998 research outputs found
Video Tester -- A multiple-metric framework for video quality assessment over IP networks
This paper presents an extensible and reusable framework which addresses the
problem of video quality assessment over IP networks. The proposed tool
(referred to as Video-Tester) supports raw uncompressed video encoding and
decoding. It also includes different video over IP transmission methods (i.e.:
RTP over UDP unicast and multicast, as well as RTP over TCP). In addition, it
is furnished with a rich set of offline analysis capabilities. Video-Tester
analysis includes QoS and bitstream parameters estimation (i.e.: bandwidth,
packet inter-arrival time, jitter and loss rate, as well as GOP size and
I-frame loss rate). Our design facilitates the integration of virtually any
existing video quality metric thanks to the adopted Python-based modular
approach. Video-Tester currently provides PSNR, SSIM, ITU-T G.1070 video
quality metric, DIV and PSNR-based MOS estimations. In order to promote its use
and extension, Video-Tester is open and publicly available.Comment: 5 pages, 5 figures. For the Google Code project, see
http://video-tester.googlecode.com
Effect of production system and slaughter age on some production traits of guinea fowl: Meat quality and digestive traits
Certain meat quality traits of guinea fowl that were reared in two production systems were determined in this study. Grey guinea fowl were reared in free-range and barn conditions. Birds were slaughtered at 14, 16 and 18 weeks old to determine meat quality traits. Some digestive traits were also determined. The type of production system affected the yellowness of breast meat significantly, and guinea fowl reared in the free-range system had yellower breast meat. The pH of both breast and thigh meat increased at older ages. Water-holding capacity, cooking loss and drip loss of breast and thigh meat were not affected by production system. Drip loss of meat decreased at older slaughter ages. The ratios of digestive system organ weights to body weight mostly decreased at older ages.Keywords: Digestive tract, free-range, meat colour, water holding capacity, p
Development and validation of a scale to measure volition for learning
Volition explains the transition from desire, or motivation, to action especially when faced with competing goals. In learning environments, the concept refers to acting with the aim of achieving learning objectives. Despite the importance of volition in learning environments, research has rarely addressed the volition construct. Thus, the purpose of this study was to explore and develop a valid and reliable scale to measure the volition construct in online and face to face learning environments. The data for this research were collected from 594 undergraduate online learners who also took some courses face to face at a state university in Turkey. After analyzing the validity and reliability of the scale, a two-factor, 13-item volition for learning scale was developed. The scale was comprised of two factors: action planning and action control. Confirmatory factor analysis results confirm the factor structure of the scale. Results indicated that the volition for learning scale is a valid and reliable instrument that can be utilized to measure learnersâ volition in learning environments
Tribological interaction between polytetrafluoroethylene and silicon oxide surfaces
Cataloged from PDF version of article.We investigated the tribological interaction between polytetrafluoroethylene (PTFE) and silicon oxide surfaces. A simple rig was designed to bring about a friction between the surfaces via sliding a piece of PTFE on a thermally oxidized silicon wafer specimen. A very mild inclination (similar to 0.5 degrees) along the sliding motion was also employed in order to monitor the tribological interaction in a gradual manner as a function of increasing contact force. Additionally, some patterns were sketched on the silicon oxide surface using the PTFE tip to investigate changes produced in the hydrophobicity of the surface, where the approximate water contact angle was 45 degrees before the transfer. The nature of the transferred materials was characterized by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). XPS results revealed that PTFE was faithfully transferred onto the silicon oxide surface upon even at the slightest contact and SEM images demonstrated that stable morphological changes could be imparted onto the surface. The minimum apparent contact pressure to realize the PTFE transfer is estimated as 5 kPa, much lower than reported previously. Stability of the patterns imparted towards many chemical washing processes lead us to postulate that the interaction is most likely to be chemical. Contact angle measurements, which were carried out to characterize and monitor the hydrophobicity of the silicon oxide surface, showed that upon PTFE transfer the hydrophobicity of the SiO2 surface could be significantly enhanced, which might also depend upon the pattern sketched onto the surface. Contact angle values above 100 degrees were obtained. (C) 2014 AIP Publishing LLC
