• Economic Analysis
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• v.25 no.4
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• pp.25-57
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• 2019

This paper studies localization effects of knowledge spillovers in Korea using U.S. patents granted over the period 1996-2015. The "sample-matching" analysis initiated by Jaffe, Trajtenberg, and Henderson (1993) is adopted. We do not find evidence of positive localization effects in Korea. In particular, controlling for the existing geographic distribution of knowledge production, the frequency of domestic citations of Korean patents is no more than the citation frequency from overseas, and the difference is decreasing within the sample period. We also examine localization effects across regions and industries, and compare Korea with Taiwan and Japan.

• Environmental and Resource Economics Review
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• v.18 no.3
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• pp.523-544
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• 2009

The purpose of this paper is to estimate the impact of foreign direct investment on environmental performance for 27 OECD countries using endogenous environmental policy model. The empirical test shows that with 1% increase in the ratio of inflow stock of foreign direct investment over domestic capital stock, emission on NOx and $CO_2$ will increase by 0.0071%(NOx) and 0.0165%($CO_2$) and 1% increase in the ratio of foreign capital stock induces 0.044%(fixed effect) and 0.047%(random effect) of economic growth. 1% increase of per labor total output increases 2.038%(fixed effect) or 1.890%(random effect) in reinforcement of environmental regulation. However, we could not confirm the Porter's hypothesis that the more strong environmental regulation leads technical innovation. The scale effects (0.0119, 0.0172) are estimated higher than the technical effects (-0.0048, -0.0007) in two pollutants (NOx, $CO_2$). It implies that each country needs to increase pollution abatement and control expenditure more aggressively to protect environment.

• Journal of Korea Water Resources Association
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• v.42 no.10
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• pp.785-793
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• 2009

Numerical model which can simulate the surge tank for unsteady flow was developed in the present study. Furthermore, reliability model which can calculate the probability of pipe breakage regarding unsteady effect was developed. For the risk estimation of pipe breakage and functional estimation of surge tank, probability of pipe breakage for pipe network with surge tank was calculated regarding unsteady effect. From the results, it was found that unsteady flow significantly increase the probability of pipe breakage and surge tank considerably decrease probability of pipe breakage as damping out the pressure oscillations.

• Land and Housing Review
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• v.13 no.3
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• pp.39-55
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• 2022

In this study, we investigate the interrelationship between housing tenure and childbirth by exploiting the correlation probability effect method that accounts for household heterogeneity. Using the newlywed household panel from 2011 to 2022, we find that home ownership has a positive impact on childbirth in newlyweds. Specifically, newlywed households with housing tenure show a 6.2%p higher birth rate and a 5.7%p higher second childbirth than newlywed households living in rented houses. For the case of first childbirth, we employ the probability effect probit model since the endogeneity was not detected between housing tenure and birth rate. We document the differential effects of housing tenure on childbirth in that the first childbirth rate is higher for households without housing tenures. The negative effects on first childbirth could be attributed to the economic burden due to initial housing ownership, while housing tenure could eventually provide housing stability, leading to positive effects on more than one childbirth. Finally, we identify that households with childbirth over the last year show a 4.2%p and 3.9%p lower probabilities of housing tenure in the total sample and second childbirth sample, respectively. This suggests that the increased living cost due to childbirth could delay home ownership.

• Journal of The Korean Association For Science Education
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• v.25 no.7
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• pp.787-793
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• 2005

The purposes of this study were to investigate the development of probabilistic thinking in relation to the cognitive level of elementary school students and to analyze the effects of probability activities in Thinking Science(TS) program on the development of probabilistic thinking. 152 6th grade elementary school students compiled the sample group which was divided into an experimental group and a control group. Probability activities in TS program were used with the experimental group, while the normal curriculum was conducted with the control group. Both the experimental and control group were assessed with Science Reasoning Task II and a probabilistic thinking test before execution of this investigation and were post-tested with probabilistic thinking test after the project period was complete. Results of this study showed that the students in the concrete operational stage and transitional stage used subjective strategy together with quantitative strategy in probability problem-solving, and students in the early formal operational stage used quantitative strategy in probability problem-solving. It was also found that the higher the cognitive level of students, the higher the probabilistic thinking level. The probability activities of the TS program influenced the development of probabilistic thinking of elementary school students. Assessing the development of probabilistic thinking on the basis of the cognitive level found that the level of effectiveness was significantly higher for students in the early concrete operational stage and transitional stage than students in any other stage.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.165-168
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• 2003

최근 사면의 안정해석분야에서 자주 사용되고 있는 확률론적 해석 방법은 현장에서 획득 되는 자료들의 분산이 심하고 충분한 양의 자료가 획득되지 못할 경우 자료 내에 포함되는 불확실성과 가변성을 효과적으로 다룰 수 있는 방법 중의 하나로 인식되어 왔다. 그러나 대개 확률론적 해석 방법에서 이용되는 몬테카를로 시뮬레이션기법(Monte Carlo simulation method)은 파괴확률을 산정하기 위하여 수 많은 반복적인 계산과정이 요구되며 따라서 많은 시간과 노력이 필요하다는 단점을 가지고 있다. (중략)

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1806-1814
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• 2015

The strategy of distributors using a PB(Private Brand) inferior to existing PB to increase choice probability of PB arouses difficulty in terms of cost. Therefore, the aim of this study is to verify incentive and compromise effects of PB using two realistic experimental methods. Looking at the verification results, incentive and compromise effects occurred to show increase in choice probability of PB when a new GB(Generic Brand) was added to NB(National Brand) and PB of a manufacturer. In specific during experiment 1, choice probability of PB, the target, was changed when decoy brand was introduced even if there is a large difference in preference and choice probability of the competitor and target due to characteristics of NB and PB. In experiment 2, incentive effect appeared when PB of competitor was positioned as an inferior alternative to increase choice probability of the company's PB. Strategic implications on the study results, limits of this study, and future directivity were proposed.

