• Journal of Computational Design and Engineering
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• 제3권2호
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• pp.151-160
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• 2016

Cutter-workpiece engagement (CWE) is the instantaneous contact geometry between the cutter and the in-process workpiece during machining. It plays an important role in machining process simulation and directly affects the calculation of the predicted cutting forces and torques. The difficulty and challenge of CWE determination come from the complexity due to the changing geometry of in-process workpiece and the curved tool path of cutter movement, especially for multi-axis milling. This paper presents a new method to determine the CWE for general milling processes. To fulfill the requirement of generality, which means for any cutter type, any in-process workpiece shape, and any tool path even with self-intersections, all the associated geometries are to be modeled as triangle meshes. The involved triangle-to-triangle intersection calculations are carried out by an effective method in order to realize the multiple subtraction Boolean operations between the tool and the workpiece mesh models and to determine the CWE. The presented method has been validated by a series of case studies of increasing machining complexity to demonstrate its applicability to general milling processes.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1999년도 추계학술대회 논문집
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• pp.31-31
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• 1999

In the preliminary design stage of an automotive interior, human sensibility is first analyzed and applied to design parameters for satisfying consumers needs using optimization and engineering judgement. Then designers try to design components that meet these needs using empirical and trial-and-error procedures. This process usually yields poor results because it is difficult to find a feasible design that satisfies the targets by trial-and-error (a feasible design is one that satisfies consumers needs and design constraints). To improve this process, we need tools to link the human sensibility with the design parameters that define the geometry of the components of an automotive interior. A methodology is presented for developing a tool for design guidance of an automotive interior. This tool translates the human sensibility into the design parameters that define the geometry of the components of an automotive interior. This tool, called interpreter, rapidly predicts the human sensibility of a given automotive interior and presents design parameters that meet or exceed given human sensibility to satisfy consumers needs and design constraints. The methodology is demonstrated on the interior design of an actual automotive.

• 한국수학교육학회지시리즈A:수학교육
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• 제60권2호
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• pp.159-172
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• 2021

본 연구의 목적은 조작 교구와 탐구형 기하 소프트웨어를 활용한 전개도 학습이 초등학교 5학년 학생들의 공간 감각에 주는 영향을 비교·분석하는 것이다. 이를 위해 한 실험집단은 조작 교구인 지오픽스를 한 실험집단은 탐구형 기하 소프트웨어인 Cabri 3D를 활용하여 전개도를 학습하였다. 비교 집단은 교구나 소프트웨어의 사용 없이 학습지만으로 학습을 진행하였다. 사전과 사후에 공간 감각 검사를 실시하여 그 수준을 파악하였고, 시선 추적 검사를 실시하여 전개도 과제를 해결하는 학생들의 전략을 분석하였다. 그 결과 조작 교구인 지오픽스를 활용한 전개도 학습이 공간 감각에 가장 효과적이었으며, Cabri 3D 또한 전개도를 학습하기 위한 좋은 도구가 될 수 있음을 확인할 수 있었다. 또한, 전개도 학습 이후 학생들의 해결 전략은 가장 효율적인 전략이었던 분석적 전략이 증가하였으며, 이러한 과정에서 시선 추적은 학생들의 전략을 탐색하는 매우 유용한 도구가 됨을 알 수 있었다.

• 한국정밀공학회지
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• 제21권2호
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• pp.21-26
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• 2004

The formed tool is used to machine the geometrical shape of bearing rubber seal efficiently. The bearing rubber seal has complex geometry for the complicated geometrical shape to prevent leakage of lubricant oil and influx of the dust effectively. Because it is difficult to machine the unique shape exactly by the conventional tool, the formed tool is used in machining a rubber seal die. In this paper, It is performed to investigate machining characteristic of the formed tool； cutting edge wear, cutting force, and surface quality. Also, an efficient precision machining condition is proposed, and the inspection results of rubber seal with CAI are discussed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1807-1810
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• 2003

The formed tool is used to machine the unique shape of rubber seal for geometrical shaping and reduction of cutting time. The bearing rubber seal produced by hot press forming has complex geometry for the complex geometrical shape to prevent leakage of lubricant oil and influx of the dust effectively. Because it is difficult to machine the unique shape exactly by the conventional tool, the formed tool is used in machining mold of the seal. In this paper, It is performed for selection of the formed tool to investigate cutting edge wear, cutting force, and surface quality. Also, an efficient high precision machining is proposed on the experiment data.

