• Journal of Korean Society on Water Environment
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• v.29 no.3
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• pp.365-376
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• 2013

The purpose of this study was to evaluate effects of spatio-temporal changes in land uses and rainfall magnitude using the Soil and Water Assessment Tool (SWAT). Prior of application of the model to real-world problem, the model should be calibrated and validated properly. In most modeling approaches, the validation process is done assuming no significant changes occurring at the study watershed between calibration and validation periods, which is not proper assumption for agricultural watersheds. If simulated results obtained with calibrated parameters match observed data with higher accuracy for validation period, this does not always mean the simulated result represents rainfall-runoff, pollutant generation and transport mechanism for validation period because temporal and spatial variables and rainfall magnitude are often not the same. In this study SWAT was applied to Mandae study watershed in Korea to evaluate effects of spatio-temporal changes in landuses using 2009 and 2010 crop data for each field at the watershed. The Nash-Sutcliffe model efficiency (NSE) values for calibration and validation with either 2009 or 2010 was evaluated and the NSE value for calibration with 2009 and calibration with 2010 were compared. It was found that if there is substantial change in land use and rainfall, model calibration period should be determined to reflect those changes. Through these approaches, inherent limitation of the SWAT, which does not consider changes in land uses over the simulation period, was investigated. Also, Effects of changes in rainfall magnitude during calibration process were analyzed.

• Economic and Environmental Geology
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• v.53 no.2
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• pp.147-157
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• 2020

Mass change in the Antarctic Ice Sheet(AIS) is the most important indicator of changes in Earth's climate system including global mean sea level rise that are largely affected by ongoing global warming. In this study, AIS mass variations are examined with satellite gravity data and outputs from a regional climate model. The analysis of gravity data shows that along the coastal region the Western AIS has experienced a continuous and significant ice loss while a slight increasing in the Eastern AIS during the study period (2002.08-2016.08). The temporal and spatial variations in ice mass changes are recovered by a regional climate model, but the recovered amplitudes are much smaller than those of observations. This under-estimation is remarkably resolved by modifying a base flow field for the ice discharge. The recovered estimates based on the ice-flow field can explain about 97% of the rate of mass change in observations before 2009. This implies that changes in ice flow dynamics along the coast line plays a pivotal role in regulating long-term budget of ice mass in AIS.

• Journal of Cadastre & Land InformatiX
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• v.47 no.1
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• pp.127-142
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• 2017

The purpose of this study is to examine the status of urbanization of Namyangju-Si from 2001 till 2008, analyze the correlation of the change of surrounding land use according to the change of accessibility and analyze the correlation of the change of land use. Based on the result from correlation analysis, I simulated from the view point of interactions between agents of land use and transportation accessibility by using MAS. I tried to forecast, based on space, the change of surrounding land use caused by the change of accessibility. I conducted landscape analysis by using a land registration map. Also, I conducted GIS analysis statistical analysis simulation analysis of traffic data, land use data in order to analyze the correlation of the change of surrounding land use according to the change of accessibility. I could find out a certain pattern that new roads and railroads causes the within 500m adjacent land to change into urban land use, which led me to construct a system through which land use changing phenomenon can be expected according to the change of accessibility. It is expected that it can make the best use of selecting the location where new transportation facilities are constructed.

• Journal of the Korean Association of Geographic Information Studies
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• v.23 no.2
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• pp.83-94
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• 2020

Busan Metropolitan City, a research site of this study, was promoted to a metropolitan city in 1995 with the implementation of the local autonomy system, and the overall change was made as it absorbed the surrounding areas to address the shortage of population and space. Twenty-five years after the introduction of the local autonomy system, it is necessary to diagnose whether balanced development of the entire city is being made in accordance with the reorganization of the metropolitan city in terms of spatial structure. In this study, changes in spatial structure and regional characteristics were analyzed by applying population potential, which means potential for future spatial interaction, in time and space. According to the analysis, the development was taking place around the center area and the sub-center established by the urban master plan, but Gangseo-gu and Gijang-gun, which were incorporated in the past, remained stagnant. In addition, it was shown that the spatial expansion of the city was suppressed by the green belt surrounding the city. However, in other regions where the green belt is located, the city has been expanded, which is different from Gijang-gun or Gangseo-gu, which was incorporated into the metropolitan city. Therefore, the cause of the decline in incorporated areas should not be limited to the institutional dimension of land use regulation. Growth management and balanced development plans will be necessary for the development of declining old downtowns and underdeveloped incorporated areas.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.1
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• pp.14-26
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• 2011

Surface currents were observed by high-frequency (HF) radars off the Keum River estuary from December 2008 to February 2009. The dataset of observed surface currents had data gaps due to the interference of electromagnetic waves and the deteriorating weather conditions. To fill the data gaps an optimal interpolation procedure was developed. The characteristics of spatial correlation in the surface currents off the Keum River estuary were investigated and the spatial data gaps were filled using the optimal interpolation. Then, the temporal and spatial distribution of the interpolated surface currents and the patterns of interpolation error were examined. The correlation coefficients between the surface currents in the coastal region were higher than 0.7 because tidal currents dominate the surface circulation. The sample data covariance matrix (C), spatially averaged covariance matrix with localization ($C^G_{sm}$) and covariance matrix fitted by an exponential function ($C_{ft}$) were used to interpolate the original dataset. The optimal interpolation filled the data gaps and suppressed the spurious data with spikes in the time series of surface current speed so that the variance of the interpolated time series was smaller than that of the original data. When the spatial data coverage was larger (smaller) than 70% of the region, the interpolation error produced by $C^G_{sm}$ ($C_{ft}$) was smaller compared with that by C.

