IEEE 802.11e specifies the Enhanced Distributed Channel Access (EDCA) for distributed access with traffic differentiation to a Wireless Local Area Network (WLAN). Traffic differentiation led to introducing several traffic queues within each station, thus introducing virtual collision. In this paper, we present a pattern based Markov chain model of EDCA including the virtual collision phenomenon...

This study integrated efforts to identify influential people and to extend theories of structural predictors of compliance. Adults (N = 195) were shown a sociogram of 11 people who were connected by friendships. Participants were asked to imagine themselves in this group, identify a position for themselves, select another member for an interaction, and predict their likelihood of complying with...

In this paper we investigate the time frequency localization (TFL) properties of different pulse shapes in OFDM/OQAM systems. Various prototype functions, such as rectangular, half cosine, Isotropic Orthogonal Transfer Algorithm (IOTA) function and Extended Gaussian Functions (EGF) are discussed and implemented in a Matlab/Octave Simulation Workbench for Software Defined Radio by direct discret...

The performance of bit-interleaved coded modulation (BICM) with bit shaping (i.e., non-equiprobable bit probabilities in the underlying binary code) is studied. For the Gaussian channel, the rates achievable with BICM and bit shaping are practically identical to those of coded modulation or multilevel coding. This identity holds for the whole range of values of signalto-noise ratio. Moreover, t...

We review the field of femtosecond pulse shaping, in which Fourier synthesis methods are used to generate nearly arbitrarily shaped ultrafast optical wave forms according to user specification. An emphasis is placed on programmable pulse shaping methods based on the use of spatial light modulators. After outlining the fundamental principles of pulse shaping, we then present a detailed discussio...

This paper presents a tutorial on the field of femtosecond pulse shaping, a technology that enables generation of nearly arbitrary, user defined, ultrafast optical waveforms, with control of phase, amplitude, and polarization. The emphasis is on Fourier transform pulse shaping, the most widely applied technique. Selected pulse shaping applications are described, with specific discussion of cohe...

The paper examines software risk management in a novel way in which managers address risks through sequential attention shaping and intervention. These risks represent incongruent states within and between the four components of Leavitt's model: task, structure, technology, and actors. Such a state can in the extreme case lead to a failure of developing or implementing the software, and thus to...