Sharif Digital Repository

This paper proposes a family of interleaved DC-DC converters for high step-up applications based on multi-winding coupled inductors, which utilize inductive and capacitive approaches to transfer the input energy to the output load. The wide output load voltage level of the proposed converter depends on the switches duty cycle and the coupled inductor (CI) turns ratio. As some features, interleaving and cascading help the converters achieve high output voltage gain, low input current ripple, low-volume input inductor, and high reliability. Moreover, employing multi-winding coupled inductors improves output voltage gain, recycles the magnetic components stored energy, cancels circulating... 

Cut-set bounds are not, in general, tight for all classes of network communication problems. In this paper, we introduce a new technique for proving converses for the problem of transmission of correlated sources in networks, which results in bounds that are tighter than the corresponding cut-set bounds. We also define the concept of 'uncertainty region' which might be of independent interest. We provide a full characterization of this region for the case of two correlated random variables. The bounding technique works as follows: on one hand, we show that if the communication problem is solvable, the uncertainty of certain random variables in the network with respect to imaginary parties... 

Cut-set bounds on achievable rates for network communication protocols are not in general tight. In this paper we introduce a new technique for proving converses for the problem of transmission of correlated sources in networks, that results in bounds that are tighter than the corresponding cut-set bounds. We also define the concept of "uncertainty region" which might be of independent interest. We provide a full characterization of this region for the case of two correlated random variables. The bounding technique works as follows: on one hand we show that if the communication problem is solvable, the uncertainty of certain random variables in the network with respect to imaginary parties... 

In this paper, we study the problem of simulating a discrete memoryless channel (DMC) from another DMC under an average-case and an exact model. We present several achievability and infeasibility results, with tight characterizations in special cases. In particular, for the exact model, we fully characterize when a binary symmetric channel can be simulated from a binary erasure channel when there is no shared randomness. We also provide infeasibility and achievability results for the simulation of a binary channel from another binary channel in the case of no shared randomness. To do this, we use the properties of Rényi capacity of a given order. We also introduce a notion of 'channel... 

Increasing the number of cores integrated on a single chip offers a great potential for the implementation of fault-tolerant techniques to achieve high reliability in real-time embedded systems. Checkpointing with rollback-recovery is a well-established technique to tolerate transient faults in multicore platforms. To consider the worst-case fault occurrence scenario, checkpointing technique requires to re-execute some parts of the tasks, and that might lead to simultaneous execution of task parts with high power consumptions, which eventually might result in a peak power increase beyond the thermal design power (TDP). Exceeding TDP can elevate on-chip temperatures beyond safe limits, and... 

In this paper, we study the problem of simulating a DMC channel from another DMC channel. We assume that the input to the channel we are simulating is i.i.d. and that the transmitter and receivers are provided with common randomness at limited rates. We prove bounds for simulating point-to-point, MAC and broadcast channels. As a special case, we recover the achievability part of the result of Cuff for point-to-point channel simulation via a noiseless link and shared randomness  

In this paper, we introduce a new measure of correlation for bipartite quantum states. This measure depends on a parameter α , and is defined in terms of vector-valued Lp -norms. The measure is within a constant of the exponential of α -Rényi mutual information, and reduces to the trace norm (total variation distance) for α =1. We will prove some decoupling type theorems in terms of this measure of correlation, and present some applications in privacy amplification as well as in bounding the random coding exponents. In particular, we establish a bound on the secrecy exponent of the wiretap channel (under the total variation metric) in terms of the α -Rényi mutual information according to... 

In this paper, a new measure of correlation is introduced. This measure depends on a parameter α, and is defined in terms of vector-valued Lp norms. The measure is within a constant of the exponential of α-Rényi mutual information, and reduces to the trace norm (total variation distance) for α = 1. We provide some properties and applications of this measure of correlation. In particular, we establish a bound on the secrecy exponent of the wiretap channel (under the total variation metric) in terms of the α-Rényi mutual information according to Csiszár's proposal. © 2019 IEEE  

Multicore platforms are becoming the dominant trend in designing Mixed-Criticality Systems (MCSs), which integrate applications of different levels of criticality into the same platform. A well-known MCS is the dual-criticality system that is composed of low-criticality and high-criticality tasks. The availability of multiple cores on a single chip provides opportunities to employ fault-Tolerant techniques, such as N-Modular Redundancy (NMR), to ensure the reliability of MCSs. However, applying fault-Tolerant techniques will increase the power consumption on the chip, and thereby on-chip temperatures might increase beyond safe limits. To prevent thermal emergencies, urgent countermeasures,... 

Low power consumption, real-time computing, and high reliability are three key requirements/design objectives of real-time embedded systems. The standby-sparing technique can improve system reliability while it might increase the temperature of the system beyond safe limits. In this paper, we propose a thermal-aware standby-sparing (TASS) technique that aims at maximizing the Quality of Service (QoS) of soft real-time tasks, which is defined as a function of the finishing time of running tasks. The proposed technique tolerates permanent and transient faults for multicore real-time embedded systems while meeting the Thermal Safe Power (TSP) as the core-level power constraint, which avoids... 

