1,721,005 research outputs found
Architecting Families of Software Systems with Process Algebras
No full textSoftware components can give rise to several kinds of architectural mismatches when assembled together in order to form a software system. A formal description of the architecture of the resulting component based software system may help to detect such architectural mismatches and to single out the components that cause the mismatches. In this paper we concentrate on deadlock related architectural mismatches arising from three different causes that we identify: incompatibility between two components due to a single interaction, incompatibility between two components due to the combination of several interactions, and lack of interoperability among a set of components forming a cyclic topology. We develop a process algebra based architectural description language called PADL, which deals with all the three causes through an architectural compatibility check and an architectural interoperability check relying on standard observational equivalences. The adequacy of the architectural compatibility check is assessed on a compressing proxy system, while the adequacy of the architectural interoperability check is assessed on a cruise control system. We then address the issue of scaling the architectural compatibility and interoperability checks to architectural styles through an extension of PADL. The formalization of an architectural style is complicated by the presence of two degrees of freedom within the set of instances of the style: variability of the internal behavior of the components and variability of the topology formed by the components. As a first step towards the solution of the problem, we propose an intermediate abstraction called architectural type, whose instances differ only for the internal behavior of their components. We define an efficient architectural conformity check based on a standard observational equivalence to verify whether an architecture is an instance of an architectural type. We show that all the architectures conforming to the same architectural type possess the same compatibility and interoperability properties
Analyzing and shaping the lifetime and the performance of barrier coverage sensor networks
No full textIn this work we model and provide the means to extend the lifetime of a barrier coverage sensor network deployed fortarget detection. We consider a scenario where sensors are randomly dropped on a bidimensional field in order to detect target traversals which occur in a stochastic way within a critical mission time. Once a target enters a sensor's detection area, the sensor transmits such information to a cluster head, in charge of receiving and retransmitting the messages received from the sensors deployed on the field. The contribution of this work is fourfold. We first identify the sensing nodes whose behavior is key to model the duration of sensing operations, assuming prior arrival and mobility models for target traversals. We then proceed, providing a heuristic estimation of the traffic received by the cluster head to quantify its energy requirements, resorting to specific lifetime definitions. We also evaluate the relationship between our probabilistic and heuristic models and the time until the barrier remains capable of detecting and reporting the traversal of any target to a sink, as obtained by simulation. Finally, we show how the lifetime of such network may be shaped, with the use of a sequential activation mechanism, for example to combat the traversals of adversaries exploiting the lifetime models obtained in this work
Models and performance evaluation of event goodput in sensor platforms
No full textDespite the introduction of novel energy harvesting technologies, the lifetime of a sensor platform remains one of its most important performance metrics. Performance, however, may also be assessed in terms of the fraction of events which may successfully/unsuccessfully be detected and reported within a time interval of interest, i.e., mission time. Such a performance metric, here termed event goodput, is key for all random event-driven networks, ranging from surveillance and intrusion detection applications operating in time critical scenarios, to mobile and wearable crowd-sensed ecosystems, where mobile sensors are utilized by a number of different applications. When reporting the appearance of a series of possible, but unknown, phenomena, predicting which event goodput may be obtained during the planned mission time is challenging. In this paper, we address this issue by reducing the network-wide problem to the analysis of the performance of individual nodes, in terms of their capability of handling given fractions of event arrivals under fixed probabilistic guarantees. This is obtained as a function of mission time, event arrival and energy consumption models of different, detection and communication schemes, all realistic
Making paper labels smart for augmented wine recognition
Full text linkAn invisible layer of knowledge is progressively growing with the emergence of situated visualizations and reality-based information retrieval systems. In essence, digital content will overlap with real-world entities, eventually providing insights into the surrounding environment and useful information for the user. The implementation of such a vision may appear close, but many subtle details separate us from its fulfillment. This kind of implementation, as the overlap between rendered virtual annotations and the camera’s real-world view, requires different computer vision paradigms for object recognition and tracking which often require high computing power and large-scale datasets of images. Nevertheless, these resources are not always available, and in some specific domains, the lack of an appropriate reference dataset could be disruptive for a considered task. In this particular scenario, we here consider the problem of wine recognition to support an augmented reading of their labels. In fact, images of wine bottle labels may not be available as wineries periodically change their designs, product information regulations may vary, and specific bottles may be rare, making the label recognition process hard or even impossible. In this work, we present augmented wine recognition, an augmented reality system that exploits optical character recognition paradigms to interpret and exploit the text within a wine label, without requiring any reference image. Our experiments show that such a framework can overcome the limitations posed by image retrieval-based systems while exhibiting a comparable performance
Integrated Functional and Performance Analyses of Concurrent Distributed Systems Described with the Language EMPA
No full textDetecting Architectural Mismatches in Process Algebraic Descriptions of Software Systems
No full textFormalizing the description of software systems helps to detect the presence of architectural mismatches that can arise when assembling software components together. In this paper we identify three causes of architectural mismatches: incompatibility between two components due to a single interaction, incompatibility between two components due to the combination of several interactions, and lack of interoperability among a set of components forming a cyclic topology. We then show how to deal with all of them within a uniform, process algebraic framework. We begin with the first two causes by strengthening a previously defined architectural compatibility check based on observational equivalences, in order to achieve a deadlock freedom result for the set of components interacting via a certain connection. We subsequently concentrate on the third cause by defining a novel architectural interoperability check based on observational equivalences, which guarantees absence of deadlock within a set of interacting components forming a cyclic topology. We finally assess the adequacy of our architectural interoperability check by applying it to the description of a cruise control system
M-AGEW: Empowering Outdoor Workouts with Data-Driven Augmented Reality Assistance
No full textAugmented Reality (AR) has gained interest in various domains, including entertainment, education, and healthcare. At the crossroads of entertainment and healthcare, users involved in physical workouts may benefit from AR systems to visualize and interact with real-world blended information. On this line, we introduce M-AGEW (Magic AuGmentEd Workout), an AR system utilizing the Magic Leap 1 headset to enhance high-intensity sports activities like jogging and workouts. The system follows a data-driven client-server model, with the client as a visualization tool on the AR headset and the server handling data processing. M-AGEW overlays a dynamic virtual interface that adapts to the user's activity, offering real-time guidance. One significant advantage is its adaptability to various AR headsets. To the best of our knowledge, M-AGEW is the first dynamic AR guidance system for outdoor running and calisthenics whose design and development process were carried out collaborating with a sports equipment company
ÆMPA: A Process Algebraic Description Language for the Performance Analysis of Software Architectures
No full textWe address the problem of describing and analyzing not only functional but also performance properties of software architectures in a formal framework. We thus develop an architectural description language with a precise syntax and semantics and we illustrate the various kinds of analysis that can be conducted on its descriptions, such as architectural compatibility and conformity checking, functional verification, and performance evaluation. The proposed architectural description language is based on stochastically timed process algebras by virtue of their compositionality, which makes them suited to work with at the architectural level
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