• Journal of the Korean Data and Information Science Society
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• 제18권1호
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• pp.41-50
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• 2007

This study attempts to test the lead-lag relationship between the stock price and the business indicator in the multivariate context. It additionally investigates the short and long-run dynamic relationships among the four market variables. The hypothesis that the stock price leads the business indicator is found to be rejected for the whole study period. When structural change is considered, the statistical result appears to reflect the reality. The causal relationships among the variables in the former period are simpler than those in the latter period, and the stock price significantly appears to lead the business indicator. On the other hand, the relationship between the stock price and the business indicator in the latter period appears to prove the recent hypothesis of their coincidence.

• 한국태양에너지학회 논문집
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• 제35권5호
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• pp.31-38
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• 2015

It is important to improve the energy performance in the industrial sector, and therefore most of the manufacturing companies need the energy performance indicators to identify the target and to verify the energy savings. However, the conventional energy performance indicators such as the total energy consumption and the energy intensity are not proper to use. The reason is that they do not consider adequate relevant variables including productions in the boundary of the manufacturing companies. Therefore, the study provides the advanced energy performance indicator using by the linear regression model according to each energy source to manage the target and to verify the energy performance properly.

• 기술혁신학회지
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• 제9권1호
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• pp.26-51
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• 2006

최근 국가 연구개발 활동에 있어서 연구개발 성과의 측정 및 관리가 중요한 이슈가 되고 있다. 특히 기술의 사업화는 연구개발의 결과물을 최종 경제적 성과로 전환하는 것으로서, 연구개발 활동의 경제적 기여를 위해 필수적인 과정이다. 이 논문에서는 국가 R&D 정책에서 중요하게 다루어지고 있는 기술사업화의 현황 및 추세를 파악하기 위하여 국가 기술사업화와 관련된 다양한 정보들을 종합한 국가기술사업화지표를 개발하였다. 개발된 지표는 기술사업화 활동, 협력 및 네트워크, 기술사업화 성과 기술사업화 환경, 심리지수의 다섯 가지 부문으로 구성되어 있고 각 부문의 지수는 각각 다섯 개의 세부 지표로 구성되어 있다. 개발된 지표는 우리나라의 기술시장 및 사업화 정책 수립을 위한 유용한 기초 자료로서 기술사업화 현황 및 수준, 예측 등 다양한 정보를 제공할 것이다.

• Structural Engineering and Mechanics
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• 제60권6호
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• pp.1093-1117
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• 2016

Global sensitivity analysis (GSA) has been widely used to investigate the sensitivity of the model output with respect to its input parameters. In this paper a new single-solution search optimization algorithm is developed based on the GSA, and applied to the size optimization of truss structures. In this method the search space of the optimization is determined using the sensitivity indicator of variables. Unlike the common meta-heuristic algorithms, where all the variables are simultaneously changed in the optimization process, in this approach the sensitive variables of solution are iteratively changed more rapidly than the less sensitive ones in the search space. Comparisons of the present results with those of some previous population-based meta-heuristic algorithms demonstrate its capability, especially for decreasing the number of fitness functions evaluations, in solving the presented benchmark problems.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제3권2호
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• pp.84-96
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• 2022

Most of the islands of Korea are distributed in the South and West Sea, and it consists of independent small stream. As a result, the fish community that inhabits the island's stream is isolated from the mainland and other island. This study utilized a Self-Organizing Map (SOM) and a random forest model to analyze the relationship between environmental variables and fish communities inhabiting islands in South Korea. Through the SOM analysis, the fish communities were divided into three clusters, and there were differences in biotic and abiotic factors between these groups. Cluster I consisted of sites with relatively larger island areas and a higher number of species and population. It was found that 15 out of 16 indicator species were included. Meanwhile, the remaining clusters had fewer species and populations. Cluster II, especially, showed the lowest impact from physical variables such as water width and depth. As a result of predicting the species richness using the random forest model, physical variables in habitats, such as stream width and water depth, had a relatively higher importance on species richness. On the other hand, forest area was the most important variables for predicting Shannon diversity, followed by maximum water depth, and gravel. The results suggest that this study can be used as basic data for establishing a stream ecosystem management strategy in terms of conservation and protection of biological resources in streams of islands.

