• Journal of the Korean Institute of Navigation
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• v.25 no.4
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• pp.443-453
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• 2001

선박조종시뮬레이터는 해기사의 교육 훈련, 항만 수로 설계 시 안전성 평가, 선박설계시 조종성능의 검토등으로 널리 활용되고 있다. 본 논문은 최근 한국해양대학교에서 개발한 선박조종시뮬레이터를 소개하고 개발 과정과 활용에 대하여 논의한다. 본 시뮬레이터는 Operation Panel, Instructor's Console, Ship Dynamics Calculation, 3D Bridge View, 2D Bird's Eye View 및 Navigational Indicators의 6구성요소로 이루어져 있으며, 이를 위해 8대의 퍼스널 컴퓨터가 배치되어 있다. 모든 구성요소들은 효율적인 정보 교환을 위하여 분산처리네트워크 방식으로 연결되어 있다. 또한, 본 논문은 항만내에서의 저속 시 조종운동 수학모델과 가상현실 모델링에 대해서도 논의한다. 마지막으로, 부산항에 대한 2축2타선박의 접안 조종 시뮬레이션 예를 보여주고 있다.

• Applied Chemistry for Engineering
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• v.26 no.2
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• pp.173-177
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• 2015

In this study, effects of both the grafted ABS-g-MAH and the added graphene oxide (GO) on the impact strength of polycarbonate (PC)/poly(acrylonitrile-butadiene-styrene) (ABS) blends were discussed. The PC/ABS blends and PC/ABS/GO composites were fabricated by using twin screw extruder with ABS-g-MAH as a compatibilizer. The ABS-g-MAH was prepared by melting extrusion of ABS and maleic anhydride (MAH) with DCP (dicumyl peroxide) as an initiator using twin screw extruder and the synthesis of ABS-g-MAH was confirmed by the presence of carbonyl group (C=O) peak at $1780cm^{-1}$ of FT-IR spectrum. According to the thermal, rheological, and impact properties of PC/ABS blends, 5 phr (parts per hundred resin) of compatibilizer was chosen as an optimum content for the PC/ABS/GO composites. It was observed that the thermal decomposition of ABS/PC/GO composites increased with GO contents, but there was no significant changes or a decrease in the impact strength. Also the composite fabricated by ABS/GO showed small increase in the impact strength. From the result of the dynamic rheometer to observe the processing properties, the complex viscosities of PC/ABS blend including the compatibilizer increased, but the complex viscosities of composites added GO were not changed.

• Korean journal of applied entomology
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• v.45 no.1 s.142
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• pp.75-78
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• 2006

Development of pellet-type artificial diet for insect was tried by using a twin screw extruder(TSE). Screws were arranged several times and two reverse screws were equipped on the foreparts of 2 axes of TSE. Pellet-type diet could be produced successfully under conditions of TSE set as the following. : 300 rpm of main motor speed, 228 rpm of feed motor speed, $75m{\ell}/min$ of running water speed and 5 mm of extrusion diameter. The optimum adding quantity of water to the manufactured diet was $1.2{\sim}1.5$ times of dry diet. On the rearing results of beet armyworm, Spodoptera exigua and common cutworm, Spedoptera litura with the pellet-type diet, the final survival ratio (emergence rate) of these two species was over than 50%, and so it was concluded that the manufactured pellet-type artificial diet was sufficient dietetically to rear those insects.

• Elastomers and Composites
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• v.46 no.3
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• pp.211-217
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• 2011

Wood Polymer Composite (WPC) has attracted a great deal of attention in environmental industries due to renewable resources, processability, excellent physical properties and logging regulations for application to housing units and engineering construction materials. In this study, commercial WPCs were prepared by using a modular intermeshing co-rotating twin screw extruder. The effect of three main factors such as wood flour contents, coupling agent concentrations and pre-treatment of wood flour on the properties of WPCs was extensively investigated. It was found that tensile strength and thermal stability were decreased with increasing wood flour contents whereas the water absorption was increased. Addition of maleic anhydride grafted polypropylene (PP-g-MA) into WPC exhibited better physical properties. On the contrary, the water absorption was slightly decreased with PP-g-MA. Finally the sample, which was prepared with pre-treated wood flour, represented the highest tensile strength. However, the water absorption of the sample was increased due to the transition of crystalline structure of cellulose.

• Food Science and Biotechnology
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• v.14 no.6
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• pp.758-765
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• 2005

Instant powders that only require mixing with water prior to consumption can be produced by extrusion for use in products such as instant beverages. Both extrusion processing conditions and particle size of powder are important to end-product characteristics. In this study, a twin-screw extruder was used under various processing conditions (feed moisture, barrel temperature, and screw speed) to produce extrudates from soft wheat flour, which were ground to powders with particle size ranges of less than 93, 93-145, and $145-249\;{\mu}m$. Effects of adding soy lecithin to wheat flour before extrusion were also investigated. Water absorption, solubility, suspension viscosity, and dispersibility of wheat powders were related to specific. mechanical energy measured during extrusion. Powder particle size was important to instant properties, especially ease of dispersal in water and stability to sedimentation. Addition of lecithin significantly improved dispersibility of powders.

• Journal of the Korean Society of Marine Environment & Safety
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• v.8 no.1
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• pp.81-87
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• 2002

High speed naval ships are configured with open shafts The shafts, bearings, and propellers are supported by shaft struts. Proper design of struts involves issues of structural, vibration, and hydrodynamic analysis and design. Strut arm cavitation in high speed occurs because of a misalignment of the strut arm with the local incident flow. Proper selection of the strut section can minimize the generation of cavitation. This paper describes issues in the design struts and notices based on the design of Patrol Craft and Amphibious Ship.

• The Korean Journal of Rheology
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• v.2 no.1
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• pp.60-66
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• 1990

혼합공정은 화학공학, 식품공학, 건축공학등 여러 가지 산업분야에 걸쳐 이용되는데 최근 고분자 분야에서도 신소재 개발 또는 제품의 물성을 향상시키기 위하여 이에대한 연구 가 활발해지고 있다. 고분자 가공에서 혼합에 이용되는 대표적인 기계로는 twin screw extruder, internal mixer, two roll mill 등이 있는데 본 연구에서는 internal mixer에서의 고 분자 유동 및 혼합거동을 파악하고자 하였다. 실험적으로는 flow visualization 방법을 써서 순환시간을 측정하였고, 시뮬레이션을 통하여 이론적으로 이를 검토하였다. 고분자 거동은 비뉴우톤을 유체로서 설명되기 때문에 본 연구에서는 혼합기의 구조적 특성을 고려한 모델 로서 $\eta$ = $\frac{\eta_o}{1+A[2trd^2]^\frac{1-n}{2}}$

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.215-218
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• 1998

XLPE/VLDPE (Crosslinked polyethylene/very low density polyethylene) blends were prepared by a twin screw extruder and their electrical properties such as water tree and breakdown characteristic were measured. it was found that both water tree and breakdown characteristics of XLPE were improved by the addition of VLDPE to polyethylene. It was also found that the extent of improvement of electrical properties by the addition of VLDPE to polyethylene depends on the type and concentration of VLDPE.

• Proceedings of the Korean Society of Rheology Conference
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• 2006.06a
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• pp.153-156
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• 2006

• Elastomers and Composites
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• v.33 no.4
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• pp.255-266
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• 1998

One-step continuous reactive blend with EPDM is investigated using a modular intermeshing corotating twin screw extruder This was performed via anionic polymerization mechanism. Mechanical properties were characterized and compared with mechanical blends.