• Korean Journal of Agricultural and Forest Meteorology
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• v.22 no.3
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• pp.183-193
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• 2020

This study was conducted to evaluate the effect of environment factors on the growth of autumn season cultivation of Kimchi cabbage using the big data in terms of public open data(weather, soil information, and growth of crop, etc.). The growth data and the environment data such as temperature, daylength, and rainfall from 2010 to 2019 were collected. As a result of composing the correlation matrix, the height and leaf number showed high correlation in growing degree days(GDDs) and daylength, and the yield showed negative correlation in growing degree days and the concentration of clay. GDDs and daylength explained about 89% and 84% of variation in height, respectively. These two environmental factors also explained about 85% and 79% of variation in leaf numbers, respectively. In contrast, the coefficient of determination was low for yield when GDDs and concentration of clay was used. The outcome of regional statistical analysis indicated that relationship between yield and sum of sand and silt were high in Haenam and Jindo areas. Hierarchical cluster analysis, which was performed to verify the association of yield, GDDs, and concentration of clay, showed that Haenam and Jindo were clustered together. Although GDDs and yield vary by year and region, and there are regions with similar concentration of clays, observation data are grouped as the result. These suggests that GDDs and soil texture are expected to be related to yield. The cluster analysis results can be used for further data analysis and agricultural policy establishment.

• Korean Journal of Social Welfare Studies
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• v.42 no.3
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• pp.291-327
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• 2011

The purpose of this study is to classify the type of retirement process among the mature-aged in Korea. The study used the panel data from Korean Labor Panel (year2~6) for the classification of retirement process through Optimal Matching and Cluster Analysis. Classification is made in 5 categories as 'peripheral-economically active', 'private-transfer dependent', 're-entering limited', 'securely exiting', 'exit-and-reentering'. First, "peripheral-economically active" is a group which frequently experienced job status change and work insecurity. Second, "private-transfer dependent" is a group in which private transfer is likely to be supplements income in the incidence of unemployment. Third, "re-entering limited" is a group in which the proportion of no financial support combined with the absence of any economic activity is the largest. Fourth, the type "Securely exit" is th group whose members switches over to non-economically active status with pension receipt. The last type is "exit-and-reenter" that the member are highly possible to reenter in the labor market and stay in long time regardless of with or without pension plan. To examine the inequality among the types of retirement process, the duration of each status is analyzed. First, in the situation of being non-economically active, the duration of status is maintain public pension receiving and duration stabile in "securely exit" group. For "private-transfer dependent" type, members are mostly dependent on private financial support and that duration of it is longest. Through the analysis of retirement process without under other financial supports, it is "securely-exiting" type for which the duration of full-time employment is longest. It appears that the duration of part-time employment is longest in "peripheral-economically active" type. And for the case of non-waged employment it is "exit-and-reenter" type. Finally, the redistribution policy based on life course perspective is necessary to prevent that the opportunity in the structure before retirement stage and the unfavorable position in labor market make worse disadvantage in retirement process and after that.

• The Korean Journal of Applied Statistics
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• v.36 no.1
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• pp.49-62
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• 2023

Solar energy, which is rapidly increasing in proportion, is being continuously developed and invested. As the installation of new and renewable energy policy green new deal and home solar panels increases, the supply of solar energy in Korea is gradually expanding, and research on accurate demand prediction of power generation is actively underway. In addition, the importance of solar radiation prediction was identified in that solar radiation prediction is acting as a factor that most influences power generation demand prediction. In addition, this study can confirm the biggest difference in that it attempted to predict solar radiation using medium-term forecast weather data not used in previous studies. In this paper, we combined the multi-linear regression model, KNN, random fores, and SVR model and the clustering technique, K-means, to predict solar radiation by hour, by calculating the probability density function for each cluster. Before using medium-term forecast data, mean absolute error (MAE) and root mean squared error (RMSE) were used as indicators to compare model prediction results. The data were converted into daily data according to the medium-term forecast data format from March 1, 2017 to February 28, 2022. As a result of comparing the predictive performance of the model, the method showed the best performance by predicting daily solar radiation with random forest, classifying dates with similar climate factors, and calculating the probability density function of solar radiation by cluster. In addition, when the prediction results were checked after fitting the model to the medium-term forecast data using this methodology, it was confirmed that the prediction error increased by date. This seems to be due to a prediction error in the mid-term forecast weather data. In future studies, among the weather factors that can be used in the mid-term forecast data, studies that add exogenous variables such as precipitation or apply time series clustering techniques should be conducted.

