• 한국태양에너지학회 논문집
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• 제32권5호
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• pp.1-10
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• 2012

This paper proposes a modeling and controller design approach for a wind-diesel hybrid system including dump load. Wind turbine depends on nature such as wind speed. It causes power fluctuations of wind turbine. Excessive power fluctuation at stand-alone power grid is even worse than large-scale power grid. The proposed control scheme for power quality is fuzzy PI controller. This controller has advantages of PI and fuzzy controller. The proposed model is carried out by using Matlab/Simulink simulation program. In the simulation study, the proposed controller is compared with a conventional PI controller. Simulation results show that the proposed controller is more effective against disturbances caused by wind speed and load variation than the PI controller, and thus it contributes to a better quality wind-diesel hybrid power system.

• 한국지능시스템학회논문지
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• 제22권4호
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• pp.454-459
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• 2012

Wenner의 4전극법으로 측정한 겉보기 대지저항률을 이용하여 대지저항률의 Kernel 함수를 추정할 수 있다. 이 때 커널함수를 추정하는 것은 비선형시스템을 푸는 과정으로 유도된다. 그러나 변수가 많은 비선형시스템은 해를 구하기가 쉽지 않다. 본 논문은 이 비선형시스템을 선형화하여 커널함수를 추정하는 방법을 제시한다. 마지막으로 제안한 방법을 평가하기 위하여 다양한 구조로 된 대지모델들을 시뮬레이션의 예로 사용한다.

• Ocean and Polar Research
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• 제26권3호
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• pp.507-514
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• 2004

A sediment core drilled from Lake langer on King George Island was analyzed for a variety of textural md geochemical properties along with $^{14}C$ age dates. These data were combined with published records of other cores to provide a detailed history of Holocene variation of total organic carbon (TOC) contents with respect to terrestrial paleoclimate change. The lithologic contrast of the lower diamicton and upper fine-grained sediments shows the glacier activity and subsequent lake formation. Low TOC contents fluctuated during the diamicton deposition whereas the increase of TOC began with the lake formation during the postglacial period that started about 5,000 yr B.p More notable are the distinct TOC peaks that may imply enhanced primary productivity during the warm period. The uniform and low TOC contents may reflect the limited productivity during the evolution of the lake. However, the recent TOC readvance clearly indicates gradual warming on King George Island. However, the paleoclimatic signature in the terrestrial lake environment during the Holocene seems to be subtle and less distinct, compared to the marine environment.

• 한국임상수의학회지
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• 제21권4호
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• pp.355-362
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• 2004

The purpose of this study was to herd management and control of dairy cows by milk components analysis in Gyeongsangnamdo. Milk components analysis were carried out milk yield (MY), milk fat (MF), milk protein (MP), milk urea nitrogen (MUN) and somatic cell count (SCC) but, milk solid (MS), day of non-pregnant condition (DNPC), and days of primipara (DPRI) involved in report. Dairy farms were divided high group, middle group, low group according to the standard records for milk components. Examination records were divided by farm, parity, year, season and month, the number of samples were 28,957. Feeding management practice and the prediction for the risk possibility of productive disease such as reproductive and metabolic disorders by evaluating fat, protein, solids. Determination of MY, MF, MP, MS were Milkoscan 4,000~5,000 Serier (FOSS Electric Co., Copenhagen, Denmark). Correlation coefficient of milk protein (MP) and milk solid (MS) was ascertain r=0.759. SCC was ascertain 372.8$\pm$11.34 (thousand unit) and DNPC was ascertain 155.3$\pm$5.15 (days) in seven parity.

• Archives of Pharmacal Research
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• 제20권2호
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• pp.138-143
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• 1997

5-Aryl-2,3-dihydroimidazo[2,1-a]isoquinolines were reported to have strong antitumor activity and one of the derivatives such as $5-[4^{l}$ -(piperidinomethyl)phenyl]-2,3-dihydroimidazo[2,1-a] isoquinoline (1, SDZ 62-434) was found to be more effective than the clinical cytostatic agent edelfosine (2) in in vitro and in vivo assays. Currently SDZ 62-434 is in clinical trials in Europe. The structure-activity relationship studies of SDZ 62-434 showed that compounds with substitution on ring A were less active than the lead compound. Ring B in SDZ 62-434 was essential for the activity because compounds without B ring had no antitumor activity. Among the 3-arylisoquinolin-1-one derivatives, $3-[4^{I}$-(piperidinomethyl)phenyl] substituted analog had no antitumor activity but simple phenyl substituted compound, such as 4, showed the most potent antitumor activity in various human tumor cell lines.

