You are invited to attend a lecture

By

Dr. Igor D. Kaganovich

Plasma Physics Laboratory, Princeton University, NJ 08543, USA*

Nonlinear Self-Organized Structures in Plasmas - From Electron Kinetics to Nano Technology

Nanomaterials have the potential to revolutionize many fields of science and technology, including electronics, chemical synthesis, energy storage, and environmental and pharmaceutical applications.

Industry is investing billions of dollars to be part of the new material revolution that will come with nanomaterials. However, commercial applications of nanomaterials require reliable, predictable, large-scale and low cost synthesis.

Synthesis by plasma has the potential to satisfy these requirements, as well as to form improved nanomaterials. Plasma synthesis offers the possibility of high throughput, short nanostructure growth time, low cost, and optimized material properties.

These remarkable features of plasma synthesis are in great part due to the ability of plasma synthesis methods to sustain a higher yield production of nanomaterials both in volume and on surfaces, and often at lower process temperature and higher

chemical purity, than conventional chemical synthesis. A critical obstacle toward these goals is the lack of understanding of plasma synthesis processes. It is a joint challenge of plasma and material sciences to understand both plasma operation and

material synthesis with plasma.

In this talk I will give two examples of research performed in this area:

Collective interaction of an electron beam with plasma in etching machines and arc self-organization during nanomaterial synthesis.

Sunday, March 27, 2016, at 12:00

Room 011, Kitot Building

You are invited to attend a lecture

By

Dr. Moti Fridman

Faculty of Engineering, Bar-Ilan University

Spontaneous PT symmetry breaking

With topological insulators

In this talk we present a novel optical isolator based on the interaction of light and

Topological insulators.

This optical isolator does not require the application of external magnetic field and is based on spontaneous time reversal symmetry braking by topological insulators.

The device is comprised of tapered fiber with Sb2Te3 topological insulating crystal on its surface.

The interaction of light with the topological insulator rotates the input polarization in a similar manner to the Faraday rotation, but without the necessity in external magnetic field.

Thursday, March 17, 2016, at 15:00

Room 011, Wolfson Classroom Building

~~(The talk will be given in English)

Speaker:   Prof. Tamir Tassa
                       The Department of Mathematics and Computer Science, Open University

Monday, May 30, 2016
15:00 - 16:00
Room 011, Kitot Bldg., Faculty of Engineering

Secure Computation of Social Prestige and Influence from Multiple Networks

Abstract

We study the problem of computing social prestige measures over multiple networks. We consider a setting in which there are several mutually non-trusting parties (called hosts), each one of them holding a proprietary social network on the same ground set of users (nodes). Those hosts wish to compute a prestige (or centrality) score for each of the users, without disclosing information about their private graphs.

We study three measures of prestige, one progressively extending the previous. The first measure counts the number of nodes reachable from a node within a given radius. The second measure, corresponding to the classic Katz score [L. Katz, A new status index derived from sociometric index, Psychometrika, 1953], extends the first one by counting the number of paths between any two nodes. The final one is an original extension of the Katz score to the multigraph case: not only the number of paths are counted, but also the multiplicity of these paths in the different networks is taken into consideration.

We then present a suite of multiparty protocols to compute the three measure of prestige. We show that our protocols are secure in the information-theoretic sense. We also study how to scale our protocols to very large graphs. Finally, we test our protocols on several real-world multigraphs: interestingly, the protocol to compute the most sensitive score (i.e., the multigraph prestige measure) is also the most scalable one and can be efficiently run on very large networks.

Joint work with Gilad Asharov, Francesco Bonchi, and David Garcia-Soriano

Bio:
Tamir Tassa is currently an associate professor in the Department of Mathematics and Computer Science at the Open University of Israel. Previously, he served as a lecturer and researcher in the School of Mathematical Sciences at Tel Aviv University, and in the Department of Computer Science at Ben Gurion University. During the years 1993-1996 he served as an assistant professor of Computational and Applied Mathematics at the University of California, Los Angeles. He earned his PhD in applied mathematics from the Tel Aviv University in 1993. His recent research interests include privacy-preserving data publishing and data mining, secure multi-party computation, secret sharing, and combinatorial optimization.