• Title/Summary/Keyword: temporal correlation

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Spatio-temporal Distribution of Sand Crab Ovalipes punctatus Larvae in the Southern Sea of Korea (한국 남부 해역에 출현하는 깨다시꽃게(Ovalipes punctatus) 유생의 시·공간적 분포)

  • Hyeon Gyu Lee;Hwan-Sung Ji;Seung Jong Lee;Youn Hee Choi
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.56 no.4
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    • pp.558-568
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    • 2023
  • The spatio-temporal distribution of the sand crab Ovalipes punctatus larvae was investigated in the Korean waters in 2019. Sea surface temperature (SST) was the lowest in February and highest in September. Sea surface salinity (SSS) was the lowest in September and highest in March. Further, sea surface chlorophyll a (SSC) was the highest in September. Larvae were distributed in the South Sea and coastal area of Jeju Island from April to June, and the abundance was the highest in May. The spatio-temporal distribution analysis suggested that larval groups showed a tendency to be dispersed over a wider area as the larvae developed, due to the increase in their swimming ability. The correlation analysis between environmental factors and larval density suggested that larvae appeared in the SST range 11.8-20.9℃ and SSS range 31.5-35.3 psu. The Megalopal stage appeared in a wider range of SST and SSS than other larval stages, possibly due to the increased environmental tolerance before settlement. Results of redundancy analysis (RDA) and Spearman's rank correlation analysis between the larval density by developmental stages and the environmental factors suggested that SST showed a positive correlation and SSC showed a negative correlation in the later stage.

Utility of Brain Computed Tomography in Detecting Fractures of the Temporal Bones Correlated with Patterns of Fracture on High-Resolution Computed Tomography (고해상도 전산화 단층촬영에서 확인된 골절 유형에 따른 측두골 골절의 진단에서 뇌전산화 단층촬영의 유용성)

  • Kwon, Bong-Seok;Shin, Dong-Hyuk;Choi, Pil-Cho;Han, Sang-Kuk;Lee, Jeong-Hun;Song, Hyoung-Gon
    • Journal of Trauma and Injury
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    • v.23 no.1
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    • pp.38-42
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    • 2010
  • Purpose: The clinical utility of brain computed tomography (CT) in detecting temporal bone fracture is not well established. We performed this study to determine the utility of brain computed tomography (CT) in detecting fractures of the temporal bones in correlation with fracture patterns. We used high resolution computed tomography (HRCT) as the gold standard for diagnosing temporal bone fracture and its pattern. Methods: From January 2007 to December 2009, patients who underwent both brain CT and HRCT within 10 days of head trauma were investigated. Among them, 58 cases of temporal bone fracture confirmed by HRCT were finally included. Fracture patterns (transverse or non-transverse, otic capsule sparing or otic capsule violating) were determined by HRCT. Brain CT findings in correlation with fracture patterns were analyzed. Results: Among 58 confirmed cases of temporal bone fracture by HRCT, 14 cases (24.1%) were not detected by brain CT. Brain CT showed a significantly lower ability to detect temporal bone fracture with transverse component than without transverse component (p=0.020). Moreover, brain CT showed lower ability to detect otic capsule violating pattern than otic capsule sparing pattern (p=0.015). Among the 14 cases of temporal bone fracture that were not detected by brain CT, 4 cases lacked any objective physical findings (facial palsy, hemotympanum, external auditory canal bleeding) suggesting fractures of the temporal bones. Conclusion: Brain CT showed poor ability to detect temporal bone fracture with transverse component and otic capsule violating pattern, which is associated with a poorer clinical outcome than otic capsule sparing pattern. Routine use of HRCT to identify temporal bone fracture is warranted, even in cases without evidence of temporal bone fracture on brain CT scans or any objective physical findings suggestive of temporal bone fracture.

Possible Causes for the Temporal Variations of 3-micron Hydrocarbon Emissions in the Auroral Regions of Jupiter

  • Kim, Sang Joon
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.55.1-55.1
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    • 2019
  • Recently, temporal variations of the 3-micron emissions of methane and ethane have been detected in the auroral regions of Jupiter observed from Gemini North (Kim et al. 2019, in preparation). These temporal variations of 3-micron hydrocarbon emissions in the auroral regions can be caused by the following phenomena: temporal variations of temperatures, mixing ratios, auroral particle bombardments and Joule heatings, and the combinations of these. Although we are not able to quantitatively determine the cause of the temporal variations at this moment, we will present the following quantitative discussions: thermal influences on the 3-micron emissions, global mixing ratio distributions of the hydrocarbon molecules, and energy distributions of auroral particles penetrating the hydrocarbon layers. We will also present a possible correlation between the temporal variations of the 3-micron emissions and solar wind activities.

