41 research outputs found
Systems Engineering of Time-Triggered Architectures - The SETTA Approach
No full textSETTA addresses the systems engineering of safetycritical distributed realtime systems with a special focus on timetriggered architectures. An innovative methodology and a corresponding engineering environment is developed which aims for a higher maturity at early development steps. Key features are the support for a virtual systems integration and the tighter interconnection between the functional development process and the safety analysis process. The supporting tool components are designed and implemented in the course of the SETTA project. The methodology is evaluated by pilot applications from the automotive, aerospace, and railway domain
Systems Engineering Of Time-Triggered Architectures --
No full textSETTA addresses the systems engineering of safety-critical distributed realtime systems with a special focus on time-triggered architectures. An innovative methodology and a corresponding engineering environment is developed which aims for a higher maturity at early development steps. Key features are the support for a virtual systems integration and the tighter interconnection between the functional development process and the safety analysis process. The supporting tool components are designed and implemented in the course of the SETTA project. The methodology is evaluated by pilot applications from the automotive, aerospace, and railway domain. Copyright 2000 IFAC Keywords: Systems Engineering, Distributed Computer Control Systems, Real-Time Systems, Safety-Critical Systems, Fault-Tolerant Systems, Verification, Validation, Automotive Control, Aerospace Control, Railways
How to efficiently build a front-end tool for UPPAAL: A model-driven approach
No full textS.319-336We propose a model-driven engineering approach that facilitates the production of tool chains that use the popular model checker Uppaal as a back-end analysis tool. In this approach, we introduce a metamodel for Uppaal's input model, containing both timed-automata concepts and syntax-related elements for C-like expressions. We also introduce a metamodel for Uppaal 's query language to specify temporal properties; as well as a metamodel for traces to interpret Uppaal's counterexamples and witnesses. The approach provides a systematic way to build software bridging tools (i.e., tools that translate from a domain-specific language to Uppaal's input language) such that these tools become easier to debug, extend, reuse and maintain. We demonstrate our approach on five different domains: cyber-physical systems, hardware-software co-design, cyber-security, reliability engineering and software timing analysis
Improving Date Fruit Sorting with a Novel Multimodal Approach and CNNs
No full textInternational audienceDate fruit is a beloved and widely consumed food in the Middle East and North Africa, and its popularity is growing globally. However, sorting these fruits can be a time-consuming and labor-intensive process, particularly when done manually. To address this challenge, we have proposed an innovative approach that uses multimodal data fusion and convolutional neural networks (CNNs) to efficiently classify Algerian date fruit. Our process involves capturing four RGB images of the date fruit from various angles, a thermal image, and the weight of the fruit. We create a new image where the first channel consists of a grayscale image obtained by averaging the four RGB images of the fruit. The second channel contains the thermal image, and the third channel contains the normalized weight data. The new dataset is then divided into training, validation, and testing sets. We conducted experiments using four different models: VGG16, InceptionV3, ResNet50, and Basic CNN. Our findings show that the VGG16 model achieved the highest accuracy during training, validation, and testing, with scores of 99.6%, 90.4%, and 94%, respectively. The InceptionV3 model had the lowest accuracy, while the ResNet50 and Basic CNN models had similar performances. Our results indicate that the VGG16 model is the most suitable for classifying Algerian date fruit. Our proposed approach offers a promising solution to improve efficiency and accuracy, ultimately enhancing the quality of sorted fruit and increasing its market value
Revisiting communities of practice : the case of Egyptian graffitists
No full textPurpose – The Egyptian Revolution gave birth to an intriguing community of graffiti artists that have been going through successful social learning processes. The naturally formed learning groups provided a fertile substance for social learning research and called for a comparison between the nature and elements of social learning and those of the learning taking place in the more traditional settings in an attempt to magnify factors of success. The purpose of this paper is to draw upon Wenger’s (1998) theory of Communities of Practice (CoP) and examines three major elements of learning in relation to it; namely, motivation, social practice, and the role of experts. Design/methodology/approach – The paper offers an in-depth analysis of perceptions of six Egyptian graffiti artists of