• Title/Summary/Keyword: standard measurement methods

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Updates to the wind tunnel method for determining design loads in ASCE 49-21

  • Gregory A. Kopp
    • Wind and Structures
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    • 제37권2호
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    • pp.163-178
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    • 2023
  • The paper reviews and discusses the substantive changes to the ASCE 49-21 Standard, Wind Tunnel Testing for Buildings and Other Structures. The most significant changes are the requirements for wind field simulations that utilize (i) partial turbulence simulations, (ii) partial model simulations for the flow around building Appurtenances, along with requirements for determining wind loads on products that are used at multiple sites in various configurations. These modifications tend to have the effect of easing the precise scaling requirements for flow simulations because it is not generally possible to construct accurate models for small elements placed, for example, on large buildings at the scales typically available in boundary layer wind tunnels. Additional discussion is provided on changes to the Standard with respect to measurement accuracy and data acquisition parameters, such as duration of tests, which are also related to scaling requirements. Finally, research needs with respect to aerodynamic mechanisms are proposed, with the goal of improving the understanding of the role of turbulence on separated-reattaching flows on building surfaces in order to continue to improve the wind tunnel method for determining design wind loads.

근대건축문화재 기록에서의 사진실측기법 활용 (A Study on the Use of Photogrammetry in Survey and Recording of Modern Architectural Properties)

  • 권순찬
    • 한국농촌건축학회논문집
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    • 제15권2호
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    • pp.9-16
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    • 2013
  • This paper is to discover how the photogrammetry method can be utilized for recording modern architectural properties. As a result of conducting photogrammetry aimed at the main building and water supply tower of Goesan Middle School, it was possible to measure actually either complicated patterns or a damaged area on the facade. However, there appeared errors in the actual measurement of the hollow or protruded area on the facade to measure actually or of an object in the cylinder form. First, for the actual measurement of the protruded area, it is possible to complete a facade by measuring actually the protruded area separately after dividing it and complementing it on the facade, Second, concerning an object in the cylinder form, it is possible to complete one facade by matching a facade which is measured actually with a Diaver method among the MSR photogrammetry methods, and three dimensional standard coordinates which are obtained through Totalstation.

Results of the key comparison in absolute pressure from 1 Pa to 1000 Pa

  • Hong, Seung-Soo;Shin, Yong-Hyeon;Chung, Kwang-Hwa;A. P. Miiller
    • Journal of Korean Vacuum Science & Technology
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    • 제6권3호
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    • pp.109-115
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    • 2002
  • This paper describes a CCM key comparison of low absolute-pressure standards at seven National Measurement Institutes that was carried out during the period March 1998 to September 1999 in order to determine their degrees of equivalence at pressures in the range 1 Pa to 1000 Pa. The Korea Research Institutes of Standards and Science(KRISS) participated from 10 Pa to 1000 Pa pressure range in 1999. The primary standards, which represent two principal measurement methods, included five liquid-column manometers and four static expansion systems. The transfer standard package consisted of four high-precision pressure transducers, two capacitance diaphragm gauges to provide high resolution at low pressures, and two resonant silicon gauges to provide the required calibration stability.

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국내 레미콘 플랜트의 단위수량관리 현황 검토에 관한 연구 (A Study on the status of unit water content control of the Ready-Mixed Concrete plants in the country)

  • 정양희;김용로;최일호;이도범;홍경선
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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    • pp.606-609
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    • 2006
  • In this study, it was selected that in order to make an investigation into the status of the unit water content control of the ready-mixed concrete plants in the country, Capacitance Measurement Method out of various methods which are able to gauge the amount of unit water content in fresh concrete. Then, it were estimated that the quantity of unit water in fresh concrete and the technical standard of every mixture design of the six ready-mixed concrete plants chosen at random in the country. Finally, based on this study, it was proposed as fundamental data to utilize measurement techniques of the quantity of unit water for the quality control of the ready-mixed concrete in construction field.

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Prediction of Chemical Compositions for On-line Quality Measurement of Red Pepper Powder Using Near Infrared Reflectance Spectroscopy (NIRS)

  • Lee, Sun-Mee;Kim, Su-Na;Park, Jae-Bok;Hwang, In-Kyeong
    • Food Science and Biotechnology
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    • 제14권2호
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    • pp.280-285
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    • 2005
  • Applicability of near infrared reflectance spectroscopy (NIRS) was examined for quality control of red pepper powder in milling factories. Prediction of chemical composition was performed using modified partial least square (MPLS) techniques. Analysis of total 51 and 21 red pepper powder samples by conventional methods for calibration and validation, respectively, revealed standard error of prediction (SEP) and correlation coefficient ($R^2$) of moisture content, ASTA color value, capsaicinoid content, and total sugar content were 0.55 and 0.90, 8.58 and 0.96, 31.60 and 0.65, and 1.82 and 0.86, respectively; SEP and $R^2$ were low and high, respectively, except for capsaicinoid content. The results indicate, with slight improvement, on-line quality measurement of red pepper powder with NIRS could be applied in red pepper milling factories.

