• The Bulletin of The Korean Astronomical Society
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• 제37권2호
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• pp.102.2-102.2
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• 2012

이 연구의 목적은 거시적인 관점에서 NOS의 중요한 요소들을 강조한 Flow map(oh, 2011)를 이용한 명시적이고 암시적인 교육의 본성교육이 얼마나 이루어졌는가를 알아본다. 과학의 본성은 지식의 내용뿐만 아니라 지식이 어떻게 형성되었는가에 있다. 이러한 과학의 본성을 이해한다는 것이 현대의 과학의 중요한 목적중의 하나인 과학적 소양을 얻는 것이다. 이를 구체적으로 실현하는 교수 모형으로 가장 중요한 이론의 생성과 실험에 의한 확증과 이론의 확증을 미시적인 관점으로 연구를 전개하였다. 따라서 먼저 Kuhn(1996)의 과학철학 이론과 NOS를 통한 Flow map 개발에 이론적 배경이 된 과학의 본성의 정의, 과학의 본성에 대해 합의된 핵심 요소들, Kuhn(1996)의 과학철학 이론을 바탕으로 한 Oh(2011)가 제안한 Flow map의 구조를 알아본다. 연구방법은 귀추(abduction)를 통한 가설의 생성과정과 확증을 보여주는 Oh(2012)의 자연과학의 추리과정을 이용하여 충북대학교 천문우주학과에서 자연과학캠프에 참여한 고등학생들을 대상으로, "Galileo의 흑점발견과정"으로부터 현대의 태양의 흑점 모형을 이해하도록 한다.

• Journal of the Society of Disaster Information
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• 제17권3호
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• pp.655-666
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• 2021

Purpose: This study is to develop a method for measuring dynamic speeding risks using vehicle trajectory big data and to demonstrate the feasibility of the devised speeding index. Method: The speed behaviors of vehicles were analysed in microscopic space and time using individual vehicle trajectories, and then the boundary condition of speeding (i.e., boundary speed) was determined from the standpoint of crash risk. A novel index for measuring the risk exposure of speeding was developed in microscopic space and time with the boundary speed. Result: A validation study was conducted with vehicle-GPS trajectory big data and ground-truth vehicle crash data. As a result of the analysis, it turned out that the index of speeding-risk exposure has a strong explanatory power (R²=0.7) for motorway traffic accidents. This directly indicates that speeding behaviors should be analysed at a microscopic spatiotemporal dimension. Conclusion: The spatial and temporal evolution of vehicle velocity is very variable. It is, hence, expected that the method presented in this study could be efficaciously employed to analyse the causal factors of traffic accidents and the crash risk exposure in microscopic space using mobility trajectory data.

• Environmental and Resource Economics Review
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• 제33권1호
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• pp.59-86
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• 2024

Recently, research on city gas demand is increasing by reflecting the characteristics of each region. The similarity of the social structure of the adjacent region and the density of the supply infrastructure induce spatial correlation with the clustering that has a microscopic relationship between regions. Accordingly, as a result of analyzing the spatial correlation after dividing the demand for city gas for civilian use into a total of 54 regions based on the jurisdiction of 34 city gas companies, it was confirmed that there was a positive spatial correlation from a global and local perspective. In this study, the demand for city gas for civilian use for 54 regions from January 2014 to December 2022 was composed of panel data, and the spatial panel regression analysis and the general panel regression analysis were compared, and it was found that the spatial error model (SEM) was the most suitable model. This presents policy and practical implications by confirming that the demand for city gas for civilian use in one region has a significant relationship with the adjacent region.

• Journal of Labour Economics
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• 제29권2호
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• pp.117-143
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• 2006

This paper illuminates the patterns of growth and declines in sizes of union membership in metal, chemical, financial, and auto transport sectors in three distinct periods during the last four decades from 1963 to 2003. This paper also calculates union densities in auto assembly, auto supply, and shipbuilding industries of the metal sector, cement, petroleum refining, and pharmaceutical industries of the chemical sector, private banking industry of the financial sector, and city bus industry of the auto transport sector. Such diversities in both sizes of union membership and union densities among sectors and industries turned out to be associated with attitudes and choices of employers and unions in interaction with sector- and industry-specific economic (growth stage and path), institutional (degrees of government intervention), and social (demographic features of employees and prevailing sizes of firms) environment. Such finding shows that theoretical reasonings on sizes of union membership and union densities across sectors and industries in advanced nations are also relevantly useful to analyze the Korean case.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• 제33권1호
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• pp.54-61
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• 2005

Characteristics of sprays injected by gas/liquid coaxial atomizers operated at atmospheric pressure are studied using shadowgraph, mechanical patternator and PDPA. The gas-to- liquid momentum flux ratio(M) and the liquid Reynolds number(Re) are selected as key parameters in characteristics of gas/liquid coaxial sprays from the dimensional analysis. The properties of shear coaxial sprays are compared with those of swirl coaxial sprays through the macroscopic and microscopic analysis. Macroscopic similarities between shear and swirl coaxial sprays are revealed under flow conditions of high momentum flux ratio. Also, empirical correlations between the mean drop diameters(D32) and operating conditions of coaxial sprays are proposed in this paper.

