• Title/Summary/Keyword: reduction procedures

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Estimating Repair Effect and Parameters of Intensity Function under BMS Repair Model (BMS 수리모형하에서 시스템의 수리효과 및 고장강도함수의 모수추정)

  • 윤원영;정석주;정일한;김종운;정상욱
    • Journal of the Korean Operations Research and Management Science Society
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    • v.25 no.4
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    • pp.45-54
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    • 2000
  • Estimation Problems of parameters of the failure process and the repair effect in repairable systems are considered. We propose estimation procedures in repairable systems without preventive maintenances. The failure process is modeled by a proportional age reduction model (Brown, Mahoney, Sivazlian [5]) which is able to consider both aging and repair effects. Maximum likelihood method is used to estimate the repair effect and parameters of intensity function simultaneously. simulations are performed to evaluate the accuracy of estimators. A numerical example is also presented.

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A blocking effect reduction method for disparity computation under the block matching algorithm (블록 매칭 기반에서 디스페리티의 블록킹 현상을 줄이는 알고리즘)

  • 송원석;유용현;문정환;김민기
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.1996-1999
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    • 2003
  • Stereo matching is an important technique in the are of computer vision. There are already many theorems to find disparity map using stereo images. Usually, disparity is searched by using block matching. However block matching result in blocking effects caused by using fixed size window for computing pixel correlations. This paper suggests an efficient method to remove the blocking effect in stereo matching procedures.

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The development study on the power system operation and protection scheme in Myanmar (미얀마 전력계통 운영 및 보호시스템 구축 사업)

  • Kim, Jong-Hwa;Choi, Young-Sung;Han, Seong-Min;Lee, Duck-Jae
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.34-35
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    • 2008
  • KEPCO conducted a third project in Myanmar regarding system operation and protection scheme. This paper deals with blackout reduction plan, reactive power compensation plan and system restoration procedures in operations parts. Moreover protection system improvement plan and standard protection schemes were suggested.

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Overview of Mandibular Condyle Fracture

  • Park, Su-Seong;Lee, Keun-Cheol;Kim, Seok-Kwun
    • Archives of Plastic Surgery
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    • v.39 no.4
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    • pp.281-283
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    • 2012
  • The mandibular condyle is a region that plays a key role in the opening and closing of the mouth, and because fracture causes functional and aesthetic problems such as facial asymmetry, it is very important to perform accurate reduction. Traditionally, there has been disagreement on how to manage fracture of the mandibular condyle. This review explores the misunderstanding of mandibular condyle fracture treatment and modern-day treatment strategies.

Reliability Evaluation for Photovoltaic Modules (태양전지 모듈의 신뢰성 평가)

  • Tanaka, Hirokazu;Kim, Keun-Soo
    • Journal of the Microelectronics and Packaging Society
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    • v.19 no.2
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    • pp.1-5
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    • 2012
  • Long-term reliability of Si photovoltaic modules is a crucial issue for the cost-reduction on the power-supply system. To elevate this reliability, several environmental tests have been created as qualification and certification procedures. This paper gives an overview about recent researches of reliability tests for Si photovoltaic modules.

Video-Assisted Thoracic Surgery Esophagectomy

  • Park, Seong Yong
    • Journal of Chest Surgery
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    • v.54 no.4
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    • pp.279-285
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    • 2021
  • Thoracoscopic esophagectomy for esophageal cancer can be performed in multiple positions, such as the lateral decubitus position or prone position, using various techniques. Each approach has its own advantages and disadvantages, and surgeons can select an appropriate approach based on their preferences. Except for the reduction of pulmonary complications, the benefits of thoracoscopic esophagectomy, including oncologic outcomes, have not been proven scientifically. This review describes the approaches and procedures of thoracoscopic esophagectomy and presents scientific evidence for this procedure.

Quantification of Uncertainty Associated with Soil Sampling and Its Reduction Approaches (토양오염도 평가시 시료채취 불확실성 정량화 및 저감방안)

  • Kim, Geonha
    • Journal of Soil and Groundwater Environment
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    • v.18 no.1
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    • pp.94-101
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    • 2013
  • It is well known that uncertainty associated with soil sampling is bigger than that with analysis. In this research, uncertainties for soil sampling when assessing TPH and BTEX concentration in soils were quantified based on actual field data. It is almost impossible to assess exact contamination of the site regardless how carefully devised for sampling. Uncertainties associated with sample reduction for further chemical analysis were quantified approximately 10 times larger than those associated with core sampling on site. Bigger uncertainties occur when contamination level is low, sample quantity is small, and soil particle is coarse. To minimize the uncertainties on field, homogenization of soil sample is necessary and its procedures are proposed in this research as well.

RBF-POD reduced-order modeling of DNA molecules under stretching and bending

  • Lee, Chung-Hao;Chen, Jiun-Shyan
    • Interaction and multiscale mechanics
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    • v.6 no.4
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    • pp.395-409
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    • 2013
  • Molecular dynamics (MD) systems are highly nonlinear and nonlocal, and the conventional model order reduction methods are ineffective for MD systems. The RBF-POD method (Lee and Chen, 2013) employed a radial basis function (RBF) approximated potential energies and inter-atomic forces of MD systems under the framework of the proper orthogonal decomposition (POD) method for the reduced-order modeling of MD systems. In this work, we focus on the numerical procedures of the RBF-POD method and demonstrate how to apply this approach to the modeling of ds-DNA molecules under stretching and bending conditions.

Evaluation of Air-side Heat Transfer and Friction Characteristics on Design Conditions of Evaporator (증발기의 설계조건에서 공기측 열전달계수 및 압력강하 산출)

  • 김창덕;이진호
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.12
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    • pp.1007-1017
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    • 2003
  • An experimental study on the air-side pressure drop and heat transfer coefficient of slit fin-tube heat exchanger has been carried out. The data reduction methodology for air-side heat transfer coefficients in the literature is not based on a consistent approach. This paper focuses on new method of data reduction to obtain the air-side performance of fin-tube heat exchanger using R22 and recommends standard procedures for dry and wet surface heat transfer estimation in fin-tube heat exchanger having refrigerant on the tube-side. Results are presented as plots of friction f-factor and Colburn j -factor against Reynolds number based on the fin collar outside diameter and compared with previous studies. The data covers a range of refrigerant mass fluxes of 150∼250 kg/$m^2$s with air flows at velocity ranges from 0.3 m/s to 0.8 m/s.

Development of Underwater Acoustic Performance Measurement System Using Pulse Tubes (펄스 튜브를 이용한 수중 음향 성능 측정 시스템 개발)

  • Seo, Yun-Ho;Kim, SangRyul;Lee, Sung-Min;Byun, Yang-Heon;Seo, Youngsoo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.04a
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    • pp.603-608
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    • 2014
  • Underwater acoustic materials are installed in order to reduce reflection, transmission and radiation of an underwater structure. The acoustic performance of the materials should be evaluated in accurately-controlled environment in terms of temperature and static pressure. In this paper, three pulse tubes, which is equipped with temperature and pressure controllers, are designed and developed to evaluate echo reduction and transmission loss for evaluating the performance below 10 kHz and 30kHz, respectively. The new procedures of the evaluation are suggested to improve the accuracy and the validation for the developed pulse tubes is carried out by comparing theoretical values to experimental ones.

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