3,888 research outputs found
A PC parallel port button box provides millisecond response time accuracy under Linux
Get PDFFor psychologists, it is sometimes necessary to measure people's reaction times to the nearest millisecond. This article describes how to use the PC parallel port to receive signals from a button box to achieve millisecond response time accuracy. The workings of the parallel port, the corresponding port addresses, and a simple Linux program for controlling the port are described. A test of the speed and reliability of button box signal detection is reported. If the reader is moderately familiar with Linux, this article should provide sufficient instruction for him or her to build and test his or her own parallel port button box. This article also describes how the parallel port could be used to control an external apparatus
Millisecond accuracy video display using OpenGL under Linux
Get PDFTo measure people’s reaction times to the nearest millisecond, it is necessary to know exactly when
a stimulus is displayed. This article describes how to display stimuli with millisecond accuracy on a
normal CRT monitor, using a PC running Linux. A simple C program is presented to illustrate how this
may be done within X Windows using the OpenGL rendering system. A test of this system is reported
that demonstrates that stimuli may be consistently displayed with millisecond accuracy. An algorithm
is presented that allows the exact time of stimulus presentation to be deduced, even if there are relatively
large errors in measuring the display time
Frontmatter (Titlepage, Table of Contents, Author List, PC List, Reviewer List)
No full textFront matter including table of contents, author list, PC list, and reviewer list
High efficiency implementation of PC and PC stable algorithms yields three-dimensional graphs of information flow for the Earth' atmosphere
Get PDFSeptember 3, 2014.Causal discovery algorithms have recently been applied to several climate applications. In particular, in prior work we have developed methods to recover pathways of interaction in the global climate system, using the classic PC algorithm. However, standard implementations of the PC algorithm cannot handle the large number of variables and temporal models required for this application. This technical report shows that a more efficient implementation of the PC algorithm can provide speed gains of a factor of 1,000 or more. This in turn enables us to calculate graphs of information flow with much higher resolution grids. Furthermore, we can now - for the first time ever - calculate information flow graphs that extend over three dimensions, i.e. rather than just including one layer of the planet's atmosphere we can now capture interactions across several height layers
PRECISE Photonic hybRid EleCtromagnetIc SolvEr
Get PDFThe Photonic hybRid EleCtromagnetic SolvEr (PRECISE) is a Matlab based library to model large and complex photonics integrated circuits. Each circuit is modularly described in terms of waveguide segments connected through multiport nodes. Linear, nonlinear, and dynamical phenomena are simulated by solving the system of differential equations describing the effect to be considered. By exploiting the steady state approximation of the electromagnetic field within each node device, the library can handle large and complex circuits even on desktop PC. We show that the steady state assumption is fulfilled in a broad number of applications and we compare its accuracy with analytical model (coupled mode theory) and experimental results. PRECISE is highly modular and easily extensible to handle equations different from those already implemented and is, thus, a flexible tool to model the increasingly complex photonic circuits.10 pages, 8 figure
State variable simulation package for IBM-PC
No full textThis thesis was scanned from the print manuscript for digital preservation and is copyright the author.
