• Title/Summary/Keyword: reduction method

Search Result 11,714, Processing Time 0.04 seconds

사면안정해석에 있어서의 유한요소법과 한계평형법의 비교 (Comparative study between Finite Element Method and Limit Equilibrium Method on Slope Stability Analysis)

  • 이동엽;유충식
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2002년도 가을 학술발표회 논문집
    • /
    • pp.483-490
    • /
    • 2002
  • This paper presents the results of a comparative study between FEM and LEM on slope stability analysis. For validation, factors of safety were compared between FEM and LEM. The results from the two methods were in good agreement suggesting that the FEM with the shear strength reduction method can be effectively used on slope stability analyses. A series of analysis were then performed using the FEM for various constitutive laws, slope angles, flow rules, and the finite element discretizations. Among the findings, the finite element method in conjunction with the shear strength reduction method can provide reasonable results in terms of factor of safety. Also revealed is that the results of FEM can be significantly affected by the way in which the type of constitutive law and flow rule are selected.

  • PDF

분산감소기법을 이용한 파라미터 추정의 효율성 (Efficiency of Estimation for Parameters by Use of Variance Reduction Techniques)

  • 권치명
    • 한국시뮬레이션학회논문지
    • /
    • 제14권3호
    • /
    • pp.129-136
    • /
    • 2005
  • We develop a variance reduction technique applicable in one simulation experiment whose purpose is to estimate the parameters of a first order linear model. This method utilizes the control variates obtained during the course of simulation run under Schruben and Margolin's method (S-M method). The performance of this method is shown to be similar in estimating the main effects, and to be superior to S-M method in estimating the overall mean response in a given model. We consider that a proposed method may yield a better result than S-M method if selected control variates are highly correlated with the response at each design point.

  • PDF

잡음 영상에서의 에지 검출 (Edge detection for noisy image)

  • 구윤모;김영로
    • 디지털산업정보학회논문지
    • /
    • 제8권3호
    • /
    • pp.41-48
    • /
    • 2012
  • In this paper, we propose a method of edge detection for noisy image. The proposed method uses a progressive filter for noise reduction and a Sobel operator for edge detection. The progressive filter combines a median filter and a modified rational filter. The proposed method for noise reduction adjusts rational filter direction according to an edge in the image which is obtained by median filtering. Our method effectively attenuates the noise while preserving the image details. Edge detection is performed by a Sobel operator. This operator can be implemented by integer operation and is therefore relatively fast. Our proposed method not only preserves edge, but also reduces noise in uniform region. Thus, edge detection is well performed. Our proposed method could improve results using further developed Sobel operator. Experimental results show that our proposed method has better edge detection with correct positions than those by existing median and rational filtering methods for noisy image.

3레벨 태양광 PCS에서의 누설전류 저감기법 개발 (Development of Leakage Current Reduction Method in 3-Level Photovoltaic PCS)

  • 한성은;조종민;안현성;차한주
    • 전력전자학회논문지
    • /
    • 제24권1호
    • /
    • pp.56-61
    • /
    • 2019
  • In this study, a reduction method of leakage current in a three-level photovoltaic power-conditioning system (PCS) is proposed and verified by simulation and experiment. Leakage current generation is analyzed through an equivalent model of the common mode voltage considering a significant parasitic capacitance existing between the photovoltaic array and ground. A leakage current reduction method using pulse-width modulation (PWM) method is also proposed, and a 10-kW three-level photovoltaic PCS simulation and experiment is performed with a $1{\mu}F$ parasitic capacitor based on 100 nF/kW. The proposed method using the PWM method is verified to reduce the leakage current by 73% compared with the conventional PWM method.

토압 영향을 받는 Down-Up 지하공사 공법의 오픈 구간 균열 저감 방안 연구 (A Study on Crack Reduction Method in open Section of Down-Up Underground Construction Method Affected by Earth Pressure)

  • 심학보;전현수;석원균
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2021년도 가을 학술논문 발표대회
    • /
    • pp.196-197
    • /
    • 2021
  • The underground method can be divided into Top-Down, Semi-Top-Down, Up-Up and Down-Up methods according to the construction order of the upper and lower structures. Among them, the Down-Up method proceeds with the construction of the first floor and its lower floors, and when the foundation is completed, the vertical members of the basement are sequentially completed from the foundation and the above-ground floor is constructed. In this paper, the crack reduction method around the open section of the Down-Up method affected by earth pressure was analyzed and divided into design and construction parts.

  • PDF

Routh Approximants with Arbitrary Order

  • 주윤석;김동민
    • 제어로봇시스템학회지
    • /
    • 제1권1호
    • /
    • pp.50-50
    • /
    • 1995
  • It has been pointed out in the literature that the Routh approximation method for order reduction has limitations in treating transfer functions with the denominator-numerator order difference not equal to one. The purpose of this paper is to present a new algorithm based on the Routh approximation method that can be applied to general rational transfer functions, yielding reduced models with arbitrary order.

