226 research outputs found

    Mobiilse värkvõrgu protsessihaldus

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    Värkvõrk, ehk Asjade Internet (Internet of Things, lüh IoT) edendab lahendusi nagu nn tark linn, kus meid igapäevaselt ümbritsevad objektid on ühendatud infosüsteemidega ja ka üksteisega. Selliseks näiteks võib olla teekatete seisukorra monitoorimissüsteem. Võrku ühendatud sõidukitelt (nt bussidelt) kogutakse videomaterjali, mida seejärel töödeldakse, et tuvastada löökauke või lume kogunemist. Tavaliselt hõlmab selline lahendus keeruka tsentraalse süsteemi ehitamist. Otsuste langetamiseks (nt milliseid sõidukeid parasjagu protsessi kaasata) vajab keskne süsteem pidevat ühendust kõigi IoT seadmetega. Seadmete hulga kasvades võib keskne lahendus aga muutuda pudelikaelaks. Selliste protsesside disaini, haldust, automatiseerimist ja seiret hõlbustavad märkimisväärselt äriprotsesside halduse (Business Process Management, lüh BPM) valdkonna standardid ja tööriistad. Paraku ei ole BPM tehnoloogiad koheselt kasutatavad uute paradigmadega nagu Udu- ja Servaarvutus, mis tuleviku värkvõrgu jaoks vajalikud on. Nende puhul liigub suur osa otsustustest ja arvutustest üksikutest andmekeskustest servavõrgu seadmetele, mis asuvad lõppkasutajatele ja IoT seadmetele lähemal. Videotöötlust võiks teostada mini-andmekeskustes, mis on paigaldatud üle linna, näiteks bussipeatustesse. Arvestades IoT seadmete üha suurenevat hulka, vähendab selline koormuse jaotamine vähendab riski, et tsentraalne andmekeskust ülekoormamist. Doktoritöö uurib, kuidas mobiilsusega seonduvaid IoT protsesse taoliselt ümber korraldada, kohanedes pidevalt muutlikule, liikuvate seadmetega täidetud servavõrgule. Nimelt on ühendused katkendlikud, mistõttu otsuste langetus ja planeerimine peavad arvestama muuhulgas mobiilseadmete liikumistrajektoore. Töö raames valminud prototüüpe testiti Android seadmetel ja simulatsioonides. Lisaks valmis tööriistakomplekt STEP-ONE, mis võimaldab teadlastel hõlpsalt simuleerida ja analüüsida taolisi probleeme erinevais realistlikes stsenaariumites nagu seda on tark linn.The Internet of Things (IoT) promotes solutions such as a smart city, where everyday objects connect with info systems and each other. One example is a road condition monitoring system, where connected vehicles, such as buses, capture video, which is then processed to detect potholes and snow build-up. Building such a solution typically involves establishing a complex centralised system. The centralised approach may become a bottleneck as the number of IoT devices keeps growing. It relies on constant connectivity to all involved devices to make decisions, such as which vehicles to involve in the process. Designing, automating, managing, and monitoring such processes can greatly be supported using the standards and software systems provided by the field of Business Process Management (BPM). However, BPM techniques are not directly applicable to new computing paradigms, such as Fog Computing and Edge Computing, on which the future of IoT relies. Here, a lot of decision-making and processing is moved from central data-centers to devices in the network edge, near the end-users and IoT sensors. For example, video could be processed in mini-datacenters deployed throughout the city, e.g., at bus stops. This load distribution reduces the risk of the ever-growing number of IoT devices overloading the data center. This thesis studies how to reorganise the process execution in this decentralised fashion, where processes must dynamically adapt to the volatile edge environment filled with moving devices. Namely, connectivity is intermittent, so decision-making and planning need to involve factors such as the movement trajectories of mobile devices. We examined this issue in simulations and with a prototype for Android smartphones. We also showcase the STEP-ONE toolset, allowing researchers to conveniently simulate and analyse these issues in different realistic scenarios, such as those in a smart city.  https://www.ester.ee/record=b552551

    A Sustainable Revolution

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    The parties of the United Nations Framework Convention on Climate Change (UNFCCC) attained the Paris Agreement to tackle climate change and to strengthen the actions required for a sustainable transition towards an environmentally friendly future. This transition will involve holistic approaches and multifaceted societal shifts, requiring answers and collaboration between private, public, and academic sectors. This book gathers together contributions which study the transition towards a more sustainable future, involving and identifying the development and implications of more sustainable alternatives, in collaboration with all relevant stakeholders (e.g. communities, firms, policy makers, researchers, etc.), to achieve this transition. The approaches proposed are all concerned with a common perspective: imaging our globe with a greener picture, built upon a transversal sustainable revolution to clean up the Earth

