Universal collision rate constants are calculated for ultracold collisions of two like bosonic or fermionic heteronuclear alkali-metal dimers involving the species Li, Na, K, Rb, or Cs. Universal collisions are those for which the short range probability of a reactive or quenching collision is unity such that a collision removes a pair of molecules from the sample. In this case, the collision r...

One of the most valid and efficient models of long rod projectile penetration in homogeneous targets is Tate and Alekseevskii’s (A&t) model. Based on Tate’s model, the present research tries to calculate the optimum speeds to achieve the maximum penetration depth in the homogeneous targets. The proposed collision speed-penetration depth diagrams are developed using Tate’s model. In this way, va...

a typical radio frequency identification system (rfid) includes one reader and a number of tags. the reader transmit to commands to the tags with interrogation radio signals, and tags receive the command and then respond with their identification. readers with interrogation signals can read tags’ responses. in rfid systems, when multiple tags respond to one reader simultaneously, tag collision ...

rfid system is a wireless technology that can transfer data between tags and readers via radio frequency. in an rfid network, readers are located close to each other to obtain optimal connectivity and sufficient coverage. in such an environment, which is called dense reader environment (dre).different types of collisions such as reader-to-reader and reader-to-tag ones, often lead to serious pro...

Collision memory in IEEE 802.11 Distributed Coordination Function (DCF) has been detected. The collision memory can increase the physical collision rate and this effect is inherent to any DCF type of countdown. In this paper, we introduce a collision memory avoidance algorithm, called Constrained Priority Countdown Freezing (CPCF). The CPCF can completely or partially remove collision memory de...

This paper focuses on the optimization of initiating dimensions of groove bearing in association with de- sired design of vehicle’s front structure which is made up of low carbon steels in the case of frontal collision. Axial bearing analysis is done numerically using nonlinear finite element code LS-DYNA. In this analysis, changes of two main parameters including measure of energy absorp...

Collision detection is an important application in the field of virtual reality, and efficiently completing collision detection has become the research focus. For the poorly real-time defect of collision detection, this paper has presented an algorithm based on the hybrid collision detection, detecting the potential collision object sets quickly with the mixed bounding volume hierarchy tree, an...