• Journal of the Korean Regional Science Association
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• v.10 no.2
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• pp.61-71
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• 1994

Despite of being the criteria to choose the efficient and reasonable alternatioves inactual planning process, the measure of accessibility rarely has applied to practices because each model has unexplicity concept of it and limitations in itself. Accessibility implies transportation system which offers opportunity of movement to overcome spatial separation and, simultaneously, land-use system which represents the location of each activity. Therefore, measures of accessibility have to represent the attractiveness of locations and the interactions of activities, that is, land-use and transportation, with an index. Considering that urban activity is based on the economic efficiency, costs and benfits, accessibility means the economic efficiency of the location of activity and the travel in view of land-use and transport repectively. Combined models that measure accessibility with considering land-use and tranportation simultaneously depend on reasonable concepts, but it is too simple for them to explain the accessibility which resulted from complex interaction of urban activities. Combined urban activity model developed by Kim (1983) and Rho (1989) explains the characteristics of activities in each regions and urban strcture in economic general equilibrium states in the long term of urban system. This model measures a regional accessibility with a dual variable which means the location surplus. This is a more systematic and comprehensive model for calculating the regional accessibility because it considers the interaction of each activity in urban system. It needs efforts to apply the accessibility index as a criterion in actual planning process through finding and quantitification of other explanatory variables to measure it in combined urban activity model.

• Journal of Korea Spatial Information System Society
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• v.11 no.4
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• pp.56-64
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• 2009

As the Internet has been improved to Web 2.0, it introduces new approaches including Rich Internet Application (RIA) technology such as Flash, AJAX, Silverlight, etc. The RIA which is platform independent technology allows applications to provide rich client-side interfaces, and allows the browser to interact with users without communication to server. In this paper, we propose a method of spatial data service based on RIA technology. Internet map service using spatial data generally requires rich client-side interfaces and various interactions. These features can be provided by the RIA. The proposed method uses Flash developed by Macromedia as RIA technology. It can be applicable on any platform including mobile environment. The spatial data server makes Flash file known as SWF (Shock Wave File) with manipulation code for map and spatial data that is requested by user, and send it to the web browser. Once the web browser receives a SWF, client SWF manipulates user interactions, such as zooming and panning, without communication with server. Experiments that execute the application on various web browsers including mobile web browser and measure time of map interaction are carried out to compare with traditional bitmap based WMS (Web Map Service). As a result of experiments, we have confirmed improvement of interactivity and performance with RIA approach.

• Structural Engineering and Mechanics
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• v.21 no.1
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• pp.53-66
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• 2005

When a large number of identical cylinders are placed in an array with equal separation distance, near-resonant phenomena may occur between cylinders at critical frequencies, and cause large wave forces on each element of the array. In this paper, 64 truncated circular cylinders arranged in 4 rows and 16 columns are considered to check occurrence of near-resonant phenomena and performance of theoretical predictions based on the potential flow. Experiments are conducted in head waves to measure the wave elevation along the longitudinal centerline of the model, and measured results are compared with numerical ones. Attention is focused on the spatial variation of the wave amplitude around the first near-trapped-mode frequency.

• Journal of the Korean association of regional geographers
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• v.16 no.2
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• pp.137-153
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• 2010

The issue of spatial equity in public healthcare services is an important issue in rural areas with lower healthcare resources. This study investigates spatial accessibility to public healthcare services by public transport, focusing on bus travel in Yeoju-gun, Gyeonggi-do. We comprehensively analyzed the spatial patterns of accessibility using the measures based on spatial interaction, and compared them with the accessibility patterns by car travel. As a result of analysis, the spatial disparity between the central part of Yeoju-gun (lower accessibility) and its peripheries (higher accessibility) was identified. More specifically, the area and population of lower accessibility areas are greater than those of higher accessibility areas, and the difference in the accessibility values between higher and lower accessible areas is considerably large. Moreover, the accessibility patterns appears somewhat different according to two different travel modes. In particular, about 20% of the entire area presented the opposite patterns between two travel modes. Interestingly, less populated peripheral areas are more included in higher accessible areas by car.

• Journal of Cadastre & Land InformatiX
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• v.46 no.2
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• pp.325-340
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• 2016

Geodesign was suggested by Dangermond(2009) as a next paradigm of GIS to be a future basis for spatial planning and design. Ko(2015) also suggested a geodesign methodology that uses spatial information from a landscape designer's perspective. Spatial planning and design fundamentally require creativity and efficiency but Ko's methodology did not include the creativity aspect. To complement the deficiency, this paper expand the research scope to deal with a designer's cognitive limits and to provide better experiences for the landscape designers. An interface was designed to improve the designer's creativity based on interactions that were derived from a script of landscape design. The expanded methodology for both efficiency and creativity is suggested for the interface by analyzing preceding researches. ESRI's GeoPlanner for ArcGIS, as a first geodesign software, is compared to improve the interface in terms of creativity. One of the difficulties as a thesis is that it is not easy to measure the improvement of design creativity physically and quantitatively. This paper tried to eliminate any stumbling block in supporting creativity and to help designers find new orders in design subconsciousness and to reach a new concept. In addition, the interface to express instantaneous design ideas would be a guide to overcome the designer's cognitive limits.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.392-393
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• 2005

Due to the temporal and spatial simultaneity and the high-frequency repetition, the data set retrieved from the satellite observation is considered to be the most desirable ones for the study of air-sea interaction. With rapidly developing sensor technology, satellite-retrieved data has experienced improvement in the accuracy and the number of parameters. Nevertheless, since it is still impossible to directly measure the heat fluxes between air and sea, the bulk method is an exclusive way for the evaluation of the heat fluxes at the sea surface. It was noted that the large deviation of air temperature in the winter season by the linear regression despite good correlation coefficients. We propose a new algorithm based on the Fourier series with which the SST and the air temperature. We found that the mean of air temperature is a function of the mean of SST with the monthly gradient of SST inferred from the latitudinal variation of SST and the spectral energy of air temperature is related linearly to that of SST. An algorithm to obtain the air temperature over the sea was completed with a proper analysis on the relation between of air temperature and of SST. This algorithm was examined by buoy data and therefore the air temperature over the sea can be retrieved based on just satellite data.

