• Environmental and Resource Economics Review
• /
• v.6 no.2
• /
• pp.209-231
• /
• 1997

본 논문은 전통적인 산업연관분석이 고정투입계수를 시용하고 있어서 상대가격체계의 변화에 따른 경제 주체들의 비용최소화 노력을 모형 내에 반영하지 못하고 있다는 한계를 극복하기 위하여 상대가격체계의 변화에 따라 가변투입계수를 갖는 "반복다중최적화(IMO) 모형"을 이용하여 탄소세 부과가 가격구조에 미치는 영향을 분석하였다. 분석 결과는 고정투입계수모형에 비하여 가격인상효과는 전반적으로 낮게 나타났으며, 특히 에너지집약산업은 고정투입계수모형에 비하여 가격상승률이 낮게 나타난 반면, 기타산업은 가격상승폭이 높게 나타났다. 이러한 결과는 에너지원에 대한 탄소세의 부과효과가 상대가격변화에 적응한 경제주체들의 비용최소화 노력으로 각 산업으로 분산된 결과라 여겨진다.

• The Korean Journal of Applied Statistics
• /
• v.34 no.6
• /
• pp.863-874
• /
• 2021

In this paper, we propose a post-selection inference procedure for the fused lasso signal approximator (FLSA). The FLSA finds underlying sparse piecewise constant mean structure by applying total variation (TV) semi-norm as a penalty term. However, it is widely known that this convex relaxation can cause asymptotic inconsistency in change points detection. As a result, there can remain false change points even though we try to find the best subset of change points via a tuning procedure. To remove these false change points, we propose a post-selection inference for the FLSA. The proposed procedure applies a permutation test based on CUSUM statistic. Our post-selection inference procedure is an extension of the permutation test of Antoch and Hušková (2001) which deals with single change point problems, to multiple change points detection problems in combination with the FLSA. Numerical study results show that the proposed procedure is better than naïve z-tests and tests based on the limiting distribution of CUSUM statistics.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.5
• /
• pp.1809-1827
• /
• 2013

Recently we need to take various measures to prepare for extreme flood that occur due to climate change. It is important that establish flood forecasting system to prepare flood over non-structure measures. The objective of this study is to develop superior real-time flood forecasting model by comparing the Neuro-fuzzy model and the multiple linear regression model. The Neuro-fuzzy model and the multiple linear regression model are established using same input data and applied for various flood events in Nakdong basin. The results show that the Neuro-fuzzy model can carry out flood forecasting results more accurately than the multiple linear regression model. This study can contribute to the establishment of a high accuracy flood information system that secure lead time in Nakdong basin.

• Journal of Korean Society of Transportation
• /
• v.22 no.3 s.74
• /
• pp.127-135
• /
• 2004

교차로 안전성 진단과 관련된 기존의 연구는 교차로 상에서 발생한 사고 자료에 기초하여 교차로 기하구조 요소, 교통량 및 신호운영방법 등과 관련된 요인을 변수로 사용하여 교통사고건수 예측모형 개발에 관한 연구가 대부분이다. 그러나, 분석하고자 하는 대상 교차로의 사고건수 예측모형을 개발하기 위해 필요한 교통사고 자료의 경우 단 기일에 걸쳐 획득되지 않으며 몇 년간의 사고 자료를 요구할 수도 있다. 이러한 자료를 이용하더라도 사고 발생 기간동안 교차로 사고에 영향을 미치는 요인(교차로 운영방법, 기하구조 등)이 변화될 수도 있다는 문제점을 지닌다. 이와 같은 이유로 교차로 안전성을 진단하는데 있어 기존 교통사고 자료는 언제나 절대적인 자료가 될 수 없다. 이에 대한 보완책으로, 3일에서 5일정도의 조사 자료만으로도 안전성 진단이 가능한 상충자료를 이용하여 교차로 안전성 진단을 할 수 있다. 본 연구는 기존사고 자료를 이용하여 사고 발생에 기인하는 여러 변수들을 교통사고심각도와의 상관관계를 분석하고, 상관관계가 높은 변수를 이용하여 신경망 사고심각도 예측모형을 개발하였으며, 모형 검증을 위해 다중회귀사고심각도 예측모형을 개발하여 비교 평가한 결과 신경망 사고심각도 예측모형의 예측력이 우수한 것으로 나타났다. 현장에서 조사된 상충자료를 신경망 사고심각도 예측모형에 적용하여 상충이 사고로 연결 될 경우 사고심각도를 예측하였으며, 예측된 사고심각도에 가중치를 부여하여 대상 교차로 위험우선순위를 결정한 결과 사고비용에 기초한 위험우선순위 결정법과 같은 순위의 결과를 도출하였다.

