• Title/Summary/Keyword: 양방향 효율

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Design and Implementation of a Spatio-Temporal Middleware for Ubiquitous Environments (유비쿼터스 환경을 위한 시공간 미들웨어의 설계 및 구현)

  • Kim, Jeong-Joon;Jeong, Yeon-Jong;Kim, Dong-Oh;Han, Ki-Joon
    • Journal of Korea Spatial Information System Society
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    • v.11 no.1
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    • pp.43-54
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    • 2009
  • As R&D(Research and Development) is going on actively to develop technologies for the ubiquitous computing environment, which Is the human-oriented future computing environment, GIS dealing with spatio-temporal data is emerging as a promising technology. This also increases the necessity of the middleware for providing services to give interoperability in various heterogeneous environments. The core technologies of the middleware are real-time processing technology of data streams coming unceasingly from positioning systems and data stream processing technology developed for non-spatio-temporal data. However, it has problems in processing queries on spatio-temporal data efficiently. Accordingly, this paper designed and implemented the spatio-temporal middleware that provides interoperability between a mobile spatio-temporal DBMS(DataBase Management System) and a server spatio-temporal MMDBMS(Main Memory DataBase Management System). The spatio-temporal middleware maintains interoperability among heterogeneous devices and guarantees data integrity in query processing through real-time processing of unceasing spatio-temporal data streams and two way synchronization of spatio-temporal DBMSs. In addition, it manages session for the connection of each spatio-temporal DBMS and manages resources for its stable operation. Finally, this paper proved the usability of the spatio-temporal middleware by applying it to a real-time position tracking system.

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Water Governance and Basic Water Law (물거버넌스와 물관리기본법)

  • Lee, Seung-Ho;Kim, Sung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2009.05a
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    • pp.385-389
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    • 2009
  • 본 연구의 목적은 물거버넌스 개념과 1997년, 2006년 물관리기본법안 분석을 통해 한국의 새로운 물관리 체제를 모색하는 것이다. 물거버넌스는 물관리정책과 계획의 수립, 시행, 평가에 있어 정부뿐만 아니라 일반 기업, 시민, 환경단체, 전문가 등 여러 이해당사자를 참여시키는 것을 핵심으로 한다. 거버넌스란 기존의 정부 주도의 정책 계획, 수립, 시행이 아닌 비정부 조직과의 타협, 협의, 논의를 통한 양방향 정책결정 과정을 뜻한다. 따라서 물거버넌스의 가장 중요한 원칙은 다양한 이해당사자 참여를 통한 정책결정의 복수화 과정이다. 한국의 물거버넌스를 시행하기 위해 가장 필요한 요건은 이해당사자 참여를 우선 중앙, 지방정부에서 그 필요성을 인식하고 법, 제도 등을 통해 제도화하는 것이다. 환경부 주도로 입안된 1997년 물관리기본법안은 물관리일원화, 적정사용, 유역관리, 비용부담, 균형배분의 5원칙을, 2006년 물관리기본법안은 물관리일원화 대신 통합물관리, 적정사용 대신 수요관리를 삽입하여 5원칙을 제시하였지만 이해당사자 참여는 원칙에 포함시키지 않았다. 이해당사자 참여 원칙의 제도화가 없이는 위의 두 법안이 제시한 원칙의 적용과 시행이 어려움에 봉착할 가능성이 높다. 왜냐하면 다른 원칙은 다양한 이해당사자 참여를 통한 사회적 합의 없이는 시행이 쉽지 않은 정치적으로 민감한 사항들이기 때문이다. 예를 들어 물의 균형배분 원칙 관련, 만약 상류와 하류 주민 간의 합의가 없이 어느 한 이해당사자의 일방적 행위가 있을 경우 큰 갈등을 유발할 수 있다. 물거버넌스을 실행하기 위해 중앙에 필요한 조직은 물이용 관련 물분쟁 발생 시 이를 조정하고 국가물관리계획을 수립하며 물관리 문제 전반을 총괄하는 조직이다. 1997년, 2006년 기본법안은 국가물관리위원회 설치를 제시하였고 2006년 기본법안에서 보다 구체적으로 위상, 운영, 역할 등에 대해 언급하였다. 하지만 국가물관리위원회는 물관련 중앙부처의 장, 지방행정조직의 장만을 포함하여 유역관리를 책임질 유역관리조직의 장에 대한 언급이 없다. 물거버넌스 실현을 위한 유역관리 시행이 바람직하기에 유역관리조직의 장도 국가물관리위원회에 참여하는 것이 바람직하다. 또한 두 기본법안 모두 국무총리실 산하에 위원회를 속하게 하였는데 이를 수정하여 대통령 직속기구로 규정하는 것이 국가물관리위원회가 정치, 행정, 재정적 압력에서 벗어나 일관성 있는 정책을 펼 수 있는 지름길이 될 것이다. 또한 지방의 물문제를 물관리계획에 적절히 반영하고 대응방안을 수립, 시행하기 위해서는 정부 관료뿐만 아니라 지방의회 의원, 환경단체, 기업, 시민, 전문가 등의 다양한 이해당사자가 참여하는 유역위원회가 필수적이다. 또한 유역 관련 물관리계획을 수립하고 사업을 추진하는 유역관리청도 필요하다. 유역위원회와 유역관리청은 유역 내 여러 이해당사자들이 물관리에 대해 다양한 의견을 개진하고 토론하며 합의점에 이르는 거버넌스를 수립할 수 있는 중요한 조직이다. 두 기본법안은 유역관리 원칙을 제시하긴 하였지만 유역관리 시행 관련 조직, 역할, 운영 등에 대해서는 언급이 없었다. 한국의 물관리는 소득, 문화 수준 향상으로 인한 양질의 물공급에 대한 요구, 시민사회의 발전, 지방분권화 등 정치, 경제, 사회의 변화를 수용하고 발전해 나가기 위해서는 여러 이해당사자의 참여와 합의에 바탕을 둔 물거버넌스 수립이 무엇보다 중요하다. 또한 이를 시행하기 위해서는 물관리기본법을 하루 속히 제정하여 제도적 기반을 갖춰 보다 효율적인 물관리시스템을 수립해야 한다.

