• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.3
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• pp.63-80
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• 2007

This study is a generalization of 'stable dynamics' recently suggested by Nesterov and de Palma[29]. Stable dynamics is a new model which describes and provides a stable state of congestion in urban transportation networks. In comparison with user equilibrium model that is common in analyzing transportation networks, stable dynamics requires few parameters and is coincident with intuitions and observations on the congestion. Therefore it is expected to be an useful analysis tool for transportation planners. An equilibrium in stable dynamics needs only maximum flow in each arc and Wardrop[33] Principle. In this study, we generalize the stable dynamics into the model with multiple traffic classes. We classify the traffic into the types of vehicle such as cars, buses and trucks. Driving behaviors classified by age, sex and income-level can also be classes. We develop an equilibrium with multiple traffic classes. We can find the equilibrium by solving the well-known network problem, multicommodity minimum cost network flow problem.

• Journal of Families and Better Life
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• v.14 no.3
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• pp.211-222
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• 1996

The purpose of this study is to classify the expenditure behaviors of housewives into some types and to identify the characteristics of the types focucing on diverse expenditure behaviors of urban households. In this study it is assumed that the expenditure behaviors are classified by there factors-(1)the orientation of money saving (2)the orientation of time saving and (3)the orientation of others. The present study suggests following three questions. (1). Can the expenditure behaviors of urban housewives be classified according to the orientation of money saving the orientation of others? (2) What distictions exist among the types? (3) Which variables are useful in classifying the expenditure behaviors? For empirical analysis the data of the study was collected from 650 housewives living in Seoul. The statistical methods adopted for data analysis are frequency percentage mean Pearson's correlation coefficient factor analysis cluster analysis one way ANOVA Duncun's multiple ran e test and discriminant analysis. As the major findings 4 types were extracted, According to the level of each dimensions the names for the each type were given as "the type of attaching importance to money saving" "the type of attaching importance to time and appearance" "the type of attaching importance to money saving and time" "the type of attaching importance to money saving and time" "the type of attaching importance to money saving and time" "the type of attaching importance to money saving and appearance" In "the type of attaching importance to money saving" the significant portion of housewives have high school degrees and compared with other types this type includes more husbands having sales and service job 55% of housewives of "The type of attaching importance to time and appearance" have graduate or higher degrees. The significant part of earned incomes range from 3 million won to 5 million won. The rate of housewives employed in the professional job is higher than other types. In "The type of attaching importance to money saving and time" the rate of the employment of housewives in this type is the highest among the types. In "The type of attaching importance to money saving and appearance" the significant portion of housewives have graduate degrees. In the jobs of he spouses the management job is major. The consciousness of belonging to the middle class is higher than other types. In this type the level of education is high but that of income is not. The result of the discriminant analysis says that the earned income and the consciousness of belonging to a calss are the most critical variables to classify the expenditure behaviors into 4 type The accuray of the classification of the discrimination equation composed of these variables is 47,5% The accuracy is improved by 10%.

• Management & Information Systems Review
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• v.28 no.3
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• pp.1-23
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• 2009

Prior bankruptcy studies have established that bankrupt firm's pre-filing financial ratios are different from those of healthy firms or of randomly selected going concerns. However, they may not be sufficiently different from the financial ratios of other firms in financial distress to allow the development of a ratio-based model that predicts bankruptcy with reasonable accuracy. As the result, in the multiple discriminant model, independent variables divided firms into bankrupt firms and healthy firms are retained earnings to total asset, receivable turnover, net income to sales, financial expenses, inventory turnover, owner's equity to total asset, cash flow to current liability, and current asset to current liability. Moreover four variables Retained earnings to total asset, net income to sales, total asset turnover, owner's equity to total asset indicate that these valuables classify bankrupt firms and distress firms. On the other hand, Owner's Equity to borrowed capital, Ordinary income to Net Sales, Operating Income to Total Asset, Total Asset Turnover and Inventory Turnover are selected to predict bankruptcy possibility in the Logistic regression model.

