• 제목/요약/키워드: current standard

검색결과 3,805건 처리시간 0.037초

20,000 A 전류변성기 국가표준 시스템 구축 (Establishment of National Standard System for 20.000 A Current Transformer)

  • 정재갑;이상화;강전홍;김명수;김윤형;한상길;한상옥
    • 전기학회논문지P
    • /
    • 제57권1호
    • /
    • pp.6-13
    • /
    • 2008
  • National standard system for calibrating current transformer(CT) up to primary current of 20,000A have been established. The system consists of 20,000 A AC high current source, CT comparator, standard CT, CT under test and CT burden. An AC high current is applied tn the primary windings of both the standard CT and the CT under test, and then the CT comparator measures the ratio error and the phase displacement by comparing the secondary currents of the two transformers. As a validity check for 20,000 A CT calibration system, the comparison with the two national standard institutes(NMIs) has been performed using same CTs. The comparison results of the CTs are consistent with those measured at two NMIs within 0.004 % for ratio error and 0.1 min for phase displacement in the primary current ranges of Ip = 10 - 20,000 A with a secondary current of Is = 5 A.

교류전류 1차 표준용 열전형 전류변환기의 제작 (Fabrication of the Thermal Current Converters as the Primary AC Current Standard)

  • 권성원;이래덕
    • 센서학회지
    • /
    • 제1권1호
    • /
    • pp.77-83
    • /
    • 1992
  • 저주파에서의 교류전류 1차표준은 교류-직류 변환기를 이용하여 직류전류표준으로부터 유도된다. 전류측 정범위 $5mA{\sim}20A$, 주파수범위 $10Hz{\sim}100kHz$에서 교류전류의 1차표준기로 사용될 15개의 교류-직류 열전형 전류변환기를 제작 및 평가한 결과, 이를 이용한 교류전류표준의 유지 및 보급의 측정 불확도는, 주파수 20 kHz이 하에서 측정 전류 20 mA까지는 최대 52 ppm, 100 mA까지는 60 ppm으로 확인되었고, 측정 전류 및 주파수가 증가함에 따라 200 ppm까지 증가하는 것으로 나타났다.

  • PDF

주거용 건축물의 재실자밀도 기준 적정성 평가에 관한 연구 (A Study on the Adequacy Evaluation of Criteria of Occupant Load Factor in Residential Buildings)

  • 서동구;황은경
    • 한국주거학회논문집
    • /
    • 제27권6호
    • /
    • pp.145-153
    • /
    • 2016
  • The purpose of this study is to grasp the effectiveness of evacuation safety design by verifying the appropriateness of the standard of occupant load factor for residential buildings. To this end, the definition and current standard of occupant load factor for residential buildings were analyzed, and the problems of the current standard were clarified by interviewing professionals. In addition, changes in occupant load factor were examined by year based on statistical research, and evaluation on the current standard $18.6m^2/pers.$ was performed. As for evaluation methods, the need of redesigning of evacuation capacity was investigated by using evacuation simulation. As a result of the analysis, the most serious problem was clarification of the applicable standard for residential officetel, where the average occupant load factor was $26.1m^2/pers.$, which was not appropriate. However, as a result of evaluation on evacuation capacity, although there was no difference between statistical research results and the current standard in terms of evacuation capacity, when the standard for business facilities was applied to officetel, evacuation time doubled. Thus, this study suggests that when the current standard is applied to residential officetel, it is necessary to separate between residential use and business use.

전류변성기 비교측정 장치의 현장 평가기술 (On-Site Evaluation Technique of Current Transformer Comparator System)

  • 정재갑;이상화;권성원;강전홍;김명수
    • 전기학회논문지
    • /
    • 제56권5호
    • /
    • pp.926-932
    • /
    • 2007
  • A recently developed methods for on-site calibration of the current transformer (CT) comparator system have been reviewed in the paper. The method utilizes several traveling standards, which consist of the CT, non-reactive standard resistors, wide ratio error CT, and shunt resistors. The traveling CT is used for absolute evaluation of a standard CT belonging to industry. The non-reactive standard resistors and a wide ratio error CT are used for the linearity check of errors in the current comparator. The shunt resistors are used for evaluation of CT burden of industry.

