• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 추계학술대회 논문집
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• pp.181-184
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• 2009

The hot press farming process, which is the press hardening of steel parts using cold dies, can utilize both ease of shaping and high strength due to the hardening effect of rapid quenching during the pressing. In this study, a thermo-elastoplastic analysis of the hot press forming process using the finite element method was performed in order to investigate the deformation behavior and temperature history during the process and the mechanical properties of the pressed parts.

• 한국학교수학회논문집
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• 제9권4호
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• pp.481-495
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• 2006

수학교육은 교사와 학생의 교수-학습 활동이 중심을 이루기 때문에, 수학교육의 질적 향상은 수학교사의 전문성 계발 및 신장과 밀접한 관련을 맺고 있다. 본 연구에서는 러시아에서 수학교사들을 대상으로 개최되고 있는 창의적 수학 경진대회의 운영 방법, 문항들, 결과들을 분석하고, 이를 바탕으로 창의적 수학 경진대회의 의의를 밝혔다. 본 연구의 결과는 수학교사의 전문성 신장 및 수학교육학 연구의 활성화를 위한 실질적이고 구체적인 방안을 모색하는데 기초 자료로 활용될 수 있을 것이다.

• 건축역사연구
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• 제16권5호
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• pp.41-54
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• 2007

The Fagus Factory at Alfeld on the Leine in Germany, which was built in 1911 and 1914, is a well-known and very important object in the history of modern architecture. Alan Colquhoun mentioned that it is "prophetic of the 'objective' (sachlich) Modern Movement of the 1920s". Vittrio M. Lampugnani evaluated it as "a Pioneer building of the architectural Realism". Most of historian of architecture explain that these achievements were accomplished mainly by the master architect Walter Gropius and sometimes by his co-worker Adolf Meyer. Through investigating the background in the planning stage and the process of design it is to try to find out what is truly happened during the project time. Furthermore, historical meanings of the building in the modern architecture is reinterpreted in the following aspects; who or which elements have influence on the Fagus Factory? and what kind of problems can be caused by the digested architectural history?

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1601-1606
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• 2011

The railway system consists of rolling stocks, facilities, electrical system, signaling and operation and so on, organically bound. Recently due to lots of train failures and accidents, especially the derailment related to track irregularity this year, all the people using the train are worried about railway safety and we paved the way for letting them knowing that all components of railway system are so important. As a result, most of developed countries operating railway have used to risk assessment methods about safety management to prevent railroad accidents in advance. The purpose of this paper is to find out how to closely apply to track field for risk assessment methods. Because there is no case to apply to and we're not interested in yet, despite of importance of track, in situations of higher train speed. Therefore, in this study we're going to investigate risk assessment methods and compare enire railway system with track system, eventually we want us try to present to safety management conditions necessary and secure safety improvement in track field.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.817-822
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• 2002

The problem of the crack which occures from the reinforced concrete structure could be caused by the complexed factors. When the crack happen, it caused fatal blemish to manage and maintain the structure such as structural problem, licking, spalling, viewing Even though they study and work hard to solve this kind of problem in the world, there are no countermeasure for perfect prevention of crack. After the crack checked out, a method of repair-reinforcement has been studied and operated actively, Generally, occurance of the crack in the concrete structure could be taken as granted, no need to mention the damage from the crack, domestic construction try to hide it rather than repair basically, In many cases the construction amount for repairing the crack has to be made in the construction area and the amount is very expensive. To save the repaing fee, companys repair it under the meeting of their desire. it can be expected for the effection of the construction. For this reason, we compare a new injection method to solve the demerits of the present method, to save and use the merit of the present method.

• 대한기계학회논문집A
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• 제21권7호
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• pp.1141-1148
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• 1997

In the stamping industry the blank shape to be stamped into a designed shape has been conventionally determined from the try out process by the press engineers. The work needs a lot of time and thus leads a loss of productivity. In this study boundary element method for 2-dimensional potential problem was used to design optimum blank shapes for irregular press forming. Here we assumed that the blank is controlled by blank holder only and material flow at blank holder was under potential flow. The developed PC code for designing the optimum blank shape shows that the blank shapes for optimal drawing can be calculated within a few minute in pentium PC and the calculated shapes agree well with the experiments. However the application of this method is constrained only to the pressed product with flat bottom.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 추계학술대회 논문집
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• pp.354-357
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• 2001

In the present study, front lower arm and engine cradle which are automotive chassis parts were developed using the hydroforming technology. For systematic establishment of parts development process, material properties of tube were reflected at the start of design and problems of initial design drawing were solved by forming analysis. Design and manufacturing technology of hydroforming die were established and the relationship between internal pressure and feeding stroke was studied during try-out. Durability and buckling strength of hydrofromed parts were estimated.

• 천문학회지
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• 제38권2호
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• pp.197-201
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• 2005

It is well known that a rotating bar potential can transport angular momentum to the disk and hence cause the evolution of the disk. Such a process is particularly important in disk galaxies since it can result in fuelling AGNs and starburst ring activities. In this paper, we will present the numerical simulations to show how this mechanism works. The problem, however, is quite complicated. We classify our simulations according to the type of Lindbald resonances and try to single out the individual roles they play in the disk evolution. Among many interesting results, we emphasize the identification of the origin of the starburst rings and the dense circumnuclear molecular disks to the instability of the disk. Unlike most of the other simulations, the self-gravitation of the disk is emphasized in this study.

• 디자인학연구
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• 제12권3호
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• pp.93-103
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• 1999

This study is investigated the formative characteristics of Rap Music and Hiphop fashion, and I try to comprehend about the fashion mind and fashion culture of teenager 1. Teenager's Hiphop Fashion is subcultures, the fashion culture of teenager reflects their unique identity. 2. The formative characters of Rap Music and Hiphop Fashion are the incompatibility ignored their body size and the popularity caused street fashion imitation, the unbalance ignored a principle of fashion design. 3. Hiphop Fashion is consist of jump-style jacket, hood -shirt, stripe T-shirt and drum pants, baggy pants, snowboard pants and so on. 4. The characters of Hiphop Fashion is the breaking of rule and the destruction. 5. They select something which they like, even though the price is high, so they is tendency to editing coordinate 6. Fashion business for teenager, it needs an ideal conversion not for 'company' but for 'individual' As this results, fashion culture of teenager came out to the surface of water, because of Hiphop Fashion.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 추계학술대회 논문집
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• pp.253-257
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• 2001

This study reveals the sheet metal working with multi-forming type ultra precision process. They require analysis of many kinds of important factors, i.e. theory and practice of metal press working and its phenomena, die structure, machining condition for die making, die material, heat treatment of die components, know-how and so on. In this study, we designed and constructed a multi-forming ultra precision progressive die as a bending and drawing working of multi-stage and performed through the try out for thin sheet metal. This part I of papers related to the analysis of production part and strip process layout design through the metal forming simulation by DEFORM and IDEAS.