Moment Characteristics Research Articles

Stressed state of chemically active polymeric systems under shear, elongation, and oscillating deformations

The stressed state of chemically active polymeric systems under the conditions of shear, elongation, and oscillating deformations has been investigated. From the viewpoint of locally nonequilibrium thermodynamics and statistical physics for systems with a complex internal structure, the moment characteristics of the locally nonequilibrium transfer process and the related components of their stress tensor deviator have been established. The influence of deformation conditions on the amount and character of the change in the stressed state of chemically active polymeric systems has been analyzed.

Study on Eliminating the Effect of Bending Moment in Torque Measurement

The function characteristics of bending moment and torque were analyzed based on the principle of torque measurement and the adverse effect of bending moment to torque measurement was proved theoretically. By distributing the positions of resistance strain gauge on the transmission shaft and the relative positions in the bridge, an effective method of eliminating the adverse effect of bending moment was proposed base on the principle of superposition and counterbalance in the bridge, and the potential errors were analyzed and corrected. Then the proposed method was applied in measuring the torque of a motor shaft. The result shows that the effect of bending moment has been eliminated, and this method is feasible and effective.

QGP flow fluctuations and the characteristics of higher moments

The dynamical development of expanding Quark-gluon Plasma (QGP) flow is studied in a 3+1D fluid dynamical model with a globally symmetric, initial condition. We minimize fluctuations arising from complex dynamical processes at finite impact parameters and from fluctuating random initial conditions to have a conservative fluid dynamical background estimate for the statistical distributions of the thermodynamical parameters. We also avoid a phase transition in the equation of state, and we let the matter supercool during the expansion. Then central Pb + Pb collisions at \( \sqrt{s_{NN}}=2.76\) TeV are studied in an almost perfect fluid dynamical model, with azimuthally symmetric initial state generated in a dynamical flux-tube model. The general development of thermodynamical extensives are also shown for lower energies. We observe considerable deviations from a thermal equilibrium source, changing skewness and kurtosis by time depending on beam energy as a consequence of the fluid dynamical expansion arising from a least fluctuating initial state.

Three Unstructured Computational Fluid Dynamics Studies on Generic Unmanned Combat Aerial Vehicle

Three independent studies from the United States (NASA), Sweden (Swedish Defense Research Agency), and Australia (Defense Science and Technology Organization) are analyzed to assess the state of current unstructured grid computational fluid dynamic tools and practices for predicting the complex static and dynamic aerodynamic and stability characteristics of a generic 53-deg swept, round-leading-edge uninhabited combat air vehicle configuration, calledSACCON (which stands for “stability and control configuration”). NASAexercised theUSM3D tetrahedral cell-centered flow solver, while the Swedish Defense Research Agency and the Defense Science and Technology Organization applied the Swedish Defense Research Agency/EDGE general-cell vertex-based solver. The authors primarily employ the Reynolds-averaged Navier–Stokes assumption, with a limited assessment of the EDGEdetached eddy simulation extension, to explore sensitivities to grids and turbulencemodels. Correlations with experimental data are provided for force and moments, surface pressure, and off-body flow measurements. The vortical flowfield over SACCON proved extremely difficult to model adequately. As a general rule, the prospect of obtaining reasonable correlations of SACCON pitching moment characteristics with the Reynolds-averaged Navier–Stokes formulation is not promising, even for static cases. However, dynamic pitch oscillation results seem to produce a promising characterization of shapes for the lift and pitching moment hysteresis curves. Future studies of this configuration should include more investigation with higher-fidelity turbulence models such as detached eddy simulation.

Analytical approach for the prediction of steady state tyre forces and moments under different normal pressure distributions

In general, all primary as well as disturbing forces acting on a vehicle (with the exception of aerodynamic forces) are generated at the tyre–road interface. The small size pneumatic tyres presented in this work are mostly used in lightweight vehicles like scooters, motor cycles and 3-wheelers that are extensively used for intercity transportation applications in India and other developing countries. Analytical approach is more advantage than experimental work due to many factors like it involves less cost, minimum time and little effort. Hence, Analytical tyre models are developed based on various normal pressure distributions with tyre contact patch as rectangle at the middle with part of circles at the ends. The tyre longitudinal and lateral force characteristic equations for proposed tyre models are developed. In addition, the equations for self – aligning moment and overturning moment characteristics for all tyre models are also derived. Results of proposed tyre models in the present study are compared with well-established earlier tyre models [4–6]. From the force and moment characteristics of all tyre models, unsymmetrical trapezoidal pressure distribution tyre model gives better performance than other models due to which better lateral stability of the vehicle can be obtained.