• Analyses & Alternatives
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• v.7 no.2
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• pp.35-77
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• 2023

This study aims to solve the entangled loop between demographic transition (DT) and economic growth by analyzing cross-country data. We undertake a national-level group analysis to verify the compressed transition of demographic variables over time. Assuming that the LA (latecomer advantage) on DT over time exists, we verify that the DT of the latecomer is compressed by providing a formal proof of LA on DT over income. As a DT has the double-kinked functions of income, we check them in multiple aspects: early maturation, leftward threshold, and steeper descent under a contour map and econometric methods. We find that the developing countries (the latecomer) have speedy DT (CDT, compressed DT) as well as speedy income such that DT of the latecomers starts at lower levels of income, lasts for a shorter period, and finishes at the earlier stage of economic development compared to that of developed countries (the early mover). To check the balance of DT, we classify countries into four groups of DT---balanced, slow, unilateral, and rapid transition countries. We identify that the main causes of rapid transition are due to the strong family planning programs of the government. Finally, we check the effect of latecomer's CDT on economic growth inversely: we undertake the simulation of the CDT effect on economic growth and the aging process for the latecomer. A worrying result is that the CDT of the latecomer shows a sharp upturn of the working-age population, followed by a sharp downturn in a short period. Compared to early-mover countries, the latecomer countries cannot buy more time to accommodate the workable population for the period of demographic bonus and prepare their aging societies for demographic onus. Thus, we conclude that CDT is not necessarily advantageous to developing countries. These outcomes of the latecomer's CDT can be re-interpreted as follows. Developing countries need power sources to pump up economic development, such as the following production factors: labor, physical and financial capital, and economic systems. As for labor, the properties of early maturation and leftward thresholds on DTs of the latecomer mean that demographic movement occurs at an unusually early stage of economic development; this is similar to a plane that leaks fuel before or just before take-off, with the result that it no longer flies higher or farther. What is worse, the property of steeper descent represents the falling speed of a plane so that it cannot be sustained at higher levels, and then plummets to all-time lows.

• Journal of Environmental Health Sciences
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• v.42 no.6
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• pp.353-364
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• 2016

Objectives: Determining the time activity patterns of urban populations is critical when performing an exposure assessment. The purposes of this study were to classify urban populations in Korea by their time activity patterns and to identify factors that influence these patterns. Methods: The time activity patterns of 31,634 and 20,263 individuals were obtained from two national databases collected in 2004 and 2009, respectively. The two largest metropolitan cities in Korea, Seoul and Busan, were selected for this analysis. For each city, multivariate linear regressions were performed to determine factors affecting the time spent in a residence and in transit. We also used cluster analysis to classify each urban population by activity pattern. Results: Nine distinctive activity patterns were identified in the Seoul and Busan populations, respectively, and the resulting classified population groups had specific characteristics. The identified patterns were similar for Seoul and Busan. The most significant factors affecting time spent in a residence were employment status, age, marriage status, education, and gender. Gender, education, employment status, and monthly income were significant factors affecting time spent in transit. Conclusion: These results indicate that, in addition to region, exposure scientists in Korea should consider classifying populations based on age, gender, and occupation.

• The Journal of Fisheries Business Administration
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• v.15 no.1
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• pp.58-80
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• 1984

The classification of islands is prerequisite for establishing a development policy to vitalize many-sided function of islands. We try to classify the 440 inhabited islands which exist in Jeon-Nam area and Kyong-Nam area by means of PCA. PCA begins with making correlation matrix of orignal variables. From this matrix we can comprehend the rough relationships between two variables. Next, we look for the eigenvalues which are roots of characteristic equation of correlation matrix. The number of eigenvalues is equal to that of original variables. We choose the largest eigenvalue λ$_1$among them and then look for the eigenvector of correlation matrix corresponding to the largest eigenvalue. Linear combination of eigenvector obtained above and original variables is namely first Principal Component (PC). Using an eigenvalue criterion(λ$\geq$ 1), we choose 3 PCs in Jeon-Nam area and 2 PCs in Kyong-Nam area. But we decide to consider only two PCs in both areas to faciliate a comparative analysis. Now, loss of information is 31.7% in Jeon-Nam area and 26.64% in Kyong-Nam area. PCs extracted by preceding procedure have characteristics as follows. The first PC relates to aggregate size of islands in case of both areas. The second PC relates to income per household, factors of agricultural production and factors of fisheries production in Jeon-Nam area, but in Kyong-Nam area it means distance from island and income per household. A classification of islands can be attained by plotting component scores of each island in graph used two PCs as axes and grouping similiar islands. 6 groups are formed in Jeon-Nam area and 5 groups in Kyong-Nam area. The result of this study in kyong-Nam area accords with prior result of study.

