• 시스템엔지니어링학술지
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• 제5권1호
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• pp.43-48
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• 2009

Korean Tilting trains have been tested on conventional lines since the beginning of 2007 for evaluating its reliability. We achieved some major performance tests which are the maximum operation speed, 180km/h test and the maximum curves increasing speed, over 30 percentage comparing with non-tilling operation train. In order to analysis reliability data of tilting train, we have used the special system engineering frame with interfacing between component suppliers effectively. And also we have developed the data aquisition system which consists of monitor, sensors and depot computer etc. As a results of calculation, until now we realized that the reliability are getting more increasing than starting point of running field test.

• Journal of Nutrition and Health
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• 제54권1호
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• pp.95-103
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• 2021

Purpose: High intake of cholesterol leads to cardiovascular disruption. Estimating the actual intake of cholesterol can be beneficial for nutrition intervention. This research aimed to develop Semi-Quantitative Food Frequency Questionnaire (SQ-FFQ) to estimate cholesterol intake and analyze its reliability and validity. Methods: SQ-FFQ was developed by sorting high cholesterol food items in Indonesian food database and food items' availability. A total of 30 older adults were randomly chosen from Public Health Center in Jagir District, Surabaya, Indonesia to test its validity. Reliability test was done by measuring the same developed SQ-FFQ in one-month period, while validity test was done by comparing SQ-FFQ results with 6-days food record. Statistical analysis used for reliability test was paired t-test, the Intra-class Correlation Coefficient (ICC), and Cronbach's α to measure the internal consistency. Meanwhile, validity of developed SQ-FFQ was analyzed using paired t-test and Bland-Altman. Results: Reliability of 2 administered SQ-FFQs showed a good agreement based on paired t-test analysis (p = 0.200), ICC (0.609), and Cronbach's α (0.757). Strong agreement was found in most of food items, but agreements for egg yolk and fried duck were poor. Significant difference was found between those food items (p = 0.001 vs. p < 0.001, respectively) with mean difference were -25.3 mg and 46.2 mg. Validity of developed SQ-FFQ2 compared to 6-days food diary records also found a strong agreement based on paired t-test and the Bland-Altman analysis. Conclusion: This baseline research provides a reasonably valid and repeatable measure of cholesterol intake estimation that can be widely used in nutrition and public health study, especially in Indonesia. No study has been conducted in Indonesia on the development of tools to estimate the cholesterol intake.

• 한국철도학회논문집
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• 제8권2호
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• pp.182-187
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• 2005

Air spring system was widely accepted for railway vehicle secondary suspension to reduce and absorb the vibration and noise. The low natural frequency ensures a comfortable ride and an invariably good stiffness. In this paper, the characteristics and durability test was conducted in laboratory by using servo-hydraulic fatigue testing system to reliability evaluation of air spring for electric railway vehicle. The experimental results show that the characteristics and durability of domestically developed productions are shown in good results. And to guarantee the adaption of air spring, the ride comfort and air pressure variation were measured in train test on subway line.

• 항공우주기술
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• 제7권1호
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• pp.183-193
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• 2008

본 논문은 KSLV-I 상단부에 대한 고장모드 분석 결과와 시스템 수준의 비행시험 신뢰도 모델을 기술한다. 먼저, KSLV-I 상단부의 14개의 주요 기능과 비행시험 임무 프로파일을 분석하고, 기능 분석 결과와 임무 구간별 수행 기능 목록을 바탕으로 시스템 체계에 따른 상단부의 고장모드 계층 구조와 시스템 수준의 비행시험 신뢰도 모델을 구성한다.

• 항공우주시스템공학회지
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• 제10권1호
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• pp.51-58
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• 2016

In this paper, we present some results on No-failure accelerated life test of aerial vehicle for reliability demonstration. The design of general accelerated life test consists of the three phases: 1) Estimating normal life test time of a single product from Weibull distribution model; 2) Determining the acceleration factor (AF) by utilizing the relation between the life of mechanical components and the applied torque; 3) Calculating the accelerated life test time, which comes from dividing the estimated normal life test time into AF. Then, we applied the calculated life test time to the real reliability test of the flap actuating system, while considering the requirement specification for mechanical components and operating environment of the actuation system. Real experimental processes and results are presented to validate the theory.

• 한국신뢰성학회지:신뢰성응용연구
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• 제12권4호
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• pp.275-285
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• 2012

This paper presents a changes of luminescence property for converted white LEDs with the commercially available silicate phosphor. If silicate phosphor's quantity increase step by step. luminescence property will be changing. we analyze luminescence property for these change and carry out the high temperature aging test for 7,000 hours, the high temperature and humidity aging test for 7,000 hours for reliability. LED degradation not only results in reduced light output but also in color changes. so we monitor correlated color temperature (CCT), chromaticity coordinates(x, y) and spectrum intensity. Those results suggest that humidity factor more bad effect in color changes than temperature factor and Lighting quality is related with quantity of phosphor.

