An ontology framework for developing platform-independent knowledge-based engineering systems in the aerospace industry

This paper presents the development of a novel knowledge-based engineering (KBE) framework for implementing platform-independent knowledge-enabled product design systems within the aerospace industry. The aim of the KBE framework is to strengthen the structure, reuse and portability of knowledge consumed within KBE systems in view of supporting the cost-effective and long-term preservation of knowledge within such systems. The proposed KBE framework uses an ontology-based approach for semantic knowledge management and adopts a model-driven architecture style from the software engineering discipline. Its phases are mainly (1) Capture knowledge required for KBE system; (2) Ontology model construct of KBE system; (3) Platform-independent model (PIM) technology selection and implementation and (4) Integration of PIM KBE knowledge with computer-aided design system. A rigorous methodology is employed which is comprised of five qualitative phases namely, requirement analysis for the KBE framework, identifying software and ontological engineering elements, integration of both elements, proof of concept prototype demonstrator and finally experts validation. A case study investigating four primitive three-dimensional geometry shapes is used to quantify the applicability of the KBE framework in the aerospace industry. Additionally, experts within the aerospace and software engineering sector validated the strengths/benefits and limitations of the KBE framework. The major benefits of the developed approach are in the reduction of man-hours required for developing KBE systems within the aerospace industry and the maintainability and abstraction of the knowledge required for developing KBE systems. This approach strengthens knowledge reuse and eliminates platform-specific approaches to developing KBE systems ensuring the preservation of KBE knowledge for the long term

Development of service-oriented architectures using model-driven development : a mapping study

Context: Model-Driven Development (MDD) and Service-Oriented Architecture (SOA) are two challenging research areas in software engineering. MDD is about improving software development whilst SOA is a service-based conceptual development style, therefore investigating the available proposals in the literature to use MDD when developing SOA may be insightful. However, no studies have been found with this purpose. Objective: This work aims at assessing the state of the art in MDD for SOA systems. It mainly focuses on: what are the characteristics of MDD approaches that support SOA; what types of SOA are supported; how do they handle non-functional requirements. Method: We conducted a mapping study following a rigorous protocol. We identified the representative set of venues that should be included in the study. We applied a search string over the set of selected venues. As result, 129 papers were selected and analysed (both frequency analysis and correlation analysis) with respect to the defined classification criteria derived from the research questions. Threats to validity were identified and mitigated whenever possible. Results: The analysis allows us to answer the research questions. We highlight: (1) predominance of papers from Europe and written by researchers only; (2) predominance of top-down transformation in software development activities; (3) inexistence of consolidated methods; (4) significant percentage of works without tool support; (5) SOA systems and service compositions more targeted than single services and SOA enterprise systems; (6) limited use of metamodels; (7) very limited use of NFRs; and (8) limited application in real cases. Conclusion: This mapping study does not just provide the state of the art in the topic, but also identifies several issues that deserve investigation in the future, for instance the need of methods for activities other than software development (e.g., migration) or the need of conducting more real case studies.Peer ReviewedPostprint (author's final draft

Towards model-driven requirements analysis for context-aware well-being systems

Research interest in the domain of pervasive systems has seen a rapid increase, evident from the amount of research papers being published each year. These systems are to blend in with everyday life, being completely unobtrusive. Through the use of sensors, pervasive systems can become context-aware. As such, they are able to use this context information in order to improve the services provided to the user. Interesting fields of application are those of health-care and well-being. The COMMIT SWELL project aims to improve both physical and mental well-being by developing a sensor-based context-aware system. This system is to (i) aid the user into improving his own lifestyle by giving him insight in his personal activity, and (ii) support the user in his work. In the domain of context-aware systems, we find that requirements have to align perfectly with the features to be offered by the system. If not, the system will become a hindrance to the user, who will then neglect it. Requirements engineering and architectural development for this type of system is largely unexplored territory. A bottom-up approach is often used: little attention is paid to requirements engineering up front, and architectures are created without having reuse in mind. Our objective is to improve the reuse of system requirements and architecture, resulting in an improvement of alignment between these artifacts. In order to facilitate this alignment, we aim to create a model-driven method that allows for bi-directional transformation between requirements and architecture at design time. Current results in the project include a literature study, a list of domain requirements for context-aware well-being systems and a reference architecture and descriptions for two demonstrators within the COMMIT SWELL project. From literature, we found that current methods for requirements engineering in this domain are either too high, or too low level, preventing proper reuse of artifacts in the next phase of the design process, as well as the need for high levels of both domain and system modeling expertise. Furthermore, we found that tool support model-driven development of context-aware well-being applications is currently lacking. Future research will initially focus on the specific requirements found in the context-aware application domain. After this, we will be looking at the link between specific requirements and architectural components, and whether this link exists uni-directionally or bi-directionally. Finally, we will be investigating if automatic alignment between requirements and architecture can be achieved

Embedding requirements within the model driven architecture.

