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1261-1280hit(1385hit)

  • A Telecommunications Management Integration Network

    Masahiko MATSUSHITA  Tetsuo OKAZAKI  Makoto YOSHIDA  

     
    PAPER

      Vol:
    E78-B No:1
      Page(s):
    17-23

    Telecommunications management activities have mostly been supported by operators; however, machines are gradually playing more important roles in the management arena by utilizing computing technology. Additionally, management systems can now be networked by using standard interface specifications. The study of human and machine integration is thus essential for achieving the sophisticated management objectives of telecommunications. This paper proposes the principles for a telecommunications management integration network (TMIN), which integrates human and machine management networks, and proposes a source text description method for transferring management communication knowledge from human to machine. First, reference models are proposed for the management process and management communication. These models cover network management activities of both humans and machines. Second, the contents of the source text are clarified. Source text presents human management knowledge in a form suitable for machine-machine communication. Third, an efficient source text description method is proposed that reduces redundancy and proliferation. Finally, a means of harmonizing management information definitions with TMIN is suggested to facilitate human-machine cooperation.

  • One-Way Functions over Finite Near-Rings

    Eikoh CHIDA  Hiroki SHIZUYA  Takao NISHIZEKI  

     
    PAPER

      Vol:
    E78-A No:1
      Page(s):
    4-10

    A near-ring is an extended notion of a usual ring. Therefore a ring is a near-ring, but the converse does not necessarily hold. We investigate in this paper one-way functions associated with finite near-rings, and show that if there exists a one-way group homomorphism, there exists a one-way non-ring near-ring homomorphism (Theorem 1); if there exists a one-way ring homomorphism (Theorem 2). Further, we introduce a discrete logarithm problem over a finite near-ring, and show that the integer factoring is probabilistic polynomial-time Turing equivalent to a modified version of this problem (Theorem 3). Theorem 1 implies that under some standard cryptographic assumption, there is an affirmative but trivial solution to the extended version of the open question: Is there an encryption function f such that both f(x+y) and f(xy) are efficiently computed from given f(x) and f(y) ?

  • Specification Description Supporting Method of Telecommunications Networks Management Using Information Model and Process Model

    Ryutaro MATSUMURA  Osamu MIYAGISHI  

     
    PAPER

      Vol:
    E78-B No:1
      Page(s):
    39-46

    Managed Objects (MOs) can be specified by the combination of a static information model and a dynamic process model. First, this paper presents a mapping of attributes from a process model diagram to an information model diagram. Then, it introduces a concept of topology into these two models and proposes a hypothesis about the relationship of topology in these two models. To explicitly explain the hypothesis, it can be stated that all attributes of incoming or outgoing data related to a process in a process model are mapped to an information model where these attributes are interconnected by an explicit relationship which corresponds to a specific meaning, such as physical containment or logical connection. From an intuitive perspective, it can be said that if two attributes have a close topological relationship in a process model, the mapped attributes also have a close topological relationship in an information model. This hypothesis provides clues for determining whether there is an error in an attribute either in the process model or in the information model. By examining the way attributes of incoming or outgoing data related to a process are mapped to an information model, we can detect whether there is an error with respect to the process. The error correction is performed with the assistance of probability analysis. The method of error detection and correction can be implemented in a computer aided tool. Then, error detection on the attribute level becomes automatic, and error correction on the attribute level becomes interactive through the computer aided tool. Finally, the validity of the hypothesis is confirmed by analyzing ITU-T Recommendation M.3100. The specification of the fabric object class defined in M.3 100 is transformed into these two models and the hypothesis is validated for the analysis of the mapping between these two models.

