• 제목/요약/키워드: Regional flow

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Rubidium-82 심근 Dynamic PET 영상과 이중적분법을 이용한 국소 심근 혈류 예측의 기본 모델 연구 (Regional Myocardial Blood Flow Estimation Using Rubidium-82 Dynamic Positron Emission Tomography and Dual Integration Method)

  • 곽철은;정재민
    • 대한의용생체공학회:의공학회지
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    • 제16권2호
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    • pp.223-230
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    • 1995
  • Rb-82 dynamic PET과 이중적분법에 의한 국소 심근 혈류측정 연구를 시행하고자 실험 개를 이용한 심근 경색 모델과 허혈성 심근질환에서 좌심실 입력함수에 의한 정상 및 관류결손 심근에서의 혈류를 측정하였다. 이중적분법이 선형회귀모델에 의한 혈류측정방법에 비하여 안정도가 높고 심근내혈류가 선형적인 가정을 배제할 수 있어 사용 가능한 방법이 될 수 있음을 확인하였다.

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통근통행에 의한 직·간접 흐름을 이용한 지역의 중심성 분석 (Analysis of Regional Centrality by Investigating Direct and Indirect Flows of Commuters)

  • 이종상;서덕수
    • 농촌지도와개발
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    • 제27권3호
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    • pp.125-134
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    • 2020
  • The regional centrality plays a very important role in national and regional planning and it is measured by data such as people, goods, and information flows among regions. The inter-regional flows are usually considered by only direct flows, yet indirect flows, which are generated accordingly from direct flows, are not critically considered. Most centrality studies have also hardly reflected the indirect flow in the network analysis. This study demonstrates the significance of the indirect flows to enhance accuracy of the regional centrality. The nationwide dataset of inter-regional commuter traffic matrix is used in this study and analysed into two groups; one to consider only direct flow and the other both direct and indirect flows. The results indicate remarkable differences of centrality raking between two groups such as Yeongam of Jeonnam Province(+60th), Eumseong of Chungbuk Province(+57th), Gwacheon of Gyeonggi Province (-35th), and Nowon of Seoul (-32nd). It clearly shows the significant influence of indirect flow for regional centrality study. This also reveals regional centrality ranking in Korea by considering direct and indirect flows of commuters. Jung, Gangnam, and Jongno of Seoul are categorized in the highest rank group and Ulleung of Gyeongbuk, Ongjin of Incheon, and Jindo of Jeonnam are in the lowest group. The top group includes seven districts of Seoul, two of Busan, and one of Gyeonggi Province. The bottom group includes mostly island and costal areas. As this study shows an accurate method of centrality measurement, it has a significant implication to lead an effective regional planning.

생맥산(生脈散)이 혈압(血壓) 및 국소뇌혈류량(局所腦血流量)에 미치는 영향(影響) (Effect of SAENGMAEKSAN extract on blood pressure and, regional cerebral blood flow)

  • 신대철;김영균;한종현;문구;김재섭
    • 대한한방내과학회지
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    • 제18권2호
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    • pp.167-176
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    • 1997
  • The purpose of this study was to investigate the effect of SAENGMAEKSAN extract on blood pressure and regional cerebral blood flow in rats. 1. High concentration of SAENGMAEKSAN extract decresed mean blood pressure in rats. 2. By depend on the dosage of SAENGMAEKSAN extract incresed mean regional cerebral blood flow in rats.

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갈수기 유량 확보에 따른 섬강 및 남한강 본류 갈수기 수질 개선 효과 분석 (Analysis of the Effect of Water Quality Improvement on Seomgang and South Han River by Securing the Flow during the Dry Season)

