• 제목/요약/키워드: U-Net++

검색결과 704건 처리시간 0.023초

가토(家兎)에 있어서 Sulfadiazine의 뇨중(尿中) 배설기전(排泄機轉) (Mechanism of Urinary Excretion of Sulfadiazine in the Rabbit)

  • 고석태;정종남;고옥현
    • Journal of Pharmaceutical Investigation
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    • 제2권1호
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    • pp.18-30
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    • 1972
  • Renal pathways for excretion of sulfadiazine has been studied by standard clearance technique in the rabbit. 1. Large part of sulfadiazine filtered in the glomeruli is reabsorbed in the tubules, as visualized from the fact that Csd (clearance of sulfadiazine) amounts only a fraction of simultaneously measured Ccr (GFR). 2. Csd changed linearly with the rate of urine flow, whether it is increased by the duir etics or decreased by clamping u reter. 3. Csd remained unchanged until the plasma level of the Csdremained unchanged drug reached 10.0 mg%, and the amount transported in the tubules increased linearly with the increase in the load, exhibiting No maximum capacity for transport. 4. Csd was increased by 2,4-dinitrophenol which is an uncoupling agent of oxidative phosphorylation and decreased by probenecid which is on uricosuric agent. 5. During sodium bicarbonate infusion net secretion of sulfadiazine by tubules observed. All the evidences obtained in the rabbit indicated that sulfadiazine was reabsorbed by active, energy-requiring, or passive, simple diffusion, process, and secreted simultaneously by a probenecid-sensitive, active procss.

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Transfer Learning 기법을 이용한 가스 누출 영역 분할 성능 비교 (Performance Comparison of Gas Leak Region Segmentation Based on Transfer Learning)

  • Marshall, Marshall;Park, Jang-Sik;Park, Seong-Mi
    • 한국산업융합학회 논문집
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    • 제23권3호
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    • pp.481-489
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    • 2020
  • Safety and security during the handling of hazardous materials is a great concern for anyone in the field. One driving point in the security field is the ability to detect the source of the danger and take action against it as quickly as possible. Via the usage of a fully convolutional network, it is possible to create the label map of an input image, indicating what object is occupying the specific area of the image. This research employs the usage of U-net, which was constructed in biomedical field segmentation to segment cells, instead of the original FCN. One of the challenges that this research faces is the availability of ground truth with precise labeling for the dataset. Testing the network after training resulted in some images where the network pronounces even better detail than the expected label map. With better detailed label map, the network might be able to produce better segmentation is something to be studied in further research.

GIS기법을 이용한 영광지역의 지하수 오염 취약성 평가 (Groundwater Pollution Susceptibility Assessment of Younggwang Area Using GIS Technique)

  • 이사로;최순학
    • 대한지하수환경학회지
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    • 제4권4호
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    • pp.223-230
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    • 1997
  • 지하수 오염에 대한 광역적인 취약성 평가를 하기 위한 DRASTIC 시스템은 미국 EPA (Environmental Protection Agency)에서 개발된 것으로 지하수위, 충진률, 대수층 매체, 토양 매체, 지형 경사, 비포화대 매체, 수리전도도 등 수리지질학적 요소들을 이용하여 지하수 오염 취약성을 상대적으로 평가하기 위한 표준화된 시스템으로 현재 널리 사용되고 있다. DRASTIC 시스템을 사용하여 분석된 지하수 오염 취약성 결과는 취수정 혹은 관측공의 위치선정, 쓰레기 매립지 적지선정, 지하수와 관련된 토지 이용 등에 기초자료로 이용될 수 있다. 본 연구는 이러한 DRASTIC 시스템을 적용하기 위해 GIS(Geographic Information System)를 이용하여 영광군 지역의 지형, 수계, 우물, 지질, 토양, 토지이용 등 수리지질학적 요소들에 대한 공간 데이터베이스를 구축하였고, 이러한 공간 데이터베이스를 GIS의 중첩기 법을 이용하여 분석하여 광역적인 지하수 오염 취약성에 대한 상대적인 분석치를 얻고 이를 도면으로 작성하였다.