• 응용통계연구
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• 제27권2호
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• pp.227-237
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• 2014

우리는 회귀분석에서 설명변수들 중 일부가 질적 변수인 경우 지시변수를 사용한다. 또한 공분산분석모형에서는 관심인자의 효과에 대한 유의성 검정시 연속변수인 공변수로 주어지는 방해인자를 미리 회귀분석으로 제거한다. 지시변수 사용 회귀모형이나 공분산분석모형을 위한 확증적 자료분석 전에 탐색적 자료분석의 한 수단으로서 자료깊이에 근거한 DD-plot을 이용하면 집단 간의 차이를 쉽게 알아볼 수 있다. 이 방법은 오차항의 통계모형을 가정하지 않으므로 유용한 탐색적 방법이 될 수 있다. 몇 가지 사례들을 통하여 DD-plot이 지시변수 사용 회귀모형이나 공분산분석모형을 위한 그래픽 탐색적 자료분석방법으로서 유용함을 보였다.

• 대한간호학회지
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• 제21권2호
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• pp.195-203
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• 1991

Correlations among body weight and sociodemographic factors, including life - style were tested as social determinants of health in a sample of 5,201 adults in Korea. The aim of this study was to determine the extent to which sociodemographic variables and life-style associated health behaviors explain body weight distribution. A second aim was to explain the relation of body weight and health status to stress the importance of body weight as an early risk indicator of health status. The canonical correlation between the weight distribution(underweight and overweight) and the independent variables was 0.29, 17% of the total variance was explained. Perceived health level represented the highest contribution(canonical coefficient 0.82) to body weight. Sociodemographic factors such as sex, economic status, and life-style factors such as smoking, exercise, regular meais and sleep showed comparatively high contributions to body weight. The relevance of body weight for health status including the rate of chronic disease and the rate of medical utilization was significant. Especially, underweight was clarified as being mere important than overweight to morbidity level and medical utilization. These findings suggest that perceived body weight is an important indicator of health status and is thus a valuable variable to be considered for nursing intervention and health education related to the promotion of health.

• 한국의류학회지
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• 제26권11호
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• pp.1605-1614
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• 2002

The purpose of this study was to identify the consumers who use the level of price as the indicator of the product quality. In order to implement the purpose of this study, Jeans market had been segmented by the mixture regression model, and price response function was calibrated for each segment. Based on the types of price response function, segments were allocated into one of two groups; the group using the level of price as the quality indicator or the group not using the level of price as that. Then, characteristics of both groups were compared in terms of product attributes and demographic variables. Data were co]looted from the sample of the 23o undergraduate and graduate students in Seoul. For the data analysis, mixture regression model, conjoint analysis, and t-test were used. As a result, jeans market was divided into 5 segments. Segment 1,2,3 were allocated into the group not using the level of price as the quality indicator while segment 4,5 were done into the other group. Significant differences existed between two groups in product attributes, not in demographic variables. Mixture model and conjoint analysis were proved to be an effective set of tools in market segmentation.

• Journal of Mechanical Science and Technology
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• 제20권12호
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• pp.2189-2196
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• 2006

The present work is concerned with the development of a procedure for adaptive computations of shear localization problems. The maximum jump of equivalent strain rates across element boundaries is proposed as a simple error indicator based on interpolation errors, and successfully implemented in the adaptive mesh refinement scheme. The time step is controlled by using a parameter related to the Lipschitz constant, and state variables in target elements for refinements are transferred by $L_2$-projection. Consistent tangent moduli with a proper updating scheme for state variables are used to improve the numerical stability in the formation of shear bands. It is observed that the present adaptive mesh refinement procedure shows an excellent performance in the simulation of shear localization problems.

• Environmental Analysis Health and Toxicology
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• 제30권sup호
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• pp.3.1-3.11
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• 2015

Objectives This study presents the indicators and proxy variables for the quantitative assessment of green chemistry technologies and evaluates the relative importance of each assessment element by consulting experts from the fields of ecology, chemistry, safety, and public health. Methods The results collected were subjected to an analytic hierarchy process to obtain the weights of the indicators and the proxy variables. Results These weights may prove useful in avoiding having to resort to qualitative means in absence of weights between indicators when integrating the results of quantitative assessment by indicator. Conclusions This study points to the limitations of current quantitative assessment techniques for green chemistry technologies and seeks to present the future direction for quantitative assessment of green chemistry technologies.