8,965 research outputs found

    Modeling of Packet Streaming Services in Information Communication Networks

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    Application of the term video streaming in contemporary usage denotes compression techniques and data buffering, which can transmit video in real time over the network. There is currently a rapid growth and development of technologies using wireless broadband technology as a transport, which is a seri- ous alternative to cellular communication systems. Adverse effect of the aggressive environment used in wireless networks transmission results in data packets undergoing serious distortions and often get- ting lost in transit. All existing research in this area investigate the known types of errors separately. At present there are no standard approaches to determining the effect of errors on transmission quality of services. Besides, the spate in popularity of multimedia applications has led to the need for optimization of bandwidth allocation and usage in telecommunication networks. Modern telecommunication networks should by their definition be able to maintain the quality of different applications with different Quality of Service (QoS) levels. QoS requirements are generally dependent on the parameters of network and application layers of the OSI model. At the application layer QoS depends on factors such as resolution, bit rate, frame rate, video type, audio codecs, and so on. At the network layer, distortions (such as delay, jitter, packet loss, etc.) are introduced

    Mathematical Models of Video-Sequences of Digital Half-Tone Images

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    This chapter is devoted to Mathematical Models (MM) of Digital Half-Tone Images (DHTI) and their video-sequences presented as causal multi-dimensional Markov Processes (MP) on discrete meshes. The difficulties of MM development for DHTI video-sequences of Markov type are shown. These difficulties are related to the enormous volume of computational operations required for their realization. The method of MM-DHTI construction and their statistically correlated video-sequences on the basis of the causal multi-dimensional multi-value MM is described in detail. Realization of such operations is not computationally intensive; Markov models from the second to fourth order demonstrate this. The proposed method is especially effective when DHTI is represented by low-bit (4-8 bits) binary numbers

    Neural Network Control of a Laboratory Magnetic Levitator

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    Magnetic levitation (maglev) systems are nowadays employed in applications ranging from non-contact bearings and vibration isolation of sensitive machinery to high-speed passenger trains. In this chapter a mathematical model of a laboratory maglev system was derived using the Lagrangian approach. A linear pole-placement controller was designed on the basis of specifications on peak overshoot and settling time. A 3-layer feed-forward Artificial Neural Network (ANN) controller comprising 3-input nodes, a 5-neuron hidden layer, and 1-neuron output layer was trained using the linear state feedback controller with a random reference signal. Simulations to investigate the robustness of the ANN control scheme with respect to parameter variations, reference step input magnitude variations, and sinusoidal input tracking were carried out using SIMULINK. The obtained simulation results show that the ANN controller is robust with respect to good positioning accuracy

    Student-produced podcasts as an assessment tool: an example from Geomorphology

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    The emergence of user-friendly technologies has made podcasting an accessible learning tool in undergraduate teaching. In a geomorphology course, student-produced podcasts were used as part of the assessment in 2008-2010. Student groups constructed radio shows aimed at a general audience to interpret and communicate geomorphological data within the context of relevant social and environmental issues. Questionnaire results suggest that the novel format engaged students, and promoted group working, IT, language and oral communication skills, and a deeper understanding of the context of geomorphic data. For teachers, podcasting technology offers efficient teaching of oral communication, with opportunities for distance and self-directed learning

    Just how difficult can it be counting up R&D funding for emerging technologies (and is tech mining with proxy measures going to be any better?)

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    Decision makers considering policy or strategy related to the development of emerging technologies expect high quality data on the support for different technological options. A natural starting point would be R&D funding statistics. This paper explores the limitations of such aggregated data in relation to the substance and quantification of funding for emerging technologies. Using biotechnology as an illustrative case, we test the utility of a novel taxonomy to demonstrate the endemic weaknesses in the availability and quality of data from public and private sources. Using the same taxonomy, we consider the extent to which tech-mining presents an alternative, or potentially complementary, way to determine support for emerging technologies using proxy measures such as patents and scientific publications

    Innovation in the Public Sector

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    Innovation is something that is new, capable of being implemented, and has a beneficial impact. It is not an event or activity; it is a concept, process, practice, and capability that defines successful organizations. Innovation in the public sector can help create value for society

    An agent-based implementation of hidden Markov models for gas turbine condition monitoring

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    This paper considers the use of a multi-agent system (MAS) incorporating hidden Markov models (HMMs) for the condition monitoring of gas turbine (GT) engines. Hidden Markov models utilizing a Gaussian probability distribution are proposed as an anomaly detection tool for gas turbines components. The use of this technique is shown to allow the modeling of the dynamics of GTs despite a lack of high frequency data. This allows the early detection of developing faults and avoids costly outages due to asset failure. These models are implemented as part of a MAS, using a proposed extension of an established power system ontology, for fault detection of gas turbines. The multi-agent system is shown to be applicable through a case study and comparison to an existing system utilizing historic data from a combined-cycle gas turbine plant provided by an industrial partner

    Prostitution or partnership? Wifestyles in Tanzanian artisanal gold-mining settlements

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    Tanzania, along with several other African countries, is experiencing a national mining boom, which has prompted hundreds of thousands of men and women to migrate to mineral-rich locations. At these sites, relationships between the sexes defy the sexual norms of the surrounding countryside to embrace new relational amalgams of polygamy, monogamy and promiscuity. This article challenges the assumption that female prostitution is widespread. Using interview data with women migrants, we delineate six ‘wifestyles’, namely sexual-cum-conjugal relationships between men and women that vary in their degree of sexual and material commitment. In contrast to bridewealth payments, which involved elders formalising marriages through negotiations over reproductive access to women, sexual negotiations and relations in mining settlements involve men and women making liaisons and co-habitation arrangements directly between each other without third-party intervention. Economic interdependence may evolve thereafter with the possibility of women, as well as men, offering material support to their sex partners
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