Linear Transmission of Composite Gaussian Measurements over a Fading Channel under Delay Constraints

Delay constrained linear transmission (LT) strategies are considered for the transmission of composite Gaussian measurements over an additive white Gaussian noise fading channel under an average power constraint. If the channel state information (CSI) is known by both the encoder and decoder, the optimal LT scheme in terms of the average mean-square error distortion is characterized under a strict delay constraint, and a graphical interpretation of the optimal power allocation strategy is presented. Then, for general delay constraints, two LT strategies are proposed based on the solution to a particular multiple measurements-parallel channels scenario. It is shown that the distortion decreases as the delay constraint is relaxed, and when the delay constraint is completely removed, both strategies achieve the optimal performance under certain matching conditions. If the CSI is known only by the decoder, the optimal LT strategy is derived under a strict delay constraint. The extension to general delay constraints is elusive. As a first step towards understanding the structure of the optimal scheme in this case, it is shown that for the multiple measurementsparallel channels scenario, any LT scheme that uses only a oneto-one linear mapping between measurements and channels is suboptimal in general

Compound Multiple Access Channels with Partial Cooperation

A two-user discrete memoryless compound multiple access channel with a common message and conferencing decoders is considered. The capacity region is characterized in the special cases of physically degraded channels and unidirectional cooperation, and achievable rate regions are provided for the general case. The results are then extended to the corresponding Gaussian model. In the Gaussian setup, the provided achievable rates are shown to lie within some constant number of bits from the boundary of the capacity region in several special cases. An alternative model, in which the encoders are connected by conferencing links rather than having a common message, is studied as well, and the capacity region for this model is also determined for the cases of physically degraded channels and unidirectional cooperation. Numerical results are also provided to obtain insights about the potential gains of conferencing at the decoders and encoders.Comment: Submitted to IEEE Transactions on Information Theor

Relaying Simultaneous Multicast Messages

The problem of multicasting multiple messages with the help of a relay, which may also have an independent message of its own to multicast, is considered. As a first step to address this general model, referred to as the compound multiple access channel with a relay (cMACr), the capacity region of the multiple access channel with a "cognitive" relay is characterized, including the cases of partial and rate-limited cognition. Achievable rate regions for the cMACr model are then presented based on decode-and-forward (DF) and compress-and-forward (CF) relaying strategies. Moreover, an outer bound is derived for the special case in which each transmitter has a direct link to one of the receivers while the connection to the other receiver is enabled only through the relay terminal. Numerical results for the Gaussian channel are also provided.Comment: This paper was presented at the IEEE Information Theory Workshop, Volos, Greece, June 200

Anti-fungal bandages containing cinnamon extract

© 2019 The Authors. International Wound Journal published by Medicalhelplines.com Inc and John Wiley & Sons Ltd.Cinnamon-containing polycaprolactone (PCL) bandages were produced by pressurised gyration and their anti-fungal activities against Candida albicans were investigated. It was found that by preparing and spinning polymer solutions of cinnamon with PCL, fibres capable of inhibiting fungal growth could be produced, as observed in disk diffusion tests for anti-fungal susceptibility. Fascinatingly, compared with raw cinnamon powder, the novel cinnamon-loaded fibres had outstanding long-term activity. The results presented here are very promising and may indeed accelerate a new era of using completely natural materials in biomedical applications, especially in wound healing.Peer reviewe

Privacy-cost trade-offs in demand-side management with storage

Demand-side energy management (EM) is studied from a privacy-cost trade-off perspective, considering time-of-use pricing and the presence of an energy storage unit. Privacy i s measured as the variation of the power withdrawn from the gri d from a fixed target value. Assuming non-causal knowledge of t he household’s aggregate power demand profile and the electric ity prices at the energy management unit (EMU), the privacy-cos t trade-off is formulated as a convex optimization problem, a nd a low-complexity backward water-filling algorithm is proposed to compute the optimal EM policy. The problem is studied also in the online setting assuming that the power demand profile is known to the EMU only causally, and the optimal EM policy is obtained numerically through dynamic programming (DP). Du e to the high computational cost of DP, a low-complexity heuri stic EM policy with a performance close to the optimal online solu tion is also proposed, exploiting the water-filling algorithm ob tained in the offline setting. As an alternative, information theor etic leakage rate is also evaluated, and shown to follow a similar trend as the load variance, which supports the validity of th e load variance as a measure of privacy. Finally, the privacy- cost trade-off, and the impact of the size of the storage unit on th is trade-off are studied through numerical simulations using real smart meter data in both the offline and online settings

Accuracy-awareness: A pessimistic approach to optimal control of triggered mobile communication networks

