• Title/Summary/Keyword: Temporal Patterns

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LANDCOVER CHANGE DETECTION USING MODIS TEMPORAL PROFILE DATA SUPPORED BY ASTER NDVI

  • Yoon, Jong-Suk;Kang, Sung-Jin;Lee, Kyu-Sung
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.382-385
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    • 2008
  • MODIS images have a great advantage of high temporal resolution to monitor land cover changes in a large area. The moderate and low spatial resolution satellite images are incomparably economic than high resolution satellite images. As diverse satellite images are provided recently, strategies using satellite images are necessary for continuous, effective and long-term land monitoring. This research purposed to use MODIS images to monitor land cover in Korean peninsula for long-term and continuous change detection. To maximize the advantages of high temporal resolution, the change detection was based on the MODIS temporal profiles of the surface reflectance for one year. In this study as the reflectance patterns of year 2005 were compared with the reflectance patterns of year 2007, the changed pixels could be detected during two years. To set up the threshold value for the decision of change, ASTER images with the higher spatial resolution, 15m, were used for this study. The test area covered the suburban area of metropolitan city, Seoul, where the landcover changes have been frequently happened.

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Characterizing three-dimensional drought events and spatio-temporal migration patterns (3차원적 가뭄사상 특성 분석 및 시공간적 이동 패턴 분석)

  • Yoo, Jiyoung;Kim, Jang-Gyeong;Yoo, Do-Guen;Kim, Tae-Woong
    • Journal of Korea Water Resources Association
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    • v.52 no.12
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    • pp.1025-1031
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    • 2019
  • There are various research works on the spatio-temporal drought analysis because spatio-temporal behaviors of drought are essential for understanding the development and migration patterns of drought events. This study quantified three-dimensional drought events using the 6-month Standard Precipitation Index (SPI6). A total of 45 drought events were found during the analysis period, and the migration patterns of drought event in South Korea were analyzed using the centers of drought events. In South Korea, more droughts were migrated frequently in the north/south direction than in the east/west direction. In addition, droughts moving eastward have decreased since 2000, while droughts moving northward have been found to be longer. The results of spatio-temporal drought analysis may be highly utilized for understanding drought development and migration patterns.

Identification of Factors Affecting the Occurrence of Temporal Patterns of Rainfall in Gamcheon Watershed (감천유역에 대한 강우양상 발생 영향인자의 규명 및 해석)

  • Ahn, Ki-Hong;Cho, Wan-Hee;Han, Kun-Yeun
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.2
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    • pp.77-85
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    • 2009
  • In South Korea, seasonal, local and temporal climatic characteristics are variable in rainfall patterns. To design or assess the reliability of hydrosystem, information about the rainfall event under consideration is important. In this process, the complete description of a design storm involves the specification of rainfall duration, depth, and its temporal pattern. Generally, to use an appropriate temporal pattern for a design storm is of great importance in the design and evaluation of hydrological safety for hydrosystem. For purpose of selecting of factors affecting the occurrence of rainfall patterns, Huff's dimensionless method was executed and examined by statistical contingency tables analysis through which the inter-dependence of the occurrence frequency of rainfall patterns with respect to geographical location, rainfall duration and depth, and seasonality is investigated. This analysis result can be used to establish flood policies and to design or assess the reliability of hydrosystem.

Voxel-wise Mapping of Functional Magnetic Resonance Imaging in Impression Formation

  • Jeesung Ahn;Yoonjin Nah;Inwhan Ko;Sanghoon Han
    • Science of Emotion and Sensibility
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    • v.25 no.4
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    • pp.77-94
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    • 2022
  • Social interactions often involve encountering inconsistent information about social others. We conducted a functional magnetic resonance imaging (fMRI) study to comprehensively investigate voxel-wise temporal dynamics showing how impressions are anchored and/or adjusted in response to inconsistent social information. The participants performed a social impression task inside an fMRI scanner in which they were shown a male face, together with a series of four adjectives that described the depicted person's personality traits, successively presented beneath the image of the face. Participants were asked to rate their impressions of the person at the end of each trial on a scale of 1 to 8 (where 1 is most negative and 8 is most positive). We established two hypothetical models that represented two temporal patterns of voxel activity: Model 1 featured decreasing patterns of activity towards the end of each trial, anchoring impressions to initially presented information, and Model 2 showed increasing patterns of activity toward the end of each trial, where impressions were being adjusted using new and inconsistent information. Our data-driven model fitting analyses showed that the temporal activity patterns of voxels within the ventral anterior cingulate cortex, medial orbitofrontal cortex, posterior cingulate cortex, amygdala, and fusiform gyrus fit Model 1 (i.e., they were more involved in anchoring first impressions) better than they did Model 2 (i.e., showing impression adjustment). Conversely, voxel-wise neural activity within dorsal ACC and lateral OFC fit Model 2 better than it did Model 1, as it was more likely to be involved in processing new, inconsistent information and adjusting impressions in response. Our novel approach to model fitting analysis replicated previous impression-related neuroscientific findings, furthering the understanding of neural and temporal dynamics of impression processing, particularly with reference to functionally segmenting each region of interest based on relative involvement in impression anchoring as opposed to adjustment.

