Advanced Materials Research Vols. 1049-1050

Abstract: Nowadays, RFID technology has been widely spread in various fields. However, the situation of the reader-to-reader collision, caused by movements of readers, is becoming more and more prominent. To solve this problem, this paper proposes an adaptive power control algorithm based on the SNR-measurements method, which uses the Kalman filtering algorithm to estimate the wireless channel characteristic at first, and then adjusts the transmission power of the reader variously according to both channel estimated results and SNR histories, which determines the step size. As shown in simulation results, the algorithm proposed could avoid reader-collision effectively. The algorithm not only provides improvements on real-time ability as well as reliability, but also improves the throughput and precision of identifying tags.

Abstract: In present paper, a DSP-based image capturing and transmitting system is described. As a shortage of peripherals on DSP, external image capturing and data transmitting components are needed in this case. A CMOS image sensor was used to capture images, and an Ethernet MAC controller with PHY was used to transmit image data. In addition, a CPLD was used as the co-controller for timing control. ARP, IP and UDP were functioning during data transmitting through Ethernet. The Driving Mechanism of two main chips and implementing of the protocols were described in detail. Images displayed on the PC show that the system provids good performance. The system is low-cost, simple and low-power.

Abstract: As a newly introduced interconnection network for parallel computing, the locally twisted cube possesses many desirable properties. In this paper, binomial tree embeddings in locally twisted cubes are studied. We present two major results in this paper: (1) For any integer n ≥ 2, an n-dimensional binomial tree B_n can be embedded in LTQ_n with dilation 1 by randomly choosing any vertex in LTQ_n as the root. (2) For any integer n ≥ 2, an n-dimensional binomial tree B_n can be embedded in LTQ_n with up to n − 1 faulty links in log(n − 1) steps where dilation = 1. The results are optimal in the sense that the dilations of all embeddings are 1.

Abstract: This paper examines the free energy potentials of damaged solids for the construction of damage mechanics constitutive models. The physical meaning of free energy in solid mechanics is analyzed in contrast with that in traditional fields of thermodynamics; 1D stress-strain curves are used to show the relationships between various thermodynamic state functions in isothermal loading processes; and the role of plastic free energy in damage evolution is discussed both macroscopically and microscopically. It is concluded that plastic free energy, which is a macroscopic representation of some additional microscopic elastic energy, cannot do work during unloading but get released when damage takes place, constituting part of the driving force for damage evolution.

Abstract: Crop segmentation from outdoor images is still an open problem. In this paper, we proposed a novel crop segmentation method using Gaussian Mixture Model (GMM), which is robust and not sensitive to the challenging outdoor light conditions and complex environmental elements. The method mainly consists of two stages, supervised learning stage and segmentation stage. The GMM is utilized in the former stage to establish crop color model in the HSI color space and a decision function is provided in the latter stage to realize the final crop segmentation. Comparing experimental results show that our method outperforms the other commonly used methods in yielding the highest performance of 94.91% with the lowest standard deviation of 3.14%.

Abstract: Real-time broadcast system of public transport crowding index belongs to the broadcast system of urban public transport environment in ITS. The remaining seats and vehicle weight of the bus can effectively reflect the current crowding of public transport. This paper proposes a real-time broadcast system about the crowding index in public transport based on the Internet of things. The system can be divided into four submodules: wireless sensor network node, Sink node, terminal analysis and evaluation system and site display platform.Operating datas in public transport collected by wireless sensor networking node are sent to terminal analysis and evaluation system by GPRS wireless communication mode. This system can help people choose the best travel route. It may be helpful for managers to make a better traffic assignment.

Abstract: This paper presents a system of audio signal processing based on FPGA,the system uses audio codec chip LM4550 to A/D transform and D/A transform the input analog audio signal and output digital audio signal.Using FPGA as the high speed signal processor to realize volume adjustment and audio effect control,so it can output different style music.Meantime, the system designs a FFT computing module and control system of VGA display interface,to compute the digital audio signal which is A/D transformed,and real-time display the frequency spectrum of audio signal on VGA.

Abstract: For awareness of the network situation, this paper proposes a set of indicators that can assess the importance of nodes and links combining with network topology and traffic information, their generating algorithm is given at the same time. Under the premise of determined network routing protocols, this algorithm is capable of assessing the importance of nodes and links based on the structure and operation state of network. In this way, it can show the special property of the unit position in the network, and can reflect the impact to each part due to the network state change so that network administrators can manage network reasonably.

Abstract: TCP Vegas has the problem that it stops slow start too early, and it is more obvious in the large delay-bandwidth network. This phenomenon can cause a very long linear growth after entering congestion avoidance phase, and it will reduce the transmission efficiency. This paper analyzes that the reasons for this phenomenon is due to the exponential growth of slow start itself, then puts forward a dynamic growth algorithms of slow start, we call it Vegas-f. Improved algorithms can dynamically adjust the growth rate of slow start, so as to improve the transmission efficiency and competitiveness in mixing network. Simulation results show that the improved algorithm has completely solved the problem and the performance is improved significantly.

Abstract: Multiple-input multiple-output (MIMO) interference broadcast channel (IBC) plays an important role in the modern wireless communications. The upper bound of degree of freedom (DoF) and corresponding achievable schemes have been investigated. However, all the achievable schemes require perfect channel state information at transmitters (CSIT). In the absence of CSIT, the DoF value is still unknown. This paper mainly focuses on the G-cell K-user MIMO IBC, where there are M antennas at each transmitter and N antennas at each receiver. The transmitters only know channel coherent time internals rather than the values of channel coefficients. The users in the same cell are assumed to be able to share the channel information. Based on a heterogeneous block fading model, a blind interference alignment (IA) scheme is proposed for this scenario. We show that when and , then a total of degrees of freedom (DoF) can be achieved. The inner bound is same with the decomposition DoF upper bound.