• Title/Summary/Keyword: Power line communication

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Study on Standardization of the Environmental Impact Evaluation Method of Extremely Low Frequency Magnetic Fields near High Voltage Overhead Transmission Lines (고압 가공송전선로의 극저주파자기장 환경영향평가 방법 표준화에 관한 연구)

  • Park, Sung-Ae;Jung, Joonsig;Choi, Taebong;Jeong, Minjoo;Kim, Bu-Kyung;Lee, Jongchun
    • Journal of Environmental Impact Assessment
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    • v.27 no.6
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    • pp.658-673
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    • 2018
  • Social conflicts with extremely low frequency magnetic field(ELF-MF) exposures are expected to exacerbate due to continued increase in electric power demand and construction of high voltage transmission lines(HVTL). However, in current environmental impact assessment(EIA) act, specific guidelines have not been included concretely about EIA of ELF-MF. Therefore, this study conducted a standardization study on EIA method through case analysis, field measurement, and expert consultation of the EIA for the ELF-MF near HVTL which is the main cause of exposures. The status of the EIA of the ELF-MF and the problem to be improved are derived and the EIA method which can solve it is suggested. The main contents of the study is that the physical characteristics of the ELF-MF affected by distance and powerload should be considered at all stages of EIA(survey of the current situation - Prediction of the impacts - preparation of mitigation plan ? post EIA planning). Based on this study, we also suggested the 'Measurement method for extremely low frequency magnetic field on transmission line' and 'Table for extremely low frequency magnetic field measurement record on transmission line'. The results of this study can be applied to the EIA that minimizes the damage and conflict to the construction of transmission line and derives rational measures at the present time when the human hazard to long term exposure of the ELF-MF is unclear.

Media Scholars and Power: The politicized intellectuals hanging on the dangerous rope (언론학자와 권력: 정치화된 지성의 위험한 줄타기)

  • Choi, Nakjin;Kim, Sunghae
    • Korean Journal of Legislative Studies
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    • v.22 no.2
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    • pp.113-156
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    • 2016
  • Media scholars take a lion stake in power circle. Not only do they take a part in media policies but seize prestigious positions like board members in Korea Communication Commission(KCC). Unfortunately, though, little has been known about who they are, what qualifications they have, and whether they meet public interests. This paper attempts to unveil the mechanism of those politicized intellectuals who are specialized on the media. Two categories divided into 'representative' and 'expertise' are employed for this purpose. On the one hand, the representative means the degree of committment into such public services as participation in conferences or non-profit organizations. On the other hand, the number of research articles, books and projects belong to the expertise. Evaluation levels consist of 'excellence, good and average' were allocated to those scholars who are(were) in 'Power Hole,' where decision makings come into being. Some interesting observations were made though this study. First of all, such criteria as representative and expertise vaguely suggested by the laws were hardly fit into those intellectuals, Rarely did they commit into public service let alone showing vigilance in academic activities. Secondly, both ideological loyalty and political activities in line with the government had much to do with taking such positions. Thirdly, not surprisingly, it showed that to graduate from Seoul National University and have Ph.D. degree from U.S.A. was one of the most essential factors. In final, most of them were very good at taking advantage of the press in way of boosting their publicity. To attend at policy making processes either in form of board members or advisers is inevitable for media experts. However, as shown in this study, such qualification of public service and academic eagerness shouldn't be underestimated. Academic integrity not selling intelligence solely for private interests needs to be protected as well. The authors hope this study to provide a valuable opportunity to establish a kind of ethical standards in participating into politics.

Sound System Design and Characteristic Analysis based on Power Line Communication (전력선통신 기반 음향 시스템 설계 및 특성 분석)

  • Kim, Kwan-Kyu;Yeom, Keong-Tae;Kim, Kwan-Woong;Kim, Yong-Kab
    • The Journal of the Korea Contents Association
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    • v.8 no.6
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    • pp.1-7
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    • 2008
  • The paper is to solve the problem of existing sound system, which has difficulties of system organization and the increase of additional install cost and unfriendly interior. To solve the existing system, we drew the new sound system based on PLC and studied it. A transmitter and a receiver were designed using the PLC chip INT5500CS. Sound system was configured with a CD player that sound signals are sent from the transmitter and a speaker connected to the receiver. For analysis of characteristics of this system, a USBPre external sound card and Smaart Live 5 which is a PC-based sound measuring program were added. As a result of our experiment, the measured signal level is $2{\sim}3$[dB] lower than reference signal, latency is 16.69[ms] and the specific character of coherency is bad in high frequency band. Otherwise, this system transmits and receives signals over 90[%] in good condition as a result of measuring pink noise, frequency(1kHz), and phase, magnitude. In view of the result so far achieved, the system designed our team has excellent performance, it resolves defect of existing audio signal transmition system.

