• Journal of the Korean association of regional geographers
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• v.14 no.4
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• pp.367-381
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• 2008

The purpose of this paper is to analyze the change in the distribution and hierarchical structure of commercial land use. Tools for analyzing the spatial structure are index of concentration, coefficient of localization and location quotient. This research is applied to Daegu, focusing on the period 1985-2003. During the 1985-2003 period, the growth rate of commercial land use volume amounted to 330%, compared with a population growth rate of 118%. The biggest component of commercial land use is the retail sector. As the lodging, medical, transportation-warehouse and entertainment sectors have the propensity for concentration and comprise the specialized commercial areas in the suburbs, the other sectors arc evenly distributed. Jung-gu has functioned as a downtown core in the hierarchical structure of commercial areas. So, in the structure of commercial land use, Daegu has continued to be a single nuclear structure. But, Dongdaegu Station influence area has evolved into the second order center since 2000. This is the sign of change in spatial structure from single-nuclear pattern to multi nuclear pattern.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2B
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• pp.129-146
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• 2011

Characterization the regional impact of the variability of summer extreme precipitation and the rain days over several thresholds (i.e. 10, 20, 30, 40, 50, 60, 70 and 80 mm/day) in South Korea was performed using daily precipitation data of 59 weather stations operated by Korean Meteorological Administration (KMA). To consider the local features of weather stations, we characterized the variability according to the difference of elevations, latitudes, longitudes, river basins, inland or shore area, and the ratio of urbanization. The results showed that the summer extreme precipitation is sensible to the geographical effect which is similar to that of the annual precipitation. Rain days over thresholds have increased during 1973-2009 while the annual rain days have decreased. This indicate that the concentration of precipitation in summer season will be intensified in the future. Increase of summer precipitation amount and number of extreme rain days is higher in inland area, urbanized area, and Han-River basin than that of shore area, unurbanized area, and the other river basins respectively.

• Journal of the Korean Association of Geographic Information Studies
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• v.27 no.1
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• pp.12-28
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• 2024

This study aims to identify the trend of changes in tourist floating population before and after COVID-19 in major tourist destinations in Jeju Island through spatial analysis. Seongsan-eup and Andeok-myeon in Jeju Island were selected as the research area, and the research period was set at 1 year before and 2 years after the COVID-19 outbreak. For the analysis, mobile floating population data was refined and processed to calculate floating population distribution and floating population increase/decrease data. This was converted into spatial data and an overlay analysis was performed with location data of major tourist attractions. As a result of the analysis, it was confirmed that the floating population of indoor tourist attractions and small facilities decreased immediately after COVID-19, and that in open coastal areas or large facilities, the floating population decreased less or actually increased. In conclusion, in tourism development, it is necessary to identify changes in floating population according to the characteristics of tourist facilities, and it is necessary to develop tourism facilities and strategies that can respond to risk situations such as pandemics when developing tourist destinations.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.361-361
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• 2011

