• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2005년도 춘계학술대회 논문집
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• pp.311-316
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• 2005

연안 준설퇴적물을 열처리, 생물침출공정을 이용한 중금속처리, 중화처리 등의 다양한 방법으로 전처리 또는 개질한 재료를 이용하여 연안해수에 함유된 질산염의 흡착특성에 대한 실험실적 연구를 수행하였다. 개질된 퇴적물의 흡창평형시간은 생물침출-열처리 퇴적물이 17분으로 가장 빨랐으며 생물침출-중화-열처리 퇴적물과 함께 생물침출퇴적물이 각각 25분, 27분으로 황토와 열처리 황토에서의 33분, 32분 보다 빠르게 흡착되는 것으로 평가되었다. 시험된 재료들에 대한 흡착공정은 Freundlich 등온흡착식으로 해석할 수 있었으나, 흡착공정은 표면의 특성에 크게 영향을 받는 것으로 평가되었다. 질산염의 흡착량은 퇴적물과 열처리 퇴적물에서 각각 2.12, 2.19mg $NO_{3}$-N/g 으로 가장 많았으며 열처리 등으로 개질된 퇴적물은 연안해수의 수질개선을 위한 흡착제로서 활용가능한 것으로 평가되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.191-195
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• 2003

The formation degree of sustain (ITO pattern) decides quality of PDP (plasma display panel). For this reason. it makes efforts in search defects more than 30 ${\mu}{\textrm}{m}$. Now, the existing inspection process is dependent upon naked eye or SEM equipment in off-line PDP manufacturing process. In this study developed prototype inspection system of PDP ITO glass. This system creates information that detects and sorts kind of defect automatically. Design ed inspection technology adopts line-scan method by slip-beam formation for the minimum of inspection time and image processing algorithm is embodied in detection ability of developed system. Designed algorithm had to make good use of kernel matrix which draws up an approach to geometry. A characteristic of area-shaped defects, as pin hole, substance, protrusion et al, are extracted from blob analysis method. Defects, as open, short, spots, et al, are distinguished by line type inspection algorithm. In experiment results, we could have ensured ability of inspection that can be detected with reliability of up to 95% in about 60 seconds

• 한국군사과학기술학회지
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• 제15권5호
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• pp.557-564
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• 2012

This paper presents UGV localization using multi-sensor fusion based on federated filter in outdoor environments. The conventional GPS/INS integrated system does not guarantee the robustness of localization because GPS is vulnerable to external disturbances. In many environments, however, vision system is very efficient because there are many features compared to the open space and these features can provide much information for UGV localization. Thus, this paper uses the scene matching and pose estimation based vision navigation, magnetic compass and odometer to cope with the GPS-denied environments. NR-mode federated filter is used for system safety. The experiment results with a predefined path demonstrate enhancement of the robustness and accuracy of localization in outdoor environments.

• 전자통신동향분석
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• 제31권6호
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• pp.88-96
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• 2016

5G RAN은 4G가 진화된 무선기술(evolved E-UTRA)과 5G 무선기술(New Radio, NR)을 모두 지원하는 새로운 무선액세스 네트워크(New RAN)이며, 코어 네트워크 (EPC and NGC)과 접속되어 5G 시스템(NextGen System)을 구성한다. 본고에서는 5G RAN(Radio Access Network,)을 대상으로, RAN 시설 배치 시나리오, RAN과 CN 간 기능 분배 및 인터페이스, 프런트-홀 네트워크의 전송 용량 및 지연, New RAN과 E-UTRA 간 모빌리티 시나리오 등에 대한 표준 이슈를 살펴본다. 마지막 절에선 RAN의 네트워크 슬라이싱 지원 방안으로 상위레벨 개념의 구조와 절차를 정리한다. 본 문서는 3GPP RAN3 그룹의 기술보고서(TR 38.801)와 SA2 기술보고서(TR 23.799)를 바탕으로 작성되었다.

• 한국수소및신에너지학회논문집
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• 제31권1호
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• pp.112-121
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• 2020

In this work energy and entransy characteristics of heat exchangers are analyzed for 12 different flow arrangements of heat exchangers. The dimensionless parameters are number of entransy dissipation (Ng), number of entransy dissipation-based thermal resistance (Nr), and entransy dissipation-based effectiveness of heat-exchanger (εg). The dimensionless parameters are expressed analytically in terms of the effectiveness of heat exchanger (ε), heat capacity ratio (c), and number of transfer unit (N) for optimal performance of heat exchangers. Results showed that the dimensionless parameters based on the entransy dissipation can be useful concepts for optimal design of heat exchangers.

