• Title/Summary/Keyword: BUILT-UP AREA

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Quantitative Flood Forecasting Using Remotely-Sensed Data and Neural Networks

  • Kim, Gwangseob
    • Proceedings of the Korea Water Resources Association Conference
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    • 2002.05a
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    • pp.43-50
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    • 2002
  • Accurate quantitative forecasting of rainfall for basins with a short response time is essential to predict streamflow and flash floods. Previously, neural networks were used to develop a Quantitative Precipitation Forecasting (QPF) model that highly improved forecasting skill at specific locations in Pennsylvania, using both Numerical Weather Prediction (NWP) output and rainfall and radiosonde data. The objective of this study was to improve an existing artificial neural network model and incorporate the evolving structure and frequency of intense weather systems in the mid-Atlantic region of the United States for improved flood forecasting. Besides using radiosonde and rainfall data, the model also used the satellite-derived characteristics of storm systems such as tropical cyclones, mesoscale convective complex systems and convective cloud clusters as input. The convective classification and tracking system (CCATS) was used to identify and quantify storm properties such as life time, area, eccentricity, and track. As in standard expert prediction systems, the fundamental structure of the neural network model was learned from the hydroclimatology of the relationships between weather system, rainfall production and streamflow response in the study area. The new Quantitative Flood Forecasting (QFF) model was applied to predict streamflow peaks with lead-times of 18 and 24 hours over a five year period in 4 watersheds on the leeward side of the Appalachian mountains in the mid-Atlantic region. Threat scores consistently above .6 and close to 0.8 ∼ 0.9 were obtained fur 18 hour lead-time forecasts, and skill scores of at least 4% and up to 6% were attained for the 24 hour lead-time forecasts. This work demonstrates that multisensor data cast into an expert information system such as neural networks, if built upon scientific understanding of regional hydrometeorology, can lead to significant gains in the forecast skill of extreme rainfall and associated floods. In particular, this study validates our hypothesis that accurate and extended flood forecast lead-times can be attained by taking into consideration the synoptic evolution of atmospheric conditions extracted from the analysis of large-area remotely sensed imagery While physically-based numerical weather prediction and river routing models cannot accurately depict complex natural non-linear processes, and thus have difficulty in simulating extreme events such as heavy rainfall and floods, data-driven approaches should be viewed as a strong alternative in operational hydrology. This is especially more pertinent at a time when the diversity of sensors in satellites and ground-based operational weather monitoring systems provide large volumes of data on a real-time basis.

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Effect of Land Use on Urban Thermal Environments in Incheon, Korea (인천시에서 토지이용이 도시 열 환경에 미치는 영향)

  • Kong, Hak-Yang;Kim, Seog Hyun;Cho, Hyungjin
    • Ecology and Resilient Infrastructure
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    • v.3 no.4
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    • pp.315-321
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    • 2016
  • To identify the relationship between land use and thermal environment in an urban area, the air temperature was measured at different places of land use, and the changes of land use and air temperature were traced for 40 years in Incheon City. The relationship between land use and temperature was also investigated using satellite image data. The results of temperature measurements on a forest, a cropland (rice paddy), a bareland (school ground), and an urban area (asphalt road) from 19 to 21 August 2014 showed that air temperature was the highest on a pavement road. The temperature increased by about $1.4^{\circ}C$ ($0.035^{\circ}C/year$) for 40 years from 1975 to 2014 in Incheon. The changes in land use patterns of Incheon for the past 40 years showed that urban dry land, bareland and grassland have increased and cultivated land, wetland and forest land have decreased gradually. The land surface temperature (LST) was correlated with the normalized difference vegetation index (NDVI) and normalized difference built-up index (NDBI) extracted from Landsat satellite image. The land surface temperature was lower at higher NDVI, and higher at higher NDBI. Therefore, it is important to conserve and restore the land use of greenery, wetlands, and agricultural land in order to mitigate the heat island effect and improve the thermal environment in an urban area.

