• 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 Biomedical Engineering Research
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• v.28 no.5
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• pp.636-646
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• 2007

Adequate postural control depends on the spatial and temporal integration of vestibular, visual, and somatosensory information. Especially, the musculoskeletal function is essential to maintain the postural control. The experimental studies was performed on the muscular activities in the lower extremities during maintaining and moving exercises on an unstable platform with Magneto Rheological(MR) dampers. The unstable platform of the developed system was controlled by electric currents to the MR dampers. A subject executed the maintaining and moving exercises which are presented through the display monitor. The electromyographies of the eight muscles in lower extremities were recorded and analyzed in the time and the frequency domain: the muscles of interest were rectus femoris(RF), biceps femoris(BF), tensor fasciae latae(TFL), vastus lateralis(VL), vastus medialis(VM), gastrocnemius(Ga), tibialis anterior(TA), Soleus(So). The experimental results showed that the muscular activities differed in the four moving exercises and the nine maintaining exercises. For the anterior-posterior pattern, the TA showed highest activities; for the left-right pattern, the TFL; for the 45, $-45^{\circ}$ pattern, the TFL and TA. Also, the rate of the increase in the muscular activities were affected by the condition of the unstable platform with MR dampers for the maintaining and moving exercises. The experimental results suggest that the choice of different maintaining and moving exercises could selectively train different muscles in various intensity. Futhermore, the findings suggested that the training using this system can improve the ability of postural control.

• Journal of Korean Society for Quality Management
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• v.48 no.2
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• pp.241-256
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• 2020

Purpose: Certain places in Seoul such as Shinchon, Hongdae, and Gangnam, often suffer from sudden overflow of mobile population which can cause serious safety problems. This study suggests the application of spatial CUSUM control chart in monitoring areal population mobility data which is recently provided by Seoul metropolitan government. Methods: Monitoring series of standardized local Moran's I enables one to detect spatio-temporal out-of-control status based on the accumulation of past patterns. Moreover, we visualize such pattern map for more intuitive comprehension of the phenomenon. As a case study, we have analyzed the female mobility population aged 25 to 29 appeared in 51 Jipgyegu near Hongik university on fridays from January, 2017 to June, 2018. They are validated by exploring related articles and through local due diligence. Results: The results of the analysis provide insights in figuring out if the change of the mobility population is short-term by particular incident or long-term by spatial alteration, which allows strategic approach in constructing response system. Specific case near popular downtown near Hongik University has shown that newly opened hotels, shops of global sports brand and franchise bookstores have attracted young female population. Conclusion: We expect that the results of our study contribute to planning effective distribution of administrative resources to prepare against drastic increase in floating population. Furthermore, it can be useful in commercial area analysis and age/gender specific marketing strategy for companies.

• The Journal of the Society of Stroke on Korean Medicine
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• v.14 no.1
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• pp.90-101
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• 2013

■ Objectives The goal of this study was to observe the gait patterns from a patient with Parkinson disease under three different walking speeds. ■ Methods The patient walked on a treadmill and we measured gait parameters using a treadmill gait analysis system for 2 minutes. The Parkinson patients walked under three different conditions, first, at the preferred walking speed, second, at slower speed than the preferred walking speed, and, third, at faster speed than the preferred walking speed. ■ Results In terms of temporal gait parameters, as speed of treadmill increased, stance phase and total double support decreased, and swing phase increased. In terms of spatial parameters, as speed of treadmill increased, step and stride length increased. In terms of kinetic parameters, max pressure increased as speed of treadmill increased. ■ Conclusion According to different walking speeds, some gait parameters of spatiotemporal and kinetic was changed.

• The Journal of the Acoustical Society of Korea
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• v.43 no.1
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• pp.1-8
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• 2024

For measuring the performance of passive sonars, we usually consider the maximum Detection Range (DR) under the environment and system parameters in operation. In shallow water, where sound waves inevitably interacts with sea surface or bottom, detection generally maintains up to the maximum range. In deep water, however, sound waves may not interact with sea surface or/and bottom, and thus there may exist shadow zones where sound waves can hardly reach. In this situation, DR alone may not completely define the performance of each sonar. For complete description of sonar performance, we employ the concept 'Robustness Of Detection (ROD)'. In the coastal region of the East Sea, the spatial variations of water masses have close relations with DR and ROD, where the two parameters show reverse spatial variations in general. The spatial and temporal analysis of the temperature by employing the Empirical Orthogonal Function (EOF) shows that the 1-st mode represents typical pattern of seasonal variation and the 2-nd mode represents strength variations of mixed layers and currents. The two modes are estimated to explain about 92 % of the variations. Assuming two types of targets located at the depths of 5 m (shallow) and 100 m (deep), the passive sonar performance (DR) gives high negative correlations (about -0.9) with the first two modes. Most of temporal variations of temperature occur from the surface up to 200 m in the water column so that when we assume a target at 100 m, we can expect detection performance of little seasonal variations with passive sonars below 100 m.

