1,391 research outputs found
Resource Allocation in a MAC with and without security via Game Theoretic Learning
In this paper a -user fading multiple access channel with and without
security constraints is studied. First we consider a F-MAC without the security
constraints. Under the assumption of individual CSI of users, we propose the
problem of power allocation as a stochastic game when the receiver sends an ACK
or a NACK depending on whether it was able to decode the message or not. We
have used Multiplicative weight no-regret algorithm to obtain a Coarse
Correlated Equilibrium (CCE). Then we consider the case when the users can
decode ACK/NACK of each other. In this scenario we provide an algorithm to
maximize the weighted sum-utility of all the users and obtain a Pareto optimal
point. PP is socially optimal but may be unfair to individual users. Next we
consider the case where the users can cooperate with each other so as to
disagree with the policy which will be unfair to individual user. We then
obtain a Nash bargaining solution, which in addition to being Pareto optimal,
is also fair to each user.
Next we study a -user fading multiple access wiretap Channel with CSI of
Eve available to the users. We use the previous algorithms to obtain a CCE, PP
and a NBS.
Next we consider the case where each user does not know the CSI of Eve but
only its distribution. In that case we use secrecy outage as the criterion for
the receiver to send an ACK or a NACK. Here also we use the previous algorithms
to obtain a CCE, PP or a NBS. Finally we show that our algorithms can be
extended to the case where a user can transmit at different rates. At the end
we provide a few examples to compute different solutions and compare them under
different CSI scenarios.Comment: 27 pages, 12 figures. Part of the paper was presented in 2016 IEEE
Information theory and applicaitons (ITA) Workshop, San Diego, USA in Feb.
2016. Submitted to journa
Previous Messages Provide the Key to Achieve Shannon Capacity in a Wiretap Channel
We consider a wiretap channel and use previously transmitted messages to
generate a secret key which increases the secrecy capacity. This can be
bootstrapped to increase the secrecy capacity to the Shannon capacity without
using any feedback or extra channel while retaining the strong secrecy of the
wiretap channel.Comment: Accepted for IEEE International Conference on Communications Workshop
(ICC) 2013, Budapest, Hungary. arXiv admin note: text overlap with
arXiv:1404.570
Life Testing Analysis of Failure Censored Generalized Exponentiated Data
A generalized exponential distribution is considered for analyzing lifetime data; such statistical models are applicable when the observations are available in an ordered manner. This study examines failure censored data, which consist of testing n items and terminating the experiment when a pre-assigned number of items, for example r ( \u3c n), have failed. Due to scale and shape parameters, both have flexibility for analyzing different types of lifetime data. This distribution has increasing, decreasing and a constant hazard rate depending on the shape parameter. This study provides maximum likelihood estimation and uniformly minimum variance unbiased techniques for the estimation of reliability of a component. Numerical computation was conducted on a data set and a comparison of the performance of two different techniques is presented
Post-collisional polycyclic plutonism from the Zagros hinterland: the Shaivar Dagh plutonic complex, Alborz belt, Iran
The petrological and geochronological study of the Cenozoic Shaivar Dagh composite intrusion in the Alborz Mountain belt (NW Iran) reveals important clues to decipher complex relations between magmatic and tectonic processes in the central sectors of the Tethyan (Alpine-Himalayan) orogenic belt. This pluton is formed by intrusion at different times of two main magmatic cycles. The older (Cycle 1) is formed by calc-alkaline silicic rocks, which range in composition from diorites to granodiorites and biotite granites, with abundant mafic microgranular enclaves. The younger cycle (Cycle 2) is formed by K-rich monzodiorite and monzonite of marked shoshonitic affinity. The latter form the larger volumes of the exposed plutonic rocks in the studied complex. Zircon geochronology (laser ablation ICP-MS analyses) gives a concordia age of 30.8 ± 2.1 Ma for the calc-alkaline rocks (Cycle 1) and a range from 23.3 ± 0.5 to 25.1 ± 0.9 Ma for the shoshonitic association (Cycle 2). Major and trace element relations strongly support distinct origins for each magmatic cycle. Rocks of Cycle 1 have all the characteristic features of active continental margins. Shoshonitic rocks (Cycle 2) define two continuous fractionation trends: one departing from a K-rich basaltic composition and the other from an intermediate, K-rich composition. A metasomatized-mantle origin for the two shoshonitic series of Cycle 2 is proposed on the basis of comparisons with experimental data. The origin of the calc-alkaline series is more controversial but it can be attributed to processes in the suprasubduction mantle wedge related to the incorporation of subducted mélanges in the form of silicic cold plumes. A time sequence can be established for the processes responsible of the generation of the two magmatic cycles: first a calc-alkaline cycle typical of active continental margins, and second a K-rich cycle formed by monzonites and monzodiorites. This sequence precludes the younger potassic magmas as precursors of the older calc-alkaline series. By contrast, the older calc-alkaline magmas may represent the metasomatic agents that modified the mantle wedge during the last stages of subduction and cooked a fertile mantle region for late potassic magmatism after continental collisio
Study on the growth and survival of Channa striatus (Bloch) postlarvae using live feed
Feeding experiments were conducted on the postlarvae of Channa striatus with two different live feeds - a copepod (Thermocyclops decipiens) and cladocerans (Moina micrura and Ceriodaphnia comuta) individually and in mixture. Food was provided at the rate of (500±50 Ind/L) and the experiments were carried out in 100 litre capacity tanks for 30 days. Results indicated better weight gain (951.85±28.77%) and survival (92.00<%) of postlarvae fed with mixed live food than individual live feed organisms
Effect of Altitudes on Soil and Vegetation Characteristics of Pinus Roxburghii Forest in Garhwal Himalaya
The present study was conducted in Pinus roxburghii forest in the District Tehri Garhwal of Uttarakhand State to assess the soil properties, forest species composition and volume along altitudinal gradients. The study revealed that the moisture content and water holding capacity of soil increased with increasing altitudes while bulk density (BD) reduced with increasing altitude. The higher proportion of soil texture was contributed of sand > clay > silt in each altitude. The soil pH of entire forest was acidic in nature. The soil organic carbon (SOC) and nitrogen increased with increasing altitude. Phosphorus and potassium has not shown any trend with altitude. The associated shrubs in Pinus roxburghii forest were Rhus parviflora, Carissa opaca, Berberis aristata, Lantana camara and Rubus ellipticus. The highest and lowest density of P. roxburghii was recorded in top and middle altitude respectively. The total basal cover (TBC) and volume of P. roxburghii was reduced with increasing altitude
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