• 한국정보통신학회논문지
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• 제13권7호
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• pp.1303-1311
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• 2009

본 논문은 과학적 탐구학습을 지원하는 비쥬얼 가상환경 저작도구 DEVISE(Drawing Environment for VR-based Inquiry-learning Science Education)에 대해서 설명한다. DEVISE는 프로그래밍 전문지식이 없는 일반인들이 2차원 Drawing 인터페이스를 사용하여 3차원 개체와 변인데이터 설정을 함으로써 탐구학습을 위한 가상현실 콘텐츠를 쉽고 빠르게 개발할 수 있도록 도와준다. 본 논문에서는 먼저 가상현실 저작도구들과 탐구학습 가상환경 관련 저작 도구에 관한 연구들과 탐구학습을 위한 가상환경 통합 시스템인 SASILE를 살펴보고 SASILE의 문제점을 지적한다. 그리고 DEVISE 구성요소와 DEVISE 도구를 사용한 작업 흐름 (Workflow)에 대해서 설명하고,탐구학습 가상현실 콘텐츠를 개발하는 사용자평가실험 관찰결과에 대해서 논한다.

• 한국BIM학회 논문집
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• 제10권4호
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• pp.22-31
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• 2020

Shop drawing tasks conducted after finishing coordinated or engineering design have great influences on the quality and cost of a project. However, despite the development of commercial BIM applications, shop drawings have mainly produced manually in certain engineering fields. Incorrect shop drawings with human errors have occurred various problems such as cost overrun, time delay and reworks. An automated shop drawing publishing from BIM is expected to resolve these problems. Despite attempts for automate shop drawing production, the field of mechanical, electrical and plumbing (MEP) is yet regarded challenging due to complexity of components and connection. In this research, we develop a process for automated producing 3D MEP shop drawings in BIM environment as following steps: to analyze conventional MEP shop drawing process, to identify detailed process that can be automated, to classify existing MEP objects and assign codes usable in BIM, and to develop an application. The validation of automated process is conducted against 10 clean room projects in which MEP is more complex and its cost is higher than other projects in terms of productivity and workers' satisfaction. Results show that the number of manpower for shop drawing is reduced by 30%, and the working time is shortened by 31%. Personal opinions of involved practitioners is interpreted as positive as the average rate of agrement on practicability, easy-to-use and necessary retouch tasks is around 66%.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 추계학술발표대회 논문집
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• pp.46-49
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• 2003

Cu have been widely used as signal transmission materials for electrical electronic components owing to its high electrical conductivity. However, it's size have been limited to small ones due to its poor mechanical properties, Until now, strengthening of the copper at toy was obtained either by the solid solution and precipitation hardening by adding alloy elements or the work hardening by deformation process. Adding the at toy elements lead to reduction of electrical conductivity. In this aspect, if carbon nanofiber is used as reinforcement which have outstanding mechanical strength and electric conductivity, it is possible to develope Cu matrix nanocomposite having almost no loss of electric conductivity. It is expected to be innovative in electric conduct ing material market. The unidirectional alignment of carbon nanofiber is the most challenging task developing the copper matrix composites of high strength and electric conductivity In this study, the unidirectional alignment of carbon nanofibers which is used reinforced material are controlled by drawing process in order to manufacture the intermediary materials for the carbon nanofiber reinforced Cu matrix nanocomposite and align mechanism as well as optimized drawing process parameters are verified via experiments and numerical analysis. The materials used in this study were pure copper and the nanofibers of 150nm in diameter and of $10~20\mu\textrm{m}$ In length. The materials have been tested and the tensile strength was 75MPa with the elongation of 44% for the copper it is assumed that carbon nanofiber behave like porous elasto-plastic materials. Compaction test was conducted to obtain constitutive properties of carbon nanofiber. Optimal parameter for drawing process was obtained by experiments and numerical analysis considering the various drawing angles, reduction areas, friction coefficient, etc Lower reduction areas provides the less rupture of cu tube is not iced during the drawing process. Optimal die angle was between 5 degree and 12 degree. Relative density of carbon nanofiber embedded in the copper tube is higher as drawing diameter decrease and compressive residual stress is occurred in the copper tube. Carbon nanofibers are moved to the reverse drawing direct ion via shear force caused by deformation of the copper tube and alined to the drawing direction.

• 한국의류학회지
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• 제39권6호
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• pp.826-837
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• 2015

This study analyzes the shapes of the adjustment of a Napoleon Collar which combines a stand collar with an upper collar. It established experimental conditions for fixing the conditions of Napoleon Collar components (lapel width, stand collar size and upper collar size) as well as varied the shape of the neckline, the length of the curve of a stand collar and the size of the drawing space at the center back. It produced 22 test clothes of muslin, which were dressed on dress form No. 8. The results indicate that: 1. Neckline shape determines the amount of stand and fall. Less curved neckline stands higher against the neck and a more curved neckline is laid lower onto the body. 2. A shorter curve length of a stand collar allows a longer roll line to fall farther away from the neck with more space between the neck and collar. However, the longer the depth of curve of a stand collar creates a shorter roll line that stands high against neck and closer to neck without any space between the neck and collar with a collar line matching the neck of the dress form. 3. The smaller the drawing space at the center back creates a shorter the style line of the upper collar. However, a narrower back width of the collar creates a bigger drawing space at the center back with a longer the style line and a more naturally placed back width of the collar. 4. A Napoleon Collar creates a longer depth of curve for a stand collar and a smaller drawing space at the center back that is tightly and stably stuck to the neck.

