• 한국건설관리학회:학술대회논문집
• /
• 한국건설관리학회 2003년도 학술대회지
• /
• pp.504-508
• /
• 2003

최근 공정관리와 원가관리의 중요도 인식에 기인하여 공정/원가 통합관리 및 공정정보와 3차원 설계정보를 연계할 4차원 설계 정보 연구가 활성화되고 있다. 공정과 원가를 통합할 수 있는 EVMS의 관리적 효과와 도형정보와 공정관리를 통합을 통하여 일정관리의 편의 및 효율을 극대화 하는 4차원 CAD(4D CAD)의 시각적 효과를 통합하는 4D-EVMS는 프로젝트 관리의 중요한 도구가 될 수 있다. 이러한 맥락에서, 본 연구의 목적은 발주자 공정/원가 총합관리를 위한 기본요건 도출 및 구현방안 제시에 있다. 이러한 연구의 결과물은 발주자 공정/원가관리의 업무효율 증대뿐만 아니라 실적자료 축적 및 홍보 관점에서도 기대효과를 가진 수 있을 것으로 판단된다.

• 한국정밀공학회지
• /
• 제15권11호
• /
• pp.21-31
• /
• 1998

This study described computer aided die design system for cold forging of non-axisymmetric parts. To design the die of cold forging. an integrated approach based on a rule-base system and commercial F. E. code were adopted. This system is implemented on the personal computer and its environment is a commercial CAD package named as AutoCAD. The system includes four modules. In the initial data input module, the variables which are necessary to design of die are inputted by user and die material are selected from the database. In the analysis and redesign module, stress distrubution action on the designed die is analyzed by commercial FEM code NISA II. The designed die is modified to prevent failure in both states of stress free and pressurizing. The developed system provides powerful capabilities for die design of non-axisymmetric parts.

• 한국정밀공학회지
• /
• 제13권10호
• /
• pp.46-55
• /
• 1996

As industrial standard data, the STL format which approximates three dimensional CAD model to triangular facets, is used for RP(Rapid Prototyping) system in recent days. Because most RP system take the only form of two dimensional line segments as an input stream inspite of its imperfectness while converting into STL format, a CAD model is converted into a standard industrial format which is composed of many triangular facets. The error verifying process is composed of four main steps, and these are 1) Remove facets with two or more vertices equal to each other. 2) Fix overlapping error such as more than three facets adjacent to anedge. 3) Fill holes in the mesh by using Delaunay triangulation method. 4) Correct the wrong direction and normal vectors. This paper is concerned with serching the mentioned errors in advance and modifying them.

• 한국건설관리학회논문집
• /
• 제16권4호
• /
• pp.30-40
• /
• 2015

건설 프로젝트에서 2차원 도면은 참여자들간의 의사소통 도구로 활용되고 있으나, 전문적인 표기 방식으로 인해 도면에 경험이 많은 전문가를 제외한 다른 참여자들이 쉽게 도면의 정보를 파악하기 어렵다. 이러한 점을 극복하기 위해 본 연구에서는 증강현실 및 4D CAD 기술을 접목한 새로운 도면을 제시하고자 한다. 제시된 도면에서는 사용자가 기존의 2차원 도면 위를 웹카메라와 같은 장비로 관찰할 때 3차원 구조물을 증강시켜 자재에 대한 상세 정보 및 시공 시뮬레이션을 할 수 있다. 이 도면을 통해 기존의 도면에 익숙한 건설 프로젝트 참여자 및 경험이 적은 참여자들과의 의사소통에 오류를 줄여줄 수 있을 것으로 기대된다. 관련분야 대학생들을 대상으로 한 설문조사를 통해 개발한 도면의 유용성을 검증하였다. 설문조사 결과, 기존의 2차원 도면 대비 개발한 도면의 유용성이 자재 정보, 시공 과정, 3차원 구조의 이해 등에서 매우 크게 나타났다.

• 산업공학
• /
• 제11권2호
• /
• pp.65-78
• /
• 1998

The letters of the automobile tire are usually engraved on the side-wall. The shape of the side-wall is a sculptured surface generated by the rotational sweeping of a profile curve. The letters laid on the side-wall are usually designed by a 2-dimensional CAD. It is impossible to machine the letters on the surface accurately by 3-axis NC machining, because the axis of cutter should be tilted to align with the normal vector of the surface. In this case. the degree of freedom for the machine is at least four. This paper describes an idea for tool path generation of a 4-axis machine by using the 2-dimensional CAD data of the letters and the surface of the side-wall. This study includes the following procedures; (1) measuring the profile of the side-wall surface and curve-fitting of the measured points. (2) the 'non-parallel projection' of the letters on the side-wall, and (3) an inverse kinematics of the 4-axis lettering machine. Procedures in this paper are programmed in C-language on Windows95 environment. With a PC based CNC controller and a 4-axis lettering machine. these are tested sucessfully for the practical use.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
• /
• pp.1024-1030
• /
• 1993

