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[Keyword] system(3183hit)

1081-1100hit(3183hit)

  • Organizational Knowledge Transfer Using Ontologies and a Rule-Based System

    Masao OKABE  Akiko YOSHIOKA  Keido KOBAYASHI  Takahira YAMAGUCHI  

     
    PAPER-Management Techniques

      Vol:
    E93-D No:4
      Page(s):
    763-773

    In recent automated and integrated manufacturing, so-called intelligence skill is becoming more and more important and its efficient transfer to next-generation engineers is one of the urgent issues. In this paper, we propose a new approach without costly OJT (on-the-job training), that is, combinational usage of a domain ontology, a rule ontology and a rule-based system. Intelligence skill can be decomposed into pieces of simple engineering rules. A rule ontology consists of these engineering rules as primitives and the semantic relations among them. A domain ontology consists of technical terms in the engineering rules and the semantic relations among them. A rule ontology helps novices get the total picture of the intelligence skill and a domain ontology helps them understand the exact meanings of the engineering rules. A rule-based system helps domain experts externalize their tacit intelligence skill to ontologies and also helps novices internalize them. As a case study, we applied our proposal to some actual job at a remote control and maintenance office of hydroelectric power stations in Tokyo Electric Power Co., Inc. We also did an evaluation experiment for this case study and the result supports our proposal.

  • Learning Multiple Band-Pass Filters for Sleep Stage Estimation: Towards Care Support for Aged Persons

    Keiki TAKADAMA  Kazuyuki HIROSE  Hiroyasu MATSUSHIMA  Kiyohiko HATTORI  Nobuo NAKAJIMA  

     
    PAPER

      Vol:
    E93-B No:4
      Page(s):
    811-818

    This paper proposes the sleep stage estimation method that can provide an accurate estimation for each person without connecting any devices to human's body. In particular, our method learns the appropriate multiple band-pass filters to extract the specific wave pattern of heartbeat, which is required to estimate the sleep stage. For an accurate estimation, this paper employs Learning Classifier System (LCS) as the data-mining techniques and extends it to estimate the sleep stage. Extensive experiments on five subjects in mixed health confirm the following implications: (1) the proposed method can provide more accurate sleep stage estimation than the conventional method, and (2) the sleep stage estimation calculated by the proposed method is robust regardless of the physical condition of the subject.

  • A Knowledge-Based Strategy for the Automated Support to Network Management Tasks

    Sameera ABAR  Tetsuo KINOSHITA  

     
    PAPER-Management Techniques

      Vol:
    E93-D No:4
      Page(s):
    774-788

    This paper presents a domain-ontology driven multi-agent based scheme for representing the knowledge of the communication network management system. In the proposed knowledge-intensive framework, the static domain-related concepts are articulated as the domain knowledge ontology. The experiential knowledge for managing the network is represented as the fault-case reasoning models, and it is explicitly encoded as the core knowledge of multi-agent middleware layer as heuristic production-type rules. These task-oriented management expertise manipulates the domain content and structure during the diagnostic sessions. The agents' rules along with the embedded generic java-based problem-solving algorithms and run-time log information, perform the automated management tasks. For the proof of concept, an experimental network system has been implemented in our laboratory, and the deployment of some test-bed scenarios is performed. Experimental results confirm a marked reduction in the management-overhead of the network administrator, as compared to the manual network management techniques, in terms of the time-taken and effort-done during a particular fault-diagnosis session. Validation of the reusability/modifiability aspects of our system, illustrates the flexible manipulation of the knowledge fragments within diverse application contexts. The proposed approach can be regarded as one of the pioneered steps towards representing the network knowledge via reusable domain ontology and intelligent agents for the automated network management support systems.

  • Agent Based Fault Tolerance for the Mobile Environment

    Taesoon PARK  

     
    LETTER-Reliability, Maintainability and Safety Analysis

      Vol:
    E93-A No:4
      Page(s):
    846-849

    This paper presents a fault-tolerance scheme based on mobile agents for the reliable mobile computing systems. Mobility of the agent is suitable to trace the mobile hosts and the intelligence of the agent makes it efficient to support the fault tolerance services. This paper presents two approaches to implement the mobile agent based fault tolerant service and their performances are evaluated and compared with other fault-tolerant schemes.

