• Title/Summary/Keyword: Temporal region

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Development of grid-based hydraulc model for ecohydraulic connectivity assessment (수리생태적 연결성 평가를 위한 격자기반 수리해석 모형 개발)

  • Kim, Chang Wan;Chegal, Sun Dong;Cho, Gil Jea
    • Journal of Korea Water Resources Association
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    • v.51 no.5
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    • pp.461-470
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    • 2018
  • Beyond river restoration focused on the inside region of main streams up to now, the river restoration including the outside region of streams has been started recently. As a part of this attempt, the restoration of abandoned rivers has been tried, but the development of a suitable model to quantitatively assess the improvement of hydraulic and ecological connectivity is not still satisfying. In this study, a grid - based hydraulic analysis model to evaluate the recovery of ecological connectivity through the restoration of abandoned rivers has been developed. In order to examine the applicability of this model, the ecohydaulic connectivity of the Cheongmi River Project area in Notap region was evaluated. This model can promptly and simply analyze the temporal and spatial distribution of the hydraulic and ecological characteristics, and it can be used as a appropriate tool to assess the hydraulic and ecological connectivity in the future.

Two-dimensional measurements of the ELM filament using a multi-channel electrical probe array with high time resolution at the far SOL region in the KSTAR

  • Hong, Young-Hun;Kim, Kwan-Yong;Kim, Ju-Ho;Son, Soo-Hyun;Lee, Hyung-Ho;Eo, Hyun-Dong;Kim, Min-Seok;Hong, Suk-Ho;Chung, Chin-Wook
    • Nuclear Engineering and Technology
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    • v.54 no.10
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    • pp.3717-3723
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    • 2022
  • For the first time, two-dimensional temporal behavior of the edge localized mode (ELM) filament is measured in the edge tokamak plasma with a multi-channel electrical probe array (MCEP). MCEP, which has 16 floating probes (4 × 4), is mounted at the far scrape-off layer (SOL) region in the KSTAR. An electron temperature and an ion flux are measured by sideband method (SBM), which can achieve two-dimensional measurements with high time resolution. Furthermore, temporal evolutions of the electron temperature and the ion flux are obtained during the ELM occurrence. In the H-mode period, short spikes from ELM bursts are observed in measured plasma parameters, and the trend is similar to that of typical Hα signal. Interestingly, when blob-like ELM filaments crash the probe, the heat flux is significantly higher in a local region of the probe array. The results show that our probe array using the SBM can measure the ELM behavior and the plasma parameters without the effect of the stray current caused by the huge device. This study can provide valuable data needed to understand the interaction between the SOL plasma and the plasma facing components (PFCs).

Spatio-temporal potential future drought prediction using machine learning for time series data forecast in Abomey-calavi (South of Benin)

  • Agossou, Amos;Kim, Do Yeon;Yang, Jeong-Seok
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.268-268
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    • 2021
  • Groundwater resource is mostly used in Abomey-calavi (southern region of Benin) as main source of water for domestic, industrial, and agricultural activities. Groundwater intake across the region is not perfectly controlled by a network due to the presence of many private boreholes and traditional wells used by the population. After some decades, this important resource is becoming more and more vulnerable and needs more attention. For a better groundwater management in the region of Abomey-calavi, the present study attempts to predict a future probable groundwater drought using Recurrent Neural Network (RNN) for future groundwater level prediction. The RNN model was created in python using jupyter library. Six years monthly groundwater level data was used for the model calibration, two years data for the model test and the model was finaly used to predict two years future groundwater level (years 2020 and 2021). GRI was calculated for 9 wells across the area from 2012 to 2021. The GRI value in dry season (by the end of March) showed groundwater drought for the first time during the study period in 2014 as severe and moderate; from 2015 to 2021 it shows only moderate drought. The rainy season in years 2020 and 2021 is relatively wet and near normal. GRI showed no drought in rainy season during the study period but an important diminution of groundwater level between 2012 and 2021. The Pearson's correlation coefficient calculated between GRI and rainfall from 2005 to 2020 (using only three wells with times series long period data) proved that the groundwater drought mostly observed in dry season is not mainly caused by rainfall scarcity (correlation values between -0.113 and -0.083), but this could be the consequence of an overexploitation of the resource which caused the important spatial and temporal diminution observed from 2012 to 2021.

