A collaborative mobile architecture for multicast live-streaming social networks

Multimedia social network analysis is an emerging research area, which analyzes the behaviour of users who share multimedia content and investigates the impact of human dynamics on multimedia systems. In collaborative mobile networks, receivers cooperate with each other to provide a distributed, highly scalable and robust platform for live streaming applications. However, every user wishes to use as much bandwidth as possible to receive a high-quality video; then, congestion control should be addressed. This paper proposes a collaborative mobile architecture to model receiver (in this case user) behaviour using congestion control and reliable strategies to stimulate user cooperation in multicast live streaming. Thus, an author´s protocol named Scalable Reliable Multicast Stair Hybrid (SRMSH) is presented as new hybrid multiple layer mechanism for multicast congestion control providing detection and recovery loss. Simulation results show that the proposed strategies can effectively stimulate user cooperation, achieve cheat free and provide reliable services within a mobile multimedia social network

Performance studio of multicast video streaming using SRMSH

With the increasing deployment of multimedia real-time Internet applications, evaluating transport protocol metrics of Quality of Service (QoS) has gained rapidly increasing importance. In this paper, a novelty protocol named Scalable Reliable Multicast Stair Hybrid (SRMSH) is presented as new hybrid multiple layer mechanism for multicast congestion control providing detection and recovery loss. Then SRMSH is simulated with video streaming traffic source to measure fundamental components to real-time multimedia applications: Throughput, latency and jitter. Work is focused on performance analysis and results obtained from NS-2 traces clearly conclude that SRMSH exhibits interesting insights using these metrics of real-time multimedia applications

Partially observable Markov decision processes with partially observable random discount factors

summary:This paper deals with a class of partially observable discounted Markov decision processes defined on Borel state and action spaces, under unbounded one-stage cost. The discount rate is a stochastic process evolving according to a difference equation, which is also assumed to be partially observable. Introducing a suitable control model and filtering processes, we prove the existence of optimal control policies. In addition, we illustrate our results in a class of GI/GI/1 queueing systems where we obtain explicitly the corresponding optimality equation and the filtering process

Usage of social and semantic web technologies to design a searching architecture for software requirement artefacts

At present, the research community recognises a complementary relationship between the semantic and the social web. The merging of these web instances could play an essential role in different knowledge domains. In this study, the authors promote a social–semantic web paradigm using software engineering as the knowledge domain specifically. The authors address a major problem – the difficulty for end-users in finding documentation related to software requirements proposed by them; this fact reduces their participation at the time of specifying the software requirements. Architecture is proposed for enhanced resources search, combining the strengths of the social (social annotations) and semantic (semantic metadata) technologies, which has been designed considering the search style of the information seekers. Such architecture is applied in a use-scenario, where the expert users who are not technicians have some restrictions and limitations to retrieve the documents they need. The preliminary results demonstrate that it is possible to take advantage of the defined infrastructure of the ontology to organise and integrate the metadata of resources which are in databases or existent files; this approach opens several possibilities as creation and validation of software requirements collaboratively among different expert-users

Categorization of indoor places by combining local binary pattern histograms of range and reflectance data from laser range finders

This paper presents an approach to categorize typical places in indoor environments using 3D scans provided by a laser range finder. Examples of such places are offices, laboratories, or kitchens. In our method, we combine the range and reflectance data from the laser scan for the final categorization of places. Range and reflectance images are transformed into histograms of local binary patterns and combined into a single feature vector. This vector is later classified using support vector machines. The results of the presented experiments demonstrate the capability of our technique to categorize indoor places with high accuracy. We also show that the combination of range and reflectance information improves the final categorization results in comparison with a single modality

Parameters that determine the wavelength of a passive mode-locked dye laser

We introduce a new stability criterion that should be added to previous theoretical models of passive mode locked lasers in order to predict emission wavelength, which is to require that the pulse spectrum reproduces itself after one transit. The CPM laser consisting of rhodamine 6G as gain medium and DODCI as saturable absorber is studied. The relative population balance of the fundamental and photoisoner species of the DODCI are computed as a function of the pulse energy and wavelength. The necessity of a spectral stability criterion follows from the dependence of the gain profile on the pulse parameters. Use of the criterion is shown to agree with previous experimental results, such as the red spectral region of emission and dependence of emission wavelength on absorber concentration. This criterion is expected to be an useful tool in order to select other dye combinations and predict the laser behavior. Parameters that determine the wavelength of a passive mode-locked dye laser

Epidemiological assessment of Wolbachia-based biocontrol for reduction of dengue morbidity