Base Location Prediction Algorithm of Serial Crimes based on the Spatio-Temporal Analysis (시공간 분석 기반 연쇄 범죄 거점 위치 예측 알고리즘)

  • Hong, Dong-Suk;Kim, Joung-Joon;Kang, Hong-Koo;Lee, Ki-Young;Seo, Jong-Soo;Han, Ki-Joon
    • Journal of Korea Spatial Information System Society
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    • v.10 no.2
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    • pp.63-79
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    • 2008
  • With the recent development of advanced GIS and complex spatial analysis technologies, the more sophisticated technologies are being required to support the advanced knowledge for solving geographical or spatial problems in various decision support systems. In addition, necessity for research on scientific crime investigation and forensic science is increasing particularly at law enforcement agencies and investigation institutions for efficient investigation and the prevention of crimes. There are active researches on geographic profiling to predict the base location such as criminals' residence by analyzing the spatial patterns of serial crimes. However, as previous researches on geographic profiling use simply statistical methods for spatial pattern analysis and do not apply a variety of spatial and temporal analysis technologies on serial crimes, they have the low prediction accuracy. Therefore, this paper identifies the typology the spatio-temporal patterns of serial crimes according to spatial distribution of crime sites and temporal distribution on occurrence of crimes and proposes STA-BLP(Spatio-Temporal Analysis based Base Location Prediction) algorithm which predicts the base location of serial crimes more accurately based on the patterns. STA-BLP improves the prediction accuracy by considering of the anisotropic pattern of serial crimes committed by criminals who prefer specific directions on a crime trip and the learning effect of criminals through repeated movement along the same route. In addition, it can predict base location more accurately in the serial crimes from multiple bases with the local prediction for some crime sites included in a cluster and the global prediction for all crime sites. Through a variety of experiments, we proved the superiority of the STA-BLP by comparing it with previous algorithms in terms of prediction accuracy.

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On-line Associative Memory Design For Temporal Pattern Storage and Classification (시변패턴의 저장과 인식을 위한 On-line 연상 메모리의 설계)

  • Yeo, Seong-Won;Lee, Chong-Ho
    • Proceedings of the KIEE Conference
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    • 1996.07b
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    • pp.1395-1397
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    • 1996
  • Many of the existing neural associative memories are trained and recalled in separate modes and are not suitable for temporal pattern storage and classification in that user must specify the time and length of input patterns. In this paper, a new on-line temporal associative memory model is presented. This memory is structured in layers of neurons and each neuron has limited number of weights so that calculation complexity can be considerably reduced and processing of patterns can be achieved in real time.

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Urban Growth Monitoring using Multi-temporal Satellite Images and Geographic Information

  • Lee, Kwang-Jae;Kim, Youn-Soo;Kim, Byung-Kyo
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.470-472
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    • 2003
  • The primary goal in this paper is to analyze urban growth patterns using multi-temporal remote sensing images and geographic information data. In order to accomplish this purpose, firstly data pre-processing is carried out, and then land-use maps are generated with ancillary data source by heads-up on-screen digitizing. Lastly, using the results of the previous stages, the patterns of land-use and urban changes are monitored by the proposed scheme. In this research, using the multi-temporal images and geographic information data, monitoring of urban growth was carried out with the application of urban land-use changes.

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Spatial and temporal distribution of driving rain on a low-rise building

  • Blocken, Bert;Carmeliet, Jan
    • Wind and Structures
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    • v.5 no.5
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    • pp.441-462
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    • 2002
  • This paper presents a practical numerical method to determine both the spatial and temporal distribution of driving rain on buildings. It is based on an existing numerical simulation technique and uses the building geometry and climatic data at the building site as input. The method is applied to determine the 3D spatial and temporal distribution of wind-driven rain on the facade a low-rise building of complex geometry. Distinct wetting patterns are found. The important causes giving rise to these particular patterns are identified : (1) sweeping of raindrops towards vertical building edges, (2) sweeping of raindrops towards top edges, (3) shelter effect by various roof overhang configurations. The comparison of the numerical results with full-scale measurements in both space and time for a number of on site recorded rain events shows the numerical method to yield accurate results.

Severe Temporal Hyper-Activated States Caused by Noise in Tinnitus and Hyperacusis with Normal Hearing

  • Bae, Eun Bit;Lee, Jun Ho
    • Korean Journal of Audiology
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    • v.23 no.3
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    • pp.160-166
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    • 2019
  • Lots of neuroimaging and animal studies have revealed that tinnitus and hyperacusis share the same patterns in the bottom up central auditory process. The aim was to identify the abnormal central patterns commonly observed in both tinnitus and hyperacusis in humans. We investigated two cases of normal hearing: a tinnitus patient and a hyperacusis patient. We compared the differences between the severe temporal hyper-activated state (STHS), with spikes, fast beta and gamma frequencies after noise exposure, and the mild temporal hyperactivated state (MTHS), in no sound exposed condition. The power of the gamma band in the two cases was increased in both auditory cortices compared to the other brain regions. Our results of human with normal hearing were the first to identify how tinnitus and hyperacusis caused by sound are abnormally active and how they maintain constant pathological states.

Severe Temporal Hyper-Activated States Caused by Noise in Tinnitus and Hyperacusis with Normal Hearing

  • Bae, Eun Bit;Lee, Jun Ho
    • Journal of Audiology & Otology
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    • v.23 no.3
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    • pp.160-166
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    • 2019
  • Lots of neuroimaging and animal studies have revealed that tinnitus and hyperacusis share the same patterns in the bottom up central auditory process. The aim was to identify the abnormal central patterns commonly observed in both tinnitus and hyperacusis in humans. We investigated two cases of normal hearing: a tinnitus patient and a hyperacusis patient. We compared the differences between the severe temporal hyper-activated state (STHS), with spikes, fast beta and gamma frequencies after noise exposure, and the mild temporal hyperactivated state (MTHS), in no sound exposed condition. The power of the gamma band in the two cases was increased in both auditory cortices compared to the other brain regions. Our results of human with normal hearing were the first to identify how tinnitus and hyperacusis caused by sound are abnormally active and how they maintain constant pathological states.