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Global Disparity Compensation for Multi-view Video Coding

  • Oh, Kwan-Jung;Ho, Yo-Sung
    • Journal of Broadcast Engineering
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    • v.12 no.6
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    • pp.624-629
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    • 2007
  • While single view video coding uses the temporal prediction scheme, multi-view video coding (MVC) applies both temporal and inter-view prediction schemes. Thus, the key problem of MVC is how to reduce the inter-view redundancy efficiently, because various existing video coding schemes have already provided solutions to reduce the temporal correlation. In this paper, we propose a global disparity compensation scheme which increases the inter-view correlation and a new inter-view prediction structure based on the global disparity compensation. By experiment, we demonstrate that the proposed global disparity compensation scheme is less sensitive to change of the search range. In addition, the new Inter-view prediction structure achieved about $0.1{\sim}0.3dB$ quality improvement compared to the reference software.

Future Weather Generation with Spatio-Temporal Correlation for the Four Major River Basins in South Korea (시공간 상관성을 고려한 일기산출기 모형을 이용한 4대강 유역별 미래 일기 변수 산출)

  • Lee, Dong-Hwan;Lee, Jae-Yong;Oh, Hee-Seok;Lee, Young-Jo
    • The Korean Journal of Applied Statistics
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    • v.25 no.2
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    • pp.351-362
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    • 2012
  • Weather generators are statistical tools to produce synthetic sequences of daily weather variables. We propose the multisite weather generators with a spatio-temporal correlation based on hierarchical generalized linear models. We develop a computational algorithm to produce future weather variables that use three different types of green-house gases scenarios. We apply the proposed method to a daily time series of precipitation and average temperature for South Korea.

Fast Encoder Design for Multi-view Video

  • Zhao, Fan;Liao, Kaiyang;Zhang, Erhu;Qu, Fangying
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.7
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    • pp.2464-2479
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    • 2014
  • Multi-view video coding is an international encoding standard that attains good performance by fully utilizing temporal and inter-view correlations. However, it suffers from high computational complexity. This paper presents a fast encoder design to reduce the level of complexity. First, when the temporal correlation of a group of pictures is sufficiently strong, macroblock-based inter-view prediction is not employed for the non-anchor pictures of B-views. Second, when the disparity between two adjacent views is above some threshold, frame-based inter-view prediction is disabled. Third, inter-view prediction is not performed on boundary macroblocks in the auxiliary views, because the references for these blocks may not exist in neighboring views. Fourth, finer partitions of inter-view prediction are cancelled for macroblocks in static image areas. Finally, when estimating the disparity of a macroblock, the search range is adjusted according to the mode size distribution of the neighboring view. Compared with reference software, these techniques produce an average time reduction of 83.65%, while the bit-rate increase and peak signal-to-noise ratio loss are less than 0.54% and 0.05dB, respectively.

Statistical network analysis for epilepsy MEG data

  • Haeji Lee;Chun Kee Chung;Jaehee Kim
    • Communications for Statistical Applications and Methods
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    • v.30 no.6
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    • pp.561-575
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    • 2023
  • Brain network analysis has attracted the interest of neuroscience researchers in studying brain diseases. Magnetoencephalography (MEG) is especially proper for analyzing functional connectivity due to high temporal and spatial resolution. The application of graph theory for functional connectivity analysis has been studied widely, but research on network modeling for MEG still needs more. Temporal exponential random graph model (TERGM) considers temporal dependencies of networks. We performed the brain network analysis, including static/temporal network statistics, on two groups of epilepsy patients who removed the left (LT) or right (RT) part of the brain and healthy controls. We investigate network differences using Multiset canonical correlation analysis (MCCA) and TERGM between epilepsy patients and healthy controls (HC). The brain network of healthy controls had fewer temporal changes than patient groups. As a result of TERGM, on the simulation networks, LT and RT had less stable state than HC in the network connectivity structure. HC had a stable state of the brain network.