  • Telemetry and Telestimulation via Implanted Devices Necessary in Long-Term Experiments Using Conscious Untethered Animals for the Development of New Medical Treatments Open Access

    Masaru SUGIMACHI  Toru KAWADA  Kazunori UEMURA  

     
    INVITED PAPER

      Vol:
    E93-B No:4
      Page(s):
    796-801

    Effective countermeasures against explosive increase in healthcare expenditures are urgently needed. A paradigm shift in healthcare is called for, and academics and governments worldwide are working hard on the application of information and communication technologies (ICT) as a feasible and effective measure for reducing medical cost. The more prevalent the disease and the easier disease outcome can be improved, the more efficient is medical ICT in reducing healthcare cost. Hypertension and diabetes mellitus are such examples. Chronic heart failure is another disease in which patients may benefit from ICT-based medical practice. It is conceivable that daily monitoring of hemodynamics together with appropriate treatments may obviate the expensive hospitalization. ICT potentially permit continuous monitoring with wearable or implantable medical devices. ICT may also help accelerate the development of new therapeutic devices. Traditionally effectiveness of treatments is sequentially examined by sacrificing a number of animals at a given time point. These inefficient and inaccurate methods can be replaced by applying ICT to the devices used in chronic animal experiments. These devices allow researchers to obtain biosignals and images from live animals without killing them. They include implantable telemetric devices, implantable telestimulation devices, and imaging devices. Implanted rather than wired monitoring and stimulation devices permit experiments to be conducted under even more physiological conditions, i.e., untethered, free-moving states. Wireless communication and ICT are indispensible technologies for the development of such telemetric and telestimulation devices.

  • Deriving Framework Usages Based on Behavioral Models

    Teruyoshi ZENMYO  Takashi KOBAYASHI  Motoshi SAEKI  

     
    PAPER-Software Development Techniques

      Vol:
    E93-D No:4
      Page(s):
    733-744

    One of the critical issue in framework-based software development is a huge introduction cost caused by technical gap between developers and users of frameworks. This paper proposes a technique for deriving framework usages to implement a given requirements specification. By using the derived usages, the users can use the frameworks without understanding the framework in detail. Requirements specifications which describe definite behavioral requirements cannot be related to frameworks in as-is since the frameworks do not have definite control structure so that the users can customize them to suit given requirements specifications. To cope with this issue, a new technique based on satisfiability problems (SAT) is employed to derive the control structures of the framework model. In the proposed technique, requirements specifications and frameworks are modeled based on Labeled Transition Systems (LTSs) with branch conditions represented by predicates. Truth assignments of the branch conditions in the framework models are not given initially for representing the customizable control structure. The derivation of truth assignments of the branch conditions is regarded as the SAT by assuming relations between termination states of the requirements specification model and ones of the framework model. This derivation technique is incorporated into a technique we have proposed previously for relating actions of requirements specifications to ones of frameworks. Furthermore, this paper discuss a case study of typical use cases in e-commerce systems.

  • An Anycast-Based Emergency Service for Healthcare Wireless Sensor Networks

    Shyr-Kuen CHEN  Pi-Chung WANG  

     
    LETTER

      Vol:
    E93-B No:4
      Page(s):
    858-861

    In this letter, we develop an anycast-based emergency service for healthcare wireless sensor networks. The new service could operate with sensors to detect and activate an alarm system based on predefined conditions that are specific to the patient and the disease. The new service is implemented on 802.15.4 ZigBee which usually has large control overhead and long transmission times. To improve the service performance, our service identifies the closest emergency service provider to alleviate the control overhead and achieve immediate assistance when a patient requests for an emergency service. We also increase the reliability of packet transmission by using a Recovery Point scheme. Our simulations and experiment demonstrate that our scheme is efficient and feasible for healthcare wireless sensor networks.

  • An Autonomic Connection Scheme for High Service Availability

    Daekeun MOON  Jinho PARK  Hagbae KIM  

     
    LETTER-Dependable Computing

      Vol:
    E93-D No:3
      Page(s):
    639-642

    In large-scale industrial plants, the process control system has multiple system servers to provide seamless services to plant operators irrespective of any system server's failure. In this paper, we present an autonomic connection scheme between the system server and the Human-Machine Interface application (HMI) without additional configuration. The proposed scheme is based on the concept of autonomic computing, supporting the fault-tolerant and/or load-balancing features. Finally, the mathematical analysis shows that the proposed scheme can provide high availability of services to users.

