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A Modeling Methodology for an RTOS
Title
A Modeling Methodology for an RTOS.
Creator
Islam, Sifat, Shankar, Ravi, Florida Atlantic University
Abstract/Description
Enhanced system design productivity is key to satisfying time-to-market demands. One will have to exploit design reuse methodology to meet project schedule requirements. Integration of components often fails due to various concurrency violations. Concurrency issues arise when components executing in parallel share resources and interact with each other. Such a system may have intermittent, yet catastrophic failures, if these concurrency issues are not addressed properly. In this thesis, we...
Show moreEnhanced system design productivity is key to satisfying time-to-market demands. One will have to exploit design reuse methodology to meet project schedule requirements. Integration of components often fails due to various concurrency violations. Concurrency issues arise when components executing in parallel share resources and interact with each other. Such a system may have intermittent, yet catastrophic failures, if these concurrency issues are not addressed properly. In this thesis, we propose a methodology for developing concurrency compliant components from a requirement document. We have applied this methodology for developing process management and memory management aspects of a Real Time Operating System (RTOS). In this methodology, we start from a "customer' s" requirement document that is then mapped to activity diagram, swimlane diagram, class diagrams, and use case diagrams. To evolve a concurrency compliant design, we use the Message Sequence Chart plug-in for the Labeled Transition State Analyzer (LTSA). This plug-in lets us use Message Sequence Charts rather than coding in Finite State Processes (FSP). Later, we use MLDesigner to simulate our R TOS sub-system and demonstrate proper behavior of this sub-system.
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Date Issued
2007
PURL
http://purl.flvc.org/fau/fd/FA00012528
Subject Headings
Computer architecture, Object-oriented programming (Computer science), Real-time programming, Operating systems (Computers)
Format
Document (PDF)
Object-oriented design of flexible manufacturing systems
Title
Object-oriented design of flexible manufacturing systems.
Creator
Abou-Haidar, Bassam., Florida Atlantic University, Fernandez, Eduardo B.
Abstract/Description
This thesis presents a systematic method for the design and modeling of flexible manufacturing systems, using object-oriented concepts and Petri nets. In the method proposed, we first define the system components in terms of an object model consisting of hierarchical sets of classes and operations. Secondly, we model the dynamic aspects of the system using statecharts, including exceptions. As a third step, we derive Petri nets from those statecharts to realize the concurrency present in the...
Show moreThis thesis presents a systematic method for the design and modeling of flexible manufacturing systems, using object-oriented concepts and Petri nets. In the method proposed, we first define the system components in terms of an object model consisting of hierarchical sets of classes and operations. Secondly, we model the dynamic aspects of the system using statecharts, including exceptions. As a third step, we derive Petri nets from those statecharts to realize the concurrency present in the system. Finally we develop a hierarchy of controllers, corresponding to the layers of the object model, for the independent components of the system based on the Petri nets obtained in the previous step.
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Date Issued
1993
PURL
http://purl.flvc.org/fcla/dt/14989
Subject Headings
Petri nets, Flexible manufacturing systems, Object-oriented programming (Computer science), Real-time control
Format
Document (PDF)
Realization and implementation of separable-in-denominator two-dimensional digital filter
Title
Realization and implementation of separable-in-denominator two-dimensional digital filter.
Creator
Huang, Ziqiang., Florida Atlantic University, Zilouchian, Ali
Abstract/Description
In this thesis, a partial fraction expansion of a separable-in-denominator 2-D transfer function is given. Based on this expansion, several novel realizations of separable-in-denominator 2-D filter are provide. These realizations have the properties of highly parallel structure and improved throughput delay. The performance figures are given in the tables. A method of evaluation of quantization error of separable-in-denominator 2-D filter is also derived by using the residue method. Formulas...
Show moreIn this thesis, a partial fraction expansion of a separable-in-denominator 2-D transfer function is given. Based on this expansion, several novel realizations of separable-in-denominator 2-D filter are provide. These realizations have the properties of highly parallel structure and improved throughput delay. The performance figures are given in the tables. A method of evaluation of quantization error of separable-in-denominator 2-D filter is also derived by using the residue method. Formulas for calculation of roundoff noise of proposed structures are provided. Two programs which can be used to calculate the roundoff noise of proposed structure are listed in the Appendix. To run the programs, we need only to input the constant coefficients of expanded transfer function. At last, an optimal block realization of separable-in-denominator 2-D filter is discussed and the criterion for the absence of limit cycles for a second-order 2-D block is given.
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Date Issued
1992
PURL
http://purl.flvc.org/fcla/dt/14879
Subject Headings
Real-time data processing, Image processing--Digital techniques, Electric filters, Digital--Computer programs
Format
Document (PDF)
Extensions to real-time object-oriented software design methodologies
Title
Extensions to real-time object-oriented software design methodologies.