International audienceWolbachia-based biological control has recently emerged as an ecologically friendly and potentially cost-effective method for prevention and control of dengue and other arboviral infections. When deliberately infected withWolbachia, major vector species, such as Aedes aegypti females, lose their vectorial competence and become less capable of transmitting the virus to humans. Thus, Wolbachia-based biocontrol aims to replace wild vectors (fully capable of transmitting arboviral infections) by Wolbachia-carrying insects that bear a reduced transmission capacity. The population replacement can be achieved by releasing mosquitoes that were transinfected with Wolbachia during the process of mass-rearing.In this presentation, we propose a sex-structured model describing the dynamics of two sup-populations of adult mosquitoes: the wild insects (males and females that are Wolbachia- free), and those deliberately infected with Wolbachia. This model is biologically viable, well-posed, and reflects the two significant features of Wolbachia: maternal transmission and cytoplasmic incompatibility. The model also exhibits bistability that agrees with the principle of competitive exclusion.Using this mosquito population dynamics model, we further construct a dengue transmission system of SEIR-SEI type to perform an epidemiological assessment of Wolbachia-based control for prevention of dengue morbidity. As an example, we simulate this type of preventive control applied to Cali, a sizeable Colombian city commonly considered a hyperendemic area regarding dengue morbidity

Soft-x-ray interferometer for single-shot laser linewidth measurements

Includes bibliographical references (page 957).A soft-x-ray Mach-Zehnder interferometer configuration that makes use of the time delay introduced by diffraction gratings to conduct single-shot measurements of the linewidth of soft-x-ray laser amplifiers is proposed and analyzed. The scheme was experimentally demonstrated in the near-IR region of the spectrum by measurement of the mode separation of a semiconductor laser. A symmetric configuration with compensated time delays that can be implemented for plasma diagnostics and for evaluating soft-x-ray optics is also discussed

Age constraints on the dispersal of dinosaurs in the Late Triassic from magnetochronology of the Los Colorados Formation (Argentina)

A measured magnetozone sequence defined by 24 sampling sites with normal polarity and 28 sites with reverse polarity characteristic magnetizations was established for the heretofore poorly age-constrained Los Colorados Formation and its dinosaur-bearing vertebrate fauna in the Ischigualasto–Villa Union continental rift basin of Argentina. The polarity pattern in this ∼600-m-thick red-bed section can be correlated to Chrons E7r to E15n of the Newark astrochronological polarity time scale. This represents a time interval from 227 to 213 Ma, indicating that the Los Colorados Formation is predominantly Norian in age, ending more than 11 My before the onset of the Jurassic. The magnetochronology confirms that the underlying Ischigualasto Formation and its vertebrate assemblages including some of the earliest known dinosaurs are of Carnian age. The oldest dated occurrences of vertebrate assemblages with dinosaurs in North America (Chinle Formation) are younger (Norian), and thus the rise of dinosaurs was diachronous across the Americas. Paleogeography of the Ischigualasto and Los Colorados Formations indicates prolonged residence in the austral temperate humid belt where a provincial vertebrate fauna with early dinosaurs may have incubated. Faunal dispersal across the Pangean supercontinent in the development of more cosmopolitan vertebrate assemblages later in the Norian may have been in response to reduced contrasts between climate zones and lowered barriers resulting from decreasing atmospheric pCO2 levels

Evidence for Avian Intrathoracic Air Sacs in a New Predatory Dinosaur from Argentina

Background: Living birds possess a unique heterogeneous pulmonary system composed of a rigid, dorsally-anchored lung and several compliant air sacs that operate as bellows, driving inspired air through the lung. Evidence from the fossil record for the origin and evolution of this system is extremely limited, because lungs do not fossilize and because the bellow-like air sacs in living birds only rarely penetrate (pneumatize) skeletal bone and thus leave a record of their presence.Methodology/Principal Findings: We describe a new predatory dinosaur from Upper Cretaceous rocks in Argentina, Aerosteon riocoloradensis gen. et sp. nov., that exhibits extreme pneumatization of skeletal bone, including pneumatic hollowing of the furcula and ilium. In living birds, these two bones are pneumatized by diverticulae of air sacs (clavicular, abdominal) that are involved in pulmonary ventilation. We also describe several pneumatized gastralia (“stomach ribs”), which suggest that diverticulae of the air sac system were present in surface tissues of the thorax.Conclusions/Significance: We present a four-phase model for the evolution of avian air sacs and costosternal-driven lung ventilation based on the known fossil record of theropod dinosaurs and osteological correlates in extant birds:(1) Phase I—Elaboration of paraxial cervical air sacs in basal theropods no later than the earliest Late Triassic.(2) Phase II—Differentiation of avian ventilatory air sacs, including both cranial (clavicular air sac) and caudal (abdominal air sac) divisions, in basal tetanurans during the Jurassic. A heterogeneous respiratory tract with compliant air sacs, in turn, suggests the presence of rigid, dorsally attached lungs with flow-through ventilation.(3) Phase III—Evolution of a primitive costosternal pump in maniraptoriform theropods before the close of the Jurassic.(4) Phase IV—Evolution of an advanced costosternal pump in maniraptoran theropods before the close of the Jurassic.In addition, we conclude:(5) The advent of avian unidirectional lung ventilation is not possible to pinpoint, as osteological correlates have yet to be identified for uni- or bidirectional lung ventilation.(6) The origin and evolution of avian air sacs may have been driven by one or more of the following three factors: flow-through lung ventilation, locomotory balance, and/or thermal regulation.</p