1,355,831 research outputs found
A DDS-Compliant P2P Infrastructure for Reliable and QoS-Enabled Data Dissemination
No full textRecent trends in data-centric systems have motivated significant standardization efforts, such as the Data Distribution Service (DDS) to support data dissemination with guaranteed Quality of Service (QoS) in heterogeneous Internet environments. Notwithstanding the central relevance of DDS in that scenario, DDS-based pub/sub solutions still exhibit limited support for reliability, by omitting advanced techniques to reduce/eliminate QoS-degradations and data losses due to possible network and DDS system faults. We propose an original solution for fault- tolerance and prompt recovery of DDS-based pub/sub systems based on a DDS-compliant P2P routing substrate that continuously achieves a guaranteed data delivery with expected QoS-levels. In contrast with similar solutions in the field, our proposal neither requires support for data persistency nor implies heavy client-side operations. We exploit a DDS-compliant data dispatching infrastructure to reliably disseminate events and to balance data distribution load. The reported experimental results point out that our solution can guarantee desired requirements together with a limited overhead: the paper reports also performance indicators for our proposal CPU and memory resource usage
IPPODAMO: A digital twin support for smart cities facility management
No full textThe steady deployment of IoT is paving the road toward concrete implementations of the smart city concept, allowing public/private institutions to sense and model (near) real-time digital replicas of physical processes and environments. This Digital Twin (DT) could be used proactively, as a decision support system, providing insights into possible optimizations of processes in a smart city context. In this article, we present the design and main building blocks of a DT solution for the Urban Facility Management (UFM) process in the metropolitan area of Bologna, Italy. The Interactive Planning Platform for city District Adaptive Maintenance Operations (IPPODAMO) is a proof of concept solution consisting of a (distributed) multi-layer geographical system, fed with heterogeneous data sources originating from different urban data providers. The data are subject to continuous refinements and algorithmic processes, used to quantify and predict near-to-long term evolution of the urban activity level, exploited for planning purposes, scheduling urban maintenance operations and interventions
A digital twin decision support system for the urban facility management process
No full textThe ever increasing pace of IoT deployment is opening the door to concrete implementa-tions of smart city applications, enabling the large-scale sensing and modeling of (near-)real-time digital replicas of physical processes and environments. This digital replica could serve as the basis of a decision support system, providing insights into possible optimizations of resources in a smart city scenario. In this article, we discuss an extension of a prior work, presenting a detailed proof-of-concept implementation of a Digital Twin solution for the Urban Facility Management (UFM) process. The Interactive Planning Platform for City District Adaptive Maintenance Operations (IPPODAMO) is a distributed geographical system, fed with and ingesting heterogeneous data sources originating from different urban data providers. The data are subject to continuous refinements and algorithmic processes, used to quantify and build synthetic indexes measuring the activity level inside an area of interest. IPPODAMO takes into account potential interference from other stakeholders in the urban environment, enabling the informed scheduling of operations, aimed at minimizing interference and the costs of operations
Comparison of application programming interfaces for rendering 2D graphics components using the graphics processing unit
No full textV diplomskem delu smo primerjali tri aplikacijske programske vmesnike: Cairo, Direct2D in Raylib. Za vsako smo analizirali hitrost izrisa, obremenitev sistemskih virov (vključno s porabo delovnega in grafičnega pomnilnika ter obremenitvijo centralne in grafične procesne enote), enostavnost uporabe in podporo operacijskim sistemom. V ta namen smo razvili tri testne aplikacije, ki vključujejo izris osnovnih likov, obdelavo slik in prikaz besedila. Ugotovili smo, da je prava izbira knjižnice odvisna od pričakovanih ciljev uporabnika. Rezultati so pokazali, da je Cairo najpočasnejši in najmanj učinkovit glede porabe virov, vendar primeren za aplikacije brez potrebe po realno časovnem izrisu. Direct2D je dosegel najboljšo učinkovitost in najnižjo porabo virov, a je vezan na operacijski sistem Windows. Raylib se je izkazal kot najhitrejši pri izrisu, z zmerno porabo virov in dobro prenosljivostjo, a slabšim skaliranjem. Ugotovili smo tudi, da je bil Raylib najlažji za uporabo, medtem ko je bil Cairo zaradi pomanjkljive dokumentacije in slabše podpore najbolj zahteven za implementacijo.In this thesis, three application programming interfaces are compared: Cairo, Direct2D, and Raylib. For each, we analyzed rendering speed, system resource usage – including system and graphics memory consumption, the load on the central and graphics processing units – as well as ease of use and operating system support. To conduct this analysis, we developed three test applications that include basic shape rendering, image processing, and text rendering. We found that the optimal choice of library depends on the user’s specific goals. The results showed that Cairo was the slowest and least efficient in terms of resource usage, but suitable for applications that do not require real-time rendering. Direct2D achieved the best performance and the lowest resource consumption, but it is limited to the Windows operating system. Raylib proved to be the fastest in rendering, with moderate resource usage and good portability, but with poorer scaling quality. We also found that Raylib was the easiest to use, while Cairo was the most challenging to implement due to its insufficient documentation and limited support
