672 research outputs found

    An object-oriented organic architecture for next generation intelligent reconfigurable mobile networks

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    Next generation mobile networks have great potential in providing personalised and effcient quality of service by using re-confgurable platforms. The foundation is the concept of software radio where both the mobile terminal and the serving network can be re-configurable. This approach becomes more effective when combined with historic-based prediction strategies that enable the system to learn about application behaviour and predict its resource consumption. We extend that concept by proposing the use of an object-oriented intelligent decision making architecture, which supports general and large-scale applications. The proposed architecture applies the principles of business intelligence and data warehousing, together with the concept of organic viable systems. The architecture is applied to the CAST (Configurable radio with Advanced Software Technology) platform

    Intelligent reconfiguration of large mobile networks using complex organic distributed architecture

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    This paper presents a possible solution to the intelligent evolution of mobile systems using a Complex Organic Distributed Architecture (CODA), which supports intelligent reconfiguration of all system components. A key feature of this architecture is the deployment of multiple warehouses. The warehouses store data in a variety of ways depending on the type of intelligence required. On Line Analytical Processing (OLAP) software is used to monitor and control data in the system. An effective system of filters and wrappers ensures that data is secure. A system of feedback loops ensures that information travels through the system quickly and effectively

    Performance Analysis of Renewable Energy Resources in Rural Areas: A Case Study of Solar Energy

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    This paper presents an overview of the recent development trends of solar photovoltaic (PV) systems and the performance in the Tanzanian context. The two types of solar power generation that are considered in this paper are: i) solar PV systems and ii) concentrated solar power (CSP). The two are compared in terms of cost of energy and energy storage mechanism. Moreover, the effect of ambient temperature on the solar PV module is analyzed. In addition, a detailed analysis on using solar axis tracking to increase the power generation is also presented. The extent to which the cell surface temperature and orientation of the solar module which determine the power generation is modeled. Since Tanzania has the possibility to utilize the solar irradiance in the Coastal region to generate solar power, and therefore it is selected as the case study in this paper.&nbsp

    Optimal Control System of Under Frequency Load Shedding in Microgrid System with Renewable Energy Resources

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    Book ChapterNowadays many of the power systems are facing serious problems because of the lack of know-how to utilize the available renewable energy resources (RER) so as to balance between the power supply and demand sides. As the consequence of the power unbalancing into their distribution networks, under frequency load shedding (UFLS) which leads to life span reduction of various expensive equipment and deteriorating production in general are of much concerns. Thus, proper control system for the load flow in a system like microgrids (MG) with RER in general is the first thing to carry out the assessment with the aim to solve the power balancing problem within the power system networks. Actually, the major problems which many utilities are facing all over the world are how to utilize the available and future energy resource reserves in order to balance between the supply and demand sides within their power distribution networks. Moreover, because of the quick, improvised and unforeseen increasing number of consumers’ power demands and lack of additional macro energy resources plants which can favorably respond to the instantaneous consumer requirements, optimal control strategy (OCS) is inevitable. The OCS is required to maintain the steady-state operations and ensure the reliability of the entire distribution system over a long period. For that case, the OCS is required to principally stabilize parameters such as voltage, frequency, and limit the injection of reactive power into the MG system under stress. Therefore, in this chapter, the OCS is proposed as an approach to be applied in an intelligent way to solve the UFLS and blackout problems (BP) in a typical MG with RER. The proposed control solution is analyzed using emergency power supply reserves integrated with RER. These typical energy resources can be wind and photovoltaic (solar PV) systems associated with the battery energy storage system (BESS), hydro pump storage, biomass power plant and fuel cell systems

    Influence of copper-impregnated basic oxygen furnace slag on the fresh- and hardened-state properties of antimicrobial mortars

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    Microbially induced concrete corrosion (MICC) is recognized as one of the main degradation mechanisms of sewer infrastructure worldwide. To help control this problem, a beneficial reuse path for basic oxygen furnace slag (BOFS) has emerged in which the incorporation of copper-laden BOFS particles into cementitious materials inhibits the growth of microorganisms responsible for MICC. This study investigated the effect of substituting fine aggregate with copper-laden BOFS particles (0.30–0.85 mm) on the hydration and microstructural evolution of portland cement mortars. In addition, the fate of copper in the cured cementitious matrix is elucidated and reported herein. As revealed by isothermal calorimetry, the total evolved heat at the end of the testing period (118 h) was similar when up to 40% of the fine aggregate mass was replaced with copper-laden BOFS particles of similar size, while delays in setting times were observed. Analysis of microstructural evolution using quantitative X-ray diffraction (QXRD) showed higher C–S–H contents when fine aggregate was replaced with copper-laden BOFS, indicating copper-laden BOFS exhibited some degree of pozzolanic reactivity. Electron microprobe analysis (EMPA) revealed that, while trace amounts of copper could be detected throughout the cement matrix, copper was predominantly localized in a 100 μm spherical region surrounding BOFS particles. Moreover, strong binding capacity of Fe-rich BOFS particles for copper was observed. Finally, compressive strengths of mixtures analyzed herein were not affected by the presence of copper-laden BOFS

