• Title/Summary/Keyword: Spatiotemporal

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Traffic Flow Prediction with Spatio-Temporal Information Fusion using Graph Neural Networks

  • Huijuan Ding;Giseop Noh
    • International journal of advanced smart convergence
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    • v.12 no.4
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    • pp.88-97
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    • 2023
  • Traffic flow prediction is of great significance in urban planning and traffic management. As the complexity of urban traffic increases, existing prediction methods still face challenges, especially for the fusion of spatiotemporal information and the capture of long-term dependencies. This study aims to use the fusion model of graph neural network to solve the spatio-temporal information fusion problem in traffic flow prediction. We propose a new deep learning model Spatio-Temporal Information Fusion using Graph Neural Networks (STFGNN). We use GCN module, TCN module and LSTM module alternately to carry out spatiotemporal information fusion. GCN and multi-core TCN capture the temporal and spatial dependencies of traffic flow respectively, and LSTM connects multiple fusion modules to carry out spatiotemporal information fusion. In the experimental evaluation of real traffic flow data, STFGNN showed better performance than other models.

A Study on the Satisfaction Analysis on Officially Assessed Land Price Using Time Seriate Geostatistical Analysis (시계열적 공간통계 기법을 활용한 공시지가의 만족도 분석에 관한 연구)

  • Choi, Byoung Gil;Na, Young Woo;Hyeon, Chang Seop;Cho, Tae In
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.36 no.2
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    • pp.95-104
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    • 2018
  • This study has the purpose of suggesting the method to analyze the spatiotemporal change of satisfaction concerning the officially assessed land price using geostatistical analysis. Analyzing the spatial distribution characteristic of officially assessed land price using present GIS (Geographic Information System) or is staying at qualitatively suggesting the improvement method of the officially assessed land price system. Grouping the appeal strength based on the official price and opinion price of officially assessed land price, GIS DB (Database) was constructed and the time seriate satisfaction were analyzed and compared through spatial density analysis and spatial autocorrelation analysis. As a result, it was found that the difference between the official price and the applicant's price differed depending on individual land, but most of the respondents requested the increase or the reduction of the average land price, which resulted in a large number of request. Analyzing the satisfaction of the officially assessed land price by using GIS, it was known that satisfaction of officially assessed land price could be analyzed by using the difference of the opinion price and not only the officially assessed land price. Spatiotemporal change of officially assessed land price satisfaction was known to be possible through spatiotemporal pattern analysis method such as spatiotemporal auto-corelation analysis and hotspot analysis etc using GIS. In short, regionally positive or negative significant relationship was investigated through spatiotemporal analysis using annual data.

A Study on Surrealistic Design by Apporaches to Spatiotemporal Idealism (시간과 공간의 관념론적 접근을 통한 초현실주의적 디자인에 관한 연구)

  • 김정아
    • Korean Institute of Interior Design Journal
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    • v.13 no.1
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    • pp.46-53
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    • 2004
  • This study has importance of that it verifies applicability of a new interpretation of surrealism to spatial design. Transcendental cognitive form of idealism, concept of time and space are premise of reality and surreality is finally condensed to the matter of time and space. Surrealistic techniques are automatic description, double association, montage and etc, and all of them are trials to approach to essence of images expressing unconsciousness through spatiotemporal changes of object. The purpose of this study is to find the surrealistic methods that can be applied to spatial design.

Observation of the Spatiotemporal Variation of Wall Charge Distribution during Reset Period in an ac POP cell

  • Jeong, Dong-Cheol;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.756-759
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    • 2003
  • We measure the spatiotemporal wall charge distributions on sustain and address electrodes during reset period in an ac PDP cell using the longitudinal electro-optic amplitude modulation method. We apply several reset waveforms like as ramp, exponentially growing and high voltage pulse, and compare the wall charge characteristics on address electrode as well as sustain electrodes for each reset waveforms.

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BIFURCATION ANALYSIS OF A SINGLE SPECIES REACTION-DIFFUSION MODEL WITH NONLOCAL DELAY

  • Zhou, Jun
    • Journal of the Korean Mathematical Society
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    • v.57 no.1
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    • pp.249-281
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    • 2020
  • A reaction-diffusion model with spatiotemporal delay modeling the dynamical behavior of a single species is investigated. The parameter regions for the local stability, global stability and instability of the unique positive constant steady state solution are derived. The conditions of the occurrence of Turing (diffusion-driven) instability are obtained. The existence of time-periodic solutions, the existence and nonexistence of nonconstant positive steady state solutions are proved by bifurcation method and energy method. Numerical simulations are presented to verify and illustrate the theoretical results.

Background Initialization by Spatiotemporal Similarity

  • Park, Goo-Man
    • Journal of Broadcast Engineering
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    • v.12 no.3
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    • pp.289-292
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    • 2007
  • A background initialization algorithm based on the spatiotemporal similarity measure in a motion tracking system is proposed. From the accumulated difference between the base frame and the other frames in a subinterval, the regions affected by moving objects are located. The median is applied over the subsequence in the subinterval in which co-located regions share the similarity. The outputs from each subinterval are filtered by second stage median filter. The proposed method showed good results even in the busy and crowded sequences where the real background does not exit.