STEADY-STATE DISTRIBUTIONS FOR HARMONIC OSCILLATOR WITH VERY FAST FREQUENCY FLUCTUATIONS

The moment and probability steady-state characteristics of harmonic oscillator with frequency fluctuations in the form of white noise are investigated. Based on well-known functional approach, we derive integro-differential Kolmogorov equation for the joint probability density function of oscillator coordinate and velocity. For white Gaussian noise, using a set of equations for joint moments, we reconstruct the approximate form of coordinate and velocity distributions in the limit of small friction. As shown, these probability density functions do not exist for zero friction because they cannot be normalized.

가정용 BLDC 전동기 세탁기의 운전특성 시뮬레이션

This paper studied about the measurement method of the instantaneous dynamic load characteristics. this experimental study, we derived the instantaneous washing load characteristics and inertial moment characteristics according to the amount of laundry and water level. Also, this studied about the dynamic driving characteristics simulation method for the prediction of washing performance based on this load characteristics analysis. For this study, the design parameters of the driving motor are obtained by FEM analysis and the experiment. By using theses motor parameters and load characteristics, the instantaneous driving characteristics simulation is accomplished and it is verified with the experimental result of various driving conditions. The results of this paper would be very useful to the prediction of washing mode operation characteristics, and it can be also utilized to the washer motor control algorithm design for the washing performance improvement.

Maxillary Arch Dimensions and Spectral Characteristics of Children With Cleft Lip and Palate Who Produce Middorsum Palatal Stops

The purpose of this study was twofold: (a) to determine maxillary arch dimensions of children with repaired cleft lip and palate (CLP) who produced middorsum palatal stops and (b) to describe some spectral characteristics of middorsum palatal stops. Maxillary arch width, length, and height dimensions and first spectral moments of /t/-/k/ contrast words were determined for three groups of children ages 7-11 years: (a) with CLP who were clinically judged to produce middorsum palatal stops ( n = 5), (b) with CLP but without middorsum palatal stops ( n = 6), and (c) typically developing controls ( n = 8). Validity of clinical judgments of middorsum palatal stops was assessed by adult listeners via forced-choice identification of /t/-/k/ contrast words. Listeners confirmed production of middorsum palatal stops for 4 of 5 children with CLP. These children had (a) the narrowest anterior maxillary arch width relative to posterior arch width ( p = .011) and (b) the lowest first spectral moment for /t/ targets ( p = .001) and the lowest /t/-/k/ difference ( p = .010). Middorsum palatal stops may occur in children with repaired CLP in response to limited anterior oral cavity space due to restricted (or collapsed) maxillary arches. First spectral moment characteristics of middorsum palatal stops are consistent with backed lingual placement during stop release.

풍력발전기 증속기에 전달되는 풍하중 변동특성 연구

본 논문은 정상풍속과 돌발풍속을 수학적으로 모델링하고 풍향에 따라 전달되는 메인축에서의 전달모멘트를 조사하여 기어박스에 전달되는 풍하중의 특성을 파악하였다. 정상풍속은 지상에서 고도가 높아짐에 따라 속도가 증가하게 설정을 하였다. 풍하중에 의해서 메인축으로 전달되는 모멘트의 평균값과 하모닉값을 풍향 입사각을 -45° ~ 45°로 변화를 주며 특성을 파악하였다. 또한 기어 트레인의 미스얼라인먼트를 유발시키는 굽힘 모멘트의 특성을 파악하였다. 정상풍속모델에서는 블레이드의 3배수 주파수(3X)로 하는 토크의 가진이 생기며, 바람의 방향이 +22.5° 일 때 수평방향의 굽힘 모멘트가 주축으로 들어가는 토크의 50%수준으로 발생하는데 이는 수평방향으로의 탄성 축 휘임을 유발하여 치가 모서리에서 물림이 발생하게 하는 원인을 제공함을 알 수 있었다. 돌발풍속의 경우, 3X, 6X, 9X를 가진주파수로 하는 토크의 가진이 바람의 방향이 +방향으로 커질수록 하모닉항의 상대 비율이 증가하였다.

ANALYSIS OF AXIALLY MAGNETIZED PERMANENT MAGNET BEARING CHARACTERISTICS

The use of permanent magnets as bearings has gained attention of researchers nowadays. The characteristics of forces and moments have to be analysed thoroughly for the proper design of permanent magnet bearings. This paper presents a mathematical model of an axially magnetized permanent magnet bearing (ring magnets) using Coulombian model and a vector approach to estimate the force, moment and stifiness. A MATLAB code is developed for evaluating the parameters for flve degrees of freedom (three translational and two rotational) of the rotor. Furthermore, it is extended to analyse stacked ring magnets with alternate axial polarizations. The proposed model is validated with the available literature. Comparison of force and stifiness results of the presented model with the results of three dimensional (3D) flnite element analysis using ANSYS shows good agreement. Finally, the cross coupled stifiness values in addition to the principal stifiness values are presented for elementary structures and also for stacked structures with three ring permanent magnets.

