Applied Mechanics and Materials Vols. 543-547

Abstract: With the rapid development of Internet of things, the RFID technology also develops very fast. Because of the RFID system has the advantage of low cost and do not require to contact identification, it has been used in many applications. But when system works, there may be many tags at the same time around the reader and may cause the collision problem. In this paper, we propose a Method of ID - BTS tag recognition based on the QT protocol. This method can effectively solve the problem of tag collision and it has fewer times of tags searching and less traffic.

Abstract: In this paper, we propose an adaptive template method based on the dark channel prior. The method combines with the haze imaging model to haze removal for a single image. This method can effectively remove haze from a single input image. According to the characteristics of the image itself and the haze removal effect of the different template we divide the input image into flat region, edge region and texture region. Then, select the lager size template dispose the flat region and use midrange or minitype template dispose the edge region and texture area. Experimental results demonstrate that the proposed algorithm has very good performance for fog removal and retains the image details more effectively.

Abstract: Aiming at the problem of poor image contrast and low visibility, a single image contrast enhancement method is put forward in this paper. The method is based on Dark-object subtraction technique, translating the fog degraded image from RGB color space to YIQ color space, and taking out the Y component. Then using the maximum entropy method to get the threshold value of image segmentation, we can put different portion of the image according to the different formula for image restoration. The processed image must be converted from YIQ color space to RGB color space In the back of the steps. Finally, the image needs a linear dynamic range adjustment to enhance the contrast and brightness. Experiments show that the method can effectively remove haze effect on the image. The dehazing effect of the processed image is obvious. The image becomes clear and bright, and the details is outstanding, which is convenient for observation and analysis.

Abstract: This paper briefly introduced the main linear damages in the network layer of electric power Optical Transmission Network which contains fiber loss, chromatic dispersion and polarization mode dispersion. Based on the engineering practice in the application of power system, this paper studied the loss in the optical fiber cable line. The paper also studied chromatic dispersion and polarization mode dispersion. The calculation models were concluded and used for simulation verification. Each model can be used to power OTN engineering design.

Abstract: In this paper, the performance of a new secured coded DS/FFH/TH hybrid spread spectrum system is evaluated. The evaluation is performed using four different spreading codes, which are long sequence, PN sequence, gold sequence, and chaotic sequence. The evaluation is performed under the effect of AWGN, Rayleigh fading, and frequency selective fading channels. The results show that the system presents a superior improvement in the performance especially in the severe fading conditions.

Abstract: Prior knowledge about anticipated distortions and their corresponding human opinion scores is needed in the most general purpose no-reference image quality assessment algorithms. When creating the model, all distortion types may not be existed. Predicting the quality of distorted images in practical no-reference image quality assessment algorithms is devised without prior knowledge about images or their distortions. In this study, a blind/no-reference opinion and distortion unaware image quality assessment algorithm based on natural scenes is developed. The proposed approach uses a set of novel features to measure image quality in a spatial domain. The extracted features which are from the scenes gist are formed using Weibull distribution statistics. When testing the proposed algorithm on LIVE database, experiments show that it correlates well with subjective opinion scores. They also show that the proposed algorithm significantly outperforms the popular full-reference peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) methods. Not only do the results reasonably well compete with the recently developed natural image quality evaluator (NIQE) model, but also outperform it.

Abstract: A joint direction of departures (DODs) and direction of arrivals (DOAs) estimation for bistatic MIMO radar with an algebraic method for blind source separation (BSS) is presented. The proposed method has the relative advantage of simplicity. The DODs and DOAs of targets can be solved in closed-form and paired automatically. Moreover, BSS techniques enable this approach to recover the source signals from the mixed signals. Simulation results verify the effectiveness of the method.

Abstract: Considering the difficulties in the wake bubbles imaging, a wake bubbles measurement system was presented based on the combination of high speed photography and laser sheet scanning technology. In this system, laser sheet was used to illuminate the wake zone to avoid the image stacking of bubbles. Because the particle size of bubbles was in a wide range (10~500um), three switchable magnification lenses were designed for the bubbles imaging. the test results show that the image quality is good and this system satisfies technical requirements.

Abstract: In order to further enhance the transmission capacity of the downlink communication, to improve the utilization of limited resources, the terminal could better demodulate data,LTE-A system increased and supplemented the downlink reference signals and gave the 8 antennas for the reference signal configuration. This paper based on the LTE downlink reference signals and analyzed the efficiency of the LTE-A (LTE-Advance) downlink reference signals. Finally, paper drew the LTE-A downlink reference signals for communication by the flowchart and simulated resource utilization and the maximum number of available resources. The simulation results reflect the LTE-A downlink reference signals have a greater transmission capacity, and confirm the LTE-A downlink reference signals effectiveness and practicality.

Abstract: Demodulation reference signal plays a very important role in channel estimation and equalization in the receiver within the LTE-A system. First, this paper provides the various formulas that generate the demodulation reference signal (DMRS) in the physical uplink Shared channel (PUSCH), and then presents the design flow chart for programming realization. After that, Using TI(Texas Instruments corporation) TMS320C6455 DSP, it generates DMRS in PUSCH by software programming. Finally, this paper specifically describes the realization of division and exponentiation because it is the hardest and most time-consuming operation in the DSP implementation. The method written in this paper could be applied to TD-LTE-Advanced system test platform development and testing techniques.