• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.501-514
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• 2015

Earthwork is a basic operation for all forms of civil works and affects construction time, cost and productivity. It is a mechanized operation that needs various construction equipment as a group and uses a lot of fuel for construction equipment. But, the problem is that earthwork operation is usually performed by equipment operator's heuristic and intuition, which can cause low productivity, high fuel consumption, and high carbon dioxide emission. As one of solutions for this problem, the fleet management system for construction equipment is suggested for effective earthwork planning, optimal equipment allocation, efficient machine operation, fast information exchange, and so forth. The purpose of this research is to suggest core methods for developing the equipment fleet management system. The methods include 3D solid parametric model generation, soil distribution using Cctree data structure, equipment fleet construction and equipment fleet operation. A simulation test is performed to verify the effectiveness of the equipment fleet management system in terms of equipment operating ratio, fuel usage, and $CO_2$ emission.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3A
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• pp.523-532
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• 2006

It is thought that the suggestion of efficient and rational design guideline based on the behavior evaluation of bridge structure system the included cross beam is necessary for the construction efficiency of two-I girder steel bridges. Therefore, in this study, the effects of influence parameters are investigated by the behavior analyses of the bridges, in which the influence parameters are location, spacing and rigidity of the cross beam. For this study, the existed two-I girder steel bridges firstly were selected with the model of case study and the FE analyses for some case models were performed to estimate the action of the cross beam in the bridge. From the analyses, it was estimated that if it consider local stress and load distribution of a floor system, shell and solid elements are compatible to modeling of the cross beams. Also, the efficient design guideline for the cross beam of two-I girder steel bridge was suggested from parameter studies used location, spacing and rigidity of the cross beam.

• Aerospace Engineering and Technology
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• v.9 no.1
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• pp.9-16
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• 2010

In this study, structural analyses were carried out on the composite sandwich panel which was tested under compression loading. In the structural analyses, three types of finite element modelling were considered and linear buckling analysis and nonlinear analysis were performed for each FE-model. Through the analyses, it was found that shell elements for face parts and solid elements for core part were appropriate for the better prediction of the buckling load of the panel. If the material failure of the face is critical than overall buckling of the sandwich panel, the use of one shell element through the thickness direction was suitable in the FE-model for the better predictions of failure location and failure load.

• Journal of the Society of Naval Architects of Korea
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• v.31 no.4
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• pp.23-31
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• 1994

The compartmentation model is represented by the characteristics and geometric information of the spaces defined by the structural members which are used for the boundary planes of the compartment. For the efficient compartment modeling a program performing the compartmentation design by the chopping and merging method was presented by authors. In this research, the development of an interactive ship compartmentation modeller is introduced. It is natural that the value of the program lessens if the input process is complicated and uneasy, even though the internal techniques for the compartmentation modeling are superior. In this paper, a method for the convenient input is proposed and implemented with the help of a graphical user interface technique. The modeling method introduced in this paper performs an efficient compartmentation modeling fast and conveniently by the solid modeling concept and the graphical user interface.

• Korean Journal of Computational Design and Engineering
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• v.6 no.1
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• pp.9-16
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• 2001

Electrical discharge machining(EDM) is an important process of machining the injection mold. This paper includes efficient design processes of electrodes for EDM. Based on the solid modeler, electrodes can be created by boolean and offset operations with core/cavity models. The built-in offset operations of the solid modeler may occur unexpected results due to the limitations of the solid modeler. We proposed the multi-step and moving-face offset processes in order to apply the EDM clearances. The proposed design processes are implemented with Unigraphics Vl5 API functions and C language and tested on Windows NT 4.0.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.257-262
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• 2001

This paper describes a specialized CAD system for injection mold design, which has been developed using the application procedure interfaces of Unigraphics. The system consists of modeling modules that are mutually independent and can be accessed without any predefined sequence. In addition, the design process modeling capability proposed in this paper facilitate mold redesign process caused by modification of part shape.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.1
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• pp.50-57
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• 2003

In this paper, an automated design and 3-D modeling system of an axial fan and a boss for cooling towers was developed. API and parametric design Provided by a commercial solid-modeler are engaged to automate modeling process. Design data of the boss are assumed to be given by a user with design experiences while the fan from the fan design program using three-dimensional flow analysis. An algorithm avoiding the interferences between fans and a boss is developed. The design data are registered on the database not only to remove duplicate design but also to transfer the data to ERP system.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.5 no.2
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• pp.20-28
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• 1996

Compound surface modeling is widely used for die cavities and punches. A compound surface is defined in 3-D space by specifying the topological relationship of several anlytic surface elements and a sculptured surface. A constructive solid gemonetry scheme is employed to model the analytic compound surface. the desired compound surface can be accomplished by specifying topological reationship in terms of boolean relations between pimitives and the sculptured surfaces. Additionally, a method is presented for checking and avoiding the tool interference occuued in machining the compound surface. Using this method. the interference of concave, convex, and side region can be checked easily and avoided rpapidly.

• Journal of KSNVE
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• v.9 no.4
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• pp.703-713
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• 1999

A side mirror is an important safety tool with which the driver can observe objects out of sight. This paper presents an organized design technology for the side mirror of improved vibration characteristics. Resonance response to forced vibration is critical to observability through the mirror to be designed. This study aims at the reduction of vibration level by the modification of mirror structures and consequent effects are predicted by computer simulations. We used a three-dimensional solid modeling and the modal and frequency analysis ; Pro/Engineer is used as a solid modeler; Pro/Mechanica for vibration analysis. The simulation results are compared with those obtained in experiemnts to check the validity by the three-dimensional modeling. The design technique of side mirror has been established and found to be effective in vibration analysis of redesigned parts.

• CDE review
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• v.3 no.2
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• pp.52-58
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• 1997

제품 개발 환경을 자세히 들여다보면, 고객의 요구 또는 창조된 새로운 제품의 컨셉(Spec)을 사람(개발자)이 도구(설계경험, CAD)를 이용해서 업무수행절차(업무처리규정, 부서별 역할)에 따라 제품을 정의(모양, 크기, 구조)하는 것을 설계행위로 볼 수 있고, 이러한 활동의 결과로써 도면 Mock-up, 각종 Document가 만들어지고 이러한 매체가 부서간, 업무공정간 의사소통의 수단으로 이용되고 있다. 여기서 CAD를 없애서는 안될 개발의 도구로 인식하고 이용하는데, 일반적으로 경쟁력있는 제품을 개발하기 위한 노력의 일환으로 3차원 CAD시스템을 도입하여 적용해 오고 있다. 현재의 3차원 CAD시스템들은 공통적으로 솔리드(Solid) 근간에, FEATURE 개념을 수용하면서 PARAMETRIC 또는 VARIATIONAL 모델링 기법을 채택하여 설계자들에게 다양한 기능을 제공하고 있다. 그러나 3차원 CAD 시스템을 적용하여 만족할 만한 결과를 얻어내기란 간단한 문제가 아니다. 본 고에서는 당 사업장에서 개발한 무선전화기 및 FAX에 3차원 설계를 적용한 사례를 중심으로, 3차원 설계에 대한 허와 실을 살펴보고 3차원 설계가 나아가야 할 방향에 대해 생각해 보고자 한다. 참고로 당 사업장은 디자인, 기구설계, 금형설계까지는 I-DEAS, CAM 작업은 CATIA를 이용하고 있다.