침무보법(鍼無補法)의 의미에 대한 고찰(考察) -『황제내경(黃帝內經)』의 보사법(補瀉法)을 중심으로- (A Study on the Meaning of Theory that Acupuncture has no Reinforcement -Focusing on the method of reinforcement and reduction in Huangdineijing-)

  • 윤기령;백유상;장우창;정창현
    • 대한한의학원전학회지
    • /
    • 제31권2호
    • /
    • pp.141-153
    • /
    • 2018
  • Objectives : Acupuncture therapy's reinforcement and reduction method is now widely used in the clinical practices. Meanwhile, there has been a voice of concern since the past that acupuncture has no reinforcement. This thought has not been given enough discussion, and the paper attempts to remedy this absence and verify the validity of the concern. Methods : The acupunctural reinforcement and reduction method found in the Huangdineijing is reviewed, and a number of medical books that discuss the idea of lack of reinforcement in acupuncture are studied. Results : Huangdineijing describes the acupunctural unique feature of reduction. The text explains that acupuncture work in a way that is different that medicine, and thus cannot be used for a disease based on deficiency. In addition, it warned the loss of the primordial qi when needling oneself. Reinforcement in the reinforcement and reduction technique as described in Huangdineijing mainly revolves around preventing the loss of the primordial qi. Conclusions : The purpose of the acupunctural reinforcement and reduction is to control the body's disproportional qi deficiency and excess, where some parts of the body has more qi than others. The reinforcement in "acupunctural reinforcement and reduction method" and the reinforcement in "acupuncture only has reduction and no reinforcement" within the thought of "acupuncture has no reinforcement" are different in that one deals with controlling the imbalance of qi in body, and the other deals with dispelling the deficiency by flowing the qi in the viewpoint of entering and out. This calls for a need to establish the proper acupunctural points, numbers, and times for each disease based on the theory of "acupuncture has no reinforcemen."

동영상 대역폭 조절을 위한 DCT 영역의 퍼지 측정값 (Fuzzy Measures to Control Video Bit-rate in the DCT Domain)

  • 김태용
    • 전자공학회논문지CI
    • /
    • 제43권4호
    • /
    • pp.113-122
    • /
    • 2006
  • 본 연구에서는 DCT 영역에서 퍼지 측정값을 이용하여 동영상의 전송 대역폭을 조절하는 방법을 제안한다. 이 방법은 비트량 할당을 위한 퍼지 측정값과 최소 왜곡을 초래하는 비트량 축소 방법으로 구성되며, 퍼지 측정값은 코드 길이, 불연속 애매성 및 수변 블록의 모멘텀으로 계산된다. 이러한 측정값은 가중치를 곱하여 계산되며 대역폭 축소의 적절한 정도를 나타내며 이러한 퍼지 애매성을 이용하여 각각의 DCT 블록은 최소 왜곡 방법에 의하여 필터링되어 동영상의 대역폭을 대상 네트워크 환경의 대역폭에 적합하도록 축소한다. 실험에서는 이러한 방법에 의하여 트랜스코딩된 영상의 화질이 시각적 및 양적으로 우월함을 나타내었고, 대역폭이 균일함을 보여준다.

개념 상승과 속성의 최적 감축에 의한 결정 규칙의 생성 (Generation of Decision Rules Bsed on Concept Ascension and Optimal Reduction of Attributes)

  • 정환묵
    • 한국지능시스템학회논문지
    • /
    • 제9권4호
    • /
    • pp.367-374
    • /
    • 1999
  • 본 논문은 대규모 데이터베이스에서 의사 결정을 위한 지식을 효율적으로 추출하기 위해 개념 상승과 속성 감축에 기반한 통합적 방법을 제안한다. 본 방법은 클리스터링 기법에 의해 개념 트리를 자동생성하고 개념 상승기법에 의해 데이터 베이스를 일반화하며 속성의 중요도를 사용한 속성 감축에 의해 최적감축을 하고 식별가능 행렬과 함수를 사용하여 효율적으로 속성값을 감축하여 최적의 최소결정 규칙을 유도한다. 본 방법은 투자 계획이나 가격 결정과 같은 의사결정 업무 각종 고장 진단이나 의료 진단을 위한 지식 베이스구축 마케팅 분석이나 실험 데이터 분석 고수준의 질의 에 의한 정보검색 등에 효과적으로 사용될수 있다.

  • PDF

A Continuous Spectrophotometric Assay for NADPH-cytochrome P450 Reductase Activity Using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium Bromide

  • Yim, Sung-Kun;Yun, Chul-Ho;Ahn, Tae-Ho;Jung, Heung-Chae;Pan, Jae-Gu
    • BMB Reports
    • /
    • 제38권3호
    • /
    • pp.366-369
    • /
    • 2005
  • NADPH-cytochrome P450 reductase (CPR) transfers electrons from NADPH to cytochrome P450 and also catalyzes the one-electron reduction of many drugs and foreign compounds. Various spectrophotometric assays have been performed to examine electron-accepting properties of CPR and its ability to reduce cytochrome $b_5$, cytochrome c, and ferricyanide. In this report, reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) by CPR has been assessed as a method for monitoring CPR activity. The principle advantage of this substance is that the reduction of MTT can be assayed directly in the reaction medium by a continuous spectrophotometric method. The electrons released from NADPH by CPR were transferred to MTT. MTT reduction activity was then assessed spectrophotometrically by measuring the increase of $A_{610}$. MTT reduction followed classical Michaelis-Menten kinetics ($K_m\;=\;20\;{\mu}M$, $k_{cat}\;=\;1,910\;min^{-1}$). This method offers the advantages of a commercially available substrate and short analysis time by a simple measurement of enzymatic activity of CPR.