We use nonlinear model predictive control to procure a joint control of mobility and transmission to minimize total network communication energy use. The nonlinear optimization problem is solved numerically in a self-triggered framework, where the next control update time depends on the predicted state trajectory and the accuracy of the numerical solution. Solution accuracy must be accounted for in any circumstance where systems are run in open-loop for long stretches of time based on potentially inaccurate predictions. These triggering conditions allow us to place wireless nodes in low energy ‘idle' states for extended periods, saving over 70% of energy compared to a periodic policy where nodes consistently use energy to receive control updates

Hierarchical Over-the-Air Federated Edge Learning

Federated learning (FL) over wireless communication channels, specifically, over-the-air (OTA) model aggregation framework is considered. In OTA wireless setups, the adverse channel effects can be alleviated by increasing the number of receive antennas at the parameter server (PS), which performs model aggregation. However, the performance of OTA FL is severely limited by the presence of mobile users (MUs) located far away from the PS. In this paper, to mitigate this limitation, we propose hierarchical over-the-air federated learning (HOTAFL), which utilizes intermediary servers (IS) to form clusters near MUs. We provide a convergence analysis for the proposed setup, and demonstrate through experimental results that local aggregation in each cluster before global aggregation leads to a better performance and faster convergence than OTA FL

Atmospheric Dispersion Patterns of Radionuclides Originating from Nuclear Power Plant Accidents under Various Release Types

Nuclear power has begun to lose its popularity after the major catastrophes of Chernobyl and Fukushima that caused a global environmental and public health problem. Radioactivity released from these accidents spread all around the world and negatively influenced large areas as a result of different meteorological conditions prevailing at the time of the accidents. Another particularly important parameter used in assessing the atmospheric dispersion of radioactivity is the characteristics of the source term that defines the release pattern of radionuclides from the accident site. Core inventory and shape and extent of the release define the source term to be used in simulating the dispersion pattern of radioactivity. Thus, mathematical representation of the source term is a crucial part of the dispersion modeling of radionuclides. Ideal types of releases (such as pulse, step, linear, sinusoidal) can occur in an accident or a combination of these types can constitute the real pattern of the release from the accident’s source. The mathematical character of the release is influential in the overall dispersion and deposition of radioactivity. Based on this premise, this study is conducted to assess the possible differences in the spatial distribution of dispersed and deposited radionuclides that can originate from a potential accident in Akkuyu nuclear power plant (NPP) in the southern Mediterranean coast of Turkey. Simulations are performed with FLEXPART model to predict the atmospheric dispersion and ground level depositions of radionuclides to be released from a hypothetical accident in Akkuyu under various release patterns and different meteorological conditions representing extreme conditions. Model simulations considered a 10-day release duration with distinct release patterns under extreme meteorological conditions for the site. A comparative assessment is then conducted to evaluate the extent and magnitude of Cs-137 dispersion and deposition, which is the most commonly used radionuclide in NPP accident simulations

A new method for fabrication of nanohydroxyapatite and TCP from the sea snail Cerithium vulgatum

Biphasic bioceramic nanopowders of hydroxyapatite (HA) and β-tricalcium phosphate (TCP) were prepared from shells of the sea snail Cerithium vulgatum (Bruguière, 1792) using a novel chemical method. Calcination of the powders produced was carried out at varying temperatures, specifically at 400°C and 800°C, in air for 4 hours. When compared to the conventional hydrothermal transformation method, this chemical method is very simple, economic, due to the fact that it needs inexpensive and safe equipment, because the transformation of the aragonite and calcite of the shells into the calcium phosphate phases takes place at 80°C under the atmospheric pressure. The powders produced were determined using infrared spectroscopy (FT-IR), X-ray diffraction, and scanning electron microscopy (SEM). The features of the powders produced along with the fact of their biological origin qualify these powders for further consideration and experimentation to fabricate nanoceramic biomaterials. © 2014 O. Gunduz et al

Saving Lives: The Principle of Distinction and the Realities of Modern War

WOS: 000332942700005PubMed ID: 24778561In this study, we assessed the feasibility of fetal RhD genotyping by analysis of cell-free fetal DNA(cffDNA) extracted from plasma samples of Rhesus (Rh) D-negative pregnant women by using real-time polymerase chain reaction (PCR). Fetal genotyping was performed on 30 RhD-negative women between 9 and 39 weeks of gestation who were referred to us for invasive testing [amniocentesis/chorionic villi sampling (CVS)]. The fetal RHD genotype was determined based on real-time PCR method. Exons 7 and 10 of the RHD and SRY genes were targeted. Among the pregnant women, 12 were carrying male and 17 were carrying female fetuses. Out of 29 pregnant women, 21 had RhD-positive and nine had RhD-negative fetuses. One sample) case 12, whose blood group was found to be AB Rh [+] (was excluded due to controversial results from repeated serological analyses. All prenatal results were in concordance with postnatal RhD status and fetal sex without false-positive or -negative results. Performing real-time PCR on cffDNA showed accurate, efficient and reliable results, allowing rapid and high throughput non invasive determination of fetal sex and RhD status in clinical samples