Optimal collaboration of thin–thick clients and resource allocation in cloud computing

Cloud computing (CC) has recently become a rising paradigm in the information and communications technology industry, drawing a lot of attentions to professionals and researchers. During the last decade, the dominance of smart phones or tablet computers (known as thin clients) over traditional desktop or laptop computers (known as thick clients) has become more and more evident, reflecting a great change in the way people access the Internet. Despite the recent technology advancements that manufacture a new generation of mobile devices with generous resources, the fact that they can offer only limited processing capacity still remains a painful experience. This problem, fortunately, has been made less severe thanks to the recent adoption of CC platform. CC enables offloading heavy processing tasks up to the “cloud”, leaving only simple jobs to the user-end capacity-limited thin clients. So far, a number of research studies have been carried out, trying to eliminate problems arising from shortcomings in the connection between thin clients and cloud networks, yet little have been found efficient. In this paper, we present a novel architecture, taking advantage of collaboration of thin and thick clients, particularly aiming at optimizing data distribution and utilizing CC resources so that expected Quality-of-Service requirements can be met. We also propose an algorithm to select an optimal resource allocation strategy to satisfy various Service Level Agreements. In order to justify our proposal, we have used both numerical analysis and programming approaches. Simulation result shows that our proposed schemes can improve resource allocation efficiency and achieve better performance than the existing ones.     

Carotenoids production from a newly isolated <Emphasis Type="Italic">Sporidiobolus pararoseus</Emphasis> strain by submerged fermentation

This work aimed at evaluating the total carotenoids production by a newly isolated Sporidiobolus pararoseus. Bioproduction was carried out in an orbital shaker, using 10% (w/v) of inoculum (25 °C, 180 rpm for 35 h), incubated for 120 h in a dark room. Liquid N₂ and dimethylsulphoxide (DMSO) were used for cell rupture, and carotenoids were extracted with a solution of acetone/methanol (7:3, v/v). Optimization of carotenoids bioproduction was achieved by experimental design technique. Initially, a Plackett–Burman design was used for the screening of the most important factors, after the statistical analysis, a complete second-order design was carried out to optimize the concentration of total carotenoids in a conventional medium. Maximum concentration of 856 μg/L of total carotenoids was obtained in a medium containing 60 g/L of glucose, 15 g/L of peptone, and 15 g/L of malt extract, 25 °C, initial pH 4.0 and 180 rpm. Fermentation kinetics showed that the maximum concentration of total carotenoids was reached after 102 h of fermentation and that carotenoids bioproduction was associated with cell growth.     

Prediction of fertility by centrifugal countercurrent distribution (CCCD) analysis: correlation between viability and heterogeneity of ram semen and field fertility

The prediction of the fertilizing ability of a sire or a given insemination dose is a primary aim in the field of artificial insemination. Centrifugal countercurrent distribution analysis (CCCD) was used to determine the relationship between some sperm parameters and the in vivo fertility rate obtained with the same sample after cervical artificial insemination. A total of 522 ewes from 26 different farms was inseminated with 53 ejaculates obtained from 25 mature Rasa aragonesa rams. Semen was diluted to 1.6 x 10(9) cells ml-1 and doses of 0.25 ml were prepared and kept at 15 degrees C until used for insemination. The same ejaculates were used for analysis of standard semen parameters and CCCD analysis. Sperm motility, concentration and viability were determined before and after CCCD. Post-CCCD parameters were derived from the analysis of the profile obtained after CCCD. The recovered viability showed the highest correlation with fertility, especially in the central chambers (V2), r = 0.415, P < 0.005). The ejaculate heterogeneity also showed a positive correlation with field fertility (r = 0.23), with a tendency towards significance (P < 0.1). The mean fertility value of all ejaculates used in this study was 46.75%, ranging from 12.5% to 75.0%. Ejaculates were classified into two categories according to their fertility: higher and lower than the mean value. Only the viability recovered in the central chambers (V2) was a parameter with a predictive capacity to discriminate between the two groups (P < 0.05). A predictive equation for field fertility with a correlation coefficient r = 0.488 and a very high level of significance (P < 0.005) was deduced by multiple analysis: PF = 6.02 + 0.069V2 + 0.315H (where PF is predictive fertility, V2 is the recovered viability in the CCCD profile central chambers and H is heterogeneity).     

