• 제목/요약/키워드: moments

검색결과 2,410건 처리시간 0.026초

Rapid prediction of inelastic bending moments in RC beams considering cracking

  • Patel, K.A.;Chaudhary, Sandeep;Nagpal, A.K.
    • Computers and Concrete
    • /
    • 제18권6호
    • /
    • pp.1113-1134
    • /
    • 2016
  • A methodology using neural networks has been proposed for rapid prediction of inelastic bending moments in reinforced concrete continuous beams subjected to service load. The closed form expressions obtained from the trained neural networks take into account cracking in concrete at in-span and at near the internal supports and tension stiffening effect. The expressions predict the inelastic moments (considering the concrete cracking) from the elastic moments (neglecting the concrete cracking) at supports. Three separate neural networks are trained since these have been postulated to represent all the beams having any number of spans. The training, validating, and testing data sets for the neural networks are generated using an analytical-numerical procedure of analysis. The proposed expressions are verified for example beams of different number of spans and cross-section properties and the errors are found to be small. The proposed expressions, at minimal input data and computation effort, yield results that are close to FEM results. The expressions can be used in preliminary every day design as they enable a rapid prediction of inelastic moments and require a computational effort that is a fraction of that required for the available methods in literature.

사람 보행시 발바닥의 힘정보를 측정하기 위한 지능형 신발시스템 개발 (Development of lntelligent Shoe System to Measure Applied Force/Moment on the Sole of a Foot during Human Walking)

  • 김갑순;김현민;허덕찬
    • 한국정밀공학회지
    • /
    • 제25권7호
    • /
    • pp.79-86
    • /
    • 2008
  • This paper describes the development of wearing intelligent shoe system to measure applied forces and moments (ground reaction forces and moments) on the soles of feet during human walking. In order to walk safely, robot must get the intelligent feet with 6-axis force/moment sensors (Fx sensor (x-direction force sensor), Fy sensor, Fz sensor, Mx sensor (Mx : x-direction moment sensor), My sensor, and Mz sensor) and detect the forces and moments data from the sensors. And the feet must be controlled with the data and controllers. While a human is walking, the forces and moments should be measured and analyzed for robot's intelligent feet. Therefore, the wearing intelligent shoe system should be developed. In this paper, four 6-axis farce/moment sensors and two high speed measuring devices were designed and fabricated, and the wearing intelligent shoe system was made using these. The characteristic tests of the wearing intelligent shoe system were performed, and the forces and moments were detected using it.

Prediction of moments in composite frames considering cracking and time effects using neural network models

  • Pendharkar, Umesh;Chaudhary, Sandeep;Nagpal, A.K.
    • Structural Engineering and Mechanics
    • /
    • 제39권2호
    • /
    • pp.267-285
    • /
    • 2011
  • There can be a significant amount of moment redistribution in composite frames consisting of steel columns and composite beams, due to cracking, creep and shrinkage of concrete. Considerable amount of computational effort is required for taking into account these effects for large composite frames. A methodology has been presented in this paper for taking into account these effects. In the methodology that has been demonstrated for moderately high frames, neural network models are developed for rapid prediction of the inelastic moments (typically for 20 years, considering instantaneous cracking, and time effects, i.e., creep and shrinkage, in concrete) at a joint in a frame from the elastic moments (neglecting instantaneous cracking and time effects). The proposed models predict the inelastic moment ratios (ratio of elastic moment to inelastic moment) using eleven input parameters for interior joints and seven input parameters for exterior joints. The training and testing data sets are generated using a hybrid procedure developed by the authors. The neural network models have been validated for frames of different number of spans and storeys. The models drastically reduce the computational effort and predict the inelastic moments, with reasonable accuracy for practical purposes, from the elastic moments, that can be obtained from any of the readily available software.

노인요양병원 간호인력의 손위생 시행시점에 관한 지식 및 이행 (Knowledge and Compliance on Hand Hygiene Moments of Nursing Care Workers in Geriatric Hospitals)

  • 박정애;양남영
    • 가정간호학회지
    • /
    • 제25권2호
    • /
    • pp.165-174
    • /
    • 2018
  • Purpose: The study investigated the knowledge and compliance on hand hygiene moments among nursing care workers in geriatric hospitals. Methods: A total of 143 nursing care workers at geriatric hospitals were selected. Data collection was conducted from February 20 to March 20, 2017. Results: For all hand hygiene scenarios, the total correct answer rate was 71.5%. On the necessary hand hygiene moments, the compliance rate was 68.3%. With respect to the general characteristics of the participants, knowledge on hand hygiene moments showed a statistically significant difference according to clinical career(p=.001), and existence of infection controller or infection control office in the nursing home(p=.038). Compliance showed differences according to clinical career(p=.023), existence of infection controller or infection control office in the nursing home(p=.033), and training experience in hand hygiene(number of times/year)(p=.035). Knowledge and compliance showed a statistically significant positive correlation(r=.90, p<.001). Conclusions: It is necessary to develop and operate an infection control education program that can improve the knowledge and awareness of hand hygiene moments and considers the individual characteristics geriatric hospitals's nursing care workers.

