• 전기학회논문지
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• 제66권7호
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• pp.1059-1065
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• 2017

In this paper, the energy harvester with a piezoelectric materials is modeled as the electric equivalent circuit, and performances of a standard DC method and a Parallel-SSHI method are verified through experiment under variable force and load conditions. Piezoelectric generator consists of mass, damper and spring constant, and it is modeled by electrical equivalent circuit with RLC components. Standard DC and Parallel-SSHI are used as power conversion methods, and standard DC consists of full-bridge rectifier and smoothing capacitor. Parallel-SSHI method is composed of L-C resonant circuit, zero-crossing detector and full-bridge rectifier. In case of simulation under $100k{\Omega}$ load condition, the harvested power is $500{\mu}W$ in Standard DC and $670{\mu}W$ in Parallel-SSHI, respectively. In experiment, the harvested power under $100k{\Omega}$ load condition is $420{\mu}W$ in standard DC and $602{\mu}W$ in Parallel-SSHI. Harvested power of Parallel-SSHI is improved by approximately 40% more than that of standard DC method.

• Journal of Electrical Engineering and Technology
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• 제6권5호
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• pp.677-683
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• 2011

The present paper describes the setup of standard partial discharge calibrator for measuring partial discharge and estimating uncertainties. The standard PD calibrator was designed and set up, consisting of a digital pulse generator, capacitor modules, and a digital oscilloscope controlled by software developed in the laboratory. Using this software, averages of charges and rising times and their standard deviations in the measured pulses can also be calculated. The standard PD calibrator generates five types of pulses: single, double, random, oscillating, and long-rising. The coefficient sensitivities to estimate the uncertainties of pulses were extracted in the model circuit of the standard PD calibrator. The uncertainties of charges and rising times in pulses of the standard PD calibrator were estimated with single pulses. These values were 0.3%-1.4% in charges and 1.9%-7.0% in rising time; however, these values are lower than the limit values in IEC 60270.

• 한국산업보건학회지
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• 제25권1호
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• pp.1-12
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• 2015

Objectives: The major objectives of this study are to review the U.S. Standard which affected Korean worker's Right-to-Know Standard and to propose the way of improving the reliability of MSDS and labels. Methods: To review the U.S. Standard historically, we used the Federal Register, other criteria documentation and peer-reviewed literatures. Then we analysed major issues in the historical debatement on the worker's Right-to-Know Standard. Results: Korean MSDS Standard benchmarked the U.S. Hazard Communication Standard which finally established by President Reagan in 1983. Reagan's Hazard Communication Standard was aimed to preempt States Right-to-Know Acts for chemical industry and not to improve the awareness of workers on chemical hazards. Too much protection on trade secrets and low reliability of hazard information were key problems of the U.S. Standard. Conclusions: We recommend some ways to improve Korean MSDS and Label Standard. First, A new analysis frame is needed to understand the U.S Standard. Second, hazard identification is the key element of reliable information and chemical name and CAS number should be on the label of the container. Third, trade secrets should be limited to low hazardous substances and be permitted by government before the chemical product is on the market.

• 한국물환경학회지
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• 제20권5호
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• pp.432-436
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• 2004

The principle and methodology of risk assessment was applied to establish the quality standard of potential impurities of drinking water treatment chemicals. The impurities(arsenic, lead, cadmium, chromium, mercury, etc.) are regulated as the contained quantity of chemicals in Korea while they are regulated as the quality standard with the idea of 10% of the national safety drinking water standard in U.S.A(NSF) and Japan(JWWA). According to risk assessment of the current standard implemented in Korea, the excess cancer risk of arsenic and lead were determined in around $10^{-5}$ and the hazard quotient(HQ) of cadmium and chromium were below $10^{-2}$, respectively. And the standard concentration of the impurities are regulated as much as 2%~6% of the national drinking water quality standard. The values are more enforced rather than the standards in U.S.A(NSF) and Japan(JWWA) regulating the concentration of impurities the 10% of the national drinking water quality standard. We conclude that the impurities standard of drinking water treatment chemicals should be reconsidered comprehensively concerning the national safety drinking water quality standard and risk assessment.

