• 한국CDE학회논문집
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• 제18권4호
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• pp.243-249
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• 2013

This paper presents a tool-path generation methods for an automated robotic system for skull drilling, which is performed to access to some neurosurgical interventions. The path controls of the robotic system are classified as move, probe, cut, and poke motions. The four motions are the basic motion elements of the tool-paths to make a hole on a skull. Probing, rough cutting and fine cutting paths are generated for skull drilling. For the rough cutting path circular paths are projected on the offset surfaces of the outer top and the inner bottom surfaces of the skull. The projected paths become the paths on the top and bottom layers of the rough cutting paths. The two projected paths are blended for the paths on the other layers. Syntax of the motion commands for a file format is also suggested for the tool-paths. Implementation and simulation results show that the possibility of the proposed methods.

• 한국CDE학회논문집
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• 제6권4호
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• pp.263-270
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• 2001

In stamping-die manufacturing, the first step is to build die patterns for lost wax casting process. A recent industry trend is to manufacture the die pattern using 3-axis NC machining. This study identifies technical considerations of the pattern machining caused by the characteristics of Styrofoam material, and proposes technical methods related to establishing a process plan and generating tool paths for optimizing the pattern machining. In this paper, the process plan includes the fellowing three items: 1) deter-mining a global machining sequence-a sequence of profile, top, bottom machining and two set-ups, 2) extracting machining features from a pattern model and merging them, and 3) determining a machining sequence of machining features. To each machining feature, this study determines the machining start point, generates the approach tool path, and proposes a tool path linking method fur reducing the distance of the cutter rapid motion. Finally, a smooth tool path generation and an automatic feedrate adjustment (AFA) method are introduced far raising the machining efficiency.

• 한국CDE학회논문집
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• 제3권4호
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• pp.236-242
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• 1998

This paper presents a development of computer aided cutting tool selection techniques for rough and finish turning operations. The developed system,. which is one of important activities for computer aided operation planning, firstly implements operation sequencing. Then, from relations of the size of machined area, recommended finishing allowance and maximum depth of cut, a main machining method is selected, a number of cut is calculated, cutting tools including toolholders and inserts are selected, and values for cutting parameters are determined. A cutting tool selection procedure is proposed for toolholders and inserts of ISO code in rough cutting, and some important parameters such as holder style, tool approach angle, tool function and its direction are described in detail. In order to demonstrate the validity of the system a case study is performed.

• 한국CDE학회논문집
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• 제11권5호
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• pp.375-383
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• 2006

Presented in this paper is a new fast and robust algorithm generating NC tool path for 2D pockets with islands. The input shapes are composed of line segments and circular arcs. The algorithm has two steps: creation of successive offset loops and linking the loops to a tool path. A modified pairwise technique is developed in order to speed up and stabilize the offset process, and the linking algorithm is focused on avoiding thin-wall cutting and minimizing tool retractions. The proposed algorithm has been implemented in C++ and some illustrative examples are presented to show the practical strength of the algorithm.

• 정보교육학회논문지
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• 제24권4호
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• pp.379-390
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• 2020

최근 코로나19 상황으로 인한 비대면 교육의 확산으로 온라인 교수·학습 및 평가 도구에 대한 관심이 높아지고 있다. 도구의 효과적인 활용을 위해서는 학습자의 정의적, 인지적 변인 간의 구조적 영향력과 인과 관계에 대한 규명이 필요하다. 본 연구는 '온라인 저지'를 활용하는 프로그래밍 교육에서 도구의 활용 횟수, 자기효능감, 몰입, 컴퓨팅 사고력, 논리적 사고력으로 구성된 연구 모형과 경쟁 모형을 설정하고, 모형의 적합도와 경로 분석을 실시하였다. 분석 결과, '도구의 활용 횟수 → 자기효능감 → 몰입 → 논리적 사고력 → 컴퓨팅 사고력'에 이르는 인과 관계를 규명하였고, 도구의 활용 횟수가 학습 동기를 거쳐 사고력에 영향을 미치는 경로 상에 '자기효능감 → 몰입'의 이중 매개 효과, 또는 '몰입'의 단독 매개 효과를 확인하는 동시에 '몰입 → 자기효능감'의 이중 매개 변인으로는 도구의 활용 횟수가 사고력으로 발현되지 않음을 확인하였다. 한편, 동일한 경로 상에 '논리적 사고력 → 컴퓨팅 사고력'의 경로는 규명되었으나, '컴퓨팅 사고력 → 논리적 사고력'의 경로는 규명되지 않았다.

