• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2019년도 춘계학술논문요약집
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• pp.69-69
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• 2019

The distillation of liquid cathode is necessary to separate cadmium from the actinide elements in the pyroprocessing since the actinide deposits are dissolved or precipitated in a liquid cathode. It is very important to avoid a splattering of cadmium during evaporation due to the high vapor pressure. Several methods have been proposed to lower the splattering of cadmium during distillation. One of the important methods is an installation of crucible cover on the distillation crucible. A multi-layer porous round cover was proposed to avoid a cadmium splattering in our previous study. In this study, the effect of crucible cover on the cadmium distillation was examined to develop a splatter shield. Various surrogates were used for the actinides in the cadmium. The surrogates such as bismuth, zirconia, and tungsten don't evaporate at the operational temperature of the Cd distiller due to their low vapor pressures. The distillation experiments were carried out in a crucible equipped with cover and in a crucible without cover. About 40 grams of Cd was distilled at a reduced pressure for two hours at various temperatures. The mixture of the cadmium and the surrogate was heated at $470{\sim}620^{\circ}C$. Most of the bismuth remained in the crucible equipped with cover after distillation under $580^{\circ}C$ for two hours, whereas small amount of bismuth decreased in the crucible without cover above $580^{\circ}C$. The liquid bismuth escaped with liquid cadmium drop from the crucible without cover. It seems that the crucible cover played a role to prevent the splash of the liquid cadmium drop. The effect of the cover was not clear for the tungsten or zirconia surrogate since the surrogates remained as a solid powder at the experimental temperature. From the results of this work, it can be concluded that the crucible cover can be used to minimize the deposit loss by prevention of escape of liquid drop from the crucible during distillation of liquid cathode.

• 가족자원경영과 정책
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• 제24권3호
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• pp.79-102
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• 2020

This study aims to provide basic resources for the construction of the archives on the official family service history in Korea. The study collected records of family policies and official family service from 1948 to 2019 and thereafter attempted to classify the official family service. In addition, experts were consulted to diagnose compliance with research contents and directions, investigate priorities of the family policies, and provide opinions on the elements of each process of archiving. The results of this study were as follows. First, there were five areas of concern to be considered in the process of establishing an archive of official family services: concept, scope, collection, arrangement, preservation, and utilization. Second, the findings suggest which processes are critical to developing a sustainable and systematic archive system for the official family service history. The construction of the archives will provide a platform for understanding the contents of integrated family policies and inform the direction of future family policies in Korea. In addition, these archives will be an important factor in building a solid Korean national identity.

• 철학연구
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• 제105권
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• pp.243-268
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• 2008

왕충은 당시 유행하던 음양오행설(陰陽五行說)에 근거한 천(天)과 인(人)의 감응(感應)함을 부정하기 위하여 하늘은 어떤 입과 귀도 없는 딱딱한 고체일 뿐이라고 보았다. 그래서 그는 자연 세계의 질서는 인간의 의지와는 무관하게 나름대로의 질서에 의해서 순환된다고 보았다. 즉 주재자의 의도성이 아닌 우연성에 따르는 것이다. 이처럼 왕충이 자연세계와 도덕(가치)의 세계로 구분한 궁극적인 까닭은 인간으로서 어쩔 수 없는 운명이나 부귀빈천(富貴貧賤)에 대한 관심을 넘어서 인간 스스로의 노력으로 이룰 수 있는 도덕(가치)적 세계의 실현에 있었다. 한편, 융은 인간의 심리적 유형을 내향성(內向性)과 외향성(外向性)으로 나누었다. 제임스와 박종홍은 이를 철학에 적용했을 때 철학의 내 외향성으로 나타난다고 보았다. 이런 관점으로 보면 왕충은 외향적 철학계열에 속한다고 볼 수 있다. 그래서 수양(修養)과 같은 내향적인 관심보다는 효험과 실증이란 방법을 사용해서 과감하게 한(漢)대 사회를 비판하였으며, 이를 비판윤리론과 기술적 정치이념으로도 표현해 내었다. 즉 왕충의 외향적 사유구조는 현실적, 비판적, 질허망 등의 개념과 나란히 같이 가고 있다.

