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배전원격관리를 위한 차세대 디지털 적산전력계 개발 (Development of ADWHM(Advanced Digital Watt-Hour Meter) for Remote Management of Distribution Systems)

  • 고윤석;윤상문;서성진;강태규
    • 대한전기학회논문지:전력기술부문A
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    • 제53권6호
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    • pp.316-323
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    • 2004
  • This paper develops an ADWHM(Advanced Digital Watt-Hour Meter) which integrates and implements the voltage management data record function and the load management data record function in the electronic watt-hour meter. ADWHM is developed based on PIC16F874 which is 8bit micro-controller of RISK type for the easy of programing and maintenance, and electronic power signal processing module is located at front of it to reduce the computing load of processor. Also, a 16kbyte EEPROM is used to record the voltage management data and load management data for a week as well as watt-hour data and USART communication mode is used to transfer data from ADWHM to PC. The accuracy of the voltage and unt measuring for ADWHM is verified by identifying the LCD display values of the ADWHM after the voltage signals of id levels from digital function generator is applied to PT(Potential Transformer) and CT(Current Transformer) output under state which it is separated from real power line. On the its basic functions such as watt-hour data recording function, voltage management data recording function and load management data recording function was verified by showing data for three days among the collected data to PC by RS232C communication from ADWHM which was connected to real power lines for a week.

우유 공동 광고 캠페인의 개선 방향 및 제언 (Plan and Suggestion for the Cooperatives Milk Campaign Improvement)

  • 백인웅
    • Journal of Dairy Science and Biotechnology
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    • 제17권1호
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    • pp.39-49
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    • 1999
  • Since IMF relief financing, domestic economy has been rapidly cooled down. At this point that we predict an overall decrease of production and sale of industries, cooperative marketing activities of the whole dairy industry are required to promote milk consumption. As everyone knows, advertisement is only one of the various factors that affect sales. Other factors include price, distribution, package, promotion, and consumer's needs and taste. The objectives of the cooperative advertising campaign should be trial purchase of new consumers, maintenance of brand loyalty of existing consumers, more positive experience of using the product, and increase of frequency of purchase. Long term analysis is essential to making these kinds of behaviour changes. Also the objectives of the communication program should be a shift of awareness of milk from 'a basic health food for children' to a substitute to the beverage even for adults. To share database of consumers among companies, we need to find ways to use interactive on-line services, the internet, D.M. events and so on as well as the mass media. It should be a precondition that the main body of the cooperative advertisement includes the milk processing board, dairy companies, livestock cooperations, farmers and the Government. To assure continuous, activities to promote milk consumption, the Government should take the lead in legislating 'An enforcement ordinance for milk promotion and research', and seek complementary measures and support to establish the ordinance.

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반주기 변조된 송신파형과 대지전위 측정을 이용한 지중 케이블 누전 고장점 탐지 시스템 (Electric Leakage Point Detection System of Underground Power Cable Using Half-period Modulated Transmission Waveform and Earth Electric Potential Measurement)

  • 전정채;유재근
    • 전기학회논문지
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    • 제65권12호
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    • pp.2113-2118
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    • 2016
  • The precise detection of electric leakage point of underground power cable is very important to reduce cost and time of maintenance and prevent electric shock accident through expedite repair of electric leakage point. This paper proposes a electric leakage point detection system underground power cable using of half-period modulated transmission waveform and earth electric potential measurement. The developed system is composed of transmitter to generate the wanted pulse waveform, receiver to measure and display earth electric potential by the transmitted pulse in electric leakage point and PC Software program to display of GPS coordinate on detection cable line. The performance of the electric leakage point detection system was tested in the constructed underground cable leakage detection test bed. The test results on signal generation voltage precision of signal transmitter, mean detection earth voltage, mean detection leakage current and electric leakage point detection error showed the developed system can be used in electric leakage point detection underground power cable.

300MW급 증기터빈의 베어링 윤활유 온도조정에 의한 오일휩 제거방법에 관한 연구 (A Case Study on the Reduction of Noise and Vibration at the Backpass Heat Surface in the Power Plant Boiler)

  • 황달연;문승재;이재헌
    • 플랜트 저널
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    • 제4권4호
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    • pp.56-61
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    • 2008
  • The phenomena of oil whip in steam turbines take place for the unbalance force between a rotor shaft and bearing oil film. The several parameters that affect onset of oil whip have been well known. However, the major parameter of oil whip is shaft mis-alinement. A oil whip causes the high vibration and the shutdown of rotor system. We mostly stop the steam turbine to adjust a shaft re-alinement concerning oil whip. In this case, it needs many costs for maintenance and long shutdown times. In this study, we study and observe the oil whip of the 300MW steam turbine in many years and we conduct the field test for another steam turbine for reducing vibration from oil whip. The results of this study are that a oil whip takes place with a particular rotating speed or a particular turbine output and the oil temperature change is a very effective method for on-line oil whip treatment.

