• Title/Summary/Keyword: communication networks

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Newly proposed points of Teaching - learning methodology in the Historical Development of Science Education (교과교육 사조의 고찰에 따라 새로 권장되는 교수학습방법)

  • 남철우
    • Journal of Korean Elementary Science Education
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    • v.18 no.1
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    • pp.75-85
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    • 1999
  • This paper describes some major trends in primary and secondary education now. It is a selective views of significant topics with important implication for the future. These trends are summarized as follows, after examining historical development of Teaching-learning Methodology in primary and secondary education. 1. Education is seen as part of interdisciplinary world; emphasis is on relating education to the students' world, which is not compartmentalized. 2. Emphasizing students' individual growth with their own goal of lives. 3. Open-education with variable contents and purposes of education. 4. Education for all from that for some. 5. Consructivist based from behavior based. 6. Cooperative learning, peer tutoring, group projects. 7. Authentic assessment; assessment integrated with instruction. 8. The teacher is a facilitator of learning and a learner as well; students are learners and teachers in some situations; networks emerge instead of one-way forms or communication. 9. Spiral curriculum from single exposure.

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A study on themes and concepts of design for architectural composition of communal spaces in general hospitals (국내 종합병원의 공용공간 구성의 디자인 테마와 디자인 컨셉에 관한 연구)

  • Ko, Young Jong;Seo, Je Sung;Lee, Jung Man
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.7 no.1
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    • pp.15-22
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    • 2001
  • Architectural design of general hospitals is progressing in the aspects of themes and concepts of design. This study aims to develope an overview of communal space design in general hospitals by analysing design compositions and themes and concepts involved in them. Organizational prototypes for communal space networks in existing hospitals are summariged for the result of this analysis, and concentration/distribution of communal spaces and hospital communications within communal spaces are included in the analysis.

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Design of Lyapunov Theory based State Feedback Controller for Time-Delay Systems (시간지연 시스템을 위한 리아푸노브 이론 기반 상태 피드백 제어기 설계)

  • Cho, Hyun Cheol;Shin, Chan Bai
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.1
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    • pp.95-100
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    • 2013
  • This paper presents a new state feedback control approach for communication networks based control systems in which control input and output observation time-delay natures are generally occurred in practice. We first establish a generic state feedback control framework based on well-known linear system theory. A maximum time-delay value which allows critical stability of whole control system are defined to make a positive definite Lyapunov function which is mathematically composed of controlled system states. We analytically derive its control parameters by using a steepest descent optimization method in order to guarantee a stability condition through Lyapunov theory. Computer simulation is numerically carried out for demonstrating reliability of the proposed NCS algorithm and a comparative study is accomplished to prove its superiority for which the traditional control approach for NCS is made use of under same simulation scenarios.

A Development of Agent-Based IEDs for Integration Control of Building Microgrid in Smart Green Building (그린빌딩에서의 빌딩마이크로그리드 통합제어를 위한 에이전트용 IED 개발)

  • Hong, Won-Pyo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.10
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    • pp.35-43
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    • 2012
  • In this paper, a development of agent-based IEDs(Intelligent electronic devices) for integration control of building microgrid in smart green building are proposed. To manage and control this complex energy system of smart green buildings, multi-agent system based networks is needed. Thus, several IEDs for utilizing multi-agent system are developed and modified for the their verification of performance as agent modules functions in the integrated experimental equipment. The good performance of these IED agents are verified from experimental results obtained from seamless bi-directional communication by SOAP/XML protocol between PC agent and IED agent.

An Energy-efficient Clustering Algorithm using the Guaranteed Minimum Coverage for ClusterHeads in Wireless Sensor Networks (무선 센서 네트워크에서의 에너지 효율을 위한 클러스터 헤더 재배치 알고리즘)

  • Kim, Nam-Hun;Park, Tae-Rim;Kwon, Wook-Hyun;Kim, Jeong-Jun;Kim, Yong-Ho;Sin, Yeong-Hui
    • 한국정보통신설비학회:학술대회논문집
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    • 2005.08a
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    • pp.349-357
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    • 2005
  • In this paper, a new clustering algorithm using the Guaranteed Minimum Coverage (GMC) is proposed. In the new protocol, an appropriate distribution of clusterheads is accomplished by guaranteeing a stochastic coverage at each clusterhead(CH)s. Using this protocol, the communication cost from clusterheads to their member nodes and the load variance in each clusterheads are reduced. Therefore, the network lifetime can be extended and the fair energy consumption for all CHs can be achieved