An Efficient and Reliable Multi-Cloud Provider Monitoring Solution
No full textCloud computing has transformed the way IT services are provisioned and consumed, shifting the burden of configuration and management to the cloud provider. A lot of research has been conducted in the field aimed at optimizing and/or devise new in-cloud service delivery models. Yet, service outages are a norm rather than an exception. A natural evolution for application developers, especially for those applications that must meet high availability requirements, is to rely on resources and services provisioned by multiple cloud simultaneously. The so-called multi-cloud, distributed deployment model coupled with a monitoring solution spanning multiple domains could help in a timely identification and isolation of faulty components, alleviating service impairment issues. To this end, we propose an extension to NoMISHAP, a Platform as a Service (PaaS) multi-cloud middleware, introducing a cross layer monitoring solution for use in distributed cloud environments. Experimental results show the effectiveness of our approach and its ease of adoption for management tasks
Resource-Awareness in Context Data Distribution for Mobile Environments
No full textContext-aware scenarios require the distribution of large amounts of context data over fixed wireless infrastructures. The opportunistic usage of mobile nodes as data carriers has received a great deal of interests in recent years in order to increase system scalability. In this paper, we focus on the overhead introduced by context distribution on mobile devices, and we highlight the need of resource-aware solutions to trade off run-time overhead with available resources. Next, we propose a novel algorithm to dynamically adapt data distribution task processing load at mobile devices. Our experimental results, obtained using a real testbed, demonstrate that our approach ensures correct resource management under a wide range of different working conditions
Oral field cancerization: History and future perspectives
No full textNotwithstanding extended surgical approaches or adjuvant chemoradiotherapy, the development of multiple neoplastic lesions arising in the oral cavity after treatment still represents a critical clinical challenge in the management of patients with oral squamous cell carcinoma. Such clinical behavior of oral squamous cell carcinoma is nowadays better known as "field" cancerization effect as suggested by Slaughter, the author that for the first time tried to describe it in a scientific paper. Field cancerization is now widely accepted not only in head and neck oncology but also in other anatomical districts as well as in different types of epithelial neoplasia. A brief history of the theory of field cancerization is here proposed and future perspectives deriving from new molecular techniques are discussed
Accretion and ejection at work in the Narrow Line Seyfert 1 galaxy 1H 0323+342: A case of intermittent activity?
No full textContext. We present a comprehensive investigation into the properties of 1H 0323+342, a prominent jetted narrow-line Seyfert 1 galaxy. Aims. The primary objective is to understand the interplay between the relativistic jet, the hot corona, and the accretion disk around the supermassive black hole. Methods. This study spans the years 2006 to 2023, incorporating a rich dataset with 172 Swift observations, including the optical, UV, and X-ray bands, integrated with Fermi Large Area Telescope (LAT) observations. Spectral analysis was conducted on the X-ray observations using the XSPEC software, and the results were compared with optical, UV, and gamma-ray flux measurements and photon index values. Results. Our key findings include the identification of three distinct zones in the X-ray photon index-flux plot, characterized by high flux and a hard photon index (zone 1), high flux and a soft photon index (zone 2), and low flux and a soft photon index (zone 3). Before similar to 2017, 1H 0323 + 342 moved back and forth between zones 1 and 2; after that epoch, it transitioned to zones 2 and 3. Correspondingly, we observed a decreasing jet activity in the Fermi/LAT data and a reduction in the accretion rate in optical/UV data from Swift/UVOT. Conclusions. We interpret these observations in the framework of an intermittent jet scenario, driven by radiation-pressure instability in the accretion disk
Optimization of the extraction of bioactive molecules from <i>Lycium barbarum</i> fruits and evaluation of the antioxidant activity: a combined study
No full textNovel food, super food, wolfberry, the Himalayan longevity fruit. Several different and, even more, colourful names define the fruits of Lycium barbarum L., one of the most popular food supplements and anti-aging remedies of the recent years. Goji derivatives find application at the interface between food and medicine thanks to the claimed antioxidant and immunomodulatory properties. Aiming at identifying the most effective extraction protocol for processing different goji berries samples (fresh and dried, commercial and from an Italian cultivar), combinations of extractive and analytical techniques were attempted. The concentration of bioactive compounds and of total phenols were measured and the antioxidant activity of the obtained extracts was studied. The results highlight the most suitable combination of source and process to obtain an extract that can be suitable for nutraceutical applications.</p
- …