Characteristics of 'Modern Cyborg' in Animation - Focused on Animations of and - (애니메이션에 나타난 '현대 사이보그' 특성 - <공각기동대>와 <이노센스>를 중심으로-)

  • Seo, Soo-Jung
    • The Journal of the Korea Contents Association
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    • v.7 no.4
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    • pp.150-159
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    • 2007
  • The remark by Andy Clark that the cleverer our world is, the more difficult we perceive our world and ourselves, is very significant to us living in digital world. As the huge power of Technology are dominating the world, the people are drifting with their body fragmented in diverse kinds of chaos, being are faced with the situation that they should reorganize themselves about personal life and ways of thinking in a new technological environment. This paper approach some characteristics of contemporary society through 'Cyborg' which is the product of limitless human desire and technology. The characteristics in modern times, such as boundary disjoint, hybridity, transformation, fusion, communication with image, digital sensitivity, womanness correspond to those of the Cyborg. This paper also investigates the history of modern Cyborg through animation, one of the remarkable medium in digital age and analyze the cyber punk animation, and by Oshii Mamoru, which provoked the extension of the concept of Cyborg. This paper will give a moment to diagnose what this age is like and to present a reference line of our contemporaries exposed to the surplus images and technology.

The Study on Centralization & Electronic for Maintenance Efficiency of Ground Signaling System (지상신호설비의 유지보수 효율화를 위한 집중화 및 전자화 연구)

  • Baek, Jong-Hyen;Kim, Yong-Kyu;Lee, Kang-Mi
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.8
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    • pp.2983-2988
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    • 2010
  • The train control system used in Gyeongbu-line is classified in ATC, IXL and CTC. Domestic railway signaling systems are being developed by electrification. In these systems the electrification of interlocking reaches 57% and the safety equipments of railway crossings in trackside devices have completed their development into an integrated system. Block systems of all the existing sections have not yet electrified and integrated so that they need a number of complement in terms of construction and maintenance. For ABS currently used in existing domestic lines, and LEU being installed in Gyeongbu and Honam lines, although a train is controlled by the signaling information of the same train in the same location, the system is separately installed so that the same information is separately divided and transmitted at the each distinct system. Therefore, in the conventional ABS and LEU, there are a lot of duplicate installed compartments such as lamp detection and a power supply unit. Hence, we have a lot of problems: for maintenance, a lot of manpower and costs need to be invested and the overall manufacturing costs get higher, as well as the construction costs by duplicate. Therefore, this paper suggest design to develop an integrated electronic Block Control Unit by the integration of the currently used ABS, and communication and electronic technology. We are to monitor and manage the block systems in the corresponding station by integrating. And we are to transmit information together with LEU, which is an ATS wayside transmitter.

Evaluation of Extremely Low Frequency Magnetic Fields emission Level from High Voltage Transmission Lines (고압 송전선로에서 극저주파 자기장 영향평가 적용에 관한 연구)

  • Jung, Joon Sig;Choi, Sung Ho;Jeon, Hyung Jin;Kim, Yoon Shin;Hong, Seung Cheol
    • Journal of Environmental Impact Assessment
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    • v.23 no.5
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    • pp.353-363
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    • 2014
  • The purpose of this study was to investigated the ELF-MF emission level of various environments such as 258 facilities near located to high voltage transmission lines and 120 high voltage transmission lines, 17 underground cable lines. In addition, ELF-MF reduction rate according to separation distance was calculated by using simulations. An appropriate separation distance showing below 4mG was at least 70m. In the case of the appropriate separation distance for 120 high voltage transmission lines, 154kV required 20m of separation distance and 345kV required 60m of separation distance. The simulation results showed that the appropriate separation distance showing below 4mG was 40m and 60m for overhead 154kV and 345kV respectively. To adjust the worst conditions considering the aspects of environmental impact assessment study and the electric power currents that will increase in the future, the appropriate minimum separation distance for HVTL is judged to be above 70m in this study. Thus, there is a need to establish the greenbelt or buffer zone within 70m so as to create an environment in which the receptors are not exposed and thereby eliminate the risk factors of ELF-MF against humans.

Field Test and Performance Verification of On-board Oriented Train Control System (차상중심 열차제어시스템의 현장시험을 통한 성능검증)

  • Baek, Jong-Hyen
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.8
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    • pp.5513-5521
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    • 2015
  • There is an operational efficiency problem about wayside equipment applied to the domestic low-density branch as the equipment has been installed and operated similarly in the mainline. On-board oriented train control system, which has been developed for train safety and operation efficiency, ensures safe train operation without expensive ground control signal devices. Such system consists of on-board control system, wayside control system, and local control system. In this paper, the details of tests such as suitability test, communication test, and interface test are described by installing the on-board control system and wayside control system in field. Installation tests include checking power, voltage, cable connection, LED status, etc. Field applicability of the developed system is also verified through the dynamic operation tests with diverse scenarios, which are performed on the virtual line similar to the real environment including switch machine and level crossing gate. Dynamic operation tests were conducted for total 7 scenarios, and several tests were repeated for each scenario. The elapsed time for each operation was computed by analyzing main process log, and we could check that each operation was accomplished within several seconds. Furthermore, the developed system was verified through field test with an accredited institute, and testing certificates were issued.

