• Title/Summary/Keyword: UPS Function

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Correlation between Ferromagnetic State and Thermally Stable Layer of Fe on the W(001) Surface

  • Sin, Min-Jeong;Park, Byeong-Gyu;Hwang, Chan-Yong;Lee, Han-Gil
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.173.1-173.1
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    • 2014
  • The variations of electronic and magnetic properties of ultrathin Fe overlayers on a W(001) surface as a function of Fe film thickness (1.0~4.0 ML) has been investigated using x-ray magnetic circular dichroism (XMCD) in conjunction with ultraviolet photoelectron spectroscopy (UPS) and low energy electron diffraction (LEED). We found that the ferromagnetic property of Fe film started to build up over 2.0 ML, as we confirmed the spin and angular moment contribution to the magnetic moment using XMCD experiments. We will systematically demonstrate that the occurrence of ferromagnetic property of Fe film on a W(001) surface is closely correlated to a themally stable layer of Fe film on a W(001) surface.

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A Study on UPS with Active Power Filter Function (능동전력필터기능을 갖는 UPS에 관한 연구)

  • Park, In-Seok;Lee, Jeong-Joon;Sung, Nark-Kuy;Oh, Bong-Hwan;Kim, Sung-Nam;Han, Kyung-Hee
    • Proceedings of the KIEE Conference
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    • 1998.07f
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    • pp.2178-2180
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    • 1998
  • Recently, for increasing consumed power and informational society, confidence of power supply is demanded. Beside, owing to most of these loads are nonlonear, utility line is polluted by these components, therefore, it is demanded compensation of harmonic current. In times past, special order of harmonic current is only compensated by passive filter, but active power filter can compensate whole harmonic current. Therefore, this paper propose uninterruptable power supply(UPS) with performance of active power filter.

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Design and Performance Evaluation of UPS System with the Circulating Function of Inverter Output Power (인버터 출력전력 순환기능을 갖는 무정전 전원공급 시스템의 설계 및 성능평가)

  • Lee, Dong Ju;Paik, Seok Min
    • Proceedings of the KIPE Conference
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    • 2013.07a
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    • pp.143-144
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    • 2013
  • 당사가 개발한 무변압기형 UPS는 정상 운전동작시에는 인버터 출력전압 고조파 함유율을 최소화하고 순환부하시험 동작시에는 인버터 출력전류 고조파 함유율을 최소화시킬 수 있는 출력필터가 필요하다. 그래서 본 연구에서는 이러한 두 설계조건을 만족하도록 하는 출력필터 설계절차를 설명하였고 그 설계절차의 타당성을 확인하기 위해서 설계된 인버터 출력필터를 적용한 3상 10kVA UPS 시제품을 제작하여 순환부하시험을 통하여 그 성능을 확인하였다.

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Development of a algorithm for thermal stress analysis of turbine rotor (터빈 로터 열응력 해석 알고리즘 개발)

  • Chang, S.H.;Baek, S.K.;Chung, C.G.
    • Proceedings of the KIEE Conference
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    • 1998.07g
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    • pp.2284-2289
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    • 1998
  • The Rotor Stress Indicator is an integrated system of hardware and program components which has been designed to read an assortment of turbine temperature and speed input devices, perform an analysis of the temperature induced stresses and output pertinent temperature and stress information to guide the turbine operator during turbine prewarming, start-ups, load changes, and shut-downs. The purpose of the RSI is to provide guidance to the plant operator during startup, shutdown, loading, and unloading of the turbine. Since the stresses are a function of the temperature changes to which the turbine is exposed, the RSI also provides guidance for operation of the boiler main steam and reheat steam temperatures as they affect the rotor stresses. This may permit more efficient overall boiler turbine start-ups. In this paper, new rotor stress analysis algorithm for RSI is introduced and compared with present system which has been used in thermal power plant.

