• Journal for History of Mathematics
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• v.15 no.2
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• pp.141-160
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• 2002

We investigate the history of the research of the existence of periodic solutions of a nonlinear wave equation with jumping nonlinearity, suggested by Mckenna and Lazer (cf. [15]). We also investigate the recent research of it; a relation between multiplicity of solutions and source terms of the equation when the nonlinearity -($bu^+$-$au^-$) crosses eigenvalues and the source term f is generated by eigenfuntions.

• Journal for History of Mathematics
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• v.30 no.2
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• pp.121-133
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• 2017

In the present study, we investigate and compare the International Mathematical Olympiad participation histories of Korea, China, and Japan. Especially, the processes for the first participation of the IMO, trends in team rankings of the IMO, and national team selection systems and education systems are compared. And we investigate and compare the policies for the talented girls mathematics Olympians. Several proposals are suggested for development of Korean Mathematical Olympiad and participations to IMO.

• Proceedings of the Korea Contents Association Conference
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• 2019.05a
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• pp.339-340
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• 2019

The society seeks creative talents. Expressive activities are educational activities that stimulate imagination, realize such through body, and enable communication with the society. In such perspective, it is quite meaningful to investigate educational objective that expressive activity shall possess as class to cultivate creativity. Therefore, this study aims to investigate creativity theory, analyze expressive activities as national curriculum at elementary schools, understand the position of expressive activities in Korea, and understand creative educational objective and value of expressive activities, in order to suggest idea for practical goal of expressive activities.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.05a
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• pp.41-44
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• 2003

First, we investigate some properties of fuzzy compactness. Second, we introduce the concept of fuzzy local compactness in fuzzy topological space and study some of its properties. Finally, we investigate some relations between F-compactness in fuzzy topological spaces and one in fuzzy hyperspaces.

• The Journal of Economics, Marketing and Management
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• v.4 no.2
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• pp.20-32
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• 2016

The purpose of the present study is to investigate the audit quality and Investment efficiency of the listed companies on the Tehran Stock Exchange (TSE). The population includes 94 firms selected through systematic sampling. The data is collected from the audited financial statements of the firms provided by TSE's website from 2008 to 2015. In this study the variables, auditor industry specialization, auditor reputation, auditor tenure and auditor independence has been used to investigate audit quality. The results of multiple linear regression analysis show that there is a significant relationship audit quality and Investment efficiency.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.4 no.2
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• pp.72-82
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• 1992

To accurately estimate nearshore current in shallow water regions. it is necessary to investigate the irregular wave transformation characteristics and radiation stress produced by random sea waves. This research is to investigate the application or the individual wave Analysis Method. the Component Wave Analysis Method and Representative Wave Analysis Method in the shallow water region. These methods were estimated by wave shallowing transformation when the waves propagate from deep water to shallow water region b)r generating regular waves, two component waves and irregular waves (Bretschneider-Mitsuyasu type). That is, the Indivisual Wave Analysis Method is to investigate from the viewpoint of shallow water transformation of wave statistical characteristics and their zero-down-crossing waves (wave height period and wave celerity). And the component Wave Analysis Method is to investigate from the view point of shallow water transformation of basic frequency component wave and their interference frequency component wave. In addition, this research is to compare the measured mean water level elevation with the calculated one from radiation stress of irreguar waves that is assumed in the three methods above.

• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.219-224
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• 2019

BACKGROUND: Soil bacteria play important roles in organic matter decomposition and nutrient cycling during the non-growing season. The purpose of this study was to investigate the effects of soil management and chemical properties on the utilization of carbon sources by soil bacteria in paddy fields. METHODS AND RESULTS: The Biolog EcoPlate was used for analyzing community-level carbon substrate utilization profiles of soil bacteria. Soils were collected from the following three types of areas: plain, interface and mountain areas, which were tested to investigate the topology effect. The results of canonical correspondence analysis and Kendall rank correlation analysis showed that soil C/N ratio and NH₄⁺ influenced utilization of carbon sources by bacteria. The utilization of carbohydrates and complex carbon sources were positively correlated with NH₄⁺ concentration. Cultivated paddy fields were compared with adjacent abandoned fields to investigate the impact of cultivation cessation. The level of utilization of putrescine was lower in abandoned fields than in cultivated fields. Monoculture fields were compared with double cropping fields cultivated with barley to investigate the impact of winter crop cultivation. Cropping system altered bacterial use of carbon sources, as reflected by the enhanced utilization of 2-hydroxy benzoic acid under monoculture conditions. CONCLUSION: These results show that soil use intensity and topological characteristics have a minimal impact on soil bacterial functioning in relation to carbon substrate utilization. Moreover, soil chemical properties were found to be important factors determining the physiological profile of the soil bacterial community in paddy fields.

• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.73-84
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• 2006

Standard safety management cost system was established in 1988 as a decree Number of 88-13, first time. And then, it has been revised fourteen times, up to now. A lot of practical investigations have been made for the revision but many problems at sites are continued to be put out so that it should be revised. This study is to find out hazard level of each work kinds through questionnaire and interview and investigate analyze the status which standard safety management costs have been used. Also, this study is to show reasonable rates of standard safety management costs in construction industry and to set up countermeasures against those problem after reviewing its status in korea with in Japan and Europe. Budget and actually performed amount of safety management costs in this study are investigated. costs for temporary work which is clarified in Japan is collected in order to compare domestic cost rate with Japanese one related to the total project amount. This study is to investigate eleven project kinds of domestic system, first, and to investigate eleven items of apartment bldg, office, civil work such as bridge, tunnel, dam, plant etc, secondly. Additionally, three items of gymnasium, railway, particular steel tower are investigated in this study. Also this study is to investigate and analyze performed costs of presently processing worker finished work so that it shows a new reasonable rate against standard safety management costs in construction industry, in order to make basical data and material to be systemized.

• Journal of Korean Academy of Nursing
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• v.5 no.1
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• pp.41-47
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• 1975

This study was conducted to investigate the influence of nursing education and clinical experience on the fear of death among nursing students and nurses. The fear responses were measured by the Collett-Lester Fear of Death Scale'which is composed of 4 subsale to measure fear of death of self, fear of death of others, fear of dying of self and fear of dying of others. To investigate the influence of nursing education on the fear of death, tile freshmen and the senior class of the nursing students were compared. The senior students were again compared with graduate nurses to investigate the influence of clinical experience on the fear of death. To investigate the possible intuitional difference in the fear response to death among different group of nurses and nursing students, students and nurses from Seoul National University and Korea University were selected to participate in the study. The three hypotheses formulated for this study are as follows: 1, Fear of death will decrease with increased educational level 2. Fear of death will decrease with increased clinical experience. 3. There wi]1 be institutional difference in the fear of death. The results obtained are as follows : 1. There was no significant differences in the fear of death between freshman and senior students. 2. There was no significant differences in the fear of death between senior students and graduate nurses. 3. There was significant difference between nurses and senior students in the subsale of fear of dying of others in which the nurses were found to be more fearful. 4. There wert significant differences in the subsale of fear of dying of self and fear of dying of others between two institutions.

• Journal of the Korean Geographical Society
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• v.38
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• pp.37-59
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• 1988

The aim of this study is to investigate the influence of the technological changes on locational changes on the assumption that technological changes cover over all industrial sectors. The study is carred on 1) To investigate the theoretical backgrounds of the technological and locational changes and their problems. 2) To investigate the location and economic characteristics of the Korean textile industry. 3) To investigate the technological development and regional variations in technological level. 4) To the relationship of the technological change to the location of the textile industries. The locational change of the Korean textile industries have been closely related to economic characteristics. In the begining stage of development in the 1950's, thetextile industries were largely concentrated in the major cities(Seoul, Pusan, Taegu, Masan et. al.). In the growing stage of development in the 1960's, the textile industries were relocated in suburban areas with the trend of large corporations building their branch plants of chemical fibers in the suburbs. With the expansion in the export industry in the 1970's, the textile companies were distributed throughout the whole country. But the research and development(R&D) activities caused the textile industries reconcentrate around Seoul and Pusan, owining to the change of the economic environments in the 1980's. The 1980's have witnessed the increased R&D investment for the development of better new and value-added products. This was because the technological level was much higher than that of Taegu and Other regions. What is more, plant birth location and branch plant location support that locational changes of textile industry were caused by technological changes. Plant birth location put stress technological environments of region, compared with branch plant locaiton. Accordingly, the technological changes of industry can be an important factor in locational changes. Through this study, it can be seen that locational changes come from technological changes. Other locational factors influence the industrial locations, but regional variations in technological level which has been relatively ignored has to be considered on the location study. Together with the accomplishments of existing location study, the study on technological change and location can better explain the location phenomena. And further research on technological change and location can provide better policy implications for regional development.