• 한국식품과학회지
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• 제43권3호
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• pp.375-380
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• 2011

DSG에 몰로키아 분말을 첨가하여 발효시킨 발효물이 콜레스테롤 개선효과를 가지는지 in vitro 및 in vivo에서 살펴보았다. B. subtilis NUC1균주로 발효한 탈지대두 grits 발효물인 FD와 탈지 대두 grit에 몰로키아를 5, 10%로 각각 첨가하여 발효한 FDC군의 콜레스테롤 흡착능을 살펴본 결과, 모든 군에서 70% 이상의 흡착능을 보였다. HepG2 세포를 이용한 apo-AI, apo-CIII의 분비능 측정에서는 FD군에 비해 몰로키아를 첨가한 FDC군에서 더 우수한 개선효과를 보였다. 한편 FDC가 고지방식이를 급여한 흰쥐의체내 콜레스테롤 개선에 미치는 영향을 살펴보고자, 기본식이군(Con), 고지방식이군(HF) 그리고 고지방식이와 FD첨가군(HFFD), 고지방식이와 FDC 첨가군(HF-FDC)으로 나누어 4주간 사육하였다. 그 결과, 혈장 내 총콜레스테롤 및 LDL-콜레스테롤 함량, 그리고 간 조직 내의 총콜레스테롤 및 중성지질 함량은 HF군에서 증가하였다가 HF-FDC 첨가군에서 유의적으로 감소하였고, 분변 내의 콜레스테롤 및 중성지질 배설량은 FDC 투여로 인해서 HF군에 비해 증가하였다. 또한 간내 HMG-CoA reductase 활성은 HF군에서 증가되었다가, HF-FDC첨가군에서 유의성 있게 감소되었다. 따라서 FDC는 콜레스테롤 흡착 및 조절능을 가지며, 그리고 혈중 콜레스테롤 함량, 조직 내의 지질 및 콜레스테롤 축적을 감소시켜 체내 콜레스테롤 개선에 효과적인 것으로 생각된다.

• 대한토목학회논문집
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• 제30권4A호
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• pp.337-342
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• 2010

일반적으로 하천 시설에 사용되는 수문은 기계식 및 유압식, 혼합식 권양기에 의하여 개폐되며, 구조물의 크기 및 구조상 2개 이상의 인양장치로 동조를 이루며 안전하게 개폐되어야 한다. 수문의 개폐 시 설계상 정확히 고려할 수 없는 수압 및 마찰로 인하여 구조물에 추가적인 하중이 발생하게 된다. 이러한 추가적인 하중은 수문의 끼임 현상 및 권양기의 과부하 등을 초래하고, 이는 수문의 안전에 중대한 영향을 미치게 된다. 본 논문에서는 이러한 수문의 개폐 시 발생하는 불안전한 요소에 대응하여 권양기가 동조를 이룰 수 있도록 유압 및 변위를 동시에 고려한 FDC(Force-Displacement Control)시스템을 설계하였다. 설계된 FDC 시스템을 XG5000프로그램의 PID 기능을 이용하여 구현하였으며, 다중 유압 실린더 수문 권양기(winch) 모형을 제작하여 FDC 시스템을 실험적으로 검증하였다. 실험 결과 개발한 FDC 시스템은 수문의 개폐 시 발생하는 다양한 외부하중에 대응하여, 다중 유압 실린더로 이루어진 수문 권양기가 동조를 이루며 개폐됨을 확인하였다. 실험 결과로부터 FDC 시스템은 수문 권양기에 적용시 효과적임을 확인 하였다.

• 한국물환경학회지
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• 제35권6호
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• pp.481-496
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• 2019

The Ministry of Environment has measured streamflow at eight-day intervals for the estimation of standard flow of the Total Maximum Daily Loads (TMDL) system. This study identified the availability of the partially measured the eight-day interval data for estimating standard flow and found the optimal extension techniques of standard flow. The study area was selected for the Nakbon-A watershed in the Nakdong River, and four streamflow record extension techniques of standard flow were considered: extension, percentile, drainagearea, and regional regression methods. The flow duration curve (FDC) using the eight-day interval streamflow data indicated very high Nash and Sutcliffe Efficiency (NSE) values above 90 % from FDC-II to FDC-VII compared to FDC-VIII, the standard FDC. This result demonstrates that FDC using daily data of three-six cumulative years could represent standard FDC fairly well. For the streamflow record extension techniques of standard flow, the percentile method was selected as the optimal alternative, showing the minimal difference from FDC-VIII. These results validate the availability of the eight-day interval streamflow data in the standard flow estimation and the application of extension techniques. It seems that these results could reduce the uncertainty of partially measured streamflow data for water quantity and quality management.

