• Communications for Statistical Applications and Methods
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• v.17 no.4
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• pp.591-598
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• 2010

A questionnaire may consist of duplicated or similar items. This study finds the duplicated or similar items by using the MDS and the cluster analysis of response patterns. By identifying the characteristics of the cluster, those items are combined into a representative item. The similarity of items is measured by the mutual information.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.10 no.3
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• pp.73-78
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• 2011

This study contains to theory and analysis research for the stress and the translation of an expand disk that fix a ring gear for tooth profile machining. The stress of the expand disk is analysed by the finite element method(FEM) to calculate design parameters. From the analysis results, the stress of the expand shows a linear tendency under various fixing force. This results show that the expand disk have a elastic characteristics as a disk spring. The maximum stress was observed on under side in split section of the expand disk. It is verified that the analysis results are useful to calculate design parameters of the expand disk.

• Korean Journal of Human Ecology
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• v.14 no.1
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• pp.1-13
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• 2005

This study has a purpose of developing a scale to evaluate maternal beliefs on preschool children's education. The subjects were 307 mothers of preschool children in Gwang-ju. The methods for data analyses included a factor analysis for construct validity, Pearson correlations between beliefs and learning-related activities for construct validity, and Cronbach's a for reliability. 4 factors were found, through literature review, in parental beliefs: passive learning, active learning, instruction, and expectation for academic-related skills acquisition. Factor analysis revealed that the 4-factor solution is the best fit. Correlations between beliefs and learning-related activities were statistically significant. Cronbach's a ranged from .65 to .87 for 4 sub-scales. It was concluded that the maternal beliefs scale is acceptable for use.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2001.04a
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• pp.116-119
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• 2001

마이크로 크기 상업용 칠 분말의 반응성 향상을 위한 변수로 포기 반응 조건인 pH 조절과 산 세척을 통한 철 분말의 표면처리를 선정하고 질산성 질소를 처리대상오염 물질로 선택하여 철 분말에 의한 질산성 질소 처리 실험을 수행하였다. 산을 이용한 초기 pH조절에 의한 반응성 향상 실험에서 가장 좋은 pH 조절제는 염산이었으며 critical pH는 2 였고 산 세척에 의한 반응성 향상 실험에서는 산 세척한 철 분말의 반응성이 그렇지 않은 철 분말보다 현저하게 좋았으며 황산의 세척능이 염산보다 더 뛰어남을 알 수 있었다. 본 연구를 통하여 초기 반응조건의 조절과 철 분말의 산 세 척을 통한 전처리로 기존의 마이크로 크기 상업용 철 분말이 지닌 반응성의 향상을 꾀하였으며 수중의 질산성 질소 처리실험을 통하여 최적의 반응조건을 확립하였다.

• 해운
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• s.91
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• pp.13-20
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• 2012

최근 그리스 경제 악화 사태에서 촉발된 유럽 전체의 재정 위기, 유가의 지속적 상승, 중국 경제의 경착륙 전망과 컨테이너선박의 공급 과잉현상이 지속됨에 따라 아시아-유럽 항로를 중심으로 글로벌 얼라이언스가 지각변동 수준으로 재편되었다. 이러한 얼라리언스의 대규모 이합집산은 컨테이너 운임시황 악화에도 불구하고 선복량 기준 세계 1위 선사인 머스크(Maersk)사가 2011년 4월 18,000TEU급 선박 20척을 발주(10척은 옵션)하고, 대규모 선대를 투입한 'Daily Service'를 시작함에 따라 촉발되었다. 이후 머스크(Maersk)사의 전략에 대응하고 독주를 막기 위해 그 외 선사의 몸집 불리기가 시작되었다. 이에 따라서 얼라이언스가 초대형화되고, 본격적인 시장점유율 경쟁이 시작되었다. 결과적으로 해운 시장 과점화 현상의 심화가 예상된다. 항만의 고객인 해운 선사 및 얼라이언스의 재편은 필수적으로 항로재편이 수반되며, 대형화 및 과점화는 항만에 여러 가지 순영향과 악영향을 미치게 될 것이다. 다음은 한국해양수산개발원 김근섭 전문연구원이 발표한 "글로벌 해운 선대 재편과 항만의 대응방안"의 주요 내용을 요약정리한 것이다.

