• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2010.04a
• /
• pp.227-229
• /
• 2010

This study presents an application of the 3D patch extraction method which is based on gradient-driven properties to obtain 3D planar patches over the terrain and man-made objects from lidar data. The method which was exploited in this study is composed of a sequence of processes: segmentation by slope, initiation of triggering patches by mode selection, and expansion of the triggering patches. Since urban areas contain many planar regions over the terrain surface, application of the method has been experimented to extract 3D planar patches not only from non-terrain objects but also from the terrain. The experimental result shows that the method is efficient to acquire 3D planar patches.

• Journal of the Korean GEO-environmental Society
• /
• v.11 no.2
• /
• pp.33-42
• /
• 2010

The main objective of this study was to offer informations about the current conditions of stream sediments and to evaluate biochemical methane potentials of stream sediments from the urban streams in Busan city using conventional BMP tests. First we select total 5 urban streams and collect sediment samples. Then, COD, proximate analysis, volatile solid, organic carbon content and elemental analysis were conducted to determine characteristics of the sediments. Results show that COD, volatile solid and organic carbon content are determined in the range of $15.20{\sim}75.07mg\;g^{-1}$, 2.34~11.54% and 1.28~34.21%, respectively. Also, several biochemical methane potential tests were performed in a laboratory. As a result, pH values of the reactors generally increased and then stabilized at 7.11~7.35. In addition, C/N ratio, ultimate methane and carbon dioxide yield (mL/g VS) and biodegradability (%) were determined to 1.05~10.27, 10.1~179.4, 10.3~34.4 and 4.0~30.1, respectively. For the determination of the correlations between ultimate methane yield and ultimate carbon dioxide yield, C/N ratio, COD, volatile solid and organic carbon content, a linear model was fitted to the data using a least-squares algorithm. As a result, except for COD ($r^2=0.7586$) and volatile solid ($r^2=0.7876$), Linear model was well fitted to each data with good values of the correlation coefficient ($r^2=0.9795{\sim}0.9858$). Finally, we propose empirical equations, which contain C/N ratio or TOC, for the prediction of ultimate methane yield for the urban streams in Busan city.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.45 no.3
• /
• pp.92-106
• /
• 2017

This paper examines the validity of issuing municipal bonds for land compensation of long-term unexecuted urban parks and greenbelts. Then it suggests that municipal bonds should be issued for compensation priority areas with high rising prices. By conducting correlation analysis and PLS(Partial Least Squares) regression for 32 long-term unexecuted urban parks and greenbelts, the factors were identified that affected 'rising prices of IAPLP(Individually Announced Public Land Price) after seven years'. According to the analysis results, Variable Importance in the Projection in PLS regression was higher in 'IAPLP of base year(1.919)' and 'Accumulated rising Rates of average IAPLP in the borough(1.176).' The implications of this study are as follows. In Seoul, the accumulated rising rates of average IAPLP over the past 12 years is higher than the accumulated interest rates for seven years of urban planning facility bonds, which means that IAPLP have risen more than the interest payments due to the issuance of municipal bonds. In addition, since the actual compensation is three times that of IAPLP, it is judged that the land price is actually much higher than the interest payments. This shows that issuing municipal bonds and preferentially compensating for areas like high rising land prices can increase the economic efficiency of the budget execution. Also, for economic efficiency of budget execution, it is necessary to propose an 'area with high IAPLP' or 'a part in the borough with high rising rate of average IAPLP,' which is expected to have a high rising land price as criteria for compensation priority areas. In the future, when issuing municipal bonds to compensate long-term unexecuted urban parks and greenbelts, variousresearch on financing for municipal bonds repayment should be conducted.

• Journal of the Korean housing association
• /
• v.25 no.3
• /
• pp.85-92
• /
• 2014

The purpose of this study is to explore the relationship between housing types and crime and to suggest the appropriate strategies and interventions of housing policies for crime prevention. For spatial analysis of crime data, spatial autocorrelation is tested by Moran's I Test. A Ordinary Least Squares-based regression model is employed because crime data used in this study fails to show spatial autocorrelation. Results show that housing type variables except non-residential housing type are not associated with crime. Among land-use characteristics, the percentage of commercial areas is likely to better explain crime occurrence rather than housing types. It is surprising that residents' satisfaction to housing environment has a positive direction in its relationship with crime even though it cannot have a statistical significance. However, fear of crime shows a negative direction with crime although it fails to have a statistical significance. The findings of this study can contribute to understand the association between housing types and crime when setting housing policies for crime prevention.

• Journal of Electrical Engineering and Technology
• /
• v.13 no.1
• /
• pp.38-50
• /
• 2018

Spatio-temporal load forecasting (STLF) is a foundation for building the prediction-based power map, which could be a useful tool for the visualization and tendency assessment of urban energy application. Constructing one point-forecasting model for each electricity cell in the geographic space is possible; however, it is unadvisable and insufficient, considering the aggregation features of electricity cells and uncertainties in input variables. This paper presents a new STLF method, with a data-driven framework consisting of 3 subroutines: multi-level clustering of cells considering their aggregation features, load regression for each category of cells based on SLS-SVRNs (sparse least squares support vector regression networks), and interval forecasting of spatio-temporal load with sampled blind number. Take some area in Pudong, Shanghai as the region of study. Results of multi-level clustering show that electricity cells in the same category are clustered in geographic space to some extent, which reveals the spatial aggregation feature of cells. For cellular load regression, a comparison has been made with 3 other forecasting methods, indicating the higher accuracy of the proposed method in point-forecasting of spatio-temporal load. Furthermore, results of interval load forecasting demonstrate that the proposed prediction-interval construction method can effectively convey the uncertainties in input variables.