their learning experiences. Findings – The paper argues that the motivational factor is underdeveloped in Wenger’s theory and that a concept that encompasses a combination of intrinsic motivation (IM) and identified regulation would provide a more accurate description of the driving force of a successful social learning process. Research limitations/implications – Although a snowballing approach was adopted, reaching the interviewees was not an easy task for security reasons; therefore, limiting the number to six was forced upon the researcher. Yet, a sense of saturation was reached. The paper underlines the vital role of social practice, which places meaning at the centre of learning, calls for revisiting the role of experts in Wenger’s theory and claims its marginality. Originality/value – Conclusions of this study suggest that the idea of a combination of passion and goal as core components of a CoP is an underdeveloped concept in Wenger’s (1998) theory and that outward motivational factors need to be discarded from the equation. This research proposes that a combination of IM and identified regulation provide a more accurate description of the driving force of a successful social learning process
Restructuring mergers – Failing firm defense
No full textΑυτή η διατριβή παρέχει μια εις βάθος εξέταση του τρόπου με τον οποίο το δίκαιο του ανταγωνισμού ανταποκρίνεται σε περιόδους οικονομικής αστάθειας και παρατεταμένης ύφεσης. Στο πλαίσιο μιας παγκοσμιοποιημένης ελεύθερης αγοράς, η οποία έχει αντιμετωπίσει πολλές παγκόσμιες οικονομικές κρίσεις που επηρεάζουν σχεδόν όλα τα κράτη και πλέον προσπαθεί να σταθεροποιηθεί υπό συνθήκες συνεχούς αβεβαιότητας και διαρκούς αλλαγής, έχει προκύψει ανάγκη για τη δημιουργία ενός προστατευτικού νομικού πλαισίου για τις επιχειρήσεις που βρίσκονται σε δυσχέρεια. Η Ευρωπαϊκή Ένωση δεσμεύεται να τηρεί αυστηρά τον ελεύθερο ανταγωνισμό, εστιάζοντας κυρίως στην προστασία της ευημερίας των καταναλωτών, ενώ ταυτόχρονα παραμένει ενήμερη για την ανάγκη παροχής κατάλληλων μέτρων στήριξης στις επιχειρήσεις που αντιμετωπίζουν οικονομικές δυσκολίες. Η ανάγκη για μια πιο ευέλικτη προσέγγιση στον έλεγχο των συγχωνεύσεων είναι ολοένα και πιο εμφανής, ιδιαίτερα σε σχέση με επιχειρήσεις που αντιμετωπίζουν σοβαρές οικονομικές δυσκολίες λόγω οικονομικών κρίσεων, ένα ζήτημα που η ΕΕ γνωρίζει εκ των έσω. Έτσι, το Failing Firm Defense - FFD αναδύθηκε ως μια έννοια που επιτρέπει σε τέτοιες εταιρείες να χρησιμοποιήσουν μια υπεράσπιση σε υποθέσεις συγχωνεύσεων, όπου η επιχείρηση είναι πιθανό να αποχωρήσει από την αγορά ανεξάρτητα από τη συγχώνευση. Η εργασία διερευνά τη δυνατότητα και τα οφέλη της διεύρυνσης της εφαρμογής της FFD μέσω μιας πιο ευέλικτης ερμηνείας των παραδοσιακά αυστηρών κριτηρίων της, συγκρίνοντας τη διαφορετική προσέγγιση που υιοθετήθηκε στην ΕΕ και τις ΗΠΑ, οι οποίες τη διαμόρφωσαν. Τα κριτήρια ενδέχεται να επανεκτιμηθούν υπό το φως των οικονομικών δυσκολιών που αντιμετωπίζουν οι επιχειρήσεις, επιτρέποντας μεγαλύτερη επιείκεια από τις αρχές ανταγωνισμού στην έγκριση συγχωνεύσεων που υπό άλλες συνθήκες θα μπορούσαν να αποκλειστούν ως αντι-ανταγωνιστικές. Η εργασία εμβαθύνει στα νομικά επιχειρήματα της FFD, αξιολογώντας αρχικά τους σχετικούς κανονισμούς και τις Κατευθυντήριες Γραμμές της ΕΕ σχετικά με την πολιτική συγχωνεύσεων και εξαγορών, με ιδιαίτερη έμφαση στις οριζόντιες συγχωνεύσεις και τα ζητήματα που προκύπτουν από αυτές. Θα επιχειρηθεί να προσδιοριστεί ο τρόπος με τον οποίο οι αρχές ανταγωνισμού την αντιμετωπίζουν, τόσο μέσω του κανονιστικού τους πλαισίου όσο και μέσω της επισκόπησης της σχετικής νομολογίας που διαμορφώνει τη στάση τους απέναντι σε αυτήν την υπεράσπιση. Αυτές οι Κατευθυντήριες Γραμμές είναι καθοριστικής σημασίας για τη διαμόρφωση του τρόπου αξιολόγησης των συγχωνεύσεων, ειδικά όταν υπάρχει πιθανότητα οι δομές της αγοράς να επηρεαστούν σημαντικά και να περιοριστεί ο ανταγωνισμός με οποιονδήποτε τρόπο. Η εργασία όχι μόνο περιγράφει τους κύριους νομικούς κανόνες που ενσωματώνονται στην προσέγγιση της Επιτροπής για τον έλεγχο των συγχωνεύσεων, αλλά παρέχει επίσης μια συγκριτική αξιολόγηση της προσέγγισης και του πλαισίου της ΕΕ και των ΗΠΑ στον έλεγχο συγχωνεύσεων υπό το δίκαιο ανταγωνισμού, αναδεικνύοντας τις διαφορές στην ποικιλία της μεταχείρισης που υιοθετούν αυτές οι δύο δικαιοδοσίες όταν αντιμετωπίζουν επιχειρήσεις σε δυσχέρεια στο πλαίσιο συγχωνεύσεων και εξαγορών, ρίχνοντας φως στις ευρύτερες επιπτώσεις των αντίστοιχων πολιτικών τους για την οικονομία. Τέλος, θα αναλυθούν οι μεταρρυθμίσεις στο ελληνικό νομικό πλαίσιο ανταγωνισμού, ιδιαίτερα μετά την εισαγωγή του Νόμου 3959/2011. Αυτός ο νόμος εισήγαγε ουσιαστικές αλλαγές στον τρόπο με τον οποίο ρυθμίζονται οι συγχωνεύσεις στην Ελλάδα, ειδικά σε ένα οικονομικό πλαίσιο που έχει επηρεαστεί σημαντικά από μια πολύ σοβαρή οικονομική κρίση. Η εργασία επιδιώκει επίσης να χαρτογραφήσει το τρέχον τοπίο του ελέγχου συγχωνεύσεων, ενσωματώνοντας πληροφορίες από βασικές διεθνείς συζητήσεις. Ειδικότερα, αντλεί στοιχεία από τις διαδικασίες της Στρογγυλής Τραπέζης του ΟΟΣΑ για την Πολιτική Ανταγωνισμού του 2009, η οποία εξέτασε πώς θα πρέπει να προσαρμοστεί ο έλεγχος συγχωνεύσεων κατά τη διάρκεια οικονομικών κρίσεων. Αναλύοντας την εξελισσόμενη