Component-based Systems Research Articles

Formal Methods for Characterization and Analysis of Quality Specifications in Component-based Systems

Formal Methods for Characterization and Analysis of Quality Specifications in Component-based Systems

Component-based Distributed Software Reconfiguration:A Verification-oriented Survey

Distributed software built from components has become a mainstay of service-oriented applications, which frequently undergo reconfigurations to adapt to changes in their operating environment or their functional requirements. Given the complexity of distributed software and the adverse effects of incorrect reconfigurations, a suitable methodology is needed to ensure the correctness of reconfigurations in component-based systems. This survey gives the reader a global perspective over existing formal techniques that pursue this goal. It distinguishes different ways in which formal methods can improve the reliability of reconfigurations, and lists techniques that contribute to solving each of these particular scientific challenges.

Modelling Uncertainty in Architectures of Parametric Component-Based Systems

In this paper, we propose a logic-based characterization of uncertainty in architectures of parametric component-based systems, where the parameter is the number of instances of each component type. For this, we firstly introduce an extended propositional interaction logic over De Morgan algebras and we show that its formulas can encode the uncertainty of several architectures applied in systems with a finite number of components. In turn, we introduce a first-order extended interaction logic over De Morgan algebras which is applied for modelling uncertainty in the interactions of well-known parametric architectures. Moreover, we prove that the equivalence problem for a large class of formulas of that logic is decidable in doubly exponential time by providing an effective translation to fuzzy recognizable series. For any such formula over a totally ordered De Morgan algebra, we further prove that we can compute in exponential time the set of sequences of parametric fuzzy interactions which ensure the trustworthiness of the formula according to a particular threshold.

A type language for distributed reactive components governed by communication protocols

Component based software engineering (CBSE) is a methodology that aims to design and build software systems by assembling together reusable and loosely coupled components. Applying CBSE in a distributed setting is appealing but challenging: distributed applications require different remote components to interact following a well-defined protocol. In this paper we consider a model for message passing component-based systems where components are assembled together with a protocol, and are reactive to messages in a flexible way. We propose a type language that allows capturing component reactive behaviour and checking its compatibility with the protocol. Moreover, we show the correspondence of component and type behaviours, which entails a progress property for components.

An Architectural Pattern for Dynamic Component Integration

The continuing increase of interest in Component-based Software Engineering (CBSE) signifies the emergence of a new development trend within the software industry. CBSE deals with the usage of reusable software components to provide complex integrated solutions at shorter development time and minimum cost. This engineering approach emphasizes the identification, selection, evaluation, procurement, integration, and evolution of reusable components for constructing complex and large-scale software solutions. Component-based development approach has a great potential for significantly reducing the cost and time to market of large-scale and complex software systems, improving system maintainability and flexibility. However the usage of components imposes some problems in the development process. Especially, the complexity of the integration process is increased due to the black box nature of the products. Integration is further influenced by problems due to architectural mismatches, component incompatibility etc. Apart from these general static integration problems, necessity for intelligent services and context aware computing paves way for the dynamic integration of components. Patterns have promising benefits in solving software design problems and their benefits have been realized in the design of component integration also. Patterns exist in different levels. Architectural patterns provide the overall structure of a system; design patterns deal with localized design choices; Idioms define patterns of usage within a particular language. Design patterns express proven techniques making it possible to reuse successful designs and provide a common vocabulary to share design descriptions. Architectural patterns cover a wider realm, specifying system-wide structural properties for an application, and impacting on subsystem architecture. This report presents the study of literature related to patterns and its application in the design of component-based systems. An Architectural pattern has been proposed in this report, for the design of a component-based system that dynamically integrates components. The dynamism is achieved using a service model.

Hierarchical Diagnosis Algorithm for Component-Based Multi-Mode Systems

This paper is focused on fault detection and isolation of component-based multi-mode systems, i.e., systems that can be operated in different continuous modes. As the system mode changes, the structure of the system also changes which impacts diagnosability analysis and synthesis. To meet this challenge, diagnosis based on a structural approach is modified to also detect and isolate faults when modes change. Here, definitions for some important diagnosis concepts are extended to cover also multi-mode systems. Then, a method for hierarchical diagnosis of component-based systems is proposed. The method is exemplified on a Li-ion battery pack to show its effectiveness.