20 kA 교류 대전류 국가표준 시스템 구축 (Establishment of 20 kA AC High Current National Standard System)

  • 정재갑;이상화;강전홍;권성원;송양섭;김명수
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2007년도 제38회 하계학술대회
    • /
    • pp.1412-1413
    • /
    • 2007
  • 20 kA AC high current national standard system has been established with a purpose for support of heavy electrical industry. The system consists of high AC current source, the standard current transformer, current transformer comparator and current transformer burden, and current transformer under test.

  • PDF

40,000 A 로고스키 코일 평가 시스템 구축 (Establishment of Evaluation System for 40,000 A Rogowski Coil)

  • 김윤형;한상길;정재갑;강전홍;이상화;한상옥
    • 전기학회논문지P
    • /
    • 제58권2호
    • /
    • pp.202-206
    • /
    • 2009
  • Evaluation system for calibrating Rogowski coiI(RC) up to primary current of 40,000 A have been established. The system consists of 40,000 A AC high current source, current transformer(CT) comparator, standard CT, RC under test, voltage to current convertor(VCC), buffer and CT burden. An AC high current is applied to the primary windings of both the standard CT and the RC under test, and then the CT comparator measures the ratio error and the phase displacement by comparing the secondary current of the standard CT with output current of VCC. For testing of RC, we have evaluated two RCs under test of primary current ranges of 0 A ${\sim}$ 2,000 A and 0 A ${\sim}$ 40,000 A with the accuracy class of 1 %. The extended uncertainty is 0.02 % ${\sim}$ 0.23 % for ratio error and 0.29 min ${\sim}$ 1.93 min for phase displacement in the primary current ranges of 10 ${\sim}$ 40,000 A.

비소세포폐암에 사용되는 항암화학요법의 요양급여기준 적절성 평가 (Assessment of Appropriateness of Standard for Insurance Coverage on Chemotherapy used in Non-small Cell Lung Cancer (NSCLC))

  • 김정연;박은지;배민경;윤정현
    • 한국임상약학회지
    • /
    • 제21권3호
    • /
    • pp.193-207
    • /
    • 2011
  • Purpose: The purpose of this study is to assess appropriateness of current standard for insurance coverage by Health Insurance Review & Assessment Service (HIRA) on chemotherapy used in the treatment of advanced non-small cell lung cancer (NSCLC), by reviewing a variety of clinical evidences, and thereby, if needed, to propose an updated evidence-based recommendations. Methods: We collected data from HIRA regarding on the insurance standard which includes the scope and conditions for coverage on systemic chemotherapy of NSCLC. We performed a search for clinical databases and examined the most current clinical evidence from clinical literature including various clinical practice guidelines. Based on the collected data the appropriateness of HIRA standard for insurance coverage of chemotherapy of NSCLC was assessed. Results: Collected data demonstrated that HIRA standard did not reflect the most current clinical practice and evidence. Some were inappropriately listed in HIRA formulary and accepted as a chemotherapy being covered by insurance, despite the lack of evidences of clinical efficacy or superiority over other chemotherapeutic agents or regimens. In addition, there seems to be a need for a modification on the standard for insurance coverage of certain newer chemotherapeutic agents based on the current accumulated data showing their clinical efficacy and benefits in the selected group of NSCLC patients. Therefore, we concluded that current HIRA standard for insurance coverage on chemotherapy of NSCLC needs to be revised and we proposed an updated recommendation based on these latest clinical evidences. Conclusion: The standard for insurance coverage of chemotherapy should be continually examined its appropriateness based on the most recent clinical evidences in a timely manner so as to provide the most effective and safe therapy to cancer patients.

