• 한국공작기계학회논문집
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• 제16권1호
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• pp.33-39
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• 2007

One of the most important processes is the face milling in processing task. It makes the smooth surface of processed goods. In processing stage, the formation of burr is inevitable. The formed burr decreases a detailed drawing and effects the safety of workers. So, it causes a deburring process for removing and a bottle-neck condition. Therefore, the study which can minimize the generation of burr is needed. In this paper, complex feature, such as line, arc, circle, spline is studied more reality than any other papers. And also, the algorithm which can predict the path of generated burr is established. Moreover, the finality goal is that the system which can produce tool-path minimized has to be developed.

• 소성∙가공
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• 제8권5호
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• pp.465-470
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• 1999

Many researchers have, nowadays, studied on spinning which can produce highly qualified products by CNC spinning machine equipped with hydraulic devices. The products have continuous metal flow which improves fatigue life, yield point, tensile strength and hardness. This study is to investigate the influence of various working conditions on the spinnability of cylindrical cups such as feed rate(ν), feed pitch(p), angle of roller holder(α), and the inclination angle of first roller path. Through experiments the feed rate of (0.4∼0.7) mm/rev was shown to give the drawing ratio of 2.5 when the angle of roller holder was 5°, However, by increasing the angle of roller holder from 5°to 20°, the range of feed rate which can produce deeper cups became wider and the spinnability was also improved. The optimum working conditions, for the maximum formability of aluminum sheet metal as well as dimensional accuracy of spun cups, are presented and discussed.

• 한국CDE학회논문집
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• 제20권3호
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• pp.263-268
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• 2015

Due to an increased sitting time in work, lumbar disc disease is one of the most frequent diseases in modern days, and this occasionally requires surgery for treatment. Endoscopic disc surgery, one of the common disc surgeries, requires a process of inserting a guide needle to the target disc for which the insertion path is manually planned by drawing lines on the patient's skin while monitoring the fluoroscopic view of the lumbar. Such procedure inevitably exposes both surgeon and patient to the fluoroscopy radiation emitted from the c-arm for a long time. To reduce the radiation exposure time, this study proposes a computer assisted method of calculating the 3D guide needle path by using 2D c-arm images of the disc in 3 different angles. Additionally, a method of the guide robot control based on the 3D needle path was developed by implementing the Hand-eye Calibration method to calculate the transformation matrix between the c-arm and robot base coordinate systems. The proposed system was then tested for its accuracy.

• 대한치과보철학회지
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• 제28권2호
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• pp.217-229
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• 1990

The Applegate-Kennedy classification, the drawing of removable partial denture design using color coding, the selective tissue placement impression method in case of Class I and Class II removable partial dentures, the design of the swing lock attachment of an alternative approach to conventional removable partial denture, the design of the intracoronal or extracoronal attachment, and the removable partial denture design using a rotational path were presented. The following conclusions from the above things were presented : 1. The swing lock attachment removable partial denture can be effective to an alternative approach when the design of conventional removable partial denture is improper with markedly mobile remaining teeth or missing key abutments. 2. Intracoronal or extracoronal attachments must be selected care-fully considering the conditions of the abutment teeth and alveolar ridge whether more occlusal loads to the abutment teeth or to the alveolar ridge are distributed. 3. It must be almost prerequisite that a functional impression is taken in case of Class I and class II removable partial dentures and in case of tooth-borne removable partial dentures, a removable partial denture using rotational path is strong, hygienic, esthetic, and can be accomplished successfully in the clinical aspect when it is properly designed and fabricated through the complete understanding of an indication and a principle. 4. All necessary informations must be achieved with carefully investigated surveying procedure according to each clinical case by Applegate-Kennedy classification which can be helpful and useful in the clinical application and it is important that dentists themselves must be in the habit of drawing a reasonable partial denture design using a color coding in the paper sheet.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.66-70
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• 2008

In this study, the formability of AZ31B magnesium alloy sheets was investigated by the analytical and experimental approaches. Tensile tests and limit dome height tests were rallied out at several temperatures between $25^{\circ}C$ and $300^{\circ}C$ to obtain the mechanical properties and forming limit diagram (FLD). The FLD-based criterion considering the strain-path and the blank temperature was used to predict the forming limit in a deep-drawing process of cross-shaped cup by finite element analysis. This criterion proved to be very useful in determining the optimal process conditions such as blank shape, punch velocity, minimum comer radius, fillet size, and so on, through the comparison between FEA and experimental data. In particular, the temperature of each tool that provided the best formability of the blank was determined by coupled temperature-deformation analyses. A practical method that can greatly reduce the forming time by increasing the punch speed during the forming process was suggested.