Fuzzy Set-Based Reliability Estimation

The rapid advancement of computer technology motivates software developers to use commercial off-the-shelf software components for system growth. For particular architectural elements (for instance, components), the reliability criteria associated with testing-based conventional procedures are unknown. In the traditional reliability estimation, the probabilistic method is applied. The source data problem, which depends on a number of factors that may or may not correspond to the real working conditions of the system, is this technique's major shortcoming. The component-based software reliability estimation is based on a number of parameters, including the individual component reliability, transition probability, failure rate, etc. Fuzzy logic converts fuzzy data into useful information, making it easier to develop creative solutions for vague and uncertain concepts based on various factors that influence reliability. To assess the reliability of component-based systems, the authors provide a fuzzy logic technique, which has the ability to improve the question of uncertainty.

Verification of component-based systems with recursive architectures

We study a sound verification method for parametric component-based systems. The method uses a resource logic, a new formal specification language for distributed systems consisting of a finite yet unbounded number of components. The logic allows the description of architecture configurations coordinating instances of a finite number of types of components, by means of inductive definitions similar to the ones used to describe algebraic data types or recursive data structures. For parametric systems specified in this logic, we show that decision problems such as reaching deadlock or violating critical section are undecidable, in general. Despite this negative result, we provide for these decision problems practical semi-algorithms relying on the automatic synthesis of structural invariants allowing the proof of general safety properties. The invariants are defined using the WSκS fragment of the monadic second order logic, known to be decidable by a classical automata-logic connection, thus reducing a verification problem to checking satisfiability of a WSκS formula.

Conceptual building blocks for modeling reconfiguration of component-based systems using Petri nets

This paper deals with the formal modeling of dynamically reconfigurable systems using Petri nets. Dynamic reconfiguration provides to a system the ability to change the behavior of its components at run-time without a system shut-down. By transferring the concepts of the coordination modeling language Paradigm to the setting of Petri nets a framework is obtained for the modeling of component-based systems. The framework then allows for reasoning about coordination of components on one level of abstraction and for analysis of reconfiguration on another level of abstraction. This factorization will be beneficial to subsequent formal assessment. A workers and scheduler example, the well-known dining philosophers, and a Festo MPS casestudy serve as illustrations.

Probabilistic mediator: A coalgebraic perspective

Mediator is a component-based modeling language where components and systems can be specified separately and precisely. In this paper, we show how to analyze probabilistic Mediator, which supports both non-deterministic and probabilistic behavior of component-based systems, from a coalgebraic perspective. Probabilistic Mediator components are modeled as coalgebras, with the powerset monad P and the distribution monad D to capture their non-determinsitic and probabilistic behavior, respectively. A coalgebraic semantics of combinators on Mediator components is developed. Such a coalgebraic view induces a suitable notion of bisimulation for comparing probabilistic Mediator components and systems.

Maintaining temporal validity of real-time data in component-based systems

Maintaining temporal validity of real-time data in component-based systems

PRINS: scalable model inference for component-based system logs

Behavioral software models play a key role in many software engineering tasks; unfortunately, these models either are not available during software development or, if available, quickly become outdated as implementations evolve. Model inference techniques have been proposed as a viable solution to extract finite state models from execution logs. However, existing techniques do not scale well when processing very large logs that can be commonly found in practice. In this paper, we address the scalability problem of inferring the model of a component-based system from large system logs, without requiring any extra information. Our model inference technique, called PRINS, follows a divide-and-conquer approach. The idea is to first infer a model of each system component from the corresponding logs; then, the individual component models are merged together taking into account the flow of events across components, as reflected in the logs. We evaluated PRINS in terms of scalability and accuracy, using nine datasets composed of logs extracted from publicly available benchmarks and a personal computer running desktop business applications. The results show that PRINS can process large logs much faster than a publicly available and well-known state-of-the-art tool, without significantly compromising the accuracy of inferred models.

Towards a component-based system model to improve the quality of highly configurable systems.

