• Journal of the Korean Society for Railway
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• v.14 no.4
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• pp.333-340
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• 2011

The purpose of this paper is to develop two kinds of finite element models for the heavy deformable obstacle defined in grade crossing collision scenario of the Europe TSI and the Korean rolling stock safety regulations and to apply the crashworthiness evaluation for the Korean high-speed EMU with the FE model. The numerical models of the heavy obstacle were changed from a past rigid one to a current deformable one whose stiffness requirement should be verified by a collision simulation defined in the regulations. Through several trial simulations, two types of numerical models for the heavy obstacle were developed, which satisfied physical properties specifies in the regulations. One is a solid-type obstacle with uniform density and the other is a shell-type. With the obstacles developed in this study, the grade crossing collision scenario for Korean high-speed EMU was simulated and evaluated for the two-type obstacle models. From the simulation results, the shell and solid-type obstacles showed quite different behaviors after collision, and the shell type model gave more severe results.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.330-337
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• 2018

The Korean Eutrophication Index($TSI_{ko}$) was estimated using water quality monitoring data of eight main sites in the SoOoak River watershed. The environmental characteristics of rivers were classified and evaluated using the $TSI_{ko}$ for each factor calculated by COD, T-P, and Chl-a. There is a good condition for the algae to grow due to shallow water depth, inflow of non-point source pollution during rainfall, influx of sewage treatment effluent and increase of residence time. It shows trophic state more than mesotrophication year round. Especially, in case of Chuso point, which is the inflow point of Daecheong Lake, the water quality deteriorated due to hydraulic characteristics and showed the eutrophic state. Therefore, it is necessary to establish the measures to improve the water quality through the precise monitoring of SoOak River.

• Korean Journal of Ecology and Environment
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• v.42 no.1
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• pp.9-18
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• 2009

The objectives of this study were to evaluate seasonal and interannual variations of water quality and nutrient input (N, P) in Junam Reservoir, a nesting waterbody of migratory birds, over 10 years during 1998$\sim$2007 along with dynamic relations of trophic parameters using empirical models. Concentrations of COD averaged 7.8 mg $L^{-1}$ during the study, while TN and TP were $1.4\;mg\;L^{-1}$ and $83{\mu}g\;L^{-1}$, respectively, indicating an eutrophic-hypereutrophic state. Values of monthly COD had strong positive relations (r=0.669, p<0.001) with conductivity, indicating that summer rainfall resulted in an ionic dilution of the reservoir water by rainwater and contributed better water quality. One-way ANOVA tests showed significant differences (F=$5.2{\sim}12.9$, p<0.05) in TN and TP between the before and after the bird migration. In other words, nutrient levels were greater in the absence of migratory birds than in the presence of the migratory birds, suggesting a no-effect on nutrient inputs by the birds. Also, one-way ANOVA indicated no significant differences (F=$0.37{\sim}0.48$, p>0.05) in $NO_{3^-}N$ and $NH_{3^-}N$ between the before and after the birds migration. Linear empirical models using trophic parameters showed that algal biomass as CHL, had significant low correlations with TN ($R^2$=0.143, p<0.001, n=119) and TP ($R^2$=0.192, p<0.001, n=119). These results suggest that influences of nutrients on the CHL were evident, but the effect was weak. This fact was supported by analysis of Trophic State Index Deviation (TSID). Over 70% in the observed values of "TSI (CHL)-TSI (SD)" and "TSI (CHL)-TSI (TP)" were less than zero, suggesting a light limitation on the CHL by inorganic suspended solids.

• International Commerce and Information Review
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• v.14 no.3
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• pp.381-403
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• 2012

The purpose of this study is to examine Technology Trade of Korea China for Korea China FTA. For this purpose, to analysis the present condition of technology trade and Trade Specialization Index(TSI), Technical Barriers to Trade(TBT). The Technology trade of Korea China is the surplus Technology trade of Korea but reducing to surplus scale. Also as a result of TSI analysis, Chemistry, plastic, primary metal, Medical precision industry, basic materials industries have weakened the Korea. In addition to Technical Barriers to Trade of China is very complexity for example, China Compulsory Certificate(CCC), China RoHS, China REACH. Therefore the Policy Technology Trade of Kore against China have to the centerpiece of Korea Technology export drive to expand in China.

• International Commerce and Information Review
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• v.10 no.1
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• pp.175-191
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• 2008

Materials Industry has a very large ripple effect on national economic development. Nevertheless, Korea has been passing over importance of this Industry. So, this study examined competitiveness on ten chief exporting items to U.S.A market based on the understanding of vital role of materials industry in the national economy. Analyzing methods were Market Share, Trade Specialization Index(TSI), and Market Comparative Advantage(MCA) and the data were collected through parts and materials statistical data which produced by Korean Commerce and Industry Minister. From this study, following results were found. i) Highly ranked items of U.S.A market share were chemical fiber drapery weaving, synthetic fiber. These items commanded over 10% share of the same market and tire, steel wire occupied 9.05%, 8.65% respectively. ii) In searching trade balance aspects through TSI, tire and steel wire secured very powerful competitiveness among examined items in trading with U.S.A. while synthetic resins and other plastic material were very weak competitiveness in the same market. iii) Analysis results of market competitiveness by MCA, indicated that chemical fiber drapery weaving, synthetic fiber and tire ensured high-powered competitiveness in U.S.A Market. Therefore, these items would be positioned as main items in the market.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.5
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• pp.433-439
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• 2017

