227 research outputs found
Implementation of a secure digital chaotic communication scheme on a DSP board
In this paper, a new a secure communication scheme using chaotic signal for transmitting binary digital signals is proposed and which is then implemented on a Digital Signal Processor (DSP) board. The method uses the idea of indirect coupled synchronization for generating the same keystream in the transmitter and receiver side. This chaotic keystream is applied to encrypt the message signal before being modulated with a chaotic carrier generated from the transmitter. Discrete chaotic maps, 3D Henon map and Lorenz system are used as transmitter/receiver and key generators respectively. The overall system is experimentally implemented in the TMS320C6713 DSK board using code composer and Simulink showing the successful message extraction thus proving the feasibility of the system in the DSP board
Acceleration of hardware code coverage closure using machine learning
Abstract. With the ever-increasing system-on-chip (SoC) design complexity, the verification of such systems is becoming more and more challenging and extremely time consuming. Hence, the human efforts put in this task seem neither to be sufficient, nor efficient enough anymore to maintain a good pace with the escalating market demands.
In this work, we will present a descent way of utilizing machine learning (ML) for reducing the overhead of hardware design verification in terms of resources consumption. Our focus in this thesis is especially about the time spent on coverage closure that usually occupies a great deal of the whole verification time. Both deep learning (DL) and reinforcement learning (RL) are deployed for this purpose, in two different experiments, in order to come out with the most coherent way to accomplish the coverage closure task. On one hand, neural networks (NNs) were used to help visualize whether a stimulus is worth to run the simulation with, by predicting the coverage number that it would generate. On the other hand, Q-learning was used to predict the minimal set of tests needed to reach some code coverage goal, by optimizing and reducing the set of tests while still achieving the same coverage levels.
The results of these experiments show captivating findings. First, the root mean square error (RMSE) of the neural network models was about 3 and 5 in predicting two different coverage values, respectively, which is quite good for a training run on a small dataset. Second, our Q-agent was able to do better than the coverage ranking utility of the simulation tool by almost 43%, where it reduced the number of tests from 63, as suggested by the simulator, to 36. This should remarkably reduce the required number of simulations in weekly regressions, hence result in a huge gain in time and resources.
Both of these approaches aim at reducing the engineers’ efforts through accelerating the verification process and automating it, which frees some of the engineers’ time and allow them to focus on more important matters
Tuning two-dimensional electron (hole) gases at LaInO/BaSnO interfaces: Impact of polar distortions, termination, and thickness
Two-dimensional election gases (2DEG), arising due to quantum confinement at
interfaces between transparent conducting oxides, have received tremendous
attention in view of electronic applications. The challenge is to find a
material system that exhibits both a high charge-carrier density and mobility,
at and even above room temperature. Here, we explore the potential of
interfaces formed by two lattice-matched wide-gap oxides of emerging interest,
, the polar, orthorhombic perovskite LaInO and the
non-polar, cubic perovskite BaSnO, employing density-functional theory
and many-body theory. We demonstrate that this material combination exhibits
all the key features for reaching the goal. For periodic heterostructures, we
find that the polar discontinuity at the interface is mainly compensated by
electronic relaxation through charge transfer from the LaInO to the
BaSnO side. This leads to the formation of a 2DEG hosted by the
highly-dispersive Sn--derived conduction band and a 2D hole gas of O-
character, strongly localized inside LaInO. Remarkably, structural
distortions through octahedra tilts induce a depolarization field counteracting
the polar discontinuity, and thus increasing the (minimal)
LaInO thickness, , required for the formation of a 2DEG. These polar
distortions decrease with increasing LaInO thickness, enhancing the polar
discontinuity and leading to a 2DEG density of 0.5 electron per unit-cell
surface. Interestingly, in non-periodic heterostructures, these distortions
lead to a decrease of , thereby enhancing and delocalizing the 2DEG. We
rationalize how polar distortions, termination, and thickness can be exploited
in view of tailoring the 2DEG characteristics, and why this material is
superior to the most studied prototype LaAlO/SrTiO
Metadata-driven Data Migration from Object-relational Database to NoSQL Document-oriented Database
