207 research outputs found
Energy-saving Resource Allocation by Exploiting the Context Information
Improving energy efficiency of wireless systems by exploiting the context
information has received attention recently as the smart phone market keeps
expanding. In this paper, we devise energy-saving resource allocation policy
for multiple base stations serving non-real-time traffic by exploiting three
levels of context information, where the background traffic is assumed to
occupy partial resources. Based on the solution from a total energy
minimization problem with perfect future information,a context-aware BS
sleeping, scheduling and power allocation policy is proposed by estimating the
required future information with three levels of context information.
Simulation results show that our policy provides significant gains over those
without exploiting any context information. Moreover, it is seen that different
levels of context information play different roles in saving energy and
reducing outage in transmission.Comment: To be presented at IEEE PIMRC 2015, Hong Kong. This work was
supported by National Natural Science Foundation of China under Grant
61120106002 and National Basic Research Program of China under Grant
2012CB31600
Bandwidth efficient multi-station wireless streaming based on complete complementary sequences
Data streaming from multiple base stations to a client is recognized as a robust technique for multimedia streaming. However the resulting transmission in parallel over wireless channels poses serious challenges, especially multiple access interference, multipath fading, noise effects and synchronization. Spread spectrum techniques seem the obvious choice to mitigate these effects, but at the cost of increased bandwidth requirements. This paper proposes a solution that exploits complete complementary spectrum spreading and data compression techniques jointly to resolve the communication challenges whilst ensuring efficient use of spectrum and acceptable bit error rate. Our proposed spreading scheme reduces the required transmission bandwidth by exploiting correlation among information present at multiple base stations. Results obtained show 1.75 Mchip/sec (or 25%) reduction in transmission rate, with only up to 6 dB loss in frequency-selective channel compared to a straightforward solution based solely on complete complementary spectrum spreading
Near-capacity dirty-paper code design : a source-channel coding approach
This paper examines near-capacity dirty-paper code designs based on source-channel coding. We first point out that the performance loss in signal-to-noise ratio (SNR) in our code designs can be broken into the sum of the packing loss from channel coding and a modulo loss, which is a function of the granular loss from source coding and the target dirty-paper coding rate (or SNR). We then examine practical designs by combining trellis-coded quantization (TCQ) with both systematic and nonsystematic irregular repeat-accumulate (IRA) codes. Like previous approaches, we exploit the extrinsic information transfer (EXIT) chart technique for capacity-approaching IRA code design; but unlike previous approaches, we emphasize the role of strong source coding to achieve as much granular gain as possible using TCQ. Instead of systematic doping, we employ two relatively shifted TCQ codebooks, where the shift is optimized (via tuning the EXIT charts) to facilitate the IRA code design. Our designs synergistically combine TCQ with IRA codes so that they work together as well as they do individually. By bringing together TCQ (the best quantizer from the source coding community) and EXIT chart-based IRA code designs (the best from the channel coding community), we are able to approach the theoretical limit of dirty-paper coding. For example, at 0.25 bit per symbol (b/s), our best code design (with 2048-state TCQ) performs only 0.630 dB away from the Shannon capacity
Efficient video identification based on locality sensitive hashing and triangle inequality
Master'sMASTER OF SCIENC
Oiling-out Crystallization of Beta-Alanine onSolid Surfaces Controlled by Solvent Exchange
Droplet formation in oiling-out crystallization has important implication for
separation and purification of pharmaceutical active ingredients by using an
antisolvent. In this work, we report the crystallization processes of
oiling-out droplets on surfaces during solvent exchange. Our model ternary
solution is beta-alanine dissolved in isopropanol and water mixture. As the
antisolvent isopropanol displaced the alanine solution pre-filled in a
microchamber, liquid-liquid phase separation occurred at the mixing front. The
alanine-rich subphase formed surface microdroplets that subsequently
crystallized with progression of solvent exchange. We find that the flow rates
have significant influence on the droplet size, crystallization process, and
growth rate, and final morphology of the crystals. At fast flow rates the
droplets solidified rapidly and formed spherical-cap structures resembling the
shape of droplets, in contrast to crystal microdomains or thin films formed at
slow flow rates. On a highly hydrophilic surface, the crystals formed thin film
without droplets formed on the surface. We further demonstrated that by the
solvent exchange crystals can be formed by using a stock solution with a very
low concentration of the precursor, and the as-prepared crystals can be used as
seeds to trigger crystallization in bulk solution. Our results suggest that the
solvent exchange has the potential to be an effective approach for controlling
oiling-out crystallization, which can be applied in wide areas, such as
separation and purification of many food, medical, and therapeutic ingredients.Comment: Advanced Materials Interfaces (2020
Proteins Identified from Saliva and Salivary Glands of the Chinese Gall Aphid Schlechtendalia chinensis
Aphid saliva plays an essential role in the interaction between aphids and
their host plants. Several aphid salivary proteins have been identified but
none from galling aphids. Here the salivary proteins from the Chinese gall
aphid are analyzed, Schlechtendalia chinensis, via an LC-MS/MS analysis.
A total of 31 proteins are identified directly from saliva collected via an
artificial diet, and 141 proteins are identified from extracts derived from
dissected salivary glands. Among these identified proteins, 17 are found in
both collected saliva and dissected salivary glands. In comparison with
salivary proteins from ten other free-living Hemipterans, the most striking
feature of the salivary protein from S. chinensis is the existence of high
proportion of proteins with binding activity, including DNA-, protein-, ATP-,
and iron-binding proteins. These proteins maybe involved in gall formation.
These results provide a framework for future research to elucidate the
molecular basis for gall induction by galling aphids
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