• Title/Summary/Keyword: On Line Maintenance

Search Result 629, Processing Time 0.036 seconds

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

  • 고윤석;윤상문;서성진;강태규
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.53 no.6
    • /
    • pp.316-323
    • /
    • 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.

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

  • Baek, In-Woong
    • Journal of Dairy Science and Biotechnology
    • /
    • v.17 no.1
    • /
    • pp.39-49
    • /
    • 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.

  • PDF

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

  • Jeon, Jeong Chay;Yoo, Jae-Geun
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.65 no.12
    • /
    • pp.2113-2118
    • /
    • 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.

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

  • Hwang, Dal-Yeon;Moon, Seung-Jae;Lee, Jae-Heon
    • Plant Journal
    • /
    • v.4 no.4
    • /
    • pp.56-61
    • /
    • 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.

  • PDF

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

  • Song, Hyunchan;Kim, Hyekyung;Kim, Ki-Young
    • Journal of Apiculture
    • /
    • v.34 no.2
    • /
    • pp.137-140
    • /
    • 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
    • International conference on construction engineering and project management
    • /
    • 2015.10a
    • /
    • pp.32-36
    • /
    • 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.

  • PDF

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

  • Cho, Hyeong-Su;Ryu, Jun-Hyung;Liu, J. Jay
    • Clean Technology
    • /
    • v.17 no.3
    • /
    • pp.215-224
    • /
    • 2011
  • It is an important issue to develop quality assessing system for biofuel for the purpose of accelerating the mass production of biofuel. It is particularly challenging to conduct testing method in the mass production of bioethanol while meeting quality specifications such as ASTM (American Society for Testing & Materials) D4806-10. In order to address this challenge, this paper proposes on-line spectroscopic quality assesment system based on Near Infrared spectrum and Partial Least Squares method in Chemometrics. As a result of testing a number of preprocessing methods and Partial Least Squares, it was found out that Savitzky-Golay method showed the best performance in terms of spectrum correction, noise reduction, and model maintenance. The proposed system allows us to assess multiple quality components continuously using spectroscopic facilities with the cheap cost. Since the value of R2 is more than 0.99, it is possible to replace the laboratory analysis.

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
    • /
    • v.22 no.8
    • /
    • pp.1186-1194
    • /
    • 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.

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

  • Jin, Go-Whan
    • Journal of the Korea Convergence Society
    • /
    • v.11 no.11
    • /
    • pp.41-46
    • /
    • 2020
  • The start of the Fourth Industrial Revolution has brought about various changes in the domestic industry in general, and smart factories have spread to companies in the fields of production, manufacturing and logistics, and they are using automation equipment. Especially in the field of logistics automation, AGVs are widely used, and most of them use the line guidance system, which is the traditional AGV drive system. In addition, the demand for AGV system developers, system operators and managers, and maintenance personnel is increasing, and the installation of systems for education is expensive and requires a large space to utilize. It is a situation where systematic education is difficult. In this paper, we propose a virtual simulation-based AGV distance education model for smooth practice of trainees. The proposed model consisted of a model that can drive the AGV by analyzing video information, instead of the line guidance method that is the conventional technology. As a result of self-diagnosis evaluation, it was confirmed that the experimental group through online education had an average satisfaction level of 0.65 higher than the control group using existing equipment, and that it could be used in an online education environment.

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

  • 조동권
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.6 no.6
    • /
    • pp.827-832
    • /
    • 2002
  • The development of dedicated network management system is essential to meet the following conditions: the system must run the configuring and repair processing for the dedicated communication network, and can manage new next generation data dedicated communication network of various types. In general it is effective that the system is consisted of decentralized module to be accessible for business logic and datum to remote area. To solve these problems, a method is to use object-oriented design techniques. That is, it is to abstract reusability objects and make component module using the abstracted objects. In this paper, we propose a management system of dedicated communication network service using object-oriented design techniques which are UML(Unified Modeling Language).