• Journal of the Society of Naval Architects of Korea
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• v.49 no.6
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• pp.469-477
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• 2012

This paper describes the characteristic analysis of ice impact force for the Arctic structure shape. In the present study an energy method has been used to predict the impact force during the ice-structure collision. This study also employs two concepts for reference contact area and normalized stress in analysis procedure. The influences of factors, such as impact velocity, full penetration depth, structure shape and ice floe size, are investigated. Full penetration occurs, particularly at lower impact velocity when ice thickness increase. But "typical size" ice floe does not expected ever to achieve full penetration during the impact procedure. The structure shape is the dominant factor in ice impact force characteristic. The results for various ice-structure collision scenarios are analyzed.

• Food Science and Biotechnology
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• v.14 no.4
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• pp.450-455
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• 2005

This study was conducted to determine firstly the composition of the essential oil from fresh changpo (Acorus calamus var. angustatus Bess) roots quantitatively and qualitatively by use of two internal standards, and secondly volatile compounds which are primarily responsible for the aroma of changpo roots. Simultaneous steam distillation and extraction method was used for essential oil extraction, and aroma extract dilution analysis (AEDA) and sniffing test by gas chromatography/olfactometry (GC/O) were used to detect the characteristic impact odorants. According to the instrumental analysis of changpo root essential oil, cis, trans-famesol (47.56 mg/kg of fresh wt), octanoic acid (23.73 mg/kg of fresh wt), trans-2-dodecenal (20.28 mg/kg of fresh wt) and trans, trans-farnesol (13.81 mg/kg of fresh wt) were the most abundant compounds. Geranyl acetate, trans-nerolidol and trans, trans-farnesyl acetate were evaluated as the characteristic impact odorants of changpo roots from results of AEDA and sniffing test. Especially, geranyl acetate was considered as the most similar odor component to changpo roots by organoleptic evaluation with GC/O.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.3
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• pp.440-449
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• 2003

Residual strength of fiber metal laminates after impact was studied. 3/4 lay up FML was fabricated using 4 ply prepreg, 2 ply aluminum sheets, and 1 ply steel sheet. Quasi isotropic ([0/45/90/-45]s) and orthotropic ([0/90/0/90]s) FRP were also fabricated to compare with FML. Impact test were conducted by using instrumented drop weight impact machine (Dynatup, Model 8250). Penetration load and absorbed energy of FML were superior to those of FRPs. Tensile tests were conducted to evaluate the residual strength after impact. Strength degradation of FML was less than that of FRP. This means that the damage tolerance of FML is excellent than that of FRP. Residual strength of each specimen was predicted by using Whitney and Nuismer(WN) Model. Impact damage area is assumed as a circular notch in WN model. Damage width is defined as the average of back face and top face damage width of each specimen. Average stress and point stress criterions were used to calculate the characteristic length. It is supposing that a characteristic length is a constant. The distribution of characteristic length shows that the assumption is reasonable. Prediction was well matched with experiment under both stress criterions.

• Journal of Environmental Impact Assessment
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• v.29 no.2
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• pp.93-111
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• 2020

Health Impact Assessment (HIA) in Korea is conducted for specific development projects within Environmental Impact Assessment (EIA) system. However, as HIA is being carried out in the implementation stage of the development project, it sometimes has failed to take proper actions despite the significant adverse health impact. Considering an environment conflict regarding adverse health impact in developing industrial complex and the current application of HIA in EIA system, it is necessary to come up with an adequacy evaluation in the industrial complex development considering health impact. This study proposes an adequacy evaluation method considering health impact for the industrial complex development and embodies the method by applying it to actual cases. Referring to methodologies of US EPA's CalEnviroScreen 3.0 and US ATSDR's Public Health Assessment, this study proposed using indicators divided by community characteristic, background exposure and development burden as an adequacy evaluation method to consider health impact. Five indicators for community characteristic, three indicators for background exposure and seven indicators for development burden were selected through literature survey, and the weights for each indicator were calculated through Analytic Hierarchy Process's survey of experts related to HIA. Through a pilot application in the three government-led industrial complex development projects, the method was further elaborated by clarifying the evaluation data and subdividing the evaluation criteria for each indicator. Adequacy criteria of plan considering health impact could be presented in three ways to be linked to the government's policy stance on the industrial complex development criteria of total score, criteria of total score and community characteristic score, and criteria of total score and community characteristic allowed by development burden.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.1279-1280
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• 2010

