• Title/Summary/Keyword: temporal-spatial change

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Spatial Analyses and Modeling of Landsacpe Dynamics (지표면 변화 탐색 및 예측 시스템을 위한 공간 모형)

  • 정명희;윤의중
    • Spatial Information Research
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    • v.11 no.3
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    • pp.227-240
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    • 2003
  • The primary focus of this study is to provide a general methodology which can be utilized to understand and analyze environmental issues such as long term ecosystem dynamics and land use/cover change by development of 2D dynamic landscape models and model-based simulation. Change processes in land cover and ecosystem function can be understood in terms of the spatial and temporal distribution of land cover resources. In development of a system to understand major processes of change and obtain predictive information, first of all, spatial heterogeneity is to be taken into account because landscape spatial pattern affects on land cover change and interaction between different land cover types. Therefore, the relationship between pattern and processes is to be included in the research. Landscape modeling requires different approach depending on the definition, assumption, and rules employed for mechanism behind the processes such as spatial event process, land degradation, deforestration, desertification, and change in an urban environment. The rule-based models are described in the paper for land cover change by natural fires. Finally, a case study is presented as an example using spatial modeling and simulation to study and synthesize patterns and processes at different scales ranging from fine-scale to global scale.

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Projection of Future Changes in Drought Characteristics in Korea Peninsula Using Effective Drought Index (유효가뭄지수(EDI)를 이용한 한반도 미래 가뭄 특성 전망)

  • Gwak, Yongseok;Cho, Jaepil;Jung, Imgook;Kim, Dowoo;Jang, Sangmin
    • Journal of Climate Change Research
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    • v.9 no.1
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    • pp.31-45
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    • 2018
  • This study implemented the prediction of drought properties (number of drought events, intensity, duration) using the user-oriented systematical procedures of downscaling climate change scenarios based the multiple global climate models (GCMs), AIMS (APCC Integrated Modeling Solution) program. The drought properties were defined and estimated with Effective Drought Index (EDI). The optimal 10 models among 29 GCMs were selected, by the estimation of the spatial and temporal reproducibility about the five climate change indices related with precipitation. In addition, Simple Quantile Mapping (SQM) as the downscaling technique is much better in describing the observed precipitation events than Spatial Disaggregation Quantile Delta Mapping (SDQDM). Even though the procedure was systematically applied, there are still limitations in describing the observed spatial precipitation properties well due to the offset of spatial variability in multi-model ensemble (MME) analysis. As a result, the farther into the future, the duration and the number of drought generation will be decreased, while the intensity of drought will be increased. Regionally, the drought at the central regions of the Korean Peninsula is expected to be mitigated, while that at the southern regions are expected to be severe.

The improve of hemiplegic patients functional ambulation profile by forceful respiratory exercise (노력성 호흡운동을 통한 편마비환자의 기능적 보행지수 개선)

  • Kim Byung-jo;Bae Sung-soo;Hwang-bo Gak
    • The Journal of Korean Physical Therapy
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    • v.16 no.1
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    • pp.32-48
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    • 2004
  • The purpose of this study was to evaluate the change of functional ambulation profile(FAP) and temporal-spatial gait parameters in hemiplegic patient by forceful respiratory exercise. 28 Hemiplegic patients due to stroke was randomized in 3 groups, forceful expiratory training(FET), forceful inspiratory training(FIT) and control group. In the experimental groups, ordinary physical therapy with forceful expiratory training and forceful inspiratory training for 20 minutes duration 3 times per week for 6 weeks were respectively performed. In the control group, only ordinary physical therapy was done. FAP and temporal-spatial gait parameters was measured at before and after experiments. The results of this experimental study were as follows : 1. In comparison of FAP before and after experiment, the FAP was significantly increased in the FET and FIT group (p<.01). In comparison of difference of FAP among 3 groups, there was the significant difference between the FIT group and the control group (p<.05). 2. The results of temporal-spatial gait parameters are as follows : 1) In comparison of gait velocity before and after experiment, the gait velocity was significantly increased in the FET and FIT group (p<.05). In comparison of difference of the gait velocity among 3 groups, there was the significantly difference between the FIT group and the control group (p<.05). 2) In comparison of gait cadence before and after experiment, the gait cadence was significantly increased in FIT group (p<.05). In comparison of the difference of the gait cadence among 3 groups, there was no significant difference between the FIT group and the control group (p>.05). Based on these results, it is concluded that the forced respiratory exercise program for 6 weeks can be improve the FAP and temporal-spatial gait parameters in hemiplegic patients. Therefore, the forced respiratory exercise is useful to improve the walking ability in hemiplegic patients.

