The damping of plasma oscillations in a weakly collisional plasma is revisited using a Fokker-Planck collision operator. It is shown that the Case–Van Kampen continuous spectrum is eliminated in the limit of zero collision frequency and replaced by a discrete spectrum. The Landau-damped solutions are recovered in this limit, but as true eigenmodes of the weakly collisional system. For small but...

In this article the existence and uniqueness theory of time dependent kinetic equations is developed for collision terms dominated in the norm by the collision frequency, thus generalizing prior work by Beals and Protopopescu.

[1] A method based on linear regularization is presented for the deduction of the effective collision frequency profile in the D-region using an incoherent scatter radar and a colocated riometer. The deduced collision frequency above EISCAT, Tromsø, for the period 09 November 2004 to 13 November 2004 matches very well with that calculated using neutral densities and temperatures from the NRLMSI...

this paper presents the results of a study on the radiation characteristics of a plasma triangular antenna in the vhf band (30-300mhz) applying the method of moment. deriving the current distribution of the antenna, it shows the relationship between radiation characteristics of the plasma antenna and the plasma parameters. both theoretical and numerical results indicate that if the plasma frequ...

This paper considers the physical layer security of frequency hopping (FH) systems. Mainly due to the collision effect among different users, the spectral efficiency of the conventional FH is very low. To overcome this limitation, in this paper, we first propose a general collision-free frequency hopping (CFFH) scheme based on secure spectrum access control; Second, we incorporate the CFFH sche...

Anti-collision algorithms are very important to solve the anti-collision problem in multi-tag and multi-reader environment. The anti-collision algorithm is divided into the anti-collision algorithm for multiple tags and the anti-collision algorithms for multiple readers. The anticollision algorithms for multiple tags are largely divided into tree-based deterministic algorithms and slot aloha-ba...

Radio Frequency Identification (RFID) technology uses radio-frequency waves to automatically identify people or objects. Despite an emergence of RFID technology, multiple tag identification, where a reader identifies a multiple number of tags in a very short time, is still a major problem. This is known as Collision problem and can be solved by using anticollision scheme. The current tree-based...

We measure a cold collision frequency shift in an 87Rb fountain clock that is fractionally 30 times smaller than that for Cs. The shift is -0.38(8) mHz for a density of 1.0(6)x10(9) cm(-3). We study the cavity pulling of the atomic transition and use it to cancel the cold collision shift. We also measure the partial frequency shifts of each clock state finding 2(lambda(10)-lambda(20))/(lambda(1...

This thesis presents HiQ, a hierarchical, online learning algorithm that finds dynamic solutions to the Reader Collision Problem in RFID systems. When the transmissions from one reader interfere with the operation of another reader, a reader collision occurs. ̊ The objective of the Reader Collision Problem is to minimize the reader collisions experienced by RFID readers while using the minimum n...

The RFID technology is affected by the reader-to-reader collision problem. Several studies propose anti-collision protocols. A high throughput adaptation protocol based on time division is Colorwave. A known mechanism, already applied to another time division protocol to improve its performance, is the introduction of a probability factor in the collision resolution routine. In this work, the e...