• The Journal of Asian Finance, Economics and Business
• /
• v.9 no.10
• /
• pp.227-234
• /
• 2022

The proportion of people living in poverty in Soc Trang is comparatively large. 27,154 households in this province are considered to be poor, which represents 8.4 percent of all households. The gap between rural and urban areas, between farmers and other social classes in this province, tends to increase, and the living standard of people in the countryside remains difficult. This paper aims to investigate the determinant factors of poor households' income in rural areas of Soc Trang province, Vietnam. Data from 120 poor households in Vinh Chau district and Ke Sach district of Soc Trang province collected in the year 2019 is employed to test the proposed hypotheses in this study. By applying the descriptive statistical method and ordinary least squares (OLS) regression, the results show that the factors of production land, number of income generation activities, access to credit, means of transportation, and means of production positively affect the income per capita of poor household in the study area, whereas household size has a negative impact on the household income per capita. Considering the empirical findings, several solutions and recommendations are proposed to improve the income of poor households in Soc Trang province.

• ETRI Journal
• /
• v.46 no.3
• /
• pp.392-403
• /
• 2024

Even though generalized frequency division multiplexing is an alternative waveform method expected to replace the orthogonal frequency division multiplexing in the future, its implementation must alleviate channel effects. Least-squares (LS), a low-complexity channel estimation technique, could be improved by using the discrete Fourier transform (DFT) without increasing complexity. Unlike the usage of the LS method, the DFT-based method requires the receiver to know the channel impulse response (CIR) length, which is unknown. This study introduces a simple, yet effective, CIR length estimator by utilizing LS estimation. As the cyclic prefix (CP) length is commonly set to be longer than the CIR length, it is possible to search through the first samples if CP is larger than a threshold set using the remaining samples. An adaptive scale is also designed to lower the error probability of the estimation, and a simple signal-to-interference-noise ratio estimation is also proposed by utilizing a sparse preamble to support the use of the scale. A software simulation is used to show the ability of the proposed system to estimate the CIR length. Due to shorter CIR length of rural area, the performance is slightly poorer compared to urban environment. Nevertheless, satisfactory performance is shown for both environments.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.36 no.6
• /
• pp.611-620
• /
• 2018

With the revitalization of alley market area becoming a major goal of the urban regeneration project, an understanding on customer characteristics that affect the sales of alley market areas is needed. As spatial heterogeneity appears to exist in alley market areas, the use of GWR (Geographically Weighted Regression) is required as an alternative to OLS (Ordinary Least Squares) regression. This study analyzes effects of customer characteristics on sales of 1007 alley market areas in Seoul. Comparing R squared and AICc, results show that GWR is better than OLS regression. According to OLS regression, the ratio of female, the ratio of 40's and 50's, the number of employees, the opening rate of establishment, the density of building and the size of alley market area have positive effects on sales, while the ratio of 20's and 30's, the distance of bus stop and that of subway station have negative effects. As a result of comparing local regression coefficients of geographically weighted regression analysis, the ratio of female customers has the greatest effect on the northwestern region, followed by the southwestern region, the central region and the northeastern region. The ratio of 20's and 30's and that of 40's and 50's effect on the southeastern and northeastern regions, and then the southwestern region. It is expected that this study will help to identify marketing target for each alley market area.

• Land and Housing Review
• /
• v.5 no.4
• /
• pp.215-224
• /
• 2014

National street has become one of open space for enhancing environmental qualities of city and country. In the developed countries such as France, U.K. U.S.A are designed symbolic malls, squares and street which are represented the historicity, culture and symbolic place. For place identity, we analyzed the relationship between element and user satisfaction in Sejong Avenue, Gwangwhamun Square. Data were analyzed using statistical methods such as descriptive statistics, ANOVA and correlation. Results of this study are as follows, i) factor analysis is carried out to extract spatial components and satisfaction. The satisfaction concerning transportation access was the higher than other factors, ii) user satisfaction was strongly correlated on the spatial elements, iii) user showed high user perception to study site. Results of this study can identify representative street management plan based on landscape elements and user satisfaction.

• The Journal of the Korea Contents Association
• /
• v.12 no.2
• /
• pp.461-471
• /
• 2012

The purpose of this paper is to visualize the housing market dynamics with ESDA (Exploratory Spatial Data Analysis) using MATLAB toolbox, in terms of the modeling housing market dynamics in the Busan Metropolitan City. The data are used the real housing price transaction records in Busan from the first quarter of 2006 to the second quarter of 2009. Hedonic house price model, which is not reflecting spatial autocorrelation, has been a powerful tool in understanding housing market dynamics in urban housing economics. This study considers spatial autocorrelation in order to improve the traditional hedonic model which is based on OLS(Ordinary Least Squares) method. The study is, also, investigated the comparison in terms of $R^2$, Sigma Square(${\sigma}^2$), Likelihood(LR) among spatial econometrics models such as SAR(Spatial Autoregressive Models), SEM(Spatial Errors Models), and SAC(General Spatial Models). The major finding of the study is that the SAR, SEM, SAC are far better than the traditional OLS model, considering the various indicators. In addition, the SEM and the SAC are superior to the SAR.