• Journal of Digital Convergence
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• v.15 no.11
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• pp.567-579
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• 2017

The purpose of this study was conducted to clarify physical activity university students on time perspective in leisure constraints and leisure flow. To achieve this purpose, subjects of this study were sampled 295 Physical Activity University Students participant using purposeful sampling method for 2 months from May to June of 2017. Using questionnaires stratified cluster random sampling in university students in D city and C city. The analysis method was used t-test, one-way ANOVA, multiple regression analysis, correlation analysis methods in order to solve problems of the study. According to the study Result, First, studies show that female have high levels of leisure constraints than males. Males have higher levels of leisure flow than females. The first grader show high level of individual constraints and past negation were also high. In the series of majors, natural affiliates and humanities are high in the past negation, present destiny, the service major currently high in pleasure and of leisure, autotelic experience of leisure flow. In the rhythmic type of Activity type, the past negation, present destiny and leisure constraints are highly likely to be higher. In the competitive have shown that is high. Second, leisure constraints on students' participation in physical activities have been found to have negative influence on their students. Third, leisure flow have shown that they have a positive effect on past affirmation and present pleasure.

• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.2
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• pp.59-71
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• 2014

At present, Korean one-person households have been continuously increased in spite of the reduction of total population. The increasement of one-person household has become a social and institutional issue. It is necessary to response socially and economically to not only changes of housing demand but also the disadvantaged classes such as the socially weak and single elderly household from the national level. In this respect, this research examined the spatial distribution (such as the increasing area, high-density area, and majority area) of one-person household with census data in the city of Busan. The clusters of one-person households were selected by focusing on the spatial distributions by time series changes of 2000, 2005, and 2010 and considering their housing characteristics. In terms of policy efficiency, the clusters of one-person households to be supported by priority were derived by analyzing the census data from 6066 output areas in the city of Busan. As a result, lots of one-person households of juniors were distributed around the university town, office facility, and station service area. Lots of one-person households at middle-aged class were distributed in Busan's original downtown and mountain-side road. Generalizing these characteristics, cluster analysis was conducted. As a result, one-person household dense area in Busan could be classified into four types. This research should be utilized as a counterplan for increasing the housing demand of one-person household or basic data for supporting small housing supply policies in the future.

• Korean Security Journal
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• no.41
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• pp.123-151
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• 2014

The purpose of this study was focused on the relationship between private guards' job embeddedness and dual commitment. In this study, job embeddedness is selected as an independent variable and dual commitment is selected as a dependent variable one. job embeddedness was divided into three sub-factors such as "fit", "links", and "sacrifice", and dual commitment is again composed with organizational commitment, and career commitment. Moreover sex, age, academic background, service period, and income were selected as a control variable. To test the hypotheses, survey data from private guards in Kyungpook are collected and analyzed. Principal component method is used to see which items cluster together in each factor and to calculate factor scores. Multiple regression analysis identifies several factors which have significant effects on dual commitment. Key finding can be summarized as follow. Fist, the factor of "fit" have significant effects on organizational commitment, and career commitment. Second, the factor of "links" have significant effects on organizational commitment, and career commitment. Third the factor of "sacrifice" have significant effects on organizational commitment, and career commitment. Finally, when all the variables with significant effects are included in the final model, "links" disappear, while "fit" and "sacrifice" remain statistically significant. Based on these finding, this study suggests some policy issues to promote private guards' dual commitment.

• Journal of the Korea Furniture Society
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• v.21 no.6
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• pp.515-524
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• 2010

In line with the government's policies for localization, furniture industry in the northern area in Gyeoggi-province at presence has been operated by several furniture industrial complexes in the region in small scale, but now it should be considered from overall view of furniture industry in order to develop more competitive industry. As a matter of this fact, Gyeonggi-province should be engaged in planning to make various industrial clusters of the furniture-related industry based on the northern area of province at structural as well as politic aspects, with the help of the analyzed status of the current furniture industry in region, in supporting them by the systemized policies and developing the overall program to foster furniture as an international-competitive industry. Therefore this study suggested 'furniture industry center' which will exclusively handle and maintain the network of each furniture company in the northern area of Gyeonggi-province and 'high-tech furniture industry complex' to keep pace with the globalization and to be competitive internationally and also 'common brand business' for the cooperation at technical phase. In order to realize and vitalize such suggestions, it is urgently necessary that the network consists of the furniture companies and the expert of the related department in local universities as the main body for furniture industry, of course Gyeonggi-province as well.

