Formal composition of partial system behaviors

Modeling the behavior of a system under development has shown to be a very effective way to ensure that it will have better chance to be constructed correctly. With the growing complexity of systems, building this model has become a major task that requires a significant time investment and a high level of expertise. Incremental approaches that help construct a system model from partial behavioral descriptions have been widely adopted. The challenge in such approaches lies in finding both the adequate behavioral formalism that fits the needs of the analyst as well as the formal composition mechanism that facilitates the generation of the expected behavioral model and produces a verifiable model. Within this framework, use case approaches have been accepted in the industry because they make the process of requirements engineering simpler. In the first stage of their development, use cases have been associated with requirements gathering and domain analysis since they allow the partial description of system behavior in a more intuitive manner. During the last decade, their use has been expanded to include all phases of the lifecycle. Consequently, the model representing use cases has an increasing importance. Although use case approaches present benefits in terms of improving the communication among stakeholders, permitting incremental construction of the system specification, and improving the requirements traceability, such approaches have some drawbacks in relation to their lack of formality. In fact, it is difficult to validate and verify use cases for completeness and consistency. This thesis addresses the problem of modeling use cases and their composition based on formal models in order to generate a system specification that can be used for validation and verification. We tackled the problem of both composing overlapping use cases that share partial similar behaviors, and composing non overlapping use cases according to additional criteria. We experimented with different formal models of use cases having different levels of expressivenesses to develop an approach for use case composition. All use case models we tackled are state-based models. We first started by proposing an approach for composing use cases expressed as extended finite state machines with variables that characterize their states. The use case model allows the definition of explicit loops. The state characterization is used as the criterion of composition. It allows the detection of common states between use cases that have to be merged in the overall system model. When composing, we proposed an approach that protects the user-defined loops from unexpected scenarios that may threaten their behavior. As a second step, we proposed to compose use cases based on the interactions they are making between each other. In this context, an interaction is defined as an invocation of a use case by another. Unlike the first approach, use cases are no more considered overlapping. When composing, we developed an approach that avoids unexpected scenarios. Finally, we proposed a general approach for composing system behaviors where partial system behaviors are defined as state based model using imperative expressions. Each use case describes a certain system concern. The imperative expression represents the composition criterion. In fact, it defines the semantics of the composition to perform. Our approach is fully automated and provides the advantage of generating a state based model that meets the intended behavior without allowing unexpected scenarios. The approach is formalized in the case of finite state machines and extended finite state machines

Nineteenth-century- Paris, capital of illusion: commercialized urban landscape in the works of Flaubert, Baudelaire and Zola

How does city space influence our behaviors in ways that might not even be perceptible? This dissertation examines Paris’s nineteenth-century urban upheaval in the works of Flaubert, Baudelaire and Zola. Haussmann’s comprehensive redesign of the French capital obliterated the narrow street patterns of medieval Paris, replacing them with wide boulevards lined with boutiques. This research shows how this radical transformation influences individuals’ inclinations. This interdisciplinary research synthesizes various representations of Paris together as a multidimensional mosaic to see what they reveal about the city and about us. This work aims to help us understand, as David Harvey says, “what the city was” and also helps us understand the modern city today and “what it could become.” This dissertation coincides with a number of new theoretical studies in architecture that aim to help us create new rapports with our cities. My argument is that the nineteenth-century French literature of this period portrays the urban space as a series of images to be visually and commercially consumed, a consumption that nourishes changes in the way individuals experience their daily lives and perceive their environment. By closely examining how these authors stress the dominance of the visual spectacle, this dissertation sheds new light on modernity’s immersion in the culture of the image, in which we even more today rely on images to experience the world and to interpret our daily lives. I use recent cultural and urban theories to show that the new open urban environment depicted in these texts created a milieu that encouraged individuals to display their personal lives before a quasi-invisible public. Flaubert, Baudelaire and Zola suggest that the dominance of commercial images in Paris brings with it a loss of reality. As a consequence, this world of illusion prompts individuals to engage in voyeuristic activities in an effort to find truth and reality. Ultimately, this research contributes to a broader understanding of our attraction to voyeurism and exhibitionism by linking the source of that attraction to nineteenth-century culture, particularly that of Paris as Walter Benjamin’s “capital of the nineteenth century.”2018-12-06T00:00:00

An Elastic Hybrid Sensing Platform: Architecture and Research Challenges

© 2016 Published by Elsevier B.V. The dynamic provisioning of hybrid sensing services that integrates both WSN and MPS is a promising, yet challenging concept. It does not only widen the spatial sensing coverage, but it also enables different types of sensing nodes to collaboratively perform sensing tasks and complement each other. Furthermore, it allows for the provisioning of a new category of services that was not possible to implement in pure WSN or MPS networks. Offering a hybrid sensing platform as a service results in several benefits including, but no limited to, efficient sharing and dynamic management of sensing nodes, diversification and reuse of sensing services, as well as combination of many sensing paradigms to enable data to be collected from different sources. However, many challenges need to be resolved before such architecture can be feasible. Currently, the deployment of sensing applications and services is a costly and complex process, which also lacks automation. This paper motivates the need for hybrid sensing, sketches an early architecture, and identifies the research issues with few hints on how to solve them. We argue that a sensing platform that reuses the virtualization and cloud computing concepts will help in addressing many of these challenges, and overcome the limitations of today\u27s deployment practices