• 한국지능시스템학회논문지
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• 제14권4호
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• pp.499-505
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• 2004

본 논문에서는 가상 AGV를 이용한 AGVS의 시스템 모델링과 교통제어 대해 연구하였다. 실제 AGV에 기초한 가상의 AGV의 모델을 제안하고 각각의 가상 AGV가 독립적으로 명령을 수행하도록 하였다. 또한 공장 환경을 모델링하기 위해 연속된 직선경로정보와 AGV가 작업할 작업장소를 Vector Drawing방식으로 모델링이 가능하도록 하였다. 그리고, 서로 다른 AGV가 경로 합류점에서의 충돌을 방지하면서 정지하지 않고 AGV를 통과시킬 수 있도록 합류구역의 교통제어방식과 경로가 정체될 때 이를 우회할 수 있도록 하는 알고리즘을 제안하였다. 그리고 제안된 모델과 교통제어방식에 대하여 시뮬레이션을 수행하여 유효성을 검증하였다.

• 대한기계학회논문집
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• 제12권3호
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• pp.466-472
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• 1988

본 연구에서는 직선 및 원과 원호가 포함된 설계도면 뿐만 아니라 단순한 수 식으로 표현할 수 없는 곡면 즉 선직선(ruled surface)을 포함한 기계 부품용 설계 도 면의 입체 도형으로의 자동 변환과, 자동 변환된 입체 도형으로부터 임의의 위치에 대 한 단면을 도출하여 CAM의 기본 요소인 NC 공작기계의 공구 경로를 발생시키는 과정의 알고리즘을 개발하고 이것을 컴퓨터 프로그램화하여 산업계에 필수적인 CAD/CAM 통합 을 위한 기초 이론을 확립하고자 한다.

• 과학교육연구지
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• 제38권1호
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• pp.182-195
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• 2014

기하광학에서의 광선작도는 빛의 진행과정을 시각적으로 형상화할 수 있다는 측면에서 중요성을 가진다. 굴절 개념의 경우, 직진이나 반사에 비해 난이도가 높은 탓에 학생들 뿐만 아니라 교사들의 경우에도 이해도가 낮다. 올바른 개념이해를 위하여 광선을 그려보는 활동과 이를 실제 상황에 적용해보는 활동이 필요하다. 이에 따라 이 연구에서는 교사들의 시각적 형상화를 돕기 위해 광선작도 활동이 포함된 빛의 굴절에 대한 동료 교수법 교사연수 프로그램을 개발 및 적용하고 개념변화 정도를 측정하였다. 예비교사 29명과 초등교사 21명에게 각각 적용하고 사전, 사후 검사 점수를 분석하였다. 사전검사의 분석 결과, 빛의 굴절을 초중등 교육과정에서 학습하였음에도 불구하고, 수업 전에는 대부분의 연구 참여자가 굴절되는 빛의 경로를 잘 이해하지 못하고 있었다. 동료 교수법 교사연수 프로그램을 적용한 후에 시행된 사후 검사 결과, 광선작도 연습이 시각적 형상화를 도와 학습한 내용을 다른 맥락에 적용할 수 있도록 해준 것을 알 수 있었다. 따라서 빛의 굴절을 이해할 수 있는 교사연수 프로그램으로서 빛의 경로를 시각적으로 형상화하여 이해하고 개념검사문항을 통해 이를 적용해볼 수 있는 프로그램을 제안한다.

• 한국생산제조학회지
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• 제21권3호
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• pp.516-524
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• 2012

Selective Laser Sintering(SLS) system consists of various element technologies. Main components of the system include a position control system, a speed control system of the roller, and nitrogen atmosphere furtherance for the powdered sintering. Other systems which make the core of the SLS system are build room and the feed room for powder epitaxial, a temperature control system, and a scan path generator for the laser. The powder material for laser sintering is necessary to produce prototypes in Solid Freeform Fabrication(SFF) based on SLS process. This powder material is sintered in powder room using $CO_2$ laser after spreading evenly using roller to reproduce mold via SFF. This study addresses an SFF system by using the SLS process which applies single laser system to enable manufacturing of 3D shape. And to evaluate applicability of the single laser system, experiments were conducted with optimal fabricating process.

• 한국정밀공학회지
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• 제32권11호
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• pp.945-952
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• 2015

In drawing sheet metal, the blank holding force is applied to prevent wrinkling of the product and to add a tensile stress to the material for the plastic deformation. Applying an inappropriate blank holding force can cause wrinkling or fracture. Therefore, it is important to determine the appropriate blank holding force. Recent developments of the servo cushion open up the possibility to reduce the possibility of fracture and wrinkling by controlling the blank holding force along the stroke. In this study, a method is presented to find the optimal variable blank holding force curve, which uses statistical analysis with consideration of the nonlinear deformation path. The optimal blank holding force curve was numerically and experimentally applied to door inner parts. Consequently, it was shown that the application of the variable blank holding force curve to door inner parts could effectively reduce the possibility of fracture and wrinkling.