• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.941-946
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• 2004

In this study the structural design of conveyor frame was carried out for the high efficiency gantry crane which can improve the productivity of the container transportation work by reducing cycle time. When the gantry crane was operated, the conveyor frame was deflected largely by its deadload and the total weight of containers placed on it. Therefore thicknesses of conveyor frame to minimize its deadload were designed by the size optimization using ANSYS program as the bending stress and the deflection cf frame due to this simulation satisfied their required values.

• Magazine of the Korea Concrete Institute
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• v.11 no.1
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• pp.89-97
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• 1999

In this study, fifteen reinforced high-strength lightweight concrete(HLC)beams were tested to investigate shear behavior of specimens according to shear reinforcement ratio. Test variables are shear span to effective depth ratio(a/d=2.5, 3.5, 4.5) and shear reinforcement ratio(0~1.0${\rho}_{v,ACI}$). Concrete compressive strength and tensile steel reinforcement ratio are constantly 439kg/$cm^2$ and 0.0203, respectively. Test results for the HLC beams showed that ACI code equation underestimates the shear strength of concrete($V_c$), and overestimates the shear strength of shear reinforcements($V_s$). It is revealed that the effectivenesses of shear reinforcements of reinforced HLC beams are lower than those of normal weight concrete beams. Then, the shear strengths of shear reinforcements are increased in proportion not to first degree of shear reinforcement ration but to square root of them.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.8
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• pp.5400-5405
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• 2014

For the development of a floating photovoltaic system, materials with light weight and high tensile strength must be applied to reduce the burden on buoyancy, and material characteristics with high resistance to corrosion in water environment is required. Accordingly, a new high strength steel material with improved strength, durability, manufacturability, and weldability that are appropriate for floating photovoltaic system structures is needed. This paper reports the results of a mechanical load test and steel corrosion test on general steel (SS400) and high strength steel (POSH 690) for the selection of an appropriate steel material for a floating photovoltaic system. The results of a test on new high strength steel revealed excellent mechanical performance compared to general steel. The new steel material was manufactured for use in an actual site, and the weight was reduced by approximately 30~40% compared to existing general steel.

• Journal of the Korean Society for Railway
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• v.19 no.4
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• pp.498-505
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• 2016

As a basic study to develop maintenance-effective optimal ballast track in preparation for upgrading a conventional line to a high speed railway, a full-scale test that combined the components of ballast track was conducted and the characteristic of track settlement was analyzed. As a result of the full-scale test, reduction in maintenance via an increase of the elasticity of only the pad was insignificant; however, the effect increased significantly with increasing of the weight of the sleeper or with increasing of the weight of the sleeper and the thickness of the ballast together with use of a pad with high resiliency. An optimal type of ballast track, in line with upgrading the speed of a conventional line, shall be developed through cost efficiency analysis considering the maintenance cost depending on the track settlement as well as the initial construction cost.

• Resources Recycling
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• v.22 no.4
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• pp.70-80
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• 2013

Waste refrigerator is the most large amount of item being recycled and the recycling process is the most complicated in WEEE (Waste Electrical and Electronic Equipment) because refrigerator is biggest product and consists of various parts and materials such as ferrous, non-ferrous, and plastics. Recently, recycling process of waste refrigerator has been being more complex since large capacity 2 door refrigerators and standing Kimchi refrigerators with various material are distributed on custom market. In addition, recycling of valuable resource from waste refrigerator is mandatory by WEEEs recycling legislation; therefore, high efficiency recycling enough for economic and environment-friendly recovery of valuable resource through present technical situation analysis and comparison of recycling technologies of waste refrigerator with advanced country.

• Food Science and Preservation
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• v.9 no.4
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• pp.362-368
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• 2002

Physicochemical properties of garlic bulb during storage with different cutting treatments were estimated. Garlic harvested in early June was used in this experiments. Various physicochemical factors of garlic bulb such as weight loss rate, rotten rate, sprouting rate, moisture content, reducing sugar content and total pyruvate content were investigated. Bulbs with roots, bulb without roots and bulb with stem length of l cm, 3 cm, 5 cm were stored at 2$\^{C}$ for eight months. The weight loss increased sharply after 8 months for all treatments. Weight loss occurred most severely in treated garlics with bulbs with 5 cm stem length and progressed steadily at low rates in bulbs with 1 cm stem length. Also, less decay and internal sprouting were observed in bulbs with 1 cm stem length. Cutting treatments of roots were not significant for internal sprouting. Incidence of other chemical properties of bulbs, contents of total sugar, reducing sugar and pyruvic acid were not significant statistically. Moisture contents of treated garlics was remarkably reduced in longer leaving stems. As a result, top-clipped leaving stems fur long, seemed to have a beneficial effect on physicochemical properties of garlic stored at 2$\^{C}$ for 8 months possibly due to reduced weight loss, rotten decaying and sprouting rates. Utilization of such results in the processing industry can be effective.

