• Korean Journal of Remote Sensing
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• v.38 no.5_2
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• pp.765-779
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• 2022

This study evaluates the accuracy in identifying the burned area in South Korea using multi-temporal data from Sentinel-2 MSI and Landsat 8/9 OLI. Spectral indices such as the Difference Normalized Burn Ratio (dNBR), Relative Difference Normalized Burn Ratio (RdNBR), and Burned Area Index (BAI) were used to identify the burned area in the March 2022 forest fire in Uljin. Based on the results of six indices, the accuracy to detect the burned area was assessed for four satellites using Sentinel-2 and Landsat 8/9, respectively. Sentinel-2 and Landsat 8/9 produce images every 16 and 10 days, respectively, although it is difficult to acquire clear images due to clouds. Furthermore, using images taken before and after a forest fire to examine the burned area results in a rapid shift because vegetation growth in South Korea began in April, making it difficult to detect. Because Sentinel-2 and Landsat 8/9 images from February to May are based on the same date, this study is able to compare the indices with a relatively high detection accuracy and gets over the temporal resolution limitation. The results of this study are expected to be applied in the development of new indices to detect burned areas and indices that are optimized to detect South Korean forest fires.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.1
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• pp.77-100
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• 2022

In the era of low growth, many provincial cities are experiencing population decline and aging. Population decline phenomena such as reduction of productive manpower, reduction of finances, deterioration of quality of life, and collapse of the community base are occurring in a chain and are being pushed to the brink of extinction of the cities. This study aims to propose a methodology to objectively estimate the employment creation centers and setting the basic unit of industrial-centered zoning by applying spatial statistical techniques and GIS for the application of the compact city plan as an efficient spatial management policy in a city with a declining population. In details, based on reviewing previous studies on compact city, 'employment complex index(ECI)' were defined considering the number of workers, the number of settlers, and the area of development land, the employment creation center was estimated by applying the 'Local Moran's I' and 'Getis-Ord's Hot-Spot Analysis'. As a case study, changes in the four years of 2013, 2015, 2017, and 2019 were compared and analyzed for Changwon City. As a result, it was confirmed that the employment creation center is becoming compacted and polycentric, which is a significant result that reflects the actual situation well. This results provide the basic data for functional and institutional territorial governance for the regional revitalization platform, and provide meaningful information necessary for spatial policy decision-making, such as population reduction, regional gross domestic product, and public facility arrangement that can respond to energy savings, transportation plans, and medical and health plans.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.685-690
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• 2023

It was analyzed that the volume of deep excavation works adjacent to existing underground structures is increasing according to the population growth and density of cities. Currently, many underground structures and tracks are damaged by external factors, and the cause is analyzed based on the measurement results in the tunnel, and measurements are being made for post-processing, not for prevention. The purpose of this study is to analyze the effect on the deformation of the structure due to the excavation work adjacent to the urban railway track in use. In addition, the safety of structures is evaluated through machine learning techniques for displacement of structures before damage and destruction of underground structures and tracks due to external factors. As a result of the analysis, it was analyzed that the model suitable for predicting the structure management standard value time in the analyzed dataset was a polynomial regression machine. Since it may be limited to the data applied in this study, future research is needed to increase the diversity of structural conditions and the amount of data.

• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1427-1435
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• 2023

Vegetation indices based on selected wavelength reflectance measurements are used to represent crop growth and physiological conditions. However, the anisotropic properties of the crop canopy surface can govern spectral reflectance and vegetation indices. In this study, we applied an ensemble of bidirectional reflectance distribution function (BRDF) models to high-resolution Sentinel-2 satellite imagery and compared the differences between correction results before and after reflectance. In the red and near-infrared (NIR) band reflectance images, BRDF-corrected outlier values appeared in certain urban and paddy fields of farmland areas and forest shadow areas. These effects were equally observed when calculating the normalized difference vegetation index (NDVI) and 2-band enhanced vegetation index (EVI2). Furthermore, the outlier values in corrected NIR band were shown in pixels shadowed by mountain terrain. These results are expected to contribute to the development and improvement of BRDF models in high-resolution satellite images.

