• 제목/요약/키워드: comparison measurement

검색결과 3,147건 처리시간 0.029초

차륜/레일 작용력 측정을 위한 레이저기술과 스트레인게이지 응용기술 비교 (Comparison of laser technology & strain gauge application technology for measurement of interaction force between wheel and rail)

  • 함영삼;정우진;서정원
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2004년도 춘계학술대회 논문집
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    • pp.219-223
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    • 2004
  • Korea Railroad Research Institute(KRRI) propelled sensing and measurement techniques development for measure of Lateral Force and Vertical Force With Italy to international cooperation research project for laser technology for measurement of wheel/rail interaction force. In this paper, we compared the laser technology for measurement of wheel/rail interaction force with the existing method. And then, we suggests interaction force measurement system procedure of hereafter.

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서미스터 마운트 교정을 위한 10 MHz에서 1 GHz 주파수 대역의 단순 직접 비교 측정시스템 설계 (Design of Simple Direct Comparison Measurement System from 10 MHz to 1 GHz for Thermistor Mounts Calibration)

  • 차윤배;장용근;김부일
    • 한국전자통신학회논문지
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    • 제15권3호
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    • pp.405-412
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    • 2020
  • 서미스터 마운트는 전력의 변화에 따른 교정인자 값이 일정하여 정밀한 무선주파수 전력 측정에 사용하고 있다. 표준 마운트의 교정인자는 직류 대체법을 이용하여 전달표준과 직접 비교를 통해 10 MHz부터 1 GHz 대역까지 불확도 0.5 % 이하로 측정할 수 있다. 최근 직류 대체법 기반 정밀한 전력계의 산업계 보급으로 보다 간단하고, 빠른 측정이 가능함에 따라 동일한 불확도 수준의 단순 직접 비교 측정시스템을 설계하고, 부정합 오차의 분석을 통해 구성품의 최소 요구 사양을 제시하였다. 시스템 유효성 검증을 위해 시스템 불확도를 평가하였으며, 불확도 결과는 측정 주파수 대역에서 0.5 % 이내에서 잘 유지되었음을 보여준다.

GIS를 활용한 서울시 도시근교공원의 접근성 지표에 관한 연구 (GIS-oriented Measurement Indicces of Accessibility of the Neighborhood Park in Seoul)

  • 허미선;진양조
    • 한국조경학회지
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    • 제24권3호
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    • pp.42-56
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    • 1996
  • The citizens seek to maximize convenience, pleasantness and safety when they use urban facilities. However, existing practices of urban neighborhood parks have applied not qualitative standards such as adequacy, efficiency, accessibility, equity, or socioeconomic issues but very limited quantitative standards such as area per person. Therefore it is not rare that citizens have lost their accessibility to near-by neighborhood parks. And park regulations based on the distance of lien are supposed to be uniformally accomplished regardless of the consideration about users or geographical special situations. Futhermore, it has been found that some urban neighborhood parks don't reach to the standards given by the regulations. This study tries to accomplished several purposes. The first purpose is to extract the boundary of real user-accessible zones derived from the city survey. Comparing with boundary of real user-accessible zones, the second one is to propose the most efficient measurement indices among many accessibility measurement index. Based upon the above arguments, the last one is to review the propriety of the access distances(e.g., semidiameter) of an urban neighborhood park in a law. The measurement indices of accessibility examined in this study are walking distance, walking time and walking difficulty. The comparison of visual discrimination, the comparison of area and the comparison of differences of maximum distance showed similar results. Each index can also be compared in the size of area and differences of maximum distance. Walking difficulty with the turning showed the best measurement values among the measurement indices. This indicates that walking difficulty with crossing and/or turning may be another important indices in measuring accessibility, while other existing studues have mainly dealt with walking time and distance as accessibility indices. The results of this study also supported that the existing regulations related to park allocation(e.g., access diameter) are close to the findings of this study.

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Comparison of Antenna Parameters of R-/S-Band Standard Gain Horn Antennas

  • Kang, Jin-Seob;Kim, Jeong-Hwan;Park, Jeong-Il
    • Journal of electromagnetic engineering and science
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    • 제15권4호
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    • pp.224-231
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    • 2015
  • A comparison of the antenna parameters for R-band (1.7-2.6 GHz) and S-band (2.6-3.95 GHz) standard gain horn antennas has been performed by the Korea Research Institute of Standards and Science (KRISS), together with seven domestic participants from private companies and public institutions. Its purpose, as a proficiency test program of the 'Antenna Measurement Club' of KRISS, was to check equivalences in antenna parameter measurements between KRISS and the participants, particularly in the R-/S-band, to support antenna manufacturers and end users in Korea. The measurement parameters of this comparison are the power gain, radiation pattern, and reflection coefficient of the traveling standards for R-/S-band pyramidal standard gain horn antennas. The comparison used a gain comparison method and an extrapolation method to measure the power gain of the two traveling standards; the radiation patterns were measured in the far-field region of the transmitting and receiving antennas.

