• Title/Summary/Keyword: Threshold model

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Estimation of Small Reservoir Storage Using Sentinel-1 Image (Sentinel-1 위성영상을 활용한 소규모 저수지 저수량 추정)

  • Jang, Moon-Yup;Song, Ju-Il;Jang, Cho-Rok;Kim, Han-Tae
    • Journal of the Society of Disaster Information
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    • v.16 no.1
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    • pp.79-86
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    • 2020
  • Purpose: In this study, a model was developed to estimate the storage in Cheonan reservoir using images taken by Sentinel-1 satellite. Method: A total of three reservoirs were studied. All three reservoirs are small reservoirs whose water level is being measured. The preprocessing of Sentinel-1 images was done using SNAP distributed by the European Space Agency(ESA), and the storage was estimated by classifying water surface by the threshold classification method. The estimated reservoir area was compared with satellite and drones images taken on the same day. The correlation was derived by comparing the estimated reservoir area with the actual measurement. Results and Conclusions: The storage values estimated by satellite image analysis showed similar values to the actual measurement data. However, because of the underestimation of the reservoir area due to green algae and Epilithic diatom of summer reservoirs and the low resolution of satellite images, it is dificult to detect reservoir area by satellite images less than 10,000㎡.

The effects of intra-articular resiniferatoxin on monosodium iodoacetate-induced osteoarthritic pain in rats

  • Kim, Youngkyung;Kim, Eun-hye;Lee, Kyu Sang;Lee, Koeun;Park, Sung Ho;Na, Sook Hyun;Ko, Cheolwoong;Kim, Junesun;Yooon, Young Wook
    • The Korean Journal of Physiology and Pharmacology
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    • v.20 no.1
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    • pp.129-136
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    • 2016
  • This study was performed to investigate whether an intra-articular injection of transient receptor potential vanilloid 1 (TRPV1) receptor agonist, resiniferatoxin (RTX) would alleviate behavioral signs of arthritic pain in a rat model of osteoarthritis (OA). We also sought to determine the effect of RTX treatment on calcitonin gene-related peptide (CGRP) expression in the spinal cord. Knee joint inflammation was induced by intra-articular injection of monosodium iodoacetate (MIA, $8mg/50{\mu}l$) and weight bearing percentage on right and left hindpaws during walking, paw withdrawal threshold to mechanical stimulation, and paw withdrawal latency to heat were measured to evaluate pain behavior. Intra-articular administration of RTX (0.03, 0.003 and 0.0003%) at 2 weeks after the induction of knee joint inflammation significantly improved reduction of weight bearing on the ipsilateral hindlimb and increased paw withdrawal sensitivity to mechanical and heat stimuli. The reduction of pain behavior persisted for 3~10 days according to each behavioral test. The MIA-induced increase in CGRP immunoreactivity in the spinal cord was decreased by RTX treatment in a dose-dependent manner. The present study demonstrated that a single intra-articular administration of RTX reduced pain behaviors for a relatively long time in an experimental model of OA and could normalize OA-associated changes in peptide expression in the spinal cord.

Development of the Marginal Scale of Rural Over-Depopulated Village by Analysing the Rural Residential Conditions (농촌마을 정주환경분석을 통한 과소마을 임계규모 결정지표 개발)

  • Bae, Yeon Joung;Lee, Ji Min;Suh, Kyo;Lee, Jeong Jae
    • Journal of Korean Society of Rural Planning
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    • v.19 no.1
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    • pp.109-122
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    • 2013
  • The rapid rural urban migration and aging has generated an over-depopulation problems in rural areas since the 1980s. The purpose of this study constructs the marginal size of rural over-depopulated village through the analysis of the residential disparities such as farmer's ratio, basic life service accessibility, and levels of social and economic factors for each village community. This marginal scale could support evaluating diverse rural policies, which have been planned to apply to the rural development programs at the village level. The major challenges for over-depopulated villages are the lack of basic facilities, production infrastructures and inactive communities in the village. Therefore, the quantitative analysis of rural residential disparities according to rural village scale can provide the criteria for rural over-depopulated villages. We utilized Korea Agricultural Survey Data(2010) including specific residential condition of village level. The present study adopt multinomial-logit model for quantitative analysis of different village scales and decomposition techniques to separate the direct effect by the village scale factor from the endowment effects by regional or area characteristics, and residual effect by unknown factors. The present study found that the minimum scale of a rural over-depopulated village was 40 and 60 houses for the respective conditions of farmer's ratios less than 50% and greater than 75%. It was concluded based on the study findings that threshold scale could support evaluating the diverse rural policies, which have been planned to apply to the rural development programs at the village level.

