• 전기학회논문지
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• 제61권5호
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• pp.711-716
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• 2012

To assess the insulation deterioration of stator windings, diagnostic and AC breakdown tests were performed on the eleven high voltage (HV) motors rated at 6kV. After completing the diagnostic tests, the AC overvoltage test was performed by gradually increasing the voltage applied to the stator windings until electrical insulation failure occurred, to obtain the breakdown voltage. Stator winding of motors 1, 3, and 8 failed at above rated voltage at 14 kV, 13.8kV, and 16.4kV, respectively. The breakdown voltage of three motors was higher than expected for good quality windings in 6kV motors. Based on deterioration evaluation criteria, the stator winding insulation of eleven HV motors are confirmed to be in good condition. The turning point of the current, $P_{i2}$, in the AC current vs. voltage characteristics occurred between 5kV and 6kV, and the breakdown voltage was low between 13.8kV and 16.4kV. There was a strong correlation between the breakdown voltage and various electrical characteristics in diagnostic tests including Pi2.

• 한국정밀공학회지
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• 제5권1호
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• pp.50-62
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• 1988

An experimental investigation of the machining characteristics of compact vermicular cast iron whose matrix were formulated under two kinds of annealing conditions has been conducted. The various characteristics of the machinability of CA cast iron depending upon its matrix and cutting condition have been obtained from the experiment. The results are as follow. As depth of cut increases, the shear stress slightly decreases in order $P_1, \P_2, \P_3$ which are classified by ferrite matrix of CV cast iron. As depth of cut increases, the normal stress increases, and annealing effect in heavy cutting is smaller than that in light cutting. The cutting energy slightly decreases, as depth of cut increases and the effect of annealing on cutting energy in light cutting is higher than that in heavy cutting. The cutting equation in this study are as follow. $P_1\:\2{\phi}\ + \1.49({\beta} - {\alpha} )=84^{\circ}$ $P_2\:\2{\phi}\ + \1.36({\beta} - {\alpha} )=82^{\circ}$ $P_3\:\2{\phi}\ + \1.34({\beta} - {\alpha} )=79^{\circ}$ Machining constants in this study for $P_1, P_2, P_3$give $74^{\circ} , 66^{\circ}, 61^{\circ}$ Tool wear increases as depth of cut increases, and decreases as ferrit matrix increases.

• 대한기계학회논문집
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• 제12권5호
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• pp.1055-1062
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• 1988

본 연구에서는 역학모델을 이용해 공구마멸 특성을 절삭속뿐만 아니라 공구와 유리섬유의 접촉길이에 대해서도 논하고, 이 결과와 실험결과를 대비 검토하였다. 또 몇 가지 공구재종으로 절삭성능을 측정하였다.

• 한국항해항만학회지
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• 제42권6호
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• pp.518-528
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• 2018

현대 사회에서의 항만공간은 과거와는 달리 단순히 항구로써의 기능만을 위한 공간이 아닌 주거, 레저, 관광 등 다양한 기능이 복합화 되고 있다. 그에 따라 더욱 많은 사람들이 밀집하는 공간으로 변모해 가고 있다. 반면 항만 공간은 지형적, 환경적 특성 상 재해에 취약한 공간이기도 하다. 하지만 아직까지 국내에서는 방재 도시계획이 명확히 자리 잡고 있는 실정이 아니다. 따라서 항만공간의 특성을 감안한 방재 도시계획을 강화하고, 이를 통해 안전성을 확보할 필요가 있다.

• 대한조선학회논문집
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• 제58권6호
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• pp.407-414
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• 2021

The manoeuvrability of a ship with an unwanted heel angle due to a maritime accident is changed from the original characteristics. The purpose of this study is to quantitatively investigate the change in the manoeuvring performance of a twin-screw ship under various hee angles and speed conditions. A series of free running model test campaigns were performed in the Ocean Engineering Basin of Korea Research Institute of Ships & Ocean Engineering (KRISO) for a twin-screw car ferry vessel. Turning circle test and zig-zag 10/10 and 20/20 tests were carried out on the heel angles of 0, -10, and -19.5 degrees. In addition, two-speed conditions were considered to understand the effect of ship speed. In order to examine the effect of the bilge keel, a heel angle of -22 degree where the bilge keel is exposed outside the water surface, was considered. Finally, the change of manoeuvring characteristics according to the heel angle for a twin-screw and a single-screw vessel is discussed.

• 대순사상논총
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• 제25_1집
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• pp.87-119
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• 2015

Typology of religious organization is a useful analysis from the stand point of sociology of region. A study on the change of type of religious organization according to typology is a academic responsibility. This study can also make a religion prepare theoretical shape for the future of the religion. Although Daesoonjinrihoe now becomes a established sect, Daesoonjinrihoe should retain characteristics as a alternative sect. This feature as a alternative sect is an important identity of Daesoonjinrihoe which was established to criticize and overcome established sect. Dotongjingyeong is an ideal world of Daesoonjinrihoe. The foundation of Dotongjingyeong as an ideal world is essential value and reason of existence of Daesoonjinrihoe. For this reason, Daesoon jinrihoe should not just maintain its position but lead to reach the Dotongjingyeong here and now. Dotongjingyeong which should be built here and now is beyond Daesoonjinrihoe as a religious organization, because Dotongjingyeong is new heaven and new earth. Daesoonjinrihoe should put an guard against trial and error through change of type. Otherwise, Daesoonjinrihoe can not retain characteristics as an alternative sector. Now Daesoonjinrihoe may be at a revolutionary turning point for the foundation of Dotongjingyeong.

