• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 추계학술대회 논문집
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• pp.304-309
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• 1997

Elastic elements, at first, were extensively used in suspensions as vibration isolators at joints. Nowadays they are used to improve stability and handling. The design of these elements has become a very important matter since the loading condition of the mechanism gives a mew suspension geometry without any modification. This paper presents an analysis of forces and moments of joints with elastic elements in the McPherson suspension mechanism to evaluate accurately the elastic deformation using the displacement matrix method in conjunction with the equilibrium equations. First the suspension is modeled as a multi-loop spatial rigid-body guidance mechanism which has elastic elements at the hardpoints of the suspension. Then a method and design euqations are developed to analyze the suspension characteristics by the various tire load. Also the displacement matrices and constraint equations for links are appllied to determine the sensitivity of the suspension mechanism. Finally this approach may conduct a realistic design of suspension mechanisms with elastic elements to improve the performance of the automobile under various driving conditions.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2005년도 BIOINFO 2005
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• pp.402-406
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• 2005

In this paper, we present a tool to calculate the distribution of amino acid contacts in proteins as well as in protein domains. The proteins are grouped according to the classification by Yanay Ofran and Burkhard Rost[1]. In addition, a protein's distribution was compared with that of proteins in the same group as well as the entire collection of proteins across all groups. With these statistics, biologists can pick out proteins which have characteristics that defer from the norm.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.311-316
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• 2008

It is needed to assess the impact of the road traffic noise for city planning. In Korea, the current noise impact assessment h3s not yet considered the impacts of the multiple reflection, the deflection and the ground attenuation caused by buildings and other obstacles. A noise map is useful tool to solve this problems. But before everything else, suitability of noise map must be assessed for variety of geometry conditions. In this study, we assessed suitability of road traffic noise map by compared measured noise levels with predicted noise levels from each road traffic noise map for Site A, B and C.

• International Journal of Precision Engineering and Manufacturing
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• 제2권3호
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• pp.27-33
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• 2001

The aim of the present work is to propose a model for Computer Aided programming of numerical Control lathe. This model is based on the concept by features. It has been developed in an Artificial Intelligence environment, that offers a rapidity as well as a precision for NC code elaboration. In this study a pre-processor has been elaborated to study the geometry of turning workpiece. This pre-processor is a hybrid system which combine a module of design by features and a module of features recognition for a piece provided from an other CAD software. Then, we have conceived a processor that is the heart of the CAD/CAM software. The main functions are to study the fixture of the workpiece, to choose automatically manufacturing cycles, to choose automatically cutting tools (the most relevant), to simulate tool path of manufacturing and calculate cutting conditions, end to elaborate a typical manufacturing process. Finally, the system generates the NC program from information delivered by the processor.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.466-469
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• 2002

Burr is a projected part of finished workpiece. It is unavoidable and undesirable by-product of most metal cutting or shearing process. Also, it must be removed to improve the fit of machined parts, safety of workers, and the effectiveness of finishing operation. But deburring process is one of manufacturing processes that have net been successfully automated, so deburring automation is strongly needed. This paper focused on developing a basic algorithm to find edge of workpiece and match two different image data for deburring automation which includes automatic recognition of parts, generation of deburring tool paths and edge/corner finding ability by analyzing the DXF drawing file which contains information of part geometry. As an algorithm for corner finding, SUSAN method was chosen. It makes good performance in finding edge and corner in suitable time. And this paper suggested a simple algorithm to find matching point between CCD image and drawing file.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1992년도 춘계학술대회 논문집 92
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• pp.27-46
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• 1992

In this study a new simplified three-dimensional numerical method and the associated computer program have been developed to simulate the non-axisymmetric extrusion processes. The two-dimensional rigid-plastic finite element method under the generalized plane-strain condition, is combined with the slab method. To define the die geometry for non-axisymmetric extrusion, area mapping technique was used. Streamlined die surface was used to miniminze the total extrusion pressure. Extrusion of square, hexagonal and "T" section from round billet have been simulated and experimented with a model material. The computed results were in good agreement with the experiments in cross-sectional grid distortion. Computational results will be valuable for designing tool geometries and corresponding processes.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.422-427
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• 2006

This paper presents force-feedback control performance of a haptic device in virtual environment of minimally invasive surgery(MIS). As a first step, based on an electrorheological(ER) fluid and spherical geometry, a new type of master device is developed and integrated with a virtual environment of MIS such as a surgical tool and human organ. The virtual object is then mathematically formulated by adopting the shape retaining chain linked(S-Chain) model. After evaluating reflection force, computational time, and compatibility with real time control, the virtual environment of MIS is formulated by interactivity with the ER haptic device in real space. Tracking control performances for virtual force trajectory are presented in time domain, and theirtrackingerrorsareevaluated.

• 한국공작기계학회논문집
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• 제11권4호
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• pp.89-96
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• 2002

This paper aims to develop an intelligent model for predicting top-bead width for the robotic GMA(Gas Metal Arc) welding process using BP(Back-propagation) neural network and multiple regression analysis. Firstly, based on experimental data, the basic factors affecting top-bead width are identified. Then BP neural network model and multiple regression models of top-bead width are established. The modeling methods and procedure are explained. The developed models are then verified by data obtained from the additional experiment and the predictive behaviors of the two kind of models are compared and analysed. Finally the modeling methods, predictive behaviors md the advantages of each models are discussed.

• 한국공작기계학회논문집
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• 제11권4호
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• pp.68-74
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• 2002

The FD process is analogous to the direct piston extrusion process where the cold feed filament acts as a piston extruding the molten filament from the heated liquefier through a nozzle. The extruded filament is deposited on top of futureless platform, where the liquefier and the nozzle move in X and Y direction control by computer based on the part geometry. After the first layer, the Z platform indexes down and the next layer get deposited on top of the first layer. the layer by layer building process introduces surface problem. This paper describes effect of slice interval of the parts built by fused deposition modelling rapid prototyping system.

• 한국공작기계학회논문집
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• 제16권3호
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• pp.8-14
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• 2007

The geometry in the weight reduction design is very required to be started from the conceptual design with low cost, high performance and quality. In this point, a topological shape fur optimization concerned with conceptual design of structure is important. The method used in this paper combines three optimization techniques, where the shape and physical dimensions of the structure and material distribution are hierachically optimized, with the maximum rigidity of structure and lightweight. As the applications, the technology of weight reduction design is applied on designs of aluminum control arm and inner panel of hood.