Effects of Ankle Joint Mobilization With Movement on Lower Extremity Muscle Strength and Spatiotemporal Gait Parameters in Chronic Hemiplegic Patients (만성 편마비 환자의 발목에 적용한 능동운동을 동반한 관절가동술이 하지근력과 보행의 시공간적 변수에 미치는 영향)

  • An, Chang-Man;Won, Jong-Im
    • Physical Therapy Korea
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    • v.19 no.3
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    • pp.20-30
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    • 2012
  • The purpose of this study was to determine the effect of ankle joint mobilization with movement (MWM) on the range of motion (ROM) in the ankle, on the muscle strength of lower extremities, and on spatiotemporal gait parameters in chronic hemiplegic patients. Fifteen subjects with chronic stroke were divided into two groups: an experimental group (8 subjects) and a control group (7 subjects). Both groups attended two or three sessions of physical therapy each week. The experimental group also attended additional MWM training sessions three times a week for five weeks. For both groups, the ROM of the ankle, the muscle strength of the lower extremities, and the spatiotemporal gait parameters in paretic limbs were evaluated before and after the training period. The results showed that the experimental group experienced more significant increases than did the control group in terms of passive (6.10%) and active (21.96%) ROM of the ankle, gait velocity (12.96%), and peak torque, of the knee flexor (81.39%), the knee extensor (24.88%), and the ankle plantar flexor (41.75%)(p<.05). These results suggest that MWM training in patients with chronic stroke may be beneficial in increasing ROM in the ankle, muscle strength in the lower extremities, and gait speed.

The Effects of Somatosensory Training on the Spatiotemporal Gait Parameters and Balance in Patients with Stroke (체성감각 훈련이 뇌졸중 환자의 시공간적 보행요소 및 균형에 미치는 효과)

  • Chae, Jung-Byung;Lee, Moon-Hwan
    • Journal of the Korean Society of Physical Medicine
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    • v.5 no.4
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    • pp.587-596
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    • 2010
  • Purpose : This study was performed to investigate the effects of somatosensory training on the spatiotemporal gait parameters and balance in patients with stroke patients. Methods : 24 stroke survivors were allocated in this study, and randomly divided into experimental(n=12) and control group(n=12), independently. Experimental group was applied somatosensory training program plus conventional physical therapy, and control group was applied only conventional physical therapy. All subjects were administered for 30 minutes per day during 8 weeks(5 times a week). Results : Spatiotemporal parameters of gait were significant difference between pre and post intervention in experimental group, except of step length asymmetry ratio(SLAR) and single support time asymmetry ratio (SSAR)(p<.05). But control group had no statistical significance(p>.05). And also there was significant difference between experimental and control group(p<.05), except of cadence and SSAR(p>.05). Balance parameters were significant difference between pre and post intervention in experimental group(p<.05). But control group had no statistical significance(p>.05). And experimental timed up and go test was significantly decreased than control group(p<.05), but berg balance scale and functional reach test were not significant difference between experimental and control group(p>.05). Conclusion : This study was suggested that somatosensory training has effectiveness on the spatiotemporal gait parameters and balance in patients with stroke survivors. So this therapeutic intervention will be effectivelyapply to the stroke survivors in the clinical setting.

Spatiotemporal Analysis of Hippocampal Long Term Potentiation Using Independent Component Analysis

  • Kim, T.S.;Lee, J.J.;Hwang, S.J.;Lee, Y.K.;Park, J.H.
    • Journal of Biomedical Engineering Research
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    • v.28 no.1
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    • pp.17-23
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    • 2007
  • Long-term potentiation (LTP) of synaptic transmission is the most widely studied model for learning and memory. However its mechanisms are not clearly elucidated and are a subject for intense investigation. Previous attempts to decipher cellular mechanisms and network properties involved a current-source density analysis (CSDA) of the LTP from small animal hippocampus measured with a limited number of microelectrodes (typically <3), only revealing limited nature of spatiotemporal dynamics. Recent advancement in multi-electrode array (MEA) technology allows continuous and simultaneous recordings of LTP with more than 60 electrodes. However CSDA via the standard Laplacian transform is still limited due to its relatively high sensitivity toward noise, inability of resolving overlapped current sources and sinks, and its requirement for tissue conductivity values. In this study, we propose a new methodology for improved CSDA. Independent component analysis and its joint use (i.e., Joint-ICA) are applied to extract spatiotemporal components of LTP. The results show that ICA and Joint-ICA are capable of extracting independent spatiotemporal components of LTP generators. The ICs of LTP indicate the reversing roles of current sources and sinks which are associated with LTP.

An Indexing Technique of Moving Point Objects using Projection (추출 연산을 활용한 이동 점 객체 색인 기법)

  • 정영진;장승연;안윤애;류근호
    • Journal of KIISE:Databases
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    • v.30 no.1
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    • pp.52-63
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    • 2003
  • Spatiotemporal moving objects are changing their Positions and/or shape over time in real world. As most of the indices of moving object are based on the R-tree. they have defects of the R-tree which are dead space and overlap. Some of the indices amplify the defects of the R-tree. In the paper, to solve the problems, we propose the MPR-tree(Moving Point R-tree) using Projection operation which has more effective search than existing moving point indices on time slice query and spatiotemporal range query. The MPR-tree connects positions of the same moving objects over time by using linked list, so it processes the combined query about trajectory effectively. The usefulness of the Projection operation is confirmed during processing moving object queries and in practical use of space from experimentation to compare MPR-tree with existing indices of moving objects. The proposed MPR-tree would be useful in the LBS, the car management using GPS, and the navigation system.