  • 이서로;이관재;한정호;이동준;김종건;임경재
    • 한국농공학회논문집
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    • 제61권2호
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    • pp.25-39
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    • 2019
  • The water pollution Accident in the South Han River is increasing due to increase of pollutants inflow from small streams from rural areas and reduced flow rate. This study predicted the change of water quality in the main stream of the South Han River due to climate change through the linkage of watershed and water quality models. Also, This study analyzed the effect of water quality improvement on Seomgang and the South Han River by securing the flow during the dry season. According to the scenarios for securing the river flow during drought season, the river flow in the Seomgang is increased up to 2.19 times, and the water quality during the drought season was improved up to $BOD_5$ 20.5%, T-N 40.8%, T-P 53.4%. Also, the water quality of the main stream of the South Han River improved to 5.22% of $BOD_5$, 5.42% of T-N and 7.69% of T-P as the river flow was secured from the Seomgang. The result of this study confirms that securing the baseflow in the Seomgang according to the scenarios for securing the river flow during the dry season has a positive effect on the improvement of the water quality of the rivers in the main river of the Seomgang and South Han River. The results of this study will contribute to the establishment of reasonable management to improve the water quality of the main stream of the Seomgang and South Han River.

유량자료의 시간적 연속성 변화가 오염부하지속곡선에 미치는 영향 비교 분석 (Influence Analysis of Temporal Continuity Change of Flow Data on Load Duration Curve)

  • 권필주;한정호;류지철;김홍태;임경재;김종건
    • 한국물환경학회지
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    • 제33권4호
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    • pp.394-402
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    • 2017
  • In korea, TMDL is being implemented to manage nonpoint pollution sources as well as point pollution sources. LDC is being used for the planning of TMDL. In order to analyze the water quality using LDC, it is necessary to prepare FDC using the daily flow data. However, only the daily flow data is measured at the WAMIS branch, and 8days flow data and water quality data are measured at the monitoring Networks. So, in many researches, the water quality is being grasped by deriving the LDC using the 8days flow or the daily flow obtained by various methods. These fluctuations may lead to differences in determining whether the target load is achieved. In this study, each LDC was prepared using the 8day flow and the related daily flow. Then, the effect using different flow data on the achievement of target load was compared according to flow conditions. As a result, the difference ratio in the number of overloads under flow condition was showed 19% in high flows, 42% in moist conditions, 49% in mid-range flows, 41% in dry conditions, and 104% in low flows. In the top ten watershed with the highest difference ratio, the flow became lower the difference ration increases. These differences can cause uncertainty in assessing the achievement of target load using LDC. Therefore, in order to evaluate the water quality accurately and reliably using LDC, accurate daily flow data and water quality data should be secured through the installation of national nonpoint measurement network.

정보공간구조의 형성과 물ㆍ인적 자원재편에 관한 고찰 (A Study on the Reorganization of Material and Labour in the Information Space Structure)

  • 원동규
    • 기술혁신학회지
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    • 제6권1호
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    • pp.20-40
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    • 2003
  • Many studies have regarded an information infrastructure as one of the crucial factors for national or regional innovation in the information society, but few studies have empirically tested the role and the effects of it. Also, the information society have been studied to what extent, but information space structure and the reorganization for the resource of the material and the labour have not been considered. Therefore, this study is examining the relation between the linkage structure and the information change in the manufacturing sector. And for the empirical analyses, regional labour data for 16 Metropolitan Areas(Si) and Provinces(Do) in 1991-1996 are used. An analytical model and hypotheses are proposed for empirical testing. The main finding is that if inter-regional wages condition is identical, inter-regional labour flow has positive correlations with regional information level.

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환경부 8일 유량.수질 자료를 이용한 SWAT 자동보정 모듈 개선 및 적용 평가 (Enhancement and Application of SWAT Auto-Calibration using Korean Ministry of Environment 8-Day Interval Flow/Water Quality data)