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Network Capacity Design in the local Communication and Computer Network for Consumer Portal System (전력수용가포털을 위한 구내 통신 및 컴퓨터 네트워크 용량 설계)

  • Hong, Jun-Hee;Choi, Jung-In;Kim, Jin-Ho;Kim, Chang-Sub;Son, Sung-Young;Son, Kwang-Myung;Jang, Gil-Soo;Lee, Jea-Bok
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.10
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    • pp.89-100
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    • 2007
  • Consumer Portal is defined as "a combination of hardware and software that enables two-way communication between energy service provider(ESP, like KEPCO) and equipment within the consumer's premises". The portal provides both a physical link(between wires, radio waves, and other media) and a logical link(translating among language-like codes and etiquette-like protocols) between in-building and wide-area access networks. Thus, the consumer portal is an important, open public shared infrastructure in the future vision of energy services. In this paper, we describe a new methodology for local communication and computer network capacity design of consumer portal, and also presents capacity calculation method using a network system limitation factors. By the approach, we can check into the limitations of existing methods, and propose an improved data processing algorithm that can expand the maximum number of the networked end-use devices up to $30{\sim}40$ times. For validation, we applies the proposed methode to our real system design. Our contribution will help electrical power information network design.

A Design of Handoff-aware DiffServ Scheduler in TDD/CDMA Networks (TDD/CDMA망에서 핸드오프를 지원하는 DiffServ 스케줄러 설계)

  • Zang, Seog-Ku;Kim, Young-Han
    • The KIPS Transactions:PartC
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    • v.14C no.6
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    • pp.493-502
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    • 2007
  • In this paper, we propose a handoff-aware DiffServ scheduler which intends to guarantee various QoS requirements of multimedia services for mobile nodes in TDD/CDMA based wireless networks. TDD is widely used duplexing mechanism in wireless communications. Unlike FDD, TDD allows a node to symmetrically communicate with a base station by using a single frequency band, resulting in high utilization of wireless resources. DiffServ is regarded as a relatively simple QoS support mechanism and thus it is easy to be extended. This is because DiffServ is not a per-flow based mechanisms and it does not require any signaling protocol. However, previously proposed DiffServ schedulers for wired networks can not be deployed directly into wireless networks since they do not consider properties of wireless networks. As a solution to the problem, DSS(DiffServ Supporting Scheduler) was proposed. DSS uses uplink channel, which is originally used for a node to require a base station to transmit packets, to support QoS efficiently. However, QoS does not consider handoff so that it can not support QoS for moving nodes from one cell to the other cell. Therefor. the proposed handoff support QoS mechanism is necessary for TCC/CDMA networks. The proposed scheme allows a mobile node to achieve seamless service without QoS degradation even for the handoff duration.