3차원 스캔측정치와 직접치수간 차이의 성별 비교 -제5차 Size Korea 성인데이터를 대상으로- (A Comparative Analysis of the Difference between 3D Body Scan Measurements and Physical Measurements by Gender -5th Size Korea Adult Data-)

  • 한현숙;남윤자
    • 한국의류학회지
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    • 제33권8호
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    • pp.1190-1202
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    • 2009
  • A 3D body scan measurement (SM) is used as an alternative to physical measurements (PM) as the information for designing industrial products. This study compared the mean difference (MD) between SM and PM by gender and analyzed the causes of the difference. The data used in this study were the scan measurements and physical measurements of adults aged twenty to seventy years old of the fifth Size Korea survey. The results of this study are as follows: 1. The comparison of MD between men and women for all subjects: The measurement of the significant differences between men and women were height, neck base girth, chest girth, under-bust girth, waist girth, armscye girth, back length, and foot length. The causes of difference are the difference of body shape. 2. The comparison of MD between men and women by BMI groups: Many measurements had significant differences between men and women at normal weight and overweight but underweight. Some measurements had significant differences only at a specific BMI group because the body shape difference between men and women is revealed clearly in the group. The comparison of MD between men and women by age groups: The measurements that show significant difference at more than four age groups were neck girth, chest girth, under-bust girth, waist girth, armscye girth, and foot length. The height and abdomen girth had a significant difference in the age range of 20's and 30's. There were measurements that increase MD with an increase in age; under-bust girth and lateral shoulder length for women and lateral shoulder length for men. This comparison of MD between men and women provide the correct guidelines for the use of SM.

가철성 다이를 가진 작업모형에서 다우엘 핀의 종류에 따른 정확도에 관한 연구 (THE ACCURACY ACCORDING TO THE VARIOUS DOWEL PINS OF WORKING CAST WITH REMOVABLE DIES)

  • 임주환
    • 대한치과보철학회지
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    • 제35권2호
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    • pp.373-384
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    • 1997
  • In this study, 4 types of dowel pin were used to fabricate removable dies using the Pindex system. The comparison of interabutment distances between before and after sawing were conducted in each type of dowel pin, and the horizontal discrepancies in the interabutment distance according to the abutment location and the type of dowel pin were comparatively analyzed. Abutments LM(left molar), LP(left premolar), A(anterior), RP(right premolar), and RM (right molar) were used for measurement. The interabutment distances were measured between each abutment : LM-LP, LM-A, LM-RP, and LM-RM. The slide scanned image of each model was magnified on the computer screen and the measurements were conducted using the meeting point of the cross on the occlusal surface of each abutment. The results were as follows : 1. In the comparison of interabutment distances between before and after sawing in each type of dowel pin, there was no significant difference in World dowel pin(double), Bi-pin(double), Maxcel dowel pin(single). In the World dowel pin(single) there was no significant difference between LM-LPs, but in the other measurements (LM-As, LM-RPs, and LM-RMs) there was significant difference between before and after sawing(p<0.05). 2. In comparison of horizontal discrepancies of the measurement according to the abutment location, there was significant difference between measurement LM-LP($0.27{\pm}0.19mm$) and the others : LM-A($0.46{\pm}0.20mm$), LM-RP($0.38{\pm}0.25mm$), LM-RM($0.45{\pm}0.22mm$) (p<0.05). 3. In comparison of horizontal discrepancies of the measurement according to the type of dowel, there was no significant difference between each dowel. As a result when fabricating a removable die using the previously mentioned 4 types of dowel pins, it is thought that the horizontal discrepancy increased in proportion to the interabutment span length and does not depend on the type of dowel pin.

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2015 개정 수학과 교육과정에 따른 교과서에 제시된 들이와 무게 내용 분석 (An Analysis of the Capacity and Weight Contents Presented in Textbooks According to the 2015 Revised Mathematics Curriculum)

  • 이대현
    • 과학교육연구지
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    • 제47권3호
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    • pp.273-285
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    • 2023
  • 초등학교 수학에서 측정은 수학을 실생활에 직접 활용할 수 있는 수학 중 하나이다. 본 연구에서는 3-4, 5-6학년군 수학 교과서가 검정 교과서로 개발된다는 점과 측정에서 들이와 무게가 교과서 지면 구성의 제한에 의해 일반적인 측정 지도 과정이 응축되어 제시되고 있다는 점에 근거를 두고 교과서 내용을 분석하였다. 분석 결과, 분석 관점인 비교 활동, 표준 단위의 필요성 인식과 도입 활동, 어림 활동의 3가지 면에서 국정 교과서를 비롯한 3종의 검정 교과서 내용은 세부적인 면에서 차이가 있었지만, 전체적인 내용 구성과 활동은 유사하였다. 이를 통해 각 측정 활동의 의미를 부각시킬 수 있는 교과서 내용 구성과 학생들의 활동 중심의 교과서를 개발할 수 있는 교육 정책의 개선과 교과서 개발에 노력이 필요함을 제기하였다.

