scholarly journals INFORMATION THEORETIC TECHNIQUE FOR EFFECTIVE KEY GENERATION

Author(s):  
Viktor Wegmayr ◽  
Joachim M. Buhmann

Abstract White matter tractography, based on diffusion-weighted magnetic resonance images, is currently the only available in vivo method to gather information on the structural brain connectivity. The low resolution of diffusion MRI data suggests to employ probabilistic methods for streamline reconstruction, i.e., for fiber crossings. We propose a general probabilistic model for spherical regression based on the Fisher-von-Mises distribution, which efficiently estimates maximum entropy posteriors of local streamline directions with machine learning methods. The optimal precision of posteriors for streamlines is determined by an information-theoretic technique, the expected log-posterior agreement concept. It relies on the requirement that the posterior distributions of streamlines, inferred on retest measurements of the same subject, should yield stable results within the precision determined by the noise level of the data source.


1996 ◽  
Vol 17 (1) ◽  
pp. 13-30 ◽  
Author(s):  
Sumit Sarkar ◽  
Ram S. Sriram ◽  
Shibu Joykutty ◽  
Ishwar Murthy

Author(s):  
Rajesh K. Sharma

This chapter provides a survey of physical layer security and key generation methods. This includes mainly an overview of ongoing research in physical layer security in the present and next generation communication networks. Although higher layer security mechanisms and protocols address wireless security challenges in large extent, more security vulnerabilities arise due to the increasingly pervasive existence of wireless communication devices. In this context, the focus of this chapter is mainly on physical layer security. Some security attacks in general are briefly reviewed. Models of physical layer security, information theoretic works, and key generation methods including quantization and reconciliation are discussed. Some latest developments for enhanced security like Multiple-Input Multiple-Output (MIMO) systems, reconfigurable antennas, and multiple relay systems are also presented. Finally, some existing and emerging application scenarios of physical layer security are discussed.


2010 ◽  
Vol 2010 ◽  
pp. 1-19
Author(s):  
Konstantinos Drakakis

In the game of Betweenies, the player is dealt two cards out of a deck and bets on the probability that the third card to be dealt will have a numerical value in between the values of the first two cards. In this work, we present the exact rules of the two main versions of the game, and we study the optimal betting strategies. After discussing the shortcomings of the direct approach, we introduce an information-theoretic technique, Kelly's criterion, which basically maximizes the expected log-return of the bet: we offer an overview, discuss feasibility issues, and analyze the strategies it suggests. We also provide some gameplay simulations.


Sign in / Sign up

Export Citation Format

Share Document