Sensor collision (interference) is studied in a large network of low bit-rate sensors that communicate via backscatter, i.e. modulate the reflection of a common carrier transmitted by a central reader. Closed-form analysis is provided, quantifying sensor collision (interference) in high-density, backscatter sensor networks (BSN), as a function of number of tags and aggregate bandwidth. Analysis...

Advances in wireless and mobile communication technologies have enabled the development of various RFID-based systems and applications in addition to the extension of the tag reading range of mobile readers. Thus, it has become commonplace that multiple readers concurrently attempt to read tags within ranges of the readers. However, this concurrent access among multiple mobile readers brings ab...

We introduce a new cryptographic tool: multiset hash functions. Unlike standard hash functions which take strings as input, multiset hash functions operate on multisets (or sets). They map multisets of arbitrary finite size to strings (hashes) of fixed length. They are incremental in that, when new members are added to the multiset, the hash can be updated in time proportional to the change. Th...

Radio Frequency Identification (RFID) is an auto recognition system that consistis of a number of tags and readers. There could be multiple tags a reader should identify. Since a medium is shared by multiple tags, a collision occurs at the reader’s side when two or more tags get transmitted simultaneously. Therefore, anti-collision mechanism that collaborately arbitrates collisions is required....

In radio-frequency identification (RFID) systems, tag collision resolution is a significant issue for fast tag identification. Dynamic framed slotted ALOHA (DFSA) is one of the most widely used algorithms to resolve tag collision. Collision detection (CD) plays an important role in determining the efficiency of DFSA-based algorithms because most DFSA-based algorithms determine the next frame si...

Train accidents occur as a result of human errors or mechanical faults in trains, in tracks, or in the signalling system. Major and costly train accidents occur due to head-on collision of trains running on the same track towards each other. Several schemes have been proposed by researchers in the past to detect the risk of possible collision and to take preventive measures. The aim of this pap...

With the emergence of active tags and RFID technology used in the fast-moving objects, readers need urgently to read and write tags in limited time. Anticollision algorithms resolve the problem of a number of tags at the same time to communicate with the reader. Traditional anti-collision algorithm is to minimize recognition time and improve search efficiency under the conditions of maintaining...

In turbulent suspensions, collision rates determine how rapidly particles coalesce or react with each other. To determine the collision rate, many numerical studies rely on the ghost collision approximation (GCA), which simply records how often pairs of point particles come within a threshold distance. In many applications, the suspended particles stick (or in the case of liquid droplets, coale...

Classical trajectory (Monte Carlo) calculation is used to calculate collision rate constants of ion-quadrupolar molecule interactions for the H¯+C2H2 system. The method presented here takes into account the effect of the induced dipole-induced dipole potential on ion-quadrupolar molecule collision rate constants. It is also assumed that the colliding particles have a d...

According to the linear viscoelastic model, the population discrete elements under the vibration working condition of the seed tray of the seeder were assumed as rigid conditions to analyze the collision process. The dynamic characteristics among the population collision process for the vibration process of the seeder were analyzed by tracing the microcosmic motion of each seed. The following c...