• Journal of Ocean Engineering and Technology
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• v.32 no.2
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• pp.77-83
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• 2018

In this study, a series of experiments were performed to investigate the variations in the behavior of green water generation and the flow kinematics of bubbly flow on deck with various flare angles. The experiments were conducted in a 2-D wave flume using a simplified model of a BW Pioneer FPSO operating in the Gulf of Mexico, with a 100-year return period wave condition. The green water phenomena were captured with a high speed CCD camera. The variations in the behavior of the green water generation were investigated with various flare angles, and the horizontal mean velocity profiles of bubbly flow on deck obtained using bubble image velocimetry (BIV) were provided. The differences in flow kinematics of bubbly flow on deck were analyzed with various flare angles.

• Journal of Ocean Engineering and Technology
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• v.26 no.4
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• pp.15-22
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• 2012

In this research, the relationship between the bow shape and green water phenomenon on the bow deck of an FPSO was studied using an experimental method. A 140,000 DWT FPSO was used as the objective hull form in the present research. The incident waves were regular types. The heights were 1.0 and 1.5 times the freeboard, and the length was equal in size to LBP. The wave heights and pressures on the deck were measured in experiments. Model tests were performed to determine the effects of bow flare angles, bow shapes, and a forecastle deck. The free heave and pitch conditions were applied to the models in these experiments. From the results of the model tests, an optimized bow shape was designed, which was found to decrease the green water impact loading. The results of this research could be used as fundamental data in the design of a bow shape.

• Microbiology and Biotechnology Letters
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• v.37 no.4
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• pp.306-315
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• 2009

Due to the depleting petroleum reserve, recurring energy crisis, and global warming, it is necessary to study the development of white biotech-based aromatic chemical feedstock from renewable biomass for replacing petroleum-based one. In particular, the production of aromatic intermediates and derivatives in biosynthetic pathway of aromatic amino acids from glucose might be replaced by the production of petrochemical-based aromatic chemical feedstock including benzene-derived aromatic compounds. In this review, I briefly described the production technology for hydroquinone, catechol, adipic acid, shikimic acid, gallic acid, pyrogallol, vanillin, p-hydroxycinnamic acid, p-hydroxystyrene, p-hydroxybenzoic acid, indigo, and indole 3-acetic acid using metabolic engineering, bioconversion, and chemical process. The problems and possible solutions regarding development of production technology for competitive white biotech-based aromatic compounds were also discussed.

• Proceedings of the Korean Society of Computer Information Conference
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• 2015.01a
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• pp.89-92
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• 2015

최근 국내 유제품 수요는 인구의 고령화, 학교급식 소비의 감소, 대체음료 시장의 성장 그리고 출산율 저하라는 여러 가지 영향에 기인하여 줄고 있다. 반대로 수입 유제품의 수요, 특히 치즈에 있어서는 눈에 띄는 성장을 보여 국내 낙농업 시장은 안타까운 실정이다. 뿐만 아니라 공급에 있어서는 계절적인 원유 수급불안 현상, 수입증가, 농가이탈에 의한 생산기반의 위축으로 인해 안정적으로 국내 낙농업 시장의 활성화가 필요한 시점이다. 이 논문에서는 낙농가에서 가장 중요한 젖소의 건강 관리(발정기, 맥박감지)를 통합해 유량을 늘리는 방안을 제시하여 낙농업계의 활성화를 목표로 한다.

• The KSFM Journal of Fluid Machinery
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• v.14 no.5
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• pp.12-17
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• 2011

The seawater lift pump system is responsible for maintaining the open canal level to provide the suction flow of circulating water pump at the set point. The objective of this paper is to design a 2-stage mixed flow pump (for seawater lifting) by inverse design method and to evaluate the overall performance and the local flow fields of the pump by using a commercial CFD code. Rotating speed of the impeller is 1,750 rpm with the flow rate of 2,700 $m^3$/h. Finite volume method with structured mesh and realized k-${\varepsilon}$ turbulent model is used to guaranty more accurate prediction of turbulent flow in the pump impeller. The numerical results such as static head, brake horse power and efficiency of the mixed flow pump are compared with the design data. The simulated results are good agreement with the design data less 3% error.

