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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Adaptation dynamique des architectures réparties pour jeux massivement multijoueurs

Legtchenko, Sergey 25 October 2012 (has links) (PDF)
Durant la dernière décennie, Les jeux massivement multijoueurs (MMOGs) sont devenus extrêmement populaires et comptent désormais plus de 20 millions d'utilisateurs actifs à travers le monde. Les MMOGs sont des systèmes distribués ayant des contraintes applicatives fortes en terme de cohérence de données, persistance, réactivité et passage à l'échelle. L'évolution des besoins applicatifs du MMOG au cours du temps est difficilement prévisible car dépendante du comportement des joueurs dans le monde virtuel. C'est pourquoi, malgré un important effort de recherche dans le domaine, aucune des architectures proposées ne satisfait pleinement toutes les contraintes requises. Cette thèse explore les capacités des architectures distribuées à s'adapter à la charge applicative grâce à une prise en compte du comportement des joueurs lors de l'exécution. Le système est alors capable de détecter des évolutions qui sont difficiles à prévoir à priori, et dynamiquement allouer les ressources nécessaires à l'application. Nous décrivons différentes techniques de surveillance des joueurs et proposons des moyens de prendre en compte ces informations au niveau de l'architecture. Nos expériences, effectuées dans des conditions réalistes, montrent que nos mécanismes ont un surcoût limité et permettent d'améliorer les performances globales du système.
62

Hotas (eller främjas) revisorns arbete av teknologier? : En kvantitativ studie om hur revisionsprocessen och revisorns komfort påverkas av framväxande teknologier / Is the auditor’s work threatened (or facilitated) by technologies? : A quantitative study of how the audit process and the auditor’s comfort are affected by emerging technologies

Pettersson, Elin, Lindau, Emelie January 2022 (has links)
Bakgrund: Den teknologiska utvecklingen går väldigt snabbt och framväxande teknologier utgör en stor påverkan på revisionsbranschen och revisorers arbete. Enklare arbetsuppgifter automatiseras och revisorns arbete innefattas allt mer av analyser och bedömning av revisionsbevis. Det kan innebära att revisorns involvering i revisionsprocessen minskar och att revisorsyrket riskerar att förändras i grunden eller till och med försvinna till följd av automatisering. Samtidigt medför teknologin att revisorn kan spendera mer tid på värdeskapande arbetsuppgifter som kan förbättra revisionskvaliteten och öka revisorns komfort. Förändringarna som teknologin medför ställer krav på att revisorn anpassar sitt arbete till att använda teknologi, samt ställer krav på revisionsbranschen, däribland standardsättare och revisionsbyråer, att anpassa standarder, regler och riktlinjer för att stödja revisorer i deras användning av teknologi.  Syfte: Syftet med studien är att kartlägga i vilken utsträckning framväxande teknologier används av revisorer och utforska hur revisorer upplever att revisionsprocessen och deras komfort påverkas av sådana teknologier. Metod: Studien är kvantitativ och har en deduktiv ansats med tvärsnittsdesign. Använd primärdata utgörs av enkätsvar från revisionsmedarbetare i Sverige.  Resultat: Resultatet indikerar att revisionsmedarbetare, vid användning av framväxande teknologier, upplever att revisionsprocessen förbättras och att deras komfort ökar. Därtill tyder resultatet på att revisionsmedarbetare upplever att det finns ytterligare faktorer som påverkar revisionsprocessen och komforten, såsom revisionsbyråns riktlinjer för användning av teknologi och revisionsmedarbetarens kunskaper inom teknologi. Resultatet indikerar även att revisionsmedarbetares användning av teknologi generellt är låg och någon skillnad mellan större och mindre revisionsbyråer har inte identifierats. Kunskapsbidrag: Studien bidrar till litteraturen genom att fokusera på revisorns perspektiv på framväxande teknologiers påverkan på revision. Kunskap om hur revisionsprocessen och revisorns komfort påverkas bidrar till att revisionsbranschen generellt och revisionsbyråer specifikt, kan hantera utmaningarna och tillvarata möjligheterna som framväxande teknologier medför, inte minst för att stödja och vägleda revisionsmedarbetare i dess användning av teknologin. / Background: The technological development is very rapid and emerging technologies have a major impact on the auditing industry and the auditor’s work. Simpler tasks are being automated and the auditor's work is increasingly consisting of analyzes and assessment of audit evidence. This may indicate that the auditor's involvement in the audit process decreases and that the audit profession risks being replaced as a result of automation. At the same time, the technology means that the auditor can spend more time on value-creating tasks that can improve the quality of the audit and increase the auditor's comfort. The changes that technology entails mean that the auditor needs to adapt his/her work to using technology, and require that the auditing industry, including standard setters and audit firms, adapts standards, rules and guidelines to support auditors in their use of technology. Purpose: The aim of the study is to map the extent to which emerging technologies are used by auditors and to explore how auditors perceive that the audit process and their comfort are affected by such technologies. Method: The study is quantitative and has a deductive approach with cross-sectional design. Primary data is based on survey responses collected from audit staff in Sweden.  Results: The results indicate that audit staff, when using emerging technologies, experience that the audit process is improved and that their comfort increases. In addition, the results indicate that audit staff perceive that there are additional factors that affect the audit process and their comfort; the audit firm’s guidelines for the use of technology and the audit staff’s knowledge of technology. The results also indicate that auditors’ use of technology is generally low and that it does not differ between larger and smaller auditing firms. Contribution: This study contributes to the literature by focusing on the auditor's perspective on the impact of emerging technologies on auditing. Knowledge of how the auditing process and the auditor's comfort are affected contributes to the auditing industry in general and auditing firms specifically being able to manage the challenges and take advantage of the opportunities that emerging technologies bring to the industry, auditing firms and auditors.
63