• Structural Engineering and Mechanics
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• 제71권4호
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• pp.433-444
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• 2019

Shear studs are often used to connect steel girders and concrete deck to form a composite bridge system. The application of precast concrete deck to steel-concrete composite bridges can improve the strength of decks and reduce the shrinkage and creep effect on the long-term behavior of structures. How to ensure the connection between steel girders and concrete deck directly influences the composite behavior between steel girder and precast concrete deck as well as the behavior of the structure system. Compared with traditional multi-I girder systems, a twin-I girder composite bridge system is more simplified but may lead to additional requirements on the shear studs connecting steel girders and decks due to the larger girder spacing. Up to date, only very limited quantity of researches has been conducted regarding the behavior of shear studs on twin-I girder bridge systems. One convenient way for steel composite bridge system is to cast concrete deck in place with shear studs uniformly-distributed along the span direction. For steel composite bridge system using precast concrete deck, voids are included in the precast concrete deck segments, and they are casted with cast-in-place concrete after the concrete segments are erected. In this paper, several sets of push-out tests are conducted, which are used to investigate the heavier of shear studs within the voids in the precast concrete deck. The test data are analyzed and compared with those from finite element models. A simplified shear stud model is proposed using a beam element instead of solid elements. It is used in the finite element model analyses of the twin-I girder composite bridge system to relieve the computational efforts of the shear studs. Additionally, a parametric study is developed to find the effects of void size, void spacing, and shear stud diameter and spacing. Finally, the recommendations are given for the design of precast deck using void for twin I-girder bridge systems.

• Advances in Computational Design
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• 제4권1호
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• pp.53-72
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• 2019

Safety measures for tower cranes are extremely important among the seismic countermeasures at high-rise building construction sites. In particular, the collapse of a tower crane from a high position is a very serious catastrophe. An example of such an accident due to an earthquake is the case of the Taipei 101 Building (the author was the project director), which occurred on March 31, 2002. Failure of the bolted joints of the tower-crane mast was the direct cause of the collapse. Therefore, it is necessary to design for this eventuality and to take the necessary measures on construction sites. This can only be done by understanding the precise dynamic behavior of mast joints during an earthquake. Consequently, we created a new hybrid-element model (using beam, shell, and solid elements) that not only expressed the detailed behavior of the site joints of a tower-crane mast during an earthquake but also suppressed any increase in the total calculation time and revealed its behavior through computer simulations. Using the proposed structural model and simulation method, effective information for designing safe joints during earthquakes can be provided by considering workability (control of the bolt pretension axial force and other factors) and less construction cost. Notably, this analysis showed that the joint behavior of the initial pretension axial force of a bolt is considerably reduced after the axial force of the bolt exceeds the yield strength. A maximum decrease of 50% in the initial pretension axial force under the El Centro N-S Wave ($v_{max}=100cm/s$) was observed. Furthermore, this method can be applied to analyze the seismic responses of general temporary structures in construction sites.

• 한국재료학회지
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• 제31권7호
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• pp.409-419
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• 2021

The effect of solidification rate on micro-segregation in investment casting of IN738LC superalloy was studied. In Ni-based superalloys, the micro-segregation of solute atoms is formed due to limited diffusion during cast and solidification. The microstructure of cast Ni-based superalloys is largely divided into dendrite core of initial solidification and interdendrite of final solidification. In particular, mosaic shaped eutectic γ/γ' and carbides are formed in the interdendrite of the final solidification region in some cases. The micro-segregation phenomena formed in regions of dendrite core and interdendrite including eutectic γ/γ' and carbides were analyzed using OM, SEM/EDS and micro Vickers hardness. As a result of analysis, the lack of (Cr, W) and the accumulation of Ti were measured in the eutectic γ/γ', and the accumulation of (Cr, Mo) and the lack of Ti were measured in the interdendrite between dendrite and eutectic. Carbides formed in interdendritic region were composed of (Ti, W, Mo, C). The segregation applied to each microstructure is mainly due to the formation of γ' with Ni₃(Al,Ti) composition. The Ni accumulation accompanied by Cr depletion, and the Ti accumulated in the eutectic region as a γ' forming elements. The Mo tends to diffuse out from the dendrite core to the interdendrite, and the W diffuse out from the interdendrite to the dendrite core. Therefore, the accumulation of Mo in the interdendrite and the deficiency of W occur in the eutectic region located in the interdendrite. Heat treatment makes the degree of the micro-segregation decrease due to the diffusion during solid solution. This study could be applied to the heat treatment technology for the micro-segregation control in cast Ni-based superalloys.

• 디자인융복합연구
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• 제14권2호
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• pp.67-87
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• 2015

문화 산업과 다양한 정보 기술의 발달로, 영상을 활용한 디지털 마케팅이 활성화 되면서, 과거 인쇄 광고에 의지해 오던 출판 업계는 영화 트레일러와 유사한 북트레일러(Book Trailer)를 홍보 수단으로 활용하기 시작했다. 본 연구에서는 앞으로 더욱 활성화 될 것이라 예상되는 북트레일러에 대한 연구가 국내외적으로 부족하여, 체계적인 기초 연구를 바탕으로 북트레일러가 발전할 기초 토대를 마련할 필요가 있다고 판단하여 본 연구를 진행하게 되었다. 본 연구에서는 북트레일러에 대한 기초 개념을 확립하는 동시에 북트레일러의 유형을 분류 해 보았다. 유형에 영향을 주는 여러 요인이 있지만, 본 연구에서는 유형 분류에 있어 가장 기본이 되는 내용적 유형과 외형적 유형을 기준으로 유형을 구분하였다. 내용적 유형은 북트레일러의 내용에 따라, 그리고 외형적 유형은 북트레일러의 이미지 조합에 따라 유형을 나누었다. 결과적으로 내용적 유형은 스토리의 구성 요소를 토대로 메시지 활용형, 갈등 활용형, 인물 활용형으로 분류 할 수 있었고, 형식적 유형은 북트레일러를 구성하는 이미지의 조합에 따라 스틸 사진 활용형, 모션 타이포그라피 형, 인터뷰형, 영화 스토리 촬영형, 애니메이션형으로 유형을 분류 할 수 있었다.