• Communications for Statistical Applications and Methods
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• v.4 no.2
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• pp.411-419
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• 1997

본 연구에서는 확률화응답모형이 가지는 두가지 한계에 대하여 고찰하였다. 첫째 민감한 속성을 갖는 모비율의 추정시 모비율 $\pi_A$가 매우 작은 값일 경우, 즉 희귀속성일 경우 확률화응답모형을 적용하게 되면 비밀보장의 효과를 감안한다고 해도 직접질문법에 비해 비효율적일 수 있음을 지적하였다. 둘째로 비밀보장에서 오는 이점과 그로 인한 효율의 손실이라는 서로 상충되는 면을 객관적으로 고려하는데 있어서 한계가 있음을 지적하였다.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.365-372
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• 2000

현장상황에 대한 불충분한 자료와 파괴 메커니즘에 대한 불완전한 이해로 인해 발생하는 가변성(variability)과 불확실성(uncertainty)은 암반사면공학뿐만 아니라 지반공학에서 흔히 접하게 되는 문제점이다. 특히 암반사면공학에서는 이러한 가변성과 불확실성이 불연속면의 방향 및 기하학적 특성, 그리고 실내실험 결과의 분산으로 나타난다. 그러나 안전율(factor of safety)의 개념을 기초로 하는 전통적인 결정론적 해석방법(deterministic analysis)은 이러한 분산을 고려하지 않은 채 단일 대표 값만을 이용하여 구조물의 안정성을 판단하여 왔다. 확률론적 해석방법(probabilistic analysis)은 이러한 가변성과 불확실성을 효과적으로 정량화하여 해석에 이용할 수 있는 방법 중의 하나로 제안되었다. 이러한 해석방법은 불연속면의 기하학적 특성과 강도 특성을 확률변수(random variable)로 취급하여 신뢰성이론(reliability theory)과 확률이론(probability theory)을 근거로 분석하였으며 이를 기초로 하여 Monte Carlo Simulation과 같은 해석법을 이용, 구조물의 붕괴가능성을 확률로 표현하였다. 확률론적 해석 방법은 기존의 안전율을 대체하여 구조물의 안정성을 붕괴확률(probability of failure)로 제안하였으며 이 붕괴확률은 안전율의 확률분포함수 (probability density function)에서 안전율이 1보다 작을 가능성을 확률로 나타낸 수치이다. 본 논문에서는 확률론적 해석방법을 이용하여 불연속면 특성들의 확률특성을 고찰하였으며 이를 기초로 하여 암반사면의 안정성 해석에 응용했다.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1131-1135
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• 2009

본 연구에서는 조선왕조실록의 호우기록을 이용하여 강우량 기록기간을 확장하는 효과를 얻어 이를 반영했을 때의 확률강우량의 변화를 검토하였다. 우리나라의 조선왕조실록은 약 500여년에 걸친 조선왕조의 주요한 사건들을 다루고 있으며 큰 피해를 입힌 홍수나 가뭄피해 및 현상을 잘 기록하고 있다. 특히 조선시대의 경우 조선초기부터 강우량의 과학적 측정에 대한 관심으로 측우기를 개발하여 전국적인 우량 관측망을 갖춘 바 있으며 현재는 영조 말년에 해당하는 1777년 이후의 측우기 기록이 남아있다. 따라서 조선왕조실록의 큰 호우사상이 발생하였을 때의 기록을 당시의 대처, 기록방법 등의 검토와 함께 측우기 기록과 비교하여 조선왕조 전체에 걸친 주요호우사상을 판별할 수 있었다. 이때, Stedinger가 제시한 censored data를 이용한 빈도해석 방법을 적용할 경우 조선왕조실록을 검토하여 얻은 주요 호우사상의 개략적인 규모 및 회수를 이용하여 확률 강우량을 산정할 수 있었다. 이 방법은 일정기간동안 특정 크기 이상의 호우사상의 크기를 안다면 연속적인 연최대강우량계열이 있는 것과 거의 동일한 수준으로 확률강우량을 산정하는 방법이다. 현대 강우빈도해석의 가장 큰 문제는 자료의 관측기간의 부족으로 인해 고빈도에 대한 신뢰도가 떨어지는 문제이다. 이에 대한 대안으로 조선왕조실록과 측우기 자료를 이용하여 장기간의 강우자료를 확보한 효과를 반영할 때 확률강우량은 현재보다 상당히 증가할 수 있는 것으로 검토되었다.