• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.3
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• pp.1390-1395
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• 2014

The objective of this study is to offer a basic data for the establishment of marketing strategies such as fixing price of a new product and creation of the development direction of the product through estimating consumers value by attributes of the newly developed university made multi cream. The Choice Experiment was used for analysis, and conditional logit model was estimated to derive the marginal willingness to pay(MWTP) of each attributes of the multi cream. Brand, container type, functionality, price were included as the attributes. As a result, MWTP were estimated at 21,754 Won/unit for large company product, 11,033 Won/unit for small company product and 16,178 Won/unit for university product, 7,476 Won/unit for enriched moisturizing, 12,107 Won/unit for enriched improvements in wrinkles. Consumers have a preference for university brand over small company brand, therefore, if university and small company cooperate and proceed a joint-venture, it will strengthen the competitive power in the low price brand market. Also, it is essential to develop products with enriched functionalities such as moisturizing and improvements in wrinkles.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.3
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• pp.163-173
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• 1997

Although numerous studies demonstrate that one technique outperforms the others for a given data set, it is hard to tell a priori which of these techniques will be the most effective to solve a specific problem. It has been suggested that the better approach to classification problem might be to integrate several different forecasting techniques by combining their results. The issues of interest are how to integrate different modeling techniques to increase the predictive performance. This paper proposes the post-model integration method, which tries to find the best combination of the results provided by individual techniques. To get the optimal or near optimal combination of different prediction techniques, Genetic Algorithms (GAs) are applied, which are particularly suitable for multi-parameter optimization problems with an object function subject to numerous hard and soft constraints. This study applies three individual classification techniques (Discriminant analysis, Logit model and Neural Networks) as base models for the corporate failure prediction. The results of composite predictions are compared with the individual models. Preliminary results suggests that the use of integrated methods improve the performance of business classification.

• Journal of Labour Economics
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• v.25 no.1
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• pp.161-182
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• 2002

The self-employment can provide work time flexibility. Work time flexibility would be a critical factor for married females' labor supply considering allocation of their time to market work and household work. This study used the 1998 and 2000 Korea Labor and Income Panel Survey for the empirical analyses. Applying the bivariate probit model with partial observability, this study analyzed factors related to the choice of participation in labor market and choice of self-employment. Also, this study examined the effects of marriage and the presence of younger children on changes in decisions related to labor supply using the multinomial logit model: exit from the labor market, increasing and decreasing work hours. The presence of the younger children showed a significantly negative effect on the participation in labor market while positive, but insignificant, effect on self-employment. Compared with females working for others, self-employers without employees and unpaid family workers are less likely to exit labor market rather than increasing work hours. The self-employment would be a good alternative to evade females' career interruption and therefore to enhance the potential human resources.

• Korean Journal of Social Welfare Studies
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• v.49 no.2
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• pp.93-124
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• 2018

Using the Korean Survey of Household Finances and Living Conditions panel data from 2012~2016, this study analyzed youth (19~34 years) poverty and employment and examined the factors that affect employment status. The analysis revealed an increase in the proportion of young people who are students or jobless; the economic conditions of the young people varied by factors such as marital status, education, job status, and loans; and the government public transfer policy had little impact on reducing the relative poverty rate of the youth. We also examined the factors affecting the youth's employment status and the risk of being employed in low-paid jobs, using multi-logit and logit regression model respectively. Considering employment status, the older and more educated the youth were, the less frequently they were employed in temporary or daily jobs instead of regular ones, but there was no difference between genders in terms of having temporary or daily jobs. A logit analysis on the determinants of low-paid jobs demonstrated that women, the less educated, spouses or children of the household, and temporary or daily workers have a greater probability of working at low-paid jobs. As women became older, their risk of having low-paid jobs increased, which demonstrated the phenomenon of "lock-in" at low-paid jobs. Temporary or daily workers of all age groups faced a higher risk of lowpaid employment, which stood out for the youth. Based on these results, we suggest that government employment and welfare policies should consider individual characteristics of the youth and their life cycle, along with efforts to supply decent jobs, continuously and stably.

• Korean Journal of Labor Studies
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• v.23 no.2
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• pp.169-193
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• 2017

This study analyzed the determinants that affect employment retention rate in order to diagnose dynamic employment stability in Korea. For this analysis, we constructed multi-level hierarchical data linking Workplace panel survey data and employment insurance job history data. And the determinants were analyzed using a multi-level analysis model suitable for these data. As result of the analysis, it is estimated that the employment stability is very low in Korea due to the widespread existence of the marginal sectors with low wage level and high level of nonstandard employment. In addition, the results of this analysis show that employment structure of Korea occupies considerable area of short-term employment where employment and unemployment are repeated, and overall employment stability is weak. This fact is likely to be a limiting factor for continued growth, as there is limited opportunity for skill development and skills formation at the corporate and individual levels. According to the results of this analysis, it is required to improve the quality of the employment structure for continuous growth and skill formation.