Predictive motion estimation algorithm using spatio-temporal correlation of motion vector (움직임 벡터의 시공간적인 상관성을 이용한 예측 움직임 추정 기법)

  • 김영춘;정원식;김중곤;이건일
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.6
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    • pp.64-72
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    • 1996
  • In this paper, we propose predictive motion estimatin algorithm which can predict motion without additional side information considering spatio-tempral correlatio of motion vector. This method performs motion prediction of current block using correlation of the motion vector for two spatially adjacent blocks and a temporally adjacent block. Form predicted motion, the position of searhc area is determined. Then in this searhc area, we estimate motion vector of current block using block matching algoirthm. Considering spatial an temporal correlation of motion vector, the proposed method can predict motion precisely much more. Especially when the motion of objects is rapid, this method can estimate motion more precisely without reducing block size or increasing search area. Futhrmore, the proposed method has computation time the same as conventional block matching algorithm. And as it predicts motion from adjacent blocks, it does not require additional side information for adjacent block. Computer simulation results show that motion estimation of proposed method is more precise than that of conventioanl method.

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Correlation between Trunk Stabilization Muscle Activation and Gait Parameters (몸통 안정화 근육과 보행요소의 상관관계)

  • Chae, Jung-Byung;Jung, Ju-Hyeon
    • PNF and Movement
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    • v.17 no.1
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    • pp.111-118
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    • 2019
  • Purpose: This study aimed to investigate the correlation between trunk stabilization muscle activation and the parameters of gait analysis in healthy individuals. Methods: Thirty healthy adults (15 male, 15 female) with no history of lower back pain (LBP) or current musculoskeletal and neurological injuries were studied. Trunk stabilization muscle activation (e.g., external oblique, internal oblique, transverse abdominis, erector spinae) were assessed using surface electromyography. To analyze gait, we measured temporal parameters (e.g., gait velocity, single support phase, double support phase, swing phase, and stance phase) and a spatial parameter (e.g., H-H base of support). Results: A statistically significant correlation was found between the internal oblique, transverse abdominis, and erector spinae muscle activity and gait velocity, single support phase, double support phase, swing phase, and stance phase. No statistically significant correlation was found between the external oblique muscle activity and the gait velocity, single support phase, double support phase, swing phase, and stance phase. No statistically significant correlation was found between the external oblique, internal oblique, transverse abdominis, and erector spinae muscle activity and the spatial parameter. Conclusion: This study demonstrated that a relationship exists between trunk stabilization muscle activation and temporal parameter (i.e., gait velocity, single support phase, double support phase, swing phase, and stance phase) during gait analysis. Therefore, the trunk's stabilizer muscles play an important role in the gait of healthy individuals.

Temporal Changes and Correlations Between the Chemical Characteristics of Soils in the Case of the Reclaimed Costal Area of Kyung-Gi Province, Korea (서해안 임해매립지 녹지공간 토양성분들의 상관성 및 경시적 변화특성)

  • 구본학;강재선;김정욱
    • Journal of the Korean Institute of Landscape Architecture
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    • v.27 no.5
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    • pp.161-169
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    • 2000
  • In this study, the temporal changes in the chemical characteristics of soil in a reclaimed coastal area, the Shihwa Industrial Complex in the West Coast in Kyung-Gi Province, and the correlations between chemical components were investigated to provide useful information needed for introducing vegetation in the area. The sites were filled with mountain forest soils from 1987 to 1996, and developed into various landuses such as neighbourhood parks, children's parks, buffer greens, pedestrian roads and others. The correlation analyses shoed that pH, organic matter(OM) and available P205 had not been closely related to other chemical parameters such as various cations electro-conductivity(EC) and cation exchange capacity(CEC): especially, pH showed a very low correlation with other factors. The EC turned out to have positive relationships with cations, especially with Na+ ions. There seemed to be fairly good correlations between cations except Ca++ ion. The relation between cations and OM was inconclusive possible because the OM contents in the soils were too low for the analysis. The OM seemed to increase slowly with time and the EC decreased slowly. The salinity and CEC in the original soils decreased rapidly possibly because of leaching. It is believed that there were some external disturbances such as rainfall which had affected the soil properties. The soils sampled in dry season showed a very high salinity. From this it is possible to assume that the rainfall would affect the sol properties significantly. So it is necessary to continue further studies to investigate the impacts of external disturbances such as rainfall on vertical soil profile and temporal variations as well as to delineate correlations between parameters with external disturbances controlled.

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