6,694 research outputs found
From line to dots: an improved computerised rod and frame system for testing subjective visual vertical and horizontal
No full textBackground Perception of subjective visual vertical (SVV) and horizontal (SVH) has traditionally been measured by rotating a mechanical rod either with or without a frame present. The computerised rod and frame (CRAF) system has previously only been used to measure SVV. We have expanded the use of this system by testing its feasibility to measure SVH. This was done by comparing two groups of subjects (n = 103) randomly assigned to be tested for SVV or SVH. Findings Preliminary results showed a higher than expected percentage of individuals with SVH errors < 0.5°. This was attributed to additional visual cues provided by the changing appearance of the rod as it approached the horizontal. A solution to this problem was sought by replacing the rod by two dots to mark its ends. In a second investigation 30 subjects were tested using both the "rod as line" and "rod as dots" presentation. Bland and Altman analysis showed no difference between the rod and dots presentations in the measurement of SVV, but confirmed a fixed error of -0.93° between rods and dots for SVH. Changing the rod from a line to dots in the computer system resulted in errors for both SVV and SVH that were comparable to previous studies using manual systems. Conclusions The computerized rod and frame system may be improved by replacement of the line with two dots. This reduces clues provided to the subject by the appearance of the rod on the screen
Performance Improvement of Downlink MC-CDMA Cellular System with an Intermittent Transmission
Get PDFThroughput performance of MC-CDMA systems depends on the success in managing interference arising from intercell transmission. In this paper, we propose a new intercell interference mitigation scheme for downlink MC-CDMA scheme. In the proposed scheme, a base station transmits downlink signals intermittently to mobile terminals at the edge of cell. The intercell interference can be seen as a partial interference depend upon the on and off period of the adjacent downlink signals. So it is possible for the channel equalizer to suppress this partial intercell interference by setting the weight changes in accordance with the intercell interference. As results, the frame error rate of the proposed scheme is always better than that of the conventional scheme and good throughput performance is achieved especially when the traffic is high.journal articl
Successive-relaying-aided decode-and-forward coherent versus noncoherent cooperative multicarrier space–time shift keying
No full textAbstract—Successive-relaying-aided (SR) cooperative multi-carrier (MC) space–time shift keying (STSK) is proposed for frequency-selective channels. We invoke SR to mitigate the typical 50% throughput loss of conventional half-duplex relaying schemes and MC code-division multiple access (MC-CDMA) to circumvent the dispersive effects of wireless channels and to reduce the SR-induced interference. The distributed relay terminals form two virtual antenna arrays (VAAs), and the source node (SN) successively transmits frequency-domain (FD) spread signals to one of the VAAs, in addition to directly transmitting to the destination node (DN). The constituent relay nodes (RNs) of each VAA activate cyclic-redundancy-checking-based (CRC) selective decode-and-forward (DF) relaying. The DN can jointly detect the signals received via the SN-to-DN and VAA-to-DN links using a low-complexity single-stream-based joint maximum-likelihood (ML) detector. We also propose a differentially encoded cooperative MC-CDMA STSK scheme to facilitate communications over hostile dispersive channels without requiring channel estimation (CE). Dispensing with CE is important since the relays cannot be expected to altruistically estimate the SN-to-RN links for simply supporting the source. Furthermore, we propose soft-decision-aided serially concatenated recursive systematic convolutional (RSC) and unity-rate-coded (URC) cooperative MC STSK and investigate its performance in both coherent and noncoherent scenarios
Interactively using Semantic Web knowledge: Creating scalable abstractions with FacetOntology
No full textThe amount of knowledge accessible on the Semantic Web is growing, and there is a need for a scalable solution to facilitate exploring that data. Currently approaches to exploring Semantic Web data either focus on exploring resources individually, following links during exploration, and making little use of collated data, or take the approach of collating and aligning multiple sources into one store for one purpose, and hand-crafting a specific browsing interface onto it. We present an approach that provides a scalable browsing interface, which can browse knowledge from the Semantic Web at will. Our approach creates abstractions of knowledge, collated into facets, which are described using FacetOntology. FacetOntology facilitates describing facets from RDF data, suitable for use in creating datasets for faceted browsing
Growth Morphologies and Mechanisms of Non-Equilibrium Solidified MC Carbide
No full textGrowth morphologies and mechanisms of the carbide of group IVB and VB elements (MC carbide), a typical faceted crystal, were studied with an estimated cooling rate from 102 to 105 K/s. Results showed that although the growth morphologies of the MC carbide vary remarkably with solidification cooling rate, the solid/liquid interface is always atomically smooth, and the growth mechanisms are always lateral growth. The growth mechanism transition from lateral to continuous growth mode, which was predicted by the classic crystal growth theory, was not observed for the TiC type MC carbide within the estimated cooling rate range of 102?105 K/s
MC-MLP:Multiple Coordinate Frames in all-MLP Architecture for Vision
Get PDFIn deep learning, Multi-Layer Perceptrons (MLPs) have once again garnered
attention from researchers. This paper introduces MC-MLP, a general MLP-like
backbone for computer vision that is composed of a series of fully-connected
(FC) layers. In MC-MLP, we propose that the same semantic information has
varying levels of difficulty in learning, depending on the coordinate frame of
features. To address this, we perform an orthogonal transform on the feature
information, equivalent to changing the coordinate frame of features. Through
this design, MC-MLP is equipped with multi-coordinate frame receptive fields
and the ability to learn information across different coordinate frames.