• Smart Media Journal
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• v.12 no.11
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• pp.175-184
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• 2023

The elderly in rural areas are faced with the dilemma of poor community environment, weak social communication ability and insufficient pension knowledge reserve. In addition, due to the serious shortage of social security facilities in rural areas and medical resources, the elderly are struggling, and the suicide rate is far higher than that in urban areas. In order to make the elderly have a comfortable pension environment and face the increasingly serious aging problem with a positive attitude, this paper takes the community environment of the Baima Tibetan elderly in Tielou Township, Gansu Province as the research object of aging transformation. First of all, literature data were used to carry out research on the aging transformation in rural areas. On the basis of sorting out previous research topics, ERG theory was determined as the guide. Secondly, the research methods of on-site investigation, interview and other research methods are adopted to investigate the number of left-behind elderly people in this area, and classify them according to the national standards. At the same time, the image of the current situation of the community environment of the elderly. Finally, combined with the ERG theory, the transformation design of the elderly living environment is implemented, mainly from the three aspects of survival, mutual relationship and growth.

• Korean Journal of Environment and Ecology
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• v.38 no.3
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• pp.310-323
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• 2024

The purpose of this study was to understand the vegetation structure and ecological characteristic of Bulgapsan(Mt.) Provincial Park by setting up and surveying 64 plots(100m²). The analysis using the TWINSPAN and DCA techniques found seven community groups: Pinus densiflora-Quercus variabilis community, P. densiflora-P. rigida-Q. serrata community, Q. variabilis-Carpinus tschonoskii community, Q. aliena-Q. variabilis-Cornus controversa community, Q. aliena-Platycarya strobilacea community, Broad-leaved miced community and Q. variabilis community. The result of vegetation community structure analysis showed that P. densiflora community and deciduous Quercus spp. community were in competition, and succession to Quercus spp. community was expected. In the case of other broad-leaved forests, the current status is expected to be maintained. But continuous monitoring is required in areas where Neolitsea sericea and Cephalotaxus appear, which grow naturally in warm temperate forest and southern temperate vegetation zone. Species diversity by communities are confirmed to be highest at 2.6654 in the actively competitive P. densiflora-P. rigida-Q. serrata community, and the lowest in the Deciduous broad-leaved forests community at 1.2548. The results of the tree rings and annual growth analysis showed that dominant trees had an average age of more than 37~87 years. Among them, N. sericea designated as a natural monument was 48~56 years old.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.4
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• pp.95-104
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• 2006

The DMZ is a 248km long thin green line which has various landscapes of fields, hills and mountains. This study focused on western part of DMZ and vicinity which consist of abandoned rice paddy, wetlands and fields. The main purpose of this study is to detect the vegetation vitality from the western part of MDL to DMZ vicinity and identify and quantify ecological buffer(ecotone) width adopting logistic function derived from 'Vegetation Index-distance curve' using an Landsat ETM+ image acquired on June of 2002. Green leaf vegetation was quantified to identify the ecotone buffer in western DMZ and vicinity(civilian control area: CCA) using Transformed Vegetation Index(TVI) which is one of common measurement among various indices. Vegetation measurement from Military Demarcation Line(MDL) to vicinity area was investigated at 500m intervals to 10kms of southern and northern part of western DMZ and vicinity. The Logistic function models the sigmoid curve of growth with three stages of growth of initial competition and maturity. In the TVI-distance logistic curve, the maturity is high vegetation vitality, the competition is vitality changing, and the initial is low vitality. In the TVI-distance curve, maturity area of high TVI value is core area for ecological conservation, and the competition area between inflection points can be an ecotone(ecological buffer). In case of southern part, maximum TVI value is 221.92 and minimum is 207.16, and maximum TVI of northen part is 215.32 and minimum is 188.35. That means forest devastation of north Korean part of DMZ and vicinity is severer than that of south Korea. The width of core area for ecological conservation is 2,311m, and ecotone in the southern part is 5,339m, so minimum width from MDL for ecological conservation can be computed as 7,651m. In case of Northern part, the width of core area is 1,841m, and ecotone buffer is 5,014m, so ecological conservation width can be estimated as 6,855m. In case of northen part, width of estimated core area is less than that of DMZ width, which means ecological disturbance is very severe in northern part of western DMZ.

• The Korean Journal of Ecology
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• v.23 no.3
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• pp.223-229
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• 2000

