• 한국항공우주학회지
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• 제33권11호
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• pp.33-40
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• 2005

무인항공기용 비행제어 시스템(FCS)의 신뢰성은 소형, 저가, 경량의 설계 제약 조건으로 인해 신뢰성이 과소평가 된다. 그러나 무인항공기에 탑재되는 비행제어 시스템의 고장은 항공기의 손실 및 추락사고로 이어지기 때문에 시스템 설계단계에서부터 정량적인 신뢰성 목표를 두어 설계검증이 이루어져야 한다. 본 논문에서는 비행제어 시스템의 개발 경험을 바탕으로 기능별 서브시스템에 따른 고장률을 예측하였다. 이를 바탕으로 시스템 신뢰성 목표를 만족시키기 위해 필요한 다중화 형상을 제시하였다. 이 결과들은 비행제어 시스템의 하드웨어 설계에 활용될 수 있다.

• Journal of Power Electronics
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• 제19권1호
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• pp.244-253
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• 2019

Finite control set model-predictive control (FCS-MPC) has received increasing attentions due to its outstanding dynamic performance. It is being widely used in power converters and multilevel inverters. However, FCS-MPC requires a lot of calculations, especially for multilevel-cascaded H-bridge (CHB) static synchronous compensators (STATCOMs), since it has to take account of all the feasible voltage vectors of inverters. Hence, an improved five-segment space vector pulse width modulation (SVPWM) method based on the non-orthogonal static reference frames is proposed. The proposed SVPWM method has a lower number of switching states and requires fewer computations than the conventional method. As a result, it makes FCS-MPC more efficient for multilevel cascaded H-bridge STATCOMs. The partial cost function is adopted to sequentially solve for the reference current and capacitor voltage. The proposed FCS-MPC method can reduce the calculation burden of the FCS-MPC strategy, and reduce both the switching frequency and power losses. Simulation and experimental results validate the excellent performance of the proposed method when compared with the conventional approach.

• Computers and Concrete
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• 제23권6호
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• pp.421-431
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• 2019

The alarming rate of depletion of natural stone based coarse aggregates is a cause of great concern. The coarse aggregates occupy nearly 60-70% by volume of concrete being produced. Research efforts are on to look for alternatives to stone based coarse aggregates from sustainability point of view. Response surface methodology (RSM) is adopted to study and address the effect of ferrochrome slag (FCS) replacement to coarse aggregate replacement in the ordinary Portland cement (OPC) based concretes. RSM involves three different factors (ground granulated blast furnace slag (GGBS) as binder, flyash (FA) as binder, and FCS as coarse aggregate), with three different levels (GGBS (0, 15, and 30%), FA (0, 15, and 30%) and FCS (0, 50, and 100%)). Experiments were carried out to measure the responses like, workability, density, and compressive strength of FCS based concretes. In order to optimize FCS replacement in the OPC based concretes, three different traditional optimization techniques were used (grey relational analysis (GRA), technique for order of preference by similarity (TOPSIS), and desirability function approach (DFA)). Traditional optimization techniques were accompanied with principal component analysis (PCA) to calculate the weightage of responses measured to arrive at the final ranking of replacement levels of GGBS, FA, and FCS in OPC based concretes. Hybrid combination of PCA-TOPSIS technique is found to be significant when compared to other techniques used. 30% GGBS and 50% FCS replacement in OPC based concrete was arrived at, to be optimal.

