Papers by tuan trung tran
2012 IEEE Global Communications Conference (GLOBECOM), 2012
Network coding offers a promising platform for multicast transmission by approaching its min-cut ... more Network coding offers a promising platform for multicast transmission by approaching its min-cut capacity. However, pushing the network throughput toward this upper bound comes with a sacrifice in delivery delay due to the decoding procedure that requires performing batch of coded packets. Further, in some transmission scenarios where the receivers experience deep fading or unable to collect a full set of the transmitted data, no useful information is recovered. The effect is more severe in the networks where the transmitted information has priority structure with hard deadline constraint due to the limited delivery time and data interdependencies. In this paper, we consider single-hop wireless networks where the transmitter wishes to multicast hard deadline constrained prioritized data to many receivers over lossy channels. We first study the network performance of a variety of transmission techniques, depending on how the transmitter schedules transmission in each time slot. We then propose an adaptive encoding and scheduling technique to maximize the network throughput. To find the optimal transmission scheduling at the presence of the network dynamics, we cast the problem in the framework of Markov Decision Processes (MDP) and use backward induction method to find an optimal solution. We further propose simulation-based algorithm and greedy scheduling technique that obtain high performance with much lower time complexity. Both analytical and simulation results have been provided to corroborate the effectiveness of the proposed techniques.
2012 IEEE International Conference on Communications (ICC), 2012
Wireless multicast for delay-sensitive data is challenging because different receivers may experi... more Wireless multicast for delay-sensitive data is challenging because different receivers may experience different packet losses. Network coding offers significant advantages over the traditional Automatic Repeat-reQuest (ARQ) protocols in that it mitigates the need for retransmission and has the potential to approach the min-cut capacity. Network-coded multicast would be, however, vulnerable to false packet injection attacks, in which the adversary injects bogus packets to prevent receivers from correctly decoding the original data. Without a right defense in place, even a single bogus packet can completely change the decoding outcome. Existing solutions either incur high computation cost or cannot withstand high packet loss. In this paper, we propose a novel scheme to defend against false packet injection attacks on network-coded multicast for delaysensitive data. Specifically, we propose an efficient authentication mechanism based on null space properties of coded packets, aiming to enable receivers to detect any bogus packets with high probability. We further design an adaptive scheduling algorithm based on Markov Decision Processes (MDP) to maximize the number of authenticated packets that can be received within a given time constraint. Both analytical and simulation results have been provided to demonstrate the efficacy and efficiency of our proposed scheme.
AIP Advances, 2022
We present a pronounced unprecedented surface modification of a crystalline Ge layer under ion ir... more We present a pronounced unprecedented surface modification of a crystalline Ge layer under ion irradiation with a Ge ion beam at the energy of 2.5 MeV. Samples were covered by a thin SiN-protection layer to protect from sputtering and surface redeposition phenomena. Under the irradiation conditions, the Ge layer did not become porous as observed for other projectiles and lower energies but develops into a severely uneven morphology with characteristic length scales of several hundred nanometers. The observed roughness monotonically increases with the irradiation doses. We show that this phenomenon is caused neither by the surface erosion effect nor by a non-uniform volumetric expansion. Rather, atomic redistribution in the bulk of the material is the major drive for the uneven surface. Furthermore, the deformation of the Ge layer likely occurs to the largest extent after irradiation, as indicated by the very flat interface around the end-of-range region. The observed morphology modification is discussed based on irradiation-induced plastic flow, coupled with a larger contribution of the electronic component in the ion-solid interactions.
Semiconductor Science and Technology, 2021
In this work a new contribution to the simulation of deep submicron, nanometer-scale MOFFET trans... more In this work a new contribution to the simulation of deep submicron, nanometer-scale MOFFET transistor characteristics is considered. Proposed approach is based on the use of traditional "compact" submicron MOS device models. Parameters of these models are verified by means of fitting procedure to results obtained by use exact physical models taking into account quantum effects accompanying charge carriers transfer in deep submicron devices. Keywords - Compact model, device parameters, extraction, deep submicron, MOS transistor, I-V characteristics, Silvaco package. I. INTRODUCTION When we are stepping into the nanometer era, integrated circuit complexity is increasing, die areas are also getting larger in order to incorporate the increased functionality, difficulties of integrated circuit and technology design is rising. Integrated circuit design in micro- and nanoelectronics is based on the solution of complex problem of charge carriers transport simulation in the device...
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Papers by tuan trung tran