Experiments demonstrate that MC-MLP outperforms most MLPs in image
classification tasks, achieving better performance at the same parameter level.
The code will be available at: https://github.com/ZZM11/MC-MLP
Experimental assessment and retrofit of full-scale models of existing RC frames
Get PDFPSD tests on two full-scale models of existing non-seismic resisting RC frame structures are
described. The testing program covered several aspects, namely assessment of seismic
performance of existing frames without and with infill panels, retrofitting of the bare frame
using Selective Retrofitting techniques, strengthening of the infill panels using shotcrete and
retrofitting of the frame using K-bracing with shear-link dissipators. The main results from
the tests are summarized and discussed and the conclusions are drawn. The tests on the bare
frame have shown how vulnerable are existing structures constructed in the 60’s and the
beneficial effects of infill panels were confirmed from the tests on the infilled frame.
Important improvements, in terms of seismic performance, were achieved by the retrofitting
of the frames. However, it was also confirmed that strengthening of the existing infill panels
in poorly detailed frames may lead to dangerous ‘local’ failures, such as the shear out of the
external columns
Ruth Klüger: la creatività per non “smarrirsi strada facendo”
No full textR. Klüger, a jewish viennese, a US citizen and a germanist, is the Author of two autobiographies “weiter leben”and “unterwegs versore”. Written in a style which alternates between essay and poetry, account and recollection, they are the occasion for the Author to establish a dialogue with the women having as a focus the exchange of experiences and reflections over the status of the feminine emancipation
Improvement of a late FDDNP PET/CT frame image after MC.
No full text<p><b>Panel A:</b> An FDDNP PET/CT study on a Down syndrome patient with 10 mm movement in z direction in a late frame of a dynamic scan. <b>Panel B:</b> 3-D orthogonal images show the improvement of the PET/CT images with proper AC after MC. All images are displayed with the same color scale and show clearly the quantitative differences in the PET images reconstructed with misaligned and aligned CT images.</p
Estudio del trabajo para incrementar la productividad en la fabricación del frame posterior en MC Soporte y Servicios, Lurigancho, 2020
Get PDFEl objetivo de la presente investigación tiene como título el estudio del trabajo
incrementa la productividad en la fabricación del frame posterior en Mc Soporte y
Servicios, Lurigancho, 2020, en lo cual se identificó un problema ¿De qué manera
el estudio del trabajo incrementa la productividad en MC Soporte y Servicios,
2020?
La investigación fue de tipo aplicada, descriptiva-explicativa y cuantitativa, se
realizó bajo un diseño cuasi experimental teniendo como población frame
posterior, esta fue equivalente a la muestra, debido a que no se realizó muestreo.
Dicha muestra fue obtenida de junio a julio (Pre test) y de setiembre a octubre
(Post test). Se empleó la técnica de la observación para obtener información de
fuentes primarias, mediante fichas de recolección de datos. Para el procesamiento
de los datos se utilizó el programa IBM SPSS Statistics y gráficos lineales
comparativos del programa Excel.
La herramienta que se utilizó nos permitió reducir tiempos y costos en el frame
posterior, con la finalidad de incrementar la productividad en la empresa MC
Soporte y Servicios S.A.C. Para ello se hizo uso del análisis descriptivo e
inferencial
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