• Korean Journal of Remote Sensing
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• v.25 no.3
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• pp.295-309
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• 2009

In this study, an iterative maximum a posteriori (MAP) approach using a Bayesian model of Markovrandom field (MRF) was proposed for despeckling images that contains speckle. Image process is assumed to combine the random fields associated with the observed intensity process and the image texture process respectively. The objective measure for determining the optimal restoration of this "double compound stochastic" image process is based on Bayes' theorem, and the MAP estimation employs the Point-Jacobian iteration to obtain the optimal solution. In the proposed algorithm, MRF is used to quantify the spatial interaction probabilistically, that is, to provide a type of prior information on the image texture and the neighbor window of any size is defined for contextual information on a local region. However, the window of a certain size would result in using wrong information for the estimation from adjacent regions with different characteristics at the pixels close to or on boundary. To overcome this problem, the new method is designed to use less information from more distant neighbors as the pixel is closer to boundary. It can reduce the possibility to involve the pixel values of adjacent region with different characteristics. The proximity to boundary is estimated using a non-uniformity measurement based on standard deviation of local region. The new scheme has been extensively evaluated using simulation data, and the experimental results show a considerable improvement in despeckling the images that contain speckle.

• Korean Institute of Interior Design Journal
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• v.17 no.5
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• pp.166-174
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• 2008

As the use of virtual environment for decision-making interior or architectural design has been increasingly broaden, the choice of media form-physical, objective properties of a display medium-became and important issue to take into consideration. This research deals with the effects and differences between two types of media for a virtual environment; wall projection screen(120") and PC monitor(17"). In addition, efficient adoption of the two media forms was also proposed in this research. A total of 90 subjects participated in pre-designed three experimental groups(A group: experiment with a wall projection screen, B group: experiment with PC monitor, C group: both) and answer the seating preferences, the presence inventory, and the decision confidence using a simulated virtual restaurant environment. The results are as follows: (1) seating preferences for the tables located in frequent traffic area and near other spaces such as restroom and th kitchen are significantly different by the media form. While there is no significant difference found in seating preferences for most tables except high traffic areas near entrances between the two media. This result demonstrates the effects of media type or screen size on user perception for the areas near structural or interior design elements. (2) The presence measure in this research consist of in this research consist of four factors: 'spatial presence,' 'object presence,' 'positive effects,' and 'the factor of negative effects. 'The mean values of the items involving engagement or interaction in the spatial presence factor and the object presence factor are significantly different by the media form. A higher sense of presence of presence was observed in the wall projection screen. (3) PC monitor condition was shown to provide a higher level of decision confidence. Based on the research finding, conclusions and implications are discussed.

• Health Policy and Management
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• v.21 no.1
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• pp.23-43
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• 2011

Access to health care is complicated to define. It is a multidimensional process. In addition to the matters of quality of care, geographical accessibility and availability of the right type of care, finance, and acceptability are all involved. The purposes of this paper are to measure the geographic distances between patient residency locations and health service organizations in which the patients hadvisited, and to investigate the association between geographical distance measures and variables involved in health service utilization. The study used the first and the second wave of the 2008 Korea Health Panel Survey. The samples of analyses were patients who had visited outpatient or used ambulatory health services, and the total observations (visit numbers) analyzed were 229,128. We divided the samples into a frequent-visit illness group (Group 1) and a non-frequent visit illness group (Group 2) based on over 5,000 total visit numbers. We exploited three level analyses using xtmixed of STATA${\Box}$ 11.1 command with/without interaction terms among age, sex, and occupation. Geographical distances were measured using the Haversine method. Group 1 was tended to older and lower equivalent income than those of Group 2, but the geographic difference were not observed in terms of area deprivation index and standard mortality ratios. Amongst group 1, diabetes mellitus patients travelled far to visit health care organizations, and arthritis patients were more deprived in terms of the personal and areal characteristics. The study revealed that residents in rural areas traveled about 10 times more long distances than those whom lived in larger cities after adjusting for various variables, which we used for analyses. This study contributed to the practical understanding of health service utilizations using empirical analyses, and found that the types of diseases and socioeconomic characteristics of patients tended to define the amount of travel distance to healthcare organizations.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.2
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• pp.1426-1433
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• 2015

CCTV-applied monitoring is an effective measure to suppress potential crimes and record objective relationship; however, there is no methodology that can quantitatively compare and assess the afore-mentioned effects. Thus, this study intended to construct the methodology and analysis application that can measure the changes in the space-corresponding performance of CCTVs depending on installation measures by using 3-dimenstional virtual simulation technology. For analysis, the raster-based Isovist theory was 3-dimensionally expanded and the amount of incident sight line to each point was accumulated. At the same time, the amount of overlapped monitoring in the CCTV cameras that were connected to each measurement node was accumulated for cross-analysis. By applying the examples and analyzing the results, it was possible to construct an analysis application in use of collision detection model and quantify the changes of monitoring performance depending on positioning alternative of the cameras. Moreover, it enabled intuitive review and supplementation by reproducing visible shadow areas in a graph.