수요기반 환기량 조절법 (DCV)의 다중이용시설 적용방안 (The Use of Demand Controlled Ventilation in Multi-Purposed Facility)

  • 정재원;노상태
    • 한국태양에너지학회:학술대회논문집
    • /
    • 한국태양에너지학회 2008년도 춘계학술발표대회 논문집
    • /
    • pp.111-116
    • /
    • 2008
  • The objective of this paper was to show the possibility of demand-controlled ventilation (DCV) using the current Korean ventilation standard for multi-purposed facilites. Two attractive DCV approaches; $CO_2$-DCV and RFID-DCV were applied to DCV simulations for a theoretical public assembly space served by a dedicated outdoor air system (DOAS) with enthalpy recovery device. A numerical model for predicting realtime occupant number, ventilation rate, and $CO_2$ concentration under given conditions was developed using a commercial equation solver program. It was found that the current ventilation standard causes unstable ventilation system control in DCV applications, especially under $CO_2$-DCV. It is because the ventilation rate (per person) used in Korea is the sum of the outdoor air required to remove or dilute air contaminants generated by both occupant and building itself, and not a pure function of occupant numbers. Finally, it makes DCV control unstable when ventilation flow is regulated only by the number of occupants. In order for solving this problem, current Korean ventilation standard was modified as a form of ASHRAE Standard 62.1-2007 showing good applicability to various DCV approaches. It was found that this modification enhances applicability of the current ventilation standard to DCV significantly.

  • PDF

표준원가 분석을 통한 재활용 기준비용 재산정에 관한 연구 (A Study on Re-calculation of Recycling Standard Cost through the Analysis on Standard Cost)

  • 이희남;최윤정
    • 대한안전경영과학회지
    • /
    • 제13권1호
    • /
    • pp.189-193
    • /
    • 2011
  • The current standard cost for recycling applied under the Extended Producer Responsibility(EPR) institution, is not coping with continuously increased number of obligatory subject items as well as a variety of variable cost changing factors regarding the recycling treatment cost caused by price fluctuation such as increased material and labor cost entirely across the society; changes in recycling treatment process following the developing technologies; and changes in the required work forces and equipments followed by the trends of automated facilities. Despite such various cost fluctuation factors, the current EPR is not coping with the trends, making the re-calculation process difficult, which causes differences between the real treatment cost for recycling. In this study, the analysis was made on main factors affecting on the related cost and the related price changing index was calculated, by conducting the influence evaluation on the standard cost factors of the current standard cost for recycling. Through theses results, more objective standard will be set for the re-calculation of standard cost for recycling to greatly contribute to setting up the midterm and long-term strategies in the future towards efficient institution.

무기 전자 수송층으로 TiO2 나노입자를 사용한 다양한 양자점 전계발광 소자의 특성 비교 연구 (A Comparison Study on Various Quantum Dots Light Emitting Diodes Using TiO2 Nanoparticles as Inorganic Electron Transport Layer)

  • 김문본;윤창기;김지완
    • 마이크로전자및패키징학회지
    • /
    • 제26권3호
    • /
    • pp.71-74
    • /
    • 2019
  • 본 연구는 발광층으로의 전자 주입을 억제하기 위해 ZnO 나노입자보다 낮은 전자 이동도를 갖는 $TiO_2$ 나노입자를 무기 전자 수송층으로 사용하여 standard와 inverted 두 가지 구조의 양자점 전계발광 소자를 제작하고 그 특성을 비교하였다. Standard 구조의 소자에서는 전류 밀도가 낮은 것에 비해 inverted 구조의 소자에서는 전류 밀도가 매우 높은 것을 확인하였다. 휘도의 경우 inverted 구조의 소자가 standard 구조의 소자보다 더 높았지만 높은 전류 밀도로 인해 낮은 전류 효율을 나타냈다. 또한 전류 밀도가 높은 만큼 구동 전압이 높았으며, 방출 파장 스펙트럼에서 적색 편이를 확인하였다. Standard 구조의 소자에서 나타난 낮은 전류 밀도를 통해, $TiO_2$ 나노입자가 양자점 전계발광 소자에서 전자 주입을 억제할 수 있는 가능성을 확인하였다.