Error resilient video transcoding for robust inter-network communications using GPRS

A novel fully comprehensive mobile video communications system is proposed in this paper. This system exploits the useful rate management features of the video transcoders and combines them with error resilience for transmissions of coded video streams over general packet radio service (GPRS) mobileaccess networks. The error-resilient video transcoding operation takes place at a centralized point, referred to as a video proxy, which provides the necessary output transmission rates with the required amount of robustness. With the use of this proposed algorithm, error resilience can be added to an already compressed video stream at an intermediate stage at the edge of two or more different networks through two resilience schemes, namely the adaptive intra refresh (AIR) and feedback control signaling (FCS) methods. Both resilience tools impose an output rate increase which can also be prevented with the proposed novel technique in this paper. Thus, an error-resilient video transcoding scheme is presented to give robust video outputs at near target transmission rates that only require the same number of GPRS timeslots as the nonresilient schemes. Moreover, an ultimate robustness is also accomplished with the combination of the two resilience algorithms at the video proxy. Extensive computer simulations demonstrate the effectiveness of the proposed system

Macro- and micro-strain in GaN nanowires on Si(111)

We analyze the strain state of GaN nanowire ensembles by x-ray diffraction. The nanowires are grown by molecular beam epitaxy on a Si(111) substrate in a self-organized manner. On a macroscopic scale, the nanowires are found to be free of strain. However, coalescence of the nanowires results in micro-strain with a magnitude from +-0.015% to +-0.03%.This micro-strain contributes to the linewidth observed in low-temperature photoluminescence spectra

Computed tomography depiction of normal inguinal lymph nodes in children

Background: The aim of the study was to establish computed tomography (CT) characteristics, distribution and provide normative data about size of normal inguinal lymph nodes in a paediatric population. Materials and methods: Four hundred eighty-one otherwise healthy children (147 girls, mean age: 8.87, range 0–17 years) underwent pelvic CT in the setting of high-energy trauma were included in the study. Both axial and coronal 1.25-mm reconstructions were evaluated for the presence, location (deep or superficial), number, presence of fat attenuation, and shape of the lymph nodes, short-axis diameter of the biggest lymph node for each of right and left inguinal regions. Results: A total of 7556 lymph nodes were detected in 481 subjects (the mean count of superficial and deep inguinal lymph nodes was 13.35 [range 6–23] and 2.36 [range 0–7] per subject, respectively): 15% (1135/7556) deep located, 85% (6421/7556) superficially located, 86.6% (6547/7556) with fat attenuation, 99.2% (7496/7556) oval in shape, 0.8% (60/7556) spherical. The short-axis diameter of the lymph nodes increased with age. Pearson’s correlation coefficient for superficial and deep lymph nodes in boys and girls, respectively: 0.538 (p < 0.001), 0.504 (p < 0.001), 0.452 (p < 0.001) and 0.268 (p < 0.001). The mean maximum short-axis diameters in different age groups and gender varied between 6.33 ± 0.85 mm and 8.68 ± 1.33 mm for superficial, 3.62 ± 1.16 mm and 5.83 ± 1.05 mm for deep inguinal lymph nodes. Conclusions: Inguinal lymph nodes were multiple, commonly contained fat, and were oval in shape. The data determined about inguinal lymph node size in different paediatric age groups may be applicable as normative data in daily clinical CT evaluation practice

Retrospective Cost Adaptive Control for Systems with Unknown Nonminimum-Phase Zeros

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90721/1/AIAA-2011-6203-626.pd

Double-orifice mitral valve and an associated malformation: secundum atrial septal defect

The authors report a case of double-orifice mitral valve (DOMV) which showed mitral stenosis and mild insufficiency. An associated anomaly was secundum atrial septal defect. DOMV is an unusual congenital heart defect. The occurrence of this anomaly with or without secundum atrial septal defect is very rare. More often it is associated with other congenital malformations arising from atrioventricular canal defects. There may be no haemodynamic consequences but mitral insufficiency and/or stenosis may complicate this malformation. Treatment can be summarised as abstention, surgical repair or valve replacement

Phase sensitive detection of dipole radiation in a fiber-based high numerical aperture optical system

We theoretically study the problem of detecting dipole radiation in an optical system of high numerical aperture in which the detector is sensitive to \textit{field amplitude}. In particular, we model the phase sensitive detector as a single-mode cylindrical optical fiber. We find that the maximum in collection efficiency of the dipole radiation does not coincide with the optimum resolution for the light gathering instrument. The calculated results are important for analyzing fiber-based confocal microscope performance in fluorescence and spectroscopic studies of single molecules and/or quantum dots.Comment: 12 pages, 2 figure

Studija o biljkama uz rub cesta (Zapadna Anatolija, Turska)

In this study, roadside plants distributed throughout the link roads of all the cities in West Anatolia in Turkey were investigated. The length of the selected 17 roads is around 2700 km. The total number of samples collected from the study area is 271 taxa belonging to 57 families. Among them, Asteraceae, Fabaceae, Poaceae are the families that have the largest number of taxa, and Bromus L., Rumex L. and Silene L. are the genera that have the largest number of taxa. The most frequently found taxon throughout the selected roads is Valerianella coronata (L.) DC. and therophytes are the most frequently found life form.Istraživane su biljke uz rub svih cesta koje povezuju gradove u Zapadnoj Anatoliji u Turskoj. Duljina 17 izabranih cesta je iznosila oko 2700 km. Prikupljeni uzorci pripadali su 271 svojti, odnosno 57 biljnih porodica. Među njima su najzastupljenije bile porodice Asteraceae, Fabaceae i Poaceae, a među rodovima to su bili Bromus L., Rumex L. i Silene L. Najčešće nađena svojta uz istraživane ceste bila je Valerianella coronata (L.) DC., a najčešći biljni oblik su bili terofiti

Formation of silicon nanocrystals in sapphire by ion implantation and the origin of visible photoluminescence

Cataloged from PDF version of article.Silicon nanocrystals, average sizes ranging between 3 and 7 nm, were formed in sapphire matrix by ion implantation and subsequent annealing. Evolution of the nanocrystals was detected by Raman spectroscopy and x-ray diffraction (XRD). Raman spectra display that clusters in the matrix start to form nanocrystalline structures at annealing temperatures as low as 800 degrees C in samples with high dose Si implantation. The onset temperature of crystallization increases with decreasing dose. Raman spectroscopy and XRD reveal gradual transformation of Si clusters into crystalline form. Visible photoluminescence band appears following implantation and its intensity increases with subsequent annealing process. While the center of the peak does not shift, the intensity of the peak decreases with increasing dose. The origin of the observed photoluminescence is discussed in terms of radiation induced defects in the sapphire matrix. (c) 2006 American Institute of Physics