In order to achieve attitude control of the six degrees of freedom Steward dynamic platform, as well as the real time simulation cockpit attitude, Washout Filtering method was adopted in this paper as the simulation a...
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In order to achieve attitude control of the six degrees of freedom Steward dynamic platform, as well as the real time simulation cockpit attitude, Washout Filtering method was adopted in this paper as the simulation algorithm to derive Washout Filter high-pass, low-pass filter transfer function into a differential equation algorithm and longitudinal acceleration tilt strategy, pitching strategies etc. Experimental examples are used to verify correctness of the algorithm.
With the significant rise in demand for same-day instant deliveries, several courier services are exploring alternatives to transport packages in a cost- and time-effective, as well as, sustainable manner. Motivated b...
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With the significant rise in demand for same-day instant deliveries, several courier services are exploring alternatives to transport packages in a cost- and time-effective, as well as, sustainable manner. Motivated by a reallife case study, this paper focuses on developing a simulation algorithm that assists same-day package delivery companies to serve customers instantly. The proposed recommender system provides the best solution with respect to three criteria: cost, time, and sustainability, considering the variation in travel time and cost parameters. The decision support tool provides recommendations on the best alternative for transporting products based on factors, such as source and destination locations, time of the day, package weight, and volume. Besides considering existing new technologies like electric-assisted cargo bikes, we also analyze the impact of emerging methods of deliveries, such as robots and air taxis. Finally, this paper also considers the best delivery alternative during the presence of a pandemic, such as COVID-19. For the purpose of illustrating our approach, we consider the delivery options in New York City. We believe that the proposed tool is the first to provide solutions to courier companies considering evolving modes of transportation and under logistics disruptions due to pandemic.
The continuous wave (CW) illuminator is aimed to simulate high-altitude nuclear electromagnetic pulse. In this article, a simulation algorithm is proposed covering the method of moments and finite difference method (F...
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The continuous wave (CW) illuminator is aimed to simulate high-altitude nuclear electromagnetic pulse. In this article, a simulation algorithm is proposed covering the method of moments and finite difference method (FDM), with the high-speed simulation of the CW illuminator with arbitrary ellipse size, arbitrary loading, and arbitrary polarization direction. Based on the surface electric field equation of the CW illuminator, the mathematical model is established with the vector potential equation and the boundary conditions. In this model, the pulse function and delta function are set as the basis function and the weight function, respectively, for the establishment of the current equation, with the current distribution determined by the simplification equation with image theory and nonuniform FDM. Finally, as the field distribution is determined by the superposition theorem. The simulation algorithm is verified by the self-built CW illuminator.
We show how bisimulation equivalence and simulation preorder on probabilistic LTSs (PLTSs), namely the main behavioural relations on probabilistic nondeterministic processes, can be characterized by abstract interpret...
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We show how bisimulation equivalence and simulation preorder on probabilistic LTSs (PLTSs), namely the main behavioural relations on probabilistic nondeterministic processes, can be characterized by abstract interpretation. Both bisimulation and simulation can be obtained as completions of partitions and preorders, viewed as abstract domains, w.r.t. a pair of concrete functions that encode a PLTS. This approach provides a general framework for designing algorithms that compute bisimulation and simulation on PLTSs. Notably, (i) we show that the standard bisimulation algorithm by Baier et al. (2000) can be viewed as an instance of such a framework and (ii) we design a new efficient simulation algorithm that improves the state of the art.
Using a new microcanonical algorithm efficiently vectorized on a Cray XMP, we reach a simulation speed of 1.5 nsec per update of one spin, three times faster than the best previous method known to us. Data for the non...
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Using a new microcanonical algorithm efficiently vectorized on a Cray XMP, we reach a simulation speed of 1.5 nsec per update of one spin, three times faster than the best previous method known to us. Data for the nonlinear relaxation with conserved energy are presented for the two-dimensional Ising model.
