• International Journal of Precision Engineering and Manufacturing
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• 제3권3호
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• pp.50-55
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• 2002

A roller gear cam mechanism is presented. It consists of two or more plate cams with particular teeth, called Conjugate Cam Tooth (CCT) and a turret with axially located rollers. A practical and available configuration has been found out by synthesizing its parameters. The profile equations of the conjugate cam are derived by using a relative velocity method. A program fur the design automation of shape of the conjugate cam and the motion simulation of this kind of mechanism has been deve1oped using the derived formulae with C++ language. Finally, an example is given.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.150-153
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• 1997

In this paper, a control and data analysis S/W of a dedicated measuring machine for cams is developed. A rotary encoder is employed to measure the angular displacement of the motor, and a linear scale does the linear displacement of the prove. The design and measuring data are interpolated by cubic spline curves respectively to compute the error which is defined by the maximum distance between two curves. Further, optimization module to find the exact error is also developed to remove the error occurred due initial measuring position. The developed system takes only 6 minutes to measure the cam and to analyze the measuring data while the CMM takes about 1 hours even with a skilled operator.

• 대한임베디드공학회논문지
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• 제3권3호
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• pp.151-157
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• 2008

In this paper, we propose a three dimensional distance measurement method for a stereo system by using web cams. Using a parallel stereo system, a robot gets two images from each webcam and equalize brightness of both images. And we suggest an image processing method such as labeling, isolating an object from background and finding center of an object. We also propose a method of calculating the focal distance by using least square algorithm based on triangulation and we can reduce calculation error by this method. From experimental results, we show that the proposed method can be effective for 3D distance measurement.

• International Journal of Precision Engineering and Manufacturing
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• 제5권4호
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• pp.21-27
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• 2004

In this paper, data acquisition and analysis of a measuring machine for marine engine's cams are discussed. A rotary encoder and linear scale of the machine to measure angular and linear displacement, respectively, are interfaced to the PC via an encoder board with 2 channels. The design and measuring data are interpolated by cubic spline curves to compute the precision error which is defined by the maximum and minimum distances between two curves. The minimum zone fit of ISO is employed to evaluate the geometric deviation. The developed system takes only 5 minutes to measure and analyze the precision error while the CMM takes over I hours even with a skilled operator.

• 한국기계가공학회지
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• 제5권3호
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• pp.80-85
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• 2006

In an effort to reduce the evaluation time of the precision of manufactured disk cams, an effective measuring method with an exclusively built profile-measuring machine and subsequent data analysis procedure is proposed. The design and measuring data are interpolated by cubic spline curves to compute the precision error which is defined by the maximum and minimum distances between two curves. The minimum zone criterion of ISO is employed to evaluate the form error, and genetic algorithm is used to search the orientation and location of design data for the measured data which minimizes the form error. The proposed system was applied to marine engine cams, and it shows that the form error is reduced to 30% down compared with the method which minimizes the form error with the assumption that the centers of measured data design cam curve are identical.

• 한국기록관리학회지
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• 제18권3호
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• pp.49-70
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• 2018

본 연구에서는 기존의 기록관리시스템, 영구기록관리시스템, 중앙영구기록관리시스템을 국가기록 클라우드로 통합하기 위한 클라우드 시스템 모델을 제시하였다. 또한 중앙영구기록관리시스템을 포함한 영구기록관리시스템을 클라우드 환경으로 전환하기 위한 구체적인 방안을 연구하였다. 국가기록 관련 시스템들을 하나의 클라우드 기반으로 통합하여 정보자원의 공유 활용 및 운영 관리 효율성 제고, 비용 절감을 도모하기 위한 클라우드 시스템 설계 전략 및 목표 모델을 도출하고, 특히 영구기록관리시스템의 단계적인 클라우드 구축 방안을 제시하였다. 또한, 클라우드 환경에서 노출되는 기술적 보안과 운영적 보안 사항을 분석하고 이를 해결하기 위한 방안도 제안하였다. 결과적으로 클라우드 기술을 도입하여 저비용 고효율 등의 효과를 볼 수 있고, 현용-준현용-비현용 단계에서의 업무 연속성을 높일 수 있는 설계가 가능하다.

