• Journal of Korean Society of Transportation
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• v.26 no.2
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• pp.147-156
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• 2008

It has been widely known that there are so many factors making travel demand errors in transportation forecasting steps. One of the reasons may stem from the level of aggregation of zone and network in analysis process. This paper investigates the effect of level of aggregation considering with number of zones in travel demand forecasting by expanding or reducing the zone and network gradually. Numerical results show that the aggregation could not make a significant impact on the travel demand, while disaggregation does. These results imply that a careful manipulation is required to add or to reduce zones and links in transportation planning process.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.4
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• pp.41-53
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• 2018

This study developed the optimization method to correct the measured traffic volume of the expressway that minimizes the measurement error and satisfies the traffic balancing with TCS. For this purpose, the model constructed in this study was compared and verified with the true traffic volume. Verification result of the model, it was found that the measurement error is reduced when the measured traffic volume is corrected for the traffic volume balance. As a result of applying it to 40 links of the Kyoungbu expressway, the measured traffic volume was corrected by -8.1%~9.6% and the measurement error was decreased as much as the corrected traffic volume. This research is meaningful in improving the accuracy of the measured traffic volume of the expressway, while the scale and role of the expressway are increasing.

• Journal of the Korea Convergence Society
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• v.11 no.7
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• pp.231-238
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• 2020

In the case of ICT-enabled organizational changes such as Smart Work, appropriate change management is required. To achieve work-life balance, organizational change management should be conducted from both a structural and a cultural perspective. This study looked at organizational factors that affect Smart Work facilitation through a case study with the view of ICT-enabled change management. From November to December 2019, eight Smart Workers of Company A were interviewed and analyzed for organizational support. The results show that structural support such as institutionalization, ICT infrastructure office environment improvement, Smart Work center as well as cultural support such as enhancing autonomy, communicating style of managers, trusting organizational climate are required. The findings suggest balanced organizational support to provide cultural support along with structural support for activating Smart Work operations. In the future, it is necessary to demonstrate the causality between structural/cultural support factors and outcome factors.

• The Korean Journal of Applied Statistics
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• v.27 no.6
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• pp.1017-1028
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• 2014

Well-known Bayes and empirical Bayes estimators have a disadvantage in respecting to overshink the parameter estimator error; therefore, a constrained Bayes estimator is suggested by matching the first two moments. Also traditional loss function such as mean square error loss function only considers the precision of estimation and to consider both precision and goodness of fit, balanced loss function is suggested. With these reasons, constrained Bayes estimators under balanced loss function is recommended for non-life insurance pricing.; however, most studies focus on the performance of estimation since Bayes risk of newly suggested estimators such as constrained Bayes and constrained empirical Bayes estimators under specific loss function is difficult to derive. This study compares the Bayes risk of several Bayes estimators under two different loss functions for estimating the risk in the auto insurance business and indicates the effectiveness of the newly suggested Bayes estimators with regards to Bayes risk perspective through auto insurance real data analysis.

• Environmental and Resource Economics Review
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• v.30 no.2
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• pp.269-297
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• 2021

Bioplastics are attracting attention as a substitute for conventional petroleum-based plastics because they are carbon neutral and can be biodegradable. This study estimated economic and environmental impact of regulating the petroleum-based plastics industry and fostering the bioplastics industry using a Recursive Dynamic CGE Model of the Korean Economy. Results show that the regulation of the conventional plastics industry exhibits a positive environmental impact by reducing greenhouse gases and plastic waste and a negative economic impact with a decrease in GDP. Meanwhile, fostering the bioplastics industry with regulation on conventional plastics industry has similar levels of greenhouse gas and waste reduction effects when there is only regulation on the conventional plastics industry. It is also shown that expanding the production of bioplastics industry offsets existing economic losses as a form of increased GDP. If petroleum-based plastics are replaced through the expansion of bioplastics production, it can contribute to the decoupling of greenhouse gas emissions and plastic waste from economic growth.

• Environmental and Resource Economics Review
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• v.30 no.2
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• pp.169-205
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• 2021

This study quantitatively analyzes the impact of greenhouse gas (GHG) emissions reduction policies on the global economy. To this end, we develop a multi-national and multi-industry static computational general equilibrium model that includes three components-GHG emissions from production, disutility due to GHG emissions, and governments' GHG emissions reduction policies. Then we calibrate the model with the relevant data and solve for the equlibrium using the most recent methodology (exact hat algebra). We find that the strengthening of unilateral GHG emissions reduction policies for each country reduces carbon emissions from domestic producers, but does not necessarily reduce global carbon emissions as production is relocated to other countries. On the other hand, we can reduce GHG emissions when all major countries simultaneously implement the strengthened reduction policies proposed by the OECD (2016). Our results imply that aligned reduction efforts of major countries are necessary to reduce global GHG emissions.

• Korea Trade Review
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• v.48 no.1
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• pp.83-126
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• 2023

The revenue histogram of venture businesses is shifting from bell-shaped normal distribution to power-law distribution, which implies that the fitness landscape of the venture businesses ecosystem is changing to be more rugged terrain. We argue that the firm should adopt both exploitation (fast follower) and exploration (or first mover) strategies not to get stuck in local maxima in the rugged fitness landscape from the complex system perspective. By designing and performing agent-based modeling simulation experiments which consist of three types of agents (new technologies, entrepreneurs, and consumers), we demonstrated that the ambidexterity strategy showed the highest performance score in three of four different environment except 'Fast Widening' case where the exploitation strategy showed the highest performance score under low technology appropriation and fast disruptive technology development speed. By investigating the financial and other statistics of 617 top venture businesses who have earned 100B won or higher annual revenue, we concluded that 82% and 9% of firms are bent on the exploitation and exploration strategy.