The Model Driven Architecture (MDA) is offered as one way forward in software systems modelling to connect software design with the business domain. The general focus of the MDA is the development of software systems by performing transformations between software design models, and the automatic generation of application code from those models. Software systems are provided by developers, whose experience and models are not always in line with those of other stakeholders, which presents a challenge for the community. From reviewing the available literature, it is found that whilst many models and notations are available, those that are significantly supported by the MDA may not be best for use by non technical stakeholders. In addition, the MDA does not explicitly consider requirements and specification. This research begins by investigating the adequacy of the MDA requirements phase and examining the feasibility of incorporating a requirements definition, specifically focusing upon model transformations. MDA artefacts were found to serve better the software community and requirements were not appropriately integrated within the MDA, with significant extension upstream being required in order to sufficiently accommodate the business user in terms of a requirements definition. Therefore, an extension to the MDA framework is offered that directly addresses Requirements Engineering (RE), including the distinction of analysis from design, highlighting the importance of specification. This extension is suggested to further the utility of the MDA by making it accessible to a wider audience upstream, enabling specification to be a direct output from business user involvement in the requirements phase of the MDA. To demonstrate applicability, this research illustrates the framework extension with the provision of a method and discusses the use of the approach in both academic and commercial settings. The results suggest that such an extension is academically viable in facilitating the move from analysis into the design of software systems, accessible for business use and beneficial in industry by allowing for the involvement of the client in producing models sufficient enough for use in the development of software systems using MDA tools and techniques

Investigating the development and delivery of integrated product-service systems

Driven by the highly cyclical nature of their increasingly commoditised product offerings, many capital goods manufacturers are seeing the benefits of delivering services integrated with their core product offerings. Whilst existing research is almost unanimous in advocating the value of a servitization strategy, understanding how these product-service systems (PSSs) can be developed and delivered remains a significant challenge. The closely related PSS field, which has its heritage in the environmental and social science disciplines, is more mature in this area and a number of models have been proposed. The research reported within this thesis contributes to knowledge by investigating whether the approaches to PSS development, reported within the PSS literature, reflects the PSS development practice of servitized manufacturers. More specifically, soft systems methodology was used to explore the delivery of PSSs within the UK railway industry in order to gain an understanding of the implications for developing new PSSs. With this understanding, the existing approaches to PSS development were evaluated with respect to one servitized manufacturer through an in-depth single case study. The findings highlighted a number of significant differences between the practice of the servitized manufacturer and the literature. A survey was used to investigate whether the differences were generalisable to a larger sample of servitized manufacturers. The findings point towards the simplification of the reported phases within PSS development and the inclusion of a number of previously unreported processes and activities. Based on these results a new model of PSS development is proposed to better reflect the practice of servitized manufacturers. The model, consisting of four phases and seventeen processes, was operationalised in the form of a workbook and tested through application. Applying the workbook resulted in the successful creation of a number of new PSS concepts

Steady-state and transient analysis of electro-thermal microactuators using finite element methods

Recent techniques in radar and communication systems favor the development of phased arrays. The major problems to such systems are size and cost due to the large number of individual transmit/receive modules required. Photonic systems implemented in MEMS technology have reduced bulk optical systems to microscale proportions. This reduction in scale is particularly important to phased arrays since it allows flexibility in deployment. This thesis aims to understand the steady state and transient characteristics of an electrically heated, thermally driven, surface micromachined MEMS polysilicon beam flexure actuator to be employed for the rotation of an r-f phase shifter utilized in phased array systems. The characteristics of the thermal actuator are examined through finite element analysis by investigating the relative importance of the temperature dependencies of the material properties of MUMPs polysilicon. The comprehensive finite element model of the thermal actuator developed using ANSYS 5.6, a commercial finite element package, has the ability to include full temperature dependencies of all parameters and also has the capacity to impose all heat transfer modes, which are beyond the capabilities of current analytical models. Steady-state thermal profiles of the thermal actuator are presented for the thermal actuator in an environment of air and vacuum. The model is validated indirectly by comparing the steady-state deflections with measured data of six thermal actuators of different geometries. The finite element simulations are also validated with a previous analytical model to compare model accuracy. The dynamic behavior of the thermal actuator is examined in both air and vacuum, which gives an insight into power and energy consumption of the thermal actuator. Initial results show a limited power and energy savings for the thermal actuator operated in vacuum over that operated in air. Design optimization of the thermal actuator is investigated using the ANSYS Parametric Design Language (APDL) with the Subproblem Approximation Method for maintaining low power consumption. An indirect method is employed by maximizing the steady-state deflection for unloaded actuators and minimizing the steady-state deflection for loaded actuators for the same applied voltage. A significant reduction in power consumption with an increase in the maximum steady-state deflection has been observed for unloaded actuators. For loaded actuators the available force output is increased slightly, the steady-state deflection decreased slightly and the power consumption increased slightly

Development of a parametric computer model for automating the production of power station dry ash dump growth plans.

