Incremental Consistency Checking in Delta-oriented UML-Models for Automation Systems

Automation systems exist in many variants and may evolve over time in order to deal with different environment contexts or to fulfill changing customer requirements. This induces an increased complexity during design-time as well as tedious maintenance efforts. We already proposed a multi-perspective modeling approach to improve the development of such systems. It operates on different levels of abstraction by using well-known UML-models with activity, composite structure and state chart models. Each perspective was enriched with delta modeling to manage variability and evolution. As an extension, we now focus on the development of an efficient consistency checking method at several levels to ensure valid variants of the automation system. Consistency checking must be provided for each perspective in isolation, in-between the perspectives as well as after the application of a delta.Comment: In Proceedings FMSPLE 2016, arXiv:1603.0857

Applying concepts of fuzzy cognitive mapping to model IT/IS investment evaluation factors

The justification process is a major concern for many organisations that are considering the adoption of Information Technology (IT) and Information Systems (IS), and is a barrier to its implementation. As a result, the competitive advantage of many companies is being put at risk because of management's inability to evaluate the holistic implication of adopting new technology, both in terms of on the benefit and cost portfolios. This paper identifies a number of well-known project appraisal techniques used in IT/IS investment justification. Furthermore, the concept of multivalent, or fuzzy logic, is used to demonstrate how inter-relationships can be modeled between key dimensions identified in the proposed conceptual evaluation model. This is highlighted using fuzzy cognitive mapping (FCM) as a technique to model each IT/IS evaluation factor (integrating strategic, tactical, operational and investment considerations). The use of an FCM is then shown to be as a complementary tool which can serve to highlight interdependencies between contributory justification factors

Object-based 2D-to-3D video conversion for effective stereoscopic content generation in 3D-TV applications

Three-dimensional television (3D-TV) has gained increasing popularity in the broadcasting domain, as it enables enhanced viewing experiences in comparison to conventional two-dimensional (2D) TV. However, its application has been constrained due to the lack of essential contents, i.e., stereoscopic videos. To alleviate such content shortage, an economical and practical solution is to reuse the huge media resources that are available in monoscopic 2D and convert them to stereoscopic 3D. Although stereoscopic video can be generated from monoscopic sequences using depth measurements extracted from cues like focus blur, motion and size, the quality of the resulting video may be poor as such measurements are usually arbitrarily defined and appear inconsistent with the real scenes. To help solve this problem, a novel method for object-based stereoscopic video generation is proposed which features i) optical-flow based occlusion reasoning in determining depth ordinal, ii) object segmentation using improved region-growing from masks of determined depth layers, and iii) a hybrid depth estimation scheme using content-based matching (inside a small library of true stereo image pairs) and depth-ordinal based regularization. Comprehensive experiments have validated the effectiveness of our proposed 2D-to-3D conversion method in generating stereoscopic videos of consistent depth measurements for 3D-TV applications

Model the System from Adversary Viewpoint: Threats Identification and Modeling

Security attacks are hard to understand, often expressed with unfriendly and limited details, making it difficult for security experts and for security analysts to create intelligible security specifications. For instance, to explain Why (attack objective), What (i.e., system assets, goals, etc.), and How (attack method), adversary achieved his attack goals. We introduce in this paper a security attack meta-model for our SysML-Sec framework, developed to improve the threat identification and modeling through the explicit representation of security concerns with knowledge representation techniques. Our proposed meta-model enables the specification of these concerns through ontological concepts which define the semantics of the security artifacts and introduced using SysML-Sec diagrams. This meta-model also enables representing the relationships that tie several such concepts together. This representation is then used for reasoning about the knowledge introduced by system designers as well as security experts through the graphical environment of the SysML-Sec framework.Comment: In Proceedings AIDP 2014, arXiv:1410.322

From business logic to business process : designing strategy-aligned business processes