• Elastomers and Composites
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• 제22권4호
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• pp.333-339
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• 1987

A modern kinetic evaluation method for nonisothermal reactions measured with Differential Scanning Calorimetry(DSC) is presented. It is based on multiple linear regression analysis using a number of curve points in a selectable range of conversion. The obtained kinetic data are the basis to compute a reaction process under any condition e.g. isothermal or adiabatic. The DSC measurements was performed on a Mettler TA3000 SYSTEM with the built in evaluation software. Mainly the following reactions are discussed: vulcanization of natural rubber compounds containing vulcanizing accelerators. The purpose of this work is to analyse the vulcanization kinetics of typical NR vulcanization systems using DSC. These systems were chosen because they are typically reactive elastomer and are commercially important.

• Macromolecular Research
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• 제9권2호
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• pp.92-99
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• 2001

Silica-filled rubber compounds have slower cure characteristics than carbon black-filled ones due to the adsorption of curatives on the silica surface. Fatty acid was used as a cure activator along with zinc oxide in a sulfur cure system. Poly(ethylene glycol), PEG, was used in silica-filled rubber compounds to prevent adsorption of the curatives on the silica surface. In this study, influence of the size of fatty acid and PEG on properties of silica-filled NR compounds was investigated. It was found that the size of fatty acid and PEG affected the curt: characteristics and physical properties. The cure rate becomes faster as the PEG size increases. By increasing the size of fatty acid or PEG, the delta torque of the compound decreases while the Mooney viscosity increases. The modulus of the vulcanizate decreases with increasing the molecular weight of fatty acid or PEG. The experimental results were explained by the filler dispersion and by the prevention of the curative-adsorption on the silica surface.

• 대한전자공학회논문지
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• 제26권11호
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• pp.1829-1838
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• 1989

This paper is proposed one method of the exact optimal switching pattern of Selected Harmonic Elimination(SHE) Pulse Width Modulation(PWM). It defined Harmonic Elimination Band (HEB) at Constant Voltage(CV) and sought all solutions which are included HEB. Then, it calculated the Generalized Klirr Factor(GKF) beling to this solution and decided the optimal switching pattern which is minimized GKF. This optimal switching solution is used as initial condition of Newto Raphson(NR) method of decided easily switching pattern at Variable Voltage(VV). We desined the inverter by Power Transister(PTR) and implemented variable speed drive of Induction Motor(IM) in order to verify the validity of this theoretical proposition, then shown this results by comparison and analysis.

• 전기학회논문지
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• 제59권5호
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• pp.882-889
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• 2010

This paper presents a method of finding the optimal operating point minimizing a given objective function with 3 phase power flow equations and operational constraints, called 3 phase optimal power flow (3POPF). 3 phase optimal power flow can provide operation and control strategies for the distribution systems with distributed generation assets, which might be frequently in unbalanced conditions assuming that high penetration rate of renewable energy sources in the systems. As the solution technique for 3POPF, this paper adopts a simulation-based method of particle swarm optimization (PSO). In the PSO based 3POPF, a utility function needs to be defined for evaluation of the degree in operational improvement of each particle's current position. To evaluate the utility function, in this paper, NR-based 3 phase power flow algorithm was developed which can deal with looped distributed generation systems. In this paper, illustrative examples with a 5-bus and a modified IEEE 37-bus test systems are given.

• International Journal of Naval Architecture and Ocean Engineering
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• 제4권4호
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• pp.374-385
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• 2012

The indoor noise of a ship is usually determined using the A-weighted sound pressure level. However, in order to better understand this phenomenon, evaluation parameters that more accurately reflect the human sense of hearing are required. To find the level of the satisfaction index of the noise inside a naval vessel such as "Loudness" and "Annoyance", psycho-acoustic evaluation of various sound recordings from the naval vessel was performed in a laboratory. The objective of this paper is to develop a single index of "Loudness" and "Annoyance" for noise inside a naval vessel according to a psycho-acoustic evaluation by using psychological responses such as Noise Rating (NR), Noise Criterion (NC), Room Criterion (RC), Preferred Speech Interference Level (PSIL) and loudness level. Additionally, in order to determine a single index of satisfaction for noise such as "Loudness" and "Annoyance", with respect to a human's sense of hearing, a back-propagation neural network is applied.