A dissertation submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of science in Engineering.Generating growth plans for power station dry ash dumps having main and standby conveyor stacking systems is very time consuming using manual analysis methods. This usually prohibits investigating sufficient options or the routine evaluation of operating variations. Not achieving or changing any of the multitude ot geometric, physical or production design. assumptions over the 50 year construction life, can result in the dump growth deviating significantly from the original plan. Out of phase or too rapid long term growth situations can ensue, with costly modifications sometimes needed to return to acceptable growth plans or provide additional capacity. It was postulated that a parametrically driven computer model would facilitate rapid and cost effective dump growth evaluation. This dissertation documents the development of a prototype, spreadsheet-based, parametric modeling program for automating the production of dry ash dump growth plans. The system showed that sensitivity, optimisation and routine evaluation exercises now become practicable.Andrew Chakane 201

Form Auto Generation: An Analysis of GUI Generation

Graphical User Interfaces (GUIs) have transformed how we interact with computers, offering visually appealing and intuitive systems. This paper explores the origins and evolution of GUIs, explicitly focusing on form auto-generation in modern GUI-driven environments. Form auto-generation has emerged as a prominent practice, enabling automatic form creation based on predefined models. To better understand form auto-generation, I investigate SurveyJS, an open-source form auto-generation library known for its active development and support. This investigation aims to understand how SurveyJS recognizes and renders objects from a JSON model. The methodology involves a trial and error examination of the library, exploring its live demos and source code. Different approaches to form auto-generation, including template-based methods, database-driven approaches, web form builders, document automation platforms, and custom programming, are explored. This research enhances our understanding of this crucial aspect of modern computing by delving into GUI origins, investigating SurveyJS, and examining various forms of auto-generation approaches. The findings suggest that form auto-generation will likely grow in popularity due to its accessibility, productivity benefits, dynamic personalization, integration with emerging technologies, and cross-platform compatibility. Organizations can leverage form auto-generation to optimize form creation processes, improve user experiences, and boost productivity across various domains

PROCESS CONFORMANCE TESTING: A METHODOLOGY TO IDENTIFY AND UNDERSTAND PROCESS VIOLATIONS IN ENACTMENT OF SOFTWARE PROCESSES

Today's software development is driven by software processes and practices that when followed increase the chances of building high quality software products. Not following these guidelines results in increased risk that the goal for the software's quality characteristics cannot be reached. Current process analysis approaches are limited in identifying and understanding process deviations and ultimately fail in comprehending why a process does not work in a given environment and what steps of the process have to be changed and tailored. In this work I will present a methodology for formulating, identifying and investigating process violations in the execution of software processes. The methodology, which can be thought of as "Process Conformance Testing", consists of a four step iterative model, compromising templates and tools. A strong focus is set on identifying violations in a cost efficient and unobtrusive manner by utilizing automatically collected data gathered through commonly used software development tools, such as version control systems. To evaluate the usefulness and correctness of the model a series of four studies have been conducted in both classroom and professional environments. A total of eight different software processes have been investigated and tested. The results of the studies show that the steps and iterative character of the methodology are useful for formulating and tailoring violation detection strategies and investigating violations in classroom study environments and professional environments. All the investigated processes were violated in some way, which emphasizes the importance of conformance measurement. This is especially important when running an empirical study to evaluate the effectiveness of a software process, as the experimenters want to make sure they are evaluating the specified process and not a variation of it. Violation detection strategies were tailored based upon analysis of the history of violations and feedback from then enactors and mangers yielding greater precision of identification of non-conformities. The overhead cost of the approach is shown to be feasible with a 3.4% (professional environment) and 12.1% (classroom environment) overhead. One interesting side result is that process enactors did not always follow the process for good reason, e.g. the process was not tailored for the environment, it was not specified at the right level of granularity, or was too difficult to follow. Two specific examples in this thesis are XP Pair Switching and Test Driven Development. In XP Pair Switching, the practice was violated because the frequency of switching was too high. The definition of Test Driven Development is simple and clear but requires a fair amount of discipline to follow, especially by novice programmers

A novel methodology for marine dual fuel engines sensors diagnostics and health management

The sensors abnormalities, faults, failure detection and diagnosis for marine engines are considered crucial for ensuring the engine safe and smooth operation. The development of such system(s) is typically based on the manufacturers experience on sensors and actuators faults and failure events. This study aims to introduce a novel methodology for the sensors diagnostics and health management in marine dual fuel engines by employing a combination of thermodynamic, functional control and data-driven models. The concept of an Engine Diagnostics System (EDS) is developed to provide intelligent engine monitoring, advanced sensors' faults detection as well as timely and profound corrective actions. This system employs a neural networks (NN) Data-Driven (DD) model along with appropriate logic controls. The DD model is set up based on the derived steady state data from a thermodynamic model of high fidelity and is capable of real-time prediction of the engine health condition behaviour. The concept of a novel Unified Digital System (UDS) is proposed that combines the engine's existing control and diagnostic systems with the EDS. The functionality of the UDS system is validated by employing a digital twin of the considered marine dual fuel engine by investigating scenarios for assessing the engine performance that entail abnormalities in the engine’s speed and boost pressure sensors. The simulation results demonstrate that the developed UDS is capable of sufficiently capturing the engine’s sensors abnormalities and applying appropriate corrective actions to restore the engine operation in its original state. This study benefits the development future systems facilitating the engines condition assessment and self-correction of the engine sensors' abnormalities, which will be required for smart and autonomous shipping