• International Journal of Naval Architecture and Ocean Engineering
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• 제6권4호
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• pp.1182-1196
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• 2014

In problems of global hydroelastic ship response in severe seas including the whipping problem, we need to know the hydrodynamic forces acting on the ship hull during almost arbitrary ship motions. In terms of ship sections, some of them can enter water but others exit from water. Computations of nonlinear free surface flows, pressure distributions and hydrodynamic forces in parallel with the computations of the ship motions including elastic vibrations of the ship hull are time consuming and are suitable only for research purposes but not for practical calculations. In this paper, it is shown that the slamming forces can be decomposed in two components within three semi-analytical models of water entry. Only heave motion is considered. The first component is proportional to the entry speed squared and the second one to the body acceleration. The coefficients in these two components are functions of the penetration depth only and can be precomputed for given shape of the body. During the exit stage the hydrodynamic force is proportional to the acceleration of the body and independent of the body shape for bodies with small deadrise angles.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권4호
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• pp.1024-1040
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• 2014

The theoretical background and a numerical solution procedure for a time domain hydroelastic code are presented in this paper. The code combines a VOF-based free surface flow solver with a flexible body motion solver where the body linear elastic deformation is described by a modal superposition of dry mode shapes expressed in a local floating frame of reference. These mode shapes can be obtained from any finite element code. The floating frame undergoes a pseudo rigid-body motion which allows for a large rigid body translation and rotation and fully preserves the coupling with the local structural deformation. The formulation relies on the ability of the flow solver to provide the total fluid action on the body including e.g. the viscous forces, hydrostatic and hydrodynamic forces, slamming forces and the fluid damping. A numerical simulation of a flexible barge is provided and compared to experiments to show that the VOF-based flow solver has this ability and the code has the potential to predict the global hydroelastic responses accurately.

• 한국식품과학회지
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• 제36권5호
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• pp.728-732
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• 2004

본 연구에서는 난백의 거품형성능력 및 안정성을 간편하게 평가하기 위한 표준방법을 제시하고자 시료의 양, whipping 속도 및 시간이 거품형성에 미치는 영향을 조사하고 적합한 거품형성조건을 선정하였다. 선정된 조건(시료량 70g, 1,200rpm, 2분)으로 난백의 거품형성능력 및 안정성을 20회 반복 측정하여 평가한 결과 높은 재현성을 나타내었으며 시료의 변화(신선한 난백, 동결건조 난백분말, 상업용 난백분말) 및 계란의 저장기간에 따른 거품형성능력 및 안정성의 유의적 차이를 효과적으로 구별할 수 있었다.

• 복식문화연구
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• 제21권6호
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• pp.844-859
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• 2013

This study investigated the characteristics and changes of cotton and silk textile production in Honam district, especially in Gurye, Jella Province from the 1930s to the 1980s. To do this, research method in this study was both literature and fieldwork research and results were as follows. First, in terms of cotton fiber cultivation of Gurye, Chinese Cotton(在來綿) has been substituted for America Cotton(陸地綿) and additionally, Yellow Cotton (黃綿) has been cultivated in the 1930s. Also, in terms of silk fiber cultivation of Gurye, Joseon Silkworm has been substituted for Japanese Silkworm by inflowing the Japanese mulberry tree. Second, in terms of spinning method, cotton spinning has been conducted at every house by an individual tool from the 1930s to the 1950s and has been gradually changed to mechanization by market shop equipped with mechanized cotton gin and cotton whipping tool. However, there have been no changes in silk spinning method from the 1930s to the 1980s. Third, loom type has been changed from the traditional Korean back-strap loom to the treadle loom between the 1930s and the 1940s. Fourth, dyeing was conducted by chemical dyestuff after weaving. The circulation of textile was done through the joint market by Japan in the 1930s~1950s and has changed to the market sales by producers since the 1950s. Fifth, since the 1970s, the outputs of cotton and silk textile of Gurye have been reduced. This was connected with the westernization and the inflow of the synthetic fiber and cloth in cotton and was related to the changes of the nation policy and silk fiber inflow from the china to the Korean farm villages.

• 한국식품과학회지
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• 제20권1호
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• pp.106-111
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• 1988

미강단백질을 식용화하기 위한 기초연구를 목적으로 산화, 환원제처리 및 인산화가 분리탈지미강단백질의 품질 및 기능성에 미치는 영향을 조사하였다. 산화, 환원제를 처리한 분리단백은 알카리처리구보다 필수아미노산 함량이 높았고, 색상, pepsin소화성이 양호하였으며 용해도, 용적밀도, 유화성 및 유화안정도 등이 개선되었다. pH 10.5, $35^{\circ}C$에서 STMP(sodium trimeta phosphate)로 분리탈지미강단백을 3시 간 반응시켜 인산화하였다. 인산화한 분리단백의 단백가는 55이었으며 용해도, 수분흡착도, 유화성과 유화안정도 및 기포성과 포립안정도등의 기능성이 향상되었으나 색상, 소화성, 용적밀도 및 지방흡착도는 인산화의 효과가 나타나지 않았다.

