Applied Mechanics and Materials Vols. 20-23

Abstract: Job-shop is the problem of allocating the tasks to machine tools with a time table satisfying a set of objectives. Currently researches on Job-shop generally take the independent production processing as the study case. It is still difficult to schedule the production processing with complex correlated features. Taking the shop with m machine tools and n waiting correlated tasks as the study case, this research proposes an evolutionary algorithm-based and correlated constraint-driven optimization method to overcome the above difficulty. First, the tasks are classed as the correlated tasks and independent tasks according to the correlated features and the priority levels, which construct the foundation of modeling for complex correlated constraints. And then, the objective function is built taking the lower production cost and higher equipment capacity factor as optimization objectives. Finally, the optimization model is developed and solved with the specialized evolution algorithm. The simulation with the Matlab demonstrates the feasibility of the novel methodology.

Abstract: In order to reach a consensus on the concept of unified communication and promote the development of unified communication, many organizations begin to research the standardization of unified communication and the reference model of unified communication is an important component. In this paper, we will do some research on the unified communication business needs and technical means, and then introduce a reference model of unified communication which is based on SIP/SIMPLE, using this model to build unified communication business will become easier.

Abstract: A wave motion compensating platform has the function of compensating the ship’s generalized heave motion (a coupling result of roll, pitch and heave). It can decrease the impact of ship motion on some sea works and equipments. The hydraulic mechanism of platform system has the characteristics of nonlinear and big inertia. In order to compensate generalized heave motion effectively, an adaptive predictive control policy is used for controlling the hydraulic mechanism. Based on equal-dimension and new information, an automation regressive model can get adaptive multi-step prediction. The model parameter estimation based on the least square algorithm is easy to blow up and be unstable when the system has random noise. To improve the problem solution, a damped recursive least square algorithm is proposed to estimate the parameters on line. For the short regulation time, strong anti-disturbance ability and great robustness, a nonlinear PID controller whose gain parameters vary with errors is suitable for controlling the hydraulic mechanism. Using the collected experimental data, the simulations suggest that adopting the above adaptive predictive control policy to control hydraulic mechanism is able to decrease the generalized heave amplitude of wave motion compensating platform.

Abstract: The traditional Dynamic Route Guidance System (DRGS) provides only the optimal path to the travelers, which may easily lead to aggregative response of the travelers and overcrowding drift. This paper presents an approach based on Ant Colony Optimization (ACO) for solving the k-shortest paths problem in DRGS. In order to improve the convergence rate, the basic ACO is improved by introducing direction function the weight coefficient of which can be adjusted to vary state transition rule and standardized transformation to eliminate the influence of the size and dimension of pheromone and heuristic information. Compared with basic ACO, simulation experiments indicate that the improved ACO is more effective and efficient.

Abstract: Wireless sensor networks are going to play a more and more important role in applications of next generation manufacturing systems. In this paper, we present a secure and intelligent wireless sensor network framework for manufacturing monitoring. We try to solve the problem of manufacturing monitoring from a new point of view. We introduce the layered architecture of the wireless sensor network framework in detail. Considering the vulnerable feature of Wireless sensor network, we also propose a secure mechanism based on the structure of wireless sensor network by using the anomaly detection technology. The major contribution of this paper is that we integrate wireless sensor network with secure and intelligent technologies to improve the overall performance of manufacturing monitoring.

Abstract: The CNC technology, which directly decides the function and performance of the manufacturing equipments, is the key technique group that supports the modern equipment manufacturing industry. And it is also the key technique for equipment layer which can push forward industrialization with informatization. By the research of open numerical control system, a kind of CNC system has been constructed based on IPC and PMAC motion control card using the designing method of modularization. By test and research, it has been proven that the Open Numerical Control system has complete functions and excellent performance, and can meet the request of modern numerical control machine tool for open numerical control system.

Abstract: The EPC of tags has uniqueness, different tags can be distinguished by its binary-tree structure. In the reader's processing area, there are a lot of idle nodes in the binary-tree that is composed of some tags. If the reader ignores them when searching, all tags can be identified with high efficiency. In this paper, its mathematic model of efficiency is analyzed from simplicity to complexity. First of all, the case of two tags with four bits EPC is explained, then the case of two tags with N bits EPC is generalized. Secondly, by converting complexity into simplicity, a general conclusion is obtained based on probability and induction. Its simulating result indicates that its rate of identification is 50%.

Abstract: Considering constant-round protocols for generating random shared values, for secure multiplication and for addition of shared values, etc are available and can be met by known techniques in all standard models of communication. Protocols are presented allowing the players to securely solve standard computational problems in linear algebra. In particular, securely, efficiently and in constant-round compute determinant of matrices product, rank of a matrix, and determine similarity between matrices. If the basic protocols (addition and multiplication, etc) are unconditionally secure, then so are our protocols. Furthermore our protocols offer more efficient solutions than previous techniques for secure linear algebra.

Abstract: Multi-hop cooperative MIMO network that consists of multiple nodes each equipped with single antenna is introduced and investigated. Optimal power allocation scheme with selective decode-and-forward (SDF) cooperative strategy is formulated and solved by means of optimization method with the purpose of minimization of system’s symbol error rate (SER), which are derived and analyzed with numerical results presented. Distributed space-time block Code (DSTBC) in multi-hop cooperative MIMO is analyzed and compared with optimal power allocation scheme with SDF strategy. Simulation results reveal that, cooperative diversity could be achieved with optimal power allocation. Optimum power allocation scheme depends on the relay’s position and channel quality between source to relay and relay to destination. Novel performance comparison between optimal power allocation and DSTBC are researched and presented. Simulation results confirm our theoretical analysis, which indicates that multi-node DSTBC outperforms optimal power allocation scheme due to the fact that cooperative diversity gain and coded gain could be obtained simultaneously for DSTBC in multi-hop cooperative MIMO network.

Abstract: We present, illustrate and analyze some basic notions of the Lagrange Representation (LR) over finite fields, and elementary theory of Optimal Extension Fields. In combining the Lagrange Representation theory and the Frobenius mapping theorem, we could establish an inversion algorithm in the LR version. Our contribution is of adapting an addition-chain-like method over an Optimal Extension Field to the Lagrange Representation.