• Journal of the Korean Regional Science Association
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• v.36 no.2
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• pp.37-49
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• 2020

Currently, the average aging rate has reached 14.8% in our country, despite the residents are aging or over the average aging rate has reached 31.8% with a population of less than 100,000. Various convenience facilities are concentrated in the town center, causing inconvenience to use. The main purpose of this study is to analyze the accessability of living convenience facilities in this area. This study builds on the population aging of the research target area and distribution of living facilities for the elderly based on MDIS data of the regional survey of the National Agriculture, Forestry and Fishing Survey of the National Statistical Office, and QGIS was used to visualize the status of the elderly, distribution of convenience facilities for the elderly, hot spot maps, and distance analysis, and also technical statistical analysis was conducted. As a result of the analysis, it was confirmed that the distribution and distance of living convenience facilities for the elderly in the area where the elderly lived a lot was located in a location that caused severe inconvenience to the use of the elderly. This suggests the necessity of the change facilities type and spatial reorganization by raising the need for space policy changes on the spatial distribution of elderly convenience facilities, reflecting the serious aging of small towns such as the study area.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.489-493
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• 2013

Purpose: This study was to investigate peripheral vision and provide people with macular degeneration with a guideline for eccentric viewing training. Methods: 30 adult subjects with normal vision took part in this study. The lateral area of $20^{\circ}$ eccentricity from the fovea of right eye was only used to measure the physiological summation. The target was sinusoidal vertical gratings within a circular aperture. The critical points in spatial and temporal summation was found to compare each other for 0.7 cpd and 3.0 cpd, respectively. Results: Critical duration and contrast sensitivity for 0.7 cpd were 540 ms and 1.1, and 315 ms and 0.98 for 3.0 cpd respectively. The critical degrees and contrast sensitivity for 0.7 cpd were $11.3^{\circ}$ and 2.8, and $5^{\circ}$ and 2.63 for 3.0 cpd respectively. Conclusions: The critical point in peripheral vision reaches relatively faster than the one in central vision. It is recommended to train the peripheral retina under the lower spatial frequency more frequently for a short time than constantly for a long time.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.345-350
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• 2017

Downsizing is widely applied to diesel engines in order to improve fuel efficiency and reduce exhaust emissions. Engine sizes are becoming smaller but pressure and temperature inside combustion chambers are increasing. Therefore, research for fuel spray under high pressure and temperature conditions is important. A constant volume chamber which simulates high temperature and pressure likely to be found in diesel engines was developed in this study. Pressure and temperature were increased abruptly because of ignition of the pre-mixture in the constant volume chamber. Then pressure and temperature were gradually decreased due to the heat loss through the chamber wall. Fuel spray occurred when temperature and pressure were reached at the target condition. In this experiment, the temperature condition should be exactly defined to understand the relation between fuel evaporation and ambient temperature. A fast response thermocouple was developed and used to measure the temporal and spatial temperature distribution during the combustion process inside the combustion chamber. In the results, the core temperature was slightly higher than the bulk temperature calculated by the gas equation. Ed-note: do you want to say 'ideal gas equation'? This was attributed to the heat transfer loss through the chamber wall. The vertical temperature deviation was higher than the horizontal temperature deviation by 5% which resulted from the buoyancy effect.

• Spatial Information Research
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• v.21 no.1
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• pp.63-73
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• 2013

Geographic features are reflected in satellite images, which contain characteristic elements. Information on changes can be obtained through a comparison of images taken at different times. If multi-temporal images can be classified through the use of an unsupervised method, this is likely to improve the accuracy of image classification and contribute to various applications. A rule-based image classification algorithm for automatic processing without human involvement has been developed, but it must be verified that its results are not affected by imperfect elements. In this study, Landsat images of Jeju Island were used to carry out a rule-based image classification. The application results were examined for complex cases, including the presence of clouds in the images, different photographed times, and the type of target area, such as city, mountain, or field. The presence of clouds did not affect calculations, and appropriate classification rules were applied, depending on the different photographed times. The expansion of the urban areas of Jeju and the increase of facilities such as vinyl greenhouses in Seoguipo were identified. Furthermore, space information changes and accurate classifications for Jeju Island were obtained. With the goal of performing high-quality unsupervised classifications, measures to generalize and improve the methods employed were searched for. The findings of this study could be used in time-series analyses of images for various applications, including urban development and environmental change monitoring.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.3
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• pp.52-67
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• 2008

Recently, frequent occurrence of flash floods caused by climactic change has necessitated prompt and quantitative prediction of precipitation. In particular, the usability of rainfall radar that can carry out real-time observation and prediction of precipitation behavior has increased. Moreover, the use of distributed hydrological model that enables grid level analysis has increased for an efficient use of rainfall radar that provides grid data at 1km resolution. The use of distributed hydrologic model necessitates grid-type spatial data about target basins; to enhance reliability of flood runoff simulation, the use of visible and precise data is necessary. In this paper, physically based $Vflo^{TM}$ model and ModClark, a quasi-distributed hydrological model, were used to carry out flood runoff simulation and comparison of simulation results with data from Imjin River Basin, two-third of which is ungauged. The spatial scope of this study was divided into the whole Imjin River basin area, which includes ungauged area, and Imjin River basin area in South Korea for which relatively accurate and visible data are available. Peak flow and lag time outputs from the two simulations of each region were compared to analyze the impact of uncertainty in topographical parameters and soil parameters on flood runoff simulation and to propose effective methods for flood runoff simulation in ungauged regions.

