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31.
Bruno L. Dalmazo João P. Vilela Marilia Curado 《International Journal of Network Management》2016,26(4):269-285
Network traffic prediction is a fundamental tool to harness several management tasks, such as monitoring and managing network traffic. Online traffic prediction is usually performed based on large sets of historical data used in training algorithms, for example, to determine the size of static windows to bound the amount of traffic under consideration. However, using large sets of historical data may not be suitable in highly volatile environments, such as cloud computing, where the coupling between time series observations decreases rapidly with time. To fill this gap, this work presents a dynamic window size algorithm for traffic prediction that contains a methodology to optimize a threshold parameter alpha that affects both the prediction and computational cost of our scheme. The alpha parameter defines the minimum data traffic variability needed to justify dynamic window size changes. Thus, with the optimization of this parameter, the number of operations of the dynamic window size algorithm decreases significantly. We evaluate the alpha estimation methodology against several prediction models by assessing the normalized mean square error and mean absolute percent error of predicted values over observed values from two real cloud computing datasets, collected by monitoring the utilization of Dropbox, and a data center dataset including traffic from several common cloud computing services. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
32.
ABSTRACT: BACKGROUND: The replacement of sucrose with HFCS in food products has been suggested as playing a role in the development of obesity as a public health issue. The objective of this study was to examine the effects of four equally hypocaloric diets containing different levels of sucrose or high fructose corn syrup (HFCS). METHODS: This was a randomized, prospective, double blind trial, with overweight/obese participants measured for body composition and blood chemistry before and after the completion of 12 weeks following a hypocaloric diet. The average caloric deficit achieved on the hypocaloric diets was 309 kcal. RESULTS: Reductions were observed in all measures of adiposity including body mass, BMI, % body fat, waist circumference and fat mass for all four hypocaloric groups, as well as reductions in exercise only group for body mass, BMI and waist circumference. CONCLUSIONS: Similar decreases in weight and indices of adiposity are observed when overweight or obese individuals are fed hypocaloric diets containing levels of sucrose or high fructose corn syrup typically consumed by adults in the United States. 相似文献
33.
Eduardo Cerqueira Luis Veloso Augusto Neto Marilia Curado Edmundo Monteiro Paulo Mendes 《Mobile Networks and Applications》2008,13(3-4):366-384
A combined control of multimedia quality level, mobility and allocation of network resources is essential for the success of next generation mobile networks. In this context, this article presents the Multi-user Session Control (MUSC) solution to control the quality level of multimedia sessions shared by multiple-users, providing Quality of Service (QoS) mapping and QoS adaptation for those sessions over heterogeneous and mobile networks. MUSC uses the self-organized principle to coordinate QoS mapping and QoS adaptation mechanisms with mobility and resource allocation controllers, allowing the adaptation of a session to the current network conditions and the dynamic selection of the suitable network service class to map the session. MUSC minimizes the blocking probability, optimizes the usage of network resources and keeps sessions with an acceptable quality of experience. MUSC was evaluated in a simulation and in an experimental environment to analyze its convergence time, percentage of session blocking as well as delay, throughput, Peak Signal-to-Noise Ratio (PSNR), Mean Option Scores (MOS) and Structural Similarity Index (SSIM) of sessions in QoS-aware mobile scenarios. 相似文献
34.
BH Olson SM Anderson MP Becker JW Anderson DB Hunninghake DJ Jenkins JC LaRosa JM Rippe DC Roberts DB Stoy CD Summerbell AS Truswell TM Wolever DH Morris VL Fulgoni 《Canadian Metallurgical Quarterly》1997,127(10):1973-1980
We conducted a meta-analysis to determine the effect of consumption of psyllium-enriched cereal products on blood total cholesterol (TC), LDL cholesterol (LDL-C) and HDL cholesterol (HDL-C) levels and to estimate the magnitude of the effect among 404 adults with mild to moderate hypercholesterolemia (TC of 5.17-7.8 mmol/L) who consumed a low fat diet. Studies of psyllium cereals were identified by a computerized search of MEDLINE and Current Contents and by contacting United States-based food companies involved in psyllium research. Published and unpublished studies were reviewed by one author and considered eligible for inclusion in the meta-analysis if they were conducted in humans, were randomized, controlled experiments, and included a control group that ate cereal providing =3 g soluble fiber/d. Eight published and four unpublished studies, conducted in four countries, met the criteria. Analysis of a linear model was performed, controlling for sex and age. Female subjects were divided into two groups to provide a rough estimate of the effect of menopausal status (premenopausal = <50 y, postmenopausal = >/=50 y) on blood lipids. The meta-analysis showed that subjects who consumed a psyllium cereal had lower TC and LDL-C concentrations [differences of 0.31 mmol/L (5%) and 0.35 mmol/L (9%), respectively] than subjects who ate a control cereal; HDL-C concentrations were unaffected in subjects eating psyllium cereal. There was no effect of sex, age or menopausal status on blood lipids. Results indicate that consuming a psyllium-enriched cereal as part of a low fat diet improves the blood lipid profile of hypercholesterolemic adults over that which can be achieved with a low fat diet alone. 相似文献
35.