• 한국운동역학회지
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• 제18권1호
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• pp.159-168
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• 2008

본 연구는 피겨스케이팅의 여자국가대표 선수 4명으로부터 고난도 스핀기술인 FSS과 FCS동작을 분석하였다. 이를 위하여 자세유형에 따른 스핀동작 간 족저압력변인 접지면적(CA), 최대힘(MF), 최대압력(PP) 그리고 인체무게중심(COG)에 의한 발바닥 9개 영역을 중심으로 압력변화를 고찰하였다. 본 회전구간에서 두 스핀기술 간 접지면적이 17.2%의 차이로 스핀축이 한 곳에 보다 잘 집중된 경우는 FCS인것으로 나타났다. 최대힘에서 FSS는 97%BW, FCS는 143%BW로서 20% 높았으며, 최대압력 또한 FCS가 FSS보다 20% 높은 수치를 보였다. 이러한 결과는 인체무게중심선과 압력중심점과의 상호관계로부터 FSS의 압력중심점이 인체무게중심선보다 발바닥 후면, 반대로 FCS는 발바닥 앞면에 위치하는 자세패턴에 의한 기능적 차이로 분석되었다. 위의 결과로부터 FCS가 상대적으로 FSS보다 스핀기술 시 높은 인체중심과 하지말단을 이용한 큰 회전반경으로부터 스핀속도를 보다 잘 통제하는 운동구조로 고찰되었다.

• 한국가축번식학회지
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• 제14권1호
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• pp.84-91
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• 1990

본 실험은 돼지난포란의 체외성숙과 체외수정 효과를 높일 수 있는 방법을 찾기 위하여 시도되었으며 직경 1~2mm와 3~7mm 난포로부터 채란된 난자를 mKRB(-BSA)에 돼지발정혈청(ESS), FCS 또는 투석돼지난포액(DFF)을 첨가한 성숙배양에서 24~48시간, 37$^{\circ}C$에서 배양하였다. 성숙된 난포란은 정소상체 정자와 24시간 배양 후 전핵행성 여부를 조사하였다. 36~48시간 배양에서 50~60%의 난자가 metaphase II에 도달되었고 난포 크기(1~2mm와 3~7mm)간에 체외성숙율의 차이는 없었으나 3~7mm 난포란에서 성숙분열이 다소 빨랐다. 체외성숙배양액에 5% ESS, 15% FCS 및 DFF 첨가시 대조구보다 다소 성숙율이 높았다. 체외수정율(전핵형성)은 5% ESS와 15% FCS 첨가 성숙시킨 난포란과 체내 수정능획득 정자와의 수정에서 각각 높은 경향이 있었다. 따라서 돼지난포란의 체외성숙과 수정에 ESS, FCS 및 투석난포액이 유효한 요인이 됨을 알 수 있다.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.583-589
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• 2011

Fluorescence correlation spectroscopy (FCS) is a sophisticated and an accurate analytical technique used to study the diffusion of molecules in a solution at the single-molecule level. FCS is strongly affected by many factors such as the stability of the excitation power, photochemical processes, mismatch between the refractive indices, and variations in the cover glass thickness. We have studied FCS near the surface of a cover glass by using rhodamine 123 as a fluorescent probe and have observed that the surface has a strong influence on the measurements. The temporal autocorrelation of FCS decays with two characteristic times when the confocal detection volume is positioned near the surface of the cover glass. As the position of the detection volume is moved away from the surface, the FCS autocorrelation becomes one-component decaying; the characteristic time of the decay is the same as the faster-decaying component in the FCS autocorrelation near the surface. This observation suggests that the faster component can be attributed to the free diffusion of the probe molecules in the solution, while the slow component has its origin from the interaction between the probe molecules and the surface. We have characterized the surface contribution to the FCS measurements near the surface by changing the position of the detection volume relative to the surface. The influence of the surface on the diffusion of the probe molecules was monitored by changing the chemical properties of the surface. The surface contribution to the temporal autocorrelation of the FCS strongly depends on the chemical nature of the surface. The hydrophobicity of the surface is a major factor determining the surface influence on the free diffusion of the probe molecules near the surface.

• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.284-293
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• 2010

To reduce anti-nutritional factors in plant protein sources for fish meal replacement in fish feeds, cottonseed and soybean meal (CS) were fermented with Aspergillus oryzae. A feeding trial was conducted to verify the effects of fermented CS (FCS) with phytase supplementation on gossypol detoxification, phosphorus digestibility, antioxidant activity, and growth performance of juvenile olive flounder over 10 weeks. Four diets were formulated to replace 0, 30, or 40% fish meal protein with CS or FCS (designated as CS0, CS30, FCS30P, and FCS40P). Phytase (1,000 FTU/kg) was added to FCS30P and FCS40P. The microbial fermentation significantly increased dietary total polyphenols and consequently led to higher DPPH radical-scavenging activities in fish feed and fish tissue. Dietary and liver gossypol concentrations were dramatically decreased by the fermentation process. Phosphorus digestibility was significantly increased in fish fed the FCS40P diet. However, growth performance decreased in fish fed FCS diets. This study demonstrates that the fermentation process and phytase supplementation can improve the phosphorus availability of plant protein sources in fish. The fermentation of CS by A. oryzae could increase antioxidant activities in feed and fish and effectively degrade toxic gossypol in cottonseed meal.

• 한국식품저장유통학회지
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• 제10권4호
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• pp.498-505
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• 2003

만두피의 반죽제조에 키토산(시판 키토산 및 제조 키토산) 및 폴리인산, 구아껌, 타피오카 등의 성분 배합비율에 따른 반죽의 물성변화를 알아보고자 하였다. 그 결과는 다음과 같다. 제조된 균류키토산의 수분함량은 6.57∼6.58%, 질소함량은 6.71∼6.91%, 용해도는 99.05∼99.13%, 점도는 2.21∼2.23cps, 아세틸화도는 12.0∼l2.7% 그리고 분자량은 3.01${\times}$$10^{5}$∼3.12${\times}$$10^{5}$Dalton으로써 산처리 온도에 따른 FCs40과 FCs95의 성분 및 물리화학적 특성의 차이는 거의 없는 것으로 나타났다. 만두피 반죽에 첨가하는 폴리인산의 적절한 농도는 만두피 전체 성분 첨가량의 0.074%인 것으로 나타났으며, 폴리인산의 첨가량이 적거나 많이 함유하였을 때는 만두피 반죽의 견고성, 응집성, 탄력성 및 점착성 등이 오히려 감소하는 경향이었다. 타피오카의 첨가량에 따른 반죽의 물성에는 큰 영향을 주지는 않았으나, 첨가량은 전체성분 중량의 6.59%정도, 또한 구아껌의 경우는 0.062%정도가 만두피 반죽의 물성에 적절하였다. 만두피의 물성에 효과적인 키토산은 고분자량의 SCs, FCs40 및 FCs95 등으로 나타났다.타났다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2000년도 춘계학술대회 학술발표 논문집
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• pp.179-182
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• 2000

A Classifier System processes a discrete coded information from the environment. When the system codes the information to discontinuous data, it loses excessively the information of the environment. The Fuzzy Classifier System(FCS) makes the classifier system be able to carry out the mapping from continuous inputs to outputs. It is the FCS that applies this ability of the machine learning to the concept of fuzzy controller. It is that the antecedent and consequent of classifier is same as a fuzzy rule of the rule base. In this paper, the FCS is the Michigan style and fuzzifies the input values to create the messages. The system stores those messages in the message list and uses the implicit Bucket Brigade Algorithms. Also the FCS employs the Genetic Algorithms(GAs) to make new rules and modify rules when performance of the system needs to be improved. We will verify the effectiveness of the proposed FCS by applying it to AMR avoiding the obstacle.

• 전력전자학회논문지
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• 제19권3호
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• pp.249-256
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• 2014

This paper proposes a torque control method of permanent magnet synchronous motor, which has small torque ripple. The proposed control method is using the finite control set-model predictive control(FCS-MPC) strategy. An optimal input voltage vector minimizing a cost function is chosen among 6 passible active input voltage vectors following the FCS-MPC strategy. Then, a modulation factor for the optimal input voltage vector is computed to minimize the torque ripple. Thus, the proposed control method yields fast torque response and small torque ripple. The efficacy of the proposed method was verified through simulation and experiment.