• Journal of Cadastre & Land InformatiX
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• 제48권2호
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• pp.171-183
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• 2018

Despite the rapid expansion of satellite images supply, the application of imagery is often restricted due to unautomated image processing. This paper presents the automated process for the selection of training areas which are essential to conducting supervised image classification. The training areas were selected based on the prior and cover information. After the selection, the training data were used to classify land cover in an urban area with the latest image and the classification accuracy was valuated. The automatic selection of training area was processed with following steps, 1) to redraw inner areas of prior land cover polygon with negative buffer (-15m) 2) to select the polygons with proper size of area ($2,000{\sim}200,000m^2$) 3) to calculate the mean and standard deviation of reflectance and NDVI of the polygons 4) to select the polygons having characteristic mean value of each land cover type with minimum standard deviation. The supervised image classification was conducted using the automatically selected training data with Sentinel-2 images in 2017. The accuracy of land cover classification was 86.9% ($\hat{K}=0.81$). The result shows that the process of automatic selection is effective in image processing and able to contribute to solving the bottleneck in the application of imagery.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• 제19권6호
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• pp.163-179
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• 2020

With the expansion of platform-based taxi service, mobility and convenience of users are getting better. However, due to profitability problem, marginalized areas in the supply of the service are expected to appear. As such, this study analyzed spatial marginalization of taxi service caused by imbalance in supply and demand during the night-time when public transportation service is suspended. According to hot-spot analysis of taxi, outskirt of a city and residential areas showed high vacancy and greater number of drop-offs compared to the number of pick-ups. On the contrary, they were confirmed low in the center and sub-centers of a city. Centrality analysis also showed a similar pattern with hot-spot analysis. Due to this, drivers may refuse to pick up a customer bound for an area with lower out-degree centrality compared to in-degree centrality as it might be difficult for the drivers to pick up another customer after dropping off the current customer. Thus, customers may need to wait for a taxi for a longer time. For this reason, improvement in spatial marginalization caused by mismatch of supply and demand is required. Also, the outcome of this study is expected to be utilized as a basic data.

• The Journal of the Convergence on Culture Technology
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• 제8권3호
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• pp.405-413
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• 2022

Since the COVID-19 outbreak, the active utilization of new health care service utilizing the ICT technology and data science such as telemedicine, smart hospital, AI dignosis has been increasingly found. In this study we examined the business model of Amazon healthcare which leads disruptive innovation in U.S. health care industry with the introduction of hybrid model of telemedicin, in-person care and customer-centric online drug delivery, home-use diagnostic kit, characterized by the integrated model combining medical care, drug delivery and the use of diagnostic kit. We showed using the multiproduct competition model that the synergy effect between the Amazon's original business areas and the healthcare business area causes the active market penetration and the increase in the customer value from utilization of the Amazon care. Using Hotelling's spatial competition model, we also showed that the competition in the health care market can be greater when consumer's choice of health care providers are available in telemedicine platform. In the long, run the issue of competition being weakened due to the exit of less competent healthcare providers may arise, to which the policymakers in the charge of fair competition in health care industry should pay attention.

• Korean Journal of Remote Sensing
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• 제39권6_1호
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• pp.1467-1475
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• 2023

The public-interest direct payment program involves providing direct payments to agricultural producers and rural residents through public funds, premised on performing public functions such as environmental conservation, stable food supply, and maintaining rural communities via agricultural activities. Scientific estimation of crop cultivation areas and production levels is crucial for formulating agricultural policies linked to regulating food supply, which increasingly impacts the national economy. Conducting comprehensive on-site inspections for compliance monitoring of direct payment programs has shown very low efficiency in relation to budget and time. The expansion of areas subject to compliance monitoring and various challenges in on-site inspections necessitate streamlining current monitoring methods and devising effective strategies. As a solution, the application of Remote Sensing technology and spatial information utilization, allowing swift acquisition of necessary information for policies without overall on-site visits, is being discussed as an efficient compliance monitoring method. Therefore, this study evaluated the potential use of remote sensing for improving operational efficiency in monitoring compliance with public-interest direct payment programs. Using satellite images during farming seasons in Gimje and Hapcheon, vegetation indices and spatial variations were utilized to identify cultivated areas, presence of mixed crops, validated against on-site inspection data.

