• Title, Summary, Keyword: international comparisons

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International Time Comparisons in Common-View via Global Positioning System (GPS) Satekkutes (GPS위성 동시수신법에 의한 국제시각비교)

  • 이창복;전인덕;정낙삼
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.15 no.2
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    • pp.81-87
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    • 1990
  • International time comparisons using a commercial GPS receiver, with the common-view program of GPS satellite time links, have been carried out between Korea Standards Research Institute(KSRI) and Communications Research Laboratory(CRL) of Japan, and also between KSRI and United Stated Neval Observatory(USNO). The frequency stability is about 1.5 parts in $10^-13$ for the averaging time of 1day. The result of time comparisons obtained by the GPS common-view technique was about 10 times better than that by the LORAN-C(Long Range Navigation) ground wave technique.

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Cross-cultural Service Variation: Airline Service Quality

  • Nam, Sung-Jip
    • The Journal of Distribution Science
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    • v.13 no.9
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    • pp.19-27
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    • 2015
  • Purpose - In a global economy, marketers are required to understand service quality from an international consumer viewpoint. Despite the increased need for cross-cultural research, few studies have developed service quality research international in scope. The present research aims to shed light on variations in airline service quality among international consumers. Research design, data, and methodology - Conducting crosscultural research, this study compares airline service quality variations, investigating an international consumer group and a Korean consumer group. T-test and factor analyses are applied to examine mean scores and factor structure of the airline service dimensions. Results - The results indicate there are significant differences in mean comparisons between the groups. The international consumers indicate significantly higher service perception scores than the Koreans. Further, we find that the factor structure of airline service quality diverges between the groups. The international group considers airline service quality in four dimensions, while Koreans consider it in two. Conclusions - The study sheds new light on international service variations and suggests that the field of airline service quality may differ by nations and/or cultures.

A Study on the Comparisons of Flags of Convenience with International Ship Register (편의치적선제도와 국제선박등록제도와의 비교연구)

  • 박용섭;이태우;임종길
    • Journal of the Korean Institute of Navigation
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    • v.15 no.1
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    • pp.95-110
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    • 1991
  • This paper aims to investigated the origins and characteristics of flags of convenience(FOC) with International Ship Register(ISR), which was recently adopted by a few Western Europe countries(for example, Norway, U.K., France) and to compare FOC with ISR in terms of shipping policy, ship management, and expenses, and tax policy.

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Oblique water entry of a three dimensional body

  • Scolan, Yves-Marie
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.6 no.4
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    • pp.1197-1208
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    • 2014
  • The problem of the oblique water entry of a three dimensional body is considered. Wagner theory is the theoretical framework. Applications are discussed for an elliptic paraboloid entering an initially flat free surface. A dedicated experimental campaign yields a data base for comparisons. In the present analysis, pressure, force and dynamics of the wetted surface expansion are assessed.

Comparisons of Quality of Life and Asymmetric Atrophy in Regularly Walking Elderly Female Stroke Survivors

  • Jee, Hea Mi
    • Journal of International Academy of Physical Therapy Research
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    • v.9 no.4
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    • pp.1576-1585
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    • 2018
  • Regularly participating in physical activity is known to improve quality of life and body composition in elderly with stroke. However, comparatively less physical activity is performed by the stroke survivors. The factors related to inactivity in elderly female stroke survivors have not been elucidated. Therefore, this study aims to compare the quality of life factors and limb compositions between the active and inactive elderly female stroke survivors. Forty nine subjects between the ages of 65 to 75 years were selected from the KNHANES data between the years 2009 to 2011. In addition, 186 agematched healthy peers were also selected for limb composition comparisons. The subjects were groups based on walking days per week: walkers; 3 days or more, non-walkers; less than 3 days per week. BMI and waist circumference were within the obesity ranges for both the non-walkers and walkers. As results, the trend for greater fat (${\pm}10%$) and lean mass (${\pm}30%$) differences were observed for non-walker and walkers, respectively. Significantly greater reasons for function limitation by stroke and hypertension were reported with significantly greater self-care difficulty was shown by the walkers. In conclusion, elderly female stroke survivals may require customized motivation and continuous support to participate in physical activity regularly.

