• 한국정밀공학회지
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• 제26권5호
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• pp.79-86
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• 2009

Recently PMSM(Permanent magnet synchronous motor) are used for the various direct drive applications such as index table, telescope system and so on. Because the position/speed control performance of direct drive PMSM is directly affected by the torque ripple, there are lots of studies to reduce the cogging torque in the motor design stage. In order to verify the motor design, the reliable cogging torque measurement system is essentially required. The measured motor must be rotated in the constant speed under 1deg/sec so that the cogging torque profile is measured correctly. In this study, the cogging torque measurement system which uses the direct drive PMSM and the speed controller to rotate the measured motor in 0.1rpm(0.6deg/sec) has been developed. Simulink/xPC target was used for the controller and data acquisition system. Based on PI controller, DOB and AFC have been applied to eliminate the low frequency disturbances and the periodic speed ripple. The experimental results show the good performance of the speed regulation for the reference speed 0.1rpm and the reliable profile of the measured cogging torque by the developed speed controller.

• Journal of Pharmaceutical Investigation
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• 제32권3호
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• pp.191-197
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• 2002

Polymer based physical mixtures or solid dispersions containing solubilizing compositions[OA, tween80 and SLS] were prepared using a spray-dryer. Lovastatin(LOS), simvastatin(SIMS), aceclofenac(AFC) and cisapride(CSP) were selected as poorly water-soluble drugs. Dextrin, poly(vinylalcohol) (PVA), poly(vinylpyrrolidone)(PVP) and polyethylene glycol(PEG) were chosen as solubilizing carriers for solid dispersions. The solid dispersions containing solubilizing compositions without drug were prepared without using organic solvents or tedious changes of formulation compositions. This system could be used to quickly screen the dissolution profiles of poorly water-soluble drugs by simply mixing with drugs thereafter. In case of solid dispersion containing drug, organic solvent systems could be used to solubilize model drugs. The dissolution rates of the drugs were higher when mixed with drug and solid dispersions containing solubilizing compositions. However, solid dispersions of LOS, AFC, and CSP simultaneously containing drug and solubilizing compositions in organic solvent systems were more useful than physical mixtures of drug and solid dispersions without drug except SIMS. Based on solubilizing capability of polymer based physical mixtures in gelatin hard capsules, optimal solid dispersion system of poorly water-soluble drugs could be formulated. However, it should be noted that dissolution rate of poorly water-soluble drugs were highly dependent on drug properties, solubilizing compositions and polymeric carriers.

• Parasites, Hosts and Diseases
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• 제32권4호
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• pp.231-242
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• 1994

자연 감염된 가재에서 폐흡충의 피낭유충을 분리하고 개에 경구 감염시켜 성충을 얻었다. 폐흡충 성충의 조효소를 ion-exchange chromatography, affinity chromatography와 gel filtration chromatoglaphy를 실시하여 cysteine proteinase를 순수 정제하였다. 이들 효소의 생화학적 특성과 분해능을 관찰하였으며. 효소면역전기영동이적법을 이용하여 순수 정제한 효소의 항원성을 관찰하였다. 정제된 효소는 저분자 합성기질인 CBZ-arg-arg-AFC 보다 CBZ-phe-arg-AFC에서 높은 활성을 보였으며. 이들 효소는 thiol-dependent이었다. 정제된 효소 및 조효소의 최적 pH는 5.5이었고. 최적 mole 농도는 0.1 M(0.1 M sodium citrate, pH 5.5)이었고, 이들 효소는 $4^{\circ}C$에서 48시간 동안 80%의 안정성을 보였다 정제된 효소의 native 분자량은 20.000 dalton이었고, SDS- PAGE상에 나타난 분자량은 17,500 dalton이었다 정제된 효소는 cysteine proteinase 특이 억제 인자인 E-64, lodoacetic acid, NEM에 의해 활성이 완전히 억제되었으며, serine proteinase, aspartic proteinase 및 metallo proteinase 특이 억제인자에 의해 활성이 억제되지 않았다. 정제된 효소는 collagen(Type I)과 hemoglobin을 분해하였고, 효소면역전기영동이적법으로 정제된 효소의 항원성을 확인하였다.