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Anti-Parasitic Activity of Lespedeza cuneata Extract on Causative Agent of Nosemosis Type C, Nosema ceranae

  • Song, Hyunchan;Kim, Hyekyung;Kim, Ki-Young
    • 한국양봉학회지
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    • 제34권2호
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    • pp.137-140
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    • 2019
  • Although honeybees (Apis mellifera) are crucial for maintenance of the ecosystem, population of honeybee has been steadily decreasing due to diseases including nosemosis. Nosemosis is a disease caused by Nosema ceranae and is now considered as a major threat to honeybees. N. ceranae is a microsporidian that stays in form of spore even before the infection, which makes it harder to control than other pathogens. People are now aware of this parasite, however, cure and preventive candidates for nosemosis are hardly found until today. In this study, in vitro experiment of Lespedeza cuneata treatment to prevent nosemosis were done using Trichoplusia ni cell line, BTI-TN5B1-4. Normal T. ni cells exhibited round shape without abnormal size. On the other hand, when N. ceranae were treated, cells deteriorated and some cells abnormally enlarged due to N. ceranae infection. Interestingly, treatment of T. ni cells with L. cuneate extract protected abnormal cell shape induced by N. ceranae infection to normal shape. Some N. ceranae spores were observed outside of the cells. Effective concentration range for N. ceranae control were experimented. Lowest concentration which can control nosemosis were 50 ㎍/mL. When the concentration of L. cuneata extract was exceeded 200 ㎍/mL, cytotoxicity started to show up.

Lessons learned from Multinational Parties Involved Program Management Consortiums in Korea

  • KO, Ok-Yeol
    • 국제학술발표논문집
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    • The 6th International Conference on Construction Engineering and Project Management
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    • pp.32-36
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    • 2015
  • This study explores the issue of program management consortia involving multinational participants. The aim of this research was to leverage advantages in program management (PM) skills and PM model improvement in product line construction in mega scale construction programs, typically funded by public funds. Such ventures involve multinational parties using dedicated partnering based on a program management consortium (PMC) to reduce confrontation between parties in complex circumstances, allowing an open and non-adversarial approach to project management. This research also seeks to implement an ongoing feedback program of best practices and lessons learned to minimize the repetition of mistakes and to reduce costs in sequenced construction. Recently, the Korean government has planned to undertake three large new projects: the Korean Peninsula major river maintenance, the reclamation of Se-Mangum, and the Science/Business City. This paper starts by providing a framework for the cost-reduction strategy for the United States Forces Korea (USFK) Relocation Program, which will be funded with public funds and a private fund investment (PFI) that combines programs executed by two governments as owners and multinational stakeholders, joined in the PMC. The establishment of project-oriented consortia is an innovative and non-adversarial approach to massive international construction projects. Such projects have used various tools effectively and skillfully. This experience may offer an opportunity to practice new and advanced program management delivery methods, and it is expected that Korea will gain a competitive advantage in the international construction market.

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근적외선 분광학과 화학계량학에 기반한 청정 바이오연료 실시간 품질 측정 기술 개발 (Development of an On-line Measurement Method for Clean Biofuel Based on Near Infrared Spectroscopy and Chemometrics)

  • 조형수;류준형;유준
    • 청정기술
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    • 제17권3호
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    • pp.215-224
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    • 2011
  • 화석연료 사용에 따른 기후 변화 문제 및 자원 고갈에 대한 염려 때문에 바이오 연료는 그 중에서 가장 바람직한 재생에너지 대안이다. 하지만 대량 생산을 할 수 있는 경제성확보가 없으면 바람직하고 현실적인 대안이라 할 수 없다. 실시간 품질측정 시스템 개발은 바이오연료의 대량생산을 위하여 반드시 필요하다. 바이오 연료 중 바이오에탄올은 ASTM (American Society for Testing & Materials) D4806-10과 같은 품질 규격을 따르며 이에 명시된 평가방법을 대량 생산에 적용하려면 여러 어려움이 뒤따른다. 따라서 본 연구에서는 바이오에탄올 제품 품질 분석의 저가격화와 시간단축 및 생산 공정의 모니터링 실시간화를 해결하기 위해 근적외선 분광분석법과 화학계량학의 부분최소 자승법(Partial Least Squares)을 융합한 실시간 분광 모니터링 시스템을 새롭게 제안하였다. 수종의 전처리와 부분최소자승법을 이용하여 모델링한 결과 스펙트럼의 산란 보정, 노이즈 감소, 검량선의 유지보수 등에서 Savitzky-Golay 전처리가 가장 우수함을 보였다. 본 연구를 통해 실시간으로 품질 측정뿐만 아니라 분광분석 장치로 여러 성분을 동시에 측정 가능함을 보임으로서 비용의 절감도 가능할 것으로 예상된다. 그리고 상관계수 R2이 0.99 이상으로 실험실분석의 대체도 가능함을 보였다.

