• 수산경영론집
• /
• 제30권1호
• /
• pp.1-29
• /
• 1999

When the international fisheries order changes following the UN Law of the Sea, the new regional fisheries order is forming among East North Asian states and era of Economic Zones is really coming. In those changes of foreign and domestic fisheries environment, to maintain sustainable growth of the industry in 21st century the North East Asian states plot adjustments to fisheries management, such as introduction of the TAC system and others. The TAC seems to be an appropriate systematic response especially because traditional functions of fisheries management have already demonstrated their limits in regards to fisheries sustainable development. Introduction of the TAC to the North East Asian fisheries not only resolves the inability of traditional fisheries management to develop the industry consequently, but also strengthens the EEZ and existing marine management systems. However, the TAC was born by thewestern industrial mentality, still contains persistent mistakes and is difficult to change. Therefore, its introduction to and implication in North East Asian region might cause numerous problems. From this point of view, introduction of the TAC system will disregard peculiarities of North East Asian fisheries, so main efforts should be concentrated on improving the functions of existing system via consecutive step-by-step approach. In addition, the TAC should be grafted into the existing fisheries system through cooperative management system, creating stable systematic ground and considering scientific and fisheries motives. Especially, TAC system, unlike the traditional fisheries' management system, is scientific, being systematically developed one, and needs to be gradually installed, considering its systematic character. Therefore, the TAC should better be introduced by systematic and scientific approaches, paying more attention to strengthening the existing fisheries system, but not immediately and in the form it is right now. Concluding, introduction of the TAC can not be made considering the outward factors deriving from the UN Law of the Sea without corrections.'h overcome limitations and ineffectiveness of traditional fisheries, most efforts should be concentrated on basic revision of 21st centuries' fisheries and strengthening the functions of traditional fisheries aimed to develop the leading business of marine industries.

• 한국항공우주학회지
• /
• 제31권7호
• /
• pp.118-126
• /
• 2003

본 연구에서는 모듈형태의 배터리 충-방전기가 정상상태뿐만 아니라 과도상태에서 예기치 못한 결함이 발생할지라도 실패 없이 전원을 공급하는 것이 가능한 병렬형 양방향 컨버터로 설계되어졌다. 컨버터 모듈은 안정성, 성능 및 고신뢰성을 얻기 위해 독립적인 제어가 가능하도록 설계되었으며, 제어기를 위해 사용된 평균전류모드방식은 노이즈 면역, 빠른 응답 및 평균전류 신호 획득과 같은 장점을 갖는다. 병렬 연결된 배터리 충-방전기에 대한 등가모델이 제시되었으며, 충전연속모드, 방전연속/불연속 모드에 대한 전달함수가 분석되었다. 병렬 양방향 컨버터는 스텝 부하변화와 하나의 컨버터 모듈 실패에 대해 각각 수행되었다. 그리고 병렬 양방향 컨버터의 성능이 실험결과들을 통해 검증되었다.

• Nuclear Engineering and Technology
• /
• 제53권1호
• /
• pp.44-60
• /
• 2021

In this paper, we validate the decay heat calculation capability via a two-step method to analyze spent nuclear fuel (SNF) discharged from pressurized water reactors (PWRs). The calculation method is implemented with a lattice code STREAM and a nodal diffusion code RAST-K. One of the features of this method is the direct consideration of three-dimensional (3D) core simulation conditions with the advantage of a short simulation time. Other features include the prediction of the isotope inventory by Lagrange non-linear interpolation and the use of power history correction factors. The validation is performed with 58 decay heat measurements of 48 fuel assemblies (FAs) discharged from five PWRs operated in Sweden and the United States. These realistic benchmarks cover the discharge burnup range up to 51 GWd/MTU, 23.2 years of cooling time, and spanning an initial uranium enrichment range of 2.100-4.005 wt percent. The SNF analysis capability of STREAM is also employed in the code-to-code comparison. Compared to the measurements, the validation results of the FA calculation with RAST-K are within ±4%, and the pin-wise results are within ±4.3%. This paper successfully demonstrates that the developed decay heat calculation method can perform SNF back-end cycle analyses.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권4호
• /
• pp.1712-1731
• /
• 2016

In this paper, we propose a novel saliency detection framework via multiple random walks (MRW) which simulate multiple agents on a graph simultaneously. In the MRW system, two agents, which represent the seeds of background and foreground, traverse the graph according to a transition matrix, and interact with each other to achieve a state of equilibrium. The proposed algorithm is divided into three steps. First, an initial segmentation is performed to partition an input image into homogeneous regions (i.e., superpixels) for saliency computation. Based on the regions of image, we construct a graph that the nodes correspond to the superpixels in the image, and the edges between neighboring nodes represent the similarities of the corresponding superpixels. Second, to generate the seeds of background, we first filter out one of the four boundaries that most unlikely belong to the background. The superpixels on each of the three remaining sides of the image will be labeled as the seeds of background. To generate the seeds of foreground, we utilize the center prior that foreground objects tend to appear near the image center. In last step, the seeds of foreground and background are treated as two different agents in multiple random walkers to complete the process of salient object detection. Experimental results on three benchmark databases demonstrate the proposed method performs well when it against the state-of-the-art methods in terms of accuracy and robustness.