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A Study of Line-Interactive UPS with Voltage Compensator (Line-Interactive 전압보상기에 관한 연구)

  • Woo Sung-Min;Kang Dae-Wook;Lee Woo-Cheol;Choi Chang-Ho;Hyun Dong-Seok
    • Proceedings of the KIPE Conference
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    • 2001.07a
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    • pp.487-490
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    • 2001
  • Power Quality and Reliability are becoming important issues for critical and sensitive loads. This paper describes the Line Interactive UPS with the function of Voltage Compensator that is 'Line interactive Dynamic Voltage Restorer(LIDVR). The main purpose of a LIDVR is to compensate for voltage sag(dip), outage and overvoltage. The overall system consists of three controller 1) current controller with prediction 2) voltage controller and 3) proposed variable DC LINK controller. The variable DC LINK control technique using the LIDVR protects DC LINK from overflowing the input current. The simulation results are depicted in this paper to show the effect of this proposed system.

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The Effect of Circuit Weight Training on the Muscular Function and Cardiopulmonary Function (육상과 선박내에서의 Circuit Weight Training 이 근기능 및 심폐기능에 미치는 영향)

  • 하해동;신군수
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1998.04a
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    • pp.163-185
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    • 1998
  • The purpose of this study was to analyze the physiology changes by circuit weight training(CWT). The subject of this study consists of 16 student on ship(experimental groups(SE) N=8, control group(SCa) N=8) and 16 students on land (experimental groups(LE) n=8, control groups(LCb) N=8). The items of measurement were the changes of CWT time and heart rate per week, musclear functino and cardiopulmonary function. The conclusions are as follows : 1. Muscular fuction 1) Back strength in SE and LE group was increased significantly (p<.01, p<.05, 8.86% and 7.08%).Grip strength was increased slightly in 4 groups but there was no significance. 2) In push-ups, all 4 groups were increased significantly (p<.05, p<.01), sit-ups also were increased significantly in SE and LE group (p<.05, 6.71% and 9.62%). 3) In SE and LE group , standing long jump was in significantly (p<.01, p<.05, 4.49% and 6.09%), but only in LE group , side step was increased significantly (p<0.1, 5.84%). 2. Cardiopulmonary function 1) HRrest was decreased slightly in all 4 groups but was not significant changes. HRmax was increased only in LE group significantly (p<.05, 2.81%), treadmill running time was increased significantly in SE and LE group respectively (p<.01, p<.05, 10.78% and 11.07%). 2) VEmax was increased significantly in SE and LE group(p<.05, p<.01, 10.59% and 13.68%), but only in LE group Rfmax was increased significantly (p<.01, 4.83%). 3) In VO2max, LCb group was increased significantly (p<.05, 6.835), but SCa group was decreased significantly (p<.05, 4.32). VO2max/kg$.$min was increased significantly in LE and LCb group respectively (p<.01 p<.05. 4.75% and 3.98%).

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Signaling Effects of Government Support on Investment Attraction of Technology-based Start-ups: An Empirical Study of a Hurdle Model (기술창업기업의 투자유치에 대한 정부지원의 신호효과: 허들모형을 이용한 실증연구)

  • Bong, Kang Ho;Kwon, Jihun;Kim, Kyu-Tae
    • Korean small business review
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    • v.42 no.4
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    • pp.309-326
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    • 2020
  • There often is information asymmetry between start-ups and the investors, which is because start-up companies in the early stages do not have track records. Meanwhile, since the government grants programs go through a fair and the intense competition process, the government grants can provide a more objective information for start-ups in the early stages and perform a signal function that guarantees a company's capabilities and potential. This study confirms the quantitative relationship between government grants and investment attraction by using the hurdler model. We found that, although there is the proportionate relationship between the scale of government grants and that of external funds, more than a certain amount of government grants is required for technology-based start-ups to exceed the stage of attracting their first external funds. Our findings suggest that it is necessary to consider the hurdles structure in the study of signaling theory perspective, as the mechanisms for determining whether or not to attract external funds are different from determining the level of external funds. In addition, differentiated policy support is needed to help early-stage technology start-ups go beyond the threshold of investment attraction-the creation of a 'threshold effect'.

