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861.
This paper targets mobile telemedicine applications that can be supported using third generation (3G) cellular networks, to provide highly flexible medical services. On the other hand, large-scale Ad hoc Sensor Networks (ASN), when deployed among mobile patients who may carry different kinds of micro-sensors to measure ECG, blood pressure, basal temperature or other physiological data, can provide a dynamic data query architecture to allow the medical specialists to monitor patients at any place. So far very little research has been conducted to explore the possibility of integrating ASN with mobile telemedicine. In this paper: 1. we suggest an integrated architecture that takes advantage of the low cost mobile sensor networks and 3G cellular networks to support multimedia medical calls with differentiated Quality-of-Service (QoS) requirements. 2. We propose a low-energy, distributed, concentric-zone-based data query mechanism that has the advantages of both proactive and reactive ad hoc routing algorithms to collect medical results from large-scale mobile patients for medical specialists who use cellular network to report patient data to the medical center. 3. In order to minimize the ambulance wireless call-dropping rate, we adopt accurate resource reservation call admission control (CAC) scheme to allocate the necessary bandwidth in the destination cell. 4. In order to meet the QoS requirements of patients’ wireless calls, we use dynamic guard channel CAC scheme to keep their handoff-call dropping rate below a certain threshold. We evaluate the validity of our schemes through simulations and analyze their performance. Our results clearly indicate the efficiency of the proposed CAC and sensor network query algorithms to meet the multimedia telemedicine QoS requirements. 相似文献
862.
Jaechul Park Changjung Kim Sunil Kim Ihun Song Sangwook Kim Donghun Kang Hyuck Lim Huaxiang Yin Ranju Jung Eunha Lee Jaecheol Lee Kee-Won Kwon Youngsoo Park 《Electron Device Letters, IEEE》2008,29(8):879-881
In this letter, we investigated the effects of source/drain series resistance on amorphous gallium-indium-doped zinc-oxide (a-GIZO) thin film transistors (TFTs). A linear least square fit of a plot of the reciprocal of channel resistance versus gate voltage yields a threshold voltage of 3.5 V and a field-effect mobility of about 13.5 cm2/Vldrs. Furthermore, in a-GIZO TFTs, most of the current flows in the distance range of 0-0.5 mum from the channel edge and shorter than that in a-Si:H TFTs. Moreover, unlike a-Si:H TFTs, a-GIZO TFTs did not show an intersection point, because they did not contain a highly doped ohmic (n+) layer below the source/drain electrodes. 相似文献
863.
K. Sunil Babu A. Venkateswara Rao P. V. V. Kishore P. Pardhasaradhi B. T. P. Madhav 《Phase Transitions》2017,90(3):244-255
Synthesis and the characterization through polarizing optical microscope (POM) textures in number of 4-hexyloxy benzylidene 4’-alkoxyanilines, 6O.Om with m = 4, 6 to 10 liquid crystalline materials are carried out. Furthermore, the density and thermal expansion coefficient results reveal that the phase transitions present, viz., isotropic–nematic, nematic–SmC and SmC–SmI show first-order nature as expected. The transition temperatures obtained thorough the differential scanning calorimetry is found to be in agreement with the literature data. The first two compounds exhibit only the nematic phase while the next four compounds show enantiotropic SmC phase as per the literature data. The compound with m = 10 exhibits monotropic SmI phase. However, we, the authors, are able to observe this phase in addition to SmC and nematic through POM only as per the literature. The parameters calculated across the phase transitions and in the phases are in agreement with the body of the data available. 相似文献
864.
The intention of this study is to explore the thermoluminescence properties of beta-irradiated Li–Zn fluoroborate glass. The glow-curve corresponding to 10?Gy shows two peaks when measured at 1°C/s. The dose response of the glass to beta irradiation was investigated. The trapping level parameters such as activation energy, frequency factor and order of kinetics associated with the observed glow-peak were determined using different methods. The thermoluminescence is affected by thermal quenching. A possible mechanism for the thermoluminescence is described. 相似文献
865.
We investigate the multifractal properties of the logarithmic returns of the Indian financial indices (BSE & NSE) by applying the multifractal detrended fluctuation analysis. The results are compared with that of the US S&P 500 index. Numerically we find that qth-order generalized Hurst exponents h(q) and τ(q) change with the moments q. The nonlinear dependence of these scaling exponents and the singularity spectrum f(α) show that the returns possess multifractality. By comparing the MF-DFA results of the original series to those for the shuffled series, we find that the multifractality is due to the contributions of long-range correlations as well as the broad probability density function. The financial markets studied here are compared with the Binomial Multifractal Model (BMFM) and have a smaller multifractal strength than the BMFM. 相似文献
866.