• Journal of the Korean Association of Geographic Information Studies
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• v.3 no.4
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• pp.73-86
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• 2000

This study focused on extracting an efficient method in the fruit cropping distribution mapping with various classification methods using multi-temporal satellite images and Geographic Information Systems(GIS). For this study, multi-temporal Landsat TM images, in observation data and existing fruit cropping area statistics were used to compare and analyze the properties of fruit cropping and seasonal distribution per classification method. As a result, this study concludes that Maximum Likelihood Method with earlier autumn satellite image was most efficient for the fruit cropping mapping using Landsat TM image. In addition, it was clarified that cropping area per administrative boundary was prepared and distribution pattern was identified efficiently using GIS spatial analysis.

• Journal of Korea Water Resources Association
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• v.39 no.7 s.168
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• pp.605-615
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• 2006

In order to analyze movement of soil moisture, Time Domain Reflectometry(TDR) with multiplex system has been installed at the Bumreunsa hillslope of Sulmachun Watershed to configure spatial-temporal variation pattern considering seasonal characteristic. An intensive surveying was performed to build a refined digital elevation model(DEM) and flow determination algorithms with inverse surveying have been applied to establish an efficient soil moisture monitoring system. Soil moisture data were collected through an intensive and long term monitoring 380 hrs in November of 2003 and 1037 hrs in May and June of 2004. Soil moisture data shows corresponding variation characteristics of soil moisture on the up slope, buffer, main channel zones of the hillslope which were classified from terrain analysis. Measured soil moisture data were discussed in conjunction with flow characteristic through terrain analysis. Regardless season, immediate responses of soil moisture about rainfall looks similar but recession and recharge are primary characteristics of intermediate soil moisture variation for spring to summer and fall to winter season, respectively.

• Korean Journal of Remote Sensing
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• v.31 no.2
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• pp.51-64
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• 2015

We improved the MODerate resolution Imaging Spectroradiometer (MODIS) land cover map over the Asia-Oceania region through the reclassification of the misclassified pixels. The misclassified pixels are defined where the number of land cover types are greater than 3 from the 12 years of MODIS land cover map. The ratio of misclassified pixels in this region amounts to 17.53%. The MODIS Normalized Difference Vegetation Index (NDVI) time series over the correctly classified pixels showed that continuous variation with time without noises. However, there are so many unreasonable fluctuations in the NDVI time series for the misclassified pixels. To improve the quality of input data for the reclassification, we corrected the MODIS NDVI using Correction based on Spatial and Temporal Continuity (CSaTC) developed by Cho and Suh (2013). Iterative Self-Organizing Data Analysis (ISODATA) was used for the clustering of NDVI data over the misclassified pixels and land cover types was determined based on the seasonal variation pattern of NDVI. The final land cover map was generated through the merging of correctly classified MODIS land cover map and reclassified land cover map. The validation results using the 138 ground truth data showed that the overall accuracy of classification is improved from 68% of original MODIS land cover map to 74% of reclassified land cover map.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.5
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• pp.333-342
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• 2012

We studied the characteristics of spatial distribution of global wave height and carried out the modelsensitivity test by changing the input field, model resolution and physical factor (effective wind factor) since the spatial and temporal resolution in wind wave forecasting is one of most important factors. Comparisons among the different cases, and also between model, buoy and satellite data have been made. As a results of the wind-wave model run using the high resolution wind field, the bias of significant wave height showed the positive tendency and the Root-Mean Square Error(RMSE) was a bit decreased based on the comparison with buoy data. When the model resolution was changed to higher, the bias and RMSE was increased, and as the effective wind factor was smaller than default value(= 1.4) the bias and RMSE showed also decreasing pattern.

• Korea Real Estate Review
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• v.27 no.4
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• pp.21-34
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• 2017

In this study, we defined abandoned vacant housing, as well as analyzed where and how the vacancies occurred. The temporal range of this study is 2005 and 2010, while the spatial range is nationwide. The minimum unit of space for the analysis is city district. First, we suggested that in the rural areas, it is necessary to manage an aged detached housing, while in the urban areas, it is necessary to manage aged apartments in order to prevent a large amount of old apartment buildings from becoming an abandoned vacant houses. Second, we proposed to select and manage the priority area in the empty area management. Finally, in the areas where other vacant houses are populated, the abandoned housing problem should be discussed with different measures from a long-term point of view in terms of population movement, population decline, and aging population.