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Spatial and Temporal Analyses of Cervical Cancer Patients in Upper Northern Thailand

  • Thongsak, Natthapat;Chitapanarux, Imjai;Suprasert, Prapaporn;Prasitwattanaseree, Sukon;Bunyatisai, Walaithip;Sripan, Patumrat;Traisathit, Patrinee
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.11
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    • pp.5011-5017
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    • 2016
  • Background: Cervical cancer is a major public health problem worldwide. There have been several studies indicating that risk is associated with geographic location and that the incidence of cervical cancer has changed over time. In Thailand, incidence rates have also been found to be different in each region. Methods: Participants were women living or having lived in upper Northern Thailand and subjected to cervical screening at Maharaj Nakorn Chiang Mai Hospital between January 2010 and December 2014. Generalized additive models with Loess smooth curve fitting were applied to estimate the risk of cervical cancer. For the spatial analysis, Google Maps were employed to find the geographical locations of the participants' addresses. The Quantum Geographic Information System was used to make a map of cervical cancer risk. Two univariate smooths: x equal to the residency duration was used in the temporal analysis of residency duration, and x equal to the calendar year that participants moved to upper Northern Thailand or birth year for participants already living there, were used in the temporal analysis of the earliest year. The spatial-temporal analysis was conducted in the same way as the spatial analysis except that the data were split into overlapping calendar years. Results: In the spatial analysis, the risk of cervical cancer was shown to be highest in the Eastern sector of upper Northern Thailand (p-value <0.001). In the temporal analysis of residency duration, the risk was shown to be steadily increasing (p-value =0.008), and in the temporal analysis of the earliest year, the risk was observed to be steadily decreasing (p-value=0.016). In the spatial-temporal analysis, the risk was stably higher in Chiang Rai and Nan provinces compared to Chiang Mai province. According to the display movement over time, the odds of developing cervical cancer declined in all provinces. Conclusions: The risk of cervical cancer has decreased over time but, in some areas, there is a higher risk than in the major province of Chiang Mai. Therefore, we should promote cervical cancer screening coverage in all areas, especially where access is difficult and/or to women of lower socioeconomic status.

Analysis of Vaginal Lactic Acid Producing Bacteria in Healthy Women

  • Nam, Hye-Ran;Whang, Kyung-Hee;Lee, Yeon-Hee
    • Journal of Microbiology
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    • v.45 no.6
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    • pp.515-520
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    • 2007
  • Vaginal lactic acid-producing bacteria of 80 pre-menopausal women were studied by isolation on Blood and DeMan-Rogosa-Sharpe agar, PCR with group-specific primers for Lactobacillus-denaturing gradient gel electrophoresis (DGGE), and PCR with specific primers for V3 region in 16S rRNA-temporal temperature gel electrophoresis (TTGE). Conventional isolation method on media detected only one lactobacillus (Lactobacillus brevis) while TTGE detected only Lactobacillus sp. DGGE detected seven Lactobacillus species; L. coleohominis, L. crispatus, L. iners, L. reuteri, L. rhamnosus, L. vaginalis, and Leuconostoc lactis. L. acidophilus and L. gasseri, which are prevalent in Western women, were not detected in Korean women. Furthermore, L. rhamnosus, Leuc. lactis, L. coleohominis, and Weissella cibaria, which were not previously reported in the vaginal microbiota of Korean women, were detected. The five most prevalent LABs in vaginal microbiota in Korean women were L. iners, Enterococcus faecalis, L. crispatus, Leuc. lactis, and W. cibaria.

A New Covert Visual Attention System by Object-based Spatiotemporal Cues and Their Dynamic Fusioned Saliency Map (객체기반의 시공간 단서와 이들의 동적결합 된돌출맵에 의한 상향식 인공시각주의 시스템)

  • Cheoi, Kyungjoo
    • Journal of Korea Multimedia Society
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    • v.18 no.4
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    • pp.460-472
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    • 2015
  • Most of previous visual attention system finds attention regions based on saliency map which is combined by multiple extracted features. The differences of these systems are in the methods of feature extraction and combination. This paper presents a new system which has an improvement in feature extraction method of color and motion, and in weight decision method of spatial and temporal features. Our system dynamically extracts one color which has the strongest response among two opponent colors, and detects the moving objects not moving pixels. As a combination method of spatial and temporal feature, the proposed system sets the weight dynamically by each features' relative activities. Comparative results show that our suggested feature extraction and integration method improved the detection rate of attention region.

