QoE modelling for VP9 and H.265 videos on mobile devices

Current mobile devices and streaming video services support high definition (HD) video, increasing expectation for more contents. HD video streaming generally requires large bandwidth, exerting pressures on existing networks. New generation of video compression codecs, such as VP9 and H.265/HEVC, are expected to be more effective for reducing bandwidth. Existing studies to measure the impact of its compression on users’ perceived quality have not been focused on mobile devices. Here we propose new Quality of Experience (QoE) models that consider both subjective and objective assessments of mobile video quality. We introduce novel predictors, such as the correlations between video resolution and size of coding unit, and achieve a high goodness-of-fit to the collected subjective assessment data (adjusted R-square >83%). The performance analysis shows that H.265 can potentially achieve 44% to 59% bit rate saving compared to H.264/AVC, slightly better than VP9 at 33% to 53%, depending on video content and resolution.

Changes in lycopene and beta carotene contents in aril and oil of gac fruit during storage

Gac fruits were physically measured and stored under ambient conditions for up to 2 weeks to observe changes in carotenoid contents (lycopene and beta carotene) in its aril. Initial concentrations in the aril of lycopene were from 2.378 mg/g fresh weight (FW) to 3.728 mg/g FW and those of beta carotene were from 0.257 to 0.379 mg/g FW. Carotenoid concentrations in the aril remained stable after 1 week but sharply declined after 2 weeks of storage. Gac oil, pressed from gac aril, has similar concentrations of lycopene and beta carotene (2.436 and 2.592 mg/g, respectively). Oil was treated with 0.02% of butylated hydroxytoluene, or with a stream of nitrogen or untreated then stored in the dark for up to 15 or 19 weeks under different temperatures (5 °C, ambient, 45 and 60 °C). Lycopene and beta carotene in control gac oil degraded following the first-order kinetic model. The degradation rate of lycopene and beta carotene in the treated oil samples were lower than that in the control oil but the first-order kinetic was not always followed. However, both lycopene and beta carotene degraded quickly in gac oil with the first-order kinetic under high temperature conditions (45 and 60 °C) regardless of the treatments used. © 2009 Elsevier Ltd. All rights reserved.

Impact of automatic region-of-interest coding on perceived quality in mobile video

At present, the most reliable method to obtain end-user perceived quality is through subjective tests. In this paper, the impact of automatic region-of-interest (ROI) coding on perceived quality of mobile video is investigated. The evidence, which is based on perceptual comparison analysis, shows that the coding strategy improves perceptual quality. This is particularly true in low bit rate situations. The ROI detection method used in this paper is based on two approaches: - (1) automatic ROI by analyzing the visual contents automatically, and; - (2) eye-tracking based ROI by aggregating eye-tracking data across many users, used to both evaluate the accuracy of automatic ROI detection and the subjective quality of automatic ROI encoded video. The perceptual comparison analysis is based on subjective assessments with 54 participants, across different content types, screen resolutions, and target bit rates while comparing the two ROI detection methods. The results from the user study demonstrate that ROI-based video encoding has higher perceived quality compared to normal video encoded at a similar bit rate, particularly in the lower bit rate range.

Quantitative assessment of total phenol contents of European oak (Quercus petraea and Quercus robur) by diffuse reflectance NIR spectroscopy on solid wood surfaces

Near infrared spectroscopy (NIRS) combined with multivariate analysis techniques was applied to assess phenol content of European oak. NIRS data were firstly collected directly from solid heartwood surfaces: in doing so, the spectra were recorded separately from the longitudinal radial and the transverse section surfaces by diffuse reflectance. The spectral data were then pretreated by several pre-processing procedures, such as multiplicative scatter correction, first derivative, second derivative and standard normal variate. The tannin contents of sawmill collected from the longitudinal radial and transverse section surfaces were determined by quantitative extraction with water/methanol (1:4, by vol). Then, total phenol contents in tannin extracts were measured by the Folin-Ciocalteu method. The NIR data were correlated against the Folin-Ciocalteu results. Calibration models built with partial least squares regression displayed strong correlation - as expressed by high determination correlation coefficient (r2) and high ratio of performance to deviation (RPD) - between measured and predicted total phenols content, and weak calibration and prediction errors (RMSEC, RMSEP). The best calibration was provided with second derivative spectra (r2 value of 0.93 for the longitudinal radial plane and of 0.91 for the transverse section plane). This study illustrates that the NIRS technique when used in conjunction with multivariate analysis could provide reliable, quick and non-destructive assessment of European oak heartwood extractives.

Solubility of ibuprofen in aqueous ethanol at low ethanol contents

The solubility of ibuprofen was measured in water (W) - ethanol (E) mixtures from 0 to 50% w/w ethanol at 10, 25 and 40 °C by the dissolution method using UV spectrophotometry to determine the ibuprofen concentrations. The UV calibration for ibuprofen in different water - ethanol mixtures showed Beer - Lambert linearity, however the slopes differed, which indicated the structure of the drug is influenced by the solvent system i.e. the water - ethanol ratio. The ibuprofen solubility in water (zero ethanol) is low (~ 50 ppm) but increases near exponentially with increasing ethanol content. At 40 °C, there is phase separation between 34% and 63% w/w E/(E+W). The solubility data will be used to select precipitation crystallizer conditions to directly produce free flowing ibuprofen particles (<5 m) for developing a dry powder inhaler (DPI) formulation for lung delivery.