Information Sharing and the Bullwhip Effect Reduction : A new Prespective Through the Lens of Blockchain Technology

Al-Sukhni, Muthana January 2023 (has links)
Globalization and the surge of competition across industries forced companies to improve their supply chain capabilities to serve their customers efficiently and effectively. Due to this fact, businesses are no longer capable of handling all supply chain operations without collaboration and coordination with other firms. One of the key obstacles to coordination is the lack of information sharing and trust between firms since they view information as a sensitive asset. Digital technologies like blockchain, with its inherited features, have the capability to facilitate real-time information sharing, solve trust issues, and improve end-to-end visibility across the supply chain. This licentiate thesis highlights the impact of multiple aspects of information sharing on the bullwhip effect mitigation and explores the potential of blockchain technology as a new coordination mechanism for reducing information distortions, enhancing trust, and orchestrating decision making. Three research papers have been produced within this context and are appended to the thesis. Paper A presents an information sharing-based blockchain architecture to mitigate the bullwhip effect in service supply chains. Paper B aims to explores the literature in terms of using multiple aspects of information sharing to lessen the bullwhip effect. Finally, Paper C introduces an agent-based modeling and simulation approach for two aspects of information sharing: “what to share” and “how to share.” The results show that blockchain technology does provide a significant solution to trust-based issues and information sharing visibility considering the bullwhip effect mitigation. The results also provide a guide for supply chain managers to achieve better coordination and serve as a roadmap for supply chain researchers.
64

A Hardware/Software Stack for Heterogeneous Systems

Lehner, Wolfgang, Castrillon, Jeronimo, Lieber, Matthias, Klüppelholz, Sascha, Völp, Marcus, Asmussen, Nils, Aßmann, Uwe, Baader, Franz, Baier, Christel, Fettweis, Gerhard, Fröhlich, Jochen, Goens, Andrés, Haas, Sebastian, Habich, Dirk, Härtig, Hermann, Hasler, Mattis, Huismann, Immo, Karnagel, Tomas, Karol, Sven, Kumar, Akash, Leuschner, Linda, Ling, Siqi, Märcker, Steffen, Menard, Christian, Mey, Johannes, Nagel, Wolfgang, Nöthen, Benedikt, Peñaloza, Rafael, Raitza, Michael, Stiller, Jörg, Ungethüm, Annett, Voigt, Axel, Wunderlich, Sascha 17 July 2023 (has links)
Plenty of novel emerging technologies are being proposed and evaluated today, mostly at the device and circuit levels. It is unclear what the impact of different new technologies at the system level will be. What is clear, however, is that new technologies will make their way into systems and will increase the already high complexity of heterogeneous parallel computing platforms, making it ever so difficult to program them. This paper discusses a programming stack for heterogeneous systems that combines and adapts well-understood principles from different areas, including capability-based operating systems, adaptive application runtimes, dataflow programming models, and model checking. We argue why we think that these principles built into the stack and the interfaces among the layers will also be applicable to future systems that integrate heterogeneous technologies. The programming stack is evaluated on a tiled heterogeneous multicore.
65

Το "παράδοξο της ενέργειας" στην ελληνική βιομηχανία : έκταση, υιοθέτηση τεχνολογιών εξοικονόμησης ενέργειας και αντιρρύπανσης και επιδράσεις στην απόδοση, αποτελεσματικότητα και παραγωγικότητα

