Computational Fluid Dynamics (CFD) deals with computing the equations of fluid flows using numerical methods. The Discrete-Event System specification (DEVS) theory has been used to approximate the continuous systems b...
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ISBN:
(纸本)9789898565693
Computational Fluid Dynamics (CFD) deals with computing the equations of fluid flows using numerical methods. The Discrete-Event System specification (DEVS) theory has been used to approximate the continuous systems by applying a quantized state system approach. In this research, we employ Cellular DEVS theory (Cell-DEVS) - originally proposed for modeling and simulation of spatial environments - to create a uniform set of rules for CFD. This harmonized set of state changes can effectively render the fluid dynamics, by applying the accurate rule that represents the behavior of the fluid. The combination of the simplicity and the mathematical backbone allows for constructing models computable on an average computer or an array of cluster computers.
The advantages of soft c-means over its hard and fuzzy versions render it more attractive to use in a wide variety of applications. Its main merit lies in its relatively higher convergence speed, which is more obvious...
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Arithmetic operation's execution time in real-time system is bounded by deadlines. The method commonly used to meet these deadlines is by employing any suitable process-scheduling algorithm, which may contain a po...
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ISBN:
(纸本)0769522033
Arithmetic operation's execution time in real-time system is bounded by deadlines. The method commonly used to meet these deadlines is by employing any suitable process-scheduling algorithm, which may contain a potential weakness. If time needed to operate is longer than its deadline, then the result's quality will be poor. This is mainly caused by the algorithms of the arithmetic operations commonly used nowadays do not choose the most significant data to be processed first. This research tries to design new algorithm and its processing unit that works based on real-time principles, which starts its computation process from the highest valued digit and provides its intermediate-results that can be accessed anytime during the process. Designing tool used in this research is MAX+plus II Baseline 10.2 software. This research accomplishes in showing the performance of the new algorithm and its processing unit, which is better than the performance of the conventional algorithm.
In response to increasing demands for true multimedia telecommunications services anywhere any time there are concerted efforts worldwide towards the definition and development of "future-generation" wireles...
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ISBN:
(纸本)076952835X
In response to increasing demands for true multimedia telecommunications services anywhere any time there are concerted efforts worldwide towards the definition and development of "future-generation" wireless systems which may be expected to enter service within the next ten years. These will differ from current and near-future systems such as second- and third-generation cellular, WIFI, WiMAX and 3G long term evolution systems, in several important aspects: The radio system will configure itself and adapt to a users' needs, the capabilities of the user's terminal, and to the environment scenario. A "user" may be a person or a device, such as a sensor. The system can easily adapt to local hot spot, metropolitan area or wide area scenarios, static or fast-moving. The system will support high user densities and a very wide range of user bit rates - Kilobits per second to hundreds of Megabits per second. All this will be achieved with efficient spectrum usage and sharing, low cost, and acceptably low terminal power consumption. Such future wireless systems (sometimes called "fourth generation" (4G), sometimes called "beyond third generation" (B3G)), capable of transporting very high bit rates In non-ideal radio propagation environments, must be robust to severe frequency selective multipath. Further requirements include moderate terminal and base station hardware costs, high spectral efficiency, and scalability of the cost of terminals with respect to their maximum bit rate capabilities. Reconfigurable air Interfaces, based on frequency domain transmission and reception methods, best meet these requirements, by adaptively selecting the uplink and downlink modulation and multiple access scheme that is most appropriate for the channel, Interference, traffic and cost constraints. In this talk we discuss a generalized frequency domain-based approach to next-generation wireless air interfaces, presenting examples and research results, including channel estimation and power
In industry, the advancement of digital engineering and the digital thread aims to reduce the impact of knowledge ‘siloes’ by providing a way to integrate data across the entire system lifecycle and across multiple ...
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We present a framework to simulate a peer-to-peer (P2P) file-sharing network, based on the Discrete Event systems Specification (DEVS) formalism. Our framework models a file-sharing network as a coupled model, compris...
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Complex physical systems have been studied for many years using different approaches. Skyscraper building heights are restricted by the design limitations of their elevator systems. Long cable elevator systems will ca...
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Large organizations now use Modeling and Simulation (MS) for complex systems. This evolution has also resulted in a lack of simple tools and processes to define models and experiments which hinders wide scale user ado...
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This paper presents a continuation of earlier work, where the performance of a MIMO-OFDM system in which a mobile terminal communicates with several antenna arrays located at different sites over a Rayleigh-Lognormal ...
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This paper presents a continuation of earlier work, where the performance of a MIMO-OFDM system in which a mobile terminal communicates with several antenna arrays located at different sites over a Rayleigh-Lognormal channel was investigated. In this paper we investigate the performance of the system when selecting antennas from distributed arrays in a Ricean-correlated channel environment. Significant improvement in ergodic capacity and in the ergodic condition number of the channel matrix is achieved due to the improved spatial properties of the MIMO channel.
Cellular networks have witnessed increasing demands for higher data rates in the recent years. Satisfying these demands presents a challenge for cellular network operators. Video traffic plays a major role in this, as...
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