Creator
Woodcock, Timothy G., Florida Atlantic University, Fernandez, Eduardo B., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
Real-time systems are systems where time is considered a system resource that needs to be managed. Time is usually represented in these systems as a deadline to complete a task. Unfortunately, by adding timing to even simple algorithms, it complicates them greatly. Real-time systems are by nature difficult and complex to understand. Object-oriented methodologies have attributes that allow real-time systems to be designed and implemented with less error and some control over the resultant...
Show moreReal-time systems are systems where time is considered a system resource that needs to be managed. Time is usually represented in these systems as a deadline to complete a task. Unfortunately, by adding timing to even simple algorithms, it complicates them greatly. Real-time systems are by nature difficult and complex to understand. Object-oriented methodologies have attributes that allow real-time systems to be designed and implemented with less error and some control over the resultant complexity. With object-oriented design, the system is modeled in the environment that it will be used in. Objects themselves, are partitions of the system, into logical, understandable units. In this dissertation, we start by surveying the current real-time object-oriented design methodologies. By comparing these methodologies and developing a set of criteria for evaluating them, we discover that certain aspects of these methodologies still need some work. The most important aspects of the methodologies are understanding the effects of deadlines on statechart behavioral models and understanding the effects of deadlines when object models are inherited or undergo aggregation. The effects of deadlines on statecharts are then explored in detail. There are two basic ways that deadlines are added to statecharts. The first, and most popular, is adding timing as a condition on a state transition. The second is adding a count down timer to a state and forcing a transition if the timer reaches zero. We show that these are equivalent and can be used interchangeably to simplify designs. Next, the effects of deadlines on behavior models when the corresponding object models undergo inheritance or aggregation are studied. We will first analyze the effects on the behavior model when object inheritance is encountered. We found eight ways that the behavior model can be modified and still maintain the properties of inheritance. Finally, deadlines are added and the analysis is repeated.
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Date Issued
1996
PURL
http://purl.flvc.org/fcla/dt/12493
Subject Headings
Real-time data processing, Computer software--Development, Object-oriented programming (Computer science)
Format
Document (PDF)
methodology for object-oriented modeling and design of real-time, fault-tolerant systems
Title
A methodology for object-oriented modeling and design of real-time, fault-tolerant systems.
Creator
Hancock, Debera R., Florida Atlantic University, Fernandez, Eduardo B.
Abstract/Description
Many methodologies for software modeling and design include some form of static and dynamic modeling to describe the structural and behavioral views respectively. Modeling and design of complex real-time software systems requires notations for describing concurrency, asynchronous event handling, communication between independent machines, timing properties, and accessing real time. Function-oriented structured analysis methodologies such as Ward and Mellor's SA/RT and Harel's Statecharts have...
Show moreMany methodologies for software modeling and design include some form of static and dynamic modeling to describe the structural and behavioral views respectively. Modeling and design of complex real-time software systems requires notations for describing concurrency, asynchronous event handling, communication between independent machines, timing properties, and accessing real time. Function-oriented structured analysis methodologies such as Ward and Mellor's SA/RT and Harel's Statecharts have provided extensions for real-time system modeling. Dynamic modeling of real time systems using object-oriented methodologies also requires extensions to the traditional state machine notations in order to convey the real time system characteristics and constraints. Shaw's Communicating Real Time State Machines (CRSM's), Harel's O-Chart notations, and the Octopus methodology provide methods for modeling real-time systems consistent with object-oriented methods. This thesis proposes an object-oriented analysis and design methodology that augments the traditional Object Modeling Technique (OMT) dynamic model with real-time extensions based on high-level parallel machines and communication notations from CRSM. An example of the proposed methodology is provided using a realistic but hypothetical example of an automated passenger train system. A design refinement step is included for fault tolerant considerations. An evaluation of the proposed methodology with its extended notations is provided.
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Date Issued
1997
PURL
http://purl.flvc.org/fcla/dt/15405
Subject Headings
Object-oriented methods (Computer science), Fault-tolerant computing, Real-time programming
Format
Document (PDF)
Industrial-strength formalization of object-oriented real-time systems
Title
Industrial-strength formalization of object-oriented real-time systems.
Creator
Raghavan, Gopalakrishna., Florida Atlantic University, Larrondo-Petrie, Maria M., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
The goal of this dissertation is to propose an industrial-strength formal model for object-oriented real-time systems that captures real-time constraints using industry standard notations and tools. A light-weight formalization process is proposed that is semi-formal, graphical and easier to read and understand. This process supports formal behavior analysis, verification and validation. It is very effective in early detection of incompleteness and ambiguities in the specifications. The...