Coastal Zone Management in the United States of America (미국의 해안관리 -New Jerseyization의 반성과 연방정부 연안역관리 프로그램의 확산-)

  • Yu, Keun-Bae
    • Journal of the Korean Geographical Society
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    • v.44 no.4
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    • pp.481-496
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    • 2009
  • Every coastal area exhibits its own unique landscape owing to the combination of the natural and cultural processes. Coastal barrier islands well show the cultural aspects of American coastal landscapes. Some 47% of barrier island area was occupied by urban and built-up area in New Jersey, while some 5% in Georgia. Tourism-related development is back to in the mid 19C. in N.J. due to the closeness to heavily populated areas such as New York and Philadelphia. Developments without proper understanding the nature of coastal processes caused New Jerseyization, the destruction of the beauty or naturalness. It was mainly due to the lack of growth-control policies and the foresight for the future coast in the processes of legislation. North Carolina's islands experienced an increase of 269% in urbanized acreage between 1956 and 1976. However, N.C. exercised her wisdom to recover the naturalness of the coastal environs: all engineering structures are banned on the beaches. Nine out of 13 barrier islands in Georgia exist in the wilderness condition owing to her unique history. The remaining islands still experienced the least development. After the Civil War most of Georgian islands were owned by rich families and maintained as wilderness. In the 1970s most of the uninhabited islands were sold or donated to research institutes or governmental agencies.

A Study on Estimating the Land Developer's Share of Infrastructure Cost : Focused on the Road Facility of Residential Development (간선시설 설치비용의 합리적 분담분 추정 : 택지개발사업시 조성되는 도로시설을 중심으로)

  • Kim, Tae-Gyun;Choi, Dae-Sik
    • Land and Housing Review
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    • v.3 no.3
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    • pp.241-248
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    • 2012
  • Although infrastructure cost comprises the great proportion of residential development cost, all of it tends to be borne by land developers which develop large area. This brings about free-riding by adjacent small development or built-up area, followed by the equity problem in terms of infrastructure development cost sharing and the privatization of development gain. This study aims to establish the method to analyze free-riding on the transportation infrastructure(roads) and investigate empirically how much the free-riding occurs. It sets several development scenarios to calculate the part generated by Bucheon Sangdong district, the case area of this study, of all the traffic flow on the roads. The Network analysis is used to estimate the proportion, by development scenarios, of traffic flow, travel time, and travel cost. As a result, the developer of Bucheon Sangdong district is responsible for 83% of the construction cost of selected roads. The methodology and empirical result of this study would contribute to determine who are liable for the infrastructure facilitation and to estimate how much of the cost the obligators have to share.

Acoustic Characteristics of Sound Field in Partially Opened Rooms -Emphasis on Vertical Coupling of Diffuse and Free Field- (실내공간의 부분적 개방에 따른 음향특성변화 II -확산음장과 자유음장의 수직적 결합을 중심으로-)

  • Jeong, Dae-Up;Choi, Young-Ji
    • Journal of Korean Association for Spatial Structures
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    • v.7 no.5
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    • pp.75-82
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    • 2007
  • The present work measured and analyzed changes in the acoustics of a sound field which has a retractable ceiling. An 1/20 scale model of an openable space was built and measurement was carried out by varying the opened area of a ceiling. The most widely used room acoustic and design parameters, RT, EDT, and D50 were investigated. The results suggest that the use of RT as an acoustic design parameter may not be proper in an openable space and further it is likely to mislead the initial acoustic design of such spaces. It is mainly due to the characteristics of RT in which non-exponential decay processes are linearly fitted. Early decay times were found to be decreased in proportion to increaing the ratio of opened area. D50, an index of speech intelligibility, was effectively shows the influence of openings on the acoustics. It is also found that EDT and D50 at the seats, not directly exposed to the opened part of a ceiling, were almost linearly decreased in proportion to the ratio of opened area, while little influence was found for the opening ratio larger than 40% at the directly exposed seats to the opened part of a ceiling.