Low power consumption, real-time computing, and high reliability are three key requirements/design objectives of real-time embedded systems. The standby-sparing technique can improve system reliability while it might increase the temperature of the system beyond safe limits. In this paper, we propose a thermal-aware standby-sparing (TASS) technique that aims at maximizing the Quality of Service (QoS) of soft real-time tasks, which is defined as a function of the finishing time of running tasks. The proposed technique tolerates permanent and transient faults for multicore real-time embedded systems while meeting the Thermal Safe Power (TSP) as the core-level power constraint, which avoids... 

In this paper the Output Statistics of Random Binning (OSRB) framework is used to prove a new inner bound for the problem of secure channel simulation. Our results subsume some recent results on the secure function computation. We also provide an achievability result for the problem of simultaneously simulating a channel and creating a shared secret key. A special case of this result generalizes the lower bound of Gohari and Anantharam on the source model to include constraints on the rates of the public discussion  

Proper functioning of electrical connectors used in high oscillation is of great importance. Vibrations in connector pins cause stress and electrical resistance variations in the contact surface. In the present paper, the impacts of vibrational loads on electrical connectors is being modeled using the finite element method, and the electrical resistance oscillations of the connectors will be examined. Ultimately, the parameters affecting the electrical resistance oscillations of contacts will be determined and their relations with oscillations in electrical resistance are specified as well. © 2018 by the authors; licensee Growing Science, Canada, 2018 Growing Science Ltd. All rights reserved... 

In this paper, we study the problem of coordinating two nodes which can only exchange information via a relay at limited rates. The nodes are allowed to do a two-round interactive two-way communication with the relay, after which they should be able to generate i.i.d. copies of two random variables with a given joint distribution within a vanishing total variation distance. We prove inner and outer bounds on the coordination capacity region for this problem. Our inner bound is proved using the technique of "output statistics of random binning" that has recently been developed by Yassaee, et al  

Being able to track objects that surround us is key for planning actions in dynamic environments. However, rigorous cognitive models for tracking of one or more objects are currently lacking. In this study, we asked human subjects to judge the time to contact (TTC) a finish line for one or two objects that became invisible shortly after moving. We showed that the pattern of subject responses had an error variance best explained by an inverse Gaussian distribution and consistent with the output of a biased drift-diffusion model. Furthermore, we demonstrated that the pattern of errors made when tracking two objects showed a level of dependence that was consistent with subjects using a single... 

The lasing mechanism and temporal output profile of distributed feedback dye lasers is investigated, using a model based on induced polarization in the dye solution, where a more accurate behavior of the laser output is predicted. It is found that the temporal output profile of the laser is mostly determined by the concentration of dye solution and the lifetime of the upper laser level of dye molecules. To a large extent, the results of this work agree with experimental studies, even at high-level pump intensities where the self Q-switched model fails to be applied. Especially, the experimentally observed irregular intensity profile of laser output is explained. It is also shown that, when... 

Nanonetworking indicates new solutions for many applications in biomedical and industrial fields. In this paper, we examine the diffusion-based molecular communication for information transmission in nano-networks. Design of practical decoders for resource-limited nano-networks requires an understanding the fundamental performance limits of memory-limited decoders. While some existing works in the literature do consider decoders with limited memory, to best of our knowledge, the tradeoff between memory and probability of error has not been studied in the literature. In this paper we make a first step by studying this tradeoff for a particular molecular communication channel between two... 

In this paper, a diffusion-based molecular communication channel between two nano-machines is considered. The effect of the amount of memory on performance is characterized, and a simple memory-limited decoder is proposed; its performance is shown to be close to that of the best possible decoder (without any restrictions on the computational complexity or its functional form), using genie-aided upper bounds. This effect is adapted to the case of Molecular Concentration Shift Keying; it is shown that a four-bit memory achieves nearly the same performance as infinite memory for all of the examples considered. A general class of threshold decoders is considered and shown to be suboptimal for a... 

The LTI-Poisson model is a natural extension of the conventional memoryless Poisson channel to include memory, and can model the ISI effect in diffusion based molecular communication networks. In this paper, we exploit prior art on linear ISI channels to provide a computable finite-letter characterization of the capacity of single-hop LTI-Poisson networks. Then we find more explicit single-letter lower and upper bounds on the capacity in the point to point case. Further, an approach for bounding mutual information in the low SNR regime using the symmetrized KL divergence is introduced and its applicability for Poisson channels is demonstrated. This leads to a non-trivial upper bound on the... 

In some applications, the variance of measurement noise depends on the signal that we aim to measure. For instance, additive Gaussian signal-dependent noise (AGSDN) channel models are used in molecular and optical communication. Herein we provide lower and upper bounds on the capacity of additive signal dependent noise (ASDN) channels. We also provide sufficient conditions under which the capacity becomes infinity. © 2017 IEEE