• 한국의학물리학회지:의학물리
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• 제13권2호
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• pp.69-73
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• 2002

본 연구는 제작된 평행평판형 검출기에서 두 전극간의 거리에 따른 극성효과의 정도를 확인하기 위하여 실행되었다. 개발된 전리함의 극성효과를 측정하기 위하여 평행평판형 전리함의 윗면과 아래 면의 전극에 극성을 바꾸어가며 방사선을 조사하고 그에 의하여 생성된 전하를 측정하여 두 양을 비교하였다. 실험은 두 전극간의 거리가 3, 6, 10 mm 일 때 각각의 명목상 체적이 0.9, 1.9, 3.1 cc인 평행평판형 전리함에 대하여 실행하였다. 조사된 방사선은 6, 10 MV 광자선과 4, 6, 9, 12, 16 MeV의 전자선이며, SSD는 100 cm 이었고, 조사면 크기는 광자선의 경우는 10$\times$10 ㎤ 이고 전자선의 경우는 10$\times$10 $\textrm{cm}^2$을 사용하였으며, 측정점은 최대선량점이고, 선량률은 240 MU/min 으로 하였다. 평행평판형 전리함의 극성의 변환은 평행평판형 전리함의 윗면 즉, 방사선이 입사되는 면의 전극이 (+)극을 갖고 아래 면이 (-)극을 갖는 positive와 방사선이 입사되는 면의 전극이 (-)극을 갖고 아래 면이 (+)극을 갖게 되는 negative 측정으로 시행하였다. 실험결과는 광자선의 경우는 0.5 % 이내의 극성효과를 나타냈고, 전자선의 경우는 1% 에서 3.5% 까지 나타났으며, 높은 에너지를 갖는 16 MeV 전자선의 경우가 다른 에너지의 전자선의 경우 보다 극성효과의 영향이 적음을 알 수 있다.

• The Journal of the Acoustical Society of Korea
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• 제14권2E호
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• pp.25-32
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• 1995

단어인식의 성능향상을 위하여 평행분기 음성단위(subunit) 모델의 사용을 제안하였으며 연속 분포 HMM에서 이 모델은 각 음성단위를 확률분포함수 (mixture components)를 이용하여 분기시킴에 의해 얻어진다. 제안된 방법을 사용한 결과에 따르면 기존에 제안된 평행분기 [1] 음성단위 모델이나 단일분기 모델보다 높은 인식률을 얻을 수 있었다. 본 연구에서는 각 음성단위에 대해 활률분포함수나 분기수의 적절한 결합을 통해 높은 인식률을 얻는데 이 1036 한국어 결리단어가 인시실험에 사용되었다.

• Design & Manufacturing
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• 제2권4호
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• pp.54-61
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• 2008

Warpage, which is one of the molding trouble, acts as possible factor which results in defect in assembly. In this study, a mold was designed to produce specimens with rib parallel to flow direction, specimens with rib perpendicular to flow direction and specimens without rib. This work researched change of warpage according to injection molding condition such as injection pressure, packing pressure, packing time, resin temperature, mold temperature in non-crystalline resins(PC, ABS), crystalline resins(PP, PA66), and 30% glass fiber reinforced-resins(PC, ABS, PP, PA66).Specimens with rib and Crystalline resins show more warpage than specimens without rib and non-crystalline resins, respectively. Glass fiber reinforced-resins and specimens with rib parallel to flow direction show smaller warpage than conventional resins and specimens with rib perpendicular to flow, respectively. Specimens with rib and specimens without rib show reduced warpage as packing time increases. In addition, warpage increase as resin temperature increases. It is found that CAE shows similar tendency with experiment as packing time, resin temperature. when the rib is caused, warpage will reduce and prevent the transformation. product of a irregular form occurs warpage. In the study It'll be basic data that product occurs warpage, preferablity.

• 한국건설관리학회논문집
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• 제22권6호
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• pp.131-137
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• 2021

철도 운행선 변경작업은 정해진 시간 내에 많은 자원이 투입되기 때문에 구체적인 작업계획과 안전관리가 중요하다. 이러한 이유로 작업일정을 사전에 공유하여 궤도, 전차선, 신호 등 철도시스템이 동시에 병행 작업을 하고 있다. 그러나 절체공사의 특성상 철도 운행이 종료되는 야간시간에 공사가 진행되고, 운행선의 한정된 구간에 많은 자원이 투입되기 때문에 안전사고의 발생 및 운행선 변경의 실패에 대한 리스크(Risk)가 높은 것으로 인식되고 있다. 그럼에도 불구하고 아직까지 운행선 변경 공사와 관련하여 국내에 충분한 연구가 이루어져 있지 않은 실정이다. 따라서 본 연구는 운행선 변경작업에 대해 실무자를 대상으로 설문조사를 실시하였고, 설문의 결과를 분석하여 운행선 변경작업의 리스크 저감을 위한 표준작업 프로세스를 도출하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 춘계학술대회 논문집
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• pp.395-400
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• 1994

Most of Commercial Remote Center Compliance(RCC) devices have been designed using deformable structures. In this work, we propose another type of assembly devices which generate the compliance effects by attaching the compliances (or spring) at the joints of the given mechainsm. The compliance models are derived for a serial-type, parallel-type, and hybrid-type mechanisms, respectively. In particular, a planar three-degree of freedom parallel structure is shown to have RCC points at the center of the workspace for its symmetric configuratings.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제34회 춘계학술대회논문집
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• pp.335-338
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• 2010

A recent study for tracing the profiles of supersonic axisymmetric Minimum Length Nozzle with uniform and parallel flow at the exit section, the stagnation temperature is taken into account. The aim of this work is to add optimization algorithm to the supersonic nozzle design in order to get the optimum nozzle shape. The comparisons of the nozzle contours based on the method of characteristics are presented. The specific heats and their ratio vary with the stagnation temperature when this temperature of a perfect gas increases. An application is made for air in a supersonic nozzle.