Effects of Static and Dynamic Stretching on Lumbar Lordotic Angle and Low Back Pain in University Students

  • Ga, Heayoung;Gim, Mina
    • Journal of International Academy of Physical Therapy Research
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    • v.10 no.3
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    • pp.1834-1839
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    • 2019
  • Background: Lumbar lordosis is a result of muscle shortening and may cause low back pain. Objective: To examine the effects of static and dynamic stretching on lumbar lordosis and low back pain in university students. Stretching is an intervention that can be applied to shortened muscles; however, very few studies have compared the effects of static and dynamic stretching on lumbar lordosis and low back pain. Design: Randomized controlled clinical trial (single-blind) Methods: The 12 selected subjects were randomly assigned static stretching and dynamic stretching groups each containing six students. The subjects in each group performed their respective stretching programs for 17 minutes, 3 times a week for 4 weeks. Lumbar lordotic angle, low back pain, and Oswestry Disability Index (ODI) were measured before and after the intervention. Results: Intragroup comparisons showed significant reductions in lumbar lordotic angle and low back pain in the static stretching group while the dynamic stretching group showed significant decreases in lumbar lordotic angle, low back pain, and ODI. The intergroup comparisons showed significantly greater differences between pre- and post-intervention in lumbar lordotic angle and low back pain in the dynamic stretching group compared to those in the static stretching group while ODI did not show any intergroup difference. Conclusions: The results of this study indicated that, while both static and dynamic stretching helped to reduce the lumbar lordotic angle and low back pain, dynamic stretching was more effective in alleviating lumbar lordotic angle and low back pain compared to static stretching.

Leakage Flow Influence on SHF pump model performances

  • Dupont, Patrick;Bayeul-Laine, Annie-Claude;Dazin, Antoine;Bois, Gerard;Roussette, Olivier;Si, Qiaorui
    • International Journal of Fluid Machinery and Systems
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    • v.8 no.4
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    • pp.274-282
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    • 2015
  • This paper deals with the influence of leakage flow existing in SHF pump model on the analysis of internal flow behaviour inside the vane diffuser of the pump model performance using both experiments and calculations. PIV measurements have been performed at different hub to shroud planes inside one diffuser channel passage for a given speed of rotation and various flow rates. For each operating condition, the PIV measurements have been trigged with different angular impeller positions. The performances and the static pressure rise of the diffuser were also measured using a three-hole probe. The numerical simulations were carried out with Star CCM+ 9.06 code (RANS frozen and unsteady calculations). Some results were already presented at the XXth IAHR Symposium for three flowrates for RANS frozen and URANS calculations. In the present paper, comparisons between URANS calculations with and without leakages and experimental results are presented and discussed for these flow rates. The performances of the diffuser obtained by numerical calculations are compared to those obtained by the three-holes probe measurements. The comparisons show the influence of fluid leakages on global performances and a real improvement concerning the efficiency of the diffuser, the pump and the velocity distributions. These results show that leakage is an important parameter that has to be taken into account in order to make improved comparisons between numerical approaches and experiments in such a specific model set up.

