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Whilst the concept of a virtual metacomputer over a networked collection of heterogeneous computer systems has slowly emerged. there are still some shortcomings of these systems. For example. some systems are still incapable of balancing the load amongst the workstations; the problem is accentuated by the heterogeneity of the computers. In this paper. we first discuss the design issue of our centralized task scheduler. and then present our implementation details. To use the task scheduler. some new library routines are provided. The task scheduler is layered above PVM; this has the advantage of retaining its portability. Since load-balancing is considered in task scheduling. our approach has been also proven to be more effective than the existing PVM round-robin task allocation scheme.

Due to their structure and complexity, chaotic systems have been introduced in several domains such as electronic circuits, commerce domain, encryption and network security. In this paper, we propose a novel multidimensional chaotic system with multiple parameters and nonlinear terms. Then, a two-phase algorithm is presented for investigating the chaotic behavior using bifurcation and Lyapunov exponent (LE) theories. Finally, we illustrate the performances of our proposal by constructing three (03) chaotic maps (3-D, 4-D and 5-D) and implementing the 3-D map on Field-Programmable-Gate-Array (FPGA) boards to generate random keys for securing a client–server communication purpose. Based on the achieved results, the proposed scheme is considered an ideal candidate for numerous resource-constrained devices and internet of the things (IoT) applications.

This paper presents a modified numerical substructure method for simulating the dynamic response of vehicle–track–bridge (VTB) systems. The method can be used to analyze large-scale VTB systems accurately and efficiently. Based on the principle of virtual work, the equations of motion are derived for two separate subsystems, i.e. a small-scale of finely modeled VTB substructure and a coarsely meshed large main bridge subsystem using different level of refinement. Different from the conventional dynamic substructuring approaches, the bridge spans close to the vehicle are modeled in both the main and substructure models, and the contradiction of repeatedly modeling is solved using a “nonlinear force corrector”. A special wheel–rail interaction (WRI) element is used to simulate the fast-moving interaction force between the vehicle and rail. In this way, the two models remain unchanged while the vehicle moves forward, and the computational accuracy is the same as the large-scale purely refined model, while the efficiency is significantly improved, particularly, for the large-scale long VTB systems. Two examples of realistic VTB systems with either smooth or un-smooth rails are used to verify the proposed method. The results demonstrate that the presented method has remarkable advantages of computational efficiency and accuracy, providing a practically useful tool for analysis of large-scale VTB systems.

In this paper, a mobile augmented reality (AR) framework for on-site finite element analysis (FEA) is proposed. The proposed framework is achieved using a client–server architecture. The performance of FEA relies on several important components, namely, computational power, visualization technique, and numerical analysis. AR renders intuitive computer-generated contents directly on a user’s surroundings. Integrating FEA with AR helps users through enhancing their perception and interaction with the engineering problems. Correct and effective visualization of these data using an AR platform can reduce the misinterpretation in spatial and logical aspects. Over the past decade, AR has undergone a transition from desktop to phablet computing. Mobile platforms enable user exploration of FEA results in situ. The client side uses a hybrid method to visualize FEA results in the mobile AR environment. In addition, a user can collaborate with other users by using the result sharing function. A prototype with basic functions has been built and a case study has been implemented to demonstrate the visualization method and evaluate the overall performance.

With the mutual promotion and development of computing technology, communication technology and control technology, building control systems by multiple machines has become a trend. The reliability of communication mechanism in these systems is the basic guarantee of system effectiveness. In this paper, a communication mechanism suitable for centralized and distributed control systems is proposed, which attempts to provide an effective framework for the design of communication subsystems in the system. The mechanism includes the logical structure of the communication network, RPC of Client-Server used in a control system, protocol and its basic functions. The basic function of the protocol is concretization and leaves a large expansion space, so this mechanism can be directly applied to the engineering design of medium and small control system, and has good flexibility and scalability.