• Journal of the Korean Society of Safety
• /
• v.15 no.3
• /
• pp.71-77
• /
• 2000

The aim of this study is to investigate the temperature dependence of the lower explosive limit(LEL) at elevated temperature. The temperature dependence of the lower explosive limit is one of the significant indices of flammability and combustibility. By using the literature data, the new equations for predicting the temperature dependence of the lower explosive limits for paraffinic hydrocarbons are proposed. The values calculated by the proposed equations were a good agreement with the literature data. It is hoped eventually that this proposed equations will support the use of the prediction for the lower explosive limit and the flash points of the flammable mixtures.

• Korean Management Science Review
• /
• v.30 no.3
• /
• pp.17-31
• /
• 2013

The purpose of this paper is to illustrate the importance of identifying and considering 'purchase dependence' when purchase of an item is dependent on availability of other items demanded in the same order. This paper is the first study to develop an inventory model for purchase-dependent inventory systems. Through simulation experiments, we demonstrate that the developed inventory model incurs less inventory operations cost than other inventory models that ignore purchase dependence. For empirical validation of the developed inventory model, the actual inventory data at the Hyundai Engine Europe Service Center is used. We explain the process of identifying purchase dependencies among items through a data mining technique. The empirical study results in similar results to the simulation experiment, demonstrating that the developed inventory model is applicable to real situations.

• Journal of the Korean Statistical Society
• /
• v.26 no.1
• /
• pp.131-146
• /
• 1997

In this paper the problem of measuring the stochastic dependence among sets fo random variates is considered, and attention is specifically directed to forming a single well-defined measure of the dependence among sets of normal variates. A new information theoretic measure of the dependence called dependence index (DI) is introduced and its several properties are studied. The development of DI is based on the generalization and normalization of the mutual information introduced by Kullback(1968). For data analysis, minimum cross entropy estimator of DI is suggested, and its asymptotic distribution is obtained for testing the existence of the dependence. Monte Carlo simulations demonstrate the performance of the estimator, and show that is is useful not only for evaluation of the dependence, but also for independent model testing.

• Journal of Korea Trade
• /
• v.24 no.3
• /
• pp.37-54
• /
• 2020

Purpose - This study is to investigate the determinants of suppliers' dependence on buyers in the home country by developing a theoretical model of innovative activities. The high dependence of auto parts suppliers on a single local buyer in South Korea due to firm ownership issues and incremental innovation is examined using data from a set of organizations that supply intermediate goods to this automotive manufacturer. Furthermore, we tested the moderating effect of FDI and global knowledge sourcing on the relationship between firm ownership and suppliers' dependence on the local buyer. Design/methodology - To test the hypotheses, we examined a sample of 101 suppliers over 10 years in the Korean automobile parts industry. In this empirical analysis, we utilized a fixed-effects generalized least squares model using panel data. Findings - In this study, domestic firms (automobile parts suppliers) were more dependent on a single local buyer (automobile assembler) than foreign-owned suppliers operating in Korea. In addition, incremental innovation was the mediating mechanism between domestic firms and dependence on the local buyer. To reduce this dependence on the buyer, we suggest two different international strategies: geographical diversification through FDI and global knowledge sourcing. Originality/value - Previous studies showed that asymmetric dependence between firms has many adverse effects. This study proved that domestic and foreign-owned suppliers have different levels of dependence on local buyers due to their heterogeneous characteristics and business strategies. We distinguish two different types of innovation - radical innovation and incremental innovation - that previous studies have often treated as equal when it comes to firm autonomy. Finally, we propose that both FDI and international knowledge sourcing as global strategies to weaken suppliers' asymmetric dependence on a single buyer.

• Communications for Statistical Applications and Methods
• /
• v.14 no.3
• /
• pp.687-698
• /
• 2007

A normal mixture model with which dependence between classes is incorporated is proposed in order to detect differentially expressed genes. Gene clustering approaches suffer from the high dimensional column of microarray expression data matrix which leads to the over-fit problem. Various methods are proposed to solve the problem. In this paper, use of simple averaging data within each class is proposed to overcome the various problems due to high dimensionality when the normal mixture model is fitted. Some experiments through simulated data set and real data set show its availability in actuality.

