Electronic and Telecommunication Research Institute ETRI
Electronic and Telecommunication Research Institute ETRI
Santoso G.Z.,Electronic and Telecommunication Research Institute ETRI |
Sok S.-W.,Electronic and Telecommunication Research Institute ETRI |
Jung Y.-W.,Electronic and Telecommunication Research Institute ETRI |
Kang D.-J.,Electronic and Telecommunication Research Institute ETRI
ACM International Conference Proceeding Series | Year: 2017
ARM CPU is expanding into server market with the introduction of virtualization extensions. Virtualization is one of the key technologies that is commonly employed in servers. Virtualization is provided by hypervisor and ViMo-S is a prototype hypervisor specifically designed for ARM servers supporting full virtualization. I/O performance is one of the main challenges in hypervisor implementation. In this paper we will explain how we optimize I/O performance in virtual machines of ViMo-S hypervisor with zero-copy method. Through rigorous performance comparison between virtual machine running with zero-copy and virtual machine without zero-copy, we note that zero-copy method have increased block device's transaction-efficiency by up to 25.4% and transfer-efficiency by 31.5%. © 2017 ACM.
Park J.-Y.,Electronic and Telecommunication Research Institute ETRI |
Han D.-G.,Kookmin University |
Yi O.,Kookmin University |
Kim J.,Electronic and Telecommunication Research Institute ETRI
Lecture Notes in Electrical Engineering | Year: 2013
The RSA-CRT algorithm has been widely used because of the efficiency of its exponent operation. The physical susceptibility of RSA-CRT to various side channel attacks has been investigated in several studies. Boer et al. proposed MRED (Modular Reduction on Equidistant Data), a brilliant differential power analysis (DPA) of CRT reduction with equidistant chosen messages. This attack targets intermediate data that depend on the value. We introduce a new approach the MRED attack, related to a subtraction algorithm that is not solely based on the value. Our approach is superficially similar to previous DPA attacks; however, is based on a totally different assumption from that of data dependent analysis. According to our results, only 256 traces are needed to reduce 1 block key to 2 key candidates, so it is a more efficient analysis method on restricted trace environments. Moreover, it can be used to attack a data-dependent trace system. One example of this kind of attack is non-Hamming weight. We describe our technique with its advantages and disadvantages, and we show simulation results using an MSP430 and based software board. © 2013 Springer Science+Business Media.
Lee J.H.,Hanyang University |
Lim J.-S.,Electronic and Telecommunication Research Institute ETRI |
Lee S.W.,Namseoul University |
Choi S.,Hanyang University
IEEE Transactions on Broadcasting | Year: 2010
This paper introduces an Advanced Terrestrial DMB (AT-DMB) system which is being developed in Korea. The aim of AT-DMB development is to provide better resolution video service on large size displays (over 24 inches) or additional data broadcasting services with increased data. In order to achieve higher data rates while maintaining backward compatibility to conventional T-DMB receivers, a hierarchical modulation method is applied. For the hierarchical modulation method, DQPSK/QPSK and DQPSK/BPSK methods are chosen for the AT-DMB standard. Coherent detection based on Decision Directed (DD) channel estimation and scalable video coding extensions of MPEG 4 AVC are also adopted. An AT-DMB system can deliver 2 Mbps of effective data, which is enough for Standard Definition (SD) picture quality. The performance of an AT-DMB system is verified through computer simulation and small scale field experimental broadcasting. With this successful result, AT-DMB is legislated as new T-DMB standards (TTAS. KO.07-0070) June of this year. © 2006 IEEE.
Lee D.,Electronic and Telecommunication Research Institute ETRI |
Nooshabadi S.,Michigan Technological University |
Kim K.,Gwangju Institute of Science and Technology
AEU - International Journal of Electronics and Communications | Year: 2012
While the joint transmit/receive (Tx/Rx) AnSS with exhaustive search is the best solution for error rate minimization, its complexity makes it difficult for implementation on practical systems. To overcome this disadvantage, we propose a two-stage AnSS algorithm for the spatial multiplexing (SM) in the multiple input multiple output (MIMO) system, which employs both the statistical (i.e., average Euclidean distance, AED) and instantaneous selection criteria (i.e., modified instantaneous Euclidean distance, M-IED). The proposed algorithm reduces the computational complexity by decoupling the joint Tx/Rx selection into two separate selections of the numbers of Tx/Rx antennas and antenna subset, respectively. We show that the proposed AED criterion can be implemented through a simple look up table (LUT), thereby significantly reducing the computational complexity. Simulation results and computational complexity comparisons, prove that the proposed two-stage AnSS algorithm for the SM scheme reduces the hardware and computational complexity without any loss of the signal-to-noise ratio (SNR) and the diversity order, compared to the exhaustive search method. © 2012 Elsevier GmbH. All rights reserved.
Chen X.-B.,Konkuk University |
Shin J.-H.,Korean University of Science and Technology |
Shin J.-H.,Electronic and Telecommunication Research Institute ETRI |
Kim H.-T.,Korean University of Science and Technology |
And 2 more authors.
Journal of Raman Spectroscopy | Year: 2012
We present the studies of the phase transition behaviors of V 2O3 thin film using temperature-dependent Raman scattering spectroscopy. Our results show that in both the cooling and heating processes of V2O3 thin film, the phase transition occurs gradually but not suddenly, contrary to that in single crystal. The coexistence of both the metal and insulator phases with co-phasing ΔTc larger than 30 K is observed in both the cooling and heating processes. We discuss that this large co-phasing ΔTc should be distinguished with the large hysteresis ΔTh reported in nanostructures. In addition, our discussions indicate that co-phasing ΔTc and hysteresis ΔTh would be mainly correlated with stress and defect states in sample, respectively. Furthermore, our Raman analyses suggest that stress would also induce phase transitions in V2O3, and the stress (pressure)-induced phase transitions would behave differently comparing with the temperature-induced transitions under normal pressure. Copyright © 2012 John Wiley & Sons, Ltd.