Monetizing Personal Data: A Two-Sided Market Approach

© 2016 The Authors. Mobile phone-based sensing is a new paradigm that aims at using smartpohnes to answer sensing requests and collect useful data. Nowadays, a wide variety of domains ranging from health-care applications to pollution monitoring are benefiting from such collected data. However, despite its increasing popularity and the huge amount of data provided by users, there is no platform where mobile phone owners can effectively sell their data. In this paper, we propose the idea of a data monetization platform using two-sided market theory. In this platform, the data is viewed as an economic good and the data sharing activity is considered as an economic transaction. The proposed platform considers the case of abundant data. An experimental analysis is conducted to compare our approach against the peer-to-peer model using a real case study from the health care domain. We show that our proposed platform has the potential to generate higher profit for both data providers and data consumers

Remote Robotic Surgery: Joint Placement and Scheduling of VNF-FGs

Remote robotic surgery is one of the most interesting Tactile Internet (TI) applications. It has a huge potential to deliver healthcare services to remote locations. Moreover, it provides better precision and accuracy to diagnose and operate on patients. Remote robotic surgery requires ultra-low latency and ultra-high reliability. The aforementioned stringent requirements do not apply for all the multimodal data traffic (i.e., audio, video, and haptic) triggered during a surgery session. Hence, customizing resource allocation policies according to the different quality-of-service (QoS) requirements is crucial in order to achieve a cost-effective deployment of such system. In this paper, we focus on resource allocation in a softwarized 5G-enabled TI remote robotic surgery system through the use of Network Functions Virtualization (NFV). Specifically, this work is devoted to the joint placement and scheduling of application components in an NFV-based remote robotic surgery system, while considering haptic and video data. The problem is formulated as an integer linear program (ILP). Due to its complexity, we propose a greedy algorithm to solve the developed ILP in a computationally efficient manner. The simulation results show that our proposed algorithm is close to optimal and outperforms the benchmark solutions in terms of cost and admission rate. Furthermore, our results demonstrate that splitting application traffic to multiple VNF-forwarding graphs (VNF-FGs) with different QoS requirements achieves a significant gain in terms of cost and admission rate compared to modeling the whole application traffic with one VNF-FG having the most stringent requirements

Hybrid verification integrating HOL theorem proving with MDG model checking

In this paper, we describe a hybrid tool for hardware formal verification that links the HOL (higher-order logic) theorem prover and the MDG (multiway decision graphs) model checker. Our tool supports abstract datatypes and uninterpreted function symbols available in MDG, allowing the verification of high-level specifications. The hybrid tool, HOL-MDG, is based on an embedding in HOL of the grammar of the hardware modeling language, MDG-HDL, as well as an embedding of the first-order temporal logic L"m"d"g used to express properties for the MDG model checker. Verification with the hybrid tool is faster and more tractable than using either tools separately. We hence obtain the advantages of both verification paradigms

Pontage fémoro-fémoral croisé avec tunnulisation périnéale sous-scrotale pour une infection grave du triangle de scarpa

Nous décrivons dans cet article une technique de revascularisation des patients ayant une infection de  prothèse vasculaire sus-crurale au niveau dutriangle de scarpa, et qui minimise le risque d'infection récurrente du greffon. Cette technique consiste en un pontage fémoro-fémoral croisé avec un tunnel périnéal sous-cutané loin du scarpa infecté que le tunnel classique sus-pubiensous-cutané ne permet pas. Nous rapportons le cas d'un patient âgé de 52 ans, artéritique, multi-opérés, admis pour infection du scarpa droit sur un pontage  fémoro-fémoral prothétique perméable, le patient a eu une explantation de ce pontage et une revascularisation par un pontage périnéal sous-scrotal veineux loin du site infectieux; l'évolution a été excellente et le pontage est encore perméable après deux ans de suivi. Le pontage fémoro-fémoral périnéal est une procédure exceptionnellement réalisée, mais qui peut constituer une vraie option thérapeutique de revascularisation chez les patients avec une infection du scarpa.Key words: Pontage, triangle de scarpa, tunnel périnéa

Diagnostic Value of Transthoracic Echocardiography in Patients with Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital coronary abnormality associated with early infant mortality and sudden death in adults. Transthoracic echocardiography (TTE) plays an important role in early detection and diagnosis of ALCAPA as a noninvasive modality. However, its diagnostic value is not well studied. The purpose of this study is to determine the performance of TTE in the diagnostic assessment of ALCAPA as compared with coronary CT and invasive coronary angiography. A total of 22 patients (13 women and 9 men, mean age, 12.9±19.5 years) with ALCAPA who underwent echocardiographic examination for clinical diagnosis were retrospectively reviewed and analyzed. Transthoracic echocardiographic features of ALCAPA were analyzed and its diagnostic value was compared with invasive coronary angiography and coronary CT angiography (CTA) with surgical findings serving as the gold standard. Surgery was performed in all of the patients to establish the dual coronary artery system. Five underwent the Takeuchi procedure and 17 had re-implantation of the anomalous left coronary artery. Of 20 patients, echocardiographic diagnoses were in good agreement with findings at surgery, resulting in the diagnostic accuracy of 90.9%. Two cases were misdiagnosed-one as the right coronary artery to pulmonary artery fistula and the other as rheumatic heart disease. The echocardiographic features of these patients with ALCAPA included: abnormal left coronary ostium arising from the pulmonary trunk with retrograde coronary artery flow in 20 patients; enlargement of the right coronary artery in 17 patients; abundant intercoronary septal collaterals in 17 patients; and moderate and significant mitral regurgitation in 14 patients. The diagnostic accuracy of invasive coronary angiography (in 17 patients) and coronary CTA (in 9 patients) was 100%. This study shows that TTE is an accurate, noninvasive imaging modality for displaying the origin of coronary arteries and demonstrating the coronary courses as well as other associated abnormalities in patients with ALCAPA