• 한국가정과학회지
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• 제4권1호
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• pp.62-67
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• 2001

달걀에 0.5∼3.0kGy의 방사선을 조사한 다음 난백을 분리하여 비조사 및 조사 난백의 물리적, 기능적 특성을 비교 $.$검토하였다. 방사선 조사 달걀을 30$\^{C}$에서 2시간 방치한 다음 난백을 분리하여 실험재료로 사용하였다. 점도는 방사선을 조사하지 않은 대조군 난백이 가장 높았다. 조사 난백의 점도는 조사선량이 가장 낮은 0.5kGy에서 급격히 감소하였으며 이 후 완만한 감소를 보였다. 달걀을 할란하여 난백의 상태를 비교한 결과, 대조군 난백은 농후난백과 수양난백의 구분이 뚜렷했으나, 조사 난백은 구별할 수 없었다. 난백의 pH는 방사선 조사의 영향을 받지 않았다. 한편 색도는 방사선 조사에 따라 명도와 녹색도가 낮아졌다(p<0.05). 난백의 기포형성력은 overrun으로 측정하였는데, 조사 난백은 대조군에 비해 overrun이 증가하였다(p<0.05). 조사선량 3kGy인 난백의 overrun은 대조군 난백에 비해 1.7배 정도 높았다. 난백의 기포 안정성은 기포를 30분 방치하는 동안 유리되는 액량으로 검토하였다. 유리액량은 대조군 난백이 가장 많았다(p<0.05). 조사 난백의 유리액량은 조사선량이 증가함에 따라 감소하였다

• 대한조선학회논문집
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• 제55권1호
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• pp.37-44
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• 2018

To understand the dynamic characteristics of the vessel with hydroelastic response, it is very important to estimate the dynamic modal parameters such as mode shapes, natural frequency, and damping ratio. These dynamic modal parameters of full scale ship are a priori unknowns, hence to be estimated directly based upon the full scale measurement data. In this paper, dynamic modal parameters were extracted by signal processing of acceleration and strain data measured from a large container ship whose loading capacity is 9400TEU. The mode shapes of the vibrating hull were identified using the proper orthogonal decomposition and the vibration response of hull was decomposed into its modal magnitudes. Natural frequencies of specific modes were derived via Fourier transform of these modal magnitude. Also, the free decay signal of the vibrating hull was obtained through the random decrement technique and the damping ratio was estimated with accuracy.

• 대한조선학회논문집
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• 제55권1호
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• pp.45-55
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• 2018

Concerns are emerging in marine industry on the additional fatigue damages induced by hydroelasticity, and large container carriers, among others, are considered to be susceptible to this hydroelastic response due to its large size, deck openings and high speed. This study focuses on the fatigue damage estimation of 9,400TEU container carrier based on the full scale measurement data via long-base strain gage installed on the ship. Some correlation analyses have been also done to check whether there was significant torsional response during the voyage. Direct cycle counting method was used to derive stress histogram and the long-term fatigue damage was estimated based upon that analyzed data. It turned out that the fatigue damage of this particular ship during the measurement period increased by more than 60% due to the hydroelastic response of the hull, and main contribution is considered to come from vertical bending mode.

• 한국식품과학회지
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• 제52권4호
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• pp.423-426
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• 2020

본 연구를 통해 전분 나노입자의 첨가가 유제품 휘핑크림의 품질특성에 미치는 영향과 휘핑크림의 안정성을 향상시킴을 확인할 수 있었다. 전분 나노입자 첨가는 유화 액적의 계면을 안정화시킴으로써 휘핑크림의 저장 안정성을 향상시킬 수 있었다. 전분 나노입자 첨가에 의한 휘핑크림의 점도 역시 증가하였고 이로 인하여 휘핑크림의 저장 안정성이 증가하였으며, 액적의 입도 크기 역시 증가하였다. 하지만 3% 이상 전분 나노입자를 첨가하였을 때 오버런은 감소하는 경향을 보였다. 본 연구결과에 따르면 1% 전분 나노입자를 휘핑크림에 첨가하였을 때 휘핑크림의 오버런에 주목할 만한 변화 없이 휘핑크림의 저장 안정성을 향상시킬 수 있었다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권4호
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• pp.1130-1147
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• 2014

Large size ships have a very flexible construction resulting in low resonance frequencies of the structural eigen-modes. This feature increases the dynamic response of the structure on short period waves (springing) and on impulsive wave loads (whipping). This dynamic response in its turn increases both the fatigue damage and the ultimate load on the structure; these aspects illustrate the importance of including the dynamic response into the design loads for these ship types. Experiments have been carried out using a segmented scaled model of a container ship in a Seakeeping Basin. This paper describes the development of the model for these experiments; the choice was made to divide the hull into six rigid segments connected with a flexible beam. In order to model the typical feature of the open structure of the containership that the shear center is well below the keel line of the vessel, the beam was built into the model as low as possible. The model was instrumented with accelerometers and rotation rate gyroscopes on each segment, relative wave height meters and pressure gauges in the bow area. The beam was instrumented with strain gauges to measure the internal loads at the position of each of the cuts. Experiments have been carried out in regular waves at different amplitudes for the same wave period and in long crested irregular waves for a matrix of wave heights and periods. The results of the experiments are compared to results of calculations with a linear model based on potential flow theory that includes the effects of the flexural modes. Some of the tests were repeated with additional links between the segments to increase the model rigidity by several orders of magnitude, in order to compare the loads between a rigid and a flexible model.