3,501 research outputs found
Decentralized Adaptive Helper Selection in Multi-channel P2P Streaming Systems
In Peer-to-Peer (P2P) multichannel live streaming, helper peers with surplus
bandwidth resources act as micro-servers to compensate the server deficiencies
in balancing the resources between different channel overlays. With deployment
of helper level between server and peers, optimizing the user/helper topology
becomes a challenging task since applying well-known reciprocity-based choking
algorithms is impossible due to the one-directional nature of video streaming
from helpers to users. Because of selfish behavior of peers and lack of central
authority among them, selection of helpers requires coordination. In this
paper, we design a distributed online helper selection mechanism which is
adaptable to supply and demand pattern of various video channels. Our solution
for strategic peers' exploitation from the shared resources of helpers is to
guarantee the convergence to correlated equilibria (CE) among the helper
selection strategies. Online convergence to the set of CE is achieved through
the regret-tracking algorithm which tracks the equilibrium in the presence of
stochastic dynamics of helpers' bandwidth. The resulting CE can help us select
proper cooperation policies. Simulation results demonstrate that our algorithm
achieves good convergence, load distribution on helpers and sustainable
streaming rates for peers
Remote probing of inhomogeneous media using parameter optimization techniques
Remote probing of inhomogeneous media using parameter optimization technique
Dissolution enhancement of gliclazide using pH change approach in presence of twelve stabilizers with various physico-chemical properties
Purpose. The micronization using milling process to enhance dissolution rate is extremely inefficient due to a high energy input, and disruptions in the crystal lattice which can cause physical or chemical instability. Therefore, the aim of the present study is to use in situ micronization process through pH change method to produce micron-size gliclazide particles for fast dissolution hence better bioavailability. Methods. Gliclazide was recrystallized in presence of 12 different stabilizers and the effects of each stabilizer on micromeritic behaviors, morphology of microcrystals, dissolution rate and solid state of recrystallized drug particles were investigated. Results. The results showed that recrystallized samples showed faster dissolution rate than untreated gliclazide particles and the fastest dissolution rate was observed for the samples recrystallized in presence of PEG 1500. Some of the recrystallized drug samples in presence of stabilizers dissolved 100% within the first 5 min showing at least 10 times greater dissolution rate than the dissolution rate of untreated gliclazide powders. Micromeritic studies showed that in situ micronization technique via pH change method is able to produce smaller particle size with a high surface area. The results also showed that the type of stabilizer had significant impact on morphology of recrystallized drug particles. The untreated gliclazide is rod or rectangular shape, whereas the crystals produced in presence of stabilizers, depending on the type of stabilizer, were very fine particles with irregular, cubic, rectangular, granular and spherical/modular shape. The results showed that crystallization of gliclazide in presence of stabilizers reduced the crystallinity of the samples as confirmed by XRPD and DSC results. Conclusion. In situ micronization of gliclazide through pH change method can successfully be used to produce micron-sized drug particles to enhance dissolution rate
The effect of individual counseling, line follow-up, and free nicotine replacement therapy on smoking cessation in the samples of Iranian smokers: Examination of transtheoretical model
Background: According to transtheoretical model(TTM), Stage matched interventions are more effective in quitting. The objective of current study was to investigate the effect of individual counseling, line follow-up, and free nicotine replacement therapy(NRT) on smoking cessation in smokers who are in preparation stage of smoking. Materials and Methods: In a randomized clinical trial design, through sending the short message system, potential participants in preparation stage of smoking were recruited and divided into control(n=60)and treatment(n=50) groups. The treatment group received an in-person counseling, line follow-up, and free NRT. TTM variables trend; pros and cons of smoking, behavioral and experiential processes, temptation, were assessed at baseline, 3 and 6months follow-up along with point prevalence and continuous abstinence. Results: Continuous abstinence at 6-month follow-up were 3.3%(n=2) in control group and 46%(n=23) in the treatment group(x 2 = 34.041, P < 0.001). Time � group analyses indicated that except cons of smoking (P > 0.05), all TTM constructs had significantly changed; temptation(F=36.864, P<0.001), pros (F=12.172, P<0.001), experiential processes(F=3.377, P<0.001), and behavioral processes(F=11.131, P<0.001). Conclusion: Interventions based on TTM variables increased the quite rate in prepared and motivated people. Our findings suggest that interventions through individual counseling along with free NRT and line follow-up in people who prepare for quitting are beneficial for our country
Defining technology strategy in state water and sewage engineering company :A case study in water and sewage company, Hamedan Province
Successful strategy definition depends on adapting the sources available to the organization and the opportunities in the environment. A great step is to know the internal waek and strong points, opportunities and outer threats in defining the strategy. Technology presents new dimensions to business view in a way that the organizations benefiting from a defined business try to put into operation a defined technology strategy in their organization, too; such strategy helps the organizations to select appropriate technology and enjoy it effectively. So, this study is to define the most appropriate technology strategy for water and sewage company, Hamedan. This article tries to define technology strategy for water and sewage company, Hamedan by Hex and Mosely model
Enhancing Transport in Classical and Quantum Systems Using Non-Hermiticity
Non-Hermiticity, the presence of gain and loss in the structures, provides a flexible platform to utilize the wave propagation in classical and quantum system. Here in this thesis by using this advantage we aim to enhance the transport in both realms
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