A case study in performance evaluation of real-time teleoparation software architecture using UML-MAST

Reference architectures for specific domains can provide significant benefits in productivity and quality for real-time systems development. These systems require an exact characterization based on quantitative evaluation of architectural features refered to timing properties, such as performance, reliability, etc. In this work, an UML-based tool has been used to obtain a measure of performance between two alternative architectures. These architectures share the same functional components with different interaction patterns. The used technique is illustrated with an industrial and real case study in a well-known real-time domain: teleoperation systems. The obtained results show clear differences in performance between two architectures, giving a clear indication of which one is better from this point of viewFinanciado parcialmente por FEDER (TAP-1FD97-0823) y GROWTH (GRD2-2001-50004

Simulating Execution Time and Power Consumption of Real-Time Tasks on Embedded Platforms

In this paper, we present PARTSim, an open-source power/thermal-aware simulator for embedded real-time systems. This tool is a fork of the well-known RTSim simulator, which can simulate the timing behavior of a set of real-time tasks with various characteristics when running on a multi-processor platform in presence of a number of real-time scheduling policies. PARTSim extends the functionality of RTSim by introducing support for power-aware embedded platforms exhibiting frequency scaling and specific architectural patterns like the ARM big.LITTLE and DynamIQ ones. Experimental results that compare simulated data against execution profiles collected on real platforms show a simulation error under 10 % for both execution time and power consumption at 90th percentile when simulating the effects of DVFS

Techniques and Patterns for Safe and Efficient Real-Time Middleware

Over 90 percent of all microprocessors are now used for real-time and embedded applications. The behavior of these applications is often constrained by the physical world. It is therefore important to devise higher-level languages and middleware that meet conventional functional requirements, as well as dependably and productively enforce real-time constraints. Real-Time Java is emerging as a safe, real-time environment. In this thesis we use it as our experimentation platform; however, our findings are easily adapted to other similar platforms. This thesis provides the following contributions to the study of safe and efficient real-time middleware. First, it identifies potential bottlenecks and problem with respect to guaranteeing real-time performance in middleware. Second, it presents a series of techniques and patterns that allow the design and implementation of safe, predictable, and highly efficient real-time middleware. Third, it provides a set of architectural and design patterns that application developers can use when designing real-time systems. Finally, it provides a methodology for evaluating the merits and benefits of real-time middleware. Empirical results are presented using that methodology for the techniques presented in this thesis. The methodology helps compare the performance and predictability of general, real-time middleware platforms

Patterns for Providing Real-Time Guarantees in DOC Middleware - Doctoral Dissertation, May 2002

The advent of open and widely adopted standards such as Common Object Request Broker Architecture (CORBA) [47] has simplified and standardized the development of distributed applications. For applications with real-time constraints, including avionics, manufacturing, and defense systems, these standards are evolving to include Quality-of-Service (QoS) specifications. Operating systems such as Real-time Linux [60] have responded with interfaces and algorithms to guarantee real-time response; similarly, languages such as Real-time Java [59] include mechanisms for specifying real-time properties for threads. However, the middleware upon which large distributed applications are based has not yet addressed end-to-end guarantees of QoS specifications. Unless this challenge can be met, developers must resort to ad hoc solutions that may not scale or migrate well among different platforms. This thesis provides two contributions to the study of real-time Distributed Object Computing (DOC) middleware. First, it identifies potential bottlenecks and problems with respect to guaranteeing real-time performance in contemporary middleware. Experimental results illustrate how these problems lead to incorrect real-time behavior in contemporary middleware platforms. Second, this thesis presents designs and techniques for providing real-time QoS guarantees in DOC middleware in the context of TAO [6], an open-source and widely adopted implementation of real-time CORBA. Architectural solutions presented here are coupled with empirical evaluations of end-to-end real-time behavior. Analysis of the problems, forces, solutions, and consequences are presented in terms of patterns and frame-works, so that solutions obtained for TAO can be appropriately applied to other real-time systems

Shape grammar and kinetic façade shading systems: a novel approach to climate adaptive building design with a real time performance evaluation.