    Concurrency in Android development – Kotlin Coroutines and RxJava

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    A faulty concurrency system may have an impact in the user experience of the software product and consequently to the company that owns that product. The main goal of this research is to understand the impact of concurrency in Android development and further help developers/companies to discretise the best approaches for concurrency. The research initially centres on the importance of concurrency in Android applications as well as the main approaches for concurrency/threading in Android development. It further illustrates why some asynchronous programming approaches do not fit modern Android development. This allowed the research to concentrate on the most relevant approaches to concurrency and consequently produce more pertinent results for the current state of Android development. After acknowledging Kotlin Coroutines and RxJava as the most relevant approaches to concurrency for Android (at the time of writing this document), this research moved on with the development of a case study application. This application was implemented using both Kotlin Coroutines and RxJava while reusing as much code as possible. There is a single module dedicated to the main user interface of the application and two modules (one for Kotlin Coroutines and one for RxJava) dedicated to concurrently run the necessary steps for each feature and further propagating the necessary data to the user interface. This allowed a clear separation of the specific code needed to perform the same features with Kotlin Coroutines and RxJava, facilitating its later comparison. The design of this application and its features required prior assessment of common use cases for concurrency in Android to form a fitting case study. With the intent of assessing the impact of using Kotlin Coroutines and RxJava in Android applications, we discretised the main software quality attributes to consider for Android development. By taking this step, we were able to focus mainly on the Performance and Maintainability of an Android application and understand how the usage of both Kotlin Coroutines and RxJava affects these attributes. The impact of each library in the performance and maintainability of an Android application was measured using software metrics that were provided by a combination of static analysis, benchmarks, and profiling tests. The process of designing the set of tests, setting up the required tools and the overall development of the test environment for this research is also explored in this document. The results for Kotlin Coroutines and RxJava were then illustrated, compared, and interpreted to fulfil our objective of understanding if, at the time of writing this document, there is a more sensible approach to concurrency for Android development according to our set of tests. The results for our set of tests and case study application revealed that RxJava and Kotlin Coroutines do not differently compromise the performance and maintainability of an Android application, for what developers and companies should not be limited when choosing between these libraries

    Cleaner production for environmental conscious manufacturing in the foundry industry

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    The purpose of the paper is to illustrate application of the cleaner production concept so as to incorporate environmental protection into business performance. The study analyses areas pertaining to the foundry industry that impact negatively on the environment leading to unsustainable resource utilisation and suggests options for promoting sustainable development within the industry, with specific focus on a foundry in a lower income country (LIC)

    Analysing the performance and costs of reactive programming libraries in Java

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    International audienceModern services running in cloud and edge environments need to be resource-efficient to increase deployment density and reduce operating costs. Asynchronous I/O combined with asynchronous programming provides a solid technical foundation to reach these goals. Reactive programming and reactive streams are gaining traction in the Java ecosystem. However, reactive streams implementations tend to be complex to work with and maintain. This paper discusses the performance of the three major reactive streams compliant libraries used in Java applications: RxJava, Project Reactor, and SmallRye Mutiny. As we will show, advanced optimization techniques such as operator fusion do not yield better performance on realistic I/O-bound workloads, and they significantly increase development and maintenance costs

    Virginia Dental Journal (Vol. 94, no. 2, 2017)

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    Management of bone defects with Bio-oss

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    Introduction: The defects in the alveolar bone might appear as a result of congenital malformations, traumatic injuries, periodontal disease, surgical traumas, chronic periapical changes and tumors from benign or malignant origin. The aim of this study was to provide solid and healthy area with application of Bio-Oss in the defect. Materials and methods: Based on the clinical diagnosisestablished by previously taken history, clinical examination and radiographic images oral-surgery interventions was made. To realize the aim of this work, augmentative material was implicated in the bone defects made in the patients after removal of follicular cyst, chronic periapical lesion, and parodontopathia. During the first and seventh day of the interventions, the patients have been followed through from aspect of possible development of local and general complications after the oral-surgery intervention. After period of one, three and six mount control x-ray was made. Results: Obtained results confirmed that: volume of the socket and defect of the bone was kept, fast revascularization was achieved, bone formation and slow resorption of the augmentative material was achieved, and period of normal healing without infection was also achieved. Conclusions: The augmentative materials used for treatment of bone defects besides their basic chemical and physical characteristics referring to their solubility in the body fluids, the transformation, modulation and resorption must be completely safe or secure, i.e. not to bring any risk of infection, immunological risk, physiological intolerance or inhibition of the process of restitutio ad integrum. In our study Bio-Oss was confirmed as augmentative material who had this characteristics. Keywords: bone defect, resorption of the bone, augmentative material, Bio-Os
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