• Wind and Structures
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• 제14권2호
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• pp.167-186
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• 2011

This paper presents the results of measurements relating to the aerodynamic forces on flat square plates which were allowed to rotate at different speeds about their horizontal axis, by modifying the velocity of the incoming flow. A 1 m square test-sheet and a 0.3 m square test-sheet were fitted with a number of pressure sensors in order to obtain information relating to the instantaneous pressure distribution acting on the test-sheet; a compact gyroscope to record the angular velocity during the rotational motion was also implemented. Previous work on autorotation has illustrated that the angular velocity varies with respect to the torque induced by the wind, the thickness and aspect ratio of the test-sheet, any frictional effects present at the bearings, and the vorticity generated through the interaction between the plate and the wind flow. The current paper sets out a method based on the solution of the equation of motion of a rotating plate which enables the determination of angular velocities on autorotating elements to be predicted. This approach is then used in conjunction with the experimental data in order to evaluate the damping introduced by the frictional effects at the bearings during steady autorotation.

• 대한가정학회지
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• 제8권1호
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• pp.159-180
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• 1970

Forty-five home account books were randomized by electing "prize for good home manager" in 1967 through all over the country in korea. With this sampling analyzed monthly home expenditure in different item by test of significance, and compared with model of home expenditure and this results. Hope this analysis will help to the house wife for better plan home expenditure and will develope in scientific way of life in home managing. 1. Significance test of home account books in their items and in months indicated that there were significant statistical differences in the total living expenses. In other words, they did not work out a budget, and their home account books were nothing but a record expenses. 2. There was a significant difference in the monthly expenditure for food caused by the preparation of cabbage pickle (kim Jang) in November. This payment in a lump to the cabbage pickle brought about unbalance to home economic. 3. Compared with others, in November and in December we could find a meaningful difference in the monthly expenditure for clothing. 4. It was noted that there were not such comparable significant differences in months as to be mentioned for housing light and heating, education, saving, transportation and communication culture, taxes.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 Asia Navigation Conference
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• pp.64-73
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• 2004

During the period of every summer to early autumn seasons, ships have been wrecked or grounded from effect of a typhoon in the waters around Korean Peninsular. Typhoon Rusa killed more than 100 people in September 2002. Super Typhoon Maemi passed southeast of South Korea in September 12-13, 2003, with gale winds blowing at a record 60 m/s and caused much ship groundings, collisions and sinkings over 3000 in dockyards, harbors and places of refuge. These are things that could have been prevented had there merely been prior warning. The aim of this study is to examine what effect these typhoons had on occurrence characteristics of the maritime accidents in South Korea. In this work, records of marine accidents caused by a typhoon are investigated for the period from 1962 to 2002. The distribution is also compared with the trajectories of typhoons, passed during the 1990-2003. It is shown that attack frequency of typhoon and number of marine accidents is the highest in August. We use the track data of Maemi such as central pressure, maximum sustained wind speed and area of each 15m/s and 25m/s winds as a case study to draw a map as a risk index.

• 한국농촌생활과학회지
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• 제10권1호
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• pp.7-19
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• 1999

The purpose of this study was to analyze effects of the mother's child-rearing patterns on children's academic achievement with respects to ‘understanding of family and work’ area in Practical Arts Education related to the 7th revision on the Curriculum of the Elementary School. The questionnaire was used for the survey. The subjects were 200 mother-child (total of 400) randomly chosen from 4 elementary schools in Seoul. Data were analyzed by frequencies, percentages, averages, standard deviations, Pearson's correlation coefficients, t-tests and one-way ANOVA's using the SPSS/PC＋ program. The results of this study were summarized as follows : The correlation between income in their home and their children's academic achievement did not analyze because of the omitting record in their questionnaire. The relations between the patterns of mother's child-rearing and children's academic achievement by children's sex and by grade were examined. But in this study, these relations scarcely have significant differences between the children's academic achievement and their mothers' child-rearing pattern except between being significant reject-sanctions type of mothers' child-rearing and the children's academic achievement. However, the child-rearing patterns of mothers which children and their mothers think were similar, then the high correlations were found between their patterns.

• International Journal of CAD/CAM
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• 제6권1호
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• pp.199-211
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• 2006

Practical automated flat pattern generation with inbuilt production features for doubly curved sheet metal components (SMCs) is addressed here utilizing a new and unique Point Transformation Algorithm (PTA). This is the third in the series of papers on practical Flat Pattern Development (FPD) [8] and Production Loft Generation Systems (PLGS) [9] complementing the pioneering work [6,7]. In the first two publications, automated loft generation programs have addressed sheet metal components having a Principal Flat Surface (PFS) only. The flat pattern development of 3-D components that do not have the flat surface(termed as Non-PFS components) having complex features of double curvature in addition to cutouts and nibbled holes typical of aircraft components were so far not addressed due to lack of relevant published algorithms. This paper traces the evolution of developments and provides the record of fully illustrated, automated loft generation scheme for aircraft SMCs including the Non-PFS components which underwent validation through production tests by sponsors. Details of some of the unique features of the system like simplified surface model generation, termed as topological model and powerful algorithms deployed with potential for CAD/CAM applications are included.

