Applied Mechanics and Materials Vols. 195-196

Abstract: Automatic segmentation of tumor in FDG PET-CT is potentially beneficial in clinical application. However, the performances of existing methods are different. This study compares several algorithms of FDG PET-CT tumor segmentation methods that were recently proposed and which can be used for clinical radiation therapy. In our work, we have researched some methods including the gradient-based (GRAD) method, the constant threshold-based (THRESH) method, and the region growing (RG) method. For each method the same work flow is used and the tumor segmentation results are compared to the manual contouring (MC) by experienced physician which is widely used in clinical radiation therapy. The results show that the region growing is the most accurate to the MC and has the potential to play the most important role in radiation therapy.

Abstract: Hydraulic resistance of water flow in the xylem is mainly caused by Pits. Pits between vessels play an important role in the water transport of plant. The pit membrane worked as porous, the water flow through pit is modeled using CFD(Computational fluid dynamics) approach of low k-ε turbulence. Consiedered the deflection of homogeneous membrane affected by pressure difference, the pit hydraulic resistance calculated according to simulation results is consisent with hydraulic resistance value from direct measurements, which indicated that the model can provide reliable estimation the flow of water through pit.

Abstract: Cone beam CT based image guided radiation therapy can be used to measure and correct positional errors for target and critical structures immediately prior to or during the treatment delivery. Data correlation between Planning CT images and daily CBCT images is the key issue for adaptive radiation therapy, including image registration and segmentation processing. In this paper, aiming for getting accurate liver contour structures automatically in daily CBCT images which is very low-contrast comparing the planning CT, probabilistic atlas is constructed from 50 high contrast planning CT images with manual delineation by oncologist. The incoming CBCT images are registered with the atlas using the deformable registration algorithm, and the liver contour structures are generated automatically by using the deformation map. The experiment results demonstrate the efficiency of our algorithm.

Abstract: In this paper, architecture of Digital Water-marking Agent (DWA) is formally described by software behavior method. Five different roles of DWA is designed with Action Information Base (AIB) and Tree of Action (TOC). And the TOC of S_Agent class DWA is described in detail. Based on software behavior formal method, the architecture of DWA is rigorous and profound. And the purpose of more formal and practical expression to the DWA information system is achieved.

Abstract: With the continuous development of UAV remote sensing technology, UAV remote sensing will become one of the main airborne remote sensing platforms, Image acquisition and its post-processing of the UAV remote sensing have become focus of todays study. This paper presents an idea of image segmentation and image publication of UAV remote sensing, and provides reliable information for decision makers. It possesses a certain value.

Abstract: In this paper a high accuracy estimation algorithm of carrier frequency offset for MPSK signals in Gaussian white noise is proposed. Like the conventional practice, first the algorithm employs nonlinear processing to convert the MPSK signal to single sinusoidal signal, followed by windowed FFT, and then a method based on energy center correction is used to achieve accurate estimation. Simulation results have proved the feasibility,easiness of implementation, and the performance improvements in terms of accuracy and data length needed.

Abstract: Higher complexities of multiscale entropy (MSE) curve present the physiological system has the better ability to adapt under environment change. Traditional way to distinguish different complexity groups of MSE curves according to the area under MSE curves (AUC) by human self-determination, but that would be difficult to judge when some curves had similar AUC or had overlapped. This paper proposed a combination clustering and MR control chart to calculate the group distances as the response to assessment the clustering result of different MSE curves combination. From the experiment analysis result for ECG signal, using the four features considered in this paper could provide a good recognition in cluster MSE curves.

Abstract: Database encryption is the last defense to ensure data security, resolving the problem of insecurity caused by unencrypted data directly stored in database. At the same time, Database encryption has brought a new troubleencryption makes query efficiency become obviously slow. Cryptograph index is an effective method. In the DAS(Database as a service) model, a method based on bucket partitioning and B+ tree, which utilizes B+ tree to sort data in the bucket and improves the efficiency due to reduce the amount of processing data, is put forth in this paper. Finally, the paper has made an analysis on its performance.

Abstract: In this paper, a novel algorithm is proposed to accurately calculate Zernike moments in Cartesian Coordinates. We connect the corners of an image pixel with the origin to construct four triangles and then assign the intensity function value of the pixel to these triangles. The Fourier Mellin moment integration of the pixel is converted to a summation of four integrations within domains of these constructed triangles. By using the trigonometric resolution, we derive the analytic equations of the four integrations of these triangles. Then, the analytic expressions of the Fourier Mellin moments and Zernike moments are obtained. The algorithm eliminates the geometric and discretization errors theoretically. Finally, a set of efficient computational recursive relations is proposed. An experiment is designed to verify the performance of the proposed algorithm.

Abstract: The scheduled aircraft maintenance mode inevitably results in gradually descending reliability of avionics equipment with the increasing service cycle and maintenance frequency. The reliability predictive method is established based on data fusion. It can realize the predictive evaluation of avionics equipment reliability. The method of defining optimum maintenance cycle on scheduled aircraft maintenance is under the MSG-3 framework at presented.