• Title/Summary/Keyword: Primary standard

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Comparison of the Sulfur Dioxide Primary Standard Gases of NPL and KRISS

  • O, Sang Hyeop;Kim, Byeong Mun;Mun, Dong Min;Kim, Jin Seok
    • Bulletin of the Korean Chemical Society
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    • v.22 no.12
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    • pp.1341-1344
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    • 2001
  • Comparison of sulfur dioxide primary standard gases of the Korea Research Institute of Standards and Science (KRISS, Korea) and the National Physical Laboratory (NPL, UK) was performed. 100 ${\times}$10-6 mol/mol and 1,000 ${\times}$10-6 mol /mol primary standard gases (designated NPL S115 and S114, respectively) prepared gravimetrically and validated in NPL were used as transfer standards. Transfer standards were analyzed by NDIR sulfur dioxide analyzer and compared with KRISS PSM 112-03-624 and PSM 112-03-625 prepared gravimetrically. Adsorption corrected relative deviations of the primary standard gases were agreed to within 0.1%, and this agreement is within the expanded uncertainties (k = 2) of the primary standards at the two laboratories.

Myringoplasty Outcomes From a 5-Year Single Surgeon's Experience and Important Surgical Technical Aspects

  • Karunaratne, Dilhara;Violaris, Nick
    • Journal of Audiology & Otology
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    • v.25 no.4
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    • pp.224-229
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    • 2021
  • Background and Objectives: The United Kingdom (UK) national standard for the closure rate for myringoplasty is 89.5% (90.6% and 84.2% for primary and revision surgeries, respectively). The average hearing gains for primary and revision myringoplasty are 9.14 dB and 7.86 dB, respectively. This study compared the myringoplasty outcomes for a single surgeon over 5 years. Subjects and Methods: Data for 68 cases were analyzed retrospectively. The outcome measures were achievement of the tympanic membrane closure and the average hearing gain or loss. Results: The overall and primary closure rates were 97% and 98%, respectively and significantly higher than the UK national standard (p=0.0210 and p=0.0287, respectively). The revision closure rate was 93%; however, it was not significantly higher than the national standard (p=0.1872). The average hearing gain was 5.18 dB. The gains for primary and revision surgeries were 5.15 dB and 5.25 dB, respectively. Conclusions: We propose that these outcomes are a result of our surgical technique, including the simultaneous use of cortical mastoidectomy in ears with discharge.

Myringoplasty Outcomes From a 5-Year Single Surgeon's Experience and Important Surgical Technical Aspects

  • Karunaratne, Dilhara;Violaris, Nick
    • Korean Journal of Audiology
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    • v.25 no.4
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    • pp.224-229
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    • 2021
  • Background and Objectives: The United Kingdom (UK) national standard for the closure rate for myringoplasty is 89.5% (90.6% and 84.2% for primary and revision surgeries, respectively). The average hearing gains for primary and revision myringoplasty are 9.14 dB and 7.86 dB, respectively. This study compared the myringoplasty outcomes for a single surgeon over 5 years. Subjects and Methods: Data for 68 cases were analyzed retrospectively. The outcome measures were achievement of the tympanic membrane closure and the average hearing gain or loss. Results: The overall and primary closure rates were 97% and 98%, respectively and significantly higher than the UK national standard (p=0.0210 and p=0.0287, respectively). The revision closure rate was 93%; however, it was not significantly higher than the national standard (p=0.1872). The average hearing gain was 5.18 dB. The gains for primary and revision surgeries were 5.15 dB and 5.25 dB, respectively. Conclusions: We propose that these outcomes are a result of our surgical technique, including the simultaneous use of cortical mastoidectomy in ears with discharge.

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

  • Kwon, Sung-Won;Lee, Rae-Duk;Klonz, Manfred
    • Journal of Sensor Science and Technology
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    • v.1 no.1
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    • pp.77-83
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    • 1992
  • A primary standard of ac current at low frequency is derived from the standard of dc current by ac-dc transfer instrument. A set of 15 thermal current converters(TCCs) have been constructed as the primary current standards from 5 mA to 20 A at the frequency range of 10 Hz to 100 kHz. It is evaluated that the uncertainties for the maintenance and dissemination of ac current standard are less than 52 ppm up to 20 mA and 20 kHz, 60 ppm up to 100 mA and 20 kHz, and rising to 200 ppm at higher currents and frequencies.

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

  • Jung, Jae-Kap;Lee, Sang-Hwa;Kang, Jean-Hong;Kim, Myung-Soo;Kim, Yoon-Hyoung;Han, Sang-Gil;Han, Sang-Ok
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.57 no.1
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    • pp.6-13
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    • 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.

Energy Performance Evaluation of A Primary School Building for Zero Energy School (제로에너지 스쿨을 위한 초등 교육시설의 에너지 성능평가)

  • Yoon, Jong-Ho;Shin, U-Cheul;Cho, Jin-Il;Park, Jae-Wan;Kim, Hyo-Jung;Lee, Chul-Sung
    • 한국태양에너지학회:학술대회논문집
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    • 2009.04a
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    • pp.121-126
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    • 2009
  • This study analyzed the standard school's energy usage and patterns as the zero-energy goal of primary school building, and proposed the energy reduction process of school building using energy analysis computing simulation tool. As a analysis simulation tool, Visual DOE 4.0 is used. For analysis of actual energy usage, selected primary school that is standard in the nation's energy consumption. Standard of the school's energy consumption analysis were devided into electric and gas energy. Input parameters of the simulation program based on the literature material and field survey material. after, but it was calibrated to comparison with the standard school's energy consumption. Finally, its energy usage analyzed by component and made the priority order of energy saving. Applied energy saving technologies are envelopment insulation, high efficiency lighting, high performance HAVC system and used active equipment system of solar collector and photovoltaic generation for additional savings.

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Manufacture Research of Gradual Standard Color Chart for the Capacity of Reinforcement of Practical Color Coordinate Education (색채활용교육의 역량강화를 위한 단계별 표준색표집의 제작 연구)

  • Lee, Kyung-Hee
    • Fashion & Textile Research Journal
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    • v.13 no.3
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    • pp.332-345
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    • 2011
  • This research designed usable standard color chart which was planned by hue and tone color system. This research studied 5 types standard color chart by designed tone map and preceding research. "Basic Color Chart 14 Colors" was planned for kindergarteners. "Primary Color Chart 63 Colors" was planned for schoolboys. "Middle Grade Color Chart 114 Colors" was planned for junior high school students. "High Grade Color Chart 152 Colors" was planned for senior high school students. "Hue and Tone 205 Colors" was planned for university students and general publics. These 5 types standard color chart were produced the trial color coordinate card and attached the Munsell notation which could reappear the spare color paper when needed. These 5 types standard color chart would be offered the data base for efficient color coordinate education as school age.

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

  • Kim, Yoon-Hyoung;Han, Sang-Gil;Jung, Jae-Kap;Kang, Jeon-Hong;Lee, Sang-Hwa;Han, Sang-Ok
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.2
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    • pp.202-206
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    • 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.

An Exploratory Study on Domestic and International Protective Clothing Standard - Focused on ISO, ASTM, CEN, KS - (보호복 관련 국내·외 표준에 대한 탐색적 조사 - ISO, ASTM, CEN, KS를 중심으로 -)

  • Han, Sul-Ah;Nam, Yun-Ja
    • Fashion & Textile Research Journal
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    • v.10 no.1
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    • pp.92-100
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    • 2008
  • When designing protective clothing, there are something to be considered such as physiological feature of human body, acting range not to restrict physical activity, and effectiveness of material. Because the primary objective of protective clothing is to protect human body from danger and it is designed through complex designing process not likely general clothing design. However, current evaluation techniques-such as the ISO, the ASTM and the CEN, and KS-provide only the standard to evaluate the primary feature of material (testing, performance requirements, material specification, selection and application, test and care, and so on). There are no standard to evaluate influence for the human body while protective clothing put on. Especially, in Korea, there is KS to evaluate protective clothing, but it is partially translated version from ISO because of lack of core technology about this field. However, developed countries recognize it is new competitive means in the time of Global Standards and they are competing to make their own standard to global standard for the protective clothing. Therefore, it can be great opportunity for Korean clothing and textile industry to revitalize if focusing on research and development for protective clothing design based on physical activity of human body, fit evaluation technique and sizing which is currently no global standard for it and developing our standard to global standard.

A Study on the Design/construction Standard of Unlined Tunneling Method (Unlined Tunnel 공법 지보재의 설계 및 시공 기준 고찰)

  • 서영화;김성구;나승훈
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.10a
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    • pp.121-134
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    • 2002
  • Tunneling is a very dangerous and expansive work. Especially, the concrete lining works need many long hours and much cost. As an alternative, the unlined tunneling methods including NMT have been developed in various country. These methods have advantages in cost, time and quality. In Korea, many considerations have been conducted to apply the unlined tunneling method in comparatively good rock. Since primary reinforcements play the role of the final supporting system in unlined tunnels, the initial stiffness and long term durability of reinforcements are very important for tunnel safety. To establish the reinforcements standard suitable to Korea, we investigated the foreign standards and construction cases, comparing geological and construction conditions of foreign land and Korea. As the result, we have proposed the standard of primary supporting system for unlined tunnel in aspects of material, design, construction and quality control etc.

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