Accuracy Improvement of Analysis Results Obtained from Numerical Analysis Model of Continuously Reinforced Concrete Pavement (연속철근 콘크리트 포장 수치해석 모델의 해석결과 정확도 개선 방법)

  • Cho, Young Kyo;Seok, Jong Hwan;Choi, Lyn;Kim, Seong-Min
    • International Journal of Highway Engineering
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    • v.18 no.1
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    • pp.73-83
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    • 2016
  • PURPOSES : The purpose of this study is to develop a method for improving the accuracy of analysis results obtained from a two-dimensional (2-D) numerical analysis model of continuously reinforced concrete pavement (CRCP). METHODS : The analysis results from the 2-D numerical model of CRCP are compared with those from more rigorous three-dimensional (3-D) models of CRCP, and the relationships between the results are recognized. In addition, the numerical analysis results are compared with the results obtained from field experiments. By performing these comparisons, the calibration factors used for the 2-D CRCP model are determined. RESULTS : The results from the comparisons between 2-D and 3-D CRCP analyses show that with the 2-D CRCP model, concrete stresses can be overestimated significantly, and crack widths can either be underestimated or overestimated by a slight margin depending on the assumption of plane stress or plane strain. The behaviors of crack width in field measurements are comparable to those obtained from the numerical model of CRCP. CONCLUSIONS : The accuracy of analysis results from the 2-D CRCP model can be improved significantly by applying calibration factors obtained from comparisons with 3-D analyses and field experiments.

Reliability and Validity of the Korean Version of ISAAC Questionnaire (한국판 국제 소아천식 및 알레르기 질환 연구 설문지의 신뢰도 및 타당도 연구)

  • Choi, Seong-Woo;Ju, Yeong-Su;Kim, Dae-Sung;Kim, Jae-Yong;Kwon, Ho-Jang;Kang, Dae-Hee;Lee, Sang-Il;Cho, Soo-Hun
    • Journal of Preventive Medicine and Public Health
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    • v.31 no.3
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    • pp.361-371
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    • 1998
  • Recent increases of asthma and allergies in childhood made the need for a standardized approach to international and regional comparisons of their prevalence and severity. To address these issues, 'International Study of Asthma and Allergies in Childhood (ISAAC)' is currently underway. In Korea, 'Nationwide Study of Asthma and Allergies in Korean Children' began in 1995 according to ISAAC protocol. ISAAC written and video questionnaires were used in this survey, but their reliability and validity were not evaluated properly yet. In this study, our aim was to evaluate the reliability and validity of two kinds of questionnaires and their usefulness in international and regional comparisons. The test and retest of two questionniares were completed by male(n=110) and female(n=111) middle school students with two and three weeks interval each. Kappa(or weighted kappa) were calculated from each questions and validity coefficients were estimated from those statistics. In Korean version of written questionnaire, the questions for allergic rhinitis, atopic dermatitis, allergic conjunctivitis, and food allergy proved to have high kappa values (or weighted kappa values) and validity coefficients and they can be used in further studies without any correction. But some questions about asthma(especially nocturnal cough, wheezing in exercise, and severe asthma) and drug allergy need to be revised for better under-standing to study subjects. Video questionnaire has the same degree of reliability and validity when compared to written questionnaire and this is the unexpected result. Accordingly, it also need to be revised to overcome the racial and cultural differences of the study subjects. In conclusion, the Korean version of written and video questionnaires may be considered to be useful methods in international and regional comparisons of asthma and allergic diseases in childhood after correction of some questions.

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Thermal Characteristics of a Partition Supply System

  • Jeong, Ky-Bum
    • International Journal of Air-Conditioning and Refrigeration
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    • v.11 no.2
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    • pp.67-72
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    • 2003
  • A partition integrated air supply system can provide highly personalized environmental control. The supply air is brought up through raised floors and supplied to outlets located on the partition panels. The purpose of this paper is to find out the best design of outlets for optimal occupant comfort within a personal task area. Real scale experiments were conducted to allow for comparisons of outlet designs within a personal task area. Experimental results indicate that the location of an outlet is the most critical factor in improving the efficiency of supply air distribution of a personal task area. Thermal characteristic comparisons were made between the under-floor and the partition supply systems. Experimental results suggest that the partition supply system is more efficient than the under-floor supply system in terms of cooling. Such a system allows occupants to personally control their immediate environment, resulting in higher productivity.