• Journal of Wetlands Research
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• v.20 no.2
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• pp.124-130
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• 2018

This study was conducted to identify the characteristics of bird population dynamics using unmanned monitoring system in rice paddy. We compared the similarity of population dynamics of birds between unmanned monitoring system and field survey, and evaluated the spatial and temporal patterns of population dynamics of birds using the unmanned monitoring system. The monitoring using the system was conducted from January 1, 2014 to December 31, 2016 in Cheolwon, Dangjin, Buan, and Heanam. The images from the system were obtained at 10-min intervals from 6:00 to 20:00. The field survey was conducted once a month in Dangjin from January to December 2016. Total 91,980 images were obtained from the unmanned monitoring system. We extracted the number of individuals for herons, shorebirds, and waterfowl from the images. The population dynamics of waterbirds using the unmanned monitoring system were similar to that in field survey. Especially, population dynamics of herons was more similar than other waterbirds. It was identified that the population dynamics of herons using the unmanned monitoring system was different among the Cheolwon, Dangjin, Buan, and Heanam. Furthermore, the unmanned monitoring system was available on various time scale such as month, day, and minute. It is expected that long-term data storage using the unmanned monitoring system can be used to identify in detail and forecast the population dynamics of birds in rice paddy.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.3
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• pp.99-105
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• 2014

Since traffic accidents account for the highest proportion of the artificial disasters which occur in urban areas along with fire, more scientific an analysis on the causes of traffic accidents and various prevention measures against traffic accidents are needed. In this study, the research selected Jinju-si, which belongs to local small and medium-sized cities as a research target to analyze the characteristics of temporal and spacial distribution of traffic accidents by associating the data of traffic accidents, occurred in 2013 with the causes of traffic accidents and location information that includes occurrence time and seasonal features. It subsequently examines the spatial correlation between traffic accidents and the characteristics of urban space development according to the plans of land using. As a result, the characteristics of accident distribution according to the types of accidents reveal that side right-angle collisions (car versus car) and pedestrian-crossing accident (car versus man) showed the highest clustering in the density analysis and average nearest neighbor analysis. In particular, traffic accidents occurred the most on roads which connect urban central commercial areas, high-density residential areas, and industrial areas. In addition, human damage in damage conditions, clear day in weather condition, dry condition in the road condition, and three-way intersection in the road way showed the highest clustering.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.1
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• pp.26-41
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• 2012

This study investigates the time-space characteristics of intra-urban passenger flows in the Metropolitan Seoul area. In particular, we analyze the relationships between transit ridership and land use through the use of the subway passenger flow data obtained from the transit transaction databases. For this purpose, the strength of each subway station, i.e., the number of total in-coming and out-going passengers at each station, in the morning, afternoon, and evening, is calculated and visualized, which reflects urban land use patterns. Then the subway stations are classified into four groups via a hierarchical analysis of the in-coming and out-going passenger flows at 353 stations. Each group appears to have characteristic properties according to the region, e.g., residential areas and central business districts. This has been confirmed by the analysis which probes explicitly the relationship between the local socio-economic variables and station groups. This analysis, disclosing the inter-relationship between the subway network and urban land use, may be useful at various stages in urban as well as transportation planning, and provides analytical tools for a wide spectrum of applications ranging from impact evaluation to decision-making and planning support.

• Journal of Korean Society of societal Security
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• v.4 no.2
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• pp.57-64
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• 2011

Although it is uncertain that the cause of changed pattern of the natural disaster related to water (i.e. flood and drought) is due to excessive carbon dioxide yielded from economic activity or the increased number of sunspots, it is apparent that there have been unusual climate change that directly affects the water resource management. Due to such a frequent unusual weather activities, there have been increased natural disaster and the most direct and major reason is considered as climate change. As we see, the climate change necessarily causes social costs. Especially, the effects on the water resource due to flood and drought take the considerable part of such costs. Therefore, this study is basic work to develop a new economic analysis technique to be used in pursuing appropriate adaptation project in field of the amount of cost damage through analysis of the effects of the climate change on the water resource. The models appeared in many reports for cost assessment of climate change were various (e.g., PAGE, DICE, AIM, IMAGE, MERGE, and etc.) and this report summarizes general characteristics of each model. To assess the effects of climate change of the water management, we defined the field of the water management on climate change. The results help post-study in field of the climate change's social-economic effect assessment, can be employed for the prioritizing process of the national fund's investment.

• Journal of Music and Human Behavior
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• v.12 no.2
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• pp.19-36
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• 2015

The purpose of this study was to examine the effects of rhythmic auditory stimulation (RAS) on gait parameters, with and without the presence of a melody, for adolescents with traumatic brain injury (TBI). Three adolescents with TBI received a total of ten individual RAS training sessions. At pre and posttest, spatiotemporal parameters including cadence, velocity and kinematic parameters were measured using the VICON 370 Motion Analysis System. The results showed no significant difference in gait velocity between the two conditions, thus the presence of the melody condition did not impact the outcome of RAS gait training. On the other hand, all participants showed improvement in gait function after RAS training. The cadence, velocity, stride length, and symmetry were increased and the stride time was reduced after training. The motion analysis demonstrated that the movement patterns of hip and knee joints improved, as they were more similar to normal gait, which indicates that the walkings tance became more stable. The research findings indicate that rhythm is the primary factor in mediating gait functions via RAS training. This study also supports that RAS training can effectively improve the gait function for adolescents with TBI.