• 한국과학교육학회지
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• 제14권1호
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• pp.24-33
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• 1994

This study is aimed at categorizing the CAl programs through analyzing the 82 science CAl programs developed by KEDI( Korean Educational Development Institutes ) and the 19 science CAl programs developed by the teachers who won the prizes in the first national educational software contest. The findings are as follows. 1) The main types of science CAl programs developed by KEDI are hybrid design type of tutorials and simulations, tutorials, and hybrid design type of instructional games and drill and practice. The other type of programs are very few. 2) The main types of science CAl programs developed by the teachers, who won the prizes in 1st educational software contest, are tutorials and hybrid design type of tutorials and simulations. There is no other type of programs except only two simulation type programs. 3) The science CAl programs developed by KEDI as well as by teachers who won the prizes in the contest are biased in two or three types, and the trend is severe in the programs developed by the teachers.

• 대한치과마취과학회지
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• 제10권2호
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• pp.203-208
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• 2010

Tremors are trembling movements and are seen in association with alcoholic intoxication, certain drugs, thyrotoxicosis, multiple sclerosis, hysteria, and nervous tension. Dental fears, such as, pain, drill, unknown, dependency, helplessness, mutilation and oral change, induce the neuroendocrine response (release of epinephrine and norepinephrine, etc). The clinical manifestations of epinephrine or other vasopressor overdose include : anxiety, tenseness, restlessness, throbbing headache, tremor, perspiration, weakness, dizziness, pallor, palpitation and respiratory difficulty. Signs of local anesthetic overdose appear clinically whenever the anesthetic level in the blood rises to an appropriate level in an individual. The clinical signs of moderate overdose levels include : talkativeness, apprehension, excitability, slurred speech, tremor and muscular twitching. This is a case report about the severe tremor care after the endodontic treatment under right mandibular block anesthesia in a 56-years old female patient.

• Spatial Information Research
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• 제12권4호
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• pp.321-328
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• 2004

본 연구는 PhotoModeler Pro를 이용하여 공간 정보를 자동적으로 추출하기 위한 기법에 관한 것이다. PhotoModeler Pro는 Windows시스템에서 개인용 컴퓨터 상에서 3차원 공간 정보를 취득할 수 있는 우수한 도구이나 스테레오 이미지를 자동적으로 병행하여 처리하는 데는 충분하지 않은 단점이 있다. 따라서 본 연구는 PhotoModeler Pro상에서 자동생성 프로그램과 DDE인터페이스를 이용한 스테레오 매칭 연구에 관한 것으로, 적용 지역은 사면과 계단이 많은 타테야마 지역(일본 나가사키 시)을 대상으로 하였다. 연구 대상 지역에 대한 자동 스테레오 매칭 결과 $100\%$의 적중률을 보였다.

• 대한기계학회논문집
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• 제14권5호
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• pp.1147-1154
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• 1990

본 연구에서는 초음파 화학 가공(ultrasonicassisted chemical mahining)을 이용하여 100$\mu\textrm{m}$이하의 전극봉을 제작하였고 제작한 전극을 이용하여 미세구멍을 방전 가공함으로써 가공특성을 파악하고, 방전액을 각각 등유(kerosene)와 물로하여 구멍의 표면을 비교, 분석하였으며 전극의 지름, 가공물의 두께에 대한 오버컷과 경사도(tap- er) 그리고 전극의 마멸을 조사하였다.

• 대한조선학회지
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• 제47권3호
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• pp.3-7
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• 2010

국내 조선소와 학교, 연구소에서 1990년대 중반 이전의 빙해선박에 대한 연구는 거의 이루어지지 않았다고 해도 과언이 아니다. 하지만 2000년대 초반부터 러시아가 St. Petersburg항을 통해 본격적으로 원유를 수출하기 시작하면서 내빙선 시장이 호황을 맞이하게 되었고 빙해선박 특히 내빙선박에 대한 관심이 집중되었다. 당시에 한국의 조선소들은 FMA rule 상의 엔진 출력이 과도한 것을 인지하고, 적정한 엔진 사양을 파악하기 위한 공격적인 연구개발로 ICE Class 1A, 1B, 1C의 선박을 상당히 많이 수주하여 선주에게 인도하였다. 또한 Ice belt의 구조적인 보강을 하기위한 설계와 연구가 활발히 진행되었다. 내빙선에 이어 쇄빙선의 연구에 관심을 집중시킨 선박은 최근 실해역에서 활동 중인 연구 조사선 "아라온"호 이다. 아라온호는 설계와 건조가 국내 조선소에서 이루어졌으며, 학계와 조선소 및 연구소에 쇄빙선에 대한 관심을 불러 일으켰다. 이와 비슷한 시기에 삼성 중공업에서 세계 최대 쇄빙선인 70K shuttle tanker를 수주 및 인도하면서 대형 쇄빙선 시장이 개척되어 국내외 조선소의 큰 관심을 불러일으키고 있다. 쇄빙 기술이 응용된 선박으로 Drill ship과 LNG FPSO등이 수주되어 현재 설계를 진행 중이다. 가장 최근에 현대중공업에서 수주한 원통형 FPSO의 경우 북해 지역에 투입을 목적으로 언론에 발표된 것과는 달리 발주처와 유럽의 관련 연구기관에서는 러시아 유전지역 투입을 염두에 두고 쇄빙관련 연구를 진행한 것으로 파악되고 있다. 본 기고에서는 이러한 빙해선박의 개발 및 건조 사례 현황을 기술하고, 향후 수주가능성이 있는 쇄빙선 분야와 조선소의 대응 전략 등에 대해서 정리해 보고자 한다.