• Journal of Family Resource Management and Policy Review
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• v.17 no.4
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• pp.189-213
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• 2013

The purpose of this work is to explore different types of intergenerational relationships in the later lives of old retirees. This will be done according to the eligibility of public pension and the old age social security system so that the factors affecting intergenerational relationships can be analyzed, and to propose a plan to improve social adaptation in later life. The data used in this work are the Fourth basic survey data of the 2011 Korea Retirement and Income Study. The study subjects of this work were 2,435 retirees over age 65 who had children. In this study, latent class analysis and logistic regression analysis were conducted to classify types of intergenerational relationships and to analyze the influence of relevant factors. As a result of the analysis, some of those in the group were eligible for public pension, and the ones who were not were classified into three types: the closely-living-together type, the separate-living-contact type, and the estrangement type. In the group not eligible for public pension, it was found that age, spouse, number of children, economic factors, and level of health satisfaction gave significant power to intergenerational relationships. In the group eligible for public pension, it was found that age, income and net assets, ADL(Activities of Daily Living), whether there was an IADL(Instrumental Activities of Daily Living) spouse, and number of children affected types of intergenerational relationships; Socio-demographic factors, economic factors, and healthy factors became significant variables according to the classified types of intergenerational relationship. Based on the study results, this work suggested such necessities to lay the foundation for an elderly welfare system for social adaptation in later life, This includes the offering of programs for retirement preparation, the use of family and local society resources, and expansion of the opportunity to participate in social activities.

• Journal of the Korean Home Economics Association
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• v.45 no.7
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• pp.105-117
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• 2007

The purposes of this study were 1) to classify adult consumers according to their desired clothing benefits on natural-dyed clothes, 2) to identify the differences of life-style among the classified groups, and 3) to determine the interest in Korean traditional culture, interest in dyeing, and demographics among the groups. The survey subjects were 283 adults. The data were analyzed utilizing factor analysis, cluster analysis, $x^2$-test, one-way ANOVA, Duncan test and multiple regression analysis. Based on the 6 dimensions of clothing benefits that were identified by factor analysis, adult consumers were classified into three clusters: eco-friendly oriented group showing the highest scores in environment conservation and comfort in clothing benefits, individuality-oriented group showing the highest scores in individuality and quality, and indifference group showing lower scores in all of the desired clothing benefits. The eco-friendly group showed the highest scores in attitude toward Korean traditional culture, and tended to have the most interest in natural and traditional methods of dyeing. The group members appeared to have passive life-styles, be older and married, and have a higher income than the other groups. The more positive attitude they had in Korean traditional culture, the higher was the purchase intention shown in the eco-friendly group. The individuality-oriented group showed active life-styles. This group tended to be younger than the other group. The more affirmative attitude in Korean traditional culture and the greater interest in the natural dyeing, the higher was the consumers' purchase intention of natural dyeing apparels. The indifference group tended to be younger, unmarried, and have a lower income. This group was not interested in natural dyeing apparels. The study findings demonstrated that consumers with different clothing benefits sought have different buying patterns on natural dyeing apparels. Finally the marketing implications are discussed.

• Asia Marketing Journal
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• v.14 no.2
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• pp.157-176
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• 2012