  • Analysis of Highly-Birefringent Fibers with a Hollow Layer Outside an Elliptical Core

    Zygmunt KRASISKI  Takashi HINATA  Shin-ichiro YAMASHITA  Adam MAJEWSKI  

     
    PAPER-Electromagnetic Theory

      Vol:
    E78-C No:1
      Page(s):
    111-116

    The improved point-matching method with Mathieu function expansion for the accurate analysis of the W-type elliptical fiber with layers of any ellipticity is proposed. Results of our method are reliable, because we expand the electromagnetic fields by a sum of the complete set of wave functions in each layer of the fiber. Numerical results are presented for the highly-birefringent fibers with a hollow layer outside an elliptical core. It is found that such fibers can realize the large value of the modal birefringence as well as they can be suitable for the single-mode and single-polarization transmission. From the convergence tests, it is confirmed that the relative error of the modal birefringence is less than 0.01%. The comparison of our results with those by previously reported method is presented. The proposed method can be extended for analysis of the elliptical-core fibers with hollow pits and electromagnetic scattering by targets of the complex elliptical geometry.

  • Unification-Failure Filter for Natural Language

    Alfredo M. MAEDA  Hideto TOMABECHI  Jun-ichi AOE  

     
    PAPER-Software Systems

      Vol:
    E78-D No:1
      Page(s):
    19-26

    Graph unification is doubtlessly the most expensive process in unification-based grammar parsing since it takes the vast majority of the total parsing time of natural language sentences. A parsing time overload in unification consists in that, in general, no less than 60% of the graph unifications performed actually fail. Thus one way to achieve unification time speed-up is focusing on an efficient, fast way to deal with such unification failures. In this paper, a process, prior to unification itself, capable of filtering or stopping a considerably high percentage of graphs that would fail unification is proposed. This unification-filtering process consists of comparison of signatures that correspond to each one of the graphs to be unified. Unification-filter (hereafter UF) is capable of stopping around 87% of the non-unifiable graphs before unification itself takes place. UF takes significantly less time to detect graphs that do not unify and discard them than it would take to unification to fail the attempt to unify the same graphs. As a result of using UF, unification is performed in an around 71% of the time for the fastest known unification algorithm.

  • Progress in Telecommunications Services and Management

    Masayoshi EJIRI  Makoto YOSHIDA  

     
    INVITED PAPER

      Vol:
    E78-B No:1
      Page(s):
    5-10

    Telecommunications management is essentially an aggregation of a wide range of activities, including operations and management (O & M) of telecommunications services and customers as well as the network and network elements. During the period of rapid growth in telecommunications, the highest priority was to meet increasing market demand and to construct a telecommunications network infrastructure. Therefore, research and development in telecommunications management were subordinated to the evolution of telecommunications services and systems. Recently, customers have been demanding higher quality services, as a variety of new, advanced services have been introduced. This has led to the need to integrate telecommunications services and O & M services. This paper first reviews the history of the development of telecommunications O & M in parallel with the progress of telecommunications in Japan and clarifies specific features in each step of this progress. This analysis identifies urgent problems and their solutions. The results suggests that telecommunications O & M and O & M services should be considered as a key to making future services possible and to the value of those services in a multi-media telecommunications services environment. Based on these studies, the future direction of O & M is then shown, focusing on cooperative O & M involving the customer in the multi-media, multidomain telecommunications environment.

  • A Two-Way Dual-View Teleteaching System Conveying Gestures and Chalkboard Contents

