• KDI Journal of Economic Policy
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• v.30 no.2
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• pp.225-270
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• 2008

We analyze macroeconomic consequences of pay-as-you-go (PAYGO) public pension system with a simple overlapping generations model. Contrary to large body of existing literatures offering quantitative results based on simulation study, we take another route by adopting a highly simplified framework in search of qualitatively tractable analytical results. The main contribution of our results lies in providing a sound theoretical foundation that can be utilized in interpreting various quantitative results offered by simulation studies of large scale general equilibrium models. We present a simple overlapping generations model with a defined benefit(DB) PAYGO public pension system as a benchmark case and derive an analytical equilibrium solution utilizing graphical illustration. We also discuss the modifications of the benchmark model required to encompass a defined contribution(DC) public pension system into the basic framework. Comparative statics analysis provides three important implications; First, introduction and expansion of the PAYGO public pension, DB or DC, result in lower level of capital accumulation and higher expected rate of return on the risky asset. Second, it is shown that the progress of population aging is accompanied by lower capital stock due to decrease in both demand and supply of risky asset. Moreover, risk premium for risky asset increases(decreases) as the speed of population aging accelerates(decelerates) so that the possibility of so-called "the great meltdown" of asset market cannot be excluded although the odds are not high. Third, it is most likely that the switch from DB PAYGO to DC PAYGO would result in lower capital stock and higher expected return on the risky asset mainly due to the fact that the young generation regards DC PAYGO pension as another risky asset competing against the risky asset traded in the market. This theoretical prediction coincides with one of the firmly established propositions in empirical literature that the currently dominant form of public pension system has the tendency to crowd out private capital accumulation.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2014.10a
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• pp.535-555
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• 2014

• Economic Analysis
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• v.27 no.3
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• pp.33-60
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• 2021

This study estimates the fiscal multiplier using Input-Output table panel data from year of 2010 to 2018. Considering the endogeneity of the government expenditure, this study uses the share of government expenditure by sector in the initial period as an instrument variable. The estimation from the panel fixed effect instrumental variables model shows that the estimate for the current period of government expenditure is 1.15~1.22 and the estimate for the cumulative multiplier is 1.23~1.32 depending on the method of controlling time trend. Since the general equilibrium effect absorbed by the time-fixed effect in the estimation equation, the estimated multiplier in this study may be different from the multiplier of the economy as a whole. The general equilibrium effect depends on the response of monetary policy, changes in tax policy, and interaction between sectors.

• Journal of the Korean Applied Science and Technology
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• v.31 no.2
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• pp.265-276
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• 2014

The purpose of this study was to evaluate the effect on lowering blood LDL-C in an adult human, by taking n-6/n-3 balanced Hanwoo beef and reducing n-6/n-3 in loin of Hanwoo beef. The randomized complete block design was used to conduct an experiment with a total of 20 castrated Hanwoo cattles, which were divided into two groups. Each group had 10 cattles, and the control group consisted of absence of linseed, while n-3 treatment group (n-3 group) had linseed. The results showed that n-6/n-3 in loin and blood was decreased to under 4:1 in n-3 group, while oleic acid as an monounsaturated fatty acid was increased by 52.79% compared to the control group. In above 70% of the clinical subjects who ate the balanced Hanwoo beef, the blood triglyceride, total cholesterol, and LDL-C were decreased by 25.35, 5.22, and 17.59%. However, in the subjects who ate the imported beef, and not the common Hanwoo beef, the same parameters were increased by 9.05, 8.21, and 21.70%, respectively. When the balanced Hanwoo beef were eaten, HDL-C were increased by 6.07% but the imported beef and common Hanwoo beef had those values decreased by 14.46 and 11.46%, respectively. The blood glucose was decreased by 6.42 and 11.82% in the subjects who ate balanced Hanwoo beef and common Hanwoo beef, respectively but the subjects who ate the imported beef had an increase by 15.19%.

