• Journal of The Korean Astronomical Society
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• v.37 no.1
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• pp.55-59
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• 2004

We have developed a two fluid solar wind model from the Sun to 1 AU. Its basic equations are mass, momentum and energy conservations. In these equations, we include a wave mechanism of heating the corona and accelerating the wind. The two fluid model takes into account the power spectrum of Alfvenic wave fluctuation. Model computations have been made to fit observational constraints such as electron($T_e$) and proton($T_p$) temperatures and solar wind speed(V) at 1 AU. As a result, we obtained physical quantities of solar wind as follows: $T_e$ is $7.4{\times}10^5$ K and density(n) is $1.7 {\times}10^7\;cm^{-3}$ in the corona. At 1 AU $T_e$ is $2.1 {\times} 10^5$ K and n is $0.3 cm^{-3}$, and V is $511 km\;s^{-1}$. Our model well explains the heating of protons in the corona and the acceleration of the solar wind.

• Journal of Korean Society of Transportation
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• v.18 no.1
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• pp.87-97
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• 2000

Signal optimization model is divided bandwidth-maximizing model and delay-minimizing model. Bandwidth-maximizing model express model formulation as MILP(Mixed Integer Linear Programming) and delay-minimizing model like TRANSYT-7F use "hill climbing" a1gorithm to optimize signal times. This study Proposed optimization model using genetic algorithm one of evolution algorithm breaking from existing optimization model This Proposed model were tested by several scenarios and evaluated through NETSIM with TRANSYT-7F\`s outputs. The result showed capability that can obtain superior solution.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.7
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• pp.1023-1033
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• 2008

The purpose of this study was to segment home-shopper market by using the demographic characteristics. This study enables a better unders landing of home-shoppers and improving the strategy of marketing. The specific objects of this study are as follow: First, it was to exam market segmentations by demographic factors using mixture model. Second, it was to exam shopping orientations of fashion merchandise according to segmentation groups. The data was collected from 637 subjects who had used the home shopping more than one time in a year. The data was analysised through frequencies, factor analysis, ANOVA, Duncan's mutiple range tests with SPSS 12.0 and Mixture model. The results of data are as follows: 1. The result of market segmentation as demographic factor using Mixture model was extracted to 4 market segments called 20's/ unmarried stage, 30's/ children bearing & rearing stage, 40's/ families with children's education stage, 50's/ aging stage. 2. Shopping orientations were extracted to 5 factors called a pleasure oriented, convenience oriented, off-line oriented, human oriented, thrift oriented.

• Journal of Digital Convergence
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• v.7 no.1
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• pp.73-80
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• 2009

In this study, the pricing performances of alternative simple option models are examined by creating a simulated market environment in which asset prices evolve according to a stochastic volatility process. To do this, option prices fully consistent with Heston[9]'s model are generated. Assuming this prices as market prices, the trading positions utilizing the Black-Scholes[4] model, a semi-parametric Corrado-Su[7] model and an ad-hoc modified Black-Scholes model are evaluated with respect to the true option prices obtained from Heston's stochastic volatility model. The simulation results suggest that both the Corrado-Su model and the modified Black-Scholes model perform well in this simulated world substantially reducing the biases of the Black-Scholes model arising from stochastic volatility. Surprisingly, however, the improvements of the modified Black-Scholes model over the Black-Scholes model are much higher than those of the Corrado-Su model.

• Journal of the Korean Home Economics Association
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• v.46 no.7
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• pp.95-108
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• 2008

The major purpose of this study was to investigate the effect of intergenerational transmission of self-differentiation on psychological adjustment of college students. Specifically, the present study endeavored to test the causal model focusing on the effect of the father's and the mother's self-differentiation on college student's psychological adjustment through the student's self-differentiation. The data were collected from 254 male and 293 female college students and their parents by using self-administered questionnaire method. The casual model was tested through structural equation model by using AMOS 7.0 program. The results showed that mother's and father's self-differentiation had direct and indirect effect on student's psychological adjustment. The results showed that both mother's and father's self-differentiation had direct effect on son's self-differentiation level, which directly influenced his psychological adjustment. The test of structural equation model also revealed that daughter's self-differentiation level was positively influenced only by mother's self-differentiation, while father's self-differentiation did not influenced female student's self-differentiation. Both male and female student's psychological adjustment was directly influenced by his or her self-differentiation level.

• Journal of Korean Society of Transportation
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• v.14 no.2
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• pp.7-29
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• 1996

Traffic flow characteristics is analysed on eight multi-lane roads which are unsignalized in urban areas. Data of traffic flow rates by classification and average speed were gathered every ten minutes interval for twenty-four hours. Machine (NC-90A) was used to acquire the field data. The major purpose of this study is to build up speed-density models on urban arterial roads. Five different kinds of models were tested. Those models are Greenshields' model, Greenberg's model, modified Greenberg's model, Underwood's model and Drake's model. The modified Greenberg's model fits best at six points and the Greenshield's model fits best two points out of eight points. The breakpoint(Kb) of modified Greenberg's model is between 10 and 32 pcphpl. Capacity drawn from speed-volume relationships were appeared to be arround 2,000 and 2,200 pcphpl at the Hannam Bridge and the Hannam Overpass and 1,100 and 1,700 pcphpl at Namsan Tunnel(No1) and the beginning point of Gyeong-Bu Expressway.