    Amane NAKAJIMA  Takashi SAKAIRI  Fumio ANDO  Masahide SHINOZAKI  

     
    PAPER

      Vol:
    E77-D No:12
      Page(s):
    1335-1343

    In current teleteaching systems, video conferencing systems have been used to transmit a motion video from a teacher's site. A video that captures a teacher or his or her chalkboard is transmitted to a remote site through a communication channel. Since the resolution of the video is not very high, a camera captures either a teacher or a chalkboard, but not both at the same time. Thus, remote students have difficulty in obtaining realistic sensation. Another approach to realizing teleteaching is to use a computer-based desktop conferencing system that supports a motion video and a computer-based shared chalkboard. In this approach, a teacher has to use a mouse or a handwriting tablet for input, and therefore cannot use a real chalkboard. Moreover, the teacher cannot use gestures to remote students. This paper presents a multimedia teleteaching system that integrates an electronic whiteboard with a multimedia desktop conferencing system for providing realistic sensation to remote students. The system provides two-way communication of a video and a computerized chalkboard. A teacher uses an electronic whiteboard as a real whiteboard using direct manipulation, and transmits his or her gestures to remote students by using video communication. The system provides dual views; one view is for teacher's gestures and the other is for chalkboard contents. By providing the dual views, the system can transmit teacher's gestures all the time. Since chalkboard contents are processed and displayed as computer data, students can see them clearly. With the computerized chalkboard, a teacher or a student can zoom contents, input data written on a paper using a scanner, or add annotation.

  • Evolution of Mixed-Signal Communications LSIs

    Masayuki ISHIKAWA  Tsuneo TSUKAHARA  Yukio AKAZAWA  

     
    INVITED PAPER-Analog LSIs

      Vol:
    E77-C No:12
      Page(s):
    1895-1902

    Mixed-signal LSIs promise to permit increased levels of integration, not only in voiceband but also in multi-GHz-band applications such as wireless communications and optical data links. This paper reviews the evolution of mixed-signal communications LSIs and discusses some of their design problems, including device noise and crosstalk noise. In the low-power and low-voltage designs emerging as new disciplines, the target supply voltage for voiceband LSIs is around 1 V, and even GHz-band circuits are approaching 2 V. MOS devices are expected to play an important role even in the frequency range over 100 MHz, in the area of wireless or optical communications circuits.

  • Power Law Slowdown of the Neural Learning

    Hideyuki CÂTEAU  Tatsuhiro NAKAJIMA  Hiroshi NUNOKAWA  Nobuko FUCHIKAMI  

     
    LETTER-Neural Networks

      Vol:
    E77-A No:12
      Page(s):
    2109-2111

    We numerically show that the learning time t of the back propagation model with the encoder topology obeys a power law described as t MD (D: constant, 1

  • Rearrangeability and Connectivity of Multistage Interconnection Networks with Nearest-Neighbour Interconnections

    Josef GIGLMAYR  

     
    PAPER-Switching and Communication Processing

      Vol:
    E77-B No:12
      Page(s):
    1546-1555

    Throughout the paper, the nearest-neighbour (NN) interconnection of switches within a multistage interconnection network (MIN) is analysed. Three main results are obtained: (1) The switch preserving transformation of a 2-D MIN into the 1-D MIN (and vice versa) (2) The rearrangeability of the MIN and (3) The number of stages (NS) for the rearrangeable nonblocking interconnection. The analysis is extended to any dimension of the interconnected data set. The topological equivalence between 1-D MINs with NN interconnections (NN-MINs) and 1-D cellular arrays is shown.

  • Phase/Frequency Modulation Combined with Multilevel Block Codes

    Woon Geun YANG  Choong Woong LEE  

     
    LETTER-Radio Communication

      Vol:
    E77-B No:12
      Page(s):
    1642-1646

    This paper proposes a new signaling technique which employs multilevel block codes in conjunction with phase/frequency modulation. The proposed scheme exhibits an increased minimum squared Euclidean distances (MSEDs) and outperforms other conventional schemes in terms of asymptotic coding gain and decoding complexity. The proposed scheme is also considered for non-constant amplitudes, which turned out to show even better performances at small modulation indices in some cases. Examples are given to demonstrate how to optimize the signal set for a given block code to maximize the coding gain.

  • A Communication Network Control Architecture to Integrate Service Control and Management

    Masaaki WAKAMOTO  Moo Wan KIM  Kenichi FUKUDA  Koso MURAKAMI  

     
    PAPER

      Vol:
    E77-B No:11
      Page(s):
    1342-1349

    Multimedia services based on broadband ISDN (B-ISDN) technology need a network architecture that satisfies the requirements of users, carriers, and vendors. This paper describes a new network architecture for B-ISDN service control and management based on INA. We list general requirements, and present implementation issues of INA. A network architecture and main components, which resolve implementation issues, is then proposed. We also describe a video-on-demand service based on our proposed architecture.