• 한국정보통신학회논문지
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• 제9권3호
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• pp.638-646
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• 2005

최근 무선통신시스템에서 직접변환 트랜시버 또는 IF 샘플링 SDR 기반 수신기가 일반적인 트랜시버 구조에 상응하여 설계되어지고 있다. 일반적인 AFC/APC 보상 회로가 기저 대역에서 RF 입력 신호와 국부발진 신호의 주파수 및 위상 오차를 보정할지라도 직접변환 수신 구조에서는 주요한 열화요소로 작용한다. 일반적인 보상 회로의 제한적인 동작 영역과 기저 대역에서의 1/Q 채널의 불평형을 용이하게 보상할 수 있도록 RF 입력 신호단에서 주파수 및 위상 오차를 보정하는 방법을 본 논문에서 제안한다. RF 입력단에서 고정된 주파수 및 위상 오차 이외에 변화하는 주파수 및 위상 오차를 제안된 early-late 보상기에 의해 효과적으로 보상할 수 있다. RF 입력단에서의 주파수 및 위상 오차의 보정으로 직접변환 수신기의 기저 대역에서의 기존 주파수 및 위상 오차 보정 회로는 간단히 설계할 수 있으며 미세한 오차 보정 구조로 용이하게 이용할 수 있다.

• 한국철도학회논문집
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• 제20권5호
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• pp.692-702
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• 2017

최근 데이터 중심적 교통정책수립 필요성 인식에 따라 교통카드데이터 활용에 관심이 고조되고 있다. 하지만 수도권 외의 많은 지역의 데이터에 하차 정보가 없어 활용에 제약이 있다. 이 논문은 승차 정보만 포함된 교통카드데이터에서 하차 정류장을 추정하는 방법론을 제시하였다. 검증은 서울시와 광주시의 데이터를 활용하였다. 추정 성공률은 서울시, 광주시 각각 78.2%, 81.6%로 나타났다. 정확도는 각각 54.2%, 33.4%로 나타났는데, 2개 정류장 오차까지 허용하는 경우 정확도가 서울시 93.6%, 광주시 94.0%로 크게 높아진다. 또한 광주시와 서울시가 오차 양상이 다름을 밝혔다. 통행사슬 방법의 핵심 매개변수인 허용 도보거리 조정에 따른 추정 성공률 및 정확도의 변화도 다루었다. 허용 도보거리가 증가됨에 따라 추정 성공률은 높아지는 반면 추정 정확도는 낮아지는 것을 확인하였으며, 500m를 전후하여 추정 결과의 변화 양상이 있음을 발견하였다.

• 한국광물학회지
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• 제4권2호
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• pp.69-89
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• 1991

The anorthositic rocks and the many other plutons which are of different varieties and age were distributed in the northern extremity of the distributed areas of H-S anorthositic rocks. The purpose of this study was to find plutons which had comagmatic relationships, and to make clear the magmatic process of anorthositic magma. The plutons were classified, and the petrological and the geochemical characteristics of the plutons were compared and researched in this study. And, because, like anorthosite, the rocks which intrude in the deep crust accompany assimilation, an AFC model calculation was performed to make the differentiation process of the anorthositic rocks clear. The plutons in this area were classified into three groups, and the three groups were composed of the Precambrian anorthositic rocks and related rocks, the Jurassic gabbro, and the plutons of undnown age. The anorthositic magma was differentiated from the anorthositic rocks through the tonalite to the alkali-feldspar granite, and it was differentiated under K, Mg, Fe free/lack condition. It was found from the result of AFC model that the anorthositic rocks were differentiated by fractional crystallization, but they were assimilated with wall-rocks, and the assimilation was performed at the rate of r$\leq$0.1. The plutons which intruded the anorthositic rocks subsequently consisted of the gabbro, the megacrystic granite, the fine-grained granite, and the gneissose granite. But they were formed by the repeated intrusion of magma, which may, or may not, be of the same origin. According to the result of the RCF model, these plutons were differentiated by simple fractional crystallization, and they were assimilated relatively less than the anorthositic rocks.