Second Moment Reliability Evaluation vs. Monte Carlo Simulations for Weld Fatigue Strength

Monte Carlo simulations have become very popular in industrial applications as a tool to study variational influences on reliability assessments. The method is appealing because it can be done without any statistical knowledge and produces results that appear very informative. However, in most cases, the information gathered is no more than a complicated transformation of initial guesses because the statistical distributions of the dominating variational influences are unknown. The seemingly informative result may then be highly misleading, in particular, when the user lacks sufficient statistical knowledge. Instead, in cases where the input knowledge of the distributional properties is vague, it may be better to use a reliability method based on the actual knowledge, often not more than second moment characteristics. This can easily be done by using a method, based on variances, covariances, and sensitivity coefficients.Here, a specific problem of fatigue life of a welded structure is studied by (i) a Monte Carlo simulation method and (ii) a second moment method. Both methods are evaluated on a fatigue strain–life approach and use experimental data showing variation in weld geometry and material strength parameters.The two methods are compared and discussed in view of the engineering problem of reliability with respect to fatigue damage. Copyright © 2011 John Wiley & Sons, Ltd.

INFLUÊNCIA DAS DISFUNÇÕES SEXUAIS NA DINÂMICA DO CASAL

Neste artigo refletiu-se sobre os diversos tipos de casal que permeiam o mundo atual, sobre as interferências que as disfunções sexuais podem gerar em seu relacionamento; assim como, sobre a presença de vários outros fatores que permeiam as relações de casal e interferem nesta dinâmica, propiciando maior ou menor intensidade de conflitos. Para tal, precisou-se enfocar características típicas do momento socio-histórico e suas interferências nas pessoas e nos casais. Pontuou-se sobre a necessária individualização dos casais e das pessoas que o compõe, observando-se suas estruturas de personalidade, crenças, valores, necessidades, significado de seus vínculos, sobre as formas de manifestação das disfunções, suas etiologias e reações ao problema.

A prototype of submersible surface ship and its hydrodynamic characteristics

The submersible surface ship (SSS) is a new concept ship that avoids rough seas by going underwater using downward lift of wings and keeping residual buoyancy for safety. A prototype of SSS consisting of a hull, a pair of main wings, and a pair of horizontal tail wings is proposed, where mathematical formulae represent the forms of main hull and bridge deck. The circular motion test clarified the characteristics of hydrodynamic forces and moments acting on a model of the prototype SSS in vertical and lateral motions. The tank tests revealed how the main and the tail wing angles affect the total hydrodynamic forces and moments as well as how their performance interact each other. The test data also tell the variation of hydrodynamic characteristics of different submerged depth and different longitudinal position of the bridge deck. Comparisons of the estimated linear hydrodynamic derivatives with those obtained by the test data analysis validate the estimation method. A mathematical model is presented to describe the observed phenomenon that the aileron angle in lateral motion induces the vertical force and pitch moment, which leads a coupled vertical and lateral motion of the prototype SSS.

Boundary discontinuous Fourier solution for plates and doubly curved panels using a higher order theory

A new analytical solution to the problem of a finite-dimensional general cross-ply plates and doubly curved panels of rectangular planform is presented using a higher order shear deformation theory (HSDT). A solution methodology, based on a boundary-discontinuous generalized double Fourier series approach, is used to solve the highly coupled linear partial differential equations, generated by the HSDT-based laminated shell analysis, with the SS1–SS3-mixed type simply supported boundary conditions prescribed at all four edges. For derivation of the complementary solution, the complementary boundary constraints are introduced through boundary discontinuities of some of the particular solution functions and their partial derivatives. The accuracy of the present solution is checked by studying the convergence characteristics of deflections and moments of an antisymmetric cross-ply shell and results are also compared with the finite element counterparts using commercially available software for distributed load. The primary aim of this study is to understand the effect of in-plane (or surface-parallel) boundary conditions, quantify this effect and provide benchmark comparisons and verifications of numerical results such as finite element, boundary element, etc. The effects of curvature, lamination, material property, thickness, and different types of loads as well as their interactions are also investigated in detail.