  • 강현우;류지철;강형식;최재완;문종필;최중대;임경재
    • 한국물환경학회지
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    • 제28권2호
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    • pp.247-254
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    • 2012
  • Soil and Water Assessment Tool (SWAT) model has been widely used in estimation of flow and water quality at various watersheds worldwide, and it has an auto-calibration tool that could calibrate the flow and water quality data automatically from thousands of simulations. However, only continuous measured day flow/water quality data could be used in the current SWAT auto-calibration tool. Therefore, 8-day interval flow and water quality data measured nationwide by Korean Ministry of Environment (MOE) could not be used in SWAT auto-calibration even though long-term flow and water quality data in the Korean Total Maximum Daily Load (TMDL) watersheds available. In this study, current SWAT auto-calibration was modified to calibrate flow and water quality using 8-day interval flow and water quality data. As a result of this study, the Nash and Sutcliffe Efficiency (NSE) values for flow estimation using auto-calibration are 0.77 (calibration period) and 0.68 (validation period), and NSE value for water quality (T-P load) estimation (using the 8-day interval water quality data) is 0.80. The enhanced SWAT auto-calibration could be used in the estimation of continuous flow and water quality data at the outlet of TMDL watersheds and ungaged point of watersheds. In the next study, the enhanced SWAT auto-calibration will be integrated with Web based Load Duration Curve (LDC) system, and it could be suggested as methods of appraisal of TMDL in South Korea.

석류가 뇌혈류 및 비만에 미치는 실험적 효과 (The Experimental Effects of Pomegranate on the Cerebral Blood Flow and Obesity in Rats)

  • 정현우;전병관
    • 한국식품영양학회지
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    • 제20권2호
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    • pp.143-149
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    • 2007
  • To examine the effects of pomegranate on cerebral blood flow and obesity, we observed regional cerebral blood flow in normal rats, as well as body weight, serum total cholesterol, serum HDL-cholesterol, serum LDL-cholesterol, serum triglycerides, serum total lipids, serum phospholipids and serum free fatty acid levels in rats fed a high fat diet. The results were as follows. Pomegranate seed extract significantly increased regional cerebral blood flow and the peel extract increased regional the cerebral blood flow in a dose dependent manner. In addition, the pomegranate extracts(seed, peel, juice) decreased body weight, serum total cholesterol, serum LDL-cholesterol, serum triglycerides, serum total lipids, serum phospholipids and serum free fatty acid levels, and increased serum HDL-cholesterol in the rats fed a high fat diet. More specially the seed extract significantly decreased serum total cholesterol, serum triglycerides and serum phospholipid levels.

영상분할을 이용한 의학영상에서의 심장혈류 측정 (The Estimation of Blood Velocity from Heart in Medical Images using Regional Segmentation)

  • 정철곤;김중규;김경섭
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1999년도 추계종합학술대회 논문집
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    • pp.517-520
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    • 1999
  • In this paper, we propose a non-invasive method to estimate blood velocity from the real medical images. To measure the magnitude and direction components associated with the blood velocity, we apply the optical flow analysis algorithm. It is demonstrated that the accuracy of the blood velocity estimate could possibly be increased by segmenting the optical flow region. We call this the Region Optical Flow(ROF) algorithm. We carried out some preliminary experiments using the aorta medical images, and corresponding regional optical flow diagrams are provided.

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분산처리 최적조류계산 기반 연계계통 급전계획 알고리즘 개발 (A New Dispatch Scheduling Algorithm Applicable to Interconnected Regional Systems with Distributed Inter-temporal Optimal Power Flow)

  • 정구형;강동주;김발호
    • 전기학회논문지
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    • 제56권10호
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    • pp.1721-1730
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    • 2007
  • SThis paper proposes a new dispatch scheduling algorithm in interconnected regional system operations. The dispatch scheduling formulated as mixed integer non-linear programming (MINLP) problem can efficiently be computed by generalized Benders decomposition (GBD) algorithm. GBD guarantees adequate computation speed and solution convergency since it decomposes a primal problem into a master problem and subproblems for simplicity. In addition, the inter-temporal optimal power flow (OPF) subproblem of the dispatch scheduling problem is comprised of various variables and constraints considering time-continuity and it makes the inter-temporal OPF complex due to increased dimensions of the optimization problem. In this paper, regional decomposition technique based on auxiliary problem principle (APP) algorithm is introduced to obtain efficient inter-temporal OPF solution through the parallel implementation. In addition, it can find the most economic dispatch schedule incorporating power transaction without private information open. Therefore, it can be expanded as an efficient dispatch scheduling model for interconnected system operation.