Quality Metric to Assess Video Streaming Service over TCP considering Temporal Location of Pauses

There is a wide range of video services over complex transmission networks, and in some cases end users fail to receive an acceptable quality level. In this paper, the different factors that degrade users' quality of experience (QoE) in video streaming service that use TCP as transmission protocol are studied. In this specific service, impairment factors are: number of pauses, their duration and temporal location. In order to measure the effect that each temporal segment has in the overall video quality, subjective tests. Because current subjective test methodologies are not adequate to assess video streaming over TCP, some recommendations are provided here. At the application layer, a customized player is used to evaluate the behavior of player buffer, and consequently, the end user QoE. Video subjective test results demonstrate that there is a close correlation between application parameters and subjective scores. Based on this fact, a new metrics named VsQM is defined, which considers the importance of temporal location of pauses to assess the user QoE of video streaming service. A useful application scenario is also presented, in which the metrics proposed herein is used to improve video services(1).

Life cycle assessment of sugarcane ethanol and palm oil biodiesel joint production

Sugarcane (Saccharum spp.) and palm tree (Elaeis guianeensis) are crops with high biofuel yields, 7.6 m(3) ha (1) y(-)1 of ethanol and 4 Mg ha(-1) y(-1) of oil, respectively. The joint production of these crops enhances the sustainability of ethanol. The objective of this work was comparing a traditional sugarcane ethanol production system (TSES) with a joint production system (JSEB), in which ethanol and biodiesel are produced at the same biorefinery but only ethanol is traded. The comparison is based on ISO 14.040:2006 and ISO 14044:2006, and appropriate indicators. Production systems in Cerrado (typical savannah), Cerradao (woody savannah) and pastureland ecosystems were considered. Energy and carbon balances, and land use change impacts were evaluated. The joint system includes 100% substitution of biodiesel for diesel, which is all consumed in different cropping stages. Data were collected by direct field observation methods, and questionnaires applied to Brazilian facilities. Three sugarcane mills situated in Sao Paulo State and one palm oil refinery located in Para State were surveyed. The information was supplemented by secondary sources. Results demonstrated that fossil fuel use and greenhouse gas emissions decreased, whereas energy efficiency increased when JSEB was compared to TSES. In comparison with TSES, the energy balance of JSEB was 1.7 greater. In addition, JSEB released 23% fewer GHG emissions than TSES. The ecosystem carbon payback time for Cerrado, Cerradao, and Degraded Grassland of JSEB was respectively 4, 7.7 and -7.6 years. These are typical land use types of the Brazilian Cerrado region for which JSEB was conceived. (C) 2012 Elsevier Ltd. All rights reserved.

Chronic Pain and Depression in the Quality of Life of Women With Migraine - A Controlled Study

Background. Migraine is comorbid to depression and widespread chronic pain (WCP), but the influence of these conditions on the health-related quality of life (HRQoL) of individuals with episodic (EM) and chronic migraine (CM) is poorly understood. Objective.-To assess the prevalence of depressive symptoms and WCP in individuals with EM and CM, as well as to estimate the joint impact of these conditions on the HRQoL of these individuals. Methods.-All women aged 18 to 65 years with a first diagnosis of EM or CM from September of 2006 to September of 2008 seen in an outpatient headache service were invited to participate. They were asked to attend a separate appointment in the service, and to bring another woman of similar age that also agreed to participate. Depressive symptoms were assessed using the Beck Depression Inventory. Questions about WCP followed the protocol of the American College of Rheumatology. HRQoL was assessed using the Short-Form 36 (SF-36). Multivariate analysis modeled HRQoL as a function of headache status, depressive symptoms, and pain, using quantile regression. Results.-Sample consisted of 179 women, 53 in the EM group, 37 in the CM group and 89 in control group. Groups did not differ by demographics. Mean scores of SF-36 were 53.6 (standard deviation [SD] = 23.5) for EM, 44.2 (SD = 18.5) for CM and 61.8 (SD = 21.5) for controls. In multivariate analysis, SF-36 scores were predicted by a CM status (P =.02; -10.05 [95% CI -18.52; -1.58]) and by a Beck Depression Inventory score (P <.01; -1.27 [95% CI -1.55; -0.99]). The influence of WCP in the SF-36 scores approached significance (P =.08; -0.78 [95% CI -1.64; 0.88]). Age did not contribute to the model. Conclusion.-Women with migraine are at an increased chance of WCP, and the chance increases as a function of headache frequency. Both depressive symptoms and CM independently predict HRQoL status.

Service Innovation: the state of the art and a proposal of a research agenda

The service sector has acquired a growing importance in every country economy, which has stimulated research in the field of service innovation, a new field in management studies. This text aimed to state a research agenda upon service innovation, based on an articulated discussion of the results of several articles that compose the state of the art of this concept. 73 empirical articles were analyzed, 33% of them exploring the innovation strategies and technology; 18% of the articles describe research on economic performance and enterprise productivity; 16% are related to antecedents and determinants of innovation; another 16% about network capacity development, alliances and collaboration among organizations; 9% of the articles explore service quality, innovation taxonomy, flexible systems and regional systems of innovation; and another 8% are related to themes such as intensive knowledge, research and development. The researches were concentrated in the Engineering & Technology and Hospitality Industries, which accounted for 31% and 24% of the texts, respectively. The remaining 45% of the articles referred to sectors such as Telecommunications, Health, Retail, Financial & Insurance and Public Services. The main gaps identified in these texts refer to the difficulties on measuring service innovation, besides the small number of researches on the public sector. At the end, a research agenda in the subject is presented, including the development of a scale for orientating the innovation and identifying the determining factors of the innovation in the public environment.

Chaotic encryption method based on life-like cellular automata

A chaotic encryption algorithm is proposed based on the "Life-like" cellular automata (CA), which acts as a pseudo-random generator (PRNG). The paper main focus is to use chaos theory to cryptography. Thus, CA was explored to look for this "chaos" property. This way, the manuscript is more concerning on tests like: Lyapunov exponent, Entropy and Hamming distance to measure the chaos in CA, as well as statistic analysis like DIEHARD and ENT suites. Our results achieved higher randomness quality than others ciphers in literature. These results reinforce the supposition of a strong relationship between chaos and the randomness quality. Thus, the "chaos" property of CA is a good reason to be employed in cryptography, furthermore, for its simplicity, low cost of implementation and respectable encryption power. (C) 2012 Elsevier Ltd. All rights reserved.

Work ability among hospital food service professionals: multiple associated variables require comprehensive intervention

The work of hospital food service is characterized by demands that can be associated with work ability - WA. The aim of this study was to evaluate factors associated with WA among hospital food service professionals and recommend intervention measures. This is a cross sectional study carried out in 2009, conducted in a hospital of Sao Paulo, Brazil. Participants were 76 (96.2%) of the eligible. They filled out a questionnaire including socio-demographic data, life styles, working conditions and WA. Multivariate linear regression analyses were performed. Factors associated with WA were age (p=0.051), over commitment (p=0.011), effort-reward ratio (p=0.002) and work injuries (p<0.001). In spite was a young population, age was associated with WA. Association with work injuries is consistent with the theoretical model that demonstrated that health status is the basis to maintain the WA. The association of effort-reward imbalance shows that issues related with work organization are relevant for these workers. The association of overcommittment suggests that workers recognize their responsibility with the therapeutic processes of patients. Results showed a number of features of different nature that should be taken into account when implementing measures to improve the WA, to be applied at different levels: individual, task and institutional.