The concept of a dynamic building enclosure is relatively radical and unexplored area in sustainable architectural design and engineering and as such could be considered a new paradigm. In this research, a novel application of shape grammar approach to design of kinetic façade shading systems has been discussed, inspired by vernacular Vietnamese architectural patterns and parametric generative design. The research reports on the system development and testing, exploring different façade shading configurations and evaluating their performance based on the real-time monitoring of daylight and heat gains, using wireless sensor technology. The strategy for BIM integrated sustainable design analysis (SDA) has also been deliberated, as a framework for exploring the integration of proposed building management system (BMS) into smart building environments (SBEs).N/

Anchoring Knowledge in Interaction: Towards a Harmonic Subsymbolic/Symbolic Framework and Architecture of Computational Cognition

We outline a proposal for a research program leading to a new paradigm, architectural framework, and prototypical implementation, for the cognitively inspired anchoring of an agent’s learning, knowledge formation, and higher reasoning abilities in real-world interactions: Learning through interaction in real-time in a real environment triggers the incremental accumulation and repair of knowledge that leads to the formation of theories at a higher level of abstraction. The transformations at this higher level filter down and inform the learning process as part of a permanent cycle of learning through experience, higher-order deliberation, theory formation and revision. The envisioned framework will provide a precise computational theory, algorithmic descriptions, and an implementation in cyber-physical systems, addressing the lifting of action patterns from the subsymbolic to the symbolic knowledge level, effective methods for theory formation, adaptation, and evolution, the anchoring of knowledge-level objects, real-world interactions and manipulations, and the realization and evaluation of such a system in different scenarios. The expected results can provide new foundations for future agent architectures, multi-agent systems, robotics, and cognitive systems, and can facilitate a deeper understanding of the development and interaction in human-technological settings

Industry 4.0 and Object-Oriented Development: Incremental and Architectural Change

Industry 4.0 in manufacturing is about combining cyber-physical systems with industrial automation systems. This integration of systems so different in nature aims to create context-aware factories in which people and machines are in real-time alignment. This paper examines the change processes triggered by Industry 4.0 from a conceptual perspective. We find that the observed patterns of change are not novel but have a lot in common with the paradigmatic shift in software development from structured to object-oriented development. The latter approach features to be incremental in the production phase and architectural in the product and process design phase. We argue that Industry 4.0 will be equally paradigmatic and mind-set changing for architects and engineers as to crafting production processes and creating products for the futur

Towards a service-oriented architecture for a mobile assistive system with real-time environmental sensing

Dalian Key Lab. of Smart Medical and Healthcare, Computer Science Department, Dalian University, China,With the growing aging population, age-related diseases have increased considerably over the years. In response to these, ambient assistive living (AAL) systems are being developed and are continually evolving to enrich and support independent living. While most researchers investigate robust activity recognition (AR) techniques, this paper focuses on some of the architectural challenges of the AAL systems. This work proposes a system architecture that fuses varying software design patterns and integrates readily available hardware devices to create wireless sensor networks for real-time applications. The system architecture brings together the service-oriented architecture (SOA), semantic web technologies, and other methods to address some of the shortcomings of the preceding system implementations using off-the-shelf and open source components. In order to validate the proposed architecture, a prototype is developed and tested positively to recognize basic user activities in real time. The system provides a base that can be further extended in many areas of AAL systems, including composite AR

Towards the definition of a pattern sequence for real-time applications using a model-driven engineering approach

Real-Time (RT) systems exhibit specific characteristics that make them particularly sensitive to architectural decissions. Design patterns help integrating the desired timing behaviour with the rest of the elements of the application architecture. This paper reports a pattern story that shows how a component-based design has been implemented using periodic concurrent tasks with RT requirements. This work has been done in the context of the development of robotic applications using a Model-Driven Software Development (MDSD) approach. In this context the model-to-code transformations are designed taking into account both the system requirements and the patterns that satisfy them. MDSD provides the conceptual technology for implementing a pattern-guided transition from component-based models to object-oriented implementations. The results of applying the described story of patterns are shown by an application that initializes, configures and schedules the execution of platform-specific components.This work has been partially supported by the Spanish CICYT Project EXPLORE (ref. TIN2009-08572), and the Fundación Séneca Regional Project COMPAS-R (ref. 11994/PI/09)