Gateway Architecture for Ubiquitous Access to ZigBee-Based Sensor Networks (ZigBee 기반 센서 네트워크로의 유비쿼터스 접근을 위한 게이트웨이 아키텍처)

  • Heo, Ung;Peng, Qiu;You, Kang-Soo;Choi, Jae-Ho
    • The Journal of the Korea Contents Association
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    • v.10 no.8
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    • pp.73-83
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    • 2010
  • This paper investigates protocol architecture of a Web-ZigBee gateway for interconnecting TCP/IP-based networks and ZigBee/IEEE802.15.4-based wireless sensor networks. The Web-ZigBee gateway delivers data between the TCP/IP network and the ZigBee network. Since those two networks have different communication protocols, a protocol translation mechanism is needed. Herein, we propose a method to deliver query messages from the Internet to the sensor network and receive data from sensors. The protocol translation is performed in the translation layer that is placed above the two application layers, i.e., the Internet application layer and ZigBee application layer. Among various interfaces, we use CGI programming to take care of translation functions efficiently. The CGI manages query information from a client on the Internet and data from the ZigBee sensor network. Whereas the TCP/IP enabled sensor network overlays two heterogeneous communication protocols, overlaying layers increase the complexity and cost of implementing the sensor network. On the contrary, the sensors in our gateway-based system are not only light (because each communication protocol works independently without overlaying), but also efficient because the translation layer mostly alleviates header overloading.

Train interval control and train-centric distributed interlocking algorithm for autonomous train driving control system (열차자율주행제어시스템을 위한 간격제어와 차상중심 분산형 연동 알고리즘)

  • Oh, Sehchan;Kim, Kyunghee;Choi, Hyeonyeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.11
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    • pp.1-9
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    • 2016
  • Train control systems have changed from wayside electricity-centric to onboard communications-centric. The latest train control system, the CBTC system, has high efficiency for interval control based on two-way radio communications between the onboard and wayside systems. However, since the wayside system is the center of control, the number of input trains to allow a wayside system is limited, and due to the cyclic-path control flows between onboard and wayside systems, headway improvement is limited. In this paper, we propose a train interval-control and train-centric distributed interlocking algorithm for an autonomous train-driving control system. Because an autonomous train-driving control system performs interval and branch control onboard, both tracks and switches are shared resources as well as semaphore elements. The proposed autonomous train-driving control performs train interval control via direct communication between trains or between trains and track-side apparatus, instead of relying on control commands from ground control systems. The proposed interlocking algorithm newly defines the semaphore scheme using a unique key for the shared resource, and a switch that is not accessed at the same time by the interlocking system within each train. The simulated results show the proposed autonomous train-driving control system improves interval control performance, and safe train control is possible with a simplified interlocking algorithm by comparing the proposed train-centric distributed interlocking algorithm and various types of interlock logic performed in existing interlocking systems.

Influencing Factors on Sensitivity of Pressure Decay Test for Membrane Damage Assessment (막 손상 측정을 위한 압력손실시험의 감도에 영향을 미치는 인자)

  • Lee, Yong-Soo;Kim, Hyung-Soo;Kim, Jong-Oh
    • Membrane Journal
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    • v.27 no.4
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    • pp.367-373
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    • 2017
  • Pressurized membrane module systems, including hollow fiber type of Microfiltration (MF) and Ultrafiltration (UF) membranes are being increasingly used in drinking water treatment due to their high removal efficiency of pathogen. However, when fibers are damaged in pressurized membrane system, the pathogen will be able to penetrate the membrane. Therefore, it is essential to guarantee the regulatory requirements for water quality by an effective on-line or off-line condition integrity monitoring methods. Recently, pressure decay test (PDT) which is one of membrane integrity tests has been reflected to drinking water treatment plants using pressurized membrane module. In this paper, three different method were used to perform PDT and three different sensitivity values were analyzed through experiments. Three types of direct integrity test methods were applied to pressure feed side, filtrate side and bidirectional pressure decay test. The results of these experiments show that the sensitivity was increasing when the volume of pressurized gas was decreasing. The sensitivity is inversely proportional to the gas volume. Furthermore, it is desirable to increase pressure difference between feed side and permeate side in order to achieve higher sensitivity in the PDT by membrane damage.

