Modelling of knitted fabric deformation.

The objective of this study was to investigate new models for the mechanical behaviour of knitted fabrics in quasi-static deformation from an initiallyrelaxed state to the extended state. In order to do so a mechanism for plain knitted structure deformation in plane was proposed, implemented and tested on a range of real samples. The problem of extension of a knitted structure is complicated by the combination of non-linear properties derived from both the characteristics of the knitted structure and the properties of the yam. To obtain a solution to this problem a finite-elementtechnique was used to evaluate the proposed model. The proposed model of mechanical behaviour of knitted fabrics is an analogue of the thin membrane problem in mechanics. The model developed is applicable to a wide range of mechanical problems where it is possible to assume that fabric is a thin membrane with zero bending rigidity. To facilitate the mechanical properties of the proposed model, standard dimensional parameters of fabric and yam combined with the mechanical properties have been used. With the purpose of obtaining important yam characteristics for the subsequent evaluation of the model, an advanced analysis of the yam path in plain knitted fabric was performed. An algorithm for loop geometry from the given fabric dimensions in course and wale directions and yam properties were developed. In order to implement the algorithms developed during this investigation complex software was written. This software allows simulation of the mechanical behaviour of different plain knitted structures under various loading and boundary conditions. At the approval stage of the model, a number of fabric samples were produced and tested; models of real samples have been simulated and compared with experimental data. The model used could be developed further to extend the application to tackle complex 3D deformation and to simulate a range of different knitted structures

Search for anomalous production of events with a high energy lepton and photon at the Tevatron

We present results of a search for the anomalous production of events containing a high-transverse momentum charged lepton ({ell}, either e or {mu}) and photon ({gamma}), accompanied by missing transverse energy (E{sub T}), and/or additional leptons and photons, and jets (X). We use the same kinematic selection criteria as in a previous CDF search, but with a substantially larger data set, 305 pb{sup -1}, a p{bar p} collision energy of 1.96 TeV, and the upgraded CDF II detector. We find 42 {ell}{gamma}E{sub T} events versus a standard model expectation of 37.3 {+-} 5.4 events. The level of excess observed in Run I, 16 events with an expectation of 7.6 {+-} 0.7 events (corresponding to a 2.7 {sigma} effect), is not supported by the new data. In the signature of {ell}{ell}{gamma} + X we observe 31 events versus an expectation of 23.0 {+-} 2.7 events. In this sample we find no events with an extra photon or E{sub T} and so find no events like the one ee{gamma}{gamma} E{sub T} event observed in Run I

INDUCTIVE LINEAR DISPLACEMENT SENSOR IN ACTIVE MAGNETIC BEARING

Active magnetic bearings are increasingly used in various fields of industry. The absence of mechanical contact makes it possible to use them in ultra-high-speed electric drives. The main trend of active magnetic bearings development is the improvement of the control system. The main problem of the control system is the displacement sensor (most of them has low accuracy and large interference). The sensor must have the following properties: simple in realization, high linearity of the characteristic, high sensitivity and noise immunity, high reliability. At the present time there is no sensor that satisfies all these conditions. Most manufacturers use various kinds of filters to get an accurate position signal. This increases the response time of the control system. Thus, problem of designing and modeling the position sensor, considered in the article is topical

Deep Integration of INS and DP: from Theory to Experiments

The recent progress of measurement devices and algorithms of inertial navigation opens up the perspective of deep integration between inertial navigation systems (INS) and dynamic positioning (DP) systems. In the literature, novel mathematical algorithms for INS-guided sensor fusion and sensor fault isolation have recently been proposed, aimed primarily at robust and resilient observation of the vessel’s attitude and position. Much less has been done for experimental testing of INS-guided DP systems in real environmental conditions. In this paper, we report experimental results (from bench tests to real sea trials), demonstrating the efficacy of a fiber-optic inertial measurement sensor in a real DP system. Besides this, we discuss some new applications of INS systems in DP operations and relevant mathematical algorithms

A note on comonotonicity and positivity of the control components of decoupled quadratic FBSDE

In this small note we are concerned with the solution of Forward-Backward Stochastic Differential Equations (FBSDE) with drivers that grow quadratically in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem is a comparison result that allows comparing componentwise the signs of the control processes of two different qgFBSDE. As a byproduct one obtains conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio