this puzzle is proved. It is proved by reducing Hamiltonian Circuit Problem of directed planar graph G such that each vertex involved in just three arcs. Furthermore, we consider subproblems, which can be solved in polynomial time.

  • Designing High-Quality Approximation Algorithms for Combinatorial Optimization Problems

    Takao ASANO  Kenichiro IWAMA  Hideyuki TAKADA  Yoshiko YAMASHITA  

     
    INVITED SURVEY PAPER-Approximate Algorithms for Combinatorial Problems

      Vol:
    E83-D No:3
      Page(s):
    462-479

    For NP-hard combinatorial optimization problems, approximation algorithms with high performances have been proposed. In many of these algorithms, mathematical programming techniques have been used and proved to be very useful. In this survey, we present recent mathematical programming techniques as well as classic fundamental techniques, by showing how these techniques are used in designing high-quality approximation algorithms for NP-hard combinatorial optimization problems.

  • How to Make Geometric Algorithms Robust

    Kokichi SUGIHARA  

     
    INVITED SURVEY PAPER-Algorithms for Geometric Problems

      Vol:
    E83-D No:3
      Page(s):
    447-454

    This paper surveys two methods for designing numerically robust geometric algorithms. The first method is the exact-arithmetic method, in which numerical computations are done in sufficiently high precision so that all the topological judgements can be done correctly. This method is usually accompanied with lazy evaluation and symbolic perturbation in order to reduce the computational cost and the implementation cost. The second method is the topology-oriented method, in which the consistency of the topological structure is considered as higher-priority information than numerical computation, and thus inconsistency is avoided. Both of the methods are described with the implementation examples.

  • Recent Developments in Mesh Routing Algorithms

    Kazuo IWAMA  Eiji MIYANO  

     
    INVITED SURVEY PAPER-Parallel and Distributed Algorithms

      Vol:
    E83-D No:3
      Page(s):
    530-540

    The two dimensional mesh is widely considered to be a promising parallel architecture in its scalability. In this architecture, processors are naturally placed at intersections of horizontal and vertical grids, while there can be three different types of communication links: (i) The first type is the most popular model, called a mesh-connected computer: Each processor is connected to its four neighbours by local connections. (ii) Each processor of the second type is connected to a couple of (row and column) buses. The system is then called a mesh of buses. (iii) The third model is equipped with both buses and local connections, which is called a mesh-connected computer with buses. Mesh routing has received considerable attention for the last two decades, and a variety of algorithms have been proposed. This paper provides an overview of lower and upper bounds for algorithms, with pointers to the literature, and suggests further research directions for mesh routing.

  • The Development of Software Components for Solving the Vehicle Routing and Facility Location Problems

    Masahiko SHIMOMURA  Mikio KUDO  Hiroaki MOHRI  

     
    INVITED SURVEY PAPER-Approximate Algorithms for Combinatorial Problems

      Vol:
    E83-D No:3
      Page(s):
    510-518

    The vehicle routing and facility location fields are well-developed areas in management science and operations research application. There is an increasing recognition that effective decision-making in these fields requires the adoption of optimization software that can be embedded into a decision support system. In this paper, we describe the implementation details of our software components for solving the vehicle routing and facility location problems.

  • Parallel Algorithms for Convex Hull Problems and Their Paradigm

    Wei CHEN  Koji NAKANO  Koichi WADA  

     
    INVITED SURVEY PAPER-Parallel and Distributed Algorithms

      Vol:
    E83-D No:3
      Page(s):
    519-529

    A convex hull is one of the most fundamental and interesting geometric constructs in computational geometry. Considerable research effort has focused on developing algorithms, both in serial and in parallel, for computing convex hulls. In particular, there are few problems whose parallel algorithms are so thoroughly studied as convex hull problems. In this paper, we review the convex hull parallel algorithms and their paradigm. We provide a summary of results and introduce several interesting topics including typical techniques, output-size sensitive methods, randomized approaches, and robust algorithms for convex hull problems, with which we may see the highlights of the whole research for parallel algorithms. Most of our discussion uses the PRAM (Parallel Random Access Machine) computational model, but still we give a glance at the results of the other parallel computational models such as mesh, mesh-of-trees, hypercube, recofigurable array, and models of coarse grained multicomputers like BSP and LogP.

  • Approximation Algorithms for Geometric Optimization Problems

    Hisao TAMAKI  

     
    INVITED SURVEY PAPER-Algorithms for Geometric Problems

      Vol:
    E83-D No:3
      Page(s):
    455-461

    We survey recent developments in the study of approximation algorithms for NP-hard geometric optimization problems. We focus on those problems which, given a set of points, ask for a graph of a specified type on those points with the minimum total edge length, such as the traveling salesman problem, the Steiner minimum tree problem, and the k-minimum spanning tree problem. In a recent few years, several polynomial time approximation schemes are discovered for these problems. All of them are dynamic programming algorithms based on some geometric theorems that assert the existence of a good approximate solution with a simple recursive decomposition structure. Our emphasis is on these geometric theorems, which have potential uses in the design and analysis of heuristic algorithms.

