Applied Mechanics and Materials Vols. 513-517

Abstract: To deal with the image contrast and color fidelity details problem in the traditional Center around the Retinex image enhancement algorithms, Enhancement algorithm of color fog image based on the adaptive scale and s-cosine curve is proposed. Firstly, the image is transformed into the RGB color space. Then the each channel pixel values can be stretched the grayscale range by S-cosine curve and introduces the local correction function. It can calculate the scale of the Gaussian kernel, and then proceeds to do the Gamma correction for the estimates of the reflection component, obtains the multi-scale image by the weighted average. Afterwards, the obtained image is used to global nonlinear correction, image sharpening and smoothing, and being superimposed reflection components, achieving the image enhancement. At last, it can carry on the intensity adjustment and grayscale adjustment for the obtained image. Through the subjective observation and objective evaluation, this algorithm is better than the traditional center around Retinex algorithm and MSRCR algorithm in processing effect.

Abstract: Regions of Interest (ROI) detection algorithm based on Visual Attention Model can rapidly focus the attention in the conspicuous target region, and extract the interested region. As to some complicated scenes, it is very difficult to detect the target accurately by using general target detecting method, but using Regions of Interest detection algorithm based on Itti Visual Attention Model can detect the target position very well. But pay attention to Itti Visual Attention Model, it utilizes the luminance, color and texture character of the target to detect the position of it. As little moving target, these characters of it are not obvious, so the detecting result is not satisfactory that utilizing Itti Visual Attention Model directly. According to the problem, this text proposes one Regions of Interest detection algorithm on the basis of improved Itti visual attention model by introducing movement character. The experiment shows that the improved model puts forward a new thinking of little moving target detection.

Abstract: An algorithm of B-spline curve approximation with the three-dimensional data is presented in this paper. In this algorithm, we will get a smooth curve which is nearly arc-length parameterization. The smoothness and uniform parameterization are key factors of the approximating curve, specifically in skinning surface and surface approximation. Firstly, the data points are fitted using local interpolation, this local fitting algorithm yields n Bezier segments, each segment having speed equal to 1 at their end and midpoints. Then segments are composed of a C¹ continuous cubic B-spline curve which named controlling curve. But the controlling curves control points are redundancy, so we find another curve to approximate the controlling curve using least square approximation with smoothness

Abstract: The fluid model driven by an M/M/1 queue with set-up and close-down period is studied. The Laplace transform of the joint stationary distribution of the fluid model is of matrix geometric structure. With matrix geometric solution method, the Laplace-Stieltjes transformation of the stationary distribution of the buffer content is obtained, as well as the mean buffer content. Finally, with some numerical examples, the effect of the parameters on mean buffer content is presented.

Abstract: This paper has make a deep theoretical analysis and experimental research according to the load loss of large capacity transformer which included the loss component decomposition, the analysis of the oil flow cooling system performance and working condition, the stray loss and temperature rise of the winding area. We have done the following work on the background of the 1000kV power transformer: The winding area loss was calculated based on the weight coefficient method and field circuit coupling method; considering that the hydraulic loss of the transformer cooling system is nonlinear and the nonlinear operating characteristics of the oil flow pump, establishing the cooling oil-way mathematical model of the transformers non winding area, and analysis the working condition of the transformer cooling system. Establishing the transformer winding multi-physics coupling mathematical model and researching the transformer winding heat problem based on the nonlinear influence of the material. The error between the windings numerical calculation results and the loss, winding temperature rise meet requirements of the engineering analysis according to this method. The calculation in this paper has high precision, and it can be used in the structure optimization of the large transformer winding.

Abstract: The problem of Cramér-Rao bound for parameter estimation in wideband bistatic Multiple-Input Multiple-Output (MIMO) radar system is considered. In many applications, it is not appropriate to approximate the wideband signal by the narrowband model. In this paper, we propose a new wideband signal model to accurately estimate parameter for wideband signals from a moving target. The Cramér-Rao bound for target parameter estimation is derived and computed in closed form which shows that the optimal performance is achieved. Target location and parameter estimation performances are evaluated and studied theoretically and via simulations.

Abstract: The ground-air communication of civil aviation is interfered by radios, which has seriously endangered the normal flight of civil airplanes. This paper proposes an airplane information estimation algorithm based on the study of the problem of interference localization. Firstly, a novel signal model to accurately estimate parameters of the airplane is proposed. A method of Doppler estimation based on peak searching is proposed, and the 2D-MUSIC algorithm is applied to estimate the azimuth angle and elevation angle. Furthermore, the velocity and location of the airplane are estimated by employing array geometry. As a result, the airplane localization is achieved in bistatic radar, laying the foundations for interference localization. The correctness and effectiveness of the proposed method are verified with the computer simulation.

Abstract: Worst case response time analysis of CAN Bus is the de facto method for evaluating the real-time performance which is a key feature of industrial bus. Compared with WCRT which aimed at nodes without buffer, a modified algorithm was presented to calculate the response time of CAN Bus consisting of nodes with both hardware and software buffers. The modified algorithm introduced local blocking time to describe the effect of buffers on response time. Based on the analysis of the different structures between hardware and software buffers, modified WCRT calculation methods of messages in hardware or software buffers were presented. Then the WCRT analysis of the whole system was obtained by consolidating the response time of node and bus. Results show that the response time calculated by the modified method is much longer than that calculated by the traditional WCRT. The modified method makes the WCRT analysis more coincident with the application of engineering, which helps the design and optimization of CAN based industrial bus.

Abstract: We introduce cryptographic primitives to the symbolic transition graph with the binary equivalence relation based on the CCS language with value-passing processes, which is designed for the description and analysis of security protocols. The STGR with cryptographic primitives, which is an extension of the STG, is applied to partition domains of conversations of security protocols that run in an infinite concurrent way, where principals possessing their relevant keys have received and transformed the message. The cryptographic primitives enable us to consider cryptographic issues on the principal conversations of security protocols in more detail. Our work results in a highly efficient solution to reduce computational complexities to prove safety properties of security protocols.

Abstract: Reinforced concrete beams are widely employed in civil engineering structures. To reduce the maintenance financial cost, structure damages have to be detected early. To this end, one needs robust monitoring techniques. The paper deals with the identification of mechanical parameters, useful for Structural Health Monitoring, in a 2D beam using inverse modeling technique. The optimal control theory is employed. As an example, we aim to identify a reduction of the steel bar cross-section and a decrease of the concrete Young modulus in damaged areas. In our strategy, the beam is instrumented with strain sensors, and a known dynamic load is applied. In the inverse technique, two space discretizations are considered: a fine dicretization (h) to solve the structural dynamic problem and a coarse discretization (H) for the beam parameter identification. To get the beam parameters, we minimize a classical data misfit functional using a gradient-like algorithm. A low-cost computation of the functional gradient is performed using the adjoint equation. The inverse problem is solved in a general way using engineer numerical tools: Python scripts and the free finite element software Code_Aster. First results show that a local reduction of the steel bar cross-section and a local decrease of concrete Young modulus can be detected using this inverse technique.