• Proceedings of the Korean Information Science Society Conference
• /
• 1998.10c
• /
• pp.108-110
• /
• 1998

가상환경은 3D 컴퓨터 시뮬레이션을 통해 실제 작업환경에서 작업하는 것과 같은 몰입감을 사용자에게 줄 수 있지만, 동적인 가상환경은 발생하는 문제들이 복잡하기 때문에 하나의 단일 에이전트로 주어진 문제를 해결하기에는 한계가 있다. 따라서 복잡한 문제들을 작은 문제들로 모듈화 시켜서 해결해야 하는데, 이에 적합한 시스템이 다중 에이전트 시스템이다. 다중 에이전트 시스템은 여러 에이전트들이 협동하여 문제를 해결해야하기 때문에 에이젼트들과의 통신문제와 정보의 공유, 그리고 동적으로 변화되는 가상환경과의 효율적인 상호작용 방법 등이 중요한 문제가 된다. 본 논문에서는 Soar라는 인공지능 아키텍처를 이용하여 이러한 다중 에이전트 시스템을 모형화하는 방법에 대해 기술하고 가상현실 시스템과 동적으로 상호작용 하면서 추론/계획하고 행위를 생성하는 방법을 제시한다.

• Journal of Korean Society of Transportation
• /
• v.29 no.1
• /
• pp.57-67
• /
• 2011

This study has been conducted to provide the basic materials about the occurrence structures, causes and choice of treatments of the traffic accident offenders' PTSD(Posttraumatic Stress Disorder). The results of this study can be summarized as follows. First, accident offenders', not victims', PTSD conditions, which has been only estimated until now, are measured by nationwide questioning survey. Second, accident offenders' changes of driving attitude after accidents could be typed by factors analysis in the 20 driving situations closely connected to the occurrence of traffic accidents. Third, by the t-test, the difference of driving attitudes in primary driving situations according to existence of PTSD is distinguished. Six driving situations, which are found significant by t-test, are applied to structural equation. So the variables related to PTSD and the models which analyze the attitude changes of driving are constructed. This study provides the basic materials to help the reduction and prevention of the occurrence of PTSD.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.8
• /
• pp.815-823
• /
• 2011

Combustion phenomena in porous media combustors are widely used in industrial fields for the combustion of lowgrade fuels and the regeneration of combustion heat. However, studies of combustion phenomena in porous media have been limited, because these phenomena are difficult to observe, and the configurations of porous media are complex. We propose a simple model combustor: a multi-channel combustor that consists of many layers of combustion channels made of quartz plates. We conducted an experimental observation of the flames in the multi-channel combustor and obtained experimental results for the flame stabilization limits. Flames formulated in the multi-channel combustor showed variation in the spatial distribution depending on the heat transfer between neighboring channels. A simple analytical model was developed and the variation in the flammability limits of the multi-channel combustor was discussed. This study will enhance our understanding of flame behavior in a porous-media combustor.

• Journal of the Economic Geographical Society of Korea
• /
• v.12 no.4
• /
• pp.521-539
• /
• 2009

This study investigates the time-space characteristics of the road traffic flows in Seoul and the relationship with land use patterns. For the purpose, we analyze the road traffic data collected at 118 observation sites over Seoul City area since 1993. We examine the time-trend of the annual average traffic flows per day during the last fourteen years. Three different trends are revealed: rapid increase during the time period between 1993 and 1997, maintenance same level after sharp decrease between year 1997 and 1998, and gradual decrease after sharp decrease between year 2003 and 2004. The spatial distribution patterns of road traffic flows have also been changed significantly during the period. The traffic flows in the urban center have been declined gradually, while the traffic flows in the boundary area and southern CBDs have increased dramatically. In order to examine the relationship with the changes in the land-use patterns and road traffic flows, we analyze the changes in the spatial distribution patterns of population and industries. We developed three multiple linear regression models to test the relationships between the changes in the land-use variables and road traffic flows.

• Journal of the Economic Geographical Society of Korea
• /
• v.17 no.2
• /
• pp.402-419
• /
• 2014

This study attempts to investigate the spatial characteristics of private tutoring markets for adults which have been expanded rapidly with labor market changes in Korea. In particular, For the purpose, we examine thoroughly various indies of labor markets and private tutoring markets for adults in Korea in first and then analyze the spatial characteristics. We classify private tutoring institutes for adults into two categories by job-statuses and education levels, and analyze the spatial distribution patterns of the attendants of the classes. In order to understand the spatial characteristic of their distributions, we distinguish whether there exist the spatial autocorrelation or not by applying Moran's I values for each categories in first. We also examine the spatial cluster patterns by Hot spots analysis utilizing $G^*$ statistics. Multiple linear regression models are developed for each category to explain the relationships between the spatial distributions of private tutoring institutes and geographical variables.

• Journal of the Korean GEO-environmental Society
• /
• v.3 no.4
• /
• pp.11-17
• /
• 2002

The purpose of this study is the prediction of pollutant loads into Seomjin river watershed using neural networks model. The pollutant loads into river watershed depend upon the water quantity of inflow from the upstream as well as the water quality of the inflow into the river. For the estimation of pollutants into river, a neural networks model which has the features of multi-layered structure and parallel multi-connections is used. The used water quality parameters are BOD, COD and SS into Seomjin river. The results of calibration are satisfactory, and proved the availability of a proposed neural networks model to estimate short-term water quality pollutants into river system.