  • Combinatorics on Arrangements and Parametric Matroids: A Bridge between Computational Geometry and Combinatorial Optimization

    Takeshi TOKUYAMA  

     
    INVITED SURVEY PAPER-Algorithms for Matroids and Related Discrete Systems

      Vol:
    E83-D No:3
      Page(s):
    362-371

    Given a combinatorial problem on a set of weighted elements, if we change the weight using a parameter, we obtain a parametric version of the problem, which is often used as a tool for solving mathematical programming problems. One interesting question is how to describe and analyze the trajectory of the solution. If we consider the trajectory of each weight function as a curve in a plane, we have a set of curves from the problem instance. The curves induces a cell complex called an arrangement, which is a popular research target in computational geometry. Especially, for the parametric version of the problem of computing the minimum weight base of a matroid or polymatroid, the trajectory of the solution becomes a subcomplex in an arrangement. We introduce the interaction between the two research areas, combinatorial optimization and computational geometry, through this bridge.

  • On the Legal Firing Sequence Problem of Petri Nets with Cactus Structure

    Toshihiro FUJITO  Satoshi TAOKA  Toshimasa WATANABE  

     
    PAPER

      Vol:
    E83-A No:3
      Page(s):
    480-486

    The legal firing sequence problem (LFS) asks if it is possible to fire each transition some prescribed number of times in a given Petri net. It is a fundamental problem in Petri net theory as it appears as a subproblem, or as a simplified version of marking reachability, minimum initial resource allocation, liveness, and some scheduling problems. It is also known to be NP-hard, however, even under various restrictions on nets (and on firing counts), and no efficient algorithm has been previously reported for any class of nets having general edge weights. We show in this paper that LFS can be solved in polynomial time (in O(n log n) time) for a subclass of state machines, called cacti, with arbitrary edge weights allowed (if each transition is asked to be fired exactly once).

  • Approximation Algorithms for Submodular Set Cover with Applications

    Toshihiro FUJITO  

     
    INVITED SURVEY PAPER-Approximate Algorithms for Combinatorial Problems

      Vol:
    E83-D No:3
      Page(s):
    480-487

    The main problem considered is submodular set cover, the problem of minimizing a linear function under a nondecreasing submodular constraint, which generalizes both well-known set cover and minimum matroid base problems. The problem is NP-hard, and two natural greedy heuristics are introduced along with analysis of their performance. As applications of these heuristics we consider various special cases of submodular set cover, including partial cover variants of set cover and vertex cover, and node-deletion problems for hereditary and matroidal properties. An approximation bound derived for each of them is either matching or generalizing the best existing bounds.

  • LAPAREX-An Automatic Parameter Extraction Program for Gain- and Index-Coupled Distributed Feedback Semiconductor Lasers, and Its Application to Observation of Changing Coupling Coefficients with Currents

    Toru NAKURA  Yoshiaki NAKANO  

     
    PAPER-Lasers, Quantum Electronics

      Vol:
    E83-C No:3
      Page(s):
    488-495

    A reliable and automatic parameter extraction technique for DFB lasers is developed. The parameter extraction program which is named "LAPAREX" is able to determine many device parameters from a measured sub-threshold spectrum only, including gain- and index-coupling coefficients, and spatial phases of the grating at front and rear facets. Injection current dependence of coupling coefficients in a gain-coupled DFBlaser is observed, for the first time, by making use of it.

  • Approximation Algorithms for MAX SAT

    Tomio HIRATA  Takao ONO  

     
    INVITED SURVEY PAPER-Approximate Algorithms for Combinatorial Problems

      Vol:
    E83-D No:3
      Page(s):
    488-495

    Maximum Satisfiability Problem (MAX SAT) is one of the most natural optimization problems. Since it is known to be NP-hard, approximation algorithms have been considered. The aim of this survey is to show recent developments of approximation algorithms for MAX SAT.

  • Distributed and Multiplexed Fibre Grating Sensors, Including Discussion of Problem Areas

    John P. DAKIN  Mark VOLANTHEN  

     
    INVITED PAPER-Multiplexing and Sensor Networking

      Vol:
    E83-C No:3
      Page(s):
    391-399

    A short review of distributed and multiplexed sensor technology, based on fibre gratings, is given. This is followed by details of more specific work in this area at the University of Southampton, particularly grating fabrication, distributed and multiplexed addressing and important practical aspects such as temperature and strain discrimination. The paper concludes with a short discussion of the problems that must be avoided in order to construct viable systems for engineering requirements.

  • Approximation Algorithms for Scheduling Problems

    Hiroaki ISHII  Minoru TADA  

     
    INVITED SURVEY PAPER-Approximate Algorithms for Combinatorial Problems

      Vol:
    E83-D No:3
      Page(s):
    496-502

    There are no efficient algorithms for almost of all scheduling problems, especially when practical scheduling models are considered. Further there may be none for multi-objective scheduling problems. So we should take efforts to develope efficient approximate algorithms for multi-objective scheduling problems. The main purpose of this paper is to survey approaches to some scheduling problems from the algorithmic view points till now and investigate some hopeful approximate approaches to multiobjective scheduling problems.

24661-24680hit(30728hit)