Explicit formulas of normalized radiation modes in multilayerwaveguides

A new formulation for the normalization of radiation modes in one-dimensional lossless multilayer waveguide structures is derived using the transmission matrix method. In this formulation, an individual radiation mode is excited by two sources located at opposite ends of the two outermost regions of the waveguide. Proper choice of the absolute phase of one of the sources results in simple expressions for the normalized radiation modes. Calculation of radiation loss of grating-assisted directional couplers is used as an example to show the simplicity and usefulness of this method     

Error measures for scene segmentation

Scene segmentation is an important problem in pattern recognition. Current subjective methods for evaluation and comparison of scene segmentation techniques are inadequate and objective quantitative measures are desirable. Two error measures, the percentage area misclassified (p) and a new pixel distance error (ε) were defined and evaluated in terms of their correlation with human observation for comparison of multiple segmentations of the same scene and multiple scenes segmented by the same technique. The results indicate that both these measures can be helpful in the evaluation and comparison of scene segmentation procedures.     

Design of integrated data/voice stations for a CSMA/CD LAN

This paper describes the design and implementation of integrated data/voice stations for a LAN environment. The stations are based on the DB16000 Development Board using a 16-bit CPU. Continuously variable slope delta modulation is selected as the voice encoding technique. Protocols were designed and implemented to handle data and voice separately. Prototypes were built to test the station's performance. The stations communicate with one another at a rate of 1.5 Mbit/s. The voice digitization rate is 16 kbit/s and the terminal speed is 9.6 kbit/s.     

Tissue Mimicry in Morphology and Composition Promotes Hierarchical Matrix Remodeling of Invading Stem Cells in Osteochondral and Meniscus Scaffolds

An integral approach toward in situ tissue engineering through scaffolds that mimic tissue with regard to both tissue architecture and biochemical composition is presented. Monolithic osteochondral and meniscus scaffolds are prepared with tissue analog layered biochemical composition and perpendicularly oriented continuous micropores by a newly developed cryostructuring technology. These scaffolds enable rapid cell ingrowth and induce zonal‐specific matrix synthesis of human multipotent mesenchymal stromal cells solely through their design without the need for supplementation of soluble factors such as growth factors.     

Ageing properties of polyurethane methacrylate and off‐stoichiometry thiol‐ene polymers after nitrogen and argon plasma treatment

Proprietary mixture of polyurethane methacrylate (PUMA) and off‐stoichiometry thiol‐ene (OSTE‐80) are evaluated as two possible polymeric substrates to prototype microfluidic biochips. Because of their lack of biocompatibility, PUMA and OSTE‐80 are modified by argon (Ar) or nitrogen (N₂) plasma treatment to introduce nitrogen moieties that are highly polar and conducive for cell attachment and growth. XPS and water contact angle measurement show that these nitrogen groups are relatively stable in the plasma‐treated PUMA and OSTE‐80 in spite of the hydrophobic recovery and volatilization of nitrogen moieties during air ageing for 15 days. This stability can be attributed to their high degree crosslinking that is reflected by the increase of elastic modulus of PUMA and OSTE‐80 during their air ageing. These results show that Ar and N₂ plasma‐treated PUMA and OSTE‐80 possess the necessary physical and chemical properties to be evaluated further to develop microfluidic biochips for biological applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44107.     

Evaluation on sampling point densities for assessing indoor air quality

In Hong Kong, the Environmental Protection Department (HKEPD) has launched an indoor air quality (IAQ) certification scheme to promote an acceptable IAQ in workplaces. However, the associated uncertainties and measurement efforts have not been detailed for practical measurement in indoor spaces. In this study, indoor carbon dioxide (CO₂) concentration is selected as an indicator of the IAQ to investigate the probable errors and measurement efforts in different sampling schemes regarding the sampling point density. In particular, a one-year measurement for sample-spatial average indoor CO₂ concentration at 17 sampling locations in a typical large office (floor area=1200 m²) has been used to evaluate the probable errors of the sample-spatial average concentrations using different sampling point densities. The result shows that the measured concentration at a single sampling point could not be representative for the space and more than one sampling locations would be required in order to increase the measurement accuracy. Mathematical expressions for the sample-spatial average concentration at a confidence level at certain sampling point densities are proposed. When doubled the required measurement points, it was found that the probability of obtaining a measured CO₂ concentration at the confidence level of 95% could be increased from 70% to 90%, as compared with the current sampling practice. It is recommended to specify the measurement uncertainties in future codes so that effort for IAQ measurements in indoor spaces could be determined for practical strategies.