• Physical Therapy Rehabilitation Science
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• 제6권1호
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• pp.20-25
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• 2017

Objective: During the physical therapy education, if we can understand the student's attitude then we can make valuable suggestions with respect to the teaching in the universities and professional employment in the country. The aim of the current study is to develop a questionnaire to test the physical therapy students' attitudes towards their education and profession and to test its test-retest reliability and content validity. Design: Cross-sectional study. Methods: A total of 47 physical therapy students who were in their final year were randomly selected to participate in the study. After the making of the questionnaire, it was given to 6 professional experts teaching in the field of physical therapy to obtain their responses for each question with a 5-point Likert scale grading. Their answers were used in making the content validity of the questionnaire. Afterwards, the physical therapy students were asked to fill the questionnaire. Instrument reliability and test-retest reliability were also assessed by having the students complete the questionnaire after one month of taking the questionnaire. Results: The content validity index was 0.71 for the whole scale and values of individual subdivisions were ranging from 0.69 to 0.75. Instrument reliability measured by Cronbach's alpha coefficient was 0.86 for the whole scale and subdivision values were ranging from 0.32 to 0.86. Test-retest reliability was assessed by intraclass correlation coefficient, which was 0.71 for whole scales and subdivision values were ranging from 0.38 to 0.70. Conclusions: This questionnaire, which assesses the physical therapy student attitude towards their education and profession, has good content validity, instrument reliability, and test-retest reliability.

• 아동학회지
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• 제30권1호
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• pp.59-75
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• 2009

The purpose of this study was to verify the validity and reliability for the Test of Oral Reading and Comprehension Skill (Gardner, 2000) for Korean lower level elementary school children. Subjects were 122 first to third grade students, tested individually. The vocabulary and comprehension sub-tests of K-WISC III and the reading comprehension test of Basic Academic Skills Assessment (Kim, 2000) were used to verify concurrent validity. Internal reliability was determined by internal consistency coefficients. Results verified concurrent validity. Test scores differed significantly by grade level. Test reliability was also confirmed. In conclusion, the Oral Reading and Comprehension Skill Test (Gardner, 2000) is reliable and valid for examination of reading comprehension skills for Korean lower level elementary school children.

• The Journal of Korean Physical Therapy
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• 제25권4호
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• pp.210-216
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• 2013

Purpose: A cost effective tool for the clinical measurement of trunk reposition sense is clearly needed. This study was to analyze intrarater and interrater Reliability of trunk repositioning error (TRE) test which assesses trunk position sense using a portable digital inclinometer. Methods: Twenty four normal healthy subjects were recruited. TRE was measured using a portable digital inclinometer. A digital inclinometer (Acumar-ACU360; Lafayetter Instrument) with precision to $1^{\circ}$ was placed on skin over the spinous process from first to second thoracic vertebra (T1-T2) and secured with double-sided tape. TRE test during sitting forward and lateral flexion movement was assessed. When they reached a point approximately 50% of full trunk flexion range, the examiner instructed the subjects to stop and told them. This was the target position that they should try to reproduce exactly. Each subject performed six trials. Results: ICC (2,1) for intrarater reliability (with-day and between-day) of TRE test in sagittal and frontal plane of movement was 0.75 and 0.78 (excellent reliability). Interrater reliability was 0.66 in sagittal and 0.64, frontal plane (fair to good reliability). However, there were poor correlations between an average of TRE test in sagittal and frontal plane. Conclusion: TRE test using a portable digital inclinometer demonstrated good to excellent reliability. The device may be a cost effective clinical measurement for trunk reposition sense measurement.

• 품질경영학회지
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• 제44권1호
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• pp.29-42
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• 2016

Purpose: This paper reviews the papers on reliability issues which are published in the Journal of the Korean Society for Quality Management (KSQM) since 1965. The literature review is purposed to survey a variety of reliability issues for several categories Methods: We divide all of reliability issues into 9 categories: acceleration test, reliability estimation, system reliability, software reliability, reliability data collection and analysis method, lifetime distribution, maintenance and warranty strategy, reliability applications, and reliability applications to military area Results: Dividing all of papers on reliability published in KSQM for 50 years into 9 categories, we provide a chronological roadmap for individual categories, and summarize the contents and contributions of surveyed papers Conclusion: The review paper is expected to provide future direction to improve reliaiblity theories and applications in manufacturing and service industries