• Journal of Korean Society of Forest Science
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• v.90 no.2
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• pp.217-226
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• 2001

This study estimated the impacts of the building permit area change on the forest products import quantities in Korea. The first objective of this dissertation is to analyze whether there is any causal relationship between change in the building permit area and changes in the import quantities of forest products in Korea. Assuming that there is any causal relationship, the second objective is to evaluate the dynamics of the impacts of the building permit area change on the forest products import quantities in Korea. The relationship between the building permit area and the import quantity was represented by bivariate vector autoregressive or vector error correction model. Whether there is any causal relationship between change in the building permit area and changes in the import quantities of forest products was analyzed by the causality test of Granger. And the dynamics of the impacts of the building permit area change on the forest products import quantities were evaluated by variance decomposition analysis and impulse response analysis. The import quantity of forest products can be explained by the lagged building permit area variables and the lagged import quantity variables in Korea. Change in the building permit area causes change in the high-density fiberboard import quantity in Korea. In the bivariate model of the high-density fiberboard import quantity, after six months, the building permit area change accounts for about ten percent of variation in the import quantity, and its own change accounts for about ninety percent of variation in the import quantity. On the other hand, the impact of a shock to the building permit area is significant for about six months on the import quantity of high-density fiberboard in Korea. That is, if the building permit area change indeed had an impact on the import quantity of high-density fiberboard in Korea, it was only of a short-term nature.

• Journal of Korea Port Economic Association
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• v.26 no.1
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• pp.61-82
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• 2010

The purpose of this study is to examine the causuality among export and import trading volume of port of Busan, Kwangyang, Incheon and to induce policy implications. In order to test whether time series data is stationary and the model is fitness or not, we put in operation unit root test, cointegration test. And We apply Granger causality and impulse response and variance decomposition based on VECM. The results indicate that the trading volume of port of Busan is not largely influenced by that of port of Kawangyang and Incheon, but the trading volume of port of Kawangyang and Incheon is largely influenced by other ports including port of Busan. The result suggest that government has to focus on policy that the port of Kawangyang and Incheon can raise its own competitiveness in the world market.

• Journal of Korean Society of Forest Science
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• v.90 no.5
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• pp.663-671
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• 2001

This study estimated the impacts of the interest rate change on the forest products import quantities in Korea. The first objective is to analyze whether there is any causal relationship between change in the interest rate and changes in the import quantities of forest products in Korea. And the second objective is to evaluate the dynamics of the impacts of the interest rate change on the forest products import quantities in Korea. The relationship between the interest rate and the import quantity was represented by bivariate vector autoregressive model. Whether there is any causal relationship between change in the interest rate and changes in the import quantities of forest products was analyzed by the causality test. And the dynamics of the impacts of the interest rate change on the forest products import quantities were evaluated by variance decomposition analysis and impulse response analysis. The import quantity of forest products can be explained by the lagged interest rate variables and the lagged import quantity variables in Korea. Change in the interest rate causes change in the plywood import quantity in Korea. In the bivariate model of the plywood import quantity, after three months, the interest rate change accounts for about twenty percent of variation in the import quantity, and its own change accounts for about eighty percent of variation in the import quantity. On the other hand, the impact of a shock to the interest rate is significant for about six months on the import quantity of plywood in Korea. That is, if the interest rate change had an impact on the import quantity of plywood in Korea, it was only of a short-term nature.

• Journal of Korean Society of Forest Science
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• v.88 no.1
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• pp.1-10
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• 1999

The dynamic relationships among import prices of roundwood are analyzed using the time series approach. A vector autoregression(VAR) model is estimated for six import prices(New Zealand, Chile, Russia, U.S.A., PNG, and Malaysia). Then Granger's causality test, variance decomposition analysis, and impulse response function analysis are also conducted. The major results are summarized as follows : (1) The prices of New Zealand and Russia are caused by only own lagged prices. (2) The prices of Chile and PNG are effected by New Zealand, the price of PNG is effected by New Zealand and Russia, and the price of U.S.A. is effected by those of Chile and PNG, respectively. (3) An exogenous shock in New Zealand will affect the prices of New Zealand, PNG, U.S.A., Chile, Russia. (4) An exogenous shock in Chile may also affect the prices of Chile, U.S.A., Russia.

• Korean Journal of Construction Engineering and Management
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• v.6 no.3 s.25
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• pp.144-155
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• 2005

