• Korean Journal of Optics and Photonics
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• v.5 no.2
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• pp.340-346
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• 1994

2.5Gbps 광통신시스템용 수광소자로서 charge plate층을 갖는 링구조의 separate absorption grading multiplication avalanche photodiode를 제작하고 그 특성을 조사 분석하였다. Avalanche Photodiode의 제작은 Metal-Organic Chemical Vapor Deposition 과 Liquid Phase Epitaxy법을 이용한 에피성장과 Br:Methanol을 이용한 채널식각 방법을 사용하였고, passivation과 평탄화는 photosensitive polyimide를 이용하였다. 제작된 ADP는 10nA 이하의 작은 누설전류를 나타내었고, -38~39 V의 항복전압을 나타내었다. 제작된 ADP를 GaAs FET hybrid 전치증폭기와 결합하여 2.5Gbps 속도에서 $2^{23}-1$의 길이를 갖는 입력 광신호에 대해 $ 10^{-10}$ Bit Error Rate에서 -31.0dBm의 수신감도를 얻었다.

• Proceedings of the Korean Society of Crop Science Conference
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• 2006.04a
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• pp.490-491
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• 2006

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.3
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• pp.71-76
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• 2020

Various machining methods are being studied to improve the processing quality of the spherical R shape in press die. In this paper, we confirmed that changes in machining quality were associated with changes in cutting direction, path, and cutting angle, which are commonly used in the machining of molds. We obtained a surface roughness graph with each condition change in one specimen using an instrument that measured geometry and surface roughness simultaneously. The results of the study showed that the best surface roughness in the finish cut of the spherical surface was obtained using upward pick feed machining.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.601-606
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• 2005

This research presents a modeling and a manufacturing method of screw flow meter. This paper introduces the efficient design and manufacturing method of screw type flow meter using reverse engineering and test technology. The methods introduced this paper utilize the reverse engineering that is increasing accuracy of modeling and manufacturing of reverse model. And then it can be used in performance test with hydraulic test equipment. Hence this can be used in the basic document for development of the quite accurate flowmeter.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.132-137
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• 2005

This research presents a modeling and a manufacturing method of screw type flow meter. This paper introduces the efficient design and manufacturing method of screw type flow meter using reverse engineering and test technology. The methods introduced this paper utilize the reverse engineering that is increasing accuracy of modeling and manufacturing of reverse model. And then it can be used in performance test with hydraulic test equipment. Hence this can be used in the basic document for development of the quite accurate flow meter.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.10
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• pp.156-163
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• 2003

This research presents modeling of a functional surface which is a constructed free-formed surface. The modeling introduced in this paper adopts modified B-spline that is utilizing approximating technique. The modified B-Spline is constructed with altered control vertices. It is applied to measure points on a surface of an impeller blade. This research builds a surface-modeler accepting inputs of measured points. Generation of cutter-paths for NC machining employs the model of the constructed surfaces. The machined surfaces which is generated in several cases are compared in the aspect of machining accuracy.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.12
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• pp.100-106
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• 2021

This paper presents a study on the improvement of the machining quality of sculptured-surfaces of molds according to the shape and posture of the tool. In the existing 3-axis machining, the methods using the ball end-mill and radius end-mill were analyzed for various cutting patterns and compared with those of the 5-axis machining. It was observed that the 5-axis machining using a ball end-mill obtained the finest surface roughness, and for the 3-axis machining, the optimal results were obtained for the one-way machining using a radius end-mill.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.11
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• pp.30-35
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• 2021

In this study, a machine simulation system was built using the actual scale of an AC-type 5-axis machine tool for mold surface machining that can be used in applications, such as, modeling and machine building, stroke, and collision detection. The validity of the 5-axis machine simulation system was verified by performing tool path generation, post-processing, machine simulation, prototype motion simulation, and an actual cutting experiment. This entire process was intended to activate the 5-axis machining in mold surface machining.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.69-74
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• 2004

We have examined the relaxative response to the water extract of Rheum undulatum L. (ERU) and water extract of alcohol steamed Rheum undulatum L. (SRU) with isolated thoracic aorta from sprague dawley (SD) rat. Rat thoracic aorta was investigated in vessel segments suspended for isometric tension recording by polygraph. Responses to ERU and SRU were investigated in vessels precontracted with 5-hydroxytryptamine(5-HT). We found that the thoracic aorta segments responded to ERU and SRU with a dose-dependent vasorelaxation : The thoracic aorta segments responded to ERU and SRU with a dose-dependent vasodilation. The amounts of emodin were 0.063%, 0.076% and 0.145% in ERU and SRU, respectable. The 5-HT induced contraction at 10-4M were inhibited by 85.2±4.76% and 84.0±2.91% after addition of the 0.1mg/mL water extract of ERU and SRU. The 5-HT induced contraction at 10/sup -3/M were inhibited by 100% after 10/sup -3/M emodin. In conclusion, vasodilation effect of the water extract of Rheum undulatum L. in rat thoracic aorta was not decreased according to the processing of alcohol steamed Rheum undulatum L.

• Journal of Veterinary Clinics
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• v.28 no.3
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• pp.332-335
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• 2011

A 6-year-old castrated male domestic short hair cat with the clinical signs of anorexia and vomiting was admitted to the local animal hospital. Abdominal radiography and ultrasonography revealed renomegaly and severe hydronephrosis in the right kidney. Surgically excised right kidney was submitted for diagnosis. On the cut surface, two milky white masses and severe dilation of renal pelvis were observed. Most of the neoplastic masses were composed of uniform well differentiated tubules lined by a single layer of cuboidal to columnar cells and projected papillae into the lumen. The neoplastic cells were strong positive for cytokeratin (CK) MNF116, but negative for CK 7. Based on the clinical and gross findings, histopathology and immunohistochemistry, this case was diagnosed as papillary renal adenoma with hydronephrosis.