• International conference on construction engineering and project management
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• 2015.10a
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• pp.41-43
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• 2015

Urban Informatics, the application of data science methodologies to the urban development and planning domain, has been increasingly adopted to improve the management and efficiency of cities. This paper introduces state of the art use cases in major cities including New York, London, Seoul and Amsterdam. It also introduces recent advances in using Big Data by multi-lateral institutions for poverty reduction, and startups utilizing open data initiatives to create new value and insights. Preliminary research performed on using Seoul's open data such as building permit data and health code violations are also introduced to demonstrate opportunities in this relatively new but promising area of research.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.388-393
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• 2002

Remote sensing data is collected and analyzed to enhance understanding of the terrestrial surface. Since Landsat satellite was launched in 1972, many researches using multispectral data has been achieved. Recently, with the availability of airborne and satellite hyperspectral data, the study on hyperspectral data are being increased. It is known that as the number of spectral bands of high-spectral resolution data increases, the ability to detect more detailed cases should also increase, and the classification accuracy should increase as well. In this paper, we classified the hyperspectral and multispectral data and tested the classification accuracy. The MASTER(MODIS/ASTER Airborne Simulator, 50channels, 0.4~13$\mu$m) and Landsat TM(7channels) imagery including Yeong-Gwang area were used and we adjusted the classification items in several cases and tested their classification accuracy through statistical comparison. As a result of this study, it is shown that hyperspectral data offer more information than multispectral data.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.682-686
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• 2003

This paper is concerned with 'reverse difference' of marine sediments at the Camau tongue in the extreme south of Vietnam. We demonstrate the importance of remote sensing in geomorphology and marine geological application, using only visual evaluation and some data-processing techniques. In this paper, about 10,000 km$^2$ of the territorial water in the extreme south of Vietnam is being studied. We show that form and behavior of Mekong and its branch can be determined by visually interpreting remote sensing images and using ERDAS IMAGE 8.5 software. Besides, the 'reverse difference' phenomenon is explained by flows of Mekong river and its branches.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.516-516
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• 2002

With the wide usage of LiDAR data and high-resolution satellite image, 3D modeling of buildings in urban areas has become an important research topic in the photogrammetry and computer vision field for many years. However the previous modeling has its limitations of merely texturing the image to the DSM surface of the study area and does not represent the relief of building surfaces. This study is focused on presenting a system of realistic 3D building modeling from consecutive stereo image sequences using digital camera. Generally when acquiring images through camera, various parameters such as zooming, focus, and attitude are necessary to extract accurate results, which in certain cases, some parameters have to be rectified. It is, however, not always possible or practical to precisely estimate or rectify the information of camera positions or attitudes. In this research, we constructed the collinearity condition of stereo images through extracting the distinctive points from stereo image sequence. In addition, we executed image matching with Graph Cut method, which has a very high accuracy. This system successfully performed the realistic modeling of building with a good visual quality. From the study, we concluded that 3D building modeling of city area could be acquired more realistically.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1000-1001
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• 2003

Like other major cities in the world, Bangkok and some other cities in Thailand are expanding rapidly. The Office of Transports and Traffic Policy and Planning had selected three cities for a study of urban change; namely, Bangkok Metropolis and vicinity ( including Nontha buri, Samut Prakan , Prathum Thani, Samut Sakhon and Nakhon Pathom), Chiang Mai and Nakhon Nayok. The main objective of the study is to monitor urban development and urban extension as well as the change of landuse from farm land to urban area during two periods by using available satellite data. LANDSAT-5 TM and SPOT-HRV panchromatic were used for the first period and LANDSAT-7 ETM+ and IRS-lD panchromatic were used for the second period with a lapsed time of 14 years. I was found that during this period Bangkok Metropolis and vicinity extended 1,222 square kilometer; Chiang Mai 68.3 square kilometer, Nakhon Nayok 5.97 square kilometer. Most landuse categories which had been changed to urban were rice paddy and mixed orchard. Some suggestion for sound urban development based on satellite data was also included.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.556-559
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• 2007

