• Korean Journal of Acupuncture
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• v.29 no.4
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• pp.573-580
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• 2012

Objectives : This study was to investigate statistical validities and trends of previously reported papers that used various statistical techniques such as t-test and analysis of variance. Methods : To analyze the statistical procedures, 54 original articles using those statistical methods were selected from The Korean Journal of Acupuncture published from 2007 to 2011. Results : T-test and analysis of variance were used in 23(25.27%), and 18 papers(19.78%) out of 54 papers, respectively. Seven articles(12.96%) did not report alpha values and 26(48.15%) out of 54 studies were not tested for normal distribution. One paper(1.85%) misused t-test and 7 papers(38.89%) did not carry out the multiple comparison. Conclusions : To improve the quality of KJA, statistician involvement in research design would be necessary to reduce errors in statistical methods and interpretation of the results.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.5
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• pp.1-11
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• 2017

This study focused on the ultimate behaviors(ultimate strength and fracture mode ) of single shear bolted connection with austenitic sainless steel(STS201) and curling effect on the ultimate strength using finite element analysis based on test results. Main variables are end distance in the parallel direction to loading and edge distance in the perpendicular direction to loading. The validation of finite element analysis procedures was verified through the comparisons of ultimate strength, fracture mode and curling(out-of-plane deformation) occurrence between test results and numerical predictions. Curling was observed in both test and analysis results and it reduced the ultimate strength of single- shear bolted connections with relatively long end distances. Strength reduction ratios caused by curling were estimated quantitatively by maximum 19%, 32%, respectively for specimens with edge distance, 48 mm and 60 mm compared with strengths of uncurled connections with restrained out-of-plane deformation. Finally, analysis strengths were compared with current design strengths and it is found that design block shear equations did not provide the accurate predictions for bolted connections with strength reduction by curling.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.1
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• pp.51-57
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• 2010

In recent years, a large number of study for rear impact has been conducted and as a result of study, researchers proposed the neck injury criteria and test procedures. But many questions, related to injury criteria and dummy biomechanical levels, remain unresolved. In recently reports, rear impact motions of BioRIDIIg is not humanlike but better than other dummy(HybridIII, RID3d). So, in this paper, 4 times sled test would be done to find the substitutable neck injury criteria in BioRIDIIg. To review corelation trend with neck injury critera and head-neck movement, we compared with recently announced neck injury criteria(NIC, Nkm, T1 ect.) and head-neck X-direction movement in BioRIDIIg. Finally, we find the head-neck X-direction movement on head C.G to T1 point may be considerable as the additional neck injury criteria.

• Journal of the Korean Society of Clothing and Textiles
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• v.15 no.3 s.39
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• pp.229-238
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• 1991

The object of this study is to develope an improved version of brassiere with better fit and improved performance by conducting a try-on test on 6 types of revised brassieres (constructed on above basis). The study procedures consisted of a try-on test of experimentally constructed brassieres and a sensory test on fit. The results of experimentally constructed brassiere trial are as follows. 1. The sizes showing performance effects due to different types of experimentally construct- ed brassieres were bust length, bust height, under bust curve length, vertical and horizontal bust diamenter, upper-lower bust slope angle (direct measurement, parallel standard, upper torso tilt rate), side bust slope angle and top bust slope angle. 2. Concerning the changes in lower cup interior, elastic materials and wider portions perfor-med better in bust up effect. 3. No effects due to different shoulder strap positions were observed, but combined with lower cup interior changes the side types proved more effective than the standard types.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.717-720
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• 2005

Acoustic loads generated by a rocket propulsion system cause severe random vibrations on payloads. In developing a new launch vehicle, a random vibration level must be specified before the detailed design of payloads or electronic equipments. This paper deals with prediction procedures of a random vibration level on payload section of KSLV-I. The prediction is based on statistical energy analysis. In order to verify the prediction methodology, test and analysis on a sub-scale payload section are performed. The predicted results subject to very high level of acoustic loads show a good agreement with the test results performed in the high intensity acoustic chamber. The predicted random vibration level on payload section of KSLV-I is also presented in this paper.

• International Journal of Contents
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• v.4 no.2
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• pp.19-23
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• 2008

This paper presents a novel method to construct a personalized e-Learning system based on dynamic estimations of item parameters and learners' abilities, where the learning content objects are of the same intrinsic quality or homogeneously distributed and the estimations are carried out using IRT(Item Response Theory). The system dynamically connects the test and the corresponding learning procedures. Test results are directly applied to estimate examinee's ability and are used to modify the item parameters and the difficulties of learning content objects during the learning procedure is being operated. We define the learning unit 'Node' as an amount of learning objects operated so that new parameters can be re-estimated. There are various content objects in a Node and the parameters estimated at the end of current Node are directly applied to the next Node. We offer the most appropriate learning Node for a person's ability throughout the estimation processes of IRT. As a result, this scheme improves learning efficiency in web-base e-Learning environments offering the most appropriate learning objects and items to the individual students according to their estimated abilities. This scheme can be applied to any e-Learning subject having homogeneous learning objects and unidimensional test items. In order to construct the system, we present an operation scenario using the proposed system architecture with the essential databases and agents.