• 한국해양공학회지
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• 제26권6호
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• pp.86-92
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• 2012

An exploration well is drilled where oil or gas potential is shown by a seismic survey and interpretation. With the advance of drilling technology, most of the easily accessible oil had been developed by the end of the 20th century. To satisfy the ever increasing demand for oil, and bolstered by high oil prices, the major oil companies started to drill in deep water, which requires a deep offshore drilling unit. Offshore drilling units are generally classified by their maximum operating water depth. Many semi-submersible rigs have been purpose-designed for the drilling industry as the allowable drilling water depth has become deeper by the developed technics since the first semi-submersible was launched in 1963. Semi-submersible rigs are commonly used for shallow to deep water up to 3,000 m. Drilling equipment such as a top drive, blowout preventer, drawworks and power system, mud circulation system, and subsea wellhead system are explained to help with an understanding of offshore drilling procedures in the oil and gas fields. The objective of this paper is to introduce the main components of a semi-submersible rig and, by doing so, to raise the awareness of offshore drilling, which accounts for over 30% of the total oil production and will continue to increase.

• 한국군사과학기술학회지
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• 제14권3호
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• pp.335-344
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• 2011

In this paper, the results of computational analysis for the stability and F.S.(Factor of Safety) of Bailey Panel Bridge have been presented by FEM(Finite Element Method). The computational analysis was conducted by using LUSAS V14.0 that is a program applicated in the field of Civil Engineering. 6-free beam elements and 3-free truss elements were considered and F.S. against Yield Stress of main sections(considered self-weight and Live-Load) was investigated through the linear-elastic analysis method. The results showed that currently used sections of bailey bridge satisfied for the standard F.S. unit and could be operated in drill of troops and battle fields.

• Ocean Systems Engineering
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• 제8권1호
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• pp.21-32
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• 2018

Due to the escalation in hydrocarbon consumption, the offshore industry is now looking for advanced technology to be employed for deep sea exploration. Riser system is an integral part of floating structure used for such oil and gas extraction from deep water offering a system of drill twines and production tubing to spread the exploration well towards the ocean bed. Thus, the marine risers need to be precisely employed. The incorporation of the strengthening material, fiber reinforced polymer (FRP) for deep and ultra-deep water riser has drawn extensive curiosity in offshore engineering as it might offer potential weight savings and improved durability. The design for FRP strengthening involves the local design for critical loads along with the global analysis under all possible nonlinearities and imposed loadings such as platform motion, gravity, buoyancy, wave force, hydrostatic pressure, current etc. for computing and evaluating critical situations. Finite element package, ABAQUS/AQUA is the competent tool to analyze the static and dynamic responses under the offshore hydrodynamic loads. The necessities in design and operating conditions are studied. The study includes describing the methodology, procedure of analysis and the local design of composite riser. The responses and fatigue damage characteristics of the risers are explored for the effects of FRP strengthening. A detail assessment on the technical expansion of strengthening riser has been outlined comprising the inquiry on its behavior. The enquiry exemplifies the strengthening of riser as very potential idea and suitable in marine structures to explore oil and gas in deep sea.

• 대한기계학회논문집A
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• 제27권9호
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• pp.1499-1507
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• 2003

Physical importance of cutting temperatures has long been recognized. Cutting temperatures have strongly influenced both the tool life and the metallurgical state of machined surfaces. Temperatures in drilling processes are particularly important, because chips remain in contact with the tool for a relatively long time in a hole. Tool temperatures tend to be higher in drilling processes than in other in machining processes. This paper concerns with modeling of thermal behaviors in drilling processes as well as estimation of the cutting temperature distribution based on remote temperature measurements. One- and two-dimensional estimation problems are proposed to analyze drilling temperatures. The proposed thermal models are compared with solutions of finite element methods. Observer algorithms are developed to solve inverse heat conduction problems. In order to apply the estimation of cutting temperatures, approximation methods are proposed by using the solution of the finite element method. In two-dimensional analysis, a moving heat source according to feedrate of the drilling process is regarded as a fixed heat source with respect to the drilling location. Simulation results confirm the application of the proposed methods.

• 한국기계가공학회지
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• 제11권6호
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• pp.22-27
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• 2012

Drilling process is usually the most efficient and economical method of making a hole in a solid body. However, there have been no analytical method to assess drilling process based on the shear and frictional characteristics. In this paper, procedures for analyzing shear and frictional processes of drilling have been established by adopting an equivalent turning system to drilling. A series of drilling experiments were carried out with varying feed, velocity and drill shape factors. Using the results of the experiments, the cutting characteristics including shear in the primary shear zone and friction in the chip-tool contact region of drilling process have been analyzed. The specific cutting energy tends to decrease exponentially with increase of feed rate. In drilling process 35-40% of the total energy is consumed in the friction process. This is greater than that of turning process in cutting of the same work material.