• Journal of Korean Society of Transportation
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• v.17 no.5
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• pp.19-32
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• 1999

In this study, the trip characteristics of workers in the city are systematically analyzed. The trip behaviors and socioeconomic characteristics of workers are analyzed using Person Trip Survey Data of 1988 and 1992 in Taegu Metropolitan area. With the results of behavioral analyses, the daily travel pattern of workers is shown as one tour contained two trips and it is relatively simple and stable. Also the rate using the same mode in a day is Presented as high ratio. So, it can be explained that the choice of worker\`s first trip is fixed his/her travel mode for his/her daily travel mode. Based on these analyses, the mode choice model for workers is developed by applying the Multi-nominal Logit Model with the choice set of bus, taxi, and car. The explanatory variables of this model include sex, age, auto, travel time, and cost. Empirical tests of the model show encouraging results. After that, the temporal transferability of the model is examined by the Pairwise t-test and five indexes far the model of 1988 and 1992. The results of examination are satisfied with each significance level of the explanatory variables and five indexes. Therefore. it can be concluded that the temporal transferability of this model developed in this study is resonable.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.10a
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• pp.199-202
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• 1996

Although numerous studies demonstrate that one technique outperforms the others for a given data set, there is often no way to tell a priori which of these techniques will be most effective to solve a specific problem. Alternatively, it has been suggested that a better approach to classification problem might be to integrate several different forecasting techniques by combining their results. The issues of interest are how to integrate different modeling techniques to increase the prediction performance. This paper proposes the post-model integration method, which means integration is performed after individual techniques produce their own outputs, by finding the best combination of the results of each method. To get the optimal or near optimal combination of different prediction techniques. Genetic Algorithms (GAs) are applied, which are particularly suitable for multi-parameter optimization problems with an objective function subject to numerous hard and soft constraints. This study applied three individual classification techniques (Discriminant analysis, Logit and Neural Networks) as base models to the corporate failure prediction context. Results of composite prediction were compared to the individual models. Preliminary results suggests that the use of integrated methods will offer improved performance in business classification problems.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.1-8
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• 2018

Whole body fatigue detection is an important phenomenon and the factors contributing to whole body fatigue can be controlled if a mathematical model is available for its assessment. This research study aims at developing a model that categorizes whole body exertion into fatigued and non-fatigued states based on physiological and perceived variables. For this purpose, logistic regression was used to categorize the fatigued and non-fatigued subject as dichotomous variable. Normalized mean power frequency of eight muscles from 25 subjects was taken as physiological variable along with the heart rate while Borg scale ratings were taken as perceived variables. The logit function was used to develop the logistic regression model. The coefficients of all the variables were found and significance level was checked. The detection accuracy of the model for fatigued and non-fatigues subjects was 83% and 95% respectively. It was observed that the mean power frequency of anterior deltoid and the Borg scale ratings of upper and lower extremities were significant in predicting the whole body fatigued when evaluated dichotomously (p < 0.05). The findings can help in better understanding of the importance of combined physiological and perceived exertion in designing the rest breaks for workers involved in squat lifting tasks in industrial as well as health sectors.

• Journal of Korean Society of Transportation
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• v.18 no.5
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• pp.69-82
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• 2000

When new subway lines are considered to construct in a large city, there is a need to establish the appropriate transfer systems between subway and other transit modes, so as to increase the use of subway system. In this study, a multi-nominal logit model is developed to analyze the travel characteristics and the mode choice of subway Passengers transferring to and from the buses, minibuses and taxi. These passengers represent a large Portion of transit Passengers in Pusan city It shows that the explanatory variables that affect Passengers\` mode choice are in order of OVIT(Out-of-Vehicle Travel Time), IVTT(In-Vehicle Travel Time), transit fare,. income, gender, and age in modeling. In particular, OVTT is shown to have more significant impact on the mode choice than IYTT due to the fact that transfer trip is involved only in a short distance. Variables associated with the travel costs, however, do have an insignificant impact on the mode choice. It shows that it would be a better Policy to improve the quality of transit service using additional financial resource by increasing transit fare rather than by reducing the fare to increase travel demand. It also shows that value of travel time of OVTT is remarkably higher than that of IVTT and value of travel time of taxi Passengers is much higher than that of minibus Passengers .

• Journal of the Economic Geographical Society of Korea
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• v.12 no.4
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• pp.507-520
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• 2009

The purpose of this study is to analyze the changes in the housing instability of low-income households through their residential mobility. The concept of housing instability is measured by taking into consideration of housing types, number of moves, period of homelessness, and housing affordability index. The result of this study shows that housing instability of low-income households owned their homes is mainly caused from their old housing built in at least 1980, and that of tenant households is due to the heavy burden of rent-to-income ratio. By using multinominal logit model, the study finds that low-income tenant households are more likely to move upwards as they are man-headed, aged and relatively high-income if we categorize residential mobility into four types: upwards, equivalent, trade-off, and downwards migration. Considering that the share of homeowners moving downwards increases while the share of tenants moving upwards decreases as they reside increasingly nearby Seoul, the study finds that low-income households living in big cities are no better off to improve their residential instability for themselves than the low-incomes in local small and midium cities. Furthermore, both low-income owners and tenants are less likely to move downwards as the ratio of single-family housing in former residence increases. Such finding has a policy implication that government needs to maintain affordable single-family housing stock rather than supplying excessive unaffordable multi-family housing in order to enhance residential instability of low-incomes households.