IEEE Transactions on Systems, Man, and Cybernetics, Part B (Cybernetics), 1996
A new formulation of the Maximal Common Subgraph Problem (MCSP), that is implemented using a two-... more A new formulation of the Maximal Common Subgraph Problem (MCSP), that is implemented using a two-stage Hopfield neural network, is given. Relative merits of this proposed formulation, with respect to current neural network-based solutions as well as classical sequential-search-based solutions, are discussed.
The Integrated Modular Avionics (IMA) approach can achieve lower overall hardware costs and reduc... more The Integrated Modular Avionics (IMA) approach can achieve lower overall hardware costs and reduced level of spares by getting multiple applications that have traditionally been implemented using separate, federated units to share hardware resources. However, the IMA approach also brings new challenges that did not exist in the federated setup. Avoiding unwanted dependencies among applications and managing the reuse of legacy code tops the list of challenges. This paper describes a two-layer software architecture, which enables the integration of multiple applications while maintaining strong spatial and temporal partitioning among application modules. In addition, the architecture allows the reusability of existent software modules by enabling the integration of applications written for different real-time operating systems.
In the recent few years, integration of multiple real-time control modules has gained increased a... more In the recent few years, integration of multiple real-time control modules has gained increased acceptance in the industry. Such integration can achieve lower overall hardware costs and reduced level of spares by sharing hardware resources among multiple applications. Single contemporary CPU can now harbor several applications which have been traditionally running on several older and slower computing platforms. However, the integrated approach faces new challenges such as the reusability of existing software and the prevention of fault propagation. The reuse of legacy application code, with minimal modifications, is strongly desirable since the cost of application redevelopment can be prohibitive. Resource sharing introduces dependencies among applications and thus requires additional design precautions to ensure that the effect of a failure in one application will not spread and impact other applications. This paper describes a two-layer software architecture, which enables the integration of multiple real-time applications while maintaining strong spatial and temporal partitioning among application modules. At the lower layer, a system executive creates multiple virtual machines. Each module accommodates an application with its choice of a real-time operating system. This architecture allows the reusability of existent software modules by enabling the integration of applications written for different real-time operating systems. The paper also addresses some issues related to the inter-application communication and to the handling of I/O devices.
Integration of multiple real-time control modules has gained increased acceptance as a new trend ... more Integration of multiple real-time control modules has gained increased acceptance as a new trend in the industry during the past few years. For example, the avionics industry is embracing a new design approach referred to as Integrated Modular Avionics (IMA) that encourages resource sharing to minimize the development and maintenance costs of avionics. However, the IMA approach also brings new challenges that do not exist in a federated implementation of avionics. Avoiding unwanted dependencies among applications and managing the reuse of legacy applications tops the list of challenges. This paper describes techniques for inter-application communication and handling of I/O devices that facilitates the integration of applications in an IMA system. These techniques enable the integration of multiple applications while maintaining strong spatial and temporal partitioning between application software modules. The presented approach is lock-free requiring the least support from the operating system and minimizes the dependency of the integrated environment on application characteristics.
Digest of Papers. Twenty-Eighth Annual International Symposium on Fault-Tolerant Computing (Cat. No.98CB36224), 1998
The trend in implementing today's embedded applications is toward the use of commercial-off-the-s... more The trend in implementing today's embedded applications is toward the use of commercial-off-the-shelf open architecture. Reducing costs and facilitating systems integration are among the motives for that trend. The use of the VME bus becomes very common in many industrial applications. The VME bus attracts developers with its rigorous specifications, multiprocessing support and boards availability through multiple vendors. However, VME bus standard supports multiprocessing through shared memory, which does not impose strong function partitioning and allows fault propagation from one board to another. Such weakness limits the use of the VME bus in highly critical applications such as avionics. This paper presents techniques for strong partitioning of multiprocessor applications that maintains fault containment on the VME bus. The suggested techniques do not require any modification in the standard and the existing boards, and consequently maintains the plugand-play advantage of the VME bus hardware products. The techniques are equally applicable to other tightly coupled multiprocessor systems. In addition, the paper describes the implementation of these techniques and reports performance results. Finally, the benefits of this technology for a space vehicle and commercial avionics are discussed.