In manufacturing press die with free surface, grinding operation is an important post process for surface finish and dimensional accuracy. With the advancement of NC technology. surface grinding operation is increasingly replaced by the gantry type manipulator. As the mechanics for grinding operation is different from machining operation, conventional CAM system for machining operation is hard to apply. In this. paper, we develop a five-axis CAM system by which an efficient gantry trajectory can be planned and verified. The developed system consists of four conceptual modules; namely CAD, PROCESS. CAM, and ANALYSIS. In the CAD module, the machined surface is represented by CL-data or surface modeler, and process parameters are specified by the PROCESS module. Then, the CAM module generates a series of grinding paths based on the grinding mechanics together with process databases for tool spaces and grinding conditions. The generated paths are verified via ANALYSIS module. Validation via real experiments is left for further study.

• 대한인간공학회지
• /
• 제21권1호
• /
• pp.15-26
• /
• 2002

The anthropometric characteristics of the intended user population are most important parameters in the equipment and workplace layout design, particularly in the airplane cockpit design. Because human body is composed of multi-dimensional body segments, single 'average' or 'extreme' manikin is not sufficient in computer-aided design(CAD) environments. To overcome this limitation, we constructed a manikin group representing Korean Male pilot population. First, we identified 16 anthropometric variables which are important parameters in the evaluation of reach, visibility, and clearance. And we found their correlations and conducted a factor analysis. Four common factors were extracted in the factor analysis. The first one was related with length dimensions, the second was with the arm reach, the third was with the sitting height, and the last was with breadth-depth dimensions. Finally, 17 manikins were constructed and presented in the CAD prototype.

• 한국산업융합학회 논문집
• /
• 제5권1호
• /
• pp.11-19
• /
• 2002

This study described computer aided die design system for cold forging of non-axisymmetric parts such as gears and splines. To design the cold forging die, an integrated approach based on a rule-base system and commercial F. E. code were adopted. This system is implemented on the personal computer and its environment is a commercial CAD package named as Auto CAD. The system includes four modules. In the initial data input module, variables which are necessary to design of die are inputted by user and die material are selected from the database according to the variables. In the analysis and redesign module, stress distribution acting on the designed die is analyzed by commercial FEM code NISA II with elastic mode. If die failure predicted, the designed die would modified in four ways to prevent die failure in both states of stress free and pressurizing. The developed system provides useful date and powerful capabilities for die design of non-axisymmetric parts.

• 한국의류학회지
• /
• 제30권9_10호
• /
• pp.1485-1493
• /
• 2006

This study was to investigate the effect of different scouring methods on mechanical properties and appearance of lyocell. Two different scouring methods were adopted for the study; one was the traditional scouring with alkali and the other was enzymatic scouring. Enzymatic scouring was carried with four different enzymes; C1 : Cellusoft L, C2 : Cellusoft UL, D1 : Denimax 992L, D2 : Denimax Acid XCL. The mechanical properties of scoured lyocell were measured using KES-FB. The appearance of scoured samples was analyzed by 3D CAD SYSTEM of i-Designer. While the untreated fabric showed the best linearity because it is stiff, alkali treated samples showed the worst dimensional stability and distorted easily. Enzyme treated samples, especially C1 treated samples showed the best dimensional stability. In addition, enzyme treated samples showed low bending rigidity compared to the alkali treated samples. It means that the enzyme treated samples are more flexible than alkali treated samples. However, the smoothness of the sample's surface treated by either of methods did not show much difference. From the study, it was suggested that the enzymatic scouring for lyocell could help to gain natural silhouette.

• 대한산업공학회지
• /
• 제17권1호
• /
• pp.37-49
• /
• 1991

This report describes an integrated approach to sculptured surface design and manufacture, and a software package for it on a multi-axis NC milling machine. The integrated software consists of four parts : (1) surface fitting procedure for generating the characteristic polyhedron from 3 dimensional CMM data, (2) surface description for generating the mathematical representation of sculptured surfaces. (3) tool path generation for approximating the surface representation into a sequence of linear cutter paths, and (4) tool control for generating the corresponding joint variable values. This integrated approach is generally applicable to sculptured surface manufacturing where multi-axis milling machines are necessary to produce smooth three-dimensional surfaces.