• 암석학회지
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• 제26권3호
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• pp.297-309
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• 2017

거창지역의 쥬라기 화강암에 대하여 결의 특성에 대한 분석을 실시하였다. 박편의 확대사진 및 간격-누적빈도 도표에서 도출한 16개 파라미터의 결합을 통하여 결에 대한 종합적인 평가를 실시하였다. 결에 대한 이들 간격의 파라미터의 대표값에 대한 분석 결과를 요약하면 다음과 같다. 첫째, 상기 파라미터는 그룹 I(간격의 빈도수(N), 총 간격($1mm{\geq}$), 상수(a), 지수(${\lambda}$), 지수 직선의 기울기(${\theta}$), 선의 길이(oa') 및 삼각비($sin{\theta}$, $tan{\theta}$) 그리고 그룹 II(평균 간격(Sm), 평균 간격과 중앙 간격 사이의 차이값(Sm-Sme), 밀도(${\rho}$), 선의 길이(oa 및 aa'), 직각삼각형(${\Delta}oaa^{\prime}$)의 면적 및 삼각비($cos{\theta}$)로 분류할 수 있다. 그룹 I에 속하는 8개 파라미터의 값은 H(3번 결, H1+H2)

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.218-221
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• 2008

Hot Press Forming (HPF), an advanced sheet forming method in which a high strength part can be produced by forming at high temperature and rapid cooling in dies, is one of the most successful forming process in producing components with complex geometric shape, high strength and a minimum of springback. In order to obtain effectively and accurately numerical finite element simulations of the actual HPF process, the flow stress of a boron steel in the austenitic state at elevated temperatures has been investigated with Gleeble system. To evaluate the formability of the thermo- mechanical material characteristics in the HPF process, the FLDo defined at the lowest point in the forming limit diagrams of a boron steel has been investigated. In addition, the simulation results of thermo-mechanical coupled analysis of an automobile one-piece lower-arm part are compared with the experimental ones to confirm the validity of the proposed simulations.

• 한국인터넷방송통신학회논문지
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• 제13권1호
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• pp.129-134
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• 2013

기존 연구실 연구에서는 메타모델 기반의 순차적 다이어그램을 통한 테스트케이스 생성의 자동화가 초점이었다. 하지만 메타모델 기반의 스테이트 다이어그램을 통한 테스트케이스 자동 생성에 관한 메커니즘에 관한 연구가 부족하다. 그래서 본 논문에서는 Model Driven Architecture(MDA) 메커니즘인 메타모델과 모델변형기법을 채택하여, UML내 스테이트 다이어그램을 통해 테스트케이스를 자동 추출메커니즘을 제안한다. 이를 위해 테스트케이스 생성단계 프로세스를 정의하고 각 단계별 메타모델 정의와 모델간의 변형 규칙을 정의한다. 제안한 기법을 통해 임베디드 소프트웨어 테스트 설계 및 테스트케이스 추출비용과 시간을 줄이고 임베디드 소프트웨어의 품질을 높이고자 한다.

• 천문학회지
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• 제32권2호
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• pp.109-117
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• 1999

UBVI CCD photometry has been obtained for a region around the Wolf-Rayet star WR 12. We found two young stellar associations in the observed field: the nearer one comprises the field members of Vela OBI association at d = 1.8kpc, while the farther one is the young open cluster Bochum 7 (Bo 7) at d = 4.8kpc. The stars associated with Bo 7 showed no central concentration which suggests that Bo 7 is not a young open cluster but simply a local concentration in the density of young stars belonging to the OB association (Vel OB3). These two associations have similar ages but remarkably different mass function slopes ($\Gamma$ = -2.1 $\pm$ 0.3 for Vel OBI and -1.0 $\pm$ 0.3 for Bo 7). The stars in Vel OBI shows an evident age spread (${\Delta}T\~ 9Myr$). We also found two strong H$\alpha$ emission stars - WR 12 and $\sharp$1066 - from narrow band H$\alpha$ photometry.

• 한국응용곤충학회지
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• 제32권1호
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• pp.68-75
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• 1993

우리나라에 발생하고 있는 벼멸구 생태형의 형태적 차이를 구명하고자 생태형 1, 2, 3의 단시형 암컷과 숫컷의 다리부분의 형태를 관찰하였다. 앞다리, 가운데 다리 그리고 뒷다리의 제3부절의 형태를 51개 부위에서 조사한 다음 통계학적 분석을 위하여 정준 판별 분석법을 도입하였다. 각 생태형간의 Mahalanobis distance는 숫컷의 경우 생태형 2와 3 사이에서 가장 짧았고, 암컷은 생태형 1과 2 사이에서 가장 길었다. Scatter plot diagram상에서 각 생태 형간 분리현상이 뚜렷하여 중심점이 각각 다르게 나타났고 각 생태형에 속하는 개체는 중심점 부근에 고르게 분포하였다. 각 생태형간의 Group membership 조사에서 암수 모두 각 생태형은 각각 동일한 생텨형을 분류되었다.