IEEE Transactions on Systems, Man, and Cybernetics, Part B (Cybernetics), 1996
A new formulation of the Maximal Common Subgraph Problem (MCSP), that is implemented using a two-... more A new formulation of the Maximal Common Subgraph Problem (MCSP), that is implemented using a two-stage Hopfield neural network, is given. Relative merits of this proposed formulation, with respect to current neural network-based solutions as well as classical sequential-search-based solutions, are discussed.
The Integrated Modular Avionics (IMA) approach can achieve lower overall hardware costs and reduc... more The Integrated Modular Avionics (IMA) approach can achieve lower overall hardware costs and reduced level of spares by getting multiple applications that have traditionally been implemented using separate, federated units to share hardware resources. However, the IMA approach also brings new challenges that did not exist in the federated setup. Avoiding unwanted dependencies among applications and managing the reuse of legacy code tops the list of challenges. This paper describes a two-layer software architecture, which enables the integration of multiple applications while maintaining strong spatial and temporal partitioning among application modules. In addition, the architecture allows the reusability of existent software modules by enabling the integration of applications written for different real-time operating systems.
In the recent few years, integration of multiple real-time control modules has gained increased a... more In the recent few years, integration of multiple real-time control modules has gained increased acceptance in the industry. Such integration can achieve lower overall hardware costs and reduced level of spares by sharing hardware resources among multiple applications. Single contemporary CPU can now harbor several applications which have been traditionally running on several older and slower computing platforms. However, the integrated approach faces new challenges such as the reusability of existing software and the prevention of fault propagation. The reuse of legacy application code, with minimal modifications, is strongly desirable since the cost of application redevelopment can be prohibitive. Resource sharing introduces dependencies among applications and thus requires additional design precautions to ensure that the effect of a failure in one application will not spread and impact other applications. This paper describes a two-layer software architecture, which enables the integration of multiple real-time applications while maintaining strong spatial and temporal partitioning among application modules. At the lower layer, a system executive creates multiple virtual machines. Each module accommodates an application with its choice of a real-time operating system. This architecture allows the reusability of existent software modules by enabling the integration of applications written for different real-time operating systems. The paper also addresses some issues related to the inter-application communication and to the handling of I/O devices.
Integration of multiple real-time control modules has gained increased acceptance as a new trend ... more Integration of multiple real-time control modules has gained increased acceptance as a new trend in the industry during the past few years. For example, the avionics industry is embracing a new design approach referred to as Integrated Modular Avionics (IMA) that encourages resource sharing to minimize the development and maintenance costs of avionics. However, the IMA approach also brings new challenges that do not exist in a federated implementation of avionics. Avoiding unwanted dependencies among applications and managing the reuse of legacy applications tops the list of challenges. This paper describes techniques for inter-application communication and handling of I/O devices that facilitates the integration of applications in an IMA system. These techniques enable the integration of multiple applications while maintaining strong spatial and temporal partitioning between application software modules. The presented approach is lock-free requiring the least support from the operating system and minimizes the dependency of the integrated environment on application characteristics.
Digest of Papers. Twenty-Eighth Annual International Symposium on Fault-Tolerant Computing (Cat. No.98CB36224), 1998
The trend in implementing today's embedded applications is toward the use of commercial-off-the-s... more The trend in implementing today's embedded applications is toward the use of commercial-off-the-shelf open architecture. Reducing costs and facilitating systems integration are among the motives for that trend. The use of the VME bus becomes very common in many industrial applications. The VME bus attracts developers with its rigorous specifications, multiprocessing support and boards availability through multiple vendors. However, VME bus standard supports multiprocessing through shared memory, which does not impose strong function partitioning and allows fault propagation from one board to another. Such weakness limits the use of the VME bus in highly critical applications such as avionics. This paper presents techniques for strong partitioning of multiprocessor applications that maintains fault containment on the VME bus. The suggested techniques do not require any modification in the standard and the existing boards, and consequently maintains the plugand-play advantage of the VME bus hardware products. The techniques are equally applicable to other tightly coupled multiprocessor systems. In addition, the paper describes the implementation of these techniques and reports performance results. Finally, the benefits of this technology for a space vehicle and commercial avionics are discussed.
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Papers by M. Aboutabl