• Korean Journal of Remote Sensing
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• v.34 no.2_2
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• pp.313-326
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• 2018

This paper introduces core techniques on ship detection and tracking based on a compact HF radar platform which is necessary to establish a wide-area surveillance network. Currently, most HF radar sites are primarily optimized for observing sea surface radial velocities and bearings. Therefore, many ship detection systems are vulnerable to error sources such as environmental noise and clutter when they are applied to these practical surface current observation purpose systems. In addition, due to Korea's geographical features, only compact HF radars which generates non-uniform antenna response and has no information on target information are applicable. The ship detection and tracking techniques discussed in this paper considers these practical conditions and were evaluated by real data collected from the Yellow Sea, Korea. The proposed method is composed of two parts. In the first part, ship detection, a constant false alarm rate based detector was applied and was enhanced by a PCA subspace decomposition method which reduces noise. To merge multiple detections originated from a single target due to the Doppler effect during long CPIs, a clustering method was applied. Finally, data association framework eliminates false detections by considering ship maneuvering over time. According to evaluation results, it is claimed that the proposed method produces satisfactory results within certain ranges.

• Journal of the Korean Geographical Society
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• v.39 no.4
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• pp.495-513
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• 2004

The shape of land surface work as a cradle for various environmental processes and human activities. As spatially distributed process modelings become increasing important in current research communities, a classification system that delineates land surface into characteristic geomorphological units is a pre-requisite for sustainable land use planning and management. Existing classification systems are either morphometric or generic, which have limitations to characterize continuous ecological processes over the landscape. A new classification system was developed to delineate the land surface into different geomorphological units from Digital Elevation Models(DEMs). This model assumes that there are pedo-geomorphological units in which distinct sets of hydrological, pedological, and consequent ecological processes occur. The classification system first divides the whole landsurface into eight soil-landscape units. Possible energy and material nows over the land surface were interpreted using a continuity equation of mass flow along the hillslope, and subsequently implemented in terrain analysis procedures. The developed models were tested at a 12$\textrm{km}^2$ area in Yangpyeong-gun, Kyeongi-do, Korea. The method proposed effectively delineates land surface into distinct pedo-geomorphological units, which identify the geomorphological characteristics over a large area at a low cost. The delineated landscape units mal provide a basic information for natural resource survey and environmental modeling practices.

• Journal of the Korean Geographical Society
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• v.42 no.4
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• pp.560-581
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• 2007

The purpose of this paper is to present a conceptual framework and a stage of development of trust building and to study the factors affecting on the trust building in economics space. Conceptual framework on trust building in economics space is combined of in the three approaches. The macro(structural and institutional) approach includes normative and regulative factors(laws, norms), and positionality in social and economic systems(beliefs, political ideologies, institutions). The meso(intersubjective) approach contains the personal fronts(expressive factors, social cues, significant symbols) and settings(physical space, intermediary such as technologies & knowledges). The micro(subjective) approach comprises the willingness(internalization of value) and calculation(risk and uncertainties analysis) of economic actors. According to sustainable cooperation among economic actors, trust building to the macro(structural and institutional) level, the meso(intersubjective) level, and the micro(subjective) level develop by stages. The factors such as long-term and repeated interaction, information sharing and reciprocity, interdependence and asset specificity, uncertainty, proximity, and culture & norm of corporate and formal institution are determinants on the trust building across economic actors in economic space.

• Journal of KIISE:Databases
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• v.27 no.1
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• pp.53-63
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• 2000

The mobile computing service market is increasing rapidly due to the development of low-cost wireless network technology and the high-performance mobile computing devices. In recent years, several methods have been proposed to effectively deal with restrictions of the mobile computing environment such as limited bandwidth, frequent disconnection and short-lived batteries. Amongst those methods, much study is being done on the caching method - among the data transmitted from a mobile support station, it selects those that are likely to be accessed in the near future and stores them in the local cache of a mobile host. Existing cache replacement methods have some limitations in efficiency because they do not take into consideration the characteristics of user mobility and spatial attributes of geographical data. In this paper, we show that the value and the semantic of the data, which are stored in the cache of a mobile host, changes according to the movement of the mobile host. We argue it is because data that are geographically near are better suited to provide an answer to a users query in the mobile environment. Also, we define spatial location of geographical data has effect on, using the spatial attributes of data. Finally, we propose two new cache replacement methods that efficiently support user mobility and spatial attributes of data. One is based on the location of data and the other on the meaningful region of data. From the comparative analysis of the previous methods and that they improve the cache hit ratio. Also we show that performance varies according to data density using this, we argue different cache replacement methods are required for regions with varying density of data.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.2
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• pp.332-342
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• 2012

The current research aims at classifying the bus stops as transfer center in order to establish the rational bus transfer systems. Existing research typically identifies characteristics of demands for bus stops and land use surrounding the bus stops and classifies and profiles the bus stops. A common problem with this type of research is that the results with cross-sectional characteristics of land use and bus stop usage do not capture the details of trip chain, the fundamental characteristics of the trips with transfer. This paper therefore examines bus stop classifications with such variables as transport mode chains, intermediate stop chains and timing chains. The analysis on the data collected on Monday 20 April 2009 for passengers of Gyeong-gi bus results in a clear classification among bus stops in terms of such trip chain variables. The research would provide useful information for the decision support of transfer stops location choice and infrastructure design.