  • An Ultrasonic and Air Pressure Sensing System for Detection of Behavior before Getting out of Bed Aided by Fuzzy Theory

    Hayato YAMAGUCHI  Hiroshi NAKAJIMA  Kazuhiko TANIGUCHI  Syoji KOBASHI  Yutaka HATA  

     
    PAPER-Computation and Computational Models

      Vol:
    E93-D No:3
      Page(s):
    542-549

    This paper proposes a sensing system for a behavior detection system using an ultrasonic oscillosensor and an air pressure sensor. The ultrasonic oscillosensor sensor has a cylindrical tank filled with water. It detects the vibration of the target object from the signal reflected from the water surface. This sensor can detect a biological vibration by setting to the bottom bed frame. The air pressure sensor consists of a polypropylene sheet and an air pressure sensor, and detects the pressure information by setting under the bed's mattress. An increase (decrease) in the load placed on the bed is detected by the increase (decrease) in the pressure of the air held in the tube attached to the sheet. We propose a behavior detection system using both sensors, complementally. The system recognizes three states (nobody in bed, keeping quiet in bed, moving in bed) using both sensors, and we detect the behavior before getting out of bed by recognized these states. Fuzzy logic plays a primary role in the system. As the fundamental experiment, we applied the system to five healthy volunteers, the system successfully recognized three states, and detected the behavior before getting out of bed. As the clinical experiment, we applied the system to four elderly patients with dementia, the system exactly detected the behavior before getting out of the bed with enough time for medical care support.

  • Performance Evaluation of Peer-to-Peer Progressive Download in Broadband Access Networks

    Megumi SHIBUYA  Tomohiko OGISHI  Shu YAMAMOTO  

     
    PAPER-Network

      Vol:
    E93-B No:3
      Page(s):
    600-608

    P2P (Peer-to-Peer) file sharing architectures have scalable and cost-effective features. Hence, the application of P2P architectures to media streaming is attractive and expected to be an alternative to the current video streaming using IP multicast or content delivery systems because the current systems require expensive network infrastructures and large scale centralized cache storage systems. In this paper, we investigate the P2P progressive download enabling Internet video streaming services. We demonstrated the capability of the P2P progressive download in both laboratory test network as well as in the Internet. Through the experiments, we clarified the contribution of the FTTH links to the P2P progressive download in the heterogeneous access networks consisting of FTTH and ADSL links. We analyzed the cause of some download performance degradation occurred in the experiment and discussed about the effective methods to provide the video streaming service using P2P progressive download in the current heterogeneous networks.

  • A Directional Route Discovery Protocol in Ad Hoc Multi-Hop Cellular Networks

    Yongsuk PARK  Taejoon PARK  

     
    LETTER-Network

      Vol:
    E93-B No:3
      Page(s):
    725-728

    In this letter, we present a route discovery protocol for ad hoc multi-hop cellular networks which uses directional information towards the base station. The proposed protocol, based on the reactive approach, reduces flooding as much as possible. To quantify this, we analyze its performance in terms of how much progress it makes per hop and how much reduction in routing packet number it achieves per route discovery. The analytical, as well as simulation, results demonstrate that the proposed protocol significantly reduces flooding overheads and finds a route to the base station in a robust manner.

  • Methods for Avoiding the Checkerboard Distortion Caused by Finite Word Length Error in Multirate System

    Hiroaki IWAI  Masahiro IWAHASHI  Hitoshi KIYA  

     
    LETTER-Digital Signal Processing

      Vol:
    E93-A No:3
      Page(s):
    631-635

    We propose two methods for avoiding the checkerboard distortion which is caused by finite word length error. The first method derives the bit length of filter coefficients required for avoiding the checkerboard distortion under a certain word length. In the second method, the checkerboard distortion can be avoided by using the cascade structure which consists of zero-hold kernel and a time-invariant filter factorized from a filter with structure for avoiding the checkerboard distortion under linear systems. It is demonstrated by simulations that we can avoid the checkerboard distortion by using these proposed methods.