• 한국수자원학회논문집
• /
• 제43권12호
• /
• pp.1083-1091
• /
• 2010

분포형 수문 모형의 일강우 입력 자료는 불가피하게 불규칙하고 밀도가 낮은 관측망에서 기록된 값을 내삽해 사용하게 되나, 흔히 사용되는 대부분의 내삽법들은 실제 일강우의 다양한 공간적 분포를 잘 재현하지 못하는 문제가 있다. 본 연구에서는 널리 사용되는 다섯 가지의 강우 내삽 방법을 두개의 유역에 사용하여 비교하고 실제 공간적 분포를 보다 잘 나타낼 수 있는 2단계 내삽법을 제안하였다. 비교에 사용된 내삽법은 (1) 역가중치 방법(IDW), (2) 다중회귀분석 (MLR), (3) 월강우를 이용한 다중회귀분석법(CMLR), (4) 국지가중치 다중회귀분석(LWP) 등이다. 보다 향상된 내삽을 위한 2단계 내삽법은 먼저 로지스틱 회귀분석으로 강우-비강우 지역을 구분하고 강우 지역에서만 기존의 내삽법을 적용하여 강우량을 구하는 방법이다. 기존 방법과의 비교결과 공간적인 편차가 심한 일강우의 특성을 2단계 내삽법에서 잘 표현하고 있는 것으로 나타났다. 제안된 방법은 수문모형에의 적용뿐만 아니라 유출량의 예보 및 대기 순환 모형의 다운 스케일링에도 효과적으로 사용될 수 있을 것으로 기대된다.

• 정보처리학회논문지D
• /
• 제11D권7호
• /
• pp.1385-1398
• /
• 2004

본 논문에서는 시계열 데이터베이스에서 타임 워핑 하의 서브시퀀스 매칭을 효과적으로 처리하는 방안에 관하여 논의한다. 타임 워핑은 시퀀스의 길이가 서로 다른 경우에도 유사한 패턴을 갖는 시퀀스들을 찾을 수 있도록 해 준다. 먼저, 사전 실험을 통하여 기존의 기본적인 처리 방식인 Naive-Scan의 성능 병목이 CPU 처리 과정에 있음을 지적하고, Naive-Scan의 CPU 처리 과정을 최적화하는 새로운 기법을 제안한다. 제안된 기법은 질의 시퀀스와 서브시퀀스들간의 타임 워핑 거리들을 계산하는 과정에서 발생하는 중복 작업들을 사전에 제거함으로써 CPU 처리 성능을 극대화한다. 제안된 기법이 착오 기각을 발생시키지 않음과 Naive-Scan을 처리하기 위한 최적의 기법임을 이론적으로 증명한다. 또한, 제안된 기법을 기존의 타임 워핑 하의 서브시퀀스 매칭 기법인 LB-Scan과 ST-Filter의 후처리 정량적으로 검증한다. 실험 결과에 의하면, 기존의 타임 워핑 하의 서비시퀀스 매칭을 위한 모든 기법들이 제안된 최적화 기법에 의하여 성능이 개선되는 것으로 나타났다. 특히, Nsive-Scan은 최적화 기법의 적용 전에는 가장 떨어지는 성능을 보였으나, 최적화 기법의 적용 후에는 모든 경우에서 ST-Filter나 LB-Scan을 사용한 경우보다 더 좋은 성능을 보였다. 이것은 성능 병목인 CPU 처리 과정을 최적화함으로써 기존 기법들인 Naive-Scan, LB-Scan, ST-Filter 간의 처리 성능 상의 순위 역전 현상이 발생하였음을 보이는 매우 중요한 결과이다.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
• /
• pp.230.1-230.1
• /
• 2010