• Proceedings of the Korea Society for Industrial Systems Conference
• /
• 2008.10b
• /
• pp.651-655
• /
• 2008

Traditional slicing techniques make slices through dependence graphs. They also improve the accuracy of slices. However, traditional slicing techniques require many vertices and edges in order to express a data communication links. Therefore the graph becomes complicated, and size of the slices is larger. We propose the representation of a dynamic object-oriented program dependence graph so as to process the slicing of object-oriented programs that is composed of related programs in order to process certain jobs. The efficiency of the proposed efficient dynamic object-oriented program dependence graph technique is also compared with the dependence graph techniques discussed previously. As a result, this is certifying that an efficient dynamic object-oriented program dependence graph is more efficient in comparison with the traditional dynamic object-oriented program dependence graph.

• International Commerce and Information Review
• /
• v.12 no.2
• /
• pp.183-211
• /
• 2010

This paper empirically investigated whether the dependence of manufacturing firms effects the influence strategies and long-term orientation based on the data from manufacturing firms in Korea. U.S., and Japan. Also, the proposed model was proven by the structural equation model with the data gathered from 105 manufacturing firms in Korea, 103 in U.S., and 83 in Japan. The findings were as follows. First, the dependence of all of manufacturing firms, regardless of country, positively affected the coercive influence strategies of distributors, whereas the dependence positively affected the noncoercive influence strategies in U.S. and Japan but in the case of Korea, it showed the reverse direction and were not statistically significant. Second, the dependence of Korean manufacturing firms positively affected the long-term orientation but American manufacturing firms showed the reverse direction and it was not statistically significant. In the case of Japanese manufacturing firms, the direction predicted in the paper was shown but was not statistically significant. Third, the coercive influence strategies positively affected the long-term orientation in Korea but it showed the negative relationship in Japan. Fourth, the noncoercive influence strategies positively affected the long-term orientation in all countries. Lastly, a few implications, limitations and future study issues were discussed.

• Journal of Korean Academy of Rural Health Nursing
• /
• v.9 no.1
• /
• pp.33-45
• /
• 2014

Purpose: This study was done to identify attitudes to smoking, beliefs about smoking and factors influencing nicotine dependence in woman smokers. Methods: Data was collected from 131 women smokers, who visited a public health center between January and July. 2012. Collected data were analyzed using the SPSS 18.0 program. Results: Mean score for attitude to smoking was $23.7{\pm}3.2$, beliefs about smoking, $18.6{\pm}2.9$, and nicotine dependence, $4.3{\pm}2.1$. Attitude to smoking of the woman smokers was significantly different according to marital status, beliefs about smoking were significantly different according to marital status and being employed. Nicotine dependence was significantly different according to frequency of alcohol consumption, stress, number of cigarettes smoked. There was a correlation between attitude to smoking and beliefs about smoking. Age when starting to smoke, number of cigarettes, and length of time one has smoked accounted for 31.0% of nicotine dependence. Conclusion: The results indicate that increasing knowledge and improving attitudes toward smoking as well as training on stress management and exercise are needed. Also, a distinct mediation should be developed for women smokers. Especially, in-depth research is needed to identify psycho-social behavior-related variables for the health promotion of young women smokers.

• Communications for Statistical Applications and Methods
• /
• v.27 no.2
• /
• pp.163-175
• /
• 2020

We consider a wide class of general weakly-dependent processes, called ψ-weak dependence, which unify almost all weak dependence structures of interest found in statistics under natural conditions on process parameters, such as mixing, association, Bernoulli shifts, and Markovian sequences. For detecting the tail behavior of the weakly dependent processes, change point tests are developed by means of cumulative sum (CUSUM) statistics with the empirical distribution functions of sample extremes. The null limiting distribution is established as a Brownian bridge. Its proof is based on the ψ-weak dependence structure and the existence of the phantom distribution function of stationary weakly-dependent processes. A Monte-Carlo study is conducted to see the performance of sizes and powers of the CUSUM tests in GARCH(1, 1) models; in addition, real data applications are given with log-returns of financial data such as the Korean stock price index.

• Journal of the Korea Society of Computer and Information
• /
• v.23 no.11
• /
• pp.203-209
• /
• 2018

The purpose of this study was social withdrawal, depression, and self - esteem affect adolescents' mobile phone dependency. For this study, I used data from the first grade of junior high school during the 7th (2016) Korean child and youth panel survey provided by Korea Youth Policy Institute. A total of 1,937 people were selected as the final target except those who do not have a mobile phone. The analysis method was SPSS 23.0 and AMOS 20.0. As a result of the study, First, the higher the depression of adolescents, the higher the dependence on mobile phones. Second, the social withdrawal and depression of adolescents have a significant impact on mobile phone dependence through self-esteem. In conclusion, I would like to provide policy data so that youths can develop and implement preventive programs that can prevent personality education and erroneous mobile phone dependency that can develop healthy and positive growth.