• Journal of Korean Society for Quality Management
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• v.30 no.3
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• pp.94-110
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• 2002

This research focuses on internet advertisement success factors derived from the relevant researches and clarified the concept of user and information characteristics. The corresponding determinants are suggested such as organizational characteristics, user characteristics, and information characteristics. Success factor of internet advertisement is used by user attitude. We then examine the impact of corresponding determinants on the success factors. Hypotheses on their characteristics were tested for 174 persons. The results indicated that organizational characteristic, user characteristic and information characteristic was partly found as a positive impact on the internet advertisement success while quality of innovation and purchase promotion traits were not significant.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1145-1148
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• 2007

Resilient materials are generally used for the floating floors to reduce the floor impact sound. Dynamic stiffness of resilient material, which has the most to do with the floor impact sound reduction. The resilient materials available in Korea include EPS (Styrofoam), recycled urethane types, EVA (Ethylene Vinylacetate) foam rubber, foam PE (Polyethylene), glass fiber & rock wool, recycled tire, foam polypropylene, compressed polyester, and other synthetic materials. In this study, we tested floor impact sound reduction characteristic to a lot of kinds of resilient material. The result of test showed that the amount of the heavy-weight impact sound reduction appeared by being influenced from this dynamic stiffness of resilient material. The dynamic stiffness looked like between other resilient materials, a similar to the amount of the heavy-weight impact sound reduction was shown.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.830-834
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• 2008

Resilient materials are generally used for the floating floors to reduce the floor impact sound. Dynamic stiffness of resilient material, which has the most to do with the floor impact sound reduction. The resilient materials available in Korea include EPS (Styrofoam), recycled urethane types, EVA (Ethylene Vinylacetate) foam rubber, foam PE (Polyethylene), glass fiber & rock wool, recycled tire, foam polypropylene, compressed polyester, and other synthetic materials. In this study, we tested floor impact sound reduction characteristic to a lot of kinds of resilient material. The result of test showed that the amount of the Light-weight impact sound reduction appeared by being influenced from this dynamic stiffness of resilient material. As the decreasing dynamic stiffness of resilient material, the impact sound reduction amount is increased, especially in the low frequency domain.

• Journal of Korean Association for Spatial Structures
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• v.11 no.3
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• pp.77-83
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• 2011

Laminated composite plates have shown their superiority over metals in applications requiring high specific strength, high specific modulus, and so on. Therefore, they have used in various industry. However, they have poor resistance to impact compared to typical metal materials. To resolve this problem by many researchers for a variety of studies have been attempted. This study investigates characteristic of impact behavior of laminated composite plates due to initial stress. Using finite element program which involved the indentation law, we investigate characteristic of impact behavior of laminated composite plates due to initial stress.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.35-38
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• 2005

The Objective of this work was to design Composite Antenna Structures (CAS) and investigate impact behavior of CAS which was various curvature. This term, CAS, indicates that structural surface becomes antenna. Constituent materials were selected considering electrical properties, dielectric constants and tangent loss as well as mechanical properties. For the antenna performance, microstrip antenna layers inserted into structural layers were designed for satellite communication at the resonant frequency of 12.5 GHz and final demonstration article was. After making five kinds of curved CAS, which radii of curvature are flat, 200, 150, 100, 50 mm. The antenna performance changed in accordance with variation of curvature. The Reflection coefficient was independent of curvature but the gain decreased with the radius of curvature. The impact test equipment was Dyna-8250 drop weight tester. The impact characteristic in accordance with curvature is maximum absorb energy is same each other. The impact energy was 8.5 J. For various Impact energy test, five energy levels 3 J, 5 J, 7 J, 10 J, 20 J were used. The performance of impact damaged antenna was estimated by measuring the return loss and the radiation pattern. It was revealed that the performance of antenna was not related to the impact damage. Because the impactor did not damage the patch directly. CAS have good impact stability for the antenna performance.