• Journal of the Korean Geographical Society
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• v.46 no.6
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• pp.707-723
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• 2011

The purpose of this study was to quantitatively evaluate the effectiveness of learning management systems (LMS) in the physical geography class. The study adopted the experimental design and three classes participated in this study. The first class was controlled using only classroom lectures, the second class used PPT slides along with the classroom lectures, and the third class used online video clips along with the lectures. The experiments were conducted from the Spring Semester 2007 to the Spring Semester 2008 for the introductory physical geography course. The study results showed that online learning tools help students improve academic performance and their attitudes towards the class and the instructor. Compared to simple PowerPoint slides, voice recording attached to the visual lecture slide materials enhanced students' motivation. Class lectures with lecture slides did not improve students' scores. However, when the visual materials were combined with voice recording, the number of internet access to online class materials increased, and class attendance and students' final grades were improved. Based on the results, the instructional design model that combines classroom and online learning was suggested.

• Journal of the Korean Geographical Society
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• v.51 no.6
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• pp.853-871
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• 2016

The interest in the prevention of sex crimes and social secure is growing as the number of cases by sexual offences becomes higher. Although various punishable ways have been introduced so far, increasing sex crime is still going on. Thus, effectiveness of legal systems for preventing crimes is questionable. More recently, the approach for environmental criminology has been paid attention for reducing criminal opportunities through environmental design and management of crimes. This study attempts to look over the spatial distribution of sexual crimes in the context of environmental criminology, and examine the correlation between regional environmental factors and the occurrence of sexual crimes empirically. To do this, we visualized the map for sex crimes at the macro-scale and explored the spatial distribution of sexual crimes and spatial clusters based on various spatial statistics using sex crime data published online by the ministry of gender equality and family. Also, we derived the environmental characteristics of sexual crimes by multivariate regression analysis on a large number of explanatory variables of regional environment. Our results will help to understand the current situation and spatial aspects of sex crimes in the nation more realistically. Further, it is respected that our results might be useful basic information for establishing regional policies and plans for the prevention of the sexual crime and enhanced public policing.

• Journal of the Economic Geographical Society of Korea
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• v.22 no.2
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• pp.214-235
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• 2019

This study adopts the concept of social innovation cluster in which social economy organizations as one of the emerging axes of economic systems operate in collaboration with government agencies, investment institutions, intermediate supporting organizations and non-profit organizations, and investigates how the clusters of this kind grow in the context of the Korean socio-economic situation for the cases of Seongdong-gu and Eunpyeong-gu in Seoul, Korea. For this purpose, it has identified the actors of the clusters and their internal relations, and analyzed the process of cluster formation. A social network analysis of the partnerships between the actors has shown that Seongdong-gu has more diversified types of the network participation of universities, global networks and investment institutions than Eunpyeong-gu. It is interpreted that this pattern has resulted from the domination of private organizations in the former area, which is also confirmed by in-depth interviews with persons involved in the clusters. Although the facets of social innovation clusters are manifested in both areas, even in their initial stage, such factors as linkages between industrial actors and convergence with other clusters, which appear in the maturing stage of cluster formation, has yet to be found. It is suggested that the sustainable growth of social innovation clusters should be accompanied by information sharing and cooperation between the two areas on the future orientation of development.

• Spatial Information Research
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• v.6 no.2
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• pp.133-152
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• 1998

This article considers the experimental foundations of geographical phenomena for the distribution of lodging houses and the development of lodging Information Systems in Shin-Chon Area. This system allows the rural students to find their lodging houses conveniently. We examine the geographical reality of lodging houses in Shin-chon area and explores the lodging information system, reflecting how students select the lodging houses. Criteria for selection of lodging houses are travel time to school, interior facilities, rent fee, members, owners of lodging houses, which are collected by field swvey. The lodging information system is built in integration of Visual Basic with spatial data which are created in Mapinfo and Arcview through MapObject, component GIS software. This system provide query tools to efficiently investigate data as well as interactive map display. Also it displays the characteristics of a selected lodging houses using the identify tool on the map.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.6
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• pp.91-98
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• 2023

The amount of power generation of a solar plant has a high correlation with weather conditions, geographical conditions, and the installation conditions of solar panels. Previous studies have found the elements which impacts the amount of power generation. Some of them found the optimal conditions for solar panels to generate the maximum amount of power. Considering the realistic constraints when installing a solar power plant, it is very difficult to satisfy the conditions for the maximum power generation. Therefore, it is necessary to know how sensitive the solar power generation amount is to factors affecting the power generation amount, so that plant owners can predict the amount of solar power generation when examining the installation of a solar power plant. In this study, we propose a polynomial regression analysis method to analyze the relationship between solar power plant's power generation and related factors such as weather, location, and installation conditions. Analysis data were collected from 10 solar power plants installed and operated in Daegu and Gyeongbuk. As a result of the analysis, it was found that the amount of power generation was affected by panel type, amount of insolation and shade. In addition, the power generation was affected by interaction of the installation angle and direction of the panel.