An Evaluation of Snowmelt Effects Using SWAT in Chungju Dam Basin (SWAT을 활용한 충주댐 유역의 융설 영향 평가)

  • Kim, Nam-Won;Lee, Byong-Ju;Lee, Jeong-Eun
    • Journal of Korea Water Resources Association
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    • v.39 no.10 s.171
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    • pp.833-844
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    • 2006
  • The objective of this study is to evaluate the snowmelt effects on the hydrological components, especially on the runoff, by using the soil water assessment tool(SWAT) which is a continuous semi-distributed long term rainfall-runoff model. The model was applied to the basin located in the upstream of the Chungju Dam. Some parameters in the snowmelt algorithm were estimated for the Chungju basin in order to reflect the snowmelt effects. The snowmelt effects were assessed by comparing the simulated runoff with the observed runoff data at the outlet of the basin. It was found out that the simulated runoff with considering the snowmelt component matches more satisfactorily to the observed one than without considering snowmelt effect. The simulation results revealed that the snowmelt effects were noticeable on March and April. Similar results were obtained at other two upstream gauging points. The effect of the elevation bands which distribute temperature and precipitation with elevation was analyzed. This study also showed that the snowmelt effect significantly affects the temporal distribution as well as quantity of the hydrological components. The simulated runoff was very sensitive to the change of temperature near the threshold temperature which the snowmelt can occur. However, the reason was not accounted for this paper, Therefore, further analyses related to this feature are needed.

Uncertainty Analysis of GCM Information in Korea Using Probabilistic Diagnostics (국내 유역에 대한 GCM 정보의 확률론적 불확실성 분석)

  • Jeong, Chang-Sam;Heo, Jun-Haeng;Bae, Deg-Hyo
    • Journal of Korea Water Resources Association
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    • v.37 no.3
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    • pp.173-184
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    • 2004
  • The objective of this study is to examine the usefulness of climate model simulations (GCM) in Korea water resource management. The methods are based on probabilistic measures of the effectiveness of GCM simulations of an indicator variable for discriminating high versus low regional observations of a target variable. The formulation uses the significance probability of the Kolmogorov-Smirnov test for detecting differences between two variables. AMIP-II(Atmospheric Model Intercomparison Project-II) type GCM simulation done by ECMWF(European Centre for Medium-Range Weather Forecasts) was used for indicator variable and observed mean average precipitation(MAP) values on 7 major river basins were used as target variable. Monte Carlo simulation is used to establish the significance of the estimator values. The results show that GCM simulations done by ECMWF are skillful in discriminating the high from the low of the observed MAP for wet season in all seven basins of Korea, but not enough for dry season.

Inundation Simulation on a Vertical Dock Using Finite Element Storm Surge Model (유한요소 폭풍해일 모형을 이용한 직립안벽에 대한 범람모의)

  • Suh, Seung-Won;Lee, Hwa-Young
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.24 no.4
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    • pp.235-246
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    • 2012
  • Typhoon induced surge simulations are done to make an establishment of coastal disaster prevention plan. To apply efficient run-up and overtopping on vertical harbor docks, in which prevailing wet-dry scheme cannot be satisfied due to infinite steepness, an imaginary internal barrier concept introduced and analyzed. Before real application on the Mokpo harbor area, feasibility tests are done on an idealized simple geometry and as a result it is found that the moderate width of the barrier might be 1 m. The threshold value of the minimum wet depth $H_{min}$ for land area, which behaves sensitive role in inundation area and depth, depends on grid size. However it is revealed that 0.01 m is adequate value in this fine finite element with 10 m spacing. A hypothetical typhoon of 100 years return period in central pressure and maximum velocity is generated based on historical tracks. Simulation of possible inundation on Mokpo area is performed with asymmetrical vortex of hypothetical typhoon and wave coupling. Model results show general agreement in pattern compared to other's prediction, however possibility of inundation enlargement is expected in harbor area.

INITIAL ESTIMATION OF THE RADIONUCLIDES IN THE SOIL AROUND THE 100 MEV PROTON ACCELERATOR FACILITY OF PEFP

  • An, So-Hyun;Lee, Young-Ouk;Cho, Young-Sik;Lee, Cheol-Woo
    • Nuclear Engineering and Technology
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    • v.39 no.6
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    • pp.747-752
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    • 2007
  • The Proton Engineering Frontier Project (PEFP) has designed and developed a proton linear accelerator facility operating at 100 MeV - 20 mA. The radiological effects of such a nuclear facility on the environment are important in terms of radiation safety. This study estimated the production rates of radionuclides in the soil around the accelerator facility using MCNPX. The groundwater migration of the radioisotopes was also calculated using the Concentration Model. Several spallation reactions have occurred due to leaked neutrons, leading to the release of various radionuclides into the soil. The total activity of the induced radionuclides is approximately $2.98{\times}10^{-4}Bq/cm^3$ at the point of saturation. $^{45}Ca$ had the highest production rate with a specific activity of $1.78{\times}10^{-4}Bq/cm^3$ over the course of one year. $^3H$ and $^{22}Na$ are usually considered the most important radioisotopes at nuclear facilities. However, only a small amount of tritium was produced around this facility, as the energy of most neutrons is below the threshold of the predominant reactions for producing tritium: $^{16}O(n,\;X)^3H$ and $^{28}Si(n,X)^3H$ (approximately 20 MeV). The dose level of drinking water from $^{22}Na$ was $1.48{\times}10^{-5}$ pCi/ml/yr, which was less than the annual intake limit in the regulations.

