• Title/Summary/Keyword: Comparison of Standards

Search Result 940, Processing Time 0.025 seconds

Development of a Time Comparison System via GPS Satellites (GPS 위성을 이용한 시각비교 수신기의 개발)

  • Lee, Chang-Bok;Lee, Dong-Doo;Chung, Nak-Sam
    • Journal of the Korean Institute of Telematics and Electronics
    • /
    • v.27 no.2
    • /
    • pp.158-165
    • /
    • 1990
  • We have developed a L1 band (1575.42 MHz), C/A (Coarse/Acquisition) code GPS (Global Positioning System) receiver for precise time comparison and evaluated the performance of the receiver. The GPS measurements have been carried out between cesium clocks onboard the GPS satellites and the master clock of Korea Standards Research Institute (KSRI) using the GPS receiver. An accuracy of time transfer better than 100ns was obtained.

  • PDF

Evaluation of Daily Jump Compensation Methods for GPS Carrier Phase Data

  • Lee, Young Kyu;Yang, Sung-Hoon;Lee, Chang Bok;Lee, Jong Koo
    • Journal of Positioning, Navigation, and Timing
    • /
    • v.4 no.1
    • /
    • pp.25-31
    • /
    • 2015
  • In this paper, we described the timing-offset comparison results between various daily jump compensation methods for GPS carrier phase (CP) measurement data. For the performance comparison, we used about 70 days GPS measurement data obtained from two GPS geodetic receivers which share the reference 1 PPS and RF signals and closely located in each other within a few meters. From the experiment results, the followings were observed. First, daily jumps existed in CP measurements depend on not only the environment but also the receiver which will make a full compensation be very hard or impossible. Second, clock bias can be occurred in the case of using a simple compensation with accumulation of daily jumps but it could be used in a short-period frequency comparison campaign (less than about 7 days) despite of its drawback.

Comparing the Housing Laws related to the disabled in various countries for Aging Society (고령화 사회를 위한 국내·외 장애인 주택관련법 비교연구)

  • Kim, Sang-Woon
    • Journal of The Korea Institute of Healthcare Architecture
    • /
    • v.18 no.2
    • /
    • pp.7-17
    • /
    • 2012
  • The purpose of this study is to be suggested the primary data when housing research related the disabled and the enactment are needed. For the purpose, this study compares the Housing Laws, such as state of legislation, composition and detailed standards in domestic and international. The scope of study is limited each space in 7 types, entrance, corridor, living room, bedroom, bathroom, kitchen, and balcony, then, laws related on each space are compared and analyzed. In addition, comparison of the foreign's Housing laws are focused on Switzerland, Germany, United States of America, and Japan where have systematic and organized Housing laws by in each space. This study were processed as follows: First, domestic and foreign laws are examined throughout state of legislation, composition, detailed standards, and types of the disabled. Then, housing laws that applied institutionally in each country are compared. Finally, similarities and differences of specific standards are analyzed by comparison on space in each country.

A Study on Comparison Test for Brake Disc Lining (제동디스크라이닝의 비교시험 연구)

  • Chung Jong-Duk;Kwon Sung-Tae;Han Seok-Yoon;Park Ki-Joon;Chun Hong-Jung
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2005.10a
    • /
    • pp.43-48
    • /
    • 2005
  • In order to facilitate technical exchange among nations and/or institutes through the establishment of mutual recognition and the reliability guarantee of testing results by testing standards standardization, the interlaboratory comparison tests on brake discs and linings between KRRI and CARS were conducted. So far, two ways of comparison tests were performed for a better understanding of mutual recognition and standardization in railroad brake linings between Korea and China. In this paper, the first and second comparison testing results have been summarized, and the suggestions for the future research work are also presented to encourage extensive research on comparison study of railroad brake discs and linings between KRRI and CARS. Eventually, the final goal of the current research will be the establishment of standardization of railroad testing standards.

  • PDF

Bilateral comparison of the absorbed dose to water in high energy X-ray beams between the KRISS and the NMIJ

  • Kim, In Jung;Kim, Byoung Chul;Yi, Chul-Young;Shimizu, Morihito;Morishita, Yuichiro;Saito, Norio
    • Nuclear Engineering and Technology
    • /
    • v.52 no.7
    • /
    • pp.1511-1516
    • /
    • 2020
  • The Korea Research Institute of Standards and Science (KRISS) established a new standard of the absorbed dose to water in LINAC X-ray beams. To confirm the equivalence of the new standard with other national metrology institutes (NMIs), a bilateral comparison study of the absorbed dose to water in high energy X-ray beams was performed between the KRISS and the National Metrology Institute of Japan (NMIJ). The comparison was made in-directly. Three transfer chambers were calibrated in the high energy X-ray beams by both laboratories and the calibration coefficients were compared. The average ratios of the calibration coefficients of the three transfer chambers obtained by the KRISS to those obtained by the NMIJ were 1.004, 1.006, 1.006, 1.007 for 6, 10, 15 and 18 MV X-ray beams, respectively. The calibration coefficients obtained at the KRISS were higher than those at the NMIJ but they were in good agreement within the expanded uncertainty of 1.0% (k = 2). The results of this study will be used as the evidence for the KRISS standard being comparable with those of other NMIs, temporarily, in the interim period up to finalizing a key comparison study, BIPM.RI(I)-K6 managed by the Consultative Committee for Ionizing Radiation.

