A collision-tolerant based anti-collision algorithm for large scale RFID system

Tag identification is an important issue in RFID system. Most existing anti-collision algorithms solely focus on reducing collision probability while suffering from vast idle slots. This paper proposes a collision-tolerant dynamic framed slotted Aloha (CE-DFSA) algorithm which attempts to identify multiple tags in a slot to reduce the total identification time in the process of identification. In CE-DFSA, tags are allocated with orthogonal Walsh Sequence (WS) so that multiple tags can be identified in a time slot without spreading the spectrum. Simulation results show that the proposed algorithm considerably accelerates the tag identification process with improved efficiency compared with existing anti-collision algorithms

Idle-slots elimination based binary splitting anti-collision algorithm for RFID

Tag collision avoidance is critical to the success of data communications in radio frequency identification (RFID) system. This paper presents an efficient idle-slots elimination based binary splitting (ISE-BS) algorithm to improve the performance of RFID system. In ISE-BS, by introducing 1 bit random number Q and 16-bits random number serial identifier (SID)which are transmitted before data exchange, tag collisions can be informed and unnecessary data exchange between reader and tags can be further eliminated. Moreover, ISE-BS exploits Q to separate conflicting tags into ‘0-1’ subsets randomly. Specifically, the tags in subset ‘0’ will start to transmit in the next period, where the success flag signal reflects the immediate data transmission. The tags in subset ‘1’ will wait in the pipeline. In such a way, the idle slots introduced by conventional binary splitting anti-collision algorithms can be removed with schedule of ISEBS. Extensive simulation results show that ISE-BS outperforms the existing proposed algorithms

Fast splitting based tag identification algorithm for anti-collision in UHF RFID System

Efficient and effective objects identification using Radio Frequency Identification (RFID) is always a challenge in large scale industrial and commercial applications. Among existing solutions, the tree based splitting scheme has attracted increasing attention because of its high extendibility and feasibility. However, conventional tree splitting algorithms can only solve tag collision with counter value equals to zero and usually result in performance degradation when the number of tags is large. To overcome such drawbacks, we propose a novel tree-based method called Fast Splitting Algorithm based on Consecutive Slot Status detection (FSA-CSS), which includes a fast splitting (FS) mechanism and a shrink mechanism. Specifically, the FS mechanism is used to reduce collisions by increasing commands when the number of consecutive collision is above a threshold. Whereas the shrink mechanism is used to reduce extra idle slots introduced by FS. Simulation results supplemented by prototyping tests show that the proposed FSA-CSS achieves a system throughput of 0.41, outperforming the existing UHF RFID solutions

Hardware and software design of BMW system for multi-floor localization

Abstract Although the Micro Electro Mechanical System (MEMS) sensors are capable of providing short-term high positioning accuracy, every positioning result significantly depends on the historical ones, which inevitably leads to the long-term error accumulation. The Bluetooth Low Energy (BLE) is independent of the accumulative error, but the positioning accuracy is suffered by the irregular jump error resulted from the Received Signal Strength Indicator (RSSI) jitter. Considering the requirement of accurate, seamless, and consecutive positioning by the existing commercial systems, we propose a new integrated BLE and MEMS Wireless (BMW) system for multi-floor positioning. In concrete terms, first of all, the way of fingerprint database construction with the reduced workload is introduced. Second, the fingerprint database is denoised by the process of affinity propagation clustering, outlier detection, and RSSI filtering. Third, the robust M estimation-based extended Kalman filter is applied to estimate the two-dimensional coordinates of the target on each floor. Finally, the barometer data are used to calculate the height of the target. The extensive experimental results show that the proposed system can not only restrain the accumulative error caused by the MEMS sensors but also eliminate the irregular jump error from the BLE RSSI jitter. In an actual multi-floor environment, the proposed system is verified to be able to achieve the Root Mean Square (RMS) positioning error within 1 m

Influences of Holes Arrangement on Creep Characteristic of Nickel-Base Single Crystal Alloy Blade Cooling Holes

Film cooling technology is developed to enhance the temperature resistant of nickel-base single crystal alloy blade. The shape, dimension, and arrangement of cooling holes impact the blade strength and life grievously. In this paper, the influences of holes arrangement on creep characteristic of cooling holes in the plate sample are investigated. The constitutive model for creep considering both cavitation and degradation damage is developed to predict the creep behavior of cooling holes. Results show that there are stress interferences among cooling holes. The distance and radius of the cooling holes impact the creep behavior of cooling holes seriously. Decreasing horizontal distance of the holes results in creep time reducing. On the contrary, increasing the vertical distance of the holes makes the creep time reduced

Cost-efficient BLE fingerprint database construction approach via multi-quadric RBF interpolation

Abstract The demand for indoor localization is becoming urgent, but the traditional location fingerprint approach takes a lot of manpower and time to construct a fine-grained location fingerprint database. To address this problem, we propose to use the approach of combining dynamic collection of fingerprint samples with Radial Basis Function (RBF) interpolation. Specifically, the raw sparse fingerprint database is constructed from a small number of fingerprints collected on a few paths, in which the pedestrian track correction algorithm improves the validity and accuracy of the sparse fingerprint database. Then, the RBF interpolation approach is applied to enrich the sparse fingerprint database, in which the Genetic Algorithm (GA) is used to optimize the free shape parameter and the cut-off radius is determined according to the experimental results. Extensive experiments show that the proposed approach guarantees high interpolation and localization accuracy and also significantly reduces the effort of manual collection of fingerprint samples

Multi-Hand Gesture Recognition Using Automotive FMCW Radar Sensor

With the development of human–computer interaction(s) (HCI), hand gestures are playing increasingly important roles in our daily lives. With hand gesture recognition (HGR), users can play virtual games together, control the smart equipment, etc. As a result, this paper presents a multi-hand gesture recognition system using automotive frequency modulated continuous wave (FMCW) radar. Specifically, we first constructed the range-Doppler map (RDM) and range-angle map (RAM), and then suppressed the spectral leakage, and dynamic and static interferences. Since the received echo signals with multi-hand gestures are mixed together, we propose a spatiotemporal path selection algorithm to separate the mixed multi-hand gestures. A dual 3D convolutional neural network-based feature fusion network is proposed for feature extraction and classification. We developed the FMCW radar-based platform to evaluate the performance of the proposed multi-hand gesture recognition method; the experimental results show that the proposed method can achieve an average recognition accuracy of 93.12% when eight gestures with two hands are performed simultaneously

Synthetic Study of Rubriflordilactone B: Highly Stereoselective Construction of the C‑5-epi ABCDE Ring System

A highly stereocontrolled construction of the C-5-epi ABCDE-ring system of rubriflordilactone B has been developed. The present synthesis features a convergent strategy to construct the C-5-<i>epi</i> AB-ring utilizing Mukaiyama–Michael reaction and forge the CDE ring in one step using intramolecular [2 + 2 + 2] cycloaddition of triynes