• The Journal of Korean Academy of Sensory Integration
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• v.17 no.1
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• pp.9-18
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• 2019

Objective : This study investigated the effect of intensive weight shift training (IWST) on the ability to balance in a sitting posture of children with spastic cerebral palsy (SCP). Methods : One child with spastic diplegia participated in this study for a total of 8 weeks using the ABA experimental design. For the pre-intervention period (A1), general physical therapy (GPT) for children with SCP was performed. The intervention period (B1 and B2), GPT and IWST were conducted for children with SCP, and GPT was conducted again for the post-intervention period (A'1 and A'2). Trunk control capacity was measured using the Korean Trunk Control Measurement Scale (TCMS-K) and Biorescue (RM Ingenierie, France). Results : All TCMS-K variables increased from A1 to B2, and decreased from B2 to A'2. The total area with limit of stability (LOS) increased from A1 to B2, and decreased from B2 to A'2. The ratio of the left/right (Lt/Rt) and anterior/posterior (Ant/Post) LOS area was closer to 1, meaning symmetry, in B2 than in A1. The ratio of the Lt/Rt LOS area decreased further from 1 in A'2 than in B2. The ratio of the Ant/Post LOS area was closer to 1 in A'2 than in B2. Conclusion : IWST had a positive effect on the improvement of balance in the sitting posture of a child with SCP. The results suggest that IWST might help to improve the balance abilities of children with SCP for independent sitting, postural control, and activities of daily living.

• Journal of the korean Society of Automotive Engineers
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• v.7 no.1
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• pp.18-23
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• 1985

내연기관은 자동차용 기관에 의하여 일반대중과 접촉하게 되었으며, 특히 20세기 중반에 이르러 자동차라는 기계가 일반가정에서 사용되는 가구로 탈피하는 과정에서 그 중요장치의 하나인 자동차용 기관도 전문가가 취급하는 기계로부터 일반인이 취급하는 가구로의 탈피를 요구함에 따라 크게 발전해 온 것이 사실이다. 종래, 내연기관의 설계에 있어서 그 출력과 연료소비를 가장 중요한 성능평가의 요소로 삼아왔지만, 가구로서의 자동차의 최적화를 위해서는 더욱 중요한 많은 성능평가의 요소가 있다는 것을 인식할 필요가 있다고 생각한다. 실은 최적화에 필요한 많은 요소의 균형을 어떻게 할 것인가 하는 것이 자동차용 기관의 설계에 있어서 가장 중요한 일이라 생각되며, 자동차용 기관을 계획할 때의 목표는 다음과 같은 3가지로 생각된다. (1) 고성능일 것 (2) 우수한 기능을 가질 것 (3) 공해가 없을 것 (1)의 고성능을 추구하는데 있어서는 비출력, 연료소비율 및 양호한 응답성이 중요한 요소로 된다. 이중 응답성의 문제는 연료공급기구나 조속기 등의 기능적인 요소와 깊은 관련이 있다. 그리고 내구성, 신뢰성, 정비점검의 무용성이라는 것이 (2)의 우수한 기능을 보장하기 위한 가장 중요한 배경으로 된다. 또한 진동이나 소음이 없고 정숙할 것이 (3)의 무공해성의 목표와도 관 련되는 중요한 요소이다. 배출가스의 무공해화가 자동차에 의한 공해방지의 입장으로부터 중요한 요소가 되는 것은 주지의 사실이다. 그리고 이 배출가스의 청정화의 문제는 성능향상을 위한 비출력증대의 방향에 대한 방해가 되는 문제이다. 이상 기술한 바와 같은 설계단계에 있어서의 계획목표를 3가지로 설정하고, 이 3가지 목표에 관련되는 요소의 균형을 어떻게 위해야 할 것인가 하는 점에 초점을 맞추어 되도록 쉽게 기술하고자 하였으나, 미비한 점이 많았을 것으로 생각하여, 다만 이 분야에 종사하는 기술자 여러분에게 약간의 도움이라도 되었으면 하는 것이 소망이다.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 1999.03a
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• pp.291-300
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• 1999