Antiepileptical Properties Of Ginsenosides From Korean Red Ginseng And Ginseng Cell Culture (Dan25)

  • ChepurnovS.A.;Park, Jin-Kyu;vanLuijtelaarE.L.J.M;ChepurnovaN.E.;StrogovS.E.;MikhaylovaO.M.;ArtukhovaM.V.;BerdievR.K.;GoncharovO.B.;SergeevV.I.;TolamachevaE.A.
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2000.10a
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    • pp.116-122
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    • 2000
  • The molecular modification of antiepileptic drugs and direct synthesis of new drugs with the predetermined antiepileptic properties are perspective. New neurochemical attacking to solve the problem including prevention and inhibition of seizures seems to be related to ginsenosides and ginseng polypeptides. The main study based on the severity of febrile convulsions of rat pups has been done from the earlier investigations of antiepileptical action of ginsenosides between KGTRI and MSU (Chepurnov, Park et al., 1995) with different kinds of experimental models of epilepsy. From the cultured cell line DAN25 of ginseng root, the extracts of ginsenosides made in "BIOKHIMMASH" were studied by the project of preclinical anticonvulsant screening (Stables, Kupferberg, 1997). The inhibition of severity of convulsions, decrease of seizures threshold, decrease of audiogenic seizures in rats of different strains and normalization of cerebral blood flow (measured by hydrogen test) were demonstrated in rats after i.c.v., intraperitoneally and orally administration, respectively. The antiepileptical effects by the combination of compounds from ginseng; were compared with the iuluence of Rg1, Rb1, Rc and with the well known antiepileptical drugs such as carbamazepine, valproic acid. The base for the research is obtained by using the WAG/Rij strain (Luijtelaar, Coenen, Kuznetcova), an excellent genetic model for human generalized absence epilepsy. The improving action of gensinosides was effectively demonstrated on the model of electrical kindling of amygdala of WAG/Rij rats with genetically determined absences, and the influences of ginsenosides on the slow wave discharges have also been being investigated. The different characteristics of a kindling process exerted in the sex-different region of the amygdala and demonstrated that the level of sex steroids and content of neurosteroids in amygdaloid tissue can modify the development of seizures. The chemical structures of ginsenosides not only have some principal differences from well-known antiepileptical drugs but the Plant Pharmacology gives us unique possibility to develop new class of antiepileptic drugs and to improve its biological activity.

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Analysis on Inundation Characteristics for Flood Impact Forecasting in Gangnam Drainage Basin (강남지역 홍수영향예보를 위한 침수특성 분석)

  • Lee, Byong-Ju
    • Atmosphere
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    • v.27 no.2
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    • pp.189-197
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    • 2017
  • Progressing from weather forecasts and warnings to multi-hazard impact-based forecast and warning services represents a paradigm shift in service delivery. Urban flooding is a typical meteorological disaster. This study proposes support plan for urban flooding impact-based forecast by providing inundation risk matrix. To achieve this goal, we first configured storm sewer management model (SWMM) to analyze 1D pipe networks and then grid based inundation analysis model (GIAM) to analyze 2D inundation depth over the Gangnam drainage area with $7.4km^2$. The accuracy of the simulated inundation results for heavy rainfall in 2010 and 2011 are 0.61 and 0.57 in POD index, respectively. 20 inundation scenarios responding on rainfall scenarios with 10~200 mm interval are produced for 60 and 120 minutes of rainfall duration. When the inundation damage thresholds are defined as pre-occurrence stage, occurrence stage to $0.01km^2$, 0.01 to $0.1km^2$, and $0.1km^2$ or more in area with a depth of 0.5 m or more, rainfall thresholds responding on each inundation damage threshold results in: 0 to 20 mm, 20 to 50 mm, 50 to 80 mm, and 80 mm or more in the rainfall duration 60 minutes and 0 to 30 mm, 30 to 70 mm, 70 to 110 mm, and 110 mm or more in the rainfall duration 120 minutes. Rainfall thresholds as a trigger of urban inundation damage can be used to form an inundation risk matrix. It is expected to be used for urban flood impact forecasting.

Model-based Macroblock Layer Rate Control for Low Bit Rate Video Coding (저전송률 비디오 압축을 위한 모델 기반 매크로블록 레이어 비트율 제어)

  • Park, Sang-Hyun
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.46 no.4
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    • pp.50-57
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    • 2009
  • This paper presents a new model-based macroblock layer rate control algorithm for low bit rate video coding which generates output bits corresponding to a target bit budget. The H.264 standard uses various coding modes and optimization methods to improve the compression performance, which makes it difficult to control the generated traffic accurately in low bit rate environments. In the proposed scheme, we first estimate MAD values of macroblocks in a frame and define a target remaining bits using the estimated MAD values before encoding each macroblock. If a difference between the target value and the actual value is greater than a threshold value, the quantization parameter is adjusted to decrease the difference. It is shown by experimental results that the new algorithm can obtain more than 66% decrease of the difference between the target bits and the resulting bits for a frame with the PSNR performance better than that of the existing rate control algorithm.