Κουνετάς, Κωνσταντίνος 13 April 2009 (has links)
Το πρόβλημα της κλιματικής αλλαγής αποτελεί έναν από τα κυριότερα σημεία έντονου ενδιαφέροντος για τις περισσότερες χώρες. Μάλιστα, τα επόμενα χρόνια αναμένεται να δοθεί μεγαλύτερη προσοχή στην ανάπτυξη πολιτικών που θα μειώνουν τις εκπομπές ρυπογόνων αέριων ρύπων. Η εξοικονόμηση ενέργειας, ως μέτρο πολιτικής, θα συνεχίσει να αποτελεί μια σημαντική στρατηγική ανάπτυξης για την οικονομία της χώρας μας, μια και συνδέεται σε σημαντικό βαθμό, με την κατανάλωση ενέργειας όπως και με την μείωση των εκπομπών αερίων ρύπων. Επιπλέον, συντονισμένες προσπάθειες τόσο από την Ευρωπαϊκή Ένωση όσο και από άλλους οργανισμούς (IEA, OECD) θέτουν σε βασικό άξονα προτεραιότητας την μείωση της κατανάλωσης ενέργειας, την χρησιμοποίηση εναλλακτικών μορφών και ανανεώσιμων πηγών και την μείωση των ρυπογόνων εκπομπών ιδιαίτερα στον βιομηχανικό κλάδο. Στα πλαίσια της παρούσας διατριβής αναλύονται θέματα που σχετίζονται με την υιοθέτηση τεχνολογιών εξοικονόμησης ενέργειας από Βιομηχανικές επιχειρήσεις. Κεντρικό στοιχείο αυτής της προσέγγισης είναι το “Παράδοξο της Ενεργειακής Αποδοτικότητας”. Τρία συγκεκριμένα θέματα εξετάζονται σε αυτή την κατεύθυνση. Πρώτον, η διερεύνηση των παραγόντων που οδηγούν στην εμφάνιση του “παραδόξου της ενεργειακής αποτελεσματικότητας” και συγκεκριμένα αν οι αποφάσεις των επιχειρήσεων για υιοθέτηση τέτοιων τεχνολογιών συνυπολογίζουν το στοιχείο της αποδοτικότητας των επενδεδυμένων κεφαλαίων. Δεύτερον, και με δεδομένο ότι στα αποτελέσματα του προηγούμενου σταδίου ανάλυσης αναδεικνύουν την σημαντικότητα του παράγοντα της πληροφορίας, αναπτύσσεται μια εκτενής προσέγγιση που αφορά τόσο το περιεχόμενο όσο και τον ρόλο του παράγοντα της πληροφορίας στην διαδικασία υιοθέτησης ΤΕΕ. Τρίτο, διερευνάται η επίδραση της υιοθέτησης των ΤΕΕ στην παραγωγική αποτελεσματικότητα και παραγωγικότητα των βιομηχανικών επιχειρήσεων. Για τις ανάγκες της ανάλυσης αυτών των θεμάτων αναπτύσσονται δύο επιμέρους μικροοικονομικά υποδείγματα και μια μέθοδος μέτρησης της παραγωγικότητας σε ετερογενής τεχνολογίες. Το πρώτο μικροοικονομικό υπόδειγμα διερευνά την διαδικασία λήψης επενδυτικών αποφάσεων σε ΤΕΕ υπό το πρίσμα της συσχέτισης της επενδυτικής επιλογής με την κερδοφορία, σε πλαίσιο μερικής παρατηρησιμότητας. Το δεύτερο μικροοικονομικό υπόδειγμα επανατοποθετεί την έννοια της πληροφορίας και διερευνά τους παράγοντες που προσδιορίζουν το επίπεδο πληροφόρησης της επιχείρησης για ΤΕΕ. Τέλος για την μέτρηση της επίδρασης των ΤΕΕ στην παραγωγική αποτελεσματικότητα και παραγωγικότητα αναπτύσσεται μια μέθοδος που λαμβάνει ρητά υπόψη της την τεχνολογική ετερογένεια. Η διερεύνηση των τριών αυτών ζητημάτων βασίζεται στην ανάλυση εμπειρικών δεδομένων που αφορούν επιχειρήσεις οι οποίες ενέταξαν στην παραγωγική τους διαδικασία τεχνολογίες εξοικονόμησης ενέργειας στην περίοδο 1990-2004. Οι επενδύσεις αυτές επιδοτήθηκαν κυρίως στα πλαίσια του Β’ και Γ’ Κοινοτικού Πλαισίου Στήριξης. Τα δεδομένα συλλέχθηκαν με την μέθοδο των προσωπικών συνεντεύξεων (ερωτηματολόγια). Συμπληρωματικά δεδομένα αντλήθηκαν από την βάση δεδομένων της ICAP. / The improvement for energy efficiency is generally viewed as an important option to reduce greenhouse gas emissions and environmental damage caused by other pollutants (e.g. NOX,SOX). Moreover, is clearly interwoven with the exploitation of new and innovative technologies through the production process and its consequent paradox, the so called “energy efficiency paradox”. This paradox has recently attracted the interest of