• Journal of Korean Society of Coastal and Ocean Engineers
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• v.10 no.2
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• pp.93-99
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• 1998

Parabolic approximation and sponge layer are applied as open boundary condition for elliptic finite difference wave model. Generalized conjugate gradient method is used as a solution procedure. Using parabolic approximation a large part of spurious reflection is removed at the spherical shoal experiment and sponge layer boundary condition needs more than 2 wave lengths of sponge layer to give similar results. Simulating the propagation of waves on a rectangular harbor, it is identified that iterative scheme can be applied easily for the non-rectangular computational region.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.31-36
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• 2000

The mineral compositions were analysed of the tip and the upper section of dried domestic antlers. The upper section was divided longitudinally into four parts. The tip and the upper section were divided traversely into the velvet and the spongy bone layers. The contents of ash, calcium, phosphorus and magnesium increased (p<0.05), and those of manganese, zinc, copper and iron decreased (p<0.05) downward from the tip both in the velvet and the spongy bone layers. The contents of ash, calcium, phosphorus, manganese and zinc of the spongy bone layer were significantly (p<0.05) higher than those of the velvet layer. The tip, which is the growth center of the antler, had the significantly (p<0.05) lowest proportions of Ca/ash, Ca/P and Ca/Fe ratios both in the velvet and spongy bone layers.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.11 no.3
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• pp.149-155
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• 1999

A treatment of wave breaking is included in the extended Boussinesq equations of Nwogu. A spatially distributed source function and sponge layers are used to reduce the reflected waves in the computa¬tional domain. The model uses fourth-order Adams predictor-corrector method to advance in time, and discretizes first-order spatial derivatives to fourth-order accuracy, and thus reducing all truncation errors to a level smaller than the dispersive terms. The generated wave fields are found to be good and the corresponding wave heights are very close to their target values. For the tests of wave breaking, although agreement is considered to be reasonable, wave heights in the inner surf zone are over-predicted. This indicates the breaking parameters in the model should be adjusted.

• Proceedings of the Korea Water Resources Association Conference
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• 1998.05a
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• pp.620-625
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• 1998

• Proceedings of the KAIS Fall Conference
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• 2008.11a
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• pp.350-353
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• 2008

과산화물 가교제의 농도가 헬리콥터 연료탱크의 자기밀폐층 소재로 적용시키기 위한 천연고무 스폰지의 팽윤에 미치는 효과를 조사하였다. 천연고무 콤파운드를 Kneader와 Roll-Mill을 활용하여 제조하고, 고압조건의 프레스에서 부분 가교시킨 후 대기압의 금형에서 발포와 완전가교를 실시하였다. 얻어진 스폰지의 겉보기밀도를 측정하고 스폰지의 셀구조를 주사전자현미경을 통하여 관찰하였다. 톨루엔, 이소옥탄과 항공유를 사용하여 실온에서 팽윤실험을 실시하였다. 용매에 2분 동안 침적 후 얻어지는 부피팽윤비 값은 과산화물 농도가 감소함에 따라 증가하다가 감소하는 경향을 보였다. 스폰지의 겉보기밀도와 셀구조는 과산화물 함량에 매우 민감하였으며 이는 또한 천연고무 스폰지의 팽윤거동에 영향을 미쳤다. 천연고무 스폰지가 연료와 접촉하여 신속한 팽윤이 얻어지기 위하여 금형에서 동시에 발생하는 두 가지 반응인 발포제의 분해반응과 천연고무의 가교반응을 적절히 조절하는 것이 중요하다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1775-1781
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• 2008

The effects of the type of curing agent on the swelling of the natural rubber(NR) sponge applicable to the self-sealing layer of a helicopter fuel tank were investigated. The curing systems employed were peroxide and mixed ones of sulfur and peroxide. The NR compounds were prepared in a kneader and a roll-mill. The compounds were partially cured in a press at high pressure and subsequently cured fully with expansion in another press at atmospheric pressure. The apparent density of the NR sponge was measured and the cell structure was observed with scanning electron microscopy. The swelling experiments were performed at room temperature using toluene, iso-octane, and an aircraft fuel as a solvent. More rapid volume swelling of the NR sponge cured by peroxide was achieved than cured by sulfur and peroxide with similar amount of curing agent added in rubber compounds. The apparent density and cell structure of the sponge were extremely sensitive to the amount of peroxide, which influences again the swelling behavior of the NR sponge. It is important to control properly two reactions of decomposition of foaming agent and crosslinking of NR in the mold to obtain rapid swelling of the NR sponge on contact of the fuel.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.369-371
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• 2003

젤형 인공피부의 약한 물성을 보완하기 위해 스폰지형 인공피부가 개발되었으나 다공성 표면구조 때문에 세포의 배양이 어려운 문제점이 남아 있었다. 이 다공성 구조를 섬유모세포의 장기 배양으로 ECM으로 채우기 위해서는 3주이상의 긴 시간이 필요하며 그 위에 상피층 배양하기 위해서는 2주 이상의 시간이 추가로 소요되기 때문에 환자에게 이식할 적절한 시기를 놓칠수가 있다. 따라서 본 연구결과로 단기일 내에 전층 인공피부를 배양함으로서 적절한 이식시기를 맞출수가 있으며 이러한 기저막이 부착된 스폰지구조는 물성도 향상되어 이식시 조작이 쉽고 볼합이 가능한 장점이 있다.

• Membrane Journal
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• v.15 no.3
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• pp.198-205
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• 2005

Double-layered polymer films to assay the radioactive contamination were formulated using polysulfone (PSF) and cerium activated yttrium silicate (CAYS), consisting of a dense support layer and a CAYS-holding top layer prepared via the diffusion-induced phase inversion. As the vapor exposure process was omitted, the CAYS-holding layer showed a typical asymmetric structure, with CAYS being transfixed into the polymer network spread with large macropores. With the increase in vapor exposure time before immersion, morphology of the films transformed from asymmetric to sponge-like structures, with CAYS being localized in cellular structure. The border structure between the two layers reflects the phase inversion behavior of a cast solution during the coagulation. In the radioactive detection, the polymer phase in a film holding a sponge-like structure is so dense that the radionuclides, deposited on the film, could not filter through the phase, consequently resulting in the loss in the detection efficiency of the film.

• Venture DIGEST
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• no.2 s.127
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• pp.21-23
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• 2009

태극마크 물결무늬 USB, 큐빅이 박힌 쥬얼리 USB, 교통카드 USB, 스폰지밥 캐릭터 USB, 자물쇠 USB${\dots}$. (주)메모렛월드(대표 최백수, www.memorette.co.kr)의 USB메모리를 소개하자면 일단 숨이 벅차다. 다양한 종류에 독특한 디자인이 한 달이 멀다하고 쏟아져 나오고 있다. 고객의 다양한 니즈를 겨냥한 만큼 '충성고객층'도 두텁다. 국내 USB메모리 시장을 선도하고 있는 (주)메모렛월드를 찾아가봤다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.6
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• pp.382-388
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• 2017

This study performed an OpenFOAM-based numerical modeling for simulating performance of wave reduction by a floating vertical plate. Based on the Waves2FOAM library, an internal wave generation and energy dissipation with sponge layers schemes were further implemented. The performance of wave generation and dissipation was first tested with a simple two-dimensional analysis. Then, numerical simulation was carried out with the experimental data of Briggs et al. (2001) for the two regular wave cases. In general, the modeling results agreed well with the experimental data, showing better agreement than the numerical analysis by WAMIT that is included in Briggs et al. (2001).