• Special Issue of the Society of Naval Architects of Korea
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• 2013.12a
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• pp.81-84
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• 2013

일반적인 Bulk carrier는 Single deck, Double bottom, Hopper side tank, Top side tank와 함께 Single side skin 또는 Double side skin으로 구성되어 Single hull bulk carrier 또는 Double hull bulk carrier라 불린다. 본 논문의 연구선박인 Double hull bulk carrier는 CSR에서 규정짓고 있는 Double hull bulk carrier의 특징 중 Hopper side tank가 없기에 일반적인 Double hull bulk carrier와는 다른 구조를 가진다. 구조적 특징으로는 Inner bottom과 Inner hull 연결부위에 응력 집중 발생, Side shell의 Shear에 대해 구조적 안전성, Double hull에 대한 CSR for bulk carrier의 Rule적용 여부에 대한 판단 등이 있다. 따라서 본 연구에서는 Double hull bulk carrier의 구조적 특징과 구조해석을 통한 응력 집중 부위의 평가 및 Fatigue analysis을 통한 피로수명을 계산하여 이를 통해 구조의 안전성을 살펴보고자 한다.

• Journal of Power System Engineering
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• v.9 no.2
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• pp.106-111
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• 2005

After many casualties of conventional bulk carriers in recent years, a double hull bulk carrier was proposed to enhance the structural safety of a side shell and a transverse bulkhead. In this paper, two alternative structural designs of a double hull bulk carrier were carried out based on the Lloyd's rule. One has the double sided hull with longitudinal stiffeners and the other has that with a girder. The final structural design was examined in comparison with an existing single hull bulk carrier from the viewpoints of cargo hold capacity and the increases of weight and construction cost. Generally, the construction cost of a ship consists of the costs of material, labor and overhead cost. But, in this study, the relative construction cost concept was introduced to compare the economical validity more precisely. In this concept, fixed overhead cost is excluded in the assessment of construction cost, and only the variable overhead cost is added up to labor cost. As the result of this study, a double hull bulk carrier can be constructed within 1% increase of weight and construction cost.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.303-310
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• 2002

After many casualties with conventional bulk carriers in recent years, double hull bulk carrier was proposed to enhance the structural safety of side shell and transverse bulkhead. In this paper, two alternative structural designs of double hull bulk carrier were executed based on the Lloyd's rule, and the results were examined in comparison with the existing single hull bulk carrier in the viewpoints of the increase of weight and construction cost. The relative construction concept was used to certify the economical validity of double hull bulk carrier.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.56-60
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• 2002

After many casualties with conventional bulk carriers in recent years, double hull bulk carrier was proposed ta enhance the structural safety of side shell and transverse bulkhead. In this paper, two alternative structural designs of double hull bulk camel were executed based an the Lloyd's rule, and the results were examined in comparison with the existing single hull bulk carrier in the viewpoints of the increase of weight and construction cost. The relative construction concept was used to certify the economical validity of double hull bulk carrier.

• Journal of Welding and Joining
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• v.16 no.5
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• pp.30-38
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• 1998

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.388-389
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• 2018

최근 차량용 인버터의 소형화 문제가 대두되고 있는 가운데, 3상 인버터의 구성품인 DC 링크 커패시터와 방열 시스템은 인버터에서 큰 부피를 차지하고 있다. DC 링크 커패시터의 부피는 커패시터에 흐르는 전류에 의해 결정되므로, 커패시터의 RMS 전류를 저감하는 것이 중요하다. 또한, 인버터의 스위칭 손실을 저감하면 방열 시스템의 크기를 줄일 수 있다. 본 논문에서는 추가적인 하드웨어 없이 PWM 방식 변경만으로 DC 링크 커패시터 RMS 전류와 스위칭 손실을 저감할 수 있는 Extended Double Carrier PWM을 소개한다. 또한, PSIM 시뮬레이션으로 이를 영구자석 동기 전동기의 구동에 적용하고, 기존에 널리 쓰이는 방식인 Space Vector PWM 및 Discontinuous PWM과 비교하여 그 특성을 살펴본다.

• Special Issue of the Society of Naval Architects of Korea
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• 2009.09a
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• pp.87-92
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• 2009

CSR for bulk carrier has been required 25 years operation life in North Atlantic condition. As the fatigue life requirement of ship structure is increased it is necessary to study to satisfy the fatigue life which is much severe. Therefore from the fatigue analysis, especially fatigue strength for double bottom & lower stool connection area is not enough. To satisfy the fatigue life, it needs to increase double bottom strength or insert thicker plate. In this study, the consideration though structure modification have been doe with 81K bulk carrier and to find the solution of fatigue problem.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1338-1341
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• 1997

In this paper, we propose angular rate computation algorithm using GPS carrier phase. A direct angylar rate masurement has not previously been available form GRS, although its availability is highly desirable for use in state feedback control. So we propose angular rate computationalgorithm which derive angular rate from the velocity of differentiated carrier phase og GPS. The proposed algorithm contains attitude determination using double-differentiated carrier phase and 2 baseline configuration whcih provide more practical applications than 3 baseline.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.9
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• pp.974-982
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• 2009

Photomixing techniques beating two optical signals with different wavelengths and strong correlations are also very useful techniques to make a continuous wave(CW) signals in the range of millimeter(mm) and terahertz(THz) frequencies. An optical double sideband-suppressed carrier(DSB-SC) technique is one of the popular techniques to generate two optical signals with different wavelengths and strong correlations. DSB-SC signals with strong correlations are generated by a CW modulation of an optical carrier with a local oscillator and an optical modulator. In the previous parers related the DSB-SC for producing the CW signals within the range of mm and THz frequencies, there have been no reports why the optical carrier should suppress. In order to clear that, we have analyzed and measured the characteristics of the mm-wave CW signals made by the DSB-SC photomixing in this paper. From our analysis and measurement results, compared with the case of the DSB with the maximized optical carrier, the power and phase noise have improved about 23.9 dB and 21 dBc/Hz(@ 1 MHz offset frequency) in the case of the DSB with the minimized optical carrier (that is to say, the DSB-SC). Consequently, it is evident reason that the optical carrier should sufficiently suppress to obtain the mm-wave CW signals with the high power and low noise. This paper has given very helpful data to make mm- and THz-wave CW signals using photomixing techniques with the DSB-SC because the reason why the optical carrier should be suppressed is reported in this paper based on the numerical and experimental results.

• Journal of the Korean Graphic Arts Communication Society
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• v.9 no.1
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• pp.27-44
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• 1991

In this research, double-layered photoconductor consist of the carrier generation layer(CGL) of ${\varepsilon}$ type copper phthalocyanine thin film by an aqueous coating method and the carrier transport layer(CGL) of polyvinyl carbazol(PVK) by spin coating. We inverstigated effect of the surfactant solution and cathod electrolysis to the crystal type of ${\varepsilon}$-CuPc in CGL with TEM, SEM and X-ray diffraction spectroscopy and studied the mechanism of an aqueous coating for the preparation of CGL. The effect of the washing of CGL about the electrophotographic characteristics of the ${\varepsilon}$-CUPC/PVK double-layered photoconductors is studied also.