  • Quantitative Diagnosis on Magnetic Resonance Images of Chronic Liver Disease Using Neural Networks

    Shin'ya YOSHINO  Akira KOBAYASHI  Takashi YAHAGI  Hiroyuki FUKUDA  Masaaki EBARA  Masao OHTO  

     
    PAPER-Neural Network and Its Applications

      Vol:
    E77-A No:11
      Page(s):
    1846-1850

    We have classified parenchymal echo patterns of cirrhotic liver into 3 types, according to the size of hypoechoic nodular lesions. We have been studying an ultrasonic image diagnosis system using the three–layer back–propagation neural network. In this paper, we will describe the applications of the neural network techniques for recognizing and classifying chronic liver disease, which use the nodular lesions in the Proton density and T2–weighed magnetic resonance images on the gray level of the pixels in the region of interest.

  • Time–Frequency Domain Analysis of the Acoustic Bio–Signal--Successful Cases of Wigner Distribution Applied in Medical Diagnosis--

    Jun HASEGAWA  Kenji KOBAYASHI  

     
    LETTER

      Vol:
    E77-A No:11
      Page(s):
    1867-1869

    By applying Wigner distribution, which has high time resolution and high random noise reducing capability, to the acoustic bio–signals, the possibility of early diagnosis in both intracranial vascular deformation and prosthetic cardiac valve malfunction increased. Especially in latter case, 1st–order local moment of the distribution showed its effectiveness.

  • Towards Flexible Communications Management for Multimedia Multipoint Communications

    Yasuhiro KATSUBE  

     
    PAPER

      Vol:
    E77-B No:11
      Page(s):
    1363-1371

    Customers' requirements for telecommunications services have been changing from simple point-to-point and single-medium communications to multiple-point and multiple-media, as well as changes in bandwidth requirements. In addition, customers' end stations (ES) will not be homogeneous, from POTS-like terminal to sophisticated multimedia workstation that handles various kind of media. This paper discusses communications management architectures that provide multimedia multipoint communications in a heterogeneous ESs environment. It summarizes existing communications management architectures, and discusses advanced architectures that provide multimedia communications, multipoint communications and heterogeneity handling capabilities in a flexible and efficient manner. The objectives of this architecture are to integrate multimedia multipoint communications capabilities into the network, and provide customers with versatile communications service request interface which can handle from plain single-medium point-to-point communications to multimedia multipoint communications. This paper especially focuses on the management functionalities for multimedia multipoint service fabrics (MMSF) which may be owned by the network provider, the third-party service provider, or the customer. It discusses variations of MMSF management protocol implementations in the case that the MMSF is owned by either of the three. It also discusses implementation of customers' various operations requests to the MMSF in the communication phase.

  • A New Formulation of Absorbing Boundary Conditions for Finite-Difference Time-Domain Method

    Pei-Yuan WANG  Shogo KOZAKI  Makoto OHKI  Takashi YABE  

     
    PAPER

      Vol:
    E77-C No:11
      Page(s):
    1726-1730

    A new simple formulation of absorbing boundary conditions with higher order approximation is proposed for the solution of Maxwell's equations with the finite-difference time-domain (FD-TD) method. Although this higher order approximation is based on the third order approximation of the one-way wave equations, we have succeeded in reducing it to an equation in a form quite similar to the second order appoximation. Numerical tests exhibit smaller reflection errors than the prevalent second order approximation.