• Journal of the Korean Association of Geographic Information Studies
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• 제26권4호
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• pp.80-96
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• 2023

The expansion of human activities and road development has led to the loss and fragmentation of ecological spaces, which is a negative factor for biodiversity. In particular, urban areas where land use and land cover have rapidly changed into urbanization zones are regions where ecological spaces are lost and isolated, making it difficult for wildlife to inhabit. Furthermore, the loss and fragmentation of ecological spaces due to urbanization can have a negative impact on ecosystem services. Therefore, to enhance biodiversity and ecosystem services in urban and national land, it is necessary to establish a practical ecological axis that reflects the current status of the city. Thus, this study analyzed the connectivity of ecological spaces and forest axis that can be used for spatial planning related to urban ecological axis of local governments in Daegu and Gyeongsangbuk-do. The ecological connectivity was analyzed by dividing the Daegu-Gyeongbuk region into 31 local government units, distinguishing between forests and natural areas using land cover data. Subsequently, the study area was divided into 20,483 hexagonal grids of 1 square kilometer each, and the restoration effects for ecological fragmentation within 100 meters were spatially clustered to visualize priority restoration areas. The forest axis was derived by considering regional conditions such as land cover, building area, slope, and others to connect 1,534 forests of 100 hectares or more. The research results are expected to be used as fundamental data for spatial planning, goal setting, and the selection of restoration areas for improving ecological connectivity.

• Korean Journal of Environment and Ecology
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• 제30권4호
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• pp.684-693
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• 2016

Daemyung retarding basin located near the confluence floodplain of the Nakdong and Kumho River is a large spawning site for the endangered Kaloula borealis, and needs for protecting the habitat of the endangered species are increasing. However, scientific studies are rarely conducted on the population characteristics and ecological knowledge on the species in the basin. This paper aims to estimate the population size and spatial distribution of the species that inhabited at the Daemyung retarding basin, using the capture-recapture method. Also, pitfall traps were installed in each habitat types classified with micro-topographic features, slope aspects, and vegetation communities to identify the spatial distribution characteristics of the Kaloula borealis of each habitat in the retarding basin. Field survey on the species was conducted from May 2013 to October 2014, showing that the species emerged in May, became more active during July and August and started to hibernate at the end of October. Using capture-recapture method, the first survey was carried out from July to August, 2014. Ninety-eight toads were captured, marked, and released back into the site. In the second survey, 68 toads including 5 marked toads of the previous survey were captured. Based on these two-sample surveys, around 535-2,131 individual toads are estimated to inhabit the Daemyung retarding basin. Fifty-seven pitfall traps were installed in four habitat types: mounded and vegetated flatland, lowland swamps, and slope areas of both the southern and western parts of the basin in order to delineate spatial abundance of the endangered Kaloula borealis during the rainy season when the species is actively spawning. Pitfall traps at the spatially explicit array indicated that the species gradually move to the slope areas near the Daemyung stream, showing high occurrence density of the Kaloula borealis compared to the lowland swamps after the spawning season. The emergence of Kaloula borealis in the lowland swamps appeared to be comparatively higher during the spawning season. However, after the spawning season the toads species rapidly moved into the neighboring land of relatively high elevation such as the slope area towards the Dalsung protected wetlands and Daemyung River. These results are closely related to the migration patterns that toads tend to return to the sheltering sites and/or hibernating grounds after the spawning season. Also, the Kaloula borealis moved to the nearest high-level vegetated areas as the lowland swamps of their spawning grounds deteriorated with the expansion of permanent ponds due to the rise in the groundwater level.

• Korean Journal of Ecology and Environment
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• 제43권1호
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• pp.44-54
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• 2010

In this study, a comprehensive exploration and evaluation of washland candidate locations by means of field monitoring as well as spatial analysis in six major river system (Han, Nakdong, Nam, Geum, Youngsan, and Seomjin Rivers). Washland(in other words, river detention basin) is an artificial wetland system which is connected to streams or rivers likely to riverine wetlands. Major purpose of washland creation is to control floodings, water supply and purification, providence of eco-cultural space to human and natural populations. Characteristics and functions of riverine wetlands can be expected as well, thus it is believed to be an efficient multi-purpose water body that is artificially created, in terms of hydrology and ecology. Geographical information and field monitoring results for the washland candidate locations were evaluated in 2009, with respect to optimal location exploration, ecosystem connectivity and educational-cultural circumstances. A total of $269\;km^2$ washland candidate locations were found from spatial analysis (main channel of Rivers South Han, 71.5; Nakdong 54.1; Nam, 2.3; Geum, 79.0; Youngsan 46.4; Seomjin 15.7), and they tended to be distributed in mid- to lower part of the rivers to which tributaries are confluent. Field monitoring at 106 sites revealed that some sites located in the Rivers Nam and Geum is appropriate for restoration or artificial creation as riverine wetlands. Several sites in the Nakdong and Seomjin Rivers were close to riverine wetlands (e.g., Upo), habitats of endangered species (e.g., otters), or adjacent to educational facility (e.g., museums) or cultural heritages (e.g., temples). Those sites can be utilized in hydrological, ecological, educational, and cultural ways when evidence of detailed hydrological evaluation is provided. In conclusion, determination of washland locations in the major river basins has to consider habitat expansion as well as hydrological function (i.e. flood control) basically, and further utility (e.g. educational function) will increase the values of washland establishment.