Due to ever-evolving software developments processes, companies are motivated to develop desired quality products quickly and effectively. Industries are now focusing on the delivery of configurable systems to provide several services to a wide range of customers by making different configurations in a single largest system. Nowadays, component-based systems are highly demanded due to their capability of reusability and restructuring of existing components to develop new systems. Moreover, product line engineering is the major branch of the component-based system for developing a series of systems. Software product line engineering (SPLE) provides the ability to design several software modifications according to customer needs in a cost-effective manner. Researchers are trying to tailor the software product line (SPL) process that integrates agile development technologies to overcome the issues faced during the execution of the SPL process such as delay in product delivery, restriction to requirements change, and exhaustive initial planning. The selection of suitable components, the need for documentation, and tracing back the user requirements in the agile-integrated product line (APL) models still need to improve. Furthermore, configurable systems demand the selected features to be the least dependent. In this paper, a hybrid APL model, quality enhanced application product line engineering (QeAPLE) is proposed that provides support for highly configurable systems (HCS) by evaluating the dependency of features before making the final selection. It also has a documentation and requirement traceability function to ensure that the product meets the desired quality. Two-fold assessments are undertaken to validate the suggested model, with the proposed model being deployed on an active project. After that, we evaluated the proposed model performance and effectiveness using after implementing it in a real-world environment and compared the results with an existing method using statistical analysis. The results of the experimental study proofs that the proposed model is practically and statistically significant as compared to the existing method in terms of effectiveness and participants’ performance. Hence, the statistical results of the comparative analysis show that the proposed model improved ease of understanding and adaptability, required effort, high-quality achievement, and version management are significant i.e., more the 50% as compared to the exiting method i.e., less than 50%. The proposed model offers to assist in the development of a highly configurable system that achieves the needed quality. Therefore, the proposed model manages the variation identification, versions control, components dependency for correct selection of components, and validation activities from domain engineering to application engineering.

Design and Development of a Solar Water Purification System with Graphene-Plasmonic Based Hybrid Nanocomposites: A Review.

Harvesting solar energy for water treatments has been considered a promising solution for a global community. The shortage of water is a great challenge for scientists due to the increased demand of the population-however, the low efficiency of absorber materials obstacles in practical applications. In addition, state-of-the-art conventional technologies require optical concentrators and multiple component-based systems, leading to lower efficiency and higher cost. In this review, a low-cost, more reliable, less energy-intensive, and more eco-friendly solar water purification system based on graphene-plasmonic hybrid nanocomposite has been demonstrated. Graphene-plasmonic-based hybrid nanocomposite has been utilized to achieve pure water from wastewater. Such hybrid nanocomposites have the ability to clean polluted water very efficiently due to their excellent properties such as higher surface area, low concentration, and working ability. Furthermore, the development of a solar water purification system has been achieved through optimized hybrid nanocomposites.

Development of a component-based interactive visualization system for the analysis of ocean data

ABSTRACT With the continuous development of various types of fixed marine observation equipment, satellite remote sensing technology and computer simulation technology, modern marine scientific research has entered the era of big data. Interactive ocean visualization has become ubiquitous owing to the use of ocean data in studies of marine disasters, global climate change and fisheries. However, the primary challenge in analyzing large amounts of ocean data originates from the complexity of the data themselves. Therefore, an interactive multi-scale, multivariate visualization system with dynamic expansion potential is needed for analyzing larger volumes of ocean data. In this study, a unified visual data service was constructed, and a component-based interactive visualization structure for multi-dimensional, spatiotemporal ocean data is presented in this paper. Based on this structure, users can easily customize the system to visualize other types of scientific data.

A Mobile System for the On-Site Assembly of Timber Frame Components: The Development of an Agile, Low-Cost Alternative to Offsite Prefabrication

Prefabricated timber component-based systems are the most prevalent industrialised system used to build housing. Along with many other countries, the UK has invested in different types of factory-based prefabrication systems as a means of increasing productivity and enhancing quality. In more recent decades, prefabrication has become part of a series of ‘modern methods of construction’ employed for, and aimed at, delivering sustainable and efficient construction. However, certain pragmatic issues remain. The industry is cyclical, and during periods of declining resources, skills and technical development can be lost. Additionally, factory-based prefabrication requires substantial initial investment and an appropriate local workforce. To help address these issues, this paper presents the concept of an alternative method of production and assembly that takes a different approach to traditional industrialised systems that involve large investments and fixed-location factories. The proposition presented in this paper is that it is possible to design and develop a small, low cost, portable micro-factory that can be taken to a temporary location or construction site, where it can then be used to construct prefabricated closed panels. We describe the development of a working prototype, effectively a micro-factory, along with its potential advantages over a fixed facility.