Efficient Generation of Spatiotemporal Images for Leukocyte Motion Detection in Microvessels

  • Kim, Eung Kyeu;Jang, Byunghyun
    • IEIE Transactions on Smart Processing and Computing
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    • v.6 no.2
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    • pp.76-84
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    • 2017
  • This paper presents an efficient method for generating spatiotemporal images in order to detect leukocyte motion in microvessels. Leveraging the constraint that leukocytes move along the contour line of the blood vessel wall, our proposed method efficiently generates spatiotemporal images for leukocyte motion detection. To that end, translational motion caused by in vivo movement is first removed by a template matching method. Second, the blood vessel region is detected by an automatic threshold selection method in order to binarize temporal variance images. Then, the contour of the blood vessel wall is expressed via B-spline function. Finally, using the detected blood vessel wall's contour as an initial curve, the plasma layer for the most accurate position is determined in order to find the spatial axis via snake, and the spatiotemporal images are generated. Experimental results show that the spatiotemporal images are generated effectively through comparison of each step with three images.

Arteriovenous Malformation of the Scalp : Efficacy of Computed Tomography Angiography

  • Moon, Kang-Seok;Yoon, Seok-Mann;Shim, Jai-Joon;Yun, Il-Gyu
    • Journal of Korean Neurosurgical Society
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    • v.38 no.5
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    • pp.396-398
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    • 2005
  • We report a rare case of scalp arteriovenous malformation[AVM]. A 55-year-old woman presented with a pulsatile palpable mass on her left temporo-parietal scalp. She complained of insomnia because of bruit, which was audible when she lay on her left side. Computed tomography angiography[CTA] for the scalp vessel showed AVM on the left temporo-parietal region. Multiple enlarged arteries, such as the superficial temporal artery, posterior auricular artery, and occipital artery, were directly connected to the elongated dilated superficial temporal vein. Digital subtraction angiography also showed similar results. Fistulous portions were clearly delineated on both modalities. Surgical excision of the malformations, including feeding arteries and the draining vein, resulted in immediate relief of the symptoms. Usefulness of CTA in the diagnosis of vascular lesions on the scalp was emphasized.

Efficient CT Image Segmentation Algorithm Using both Spatial and Temporal Information

  • Lee, Sang-Bock;Lee, Jun-Haeng;Lee, Samyol
    • Proceedings of the Korea Contents Association Conference
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    • 2004.11a
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    • pp.505-510
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    • 2004
  • This paper suggests a new CT-image segmentation algorithm. This algorithm uses morphological filters and the watershed algorithms. The proposed CT-image segmentation algorithm consists of six parts: preprocessing, image simplification, feature extraction, decision making, region merging, and postprocessing. By combining spatial and temporal information, we can get more accurate segmentation results. The simulation results illustrate not only the segmentation results of the conventional scheme but also the results of the proposed scheme; this comparison illustrates the efficacy of the proposed technique. Furthermore, we compare the various medical images of the structuring elements. Indeed, to illustrate the improvement of coding efficiency in postprocessing, we use differential chain coding for the shape coding of results.

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Temporal Changes in Abundances of the Toxic Dinoflagellate Alexandrium minutum (Dinophyceae) in Chinhae Bay, Korea

  • Park, Tae-Gyu;Kang, Yang-Soon
    • Journal of Environmental Science International
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    • v.18 no.12
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    • pp.1331-1338
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    • 2009
  • Marine dinoflagellate Alexandrium minutum producing paralytic shellfish toxins is responsible for paralytic shellfish poisoning (PSP). To investigate its temporal distributions in Chinhae Bay where PSP occurs annually, SYBR Green I based A. minutum-specific real-time PCR probe was developed on the LSU rDNA region. Assay specificity and sensitivity were tested against related species, and its specificity was further confirmed by sequencing of field-derived samples. Ten months field survey in 2008 (a total 100 surface water samples) by using the real-time PCR probe showed that A. minutum was detected at very low densities of 1-4 cells $L^{-1}$ in May and June being spring in Chinhae Bay, Korea.