The Urban Environmental Quality (UEQ) indicates a complex and various parameters resulting from both human and natural factors in an urban area. Vegetation, climate, air quality, and the urban infrastructure may interact to produce effects in an urban area. There are relationships among air pollution, vegetation, and degrading environmental the urban heat island (UHI) effect. This study investigates the application of multi-spectral remote sensing data from the Landsat ETM and TM sensors for the mapping of air quality and UHI intensity in Seoul from 2000 to 2006 in fine resolution (30m) using the emissivity-fusion method. The Haze Optimized Transform (HOT) correction approach has been adopted for atmospheric correction on all bands except thermal band. The general UHI values (${\Delta}(T_{urban}-T_{rural})$) are 8.45 (2000), 9.14 (2001), 8.61 (2002), and $8.41^{\circ}C$ (2006), respectively. Although the UHI values are similar during these years, the spatial coverage of "hot" surface temperature (>$24^{\circ}C$) significantly increased from 2000 to 2006 due to the rapid urban development. Furthermore, high correlations between vegetation index and land surface temperature were achieved with a correlation coefficients of 0.85 (2000), 0.81 (2001), 0.84(2002), and 0.89 (2006), respectively. Air quality is shown to be an important factor in the spatial variation of UEQ. Based on the quantifiable fine resolution satellite image parameters, UEQ can promote the understanding of the complex and dynamic factors controlling urban environment.

• Korean Journal of Remote Sensing
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• v.26 no.6
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• pp.617-627
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• 2010

Although many researches for heat island study have been developed, there is little attempt to link the findings to actual and hypothetical scenarios of urban developments which would help to mitigate the Urban Heat Island (UHI) in cities. The aim of this paper is to analyze the UHI at urban area with different geometries, land use, and environmental factors, and emphasis on the influence of different geometric and environmental parameters on ambient air temperature. In order to evaluate these effects, the parameters of (i) Air pollution (i.e. Aerosol Optical Thickness (AOT)), (ii) Green space Normalized Difference Vegetation Index (NDVI), (iii) Anthropogenic heat (AH) (iv) Building density (BD), (v) Building height (BH), and (vi) Air temperature (Ta) were mapped. The optimum operational scales between Heat Island Intensity (HII) and above parameters were evaluated by testing the strength of the correlations for every resolution. The best compromised scale for all parameters is 275m resolution. Thus, the measurements of these parameters contributing to heat island formation over the study areas of Hong Kong were established from mathematical relationships between them and in combination at 275m resolution. The mathematical models were then tabulated to show the impact of different percentages of parameters on HII. These tables are useful to predict the probable climatic implications of future planning decisions.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1005-1005
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• 2003

The purpose of this study is to evaluate the potential application of TERRA-ASTER data in Thailand. ASTER VNIR, SWIR and TIR data covering greater Bangkok and Chiangmai province were processed with various techniques in the spatial domain to study the applicability to various disciplines. ASTER data was also combined with other satellite data in order to utilize multi-sensor methods. It was found that VNIR data can clearly identify urban pattern including road network and vegetation index. While SWIR and TIR data can well separate between urban and non urban area and TIR data can differentiate among thermal surfaces. Furthermore, dense urban areas such as central business area could be highlighted. Land utilization, vegetable distribution and differences of temperature distribution were investigated.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.134-137
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• 2005

Unsupervised spectral angle classification (USAC) is the algorithm that can extract ground object information with the minimum 'Spectral Angle' operation on behalf of 'Spectral Euclidian Distance' in the clustering process. In this study, our algorithm uses the unit vector instead of the spectral distance to compute the mean of cluster in the unsupervised classification. The proposed algorithm (MUSAC) is applied to the Hyperion and ETM+ data and the results are compared with K-Meails and former USAC algorithm (FUSAC). USAC is capable of clearly classifying water and dark forest area and produces more accurate results than K-Means. Atmospheric correction for more accurate results was adapted on the Hyperion data (Hyperion-FLAASH) but the results did not have any effect on the accuracy. Thus we anticipate that the 'Spectral Angle' can be one of the most accurate classifiers of not only multispectral images but also hyperspectral images. Furthermore the cluster unit vector can be an efficient technique for determination of each cluster mean in the USAC.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1711-1720
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• 2011

This study was performed to determine the levels of suicide awareness and attitudes among the high school students in urban and rural areas, and to reveal its related factors. The interviews were performed, during the period from July 1, to July 31, 2009, to the 2,082 students in urban and rural areas. As a results, the suicide awareness rate of subjects was 38.8%, and they were not significant between urban and rural areas. The levels of suicide awareness and attitudes were significantly higher in rural students than that of urban students. The factors affecting suicide awareness in urban areas were living with parents, academic speciality, suicide ideation, suicide attitudes, and sex, argument with parents, suicide ideation and suicide attitudes were affected in rural areas. The factors affecting suicide attitudes in urban areas were academic speciality, suicide awareness, and sex, smoking and suicide awareness were affected in rural areas. In conclusion, the development of suicide prevention programs would required to keep under management of the factors affecting suicide awareness and attitudes such as the factors family and school lifes.