    Stability of undissociated screw dislocations in zinc-blende covalent materials from first principle simulations

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    The properties of perfect screw dislocations have been investigated for several zinc-blende materials such as diamond, Si, β\beta-SiC, Ge and GaAs, by performing first principles calculations. For almost all elements, a core configuration belonging to shuffle set planes is favored, in agreement with low temperature experiments. Only for diamond, a glide configuration has the lowest defect energy, thanks to an sp2^2 hybridization in the core

    Comparison between classical potentials and ab initio for silicon under large shear

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    The homogeneous shear of the {111} planes along the direction of bulk silicon has been investigated using ab initio techniques, to better understand the strain properties of both shuffle and glide set planes. Similar calculations have been done with three empirical potentials, Stillinger-Weber, Tersoff and EDIP, in order to find the one giving the best results under large shear strains. The generalized stacking fault energies have also been calculated with these potentials to complement this study. It turns out that the Stillinger-Weber potential better reproduces the ab initio results, for the smoothness and the amplitude of the energy variation as well as the localization of shear in the shuffle set

    Multi-tasking Sulf1/Sulf2 enzymes do not only facilitate extracellular cell signalling but also participate in cell cycle related nuclear events

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    This study demonstrates highly dynamic spatial and temporal pattern of SULF1/SULF2 expression in a number of neuronal cell types growing in normal culture medium that included their transient nuclear mobilisation. Their nuclear translocation became particularly apparent during cell proliferation as both SULF1/SULF2 demonstrated not only cell membrane associated expression, their known site of function but also transient nuclear mobilisation during nuclear cell division. Nuclear localisation was apparent not only by immunocytochemical staining but also confirmed by immunoblotting staining of isolated nuclear fractions of C6, U87 and N2A cells. Immunocytochemical analysis demonstrated rapid nuclear exit of both SULF1/SULF2 following cell division that was slightly delayed but not blocked in a fraction of the polyploid cells observed in C6 cells. The overexpression of both Sulf1 and Sulf2 genes in C6 and U87 cells markedly promoted in vitro growth of these cells accompanied by nuclear mobilisation while inhibition of both these genes inhibited cell proliferation with little or no nuclear SULF1/SULF2 mobilisation. SULF1/SULF2 activity in these cells thus demonstrated a clear co-ordination of extracellular cell signalling with nuclear events related to cell proliferation

    Traumatic brain injury patients: does frontal brain lesion influence basic emotion recognition?

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    Adequate emotion recognition is relevant to individuals' interpersonal communication. Patients with frontal traumatic brain injury (TBI) exhibit a lower response to facial emotional stimuli, influencing social interactions. In this sense, the main goal of the current study was to assess the ability of TBI patients in recognising basic emotions. Photographs of facial expressions of five basic emotions (happiness, sadness, fear, anger, and surprise) were presented to 32 TBI patients and 41 healthy controls. Emotion recognition was measured by accuracy and reaction time. Overall performance of the TBI group was poorer than control group for emotion recognition, both in terms of accuracy and reaction time. It is suggested that TBI patients show impairment on emotion recognition, and this relation seems to be moderated by the lesion localization

    Changes in social emotion recognition following traumatic frontal lobe injury

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    WOS:000299915100004Changes in social and emotional behaviour have been consistently observed in patients with traumatic brain injury. These changes are associated with emotion recognition deficits which represent one of the major barriers to a successful familiar and social reintegration. In the present study, 32 patients with traumatic brain injury, involving the frontal lobe, and 41 age- and education-matched healthy controls were analyzed. A Go/No-Go task was designed, where each participant had to recognize faces representing three social emotions (arrogance, guilt and jealousy). Results suggested that ability to recognize two social emotions (arrogance and jealousy) was significantly reduced in patients with traumatic brain injury, indicating frontal lesion can reduce emotion recognition ability. In addition, the analysis of the results for hemispheric lesion location (right, left or bilateral) suggested the bilateral lesion sub-group showed a lower accuracy on all social emotions
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