• Communications for Statistical Applications and Methods
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• v.7 no.3
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• pp.721-729
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• 2000

In this paper, we propose a new conditional randomized response model that has improved the Carr et al.'s model in view of he variance and the protection of privacy of respondents. We show that he suggested model is more effective and protective than the Loynes' model and Carr et al.' model.

• Korean Institute of Interior Design Journal
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• v.21 no.6
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• pp.212-223
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• 2012

The "Eco-friendly", "Green" concepts was began around 1992 after the Rio Environmental Summit, and the need for sustainable development globally widespread. The green building certification system was began around 2000 and the concept of green building was started in the late 1990s. The green building, which welcomes a period of radical change, is for the survival of the Earth "climate change" and reducing energy consumption in building sector. In this architecture of eco-friendly concept, the green building is rapidly expanding and existing as a ecological environment preservation. Moreover, the realization of zero energy house is to mandate for new buildings in 2025. The aim of further eco-friendly is through the prior ecosystems to restore and product energy for the 9 Green Building model houses in this paper. Building in the concept of ecology is to show about change into 7R's from the 3R's. The "Reduce", "Reuse", "Recycle" consisting of "3R's" is correlated with the traditional to the present Green Building Design. U.S. NCARB (National Council of Architectural Registration Boards) change into the concept of 7R's as "Receive", "Restore", "Respect" and "Remember", added to "3R's". In this paper, the 9 Green Building model houses do not meet the criteria of 7R's. But, the Green Tomorrow of Samsung C & T Corporation meet the 6 criteria for 7R's. This company is most comfortable at low carbon Green Building model houses. Conclusionally, introduction of eco-friendly technologies and amenities for the health of human and natural community life is to advance eco-friendly construction and enhance brand value of housing. By the way, The problem of eco-friendly architecture is initial investment and maintenance. Therefore, eco-friendly architecture and government has to try solving of this difficulty.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.5
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• pp.37-48
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• 2013

The objective of this study is to assess the impact of potential climate change on the hydrological components, especially on the streamflow, evapotranspiration and snowmelt, by using the Soil Water Assessment Tool (SWAT) for 17 Hanriver middle watersheds of South Korea. For future assessment, the SWAT model was calibrated in multiple sites using 4 years (2006-2009) and validated by using 2 years (2010-2011) daily observed data. For the model validation, the Nash-Sutcliffe model efficiency (NSE) for streamflow were 0.30-0.75. By applying the future scenarios predicted five future time periods Baseline (1992-2011), 2040s (2021-2040), 2060s (2041-2060), 2080s (2061-2080) and 2100s (2081-2100) to SWAT model, the 17 middle watersheds hydrological components of evapotranspiration, streamflow and snowmelt were evaluated. For the future precipitation and temperature of RCP 4.5 scenario increased 41.7 mm (2100s), $+3^{\circ}C$ conditions, the future streamflow showed +32.5 % (2040s), +24.8 % (2060s), +50.5 % (2080s) and +55.0 % (2100s). For the precipitation and temperature of RCP 8.5 scenario increased 63.9 mm (2100s), $+5.8^{\circ}C$ conditions, the future streamflow showed +35.5 % (2040s), +68.9 % (2060s), +58.0 % (2080s) and +63.6 % (2100s). To determine the impact on snowmelt for Hanriver middle watersheds, snowmelt parameters of SWAT model were determined through evaluating observed streamflow data during snowmelt periods (November-April). The results showed that average SMR (snowmelt / runoff) of 17 Hanriver middle watersheds was 62.0 % (Baseline). The annual average SMR were 42.0 % (2040s), 39.8 % (2060s), 29.4 % (2080s) and 27.9 % (2100s) by applying RCP 4.5 scenario. Also, the annual average SMR by applying RCP 8.5 scenario were 40.1 % (2040s), 29.4 % (2060s), 18.3 % (2080s) and 12.7 % (2100s).

• The Journal of Asian Finance, Economics and Business
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• v.7 no.8
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• pp.131-141
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• 2020

This study is designed to investigate the impact of China exchange rate policy on its trading partners by using a country multi-dataset GVAR model. Our model includes samples of 30 countries, six from high-income, six from middle-income and eighteen from low-income countries. This study used annual time series data over the period 1992 to 2017. We constructed currency misalignment index and it provided some interesting features about the currency undervaluation and overvaluation. The results of the currency misalignment shows that China's Renminbi is structurally more undervalued over the sample period as compared to other countries, and fluctuation in major currencies effects the global trade around the world. The overall empirical results of the GVAR model indicate that RMB undervaluation affects the trade pattern and macroeconomic performance of China's trading partners. Overall, China's exchange rate undervaluation has mixed effects on trading partner's GDP, exports and imports. The devaluation of China's RMB efficiently stimulated China's exports and reduced imports. While, in some countries, this effect is reverse, the RMB undervaluation increases the GDP of partner countries and also increases their exports to China. The results confirm the strong and leading role of the Chinese Renminbi in the global trade.