A new behavioural model for performance evaluation of common mode chokes

A galvanically isolated three-phase AC/AC converter with a high-frequency AC-link has been analyzed from an EMC point of view. This is a special configuration because of a large number of switches, a high frequency transformer, and a fourwire output. The essential coupling paths are identified. Corresponding suppression remedies are given. The results, before and after measures, have been presented to demonstrate the improvement in EMC. Keywords: AC/AC converter; electromagnetic interference; galvanically isolate

Performance optimization aspects of common mode chokes

Optimization aspects of common mode chokes are presented. These are based on a behavioral model for common mode chokes and its sensitivity study. Results are used to show the influence of the designable parameters on the final performance of the choke placed in a circuit

Linear Categorical Marginal Modeling of solicited symptoms in vaccine clinical trials

Analysis of the occurrence of adverse events, and in particular of solicited symptoms, following vaccination is often needed for the safety and benefit-risk evaluation of any candidate vaccine, and typically involves taking repeated measurements. In this article, it is shown that Linear Categorical Marginal Models (LCMMs) are well suited to take into account the dependencies in the data arising from the repeated measurements and provide detailed and useful information for comparing safety profiles of different products while remaining relatively easy to interpret. LCMMs are presented and applied to a Phase III clinical trial of a candidate meningococcal pediatric vaccine

Foot placement variables of pedestrians in community setting during curve walking

Background: There is no precise description of changes of gait during curve walking. Research in curve walking is exclusively performed in clinical settings. Research question: Is there a difference in foot placement variables between the inner- and the outer leg during curve walking in a natural environment? And are these differences correlated with time or the curvature of the path? Method: During this observational study, camera footage was shot on a crossing where pedestrians were not aware of being filmed. Participants (n = 21, male, 18?40 yrs) were selected from this video footage. Using the software package ?Movieprocessing?, the kinematic variables (time, curvature, stride length, step length, step width and relative foot angle (RFA)) were extracted from the collected data. A MANOVA and Pearson correlation test were performed to explore the data. Results: MANOVA showed no significant differences in stride length and step length between inner- and outer leg. In contrast, a significant difference between the inner (M = 0.06, SD = 0.05) and outer leg (M = 0.10, SD = 0.06, F(20,256) = 3.577, p < .001) for the step width, and the inner (M = 11.72, SD = 7.99) and outer leg (M = 11.30, SD = 8.07, F(20,256) = 4.542, p < .001) for RFA was found. Pearson correlation was significant for curvature and step width for both legs pooled (r = .28, p < .01) and the outer leg (r = .64, p < .01), as well for time and RFA in the inner (r= -.25, p < .01) and outer leg (r = .213, p < .01). Significance: This research funds further research in curve walking in natural conditions, since curve walking is found to be performed non-symmetrically and not determined by geometrics but by choice. Foot placement variables change gradually and differently for both legs during walking a curve

Model comportemental pour l`evaluation des performances de chokes de mode commun

Un model comportemental pour l’évaluation des performances de choke de mode commun (CMC) est proposé : la topologie et les méthodes utilisés pour modéliser les différentes propriétés de la CMC sont décrites. Il s’agit de la combinaison d’une modélisation précise de la perméabilité complexe du matériau, de la saturation, des inductances de fuite et des capacités parasites. Les données necessaries fournies par le designer sont les valeurs de courants, tensions et impédances du système actuel sans CMC et des paramètres disponibles dans la littérature et /ou des manufacturiers en ce qui concerne la CMC modélisée. Ce model comportemental s’avère essentiel dans la simulation des effets des interférences électromagnétiques (EMI)

Binary Models for Marginal Independence

Log-linear models are a classical tool for the analysis of contingency tables. In particular, the subclass of graphical log-linear models provides a general framework for modelling conditional independences. However, with the exception of special structures, marginal independence hypotheses cannot be accommodated by these traditional models. Focusing on binary variables, we present a model class that provides a framework for modelling marginal independences in contingency tables. The approach taken is graphical and draws on analogies to multivariate Gaussian models for marginal independence. For the graphical model representation we use bi-directed graphs, which are in the tradition of path diagrams. We show how the models can be parameterized in a simple fashion, and how maximum likelihood estimation can be performed using a version of the Iterated Conditional Fitting algorithm. Finally we consider combining these models with symmetry restrictions

Measurement of the CMS Magnetic Field

The measurement of the magnetic field in the tracking volume inside the superconducting coil of the Compact Muon Solenoid (CMS) detector under construction at CERN is done with a fieldmapper designed and produced at Fermilab. The fieldmapper uses 10 3-D B-sensors (Hall probes) developed at NIKHEF and calibrated at CERN to precision 0.05% for a nominal 4 T field. The precise fieldmapper measurements are done in 33840 points inside a cylinder of 1.724 m radius and 7 m long at central fields of 2, 3, 3.5, 3.8, and 4 T. Three components of the magnetic flux density at the CMS coil maximum excitation and the remanent fields on the steel-air interface after discharge of the coil are measured in check-points with 95 3-D B-sensors located near the magnetic flux return yoke elements. Voltages induced in 22 flux-loops made of 405-turn installed on selected segments of the yoke are sampled online during the entire fast discharge (190 s time-constant) of the CMS coil and integrated offline to provide a measurement of the initial magnetic flux density in steel at the maximum field to an accuracy of a few percent. The results of the measurements made at 4 T are reported and compared with a three-dimensional model of the CMS magnet system calculated with TOSCA.Comment: 4 pages, 5 figures, 15 reference

Constraints on a Massive Dirac Neutrino Model

We examine constraints on a simple neutrino model in which there are three massless and three massive Dirac neutrinos and in which the left handed neutrinos are linear combinations of doublet and singlet neutrinos. We examine constraints from direct decays into heavy neutrinos, indirect effects on electroweak parameters, and flavor changing processes. We combine these constraints to examine the allowed mass range for the heavy neutrinos of each of the three generations.Comment: latex, 29 pages, 7 figures (not included), MIT-CTP-221

The Gross--Llewellyn Smith Sum Rule in the Analytic Approach to Perturbative QCD

We apply analytic perturbation theory to the Gross--Llewellyn Smith sum rule. We study the $Q^2$ evolution and the renormalization scheme dependence of the analytic three-loop QCD correction to this sum rule, and demonstrate that the results are practically renormalization scheme independent and lead to rather different $Q^2$ evolution than the standard perturbative correction possesses.Comment: 17 pages, 9 eps figures, REVTe

Revising Neutrino Oscillation Parameter Space With Direct Flavor-Changing Interactions

We formulate direct, neutrino flavor-changing interactions in a framework that fits smoothly with the parameterization of two-and three-state mixing of massive neutrino states. We show that even small direct interaction strengths could have important consequences for the interpretation of currently running and proposed oscillation experiments. The oscillation amplitude and the borders of the allowed regions in two-and three-flavor mixing parameter space can be sensitieve to the presence of direct interactions when the transition probability is small. We use extensively the high sensitivity of the NOMAD experiment to illustrate potentially large effects from small, direct flavor violation. In the purely leptonic sector, we find that the clean muon neutrino and electron neutrino beams from a muon collider could provide the sharpest tests of direct flavor violation.Comment: 16 pages, 10 figure