• Journal of Korean Neurosurgical Society
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• 제37권5호
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• pp.345-349
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• 2005

Objective: Anterior screw fixation provides the best anatomical and functional results for type II odontoid process fracture (type II-A, II-N, and II-P) with intact transverse ligament. The purpose of this study is to evaluate the usefulness of the 4.5mm diameter, cannulated Herbert screw in anterior screw fixation. Methods: From Jan. 2003 to Feb. 2004, consecutive 10cases of type II odontoid process fractures were treated with anterior screw fixation using a Herbert screw. The Herbert screw has double threads, with different pitches on the distal and proximal ends. It has no head, so it can be inserted through articular cartilage and buried below bone surface. It was originally developed for treating scaphoid fractures. Results: There were 8male and 2female patients whose ages ranged from 15 to 67years (mean 42.1years). The fracture type was type II-A in 4patients, II-N in 3 patients, and II-P in 3 patients. The fracture line was oblique downward and backward in 6cases, oblique downward and forward in 1 case, and horizontal in 3cases. The range of follow-up was 5 to 18months (mean 12months). Bone fusions were achieved in all cases without any instrumental failures or postoperative complications. Conclusion: The Herbert screw is very useful in anterior fixation for type II odontoid process fracture. This series showed successful results also in type II-A odontoid fracture when treated with the Herbert screw, but further more studies are required.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.981-984
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• 1995

The feed system using ball screw is constructed by ball screw, support bering and LM guide, and servo system for driving ball screw. AC servo motr drives ball screw which was connected by coupling. In this study, a new axial direction dynamic modeling of ball screw driving system was developed, and forced vibraition test using the impact hammer was experimented. The simulation result is compared with experimental result, which defines the reliability of mathematical modeling.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 추계학술대회 논문
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• pp.79-84
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• 1996

Recently a symmetric and non-symmetric profile of screw rotor has been designed in the interior. Howere the processing method of screw rotor and the cutter design for screw rotor were not studied. Therefor we could not make the shape of the screw rotor designed by profile function with computer. In this study we have made cutter profile design program and manufactured cutters for screw rotors using H.S.S We machined screw rotors of symmetric 4x6 profile non-sysmmetric 4x6 profile with almighty milling machine.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.907-912
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• 1994

Recently, a symmetric and non-symmetric profile of screw rotor has been designed in the interior. However the processing method of screw rotor and the cutter design for screw rotor were not studied. Therefore we could we could not make the shape of the screw rotor designed by profile function with computer. In this study, we have made cutter profile design program, and manufactured cutters for screw rotors using H.S.S. We have machined screw rotorts of symmetric 4*6 profile, non-symmetric 4*6 profile with almighty milling machine.

• 대한조선학회 특별논문집
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• 대한조선학회 2008년도 특별논문집
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• pp.84-89
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• 2008

Twin screw mode LNG Carrier is appeared. Because LNG CARRIER is larger recently. In this paper introduces maneuvering characteristics of Twin screw LNG CARRIER on single screw mode, which are found when the non-using screw mode is fixed or not(wind mill).

• 한국자동차공학회논문집
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• 제8권2호
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• pp.72-80
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• 2000

This study aims at the optimal design of the screw rotor, its performance analysis, and development of a small screw supercharger which has a low noise compared with the root type supercharger. The basic theoretical equations and the basic design of the screw supercharger have been established. The optical design of the screw rotor's shape has been also performed theoretically. Also, the performance analysis technique of the designed screw rotor has been developed.

• 한국식품영양과학회지
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• 제43권9호
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• pp.1407-1414
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• 2014

쌀가루, 고아밀로오스 전분, 분리대두단백, 설탕 및 소금을 첨가하여 feed 수분함량 19~23%, screw speed 200~400 rpm, feed rate 43.6 kg/hr 조건에서 제조한 쌀 스낵의 이화학적 특성을 분석한 결과는 다음과 같다. 쌀 스낵의 bulk density는 0.06~0.21, apparent density는 0.55~0.65 정도로 나타났고, feed 수분함량이 많을수록, screw 속도가 감소할수록 증가하는 경향을 보였다. 쌀 스낵의 팽화율은 density와는 반대로 feed 수분함량이 낮을수록, screw 속도가 증가할수록 증가하였다. 쌀 스낵의 WAI는 feed 수분함량이 많을수록, screw 속도가 감소할수록 증가한 반면, WSI는 WAI와는 반대의 경향을 나타냈다. 쌀 스낵의 breaking strength는 feed 수분함량이 증가할수록, screw 속도가 감소할수록 증가하였다. 쌀 스낵의 색도 중 L값은 feed 수분함량 19%, 21%에서는 screw 속도가 증가할수록 L값은 낮았으나, feed 수분함량 23%에서는 screw 속도에 따른 유의적인 차이는 없었다. a, b값은 feed 수분함량 19%에서는 screw 속도가 증가함에 따라 높아졌다. 쌀 스낵의 x-ray 회절도는 feed 수분함량이 낮을수록, screw 속도가 높을수록 회절강도가 낮게 나타났고, feed 수분함량 19%, 21%, screw 속도 300 및 400 rpm에서는 V 도형의 특징을 나타냈다. 쌀 스낵의 내부 단면구조는 feed 수분함량이 많을수록, screw 속도가 낮을수록 기공의 생성이 잘 되지 않았고 세포벽이 두껍게 나타났다.

• 한국생산제조학회지
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• 제7권4호
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• pp.73-78
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• 1998

In this paper, we have studied about the thermal expansion of the ball screw used for the CNC machine tools. The hollow ball type is used for the ball screw. We have compared the conventional cooling system and function with the improved cooling system and function which is developed the path providing cooling oil in hollow ball screw. That is the temperature variation and positioning accuracy are analyzed of the ball screw. We have obtained the following results through this experiment. 1) The improved cooling system of the hollow ball screw for CNC machine tools was developed 2) The improved cooling system of the hollow ball screw has a large effectiveness on restraining the thermal expansion of the ball screw. 3) The positioning accuracy of the ball screw was improved about 2~4$\mu$m using temperature -controlled cooling oil.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.375-380
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• 2000

The purpose of this study is to verify the relations with the fatigue life and stress distribution on the screw thread for thoracic and lumbar spine. These screws are now developed for Korean in this research group. The fatigue life of single screw was found longer than that of up-left-screw, but shorter than that of up-right-screw. The fatigue life of screw used was associated with the angie between bending and thread direction. In the case of upper left and right screw were fractured in the region of one pitch and two pitch of the thread valley from the shank of pedicle screw, respectively.

• 한국공작기계학회논문집
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• 제11권6호
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• pp.24-30
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• 2002

The friction/wear testing has been carried out for investigating the tribological characteristics between a conventional screw and tribotreated one. The tribotreated screw is manufactured by blasting a fine polymer power to the heat-treated surface of the conventional screw. The injection molding pressure that is developed between the screw and the cylinder has been applied to the rubbing surface on the specimen in a pin-on-disk wear tester. The measured results show that the friction coefficient and wear rate of a tribotreated screw are relatively low compared with the conventional one. This means that the tribotreated screw may be recommended for using an injection mold machine.