Japanese central bank interventions and the dispersion of individual exchange rate expectations: differential impact on four moment characteristics

We investigate the influence of Japanese central bank interventions on market participants' opinions about the future path of exchange rates. Based on a survey of individual forecasts made by 31 analysts, we investigate the sensitivity of the change, dispersion, directionality and flatness of expectation distributions between January 1995 and December 2004. In line with previous findings, we provide evidence that exchange rate market volatility is positively linked to the degree of dispersion among market participants' expectations. Only large and transparent central bank interventions have a significant influence on market participants' opinions about the future path of exchange rates. Uncertainty is exclusively reduced among 12-month forecasts. It should be stressed furthermore that for these forecasts positive interest rate spreads and interventions are shown to have an asymmetric impact on heterogeneity: they tend to increase the degree of consensus among forecasters who attach more weight to a stronger yen and to increase the degree of disagreement among the others.

Research on Attitude Law of Mass Moment Missile Based on Mulriple Control

Aimed at characteristics of mass moment of missiles in exo-atmosphere, it’s inferred that 6-DOF mathematical model based on mass moment controlling stabilities on three axes. Considering the problem of harmoniously controlling two moving masses, moving mass based non-linear theorem was used to solve a series of problems met in attitude control system design. In order to weaken the chattering of the system, a saturation function is introduced to substitute for Sign function to improve the variable structure control law so that the chattering can be depressed. The simulation results illustrate the efficiency of this method.

Bending Moment Characteristics on Repeated Folding Motion of Coated Paperboard Scored by Round-Edge Knife

This work deals the creasing characteristics of coated paperboard. It was not clarified to estimate the deformation behavior of creased line from the first peak bending moment Mp1 and the initial gradient C1 of bending moment. In this study, a new prototype testing apparatus has been developed for seeking the bending moment and the side view picture of creased part during repeated folding motion. The permanent (residual) deformation angles, the variance of residual stiffness and the hysteresis characteristics of bending moment were analyzed for the nominal shear strain (the scoring depth) γ . The obtained results were as follows: (1) C1 was characterized with γ, while the second term gradient C2 was characterized with γ and the inverse of tracking angle Θ-1. (2) By introducing the area of closed curve of second term hysteresis ACC, it is revealed that the gradient of ACC was remarkably varied with Θ at near the peak point Mp1.

Neuronal Jitter: Can We Measure the Spike Timing Dispersion Differently?

We propose a novel measure of statistical dispersion of a positive continuous random variable: the entropy-based dispersion (ED). We discuss the properties of ED and contrast them with the widely employed standard deviation (SD) measure. We show that the properties of SD and ED are different: while SD is a second moment characteristics measuring the dispersion relative to the mean value, ED measures an effective spread of the probability distribution and is more closely related to the notion of randomness of spiking activity. We apply both SD and ED to analyze the temporal precision of neuronal spiking activity of the perfect integrate-and-fire model, which is a plausible neural model under the assumption of high input synaptic activity. We show that SD and ED may give strikingly different results for some widely used models of presynaptic activity.

Experimental investigation into the interference aerodynamics of two slender bodies in close proximity

Aerodynamic interference between high-speed slender bodies can detrimentally affect the force and moment characteristics. This is investigated through a wind tunnel study using pressure sensitive paint and force measurements on a receiver body placed adjacent to a generator body. The aim of this paper is to understand both the force and moment changes as well as the underlying aerodynamics of the interference loads which are induced by the disturbance flowfield. The impact of receiver incidence and the strength of the disturbance field are also assessed. The observed interference loads primarily depend on a complex balance of static pressure footprints and tend to be bespoke to each configuration. As a result, overall trends are difficult to extract, but in general the magnitude of the interference loads increases when the receiver is at incidence and also when the strength of the imposed disturbance flowfield increases.

Lower-Dimensional Feature Sets for Template-Based Motion Recognition Approaches

Problem statement: In template-based motion recognition approaches, feature sets are computed from the template for classification. Hu invariants are widely employed for this purpose since its inception. However, development of lower-dimensional feature vector sets is required for faster computation along with robust recognition. The concept of reduced size of Hu moment is really interesting. From its inception, seven higher orders Hu moments have been employed by many researchers without considering why seven and why not less numbers. Approach: In this study, we analyzed with various feature sets with different number of Hu moments and rationalized that based on the characteristics of central moments, it is not necessary to employ all the seven moments in every applications and, in that way, we can reduce the computational cost and make it faster. Results: Based on various feature vectors sets, it is evident that we can use lower dimensional feature vectors for our Directional Motion History Image (DMHI) method and other methods. Conclusion: Therefore, we can conclude that we do not need all seven invariants, rather 1st two or three invariants seem enough-as we are not reproducing the image. Higher invariants are noisy and hence can be ignored. The 0th order moment for Energy images provide enough information about the mass area and hence, no need to calculate the other seven invariants.