The Optimum Dietary Essential Amino Acid Pattern for Male Taiwan Country Chicks

  • Wei, Hen-Wei;Kuo, Hsin-Mei;Chiu, Wen-Zan;Chen, Bao-Ji
    • Asian-Australasian Journal of Animal Sciences
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    • 제22권8호
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    • pp.1186-1194
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    • 2009
  • The objective of this study was to estimate the optimum dietary essential amino acid pattern for male Taiwan country chicks. A series of experiments was conducted with chicks, 14 d of age, for 2 wks. A basal synthetic diet was established using a dose response test for all essential amino acids referring to the broiler requirements recommended by NRC (1994). Twelve chicks were sacrificed at the beginning to provide initial body nitrogen data, and every group of six birds received the basal diet or a diet with a deficiency in a single essential amino acid in twenty one treatments by intubation according to their daily metabolic body weight (MBW). Deposited body nitrogen was determined using comparative slaughtering. According to the daily intake from the limiting amino acid per unit of MBW and the body nitrogen accretion rates for every two deficient groups with the same limiting amino acid but at different levels, a corresponding straight line was computed for each essential amino acid to intersect with a horizontal line made by the body nitrogen accretion rate of the control group. The x coordinate of the intersection represented the daily requirement for growth plus maintenance based on MBW corresponding to the essential amino acid. The amino acid ratios can be considered as the optimum pattern of dietary essential amino acids. The results, expressed with respect to lysine = 100, were arginine 105, methionine 81, histidine 34, tryptophan 18, leucine 103, phenylalanine 135, isoleucine 69, threonine 65 and valine 79. This pattern could be utilized to compute the dietary requirements (g/kg feed) for all essential amino acids by multiplying by the requirement of a single essential amino acid cited from the literature.

가상 시뮬레이션 기반의 AGV 원격 교육 모델 (AGV Distance Learning Model Based on Virtual Simulation)

  • 진고환
    • 한국융합학회논문지
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    • 제11권11호
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    • pp.41-46
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    • 2020
  • 4차산업혁명의 시작은 국내 산업 전반에 다양한 변화를 가져오고 있으며, 생산 제조 및 물류 분야의 기업에 스마트 팩토리가 확산되면서, 자동화 설비를 사용하고 있다. 특히 물류 자동화 현장에서는 AGV가 널리 사용되고 있으며, 전통적인 AGV의 구동 방식인 라인 유도 방식의 사용이 대부분이다. 또한 AGV 시스템 개발자 및 시스템 운영자 및 관리자, 유지보수 인력의 수요도 증가하고 있는 추세이나, 교육을 위한 시스템의 설치에 고가의 비용이 소요되고, 넓은 공간을 필요로 하는 특성을 가지고 있어, 체계적인 교육이 어려운 상황이다. 본 논문에서는 교육생들의 원활한 실습을 위하여 가상 시뮬레이션 기반의 AGV 원격 교육 모델을 제안한다. 제안 모델은 기존 기술인 라인 유도 방식이 아닌 영상 정보를 분석하여 AGV를 구동할 수 있는 모델로 구성하였으며, 자가진단 평가 결과 기존 기자재를 활용한 통제 집단 보다 온라인 교육을 통한 실험 집단이 평균 0.65의 만족도가 상승하여, 온라인 교육 환경에서 활용할 수 있는 가능성을 확인하였다.

UML 기반 전용회선 운용관리시스템 설계 (A dedicated line operating and maintenance system design based on UML)

  • 조동권
    • 한국정보통신학회논문지
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    • 제6권6호
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    • pp.827-832
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    • 2002
  • 고속의 전용회선 통신서비스에 대한 급격한 수요로 통신망은 그 양과 종류가 급격하게 증가하고 있어서 전용회선 통신망 운용에 따른 망구성 및 고장처리 체계의 정립이 필요하게 되었다. 전용회선은 특성상 가입자 구간에서 시작하여 여러 전화국의 전송장치를 경유하고 다시 가입자구간으로 연결된다. 전용회선의 유지보수 및 운용관리는 전국 규모로 전용회선을 단대단으로 시험할 수 있고, 운용관리 업무를 집중화, 자동화, 전산화시킴으로써 전용회선에 대한 시험 및 운용관리업무를 일원화한 집중운용보전체제를 필요로 한다. 이러한 요구에 부응하기 위해서는 확장성이 높고 유연하여 데이터를 원격지에서도 접근할 수 있도록 하는 분산 시스템의 구성이 필수적이다. 분산시스템 설계의 하나의 방법으로 객체지향 설계가 많이 적용하고 있다. 본 논문에서는 새롭게 요구되는 환경에서의 전용회선 통신망에 대한 구성 및 고장관리 요구사항을 정리하고 객체지향설계 언어인 UML(Unified Modeling Language)을 적용한 전용회선운용관리시스템설계 방법을 제안한다