우리나라의 과거 기상자료 분석결과를 보면 최근 10년(1999~2008년)과 과거 30년(1971~2000년)의 자료를 비교하였을 때 연 평균 강수량과 기온이 각각 9.1%, 0.6$^{\circ}C$ 상승하였고 2010년 전 지구 기온은 $14.52^{\circ}C$로 20세기 평균인 $13.90^{\circ}C$보다 $0.62^{\circ}C$ 높아 기온 관측이 시작된 1880년 이래 최고를 기록하였으며(2005년과 공동 1위), 2010년 북반구 기온편차는 $0.73^{\circ}C$로 역대 기온 관측 사상 가장 높았고 남반구 또한 $0.61^{\circ}C$로 상위 6위에 위치되었다. 또한 우리나라에서는 겨울철 이상 저온 현상을 경험하기도 하였다. 이에 본 연구에서는 우리나라 전역 기상청 60개 지점 1980년 1월 1일부터 2009년 12월 31 일까지의 자료를 바탕으로 기록 일 최저 기온 및 기록 일 최고 기온의 발생빈도를 분석하고자 하였다. 확률이론에 따르면 동일한 분포를 갖는 확률변수의 독립적인 시계열의 경우 최대값 또는 최소값의 발생빈도는 ��/n의 비율로 감소하게 된다. 여기서 /n은 관측이 시작된 시점부터 해당 시점까지 자료의 수이다. 본 연구의 경우에는 특정 지점의 특정 시점에 관측된 일 최대 기온이 동일한 분포를 갖는 독립적인 시계열을 이룬다고 한다면(즉, 증가 또는 감소 추세가 있지 않다면), 어떤 해에 관측된 일 최고 기온이 그 동안에 특정 시점에 관측된 일 최고 기온들보다 높을 확률은 1/n이 될 것이다. 그러나 만약 일 최대(또는 최저) 기온의 기록경신 발생빈도가 감소 비율로부터 유의하게 이탈하게 된다면, 이는 일 최고(또는 최저) 기온의 분산이 커지거나 작아지는 현상이 벌어진 경우이거나 일 최고(또는 최저) 기온의 평균이 어떤 추세를 갖게 되는 경우가 될 것이다. 그 결과 기록 일 최저 기온 발생빈도에 대한 기록 일 최고 기온 발생빈도의 비는 현재 약 2.5정도의 값이 나오는 것으로 분석되었으며 이러한 결과는 1980년 이후로 기록 일 최고 기온의 발생빈도는 /n의 비율로 감소하지만 기록 일 최저 기온의 발생빈도는 /n의 비율보다 낮게 발생하기 때문인 것으로 파악되었다. 이러한 과거 자료의 분석을 통하여 지금까지 진행되어 오고 있는 기후변화의 패턴을 보다 명확하게 인식하고자 하였으며, 추후 다양한 기후수치실험으로부터 도출된 결과들의 신뢰성을 평가할 때 기초적인 비교 자료를 제공할 수 있을 것이다.

• Korean Chemical Engineering Research
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• v.44 no.3
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• pp.294-299
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• 2006

Computational simulation was performed to analyze flow velocities and particle trajectories onto the surface of bag-shaped filters with a different permeability. When the permeability of a filter is lower than that of a low-efficient fabric bag-filter widely used, the distributions of flow velocities and particle trajectories on the filter surface were not different with decreasing the filter permeability. The distributions of streamlines and radial directional gas velocities were uniform on the filter surface except for the neighbors of the bottom edge and outlet of the filter. The particle trajectories onto filter surface were more densely distributed around the bottom edge of the filter, so that the particle number on the filter surface was maximized near the bottom edge and decreased in the direction of the filter outlet.

• Spatial Information Research
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• v.18 no.5
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• pp.27-36
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• 2010

This study observed distribution of vegetation to confirm change of tundra-taiga boundary. Tundra-taiga boundary is used to observe the transfer of vegetation pattern because it is very sensitive to human activity, natural disturbances and climate change. The circumpolar tundra-taiga boundary could observe reaction about some change. Reaction and confirmation about climate change were definite than other place. This study used Leaf Area Index(LAI) 8-Day data in August from 2000 to 2009 that acquire from Terra satellite MODerate resolution Imaging Spectroradiometer(MODIS) sensor and used K$\"{o}$ppen Climate Map, Global Land Cover 2000 for reference data. This study conducted analysis of spatial distribution in low density vegetated areas and inter-annual / zonal analysis for using the long period data of LAI. Change of LAI was confirmed by analysis based on boundary value of LAI in study area. Development of vegetation could be confirmed by area of grown vegetation($730,325km^2$) than area of reduced vegetation ($22,372km^2$) in tundra climate. Also, area was increased with the latitude $64^{\circ}$ N~$66^{\circ}$ N as the center and around the latitude $62^{\circ}$ N through area analysis by latitude. Vegetation of tundra-taiga boundary was general increase from 2000 to 2009. While area of reduced vegetation was a little, area of vegetation growth and development was increased significantly.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.379-384
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• 2009