• Journal of the Korean housing association
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• v.16 no.3
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• pp.101-107
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• 2005

The reason that compulsory removals of a low-quality housing redevelopment such as involuntary or unintentional migration present a problem for urban communities is that whether involuntary movers adapt themselves to their new home has an influence on the urban communities that surround them. Moreover, involuntary emigrants have higher probability of choosing faulty residential areas than voluntary emigrants do. This gives rise to a problem of another residential migration for involuntary movers. In order to solve these problems, there is a need for a new housing policy that enables original residents to come back to their old community. However studies for resettlement had not conducted subjects about housing redevelopment characteristics which influences the involuntary movers directly. Instead personal microscopic characteristics such as statistics of resettlement, the moving distance, the reason of moving, improvement of living environment, had been main subjects of farmer studies. So the purpose of this study is to analyze an analysis of the relationship between resettlement and housing redevelopment characteristics. The data used in this study was obtained at 47 areas designated by Seoul (metropolis) since 1990 for redevelopment. Cluster Analysis Is used for dividing high rate of resettlement with low rate of resettlement and Regression Analysis is used for the analysis of the relationship between resettlement and housing redevelopment characteristics. The results of examining the effects of a redeveloped housing complex on returning residents at 47 areas designated by Seoul (metropolis) since 1990 fur redevelopment are as follows: First, A housing complex with a high returning rate (remove-in rate?) has no state/public land, unauthorized building owners who are in the low-income brackets, and few interested parties such as union members. This is the characteristic of a redeveloped housing complex with a short-period project span. On the contrary, a housing complex that has a low returning rate is crowded by state/public land, and numerous unauthorized building owners, and interested parties. Second, According to the linear regression analysis, among the factors that affect returning residents, 'physical properties(characteristics) of a region', 'population properties within a region', and 'properties of a project span' indicate a negative(-)influence whereas 'properties of a complex density' shows a positive(+) influence. In a nutshell, the more the physical properties, population properties, projectspan properties, the lower the returning rate and the more the complex density properties, the higher the returning rate. In detail, an area with many small land and new/large buildings, a high population, and a long project duration has a low returning rate of original residents while an area holding large capacity and buildings with many number of floors (multiple-storied building) has a high returning rate.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.4
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• pp.139-148
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• 2016

The importance of technology commercialization is being emphasized more and more, but high technology excellence does not always lead to a successful business. In addition, companies that invest heavily in basic research and technology development are also not always able to guarantee high profits. This is due to the technical problems when present in step research and development levels are difficult to commercialize. And the market will not work rationally is also the cause of the problem. Therefore, to effectively utilize the resources necessary to ensure such partners to build alliances and cooperation with external funding or manpower is crucial to commercialize the research results of basic science successfully. In previous studies, it has been made many studies in accordance with the approach to the technology (e.g. Research and Development, Management of Technology, Technology Innovation, etc.). But the study of technology commercialization point of view is not being done much. This study should explores the available business required, or realized in the process of researching the basic science and trying to understand the imperfections of the market through the property of technology (tacit knowledge, objectified value of technology and the information asymmetry between innovation subjects, etc.). In addition, this paper, we try to focus on a strategic approach to the role of International Science Business Belt (ISBB) with success in science and technology business as appropriate countermeasures about breaking the 'Valley of Death.

• Journal of Preventive Medicine and Public Health
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• v.36 no.1
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• pp.63-70
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• 2003

Objectives : To investigate the prevalence of cognitive impairment and dementia in elderly people, aged 65 or above, residing in Busan Metropolitan City. Methods : Total of 1,101 old people, aged 65 or above, living in Busan as of December 31, 2001 were selected using stratified three-stage cluster sampling. Cognitive impairment was determined from the MMSE-K score, and dementia confirmed from five psychometric measures and the Barthel index. The crude prevalence, sex-age adjusted for the Korean population, were obtained. Results : With the cut-off point for cognitive impairment was set at 24 points, or below, on the MMSE-K scale, the crude rate of cognitive impairment was 29.3% (15.7% for men and 37.5% for women), and the sex-age adjusted prevalence was 30.5% (17.5% for men and 37.0% for women). When the cut-off point for cognitive impairment was set at 20 points, or below, on the MMSE-K scale, the crude rate of cognitive impairments were 10.0% (4.1% for men and 13.5% for women), and 10.6% (4.7% for men and 13.1% for women), respectively. The crude dementia, and the sex-age adjusted rates were 7.4% (2.4% for men and 10.5% for women), and 8.0% (2.7% for men and 10.0% for women), respectively. Conclusions : The prevalence of dementia in this study was somewhat lower than that reported by other domestic and foreign studies. Our results related to the difference in time and space, diagnostic tools, response rates, and distribution of male and female subjects, etc.