researchers and organizations (IEA,OECD) in an attempt to bring to light the source of it, the causalities between the adoption of energy efficient technology (EET) and the behaviour of firms . Three research questions have been examined in the specific Phd Thesis. Our first main research question were examined by formulating and testing the following hypothesis: the decision of the firms to adopt or not EET, is correlated to their profitability. Our second research project develops in two stages. The first stage aims at examining the factors influencing retrieval of information concerning EETs by manufacturing firms, while at the second stage we distinguish between readily available and emerging energy efficiency technologies and examine the factors affecting information acquisition for each one of these two broad sets of technologies. Finally, in order to disentangle firm’s heterogeneity we developed a methodological framework to calculate total factor productivity and its components differences arising from EETs adoption. Our first research question examines the energy efficiency paradox demonstrated in Greek manufacturing firms through a partial observability approach. Maximum likelihood estimates that arise from an incidental truncation model reveal that the adoption of the energy saving technologies is indeed strongly correlated to the returns of assets that are required in order to undertake the corresponding investments. The source of the energy efficiency paradox lies within a wide range of factors. Policy schemes that aim to increase the adoption rate of energy saving technologies within the field of manufacturing are significantly affected by differences in the size of firms. Finally, mixed policies seem to be more effective than polices that are only capital subsidy or regulation oriented. Answering the second research question, we aim to redefine the notion of awareness regarding the adoption of EETs. In a second stage we explore the crucial factors that affect the information level of EET adopters, distinguishing between epidemic and emerging technologies information. Our empirical findings reveal that the main factor that exerts positive influence on the level of information acquired by the firms may be encompassed in a set of variables that reflect what may be called a “business culture” regarding the EET Finally, we examined the impact of EETs adoption to Greek manufacturing firms operating under heterogeneous technology sets and we measured the components of total factor productivity (TFP) and its components arising from scale and technological differences. In order to examine our research questions we formulate a unique database. Our database came to light from the necessity of the Greek government to conserve energy in manufacturing and to reduce dangerous emissions in order to meet the criteria of the Kyoto Protocol. An extensive questionnaire was addressed to the 298 firms across the country that adopt EETs that have been subsidized from (i) the Support Frameworks for Regional and Industrial Development, (ii) the Energy Operational Program (OPE), which was part of the second European Union Support Framework (1994-2000) and (iii) the Operational Program ‘Competitiveness’, which is part of the third European Union Support Framework (2000-2006). Finally, 161 of them agreed to be interviewed on the basis of the questionnaire. Face to face interviews took place in the first six months of 2004. Additional data derived from ICAP financial database.
66

