• 한국초지조사료학회지
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• 제15권1호
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• pp.67-72
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• 1995

To select the highest yield soiling type forage, the yield performance of selected sorghum-sudangrass hybrids imported in 1992 have been evaluated at Chonnam region. The soiling type hybrids used in this experiment were TE-haygrazer, FP-5 Sudan, Sweet sioux V, and X -78050. Three different cuttings were done on July 6, August 6 and September 16 in 1992. This trial was arranged as a randomized complete block design with three replications under taken over a period 5 months from May to September in 1992. The results of this experiment were summarized as follows: The hybrids tested were not significantly different by plant height, leaf blade length, leaf blade width and stem diameter. In the first cutting, dry matter yield of FP-5 Sudan was the highest. In the second and third cutting, dry matter yield of Sweet sioux V was the highest among hybrids. The contents of crude protein, hemicellulose, relative feeding value(RFV), and amino acid were the highest by the first cutting, but NDF and ADF were shown the lowest.

• International Journal of Precision Engineering and Manufacturing
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• 제4권1호
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• pp.23-29
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• 2003

Stencil is used normally as a mask for solder pasting on pad of a printed circuit board (PCB). The objective of this study is to develop a stencil cutting system and determine the optimal conditions to make good-quality stencil by using a Nd:YAG laser. The effects of process parameters such as laser power, type of mask, gas pressure, cutting speed and pulse duration on the cut edge quality were investigated. In order to analyze the cut surface characteristics (roughness, kerfwidth, dross) optical microscopy, SEM microscopy and roughness measurements were used. As a result, the optimal conditions of cutting process parameters were determined, and the practical feasibility of the proposed system was also examined by using a commercial Gerber file for PCB stencil manufacturing.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.553-558
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• 1994

In this paper, we present a new approach for the automation of deburring process. An algorithm for teaching skills of a human expert to a robot manipulator is developed. This approach makes use of TSK fuzzy model that can express a highly nonlinear functional relation with small number of rules. Burr features such as height, width, area, cutting area are extracted from image processing by use of the vision system. Cutting depth, repeative number and normal cutting force are chosen as control signals representing actions of the human expert. It is verified that our processed fuzzy model can accurately express the skills of human experts for the deburring process.

• 한국정밀공학회지
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• 제15권8호
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• pp.33-38
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• 1998

TiYN coated high speed steel tools have been developed and their tool lifes were assessed. First yttrium alloyed titanium target was manufactured, then using the arc ion plating(AIP) technique TiYN coating was deposited onto high speed steel substrate. Three kinds of varying thickness of TiYN coated tools were prepared. Cutting tests were carried out with theses tools and for comparison with the commercially available uncoated, TiN, TiCN and TiAlN coated tools. During the cutting tests flank wear width vs. cutting time was measured. It has been revealed that the newly developed TiYN coated tools show superior tool life characteristics to others.

• 한국정밀공학회지
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• 제4권3호
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• pp.60-68
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• 1987

An optoelectronical method for in process monitoring of flank wear of cutting tools is presented. The method is based upon real-time vision technology in which the tool is illuminated by a beam of laser and then the image of wear zone is taken by a vidicon camera. The image is converted to a series of digital pixel data and processed through an algorithm specially developed for measurement of the wear land width. Detailed aspects of the prototype measurement system byilt for experiment are described, and test results are discussed. As conclusions, it is proved that the methods are effec- tive especially for-in situ application with a measuring accuracy of 0.01mm.

• 한국산학기술학회논문지
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• 제10권11호
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• pp.3066-3073
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• 2009

3축 파이프 형상절단기에서 다양한 접합형상에 대하여 모관과 지관의 접합궤적을 수학적으로 유도하였다. 그 접합궤적에 절단폭 등의 공구 보정하여 실제로 가공할 절단궤적을 결정하여 이 공구궤적에 해당하는 CL-data를 생성하고, 또한 공구 궤적을 확인하기 위하여 ghost 기능을 구현하였다. 생성된 CL data를 PLC의 위치결정제어 모듈에 로딩하여 동시 3축($\alpha$, X, $\beta$축)의 이송을 제어하여 경로를 따라서 형상절단과 동시에 개선을 할 수 있도록 동시3축 파이프 형상절단 시스템을 개발하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.439-440
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• 2008

• 한국정밀공학회지
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• 제30권5호
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• pp.537-543
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• 2013

In this paper, a novel radial beam coupling model was proposed and the design parameters were studied for the efficient transmission of torque. To develop a high performance radial beam coupling, an analytical way to predict the performance in design phase is required. One of the best ways to estimate the performance of the coupling without manufacturing is to evaluate the stress and torsional stiffness by building a finite element model with a special attention to the radial beam cutting part. For the best results of FEA, the material properties were obtained through testing. To verify the reliability of finite element model, the results of FEA were compared with the experiments. The main design parameters of radial beam cutting width, radial beam cutting depth, and radial beam cutting direction were considered for the performance of radial beam coupling.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.151-156
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• 1995

This paper presents a methodology for real-time detecting and identifying the runout geometry of an end mill. Cutter runout is a common but undesirable phenomenon in multi-tooth machining such as end-milling process because it introduces variable chip loading to insert which results in a accelerated tool wear,amplification of force variation and hence enlargement vibration amplitude. Form understanding of chip load change kinematics, the analytical sutting force model was formulated as the angular domain convolution of three dynamic cutting force component functions. By virtue of the convolution integration property, the frequency domain expression of the total cutting forces can be given as the algebraic multiplication of the Fourier transforms of the local cutting forces and the chip width density of the cutter. Experimental study are presented to validata the analytical model. This study provides the in-process monitoring and compensation of dynamic cutter runout to improve machining tolerance tolerance and surface quality for industriql application.

• Design & Manufacturing
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• 제14권1호
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• pp.63-68
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• 2020

Ultra-high brightness and thin displays need to optical micro-patterns which can uniformly diffuse the lights and low loss. The micro random patterns have characteristics to rise the optical efficiency such as light extraction, uniform diffusion. For this reason, various fabrication processes are studied for random patterns. In this study, the micro random patterns were machined by diamond turning which used a controlled cutting tool path with random cutting depth. The machined patterns had random shape and directionality along the circumferential direction. The average width and length of machined random pattern according to rotation radius were 40.13㎛~55.51㎛ and 37.25㎛~59.49㎛, and these results were compared with the designed result. Also, the machining error according to rotation radius in diamond turning using randomly controlled cutting depth was discussed.