AquaÂ[4-(hydroxyÂiminoÂmethÂyl)pyridine-ÎșN 1](pyridine-2,6-dicarboxylÂato-Îș3 O 2,N,O 6)copper(II)
In the title compound, [Cu(C7H3NO4)(C6H6N2O)(H2O)], the coordination geometry of the CuII atom can be described as distorted square pyramidal. The basal plane is defined by one N atom and two O atoms from the deprotonated pyridine-2,6-dicarboxylÂate ligand, and a pyridyl N atom from the 4-pyridyl aldoxime ligand. The apical position is occupied by a water molÂecule. OâHâŻO hydrogen bonds lead to the formation of a two-dimensional network
Volume XCIII, Number 15, February 22, 1974
11th International Conference of Inborn Errors of Metabolism -- AUG 29-SEP 02, 2009 -- San Diego, CAWOS: 00026894260018
Asymptotic Bounds for the Time-Periodic Solutions to the Singularly Perturbed Ordinary Differential Equations
The periodical in time problem for singularly perturbed second order linear ordinary differential equation is considered. The boundary layer behavior of the solution and its first and second derivatives have been established. An example supporting the theoretical analysis is presented
Impacto de diferentes niveles de nisina como agente bioconservador en la calidad quĂmica, sensorial y microbiolĂłgica de filetes de lubina (Dicentrarchus labrax) envasados al vacĂo y almacenados a 4 ± 2 °C.
Nisin is produced by Lactococcus lactis subsp. lactis and is also known as an antimicrobial agent especially effective against gram-positive bacteria. It has long been used as a preservative in foods and beverages and is generally regarded as safe (GRAS). In the present work, the effects of different concentrations of nisin (0.2, 0.4 and 0.8%) on the sensory, chemical and microbiological quality and shelf-life of vacuum-packed sea bass (Dicentrarchus labrax) fillets were investigated during chilled (4 ± 2 °C) storage. The sensory points for raw and cooked fillets increased with time during the storage period (p < 0.05). The control group, with scores of 9.08, was rejected by panelists on day 12; whereas nisin-treated groups were rejected on day 14 with scores ranging from 9.00-9.17 score. As a result of chemical analyses, lower values (p < 0.05) were obtained from the nisin groups with low oxidative rancidity. Moreover, nisin inhibited microbial growth, which shows antimicrobial activity. Consequently, it was concluded that the application of nisin (especially 0.8%) preserved the organoleptic quality and extended the shelf-life of sea bass fillets.La nisina es producida por Lactococcus lactis subsp. lactis y conocida como agente antimicrobiano, especialmente contra las bacterias grampositivas. Se ha utilizado como conservante en alimentos y bebidas durante mucho tiempo y generalmente se considera seguro (GRAS). En el presente trabajo, se investigaron los efectos de diferentes concentraciones de nisina (0,2, 0,4 y 0,8%) sobre la calidad sensorial, quĂmica y microbiolĂłgica y la vida Ăștil de los filetes de lubina (Dicentrarchus labrax) envasados al vacĂo durante el enfriamiento y almacenamiento (4 ± 2 °C). La puntuaciĂłn sensorial de los filetes crudos y cocidos aumentĂł con el tiempo durante el perĂodo de almacenamiento (p <0,05). El grupo de control con puntuaciĂłn de 9,08 fue rechazado por los panelistas el dĂa 12, mientras que los grupos de tratamiento con nisina fueron rechazados el dĂa 14 con un rango de puntuaciĂłn de 9,00-9,17. Como resultado de los anĂĄlisis quĂmicos, se obtuvieron valores mĂĄs bajos (p < 0,05) de los grupos de nisina con baja rancidez oxidativa. AdemĂĄs, la nisina inhibiĂł el crecimiento microbiano que muestra actividad antimicrobiana. En consecuencia, se evaluĂł que la aplicaciĂłn de nisina (especialmente 0,8%) conservĂł la calidad organolĂ©ptica y prolongĂł la vida Ăștil de la lubina
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