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Analyses and improvement of fuel temperature coefficient of rock-like oxide fuel in LWRs from neutronic aspect

  • Shelley, Afroza
    • Nuclear Engineering and Technology
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    • 제52권6호
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    • pp.1156-1163
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    • 2020
  • Fuel temperature coefficient (FTC) of PuO2+ZrO2 (ROX) fueled LWR cell is analyzed neutronically with reactor- and weapons-grade plutonium fuels in comparison with a U-free PuO2+ThO2 (TOX), and a conventional MOX fuel cells. The FTC value of a ROX fueled LWR is smaller compared to a TOX or a MOX fueled LWRs and becomes extremely positive especially, at EOL. This is because when fuel temperature is increased, thermal neutron spectrum is shifted to harder, which is extreme at EOL in ROX fuel than that in TOX and MOX fuels. Consequently at EOL, 239Pu and 241Pu contributes to positive fuel temperature reactivity (FTR) in ROX fuel, while they have negative contribution in TOX and MOX fuels. The FTC problem of ROX fuel is mitigated by additive ThO2, UO2 or Er2O3. In ROX-additive fuel, the atomic density of fissile Pu becomes more than additive free ROX fuel especially at EOL, which is the main cause to improve the FTC problem. The density of fissile Pu is more effective to decrease the thermal spectrum shifts with increase the fuel temperature than additive ThO2, UO2 or Er2O3 in ROX fuel.

가계의 경제적 안정도: 단기지표와 장기지표의 비교 (Economic Security of Household: The Comparison of Short-term and Long-term Indicators)

  • 김강자
    • 가정과삶의질연구
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    • 제11권1호
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    • pp.107-118
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    • 1993
  • A dimension of well-being economic security was analyzed and compared with economic adequacy. Again it was tested whether two indicators of economic security(short-term vs. long-term) yield same distribution across all household groups. Economic Security was defined as the household ability to sustain a given level of consumption in the case of economic emergency; specifically loss of income. Measure of 8 different kinds of economic security were constructed from household net worth including and excluding home equity. Data were taken from the 1988 U.S. Consumer Expenditure Survey and 2148 households were selected to test hypotheses concerning the economic security of American households Empirical results showed a very low level of economic security in general. The first hypothesis that distribution of economic adequacy and economic security are same across all population groups was rejected. On the average security measure rather than adequacy measure was favor to white female-headed households and households who have old and highly educated house-holder. The second hypothesis that the indicators of long-term and short-term economic security yield the same results across all household was not rejected. In general the level of economic security was relatively higher when long-term indicator was used than short-term indicator was however the direction and relative size of effect of income and each control variable was almost same.

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산업부산물을 이용한 비소성 고화제 혼합토의 역학적 특성 (Engineering Characteristics of Non-sintering Binder-stabilized Mixture using Industrial By-Products)

  • 윤대호;문경주;김윤태
    • 한국해양공학회지
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    • 제28권2호
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    • pp.140-146
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    • 2014
  • This study investigated the engineering characteristics of non-sintering binder-stabilized mixtures consisting of different ratios of a hardening agent(3%, 6%, 9%, 12%) for recycling industrial by-products through several series of laboratory tests. The hardening agents consisted of two kinds of non-sintering binders(NSB-1, NSB-2), which were developed by using inter-chemical reactions among blast furnace slag, phospho-gypsum, and an alkali activator. In addition, ordinary Portland cement(OPC) was used to compare the engineering characteristics of the stabilized mixture. An unconfined compressive test showed that the unconfined compressive strength increased with the curing time and mixing ratio. Experimental test results indicated that the 7-day strength of the NSB-1 mixture was similar to that of the OPC mixture. However, its 28-day strength was higher than that of the OPC mixture. The secant module of elasticity showed a range of $E_{50}=(42-109)q_u$ regardless of the agents. Based on the results of triaxial tests, the cohesion and friction angle increased with the mixing ratio.