• Culinary science and hospitality research
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• v.22 no.2
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• pp.104-114
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• 2016

In this study, the quality characteristics of different drying methods of Cirsium setidens Nakai, which contains large amounts of biological substances, were investigated for the improvement of their practical use. During the drying period, the weight reduction was the highest with hot-air drying(82.7%). As for the general component and mineral contents analysis results of Cirsium setidens Nakai, there were no significant difference. Cyclic low pressure drying resulted highest amount of total phenolic components and 1,1-diphenyl-2-picrylhydrazyl (DPPH). Hence, cyclic low pressure drying method is the best method for enhancing antioxidant activity of Cirsium setidens Nakai.

• Journal of Conservation Science
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• v.29 no.3
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• pp.243-247
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• 2013

This study was conducted to investigate the penetration of PEG for conservation treatment conditions of archaeological waterlogged wood. The weight percent gain was examined, depending on the solvent of PEG, concentration and treatment period and temperature of treatment solutions. The penetration of PEG in the cell lumina of treatment woods was observed by scanning electron microscope. The results showed that the type of solvents had no influence on PEG penetration. In the concentration of the PEG treatment solutions, the weight percent gains (WPGs) were increased with increase in concentration of PEG. In terms of the period of the soaking treatment, a maximum WPGs were obtained for only 20 days. There was no distinctive difference in the WPGs by difference the temperature of the treatment. In conclusion, in the conservation of small size of archaeological waterlogged wood, it is confirmed that optimal solvent type and treatment period of PEG are water and 20 days, respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.2
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• pp.129-138
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• 2012

A MDO study of a midium-sized solar powered High Altitude Long Endurance (HALE) UAV has been performed, focused on energy balance. In the MDO process, Vortex Lattice Method(VLM) is employed for the aerodynamic modeling of the vehicle, of which structural weight is estimated with the modeling proposed by Cruz. Tail volume ratios have been set as constants, while the location of tail surfaces is determined from longitudinal static stability criterion. By balancing the available energy from solar cells, battery, and altitude, with the energy-requirement of the vehicle, the possibility of continuous flight over 24-hours has been investigated. The solar radiation level is set as that of summer at the latitude of $36^{\circ}$ north. During the daytime, the aircraft climbs using solar energy, accumulating potential energy, which supplements energy balance during the night. Optimizations have been sought in size of the vehicle, its weight distribution, and flight strategy.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.161.1-161
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• 2003

본 시험은 곶감건조초기의 높은 습도로 인한 불량환경을 극복하고 고품질의 우수한 곶감을 생산하기 위하여 현재 국내에서 가장 많이 재배되고 있는 상주둥시와 갑주백목 품종을 사용하여 수행하였고, 저장을 통하여 곶감의 건조시기를 달리한 다음 곶감을 제조하여 상품성을 비교하였다. 저장에 따른 품종별 과중변화는 저장 30일에 품종별로 0.32~0.38%의 무게감소를 나타내었다. 과실의 경도는 저장 30일에 두품종 공히 2.3kg/$\Phi$5mm로 나타나 저장기간이 증가할수록 감소하였지만 이러한 경도의 감소는 곶감을 제조하기 위한 박피작업에는 무리가 없었다. 저장중에 발생한 비상품과는 저장 30일에 품종별로 3.2~4.2% 발생되었고 과실의 당도는 수확시와 비교하여 약간 감소하는 경향이었으며, 과실표면의 색도 역시 적색도는 약간 증가하였으나 유의성은 없었다. 곶감 건조중 무게변화는 박피 2주경에 대부분 박피시 중량보다 30~40%감소되었고 그 후는 완만하게 감소되어 처리 6주후에는 박피중량의 30% 이내로 되었다. 품종별로는 대과종인 갑주백목의 중량감소가 다소 늦었다. 박피시기가 늦을수록 감의 건조속도도 완만하여 30일 저장한 처리구는 박피후 8~9주에 건조가 완료되었다. 곶감 제조중 품종별 경도의 변화는 건조 1주후에 품종별로 0.38~0.42kg/$\Phi$5mm로 급격히 감소하였다가 건조 후기로 갈수록 다시 증가하여 건조 6주후에는 1.52~1.85kg/$\Phi$5mm나타났다. 곶감 제조후 상품성에 있어서 곶감의 당 함량은 수확직후 제조한 곶감이 저장한 후 제조한 곶감과 비교하여 약간 높은 경향이었으나 큰 차이는 없었다. 가용성 탄닌의 함량은 곶감 제조후 품종별로 0.7~0.9mg/g으로 나타나 떫은맛이 완전히 제거되었고 저장기간별로는 차이를 보이지 않았다. 곶감의 외관상 상품성을 나타낼 수 있는 색도는 박피시기가 늦어질수록 두 품종 공히 증가되었다. 특히 갑주백목 품종의 경우 수화직후 8.4인 적색도가 저장 30일후 13.2로 증가되었고 황색도도 13.5에서 33.1로 증가되어 곶감표면의 색도가 박피시기를 연장함으로써 크게 향상된 것으로 나타났다.