IJIEEB Vol. 2, No. 2, Dec. 2010
Cover page and Table of Contents: PDF (size: 124KB)
REGULAR PAPERS
According to the high precision demand of estimating frequency of arrival (FOA) and time of arrival (TOA) in Galileo search and rescue (SAR) system, and considering the uncertainty of message bit width in actual received COSPAS-SARSAT beacons, a new FOA and TOA estimation algorithm which combines the Multiple Dimensions Joint Maximum Likelihood Estimation (MJMLE) algorithm and Barycenter calculation algorithm is proposed. The principle of the algorithm is derived and the concrete realization of the algorithm is given. Both Monte Carlo simulation and experimental results show that when CNR equals to the threshold of 34.8dBHz, root-mean-square errors (rmse) of FOA and TOA estimation in this algorithm are respectively within 0.03Hz and 9.5us, which are less than the system requirements of 0.05Hz and 11us. This algorithm has been applied to the Galileo Medium-altitude Earth Orbit Local User Terminal (MEOLUT station).
[...] Read more.Stress wave propagation effect and failure characteristic of limestone were studied by one-stage light-gas gun induced-plate impact experiment technology. The experiment results indicate that dispersion effect and attenuation characteristic exist in impacting rock. The failure of rock sample has division characteristics, which are head failure zone, middle tension-compression failure zone and tail fracture failure zone. On this basis, the dynamic mechanical response of rock target under impact loading was analyzed by LS-DYNA finite element method. Stress-time curves in different impact velocities were obtained by sensors buried in rock target. The comparative analysis of experiment and simulation show that the main reason of rock failure is the joint action of longitudinal compression wave and transverse sparse wave, and the conclusions have some significance on guiding farther dynamic mechanical experiment of rock.
[...] Read more.This research builds a VMI inventory decision model of supplier-driver supply chain to analyze the effects of VMI on a supply chain performance and announce the important function of VMI in promoting supply chain coordination, reducing costs and increasing profits. According to this model, VMI is found always to reduce the system’s(buyer and supplier together) and the buyer’s inventory related costs in the short-term, but the supplier's inventory related costs varies. Under certain cost conditions between buyer and supplier, VMI can increase the system’s and the buyer’s profits. And the supplier's profits can be increased under other conditions. Using the corresponding MATLAB program, obtains some calculation results. And through computer simulation, analyzes the effects of VMI on supply chain performance, and announces the important function of VMI in promoting supply chain coordination, reducing costs and increasing profits.
[...] Read more.The compound Poisson risk model and the compound Poisson risk model perturbed by diffusion are considered in the presence of a dividend barrier with solvency constraints. Moreover, it extends the known result due to [1]. Ref. [1] finds the optimal dividend policy is of a barrier type for a jump-diffusion model with exponentially distributed jumps. In this paper, it turns out that there can be two different solutions depending on the model’s parameters. Furthermore, an interesting result is given: the proportional transaction cost has no effect on the dividend barrier. The objective of the corporation is to maximize the cumulative expected discounted dividends payout with solvency constraints before the time of ruin. It is well known that under some reasonable assumptions, optimal dividend strategy is a barrier strategy, i.e., there is a level so that whenever surplus goes above the level , the excess is paid out as dividends. However, the optimal level may be unacceptably low from a solvency point of view. Therefore, some constraints should imposed on an insurance company such as to pay out dividends unless the surplus has reached a level . We show that in this case a barrier strategy at optimal.
[...] Read more.The estimation of aeroengine component deviation parameters (CDP) is an important portion of aeronautical propulsion system performance-seeking control (PSC), which employs linear Kalman filter based on piecewise state variable model (SVM) traditionally. But it’s not easy to get SVM, and the process of linearizing the nonlinear model to get the SVM will introduce errors. So parameters nonlinear estimation was introduced based on the nonlinear aeroengine model directly. The nonlinear estimation model is established according to aeroengine operation balance and the measured and calculated values matching of measurable parameters. The nonlinear estimation was changed to a problem of solving complex nonlinear equations, which is equal to an optimization problem. Time-varying inertia weight particle swarm optimization (PSO) with constriction factor was employed to solve the problem in order to satisfy the requirement of precision and calculation speed. The simulation results of a given turbofan engine show that utilizing the improved PSO algorithm can estimate the CPD precisely with satisfied converging speed.
[...] Read more.In order to solve the problem due to the vehicle-oriented society such as traffic jam or traffic accident, intelligent transportation system(ITS) is raised and become scientist’s research focus, with the purpose of giving people better and safer driving condition and assistance. The core of intelligent transport system is the vehicle recognition and detection, and it’s the prerequisites for other related problems. Many existing vehicle recognition algorithms are aiming at one specific direction perspective, mostly front/back and side view. To make the algorithm more robust, our paper raised a vehicle recognition algorithm for oblique vehicles while also do research on front/back and side ones. The algorithm is designed based on the common knowledge of the car, such as shape, structure and so on. The experimental results of many car images show that our method has fine accuracy in car recognition.
[...] Read more.In this paper, we consider an extension to a dual model under a barrier strategy, in which the innovation sizes depend on the innovation time via the FGM copula. We first derive a renewal equation for the expected total discounted dividends until ruin. Some differential equations and closed-form expressions are given for exponential innovation sizes. Then the optimal dividend barrier and the Laplace transform of the time to ruin are considered. Finally, a numerical example is given.
[...] Read more.In this paper, the theory of a variable structure model following control (VSMFC) is employed to the design of the controller for an active suspensions of 4-degree-of-freedom (4-DOF) automobile model. The sliding mode equation is derived by applying VSMFC theory and the parameters of the switching function are obtained by using the method of pole assignment; a hierarchical algorithm with control variables started in sequence is applied to solve the active force; a method of exponential approach law is used to improve the dynamic performance of the controller. The efficacy of the controller is verified by simulation carried out with the help of Matlab/ Simulink. The results show that the active suspension controller based on VSMFC theory is superior in both robustness and performance.
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