• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.67-68
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• 2009

In this study, we studied the nature of thin films formed by photodoping chalcogenide materials with for use in programmable metallization cell devices, a type of ReRAM. We investigated the resistance of Ag-doped chalcogenide thin films varied in the applied voltage bias direction from about $1\;M{\Omega}$ to several hundreds of $\Omega$. As a result of these resistance change effects, it was found that these effects agreed with PMC-RAM. The results imply that a Ag-rich phase separates owing to the reaction of Ag with free atoms from the chalcogenide materials.

• 한국자동차공학회논문집
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• 제10권1호
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• pp.9-16
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• 2002

The particles velocity in the instantaneous flow field and velocity change of particles along the jet centerline for various particle diameter in a circular turbulent impingement jet are investigated by using particle image velocimetry(PIV) and an equation of particle motion simplified by terms of inertia forces, drag and gravitational force. The jet Reynolds number was 3300 and 8700, and glass beads of 30,58 and 100$\mu$m in diameter were used. The PIV results show that the direction and size of velocity depends not only on the number density of particle but also on the particle momentum. The results obtained form calculation suggest that the particle velocity near the first impingement region deviated from local air velocity, which accords well with the PIV results. The rebound height of particle increase with the particle diameter. In the second-impingement, particle velocities increased sluggishly with Re=3300 but particle velocities uniformed with Re=8700 in stagnation region.

• 열처리공학회지
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• 제20권5호
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• pp.243-249
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• 2007

The age hardening behavior and mechanical properties of an extruded Al-Zn-Mg-(Cu)-0.1 wt.%Sc alloy were investigated with the Sc addition and ageing temperature. The results showed that the $Al_3Sc$ compounds were formed by Sc addition and distributed preferentially along the extrusion direction. The age hardening of Al-Zn-Mg-Cu-0.1 wt.%Sc alloy which was treated by T6 process was more significant than that of Al-Zn-Mg-0.1 wt.%Sc alloy. The tensile property of Al-Zn-Mg-Cu+0.1 wt.%Sc alloy was also higher than that of Al-Zn-Mg-0.1 wt.%Sc alloy, which is 691 MPa and 584 MPa in strength and 9% and 11% in elongation, respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.905-907
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• 2004

This paper deals with the PM performance evaluations in a variable flux memory motor (VFMM) using a coupled finite element method (FEM) and Preisach modeling, which is presented to analyze the magnetic characteristics of permanent magnets. The focus of this paper is the operation characteristics evaluation relative to magnetizing direction and quantity of permanent magnets on re-, demagnetization condition in a variable flux memory motor(VFMM)

• 드라이브 ㆍ 컨트롤
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• 제19권1호
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• pp.1-7
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• 2022

Recently, a re-painting robot was developed to semi-automatically conduct blasting work in bridge spaces to improve work productivity and worker safety. In this study, a vision sensor-based monitoring module was developed to automatically move the re-painting robot along the path. The monitoring module provides direction information to the robot by analyzing the boundary between the painting surface and the metal surface. To stably measure images in unstable environments, various techniques for improving image visibility were applied in this study. Then, the driving performance was verified in a similar environment.

• 한국결정성장학회지
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• 제26권4호
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• pp.131-134
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• 2016

Czochralski 법으로 성장한 RE : YAG ($RE=Nd^{3+}\;,Er^{3+}\;,Yb^{3+}$) 단결정의 표면 결함을 측정하는 chemical polishing 및 etching 조건에 대하여 조사하였다. 최적의 chemical polishing 조건은 시편을 수직 방향으로 고정하고 85 % $H_3PO_4$ 용액에서 $330^{\circ}C$, 30분 동안 진행한 것이었다. 또한 최적의 chemical etching 조건은 85 % $H_3PO_4$ 용액에서 $260^{\circ}C$, 1시간 동안 진행한 것이었고, (111) 면에 $70~80{\mu}m$ 크기의 삼각형 etch pit들이 관찰되었다. 결함 밀도 분석 결과, Nd(1 %) : YAG는 $1.9{\times}10^3$개/$cm^2$, Er(7.3 %) : YAG는 $4.3{\times}10^2$개/$cm^2$, Yb(15 %) : YAG는 $5.1{\times}10^2$개/$cm^2$로 측정되었다.