To develop the restoration technique from urban planted forest to natural forest, sprout growth and its effects on vegetation composition in the early stage after lumbering, were studied, using only Populus albaglandulosa of the tree layer in Chungdam Park Chungdam-dong, Kangnam-gu, Seoul during the two years from 1997 to 1998. The results were as follow. After lumbering, the more basal areas of the parent stump, the more sprouts were generated. The basal area of parent stump was related more to biomass than to the number of sprouts. In the cutting area, biomasses of sprouts were 552.7 g?DW/㎡ in first year and 8.7 g?DW/㎡ in second year after lumbering. Therefore, cutting of sprouts in first year resulted in decrease of sprout production in second year. In the non-cutting area, biomass of sprouts was 657.4 g?DW/㎡ and more than that of the experiment. Especially, 2-year sprouts grew to a 304 cm height by the end of the growing season in the second year. The growing season of sprouts was from early April to early September and almost all the leaves of the sprouts remained at the end of the growing season. Specific leaf area decreased along with time elapse and plant height but the differences were not conspicuous. Therefore, it is thought that the reason why p. albaglandulosa sprouts grew fast was due to a long growing period and lower layer leaves which remained at the end of the growing season. In the cutting area of the P. albaglandulosa sprouts, there were no changes in the number of species in the shrub layer but an conspicuous increase in the herb layer. Coverage was no changes in the shrub layer but an increase in the herb layer. In the non-cutting area of P albaglandulosa sprouts, the number of species and the coverage changed a little, and the main species of the herb layer were Phytolacca americana, Eupatorium rugosum and Panicum dichotomiflorum, which are tall plant species.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.1
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• pp.133-148
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• 2014

In order to investigate community formation ability, herbaceous perennials such as Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne, Pennisetum alopecuroides (L.) Spreng. and Arundinella hirta Tanaka were planted in April 2009 at the levee slope of Gwangju Stream in South Korea. Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne and Pennisetum alopecuroides (L.) Spreng. which grew in pots for two years and divided rhizomes of Arundinella hirta Tanaka gathered from fields were employed. Weeds growing on the experiment sites were removed twice a year until 2011 when the plant species were formed into community. Weeds were not eradicated during 2012 and 2013 to observe community sustainability of the species. T-tests on stem numbers and heights in May, July and September were conducted between 2011 and 2012, and between 2012 and 2013. Stem numbers of the five species in 2012 were significantly reduced(p<0.001) compared with those in 2011, which were attributed to weed growth in 2012. Heights of Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne, Pennisetum alopecuroides (L.) Spreng. and Arundinella hirta Tanaka in 2012 were significantly lower than those in 2011(p<0.001), which resulted from weed invasion. Heights of Miscanthus sacchariflorus Bentham in May and July 2012 were significantly decreased compared with those in 2011(p<0.001), however, heights of Miscanthus sacchariflorus Bentham in September 2012 were almost the same as those in 2011(p>0.05). Miscanthus sacchariflorus Bentham was able to compete against weeds in September 2012. Stem numbers and heights of Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne and Pennisetum alopecuroides (L.) Spreng. in 2013 were similar to those in 2012(p>0.05). However, stem numbers and heights of Arundinella hirta Tanaka in 2013 were significantly decreased compared with those in 2012(p<0.001). After community formation, Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne and Pennisetum alopecuroides (L.) Spreng. were able to maintain its community without weed removal. However, Arundinella hirta Tanaka was unable to establish its community due to the weed growth. Miscanthus sacchariflorus Bentham, Miscanthus sinensis var. purpurascens Rendle, Imperata cylindrica Linne are more suitable to stream levee slope environment in terms of community formation and maintenance, stream landscape enhancement and slope erosion control.

• Journal of the Korean Regional Science Association
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• v.36 no.2
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• pp.13-24
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• 2020

In modern society, the number of one-person households is increasing significantly. In particular, one-person households have rapidly increased around local small and medium-sized cities. This study examines the characteristics of local small and medium-sized cities by factor and cluster analysis. Analysis of variance are applied to the characteristics of one-person household in different local cities to find the relationship between different types of cities and the characteristics of one-person households. As a result of the study, local small and medium-sized cities are classified into growth stagnation cities, industrial leading cities, regional base cities, and population outflow cities. It is also found that there are several different types of local cities based on the characteristics of one-person households. The growth stagnation city is a city where the regional economy is revitalized due to the development of regional industries in the past. One-person households have a small age group in their 30s and 40s, which are the basis of industrial activities. They have a high proportion of older generation living in more than three rooms in their homes. It is necessary to supply long-term public rental housing and share houses for older generation. The leading city of the industry is a city where the local economy is revitalized as workers are concentrated. One-person households are evenly distributed among all age groups, and the apartment occupancy rate is the highest compared to other types. It is necessary to provide happy housing for youth generation and reconstruction or renovation housing of manhood generation. The regional base city leads the regional base function and the regional economy, but it has reduced workers. Many of one-person households are younger than 30 years old and college educated. They are also high rate of unmarried and live at one room as rental houses. It is needed to expand the supply of small houses such as apartments, officetels and rented houses for youth generation. The population outflow city has a slow local economy and a rural residential environment. It is found that the households of one-person households have high rate of bereavement and the age. They live more than four rooms in single-family homes. It is necessary not only to provide welfare housing but also to create a sound residential environment where cultural exchange is possible.