The high temperature performance of PEM type electrolyser at $120^{\circ}C$ based on covalently cross-linked sulfonated poly ether ether ketone (SPEEK) composie membrane was investigated. Ion conductivity and other properties of SPEEK membrane were improved by adding heteropoly acid and Ceria. The membrane electrode assemblies were prepared using commercial PtC and nano-sized $IrRuO_2$ catalyst by electro-spraying and decal process. Voltage efficiency of MEA equipped with SPEEK membrane was slightly better than that of $Nafion^{(R)}$ membrane, due to its higher proton conductivity at high temperature. The cell performance of MEA with CL-SPEEK/Cs-TSiA/Ceria is 1.71 V at $1A/cm^2$ and $120^{\circ}C$.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.762-770
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• 2014

Tangible Space Initiative (TSI) is a new framework that can provide a more natural and intuitive Human Computer Interface for users. This is composed of three cooperative components: a Tangible Interface, Responsive Cyber Space, and Tangible Agent. In this paper we present a Tangible Tele-Meeting system in TSI, which allows people to communicate with each other without any spatial limitation. In addition, we introduce a method for registering a Tangible Avatar with a Tangible Agent. The suggested method is based on relative pose estimation between the user and the Tangible Agent. Experimental results show that the user can experience an interaction environment that is more natural and intelligent than that provided by conventional tele-meeting systems.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.72-81
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• 2007

The purpose of this study was to develop a multi-metric Lentic Ecosystem Health Assessment (LEHA) model and apply model to dataset sampled from Daechung Reservoir in September 2005. The metrics were composed of 11 parameters such as physical, chemical and biological variables. The metric attributes of $M_1{\sim}M_8$ followed after the model of biological integrity using fish assemblages that previously adapted in lotic ecosystems, while the metrics of $M_9{\sim}M_{11}$ were added on the basis of literature. The metric of $M_9$ reflected habitat conditions in the littoral zone and the metric of $M_{10}$ reflected chemical conditions of the reservoir. For the application of regression analysis of long-transformed conductivity [$Log_{10}$(Cond)] against $COD_{Mn}$, based on 150 sampling sites at Korean reservoirs, showed that the variation of conductivity was explained 77.4% [$COD_{Mn}=4.42{\times}Log_{10}(Cond)-5.43;\;R^2=0.774$, p<0.01, n=150] by the variation of $COD_{Mn}$. The metric of $M_{11}$ was based on Tropic State Index (TSI), based on chlorophyll-${\alpha}$ concentrations (Chl-${\alpha}$). Analysis of TSI $(Chl-{\alpha})$ showed that above 50 was estimated "1", $40{\sim}50$ was estimated "3" and below 40% was estimated '5'. Overall, velues of LEHA in the reservoir averaged 30.5, indicating a "fair${\sim}$poor condition", which is judged by the criteria of U.S. EPA (1993). More studies such as metric numbers and attributes should be done for the application of the model.

• Korean Journal of Ecology and Environment
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• v.40 no.2
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• pp.214-222
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• 2007

This study was conducted to assay the relationship between the characteristics of watershed and water quality, and to evaluate water quality characteristics of the classified types by TSI deviation analysis with the collected data from 490 reservoir. Relatively shallow depth (<5m) reservoirs out of selected 490 appeared to be eutrophic. The mean TP concentration in reservoirs with the PFA+UFA/watershed area of above 30% was ${\geq}0.1$ mg $L^{-1}$. The mean TN concentration in reservoirs with the PFA/watershed area of above 25% was ${\geq}2.6$ mg $L^{-1}$. Based on the TSI deviation analysis, water quality parameters in TYPE III reservoirs were in high concentration compared to other reservoirs types. Characteristics of Type III generally showed eutrophic, small DA/RA ratio, shallow depth, and large paddy field and upland field to watershed ratio compared to other types of reservoirs. Both water quality and morpho-physical parameters, Type I and II reservoirs were similar with the exceptions of BOD and chi. ${\alpha}$ concentration. Phosphorus in Type I reservoirs was not the primary limiting factor on algal growth, but significant decrease chl. ${\alpha}$ concentration with the increasing TN/TP indicated that phosphorus was the possible secondary limiting factor. Overall results indicated that type of land use, such as PFA and UFA area in watershed, was important parameters for the assessment of water quality characteristics, and phosphorus was limiting nutrient on algal growth in 490 reservoirs.

• Korean Journal of Ecology and Environment
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• v.36 no.2 s.103
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• pp.161-171
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• 2003

The present study evaluated water quality variation, limiting nutrient, and sediment of a shallow eutrophic lake (Lake Ilgam) in the metropolitan area from 2000 to 2002. According to annual mean chl.a ($77.2{\pm}36.6\;{\mu}g/l) and TP ($66.6{\pm}20.5\;{\mu}g/l) concentration and trophic state index (>60), Lake llgam was in very eutrophic status. Both inorganic nitrogen ($NH_3-N$ and $NH_3-N$) and phosphorus (SRP) concentrations in the water column increased during winter and spring, but decreased during summer followed by the phytoplankton development. Evidence for phosphorus and nitrogen as being the potential limiting nutrients for phytoplankton growth was supported by the ratio of DIN/DIP (by mass) (${\sim}$835.8), TSI derivations analysis, and algal growth potential bioassay. Based on the results of TSI derivations, strong nutrient limitation by both N and P occurred from September to November when P content in sediment (114.6 mg P/kg) was relatively low compared with the summer. Sediment contained a large amount of nitrogen (TKN: 4,452${\pm}$283.0mg N/kg dry sediment). Phosphorus content in sediment (TP: 313${\pm}$155 mg P/kg) was relatively low with temporal change. P release rate (0.29${\pm}$0.02 mg $m^{-2}$ $day^{-1}$) was high under the aerobic condition at pH 9. These results indicate that the sediment could play an important role as a source of a limiting nutrient, and temporal change of P content in the sediment is closely related with water quality, especially algal biomass change in Lake llgam.