Researchers can access this thesis by asking their local university, institution or public library to
make a request on their behalf. Monash staff and postgraduate students can use the link in the References field
Degradation of bisphenol-a-polycarbonate (BPA-PC) optical lenses under simulated harsh environment conditions
No full textThis paper investigates degradation and failure mechanisms of BPA-PC lenses in simulated harsh environment conditions. Exposure of secondary optics in Light Emitting Diode LED-based systems or any other similar applications to environmental stresses can adversely effect the performance and lifetime of products. This paper simulates a harsh environment condition, using a salt bath oven. Salt spray exposure/ageing tests at 45° C were carried out up to four months. Fourier transform infrared-attenuated total reflection FTIR-ATR spectrometer and Lambda 950 Ultraviolet-Visible (UV-VIS) spectrophotometer were used to study the optical and chemical characteristics of aged plates. Results showed that salt bath exposure test resulted in the severe deterioration of optical characteristics BPA-PC samples. Degradation of optical properties of BPA-PC plates is attributable to the oxidation of samples.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic Components, Technology and Material
Heavy pentaquark states Pc(4380) and Pc(4450) in the J/ψ production induced by pion beams off the nucleon
No full textAbstractIn this study, we investigate the J/ψ production induced by pion beams off the nucleon, particularly the heavy pentaquarks Pc(4380) and Pc(4450) in intermediate states, based on a hybridized Regge model. The process involving ρ and π meson exchange in the t channel is considered as background, and the heavy pentaquark exchange is included in the s channel. The coupling constants such as the ρNN and πNN vertices are taken from the NN potentials, whereas those for the J/ψρπ and J/ψππ vertices are determined by using experimental data based on the branching ratios. In order to estimate the Pc(4380) and Pc(4450) coupling constants, we use the experimental upper limit on the total cross section as a guide for the πN→J/ψN reaction. The background total cross section is the order of 10−4–10−3 nb. In the vicinity of the heavy pentaquark masses, the total cross section reaches about 1 nb
Labeling male anorectal malformations: objective evaluation of radiologic imaging before surgery
Get PDFPurposeProne cross-table lateral x-ray (CTLxR) and colostogram aid surgical planning for anorectal malformations (ARMs) without perineal fistulas. We suggest objective imaging tools to classify ARMs.MethodsThree observers prospectively evaluated CTLxR and colostograms of male ARM patients (2012–2022) without perineal fistulas. The level of the rectal pouch was estimated with pubococcygeal (PC) and ischiatic (I) lines. On CTLxR, we described the “pigeon sign”, defined as the rectal pouch ending with a beak-like image, suspicious for a rectourinary fistula. ARM was defined as rectobulbar when the rectal pouch was below the I line, rectoprostatic when between PC and I lines, and rectovesical when above the PC line. Concordance was assessed with Fleiss' kappa. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the “pigeon sign” were calculated.ResultsThirteen patients were included in this study. The interobserver agreement on CTLxR was 69.2% (k = 0.54) on pouch ending, 84.6% (k = 0.69) on the “pigeon sign”, and 76.9% (k = 0.69) on diagnosis; concordance between observers and intraoperative diagnosis was 66.6% (k = 0.56). The “pigeon sign” had 75% sensitivity, 100% specificity, 100% PPV, and 50% NPV. The interobserver agreement on colostograms was 84.6% (k = 0.77) on pouch ending and 89.7% (k = 0.86) on diagnosis; concordance between observers and intraoperative diagnosis was 92.3% (k = 0.90).ConclusionPC and I lines and the “pigeon sign” are useful tools in examining CTLxR and colostograms. Adequate CTLxR interpretation may modify surgical strategy
Data Assimilation for Full 4D PC-MRI Measurements: Physics-Based Denoising and Interpolation
No full textPhase-Contrast Magnetic Resonance Imaging (PC-MRI) surpasses all other imaging methods in quality and completeness for measuring time-varying volumetric blood flows and has shown potential to improve both diagnosis and risk assessment of cardiovascular diseases. However, like any measurement of physical phenomena, the data are prone to noise, artefacts and has a limited resolution. Therefore, PC-MRI data itself do not fulfil physics fluid laws making it difficult to distinguish important flow features. For data analysis, physically plausible and high-resolution data are required. Computational fluid dynamics provides high-resolution physically plausible flows. However, the flow is inherently coupled to the underlying anatomy and boundary conditions, which are difficult or sometimes even impossible to adequately model with current techniques. We present a novel methodology using data assimilation techniques for PC-MRI noise and artefact removal, generating physically plausible flow close to the measured data. It also allows us to increase the spatial and temporal resolution. To avoid sensitivity to the anatomical model, we consider and update the full 3D velocity field. We demonstrate our approach using phantom data with various amounts of induced noise and show that we can improve the data while preserving important flow features, without the need of a highly detailed model of the anatomy.Computer Graphics and Visualisatio
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