Brand switching data frequently used in market structure analysis is adequate to analyze non- durable goods, because it can capture competition between specific two brands. But brand switching data sometimes can not be used to analyze goods like automobiles having long term duration because one of main assumptions that consumer preference toward brand attributes is not changed against time can be violated. Therefore a new type of data which can precisely capture competition among durable goods is needed. Another problem of using brand switching data collected from actual purchase behavior is short of explanation why consumers consider different set of brands. Considering above problems, main purpose of this study is to analyze market structure for durable goods with consideration set. The author uses exploratory approach and latent class clustering to identify market structure based on heterogeneous consideration set among consumers. Then the relationship between some factors and consideration set formation is analyzed. Some benefits and two demographic variables - age and income - are selected as factors based on consumer behavior theory. The author analyzed USA automotive market with top 11 brands using exploratory approach and latent class clustering. 2,500 respondents are randomly selected from the total sample and used for analysis. Six models concerning market structure are established to test. Model 1 means non-structured market and model 6 means market structure composed of six sub-markets. It is exploratory approach because any hypothetical market structure is not defined. The result showed that model 1 is insufficient to fit data. It implies that USA automotive market is a structured market. Model 3 with three market structures is significant and identified as the optimal market structure in USA automotive market. Three sub markets are named as USA brands, Asian Brands, and European Brands. And it implies that country of origin effect may exist in USA automotive market. Comparison between modal classification by derived market structures and probabilistic classification by research model was conducted to test how model 3 can correctly classify respondents. The model classify 97% of respondents exactly. The result of this study is different from those of previous research. Previous research used confirmatory approach. Car type and price were chosen as criteria for market structuring and car type-price structure was revealed as the optimal structure for USA automotive market. But this research used exploratory approach without hypothetical market structures. It is not concluded yet which approach is superior. For confirmatory approach, hypothetical market structures should be established exhaustively, because the optimal market structure is selected among hypothetical structures. On the other hand, exploratory approach has a potential problem that validity for derived optimal market structure is somewhat difficult to verify. There also exist market boundary difference between this research and previous research. While previous research analyzed seven car brands, this research analyzed eleven car brands. Both researches seemed to represent entire car market, because cumulative market shares for analyzed brands exceeds 50%. But market boundary difference might affect the different results. Though both researches showed different results, it is obvious that country of origin effect among brands should be considered as important criteria to analyze USA automotive market structure. This research tried to explain heterogeneity of consideration sets among consumers using benefits and two demographic factors, sex and income. Benefit works as a key variable for consumer decision process, and also works as an important criterion in market segmentation. Three factors - trust/safety, image/fun to drive, and economy - are identified among nine benefit related measure. Then the relationship between market structures and independent variables is analyzed using multinomial regression. Independent variables are three benefit factors and two demographic factors. The result showed that all independent variables can be used to explain why there exist different market structures in USA automotive market. For example, a male consumer who perceives all benefits important and has lower income tends to consider domestic brands more than European brands. And the result also showed benefits, sex, and income have an effect to consideration set formation. Though it is generally perceived that a consumer who has higher income is likely to purchase a high priced car, it is notable that American consumers perceived benefits of domestic brands much positive regardless of income. Male consumers especially showed higher loyalty for domestic brands. Managerial implications of this research are as follow. Though implication may be confined to the USA automotive market, the effect of sex on automotive buying behavior should be analyzed. The automotive market is traditionally conceived as male consumers oriented market. But the proportion of female consumers has grown over the years in the automotive market. It is natural outcome that Volvo and Hyundai motors recently developed new cars which are targeted for women market. Secondly, the model used in this research can be applied easier than that of previous researches. Exploratory approach has many advantages except difficulty to apply for practice, because it tends to accompany with complicated model and to require various types of data. The data needed for the model in this research are a few items such as purchased brands, consideration set, some benefits, and some demographic factors and easy to collect from consumers.

• Journal of Families and Better Life
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• v.14 no.4
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• pp.71-84
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• 1996

The purposes of this study were to classify the family types based on the intra system dynamics and to examine sociodemographic backgrounds and the life satisfaction of these families. The data were collected by means of questionnaire distributed to a stratified sample of 544 housewives in Seoul who lived with housbands and children. The questionnaire included FACES II and III Communication Scale managerial behavior scale and life satisfaction Scale. Frequency percentile mean correlation factor analysis cluster analysis one-way ANOVA with scheffe test and chi-square test were used to analyze the data. This study had resulted in four major findings. The first was that highly positive relationships were found among four intra system dynamics elements. The first was that highly positive relationships were found among four intra system dynamics elements. The second finding was that families were clustered by four types named personal-oriented enervated dynamic and managerial-orien ed family. The third finding was that the four types of family were influenced by education level and job of husbands and family income. The last one was that the differences in life satisfaction were found among four types of family. The housewives of dynamic family type showed the highest level of satisfaction whereas the lowest level of life satisfaction was found among housewives of enervated family type. The recommendations for future esearch and better ways to educate and counsel families were suggested.