# jemdoc: showsource # jemdoc: menu{MENU.txt}{publications.jemdoc.txt.html} = Aly El Gamal {{}} == Postdoctoral Research: Big Data Analytics I am currently working on a study of semi-supervised learning in collaboration with the research group of Prof. Antonio Ortega. The study consists of two parts, analyzing the optimal structures to represent the sampled data and analyzing optimal reconstruction methods to recover the labels of unlabeled data from few labeled examples. Understanding fundamental limits in this setting is important to derive benchmarks for the performance of practical algorithms in the context of big data analytics where large sets of unlabeled samples are available with few labeled examples that are provided through expert feedback.\n\n In the accomplished part of this project, we analyzed the recently introduced method of Band-limited Interpolation of Graph-signals (BIG) for semi-supervised learning. By analyzing the convergence of the bandwidth of the graph signal, we showed that as the number of samples increases, the decision boundary recovered through the BIG approach is closely related to the low density separation problem. By analyzing the distribution of the graph Laplacian eigenvalues, we derived the required number of labels by the BIG approach, and compared it with spectral clustering methods to highlight the value of labelled samples when clustering is not a good solution. == M.Sc. and Ph.D. Research: Interference Management and Security of Wireless Networks My M.Sc. and Ph.D. studies have been focused on analyzing the information theoretic limits of wireless communication scenarios that have practical significance. The goal of my M.Sc. work was to find novel ways to exploit features of the wireless channel in order to achieve physical-layer secure communication regardless of the computational capabilities of the adversary. We developed a randomized transmission scheme to achieve information theoretic secrecy using two-way communication, and inspired by the fact that a binary erasure channel has larger capacity than that of an erroneous counterpart with the same probability of erased/corrupt symbols.\n\n The goal of my Ph.D. thesis is to provide an information-theoretic characterization of the potential gains offered by Coordinated Multi-Point (CoMP) transmission in interference networks. We consider the problem in which each user's message can be available at more than one transmitter in the network. The selection of a message assignment reflects the setup of backhaul links in a cellular downlink scenario. Given limited backhaul capacity, we analyze Degrees of Freedom (DoF) optimal assignment of messages and transmission scheme in interference networks with various architectures.\n == Journal Publications [http://arxiv.org/abs/1502.04248 Asymptotic Justification of Band-Limited Interpolation of Graph Signals for Semi-Supervised Learning], A. Anis, A. El Gamal, A. S. Avestimehr, A. Ortega, in preparation for submission.\n\n [http://arxiv.org/abs/1312.0040 Dynamic Interference Management], A. El Gamal, V. V. Veeravalli, submitted to IEEE Transactions on Wireless Communications. Jul. 2015. \n\n [http://arxiv.org/abs/1501.07544 When Does an Ensemble of Matrices with Randomly Scaled Rows Lose Rank?], N. Naderializadeh, A. El Gamal, A. S. Avestimehr, submitted to IEEE Transactions on Information Theory. Apr. 2015.\n\n [http://arxiv.org/abs/1211.2897 Interference Channels with CoMP: Degrees of Freedom, Message Assignment, and Fractional Reuse], A. El Gamal, V. S. Annapureddy, V. V. Veeravalli, IEEE Transactions on Information Theory, vol. 60, no. 6, pp. 3483-3498, Jun. 2014.\n\n [http://arxiv.org/abs/1006.0778 The Two-Way Wiretap Channel: Achievable Regions and Experimental Results], A. El Gamal, O. O. Koyluoglu, M. A. Youssef, H. El Gamal, IEEE Transactions on Information Theory, vol. 59, no. 12, pp. 8099-8114, Dec. 2013.\n\n [http://arxiv.org/abs/1109.5396 Degrees of Freedom of Interference Channels with CoMP Transmission and Reception], V. S. Annapureddy, A. El Gamal, V. V. Veeravalli, IEEE Transactions on Information Theory, vol. 58, no. 9, pp. 5740-5760, Sep. 2012.\n == Conference Publications [http://arxiv.org/abs/1501.07544 When Does an Ensemble of Matrices with Randomly Scaled Rows Lose Rank?], A. El Gamal, N. Naderializadeh, A. S. Avestimehr, accepted for publication in proceedings of the IEEE International Symposium on Information Theory (ISIT), Mar. 2015. \n\n Flexible Backhaul Design with Cooperative Transmission in Cellular Interference Networks, M. Bande, A. El Gamal, V. V. Veeravalli, accepted for publication in proceedings of the IEEE International Symposium on Information Theory (ISIT), Mar. 2015. \n\n [http://arxiv.org/abs/1502.04248 Asymptotic Justification of Band-Limited Interpolation of Graph Signals for Semi-Supervised Learning], A. Anis, A. El Gamal, A. S. Avestimehr, A. Ortega, accepted for publication in proceedings of the International Conference on Acoustics, Speech and Signal Processing (ICASSP), Jan. 2015. \n\n [http://arxiv.org/abs/1502.03147 Topological Interference Management with just Retransmission: What are the Best Topologies], N. Naderializadeh, A. El Gamal, A. S. Avestimehr, accepted for publication in proceedings of the International Conference on Communications (ICC), Jan. 2015. \n\n [http://arxiv.org/abs/1401.3375 Flexible Backhaul Design and Degrees of Freedom for Linear Interference Channels], A. El Gamal, V. V. Veeravalli, IEEE International Symposium on Information Theory (ISIT), Hawaii, Jul. 2014.\n\n [http://arxiv.org/abs/1312.0040 Dynamic Interference Management], A. El Gamal, V. V. Veeravalli, Asilomar Conference on Signals, Systems, and Computers, Nov. 2013.\n\n Degrees of Freedom of Locally Connected Interference Channels with Cooperating Multiple-Antenna Transmitters, A. El Gamal, V. S. Annapureddy, V. V. Veeravalli, IEEE International Symposium on Information Theory (ISIT), MIT, Jul. 2012.\n\n [http://arxiv.org/abs/1109.1604 Degrees of Freedom of Locally Connected Interference Channels with Coordinated Multi-Point (CoMP) Transmission], A. El Gamal, V. S. Annapureddy, V. V. Veeravalli, International Conference on Communications (ICC), Ottawa, Jun. 2012.\n\n [http://arxiv.org/abs/1202.6278 On Optimal Message Assignments for Interference Channels with CoMP Transmission], A. El Gamal, V. S. Annapureddy, V. V. Veeravalli, 46th Annual Conference on Information Sciences and Systems (CISS), Princeton, Mar. 2012.\n\n Degrees of Freedom of Cooperative Interference Networks, V. S. Annapureddy, A. El Gamal, V. V. Veeravalli, IEEE International Symposium on Information Theory (ISIT), Saint Petersburg, Aug. 2011.\n\n Degrees of Freedom of the K-user Interference Channel with Transmitter Cooperation, V. S. Annapureddy, A. El Gamal, V. V. Veeravalli, IEEE International Symposium on Information Theory (ISIT), Austin, Jun. 2010.\n\n New Achievable Secrecy Rate Regions for the Two Way Wiretap Channel, A. El Gamal, O. O. Koyluoglu, M. A. Youssef, H. El Gamal, IEEE Information Theory Workshop (ITW), Cairo, Jan. 2010.\n\n [http://arxiv.org/abs/0908.3710 Randomization for Security in Half-Duplex Two Way Gaussian Channels], A. El Gamal, M. A. Youssef, H. El Gamal, IEEE Global Communications Conference (Globecom), Hawaii, Dec. 2009.