Show moreThe goal of this dissertation is to propose an industrial-strength formal model for object-oriented real-time systems that captures real-time constraints using industry standard notations and tools. A light-weight formalization process is proposed that is semi-formal, graphical and easier to read and understand. This process supports formal behavior analysis, verification and validation. It is very effective in early detection of incompleteness and ambiguities in the specifications. The proposed process uses industry standard tools and fits well within stringent industrial schedules. Formal requirements analysis is conducted using High Level Message Sequencing Chart (HMSC) and Message Sequencing Chart (MSC). In the formal analysis phase, the static structures are modeled using Unified Modeling Language (UML) and the constraints are formalized using Object Constraint Language (OCL). System behavior is formally modeled using Specification and Description Language (SDL) during the formal design phase. SDL is used for behavior modeling due to wide commercial availability of SDL-based tools for formal behavior analysis and validation. Transition rules mapping from UML Class Diagrams and Statecharts to SDL models are proposed. SDL models are formally simulated and validated during the formal validation phase. Using the proposed process real-time clock, timer, periodic process, aperiodic process, resource and precedence constraints were formalized. Different types of timers, such as periodic, aperiodic, one-shot, fixed-interval and variable-interval timers are derived using inheritance models. Semaphore wait and signal operations are formalized as part of the resource constraint. Pre-conditions, post-conditions and invariants for the real-time constraints were captured using OCL. Behavior of the proposed models were captured using Statecharts. The proposed mapping rules were used to translate the behavior models to SDL. The SDL models were formally simulated and validated using Telelogic Software Development Tool (SDT). The tools allowed extensive model analysis and helped uncover several design flaws. The real-time constraints were stereotyped and packaged into reusable formal components. These components can be easily imported by applications. Two case studies, Cruise Control System and Bottle Filling System, are included to illustrate the use of the proposed process and the real-time package. The "industrial-strength" of the process was validated by utilizing the proposed process in an industrial project where it was found to accelerate the development process.
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Date Issued
2000
PURL
http://purl.flvc.org/fcla/dt/12632
Subject Headings
Object-oriented programming (Computer science), Real-time data processing, Formal methods (Computer science)
Format
Document (PDF)
Cache optimization for real-time embedded systems
Title
Cache optimization for real-time embedded systems.
Creator
Asaduzzaman, Abu Sadath Mohammad, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
Cache memory is used, in most single-core and multi-core processors, to improve performance by bridging the speed gap between the main memory and CPU. Even though cache increases performance, it poses some serious challenges for embedded systems running real-time applications. Cache introduces execution time unpredictability due to its adaptive and dynamic nature and cache consumes vast amount of power to be operated. Energy requirement and execution time predictability are crucial for the...
Show moreCache memory is used, in most single-core and multi-core processors, to improve performance by bridging the speed gap between the main memory and CPU. Even though cache increases performance, it poses some serious challenges for embedded systems running real-time applications. Cache introduces execution time unpredictability due to its adaptive and dynamic nature and cache consumes vast amount of power to be operated. Energy requirement and execution time predictability are crucial for the success of real-time embedded systems. Various cache optimization schemes have been proposed to address the performance, power consumption, and predictability issues. However, currently available solutions are not adequate for real-time embedded systems as they do not address the performance, power consumption, and execution time predictability issues at the same time. Moreover, existing solutions are not suitable for dealing with multi-core architecture issues. In this dissertation, we develop a methodology through cache optimization for real-time embedded systems that can be used to analyze and improve execution time predictability and performance/power ratio at the same time. This methodology is effective for both single-core and multi-core systems. First, we develop a cache modeling and optimization technique for single-core systems to improve performance. Then, we develop a cache modeling and optimization technique for multi-core systems to improve performance/power ratio. We develop a cache locking scheme to improve execution time predictability for real-time systems. We introduce Miss Table (MT) based cache locking scheme with victim cache (VC) to improve predictability and performance/power ratio. MT holds information about memory blocks, which may cause more misses if not locked, to improve cache locking performance., VC temporarily stores the victim blocks from level-1 cache to improve cache hits. In addition, MT is used to improve cache replacement performance and VC is used to improve cache hits by supporting stream buffering. We also develop strategies to generate realistic workload by characterizing applications to simulate cache optimization and cache locking schemes. Popular MPEG4, H.264/AVC, FFT, MI, and DFT applications are used to run the simulation programs. Simulation results show that newly introduced Miss Table based cache locking scheme with victim cache significantly improves the predictability and performance/power ratio. In this work, a reduction of 33% in mean delay per task and a reduction of 41% in total power consumption are achieved by using MT and VCs while locking 25% of level-2 cache size in an 4-core system. It is also observed that execution time predictability can be improved by avoiding more than 50% cache misses while locking one-fourth of the cache size.
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Date Issued
2009
PURL
http://purl.flvc.org/FAU/359919
Subject Headings
Real-time embedded systems and components, Embedded computer systems, Programming, Computer architecture, Integrated circuits, Design and construction, Signal processing, Digital techniques, Object-oriented methods (Computer science)
Format
Document (PDF)