Since 1950s, the Korean housing market has continually experienced the chronicle lack of housing stock because of lower housing investment in comparison with a population explosion, prompt urbanization and rapid restructuring of family. The Korean housing market have thus been driven not by the pricing model by housing demand-supply chain but by the Korean housing policies focusing on the increase of housing supply and the living stability of the middle or low-income bracket. After all, repetitive economic vicious circle of housing price and the increase of unsold apartments aggravated the malfunction of the Korean housing market. Meanwhile, the Korean construction firms have exacerbated their profitability. Such terrible situations are mainly triggered by the Korean construction firms that weighed on the short-term profits and quick response of the government policy alterations rather than the prospect of housing market Therefore, this research focusing on the dynamics of housing market identified and classified the demand and supply elements that consist not only of housing system structures but also of the environmental elements that affect the structures. Based on the system thinking and traditional theory of consumer's choice, the interactions of these elements were constructed as a causal loop diagram that explains the mutual influences among housing subsystems with feedback loops. This paper describes and discusses about the causes of the dynamic changes in the Korean housing market. This study would help housing suppliers, including housing developers, construction firms, etc., to form a more comprehensive understanding on the fundamental issues that constitute the Korean housing market and thereby increasing their long term as well as minimizing the risk involved in the housing supply businesses.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.357-368
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• 2012

The purpose of this study is to empirically examine the impact of enterprise R&D investment on international trade in Korea under the new Normal Era. In order to test whether the time series data of trade variables are stationary or not, we put in operation unit root test and cointegration test. Based on VECM (Vector Error Correction Model), we also apply impulse response functions and variance decomposition to estimate the dynamic effects in the short-run and long-run. The results show that the relationship between enterprise R&D investment and international trade (export and import) exists in the long-run as well as in the short-run. The results of applying impulse response functions and variance decomposition also indicate that the impact of enterprise R&D investment on international trade is positive, and a significant portion of fluctuations in the trade variable is explained by enterprise R&D investment. Therefore, enterprise R&D investment must be continuously increased to improve economic growth with promoting trading competition power in Korea under the new Normal Era.

• Korean Business Review
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• v.11
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• pp.15-38
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• 1998

This study explores the evolution of technical innovation over time. It focuses on sectors of the information technology because this industry can be referred to as one of the most dynamic industries of all times. Following evolutionary theorists, we argue that technological change is gradual and that superior firms and technologies are reward by the' selection' environment. In the initial phase of the industry life cycle, technological change is expected to be radical and uncertainty is high. Over time a product or technology is likely to arise which stands out above all other products or technologies. These so-called 'basic designs' serve as sorts of 'technological guideposts' for further developments in the technology. Once a basic design established, technological progress tends to follow consistent paths or trajectories. The cumulative character of technological progress facilitates a rapid expansion of the boundaries of the technology until the natural limits of the technology are approached and technological progress slows down. Following ecological theories, supply-side developments in the industry are described on the basis of five different organizational types. On the basis of this pattern of market and technological evolution we came up with seven basic propositions.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.126-126
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• 2019

과거부터 수자원분야는 공학적인 측면을 주로 강조하였으며, 따라서 인문사회학적 요소(예, 토지이용, 인구, 생태 환경, 경제발전 등)가 종종 배제된 채 시설물 계획이 이루어졌다. 그러나, 경제가 발전하고 사회의 모습이 복잡해짐에 따라, 수자원 관련 시설물의 계획에 있어 다양한 인문사회학적 요소를 고려할 필요성이 높아지고 있다. 본 연구에서는 사회-수문 모델링 기법을 이용하여 사회-수문 상호 간 순환적 관계를 파악하고, 특히 다목적댐이 인문사회에 미치는 영향을 정략적으로 파악하고자 하였다. 우리나라는 기후변화에 의한 극한가뭄과 홍수발생 빈도가 증가하고 있다. 이에 대한 대책으로, 다목적댐을 건설하여 효율적인 수자원 관리를 하고 있다. 본 연구에서는 대상지역으로 국내 강원도의 횡성댐을 선정하였다. 횡성댐은 하류에 위치한 횡성군과 원주시에 생 공 농업용수를 공급하는 용수원의 역할과 섬강 하류지역에 발생하는 홍수를 방어하는 역할을 하고 있다. 횡성댐 유역의 사회-수문학적 관계를 이해하기 위해 인과지도를 이용한 시스템 요소간의 상호연관성을 파악하였고, 이를 바탕으로 수문학적 요소와 인문사회학적 요소 사이의 관계식을 구성하였다. 수자원 분야에 해당하는 요소로는 생 공 농업용수 이용량 및 댐 저수량과 방류량을 선정하였으며, 인문사회학적 요소는 인구, 공업지역 농경지 주거지역의 면적 및 지역 내 총생산액을 선정하였다. 이와 같은 사회-수문학 요소를 바탕으로 해당 지역의 사회-수문 전체의 동태적 변화를 이해하기 위해 시스템 동적모의(System Dynamics) 모형을 이용한 모델링을 진행하였다. 다목적댐 건설 전 후로 대상지역의 용수 이용량과 인구 및 지역 총생산액 등의 데이터를 수집하여 모델을 검증하였다. 나아가 구현한 모형을 활용하여 향후 기후변화 발생 시 다목적댐이 대상지역의 용수이용 및 인구변화, 지역경제에 미치는 영향을 정량적으로 분석하였다. 본 연구는 인문사회분야와 수자원분야 사이의 영향관계를 이해하고, 모델을 이용한 정량적인 분석을 통해 향후 수자원 시설물 계획 및 정책마련을 위한 의사결정도구로 활용될 수 있을 것으로 기대한다.