Het ontwerpen van strategisch gealigneerde bedrijfsprocessen vereist een coördinatie tussen de strategie en de processen binnen een onderneming. Binnen het onderzoeksgebied van het Conceptueel Modelleren kan deze coördinatie verwezenlijkt worden door het gebruik van waardemodellen. Modelleertalen voor waardemodellen brengen zowel de creatie van waarde binnen de onderneming, als de uitwisseling van waarde tussen de onderneming en haar ruimer netwerk, in kaart. Binnen dit doctoraatsonderzoek wordt het gebruik van deze modelleertalen gecombineerd met het bedrijfsmodel van de onderneming, een concept dat zijn oorsprong vindt in Strategisch Management. Het combineren van conceptuele modelleertalen met relevante raamwerken uit de management literatuur zorgt er voor dat conceptuele modellen ontwikkeld kunnen worden binnen een afgelijnde strategische context. Hierdoor worden concepten gebruikt die een duidelijke betekenis hebben voor de eindgebruikers binnen de onderneming, waardoor het eenvoudiger wordt voor hen om de uiteindelijke modellen te begrijpen. Het onderzoek binnen dit doctoraatsproefschrift is opgesplitst in drie delen. Het eerste deel (hoofdstuk 2) beschrijft de ontwikkeling van een integrerend raamwerk voor het bedrijfsmodel, zoals het gepercipieerd wordt binnen Strategisch Management. De belangrijkste reden voor dit onderzoek was het gebrek aan een gemeenschappelijke visie binnen dit onderzoeksdomein. Het raamwerk werd ontwikkeld door middel van een literatuurstudie en leidde tot de identificatie van 10 elementen en hun onderlinge relaties binnen het bedrijfsmodel. De toepasbaarheid van dit raamwerk werd geïllustreerd door het toe te passen op de Southwest Airlines gevalstudie. Het onderzoek uit hoofdstuk 3 bouwt verder op dit raamwerk aangezien het gericht is op de realisatie van IT support voor de ontwikkeling van bedrijfsmodellen. Hiervoor zijn we nagegaan welke modelleerconstructen, die gebruikt worden bij het opstellen van waardemodellen, geschikt zijn om de elementen binnen het bedrijfsmodel weer te geven. Nadien zijn deze modelleerconstructen gecombineerd tot het nieuwe business model viewpoint binnen VDML. Deze modelleertaal werd recent ontwikkeld door de Object Management Group als een standaard voor het modelleren van de waardecreatie en –uitwisseling door de onderneming. Het VDML business model viewpoint heeft als doel om het begrip van de eindgebruikers over de onderliggende bedrijfsinformatie te vergroten. Dit effect werd nagegaan door het uitvoeren van een experiment, waarvan de statistische resultaten aantonen dat het gebruik van dit nieuwe model een significante en positieve invloed heeft op het de accuraatheid en de snelheid waarmee eindgebruikers de onderliggende informatie kunnen afleiden. Het laatste deel van het onderzoek (hoofdstuk 4) is gericht op the realiseren van strategische afstemming binnen de bedrijfsarchitectuur. Dit werd verwezenlijkt door de ontwikkeling van een modelleertechniek die gericht is op de creatie van business architecture heat maps. Deze techniek steunt op raamwerken uit Strategisch Management om de relevante elementen binnen de bedrijfsarchitectuur te identificeren. In dit opzicht maken we hier dus ook gebruik van de onderzoeksresultaten uit hoofdstuk 2. De realisatie van de heat maps is gebaseerd op het toevoegen van een kleurencode die zowel de prestatie als het strategisch belang aanduidt van de elementen binnen de bedrijfsarchitectuur. De creatie van deze heat maps wordt ondersteund door een software programma dat ontwikkeld werd via het ADOxx platform. De voorgestelde modelleertechniek werd toegepast en geëvalueerd door middel van drie gevalstudies bij een grootschalig internationaal bedrijf dat software ontwikkelt. De resultaten van deze gevalstudies hadden tot doel om de voorgestelde modelleertechniek verder te verfijnen, waardoor een mooie balans gevonden werd tussen het bijdragen van kennis aan de betrokken onderzoeksdomeinen en het bieden van een oplossing voor een praktisch bedrijfsprobleem

A Process Modelling Framework Based on Point Interval Temporal Logic with an Application to Modelling Patient Flows

This thesis considers an application of a temporal theory to describe and model the patient journey in the hospital accident and emergency (A&E) department. The aim is to introduce a generic but dynamic method applied to any setting, including healthcare. Constructing a consistent process model can be instrumental in streamlining healthcare issues. Current process modelling techniques used in healthcare such as flowcharts, unified modelling language activity diagram (UML AD), and business process modelling notation (BPMN) are intuitive and imprecise. They cannot fully capture the complexities of the types of activities and the full extent of temporal constraints to an extent where one could reason about the flows. Formal approaches such as Petri have also been reviewed to investigate their applicability to the healthcare domain to model processes. Additionally, to schedule patient flows, current modelling standards do not offer any formal mechanism, so healthcare relies on critical path method (CPM) and program evaluation review technique (PERT), that also have limitations, i.e. finish-start barrier. It is imperative to specify the temporal constraints between the start and/or end of a process, e.g., the beginning of a process A precedes the start (or end) of a process B. However, these approaches failed to provide us with a mechanism for handling these temporal situations. If provided, a formal representation can assist in effective knowledge representation and quality enhancement concerning a process. Also, it would help in uncovering complexities of a system and assist in modelling it in a consistent way which is not possible with the existing modelling techniques. The above issues are addressed in this thesis by proposing a framework that would provide a knowledge base to model patient flows for accurate representation based on point interval temporal logic (PITL) that treats point and interval as primitives. These objects would constitute the knowledge base for the formal description of a system. With the aid of the inference mechanism of the temporal theory presented here, exhaustive temporal constraints derived from the proposed axiomatic system’ components serves as a knowledge base. The proposed methodological framework would adopt a model-theoretic approach in which a theory is developed and considered as a model while the corresponding instance is considered as its application. Using this approach would assist in identifying core components of the system and their precise operation representing a real-life domain deemed suitable to the process modelling issues specified in this thesis. Thus, I have evaluated the modelling standards for their most-used terminologies and constructs to identify their key components. It will also assist in the generalisation of the critical terms (of process modelling standards) based on their ontology. A set of generalised terms proposed would serve as an enumeration of the theory and subsume the core modelling elements of the process modelling standards. The catalogue presents a knowledge base for the business and healthcare domains, and its components are formally defined (semantics). Furthermore, a resolution theorem-proof is used to show the structural features of the theory (model) to establish it is sound and complete. After establishing that the theory is sound and complete, the next step is to provide the instantiation of the theory. This is achieved by mapping the core components of the theory to their corresponding instances. Additionally, a formal graphical tool termed as point graph (PG) is used to visualise the cases of the proposed axiomatic system. PG facilitates in modelling, and scheduling patient flows and enables analysing existing models for possible inaccuracies and inconsistencies supported by a reasoning mechanism based on PITL. Following that, a transformation is developed to map the core modelling components of the standards into the extended PG (PG*) based on the semantics presented by the axiomatic system. A real-life case (from the King’s College hospital accident and emergency (A&E) department’s trauma patient pathway) is considered to validate the framework. It is divided into three patient flows to depict the journey of a patient with significant trauma, arriving at A&E, undergoing a procedure and subsequently discharged. Their staff relied upon the UML-AD and BPMN to model the patient flows. An evaluation of their representation is presented to show the shortfalls of the modelling standards to model patient flows. The last step is to model these patient flows using the developed approach, which is supported by enhanced reasoning and scheduling