• Korean Journal of Oriental Medicine
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• v.18 no.3
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• pp.127-132
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• 2012

Background and Purpose : This study was to investigate statistical validities and trends of previously reported papers that used various statistical techniques such as t-test and analysis of variance. Methods : To analyze the statistical procedures, 38 original articles using those statistical methods were selected from Journal of Korea Institute of Oriental Medicine(JKIOM) published from 2010 to 2012. Results : Analysis of variance and t-test were used in 20 papers (38.5%), 16 papers (30.8%) of 52 papers. Four articles(10.5%) did not report ${\alpha}$ values and nineteen papers(50.0%) of 38 ones were not tested for normal distribution. Five papers (13.2%) misused t-test and 3 papers (7.9%) did not carry out the multiple comparison. Conclusions : To improve the quality of JKIOM, The participation of statisticians in research design will reduce the significant errors in statistical interpretation of the results.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.377-380
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• 2005

In this paper, accelerated stress test(AST) for Magnetic Switch (MS) are applied to assure specified reliability of the products. Magnetic contactor that functions with over-current relay is called MS. Magnetic contactor closes and opens the motor load with ON/OFF switch of electronic contactor. It is also used for protecting and controlling the load. Magnetic contactor detects the over-current flow in the load with a over-current relay and disconnects the load by opening its control power. In this study, AST for product assembly are developed in order to improve the weak point so that increase the product reliability. Also we will show the basic information for the accelerated life test(ALT). The proposed AST results and procedures may be extended and applied to testing similar kinds of products to reduce test times and costs of the tests remarkably. Finally the results of this study will contribute to improving reliability of products and strengthening competitiveness of our products in the world markets.

• Physical Therapy Korea
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• v.6 no.4
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• pp.15-21
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• 1999

이 연구의 목적은 Motor-Free Visual Perception Test (MVPT)와 Mariannene Frostig Developmental Test of Visual Perception (DTVP)을 사용하여 뇌성마비 아동과 정상아동의 시 지각 능력의 차이를 알아보고, 뇌성마비의 사지마비군과 양하지마비군, 그리고 정상아동군에서 두 평가도구의 결과에서 제시한 시 지각능력의 차이를 비교하기 위한 것이다. 뇌성마비 아동 21명(사지마비 11명, 양하지마비 10명)과 정상아동 8명을 대상으로 하였다. 대상의 연령범위는 4세에서 8.5세이었다. 시 지각 능력을 평가하기 위하여 운동기능을 포함하지 않은 MVPT와 운동기능을 포함한 DTVT를 사용하였다. 평가과정과 방법은 표준화된 지침서에 따라 수행하였다. 자료분석은 SPSS를 사용하여 Wilcoxon signed rank test와 Mann-Whitney, Kruskal-Wallis를 하였다. MVPT와 DTVP의 지각지수를 뇌성마비 아동과 정상아동을 비교한 결과 뇌성마비 아동의 지각지수가 정상 아동보다 유의하게 낮았다. 아동의 교정연령과 MVPT와 DTVP의 지각연령의 차(CA-PA)를 사지마비군, 양하지마비군, 그리고 정상군과 비교한 결과 정상군에서는 두 평가도구 간의 차이가 없었으나, 사지마비군에서는 두 평가도구 사이에 유의한 차이가 있었다. 이 연구의 결과는 뇌성마비 아동의 시 지각능력을 평가하기 위한 도구로 MVPT의 사용을 제시하였다.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1434-1441
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• 2005

For anchored system applications, each ground anchor is tested after installation and prior to being put into service to loads that exceed the design. This load testing methodology, combined with specific acceptance criteria, is used to verify that the ground anchor can carry the design load without excessive deformations and that the assumed load transfer mechanisms have been properly developed behind the assumed critical failure surface. After acceptance, the ground anchor is stressed to a specified load and the load is locked-off. The two types of load tests conducted during the research program included performance test and creep test which were carried out in accordance with testing procedures by AASHTO(AASHTO 1990) and FHWA(Weatherby 1998) at Samsung-Dong 00 Site. Form the measurements, ultimate load and creep rate of anchors are proposed for straight shaft pressured grouted anchors in waste landfill. The load distribution on the grout was obtained from the measured strain data at each fraction of the ultimate load during the load tests.