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Determination of Unit Hydrograph for the Hydrological Modelling of Long-term Run-off in the Major River Systems in Korea (장기유출의 수문적 모형개발을 위한 주요 수계별 단위도 유도)

  • 엄병현;박근수
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.26 no.4
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    • pp.52-65
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    • 1984
  • In general precise estimation of hourly of daily distribution of the long-term run-off should be very important in a design of source of irrigation. However, there have not been a satisfying method for forecasting of stationar'y long-term run-off in Korea. Solving this problem, this study introduces unit-hydrograph method frequently used in short-term run-off analysis into the long-term run-off analysis, of which model basin was selected to be Sumgin-river catchment area. In the estimation of effective rainfall, conventional method neglects the Soil moisture condition of catchment area, but in this study, the initial discharge (qb) occurred just before rising phase of the hydrograph was selected as the index of a basin soil moisture condition and then introduced as 3rd variable in the analysis of the reationship between cumulative rainfall and cumulative loss of rainfall, which built a new type of separation method of effective rainfall. In next step, in order to normalize significant potential error included in hydrological data, especially in vast catchment area, Snyder's correlation method was applied. A key to solution in this study is multiple correlation method or multiple regressional analysis, which is primarily based on the method of least squres and which is solved by the form of systems of linear equations. And for verification of the change of characteristics of unit hydrograph according to the variation of a various kind of hydrological charateristics (for example, precipitation, tree cover, soil condition, etc),seasonal unit hydrograph models of dry season(autumn, winter), semi-dry season (spring), rainy season (summer) were made respectively. The results obtained in this study were summarized as follows; 1.During the test period of 1966-1971, effective rainfall was estimated for the total 114 run-off hydrograph. From this estimation results, relative error of estimation to the ovservation value was 6%, -which is mush smaller than 12% of the error of conventional method. 2.During the test period, daily distribution of long-term run-off discharge was estimated by the unit hydrograph model. From this estimation results, relative error of estimation by the application of standard unit hydrograph model was 12%. When estimating by each seasonal unit bydrograph model, the relative error was 14% during dry season 10% during semi-dry season and 7% during rainy season, which is much smaller than 37% of conventional method. Summing up the analysis results obtained above, it is convinced that qb-index method of this study for the estimation of effective rainfall be preciser than any other method developed before. Because even recently no method has been developed for the estimation of daily distribution of long-term run-off dicharge, therefore estimation value by unit hydrograph model was only compared with that due to kaziyama method which estimates monthly run-off discharge. However this method due to this study turns out to have high accuracy. If specially mentioned from the results of this study, there is no need to use each seasonal unit hydrograph model separately except the case of semi-dry season. The author hopes to analyze the latter case in future sudies.

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Research on the Spatio-temporal Distribution Pattern of Temperature Using GIS in Korea Peninsular (GIS를 이용한 한반도 기온의 시·공간적 분포패턴에 관한 연구)

  • KIM, Nam-Shin
    • Journal of The Geomorphological Association of Korea
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    • v.15 no.2
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    • pp.85-94
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    • 2008
  • This study is to construe spatio-temporal characteristics of temperature in cities and changes of climatical regions in analyzing a change of Korea Peninsular climate. We used daily mean air temperature data which was collected in South and North Korea for the past 34 years from 1974 to 2007. We created temperature map of 500m resolution using Inverse Distance Weight in application with adiabatic lapse rate per month in linear relation with height and temperature. In the urbanization area, the data analyzed population in comparison with temperature changes by the year. An annual rising rate of temperature was calculated $0.0056^{\circ}C$, and the temperature was increased $2.14^{\circ}C$ from 1974 to 2107. The south climate region in Korea by the Warmth index was expanded to the middle climate region by the latitude after 1990s. A rise of urban area in mean temperature was $0.5-1.2^{\circ}C$, Seoul, metropolitan and cities which were high density of urbanization and industrialization with the population increase between 1980s and 1990s. In case of North Korea, Cities were Pyeongyang, Anju, Gaecheon, Hesan. A rise in cities areas in mean temperature has influence on vegetation, especially secondary growth such as winter buds of pine trees appears built-up area and outskirts in late Autumn. Finally, nowaday we confront diverse natural events over climatical changes, We need a long-term research to survey and analyze an index on the climatical changes to present a systematic approach and solution in the future.

