• Environmental and Resource Economics Review
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• v.5 no.2
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• pp.253-278
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• 1996

본 연구는 전력사업에서 공급설비가 다양할 때 계절 시간대별 요금에서 최적투자 및 가격정책을 도출하기 위한 동태적 분석방법을 제공하는 데 있다. 이를 위하여 수요의 교차 가격탄력성을 고려한 동태적 모형을 설정하여 최대원리법(Maximum Principle)을 적용하였으며, 최적해 도출시 해석적 방법을 이용하여 모형의 수리적 해석에 대한 방법론을 제시하였다. 특히 순 사회편익을 목적함수로하고 이를 최대화하는 제어변수를 설비투자로하여 각 시간경로 (Time Path)에 따른 최적 가격이 단기 및 장기 한계비용과 어떻게 연관되는지를 보여주었다. 또한 제어변수인 설비투자가 계속적인 수요증가가 발생하는 시간경로에 따라 최적값이 어떻게 변하는지도 보여 주었다.

• Economic Analysis
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• v.27 no.4
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• pp.43-69
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• 2021

As the trade linkages and the financial relationship between China and Korea grow stronger, China's influence on Korea is also growing larger. Therefore, it is meaningful to examine key features of Chinese monetary policy operations and the current situation, and to analyze the transmission mechanism of China's monetary policy shocks onto the Korea economy. China's monetary policy shocks can have an impact on the Korea economy through the trade, financial and oil-price channels. In the trade channel, an expansionary Chinese monetary policy can increase Korea's exports of intermediate goods to China under the vertical trade structure, via the vertical trade integration effect. Meanwhile, the expenditure switching effect and the income demand effect show no statistical significance. In the financial and oil-price channels, expansionary Chinese monetary policy shocks can decrease the interest rate and increase both stock prices and the consumer price index in Korea through changes in global portfolio capital flows, interest rates, and raw material prices.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1011-1016
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• 2020

Rapid change in network topology in high-speed VANET(: Vehicular Ad Hoc Network) is an important task for routing protocol design. Selecting the next hop relay node that affects the performance of the routing protocol is a difficult process. The disadvantages of AODV(: Ad Hoc On-Demand Distance Vector) related to VANET are end-to-end delay and packet loss. This paper proposes the AAODV (Advanced AODV) technique to reduce the number of RREQ (: Route Request) and RREP (: Route Reply) messages by modifying the AODV routing protocol and adding direction parameters and 2-step filtering. It can be seen that the proposed AAODV reduces packet loss and minimizes the effect of direction parameters, thereby increasing packet delivery rate and reducing end-to-end delay.

• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.353-355
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• 2010

본 논문에서는 터널환경에서 전파의 경로 손실 특성을 예측할 수 있도록 시뮬레이터를 개발하였다. 전파의 경로를 정확히 분석하기 위하여 image theory 방법을 이용하였으며, 직선 터널 구간뿐만 아니라 곡선 터널 구간에서도 전파 손실을 예측할 수 있도록 구현하였다. 시뮬레이터는 다양한 변수들을 입력받아 실시간으로 전파 경로를 도식화하여 결과를 보여줄 수 있으며, 송신부와 수신부의 위치를 변경하며 결과를 예측할 수도 있다. 개발된 시뮬레이터를 다양한 직석터널과 곡선터널에 적용하여 결과를 비교 분석하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.649-654
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• 2008

In the definition of non additive path, the sum of travel costs of links making up the path is not equal to the path cost. There are a variety of cases that non-additivity assumption does not hold in transportation fields. Nonetheless, traffic equilibrium models are generally built up on the fundamental hypothesis of additivity assumption. In this case traffic equilibrium models are only applicable within restrictive conditions of the path cost being linear functions of link cost. Area-wide road pricing is known as an example of realistic transportation situations, which violates such additivity assumption. Because travel fare is charged at the moment of driver's passing by exit gate while identified at entry gate, it may not be added linearly proportional to link costs. This research proposes a novel Wordrop type of traffic equilibrium model in terms of area-wide road pricing schemes. It introduces binary indicator variable for the sake of transforming non-additive path cost to additive. Since conventional shortest path and Frank-Wolfe algorithm can be applied without route enumeration and network representation is not required, it can be recognized more generalized model compared to the pre-proposed approaches. Theoretical proofs and case studies are demonstrated.

• Journal of the Korean Geosynthetics Society
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• v.11 no.2
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• pp.1-9
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• 2012

In order to review the utility of Lade's single hardening constitutive model, a series of isotropic compression-expansion tests and consolidated drained triaxial tests including as CTC, TC, RTC, and OSP were performed by Baekma river sand with various of stress path. Parameters required in model were determined using these tests. The accuracy of analysis was reviewed by back analysis of test results used to determine the 11 parameters of soil property through the test of each stress path. Also. for verifying the accuracy of prediction for the stress-strain behavior using failure criterion related 9 parameters with correlational equation and constant and yield criterion related parameters h, ${\alpha}$ and ${\eta}_1$, when stress path is different with each other, it has been obtained in the review result of stress path dependent characteristics of the constitutional model through the analyzing results of CTC, TC, RTC, OSP, and fine silica sand tests.

