Applied Mechanics and Materials Vols. 397-400

Abstract: Change orders present one of the largest sources of cost growth on building construction projects and have negative impact on productivity, labor efficiency and building environment. Building Information Modeling (BIM) is proved a high technology that greatly benefits both design and construction, greatly promoting the design visualization and construction 4-D modeling. Driven by BIM, Integrated Project Delivery (IPD) emphasizes communication in the collaborative process by avoiding adversarial or counter-productive professional relationships to reduce waste and rework. If BIM&IPD can be properly applied in project, quite a lot change orders can be avoided and then project cost will be reduced. This paper investigates the impact of BIM&IPD on construction change orders using Bayesian Network method. Bayesian Network is a graphic model representing cause and effect relationship between change orders and BIM&IPD. In this paper, evidence reasoning and probabilistic inference analyses are conducted to indicate the causes in light of the results and forecast the results according to causes. From the analysis, Bayesian Network is proved a good tool for construction managers to make decisions.

Abstract: Aiming at the problems of institutional repositories content constructing, this paper firstly introduces the overview, development and working mechanism of SWORD(Simple Web-service Offering Repository Deposit), and then analyzes some methods based on SWORD to deposit content into institutional repositories.

Abstract: A new AQM algorithm based on state variable feedback control (SPC) is proposed. The future dynamic queue length in data buffer predicted by state space model is successfully introduced into feedback data's advanced prediction to compensate feedback delay. Finally, the control requirement of congestion is converted to optimal control objective function, and drop probability is obtained by solving the optimal problem. The simulation results show that the queue length with SPAQM algorithm reaches the desired value with minimal tracking error and lower drop probability. SPAQM algorithm has better performance than PID algorithms and RED algorithms in terms of disturbance rejection, stability, and robustness.

Abstract: This paper discusses synchronization of two different complex dynamical networks with interconnection, an useful criteria for synchronization is given. We can draw a conclusion that the more points to connect between two different networks, the shorter time to achieve synchronization.

Abstract: Computer network is popular in colleges for undergraduate students, which is focusing on practice and demands the students to grasp the configuration for different kinds of network devices, but network laboratory is not established completely in colleges due to the high cost of network devices .The article put forwards a solution based on virtualization tool named Packet Tracer, which provides network simulation, visualization and collaboration capabilities. This paper presents the features of the virtual simulation tool, and the configuration example for mini VLAN practice project, this method can help students to understand and master the complex and abstract network concepts.

Abstract: Due to the problem of network structure, security, redundant path in traditional network, this can be solved by Virtual Local Area Network (VLAN) technology. As the network laboratory in colleges and universities is not perfect because of high cost, a virtual simulation tools named Packet Tracer has been introduced to computer network experimental curriculum, this paper put forwards the detail design scheme by the example of VLAN with three switches, and provides the experiment and theoretical analysis and simulation verification .The practice has proved this method not only deepens students comprehension of network, but also cultivates the students' actual comprehensive ability.

Abstract: Video encryption has been widely researched in digital right management in recent years, especially selective video encryption. Selective video encryption has been the main trend with the development of compression coding methods, which selects an important subset of the comparative large compressed video data to encrypt in order to satisfy the real-time features and ensure the security of the video at the same time. In this paper, according to a particular evaluation criterion we proposed, we mainly analyze several selective video encryption algorithms based on the H.264 standard. Through the analysis we find out how to select the different vital data sets of the video to encrypt according to various security levels and applications.

Abstract: Due to the incipient fault attributes of gear are not obvious, So a hybrid diagnosis model to gear diagnosing based on Ensemble Empirical Mode Decomposition (EEMD) and Genetic-Support Vector Machine (GSVM) was proposed. With the method of EEMD,the gear vibration signals are adaptively decomposed into a finite number of Intrinsic Mode Function (IMF),which can alleviate model mixing that may appear in conventional EMD method. It calculates the energy character vectors of every IMF components,energy feature extracted from a number of IMFs that contained the most dominant fault information could serve as input genetic-vectors of support vector machine. The proposed model is applied to the gear testing system, and the results show that the diagnosis approach was effectively.

Abstract: The time resolved partial discharge (TRPD) signals collected by Ultra High Frequency (UHF) sensors of transformer contain important informations of the properties of faults. Wealth of information can be utilized for fault identification by different signal analyzing techniques, such as time domain analysis, frequency domain analysis and the wavelet analysis. An integrated characteristic information fusion system based on the Platt posterior probability model and support vector machine (SVM) one-against-one method is proposed. From the recognition result of the four typical insulation defects, the recognition system shows strong advantages in accuracy and reliability.

Abstract: To improve the resolution of the seismic section after deconvolution, a method based on frequency-domain experience mode decomposition was proposed. Empirical mode decomposition (EMD) method is usually used to analyze the time domain non-stationary signal, in order to better recover original reflection coefficient sequence, empirical mode decomposition was implemented for frequency-domain amplitude spectrum. Through the different characteristics between the equivalent filter amplitude after deconvolution and reflection coefficient sequence amplitude in frequency-domain, the real reflection coefficient sequence was recovered. Simulation results indicate that the method is effective and feasible.