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Computer systems provide indispensable support in constructing, solving and implementing simulation models. This paper discusses a smoked meat inventory model with simulated demand. In order to make a more precise estimate of the demand, the proposed model implies the use of the beta distribution. Simulated demand values, generated by means of a computer, represent the inputs in the inventory model with price breaks. This model is characterized by taking into account the possibility of decreasing the purchase price when the ordered quantity is increased. In addition, the management needs to consider the fact that unsold smoked meat products past use-by date directly increase the costs and thus reduce store operation efficiency. In this model, for each simulated demand rate the order quantity is determined which results in minimum overall costs. The optimum order is thought to be the one which has been determined most frequently within the conducted set of simulations. In order to increase the model's use value, the decision-making process based on its use has been shown in a flowchart. Furthermore, the paper proposes an adequate computer program for solving the model, written in LINGO's modelling language. [ABSTRACT FROM AUTHOR]

This paper presents using of FlightGear application for flight simulation of a mini-UAV (Unmanned Aerial Vehicle). The first part of the paper is about general information of UAVs and about the fundamentals of airplane flight mechanics. The main section summarizes the information about FlightGear application and describes a way of using the application to simulate a mini-UAV. The process of altitude change by using autopilot has been simulated. In the created simulation, three stage cascade controller was used for an altitude control. Heading was controlled by 2 stage cascade PID (Proportional-Integral-Derivative) controller. An automatic throttle system was applied for a velocity control. The setting of all controllers is included in the description of the simulation. Finally, the results of FlightGear simulation are discussed. [ABSTRACT FROM AUTHOR]

Due to the physical limitations on the speed of individual processors, we are currently experiencing a paradigm shift in computer architecture towards multi-processor, multi-core and multi-subcore systems. In order to take full advantage of these new architectures, some of the basic models, algorithms and data structures in Molecular Dynamics simulations need to be re-thought. In this paper, I present some simple, generic algorithmic considerations that can improve the performance of such simulations on the IBM Cell Broadband Engine Architecture, a multi-subcore processor. The accumulated effects of these improvements are on par with what can be achieved with hand-tuned architecture-specific optimizations in the innermost loops of the simulation. [ABSTRACT FROM AUTHOR]

The paper is a contribution to effective using of simulation optimization. The article presents the results of the study evaluation of strategies control of production system. The authors have realized several control strategy on various simulation models. The simulation models of systems were created in the simulator Witness. The main goal was to show that mathematical formulas do not reflect so many factors, as like the objectives of production operates. The authors point out that the implementation of simulation optimization is better way to take into account the interdependence of the functions and limitations in the evaluation of control strategies. [ABSTRACT FROM AUTHOR]

The Exploration Systems Architecture defines missions that require rendezvous, proximity operations, and docking (RPOD) of two spacecraft both in Low Earth Orbit (LEO) and in Low Lunar Orbit (LLO). Uncrewed spacecraft must perform automated and/or autonomous rendezvous, proximity operations and docking operations (commonly known as Automated Rendezvous and Docking, AR&D). The crewed versions may also perform AR&D, possibly with a different level of automation and/or autonomy, and must also provide the crew with relative navigation information for manual piloting. The capabilities of the Rendezvous, Proximity Operations and Docking (RPOD) sensors are critical to the success of the Constellation Program; this is carried as one of the CEV Project top risks. The Exploration Technology Development Program (ETDP) AR&D Sensor Technology Project seeks to reduce this risk by increasing technology maturation of selected relative navigation sensor technologies through testing and simulation. One of the project activities is a series of “pathfinder” testing and simulation activities to integrate relative navigation sensors with the Johnson Space Center Six-Degree-of-Freedom Test System (SDTS). The SDTS will be the primary testing location for the Orion spacecraft's Low Impact Docking System (LIDS). Project team members have integrated the Orion GN&C simulation with the SDTS computer system so that real-time closed loop testing can be performed with relative navigation sensors and the docking system in the loop during docking and undocking scenarios. Two relative navigation sensors are being used as part of a “pathfinder” activity in preparation for future testing with the actual Orion sensors. This paper describes the test configuration and test results. [ABSTRACT FROM AUTHOR]

The conveyors with rollers are good examples for man-made anticipatory systems in the weak sense, as they represent rather complex systems. The control of them has to anticipate into their future. Nowadays the control is performed by computers and an idea arises to implement the model serving for the anticipation as a simulation model running at the controlling computer. The quality of the design is tested by simulation, too, and therefore the design-oriented simulation of the conveyors has to include their controlling and simulating computers. In other hand, the design-oriented simulation has to reflect the operating-oriented simulation. Some running models have been implemented using SIMULA and are presented. © 2004 American Institute of Physics [ABSTRACT FROM AUTHOR]