  • Design and Evaluation of 10 Gbps Optical Access System Using Optical Switches

    Koji WAKAYAMA  Michitaka OKUNO  Jun SUGAWA  Daisuke MASHIMO  Hiroki IKEDA  Kenichi SAKAMOTO  

     
    PAPER

      Vol:
    E93-B No:2
      Page(s):
    272-279

    We propose an optical switch control procedure for the Active Optical Access System (AOAS). Optical switches are used in AOAS instead of optical splitters in PON. In the proposed procedure, an OLT determines the switching schedules of optical switches on OSW (Optical Switching Unit) which is installed between OLT and ONU, and informs the OSW of them with a switch control frame preceding of data frame transmission. Then the switch controller on OSW controls the optical switches based on the switching schedules. We developed the prototype systems of OSW, OLT, and ONU. We implemented the optical switch control function with logic circuits on the prototype systems. We demonstrate the proposed procedure works effectively with logic circuits. We also evaluate the 10 Gps optical signal transmission between OLT and ONU. We demonstrate the receiver sensibility on OLT and ONU achieves the distance of 40 km for optical signals transmission with FEC (Forward Error Correction). These receivers are applicable for both AOAS and 10G-EPON.

  • A Direct Conversion Receiver Adopting Balanced Three-Phase Analog System

    Takafumi YAMAJI  Takeshi UENO  Tetsuro ITAKURA  

     
    PAPER

      Vol:
    E93-A No:2
      Page(s):
    367-374

    Recent advanced technology makes digital circuits small and the number of digital functional blocks that can be integrated on a single chip is increasing rapidly. On the other hand, reduction in the size of analog circuits has been insufficient. This means that the analog circuit area is relatively large, and reducing analog circuit area can be effective to make a low cost radio receiver. In this paper, a new wireless receiver architecture that occupies small analog area is proposed, and measured results of the core analog blocks are described. To reduce the analog area, a balanced 3-phase analog system is adopted and the functions of analog baseband filters and VGAs are moved to the digital domain. The test chip consists of a 3-phase downconverter and a 3-phase ADC. There is no analog baseband filter on the chip and the analog filter is assumed to be replaced with a digital filter. The downconverter and ADC occupy 0.28 mm2. The measured results show the possibility that the requirements for IMT-2000 are fulfilled even with a small chip area.

  • An Artificial Immune System with Feedback Mechanisms for Effective Handling of Population Size

    Shangce GAO  Rong-Long WANG  Masahiro ISHII  Zheng TANG  

     
    PAPER-Neural Networks and Bioengineering

      Vol:
    E93-A No:2
      Page(s):
    532-541

    This paper represents a feedback artificial immune system (FAIS). Inspired by the feedback mechanisms in the biological immune system, the proposed algorithm effectively manipulates the population size by increasing and decreasing B cells according to the diversity of the current population. Two kinds of assessments are used to evaluate the diversity aiming to capture the characteristics of the problem on hand. Furthermore, the processing of adding and declining the number of population is designed. The validity of the proposed algorithm is tested for several traveling salesman benchmark problems. Simulation results demonstrate the efficiency of the proposed algorithm when compared with the traditional genetic algorithm and an improved clonal selection algorithm.

  • Propagation of Light in a Disordered Waveguide System: Average Amplitude

    Akira KOMIYAMA  

     
    PAPER

      Vol:
    E93-C No:1
      Page(s):
    46-51

    The coupled mode equation describing the propagation of light in a disordered waveguide system composed of randomly different cores in size is analytically solved by the perturbation method and the average amplitude of light is derived. In the summation of a perturbation series only successive scatterings from different cores are taken into account. The result obtained shows that the average amplitude behaves as if in an ordered waveguide system composed of identical cores at short distance and decreases exponentially with increasing distance at large distance. The result is compared with the result obtained by the coherent potential approximation and the both results are in good agreement with each other. The results are also compared with the results obtained by numerically solving the coupled mode equation.

  • On Patarin's Attack against the IC Scheme

    Naoki OGURA  Shigenori UCHIYAMA  

     
    PAPER-Public Key Cryptography

      Vol:
    E93-A No:1
      Page(s):
    34-41

    In 2007, Ding et al. proposed an attractive scheme, which is called the -Invertible Cycles (IC) scheme. IC is one of the most efficient multivariate public-key cryptosystems (MPKC); these schemes would be suitable for using under limited computational resources. In 2008, an efficient attack against IC using Grobner basis algorithms was proposed by Fouque et al. However, they only estimated the complexity of their attack based on their experimental results. On the other hand, Patarin had proposed an efficient attack against some multivariate public-key cryptosystems. We call this attack Patarin's attack. The complexity of Patarin's attack can be estimated by finding relations corresponding to each scheme. In this paper, we propose an another practical attack against the IC encryption/signature scheme. We estimate the complexity of our attack (not experimentally) by adapting Patarin's attack. The attack can be also applied to the IC- scheme. Moreover, we show some experimental results of a practical attack against the IC/IC- schemes. This is the first implementation of both our proposed attack and an attack based on Grobner basis algorithm for the even case, that is, a parameter is even.