Scat contents of the spotted-tailed quoll Dasyurus maculatus in the New England gorges, north-eastern New South Wales

In 1313 scats of the spotted-tailed quoll Dasyurus maculatus, collected over 5 years from the gorge country of north-eastern New South Wales, the most frequent and abundant items were derived from mammals and a restricted set of insect orders. These quolls also ate river-associated items: waterbirds, eels, crayfish, aquatic molluscs and even frogs. Macropods contributed most of the mammal items, with possums, gliders and rodents also being common. Some food, particularly from macropods and lagomorphs, had been scavenged (as shown by fly larvae). The most frequent invertebrates were three orders of generally large insects Coleoptera, Hemiptera and Orthoptera, which were most frequent in summer and almost absent in winter scats. Monthly mean numbers of rodent and small dasyurid items per scat were inversely related to these large insects in scats. The numbers of reptile items were inversely related to the numbers of mammal (especially arboreal and small terrestrial mammal) items per scat, thus types of items interacted in their occurrences in monthly scat samples. Frequencies of most vertebrate items showed no seasonal, but much year-to-year, variation. This quoll population ate four main types of items, each requiring different skills to obtain: they hunted arboreal marsupials (possibly up trees), terrestrial small mammals and reptiles (on the ground), and seasonally available large insects (on trees or the ground), and scavenged carcases, mostly of large mammals but also birds and fishes (wherever they could find them).

Polyphenolic contents and the effects of methanol extracts from mango varieties on breast cancer cells

Bioactivities of peel and flesh extracts of 3 genetically diverse mango (Mangifera indica L.) varieties were studied. Nam Doc Mai peel extracts, containing the largest amounts of polyphenols, were associated with an effect on MCF-7 viable cell numbers with an IC50 (dose required for 50% inhibition of cell viability) of 56 μg/mL and significantly (p<0.01) induced cell death in MDA-MB-231 cells, compared with other varieties. Hydrophilic fractions of Nam Doc Mai peel extracts had the highest bioactivity values against both MCF-7 and MDA-MB-231 cells. Soluble polyphenols were present in the largest amounts in most hydrophilic fractions. The Nam Doc Mai mango variety contains high levels of fruit peel bioactivity, which appears to be related to the nature of the polyphenol composition.

Recommendation of Multimedia Objects Using Metadata and Link Analysis

We investigate methods for recommending multimedia items suitable for an online multimedia sharing community and introduce a novel algorithm called UserRank for ranking multimedia items based on link analysis. We also take the initiative of applying EigenRumor from the domain of blogosphere to multimedia. Furthermore, we present a strategy for making personalized recommendation that combines UserRank with collaborative filtering. We evaluate our method with an informal user study and show that results obtained are promising.

Light- and cytokinin-induced changes in the levels of leucine and tyrosine isoaccepting tRNA species and modified nucleotide contents of total tRNA in cucumber seedlings

We have determined relative levels of chloroplast leucine and tyrosine isoaccepting tRNAs and modified nucleotide contents from total tRNAs isolated from dark-grown, light-grown, N6-isopentenyladenine (i6A)-treated dark-grown and i6A-treated light-grown cucumber seedlings. Significant increases in the relative amounts of tRNA(Leu)2 and tRNA(Leu)3 were observed in the i6A-treated dark-grown seedlings compared to dark-grown, light-grown and i6A-treated light-grown seedlings. On the other hand, i6A-treated light-grown seedlings tRNA(Tyr)1 increased to 85% of total tRNAs(Tyr) from about 9% in light-grown seedlings and tRNA(Tyr)2 decreased to 15% compared with 91% in light-grown seedlings. Analysis of modified nucleotide of total tRNAs indicated that pT, pI, pm1A, pm5C, pGm, pm1G, pm2G and pm7G contents were significantly higher in the total tRNA of i6A-treated dark-grown seedlings than those from untreated dark-grown seedlings. Illumination of 8-day-old dark-grown seedlings for 12 h increased the contents of pT, pI, pGm and pm1G when compared to 8-day-old dark-grown seedlings with extended growth for 12 h in dark. On the contrary, i6A had no stimulatory effect in the contents of modified nucleotide in the light-grown seedlings.

Design of multimedia surveillance systems

This article addresses the problem of how to select the optimal combination of sensors and how to determine their optimal placement in a surveillance region in order to meet the given performance requirements at a minimal cost for a multimedia surveillance system. We propose to solve this problem by obtaining a performance vector, with its elements representing the performances of subtasks, for a given input combination of sensors and their placement. Then we show that the optimal sensor selection problem can be converted into the form of Integer Linear Programming problem (ILP) by using a linear model for computing the optimal performance vector corresponding to a sensor combination. Optimal performance vector corresponding to a sensor combination refers to the performance vector corresponding to the optimal placement of a sensor combination. To demonstrate the utility of our technique, we design and build a surveillance system consisting of PTZ (Pan-Tilt-Zoom) cameras and active motion sensors for capturing faces. Finally, we show experimentally that optimal placement of sensors based on the design maximizes the system performance.

