Requirements modelling and formal analysis using graph operations

The increasing complexity of enterprise systems requires a more advanced analysis of the representation of services expected than is currently possible. Consequently, the specification stage, which could be facilitated by formal verification, becomes very important to the system life-cycle. This paper presents a formal modelling approach, which may be used in order to better represent the reality of the system and to verify the awaited or existing system’s properties, taking into account the environmental characteristics. For that, we firstly propose a formalization process based upon properties specification, and secondly we use Conceptual Graphs operations to develop reasoning mechanisms of verifying requirements statements. The graphic visualization of these reasoning enables us to correctly capture the system specifications by making it easier to determine if desired properties hold. It is applied to the field of Enterprise modelling

Knowledge formalization in experience feedback processes : an ontology-based approach

Because of the current trend of integration and interoperability of industrial systems, their size and complexity continue to grow making it more difficult to analyze, to understand and to solve the problems that happen in their organizations. Continuous improvement methodologies are powerful tools in order to understand and to solve problems, to control the effects of changes and finally to capitalize knowledge about changes and improvements. These tools involve suitably represent knowledge relating to the concerned system. Consequently, knowledge management (KM) is an increasingly important source of competitive advantage for organizations. Particularly, the capitalization and sharing of knowledge resulting from experience feedback are elements which play an essential role in the continuous improvement of industrial activities. In this paper, the contribution deals with semantic interoperability and relates to the structuring and the formalization of an experience feedback (EF) process aiming at transforming information or understanding gained by experience into explicit knowledge. The reuse of such knowledge has proved to have significant impact on achieving themissions of companies. However, the means of describing the knowledge objects of an experience generally remain informal. Based on an experience feedback process model and conceptual graphs, this paper takes domain ontology as a framework for the clarification of explicit knowledge and know-how, the aim of which is to get lessons learned descriptions that are significant, correct and applicable

New method for summative evaluation of UML class diagrams based on graph similarities

This paper deals with the problem of the evaluation of the student's productions during the construction of a UML class diagram from textual speciations, which can be a tedious task for teachers. The main objective is to propose a method of summative and semi-automatic evaluation of the class diagrams produced by the students, in order to provide an educational reaction on the learning process, and to reduce the evaluation work for the teachers. To achieve this objective, we must analyze these productions and study the transformation, matching, similarity measurement and comparison of several UML graphs. From this study, we adopted a method based on the comparison and matching of the components of several UML diagrams. This proposal is applied to evaluate UML class diagrams and focuses on the structural and semantic aspects of the UML graph produced by students compared to several solutions proposed by the teacher

Bounded Rationality and Heuristics in Humans and in Artificial Cognitive Systems

In this paper I will present an analysis of the impact that the notion of “bounded rationality”, introduced by Herbert Simon in his book “Administrative Behavior”, produced in the field of Artificial Intelligence (AI). In particular, by focusing on the field of Automated Decision Making (ADM), I will show how the introduction of the cognitive dimension into the study of choice of a rational (natural) agent, indirectly determined - in the AI field - the development of a line of research aiming at the realisation of artificial systems whose decisions are based on the adoption of powerful shortcut strategies (known as heuristics) based on “satisficing” - i.e. non optimal - solutions to problem solving. I will show how the “heuristic approach” to problem solving allowed, in AI, to face problems of combinatorial complexity in real-life situations and still represents an important strategy for the design and implementation of intelligent systems

Assessing Asymmetric Fault-Tolerant Software

The most popular forms of fault tolerance against design faults use "asymmetric" architectures in which a "primary" part performs the computation and a "secondary" part is in charge of detecting errors and performing some kind of error processing and recovery. In contrast, the most studied forms of software fault tolerance are "symmetric" ones, e.g. N-version programming. The latter are often controversial, the former are not. We discuss how to assess the dependability gains achieved by these methods. Substantial difficulties have been shown to exist for symmetric schemes, but we show that the same difficulties affect asymmetric schemes. Indeed, the latter present somewhat subtler problems. In both cases, to predict the dependability of the fault-tolerant system it is not enough to know the dependability of the individual components. We extend to asymmetric architectures the style of probabilistic modeling that has been useful for describing the dependability of "symmetric" architectures, to highlight factors that complicate the assessment. In the light of these models, we finally discuss fault injection approaches to estimating coverage factors. We highlight the limits of what can be predicted and some useful research directions towards clarifying and extending the range of situations in which estimates of coverage of fault tolerance mechanisms can be trusted

A Labelling Framework for Probabilistic Argumentation

The combination of argumentation and probability paves the way to new accounts of qualitative and quantitative uncertainty, thereby offering new theoretical and applicative opportunities. Due to a variety of interests, probabilistic argumentation is approached in the literature with different frameworks, pertaining to structured and abstract argumentation, and with respect to diverse types of uncertainty, in particular the uncertainty on the credibility of the premises, the uncertainty about which arguments to consider, and the uncertainty on the acceptance status of arguments or statements. Towards a general framework for probabilistic argumentation, we investigate a labelling-oriented framework encompassing a basic setting for rule-based argumentation and its (semi-) abstract account, along with diverse types of uncertainty. Our framework provides a systematic treatment of various kinds of uncertainty and of their relationships and allows us to back or question assertions from the literature

