• Advances in nano research
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• v.12 no.3
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• pp.319-336
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• 2022

Evaluating the temporal and spatial changes in the ecosystem service value (ESV) of the Sanjiangyuan Nature Reserve is important for understanding the impact of human activities on natural ecosystem and guiding ecosystem restoration and environmental pollution control. In this study, remotely sensed land-cover data and the equivalent factor method were used to analyze the spatiotemporal evolution characteristics of the ESV in Sanjiangyuan Nature Reserve from 1992 to 2015, and regression analysis was employed to determine the factors driving changes in the ESV. The results show that grassland was the main type of ecosystem in the study area, and the transformation of grassland into bare areas was the primary change in land cover. Additionally, the ESV in the study area first decreased and then increased, with an annual growth rate of 0.69%. The ESV mainly increased in the north of the Yellow River's source area, and mainly decreased in the northwest of the Yangtze River's source area. Finally, the gross output value of agriculture, urbanization rate and proportion of secondary industry were found to be the main factors driving the ESV in the study area.

• Journal of Environmental Impact Assessment
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• v.15 no.1
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• pp.45-52
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• 2006

The purpose of this study is to assess spatiotemporal variation of coastal water quality according to time and location changes. For this we developed numerical marine trophic index base on four water quality components (chlorophyll, suspended solids, dissolved inorganic nitrogen and phosphorus) and applied this index to the water quality data measured in the korean coastal zone for the 7-years period from 1997 to 2003. Water quality data are obtained only at selected sites even though they are potentially available at any location. Therefore, in order to estimate spatial variation of coastal water quality, it is necessary to estimate the unknown values at unsampled locations based on observation data. In this study, we used IDW (Inverse Distance Weighted) method to predict water quality components at unmeasured locations and applied marine trophic index to predicted values obtained by IDW interpolation. The results of this study indicate that marine trophic index and spatial interpolation are useful for understanding spatiotemporal characteristics of coastal water quality.

• 한국공간정보시스템학회:학술대회논문집
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• 2004.12a
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• pp.81-88
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• 2004

GIS (geographic information system) applications increasingly require the representation of geospatial objects with fuzzy extent and querying of time-varying information. In this paper, we Introduce a FSTDB (fuzzy spatiotemporal database) to represent and manage states and events causing changes of dynamic fuzzy objects using fuzzy set theory. We also propose the algorithms for the operators to be included in a GIS to make it able to answer queries depending on fuzzy predicates during a time interval and a method to identify the development process of objects during a certain period based on the designed database. They can be used in application areas handling time-varying geospatial data, including global change (as in climate or land cover change) and social (demographic, health, ect.) application.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.78-81
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• 2003

The present study illustrates a method for monitoring the urban vegetation around Shaoxing city, Monitoring spatiotemporal changes in urban areas will become increasingly important as the number and proportion of urban residents continues to increase. The synoptic view of urban land cover provided by satellite and airborne sensors is an important complement to in situ measurements of physical, environmental and socioeconomic variables in urban settings. The results obtained have revealed a notable change in the vegetation cover in and around the City premises. In this study, we discussed methodology for measurement of urban vegetation and vegetation distributions based on band ratioing in Shaoxing city using Land sat TM imageries. A systematic analysis of the spatiotemporal dynamics of vegetation in urban areas is required to ensure a healthy sustainable environment.

• Journal of the Korean Society of Physical Medicine
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• v.15 no.3
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• pp.117-125
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• 2020

PURPOSE: Aging causes changes in the postural alignment and gait due to changes in the nervous and musculoskeletal systems. On the other hand, the relationship between the changes in posture alignment and gait is unclear. This study examined the relationship between the postural alignment and spatiotemporal gait parameters in Korean elderly women. METHODS: Thirty-two-healthy elderly women participated in this study. All subjects were assessed for their posture alignment and gait ability. Stepwise multiple linear regression was performed to determine to what extent the postural alignments could explain the spatiotemporal gait parameters. RESULTS: Coronal head angle was moderately correlated with the velocity (r = -.51), normalized velocity (r = -.46) and gait-stability ratio (r = .58) (p < .05). The trunk angle was moderately correlated with the normalized velocity (r = -.32) and gait-stability ratio (r = .32) and weakly correlated with the velocity (r = -.28) (p < .05). The coronal shoulder angle was moderately correlated with the swing phase (r = -.57), stance phase (r = .56), single limb stance (r = -.56) and double limb stance (r = .51) (p < .05). The coronal head angle and trunk angle accounted for 36% of the variance in velocity, 33% variance in normalized velocity and 46% variance in the gait-stability ratio (p < .05). The coronal shoulder angle accounted for 32% variance in the swing phase, 32% variance in the stance phase, 31% variance in the single limb stance and 26% variance in the double limb stance (p < .05). CONCLUSION: Changes in posture alignment in elderly women may serve as a biomarker to predict a decrease in walking ability due to physical aging.

