The commercial software industry has a number of different operating system vendors offering various features. Real-time operating systems (RTOS's) are primarily proprietary, closed source, expensive, and uniquely...
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The commercial software industry has a number of different operating system vendors offering various features. Real-time operating systems (RTOS's) are primarily proprietary, closed source, expensive, and uniquely designed to specific applications. software designers must examine a given real-time operating system to ensure an RTOS will meet the real-time requirements for an intended platform. An RTOS does often not meet the original real-time constraints, when product evolves to new hardware platforms. This makes the evolution of real-time systems a cumbersome and difficult problem. In this paper we describe a new approach to real-time system development. Instead of reinventing software for a real-time system, we provide a generic and platform independent virtual machine. We discuss the design, architecture, and implementation of a real-time virtual machine (RTVM). The RTVM provides a generic real-time platform, where real-time applications using the Java paradigm can operate on various platforms without re-writing the code
Real-time software development from formal specifications requires tools and suitable supporting environments to facilitate the development process. The need for such tools becomes more pronounced if the development l...
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Real-time software development from formal specifications requires tools and suitable supporting environments to facilitate the development process. The need for such tools becomes more pronounced if the development language is Java; because Java suffers from the unpredictable behavior of the garbage collector. This paper presents a supporting environment for developing real-time software using Java from formal specifications in RTPA. The supporting environment has two major components: a real-time support library that provides extended real-time library functions for the generated Java code, and a real-time kernel (RTOS+) that provides efficient real-time services to the system. By automatically generating Java code from formal specifications, the programmer is relieved of the burden of interpreting the specification before writing code in Java and at the same time is able to take advantage to develop real-time applications in Java under the support of the real-time support environment
An abstract data type (ADT) is an abstraction of a data structure that specifies what information can be stored in the ADT and what operations can be done on/by the ADT. The file as a common type plays a primordial ro...
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An abstract data type (ADT) is an abstraction of a data structure that specifies what information can be stored in the ADT and what operations can be done on/by the ADT. The file as a common type plays a primordial role in software system development since it provides a means for manipulating large volumes of information and persistent data. However, the file ADT has not been given a formal semantics. Access to data stored in an ADT is through its interfaces. These interfaces and the operations that they represent should be rigorously defined so as to guarantee that their use will give expected results. This paper illustrates the use of real-time process algebra (RTPA) to formally describe both the data and operations of the file ADT. The difficulties in the file ADT specification are the formal description of its logical and physical models. The logical model of the file ADT is modeled using an indexing mechanism in which each record stored in the file is accessed through its address. The formal model is used in the file management system of RTOS+, a novel real-time operating system developed by the authors. RTPA has been found a very useful notation for describing the behavior of software systems
Two types of sensors are used in a two-tiered wireless sensor network (WSN). In each cluster of a given environment, there are small and low-cost sensor nodes (SN) that sense the environment phenomenon and send their ...
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Two types of sensors are used in a two-tiered wireless sensor network (WSN). In each cluster of a given environment, there are small and low-cost sensor nodes (SN) that sense the environment phenomenon and send their information to application nodes (AN). ANs remove redundant information and then transmit the data to base station (BS). Since the coverage of each cluster depends on the operation of its AN, power consumption of ANs is a critical factor in network lifetime. In this paper a power efficient data routing method to increase the network's lifetime in a two-tiered WSN is proposed which has fixed location ANs and BS. The proposed routing approach can be used in controlling the data flow routing path in time variant data bit rate WSNs in order to use the remaining power of the network as efficient as possible.
CBSD needs to customize and compose components. Customization and composition can cause faults which are hard to detect by existing testing techniques, since components have different structures from traditional progr...
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XP/Agile education and training remains a challenge from the perspective of determining relevant content;identifying effective methods for delivery;and maintaining the focus and motivation of students. This panel brin...
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In this paper, fuzzy sliding mode controller is designed to govern the dynamics of switched reluctance motor. First, magnetic characteristics data of the motor obtained by finite element method (FEM) is utilized for a...
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In this paper, fuzzy sliding mode controller is designed to govern the dynamics of switched reluctance motor. First, magnetic characteristics data of the motor obtained by finite element method (FEM) is utilized for a fuzzy estimation. Next, fuzzy sliding mode control approach has been utilized as a nonlinear robust control algorithm to deal with a highly nonlinear system with an unknown model and a variable load torque. Simulation results show an excellent tackling the problem with an acceptable control effort. Finally, an effective commutation algorithm has been coupled with the proposed controller which can reduce the acoustic noise resources.
This paper presents a new suboptimal design for stable fuzzy controller. Using fuzzy plant model and locally optimal gains (based on LQR design), we suggest a sufficient condition for stability of the closed-loop syst...
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This paper presents a new suboptimal design for stable fuzzy controller. Using fuzzy plant model and locally optimal gains (based on LQR design), we suggest a sufficient condition for stability of the closed-loop system that can be expressed as Linear Matrix Inequaloities. Provided that we have an accurate fuzzy model of the plant, the real system is globally stabel too. This new approach facilitates the design process much yielding sub-optimal global design. Simulation results show that even if we have not an exact fuzzsy model representation, this method increases attraction domain of the system comparing with conventional linear optimal contrllers.
A relatively general framework for designing robust controllers over communication networks is presented. It has the capability of handling randomly time-varying packet transmission delays and probability of packet lo...
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A relatively general framework for designing robust controllers over communication networks is presented. It has the capability of handling randomly time-varying packet transmission delays and probability of packet losses. The presented method can also handle multiple channels of communication simultaneously. Results are based on continuous time methods that use Lyapunov-Krasovskii functionals. It is shown via an example that how state feedback controllers can be designed based on LMIs. Fixed structure output feedback controllers have been designed based on BMIs.
A game is a decision making situation in which each player attempts to act in such a way that the game's circumstances get close to what desirable for him. To reach this goal, a player needs to have a suitable est...
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A game is a decision making situation in which each player attempts to act in such a way that the game's circumstances get close to what desirable for him. To reach this goal, a player needs to have a suitable estimation of the other players' decisions. In this paper, we propose a fuzzy approach by which a player can attain an estimation of the other players' actions and pursue a strategy which maximizes its performance. Finally, the results of applying the proposed approach to the well-known "prisoner's dilemma" problem are brought to show the effectiveness of the method
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