Managing Mobility for Distributed Smart Cities Services

LUZURIAGA QUICHIMBO, JORGE ELOY 07 July 2017 (has links)
The IoT refers to the idea of internetworking physical devices, vehicles, buildings, and any other item embedded with the appropriate electronics, software, sensors, actuators, and network connectivity to allows them to interchange data and to provide highly effective new services. In this thesis we focus on the communications issues of the IoT in relation to mobility and we provide different solutions to alleviate the impact of these potential problems and to guarantee the information delivery in mobile scenarios. Our reference context is a Smart City where various mobile devices collaboratively participate, periodically sending information from their sensors. We assume that these services are located in platforms based in cloud infrastructures where the information is protected through the use of virtualisation ensuring their security and privacy. This thesis is structured into seven chapters. We first detail our objectives and identify the current problems we intend to address. Next, we provide a thorough review of the state of the art of all the areas involved in our work, highlighting how we improved the existing solutions with our research. The overall approach of the solutions we propose in this thesis use prototypes that encompasses and integrates different technologies and standards in a small infrastructure, using real devices in real scenarios with two of the most commonly used networks around the world: WiFi and 802.15.4 to efficiently solve the problems we originally identified. We focussed on protocols based on a producer/consumer paradigm, namely AMQP and particularly MQTT. We observed the behaviour of these protocols using in lab experiments and in external environments, using a mesh wireless network as the backbone network. Various issues raised by mobility were taken into consideration, and thus, we repeated the tests with different messages sizes and different inter-message periodicity, in order to model different possible applications. We also present a model for dimensioning the number of sources for mobile nodes and calculating the number of buffers required in the mobile node as a function of the number of sources and the size of the messages. We included a mechanism for avoiding data loss based on intermediate buffering adapted to the MQTT protocol that, in conjunction with the use of an alternative to the Network Manager in certain contexts, improves the connection establishment for wireless mobile clients. We also performed a detailed study of the jitter behaviour of a mobile node when transmitting messages with this proposal while moving through a real outdoor scenario. To emulate simple IoT networks we used the Cooja simulator to study and determine the effects on the probability of delivering messages when both publishers and subscribers were added to different scenarios. Finally we present an approach that combines the MQTT protocol with DTN which we specifically designed for constrained environments and guarantees that important information will never be lost. The advantage of our proposed solutions is that they make an IoT system more resilient to changes in the point of attachment of the mobile devices in an IoT network without requiring IoT application & service developers to explicitly consider this issue. Moreover, our solutions do not require additional support from the network through protocols such as MobileIP or LISP. We close the thesis by providing some conclusions, and identifying future lines of work which we unable to address here. / Internet de las cosas (IoT) se refiere a la idea de interconectar sensores, actuadores, dispositivos físicos, vehículos, edificios y cualquier elemento dotado de la electrónica, así como del software y de la conectividad de red que los hace capaces de intercambiar datos para proporcionar servicios altamente efectivos. En esta tesis nos centramos en temas relacionados con la comunicación de sistemas IoT, específicamente en situaciones de movilidad y en los problemas que esto conlleva. Con este fin ofrecemos diferentes soluciones que alivian su impacto y garantizan la entrega de información en estas situaciones. El contexto de referencia es una ciudad inteligente donde varios dispositivos móviles participan de forma colaborativa enviando periódicamente información desde sus sensores hacia servicios ubicados en plataformas en la nube (cloud computing) donde mediante el uso de virtualización, la información está protegida garantizando su seguridad y privacidad. Las soluciones propuestas en esta tesis se enfocan en probar sobre una pequeña infraestructura un prototipo que abarca e integra diferentes tecnologías y estándares para resolver eficientemente los problemas previamente identificados. Hemos enfocado nuestro esfuerzo en el uso de dispositivos sobre escenarios reales con dos de las redes más extendidas en todo el mundo: WiFi y enlaces 802.15.4. Nos enfocamos en protocolos que ofrecen el paradigma productor/consumidor como el protocolo avanzado de colas de mensajes (AMQP) y particularmente el protocolo de transporte de mensajes telemétricos (MQTT), observamos su comportamiento a través de experimentos en laboratorio y en pruebas al aire libre, repitiendo las pruebas con diferentes tamaños de mensajes y diferente periodicidad entre mensajes. Para modelar las diferentes posibles aplicaciones de la propuesta, se tomaron en consideración varias cuestiones planteadas por la movilidad, resultando en un modelo para dimensionar eficientemente el número de