We investigate the performance of a network coding based secondary network in a cognitive radio system under spectrum sharing constraints. The secondary network is composed of two users that cooperate to transmit thei...
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ISBN:
(纸本)9781479946037
We investigate the performance of a network coding based secondary network in a cognitive radio system under spectrum sharing constraints. The secondary network is composed of two users that cooperate to transmit their information to a common secondary destination. The outage probability is analyzed under a given maximum interference constraint set by the primary network as well as to the maximum transmit power limit of the secondary users. Theoretical and numerical results show that the adequate use of network coding by the secondary network can provide significant gains in terms of outage probability and diversity order when compared to non cooperative or traditional cooperative techniques.
The elders with dementia often have difficulties in daily activities because of declining cognitive ability. It has been recognized that context-aware reminding systems can assist those suffering from dementia. Remind...
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ISBN:
(纸本)9781424440085
The elders with dementia often have difficulties in daily activities because of declining cognitive ability. It has been recognized that context-aware reminding systems can assist those suffering from dementia. Reminding systems usually pre-define activities into a plan and prompt the elders if they jail to execute it. However, in real life, people sometimes ignore the plan and choose to do other urgent disruptive activities, that overlap with pre-planned ones. In this paper, we focus on the problem of how to handle the conflicts between pre-planned and real-time disruptive activities. We adopt a planning approach to describe the temporal constraints of daily activities, and define three disruptive activities in our reminding system. A context-aware reminding strategy is proposed, which handles the conflicts between pre-planned and disruptive activities. A simple software tool for caregivers is also presented in order to facilitate their interaction with the system.
One of the fundamental hypotheses the radiocarbon dating technique is based on is the fact that the sample to be dated has to be considered as a close system. However, when we would like to date a finding that has bee...
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In order to investigate the flow field and behavior of underexpanded impinging Jet oil a cone, the flow field is visualized by schlieren and shadowgraph method, and the pressure distribittions oil the cone are measure...
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ISBN:
(纸本)9780791842881
In order to investigate the flow field and behavior of underexpanded impinging Jet oil a cone, the flow field is visualized by schlieren and shadowgraph method, and the pressure distribittions oil the cone are measured A cone used for the experiment has a cone angle of 120 deg. The pressure ratio across the nozzle NPR, the ratio of stagnation to ambient pressure, is varied from 2.0 to 4.0 at the nozzle-cone distance non-dimensionalized by the nozzle diameter from 1. 0 to 3.5. The shape of the pressure distribution oil the wall has different types at different nozzle-cone distances. The visualized flow patterns show that the expansion regions and compression regions are present in the wall jet which cat? also be seen from the wavy distribution of the pressure. The plate shock, which forms in front of the cone, varies its geometry between flat type and bow type dependent upon nozzle-cone distance. The flat ope shock wave is obtained when it is in the expansion region of the jet and the bow type shock when in the compression region. This is qualitatively valid reggardless of NPR. When the nozzle-cone distance is short, the jet is very stable without any flow oscillation, while the oscillation occurs more violently as the nozzle-cone distance becomes larger. It is probably due to the more unstable nature of the jet boundary at distance further from the nozzle.
One hundred and sixteen species of Rotifera are recorded from seven floodplain lakes of the Brahmaputra basin (northeastern India), the highest rotifer biodiversity recorded from these biotopes in the Indian subcontin...
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One hundred and sixteen species of Rotifera are recorded from seven floodplain lakes of the Brahmaputra basin (northeastern India), the highest rotifer biodiversity recorded from these biotopes in the Indian subcontinent to date. The Australasian Brachionus dichotomus reductus and Lecane batillifer;the Oriental Keratella edmondsoni, Lecane blachei and L. acanthinula;the Palaeotropical Lecane braumi, L. lateralis, L. unguitata, Trichocerca tropis, Testudinella greeni and T. brevicaudata;the Pantropical Brachionus donneri and a rather widely distributed Horaella brehmi represent taxa of biogeographical interest. Three species are new additions to the Indian rotifer fauna and eight are new to the N.E. region. Lecanidae > Brachionidae = Colurellidae > Trichocercidae > Testudinellidae comprise the largest fraction (68.0%) of the examined fauna. Comments are made on the general nature and composition of the rotifer taxocoenosis as well as on acidophilic elements, ecology of various taxa and on the species richness of different lakes.
There is high demand for I/O tracing in High Performance Computing (HPC). It enables in-depth analysis of distributed applications and file system performance tuning. It also aids distributed application debugging. Fi...
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ISBN:
(纸本)9781595938992
There is high demand for I/O tracing in High Performance Computing (HPC). It enables in-depth analysis of distributed applications and file system performance tuning. It also aids distributed application debugging. Finally, it facilitates collaboration within and between government, industrial, and academic institutions by enabling the generation of replayable I/O traces, which can be easily distributed and anonymized as necessary to protect confidential or sensitive information. As a response to this demand for tracing tools, various means of I/O trace generation exist. We first survey the I/O Tracing Framework landscape, exploring three popular such frameworks: LANL-Trace [3], Tracefs [1], and //TRACE1 [2]. We next develop an I/O Tracing Framework taxonomy. The purpose of this taxonomy is to assist I/O Tracing Framework users in formalizing their tracing requirements, and to provide the developers of I/O Tracing Frameworks a language to categorize the functionality and performance of them. The taxonomy categorizes I/O Tracing Framework features such as the type of data captured, trace replay ability, and anonymization. The taxonomy also considers elapsed-time overhead and performance overhead. Finally, we provide a case study in the use of our new taxonomy, revisiting all three I/O Tracing Frameworks explored in our survey, to formally classify the features of each. Copyright 2007 ACM.
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