• 수산해양기술연구
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• 제56권2호
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• pp.163-171
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• 2020

Engaged in trawling in limited fishing grounds with a number of fish schools could cause collisions between fishing vessels. Therefore, providing accurate maneuver information according to the situation could be regarded as essential for improving seafarers safety and fishing efficiency as well as safety of navigation. It is difficult to obtain all maneuver information through sea trial tests only, so a method through empirical formula is necessary. Since most empirical formulas are developed for merchant ship types, especially the characteristics of hull shape parameter like C_bB/L and dC_b/B etc. are clearly different between fishing vessels and merchant ships, this could occur estimation errors. Therefore, in this study, the authors have selected target fishing vessels and merchant ships and analyzed the characteristics of hull shape parameter according to the ship types. Based on this analysis, the empirical formula developed for the merchant ship type has applied to the target fishing vessels; it has verified through the turning motion simulation that the estimation error could be generated. In conclusion, it is necessary to include the characteristics of the hull shape parameter of fishing vessels in the empirical formula in order to apply the empirical formula has developed for merchant ship types to fishing vessel types.

• 한국항해항만학회지
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• 제44권3호
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• pp.264-274
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• 2020

로로 페리선은 급선회 시 선박의 선미부 객실의 증개축으로 인한 무게중심 상승, 과도한 화물적재, 발라스트 부족 등으로 인한 복원성 결여 및 고박 부실 등의 여러 가지 원인으로 전복되어 해저에 침몰하였다. 이 연구의 목적은 유체-구조 연성(Fluid-Structure Interaction; FSI) 해석기법을 이용하여 급선회에 따른 빠른 침수 및 전복에 이어 침몰사고로 진척된 원인을 과학적이고 정확하게 규명하고 분석하는 것이다. 이를 위해 사고 당시의 동영상과 사진들을 분석하여 시간에 따른 선박의 정확한 자세를 구현하고, 이에 따른 화물 이동과 선체 외부의 해수 유입구와 선체 내부에서의 유입된 해수의 이동 경로에 따른 해수 유입량을 실선 부양 시뮬레이션 및 유체정역학적 특성치 프로그램을 사용하여 정확히 검증하여 실선 침수·침몰 시뮬레이션을 수행하여 사고원인을 정확하고 객관적으로 규명하고자 하였다.

• 한국도로학회논문집
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• 제19권1호
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• pp.91-106
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• 2017

PURPOSES : Because elderly drivers are more prone to becoming confused when approaching an urban intersection and thus may yield prolong judgment and decision times than non-elderly drivers, to increase the comfort and safety of the intersection environment for elderly drivers, this study applied autonomous driving tests at an urban intersection to examine their driving characteristics. METHODS : To obtain a more comprehensive understanding of driving features, this study collected drive data of non-elderly drivers and elderly drivers via an autonomous experiment using OBD2 and an eye-tracker, in addition to performing a literature review on the measured visibility range of elderly drivers at intersections. This literature review was conducted considering the general knowledge of elderly drivers having relatively reduced visibility. Additionally, as they are commonly more vulnerable, this study analyzes characteristics of elderly drivers as compared to those of non-elderly drivers. CONCLUSIONS : The results of this study can be summarized as follows: 1) the peripheral visible distance of elderly drivers is reduced as compared to that of non-elderly drivers; 2) elderly drivers approach and proceed through intersections at slower speeds than non-elderly drivers; and 3) elderly drivers yield increased driving distances when performing a right or left turn as compared to non-elderly drivers as a result of their reduced speed and acceleration and larger turning radii relative to non-elderly drivers.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2005년도 춘계학술발표대회 논문집
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• pp.69-74
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• 2005

Despite the advancement of knowledge and techniques, architectural design has been developed by similar method and science as the logical tool since the development of Le Corbusier's 'module'. However, in the new millenium emotional design has become a key issue and today is the turning point regarding new method for designing human space. While architecture discipline of the West focused on logic, Japan based its origin in eastern discipline has developed a unique design concept called 'metabolism' and advanced it very effectively. Since its development of the unique concept, Toyo Ito has become one of the most Influential architect in and out of Japan who devoted his design career in developing new space concept. This study is specifically focused on Ito's project by finding characteristics of his projects and analyze emotional design factors by using 5 analytical tool - experiencing the space, five senses, landmark, sequence, and scale. Ito's work between 2000-2004, such as Sendai Mediatheque, showed more visible sign of emotional design characteristics compared to the works done in 1990's. Because of the analytical studies researching those emotional design characteristics and methods, the future advancement in new space design will be possible with great success. The result proves that continuing proper analysis and research in design method will assist in approaching new space design method into more advanced realm in very efficient time period with more definite design elements to accomodate and fulfill human needs in given space.