• 한국자기공명학회논문지
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• 제10권1호
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• pp.74-88
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• 2006

Since the first commercial NMR spectrometer came out in 1953 from Varian, much of the hardware development has been improved and matured through commercial equipments. Many of magnetic resonance laboratories however still build and use home-built spectrometers, which are satisfactory even with the consideration of educational purpose only. The home-built NMR spectrometer could be further advantageous and could be often an only option for investigating new ideas with demanding experimental conditions or new hardware support. A solid state NMR spectrometer was designed with extra interest in stochastic experiment and built for an 8.93 T superconducting magnet from Oxford instrument. Super-heterodyned system was implemented for the transmitter and receiver parts. Intermediate frequency (IF) for the heterodyne system was chosen to 70 MHz for the first and the second channels, with additional 120 MHz for the third channel for maximum NMR frequency capability. We will show overall schematics, and discuss the designs with detailed diagrams, then demonstrate the applicability of home-built spectrometer with stochastic-excitation in solid state NMR and in applications to quadrupolar nuclear Spins.

• Computers and Concrete
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• 제10권6호
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• pp.649-662
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• 2012

This paper presents the results of an investigation on the compressive strength and weight loss of mortars containing three types of fillers as cement replacements; Limestone Filler (LF), Silica Fume (SF) and Trass (TR), subjected to elevated temperatures including $400^{\circ}C$, $600^{\circ}C$, $800^{\circ}C$ and $1000^{\circ}C$. Results indicate that addition of TR to blended cements, compared to SF addition, leads to higher compressive strength and lower weight loss at elevated temperatures. In order to model the influence of the different parameters on the compressive strength and the weight loss of specimens, artificial neural networks (ANNs) were adopted. Different diagrams were plotted based on the predictions of the most accurate networks to study the effects of temperature, different fillers and cement content on the target properties. In addition to the impressive RMSE and $R^2$ values of the best networks, the data used as the input for the prediction plots were chosen within the range of the data introduced to the networks in the training phase. Therefore, the prediction plots could be considered reliable to perform the parametric study.

• Journal of Pharmaceutical Investigation
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• 제39권6호
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• pp.417-422
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• 2009

Budesonide belongs to Class II in the Biopharmaceutics Classification System (BCS) for its high permeability and poor aqueous solubility. The purpose of this study was to improve the solubility and dissolution rate of budesonide using an o/w microemulsion system in order to develop a nasal formulation. Based on the results of the solubility study and pseudo ternary phase diagrams, microemulsions of about 80 nm in mean diameter were formulated using isopropyl myristate and Labrasol$^{(R)}$ as an oil phase and a surfactant, respectively. Solubility of budesonide in the microemulsions increased up to 6.50 mg/mL, which is high enough for a nasal formulation. In vitro release profiles of budesonide significantly increased from the microemulsions compared to that of the budesonide powder. These results suggest that the microemulsions of budesonide could further be developed into a clinically useful nasal formulation.

• 대한기계학회논문집A
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• 제23권11호
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• pp.2022-2032
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• 1999

In recent years, the subject of remaining life assessment has drawn considerable attention in the power generation industry. In power generation systems a variety of structural components, such as steam pipes, turbine rotors, and superheater headers, typically operate at high temperatures and high pressures. Thus a life prediction methodology accounting for fracture and rupture is increasingly needed for these components. For accurate failure assessment, in addition to the single parameter such as K or J-integral used in traditional fracture mechanics, the second parameter like T-stress describing the constraint is needed. The most critical defects in such structures are generally found in the form of semi-elliptical surface cracks in the welded piping-joints. In this work, selecting the structures of surface-cracked plate and straight pipe, we first perform line-spring finite element modeling, and accompanying elastic-plastic finite element analyses. We then present a framework for including constraint effects (T-stress effects) in the R6 failure assessment diagram approach for fracture assessment.

• 천문학회지
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• 제43권5호
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• pp.141-152
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• 2010

UBV I CCD photometry is obtained for the open clusters NGC 4609 and Hogg 15 in Crux. For NGC 4609, CCD data are presented for the first time. From new photometry we derive the reddening, distance modulus and age of each cluster - NGC 4609 : E(B-V ) = $0.37{\pm}0.03$, $V_0-M_V=10.60{\pm}0.08$, log $\tau$= 7.7 $\pm$ 0.1; Hogg 15 : E(B - V ) = 1.13 $\pm$ 0.11, $V_0-M_V$ = 12.50 $\pm$ 0.15, log $\tau$ $\lesssim$ 6.6. The young age of Hogg 15 strongly implies that WR 47 is a member of the cluster. We also determine the mass function of these clusters and obtain a slope $\Gamma$ = -1.2 ($\pm$0.3) for NGC 4609 which is normal and a somewhat shallow slope (${\Gamma}=-0.95{\pm}0.5$) for Hogg 15.