The Effect of Health Exercise Program on the Body Composition, Cardiopulmonary Function, Physical Fitness in Middle-Aged Women (건강운동 프로그램이 중년여성의 신체조성과 심폐기능 및 체력에 미치는 영향)

  • 김도희
    • Korean Journal of Health Education and Promotion
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    • v.18 no.3
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    • pp.177-186
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    • 2001
  • The purpose of this study was to investigate the of regular worksite health exercise program participation on related fitness. Subject for study were 34 middle-aged women in Kwangju-city. To achieve this, body composition, cardiopulmonary function, physical fitness of every subjects were measured before and post regular health exercise program participation during 12 week. The results of this study were as follows: 1. Regular health exercise program participation result from improving the body composition, but there is not significant different statistically(p〈.05). 2. Significant differences were observed in the cardiopulmonary function(vital capacity, VO$_2$ max) after regular exercise program during 12 week(p〈.05). 3. Significant differences were observed in the flexibility(sitting trunk flexion), abdominal endurance(sit-ups), power (standing high jump), agility(trunk reaction time) after regular exercise program during 12 week(p〈.05).

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Active Power Filter with Voltage Compensating Function (전압보상 기능을 갖는 능동 전력 필터)

  • Kang, Sung-Kon;Lee, Kwang-Joo;Choe, Ki-Won;So, Jung-Hwan;Choe, Gyu-Ha
    • Proceedings of the KIEE Conference
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    • 1994.07a
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    • pp.334-336
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    • 1994
  • The conventional APF(Active Power Filter) system performs only function which is compensated for source harmonic by injecting harmonic compensation current as well as reactive power component by PWM. This paper presents a new APF which provides the combined functions of VC(Voltage Compensator) and conventional APF, because the structure of APF is similar to stand- alone UPS in parallel type. Single-chip microprocessor plays an important role in controlling each function. Simulation obtained from ACSL are shown to verify multi-functions of new APP.

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The Effect of Satisfaction Level with the University Entrepreneurship Education, Recognition of Support System, and Mentoring on the Entrepreneurial Intention: The Moderating Effect of Entrepreneurial Self-Efficacy (대학생의 창업교육 만족도와 창업지원제도인식, 창업멘토링이 창업의지에 미치는 영향: 창업효능감을 조절효과로)

  • Yu, Young Cheul;Lee, Won Il
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.2
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    • pp.187-200
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    • 2023
  • The purpose of this study is to examine how the start-up education, start-up support system, and start-up mentoring directly and indirectly conducted in universities affects entrepreneurial Intention, and to present programs and directions that can increase the possibility of start-up for college students. This study analyzed the effects of college students' satisfaction with university entrepreneurship education, awareness of the entrepreneurship support system, and entrepreneurship mentoring on entrepreneurial will, and then analyzed how entrepreneurship efficacy affects entrepreneurial will as a moderating effect. The recognition of the start-up support system was divided into the government start-up support policy and the university start-up support project, and start-up mentoring was divided into mentoring function (problem-solving function, networking function, communication function, motivation function) and mentor trust (cognitive trust, emotional trust). Regression analysis was performed on satisfaction with college entrepreneurship education, perception of entrepreneurship support system, entrepreneurship mentoring as independent variables, and willingness to entrepreneurship as dependent variables. In addition, entrepreneurship efficacy was designated as a moderating variable and analyzed. As a result of the study, first, it was found that satisfaction with start-up education had a positive (+) effect on college students' willingness to start a business. Second, among the start-up support systems, university start-up support projects were found to have a positive (+) effect on college students' willingness to start a business. Third, as a result of verifying whether entrepreneurial self-efficacy has a moderating effect on the relationship between college start-up support projects and college students' willingness to start a business while recognizing the start-up support system, it was found to have a moderating effect. The following implications can be derived based on the analysis results of this study. First, efforts to improve start-up education will be needed to increase the satisfaction of start-up education. Second, Through the operation of the start-up counseling center in the university, it will be possible to recognize the education system supported by the university, the university start-up support project that can carry out the indirect experience of start-up, and the government start-up support policy that supports funds. Third, It will be necessary to open a program that can provide start-up mentoring through connection with mentors in the start-up field, such as professors, employees, and senior start-ups in universities. Fourth, It is necessary to develop thorough education on the preparation process of start-ups, start-up special lectures where senior start-ups can indirectly experience the failure of start-ups, and programs for customized start-up education according to college students' major and individual tendencies.

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