The Direction for Revising the Achievement Standards in Korean Home Economics Education: Focussing on the Comparison with the U.S. National Standards (가정교과 성취기준의 서술방식 개선 방향 - 미국 국가 기준과의 비교를 중심으로 -)

  • Kim, Eun Jeung;Kwon, Yoojin;Lee, Yoon-Jung
    • Journal of Korean Home Economics Education Association
    • /
    • v.25 no.1
    • /
    • pp.37-54
    • /
    • 2013
  • This study aimed at examining the characteristics of the Korean home economics achievement standards at secondary education level, and comparing with those of U.S. home economics national standards. The specific research questions were as follows. First, the characteristics of Korean and U.S. achievement standards were examined respectively. Second, the standards of the two countries were examined in terms of the grades involved, development areas, specification level, sequence of courses, and format of statements, adopting the analysis framework of Lee, Jang, and Park(2012). Third, the achievement standards of the two countries for specific content areas, i.e. 'understanding adolescents' and 'understanding family' were compared in terms of the styles and format of statements. The findings suggest that in developing the Korean achievement standards, integration with the curriculum and detailed and specific statements are important to facilitate adoption at schools. The results of the comparison with the U.S. national standards indicates that it is important to emphasize academic rationale to home economics as a subject by clearly presenting the concepts, contents, and categories. Also, the standards will need to be stated in specific terms to allow practices and evaluations, rather than in terms that reflect value judgments.

  • PDF

Inter-comparison of temperature measurement capability using standard platinum resistance thermometers (표준백금저항온도계를 이용한 온도측정능력 상호비교)

  • Gam, K.S.;Kang, C.S.;Lee, Y.J.;Lee, K.B.;Kim, Y.G.;Park, S.N.
    • Journal of Sensor Science and Technology
    • /
    • v.18 no.1
    • /
    • pp.86-94
    • /
    • 2009
  • Temperature measurement capability was inter-compared using the transfer standard platinum resistance thermometers(SPRT) among four laboratories of KRISS. The transfer SPRTs were primarily calibrated at the triple point of water and Ga melting point, then used at inter-comparison experiment. Temperature difference of calibration value between temperature laboratory and length laboratory at $20^{\circ}C$ was -0.7 mK and +2.4 mK at density laboratory. Temperature measured near $20^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$ at fluid flow laboratory was deviated by $34.2{\sim}80.4\;mK$ from the calibration values of the transfer SPRT. Ga melting points was inter-compared among three laboratories, and the difference of Ga melting points against the standard Ga melting point of temperature laboratory were $0.03{\sim}0.54\;mK$ at length laboratory and 0.02 mK at density laboratory.

Performance Analysis of Short Baseline Integer PPP (IPPP) for Time Comparison

  • Lee, Young Kyu;Yang, Sung-hoon;Lee, Ho Seong;Lee, Jong Koo;Hwang, Sang-wook;Rhee, Joon Hyo
    • Journal of Positioning, Navigation, and Timing
    • /
    • v.10 no.4
    • /
    • pp.379-385
    • /
    • 2021
  • In order to synchronize a remote system time to the reference time like Coordinated Universal Time (UTC), it is required to compare the time difference between the two clocks. GNSS Precise Point Positioning (PPP) is one of the most general geodetic positioning methods and can be used for time and frequency transfer applications which require more precise time comparison performance than GNSS code. However, the PPP technique has a main drawback of day-boundary discontinuity which comes from the PPP model that the code measurements are applied to resolve the floating carrier-phase ambiguities. The Integer PPP (IPPP) technique is one of the methods which has been studied to compensate the day-boundary discontinuities exited in the conventional PPP. In this paper, we investigate the time and frequency capabilities of PPP and IPPP by using the measurement data obtained from two time transfer receivers which are closely located and using common reference 1 Pulse Per Second (PPS) and RF signals. From the experiment, it is investigated that the IPPP method can effectively compensate the day-boundary discontinuities without producing frequency offset. However, the PPP method can generating frequency offset which can severely degrade the time comparison performance with long-term period data.

A NEW AGE IN MATHEMATICS EDUCATION IN THE U.S.: INTERPRETING THE COMMON CORE STATE STANDARDS FOR MATHEMATICS

  • Noh, Jihwa;Huh, Nan;Ko, Ho-Kyoung
    • Korean Journal of Mathematics
    • /
    • v.20 no.4
    • /
    • pp.493-505
    • /
    • 2012
  • For the first time ever in its history, the United States has a national version for K-12 mathematics programs, the Com-mon Core State Standards for Mathematics. Since its final version appeared in 2010 in the United States, the Common Core State Standards have started getting much attention from the Korean mathematics and mathematics education communities. Although attempts have been made to translate the original text of the stan-dards, the information such as the paradigm shift that led to the development of the standards, design principles and a comparison with the NCTM Standards would aid understating the standards in the intended way and avoiding unnecessary confusion.

Interlaboratory Comparison of Critical Current Measurements on Ag-sheathed Bi-2223 tapes (Bi-2223선재의 임계전류 측정기술 비교)

  • Lee, Kyu-Won;Han, Gi-Youl
    • Progress in Superconductivity
    • /
    • v.3 no.1
    • /
    • pp.99-103
    • /
    • 2001
  • We have conducted two runs of interlaboratory comparison on Ag-sheathed Bi-2223 tapes to evaluate the level of measurement techniques for the critical current measurement. Two classes of specimens were prepared for parallel and serial routings and sent to four participating laboratories. The critical currents of specimens were measured at 77 K in zero magnetic field. In the first comparison, we used twenty different Bi-2223 tapes as specimens for comparison and participating laboratories measured the specimens using their own instruments and procedures. As a result, the scattering of data on the first comparison showed -3.0% to +l2.2% for the parallel routing and -0.7% to +l5.1% for the serial routing. Major sources of these variations were attributed to different measurement techniques. Thus, the second comparison of measurement was done on the same specimens under specified measurement conditions, particularly in terms of cooling procedure and sweep rate of the test current. The variations for the second comparison were decreased -3.1% to +3.2% far the parallel routing and -1.8% to +7.7% fur the serial routing.

  • PDF