Intelligent agent for formal modelling of temporal multi-agent systems

Software systems are becoming complex and dynamic with the passage of time, and to provide better fault tolerance and resource management they need to have the ability of self-adaptation. Multi-agent systems paradigm is an active area of research for modeling real-time systems. In this research, we have proposed a new agent named SA-ARTIS-agent, which is designed to work in hard real-time temporal constraints with the ability of self-adaptation. This agent can be used for the formal modeling of any self-adaptive real-time multi-agent system. Our agent integrates the MAPE-K feedback loop with ARTIS agent for the provision of self-adaptation. For an unambiguous description, we formally specify our SA-ARTIS-agent using Time-Communicating Object-Z (TCOZ) language. The objective of this research is to provide an intelligent agent with self-adaptive abilities for the execution of tasks with temporal constraints. Previous works in this domain have used Z language which is not expressive to model the distributed communication process of agents. The novelty of our work is that we specified the non-terminating behavior of agents using active class concept of TCOZ and expressed the distributed communication among agents. For communication between active entities, channel communication mechanism of TCOZ is utilized. We demonstrate the effectiveness of the proposed agent using a real-time case study of traffic monitoring system

CORBA-JS: An Open-Standards Framework for Distributed Object Computing over the Web

poster abstractDistributed object computing (DOC) is a well-established software engineering paradigm for implementing distributed real-time and embedded (DRE) systems, such as real-time monitoring systems. Likewise, CORBA is a well-established DOC open-standard used in DRE systems. Due to many technological limitations, DOC was traditionally unavailable in Web-based applications (i.e., stateful applications that communicate over HTTP, and are accessible via a Web browser) without the use of proprietary, custom technologies. The problem with using proprietary, custom technology is it creates fragmentation in the solution space where some solutions are not available to all end-users (e.g., Web sites that only work within a certain Web browser because of the used technology). With the advent of HTML5 and WebSockets, which is an open-standard for enabling two-way communication over HTTP, DOC now has the necessary technological foundations to be realized within Web applications without the use of proprietary, custom technologies. To date, however, no researchers have attempted to apply DOC over HTTP using well-established DOC open-standards, such as CORBA. This research therefore is an initial investigation into implementing CORBA atop of HTML5 and WebSockets. As part of this research, we are investigating the challenges in realizing the solution, and proposing ways to improve the target programming languages and CORBA specification. Doing so will enable developers to create feature-rich real-time Web applications that improve upon current state-of-the-art approaches, e.g., Asynchronous XML and JavaScript (AJAX), that are resource intensive (e.g., use a lot of CPU, network bandwidth, and memory) and hard to program

Real time, Non-Intrusive Instrumentation & Monitoring of Standards-based Event-based Middleware

poster abstractStandards-based middleware, such as the Common Object Request Broker Architecture (CORBA) Component Model and the Data Distribution Service, support event-based services for decoupled, asynchronous messaging between software components in a distributed system. The messaging models use the publisher-subscriber paradigm where one or more subscribers can subscribe to events from one or more publishers. The advantage of this paradigm is neither the publisher nor subscriber needs to be aware of the other. Instead, either entity is only concerned with the publication or receipt of an event. A critical aspect of these systems, however, is their instrumentation for analysis purposes, like monitoring its performance, state, and behavior to ensure the system is executing as expected. Traditionally, instrumenting such systems relied on intrusive instrumentation approaches, where developer inserted code snippets into the source code to collect the information needed. This means that developers must understand the original code, run the risk of inserting malicious code, and intermix code related to instrumentation with the normal business logic. Moreover, as the normal business logic evolves, the instrumentation code must also evolve. This can become a burden on developers until the business logic become less volatile. To overcome this complexity, we present Dynamic Event Monitor, a tool that can non-intrusively instrument and monitor events in a large scale distributed system at run time, using dynamic binary instrumentation. It operates in contexts without any a priori knowledge of the concrete events in the system, or how the system is composed. We have applied Dynamic Event Monitor to applications implemented in CORBA. Our results show that once the application is completely instrumented, the performance impact of actually monitoring events is minimal. For the applications we have tested, the instrumentation time is about 30-45 seconds and the time for real-time monitoring of events is about 2 milliseconds

An Agent Architecture for Supervising a Pilot WWTP

Abstract: This paper describes the development and implementation of a real-time Knowledge-Based System (KBS) for the supervision and control of a wastewater treatment pilot plant (WWTPP) with biological removal of organic matter and nutrients. The hardware architecture contains different supervision levels, including two autonomous process computers (plant control and analyzers control) and a PLC, being the KBS the top supervisory level. The KBS has been developed using the G2 expert systems shell, and it is implemented for real-time operation. The implementation of the different components of the KBS is done under the Intelligent Agents paradigm. The knowledge is organized in several distributed agents, representing the available knowledge for every sub-process of the WWTPP. In addition to these independent agents, a Supervisor Agent acts as the master of the independent agents. The implementation of the KBS in the pilot plant has supposed the transformation of a classical control system with a fixed behavior in a system adaptable to different problems that could appear in a WWTP. The main achievement of this prototype is a versatile framework able to deal with different plant configurations, based on the object-oriented paradigm and on rule-based reasoning

A distributed Real-Time Java system based on CSP

CSP is a fundamental concept for developing software for distributed real time systems. The CSP paradigm constitutes a natural addition to object orientation and offers higher order multithreading constructs. The CSP channel concept that has been implemented in Java deals with single- and multi-processor environments and also takes care of the real time priority scheduling requirements. For this, the notion of priority and scheduling has been carefully examined and as a result it was reasoned that priority scheduling should be attached to the communicating channels rather than to the processes. In association with channels, a priority based parallel construct is developed for composing processes: hiding threads and priority indexing from the user. This approach simplifies the use of priorities for the object oriented paradigm. Moreover, in the proposed system, the notion of scheduling is no longer connected to the operating system but has become part of the application instead

Experiences modelling and using object-oriented telecommunication service frameworks in SDL

This paper describes experiences in using SDL and its associated tools to create telecommunication services by producing and specialising object-oriented frameworks. The chosen approach recognises the need for the rapid creation of validated telecommunication services. It introduces two stages to service creation. Firstly a software expert produces a service framework, and secondly a telecommunications ‘business consultant' specialises the framework by means of graphical tools to rapidly produce services. Here the focus is given to the underlying technology required. In particular, the advantages and disadvantages of SDL and tools for this purpose are highlighted

Developmental Robots - A New Paradigm

It has been proved to be extremely challenging for humans to program a robot to such a sufficient degree that it acts properly in a typical unknown human environment. This is especially true for a humanoid robot due to the very large number of redundant degrees of freedom and a large number of sensors that are required for a humanoid to work safely and effectively in the human environment. How can we address this fundamental problem? Motivated by human mental development from infancy to adulthood, we present a theory, an architecture, and some experimental results showing how to enable a robot to develop its mind automatically, through online, real time interactions with its environment. Humans mentally “raise” the robot through “robot sitting” and “robot schools” instead of task-specific robot programming