An Adaptive Tag Anti-Collision Protocol in RFID Wireless Systems

A novel anti-collision algorithm in RFID wireless network is proposed.As it is put forward on the basis of collision tree(CT)and improved collision tree(lCT) anti-collision protocols,we call it adaptive collision tree protocol(ACT).The main novelty of this paper is that the AD strategy is introduced and used in ACT to decrease collisions and improve the tag system throughput.AD strategy means that query strings will divide into two or four branches adaptively according to the label quantity.This scheme can decrease both depth of query and collision timeslots,and avoid producing too much idle timeslots at the same time.Both theoretical analysis and simulation results indicate that the novel proposed anticollision protocol ACT outperforms the previous CT and ICT protocols in term of time complexity,system throughput,and communication complexity.

Design of Anti-Collision Integrated Security Mechanism Based on Chaotic Sequence in UHF RFID System

Collision and security issues are considered as barriers to RFID applications.In this paper,a parallelizable anti-collision based on chaotic sequence combined dynamic frame slotted aloha to build a high-efficiency RFID system is proposed.In the tags parallelizable identification,we design a Discrete Markov process to analyze the success identification rate.Then a mutual authentication security protocol merging chaotic anti-collision is presented.The theoretical analysis and simulation results show that the proposed identification scheme has less than 45.1%of the identification time slots compared with the OVSF-system when the length of the chaos sequence is 31.The success identification rate of the proposed chaotic anti-collision can achieve 63%when the number of the tag is100.We test the energy consumption of the presented authentication protocol,which can simultaneously solve the anti-collision and security of the UHF RFID system.

An Overview of Anti-Collision Protocols for Radio Frequency Identification Devices

Radio frequency identification(RFID) is a new type of non-contact automatic identification technology.Due to its low energy consumption,low cost,and its adaptability to harsh environments,it has been applied to many fields.In the RFID systems,data collision is inevitable when the reader sends a communication request and multiple tags respond with simultaneous data transmission.Data collision is prone to causing problems such as:identification delay,spectrum resource waste,a decreased system throughput rate,etc.Therefore,an efficient,stable anti-collision protocol is crucial for RFID systems.This research analysed the current research into RFID anticollision protocols and summarised means for its improvement through the mechanism of implementation of different types anticollision protocols.Finally,a new direction is proposed for the future development of RFID anti-collision protocol systems.

Research on the adaptive hybrid search tree anti-collision algorithm in RFID system

Due to more tag-collisions result in failed transmissions,tag anti-collision is a very vital issue in the radio frequency identification(RFID) system.However,so far decreases in communication time and increases in throughput are very limited.In order to solve these problems,this paper presents a novel tag anti-collision scheme,namely adaptive hybrid search tree(AHST),by combining two algorithms of the adaptive binary-tree disassembly(ABD) and the combination query tree(CQT),in which ABD has superior tag identification velocity and CQT has optimum performance in system throughput and search timeslots.From the theoretical analysis and numerical simulations,the proposed algorithm can colligate the advantages of above algorithms,improve the system throughput and reduce the searching timeslots dramatically.

一种改进的动态帧时隙ALOHA算法

射频识别系统的最大缺点之一是当标签碰撞时的低标签识别效率。传统的射频识别防碰撞算法在标签数量庞大时,解读标签所需的时隙数会成倍增加。为了解决这一问题,文章提出一种改进的动态时隙ALOHA算法,它根据标签数调整每帧中的时隙数,以使系统能以高吞吐量工作,缩短读取时间,提高了整个系统的效率。