• 한국지리정보학회지
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• 제20권3호
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• pp.52-66
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• 2017

본 연구는 풍수해 피해예측지도 활용 고도화에 필요한 표준 메타데이터를 시범 설계하고, 이를 기반으로 표준메타정보관리 프로토타입 시스템 구축을 목적으로 하였다. 이를 위해, 국내 외 메타데이터 표준 현황 조사를 통해 가장 활용도가 높은 것으로 분석된 ISO/TC211 19115 국제표준을 기반으로 표준 메타데이터 설계 방향을 설정하였으며, 식별정보, 기준계정보, 배포정보 등 9개의 클래스로 구분하여 메타데이터를 시범 설계하였다. 또한, 본 연구에서 설계한 표준 메타데이터를 바탕으로 메타속성정보를 확인 및 다운로드할 수 있는 표준메타정보관리 프로토타입 시스템을 HTML 기반 JAVASCRIPT 언어로 구축하였다. 본 연구결과를 활용한다면, 표준화된 통합 풍수해 피해예측지도 데이터베이스 구축을 통해 향후 구축되는 피해예측지도의 품질유지가 가능해지며, 풍수해 피해예측 시스템 운영에 필요한 데이터 관리 및 제공 등을 통해 효율적인 재난대응에 활용가능할 것으로 사료된다.

• 동의생리병리학회지
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• 제23권4호
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• pp.779-788
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• 2009

To establish the fundament for EBM of Traditional Korean Medicine, the papers on Samul-tang which was frequently used in medical institutions of Traditional Korean Medicine were analyzed through researching domestic and international literatures. The papers were classified by the registration of domestic or international journals, by the year of publishment, by experimental methods, by laboratory animals used in biological experiment and by the kinds of studies on biological efficacy. Of total 67 papers on Samul-tang, 58 volumes were registered in domestic journals and 9 volumes were in international journals of which 8 volumes were in SCI journals. Since 1978, publishments of papers have continuously increased. The papers on instrumental analyses were 6, biological studies were 58 volumes, clinical studies were 3. Instrumental analyses were preceeded with standard compounds(gallic acid, albiflorin, paeoniflorin, benzoic acid, ferulic acid, 5-HMF). And biological studies showed improvement of cardiovascular function and circulation, antianemia, brain protection, immunoregulation, antistress, radioprotection, antifatigue, antiinflammation and antiallergy, antioxidative effect. Through clinical studies, antifatigue, improvement of insomnia and osteoporosis were reported. Samul-tang could be used to tonify and activate blood. And further study on clinical field need to be conducted in accordance with biological study.

• 센서학회지
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• 제1권1호
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• pp.77-83
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• 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.

• 한국식품과학회지
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• 제5권4호
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• pp.197-200
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• 1973

1. 양조폐수장, 폐수구에서 분리한 K-73-3은 초산염을 자화하여 L-G, A를 20g/l 생산하였다. 2. 분리된 균주는 형태학적, 생리학적, 분류학적, 배양학적인 특성으로 보아 Corynebacterium glutamicusnov sp.로 간주된다.

• 센서학회지
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• 제30권5호
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• pp.349-356
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• 2021

The Korea Research Institute of Standards and Science (KRISS), a National Metrology Institute of Korea, participated in the second-round of the international key comparison CCT-K7.2021 of triple point of water (TPW) cells. For the key comparison, three TPW cells, one of which had been used in the old CCT-K7 comparison, were assigned as the national standard of the TPW. The temperature difference (ΔT) between the average of the new and old national standards and ΔT between the new national standard and the transfer standard were measured. The comparison between the new and old national standards indicated a temperature increase of 69.5 µK after both the standards were corrected for the isotopic composition. The uncertainty of the national standard of the TPW temperature was 28 µK, and the uncertainty of ΔT was 14 µK. Three aspects of improvements in the new comparison compared to the old one were noted: (1) inclusion of two quartz cells in the national standard strengthens its long-term stability; (2) the standard deviation associated with the measurement of ΔT was reduced from 21 µK to 9.6 µK; (3) and the measured immersion profile of the TPW cells was much closer to the theoretically predicted dependence.

• 식품산업과 영양
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• 제21권2호
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• pp.1-7
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• 2016