• Wind and Structures
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• 제30권6호
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• pp.633-648
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• 2020

The objective of this work was to investigate the interference effects of two-parallel bridge decks on aerodynamic coefficients, vortex-induced vibration, flutter instability and flutter derivatives. The two bridges have significant difference in cross-sections, dynamic properties, and flutter speeds of each isolate bridge. The aerodynamic static tests and aeroelastic tests were performed in TU-AIT boundary layer wind tunnel in Thammasat University (Thailand) with sectional models in a 1:90 scale. Three configuration cases, including the new bridge stand-alone (case 1), the upstream new bridge and downstream existing bridge (case 2), and the downstream new bridge and the upstream existing bridge (case 3), were selected in this study. The covariance-driven stochastic subspace identification technique (SSI-COV) was applied to identify aerodynamic parameters (i.e., natural frequency, structural damping and state space matrix) of the decks. The results showed that, interference effects of two bridges decks on aerodynamic coefficients result in the slightly reduction of the drag coefficient of case 2 and 3 when compared with case 1. The two parallel configurations of the bridge result in vortex-induced vibrations (VIV) and significantly lower the flutter speed compared with the new bridge alone. The huge torsional motion from upstream new bridge (case 2) generated turbulent wakes flow and resulted in vertical aerodynamic damping H1^* of existing bridge becomes zero at wind speed of 72.01 m/s. In this case, the downstream existing bridge was subjected to galloping oscillation induced by the turbulent wake of upstream new bridge. The new bridge also results in significant reduction of the flutter speed of existing bridge from the 128.29 m/s flutter speed of the isolated existing bridge to the 75.35 m/s flutter speed of downstream existing bridge.

• 실천공학교육논문지
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• 제14권2호
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• pp.377-385
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• 2022

산학협력의 한가지 방법으로 산업사회의 요구에 부응하는 인력 양성을 위한 계약학과는 도입된 지 20년이 가까워지고 있다. 특히 중소기업의 인력육성 지원정책의 일환으로 계약학과에 대한 관심이 새 정부 들어서 더욱 증가하고 있어 당분간 신설되는 계약학과 또한 늘어날 것으로 예상된다. 학습자 유형과 계약 방식에 따른 계약 학과별 특성을 파악하고 중소기업에 적합한 재교육형, 3자계약방식 계약학과의 신설에 따른 절차와 고려사항에 대해 제안하고자 한다. 특히 공급자인 운영기관의 입장과 수요자인 다수의 기업의 요구사항을 조화롭게 반영하여 선 순환되는 구조가 되도록 교과과정을 설계하는 방법에 대해 K 대학 사례를 들어 제시하고자 한다.

• International Journal of Advanced Culture Technology
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• 제12권2호
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• pp.136-143
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• 2024

The purpose of this study is to analyze the mediating effects of major satisfaction, positive psychological capital, and job-Seeking Stress in the relationship between college students' self-directed learning and career preparation behavior. For this purpose, the study was conducted on 253 college students. The parallel mediation effect was analyzed using SPSS (24.0). Process Macro and Bootstrapping. The following results were confirmed. First, self-directed learning, major satisfaction, positive psychological capital, job-Seeking stress, and career preparation behavior were found to have a mutually significant influence relationship. Second, in the relationship between self-directed learning and career preparation behavior, major satisfaction, positive psychological capital, and job-seeking stress were confirmed to be variables that affect the parallel mediation effect and serial multiple mediation effect.Third, college students' self-directed learning was found to increase career preparation behavior through the mediating roles of major satisfaction, positive psychological capital, and employment stress. Therefore, in order to increase the career outcomes and success rates of college students, their own efforts, professors, and schools must create diverse environments and develop programs for college students' careers. Additionally, follow-up research must continue to supplement this.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2001년도 추계학술대회 논문집
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• pp.25-28
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• 2001

Today enterprises are bringing forward the strong needs for the Global Work Space that is able to realize the collaboration of the virtual enterprise in order to achieve the rapid entrance to market, the quality improvement as well as the cost reduction of their new products. Especially, they are building the efficient Product Management Infrastructure in parallel with the real-time knowledge management for the information generated in the course of a product lifecycle and the Process Innovation making the Concurrent Engineering possible. Building a system in the web environment cannot be the entire effort to realize the Global Work Space within an enterprise that is an essential factor for the reduction of a product development period which in turn contributes to Time to Market. Various work models and processes are found in enterprises and many different application programs are developed and utilized to support these. This study proposes a scheme for the optimized Collaborative Workflow System Architecture that is able to take in and apply various application programs accompanied by the product development work process. Through this, we are to examine various limits and problems existing in the real-time collaborative system between enterprises and to reform these.