• 한국수소및신에너지학회논문집
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• 제27권1호
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• pp.63-70
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• 2016

In this study, ash free coals(AFCs) were produced with lignite and anthracite coals in a microwave. The AFCs were analyzed with proximate analysis, fourier transform infrared spectrometry (FTIR), X-ray diffraction analysis, and thermogravimetric analysis (TGA). The extraction yields of the AFCs were 16.4 wt%, 7.6 wt% at lignite and anthracite coal, respectively. The chemical and physical properties of the AFCs were similar regardless of the original coal types. Oxidation behavior of the AFCs was investigated by supplying a mixture of 3g of AFC and 3g of electrolyte into the coin-type molten carbonate fuel cell (MCFC). For the evaluation of AFC fuel performance, electrochemical analysis of the steady-state polarization and step-chronopotentiometry were conducted based on the standard hydrogen fuel (69 mol% $H_2$, 17 mol% $CO_2$, 14 mol% $H_2O$). The AFCs showed similar electrochemical oxidation behaviors regardless of the original coal types. The overvoltage of the AFCs was larger than the hydrogen fuel, although OCV of the AFCs was higher.

• Animal Bioscience
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• 제35권7호
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• pp.955-963
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• 2022

Objective: The aim of this study was to estimate genetic parameters for 305-day cumulative milk yield and components, growth, and reproductive traits in Guzerá cattle. Methods: The evaluated traits were 305-day first-lactation cumulative yields (kg) of milk (MY305), fat (FY305), protein (PY305), lactose (LY305), and total solids (SY305); age at first calving (AFC) in days; adjusted scrotal perimeter (cm) at the ages of 365 (SP365) and 450 (SP450) days; and adjusted body weight (kg) at the ages of 210 (W210), 365 (W365), and 450 (W450) days. The (co)variance components were estimated using the restricted maximum likelihood method for single-trait, bi-trait and tri-trait analyses. Contemporary groups and additive genetic effects were included in the general mixed model. Maternal genetic and permanent environmental effects were also included for W210. Results: The direct heritability estimates ranged from 0.16 (W210) to 0.32 (MY305). The maternal heritability estimate for W210 was 0.03. Genetic correlation estimates among milk production traits and growth traits ranged from 0.92 to 0.99 and from 0.92 to 0.99, respectively. For milk production and growth traits, the genetic correlations ranged from 0.33 to 0.56. The genetic correlations among AFC and all other traits were negative (-0.43 to -0.27). Scrotal perimeter traits and body weights showed genetic correlations ranging from 0.41 to 0.46, and scrotal perimeter and milk production traits showed genetic correlations ranging from 0.11 to 0.30. The phenotypic correlations were similar in direction (same sign) and lower than the corresponding genetic correlations. Conclusion: These results suggest the viability and potential of joint selection for dairy and beef traits in Guzerá cattle, taking into account reproductive traits.

• International Journal of Oral Biology
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• 제31권3호
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• pp.81-86
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• 2006

SET (Suppressor of variegation, Enhancer of zeste, and the Trithorax) domain-containing proteins are known to have methyltransferase activity at lysine residues of histone proteins. In this study, we identified a novel SET domain-containing protein from mouse and named Kodo7. Indeed, Kodo7 has methyltransferase activity at K9 residue of the H3 protein as demonstrated by a histone methyl-transferse activity assay using GST-tagged Kodo7. Confocal microscopy showed that Kodo7 is co-localized with histones in the nucleus. Interestingly, ectopic expression of Kodo7 by transient transfection induced cell death and treatment of the transfectants with a caspase-3 inhibitor, Ac-DEVD-AFC decreased Kodo7-induced apoptosis. These results suggest that Kodo7 induces apoptotic cell death through increased methylation of histones leading to transcriptional repression.

• 한국소음진동공학회논문집
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• 제24권2호
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• pp.139-145
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• 2014

Periodic disturbance compensators are widely used in track following servo systems. They are commonly designed and implemented by adaptive feedforward compensators or internal model based compensators. In track following servo systems, the gains of the compensators should be determined considering the change of the sensitivity transfer function and the implementation methods should be selected considering the system environment. This paper proposes a guide for determining gains of the periodic disturbance compensators. Various simulation and experimental results are presented to see the effect of gains. In addition, this paper introduces the various types of implementation methods and compares their merits and demerits.