• 한국CDE학회논문집
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• 제9권4호
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• pp.373-381
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• 2004

Using standard components of a press die is recognized as a way for a cost reduction and a short lead time. It also provides a way for a quick maintenance of a die under repair. It is expected to contribute to integration of CAD/CAM system for manufacturing dies in the future. This paper presents a 3D CAD library which is constructed using the standard components and is used for designing a press die. This 3D CAD library is generated by a database system made of Microsoft Access for standard components and by CATIA V5 R10 API for geometric features. The library is implemented using Visual Basic 6.0 utility of CATIA API function in the Windows NT environment. It creates a 3D model of the standard components of press die easily when a die designer inputs numerical values of geometric features and the BOM of the completely assembled parts. It also generates automatically the assembly drawing of die set by using variables for standard values of die parts. Therefore users can save the cost of time to design the press die components, and even a beginner can use this program with ease. The test results of the 3D CAD library for designing shearing and bending dies verify its usefulness and feasibility.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.149-153
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• 2008

Since magnesium alloy sheets have been employed in industrial field which requires the light weight and thin engineering components, most of researches have been focused on the formability of magnesium ahoy sheet. In warm press forming of magnesium alloy sheet, it is important to control the sheet temperature by heating the sheet in closed die. When forming a commercial AZ31 magnesium alloy sheets which are 0.5mm and 1.0mm thick, respectively, time arriving at target temperature and temperature variation in magnesium alloy sheet have been investigated. Sheet metals were mostly formed in simple shapes such as circular or rectangular. Few studies about forming of complex shapes were reported. Thus, the formability of magnesium alloy sheet for complex shapes is investigated. The process variable for a double sink shape deep drawing with circular and rectangular shape was investigated by varying temperature, velocities, and clearances. Accordingly, temperature, velocities, and clearances suitable for forming were suggested through investigating the thickness variation of the product.

• 한국재료학회지
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• 제30권6호
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• pp.308-314
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• 2020

A commercial AA1070 alloy for electrical wire is severely deformed by drawing process in which a rod with an initial diameter of 9mm into is reduced to a wire of 2mm diameter. The drawn AA1070 wire is then annealed at various temperatures from 200 to 450 ℃ for 2h. Changes in microstructure, mechanical properties and electrical properties of the specimens with annealing temperature are investigated in detail. The specimen begins partially to recrystallize at 250 ℃; above 300 ℃ it is covered with equiaxed recrystallized grains over all regions. Fiber textures of {110}<111> and {112}<111> components are mainly developed, and {110}<001> texture is partially developed as well. The tensile strength tends to decrease with annealing temperature due to the occurrence of recovery or/and recrystallization. On the other hand, the elongation of the annealed wire increases with the annealing temperature, and reaches a maximum value of 33.3 % at 300 ℃. Electric conductivity of the specimens increases with annealing temperature, and reaches a maximum value of 62.6 %IACS after annealing at 450 ℃. These results are discussed in comparison with those for the other aluminum alloy.

• 한국멀티미디어학회논문지
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• 제9권8호
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• pp.982-999
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• 2006

본 논문에서는 복합 칼라정보와 얼굴의 기하학적 정보를 이용한 인터넷 기반 얼굴관상해석 및 자동 얼굴 컨텐츠 생성시스템을 제안하였다. 제안한 시스템은 YCbCr과 YIQ 칼라모델의 Cr과 I 성분의 논리곱 연산처리로 얼굴영역을 검출하였다. 검출한 얼굴영역에서 얼굴의 기하학적 정보로부터 얼굴 특징자를 추출 하였으며 각 특징자들을 세부 분류하여 얼굴 관상을 해석하도록 하였다. 또한 제안한 시스템은 추출과 분류된 특징자로부터 개인의 얼굴에 가장 적합한 얼굴 아바타 컨텐츠를 자동 생성할 수 있게 하였다. 실험결과 제안한 방법은 기존의 얼굴인식 방법에 비해 실시간 얼굴검출과 인식은 물론 정량적인 얼굴관상해석과 자동 얼굴 아바타 생성이 가능하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2000년도 추계학술대회 논문집
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• pp.132-135
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• 2000

A process design expert system for rotationally symmetric deep drawing products has been developed The application of the expert system to non-axisymmetric components, however, has not been reported yet. Thus, in this present study, the expert system for non-axisymmetric deep drawing products with elliptical shape was constructed by using process sequence design. The system developed in this work consists of four modules. The first one is a recognition of shape module to recognize non-axisymmetric products. The second one is three dimensional (3-D) modeling module to calculate the surface area for non-axisymmetric products. The third one is a blank design module to create an oval-shaped blank with the identical surface area. The forth one is a process planning module based on the production rules that play the best important role in an expert system for manufacturing. The production rules are generated and upgraded by interviewing with field engineers.

• 한국재료학회지
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• 제15권10호
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• pp.632-638
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• 2005

To investigate the effect of Mo and Cu contents on tensile strength of cold drawn stainless steel 304H wires, metallographical and mechanical tests were performed for the wire specimens drawn to different drawing strains at room temperature. It was confirmed that the contents of Mo ana Cu have little influence on the tensile strength of drawn specimens, even though the strain induced martensite transformation decreased with increasing the contents of Mo and Cu. These results were explained by the strengthening of the formed martensite itself due to the solid solution effect of interstitial solutes, carbon and nitrogen. The contents of these elements were slightly higher in the specimens containing additionally added Mo and Cu.