• Title/Summary/Keyword: National comparison

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Measurement of triple point of water temperature for improvement of the national standards and key comparison (국가표준향상과 핵심국제비교를 위한 물의 삼중점 온도 측정)

  • Yang, Inseok;Lee, Young Hee
    • Journal of Sensor Science and Technology
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    • v.30 no.5
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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.

Social Comparison Information, Ethnocentrism, National Identity Associated with Purchase Intention in China

  • FANG, Yuantao;OH, Han-Mo;YOON, Ki-Chang;TENG, Zhuoqi
    • Journal of Distribution Science
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    • v.17 no.5
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    • pp.39-50
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    • 2019
  • Purpose - The purpose of our study is to provide an understanding of the relationships among consumer attention to social comparison information (ATSCI), consumer ethnocentrism (CET), national identity (NI), and consumer purchase intention to domestic brands (PIDB). Drawing on the social comparison theory (SCT) and social identity theory (SIT), we developed a model that is empirically testable and explains consumer behavior of domestic brands and products. Research design, data, and methodology - The conceptual framework was tested with primary data collected through a survey in China. Structural equation modeling was employed to test hypotheses. Results - The results from empirical analyses indicated that the ATSCI positively influenced CET and NI, and CET and NI affect consumer PIDB. In addition, the mediating effects of CET and NI on the relationship between ATSCI and PIDB were identified. Nonetheless, little direct impact of ATSCI on PIDB was reported. Conclusions - We suggested that international marketers use given information to attract consumer attention and develop appropriate promotions, especially for Chinese young generations that would pay much attention to social comparison information in their purchase decisions. Our study originally connected one socio-psychological antecedent, ATSCI, with CET and NI and estimated the relationships among the three antecedents and their effects on PIDB in order to predict consumer behavior in China.

Development of a Comparison-Shopping Agent System Considering Buyer's Preference (구매자 선호도를 고려한 비교쇼핑 에이전트 시스템의 개발)

  • Lee Han-Jin;Yum Chang-Sun
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.28 no.1
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    • pp.84-91
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    • 2005
  • Recently comparison-shopping agent systems are promising to support purchase of buyers in online-shopping environment. This paper proposes a comparison-shopping agent system considered easy access and buyer's preference. Easy access is achieved by minimizing questions to buyer. Buyer's preference is considered by using pairwise comparison of products attributes. Procedure of the proposed system is explained with a case of notebook. Finally a prototype has been implemented.

Temperature Analysis of Each Coolant Level by a Multiple Comparison in Turning Process (다중비교를 이용한 선삭가공시 절삭유량에 따른 온도변화분석)

  • Park, Tae-Jun;Yang, Seung-Han;Lee, Yeong-Mun;Kim, Hui-Sul
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.12
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    • pp.110-115
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    • 2001
  • In this paper, a multiple comparison was proposed to minimize the amount of coolant. And new coolant level, called "low level", was suggested to show usefulness of multiple comparison for experiments. The amount of this levee is about 1/4 of conventional coolant amount-called "high level", and dry cutting is called "none level". Using these coolant levels, the cutting temperatures of each coolant level in turning process were analyzed by analysis of variance(ANOYA)-test and a multiple comparison. As the result of ANOVA-test, we have just known that the average of temperature of each coolant level is not equal. However by Tukey's HSD, one of multiple comparison. it was analyzed that the average of temperature of low level is similar to that of high levee and different from that of none level.erent from that of none level.

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An Investigation Into 3-, 4-, and 5-Year-Old Children's Nonsymbolic Magnitude Comparison Ability According to Ratio Limit and Task Condition (비율제한 및 과제제시방법에 따른 3, 4, 5세 유아의 비상징 수 비교능력)

  • Cho, Woomi;Yi, Soon-Hyung
    • Korean Journal of Child Studies
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    • v.38 no.1
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    • pp.117-126
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    • 2017
  • Objective: The purpose of this study was to investigate young children's nonsymbolic magnitude comparison ability according to ratio limit and task condition. Methods: The participants included 40 3-year-old children, 42 4-year-old children, and 41 5-year-old children recruited from 4 childcare centers located in Seoul, Korea. All magnitude comparison tasks were composed of image material tasks and concrete material tasks. In addition, each magnitude comparison task varied with the ratio of the two quantities; 0.5 ratio, 0.67 ratio, 0.75 ratio. Results and Conclusion: The results revealed that 3-, 4-, and 5-year-old children could perform nonsymbolic magnitude comparison tasks without learning experiences. Also, 3-, 4-, and 5-year-old children could perform concrete material tasks better than image material tasks in nonsymbolic magnitude comparison tasks. Furthermore, children's performance on nonsymbolic magnitude comparison tasks indicated the ratio signature of the approximate number system. Children have a degree of numerical capacity prior to formal mathematics instruction. Also, children were influenced by task conditions or sense stimulus when they processed numerical information. Furthermore, the approximate number system can be used in understanding the ordinality of number.

