• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.3
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• pp.230-236
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• 2012

The purpose of this research is to determine the calibration constants of the wind speed measurement systems required to calculate the wind tunnel velocity in the test section. In the present work, the aerodynamic calibration tests of the test section were conducted in the Agency for Defense Development's Low-Speed Wind Tunnel. The test speed ranged from 10 to 100 m/s with a reference pitot-static pressure probe. The validity of the calibration results was evaluated by comparing them with the previous calibration constants. The calibration results show that fair to good agreement is obtained with resonable accuracy.

• Journal of Oral Medicine and Pain
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• v.16 no.1
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• pp.95-102
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• 1991

The purpose of this study carried into the Electric pulp test for having knowledge of the difference of each one's stimulant threshold in normal teeth, the stimulant threshold at 10:00 A.M. and 3:00 P.M. in the same teeth, the differendce of the stimulant threshold between dental caries and normal contralateral teeth. In this study, 27 students aged between 22 and 24 years were selected from a pool of students who are sttending school of dentistry, chosun university who did not possessed dental disease like the dental caries, periodontal disease and restoration etc., and 30 outpatients who possessed dental caries(++). The obtained results were as follows : 1. The stimulant thresholds of the premolars and canine were higher than that of the incisors. 2. The stimulant thresholds of the carious teeth were lower than that normal contralateral teeth. 3. There were no difference stimulant threshold at 10:00 A.M. and 3:00 P.M.

• Journal of Families and Better Life
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• v.23 no.1 s.73
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• pp.31-39
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• 2005

This study was conducted to examine the meaning and motivation for family leisure activities, and to analyze how the family's attitude and motivation affect the satisfaction over family leisure activities. The participants of this study were sixty-five married couples who were living in Seoul. Sata were analyzed by frequency, mean, ANOVA, T-Test, and Duncan test. The major results of this research were as follows; first, there were statistically significant differences in the meanings the families attributed to, and motivations for, family leisure activities according to social-demographic characteristics (gender, age, education, job, and income and debt levels). Second, satisfaction over family leisure activities was affected by their meanings and motivations. The participants who participated voluntarily in family activities as 'leisure activities' showed a higher level of satisfaction.

• The International Journal of Costume Culture
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• v.7 no.1
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• pp.48-57
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• 2004

The purpose of this study is to investigate how three factors--designer's capability, product market strategy, and product organization--supposed to determine the design process are related to each other. These factors influence Korean knitwear companies' market performances. For this purpose, we did not only library research on relevant theories such as the transaction cost economics but also empirical research largely based on a questionnaire. The respondents of the questionnaire were 59 designers, merchandisers(MDs), and top managers of knitwear companies located in Seoul. We analyzed the collected questionnaire data by using such statistical tools as χ²-test, t-test, and one-way ANOVA. Findings of this study were as follows. While there was a significant relation between organization form and designer's capability, no significant difference in designer's capability was found between trust enhanced network and unenhanced network. No significant relation was found between organization form and product market strategy, in discordance with Carney's arguments. Also, it appeared that there was no significant relationship between knitwear companies' product market strategies and their designers' capabilities.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2C
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• pp.109-116
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• 2006

Many application scenarios of ultra-wideband(UWB) radio assume non-line-of-sigit(non-LoS) signal propagations. Through-material propagation of UWB signal introduces a distortion of the waveform as well as attenuation, which will introduce a decrease of the correlation coefficient between the correlator template and the received signal. A hypothesis test approach to selection of the template waveform for UWB rake receivers is posed. Linde-Buzo-Gray(LBG) algorithm is used to select the candidate waveforms which are used to setup the hypothesis test. The performance of the algorithm is tested using a set of indoor non-LoS propagation measurement data.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.834-837
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• 2004

In this study, the electric accelerated reinforcing bar corrosion test was carried out to estimate the coefficient of electrolytic corrosion based on the concept of Faraday's law according to rebar corrosion rate and concrete compressive strength which had an effect on the actual corrosion mass loss. The results of this paper allow the prediction of corrosion amount in the electric accelerated reinforcing bar corrosion test method.

• Restorative Dentistry and Endodontics
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• v.49 no.1
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• pp.3.1-3.8
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• 2024

This article is a narrative review that discusses the recommended sample size requirements to design a pilot study to assess the reliability of a questionnaire. A list of various sample size tables that are based on the kappa agreement test, intra-class correlation test and Cronbach's alpha test has been compiled together. For all calculations, type I error (alpha) was set at a maximum value of 0.05, and power was set at a minimum value of 80.0%. For the kappa agreement test, intra-class correlation test, and Cronbach's alpha test, the recommended minimum sample size requirement based on the ideal effect sizes shall be at least 15, 22, and 24 subjects respectively. By making allowances for a non-response rate of 20.0%, a minimum sample size of 30 respondents will be sufficient to assess the reliability of the questionnaire. The clear guideline of minimum sample size requirement for the pilot study to assess the reliability of a questionnaire is discussed and this will ease researchers in preparation for the pilot study. This study provides justification for a minimum requirement of a sample size of 30 respondents specifically to test the reliability of a questionnaire.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.155-156
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• 2006

Developed and conducted a performance test of the Water mist system that is satisfied with the requirement of a fire test requiring Class 3 Engine Mock-up exceeding net volume $3,000m^3$ as per IMO's MSC/Circ. 668 Appendix B(Test method for fire testing equivalent water-based fire-extinguishing systems for machinery spaces of category A and cargo pump rooms).Even though fuel atomizing was continued for 15 sec. after stopping of the system according to the test method relating to the atomizing fire type, no fire was reignited. This result shows the excellence of the system. There was no damage to the contents of the system after the test.

• The KSFM Journal of Fluid Machinery
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• v.15 no.5
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• pp.5-10
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• 2012

An experimental test facility for the complete characteristics of pumps is constructed at KIMM(Korea Institute of Machinery and Materials). All sensors instrumented in test facility for measuring flow rate, pressure, force and moment are in-situ calibrated by primary method. This paper describes the test facility and test technique of the complete characteristics of pumps, together with an experimental test results for a reactor coolant pump which is designed at KIMM for the first time in Korea. The test results for the mixed-flow type pump of $n_s$=1.425 are presented by three curves: constant head, torque, and speed.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.829-835
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• 2011

This paper aims for proposed the deflection limit on vibration serviceability of high-speed railway bridges considering passenger's comfort when a train passes a railway bridge. The vertical acceleration signals of passenger cars obtained from test were compared with them from the bridge-train transfer function by riding KTX. The deflections by KTX of seven high speed railway bridges were assumed as sine and haversine wave. The deflection limit on vibration serviceability of high-speed railway bridges considering passenger's comfort when a train passes a railway bridge duration can be expanded using bridge-train transfer function and bridge comfort limit considering serviceability due to bridge vibration. And it was compared to other allowable deflection limits of railway bridge design specifications.