  • Stepwise Refinement of Communications Service Specifications for Conforming to a Functional Model

    Akira TAKURA  Tadashi OHTA  

     
    PAPER

      Vol:
    E77-B No:11
      Page(s):
    1322-1331

    A stepwise refinement method of communications service specifications is proposed to generate communications software that can conform to any network architecture. This method uses a two-layered language; one layer is a service specification description language (STR), and the other layer is a supplementary specification description language for implementing STR description on a communications system (STR/D). STR specifies terminal behaviors that can be recognized from a perspective outside of the communications systems. With STR, a communications service is defined by a set of rules that can be described without detailed knowledge of communications systems or communications network architectures. Each STR rule describes a global state transition of terminals. Supplementary specifications, such as terminal control and network control, are needed to implement communications services specified by STR rules. These supplementary specifications are described by STR/D rules. Communications services, such as UPT (Universal Personal Telecommunication), are standardized so that they can be provided on a given functional model consisting of functional entities. Specifications for each functional entity in a network are obtained from the two kinds of initially described specifications mentioned above. The obtained specifications are described by STR(L) and STR/D(L) rules, which specify local specifications of a functional entity. These specifications for functional entities are then transformed into software specifications, and finally communications software is generated from these software specifications. This stepwise refinement method makes it possible to generate communications software that can conform to any functional model from service specifications.

  • Distributed Communications System Technology

    Keiichi KOYANAGI  Hiroshi SUNAGA  Tetsuyasu YAMADA  Makoto TOMURA  Nobuaki KURIHARA  

     
    PAPER

      Vol:
    E77-B No:11
      Page(s):
    1350-1362

    This paper describes two main technologies for achieving reliable real-time distributed communications systems. One is the technology to prevent the influence of a fault in an autonomous distributed system from spreading to the whole system (called autonomous distributed system control). The other is a software structure based on distributed processing, the object-oriented approach, and layering for better maintainability and expandability (called OO software structure). For the autonomous distributed system control, several inter-subsystem communication methods are proposed and evaluated. From the standpoints of the fault processing and processing load, frames should be sent through a data link over ATM connection and when a fault occurs the link should be switched over without loss of data. A pilot system achieved good reliability without an excessive number of dynamic steps. This autonomous control method will lead to a highly reliable communications system with large capacity. For the OO software structure, this paper gives experimental results from the implementation of a prototype system. Its distributed environment should lead to high reliability by extending the CHILL run-time routine (RTR). This software structure promises to provide service quickly, to reduce costs, and to make the development of each layer's software independent. A real-time OS, e.g., CTRON kernel combined with RTR can give real-time performance, high reliability and high productivity over the distributed system. The use of RTR can reduce the time for the call recovery process.

  • A Petri Net Model for Nonmonotonic Reasoning Based on Annotated Logic Programs

    Chuang LIN  Tadao MURATA  

     
    INVITED PAPER

      Vol:
    E77-A No:10
      Page(s):
    1579-1587

    Nonmonotonic reasoning is a logical inference system which attempts to approximate human commonsense reasoning and is characterized as defeasible: having reasonably drawn a conclusion from some premises we may be forced to retract that conclusion upon learning new facts. This paper introduces a Petri net model for nonmonotonic reasoning with nonmonotonic rules generated by annotated logic programs and the unless operator. In the Petri net model, a fixpoint of a nonmonotonic theory can be represented as a maximal and consistent support of a firing sequence. We propose a structural method for finding extensions (coherent consequences) for a given set of nonmonotonic logic rules. It is based on the T-invariant technique for testing fireability of a goal transition in the Petri net model of Horn clause logic programs.

  • Shape and Reflectance of a Polyhedron from Interreflections by Two-Image Photometric Stereo

    Jun YANG  Noboru OHNISHI  Noboru SUGIE  

     
    LETTER

      Vol:
    E77-D No:9
      Page(s):
    1017-1021

    In this paper, we extend two-image photometric stereo method to treat a concave polyhedron, and present an iterative algorithm to remove the influence of interreflections. By the method we can obtain the shape and reflectance of a concave polyhedron with perfectly diffuse (Lambertian) and unknown constant reflectance. Both simulation and experiment show the feasibility and accuracy of the method.

1261-1280hit(1385hit)