στάση της Επιτροπής σε πρόσφατες υποθέσεις συγχωνεύσεων, η έρευνα προσφέρει κρίσιμες πληροφορίες σχετικά με το πώς το δίκαιο του ανταγωνισμού μπορεί να συνεχίσει να αναπτύσσεται σε απάντηση στις οικονομικές προκλήσεις.This dissertation provides an in-depth examination of how competition law responds during periods of economic instability and prolonged recession. In the context of a globalized free market, which has faced many global economic crises affecting almost all states and now strives to stabilize under continued uncertainty and constant change, there has been significant advocacy for the establishment of a protective legal framework for businesses in distress. The European Union is committed to rigorously upholding free competition, with its primary focus being the protection of consumer welfare, while at the same time, it remains cognizant of the need to provide appropriate support measures for companies struggling financially. The need for a more accommodating approach to merger control is ever more prominent, particularly in relation to firms facing severe financial difficulties due to economic crises, an issue the EU knows from firsthand. Hence, the Failing Firm Defense (FFD) emerged as a concept which enables such companies to use a defense in merger cases where the failing firm is likely to exit the market regardless of the merger. The dissertation explores the possibility and benefits of expanding the application of the FFD through a more flexible interpretation of its traditionally stringent criteria, comparing the different approach adopted in the EU and the U.S.A., both of which crystalized this defense. These, difficult to satisfy, criteria may be reassessed considering the financial difficulties firms possess, allowing for greater leniency by the competition authorities in approving mergers which might otherwise be blocked as anticompetitive. The study delves into the legal arguments of the FFD assessing firstly the relevant EU regulations and Guidelines regarding the merger and acquisitions policy, focusing particularly on the horizontal mergers, and the issues stemming from them. There will be an attempt to identify the way the competition authorities view it, both through their regulatory frameworks and through a review of relevant case law which shapes their attitudes towards this defense. These Guidelines are pivotal in the shaping of how mergers are evaluated, especially when there is a possibility of the market structures being significantly affected and competition hindered in any way. The research not only contours the key main legal principles embedded in the Commission’s approach to merger control but also provides a comparative evaluation of the EU and the U.S. approach and frameworks to merger control under competition law, establishing the differences in the diverse treatment those two jurisdictions adopt when dealing with distressed firms in M&A, shedding light on the broader implications of their respective policies for the economy. Finally, the reforms in the Greek competition legal framework will be analyzed, particularly following the introduction of Law 3959/2011. This law introduced substantial changes to the way mergers are regulated in Greece, especially in the context of an economy that has been significantly affected by a very important financial crisis. The thesis also seeks to map the current landscape of merger control, incorporating insights from key international discussions. Notably, it draws on the proceedings of the 2009 OECD Roundtable on Competition Policy, which explored how merger control should be adapted during economic crises. By analyzing the Commission’s evolving stance on merger control in recent cases, the research offers critical insights into how competition law may continue to develop in response to economic challenges. Ultimately, this dissertation concludes by reflecting on the potential future direction of merger control policy in the EU, particularly in light of the ongoing challenges posed by economic instability. It argues that while the FFD remains an exceptional legal argument, its relevance and applicability may increase as competition authorities seek to strike a balance between maintaining competitive markets and preventing widespread business failures. As the global economy continues to face uncertainties, the role of competition law in fostering both economic resilience and market fairness will be increasingly significant, making the careful application of the FFD an important tool in safeguarding market stability
L’impact des mécanismes de contrôle sur la performance des organisations complexes : cas des entreprises marocaines