• Korean Journal of Child Studies
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• v.29 no.3
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• pp.303-318
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• 2008

Participants in this study of the validity and reliability of PIPPS (Penn Interactive Peer Play Scale; Fantuzzo et al., 1998) for Korean children were 248 5-to 6-year - old children and 11 teachers. Instruments included the Peer Rating Scale(PRS; Singleton et al., 1979), Social Competence and Behavior Evaluation (SCBE; LaFreniere & Dumas, 1995), and Preschool Behavior Questionnaire (PBQ; Behar & Stringfield, 1974). The structure of PIPPS resulted in 3 factors, 'play disruption', 'play interaction', and 'play disconnection' with 30 items similar to the original PIPPS factors. Validity was evidenced by inter-correlations among sub-factors and by correlations between PIPPS and criterion measures. PIPPS scores were validated by ratings from PRS, SCBE and PBQ sub-areas scores. Cronbach's a reliability of PIPPS factors ranged from .88 to .92.

• Journal of the Korean Home Economics Association
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• v.48 no.10
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• pp.133-141
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• 2010

The purpose of this study was to investigate the construct validity of the Penn Interactive Peer Play Scale on the parent version. The participants of this study were 231 children in the Seoul and Gyeonggi provincial areas. The instruments included the 32-item exploratory PIPPS (Choi & Shin, 2008), and the Preschool Behavior Questionnaire (PBQ; Park, 1992). The data were analyzed by descriptive statistics, factor analysis, Pearson's r and Cronbach ${\alpha}$. The results were as follows. First, the PIPPPS on the parent version was validated with supporting three factors: Play Disruption, Play Disconnection and Play Interaction with 30 items. The sub-factors of the PIPPS were related with those of the PBQ as criterion measurements. The reliability coefficients of the sub-factors of the PIPPS were ranged from .78 to .82.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.88-90
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• 2013

최근 지구온난화의 영향으로 하절기 북극해의 얼음이 예상보다 빨리 녹고 있어 북극해항로의 상용화가 더욱 가속화될 전망이다. 지난해 여름 북극해빙의 크기는 1979년 인공위성관측 이래 최소치를 기록하였으며 또한 다년생 얼음구성비율도 낮아져 대부분이 1년생 얼음으로 대체됨으로써 선박의 운항기간도 점차 늘어나게 되었다.. 이러한 해빙의 가속화가 지속된다면 2030년경에는 북극해의 얼음이 완전히 녹을 것으로 예측되고 있다. 한편 러시아의 NSR 개방이후 비러시아 선박으로서는 2009년 독일 벨루가 선사 소속의 화물선 두 척이 NSR을 통과한 이래 지난 해에는 46척, 금년에는 그 수가 더욱 급격히 늘어나고 있어 앞으로 한.중.일의 NSR 선점경쟁이 더욱 치열해질 것으로 예상된다.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.3
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• pp.149-154
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• 2015

This study has focused on the deburring technology of a vacuum plate for MLCC lamination using electrolytic in-process dressing (ELID) grinding, and the magnetic-assisted polishing (MAP) process. The surface of the vacuum plate has many micro-holes for vacuum suction. They are easily blocked by the burrs created in the surface-flattening process, such as the conventional grinding process. In this study, the MAP process, the ELID grinding process, and an ultrasonic vibration table are examined to remove the micro-burrs that lead to the blockage of the holes. In the results of the experiments, the MAP process and ELID grinding technology showed significant improvements of surface roughness and deburring performance.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.5 no.1
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• pp.27-32
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• 1996

This paper deals with the distributions of magnetic flux of an electro-magnetic chuck which is one of the most commonly used chucking attachments in a surface grinding machine. The measured results showed good correspondence with the theoretical results which were previously presented by the same author. The normal and tangential components of the magnetic flux density were measured using the gauss meter. The measured results indicated that the magnetic flux density was periodically changing over the transverse position to the magnetic pole. The normal component of magnetic flux decreases very rapidly for the increased z position.