• Communications for Statistical Applications and Methods
• /
• v.9 no.1
• /
• pp.75-86
• /
• 2002

We consider the problem of estimating the change-point in mean change model with one change-point. Gombay and Huskova(1998) derived a class of change-point estimators with the score function of rank. A change-point estimator with the log score function of rank is suggested and is shown to be involved in the class of Gombay and Huskova(1988). The simulation results show that the proposed estimator has smaller rose, larger proportion of matching the true change-point than the other estimators considered in the experiment when the change-point occurs in the middle of the sample.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.146-146
• /
• 2019

The aridity index, which is determined as the ratio of potential evapotranspiration to precipitation, is one of key parameters in drought characterization. Whereas the evaporative index, which is defined as the ratio of actual evapotranspiration to precipitation, represents the fraction of available water consumed by the evapotranspiration process. This study investigates variation of the aridity and evaporative indexes due to climate change during the 21st century in South Korea. Estimations of the aridity and evaporative indexes are obtained using SWAT mode based on ensemble of 13 different GCMs over 5 large basins of South Korea for 2 RCP scenarios (RCP 4.5 and RCP 8.5). The results shows the opposite trends of the two indexes, where the aridity index is projected as always increase, while the evaporative index is expected to decrease in all of 3 future period (2011-1940, 1941-1970, 1971-2099). The estimated results also suggest that land cover influenced significantly evapotranspiration along with the change of climate. The study indicates that South Korea will be facing with a high risk of water scarcity in future due to climate change, which is seriously challenging for water planing and management in the country.

• Journal of the Korean Society of Visualization
• /
• v.21 no.2
• /
• pp.34-45
• /
• 2023

When lithium-ion batteries operate out of the proper temperature range, their performance can be significantly degraded and safety issues such as thermal runaway can occur. Therefore, battery thermal management systems are widely researched to maintain the temperature of Li-ion battery cells within the proper temperature range during the charging and discharging process. This study investigates the cooling performance and isothermal maintenance of cooling materials by measuring the surface temperature of a battery cell with or without cooling materials, such as silicone oil, thermal adhesive, and phase change materials during discharge process of battery by the experimental and numerical analysis. As a result of the experiment, the battery pack filled with phase change material showed a temperature reduction of 47.4 ℃ compared to the case of natural convection. It proves the advanced utility of the cooling unit using phase change material that is suitable for use in battery thermal management systems.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.24 no.4 s.175
• /
• pp.824-829
• /
• 2000

The industries use polymer materials for many purposes because they have many merits. But these materials' costs take up too much proportion in overall cost of products that use these materials as their major material. So it is very economical for polymer industries to reduce these costs. Microcellular foaming process appeared in 1980's to solve this problem and it proved to be quite successful. This process uses inert gases such as CO2, N2. As these gases are dissolved into polymer matrices. many properties are changed. Glass transition temperature is one of these properties. DSC, DMA are devices that measures this temperature, but these are not sufficient to measure the temperature of polymer containing gas. In this paper, we devised a new tester that uses magnetism. We used this device to acquire data of the change of glass transition temperature and made Cha-Yoon model that can predict the change of glass transition temperature. Using this model, the change of this temperature can be estimated as a function of weight gain of gas. Cha-Yoon model proved that Chow's model is inappropriate to predict the change of glass transition temperature of polymer matrices containing gas.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.15 no.2
• /
• pp.149-162
• /
• 2012

Habitat loss and fragmentation are ongoing major anthropogenic impacts on landscapes, which can strongly affect ecosystems, populations and species. The studies on forest fragmentation have been progressed, but the studies on definition of forest fragmentation and their synthetic trend in South Korea still leaves much to be desired. Therefore we set the definition of forest fragmentation and reviewed the related papers. We can give a definition that forest fragmentation is not only a process of spatial landscape transformation, but also a process of ecosystem change by it. The trend of studies on forest fragmentation divided into two fields, landscape and ecosystem changes. Forest fragmentation caused by land change altered the composition and configuration of forest patches. Most studies related on that analyzed the change using landscape index. The effects of forest fragmentation on ecosystem subdivided into three fields : biodiversity, edge effects, and invasive species, but the studies in South Korea is short. The study on relations between forest fragmentation and ecosystem change is necessary to face the Convention on Biological Diversity in South Korea. In addition, the fundamental studies on biodiversity is important to mitigate against forest fragmentation.

• KIEAE Journal
• /
• v.12 no.1
• /
• pp.65-71
• /
• 2012

This study aims to find out a institutional base in urban planning and urban project, confronted with climate change and necessity of sustainable development in France. The establishment of Grenelle Environment Law became a start point to draw concrete effect and implement urban projects. The relation in urban policy on climate change and its concrete shape in urban projects are examined in this paper, especially focused on HQE2R criteria and Eco-Quartier projects. It provides various information on ways to improve Korea urban planning, urban revitalization and development projects, which is in similar situations and necessity in France. As shown in the case of France, for the sustainable urban development related on climate change, it is necessary of Central Government's firm and clear policy framework, as well as the institutions and organizations linked to actual process of local communities are required. In addition, through the development of indicators applicable to urban development and architectural process, objective and rational framework for planning and design standards should be established.