• Journal of Labour Economics
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• v.28 no.1
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• pp.105-133
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• 2005

This paper attempts to verify that the economic gap between the workers in (large) firms with unions and those in (small and medium size) firms with no unions has recently been widened rapidly. A comparison of the wages of the workers belonging to the business establishments with and without trade union shows that the union premium has increased very sharply since 1997, after a relatively long periods with little changes. Also found is that union sector has witnessed a sharper decline in the share of the new entrants among workers as well as a faster increase of the average tenure of workers. These all indicate that the trade unions have forced a market equilibrium to move farther away from the competitive equilibrium in recent years.

• The Korean Journal of Financial Management
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• v.10 no.2
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• pp.1-51
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• 1993

본 논문의 목적은 첫째, 자본자유화로 인해 통화공급 구조가 이미 균형에서 이탈하여 심각한 수준의 불균형 상해에 있다는 점을 실증적으로 입증하고자 한다. 둘째, 자본유입에 따른 정책조정 비용을 감안한 통화정책 모형을 통해 주장에 대한 이론적 근거를 제시하고, 정책 조절에 수반되는 손실비용(損失費用)과 Mundell의 $\ulcorner$할당 문제(割當 問題)$\lrcorner$를 다시 조명해 보고자 한다. 세째, 자본유입에 따르는 문제점들을 해결할 수 있는 정책방안들을 Modigliani ar Miller의 명제(命題)에 입각한 새로운 각도에서 합리적 인 증시정책을 모색해 보고자 한다. 분석의 이론적 틀로서는 자본유입에 따라 수반되는 불확실성하의 정책조절 비용을 감안한 손실비용 최소화(loss cost minimization)를 통해, 통화 당국자는 총통화량을 정책적으로 내정된 목표값에 수렴시킨다고 가정하였다. 다른 한편, 자본유입에 따르는 문제점들을 통화시장에만 제한시키는 부분적(部分的) 균형분석(均衡分析) 대신, 이를 증권시장으로 직접 연계시켜 두 시장으로 확장된 틀을 활용하였다. 본 논문의 연구방법은 다음 두가지 측면의 접근식을 따랐다. 첫째, 자본자유화정책의 특성을 살펴보기 위해, 자본자유화 시점을 기준으로 삼아 과거 자본통제 시대의 $\ulcorner$사후적(事後的)인 중화정책(中和政策)$\lrcorner$에 의존하는 $\ulcorner$소극적(消極的)인 증권정책(證券政策)$\lrcorner$과 자본자유화시대의 $\ulcorner$사전적(事前的)인 상살정책(相殺政策)$\lrcorner$에 의한 $\ulcorner$거시적(巨視的)인 증권정책(證券政策)$\lrcorner$을 통해 고찰하는 비교분석론에 입각한 접근식을 택했다. 둘째, 외국자본의 유입동기(流入動機)를 문제해결의 시발점으로 삼아 이를 새로운 개방정책과 직결시켜 문제해결의 실마리를 풀어 보려는 선험적(先驗的) 접근식(接近式)을 택했다.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.153-161
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• 2002

다사용자계층 통행배정(Multiple User Class Assignment) 문제란 교통망을 이용하는 통행자들이 이질적인 통행계층으로 구성된 경우, 이들 각 계층의 통행수요를 교통망에 배정하는 문제를 의미한다. 이는 기존 통행 배정모형들이 모든 통행자의 통행특성이 동질적이라고 가정함으로서 발생하는 불합리한 통행배정 결과를 완화시키기 위한 방법이다. 또한, 최근 지능형교통체계(Intelligent Transportation Systems, ITS)사업에서 교통정보제공시스템이 구현될 예정임에 따라, 교통정보를 제공받는 계층과 그렇지 못한 계층간의 영향을 분석하거나 혼잡통행료부과 등과 같은 교통관리전략을 정확히 평가하기 위해서 다사용자계층 통행배정모형에 대한 관심이 증가하고 있다. 그러나, 다사용자계층 통행배정모형의 경우, 사용자간의 상호영향으로 통행비용함수의 1차 편미분행렬(Jacobian matrix)이 비대칭(Asymmetric)이 되어 동등 수리최소화문제(Equivalency mathematical Minimization program)로 구성할 수 없고 또한 수치적으로 풀기가 어렵다는 문제가 있다. 본 연구는 이런 문제점을 극복할 수 있는 모형식과 알고리듬을 제시코자 한다. 본 연구에서 제시된 모형은 2가지 특징이 있다. 먼저, 각 사용자 계층간의 상호영향을 모형내에 반영하며, 기종점쌍간의 통행시간변화에 따른 수요변화를 고려한다는 점이다. 이를 위하여 변동부등모형(Variational Inequality Model. VI)으로 문제를 구성하며, 이에 대한 해석 알고리듬도 제시한다. 또한, 변동부등모형으로 구축된 다사용자계층 모형이 다사용자계층 균형조건과 동일함을 보여주는 동등성조건(Equivalency condition)도 제시한다.