• 대한기계학회논문집A
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• 제27권11호
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• pp.1917-1924
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• 2003

This paper proposes a roughing path generation method fer machining impeller with 5-axis machining center. Traditional researches are focus on finishing for machining impeller. To achieve efficient machining, roughing method must be studied. The proposed method consists two steps : One is to select optimal tool size and tool attitude by dividing cutting area into two regions to reduce cutting time. The regions are automatically divided by character point on the geometry of impeller blade. After dividing, the tool of the optimal size is selected for each divided region. The other is avoidance of tool interference. Tool interference in cutting areas is avoided by checking the distance between tool axis vector and ruling line on blade surface or approximated plan between ruling line. Using this method, the cutting time is reduced efficiently.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1998년도 추계학술대회 및 정기총회
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• pp.204-208
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• 1998

The fundamental issues to evaluate machine tool's performance through simulation pertain to the physical models of the machine tool itself and of process while the practical problems are related to the development of the modular software structure. It allows the composition of arbitrary machine/process models along with the development of programs to evaluate each state of machining process. Surface roughness is one of the fundamental factors to evaluate machining process and performance of machine tool, but it is not easy to evaluate surface roughness due to its tribological complexity. This paper presents an algorithm to calculate surface roughness considering cutting geometry, cutting parameters, and contact dynamics of cutting between tool and workpiece as well as tool wear in turning process. The designed virtual machining system can be used to evaluate the surface integrity of a turned surface during the design and process planning phase for the design for manufacturability analysis of the concurrent engineering.

• 오토저널
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• 제12권2호
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• pp.59-70
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• 1990

Crack of breaking toughness of most Ceramics material is 1-5MPa .root.m but that of Zirconia Ceramics is improved to be 6-8MPa .root.m and its development of machining difficult-to-machine material is on the rise as urgent subject. For general Zirconia Ceramics machining, diamond grinding wheel is generally used by selecting an appropriate one and establishing grinding condition but due to such limitations as economics, grinding efficiency and machining geometry, great interest in machining method being used for diamond tool is emphasized. But it is reported that diamond tool is oxidized by cutting heat in the air and is graphitized in vacuum, which causes bad effects on tool life. In this study, to restraint cutting heat the internal side of tool is cooled, and restraint low temperature cooling system and being experimented. Further, the machinability of diamond tool for Zirconia Ceramics machining is analyzed with respect to tool wear and stress.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.225-232
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• 2004

Recently, there has been a rapid development in computer technology, which has in turn led to develop the automated welding system using Artificial Intelligence (AI). However, the automated welding system has not been achieved duo to difficulties of the control and sensor technologies. In this paper, the classification of the optimized bead geometry such as bead width, height penetration and bead area in the Gas Metal Arc (GMA) welding with fuzzy logic is presented. The fuzzy C-Means algorithm (FCM), which is best known an unsupervised fuzzy clustering algorithm is employed here to analysis the specimen of the bead geometry. Then the quality of the GMA welding can be classified by this fuzzy clustering technique and the choice for obtaining the optimal bead geometry can also be determined.

• 한국공작기계학회논문집
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• 제17권5호
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• pp.30-35
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• 2008

As the quality of a weld feint is strongly influenced by process parameters during the welding process, an intelligent algorithms that can predict the bead geometry and shape to accomplish the desired mechanical properties of the weldment should be developed. This paper focuses on the development of mathematical models fur the selection of process parameters and the prediction of bead geometry(bead width, bead height and penetration) in robotic GMA(Gas Metal Arc) welding. Factorial design can be employed as a guide for optimization of process parameters. Three factors were incorporated into the factorial model: arc current, welding voltage and welding speed. A sensitivity analysis has been conducted and compared the relative impact of three process parameters on bead geometry in order to verify the measurement errors on the values of the uncertainty in estimated parameters. The results obtained show that developed mathematical models can be applied to estimate the effectiveness of process parameters for a given bead geometry, and a change of process parameters affects the bead width and bead height more strongly than penetration relatively.