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Energy-efficient Routing Protocol in Wireless Sensor Networks (센서 네트워크에서의 효율적 에너지 소비를 위한 라우팅 프로토콜)

  • Song, Yasong-A;Kim, Jeong-Genm;Lee, Jae-Hyun
    • 한국정보통신설비학회:학술대회논문집
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    • 2005.08a
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    • pp.358-363
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    • 2005
  • 본 논문에서는 전력 제어를 통해 에너지 소비를 최소화하여 네트워크 수명을 극대화 시킬 수 있는 효율적인 라우팅 방안을 제안하였다. 제안한 프로토콜에서 센서 노드들은 여러 개의 단위 전력을 가지고 있어 독립적인 라우팅 테이블을 형성하게 된다. 이를 토대로 가장 에너지 소비가 적은 경로를 설정하여 데이터를 전송하게 된다. 또한 특정 노드가 더 이상 기능을 하지 못하는 경우에도 적응적으로 경로를 재설정하여 데이터를 전송할 수 있도록 설계하였다. 이렇게 제안한 프로토콜과 기존의 방식과의 비교 실험을 통해 제안한 라우팅 방식의 성능을 효율적 에너지 소비 측면에서 분석하였다. 그 결과 논문에서 제안한 프로토콜의 성능이 기존의 방식과 비교하여 향상되었음을 확인하였다.

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A Framework of QoE Measurement and Management for Next Generation Wired/Wireless Communication Networks (차세대 유무선통신망의 QoE 측정 및 관리를 위한 프레임워크의 제안)

  • Zhang, Jie;Kim, Hwa-Jong
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.9 no.1
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    • pp.24-28
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    • 2010
  • The Quality of Experience (QoE) of next Generation wired/wireless network services based upon IP networking is becoming a popular issue in recent years. The user experience of Internet services such as IPTV, online game, web surfing and etc, are becoming the most desirable factors to service providers to improve service performance and customer's satisfaction. However, collecting user experience from customers and obtaining the QoE parameters from the Quality of Service (QoS) parameters such as bandwidth, delay, jitter or admission control algorithm, are difficult subjects because of the various service types and user characteristics. In this paper, we propose a framework which contains service classification, QoE analysis and service enhancement steps for a suitable QoE measurement and management protocol. We define the user satisfaction indicators of the Internet services, classify the categories of each type of services, and analyse the Key Performance Indicator (KPI) in each type of services to perform the QoS parameters and improving the service qualities.

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Modulation Schemes for Wireless Infrared Communication System (무선 적외선 통신시스템의 변조기법)

  • 신송섭;강영홍
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 1999.11a
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    • pp.110-115
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    • 1999
  • The emergence of portable information terminals in work and living environments is accelerating introduction of wireless digital links and local-area networks(LANs). Transmission using infrared radiation recently become a viable option. As a transmission medium, infrared offers several advantage over radio. The infrared spectral region offers a virtually unlimited bandwidth that is unregulated worldwide. In this paper we examine the performance of several modulation schemes on the wireless infraredcommunication system. We compare the power and bandwidth efficiency of several schemes.

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An IPSec Accelerator for the High-performance Virtual Private Networks

  • Ryu, Dae-Hyun;Na, Jong-Whoa;Shin, Seung-Jung;Jang, Seung-Ju;Kim, Jung-Tae
    • Journal of information and communication convergence engineering
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    • v.1 no.1
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    • pp.48-52
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    • 2003
  • A cost efficient IPSec Accelerator board utilizing a crypto chip and an entry-level Linux PC for the high performance VPN is presented in this paper. The IPIP (IP-over-IP tunneling) processing, encryption & decryption processing, HASH processing, and the integrity test functions of IPSec are processed in the IPSec Accelerator board. The proposed IPSec Accelerator has demonstrated successful execution of the required functions of the IPSec packet processing and verified its performance by processing the IPSec packets at the rate of over 1 Gbps.

An Efficient TCP Congestion Control Scheme in ATM Networks (ATM 망에서 효율적인 TCP 폭주 제어 기법)

  • 최지현;김남희;김변곤;전용일;정경택;전병실
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.7 no.8
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    • pp.1653-1660
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    • 2003
  • In this paper, we proposed an enhanced TCP congestion control algorithm using RTT with congestion window parameter cwnd to minimize the effect of TCP congestion. The proposed scheme could avoid the occurrence of frequent congestion and decrease the delay caused by the recovery time and the using amount of switch buffer. Through the simulation, we showed that the proposed scheme cm acquire higher performance than the existing scheme. There are 22.56% improvement at the average using buffer efficiency, and packet drop rate is 0.1% which is less than existing scheme.