In this thesis, the author concentrates on marine accident frequency models and on the analytical estimation of accident frequency in the Gulf of Finland. The Gulf of Finland is a sensitive sea area and a part of Baltic Sea. Automatic Identification System (AIS) data of 2008 is used in the calculations of ship-ship collision and grounding frequency. In addition, an estimate of collision frequen...

We report on ultracold atomic collision experiments utilizing frequency-chirped laser light. A rapid chirp below the atomic resonance results in adiabatic excitation to an attractive molecular potential over a wide range of internuclear separation. This leads to a transient inelastic collision rate which is large compared to that obtained with fixed-frequency excitation. The combination of high...

In recent years, radio frequency identification(RFID) technology has moved from obscurity into mainstream applications that speed up in identifying objects(e.g. manufactured goods, healthcare services, etc.) which affect our daily lives. However, there are several issues arises such as RFID tag collision problem which occurs due to the usage characteristics of radio frequency communication. The...

Abstract. We consider the regularity of the solutions to the stationary linearized Boltzmann equations in bounded C convex domains in R for gases with cutoff hard potential and cutoff Maxwellian gases. Suppose that a solution has a bounded weighted L norm in space and velocity with the weight of collision frequency, which is a typical functional space for existence results for boundary value pr...

This paper introduces a modified version of anti-binary collision algorithm. The proposed method enhances data collision problems done among multiple tags in the range of the RFID reader's action. The proposed algorithm is called (MABS). It is one blocking protocol, based on Adaptive binary splitting protocol. MABS not only inherits the essence of ABS which uses the information of recognized ta...

Recently, the use of RFID(Radio Frequency Identification) for object identification is used more often, but the tag collision problem by the use of a radio frequency still exists. Therefore, in this paper, we analyzed tag identification time to minimize tag collisions and improve tag identification time by applying various tag anti-collision algorithms in the suggested method. As a result, we d...

In this work, we focus on framed slotted Aloha (FSA) and passive ultra high-frequency radio frequency identification multi-antenna systems with physical layer collision recovery. We modify the tags slightly by adding a so-called ‘postpreamble’ that facilitates channel estimation. Furthermore, we investigate the throughput performance of advanced receiver structures in collision scenarios. More ...

The often-studied problem known as Kramers’ problem, in the general area of rarefied-gas dynamics, is investigated in terms of a linearized, variable collision frequency model of the Boltzmann equation. A convenient change of variables is used to reduce the general case considered to a canonical form that is well suited for analysis by analytical and/or numerical methods. While the general form...

The medium-access control (MAC) protocols for wireless networks proposed or implemented to date based on collision-avoidance handshakes between sender and receiver either require carrier sensing or the assignment of unique codes to nodes to ensure that intended receivers hear data packets without interference from hidden sources. We present and analyze a new collision-avoidance MAC protocol tha...