• 대한조선학회논문집
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• 제53권4호
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• pp.275-281
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• 2016

One of the most important things for quality to meet ship-production schedule is an accuracy control. A ship is assembled by welding through whole production process, so it is important that loss by correction will not happen as much as possible by using some engineering skills like reverse design, reverse setting and margin for thermal shrinkage. These efforts are a quite effective in fabrication stages, but not in erection stages. If a ship block which consists of common steel is exposed to directional solar radiation, its dimensional accuracy will change high as time by its thermal expansion coefficient. Therefore, the measuring work would be often done at dawn or evening even with having a very accurate device. In this study, an FE analysis method is developed to solve this problem. It can change measured data affected by solar thermal distortion to ones not, even though ship-block is measured at an arbitrary time. It will use the time when measuring, the direction of block and the weather record by satellites. It is confirmed by a comparison between measured data of a ship-block and the result by suggested analysis method. Furthermore, a pre-processing system is also developed for fast application of the suggested analysis method.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1148-1158
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• 2010

This paper addresses prospect of the technology for development of NxTIS (NeXt generation Transport Information System) that is targeted to shifting Korean public transit framework to railway-centered one. The Seoul metropolitan area has adopted the smart-card as a payment system for the public transportation since 2004. The transportation record can be used as quite useful information for better planning and operating of the railway system, particularly when the smart-card based payment system is extended to whole nation. This paper introduces technologies to develop Real OD DB and NxTIS, and presents road-map for them. A variety of benefits from the development of the system are estimated both in quantitative and qualitative. The Real OD DB based NxTIS will work to highly prospective for creating a novel value in the railway as a public transportation system.

• 한국문헌정보학회지
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• 제39권1호
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• pp.195-220
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• 2005

이 연구에서는 관련 저록간의 서지적 관계를 계층화하여 효과적으로 연계하기 위한 IFLA의 FRBR 모형의 개념과 응용사례에 나타난 문제점을 검토한 후. 모형에 반영된 기본표목의 관점을 배제하구 관련 저작의 연결장치로서 ISTC를 도입하여 FRBR 모형을 M-FRBR 모형으로 수정하였다 수정된 M-FRBR 모형을 한국문학작품에 적용하여 그 활용성을 검토한 후, 이를 토대로 MODS의 데이터 요소를 재조정하여 레코드 형식을 개발하고 서지시스템을 구현하였다.

• 한국비블리아학회지
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• 제24권1호
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• pp.249-268
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• 2013

이 글은 공연예술단체나 공연예술아카이브가 공연예술기록을 수집하는 과정에서 직면하게 되는 저작권 문제를 검토하기 위한 것이다. 이를 위해 공연예술 현장에서 수집할 수 있는 기록물의 종류를 구분하고, 기록물의 종류별로 저작권 문제를 법리적으로 분석하였다. 연구의 결과로 공연예술은 음악 무대 의상 등 다양한 영역이 어우러져 하나의 작품으로 재탄생하는 종합예술로서의 성격을 지니고 있어 그 자체로 상당히 복잡한 저작권 체계를 구성하고, 그 기록물은 공연 자체의 저작권과는 구별되는 또 다른 저작권을 발생시킬 수 있으며, 저작권은 기록의 종류와 실질적인 생산주체에 따라 다양한 양상으로 구성될 수 있음을 밝혔다.

• 한국안전학회지
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• 제15권4호
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• pp.139-149
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• 2000

This study aims to review and assess the existing postural classification schemes used for evaluating postural loads in industry. The schemes can be classified into three categories: self-report, observational and instrument-based techniques depending upon how to record working postures. Of the three techniques, this study was mainly focused on the observational methods. The observational technique is most widely used in the industrial sites because it does not interfere with work, and is easy and simple to use and cost-effective without requiring the use of expensive equipment for estimating the angular deviation of a body segment from the neutral position. In spite of the usefulness and applicability, the techniques have some problems: 1) The existing observational techniques lack the consistency in the class limits of the motion categories in each body segment; 2) Most of them do not provide the post-analysis criteria needed to judge whether or not any posture is acceptable in view point of the postural load; and 3) They can not precisely evaluate the postural load for a given posture because the external loads and dynamic factors including acceleration, moment and force were not taken into consideration.