• 한국물환경학회지
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• 제29권3호
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• pp.343-353
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• 2013

Flow duration curve (FDC) can be developed by linking the daily flow data of stream flow monitoring network to 8-day interval flow data of the unit watersheds for the management of Total Maximum Daily Loads. This study investigated the applicable method for the development of long term FDC with the selection of the stream flow reference sites, and suggested the development of the FDC in 4 river basins. Out of 142 unit watersheds in 4 river basins, 107 unit watersheds were shown to estimate daily flow data for the unit watersheds from 2006 to 2010. Short term FDC could be developed in 64 unit watersheds (45%) and long term FDC in 43 unit watersheds (30%), while other 35 unit watersheds (25%) were revealed to have difficulties in the development of FDC itself. Limits in the development of the long term FDC includes no stream monitoring sites in certain unit watersheds, short duration of stream flow data set and missing data by abnormal water level measurements on the stream flow monitoring sites. To improve these limits, it is necessary to install new monitoring sites in the required areas, to keep up continuous monitoring and make normal water level observations on the stream flow monitoring sites, and to build up a special management system to enhance data reliability. The development of long term FDC for the unit watersheds can be established appropriately with the normal and durable measurement on the selected reference sites in the stream flow monitoring network.

• 한국물환경학회지
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• 제28권2호
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• pp.224-231
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• 2012

It is necessary to develop flow duration curve (FDC) on each unit watershed in order to analyze flow conditions in the stream for the management of Total Maximum Daily Loads (TMDLs). This study investigated a simple method to develop FDC for the general use of the curve. A simple equation for daily flow estimation was derived from the regression analysis between the 8-day interval flow data of a unit watershed and the daily flow monitoring data of an adjacent upstream region. FDC can be prepared with the calculation of daily flow by the equation for each unit watershed. An annual and a full-period FDC were drawn for each unit watershed in Guem river basin. Standard flow such as low and ordinary flow can be obtained from the annual FDC. Major percentile of flow such as 10, 25, 50, 75 or 90% can be obtained from the full-period FDC. It is considered that this simple method of developing FDC can be utilized more widely for the calculation of standard flow and the assessment of water quality in the process of TMDLs.

• 한국습지학회지
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• 제20권2호
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• pp.136-144
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• 2018

환경부에서는 유역단위의 통합 물관리를 위하여 물환경관리계획, 수질오염총량제 등을 실시하고 있으며, 측정망에서 측정된 수질을 이용하여 설정된 목표수질의 달성 정도를 판단하고 있다. 유역 하류부에 위치한 측정망의 지점에서의 수질 농도는 유역의 각 지류에서 오염원 유입과 하천의 자정작용 등의 복잡한 메커니즘을 거쳐서 만들어진 결과물이다. 이에 본 연구에서는 유역의 오염원 추적 및 초과율을 이용해 본류 및 지류의 수질이 목표수질 지점에 미치는 영향의 정도에 대하여 분석하였다. 이를 위해 오염총량제의 대상물질인 BOD와 T-P를 포함한 총 6가지의 수질항목에 대하여 FDC와 초과율 분석을 수행하였고, 이를 통해 목표수질 지점에 유황별 영향을 미치는 수질항목 및 지점을 도출할 수 있었다. 본 연구에서 제시한 FDC 분석을 통한 오염원 추적은 목표수질 달성을 위해 지류별 수질관리 전략을 보다 효율적으로 수립할 수 있을 것이다.

• 한국임상약학회지
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• 제32권1호
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• pp.13-19
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• 2022