• 정보교육학회논문지
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• 제19권3호
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• pp.271-278
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• 2015

본 연구에서 알고리즘 능력을 측정하여 정보 영재를 판별할 수 있는 도구를 개발하였다. 판별 도구는 Computational Thinking의 Concept을 재구성하여 해당 영역이 중점적으로 포함되어있는 문항을 제작하였다. 문항의 유형을 단일 속성 문항, 복합 동일 속성 문항, 복합 집중 속성 문항으로 나누어 세분화하였으며 문제 해결방식을 전체 스크립트 제작, 스크립트의 일부 수정, 스크립트의 결과 추측하기로 나누어 스크래치 프로그램으로 개발하였다. 개발한 판별도구를 영재학생들에게 적용한 결과 문항의 타당도와 신뢰도가 높은 것으로 나타났다.

• 한국CDE학회논문집
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• 제9권1호
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• pp.35-43
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• 2004

It is well known that the five-axis machining has advantages of tool accessibility and machined surface quality when compared with conventional three-axis machining. Traditional researches on the five-axis tool-path generation have addressed interferences such as cutter gouging, collision, machine kinematics and optimization of a CL(cutter location) or a cutter position. In the paper it is presented that optimal CL data for a face-milling cutter moving on a tool-path are obtained by incorporating TSS(tool swept surface) model. The TSS model from current CL position to the next CL position is constructed based on machine kinematics as well as cutter geometry, with which the deviation from the design surface can be computed. Then the next CC(cutter-contact) point should be adjusted such that the deviation conforms to given machining tolerance value. The proposed algorithm was implemented and applied to a marine propeller machining, which proved effective from a quantitative point of view. In addition, the algorithm using the TSS can also be applied to avoid cutter convex interferences in general three-axis NC machining.

• 한국CDE학회논문집
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• 제9권4호
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• pp.334-350
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• 2004

Until now, architects have used traditional methods in order to develop architectural forms and use a digital technology as presentation tools. The field of digital technology has been expanded to control easily architectural data, eventually leads to the creation for creative ideas, which were belong to mainly designer's talent. It has been educated by using digital tool in foreign universities but in our case a little university try to do. So we need an adequate curriculum and educational media because of digitalized data, originated architectural form and reduction of time and money. In this paper, as it is surveyed the present situation of architetural education by using digital tool in domestic and foreign country, it can be used as the fundamental data that architectural education by using digital tool is initiated In our universities.

• 한국CDE학회논문집
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• 제4권3호
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• pp.247-258
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• 1999

With the contemporary CAD/CAM system, where the tool path is generated and verified purely based on the geometric operation, geometric accuracy of the machined surface cannot be guaranteed dut to the cutting mechanics, meaning that the cutting mechanics should be incorporated in some fashion. In this paper, we incorporate the instantaneous cutting force and the tool deflection phenomena in predicting the machined surface for the finish-cut and milling operation. For the given NC dat including cutting conditions, the developed algorithm computes cutting force and deflection amount along the tool trajectory, and outputs the 3D graphic model of the machined surface together with error analysis. The validity and accuracy of the presented method has been tested by the actual cutting experiments. Experimental results and accuracy enhancement method together with implementing architecture of the VMCS (Virtual Machining CAM System) are discussed in the paper.

• 한국CDE학회논문집
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• 제17권1호
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• pp.7-16
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• 2012

One distinguishing feature of BIM(Building Information Modeling) is the objectification of spatial elements independently, which makes it easy to represent spatial network. From this perspective, this study aimed to develop the spatial network analysis tool based on open BIM technologies. From the literature review, an object model of spatial network with nodes and links and a process model from construction to visualization were established. A prototype system implementing the proposed models, named SNAT(Spatial Network Analysis Tool), was developed in Java platform with using its open source packages. SNAT can create a spatial network from IFC-BIM model, calculate the indices of spatial network analysis, and visualize it with the representing types(map, graph, matrix and table).