Search results for "Placement."

Hybrid optical-digital method for local-displacement analysis by use of a phase-space representation.

2010

A method for evaluating the local deformation or displacement of an object in speckle metrology is described. The local displacements of the object in one direction are digitally coded in a one-dimensional specklegram. By optically performing the local spectrum of this pattern, one simultaneously achieves information about the local displacement and its spatial position. The good performance of this technique is demonstrated with computer-generated test signals.

Analysis of the Effect of Human Presence on a Wireless Sensor Network

2011

Wireless Sensor Networks (WSNs) are gaining an increasing industry wide adoption. However, there remain major challenges such as network dimensioning and node placement especially in Built Environment Networks (BENs). Decisions on the node placement, orientation, and the number of nodes to cover the area of interest are usually ad-hoc. Ray tracing tools are traditionally employed to predict RF signal propagation; however, such tools are primarily intended for outdoor environments. RF signal propagation varies greatly indoors due to building materials and infrastructure, obstacles, node placement, antenna orientation and human presence. Because of the complexity of signal prediction, these f…

Structural assessment of the EU-DEMO WCLL Central Outboard Blanket segment under normal and off-normal operating conditions

2021

Abstract Within the framework of the EUROfusion design activities concerning the EU-DEMO Breeding Blanket (BB) system, a research campaign has been carried out at the University of Palermo with the aim of investigating the structural behaviour of the DEMO Water-Cooled Lithium Lead (WCLL) Central Outboard Blanket (COB) segment. The assessment has been performed considering three different loading scenarios: the Normal Operation (NO), the Over-Pressurization (OP) and the Upward Vertical Displacement Event (VDE-up). In particular, NO scenario represents the loading case referring to the nominal operating conditions, whereas the OP scenario refers to the loading conditions due to an in-box LOCA…

Dynamics of Vertebral Column Observed by Stereovision and Recurrent Neural Network Model

2005

A new non-invasive method for investigation of movement of selected points on the vertebral column is presented. The registration of position of points marked on patient's body is performed by 4 infrared cameras. This experiment enables to reconstruct 3-dimensional trajectories of displacement of marked points. We introduce recurrent neural networks as formal nonlinear dynamical models of each point trajectory. These models are based only on experimental data and are set up of minimal number of parameters. Therefore they are suitable for pattern recognition problems.

Maximum Displacement Variability of Stochastic Structures Subject to Deterministic Earthquake Loading

1998

The variability of the maximum response displacement of random frame structures under deterministic earthquake loading are examined in this paper using stochastic finite element techniques. The elastic modulus and the mass density are assumed to be described by cross-correlated stochastic fields. Specifically, a variability response function formulation is used for this problem, which allows for calculation of spectral-distribution-free upper bounds of the maximum displacement variance. Further, under the assumption of prespecified correlation functions describing the spatial variation of the material properties, variability response functions are used to calculate the corresponding maximum…

Cardiovascular Disease and SERMs

2006

Accuracy of stereotactic coordinate transformation using a localisation frame and computed tomographic imaging

1999

The accuracy of coordinate transformation from a CT image to a stereotactic frame was investigated for stereotactic systems using a localisation frame and matrix-based coordinate transformation. The main source of error influencing calculation was input data, due to inaccurate calculation of the centres of the rods of the localisation frame in the CT image, and the propagation of this input error during subsequent matrix calculation. Systemic errors during matrix calculation do not exist, and rounding off errors were of subordinate importance compared to the input data error. The influence of input data error on coordinate transformation was studied by geometric methods, computer simulation…

Effect of the lack of primary stability in the survival of dental implants

2018

Background The survival of dental implants has been linked to primary stability. The aim of this study is to analyse the factors that influence the survival of dental implants placed without primary stability. Material and methods A cohort study of implants placed without primary stability was carried out between September 2011 and July 2016. All cases with registered information on the patient and surgical intervention were used. Cases that did not have a 12-month follow-up after implant placement were excluded. Results Out of 2,400 analysed implants, 92 were placed without primary stability. The absence of primary stability was classified as B in 49 cases, C in 38 cases and D in 5 cases. …

Sensorless control of permanent magnet synchronous motors for wide speed range applications

2006

This paper deals with sensorless control of Interior Permanent Magnet Synchronous Motors (IPMS) based on the estimation of speed and rotor angular position. The above estimate is based on the injection of high frequency stator currents able to generate a signal similar to that generated by a resolver connected to the axis of the motor. A new digital algorithm has been designed to demodulate the above signal whose implementation can be carried out on the same DSP that processes the control algorithm. In this paper a new scheme of speed and angular position estimator is proposed and justified on the theoretic point of view. The experimental results here shown validate the effectiveness of the…

Digital Hydraulic Winch Drives

2018

This paper presents the planned use of digital displacement high torque low speed motors to drive large winches in off-shore and maritime applications. The digital displacement technology uses forced actuation of high- and low pressure valves for each cylinder chamber, i.e. valves are opened and closed by actuation forces independently of cylinder pressure and supply pressures. Motors equipped with the technology are well suited for low speed secondary controlled operation including start and stop. It also enables unloading of motor cylinders that are not needed to produce torque, whereby excellent efficiency at partial displacement is obtained. A research project on application of multi di…