This study was carried out to understand the national and regional distribution of the biomass resources produced in Korea annually via establishing database (DB) and distribution maps of biomass resources data including as livestock manures, food wastes and agricultural by-product. The information of the annual production of each biomass resources was obtained from Ministry for Food, Agriculture, Forestry and Fisheries (MIFAFF), Ministry of Environment (MOE) and National Statistical Office (NSO). Based on biomass resources data, we established database architecture table about livestock manures and food wastes. The distribution maps for the total amount of manures produced from each livestock animal were built up in both national and regional scales and used for analysis of the space-based and time-based distribution of the manure resources. Distribution maps for food wastes and agricultural by-product were also produced, respectively. It was shown that the analysis through resource mapping can be used to identify the sources of collectable biomass feasibly determining suitable region for establishment of a biomass-energy production. The biomass distribution maps graphically provide the information regarding biomass resources to policy-makers, farmers, general users and it was expected to be utilized for policy-making of environmental-friendly agriculture and bio-energy.

• The KIPS Transactions:PartD
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• v.15D no.4
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• pp.485-494
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• 2008

Huge amounts of various web items such as keywords, images, and web pages are being made widely available on the Web. The popularities of such web items continuously change over time, and mining temporal patterns in popularities of web items is an important problem that is useful for several web applications. For example, the temporal patterns in popularities of search keywords help web search enterprises predict future popular keywords, enabling them to make price decisions when marketing search keywords to advertisers. However, presence of millions of web items makes it difficult to scale up previous techniques for this problem. This paper proposes an efficient method for mining temporal patterns in popularities of web items. We treat the popularities of web items as time-series, and propose gapmeasure to quantify the similarity between the popularities of two web items. To reduce the computation overhead for this measure, an efficient method using the Fast Fourier Transform (FFT) is presented. We assume that the popularities of web items are not necessarily following any probabilistic distribution or periodic. For finding clusters of web items with similar popularity trends, we propose to use a density-based clustering algorithm based on the gap measure. Our experiments using the popularity trends of search keywords obtained from the Google Trends web site illustrate the scalability and usefulness of the proposed approach in real-world applications.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.313-320
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• 2018

In the spring of 2018, opened-flowers of fruit trees were frozen to death due to abnormal low temperature around Jeonbuk Province and southern Gyeonggi Province areas. In the 2000s, abnormal weather is observed all over the world very frequently. As a consequence, various sectors of the society suffer from economic damage and negative effects of the abnormal weather. Moreover, recent global climate change is believed to increase the incidence of extreme weathers, which are out of the normal range of the local climate. It is necessary to identify these abnormal weather phenomena accurately and analyze the effects of them on crops in order to understand the effects of them on crop yields. This study projected the trend of the low-temperature occurrence in the future by predicting the changes in future flowering dates and quantifying the temperature distribution after flowering using climate change scenarios. This study targeted areas actually producing a major portion of pear, peach, and apple in South Korea. The results of this study predicted that the flowering dates of these fruits will be approximately 20 days earlier than the current normal year in the future (2071-2100) for the study area. Moreover, it was found that the distribution of low temperature would vary by fruit type and region to some degree. The results of this study present only a portion of fruit trees cultivars grown in South Korea. It was expected that, when this approach is applied to various crops and fruit trees, it will be possible to contribute to preparing countermeasures for climate change in the agricultural sector.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.4
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• pp.291-306
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• 2021

From the climate change scenario experiments of 21 models participating in Coupled Climate Model Inter-comparison Project Phase 6, future changes of sea surface temperature (SST) and Kuroshio in the Northwest Pacific were analyzed. The spatial feature of SST change was found to be related to the change of the current speed and spatial distribution of Kuroshio. To investigate the relationship between the change in latitude of the Kuroshio extension region, which flows along the boundary between the subtropical gyre and the subarctic gyre in the North Pacific, and the large-scale atmospheric circulation due to global warming, the zero-windstress curl line for each climate change experiment from 9 out of 21 models were compared. As the atmospheric radiative forcing increases due to the increase of greenhouse gases, it was confirmed that the zero-windstress curl line moves northward, which is consistent with the observation. These results indicate that as the Hadley Circulation expands to the north due to global warming, the warming of the mid-latitudes to which the Korean Peninsula belongs may be accelerated. The volume transport and temperature of the Tsushima Warm Current flowing into the East Sea through the Korea Strait also increased as the atmospheric radiative forcing increased.