Background: The use of combination therapy and fixed-dose combination therapy is increasing for the treatment of type 2 diabetes. Sodium glucose cotransporter-2 inhibitor (SGLT2i) is a drug class used in combination with metformin. Methods: Type 2 diabetes patients on SGLT2i/metformin combination therapy were extracted from the 2019 Health Insurance Review & Assessment Service-National Patients Sample. On July 1, 2019, SGLT2i and metformin fixed-dose combination (SGLT2i/metformin FDC) and two-pill combination (TPC) groups were identified, and a chi-square test and multiple logistic regression were performed. Results: Of total 2,992 patients, 1,077 (36%) were prescribed SGLT2i/metformin FDC and 1,915 (64%) were prescribed TPC. We found that the most common comorbidities were in the order of dyslipidemia, gastrointestinal disease, and hypertension. Multiple logistic regression analysis showed that the use of SGLT2i/metformin FDC was lower than TPC in patients with diabetic neuropathy (OR=0.76, p=0.008). Clinic (OR=2.09, p<0.001) and general hospital (OR=1.40, p=0.019) showed higher tendency to prescribe SGLT2i/metformin FDC compared to tertiary hospital. The tendency of prescribing SGLT2i/metformin FDC was lower in Kyeonggi (OR=0.79, p=0.037), Gyeongsang (OR=0.77, p=0.025) and Chungcheong (OR=0.68, p=0.007) than Seoul. Conclusion: Factors related to the use of SGLT2i/metformin FDC in patients with type 2 diabetes were complication, medical institution and region. The tendency to prescribe SGLT2i/metformin FDC was relatively higher in clinics than in tertiary general hospitals and in Seoul than in other regions.

• IMMUNE NETWORK
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• 제3권3호
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• pp.176-181
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• 2003

Background: The molecular basis of follicular dendritic cells (FDC)-germinal center (GC) B cell interaction is largely unknown, although this cellular interaction is thought to be important for the whole process of GC B cell differentiation. Methods: Using FDC-like cells, HK, and highly purified GC B cells, we attempted to identify the molecules that play critical roles in the interactions between FDC and B cells. GC B cells were co-cultured with HK cells and soluble CD154 in the presence or absence of various function-blocking monoclonal antibodies to examine their effect on GC B cell binding to HK cells and B cell proliferation. Results: Anti-CD11a and anti-CD54 antibodies inhibited GC B cell binding to HK cells while anti-CD49d and anti-CD106 antibodies did not. GC B cell proliferation was not impaired by the disruption of GC B cell-HK cell adherence. Conclusion: Our results suggest that CD11a/CD18-CD54 interactions play an important roles in the initial binding of GC B cells to FDC and diffusible growth factors from FDC may be responsible the massive proliferation of GC B cells.

• 한국물환경학회지
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• 제35권6호
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• pp.497-509
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• 2019

After the Total Maximum Daily Loads(TMDLs) was applied, it became beyond the limit of concentration management. However, it does not adequately reflect the characteristics of various watersheds, and causes problems with local governments because of the standard flow set. Thus, in this study, the Han River system is organized into four groups in estimating the Pollution Contribution by applying the Flow Duration Curve(FDC) created by the daily flow of data from the HSPF. And the method of this study is expected to be valuable as basic data for the TMDLs. As a result, Group I contains the main watersheds with no large hydraulic structures and tributary watersheds. There is no specificity in the FDC and the Pollution Contribution is estimated as rainfall runoff. Group II contains watersheds near the city where the FDC is maintained above a certain level during the Low Flow Conditions and the Pollution Contribution is estimated as the discharge flow of large scale point pollution facilities. Group III contains the main watersheds in which the large hydraulic structures are installed and FDC is curved in the Low Flow Conditions. So the Pollution Contribution is estimated as the water quality of the large hydraulic structures. Group IV contains the upstream in mainstream watersheds in which the large hydraulic structures are installed and the FDC is disabled before the Low Flow Conditions. As the flow is concentrated in the High Flow Conditions, the non-point pollution sources are estimated as the Pollution Contribution.

• 전력전자학회논문지
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• 제27권1호
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• pp.26-32
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• 2022

This paper proposes a power system that includes a 120k W fuel cell DC-DC converter (FDC) and 30 kW bidirectional DC-DC converter (BHDC) for a 150 kW fuel-cell vehicle. With a high DC link voltage of 800 V, the efficiency and power density of the power electronic components are improved. Through the modular design of FDC and BHDC, electric components are shared, resulting in reduced mass production costs. The switching frequency of 30 kHz of full SiC devices and optimal design of coupled inductor reduce the volume, achieving a power density of 8.3 kW/L. Furthermore, a synergetic operation strategy using variable limiter control of FDC and BHDC was proposed to efficiently operate the fuel cell vehicle considering the fuel cell stack efficiency according to the load. Finally, the performance of the prototype was verified by Highway Fuel Economy Driving Schedule testing, EMI test, and the linked operation between FDC and BHDC. The full load efficiencies of the FDC and BHDC prototypes are 98.47% and 98.74%, respectively.