조촉매(Promotor)인 Na은 수성가스전이(Water Gas Shift, WGS) 반응 시 생성된 포름산염의 C-H결합을 쉽게 분해하는 역할을 한다. 본 연구에서는 $Pt/CeO_2$ 촉매의 성능 향상을 위해 Na의 담지량을 변화시켜 촉매적 활성을 비교하여 보았다. 제조된 담체는 침전법(Precipitation)을 사용하여 제조하였으며 $500^{\circ}C$에서 6시간 소성하였다. Pt 담지량은 1wt%로 고정하였고 Na 담지량은 1 wt%~5 wt%로 변화를 주어 동시(공)-함침법(Co-incipient wetness method)으로 담지 시켰다. 반응 실험은 공간속도(Gas Hourly Space Velocity, GHSV) $45,385h^{-1}$에서 수행하였다. WGS 반응 결과 3 wt%의 Na이 담지된 $Pt/CeO_2$ 촉매의 경우를 제외하고 나머지 Na이 담지된 촉매들은 비교적 높은 CO의 전환율을 나타내었다. 특히 2 wt%의 Na이 담지된 $Pt/CeO_2$ 촉매는 가장 높은 CO의 전환율을 나타내었다. 따라서 Na 담지량의 변화가 포름산염의 C-H결합 분해에 영향을 미친다는 것을 알 수 있다.

• 한국식품과학회지
• /
• 제51권6호
• /
• pp.558-564
• /
• 2019

Hypertriglyceridemia is one of the metabolic syndrome that is often observed as a result of lipid abnormalities. It is associated with other lipids, metabolic disorders, cardiovascular disease and liver disease. Korean red ginseng is known to affect obesity, dyslipidemia, liver disease and liver function, but the mechanism of its effect is not clear. This study examined the beneficial effects of hypertriglyceridemia and the mechanism of action of Jinan red ginseng extract (JRG) in hepatoma cells. To measure the levels of triglyceride accumulation, we studied the expression of proteins and mRNAs related to lipidogenesis in hepatoma cells (Huh7 and HepG2). JRG decreases the lipidogenic markers, peroxisome proliferator-activated receptor γ (PPARγ), CCAAT-enhancer-binding proteins α (C/EBPα) and C/EBPβ which are major regulators of triglyceride synthesis in hepatoma cells. We also found that JRG reduced sterol regulatory element binding proteins 1c (SREBP-1c), C/EBPα and C/EBPβ by regulating liver X receptor (LXR) and stearoyl CoA desaturase (SCD) expressions. In addition, the first-limited step of synthesis triglyceride (TG), glycerol-3-phosphate (G3P) is decreased by JRG. These results suggest that the anti-hypertriglyceride effect of JRG in hepatoma cells could be accompanied with the inhibition of lipidogenic transcription factors by regulating LXR and SCD expression.

• 한국입자에어로졸학회지
• /
• 제13권1호
• /
• pp.33-40
• /
• 2017

Cobalt-iron oxides have emerged as alternative electrode materials for supercapacitors because they have advantages of low cost, natural abundance, and environmental friendliness. Graphene loaded with cobalt ferrite ($CoFe_2O_4$) nanoparticles can exhibit enhanced specific capacitance. In this study, we present three-dimensional (3D) crumpled graphene (CGR) decorated with $CoFe_2O_4$ nanoparticles. The $CoFe_2O_4$-graphene composites were synthesized from a colloidal mixture of GO, iron (III) chloride hexahydrate ($FeCl_3{\cdot}6H_2O$) and cobalt chloride hexahydrate ($CoCl_2{\cdot}6H_2O$) respectively, via one step aerosol spray pyrolysis. Size of $CoFe_2O_4$ nanoparticles was ranged from 5 nm to 10 nm when loaded onto 500 nm CGR. The electrochemical performance of the $CoFe_2O_4$-graphene composites was examined. The $CoFe_2O_4$-graphene composite electrode showed the specific capacitance of $253F\;g^{-1}$.

• 한국정밀공학회지
• /
• 제21권12호
• /
• pp.100-108
• /
• 2004

In reverse engineering, data acquisition methodology can generally be categorized into contacting and non-contacting types. Recently, researches on hybrid or sensor fusion of the two types have been increasing. In addition, efficient construction of a geometric model from the measurement data is required, where considerable amount of user interaction to classify and localize regions of interest is inevitable. Our research focuses on the classification of each bounded region into a pre-defined feature shape fer a hybrid measuring scheme, where the overall procedures are described as fellows. Firstly, the physical model is digitized by a non-contacting laser scanner which rapidly provides cloud-of-points data. Secondly, the overall digitized data are approximated to a z-map model. Each bounding curve of a region of interest (featured area) can be 1.aced out based on our previous research. Then each confined area is systematically classified into one of the pre-defined feature types such as floor, wall, strip or volume, followed by a more accurate measuring step via a contacting probe. Assigned to each feature is a specific digitizing path topology which may reflect its own geometric character. The research can play an important role in minimizing user interaction at the stage of digitizing path planning.