• Research in Community and Public Health Nursing
• /
• v.13 no.4
• /
• pp.732-742
• /
• 2002

There are few research on the social drinking experience reported by women. Thus, it is necessary to understand the increasing tendency of womens drinking experience in the sociocultural context. This study was aimed to explore and delineate the drinking experience of full-time house wives base don Strauss and Corbin's grounded theory (1998). The subjects of this study were 10 full-time middle-aged house wives who were living in Seoul region. The data were collected through several in-depth interviews and observations until the theoretical saturation was achieved. The data were analyzed using Strauss and Corbin's grounded theory method. The results of this study generated a paradigm that the drinking experience of the full-time middle-aged house wives has a core category of 'free-oneself-from' and is also connected with mingling, anguish, accessibility, reaction of other people, change, personal resources, self-expression and building relationships by drinking. All processes from the occurrence of the central phenomenon to extinction are as follows; 1) Starting the process of the drinking experience for mingling and resolving anguish, and by having an easy accessibility; 2) Perceiving the process of reaction by other people, physical change of herself. and psycho-behavioral change; 3) Experiencing the process of free-oneself from thorough drinking; 4) Acknowledging the process of the resources for free-oneself-from; 5) Selecting the process of self-expression according to the resources; 6) Building the process of the relationship with drinking as a way of self-expression. Based on this paradigm, 4 hypothesis and 4 types are generated. Thus, this study suggests that it is useful to develop nursing interventions to improve the self-esteem of the full-time middle-aged house wives and to provide them various methods of problem solving strategies. This study also proposes that there should be a strategic program for the women so that they could make a route for positive self-expression by achieving a proper relationship with drinking.

• Korean Journal of Construction Engineering and Management
• /
• v.9 no.6
• /
• pp.194-203
• /
• 2008

Construction companies require management system to increase efficiency and profit because of receiving competition and globalizing business environment. Since 1990s, construction companies have made various attempts to innovate business structure both internally and externally by means of BPR, 6 Sigma, PI, and Workflow. Some improvements were made, but most of them were temporary, and insufficient to provide the much-needed promptness of business process in responding to the changes. Furthermore, the recent methods of applying BPM and practical using are limited to the theory and method of other industries, and also the attempts of applying BPM in construction industry are at the stage of theoretical approaching and examining in a few construction companies. Accordingly, this study deduces the necessity of adopting BPM based on change of business paradigm for construction companies and limits of current researches, failure causes and problems of application attempts of BPM and process management. And also, we analyze Advance of BPM and suggest the application method of business process management model for construction companies.

• Journal of Pharmacopuncture
• /
• v.13 no.2
• /
• pp.33-49
• /
• 2010

Objectives: The aim of this experiment is to provide an objective differentiation of cultivated ginseng, mountain ginseng through component analysis, and to know the change of gin senoside components in the process of heating and fermentation Methods: Comparative analyses of ginsenoside $Rb_1$, $Rb_2$, Rc, Rd, Re, Rf, $Rg_1$, $Rg_3$, $Rh_1$, and $Rh_2$, from the cultivated ginseng 4 and 6 years, and mountain cultivated ginseng were conducted using HPLC (High Performance Liquid Chromatography, hereafter HPLC). And the same analyses were conducted in the process of heating and fermentation using mixed Lactobacillus rhamnosus, Lactobacillus plantarum, Bifidobacterium lactis for 7 days. Results: The change of ginsenosides to the process of red ginseng and fermentation, cultivated ginseng and mountain cultivated ginseng were showed another results. Mountain ginseng showed a lot of change compared with cultivated ginsengs. In the 7 days of fermentation, mountain ginseng showed that ginsenoside $Rg_1$, $Rb_1$, $Rb_2$, Rc, and Rd were decreased and increased ginsenoside Re, Rf, $Rg_3$ and $Rh_1$ were increased compared with cultivated ginseng Conclusions: It seemed that ginsenosides of mountain cultivated ginseng was better resolved than cultivated ginseng because the difference of structure or distribution of ginsenosides in the condition of fermentation.

• Journal of Families and Better Life
• /
• v.30 no.6
• /
• pp.129-150
• /
• 2012

This study examined difference in the responses of children and therapists depending on children's problem type(internalization or externalization) and the therapists' levels of psychological burnout. Play therapy' cases (March 2010 ~ September 2011) were successfully concluded in more than 36 sessions, which targeting 14 children aged 4~9 who had emotional and behavioral problems and two therapists who consulted with the children. To examine the change in the play therapy stepwise process in this case, the responses in the children and the therapists were examined by dividing the stages of therapy into the early stage, the middle stage, and the late stage. The Results showed that (1) the children's response during the play therapy process were not significant different for both types of children's problems. Moreover, there were no differences with different levels psychological burnout by the therapist. (2) A change in the children's response during the play therapy process was noted in both children who had internalization problem and in those who had externalization problems. Moreover, according to the therapist's levels of psychological burnout, a change in the children's responses was indicated in the play therapy process. (3) The therapist's responses in the play therapy process did not show significant difference according to children's problem type or therapists' levels of psychological burnout. (4) A significant difference was noted in the responses between the therapists experiencing psychological burnout depending on their level.