• Journal of the Korean earth science society
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• v.32 no.6
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• pp.525-536
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• 2011

In any applications using various types of spatial data, it is very important to account for the scale differences among available data sets and to change the scale to the target one as well. In this paper, we propose to use a geostatistical downscaling approach based on vaiorgram deconvloution and block simulation to generate fine-scale categorical thematic maps from coarse-scale fraction data. First, an iterative variogram deconvolution method is applied to estimate a point-support variogram model from a block-support variogram model. Then, both a direct sequential simulation based on area-to-point kriging and the estimated point-support variogram are applied to produce alternative fine-scale fraction realizations. Finally, a maximum a posteriori decision rule is applied to generate the fine-scale categorical thematic maps. These analytical steps are illustrated through a case study of land-cover mapping only using the block fraction data of thematic classes without point data. Alternative fine-scale fraction maps by the downscaling method presented in this study reproduce the coarse-scale block fraction values. The final fine-scale land-cover realizations can reflect overall spatial patterns of the reference land-cover map, thus providing reasonable inputs for the impact assessment in change of support problems.

• Spatial Information Research
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• v.23 no.3
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• pp.35-44
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• 2015

Recently, the government aims to discover and provide services to citizens on the development strategy for activating the U-City. So, this study aims to offer a service discovery direction by analyzing the service issues and trends. The target is newspaper article about U-City Service from 2009 to 2014. Prepared 723 newspaper article for analysis. Next step is frequency analysis of keyword and used that result for Network analysis and measure of information. Network analysis can show result through "Degree Centrality", "Betweenness Centrality" and "Closeness Centrality". As a result, "Information", "IT", "Environment", "Technology", "Center" is higher than another. These 5 keywords are important factors for driving the U-City the past six years. Information measurement results, Already U-City were put an emphasis on building the infrastructure and able to identify a trend that provided the center of the public service. Those Service field are "Tour(2009)", "Crime prevention and Disaster Prevention(2010)", "Facility Management(2011)", "administration(2012)" and "Facility Management(2013, 2014)". Result of this study found implications what on citizen participation. So, services field on the existing infrastructure should be discovered and provided. Finally, this study can expected to be a reference in the local government planning for U-City.

• Journal of the Korean Society for Nondestructive Testing
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• v.35 no.2
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• pp.112-119
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• 2015

Photoacoustic microscopy is capable of providing high-resolution molecular images, and its spatial resolution is typically determined by ultrasonic transducers used to receive the photoacoustic signals. Therefore, ultrasonic transducers for photoacoustic microscopy (PAM) should have a high operating frequency, broad bandwidth, and high signal-reception efficiency. Polyvinylidene fluoride (PVDF) is a suitable material. To take full advantage of this material, the selection of the backing material is crucial, as it influences the center frequency and bandwidth of the transducer. Therefore, we experimentally determined the most suitable backing material among EPO-TEK 301, E-Solder 3022, and RTV. For this, three PVDF high-frequency single-element transducers were fabricated with each backing material. The center frequency and -6 dB bandwidth of each transducer were ascertained by a pulse-echo test. The spatial resolution of each transducer was examined using wire-target images. The experimental results indicated that EPO-TEK 301 is the most suitable backing material for a PAM transducer. This material provides the highest signal magnitude and a reasonable bandwidth because a large portion of the energy propagates toward the front medium, and the PVDF resonates in the half-wave mode.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.4
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• pp.35-41
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• 2015

Real estate appraisal methods include profit-based, cost-based and comparison-based measures. The purpose of this study is to scientifically quantify the comparison-based method mostly utilized in valuating real estate property among the appraisal methods. The comparison method is to estimate the value of target property from other previously-traded property cases by comparing and adjusting their temporal gap, spatial gap and space-time gap. In appraisal practices, this comparison method is used generally for land property. If based on previous transactions; prices, time point of transaction, region and individual factors were analyzed to valuate. If based on official land values; official value, time point, region and individual factors are analyzed. Of these, the individual factors are an important process of comparing individual characteristics where real estate appraisers' subjective assessment could intervene. Though appraisers, as experts make generally precise assessment, still, it is a subjective judgment open to difference between appraisers themselves, causing disputes from time to time. In this recognition, the study seeks to quantify such a subjective assessment of appraisers by running GIS analysis on individual factor components including street condition, access condition;and plotting condition.

• Journal of Korean Society of Disaster and Security
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• v.13 no.2
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• pp.53-63
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• 2020

In this study, the two-dimensional flow analysis model Hydro_AS-2D model was used to simulate the situation of flooding in Seongsangu and Uichang-gu in Changwon in the event of rising sea levels and extreme flooding, and the results were expressed on three-dimensional topography and the optimal evacuation path was derived using BIM technology. Climate change significantly affects two factors in terms of flood damage: rising sea levels and increasing extreme rainfall ideas. The rise in sea level itself can not only have the effect of flooding coastal areas and causing flooding, but it also raises the base flood level of the stream, causing the rise of the flood level throughout the stream. In this study, the rise of sea level by climate change, the rise of sea level by storm tidal wave by typhoon, and the extreme rainfall by typhoon were set as simulated conditions. The three-dimensional spatial information of the entire basin was constructed using the information of topographical space in Changwon and the information of the river crossing in the basic plan for river refurbishment. Using BIM technology, the target area was constructed as a three-dimensional urban information model that had information such as the building's height and location of the shelter on top of the three-dimensional topographical information, and the results of the numerical model were expressed on this model and used for analysis for evacuation planning. In the event of flooding, the escape route is determined by an algorithm that sets the path to the shelter according to changes in the inundation range over time, and the set path is expressed on intuitive three-dimensional spatial information and provided to the user.