A configurable multimedia middleware platform

Experience demonstrates the benefits and feasibility of supporting multimedia applications in distributed middleware architectures. However, deployment of multimedia-capable middleware platforms has not yet occurred on a large scale. This article describes designing such a platform and its attempts to maximize performance, predictability, and configurability in a standard workstation operating system environment     

Dynamic rheological behavior of poly(ether ketone ketone) from solid state to melt state

High performance thermoplastic poly(ether ketone ketone) (PEKK) polymers with various meta phenyl links ratio were investigated by dynamical mechanical analysis. Analyses were carried out in a wide range of temperature from solid state (torsion rectangular mode) to the melt state (torsion parallel plates mode) as function of thermal history and environmental conditions. In the solid state, this study was focused on the secondary relaxations in the vitreous state. A complementary investigation conducted with different poly(aryl ether ketones) allowed us to propose a molecular interpretation of PEKK sub‐vitreous relaxations. In the molten state, storage modulus (G′), loss modulus (G″), storage viscosity (η′), and loss viscosity (η″) were studied to determine zero shear‐rate viscosity (η₀) and thermal activation energy E_a. Master curves were built and the shift factor a_T was determined. Thermal activation energies were extracted from an Arrhenius model on the shift factor temperature's dependency. Finally, E_a and η₀ were determined thanks to the dynamic viscosity fit with Cross model and Cole–Cole representation. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46456.     

Thermal conductivity and diffusivity of carbon-reinforced polyetherketoneketone composites

Heat transfer properties play an important role in processing of polyetherketoneketone (PEKK)/carbon fiber (CF) composites. Accordingly, thermal conductivity and diffusivity of PEKK, PEKK/glassy carbon (GC), and PEKK/CF composites have been studied. Observed increase in conductivity and diffusivity with carbon filler addition was analyzed using the Maxwell–Eucken model. PEKK/GC composites with low carbon fraction indicated good fitting experimental points of the model, indicating good dispersion of particles. For PEKK/CF composites, the thermal conductivity and diffusivity increase is a reflection of a decrease in porosity. Results as observed from the model points to a homogenous dispersion within the PEKK/CF composites as well. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47975.     

The design of a configurable and reconfigurable middleware platform

Summary. It is now well established that middleware platforms must accommodate an increasingly diverse range of requirements arising from the needs of both applications and underlying systems. Moreover, it is clear that to achieve this accommodation, platforms must be capable of both deployment-time configurability and run-time reconfigurability. This paper describes a middleware platform that addresses these requirements. The platform is built using a well-founded lightweight component model, uses reflective techniques to facilitate (re)configuration, and employs the notion of component frameworks to manage and constrain the scope of reconfiguration operations. Importantly, the platform also aims to achieve high performance and a level of standards conformance (e.g., with CORBA and COM). We demonstrate that, despite its high degree of configurability, the platform performs on a par with standard commercial CORBA ORBs. Received: April 2001 / Accepted: September 2001     

Supporting mobile multimedia applications through adaptivemiddleware

The traditional approach to developing middleware platforms is to adopt a “black box” philosophy whereby the platform offers a fixed programming model to applications together with fixed per-platform implementations. In this paper, we describe research which is exploring an open approach to the implementation of middleware platforms. Our motivation is to accommodate the demanding requirements for quality-of-service (QoS) adaptation as imposed by mobile multimedia applications. We use an extended CORBA computational model featuring the concept of explicit open bindings. This provides an architectural framework for openness and QoS adaptation. The paper concludes by considering the more general application of an open systems philosophy; in particular, we introduce the concept of reflective middleware     

Maximum likelihood synchronization for OFDM using a pilot symbol:algorithms

The design of a pilot symbol for orthogonal frequency-division multiplexing packet detection and synchronization is presented. Algorithms are described for packet detection and for synchronization using maximum likelihood estimation of channel frequency offset, phase offset for coherent detection, and subsample timing offset. The efficacy of the detection and synchronization algorithms is demonstrated experimentally     

Substantial Receptor‐induced Structural Rearrangement of Rotavirus VP8*: Potential Implications for Cross‐Species Infection

Rotavirus–cell binding is the essential first step in rotavirus infection. This binding is a major determinant of rotavirus tropism, as host cell invasion is necessary to initiate infection. Initial rotavirus–cell interactions are mediated by carbohydrate‐recognizing domain VP8* of the rotavirus capsid spike protein VP4. Here, we report the first observation of significant structural rearrangement of VP8* from human and animal rotavirus strains upon glycan receptor binding. The structural adaptability of rotavirus VP8* delivers important insights into how human and animal rotaviruses utilize the wider range of cellular glycans identified as VP8* binding partners. Furthermore, our studies on rotaviruses with atypical genetic makeup provide information expected to be critical for understanding the mechanisms of animal rotavirus gene emergence in humans and support implementation of epidemiologic surveillance of animal reservoirs as well as future vaccination schemes.     

Maximum likelihood synchronization for OFDM using a pilot symbol:analysis

A performance analysis of algorithms for maximum likelihood estimation of channel parameters for orthogonal frequency-division multiplexing packet detection and synchronization is presented. The detection and synchronization algorithms, which are based on the use of a pilot symbol, are described in Coulson (2001). The performance analyses concentrate on operation in additive white Gaussian noise channels, and the accuracy of these analyses are demonstrated using experimental and simulation data. Methods to extend these analyses to frequency flat multipath fading channels are presented     

Cleft palate associated with prolonged orotracheal intubation in infancy

A hot-loop test was found to be more rapid, convenient, and reliable for the detection of carbon dioxide production than were conventional methods such as displacement of agar plugs and precipitation in barium hydroxide.     

Parental investment, reproductive success and polygyny in the lapwing, Vanellus vanellus

We studied the consequences of monogamy and polygyny for male and female lapwings at a site in northern England between 1993 and 1995. Males and females differed in breeding behaviour, and thus the pattern of reproductive investment: males contributed less time than females to the care of their offspring and more time to mating behaviour. We argue that this has resulted from sexual selection. Reproductive behaviour was similar in monogamous and polygynous individuals of both sexes. Male mating success was related to territory size, with males on the largest territories gaining more females. Polygynous male lapwings reared on average between 58 and 100% more chicks each year than monogamous males because of fewer complete breeding failures; between-year return rates of males to the area were similar. This would result in a strong advantage in terms of lifetime reproductive success for polygynous male lapwings. The seasonal breeding success of polygynous females was marginally, but not significantly, lower than that of monogamous females. Between-year return rates of monogamous and polygynous females were similar. Copyright 1998 The Association for the Study of Animal Behaviour.