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Characteristics Change of Spatial and Temporal Parameters of Gait in Spastic Hemiplegic Patients by Reciprocal Inhibition (상호억제 기법에 의한 경직성 편마비 환자 보행의 공간적, 시간적 특성 변화)

  • Kim Jong-Soon;Lee Hyun-Ok;Ahn So-Youn;Koo Bong-Oh;Bae Sung-Soo
    • The Journal of Korean Physical Therapy
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    • v.16 no.4
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    • pp.59-79
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    • 2004
  • The purpose of this study was to determined the effects of reciprocal inhibition on spatial-temporal gait parameters in spastic hemiplegic patients through GaitRite system. The subjects were consisted 45 patients who had spastic hemiplegia due to stroke. All subjects randomly assigned to 3 group : manual reciprocal inhibition program group(manual group), neuromuscular electrical stimulation group(NMES group) and control group. The manual group received voluntary isometric contraction of pre-tibia muscle. The NMES group received neuromuscular electrical stimulation on tibialis anterior. The control group was not recieved any therapeutic intervention. Before and after experiments, spatial-temporal gait parameters and functional ambulatory profile was measure in all patients. The data of 30 patients who complete experimental course were statistically analysed. The results of this study were as following : 1. The percentage of change of functional ambulatory profile were markedly increased in manual group but statistically non significant(p>.01). 2. The percentage of change of gait velocity and cadence were markedly increased in manual group but statistically non significant(p>.01). 3. Asymmetry ratio of gait elements were more improved in manual group but statistically non significant(p>.01). 4. There were no statistical difference between pre-test and post-test with functional ambulatory profile, gait velocity, cadence and asymmetry ratios in NMES group(p>.01). 5. There were no statistical difference between pre-test and post-test with unctional ambulatory profile, gait velocity, cadence and asymmetry ratios in control group(p>.01). In conclusion, the present results revealed that reciprocal inhibition which produced by voluntary isometric contraction of pre-tibia muscle can be improved spatial-temporal gait parameters including functional ambulatory profile in hemiplegic patients. Therefore, reciprocal inhibition is useful to improve functional activities in hemiplegic patient. Further study should be done to analyze the effects of intervention duration of reciprocal inhibition, appropriate muscle contraction, optimal time to apply the reciprocal inhibition in more long period.

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Spatial Relationship of Suburb, Road and River in respect to Forest Canopy Density Change Using GIS and RS

  • Pantal, Menaka;Kim, Kye-Hyun
    • 한국공간정보시스템학회:학술대회논문집
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    • 2005.11a
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    • pp.257-270
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    • 2005
  • Many studies states that improperly uprising of infrastructure may cause leading the forest degradation and canopy reduction in many tropical forest of Asian countries. Other studies revealed that habitat destruction and fragmentation, edge effects, exotic species invasions, pollution are provoked by roads. Similarly, environmental effects of road construction in forests are problematic. Similarly, many researches have been indicated that roads have a far greater impact on forests than simply allowing greater access for human use. Moreover, people using river as means of transportation hence illegal logging and felling cause canopy depletion in many countries. Therefore, it is important to comprehend the study about spatial relation of road, river and suburb followed by temporal change of forest canopy phenomena. This study also tried to examine the effect of road, river and suburb in forest canopy density change of Terai forest of Nepal from you 1988 to 2001. So, Landsat TM88, 92 and 001 and FCD (Forest Canopy Density) mapper were used to perform the spatial .elation of canopy density change. ILWIS (Integrated Land and Water Information System) which is GIS software and compatible with remote sensing data was used to execute analysis and visualize the results. Study found that influence of distance to suburb and river had statistically significance influenced in canopy change. Though road also influenced canopy density much but didn't show a statistical relation. It can be concluded from this research that understanding of spatial relation of factors respect with canopy change is quite complex phenomena unless detail analysis of surrounding environment. Hence, it is better to carry out comprehensive analysis with other additional factors such as biophysical, anthropogenic, social, and institutional factors for proper approach of their effect on canopy change.

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Quantification of future climate uncertainty over South Korea using eather generator and GCM