fuentes para un nodo móvil y para calcular el tamaño requerido del buffer, en función del número de fuentes y del tamaño de los mensajes. Proponemos un mecanismo adaptado al protocolo MQTT que evita la pérdida de datos en clientes móviles, basado en un buffer intermedio entre la producción y publicación de mensajes que, en conjunto con el uso de una alternativa al gestor de conexiones inalámbricas "Network Manager", en ciertos contextos mejora el establecimiento de las conexiones. Para la evaluación de esta propuesta se presenta un estudio detallado de un nodo móvil que se mueve en un escenario real al aire libre, donde estudiamos el comportamiento del jitter y la transmisión de mensajes. Además, hemos utilizado emuladores de redes IoT para estudiar y determinar los efectos sobre la probabilidad de entrega de mensajes, cuando se agregan tanto publicadores como suscriptores a diferentes escenarios. Finalmente, se presenta una solución totalmente orientada a entornos con dispositivos de recursos limitados que combina los protocolos MQTT con redes tolerantes a retardos (DTN) para garantizar la entrega de información. La ventaja de las soluciones que proponemos reside en el hecho de que los sistemas IoT se vuelven resilientes a la movilidad y a los cambios de punto de acceso, permitiendo así que los desarrolladores creen fácilmente aplicaciones y servicios IoT evitando considerar estos problema. Otra ventaja de nuestras soluciones es que no necesitan soporte adicional de la red como sucede con protocolos como MobileIP o el protocolo que separa el identificador del localizador (LISP). Se destaca cómo hemos mejorado las soluciones existentes hasta el momento de la escritura de esta disertación, y se identifican futuras líneas de actuación que no han sido contempladas. / Internet de les coses (IoT) es refereix a la idea d'interconnectar sensors, actuadors, dispositius físics, vehicles, edificis i qualsevol element dotat de l'electrònica, així com del programari i de la connectivitat de xarxa que els fa capaces d'intercanviar dades per proporcionar serveis altament efectius. En aquesta tesi ens centrem en temes relacionats amb la comunicació de sistemes IoT, específicament en situacions de mobilitat i en els problemes que això comporta. A aquest efecte oferim diferents solucions que alleugeren el seu impacte i garanteixen el lliurament d'informació en aquestes situacions. El context de referència és una ciutat intel·ligent on diversos dispositius mòbils participen de forma col·laborativa enviant periòdicament informació des dels seus sensors cap a serveis situats en plataformes en el núvol (cloud computing) on mitjançant l'ús de virtualització, la informació està protegida garantint la seva seguretat i privadesa. Les solucions proposades en aquesta tesi s'enfoquen a provar sobre una xicoteta infraestructura un prototip que abasta i integra diferents tecnologies i estàndards per a resoldre eficientment els problemes prèviament identificats. Hem enfocat el nostre esforç en l'ús de dispositius sobre escenaris reals amb dos de les xarxes més esteses a tot el món: WiFi i enllaços 802.15.4. Ens enfoquem en protocols que ofereixen el paradigma productor/consumidor com el protocol avançat de cues de missatges (AMQP) i particularment el protocol de transport de missatges telemètrics (MQTT), observem el seu comportament a través d'experiments en laboratori i en proves a l'aire lliure, repetint les proves amb diferents grandàries de missatges i diferent periodicitat entre missatges. Per a modelar les diferents possibles aplicacions de la proposta, es van prendre en consideració diverses qüestions plantejades per la mobilitat, resultant en un model per a dimensionar eficientment el nombre de fonts per a un node mòbil i per a calcular la grandària requerida del buffer, en funció del nombre de fonts i de la grandària dels missatges. Proposem un mecanisme adaptat al protocol MQTT que evita la pèrdua de dades per a clients mòbils, basat en un buffer intermedi entre la producció i publicació de missatges que en conjunt amb l'ús d'una alternativa al gestor de connexions sense fils "Network Manager'', en certs contextos millora l'establiment de les connexions. Per a l'avaluació d'aquesta proposta es presenta un estudi detallat d'un node mòbil que es mou en un escenari real a l'aire lliure, on estudiem el comportament del jitter i la transmissió de missatges. A més, hem utilitzat emuladors de xarxes IoT per a estudiar i determinar els efectes sobre la probabilitat de lliurament de missatges, quan s'agreguen tant publicadors com subscriptors a diferents escenaris. Finalment, es presenta una solució totalment orientada a entorns amb dispositius de recursos limitats que combina els protocols MQTT amb xarxes tolerants a retards (DTN) per a garantir el lliurament d'informació. L'avantatge de les solucions que proposem resideix en el fet que els sistemes IoT es tornen resilients a la mobilitat i als canvis de punt d'accés, permetent així que els desenvolupadors creuen fàcilment aplicacions i serveis IoT evitant considerar aquests problema. Un altre avantatge de les nostres solucions és que no necessiten suport addicional de la xarxa com succeeix amb protocols com MobileIP o el protocol que separa l'identificador del localitzador (LISP). Es destaca com hem millorat les solucions existents fins al moment de l'escriptura d'aquesta dissertació, i s'identifican futures línies d'actuació que no han sigut contemplades. / Luzuriaga Quichimbo, JE. (2017). Managing Mobility for Distributed Smart Cities Services [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/84744
67