Design Optimization of Differential FPCB Transmission Line for Flat Panel Display Applications (평판디스플레이 응용을 위한 차동 FPCB 전송선 설계 최적화)

  • Ryu, Jee-Youl;Noh, Seok-Ho;Lee, Hyung-Joo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.5
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    • pp.879-886
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    • 2008
  • This paper addresses the analysis and the design optimization of differential interconnects for Low-Voltage Differential Signaling (LVDS) applications. Thanks to the differential transmission and the low voltage swing, LVDS offers high data rates and improved noise immunity with significantly reduced power consumption in data communications, high-resolution display, and flat panel display. We present an improved model and new equations to reduce impedance mismatch and signal degradation in cascaded interconnects using optimization of interconnect design parameters such as trace width, trace height and trace space in differential flexible printed circuit board (FPCB) transmission lines. We have carried out frequency-domain full-wave electromagnetic simulations, time-domain transient simulations, and S-parameter simulations to evaluate the high-frequency characteristics of the differential FPCB interconnects. The 10% change in trace width produced change of approximately 6% and 5.6% in differential impedance for trace thickness of $17.5{\mu}m$ and $35{\mu}m$, respectively. The change in the trace space showed a little change. We believe that the proposed approach is very helpful to optimize high-speed differential FPCB interconnects for LVDS applications.

Research on rapid source term estimation in nuclear accident emergency decision for pressurized water reactor based on Bayesian network

  • Wu, Guohua;Tong, Jiejuan;Zhang, Liguo;Yuan, Diping;Xiao, Yiqing
    • Nuclear Engineering and Technology
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    • v.53 no.8
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    • pp.2534-2546
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    • 2021
  • Nuclear emergency preparedness and response is an essential part to ensure the safety of nuclear power plant (NPP). Key support technologies of nuclear emergency decision-making usually consist of accident diagnosis, source term estimation, accident consequence assessment, and protective action recommendation. Source term estimation is almost the most difficult part among them. For example, bad communication, incomplete information, as well as complicated accident scenario make it hard to determine the reactor status and estimate the source term timely in the Fukushima accident. Subsequently, it leads to the hard decision on how to take appropriate emergency response actions. Hence, this paper aims to develop a method for rapid source term estimation to support nuclear emergency decision making in pressurized water reactor NPP. The method aims to make our knowledge on NPP provide better support nuclear emergency. Firstly, this paper studies how to build a Bayesian network model for the NPP based on professional knowledge and engineering knowledge. This paper presents a method transforming the PRA model (event trees and fault trees) into a corresponding Bayesian network model. To solve the problem that some physical phenomena which are modeled as pivotal events in level 2 PRA, cannot find sensors associated directly with their occurrence, a weighted assignment approach based on expert assessment is proposed in this paper. Secondly, the monitoring data of NPP are provided to the Bayesian network model, the real-time status of pivotal events and initiating events can be determined based on the junction tree algorithm. Thirdly, since PRA knowledge can link the accident sequences to the possible release categories, the proposed method is capable to find the most likely release category for the candidate accidents scenarios, namely the source term. The probabilities of possible accident sequences and the source term are calculated. Finally, the prototype software is checked against several sets of accident scenario data which are generated by the simulator of AP1000-NPP, including large loss of coolant accident, loss of main feedwater, main steam line break, and steam generator tube rupture. The results show that the proposed method for rapid source term estimation under nuclear emergency decision making is promising.

A Study on a Roadmap for Establishing Spatial Information in the North Korean Region through Analysis of National Infrastructure Priorities - On the Premise that the North Korean Region is Accessible - (국가인프라 우선순위 분석을 통한 북한지역 공간정보구축 로드맵 연구 - 북한지역 접근가능을 전제로 -)

  • Kim, changjae;Lee, Byoungkil;Pyeon, Mu Wook
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.39 no.3
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    • pp.149-156
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    • 2021
  • This study collected and analyzed case studies related with the use of spatial information in North Korea to prioritize construction and required supporting processes in order to propose a short-term and long-term road map for the establishment of spatial information in North Korea. Recent research cases related to the prioritization of spatial information development were analyzed, and priority for the construction of infrastructure was derived based on the interconnectedness and relationship of national infrastructure. Due to the inaccessibility and remoteness of North Korea, all of the five studies determined priorities according to questionnaires and consulting of refugees and knowledgeable figures by expert groups. In summary, priority was given to unarmed and transborder areas, major cities, special zones, and development zones, while in terms of facilities, priority was given to power communication, railroads, water and sewage architectural buildings, roads, and dams. In the case of prioritizing the establishment of national infrastructure for the unified Korean Peninsula, the development of major areas, ports, and the related city-level spots to develop a line that promotes the sharing of routes such as transportation networks, water, and energy, thus leading to a scenario involving the development of cotton at an urban and national level.