산업용 백금저항온도센서의 결선방식에 따른 측정불확도 평가방법 (Uncertainty assessment of industrial platinum resistance thermometers for different lead-wire connection methods)

  • 김용규;감기술;양인석
    • 센서학회지
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    • 제18권4호
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    • pp.322-326
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    • 2009
  • To estimate the measurement uncertainty for industrial platinum resistance thermometers(IPRTs) made with 3-wire connection, the immersion temperature profile was investigated using a liquid bath. Two types of IPRTs having lead wires made of silver and nickel were constructed and the immersion profiles were measured at temperatures from -50 $^{\circ}C$ to 250 $^{\circ}C$ using 3-wire and 4-wire method. As immersion depth and temperature increased, the resistances measured by 3-wire method increased linearly but not for 4-wire method. To calibrate a 3-wire IPRT, the immersion effect must be accounted for. We propose a linear equation to assess correctly the measurement uncertainty.

무선통신서비스 주파수대역에서의 고속전철 시스템의 RFI 내성기준 및 측정방법 연구 (RFI Susceptibility Standard and Measurement Method of the High-Speed Train System at Wireless Communication Service Frequency Band)

  • 김윤명;주영준
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.305-310
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    • 2008
  • 최근 통신기술이 발달함에 따라 무선통신 주파수 대역폭은 더 넓어지게 되었고, 고집적 반도체 소자는 고속전철 시스템에 더 많이 적용되고 있다. 고속전철 시스템에서 사용되는 집적된 전력 반도체의 RFI (Radio Frequency Intereference, 라디오파 방해) 민감도 [또는 내성(耐性)]는 시스템의 안전에 많은 영향을 준다. 이 연구에서는 고속전철 시스템의 무선통신 주파수 대역에서 RFI 민감도 기준과 측정방법이 조사되었다.

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전립선 비대증 진단에서의 비침습적 방광내압계측 유용성 평가 (Usefulness Assessment of Noninvasive Bladder Pressure Measurement for BPH Diagnosis)

  • 정도운;정완영
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2006년도 하계종합학술대회
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    • pp.865-866
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    • 2006
  • The aim of this study was to implement the system that could evaluate the function of urinary tract with noninvasive and comfort methods. There for in this study hardware device and computer software have been developed that enables the analysis of the urine flow rate and vesical pressure signal measured during voiding. These signals were recorded simultaneously and transmitted to the PC. For the measurement system evaluation, the model system for the lower urinary system of men was designed. From the evaluation of the model system, vesical pressure was correlated with the occlusion degree. In a pilot study on 5 male subjects, means of standard deviation was 1.06, average error rate was 2.09 and coefficient variation was 2.09.

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반도체 근로자 질병의 직무관련 논란으로 본 우리나라 산업위생 활동 개선방향 (Suggestions to improve occupational hygiene activities based on the health problems of semiconductor workers)

  • 박동욱;윤충식
    • 한국산업보건학회지
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    • 제22권1호
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    • pp.1-8
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    • 2012
  • Objectives: The aim of this study is to review occupational hygiene activities, including work environment measurement as required by the industrial safety and health laws of Korea, and suggest improvements required to establish an effective exposure surveillance system. Methods: The controversial limitations of exposure surveillance examining the work-association of several types of cancers in semiconductor workers were reviewed. Results: The bulk of the exposure surveillance system was found to focus purely on work environment measurements without providing other important exposure surrogates, such as job title, operation, exposure duration, etc. The current work environment measurement system is limited in terms of the efficient assessment of the exposure status of workers due to a lack of exposure information. Conclusion: The introduction of a national standard classification of occupations and job titles into the exposure and health effect surveillance system should be discussed in order to retrospectively assess exposure characteristics.

Development of a Mushroom Powder Certified Reference Material for Element Analysis

  • Betru, Tegegn Gizachew;Yim, Yong-Hyeon;Lee, Kyoung-Seok
    • Mass Spectrometry Letters
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    • 제11권4호
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    • pp.108-112
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    • 2020
  • A certified reference material (CRM) for the analysis of nutrient elements in an edible mushroom (Ganoderma lyceum) powder has been developed (KRISS CRM 108-10-011). The mass fractions of calcium (Ca), iron (Fe), and zinc (Zn) were measured by isotope dilution inductively coupled plasma mass spectrometry (ID ICP/MS). To dissolve the fungi cell wall of mushroom consisted of chitin fibers, sample preparation method by single reaction chamber type microwave-assisted acid digestion with acid mixtures was optimized. The mean measurement results obtained from 12 sample bottles were used to assign as the certified values for the CRM and the between-bottle homogeneities were evaluated from the relative standard deviations. The certified values were metrologically traceable to the definition of the kilogram in the International System of Units (SI). This CRM is expected to be used for validation of analytical methods or quality control of measurement results in analytical laboratories when they determine the mass fractions of elements in mushroom or other similar samples.