• 한국노년학
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• v.37 no.3
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• pp.527-547
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• 2017

The purpose of this study is to investigate how depression, death anxiety, and social support can exert influence on the psychological well-being of elderly living alone through a parameter of resilience. A survey was conducted involving 988 elderly over the age of 65 living alone in the Daejeon metropolitan area and Chungcheongnam-do and the data were analyzed using structure equation model. The results were as follows. First, in the measurement of variables according to demographic characteristics, depression showed significant differences depending on gender, level of education, health, and financial condition, while death anxiety differed depending on gender, and level of education. Social support was significantly different by gender, age, level of education, region, health, and financial condition. The level of resilience was significantly different by gender, age, level of education, health, and financial condition. Psychological well-being varied according to gender, level of education, health, and financial condition. Second, the effects of depression, death anxiety and social support on psychological well-being were examined. It was found that depression had a negative influence and social support had a positive impact while death anxiety showed no influence. Third, with regard to the effects of depression, death anxiety, social support on resilience, depression was found having negative influence, whereas social support having positive influence. Forth, psychological well-being was positively affected by resilience. Also, through the mediated pathway of resilience, their psychological well-being seemed to totally improve when the negative factors were reduced and the positive ones promoted. This study may have some significance in reference to examine the factors affecting the psychological well-being of elderly living alone and to develop social welfare service programs and policies in the field.

• Journal of Distribution Research
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• v.16 no.3
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• pp.105-133
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• 2011

Short Abstract: This study investigates the effects of price and other variables on consumers' purchasing decision for eco-friendly foods. This study pays particular attention to the effect of price that may influences consumers' decision to buy eco-friendly foods. The empirical findings are summarized as follows. First, the descriptive results of the survey show that "detailed explanation for the products," "distribution channel," "reliability of the labeling for eco-friendly foods" are more important than price and other factors. Second, the ordered logit analysis vindicates that such situational factors as number of children and existence of patient in the family are the most important variables to explain the degree of satisfaction level when considering the price level of eco-friendly foods. Finally, the results of the conjoint analysis indicate that consumers regard distribution channel as the most important factor, and reliability of labeling system and level of price position second and third, respectively. The present study concludes with suggesting some policy implications and directing future studies.

• Informatization Policy
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• v.24 no.1
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• pp.48-78
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• 2017

In this study, to reveal determinant factors for degree of open data it conduct empirical analysis for ODB(Open Data Barometer) and OUR Index(Open, Useful, Reusable Government Data Index) that are global open data index among 26 countries. As a result of multiple regression analysis, First focus is on ODB. In the Model 1 with independent variables, e-Government, SW Market size and government efficacy are significantly positive effect for ODB. In the Model 2 with independent variables and moderating variable, e-Government, SW market size and social capital are significantly positive effect for ODB. In the Model 3 with independent variables, moderating variable and interaction term, e-Government and social capital are significantly positive effect for ODB. Second focus is on OUR Index. In the Model 1 and the Model 2 e-Government is significantly positive effect for OUR Index. In the Model, e-Government and SW market size ${\times}$ social capital(interaction term) are significantly positive effect for OUR Index. And in path analysis, only ODB alternative model show Government efficacy with social capital has full mediation effect. In OUR Index alternative model there is no mediation effect with social capital.

• Journal of Radiation Protection and Research
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• v.25 no.1
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• pp.11-19
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• 2000

The sensitivity analysis of input parameters for a dynamic food chain model DYNACON was conducted as a function of deposition date for the long-lived radionuclides $(^{137}Cs,\;^{90}Sr)$. Also, the influence of input parameters for the short and long-terms contamination of selected foodstuffs (cereals, leafy vegetables, milk) was investigated. The input parameters were sampled using the LHS technique, and their sensitivity indices represented as PRCC. The sensitivity index was strongly dependent on contamination period as well as deposition date. In case of deposition during the growing stages of plants, the input parameters associated with contamination by foliar absorption were relatively important in long-term contamination as well as short-term contamination. They were also important in short-term contamination in case of deposition during the non-growing stages. In long-term contamination, the influence of input parameters associated with foliar absorption decreased, while the influence of input parameters associated with root uptake increased. These phenomena were more remarkable in case of the deposition of non-growing stages than growing stages, and in case of $^{90}Sr$ deposition than $^{137}Cs$ deposition. In case of deposition during growing stages of pasture, the input parameters associated with the characteristics of cattle such as feed-milk transfer factor and daily intake rate of cattle were relatively important in contamination of milk.