• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.577-580
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• 2004

To overcome with large size noise source distribution network design difficulty in interferometric radiometer system, especially for sub-Y-type array, a new on-board calibration technique using noise re-radiation is proposed in this paper. The suggested calibration technique is using noise re-radiation effect of center antenna after noise source injection from matched load. This approach is especially proper to sub-Y-type array interferometric synthetic aperture radiometer in mm-wave frequency band. Compared with noise injection network of a conventional synthetic aperture radiometer, the system mass, volume, and hardware complexity is reduced and cost-effective. Only one internal noise source, matched load, is used for injection using noise re-radiation technique a small set of sub-Y receiver channels is calibrated. Detailed calibration scenario is discussed and simulation results about noise re­radiation effect are presented.

• Restorative Dentistry and Endodontics
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• 제24권3호
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• pp.490-494
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• 1999

The aim of this in vitro study was to investigate the coronal leakage of obligate anaerobes into root canals obturated with two different techniques. 48 extracted human teeth with straight, single root canals were prepared with crown-down technique with Profile under copious irrigation until the master apical file was size 40. The teeth were divided randomly into experimental groups (40 teeth) and control groups (8 teeth). In the experimental groups, 20 teeth were obturated with lateral condensation and other 20 teeth were obturated with continuous wave technique with System B. Coronal leakage of two root canal filing technique was evaluated using anaerobic bacterial leakage model with Fusobacterium nucleatum(ATCC 25586) for 60 days. The results were as follows 1. The incidence of bacterial leakage of experimental groups was 65% in group 1 (lateral condensation) and 60% in group 2 (continuous wave technique with System B). This difference was not statistically significant (P>0.05). 2. There was no statistically significant difference(P>0.05) in leakage score between group 1 (lateral condensation) and group2 (continuous wave technique with System B).

• 한국멀티미디어학회논문지
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• 제13권1호
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• pp.111-121
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• 2010

중소기업들은 산업기술 유출방지에 필요성을 인식하여 많은 예산을 들여 정보보호 시스템을 구축하고 있으나, 정보보호 전담조직을 구성하여 통합적인 정보보호 관리체계에 따라 일관성 있는 정보보호 시스템을 구축하지 못하고 특정시스템의 단발성 도입이 이루어지고 있다. 본 연구에서는 중소기업 산업기술 유출현황 조사결과를 바탕으로 대기업과 차별된 중소기업 산업기술 유출방지를 위한 정보보호 관리체계를 설계하고 하였다. 세부적으로 중소기업 산업기술 유출현황 및 취약점 등에 관한 사례를 분석하여 정리하고, 델파이 방법을 적용하여 중소기업 산업기술 유출방지 관리체계를 설계한 다음 이에 대한 적합성을 검증하였다. 본 연구의 결과를 활용하여 중소기업은 적정한 정보보호 투자수준을 산정하고 이에 대한 통제도구를 개발할 수 있을 것으로 기대된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1392-1397
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• 2003

This paper deals with a control technique of eliminating the transient vibration of a twin-drive geared mechanical system. This technique is based on a model-based control in order to establish the damping effect at the driven machine part. The control model is composed of reduced-order electrical and mechanical parts. This control model estimates a load speed converted to the motor shaft. The difference between the estimated load speed and the motor speed is calculated dynamically and it is added to the velocity command to suppress the transient vibration generated at the load. This control technique is applied to a twin-drive geared system with backlash. In the previous work, the performance of this control method is examined by simulations. In this paper, the effectiveness of this control technique is verified by experiments. The settling time of the residual vibration generated at the loading inertia can be shortened down to about 1/2 of the uncompensated vibration level.

• 전산구조공학
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• 제4권2호
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• pp.119-129
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• 1991

본 논문은 교량구조의 체계신뢰도를 추정하기 위한 효율적인 중요도 표본추출기법의 개발을 목적으로 한다. 기존의 체계신뢰성 해석을 위한 방법은 1차 모멘트법, 2차 모멘트법, AFOSM 근사해법, 그리고 시뮬레이션 방법등이 있다. 중요도 표본추출기법은 아주 적은 경비와 노력으로 정확한 해를 구하는 시뮬레이션 방법이다. 적용 예를 통하여 중요도 표본추출기법은 교량구조의 체계신뢰성해석에 아주 효과적인 방법임을 알 수 있었다.

• 한국항해항만학회지
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• 제35권4호
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• pp.317-321
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• 2011

In this paper, a foggy-degraded image restoration technique with a physics-based degradation model is proposed for the measurement system. When the degradation model is used for the image restoration, its parameters and a distance from the spreader to the camera have to be previously known. In the proposed image restoration technique, the parameters are estimated from variances and averages of intensities on two foggy-degraded landmark images taken at different distances. Foggy-degraded images can be restored with the estimated parameters and the distance measured by the measurement system. On the basis of the experimental results, the performance of the proposed foggy-degraded image restoration technique was verified.

• Journal of Korean Neurosurgical Society
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• 제42권4호
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• pp.245-250
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• 2007

Tubular retractor system as a minimally invasive surgery (MIS) technique has many advantages over other conventional MIS techniques. It offers direct visualization of the operative field, anatomical familiarity to spine surgeons, and minimizing tissue trauma. With technical advancement, many spinal pathologies are being treated using this system. Namely, herniated discs, lumbar and cervical stenosis, synovial cysts, lumbar instability, trauma, and even some intraspinal tumors have all been treated through tubular retractor system. Flexible arm and easy change of the tube direction are particularly useful in contralateral spinal decompression from an ipsilateral approach. Careful attention to surgical technique through narrow space will ensure that complications are minimized and will provide improved outcomes. However, understanding detailed anatomies and keeping precise surgical orientation are essential for this technique. Authors present the technical feasibility and initial results of use a tubular retractor system as a minimally invasive technique for variaties of spinal disorders with a review of literature.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2597-2599
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• 2005

This research is developing the technique of troubleshooting in digital excitation system of nuclear power plant. and the design technique of excitation system is thought to be advanced through this research. Especially, the development of simulator enables to accumulate digital control technique, more analysis for excitation system algorithm. etc helps to develop other nuclear power plants.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.274-279
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• 1991

The development of a guided weapon system, such as a tactical missile, requires a performance analysis of a nonlinear system. Generally, the Monte Carlo analysis method is used for this purpose. The limitation of this method, a large number of simulations, for a nonlinear system performance analysis strongly motivated the development of a more efficient analytic technique. In this paper, the statisfical linearization methods is used for the performance analysis to the guided weapon system with the help of covariance analysis technique. Because the statistical linearization methods cannot be used to the look-up table nonlinear form such as aerodynamic coefficients, the second order polynomial representations is obtained from the table using the Lagrange interpolating polynomial and linearized statistically. Simple simulations about initial state conditions and random component in guidance command shows the results of this technique.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.221-223
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• 1997

This paper presents the Simplified Simulation Technique that evaluates the adequacy of an electric power system using only a portion of the outage period instead of each hour. Reliability evaluation may be performed at various hierarchical levels, generation, transmission and distribution system. The Simplified Simulation Technique simplifies the adequacy evaluation process reducing the number of calculations considerably. Therefore the computation time can be significantly reduced. This paper is done to compare the results of the simulation model with the Simplified Simulation Technique against the results of the simulation model without the Simplified Simulation Technique. The reliability indices such as the Loss of Load Probability(LOLP), the loss of load frequency(LOLF), the average duration of load curtailment(DLC) and the average demand of load curtailment(ADLC) are calculated. The proposed methods and procedures are tested by using the IEEE-RTS with 24-bus system.