In milling process, surface topography is a significant factor that affects directly the surface integrity and constitutes a supplement to the form error associated with the workpiece deformation. Based on the tool ma...
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In milling process, surface topography is a significant factor that affects directly the surface integrity and constitutes a supplement to the form error associated with the workpiece deformation. Based on the tool machining paths and the trajectory equation of the cutting edge relative to the workpiece, a new and general iterative algorithm is developed here for the numerical simulation of the machined surface topography in multiaxis ball-end milling. The influences of machining parameters such as the milling modes, cutter runout, cutter inclination direction, and inclination angle upon the topography and surface roughness values are studied in detail. Compared with existing methods, the basic advantages and novelties of the proposed method can be resumed below. First, it is unnecessary to discretize the cutting edge and tool feed motion and rotation motion. Second, influences of cutting modes and cutter inclinations are studied systematically and explicitly for the first time. The generality of the algorithm makes it possible to calculate the pointwise topography value on any sculptured surface of the workpiece. Besides, the proposed method is proved to be more efficient in saving computing time than the time step method that is commonly used. Finally, some examples are presented and simulation results are compared with experimental ones.
The paper considers an efficient simulation algorithm for discrete event systems with a great number of elements. With the use of Petri-object simulation and parallel computing, the algorithm is developed that simulta...
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The paper considers an efficient simulation algorithm for discrete event systems with a great number of elements. With the use of Petri-object simulation and parallel computing, the algorithm is developed that simultaneously reproduces operation of Petri objects in separate streams. The linear dependence of the runtime of the algorithm on model's complexity is confirmed by experimental results.
A time-reversible algorithm for the rotation of rigid body in the quaternion representation named "Improved Fast Time-reversible algorithm(IFT)" is *** a preceding paper,we have proposed "Fast Time-reve...
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ISBN:
(纸本)9781510811980
A time-reversible algorithm for the rotation of rigid body in the quaternion representation named "Improved Fast Time-reversible algorithm(IFT)" is *** a preceding paper,we have proposed "Fast Time-reversible algorithm(FT)" that is not only time reversible but also conserves the total energy well and one of the simplest time reversible ***,the algorithm involves a square root,which yields the risk of computer crash at extreme high *** IFT gets rid of the risk of crash and the stability is no less than the Fast Timereversible *** IFT can be used more widely than *** also introduce some results concerning quasi liquid layer obtained from large-scale *** simulations were performed by the use of IFT algorithm.
Gas-solid heat transfer during dilute phase pneumatic conveying is numerically studied by formulating and solving a two-dimensional, two-fluid model. The model is arrived after neglecting minority terms in the governi...
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Gas-solid heat transfer during dilute phase pneumatic conveying is numerically studied by formulating and solving a two-dimensional, two-fluid model. The model is arrived after neglecting minority terms in the governing equations. A new algorithm for solution of governing equations is proposed, that is non-iterative and computationally less intensive. The performance of simulation algorithm is verified in comparison with the literature data. Heat transfer simulations have been carried out for particles of different sizes at a constant solid to gas mass flow ratio. Various aspects of profiles of phase velocities and temperatures and the effect of particle size on these profiles have been discussed. (c) 2006 Elsevier Ltd. All rights reserved.
Time Petri nets (TPNs) have been widely used for modeling discrete event systems such as manufacturing, supply chain, and military systems. However, TPNs still have many drawbacks in some scenarios where an operation ...
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Time Petri nets (TPNs) have been widely used for modeling discrete event systems such as manufacturing, supply chain, and military systems. However, TPNs still have many drawbacks in some scenarios where an operation or process is associated with probability, and also lack appropriate simulation algorithms for analyzing different types of systems. In this paper, we address these two issues by proposing a class of extended time Petri nets (ETPNs) and presenting an appropriate simulation algorithm. We illustrate and validate our approach using a hypothetic command and control system, which shows that this approach could be a powerful tool for modeling and analyzing discrete event systems.
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