Compositional Analysis of Hierarchical UML Statecharts

Quantitative evaluation of stochastic models supports early verification of design choices and assessment of non-functional requirements. Model Driven Engineering (MDE) leverages automated derivation of formal stochastic models from semi-formal artifacts of the Unified Modeling Language (UML) to facilitate deployment of quantitative evaluation methods without disrupting industrial practices. As a major limitation, when generally distributed (GEN) temporal parameters are considered to enhance the model expressivity, the structure and complexity of the underlying stochastic process cannot be easily controlled, possibly impairing the model analyzability. We present a hierarchical modeling formalism based on UML statecharts with GEN durations, designed to guarantee ease of modeling and efficient evaluation of steady-state or transient behaviour until absorption. To this end, fairly lax restrictions are applied to the model syntax to enable separate analysis of the Semi-Markov Process (SMP) underlying each model component. Scalability of solution is assessed by analyzing a suite of synthetic models referred to the context of timed Failure Logic Analysis (FLA) of component-based systems, specifically designed to point out each factor of computational complexity. Notably, the analysis derives both the probability that the system is in each step before failure and the Cumulative Distribution Function (CDF) of the duration of the overall failure process. A challenging case study that significantly and jointly stresses the main factors of computational complexity is finally addressed, performing steady-state analysis of a non-Markovian variant of a server virtualized system from the literature on software rejuvenation.

Architectures in parametric component-based systems: Qualitative and quantitative modelling

One of the key aspects in component-based design is specifying the software architecture that characterizes the topology and the permissible interactions of the components of a system. To achieve well-founded design there is need to address both the qualitative and non-functional aspects of architectures. In this paper we study the qualitative and quantitative formal modelling of architectures applied on parametric component-based systems, that consist of an unknown number of instances of each component. Specifically, we introduce an extended propositional interaction logic and investigate its first-order level which serves as a formal language for the interactions of parametric systems. Our logics achieve to encode the execution order of interactions, which is a main feature in several important architectures, as well as to model recursive interactions. Moreover, we prove the decidability of equivalence, satisfiability, and validity of first-order extended interaction logic formulas, and provide several examples of formulas describing well-known architectures. We show the robustness of our theory by effectively extending our results for parametric weighted architectures. For this, we study the weighted counterparts of our logics over a commutative semiring, and we apply them for modelling the quantitative aspects of concrete architectures. Finally, we prove that the equivalence problem of weighted first-order extended interaction logic formulas is decidable in a large class of semirings, namely the class (of subsemirings) of skew fields.

Bridging the gap between single- and multi-model predictive runtime verification

This paper presents an extension of the Predictive Runtime Verification (PRV) paradigm to consider multiple models of the System Under Analysis (SUA). We call this extension Multi-Model PRV. Typically, PRV attempts to predict the satisfaction or violation of a property based on a trace and a (single) formal model of the SUA. However, contemporary node- or component-based systems (e.g. robotic systems) may benefit from monitoring based on a model of each component. We show how a Multi-Model PRV approach can be applied in either a centralised or a compositional way (where the property is compositional), as best suits the SUA. Crucially, our approach is formalism-agnostic. We demonstrate our approach using an illustrative example of a Mars Curiosity rover simulation and evaluate our contribution via a prototype implementation.

Dealing with Communication Channels within IEC61499 Component-Based Systems

Traditional approaches for developing automation systems consider system itself hardly can be changed. Current challenges in automation applications include the need of autoreconfiguration in response to process changes or event triggering. In order to face these requirements, new automation methodologies are necessary. Component-based technologies, initially defined for achieving efficient, structured and reusable designs can also be used to achieve adaptation. In this work, an IEC 61499-based framework that uses the concept to deal with reconfiguration issues is presented. The final output of the framework is a distributed system IEC61499 compliant. A new concept, the communication channel, is introduced providing a new abstraction layer to deal with communication between components. The joint use of automation components and communication channels allows defining complex automation systems in an easy way.