ENHANCED ENERGY-SAVING ANTICOLLISION ALGORITHMS WITH IMPROVING THROUGHPUT FOR RFID SYSTEM

Tag collision algorithm is a key issue for energy saving and throughput with Radio Frequency IDentification (RFID) system more popular in sensing infrastructure of covering wider area on a large scale. Exploiting low energy consumption strategy would enable longer operational life of tags and reader with battery energy supply. And improving throughput is required on a large scale to preserve the capability of the correct reception. Therefore, this paper proposes an enhanced anti-collision algorithm called Dynamic Slotted with Muting (DSM), which uses multiple slots within a frame per node in a binary tree and takes tag estimation function to optimize the number of slots, and adds a mute command to put identified tags silence. The performance of the proposed algorithm is analytically provided, and simulation results show that DSM saves more than 40% energy consumptions both at reader and tags, and improves more than 35% throughput compared to the existing algorithms. Thus our algorithm is demonstrated to perform efficient energy savings at reader and tags with throughput improvement.

Research on Prevention of Ship Collisions with Oil Rigs

The consequences of ship collisions with an oil rig, offshore installation or platform can be far more expensive in relation to safety, environment and costs of damage. The damage due to a single incident of an Oil Rig Collision can be catastrophic due to the number of people on board and the added risk of explosion. However, the existing rules and regulations of collisions prevention are insufficient. The purpose of this article is to critically evaluate the risk of ships collisions with offshore platforms and installations and therefore propose an international regulation for the preventions of this type of collisions.

Global Bioethical Prevention of the Collision of Biological and Cultural Evolution on Miserable Human Survival

With the cultural myth that science can only determine the way the world ＂is＂ （facts）, while humanities, social sciences, lawyers, philosophers, and theologians must determine the way the world ＂ought to be＂ （values）, those in position of global-, national-, and local-political power make major decisions of the use （or non-use） of scientific knowledge and technology. As a result, the human being has created a non-scientifically based cultural environment that is affecting his ability to survive. In effect, cultural evolution is occurring more rapidly than biological evolution that can adapt to the changes brought about in the physical and psycho-social environments. In a pluralistic cultural world, where each society has generated a different view of human nature and different ethical values, the use, misuse, or non-use of scientific and technological advances are derived from these unscientific views of human nature. Since all life depends on limiting interacting environmental and ecological factors, it is imperative that scientific information be used to govern how to minimize irreversible effects on life-sustaining ecological factors, but also scientific information bearing on understanding human nature ought to be integrated into a ＂global bioethics＂. While ethical values cannot be directly derived from scientific factors, it is also true that human values or our ＂ought＂ cannot be maintained in ignorance or defiance of the facts or the ＂is＂.

Research on Anti-collision Algorithm of Short Distance Data communication based on Binary-Tree Disassembly

This paper puts forward adaptive anti collision algorithm based on two fork tree decomposition. New search algorithm built on the basis of binary-tree algorithm, using the uniqueness of the label EPC, to estimate the distribution of label by slot allocation, the huge and complicated two fork tree is decomposed into several simple binary-tree by search the collision slots for binary-tree, so, it can simplifies the search process. The algorithm fully considers4 important performance parameters of the reader paging times, transmission delay, energy consumption and throughput label, the simulation results show that, the improved anti-collision algorithm is obviously improved performance than other two fork tree algorithm, it is more suitable for RFID anti-collision protocols.

Investigation of Braking Timing of Drivers for Design of Pedestrian Collision Avoidance System

The braking behavior of drivers when a pedestrian comes out from the sidewalk to the road was analyzed using a driving simulator. Based on drivers＇ braking behavior, the braking control timing of the system for avoiding the collision with pedestrians was proposed. In this study, the subject drivers started braking at almost the same time in terms of TTC （Time to Collision）, regardless of the velocity of a subject vehicle and crossing velocity of pedestrians. This experimental result showed that brake timing of the system which can minimize the interference for braking between drivers and the system is 1.3 s of TTC. Next, the drivers＇ braking behavior was investigated when the system controlled braking to avoid collision at this timing. As a result, drivers did not show any change of braking behavior with no excessive interference between braking control by the system and braking operation by drivers for avoiding collisions with pedestrians which is equivalent to the excessive dependence on the system.