• Proceedings of the Korean System Dynamics Society
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• 2004.08a
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• pp.87-107
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• 2004

우리나라에 이동통신이 처음 소개된 이래로 눈부신 발전을 거듭하여 왔으며, 급기야. 무선통신 서비스를 중심으로 새로운 성장력과 패러다임 전환의 가능성에 대한 전망을 논할 수 있는 수준이 되었다. 이러한 추세에 맞추어 휴대인터넷 시장에 대한 연구가 활발히 진행되고 있으며 국민경제적 효과변화나 시장 경쟁환경의 변화에 가장 영향을 미칠 수 있는 요인들 중, 사업자 수를 어떻게 선정할 것인가에 대해 다양한 접근이 시도되고 있다. 기존의 연구들은 휴대인터넷 시장을 분석하는데 있어 시장규모가 일방향으로 사업자 수에 영향을 미친다는 측면에서 이루어지고 있으며, 대부분 휴대인터넷 시장을 단일시장으로 범위를 한정하고 성장중인 시장을 정적으로 가정하여 시장성장 추이 분석 등에 주안점을 두는 단편적 연구가 수행되어져 왔다. 휴대인터넷 시장의 단편적 분석이 아닌 '모바일인터넷' , '초고속유선인터넷', '무선인터넷', '휴대인터넷' 등 네 가지 영역을 동시에 고려함으로써 영역간 복잡성과 동적인 관계 속에서 시장이 성장해 나아간다는 가정을 바탕으로, 시장에 내재되어 있는 관련요소간 상호영향과 신규정책 및 제도적 변화 수용에 있어 발생하는 시간적 공간적 지연 등을 고려한 동태적 분석을 수행하였다. 연구를 수행하기 위해 다양한 변수간의 인과관계, 피드백 구조와 시간흐름에 따른 시스템의 변화를 파악하는데 매우 유용한 도구인 시스템다이내믹스 기법을 활용하여 휴대 인터넷 시장의 동적인 구조를 알아보고 사업자 선정정책의 시행을 앞두고 있는 현재시점에서 의미있는 시사점을 제공하였다.시하고자 한다.채취하여 임신진단키트(제네디아프로테 트, 녹십자)를 이용하여 임신여부를 1차적으로 확인하였다. 과배란을 유기한 13두의 공란우중 9두(69.2%)가 과배란 반응을 나타내었으며, 회수된 수정란 51개중 이식가능수정란은 38개(74.5%) 였다. 발정동기화를 유도한 수란우 40두중에서 35두(87.5%)가 발정이 동기화되었으며, 그 중 황체검사를 통하여 30두의 수란우에 수정란을 이식하였다. 수정란이식후 13일(발정주기 21일)에 혈액을 이용한 임신진단에서 농가별 수태율은 각각 37.5%, 70.0%, 60.0% 및 71.4% 로서 평균 60.0%를 나타내었다.서 39$^{\circ}C$, 5% $CO_2$ 배양기에 48시간 배양하면서 생존여부를 판단하였다. 실험 2에서 확장배반포배 수정란이 25.3%의 생존율을 나타내었으며, 실험 1과 실험 3에서는 수정란의 형태와 관계없이 생존성을 확인할 수 없었다. 이상의 결과로 보아 glycerol 완만동결에서는 확장배반포기 수정란 이상이 보존가능한 것으로 추정되나 더 추가적인 연구가 요구된다.c kinase 활성의 변동은 정소 내 간충조직, 세정관 상피의 증식 및 기능적 분화 과정을 매개하는 생리적 활성분자 수용체 하위의 신호전달 과정에 Src-Csk loop에 의한 조절가능성을 확인할 수 있었다.rugrene의 향기성분이 주요 성분군으로 확인되었다. 2. 생강나무에서 생강의 향기를 발산하는 성분으로는 $\beta$-myrcene, o-terpinolene, phellandrone, ι-limonene, $\b

• The Korean Journal of Financial Management
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• v.24 no.4
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• pp.107-134
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• 2007

This paper tests the relationship among returns, volatilities, contracts and open interests of KOSPI 200 futures markets with the various dynamic models such as granger-causality, impulse response, variance decomposition and ARMA(1, 1)-GJR-GARCH(1, 1)-M. The sample period is from July 7, 1998 to December 29, 2005. The main empirical results are as follows; First, both contract change and open interest change of KOSPI 200 futures market tend to lead the returns of that according to the results of granger-causality, impulse response and variance decomposition with VAR. These results are likely to support the KOSPI 200 futures market seems to be inefficient with rejecting the hypothesis 1. Second, we also find that the returns and volatilities of the KOSPI 200 futures market are effected by both contract change and open interest change of that due to the results of ARMA(1,1)-GJR-GARCH(1,1)-M. These results also reject the hypothesis 1 and 2 suggesting the evidences of inefficiency of the KOSPI 200 futures market. Third, the study shows the asymmetric information effects among the variables. In addition, we can find the feedback relationship between the contract change and open interest change of KOSPI 200 futures market.