Nature of Creativity and its Development in the Area of Art: Changes of Self-consciousness (예술 분야에서의 창의성의 본질과 발달 과정 탐색: 자의식 변화를 중심으로)

  • Shin, Jongho;Mun, Ji-Won;Kim, Gyeong-Hwa;Jo, Eun-Byeol;Ju, Si-Wa;Hong, Ae-Ryeong
    • (The) Korean Journal of Educational Psychology
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    • v.26 no.4
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    • pp.901-926
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    • 2012
  • Previous research on creativity mainly investigated the characteristics of creative individuals and environments. In this study, those factors were also investigated in art by critically reviewing various documents on 5 creative artists: Nam June Paik, Isang Yun, Marcel Duchamp, John Cage and Pina Bausch. The results of the study showed that creativity in art developed through three different developmental stages with the changes of artist's self or self-consciousness: the discovering self, strengthening self-consciousness, and refining self-consciousness stages. The first stage of discovering self is the period during which the creative artists discovered their talents in the area of art and decided to pursue their career in art. During this stage, creative artists expressed a strong curiosity, tried to learn the world of art with intense efforts, and established a good foundation of knowledge. During the second stage of strengthening self-consciousness, creative artists built up their own aesthetic worlds. They tried to slake their thirst for the novelty in the field and made a strong commitment to the field they belong to. Finally, during the refining self-consciousness stage, they expressed their aesthetic worlds with refined self and expanded their aesthetics from personal to social dimensions. And they pursued an integration of various domains to produce a new artistic genre and shared their creative aesthetics with members outside of their field. The main implication of the findings of this study was that creativity could be defined and understood meaningfully by the perspective of self or self-consciousness in the area of art.

A Study on the Christianization of Roman Basilica and Romanization of Christian Building on the Early Christian Church Architecture - Focused on the 4th Century Constantinus Basilica Churches - (초기 기독교 교회건축에서 로마 바실리카의 기독교화와 기독교 건축의 로마화에 관한 연구 - 4세기 콘스탄티누스 바실리카 교회를 중심으로 -)

  • Hong, Soon-Myung
    • Korean Institute of Interior Design Journal
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    • v.22 no.6
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    • pp.151-161
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    • 2013
  • This study which analyzed 4th century Constantinus basilica church architecture is on how the Roman basilica architecture became to christianized and christian architecture became romanized. Basilica architecture of Rome which has strong public characteristic had approach from various direction, especially it has formed inter communicable open space to center forum. Even though, the early christian church has became to bigger size on the process of domus ecclesia centered growth, but it has formed essencially unhierarchy community of home based, it also seemed to have loose religious community below hundred. The result of analyzing 22 of 4 century basilica churches had been shown that more than 60% of them were built on historical place such as tomb of martyr, nearly 70% of them were long axis type, the size of church showed up $3,200m^2$ of average total area. In conclusion, this study concluded the result of christianized showed closeness pursue holiness by separation from the secular world, and long axis it was revealed as mass for the procession ceremony of catholic church. The result of romanized occurred from the process that the basilica church abandoned the unhierarchy, small sizing, worship simplicity of early domus ecclesia characteristics and accept hierarchy, big sizing, worship formalism and complexity of Roman empire system in the roman basilica churches. Through this study it could be grasp that the romanized of early christianity bring not only the change of church architecture but also degeneration of christian itself.

Predicting Land Use Change Affected by Population Growth by Integrating Logistic Regression, Markov Chain and Cellular Automata Models

  • Nguyen, Van Trung;Le, Thi Thu Ha;La, Phu Hien
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.35 no.4
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    • pp.221-230
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    • 2017
  • Demographic change was considered to be the most major driver of land use change although there were several interacting factors involved, especially in the developing countries. This paper presents an approach to predict the future land use change using a hybrid model. A hybrid model consisting of logistic regression model, Markov chain (MC), and cellular automata (CA) was designed to improve the performance of the standard logistic regression model. Experiment was conducted in Giao Thuy district, Nam Dinh Province, Vietnam. Demography and socio-economic variables dealing with urban sprawl were used to create a probability surface of spatio-temporal states of built-up land use for the years 2009, 2019, and 2029. The predicted land use maps for the years 2019 and 2029 show substantial urban development in the area, much of which are located in areas sensitive to source protections. It also showed that aquacultural land changes substantially in areas where are in the vicinity of estuary or near the sea dike. There was considerable variation between the communes; notably, communes with higher household density and higher proportion of people in working age have larger increases in aquacultural areas. The results of the analysis can provide valuable information for local planners and policy makers, assisting their efforts in constructing alternative sustainable urban development schemes and environmental management strategies.