Market analysis for electric vehicle supply equipment : The case of China / Analys av marknaden för laddningsutrustning för elbilar : Fallet Kina

BUSK, ANDREY, JOELSSON WARRENSTEIN, ARVID January 2014 (has links)
Personliga eldrivna fordon (EV) är ett nytt teknikområde som är på väg att uppnå stort momentum på flera av världens marknader. Eftersom branschen fortfarande ligger i sin linda finns det i nuläget inga tydliga strukturer, som gäller för alla marknader världen över, gällande relationerna mellan aktörer, vilket leder till osäkerheter när det kommer till att ta strategiska beslut. Uppdragsgivaren för denna studie är Hong Kong EV Power Ltd. (EV Power), en Hongkong-baserad leverantör av laddningsstationer för elbilar och relaterade tjänster, som har ambitionen att inträda marknaden på det kinesiska fastlandet inom den närmaste framtiden. Emellertid har EV Power ännu inte bestämt sig vilken stad de vill rikta in sig på i det första skedet. Denna avhandling ämnar formulera en modell som kan användas för att utvärdera och jämföra geografiska marknader med avseende på lämpligheten för ett marknadsinträde av en leverantör av laddningsstationer för elbilar. Dessutom kommer modellen testas på tre städer på kinas fastland (Peking, Shanghai och Shenzhen), med syfte att komma fram till vilken stad som är mest attraktiv för EV Power, samt att utvärdera modellens funktionsduglighet. Sist kommer resultaten från utvärderingen av de tre städerna att tjäna som utgångspunkten för en analys som ämnar ta fram framgångsfaktorer för ett marknadsinträde på kinas fastland. För att uppnå detta har fyra olika datainsamlingsmetoder använts: Först studerades teori, med syfte att få bakgrundskunskap likväl som att få förståelse för specifika faktorer som påverkar ett marknadsinträde som detta. För det andra observerades EV Powers nuvarande verksamhet i Hong Kong, i avsikt att förstå vad som har lett till den framgång som företaget upplevt på sin hemmamarknad. För det tredje intervjuades branschexperter för att få ett perspektiv på branschen som helhet. Sist samlades sekundär data kring de tre städerna in, för att kunna utvärdera de olika faktorerna som ingår i den framtagna modellen. Den slutgiltiga modellen består av fem faktorer som påverkar en stads attraktivitet för ett marknadsinträde av en leverantör av laddningsstationer för elbilar. De identifierade faktorerna är: ’Marknadens tillgänglighet’, ’Kortsiktig efterfrågan’, ’Förväntad marknadsandel’, ’Vinstmarginal’ och ’Långsiktig produktpotential’. Dessa faktorer är i sin tur indelade i subfaktorer som har sina egna uppsättningar av drivare. Efter att ha använt modellen för att utvärdera de tre städerna konstaterades det att Shanghai är den lämpligaste staden för ett marknadsinträde av EV Power, främst på grund av stadens dominans på marknaden för privatanvända elbilar och ett gynnsamt regelverk. Slutligen hittades tre framgångsfaktorer för ett sådant inträde: ’Fokusera på tjänster’, ’Bibehåll partner-relationer’ och ’Inträd tidigt’. / Personal electric vehicles (EV) is an emerging technology that has gained much momentum in several markets during the past decade, and China is currently one of the markets where the growth in EV sales is the highest. Since the industry is still in its infancy, there are currently no clear structures regarding the relationships between different actors that apply to all markets globally, leading to great uncertainty in strategic decisions. The commissioner of this study is Hong Kong EV Power Ltd. (EV Power), a producer of EV supply equipment (EVSE) and related services in Hong Kong, which aspires to enter the Chinese mainland in the near future. However, EV Power has yet to decide which city they want to target first. This thesis aims to formulate a model that can be used to evaluate and compare geographic markets for a market entry by an EVSE company. Furthermore, the model is tested on three cities in Mainland China (Beijing, Shanghai and Shenzhen), in order to derive the most attractive city for EV Power and to evaluate the adequacy of the model. Lastly, with the results from the city evaluation, as a point of departure, success factors for an entry into Mainland China by the commissioning company will be summarized. In order to achieve this objective, four distinct data collection methods have been used: First, theory was studied, in order to gain background knowledge as well as to understand specific factors that impact a market entry decision such as this. Second, EV Power’s current business in Hong Kong was observed, with a view to achieve an understanding of what has led the company to experience success in its home market. Third, Interviews with industry experts were conducted, so as to get a perspective on the industry as a whole. Fourth and last, secondary data for the different cities was collected, for the sake of evaluating them according to the developed model. The final model consists of five main factors that encompass the elements that influence a cities level of attractiveness for entry by an EV charging station supplier. The identified factors are: ‘Market accessibility’, ‘Short-term demand’, ‘Expected market share’, ‘Profit margin’, and ‘Long-term product potential’. These factors are in turn divided into sub factors that have their own set of drivers. Using the model to evaluate the cities, it was found that Shanghai is the most suitable city for a market entry by EV Power, mainly due to its dominance in the market for private EVs and a favourable regulatory environment. Finally, three main success factors, for such a market entry, were found: ‘Focus on services’, ‘Maintain partner relationships’, and ‘Enter early’.
68

Leveraging IoT Protocols : Integrating Palletization Algorithm with Flexible Robotic Platform

Ferm Dubois, Mathias January 2024 (has links)
This thesis explores the integration of IoT protocols to enhance supply chain efficiency and sustainability by developing a flexible automated system. The research covers the integration of a palletization optimizer with a flexible robotic platform, a project conducted in collaboration with OpiFlex and Linköping University. Flexibility and sustainability in production, particularly in the food and beverage industry, are critical yet challenging to achieve. This research addresses these challenges by proposing a system that aligns the output with customer needs by combining these technologies. The research employs a combination of case study and exploratory methodologies. The development approach synthesizes elements from Set-Based Design, Point-Based Design, and Agile development frameworks. The primary research questions focus on identifying the best system architecture for integrating the palletization optimizer with a lower-level automation platform and outlining the steps needed to transform this integration into a commercially viable product. The system includes the optimizer, capable of processing customer orders and configuring products on mixed output pallets, integrated with a flexible robotic system provided by OpiFlex. The work involved evaluating communication protocols, MQTT, OPC UA, and TCP/IP, and designing robust interactions and interfaces between the subsystems. The results demonstrate the system's architecture and interaction protocols.  The thesis concludes with a discussion of the results in comparison to the application scenario and the standards consulted. The conclusion is that the chosen interface practices should remain largely intact but be re-developed using an OPC UA-based architecture. The main reasons for this are its support for both pub/sub and client-server models, increased security, and greater support for enterprise application integration. However, depending on the specific application, the downsides of OPC UA may outweigh its benefits.
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Hyperloop in Sweden : Evaluating Hyperloops Viability in the Swedish Context / Hyperloop i Sweden : Utvärdering av Hyperloops Möjligheter i den Svenska Kontexten