• Journal of Ocean Engineering and Technology
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• v.21 no.6
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• pp.59-63
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• 2007

This study discusses the spatiotemporal characteristics of the geomorphological changes in Gwangyang Bay. In this study, we analyzed four aerial photos and nautical charts. The geomorphological changes that have occurred over time were identified using an MGIS (Marine geographic information system) overlay analysis. As a result, we were able to identify the geomorphological changes that have resulted from the coastal development and fairway dredging of Gwangyang Bay. This paper demonstrates that the marine geographic information system can be effective in monitoring the geomorphological changes in coastal zones.

• Journal of Biomedical Engineering Research
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• v.28 no.2
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• pp.258-264
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• 2007

Spatiotemporal changes of brain rhythmic activity at a certain frequency have been usually monitored in real time using scalp potential maps of multi-channel electroencephalography(EEG) or magnetic field maps of magnetoencephalography(MEG). In the present study, we investigate if it is possible to implement a real-time brain activity monitoring system which can monitor spatiotemporal changes of cortical rhythmic activity on a subject's cortical surface, neither on a sensor plane nor on a standard brain model, with a high temporal resolution. In the suggested system, a frequency domain inverse operator is preliminarily constructed, considering the individual subject's anatomical information, noise level, and sensor configurations. Spectral current power at each cortical vertex is then calculated for the Fourier transforms of successive sections of continuous data, when a single frequency or particular frequency band is given. An offline study which perfectly simulated the suggested system demonstrates that cortical rhythmic source changes can be monitored at the cortical level with a maximal delay time of about 200 ms, when 18 channel EEG data are analyzed under Pentium4 3.4GHz environment. Two sets of artifact-free, eye closed, resting EEG data acquired from a dementia patient and a normal male subject were used to show the feasibility of the suggested system. Factors influencing the computational delay are investigated and possible applications of the system are discussed as well.

• PNF and Movement
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• v.11 no.1
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• pp.63-68
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• 2013

Purpose : The purpose of this study was to examine changes in spatiotemporal gait parameters(STGPs) in healthy adults before and after a immediate intervention of a Mulligan taping program(MTP). Methods : A total of 12 healthy adults(mean age, 20.82 years; age range, 19-24 years) participated in the study. performance was assessed by recording changes in the STGPs using GaitRite. comparisons of changes in the STGPs at pre-intervention and at dischange were analyzed using the Wilcox signed rank test and Mann-Whithney U test. Results : There was a significant improvement in the outcome measures of STGPs(stride length, velocity) after immediate of MTP(p<0.05). However, no significant different pre-test and post-test step width, toe angle(p>0.05). Conclusion : Participants in a MTP improves STGPs, thereby increasing the ability of healthy adults to maintain gait. MTP appears to be a safe and efficacious, noninvasive treatment modality for patients with knee joint disease.

• Journal of Environmental Impact Assessment
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• v.6 no.1
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• pp.55-66
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• 1997

This study summarizes the use of satellite data to detect the change of southwestern coastal wetlands in Korea. The images used for this study were two Landsat Thematic Mapper(TM) images (June 12, 1984 & June 2, 1992). TM images were used to classify such different types of wetlands as aquatic bed, nonaquatic bed and other land use in the region. Then it, was possible to a) determine the status of wetlands using image classification products, and b) detect the changes of various types of wetlands influenced by both human and nature. The results from spatiotemporal analysis showed that approximately 120 lad of coastal wetlands were lost from the year of 1984 to 1992. 71 % of the lost wetlands were converted to the reclaimed land. This loss of wetlands has been causing the profound environmental impacts. It has been successfully proved that satellite data are very effective for spatiatemporal change analysis, especially for that of coastal wetlands.

• Journal of Environmental Science International
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• v.29 no.5
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• pp.531-539
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• 2020

To understand the composition, quantity, and quality of Suspended Particulate Organic Matter (SPOM) in the Gangneung Namdae Stream, Korea, we examined spatiotemporal variations in water temperature, salinity, chlorophlly a (Chl a), Particulate Organic Carbon (POC) and nitrogen (PON), and carbon stable isotope (δ¹³C) of SPOM at six stations in June (pre-monsoon), July (monsoon), and September (post-monsoon) 2017. With increasing precipitation, the average POC and C/N values increased significantly in July than in June. In September, the values decreased with decreasing precipitation. The δ¹³C values showed irregular spatiotemporal fluctuations among the stations and periods, thereby suggesting a greater contribution of autochthonous organic matter to the pool of SPOM than that of allochthonous organic matter derived from upstream. In addition, the large and irregular changes in POC, C/N ratio, C:Chl a, and δ¹³C compared to that of PON were observed for all periods among the stations, indicating a serial discontinuity of the stream. Our results suggest that the Gangneung Namdae Stream is significantly influenced by the increase in freshwater discharge caused by heavy rainfalls during the summer monsoon and post-monsoon periods.