• Korean Chemical Engineering Research
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• v.44 no.4
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• pp.329-339
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• 2006

The production of lower olefins from methanol becomes an attractive process because of the rapid increase in crude oil price. This paper reivews the conversion mechanisms of methanol to hydrocarbons over zeolite and SAPO molecular sieve catalysts to understand the formation steps of lower olefins from methanol. The feasibility of the conversion mechanisms such as the direct mechanism based on well-defined intermediates and the hydrocarbon pool mechanism involving hydrocarbon moieties as an active centers is discussed with reepect to the induction period, the selectivity for products and the deactivation phenomena of the methanol conversion. The literature appeered since 1999 for the structure of the hydrocarbon pool and its catalytic role in the methanol conversion are summariged, and the prospect for the methanol-to-olefins process is described.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.26 no.3
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• pp.298-307
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• 2016

In the building process of FPSOs(floating production, storage and offloading units) is the increasing demand of high performance piping joints that can be installed on its turret system and maintain smooth and long-term flow of ultra-high pressure crude oil, being subjected to external excitations such as wind and wave on the sea. Following such a trend, in this paper, a new-type piping joint of four effective degrees of freedom has been designed, and its dynamic characteristics predicted through mathematical modeling and computer simulations. Moreover, via an example it was shown how the yaw motion in particular can be independently controlled for future durability test despite strong kinetic couplings.

• Korean Journal of Animal Reproduction
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• v.21 no.1
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• pp.9-18
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• 1997

These studies were carried out to establish an effective and practical system for commercialization of embryo production techniques by analyzing several factors influencing in vivo embryo production in Korean native cattle. In vivo embryos were flushed 226 times from 128 donors. The results obtained in studies on the factors influencing in vivo embryo production were as follows : 1. There were no significant differences in the number of total recovered, fertilized, transferable and freezable embryos among the hormone doses(FSH-P, 28∼34mg; SUPER-OV, 75IU) used for superovulation. However, over 30mg doses of FSH-P showed a slightly higher effect than others. 2. There were slight decrease in the number of fertilized, transferable and freezable embryos in 3 times repeated superovulation. But there were no significant differences among 1, 2 and 3 times repeated superovulations. 3. Age of donors did not affect the number of transferable and freezable embryos, but the number of fertilzed embryos were highest in 2∼3 years old donors and were lowest in 8∼9 years old donors(P<0.05). 4. Season had a significant effect on the production of embryos(P<0.05). the embryo production, and the number of fertilized, transferable and freezable embryos were most effective in summer and follow by spring, autumn and winter. 5. The number of transferable and freezable embryos was highest in donors flushed at 7∼8 days after estrus(P<0.05).

• Journal of the Society of Naval Architects of Korea
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• v.52 no.1
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• pp.77-87
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• 2015

For a floating offshore plant such as FPSO(Floating, Production, Storage, and Off-loading unit), various equipment should be installed in the restricted space, as compared with an onshore plant. The requirement for an optimal layout method of the plant has been increased in these days. Thus, a layout method of the floating offshore plant was proposed in this study. For this, an optimization problem for layout design was mathematically formulated, and then an optimization algorithm based on the genetic algorithm was implemented with C++ language in order to solve it. Finally, the proposed method was applied to an example of FPSO topsides. As a result, it was shown that the proposed method can be applied to layout design of the floating offshore plant such as FPSO.

• Journal of the Society of Naval Architects of Korea
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• v.50 no.5
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• pp.273-281
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• 2013

In this paper, the effects of bow deck shape on the green water are studied by numerical and experimental method. Varying the deck shapes to triangular, elliptic and circular, the thickness and advancing velocity of green water leading edge are compared using numerical method. Also the motion, the pressure on the vertical wall and the height on the deck of green water are compared among the three bow deck shapes in the heave and pitch motion free condition by experimental method. To remove the effects of the difference of motions among the deck shapes, numerical simulations are performed varying the deck shape with the same motion. In the same motion condition, smallest impulsive pressure occurred in the condition of elliptic deck shape.