전이학습을 수행한 신경망을 사용한 압축센싱 심장 자기공명영상 (Compressed-Sensing Cardiac CINE MRI using Neural Network with Transfer Learning)

  • 박성재;윤종현;안창범
    • 전기전자학회논문지
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    • 제23권4호
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    • pp.1408-1414
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    • 2019
  • 전이학습을 수행한 심층 인공신경망을 압축센싱 심혈관 자기공명영상에 적용하였다. 전이학습은 선행학습 신경망의 구조나 필터 커널, 가중치를 현재의 학습이나 응용에 활용하는 방법이다. 전이학습은 학습 속도를 향상시키고, 학습 데이터가 제한적일 때 신경망의 일반화에 도움이 된다. 8명의 건강한 지원자가 참여한 심장 자기공명영상 실험에서 전이학습을 수행한 신경망은 단독학습 신경망에 비해 학습시간이 5배 이상 단축되었다. 시험 데이터에 대해서도 전이학습을 수행한 신경망은 전이학습을 수행하지 않은 신경망에 비하여 낮은 정규화 평균제곱오차와 향상된 재구성 영상화질을 보였다.

J적분에 의한 SB41강의 피로균열 진전 특성 평가 (Description of crack growth behavior of SB41 steel in terms of J integral)

  • 배원호;김상태;이택순
    • 대한기계학회논문집
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    • 제14권6호
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    • pp.1568-1575
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    • 1990
  • 본 연구에서는 중앙균열을 가진 SB41강의 평판이 하중제어와 변형률제어 피로 상태에서 소규모 항복, 대규모 항복, 또는 전면 항복의 각 응력에서 피로균열 진전 속 도와 J적분 범위, .DELTA.J와의 관계를 조사하는 한편, 피로균열 진전 속도를 지배하는 국 소적 역학 인자인 균열선단 개구변위, COD와 균열 진전 속도와 관계 및 그 특성을 고 찰하였다.

A Lattice-Based Monte Carlo Evaluation of Canada Deuterium Uranium-6 Safety Parameters

  • Kim, Yonghee;Hartanto, Donny;Kim, Woosong
    • Nuclear Engineering and Technology
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    • 제48권3호
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    • pp.642-649
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    • 2016
  • Important safety parameters such as the fuel temperature coefficient (FTC) and the power coefficient of reactivity (PCR) of the CANada Deuterium Uranium (CANDU-6) reactor have been evaluated using the Monte Carlo method. For accurate analysis of the parameters, the Doppler broadening rejection correction scheme was implemented in the MCNPX code to account for the thermal motion of the heavy uranium-238 nucleus in the neutron-U scattering reactions. In this work, a standard fuel lattice has been modeled and the fuel is depleted using MCNPX. The FTC value is evaluated for several burnup points including the mid-burnup representing a near-equilibrium core. The Doppler effect has been evaluated using several cross-section libraries such as ENDF/B-VI.8, ENDF/B-VII.0, JEFF-3.1.1, and JENDL-4.0. The PCR value is also evaluated at mid-burnup conditions to characterize the safety features of an equilibrium CANDU-6 reactor. To improve the reliability of the Monte Carlo calculations, we considered a huge number of neutron histories in this work and the standard deviation of the k-infinity values is only 0.5-1 pcm.

DETERMINATION OF THE TRANSURANIC ELEMENTS INVENTORY IN HIGH BURNUP PWR SPENT FUEL SAMPLES BY ALPHA SPECTROMETRY-II

  • Joe, Kih-Soo;Song, Byung-Chul;Kim, Young-Bok;Jeon, Young-Shin;Han, Sun-Ho;Jung, Euo-Chang;Song, Kyu-Seok
    • Nuclear Engineering and Technology
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    • 제41권1호
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    • pp.99-106
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    • 2009
  • The contents of transuranic elements ($^{237}Np$, $^{238}Pu$, $^{239}Pu$, $^{240}Pu$, $^{241}Am$, $^{244}Cm$, and $^{242}Cm$) in high-burnup spent fuel samples ($35.6{\sim}53.9\;GWd/MtU$) were determined by alpha spectrometry. Anion exchange chromatography and diethylhexyl phosphoric acid extraction chromatography were applied for the separation of these elements from the uranium matrix. The measured values of the nuclides were compared with ORIGEN-2 calculations. For plutonium, the measurements were higher than the calculations by about $2.6{\sim}32.7%$ on average according to each isotope, and those for americium and curium were also higher by about $35.9{\sim}63.1%$. However, for $^{237}Np$, the measurements were lower by about 52% on average for the samples.