미분구적법(DQM)을 이용한 곡선보의 외평면 좌굴해석 (Out-of-Plane Buckling Analysis of Curved Beams Using DQM)

  • 강기준
    • 한국안전학회지
    • /
    • 제17권4호
    • /
    • pp.189-195
    • /
    • 2002
  • I-단면 곡선보 (curved beam)의 모멘트 하중 하에서 비틀림(warping)을 포함한 평면외 (out-of-plane)의 좌굴을 미분구적법 (DQM)을 이용하여 해석하였다. 다양한 경계조건(boundary conditions) 및 굽힘각(opening angles)에 따른 임계모멘트 (critical moments)를 계산하고, DQM의 해석결과는 해석적 해답 (exact solution) 과 비교 분석하였다. DQM은 적은 요소(grid points)를 사용하여 정확한 해석결과를 보여주었고, 두 경계조건 (고정-고정, 고정-단순지지)하에서 새로운 결과 또한 제시하였다.

RECURRENCE RELATIONS FOR HIGHER ORDER MOMENTS OF A COMPOUND BINOMIAL RANDOM VARIABLE

  • Kim, Donghyun;Kim, Yoora
    • East Asian mathematical journal
    • /
    • 제34권1호
    • /
    • pp.59-67
    • /
    • 2018
  • We present new recurrence formulas for the raw and central moments of a compound binomial random variable. Our approach involves relating two compound binomial random variables that have parameters with a difference of 1 for the number of trials, but which have the same parameters for the success probability for each trial. As a consequence of our recursions, the raw and central moments of a binomial random variable are obtained in a recursive manner without the use of Stirling numbers.

후진 미분 연산자를 이용한 이산확률분포의 적률 유도 (Derivations of moments for discrete probability distributions using backward difference operators)

  • 조길호
    • Journal of the Korean Data and Information Science Society
    • /
    • 제22권3호
    • /
    • pp.505-513
    • /
    • 2011
  • 본 논문의 목적은 후진 미분 연산자를 이용하여 이산확률분포에 대한 원점으로부터의 r차 적률을 구하는 공식을 유도한다. 이 공식을 이용함으로써 r차 적률은 0에서 계산된 $x^r$의 r번째 후진 미분 연산자까지의 일차결합으로써 계산됨을 알 수 있다.

CONVERGENCE RATES FOR THE MOMENTS OF EXTREMES

  • Peng, Zuoxiang;Nadarajah, Saralees
    • 대한수학회보
    • /
    • 제49권3호
    • /
    • pp.495-510
    • /
    • 2012
  • Let $X_1$, $X_2$,${\ldots}$, $X_n$ be a sequence of independent and identically distributed random variables with common distribution function $F$. Convergence rates for the moments of extremes are studied by virtue of second order regularly conditions. A unified treatment is also considered under second order von Mises conditions. Some examples are given to illustrate the results.

Moments of a Class of Internally Truncated Normal Distributions

  • Kim, Hea-Jung
    • Communications for Statistical Applications and Methods
    • /
    • 제14권3호
    • /
    • pp.679-686
    • /
    • 2007
  • Moment expressions are derived for the internally truncated normal distributions commonly applied to screening and constrained problems. They are obtained from using a recursive relation between the moments of the normal distribution whose distribution is truncated in its internal part. Closed form formulae for the moments can be presented up to $N^{th}$ order under the internally truncated case. Necessary theories and two applications are provided.

Object Tracking Method Based on Local Moments

  • Takamatsu, R.;Kawarada, H.;Sato, M.
    • 한국방송∙미디어공학회:학술대회논문집
    • /
    • 한국방송공학회 1997년도 Proceedings International Workshop on New Video Media Technology
    • /
    • pp.113-118
    • /
    • 1997
  • This paper proposes a object tracking method based on the local moments, or moment based on the local moments, or moment of some restricted area, in which the idea of the viewpoint and the visual filed corresponding to the local area of an image is introduced. Using local moment with the optimally controlled viewpoint and visual field, the target position and its breadth are estimated robustly. By two experiments, the validity of the proposed method is shown.

  • PDF