• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.2
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• pp.437-444
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• 2017

The purpose of this study is to analyze the factors affecting the reverse mortgage utilization and satisfaction of the elderly. Based on the survey data of the reverse mortgage demand in 2016, we carried out empirical analysis using the binary logit model and the ordered logit model. First of all, as a result of the empirical analysis using the binary logit model, the determinants of using the reverse mortgage were age, region, assets, household member, children with financial help, and education level. As a result of the empirical analysis using the ordered logit model, the determinants of the satisfaction level of the reverse mortgage were estimated to be age, gender, and region. Based on the results of the empirical analysis, it is necessary to find a way to increase the participation rate of the reverse mortgage and to improve the satisfaction of the user.

• The Korean Journal of Applied Statistics
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• v.15 no.2
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• pp.355-366
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• 2002

Nonparametric statistical inference for the parameter of logit model were examined. Usually nonparametric approach is milder than parametric approach based on normal theory assumption. We compared the two nonparametric methods for legit model, the bootstrap and random permutation in the sense of coverage probability. Monte Carlo simulation is conducted for small sample cases. Empirical power of hypothesis test and coverage probability for confidence interval estimation were presented for simple and multiple legit model respectively. An example were also introduced.

• Journal of Korean Society of Transportation
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• v.18 no.2
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• pp.63-71
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• 2000

One Problem of the choice Property in logit model is interpreted as the Problem of common links and common nodes in choice set. Common node Problem Plays important role in deciding the efficiency of network loading and common link problem is connected with choice Problem, both of which are to be solved to improve the logit choice model. Although much need has been pointed out for research on the topic, however, no Paper as yet considers these two factors at the same time. In the Paper we develop a new logit formulation, which is able to ease the logit Problem, widely known as the Problem of IIA(Independence of Irrelevant Alternatives). An example network is used to assess the Proposed model and compare it with other conventional models. From the results, we find out that the model is superior to others.

• Journal of Korean Society of Transportation
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• v.21 no.4
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• pp.57-66
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• 2003

Because the Logit model easily calculates probabilities for choice alternatives and estimates parameters for explanatory variables, it is widely used as a traffic mode choice model. However, this model includes an assumption which is independently and identically distributed to the error component distribution of the mode choice utility function. This paper is a study on the estimation of the Heteroscedastic Logit Model. which mitigates this assumption. The purpose of this paper is to estimate a Logit model that more accurately reflects the mode choice behavior of passengers by resolving the homoscedasticity of the model choice utility error component. In order to do this, we introduced a scale factor that is directly related to the error component distribution of the model. This scale factor was defined so as to take into account the heteroscedasticity in the difference in travel time between using public transport and driving a car, and was used to estimate the travel time parameter. The results of the Logit Model estimation developed in this study show that Heteroscedastic Logit Models can realistically reflect the mode choice behavior of passengers, even if the difference in travel time between public and private transport remains the same as passenger travel time increases, by identifying the difference in mode choice probability of passengers for public transportation.

• Environmental and Resource Economics Review
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• v.14 no.1
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• pp.51-73
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• 2005

The purpose of this study is estimating the value of recreation of the eighteen national parks in Korea. A conditional logit model and a nested logit model have been estimated for the purpose. The data used for the study have been collected via a national level off-site survey. In addition, the annual aggregate data on the number of visitors to each park have been combined with the survey data to derive more reliable estimates. The paper finds that there are substantial differences in preferences for mountain and marine national parks. Not only the value of each park but also the values of the main characteristics of the parks are estimated.

• Proceedings of the KOR-KST Conference
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• 1999.10a
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• pp.59-64
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• 1999

• Journal of Korea Port Economic Association
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• v.39 no.2
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• pp.97-110
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• 2023

This study examines the effect of macroeconomic shocks on the financial stability of the Korean shipping industry. Using Firth logistic regression model, this study estimates the default probability of a shipping company. The results from a default prediction model suggest that total assets are negatively correlated with default probability, while total debt is positively correlated with default probability. Based on the results from a default prediction model, this study investigates the effect of macroeconomic shocks, namely total assets, sales, and total debt shocks, on a shipping company's default probability. The stress test results indicate that a decrease in sales and total assets significantly deteriorates the financial stability of a shipping company.