  • Reliability Analysis and Modeling of ZigBee Networks

    Cheng-Min LIN  

     
    PAPER-Dependable Computing

      Vol:
    E93-D No:1
      Page(s):
    68-78

    The architecture of ZigBee networks focuses on developing low-cost, low-speed ubiquitous communication between devices. The ZigBee technique is based on IEEE 802.15.4, which specifies the physical layer and medium access control (MAC) for a low rate wireless personal area network (LR-WPAN). Currently, numerous wireless sensor networks have adapted the ZigBee open standard to develop various services to promote improved communication quality in our daily lives. The problem of system and network reliability in providing stable services has become more important because these services will be stopped if the system and network reliability is unstable. The ZigBee standard has three kinds of networks; star, tree and mesh. The paper models the ZigBee protocol stack from the physical layer to the application layer and analyzes these layer reliability and mean time to failure (MTTF). Channel resource usage, device role, network topology and application objects are used to evaluate reliability in the physical, medium access control, network, and application layers, respectively. In the star or tree networks, a series system and the reliability block diagram (RBD) technique can be used to solve their reliability problem. However, a division technology is applied here to overcome the problem because the network complexity is higher than that of the others. A mesh network using division technology is classified into several non-reducible series systems and edge parallel systems. Hence, the reliability of mesh networks is easily solved using series-parallel systems through our proposed scheme. The numerical results demonstrate that the reliability will increase for mesh networks when the number of edges in parallel systems increases while the reliability quickly drops when the number of edges and the number of nodes increase for all three networks. More use of resources is another factor impact on reliability decreasing. However, lower network reliability will occur due to network complexity, more resource usage and complex object relationship.

  • The Influence of a Low-Level Color or Figure Adaptation on a High-Level Face Perception

    Miao SONG  Keizo SHINOMORI  Shiyong ZHANG  

     
    PAPER-Biocybernetics, Neurocomputing

      Vol:
    E93-D No:1
      Page(s):
    176-184

    Visual adaptation is a universal phenomenon associated with human visual system. This adaptation affects not only the perception of low-level visual systems processing color, motion, and orientation, but also the perception of high-level visual systems processing complex visual patterns, such as facial identity and expression. Although it remains unclear for the mutual interaction mechanism between systems at different levels, this issue is the key to understand the hierarchical neural coding and computation mechanism. Thus, we examined whether the low-level adaptation influences on the high-level aftereffect by means of cross-level adaptation paradigm (i.e. color, figure adaptation versus facial identity adaptation). We measured the identity aftereffects within the real face test images on real face, color chip and figure adapting conditions. The cross-level mutual influence was evaluated by the aftereffect size among different adapting conditions. The results suggest that the adaptation to color and figure contributes to the high-level facial identity aftereffect. Besides, the real face adaptation obtained the significantly stronger aftereffect than the color chip or the figure adaptation. Our results reveal the possibility of cross-level adaptation propagation and implicitly indicate a high-level holistic facial neural representation. Based on these results, we discussed the theoretical implication of cross-level adaptation propagation for understanding the hierarchical sensory neural systems.

  • Coherent Optical Wireless Link Employing Phase Estimation with Multiple-Beam, Multiple-Aperture, for Increased Tolerance to Turbulence

    Arturo Arvizu MONDRAGON  Juan-de-Dios Sachez LOPEZ  Francisco-Javier Mendieta JIMENEZ  

     
    LETTER-Optical Wireless Communications

      Vol:
    E93-B No:1
      Page(s):
    226-229

    We present a BPSK coherent optical wireless link in a multiple-beam, multiple-aperture configuration. The data are recovered using the signal obtained by the coherent addition of a set of maximum likelihood optical phase estimates and a select-largest stage. The proposal offers higher performance than the combining methods commonly used in optical wireless systems with diversity transmission and coherent detection.

1081-1100hit(3183hit)