AUTO CAD를 이용한 프라스틱 사출금형 자동설계의 개발에 관한 연구

이태홍,이성수 한국생산제조학회 2000 한국공작기계학회 춘계학술대회논문집 Vol.2000 No.4

Development of a Theoretical Model to Predict Cutting Forces for Hard Machining

이태홍 한국정밀공학회 2011 International Journal of Precision Engineering and Vol. No.

In this study, a theoretical model was developed to predict cutting forces for machining hard materials that contain more than 0.58% carbon. The model is based on the Oxley machining theory, and it uses the Johnson-Cook empirical constitutive law for the flow stress data or the equation of a hard material and the tool geometric parameter, the nose radius. However,Oxley and his co-workers showed that the flow stress data obtained from high-speed compression tests for a range of only plain carbon steels (less than 0.58% carbon) is suitable for making analytical machining predictions assuming a perfectly sharp tool. In this study, an experiment was carried out to obtain the flow stress in the Johnson-Cook law and the geometry of the tool was simplified to obtain the nose radius. The cutting forces from the developed theoretical model were found to be in good agreement with those measured from an experiment of hard machining with an AISI 4140 steel heat-treated bar.

휘발성 데이타 메모리의 불휘발성 프로그램 메모리化에 관한 一方案

李泰鴻 嶺南大學校 工業技術硏究所 1982 연구보고 Vol.10 No.2

A simple and general purposed nonvolatile read-write-memory system applicable to any circuit in place of EAROM, which is very complicated and difficult to use because of its diverse voltages, timing and control signals, is suggested in this paper. Using CMOS RAM and rechargeable battery back up, we can modify easily the data table or even the program memory in circuit without extracting memory devices. It is convenient for the equipments containing time variant parameters or data in its program. It is also examined how long the data can be retained when the back up supply recharged for once. Since this system recharges the back up supply whenever the main voltage source is used, the retention of data is almost everlasting.

FDM 3D Printing 적층조건에 따른 기계적 물성의 연구

이태홍,김범준,손일선 한국금형공학회 2018 한국금형공학회지 Vol.12 No.3

Fused deposition Modeling (FDM) is one of the most widely used for the prototype of parts at ease. The FDM 3D printing method is a lamination manufacturing method that the resin is melted at a high temperature and piled up one by one. Another term is also referred to as FFF (Fused Filament Fabrication). 3D printing technology is mainly used only in the area of prototype production, not in production of commercial products. Therefore, if FDM 3D printer is applied to the product process of commercial products when considered, the strength and dimensional accuracy of the manufactured product is expected to be important. In this study, the mechanical properties of parts made by 3D printing with FDM method were investigated. The aim of this work is to examine how the mechanical properties of the FDM parts, by changing of processing FDM printing direction and the height of stacking layer is affected. The effect of the lamination direction and the height of the stacking layer, which are set as variables in the lamination process, by using the tensile specimen and impact specimen after the FDM manufacturing process were investigated and analyzed. The PLA (Poly Lactic Acid) was used as the filament materials for the 3D printing

화상의 반복 복원처리

이태홍 嶺南大學校 工業技術硏究所 1992 연구보고 Vol.20 No.1

An iterative image restoration is introduced that processes with varying iteration numbers according to the variance of the neighborhood pixels. In general the other method is applied to the whole image without considering the local pixel informations, which is not so effective for the processing time. So in this paper we process local iterative restoration method which iterates many times on detailed portion while in the flat region the iteration decreases. Local iteration method can use any iteration method because it varies in the iteration numbers only. not convergence, which shows decreased processing time.

유전적 탐색 알고리듬을 이용한 계조영상의 복원

조영창,이태홍 嶺南大學校 工業技術硏究所 1997 工業技術硏究所論文集 Vol.25 No.2

In image restoration for the severe degradation of noise, the solution spaces which have many local optima around global solution appear. Thus the algorithms which find the global optima among many local optima in the solution space are superior to the general restoration technique like gradient methods. We introduce genetic algorithm is this paper and restore the image degraded by severe noise. And we proposed genetic operators, crossover and mutation, suited for gray scaled images. Finally we also proposed the local fine tuning of window size and visit number for delicate searching mechanism in the vicinity of the global solution. Through the experimental results we verified the effectiveness of the proposed genetic operators on the gray scaled images over the conventional ones, as well as the improved performance of local fine tuning.

모니터 커버 설계를 위한 최적의 사출 위치 선정에 관한 연구

이태홍,이성수 한국공작기계학회 2000 한국공작기계학회 추계학술대회논문집 Vol.2000 No.-

The object is design an optimal injection position on the Monitor Cover. In this paper, the defined injection position are three types, which simulate in melting temperature, molding temperature and weld line in variation. We obtained a result from simulation and descried the result related injection pressure with injection position.

Steepest-Descent방법에 의한 정칙화 반복 복원

홍성용,이태홍 嶺南大學校 工業技術硏究所 1994 工業技術硏究所論文集 Vol.22 No.1

We studied on the regularized iterative image restoration method based on the method of Steepest-Descent for restoring the noisy blurred images. Conventional regularized iterative method proposed by Jan Biemond et al. determined the value of regularization parameter experimentally from the degraded image to be restored. But proposed method estimated and applied it in each pixels of the restored images. As a results, it was possible to suppress the noise amplification and ringing effects. After 30 times iterative restoration, we got MSE equal to 183 compared with the result proposed by Jan Biemond et al. of which MSE is equal to 216.

선형 Filter와 비선형 Filter 조합에 의한 화상복원

李泰鴻 嶺南大學校 工業技術硏究所 1986 연구보고 Vol.14 No.1

In the image restoration, the smoothing filter to reduce the effect of white Gaussian noise can be used. For the image of lower noise it acts well. But for the higher noise iterative smoothing is needed. Each time an iteration is processed, some area shows better result, while the others worse. Linear filter usually blurrs the edge portion, but it shows better effect for the flat plateau or back ground. Nonlinear filter shows excellent effect for preserving edges. Severe noise makes the both filters helpless. Iteration is needed in that case. The iterated linear filter makes the edge blurred excessively, while the iterated nonlinear filter makes streaks in line because of the propagated error. Combinations of both types of filter will have superior performance to that of filter used separately.

윤곽을 고려한 영상의 정칙화 반복 복원

홍성용,이태홍 嶺南大學校 工業技術硏究所 1993 工業技術硏究所論文集 Vol.21 No.2

We studied on the regularized iterative restoration method considering edge-sensitive parameters in order to make edge sharpening and suppression of the noise amplification in the course of restoration. Proposed method estimated regularization parameter and relaxation parameter from each pixels of the restored image for each iteration and applied them to the next iterative restored image in order to enhance the edge sharpening in the edge region and to reduce the artifacts in the flat region, while the conventional method use the constraints determined experimentally. Through the experimental results we verified that the proposed method showed the better results compared with the conventional regularized iterative restoration method. Proposed method has the better restoration results for the restoration of nosiy-blurred image.