• Journal of Korean Society of Transportation
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• v.26 no.1
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• pp.113-126
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• 2008

This research aims to explore the effects of multicollinearity on the reliability and goodness of fit of logit model. To investigate the effects of multicollinearity on the multinominal logit model, numerical experiments are performed. The exploratory variables(attributes of utility functions) which have a certain degree of correlations from (rho=) 0.0 to (rho=) 0.9 are generated and rho-squares and t-statistics which are the indices of goodness of fit and reliability of logit model are traced. From the well designed numerical experiments, following findings are validated : 1) When a new exploratory variable is added, some of rho-squares increase while the others decrease. 2) The higher relations between generic variables lead a logit model worse with respect to goodness of fit. 3) Multicollinearity has a tendency to produce over-evaluated parameters. 4) The reliability of the estimated parameter has a tendency to decrease when the correlations between attributes are high. These results suggest that we have to examine the existence of multicollinearity and perform the proper treatments to diminish multicollinearity when we develop logit model.

• Proceedings of the Korea Association of Information Systems Conference
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• 2005.12a
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• pp.119-129
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• 2005

현재의 이동통신시장은 시장의 포화상태로 인해 신규 고객의 확보보다는 기존 고객의 유지에 마케팅 활동을 강화하고 있다. 본 연구에서는 이탈고객관리(churn management)를 위한 방안으로 데이터마이닝 기법에 기반하여 고객을 등급별로 세분화하였다. 이동통신 고객데이터를 활용하여 로짓모형, 인공신경망, SVM 등을 이탈고객 예측모형을 개발하였고, 각 모형별 성과를 통계적으로 비교하였다. 이탈고객 예측모형을 통해 고객의 이탈가능성을 등급화하여 등급별 이탈확률과 점유율, 적중률을 산출하였다. 제안된 고객등급화 방법을 통해 이동통신사들은 고객의 이탈확률에 따른 차별화된 마케팅 전락을 수행할 수 있을 것으로 기대된다.

• Journal of Korean Port Research
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• v.7 no.1
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• pp.25-42
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• 1993

지난 20여년간 화물수송 분야에는 큰 변화가 있었다. 수송 공급 측면에서는 보다 다양하고 기술적으로 앞선 수송수단들이 등장했으며, 수송 수요 측면에서는 로지스틱스 개념의 도입으로 화주들의 보다 높은 수송 서비스가 요구 되었다. 수송수단의 수송 분담에 있어서도 특히 철도에서 공로로의 두드러진 화물이동 현상이 나타났다. 이러한 변화는 수송 현안 해결에 대한 관심을 높이고 화물수송수요 예측기법의 이론적, 개념적인 발달을 가져왔다. 그 중 두드러진 발달은 화주의 행태를 반영하는 행태모형의 개발과 새로운 자료수집 방법 및 자료형태이다. 전통적으로 화물수송 및 교통 연구에 널리 사용된 행태모형은 확률표본을 사용하여 왔으나, 80년대 부터 비확률 표본 사용에 관심이 높아졌다. 그 대표적인 것으로 기반근거 데이터를 들 수 있다. 이 데이터는 제한된 정보를 제공한다는 자료자체의 한계를 지니고 있으나, 자료수집이 용이하고 비용이 저렴하다는 장점을 가지고 있다. 화물수송 분야에서 선택기반 데이터를 이용한 연구는 현재까지 두 편이 발표 되어 있다. 따라서 볼 연구는 선택기반 데이터를 이용한 개별선택모형의 잠재력을 검증하는 것을 그 목적으로 하고, 네 종류의 제조품 그룹을 대상으로 기반근거 데이터를 수집하여 로짓모형을 추정하였으며, 추정결과를 이전 연구들의 결과와 비교하여 그 타당성을 검토 하였다. 추정된 결과는 통계적으로 유의하며 직관적으로 타당한 것으로 나타난다. 또한 그 결과는 문헌의 결과와도 일치하였다. 수송계획에 있어서 자료수집비용 절감의 필요성을 생각할 때 이것은 중요한 의미를 지닌다.