본 논문은 인공신경망과 귀납적 학습방법 등의 인공지능 방법과 선물가격결정에 대한 기존 재무이론을 사용하여 일상어휘로 표현되는 파생상품 가격예측 모형을 개발하는데 있다. 모형의 개발은 1단계로 인공신경망이나 기존의 선물가격결정이론(평균보유비용모형이나 일반균형모형)을 이용하여 선물 가격을 예측한 후, 서로 비교분석하여 인공신경망 모형의 우수성을 확인하였다. 귀납적 학습방법중 CART 알고리듬을 사용하여 If-Then 규칙을 생성하였다. 특히 실용적 측면에서 선물가격의 일상어휘화를 통한 모형개발을 여러 가지 방법으로 시도하였다. 이러한 선물가격 예측모형의 유용성은 일단 If-Then 규칙으로 표현되어 전문가의 판단에 확실한 이론적인 근거를 제시할 수 있는 장점이 있으며, 특히 의사결정지원시스템으로 활용화 될 경우 매우 유용한 근거자료로 활용될 수 있다. 이러한 선물가격 예측모형은 정확성은 분석표본과 검증표본으로 나누어 검증표본에서 세가지 기본모형(평균보유비용모형, 일반균형모형, 인공신경망 모형)과 각 모형의 귀납적 학습방법 모형의 다른 3가지 어휘표현방법 3가지를 모형별로 비교 분석하였다. 분석결과 인공신경망모형은 상당한 예측력을 갖고 있는 것으로 판명되었으며, 특히 CART를 기반으로 한 일상어휘 기반의 선물가격예측 모형은 예측력이 높은 것으로 나타났다.

• Environmental and Resource Economics Review
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• v.12 no.2
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• pp.245-274
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• 2003

This paper analyzes the economic and environmental impacts of domestic policy to reduce greenhouse gas emissions by focusing on carbon tax, domestic emissions trading and the mixture of these policies. By utilizing a dynamic CGE model, KORTEM, this study shows that the economic cost under carbon tax is projected to be higher than that under emission trading. It is because under carbon tax scheme each emitter in economy must meet its emission target regardless of the abatement cost. On the other hand, emission trading allows emitters to reduce the marginal cost of abatement through trading of emission permits. In designing policy portfolio to address the climate change problem in Korea, therefore, this paper proposes the introduction of domestic emission trading scheme as the main domestic policy Instrument.

• KDI Journal of Economic Policy
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• v.31 no.1
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• pp.1-25
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• 2009

This paper attempts to estimate the natural rates of output and interest of Korea in a simple DSGE set-up with a few stylized New Keynesian features using Bayesian methods. The major findings of this paper are as follows. First, the estimates of output gaps are less volatile than the measures from conventional approaches, although they exhibit non-negligible variations depending on the model specification. Another key finding is that the hybrid type Phillips curve with a backward-looking component and/or habit formation in consumption may play an important role in characterizing the macroeconomic dynamics of Korea.

• Journal of the Korea Society of Computer and Information
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• v.17 no.9
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• pp.139-147
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• 2012

This paper suggests simple search algorithm for optimal solution in assignment problem. Generally, the optimal solution of assignment problem can be obtained by Hungarian algorithm. The proposed algorithm reduces the 4 steps of Hungarian algorithm to 1 step, and only selects the minimum cost of row and column then gets the optimal solution simply. For the 27 balanced and 7 unbalanced assignment problems, this algorithm finds the optimal solution but the genetic algorithm fails to find this values. This algorithm improves the time complexity O($n^3$) of Hungarian algorithm to O(n). Therefore, the proposed algorithm can be general algorithm for assignment problem replace Hungarian algorithm.