An experimental investigation is conducted to bring out the effects of coolant injector configuration on film cooling effectiveness,
film cooled length and film uniformity associated with gaseous and liquid coolants. A series of measurements are performed
using hot air as the core gas and gaseous nitrogen and water as the film coolants in a cylindrical test section simulating
a thrust chamber. Straight and compound angle injection at two different configurations of 30°–10° and 45°–10° are investigated
for the gaseous coolant. Tangential injection at 30° and compound angle injection at 30°–10° are examined for the liquid coolant.
The analysis is based on measurements of the film-cooling effectiveness and film uniformity downstream of the injection location
at different blowing ratios. Measured results showed that compound angle configuration leads to lower far-field effectiveness
and shorter film length compared to tangential injection in the case of liquid film cooling. For similar injector configurations,
effectiveness along the stream wise direction showed flat characteristics initially for the liquid coolant, while it was continuously
dropping for the gaseous coolant. For liquid coolant, deviations in temperature around the circumference are very low near
the injection point, but increases to higher values for regions away from the coolant injection locations. The study brings
out the existance of an optimum gaseous film coolant injector configuration for which the effectiveness is maximum. 相似文献
867.
A Nonlinear Stability Analysis for Thermoconvective Magnetized Ferrofluid Saturating a Porous Medium
The generalized energy method is developed to study the nonlinear stability analysis for a magnetized ferrofluid layer heated
from below saturating a porous medium, in the stress-free boundary case. The mathematical emphasis is on how to control the
nonlinear terms caused by magnetic body force. By introducing a suitable generalized energy functional, we perform a nonlinear
energy stability (conditional) analysis. It is found that the nonlinear critical stability magnetic thermal Rayleigh number
does not coincide with that of linear instability analysis, and thus indicates that the subcritical instabilities are possible.
However, it is noted that, in case of non-ferrofluid, global nonlinear stability Rayleigh number is exactly the same as that
for linear instability. For lower values of magnetic parameters, this coincidence is immediately lost. The effect of magnetic
parameter, M
3, and medium permeability, Da, on subcritical instability region has also been analyzed. It is shown that with the increase of magnetic parameter (M
3) and Darcy number (Da), the subcritical instability region between the two theories decreases quickly. We also demonstrate coupling between the
buoyancy and magnetic forces in nonlinear energy stability analysis as well as in linear instability analysis. 相似文献
868.
Fei Hu Yamin Malkawi Sunil Kumar Yang Xiao 《Wireless Communications and Mobile Computing》2008,8(9):1165-1181
Underwater Acoustic Networks (UANs) have important applications in ocean exploration and lake pollution monitoring. UANs are however different from terrestrial sensor networks due to their highly variable, long propagation delay, and mobility. Clock synchronization is an important protocol to achieve timing‐based sensor communications. In this paper, we propose a three dimensional, scalable UAN time synchronization scheme that can achieve both horizontal (i.e., in the same water depth) and vertical (i.e., from bottom up to the surface) clock synchronization to overcome the effects of long acoustic delay. To secure UAN clock synchronization services, we also propose a two‐step security UAN synchronization model: (1) correlation test and (2) statistical reputation and trust model. The proposed model can detect outlier timestamp data and identify nodes generating insider attacks. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
869.
870.
A three-component highly regio- and diastereoselective 1,3-dipolar cycloaddition reaction between isatin, a series of primary amino acids (10 nos), and exocyclic α,β-unsaturated ketones was developed towards the synthesis of a small library of bispirooxindole (20 nos) at ambient temperature. The developed reaction afforded highly substituted 3,2′-pyrrolidine-bispirooxindole with two vicinal spiro-quaternary and four contiguous stereocenters from the cheap and abundant starting materials. The products were obtained with good to excellent yields (50–95%) and as a single diastereoisomer in the majority of the cases. Primary amino acids were served as amine component for the in-situ generation of azomethine ylides from isatin. Molecular docking studies were carried out to explore the synthesized bispirooxindoles as inhibitors of the epidermal growth factor receptor (EGFR). Two compounds exhibited excellent binding affinity towards EGFR receptor. 相似文献