Cross-layer Design of Joint Routing and Scheduling for Maximizing Network Capacity of IEEE 802.11s based Multi-Channel SmartGrid NAN Networks (IEEE 802.11s 를 사용한 스마트그리드 NAN 네트워크의 최대 전송 성능을 위한 다중 채널 스케쥴링과 라우팅의 결합 설계)

  • Min, Seok Hong;Kim, Bong Gyu;Lee, Jae Yong;Kim, Byung Chul
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.5
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    • pp.25-36
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    • 2016
  • The goal of the SmartGrid is to maximize energy efficiency by exchanging bi-directional real-time power information with the help of ICT(Information and Communication Technology). In this paper, we propose a "JRS-MS" (Joint Routing and Scheduling for Multi-channel SmartGrid) algorithm that uses numerical modeling methods in IEEE 802.11s based STDMA multi-channel SmartGrid NAN networks. The proposed algorithm controls the amount of data transmission adaptively at the link layer and finds a high data-rate path which has the least interference between traffic flows in multi-channel SmartGrid NAN networks. The proposed algorithm improve transmission performance by enhancing network utilization. By comparing the results of performance analysis between the proposed algorithm and the JRS-SG algorithm in the previous paper, we showed that the JRS-MS algorithm can improve transmission performance by maximally utilizing given network resources when the number of flows are increasing in the multi-hop NAN wireless mesh networks.

Smart meter data transmission device and power IT system using LTE and IoT technologies (LTE와 IoT 기술을 이용한 스마트미터 데이터 전송장치와 전력 IT 시스템)

  • Kang, Ki-Beom;Kim, Hong-Su;Jwa, Jeong-Woo;Kim, Ho-Chan;Kang, Min-Jae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.10
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    • pp.117-124
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    • 2017
  • A Smart Grid is a system that can efficiently use energy by exchanging real-time information in both directions between a consumer and a power supplier using ICT technology on an existing power network. DR(Demand response) is an arrangement in which electricity users can sell the electricity they save to the electricity market when the price of electricity is high or the power system is crisis. In this study, we developed a power meter data transmission device and power IT system that measure the demand information in real-time using a smart meter and transmit it to a cloud server. The power meter data transmission device developed in this study uses alight sensor connected to a Raspberry Pi 3 to measure the number of blinking lamps on the KEPCO meter per unit of power, in order to provide reliable data without any measurement errors with respect to the KEPCO power data. The power measurement data transmission device uses the standard communication protocol, OpenADR 2.0b. The measured data is transmitted to the power IT system, which consists of the VEN, VTN, and calculation program, via the LTE WiFi communication network and stored in its MySQL DB. The developed power measurement data transmission device issues a power supply instruction and performs a peak reduction DR when a power system crisis occurs. The developed power meter data transmission device has the advantage of allowing the user to adjust it every 1 minute, where as the existing smart metering time is fixed at once every 15 minutes.

Hierarchical Internet Application Traffic Classification using a Multi-class SVM (다중 클래스 SVM을 이용한 계층적 인터넷 애플리케이션 트래픽의 분류)

  • Yu, Jae-Hak;Lee, Han-Sung;Im, Young-Hee;Kim, Myung-Sup;Park, Dai-Hee
    • Journal of the Korean Institute of Intelligent Systems
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    • v.20 no.1
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    • pp.7-14
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    • 2010
  • In this paper, we introduce a hierarchical internet application traffic classification system based on SVM as an alternative overcoming the uppermost limit of the conventional methodology which is using the port number or payload information. After selecting an optimal attribute subset of the bidirectional traffic flow data collected from the campus, the proposed system classifies the internet application traffic hierarchically. The system is composed of three layers: the first layer quickly determines P2P traffic and non-P2P traffic using a SVM, the second layer classifies P2P traffics into file-sharing, messenger, and TV, based on three SVDDs. The third layer makes specific classification of the entire 16 application traffics. By classifying the internet application traffic finely or coarsely, the proposed system can guarantee an efficient system resource management, a stable network environment, a seamless bandwidth, and an appropriate QoS. Also, even a new application traffic is added, it is possible to have a system incremental updating and scalability by training only a new SVDD without retraining the whole system. We validate the performance of our approach with computer experiments.