Eduardo Cerqueira Sherali Zeadally Mikołaj Leszczuk Marilia Curado Andreas Mauthe 《Multimedia Tools and Applications》2011,54(3):635-647
In recent years, the ubiquity of multimedia services along with the proliferation of mobile devices and the demand for new
audio and video applications are changing the life style of users. User demands for multimedia access anywhere, anytime from
any device are creating new challenges for research communities from both academia and industry. It is expected that video-based
services alone will account for 50 percent of all consumer network traffic in 2012 and we will continue to witness the explosive
growth in users sharing multimedia content over the Internet. In this context, new network, application, and user-based approaches
must be created to deal with such complex multimedia systems. This paper presents some of the recent advances in multimedia
networking focusing primarily on areas that have been receiving attention recently and are expected to continue to generate
further interests in coming years. These areas include Quality of Experience (QoE) and various related standardization issues,
Content Distribution Networks (CDNs), multimedia communications, mobile Multimedia. This paper also briefly highlights some
of the major challenges that still need to be addressed to enable the support and delivery of multimedia services anywhere,
anytime over highly heterogeneous infrastructures and user terminal devices. 相似文献
36.
37.
Zhang H Sabooni M Rippe L Kim C Kröll S Wang LV Hemmer PR 《Applied physics letters》2012,100(13):131102-1311025
Slow light has been extensively studied for applications ranging from optical delay lines to single photon quantum storage. Here, we show that the time delay of slow-light significantly improves the performance of the narrowband spectral filters needed to optically detect ultrasound from deep inside highly scattering tissue. We demonstrate this capability with a 9?cm thick tissue phantom, having 10?cm(-1) reduced scattering coefficient, and achieve an unprecedented background-free signal. Based on the data, we project real time imaging at video rates in even thicker phantoms and possibly deep enough into real tissue for clinical applications like early cancer detection. 相似文献
38.
Coutinho Marilia Balbachevsky Elizabeth Holzhacker Denilde Oliveira Da Costa Patrao Diogo Vencio Ricardo Nicoliello Zorzetto Da Silva Rodrigo Luiz Medeiros Lucatelli Márcio Luís Gomes Dos Reis Lucimara Flávio Marin Maria Angélica 《Scientometrics》2003,58(3):641-656
Brazil is considered to have an immature national innovation system. One significant situation that contributes to it is that
Brazil concentrates its research efforts and inventiveness in academic environments, while the private sector has very little
access to this activity. Measures are being taken to correct this situation. Nevertheless, scientists' attitudes towards the
new situation will be instrumental for the success of such measures. For this reason, we have studied the behavior of Brazilian
scientists from the biotechnological fields concerning Intellectual Property Rights. In this research 1032 researchers were
electronically contacted and 150 responded. The 41 questions include indicators about the interviewees' perceptions about
their institutions' support for patenting research results, their attitudes towards recent changes in Intellectual Property
Rights legislation and about the interaction of researchers with demands from external interests.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
39.
Marilia S. da Nascimento Santos Joedyson Emmanuel M. de Magalh?es Luiza Sheyla Evenni P. Will Castro Thuane de Sousa Pinheiro Diego Araujo Sabry Leonardo Thiago Duarte B. Nobre Jo?o Paulo Matos Santos Lima Iuri Goulart Baseia Edda Lisboa Leite 《International journal of molecular sciences》2014,15(2):2368-2385
In this study, we evaluated the effect of different doses of polysaccharides extracted from Caripia montagnei mushroom at different intervals of treatment on colonic injury in the model of colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). The FT-IR analysis and NMR showed that the polysaccharides from this species of mushroom are composed of α- and β-glucans. The colonic damage was evaluated by macroscopic, histological, biochemical and immunologic analyses. The results showed the reduction of colonic lesions in all groups treated with the glucans. Such glucans significantly reduced the levels of IL-6 (50 and 75 mg/kg, p < 0.05), a major inflammatory cytokine. Biochemical analyses showed that the glucans from C. montagnei acted on reducing levels of alkaline phosphatase (75 mg/kg, p < 0.01) and myeloperoxidase (p < 0.001), a result confirmed by the reduction of cellular infiltration observed microscopically. The increase of catalase activity possibly indicates a protective effect of these glucans on colonic tissue, confirming their anti-inflammatory potential. 相似文献
40.
Wireless Mesh Networks form a wireless backbone that provides ubiquitous Internet access and support of multimedia services. In this scenario, traffic crosses multi-hop paths, through mesh routers and gateways, causing high levels of interference. To address this problem, the use of schemes that introduce routing metrics that take into account the characteristics of the interference have been made to improve the application performance. Given the diversity of interference-aware routing metrics for Wireless Mesh Networks, it is necessary to assess the impact of employing these routing metrics on multimedia traffic performance, and in particular, on video streaming. This paper seeks to fill this gap, by using simulation to evaluate the video streaming performance when the most relevant interference-aware routing metrics are used. The degree of video quality can be evaluated from two perspectives, the network viewpoint and the standpoint of the user perception. At the network level, video streaming quality is assessed through IP measures, that is, throughput, delay, jitter and routing overhead. At the user level, ‘Quality of Experience’ metrics are employed to measure the user perception with regard to the video quality. The evaluation of the performance takes account of outdoor and indoor environments. The results of the simulation study have shown that routing metrics based on the information that detects interference using accurate measures achieve a better network and user perception performance. However, depending on the environment (i.e., whether it is indoor or outdoor), all the routing metrics result in a different performance being achieved. Although interference-aware routing metrics affect the performance of both the network and the user levels, there are some cases where they have less impact on the user level, because the user perception parameters are less influenced by the behaviour of the network. 相似文献