Absence of parallelism between polyamine and nucleic acid contents during induced growth of cucumber cotyledons

The cytokinins (benzyladenine or benzyladenosine) decreased spermidine and spermine contents despite increasing putrescine content, when administered to isolated cotyledons of Cucumis sativus L. var. Guntur in organ culture. KCl decreased putrescine contents, although marginally increasing polyamine contents. The cytokinins and/or KCl augmented nucleic acid biosynthesis and accumulation, resulting in enhanced growth and differentiation of the isolated cotyledons. These observations show that polyamine accumulation and growth are not always coupled.

Design a simulated multimedia enriched immersive learning environment (SMILE) for nursing care of dementia patient

This thesis is to establish a framework to guide the development of a simulated, multimedia-enriched, immersive, learning environment (SMILE) framework. This framework models essential media components used to describe a scenario applied in healthcare (in a dementia context), demonstrates interactions between the components, and enables scalability of simulation implementation. The thesis outcomes also include a simulation system developed in accordance with the guidance framework and a preliminary evaluation through a user study involving ten nursing students and practicioners. The results show that the proposed framework is feasible and effective for designing a simulation system in dementia healthcare training.

Differences in the levels of aminoacylation and contents of modified nucleotides between total tRNAs from N2- and NH4+-grown Azospirillum lipoferum cells

Total tRNAs isolated from N2- and NH4(+)-grown Azospirillum lipoferum cells were compared with respect to amino acid acceptance, isoacceptor tRNA species levels and extent of nucleotide modifications. Amino-acylation of these two tRNA preparations with ten different amino acids indicated differences in the relative acceptor activities. Comparison of aminoacyl-tRNA patterns by RPC-5 column chromatography revealed no qualitative differences in the elution profiles. However, quantitative differences in the relative amounts of some isoacceptors were observed. These results indicate that alterations of relative amounts of functional tRNA species occur to match cellular requirements of the bacterial cells using N2 or NH4+ as nitrogen source. In addition, the content of modified nucleotides in total tRNAs of N2- and NH4(+)-grown cells was determined. In the NH4(+)-grown cells, content of most of the modified nucleotides decreased significantly. Based upon these results, the relationship of chargeability of tRNAs to base modifications is discussed.

An analytical model for performance evaluation of multimedia applications over EDCA in an IEEE 802.11e WLAN

We extend the modeling heuristic of (Harsha et al. 2006. In IEEE IWQoS 06, pp 178 - 187) to evaluate the performance of an IEEE 802.11e infrastructure network carrying packet telephone calls, streaming video sessions and TCP controlled file downloads, using Enhanced Distributed Channel Access (EDCA). We identify the time boundaries of activities on the channel (called channel slot boundaries) and derive a Markov Renewal Process of the contending nodes on these epochs. This is achieved by the use of attempt probabilities of the contending nodes as those obtained from the saturation fixed point analysis of (Ramaiyan et al. 2005. In Proceedings ACM Sigmetrics, `05. Journal version accepted for publication in IEEE TON). Regenerative analysis on this MRP yields the desired steady state performance measures. We then use the MRP model to develop an effective bandwidth approach for obtaining a bound on the size of the buffer required at the video queue of the AP, such that the streaming video packet loss probability is kept to less than 1%. The results obtained match well with simulations using the network simulator, ns-2. We find that, with the default IEEE 802.11e EDCA parameters for access categories AC 1, AC 2 and AC 3, the voice call capacity decreases if even one streaming video session and one TCP file download are initiated by some wireless station. Subsequently, reducing the voice calls increases the video downlink stream throughput by 0.38 Mbps and file download capacity by 0.14 Mbps, for every voice call (for the 11 Mbps PHY). We find that a buffer size of 75KB is sufficient to ensure that the video packet loss probability at the QAP is within 1%.

An agent based adaptive bandwidth allocation scheme for multimedia applications

Bandwidth allocation for multimedia applications in case of network congestion and failure poses technical challenges due to bursty and delay sensitive nature of the applications. The growth of multimedia services on Internet and the development of agent technology have made us to investigate new techniques for resolving the bandwidth issues in multimedia communications. Agent technology is emerging as a flexible promising solution for network resource management and QoS (Quality of Service) control in a distributed environment. In this paper, we propose an adaptive bandwidth allocation scheme for multimedia applications by deploying the static and mobile agents. It is a run-time allocation scheme that functions at the network nodes. This technique adaptively finds an alternate patchup route for every congested/failed link and reallocates the bandwidth for the affected multimedia applications. The designed method has been tested (analytical and simulation)with various network sizes and conditions. The results are presented to assess the performance and effectiveness of the approach. This work also demonstrates some of the benefits of the agent based schemes in providing flexibility, adaptability, software reusability, and maintainability. (C) 2004 Elsevier Inc. All rights reserved.