The object-relational databases (ORDB) are powerful for managing complex data, but they suffer from problems of scalability and managing large-scale data. Therefore, the importance of the migration of ORDB to NoSQL derives from the fact that the large volume of data can be handled in the best way with high scalability and availability. This paper reports our metadata-driven approach for the migration of the ORDB to document-oriented NoSQL database. Our data migration approach involves three major stages: a preprocessing stage, to extract the data and the schema's components, a processing stage, to provide the data transformation, and a post-processing stage, to store the migrated data as BSON documents. The approach maintains the benefits of Oracle ORDB in NoSQL MongoDB by supporting integrity constraint checking. To validate our approach, we developed OR2DOD (Object Relational to Document-Oriented Databases) system, and the experimental results confirm the effectiveness of our proposal
Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law
28We discuss the equations describing the dynamic of the heat transfer in a magnetic fluid flow under the action of an applied magnetic field. Instead of the usual heat transfer equation we use a generalization given by the Maxwell-Cattaneo law which is a system satisfied by the temperature and the heat flux. We prove a global existence of weak solutions to the system having a finite energy
Evaluation of e-Government information systems Agility: a Method and Case study
Development of e-government evaluation frameworks began around 2000s. Most of the developed approaches are technologically driven in which they focus on the “E” rather than the “Government”. Moreover, they tend to evaluate tangible measures (such as costs, benefits, etc.) and neglects important intangible measures (such as agility, sustainability, etc.). The state of the art tells that the evaluation of agility within e-government has been proved to be important but complex. However, the importance is due to the increasing need for governments to justify investments, assess impacts and monitor progress in the ever-changing environment. On the other side, the complexity comes with the concept’s multi-disciplinary, the inherited difficulty when quantifying its –intangible dimensions, and developing appropriate evaluative parameters and metrics. Based on that, our paper addresses all these considerations through a practical method for agility evaluation. This method is originally applied to a real case study of e-Algeria project as part of the review of 10 years since its launch in 2013. The objective is to evaluate the agility of TAWASSOL framework that is designed to be one-stop-shop for government services. As far as results of valuation showed low degrees of agility -in both FO (Front Office) side and BO (Back office) side, improvements are recommended for the government heads to improve the overall agility of the framework
Analogue private communication based on hybrid chaotic systems with delays
International audienceSince most of private communication schemes based on chaotic synchronization are not robust again plain-texts attacks, the introduction of delays in the schemes can be regarded as an efficient method to improve the security degree with respect to such attack. As an extension of our recent work, this paper proposes a new analogue private communication scheme based on hybrid chaotic systems with delays. The proposed scheme is based on the notation of weakly left invertibility of switched systems, and an illustrative example is given for the purpose of highlighting the feasibility of the proposed method
Nouvelle méthode intégrée pour résoudre le problème de planification et d'ordonnancement
2 pagesInternational audienceUne nouvelle méthode pour résoudre de manière intégrée le problème de planification et d'ordonnancement de la production dans des systèmes multi-niveaux est présentée. Des contraintes de capacité détaillées et de nomenclature sont inclues dans le modèle de planification, de manière à garantir des solutions réalisables. Une heuristique Lagrangienne et une heuristique de lissage sont utilisées pour résoudre le problème
Diversity techniques for a free-space optical communication system in correlated log-normal channels
International audiencePerformance analysis of free-space optical (FSO) communication systems in different channel conditions has gained significant attention in literature. Nevertheless, most existing studies consider uncorrelated channel conditions. An uncorrelated channel requires sufficient spacing between transmitters and limits the receiver field of view and link distance. However, this might not be feasible in all applications. Thereby, this paper studies repetition code (RC) and orthogonal space time block code (OSTBC) performance in correlated log-normal FSO channels using intensity modulation and direct detection. An approximate analytical expressions using moment generating function for the average bit error probability are derived. Our simulation results show that RCs are superior to OSTBCs in correlated channel conditions
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