• Journal of Korean Society of Transportation
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• v.22 no.3 s.74
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• pp.159-166
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• 2004

The capacity concept presented in the Highway Capacity Manual is for steady-state traffic flow assuming that there is no restriction in downstream flowing, which is traditionally used for planning, design, and operational analyses. In the congested traffic condition, the control objective should be to keep the congested regime from growing and to recover the normal traffic condition as soon as possible. In this control case, it is important to predict the spatial-temporal pattern of congestion evolution or dissipation and to estimate the throughput reduction according to the spatial-temporal pattern. In this context, the new concept of dynamic capacity for managing congested traffic is developed in terms of spatial-temporal evolution of downstream traffic congestion and in view of the 'input' concept assuming that flow is restricted by downstream condition rather than the 'output' concept assuming that there is no restriction in downstream flowing (e.g. the mean queue discharge flow rate). This new capacity is defined as the Maximum Sustainable Throughput that is determined based on the spatial-temporal evolution pattern of downstream congestion. And the spatial-temporal evolution pattern is estimated using the Newell's simplified q-k model.

• Journal of Korean Society for Geospatial Information Science
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• v.19 no.4
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• pp.3-12
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• 2011

Understanding of water sediment trends is an important part of water quality monitoring. Water quality variables change over time and space, and cannot be modeled or explained clearly by either temporal or spatial analysis alone. This research analysed the trends of temperature, pH levels and dissolved oxygen levels based on the sediment records and spatial data obtained in Lower Mekong Basin (LMB) during 1985-2005. Our aim is to evaluate spatio-temporal trends and graphical analyses using an Inverse Distance Weighting (IDW) interpolation method. The main results from this research can be summarized as follows. The maximum temperature and pH have been stable during the study period and the maximum dissolved oxygen has been increasing gradually until 2002. The minimum pH and dissolved oxygen have been changing in an unsteady trend during the period. A spatial analysis shows that the water temperature in this region has been increasing over time. The pH trend shows that it is decreasing during 1993-2005. Dissolved oxygen concentration has been increasing from 1989 onwards and stays in that track.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3B
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• pp.285-293
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• 2010

Soil moisture is a key factor to control the exchange of water and energy between the surface and the atmosphere. In recent, many researches for spatial and temporal variability analyses of soil moisture have been conducted. In this study, we analyzed the spatio-temporal variability of soil moisture in Walnut Gulch Experimental Watershed, Arizona, U.S. during the Soil Moisture Experiment 2004 (SMEX04). The spatio-temporal variability analyses were performed to understand sensitivity of five observation sites with precipitation and relationship between mean soil moisture, and its standard deviation and coefficient of variation at the sites, respectively. It was identified that log-normal distribution was superior to replicate soil moisture spatial patterns. In addition, precipitation was identified as a key physical factor to understand spatio-temporal variability of soil moisure based on the temporal stability analysis. Based on current results, higher spatial variability was also observed which was agreed with the results of previous studies. The results from this study should be essential for improvement of the remotely sensed soil moisture retrieval algorithm.

• Journal of the Korean Data and Information Science Society
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• v.17 no.4
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• pp.1181-1190
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• 2006

Statistical analyses for spatial data are important features for various types of fields. Spatial data are taken at specific locations or within specific regions and their relative positions are recorded. Lattice data are synoptic observation covering an entire spatial region, like cancer rates corresponding to each county in a state. Until now, the echelon analysis has been applied only to univariate spatial data. As a result, it is impossible to detect the hotspots on the multivariate spatial data In this paper, we expand the spatial data to time series structure. And then we analyze them on the time space and detect the hotspots. Echelon dendrogram has been made by piling up each multivariate spatial data to bring time spatial data. We perform the structural analysis of temporal spatial data.

• Journal of Veterinary Science
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• v.25 no.1
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• pp.13.1-13.9
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• 2024

Background: Foot-and-mouth disease (FMD) is a highly contagious viral disease in livestock that has tremendous economic impact nationally. After multiple FMD outbreaks, the South Korean government implemented a vaccination policy for efficient disease control. However, during active surveillance by quarantine authorities, pig farms have reported an insufficient antibody positivity rate to FMD. Objective: In this study, the spatial and temporal trends of insufficiency among pig farms were analyzed, and the effect of the number of government veterinary officers was explored as a potential preventive factor. Methods: Various data were acquired, including national-level surveillance data for antibody insufficiency from the Korea Animal Health Integrated System, the number of veterinary officers, and the number of local pig farms. Temporal and geographical descriptive analyses were conducted to overview spatial and temporal trends. Additionally, logistic regression models were employed to investigate the association between the number of officers per pig farm with antibody insufficiency. Spatial cluster analysis was conducted to detect spatial clusters. Results: The results showed that the incidence of insufficiency tended to decrease in recent years (odds ratio [OR], 0.803; 95% confidence interval [95% CIs], 0.721-0.893), and regions with a higher density of governmental veterinary officers (OR, 0.942; 95% CIs, 0.918-0.965) were associated with a lower incidence. Conclusions: This study implies that previously conducted national interventions would be effective, and the quality of government-provided veterinary care could play an important role in addressing the insufficient positivity rate of antibodies.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.4
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• pp.461-477
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• 2022