Avoimeen dataan perustuvan jokivirtaamatyökalun arvo Kaakkois-Aasiassa

Water governance deals with a substance that is essential for sustaining life. Managing a physical substance, which runs in multiple interconnected systems crossing administrative borders of all scales, creates controversies when the interests of different stakeholders collide. Creating policies and making decisions related to water requires efficient science-policy interaction, to which environmental modelling is inarguably an important input that provides salient, credible, and legitimate information to be used. However, modelling the endless complexity of the physical world leaves the modelers facing uncertainties. This work demonstrates the environmental modelling process, conducts an uncertainty quantification, and finally investigates the potential of adopting open-source solutions as a part of environmental modelling and policy support. This work applies both quantitative and qualitative methods. The main quantitative methods are hydrostreamer, a newly developed open-source tool that can estimate river streamflow, and Monte Carlo simulation, which is applied to quantify a type of uncertainty related to hydrostreamer. Within the qualitative methods, a survey and semi-structured interviews are applied to assess the current state of hydrostreamer and its applicability in the 3S river basin located in Southeast Asia, and also to investigate the potential of open-source based environmental modelling solutions in a more general manner. In the work, one of the contributors of uncertainty related to modelling streamflow with hydrostreamer is quantified and shown to behave with respect to Strahler order. Minor applications for hydrostreamer in its present state are found in the study area, and potential for adopting open-source solutions is shown, primarily due to low costs and through major donor organizations. In the resulting discussion, it is emphasized that trade-offs between modelling tool applicability and accuracy should be addressed to make the environmental modelling process truly open, instead of limiting the openness to only few of those with the required capabilities. Evaluating uncertainties related to a modelling process helps building confidence on the methods used; however, it should be considered carefully how to present the analysis and results for those who are not familiar with the subject. The work is a technical approach with ultimate goals in incorporating non-technical people and arguing for open data and transparency. It is concluded that open-source tools exhibit potential to be incorporated in complicated policy-making contexts despite the fact that no single tool can provide a panacea for complex issues.Vesi on keskeinen elämää ylläpitävä aine, ja sen merkitys lähes kaikille elinkeinoille on hyvin suuri. Se kiertää luonnon toisiinsa liittyneissä järjestelmissä jatkuvasti, ja vesivarojen hallinnoinnin on kyettävä toimimaan hallinnollisten rajojen yli. Veden käyttöön liittyy usein intressiristiriitoja eri toimijoiden välillä. Tieteellistä tietoa ja ympäristömallintamista hyödynnetään päätöksenteossa vesialalla, jolloin tuotetun tiedon tulisi olla mahdollisimman hyödyllistä ja luotettavaa. Fyysisen maailman loputon monimutkaisuus kuitenkin aiheuttaa epävarmuutta mallintamiseen. Tässä työssä esitellään ympäristömallintamisen prosessi ja arvioidaan erästä epävarmuustekijää numeerisesti. Lopuksi arvioidaan avoimeen lähdekoodiin perustuvien ratkaisujen potentiaalia osana ympäristömallintamista ja päätöksenteon tukea. Tässä työssä käytetään sekä laskennallisia että laadullisia menetelmiä. Laskennallisia menetelmiä ovat hydrostreamer, uusi avoimeen lähdekoodiin perustuva työkalu jokivirtaaman arviointiin, ja Monte Carlo -simulaatio, jota käytetään epävarmuuden simuloimiseen ja arviointiin. Kyselytutkimusta sekä puolistrukturoituja haastatteluja sovelletaan hydrostreamerin nykytilan ja sovellettavuuden arviointiin käyttäen nk. 3S-jokilaaksoa Kaakkois-Aasiassa esimerkkialueena. Työn tuloksena näytetään arvioidun spatiaalisen epävarmuuden käyttäytyvän käänteisesti Strahlerin luvun suhteen. Pienimuotoisia sovelluskohteita hydrostreamerille osoitetaan olevan tutkimusalueella, ja avointen työkalujen käyttöä ympäristömallintamisessa arvioidaan laadullisten tulosten perusteella. Työn pohdinnassa korostetaan, että mallintamistyökalujen valinnassa ja käytössä tulisi ottaa huomioon kompromissit sovellettavuuden ja tarkkuuden välillä. Tällöin mallinnusprosessista tulisi aidosti avoin sen sijaan, että avoimuus rajoittuisi vain pienelle joukolle toimijoita, joilla on tarvittava osaaminen ja data käytössään. Mallinnukseen liittyvien epävarmuuksien analysointi auttaa rakentamaan luottamusta kehitettyihin menetelmiin: epävarmuusanalyysin toteutus ja tulosten esittäminen muille voivat kuitenkin olla haastavia ja vaativat huolellista suunnittelua. Työ on lähtökohtaisesti tekninen, mutta sen pohjalta voidaan myös saada ei-teknisiä toimijoita osallistumaan mallintamiseen entistä enemmän. Yhteenvetona voidaan todeta, että potentiaalia sisällyttää avoimet työkalut osaksi monimutkaisia päätöksentekoprosesseja on olemassa, vaikkakaan mikään työkalu ei voi yksinään ratkaista kaikkia ongelmia