No full textCette étude aborde la problématique de l’influence des mécanismes de contrôle sur la performance des organisations complexes. Notre modèle schématise les relations éventuelles entre l’organisation du processus décisionnel et la performance via les mécanismes de contrôle. Nous avons choisi de tester la plausibilité de ce modèle sur un échantillon de 74 entreprises marocaines en recourant à une approche quantitative. Les résultats obtenus corroborent l’existence de relations positives entre la décentralisation des droits décisionnels et les mécanismes de contrôle, d’une part ; et ces derniers et la performance dans une organisation complexe, d’autre part.Mots clés : Mécanismes de contrôle, performance, étude quantitative, entreprises marocaines.Abstract:This study addresses the issue of the influence of control mechanisms on the performance of complex organizations. Our model schematizes the possible relationships between the organization of the decision-making process and performance via control mechanisms. We have chosen to test the plausibility of this model on a sample of 74 Moroccan companies adopting a quantitative approach. The results obtained corroborate the existence of positive relationships between the decentralization of decision-making rights and the control mechanisms, on the one hand; and the latter and the performance in a complex organization, on the other hand.Keywords Control mechanisms, performance, quantitative study, Moroccan companies
The population genetic structure approach adds new insights into the evolution of plant LTR retrotransposon lineages
No full textLong terminal repeat retrotransposons (LTR-RTs) in plant genomes differ in abundance, structure and genomic distribution, reflecting the large number of evolutionary lineages. Elements within lineages can be considered populations, in which each element is an individual in its genomic environment. In this way, it would be reasonable to apply microevolutionary analyses to understand transposable element (TE) evolution, such as those used to study the genetic structure of natural populations. Here, we applied a Bayesian method to infer genetic structure of populations together with classical phylogenetic and dating tools to analyze LTR-RT evolution using the monocot Setaria italica as a model species. In contrast to a phylogeny, the Bayesian clusterization method identifies populations by assigning individuals to one or more clusters according to the most probabilistic scenario of admixture, based on genetic diversity patterns. In this work, each LTR-RT insertion was considered to be one individual and each LTR-RT lineage was considered to be a single species. Nine evolutionary lineages of LTR-RTs were identified in the S. italica genome that had different genetic structures with variable numbers of clusters and levels of admixture. Comprehensive analysis of the phylogenetic, clusterization and time of insertion data allowed us to hypothesize that admixed elements represent sequences that harbor ancestral polymorphic sequence signatures. In conclusion, application of microevolutionary concepts in genome evolution studies is suitable as a complementary approach to phylogenetic analyses to address the evolutionary history and functional features of TEs.</div
Student Experience of Access to Egyptian Higher Education.
No full textFocusing on the relationship between Higher Education (HE) and social justice in Egypt, this study attempts to identify the main socioeconomic factors affecting HE access in Egypt from the students' perspective through tracing and comparing students' narratives of their access processes in distinctively different socioeconomic settings. The study investigates the perceived effects of the General Secondary Education Certificate (GSEC) students' socioeconomic conditions on determining their academic choices. Different socioeconomic dimensions, such as culture, social conditions and finance are examined. The study also looks at the way students incorporate issues of social justice such as fairness, distribution of resources and social connections into understanding the process of HE access. Following a snowballing approach to recruiting the research participants, 55 students of the Egyptian GSEC took part in the research. The analysis is based on two sets of data: 1) Quantitative data were derived from two questionnaires examining the participants' socioeconomic classes, their perception of their academic experience, their aspirations and attitudes towards HE, determinants of their HE access process, and their views of the (in)equality of the access process. Allocating the participants into 3 socioeconomic groups, the Statistical Package for Social Sciences (SPSS) was used and cross-tabulation and comparisons were made between the three groups and correlations were examined. 2) Qualitative data were derived from interviews: Narratives of 17 students were sought through comprehensive semi-structured interviews that aimed at capturing the students' perceptions of their journeys through GSEC and the HE access process. The interviewed cases were regarded as instruments to dig into the impact of the socioeconomic factors onto the HE access process. Bourdieu's theory of social and cultural reproduction was drawn upon to explain social inequality as an outcome of inequitable access to HE and socially differentiated educational attainment. The theory provides a framework of understanding that explains how education, rather than becoming a means of social reform and equality, has become a tool for the reproduction of classism. The study also examines social media as a research tool and discusses its potentialities and limitations in social sciences research