• Journal of the Korean Geotechnical Society
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• 제19권2호
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• pp.171-178
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• 2003

Wing and secondary cracks are unique types of cracks observed in rock masses subjected to uniaxial and biaxial compressive loading conditions. In this study, morphological features of wing and secondary cracks developed in gypsum specimens are investigated in the macro and micro scales. Along the path of wing crack, microtensile cracks are observed. Microtensile cracks coalesce with pores and show branch phenomenon. From the onset of the wing crack, multiple initiations of microtensile cracks are observed. Microtensile cracks show tortuous propagation paths and relatively constant aperture of the cracks during the propagation. It is shown that microtensile cracks propagate by splitting failure. At the micro scale, microfsults are observed in the path of the secondary cracks. Along the path of the secondary cracks, separation of grains and conglomerate grains, oblique microfaults, and irregular aperture of microfault are observed. These features show that the secondary cracks are produced in shear mode. The measured sizes of fracture process zone across the propagation direction near the tip of wing and secondary cracks range from 10$\mu{m}$ to 20$\mu{m}$ far wing cracks and from 100$\mu{m}$ to 200$\mu{m}$ for secondary cracks, respectively.

• Journal of Korean Port Research
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• 제11권1호
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• pp.85-99
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• 1997

The improvements of berth productivity is closely related to berth/port systems and its relationship extends to the overall pattern of port development/logistics, transport and trade. Since ports in general and berths in specific function as a bridge transferring seaborne cargoes from seaside to landside and vice versa, berth productivity improvements should be considered in terms of the total system in which the cargoes are transported from origin to destination via berths/ports. In that respect, the objective of this study is to improve berth productivity which is a vital factor in the strategic planning in port development and operation and logistics. According to a literature survey on the subject, the contents of the studies have been limited to either a macro-perspective or a micro-perspective which is only a partial solution to the problem. Hence, this limitation requires an integrated approach to find and ultimate solution, which should be considered not separately, but as a whole. The contents and scope of this study cover the improvements of berth productivity in conjunction with strategic planning in port development. efficient operation and logistics from two different viewpoints, macro- and micro-perspective. After that, a combination of these two perspectives is applied to the integrated approach due to lacking a comprehensive perspective from either macro-approach or micro-approach. In reality, a port itself is a complex and dynamic organization. Therefore, a comprehensive insight needs an integrated approach for the long-term national economic development. In this approach, the utmost importance is how to find the bottlenecks and to solve the problems effectively from the beginning stage in port development. In conclusion, derived from the macro- and micro-perspective. the attempt to establish an integrated approach is the merit of this study, which is required as a comprehensive measure since none of the two can be a solution independently. In terms of reinforcing this study, it needs further empirical research due to the restriction of the theoretical method of this paper. Consequently, the reinforced research will be able to enhance the integrated approach on the basis of the conceptual perspective.

• Journal of the Korean association of regional geographers
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• 제9권3호
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• pp.297-313
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• 2003

Problems caused by the U.S. military bases have attracted little attention until recently due to the national security of S.Korea and the peace of North-Eastern Asia, emphasized from the perspective of macro-geopolitics. However, since the political regime has been democratized and political discourses have been liberalized from the 1990s, those problems become a nation-widely serious social issue, though they have been brought about on the local areas. Thus, it can be suggested that micro-geopolitics is highly relevant and significant in approaching the local problems caused by the U.S. military bases, and ultimately resolving the macro-geopolitical problem of longstanding unfair relations in the SOFA and the withdrawal of U.S. troops. This paper aims to consider local problems caused by the U.S. military bases and resolving strategies from the perspective of micro-geopolitics. First of all, it discusses some significance of the micro-geopolitical perspective, as it has been recently emphasized in political geography in considering local problems and politics of life on the basis of place, then looks on empirically criminal and environmental problems caused by the U.S. military bases, analyses the questionnaire date on the perception of local dwellers around the military camps in Nam-gu Daegu, and finally suggests strategies to resolve those problems, which level up from the micro to the macro-scale of geopolitics.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제14권10호
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• pp.4719-4725
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• 2013

In this paper, we propose that a model based design for an electric motor cycle system using Automotive Simulation Models. Before prototyping a realistic electric motorcycle, a reliable simulation program is required to test the capacities of the power sources and optimize the parameters of an electric motorcycle. In the past, The research of electric motorcycle was conducted at macro rather than micro level. However, this research suggests the detailed analysis method of specific key components. This paper can get a good error ratio, 2.3%, as a consequence of the interpretation of experiment and simulation. With the analysis of specific electric motorcycle, it is able to analyze design factor and improve accuracy of electric motorcycle interpretation. Also, this research suggests the effective way to get fail safety so that it can solve the fail which can be encountered in electric motorcycle.

• Proceedings of the Korea Information Processing Society Conference
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• 한국정보처리학회 2022년도 춘계학술발표대회
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• pp.393-396
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• 2022

본 연구는 국방과학기술 분야의 특허 및 논문 실적을 이용하여 통계기반 기계학습 모델 4 종을 학습하고, 실제 분석 대상기관의 데이터 입력결과를 분석하여 실용성에 대한 한계점 분석을 목적으로 한다. 기존 연구에서는 특허분류코드를 기준으로 분류하여 특수 목적으로 활용하거나 세부 연구 범위 내 연구 주제탐색 및 특징연구 등 미시적인 관점에서의 상세연구 활용 목적인 반면, 본 연구는 거시적인 관점에서 연구의 전체적인 흐름과 경향성 파악을 목적으로 한다. 이에 ICT 기술 138 종의 특허 및 논문 30,965 건과 국방과학기술 192 종의 특허 및 논문 23,406 건을 학습데이터로 각 모델을 학습하였다. 비교한 통계기반 학습모델은 Support Vector Machines, Decision Tree, Naive Bayes, XGBoost 모델이다. 학습데이터에 대한 학습검증 단계에서는 최대 99.4%의 성능을 보였다. 다만, 실제 분석대상기관의 특허 및 논문 12,824 건으로 입력분석한 결과, 모델별 편향성 문제, 데이터 전처리 이슈, 다중클래스 및 다중레이블 문제를 확인, 도출한 문제에 대한 해결방안을 제시하고 추가 연구의 방향성을 제시한다.