• ETRI Journal
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• 제24권2호
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• pp.109-116
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• 2002

We propose a novel very short (< $300{\mu}m$) vertical directional coupler switch with high extinction ratios larger than 30 dB. The device consists of a switching operation induced section (SOIS), an extinction ratio adjusted section (ERAS), and an extinction ratio enhanced section (ERES). These are achieved by changing the refractive index of one core. The switching operation is induced by changing the refractive index of one core in the SOIS. The improvement of extinction ratios larger than 30 dB for both the cross and bar states is made by controlling the asymmetry of the refractive indices of both cores in the ERES. Through the ERAS, different extinction ratios between the cross and bar states at the end of the SOIS are changed to the same value. For this reason, the optimum asymmetry of the refractive indices of the cores for the maximum extinction ratios and the lengths of ERES are the same for cross and bar states. Design guidelines for high extinction ratios with large tolerances are presented.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2005년도 춘계종합학술대회
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• pp.705-708
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• 2005

본 연구에서는 점대점(point-to-point) 링크상에서 각 스테이션 간의 안테나 빔의 스위트 스폿을 찾고 유지하는 방법을 제안 한다. 제안한 방식은 송수신 데이터에 안테나의 정보를 같이 실어 보내고 그 정보를 이용하여 신경회로망 중에서 간단한 두개의 ADALINE으로 스위트 스폿을 찾고 유지 한다. 통신방식은 시분할 이중화 방식으로 하고, 두개의 ADALINE을 병렬로 연결하여 원하는 목표값에 수렴하고 유지한다. 제안한 방식의 유용성을 점대점(Point-to-Point) 링크상에서 잡음이 없는 경우와 잡음이 첨가된 경우에 대하여 시뮬레이션을 통하여 확인하였다

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.496-496
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• 2017

위성을 이용한 원격탐사 기술이 발전하고 다양한 산출물이 나타남에 따라 수자원 및 하천관리에서의 원격탐사기술의 활용의 폭이 넓어지고 있다. 특히, 위성에서 관측할 수 있는 다양한 정보들을 이용하여 수자원 및 하천관리에 사용하려하는 연구가 활발히 진행되고 있으며, 기본적인 가시영상 이외에도 적외영상, 초분광영상, 수위정보, 레이더 반사도 등을 활용하여 수문량을 추정하려는 시도가 이루어져왔다. 원격탐사의 대표적인 장비인 위성은 광범위한 정보를 쉽게 취득할 수 있지만 위성마다 탑재된 센서에 따라 획득할 수 있는 자료가 서로 다르고, 산출물의 시공간 해상도에 따라 자료의 질이 결정된다. 본 연구에서는 원격탐사영상을 이용한 하천유량추정기법을 수립하기 위해 통제된 실험하천 규모에서 드론을 이용하였다. 실험은 대한민국 안동에 위치한 한국건설기술연구원 하천실험센터에서 수행되었으며, DJI Phantom 3 standard 드론을 활용하여 영상을 획득하였다. 하천유량추정의 방법론은 운동량 방정식과 Manning 유속공식을 활용한 하폭기반 유량추정 기법을 수립하였다. 1차 실험은 하천유량을 증가시키고 감소시키는 동시에 드론을 이용하여 하천을 촬영함으로써 하폭의 변화와 동시에 유량의 변화를 추정할 수 있는지 확인하였다. 2차 실험에서는 배수효과가 존재하는 조건에서 드론영상을 이용한 하천유량을 산정하고 보정계수를 산정하였다. 본 연구에서 수립된 하천유량추정기법은 위성영상을 이용한 하천유량 추정에 활용할 수 있으리라 기대한다.

• 전기전자학회논문지
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• 제23권1호
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• pp.318-321
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• 2019

겉보기대지저항률은 층의 깊이와 대지저항률과 같은 다층 대지파라미터들을 추정하는 데 사용된다. 겉보기대지저항률은 측정 될 수 있으며, 또한 겉보기대지저항률은 이들 파라미터들의 함수이기 때문에 주어진 대지 파라미터들로 계산 될 수 있다. 따라서 모든 최적화 알고리즘을 사용하여 계산된 겉보기대지저항률을 측정된 대지저항률에 가깝게 만드는 이들 파라미터들을 찾을 수 있다. 겉보기대지저항률을 계산하기위한 방정식은 0 차 Bessel함수를 포함하는 무한 적분으로 구성되어 있기 때문에 복잡하고 시간 소모적이다. 본 논문에서는 수평 다층 구조의 겉보기대지저항률을 계산하기 위한 빠른 알고리즘이 복소수이미지 방법을 사용하여 제시되었다.

• 구강회복응용과학지
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• 제20권2호
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• pp.71-81
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• 2004

The purpose of this study was to compare the distributing pattern of stress on the finite element models of two units implant prosthesis with one angulated placement of two implant fixtures. The two unit implant crowns simulated to mandibular first and second molars were made. The two kinds of finite element models were designed according to angulation of fixture ($4.0mm{\times}11.5mm$) : Model 1($15^{\circ}$ buccally angulated placement of one fixture on second molar area), Model 2($15^{\circ}$ lingually angulated placement of one fixture on second molar area). Axial loads of 200N were applied to the center of central fossa and to distance of 2mm and 4mm apart from the center of central fossa. Von-Mises stresses were recorded and compared in the fixtures, and buccolingual section of implants. The results were as follows: 1. Under axial loading at the central fossa, the stress was distributed along the straight fixture except apical portion, while on buccally or lingually angulated placement, the highest stresses were concentrated in the neck portion on the opposite side of the angulated fixture. 2. With offset distance increasing, the stresses were concentrated greater in buccal neck of lingually angulated fixture than in lingual neck of buccally angulated fixture. From the above results, in designing of the occlusal scheme for implant prosthesis with the angulated fixture, occlusal contacts should be placed to distribute stress axially in maximum intercuspation and to avoid offset force during eccentric movements.