• 벤처창업연구
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• 제10권6호
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• pp.235-252
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• 2015

정부는 역동적 혁신경제로 경제 대도약을 위해 선순환 벤처 창업 생태계를 구축하고 있다. 이와 같은 생태계 구축은 실패를 두려워 하지 않는 기업가정신을 지닌 우수인력의 도전적 벤처창업과 실패를 관용하고 이를 경험으로 재창업할 수 있는 사회적 환경이 마련되어야 가능하다. 정부의 벤처 창업 붐 조성 노력으로 벤처기업 및 신설법인 수 등이 매년 증가 하고 있으나, 이들 기업이 실패할 경우 재창업 등으로 재기 할 수 있는 사회적 환경 조성과 지원제도 마련의 노력은 최근에야 시작되었다. 실패기업에 대한 정확한 실태조사, 지원제도가 부족한 상황에서 본 연구는 실패한 기업에 대한 그간의 선행연구를 기반으로 국내 실패기업인의 재도전, 재창업과 관련된 현황을 파악 후 해외 선진국 사례와 국제비교를 통해 적용 가능한 정책적 시사점을 도출하여 국내 실패기업의 재창업을 원활히 할 수 있는 정책적 방향을 제시하고자 한다. 미국과 같이 실패를 성공의 한 단계로 인식하는 창업문화가 형성되기 전까지는 EU의 SBA법과 같은 재도전 정책을 지속적으로 추진할 수 있는 법적근거 마련과 일본의 민간 중심의 중소기업재생지원협의회 구성 운영을 참고할 필요가 있다. 또한 실패기업인의 삶의 질 보장도 함께 고려하는 것이 필요하다. 도출된 시사점을 바탕으로 내린 결론에 대한 추가 연구와 정부 정책이 보완된다면 국내 재창업 활성화를 위한 깊은 통찰을 제공할 수 있을 것이다.

• 의학교육논단
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• 제19권3호
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• pp.115-120
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• 2017

Despite the importance of how the premedical education curriculum is organized, the basic direction of the curriculum has not been evaluated at a fundamental level. In order to explore the basic directions of the premedical education curriculum, this study examined medical education as a university education, the historical basis of premedical education, and the direction of the premedical education curriculum. Historically, as medical education was incorporated into the university education system, premedical education developed based on basic science and liberal arts education. Accordingly, the direction of the premedical education curriculum began to split into two approaches: one believing in a basic science-based education intended to serve as the foundation of medical training, and the other believing in a liberal arts-based education intended to cultivate the qualities of a doctor. In recent years, however, the binary division in the direction of premedical education has ceased to exist, and the paradigm has now shifted to an agreement that premedical education must cultivate the basic scientific competence required for learning medical knowledge as well as the social qualities that a doctor should have, which are cultivated through the liberal arts. Furthermore, it has been asserted that the direction of premedical education should move toward the qualities that will be required in the future. With the fourth industrial revolution underway, the role of doctors is now being re-examined. This means that today's medical education must change in a future-oriented way, and the direction of the premedical education curriculum must be on the same page.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2845-2850
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• 2007

Flow-induced forces on two identical nearby circular cylinders immersed in the cross flow at Re =100 were numerically studied. We consider all possible arrangements of the two circular cylinders in terms of the distance between the two cylinders and the inclination angle with respect to the direction of the main flow. It turns out that significant changes in the characteristics of flow-induced forces are noticed depending on how the two circular cylinders are positioned, resulting in quantitative changes of force coefficients on both cylinders. Collecting all the numerical results obtained, we propose a contour diagram for drag coefficient and lift coefficient for each of the two cylinders. The perfect geometrical symmetry implied in the flow configuration allows one to use those diagrams to estimate flow-induced forces on two identical circular cylinders arbitrarily positioned in physical space with respect to the main flow direction.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2890-2895
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• 2007

Heat transfer on two identical nearby circular cylinders immersed in the uniform cross flow at Re = 100 and Pr = 7.0 was numerically studied. We consider all possible arrangements of the two circular cylinders in terms of the distance between the two cylinders and the inclination angle with respect to the direction of the main flow. It turns out that significant changes in the characteristics of heat transfer are noticed depending on how the two circular cylinders are positioned, resulting in quantitative changes of heat transfer coefficients on both cylinders. Collecting all the numerical results obtained, we propose a contour diagram for averaged Nusselt number for each of the two cylinders. The perfect geometrical symmetry implied in the flow configuration allows one to use those diagrams to estimate heat transfer rates on two identical circular cylinders arbitrarily positioned in physical space with respect to the main flow direction.