We investigated the community structure and performed detailed characterization of fish larvae assemblages collected from the southern coast of Korea in the spring and summer of 2021. The total abundance of fish larvae varied from 193.6 to 1,915.6 ind. 10 m^-3. The species were distributed across 10 orders with 23 families, and 41 taxa. The dominant taxa were Gobiidae spp., Engraulis japonicus, Nibea albiflora, Sebastiscus spp., Callionymus valenciennei, Pennahia argentata, Sebastes thompsoni, Parablennius yatabei, and Platycephalus indicus. Engraulis japonicus individuals were collected from April to August and their presence contributed greatly to the total abundance of fish larvae. The total number and abundance of species peaked in early summer and the Shannon-Weaver index was in the range 0.11-1.49. Redundancy analyses revealed that the major environmental factors affecting the fish larvae assemblage differed according to the dominant taxa. Water temperature, zooplankton density, and Paracalanus parvus s. l. density were the key factors affecting the spatial and temporal distribution of fish larvae in the southern coast of Korea in spring and summer.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.471-472
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• 2010

In this study, a new modeling framework for predicting temperature and structural behaviors of structures under fire condition is proposed. The proposed modeling framework including fire simulation, heat transfer and structural analysis is applied to simulate fire tests performed on the steel-concrete composite structures in Cardington, UK, for model validations. Good predictions are shown for spatial-temporal temperatures and deflections of fire-damaged steel-concrete structures.

• Physical Therapy Korea
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• v.22 no.2
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• pp.1-10
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• 2015

The common features of walking in patients with stroke include decreased gait velocity and increased asymmetrical gait pattern. The purpose of this study was to identify important factors related to impairments in gait velocity and asymmetry in chronic stroke patients. The subjects were 30 independently ambulating subjects with chronic stroke. The subjects' impairments were examined, including the isokinetic peak torque of knee extensors, knee flexors, ankle plantarflexors, and ankle dorsiflexors. Passive and active ranges of motion (ROM) of the ankle joint, ankle plantarflexor spasticity, joint position senses of the knee and ankle joint, and balance were examined together. In addition, gait velocity and temporal and spatial asymmetry were evaluated with subjects walking at their comfortable speed. Pearson correlations and multiple regressions were used to measure the relationships between impairments and gait speed and impairments and asymmetry. Regression analyses revealed that ankle passive ROM and peak torque of knee flexors were important factors for gait velocity ($R^2=.41$), while ankle passive ROM was the most important determinant for temporal asymmetry ($R^2=.35$). In addition, knee extensor peak torque was the most significant factor for gait spatial asymmetry ($R^2=.17$). Limitation in ankle passive ROM and weakness of the knee flexor were major contributors to slow gait velocity. Moreover, limited passive ROM in the ankle influenced the level of temporal gait asymmetry in chronic stroke patients. Our findings suggest that stroke rehabilitation programs aiming to improve gait velocity and temporal asymmetry should include stretching exercise for the ankle joint.

• Journal of Broadcast Engineering
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• v.12 no.2
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• pp.93-101
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• 2007

In heterogeneous networks SVC (Scalabile Video Coding) will be used for IPTV service. This paper analyses how to determine the optimal inter-layer reference scheme according to final level to be displayed in hybrid scalable coding which consists of spatial, quality and temporal layer. It determines where to stop layering quality layer stacks in lower spatial layer according to the relationship between noise induced by loss of high frequency component eliminated by filter in order to get rid of aliasing when spatial layering is processed and noise induced by quantization when quality layering is processed. This paper shows the choice of the level of layering between spatial and quality to get better coding efficiency and then presents what is needed for determining it.

• Journal of Fisheries and Marine Sciences Education
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• v.24 no.2
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• pp.333-345
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• 2012

NOAA/AVHRR, Topex/Poseidon, and Jason-1 data were used to analyze sea surface temperatures and thermal fronts in the North East Asia Seas. Temporal and spatial analyses were based on data from 1993 to 2008. The amplitude and phase for the annual mode on SL and SST were investigated with harmonic analysis. The geographical distribution of amplitudes for comparison of SL and SST are slightly reverse in southwest-northeast tilted direction. The time series analysis conducted on the entire researched area presented consistent pattern. Peak of Sea Level was presented 1~2 months after the peak of the surface sea temperature was shown. This explains that Sea Level change occurs after the generation of surface sea temperature change in sea. The Sobel edge detection method delineated four fronts. Thermal fronts generally occurred over steep bathymetric slopes. Annual amplitudes and phases were bounded within these frontal areas.