• BMB Reports
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• 제46권5호
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• pp.276-281
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• 2013

In this study, we aimed to compare the morphogenetic and neuronal characteristics between monolayer cells and spheroids. For this purpose, we established spheroid formation by growing SH-SY5Y cells on the hydrophobic surfaces of thermally-collapsed elastin-like polypeptide. After 4 days of culture, the relative proliferation of the cells within spheroids was approximately 92% of the values for monolayer cultures. As measured by quantitative assays for mRNA and protein expressions, the production of synaptophysin and neuronspecific enolase (NSE) as well as the contents of cell adhesion molecules (CAMs) and extracellular matrix (ECM) proteins are much higher in spheroids than in monolayer cells. Under the all-trans-retinoic acid (RA)-induced differentiation condition, spheroids extended neurites and further up-regulated the expression of synaptophysin, NSE, CAMs, and ECM proteins. Our data indicate that RA-differentiated SH-SY5Y neurospheroids are functionally matured neuronal architectures.

• 한국공작기계학회논문집
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• 제14권2호
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• pp.83-90
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• 2005

A mirror cam mechanism a kind of conjugate cam mechanism consists of two cams, two rollers, and two links. Since profiles of two mirror cam are identical, a simultaneous machining of two cams is achievable. Some machining errors on cam profiles do not result in the internal acting force, which often causes problems in high speed cam mechanism between two links. Also, since angular accelerations of two links are same, the internal acting force by the difference of the angular accelerations does not occur in the mechanism. Thus the mirror cam mechanism is very useful in high speed machinery. This paper studies a design method as well as a machining method, and develops an exclusive CAD/CAM software for mirror cam profiles. The developed CAD/CAM software is applied to a typical mirror cam mechanism and a mock-up equipment is built in order to test the machinism mirror cm. Experimental investigations show that the contact between cam surface and roller surface according to cam rotation agrees well with the simulation on the developed CAD/CAM software.

• 한국융합학회논문지
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• 제8권10호
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• pp.193-199
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• 2017

기계적 태핏은 유압 태핏과 비교하여 원가와 마찰 손실을 줄일 수 있어 사용된다. 그러나 기계적 태핏은 캠과 밸브 사이의 간극을 조절하는 기능이 없으므로 밸브의 열팽창을 고려하여 캠과 밸브 사이의 거리를 측정하여 선정된다. 그러므로 충분한 워밍 업 후에는 밸브 간극이 거의 없지만 그 전에는 밸브 간극이 존재한다. 특히 냉간 작동 조건에서는 비교적 큰 편이고 소음과 진동 같은 문제를 발생시킬 수 있다. 본 논문에서는 밸브 간극을 변경시켜 가며 각각의 조건에서의 밸브 리프트, 속도, 가속도, 시팅 속도, 바운싱 높이 등에 대하여 시험과 해석을 통하여 연구되었다. 밸브 간극이 증가할수록 램프 구간이 감소하게 되어 밸브의 거동에 좋지 않은 영향을 미치는 것을 확인할 수 있었다.

• 한국동물위생학회지
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• 제17권3호
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• pp.167-173
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• 1994

This study were performed to distribution of dermatophytes isolated from pet dogs in Pusan area and pathogenicity of the isolates. During the period from March 1993. to April 1994, 201 pet dogs of house breeding were examined. The result of obtained were summarized as followes； 1. Isolation rate of dermatophytes were 4.7%(7/149) in no lesion and 23.1%(12/52) in lesion of dog's skin. 2. According to breeding conditions, isolation rate of dermatophytes were 1) 3.8% in no lesion and indoor breeding, 2) 16.7% in lesion and indoor breeding, 3) 13.5% no lesion and outdoor breeding, and 4) 37.5% in lesion and outdoor bleeding. 3. Among the 201 Pet dogs, 16 strains of M. cams(84.2%), 1 of M. gypseum(5.3%), and 2 of T. mentagrophytes (10.5%) were isolated. 4. For Pathogenicity test, one strain of each M. canis, M, gypseum, T. mentagrophytes isolated from skin lesions were inoculated to the skin of the posterior back of guinea pigs. All of dermatophytes tested were induced skin lesions. Among them, M. cams and T. mentagrophytes were more virulent than M. gypseum.