경질유 유량표준장치의 신뢰도 검증을 위한 측정정확도 비교 (Intercomparison of Light Oil Flow Standard System for the Reliability of Measurement Accuracy)

  • 임기원
    • 대한기계학회논문집B
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    • 제32권9호
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    • pp.712-719
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    • 2008
  • Light Oil Flow Standard System(LOFSS), as a national oil flow standard system, in Korea Research Institute of Standards and Science(KRISS) was developed for oil flowmeter calibration, and the expanded uncertainty of flow quantity determination was estimated within 0.04 %. In order to improve the reliability of the LOFSS measurement, a proficiency test was carried out in the flow range of 20 and $240\;m^3/h$ (Reynolds number $20,000{\sim}900,000$). A turbine flowmeter was used as a transfer package in round robin test. The water flow standard system of KRISS, the pipe prover of the national calibration and test organization and the master meter calibrator of the turbine flowmeter supplier, which used the different working fluid respectively, were compared with the turbine flowmeter measurement. The maximum difference of measurement was 0.15 % between the LOFSS and the pipe prover. The En numbers of the each system measurement were evaluated at the same Reynolds number. It was found that the En numbers were less than 1 in the comparison, which means the procedures of the uncertainty estimation of the each calibrators were reasonable and reliable.

Comparison of the standards for absorbed dose to water of the IAEA and the KRISS, Korea in accelerator photon beams

  • L. Czap;I.J. Kim;J.I. Park;C.-Y. Yi;Y. Kim;Z. Msimang
    • Nuclear Engineering and Technology
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    • 제56권7호
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    • pp.2698-2703
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    • 2024
  • A bilateral comparison was conducted between the International Atomic Energy Agency (IAEA) and the Korea Research Institute of Standards and Science (KRISS) to measure the absorbed dose to water in accelerator photon beams. KRISS served as a linking laboratory to compare the IAEA standard with the key comparison reference value (KCRV) of the BIPM.RI(I)-K6 program, in which KRISS participated in 2017. Two ionization chambers from the IAEA were used as transfer instruments for the comparison. Both laboratories measured the calibration coefficients of these instruments and calculated the ratios. The ratio of the KRISS standard to the KCRV was applied to obtain the degree of equivalence of the IAEA, along with its uncertainty. The largest deviation of the IAEA measurement from the KCRV was 3.4 mGy/Gy, significantly smaller than the expanded uncertainty of 10.7 mGy/Gy (k = 2, 95% level of confidence). This study demonstrates the equivalence of IAEA's measurement standard for accelerator photon beams to other primary standard dosimetry laboratories. It provides evidence for the satisfactory operation of IAEA's quality management system and enhances the international credibility of the IAEA SSDL network, particularly in high-energy accelerator photon beams from linear accelerators.

한국여성과 일본거주 한인여성의 신체 계측치 비교연구 (The Research of Difference of Body Measurements between Korean Women Residing in Korea and Korean Women Residing in Japan)

  • 이종숙;임순
    • 한국의상디자인학회지
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    • 제9권2호
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    • pp.93-101
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    • 2007
  • The purpose of the study was to offer basic documents to the textile fashion industry by investigating changes of figures followed by various factors as each other social and cultural environment regardless of the same race. The study conducted a questionnaire survey of Korean women and Korean women in Japan to twenties, forties and sixties. The study enforced measurement from February, 2006 to March, 2006 and from July, 2006 to August, 2006 with R. Martin's Measurement Method of Anthropometry in total 49 measurement items. Also, the study treated statistics of the documents with SPSS WIN 10.0 program. As the result which studied comparison of figures with basic statistics, t-test and more, the study got the following conclusion. Most of Korean women and Korean women residing in Japan have big individual differences in obesity, especially width, thickness, and girth of waist showed the largest variation proving considerable individual difference in waist. In a body measurement comparison, twenties, forties, and sixties of Korean women residing in Japan are higher in heights compare to Korean women, while Korean women have wider and thicker waists than Korean women residing in Japan. In a body difference comparison, categories that showed significant differences are 40's>20's>60's in order and twenties and sixties showed only small difference. In conclusion, Korean women have longer, wider, thicker and smaller waist than Korean woman residing in Japan. When divided by age groups, forties and sixties Korean women are longer in waist, shorter in heights, fatter in weights. Twenties have long waist similar to forties and sixties, but had no significant difference in heights and weights.

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