• 한국재료학회지
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• 제33권6호
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• pp.242-250
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• 2023

Titanium, which has excellent strength and toughness characteristics, is increasingly used in the aerospace field. Among the titanium alloys used for body parts, more than 80 % are Ti-6Al-4V alloys with a tensile strength of 931 MPa. The spark plasma sintering (SPS) method is used for solidification molding of powder manufactured by the mechanical milling (MM) method, by sintering at low temperature for a short time. This sintering method avoids coarsening of the fine crystal grains or dispersed particles of the MM powder. To improve the mechanical properties of pure titanium without adding alloying elements, stearic acid was added to pure titanium powder as a process control agent (PCA), and MM treatment was performed. The properties of the MM powder and SPS material produced by solidifying the powder were investigated by hardness measurement, X-ray diffraction, density measurement and structure observation. The processing deformation of the pure titanium powder depends on the amount of stearic acid added and the MM treatment time. TiN was also generated in powder treated by MM 8 h with 0.50 g of added stearic acid, and the hardness of the powder was higher than that of Ti-6Al-4V alloy when treated with MM for 8 h. When the MM-treated powder was solidified in the SPS equipment, TiC was formed by the solid phase reaction. The SPS material prepared as a powder treated with MM 8 h by adding 0.50 g of stearic acid also formed TiN and exhibited the highest hardness of Hv1253.

• 대한토목학회논문집
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• 제26권3A호
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• pp.523-532
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• 2006

2거더 강교량의 건설 효율성 등을 위해서는 구조형식, 특히 가로보를 포함하는 구조계의 거동평가에 기초한 효율적이고 합리적인 설계기준 등의 제시가 필요할 것으로 생각된다. 따라서, 본 연구에서는 2거더 강교량에서 하중전달 역할을 하는 가로보의 위치, 간격 및 강성의 영향인자가 2거더 강교량의 거동 특성에 미치는 영향을 조사하고 합리적인 가로보 배치 기준을 제시하고자 한다. 기존 2거더 강교량을 대상교량으로 선정하고 가로보 특성을 적절하게 평가할 수 있는 몇가지 구조 모델링에 대해 구조해석을 실시한 결과, 가로보의 모델은 국부적인 응력집중과 바닥판의 하중분배 효과를 고려할 수 있는 쉘요소 및 솔리드 요소가 적합할 것으로 판단된다. 이러한 쉘요소 및 솔리드 요소를 사용하여 가로보의 배치 위치, 배치 간격 및 강성을 변수로 구조해석을 실시하여 효율적인 가로보 설계기준을 제시하였다.

• 대순사상논총
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• 제18권
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• pp.123-134
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• 2004

The aim on this paper is to explain the present state and circumstance in the course of arranging historic classical books in China. In order to approach its purpose, it should make it clear to define the word of "The present"(當代). Furthermore, we need to take a deep notice on the arrangements itself of historic classical books, its influences and contributions, reflecting this process carefully with those historical, cultual and social points of view due to the meaning of "The present" in China. Starting from this considerate view, first of all, I would like to determine the accurate time of "The present" to be the period of time from October, 1949 to December, 2003. It can be described very suitably well as "bamboo sprouts grow fast after a rainfall"(雨後春荀). This tremendous works in the arrangements of Classics have gone through sweets and bitters of times during 50 and several years. However, this work in process has overcome so much troubles and exclude obstacles in doing so, gradually begun to bear tasteful fruit of many publications, about 10,000 works so far. Although it has gone far with very little amount of works in comparison with the remains that would be put in order in the incoming future, it succeed effectively to the spirit and soul in Chinese culture and people. Illuminating the development in its historical steps and analyzing elaborately flows in cultural and ideal elements, it is known that this work of arrangements not only give a very firm basis for excellent Chinese cultural tradition, but also extend high level of idea and thoughts in their thoughts so that build up the spirit in socialism on the solid foundation. This paper will give a explanation and analysis on this works and its contributions. At the same time, it examine and give a good, careful, and close look on the arrangement of historic classical books in China by various means of classifying into various types and style, searching for many methods, and showing indication and directions that might be right in "the present".