• The Transactions of the Korea Information Processing Society
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• 제2권6호
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• pp.903-917
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• 1995

In most database systems images have been indexed indirectly using related texts such as captions, annotations and image attributes. But there has been an increasing requirement for the image database system supporting the storage and retrieval of images directly by content using the information contained in the images. There has been a few indexing methods based on contents. Among them, Pertains proposed an image indexing method considering spatial relationships and properties of objects forming the images. This is the expansion of the other studies based on '2-D string. But this method needs too much storage space and lacks flexibility. In this paper, we propose a more flexible index structure based on kd-tree using paging techniques. We show an example of extracting keys using normalization from the from the raw image. Simulation results show that our method improves in flexibility and needs much less storage space.

• Korean Institute of Interior Design Journal
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• 제22권6호
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• pp.162-172
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• 2013

This study focuses on the genealogical analysis of the urban public spaces by the local history of Seoul which is significantly different from western cities. The analysis targets the discourse of the urban street which defines urban space-structure among the urban public spaces. Based on the analysis, we define the progress levels of urban public design policy in Seoul. Firstly, in 1960's and 1970's, 'urban reconstruction' was intensively carried out for the country modernization, and 'vehicle preferred street expansion' resulted in damages to historical inheritance, in-humanized street, and cultural uniformity. 1980's and 1990's would be defined as 'politic acceptance of plural values to the urban street.' There were the Olympic Games held in Seoul in 1988, which were the celebrations of the 600th capital establishment and the autonomous local government system. In the meanwhile, diverse values on the urban street were discussed in terms of globalization. There also were the self-reflection for the urban skyscrapers and high-population rate, the cultural uniformity of urban street, and the commercialization in downtown with urban reconstruction plans. Then, the sense of landscape and amenity was focused. Various urban projects and regulations were held according to the changes of value recognition. 2000's can be defined as 'introduction to the organic integration and the urban public design governance.' In the 21st century, types of recognition have changed significantly, which include publicness, humanism, sustainability, symbolism, artistry, placeness, and communication. They cause the establishment of ordinances and the installation of integrated organization via urban design administration. The legislation has been revised in order to support the various methods for the maintenance and operation of urban landscape in terms of local characteristics. New regulations were established for residents to participate in the processes of the urban planning with street design policy.

• Steel and Composite Structures
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• 제18권1호
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• pp.1-28
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• 2015

In this paper, the dynamic response of functionally gradient steel (FGS) composite cylindrical panels in steady-state thermal environments subjected to impulsive loads is investigated for the first time. FGSs composed of graded ferritic and austenitic regions together with bainite and martensite intermediate layers are analyzed. Thermo-mechanical material properties of FGS composites are predicted according to the microhardness profile of FGS composites and approximated with appropriate functions. Based on the three-dimensional theory of thermo-elasticity, the governing equations of motionare derived in spatial and time domains. These equations are solved using the hybrid Fourier series expansion-Galerkin finite element method-Newmark approach for simply supported boundary conditions. The present solution is then applied to the thermo-elastic dynamic analysis of cylindrical panels with three different arrangements of material compositions of FGSs including ${\alpha}{\beta}{\gamma}M{\gamma}$, ${\alpha}{\beta}{\gamma}{\beta}{\alpha}$ and ${\gamma}{\beta}{\alpha}{\beta}{\gamma}$ composites. Benchmark results on the displacement and stress time-histories of FGS cylindrical panels in thermal environments under various pulse loads are presented and discussed in detail. Due to the absence of similar results in the specialized literature, this paper is likely to fill a gap in the state of the art of this problem, and provide pertinent results that are instrumental in the design of FGS structures under time-dependent mechanical loadings.