• Applied Microscopy
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• v.38 no.4
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• pp.347-351
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• 2008

The morphological characteristics of the cut sections of hair using razor, clipper and scissors were investigated with scanning electron microscopy. With the razor, the cutting section had a long elliptical form and a rhythmical ribbon shape. It was curved outward since the end part of it became thinner. With the scissors, the cutting section had a flat, circular form. It seemed to be because the scissors imposed a constant strength on the hair. With the clipper, the cutting section had also a circular form but a layer of the macrofibril was generated in the middle part of the cortex. It seemed to be generated while the rapidly moving blades of the clipper cut the hair in an instant.

• Journal of the Korean Geographical Society
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• v.39 no.6 s.105
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• pp.845-862
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• 2004

The aim of this study is to investigate distribution characteristics of incised meander cutoff in Gyeonggi and Gangwon Provinces of Central Korea. The density of meander cutoff is highest in the mountain rivers including Naerin and Dongdae flowing on Jeongseon-gun and Inje-gun of Gangwon Province. Most of meander cutoff process has been occurred repeatedly during the Quaternary period, especially concentrated in the period of climatic change between glacial and interglacial stages. In the aspect of the lithology, the density of cutoff is highest in sedimentary rock, but lowest in igneous rock. As for geological structure, its frequency is high at $11{\sim}20km$ westerly away from the Taebaek Mountains, at subsequent channel, lower part of resequent channel, and channels crossing the fault line. The relation between distance from the Taebaek Mountains and altitude is very obvious at the western side of the Taebaek Mountains. The values of altitude, height from riverbed, and stream order are highest at sedimentary rock and lowest at volcanic rock.

• Journal of the Korea Society of Computer and Information
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• v.14 no.4
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• pp.1-8
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• 2009

In this paper, we deal an implementation of the software that produces sub-optimal solution of cutting-ironbar planning problem using dynamic programming. Generally, it is required to design an optimization algorithm to accept the practical requirements of cutting ironbar manufacturing. But, this problem is a multiple-sized 1-dimensional cutting stock problem and Linear Programming approaches to get the optimal solution is difficult to be applied due to the problem of explosive computation and memory limitation. In order to overcome this problem, we reform the problem for applying Dynamic Programming and propose a cutting-ironbar planning algorithm searching the sub-optimal solution in the space of fixed amount of combinated columns by using heuristics. Then, we design a graphic user interfaces and screen displays to be operated conveniently in the industry workplace and implement the software using open-source GUI library toolkit, GTK+.

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.15-17
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• 2004

철강재의 산소절단은 연료가스의 연소열 및 철의 산화 반응열을 이용하여 강재를 절단하는 방법이다. 연료가스의 연소열을 이용하여 강재를 가열 및 용융시키고, 여기에 고순도의 산소를 취입하면 강재의 용융물질 중 철의 급격한 산화반응이 발생된다. (중략)

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.1
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• pp.24-31
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• 2003

In the gas cutting of plate steel, the quality of the cut surfaces and sections is strongly dependent on the cutting conditions such as cutting speed, kerf width, plate thickness, material, distance between tip and specimen, and cutting oxygen pressure etc. The cutting tests of plate steel were carried out using CNC gas cutting machine. This paper deals with cut surface and section characteristics of plate steel in CNC gas cutting. Both top and bottom widths of kerf, the surface roughness(Ra, Rmax) of cutting surfaces are measured under various cutting conditions such as cutting speed, material, distance between tip and specimen, and cutting thickness. The photographs of cut surface and cut section are also analyzed under various cutting conditions.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.1
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• pp.144-149
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• 2008

This study presents the selection of cutting conditions in high speed pipe cutting machine for the better quality. A high speed pipe cutting machine which uses a rotary knife can make good quality products in short time. But, the machine is much sensitive by cutting conditions because of the complicated mechanism. In this reason, many experiments for cutting condition selection are necessary to improve quality of production. This study carried out cutting experiments with the three factors that are cutting RPM, cutting force and pooling force. 2-dimensional profile measuring instrument is used to measure which is represented by ${\Delta}h$, a sum of burr and collapse height. The effects of factors are analyzed by using MINITAB, the commercial software.

• Explosives and Blasting
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• v.29 no.1
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• pp.27-33
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• 2011

Concussion shots were conducted for SS400, a general structural steel, and SM490, a structural steel for welding, using TNT, which is used as a standard explosive. The ability to cut the steels was compared for different combinations of charges and materials. The results show that the amount of explosives used for SM490 requires more 30% than SS400.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.2
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• pp.118-126
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• 2005

Abrasive waterjet (AWJ) cutting is an emerging technology for precision cutting of difficult-to-machining materials with the distinct advantages of no thermal effect, high machinability, high flexibility and small cutting forces. This paper investigated theoretical and experimental cutting characteristics associated with abrasive waterjet cutting of quartz GE214. It is shown that the proper variations of several cutting parameters such as waterjet cutting pressure, cutting speed and cutting depth improve the roughness on workpiece surfaces produced by AWJ cutting. From the experimental results by AWJ cutting of quartz GE214, the optimal cutting conditions to improve the surface roughness and precision were proposed and discussed.

• Proceedings of the Korean Society of Computer Information Conference
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• 2008.06a
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• pp.211-216
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• 2008

이 논문은 철근 가공 산업 현장에서 스프레드쉬트에 의해 수작업으로 행하던 절단 작업의 계획 수립을 자동화된 시스템에 의해 최적의 절단 계획을 생성하도록 하는 소프트웨어의 개발을 다룬다. 이를 위하여, 먼저 시스템의 데이터 표현과 최적 문제 풀이를 위한 자동 계획 알고리듬의 설계가 요구된다. 이것은 다중 규격의 1차원 자재 절단 문제를 푸는 것으로, 동적계획법에 근거하여 자재 절단 문제를 재구성하고, 유한 범위의 조합 열에서도 근사 최적의 해를 찾을 수 있는 탐색 기법을 사용한 자재 절단 계획 알고리듬을 사용하였다. 그리고, 자동화된 철근 가공 산업용 소프트웨어는 작업 환경에 맞게 사용이 편리한 그래픽 화면과 사용자 인터페이스가 요구되는데, 공개 소프트웨어를 활용한 GUI 라이브러리 툴킷인 GTK+를 활용하여 이를 구현하였다.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.10
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• pp.2418-2425
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• 1993

A two-dimensional transient heat transfer model for reactive gas assisted laser cutting process with a moving Gaussian heat source is developed using a numerical finite difference technique. The kerf width, melting front shape and temperature distribution were calculated by using the boundary-fitted coordinate system to handle the ejection of workpiece material and heat input from reaction and evaporation. An analytical solution for cutting front movement was adopted and numerical simulation was performed to calculate the temperature distribution and melting front thickness. To calculate the moving velocity of cutting front, the normal distribution of the cutting gas velocity was used. The kerf width was revealed to be dependent on the cutting velocity, laser power and cutting gas velocity.