Comparison between analytic and numerical approaches to calculate screening current induced field in HTS magnet

  • Bang, Jeseok;Kim, Seokho;Kim, Jaemin;An, Soobin;Im, Chaemin;Hahn, Seungyong
    • Progress in Superconductivity and Cryogenics
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    • v.21 no.2
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    • pp.45-49
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    • 2019
  • This paper reports comparison between analytic and numerical simulation approaches for calculation of screening current and screening current induced field in a high temperature superconductor magnet. Bean slab model is adopted to calculate screening current and SCF analytically, while the finite element method numerically. A case study of screening current and SCF calculation are conducted with a magnet, a 7 T 68 mm cold-bore multi-width no-insulation GdBCO magnet built and tested by Massachusetts Institute of Technology Francis Bitter Magnet Laboratory. In this study, we assume the magnet is dunked in liquid nitrogen at 77 K. Furthermore, the simulation results are compared in terms of computation time and accuracy. Finally, discussion on the different methods together with the comparison between the calculations and experiment is provided.

A Study on the Strength and Deformation Characteristics of Clay due to the Specimen Shaping (시료성형에 따른 점성토의 변형.강도 특성에 관한 연구)

  • Park, Jong-Su;Park, Choon-Sik;Jang, Jeong-Wook
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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    • pp.1227-1232
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    • 2005
  • This study carried out unconfined compression tests to identify deformation and strength characteristics of clay. The conclusions are presented in the following. (1) The comparison of unconfined compression strengths according to specimen disturbance showed great differences, except for a few data. (2) The comparison of ${E_{50}}'s$ according to specimen disturbance proved that the two values were similar in general. (3) The comparison of strains at the peak according to specimen disturbance showed that non-shaped specimens had been slightly more disturbed in general. (4) The comparison of $E_{50}/q_u$ also suggested that non-shaped specimens had been slightly more disturbed in general.

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Comparison and Electromagnetic Analysis of BLDC Motors with Radial and Polar Plastic Magnets (반경 및 원주 방향 자화된 플라스틱 자석을 갖는 BLDC 전동기의 전자기적 특성해석 및 비교)

  • Jang, Seok-Myeong;Cho, Jang-Young;Cho, Han-Wook;Yang, Hyun-Sup;Lee, Sung-Ho;Jeong, Sang-Sub
    • Proceedings of the KIEE Conference
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    • 2005.04a
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    • pp.25-27
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    • 2005
  • This paper deals with the comparison and analysis of brushless DC (BLDC) motor with radial and polar anisotropic plastic magnet. The open-circuit field distributions and back-emf for BLDC motor with polar plastic magnet are established analytically and the results are validated extensively by comparison with finite element (FE) analyses. On the basis of two dimensional (2-D) analytical solutions, this paper predicts open-circuit field characteristics according to design parameters and makes a comparison between BLDC motor with polar plastic magnet and it with radial plastic magnet in terms of required magnet volume and harmonic of air-gap flux density waveform.

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Comparison of two retargetable compilers: GCC and SoarGen

  • Zhiwen, Zheng;Ahn, Minwook;Youn, Jonghee M.;Kim, Yongjoo;Kwon, Yongin;Paek, Yunheung
    • Proceedings of the Korea Information Processing Society Conference
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    • 2009.11a
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    • pp.17-18
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    • 2009
  • This paper shows our empirical comparison result between two retargetable compilers, GCC and SoarGen. SoarGen is our retargetable compiler. According to our experimental result, using SoarGen for targeting ODALRISC is proved to be easier and faster than using GCC. The average retarget time of the SoarGen is much less than the retarget time of the GCC.

International Comparison of high resistance and Mutual Recognition between National Metrology Institutes (전기저항의 국제비교 및 계측기술에 관한 국제적 상호인정 추세)

  • Yu, Kwang-Min;Ryu, Je-Cheon;Kang, Jeon-Hong;Kim, Han-Jun
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.606-608
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    • 1999
  • Mutual Recognition Agreement(MRA) between national metrology institutes is started on October 1999 and International Key Comparison is essentially to be used as technical basis for the agreement. High resistance is one of the Key Comparison and high resistance measurement system is established in KRISS for the purpose of the Key Comparison. Total combined uncertainty of the system is about 4ppm in $10M{\Omega}$ and 8ppm in $1G{\Omega}$. With the system, the difference of comparison results for $10M{\Omega}$ and $1G{\Omega}$ among KRISS, VNIIM in Russia and NIM in China is agreed about 6ppm within total combined uncertainty of three institutes.

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