  • Tanveer, Muhammad Ejaz;Bae, Deg-Hyo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.154-154
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    • 2018
  • To interpret the climate projections for the future as well as present, recognition of the consequences of the climate internal variability and quantification its uncertainty play a vital role. The Korean Peninsula belongs to the Far East Asian Monsoon region and its rainfall characteristics are very complex from time and space perspective. Its internal variability is expected to be large, but this variability has not been completely investigated to date especially using models of high temporal resolutions. Due to coarse spatial and temporal resolutions of General Circulation Models (GCM) projections, several studies adopted dynamic and statistical downscaling approaches to infer meterological forcing from climate change projections at local spatial scales and fine temporal resolutions. In this study, stochastic downscaling methodology was adopted to downscale daily GCM resolutions to hourly time scale using an hourly weather generator, the Advanced WEather GENerator (AWE-GEN). After extracting factors of change from the GCM realizations, these were applied to the climatic statistics inferred from historical observations to re-evaluate parameters of the weather generator. The re-parameterized generator yields hourly time series which can be considered to be representative of future climate conditions. Further, 30 ensemble members of hourly precipitation were generated for each selected station to quantify uncertainty. Spatial map was generated to visualize as separated zones formed through K-means cluster algorithm which region is more inconsistent as compared to the climatological norm or in which region the probability of occurrence of the extremes event is high. The results showed that the stations located near the coastal regions are more uncertain as compared to inland regions. Such information will be ultimately helpful for planning future adaptation and mitigation measures against extreme events.

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Analysis on Urban Sprawl and Landcover Change Using TM, ETM+ and GIS

  • Xiao, Jieying;Ryutaro, Tateishi;Shen, Yanjun;Ge, Jingfeng;Liang, Yanqing;Chang, Chunping
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.978-980
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    • 2003
  • This study explores the temporal and spatial features near 67years (1934 ?2001) and landcover change in last 14 years (1987-2001) in Shijiazhuang, China, based on 67-year time series data edited from historical maps, TM and ETM+ imageries by integrating GIS and remote sensing method. An index named Annual Growth Rate (AGR) is used to analyze the spatial features of urban sprawl, and Maximum Likelihood classification method is utilized to detect the land cover types change. At last, the relationship between urbanization and factors is analyzed.

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Spatial Downscaling of MODIS Land Surface Temperature: Recent Research Trends, Challenges, and Future Directions

  • Yoo, Cheolhee;Im, Jungho;Park, Sumin;Cho, Dongjin
    • Korean Journal of Remote Sensing
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    • v.36 no.4
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    • pp.609-626
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    • 2020
  • Satellite-based land surface temperature (LST) has been used as one of the major parameters in various climate and environmental models. Especially, Moderate Resolution Imaging Spectroradiometer (MODIS) LST is the most widely used satellite-based LST product due to its spatiotemporal coverage (1 km spatial and sub-daily temporal resolutions) and longevity (> 20 years). However, there is an increasing demand for LST products with finer spatial resolution (e.g., 10-250 m) over regions such as urban areas. Therefore, various methods have been proposed to produce high-resolution MODIS-like LST less than 250 m (e.g., 100 m). The purpose of this review is to provide a comprehensive overview of recent research trends and challenges for the downscaling of MODIS LST. Based on the recent literature survey for the past decade, the downscaling techniques classified into three groups-kernel-driven, fusion-based, and the combination of kernel-driven and fusion-based methods-were reviewed with their pros and cons. Then, five open issues and challenges were discussed: uncertainty in LST retrievals, low thermal contrast, the nonlinearity of LST temporal change, cloud contamination, and model generalization. Future research directions of LST downscaling were finally provided.

Analysis of Spatio-Temporal Patterns of Nighttime Light Brightness of Seoul Metropolitan Area using VIIRS-DNB Data (VIIRS-DNB 데이터를 이용한 수도권 야간 빛 강도의 시·공간 패턴 분석)

  • Zhu, Lei;Cho, Daeheon;Lee, Soyoung
    • Journal of Cadastre & Land InformatiX
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    • v.47 no.2
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    • pp.19-37
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    • 2017
  • Visible Infrared Imaging Radiometer Suite Day-Night Band (VIIRS-DNB) data provides a much higher capability for observing and quantifying nighttime light (NTL) brightness in comparison with Defense Meteorological Satellite-Operational Linescan System (DMSP-OLS) data. In South Korea, there is little research on the detection of NTL brightness change using VIIRS-DNB data. This study analyzed the spatial distribution and change of NTL brightness between 2013 and 2016 using VIIRS-DNB data, and detected its spatial relation with possible influencing factors using regression models. The intra-year seasonality of NTL brightness in 2016 was also studied by analyzing the deviation and change clusters, as well as the influencing factors. Results are as follows: 1) The higher value of NTL brightness in 2013 and 2016 is concentrated in Seoul and its surrounding cities, which positively correlated with population density and residential areas, economic land use, and other factors; 2) There is a decreasing trend of NTL brightness from 2013 to 2016, which is obvious in Seoul, with the change of population density and area of industrial buildings as the main influencing factors; 3) Areas in Seoul, and some surrounding areas have high deviation of the intra-year NTL brightness, and 71% of the total areas have their highest NTL brightness in January, February, October, November and December; and 4) Change of NTL brightness between summer and winter demonstrated a significantly positive relation with snow cover area change, and a slightly and significantly negative relation with albedo change.