Magnusson, Fredrik, Widegren, Fredrik January 2018 (has links)
Transportations role in society is increasingly important and today it has a prominent role in business, citizens lives as well as in the world economy. The increasing globalization and urbanization puts significant pressure on the existing transport system, with increasing demand for high-speed travel. However, this comes with implications on the environment, and the environmental concerns constitutes one of the biggest pressures in transport. And as the contemporary modes are bound by their technologies, enabling marginal rather than radical improvements, a possible window of opportunity for new radical technologies to enter the market can emerge. One new technology emerging within transportation today is called hyperloop, a technology that could prove to meet demand for faster, cheaper, safer and more environmentally efficient transportation. However, the technology is still in an early stage of development and hence surrounded by major uncertainties. Further, the nature of the technology necessitates overcoming several obstacles before it can reach commercial practice. And this together with a limited knowledge of the concept in Sweden makes it difficult to predict if hyperloop can become a viable transport alternative on the Swedish market. Which condensed lays the foundation to the purpose of this paper: "To give an overarching understanding of the Swedish transport market dynamics, together with a comprehensive evaluation of the hyperloop concept. And hence contribute to more inclusive knowledge and understanding of hyperloop’s viability in the Swedish context." Since the phenomenon has not been comprehensively studied previously, the elected research design is that of an exploratory case study, with an inductive, qualitative approach. To address the purpose, a literary review of the theoretical field was conducted. Looking in to previous research on disruptive innovation, diffusion of innovations, technical transitions, transformational pressure as well as window of opportunity. The empirical material gathered during the research process was derived from two main channels. Firstly, an extensive review of scientific articles about the hyperloop technology was conducted, providing insights on the technology and its surroundings. This was complemented by qualitative interviews to obtain material on the dynamics of the Swedish transport market as well as for understanding hyperloop in the Swedish context. The empirical study was further accompanied by a review of news articles and websites to map the most recent progress in the hyperloop development. By analyzing the empirical material through three frameworks; Characteristics of Diffusion, the Multi-Level Perspective (MLP) and Technology Readiness Level (TRL), interesting findings and conclusions were drawn. These together points towards that hyperloop, if the technology reaches its predicted performance, will have significant relative advantages and observable effects in the relation to the contemporary modes of transportation. Further, a noticeable window of opportunity, sprung from capacity shortages and pressure towards environmental sustainability, seems to exist on the Swedish market. A window which could be capitalized upon and justify hyperloop in the Swedish context. The current state of the technology does however come with implications as it so far is insufficient to decrease uncertainty amongst the potential adopters. Factors that likely will prolong the adoption of the technology in Sweden relates to the relative complexity of the system, its limited compatibility with existing practices and the low maturity of the technology. Hence, the hyperloop companies must prove the concept feasible and increase the maturity to gain sufficient acceptance and recognition. This paper contributes to the academic community by assessing the compatibility of hyperloop on the Swedish market, as well as if hyperloop could become a viable alternative transport solution in Sweden. It provides insight to specific perspectives of the Swedish market, its requirements and the demand for alternative transport solutions. Hence, this paper is considered to make both an analytical contribution in terms of evaluating the viability of disruptive technologies. And an empirical contribution by shedding light on new important insights for the potential diffusion of hyperloop. Insights that are significant for hyperloop actors as well as for dominant actors on the Swedish transport market. / Transporters roll i samhället blir allt viktigare och de har idag en framträdande roll inom näringsliv, medborgares liv samt världsekonomin. Den ökande globaliseringen och urbaniseringen sätter dock ett betydande tryck på det existerande transportsystemet, med ökande efterfrågan för höghastighetsalternativ. Detta medför implikationer för miljön, och oron kring transporters miljöpåverkan är ett av de största bekymren för transportsektorn. Eftersom de existerande transportalternativen är bundna av sin teknik, vilket begränsar dem till inkrementella snarare än radikala förbättringar, kan en möjlighet för nya transportsätt att komma in på marknaden öppna sig. En kommande ny teknik som utvecklas inom transport idag kallas hyperloop, en teknik som kan visa sig möta efterfrågan för snabbare, billigare, säkrare och mer miljösmarta transporter. Tekniken är dock i ett tidigt utvecklingsskede och är därav omgärdad av stora osäkerheter. Vidare kräver teknikens natur att flertalet hinder kommer att behöva överkommas innan tekniken kan nå kommersiellt bruk. Detta tillsammans med den begränsade kunskap som finns kring konceptet i Sverige gör det svårt att förutspå om hyperloop kan bli ett möjligt transportalternativ på den svenska marknaden. Kondenserat ligger detta till grund för syftet med den här uppsatsen: "Att ge en övergripande förståelse av dynamiken på den svenska transportmarknaden, tillsammans med en djupgående utvärdering av hyperloop konceptet. Och därav bidra till en mer inkluderande kunskap och förståelse kring hyperloops möjligheter i den svenska kontexten." Eftersom detta fenomen inte tidigare har studerats i större utsträckning valdes en forskningsdesign i form av en undersökande fallstudie med ett induktivt, kvalitativt tillvägagångssätt. För att adressera syftet gjordes en litterär översyn av det teoretiska fältet. Med inblickar i tidigare forskning kring disruptiv teknik, diffusion av innovation, tekniska övergångar, transformationstryck samt möjlighetsfönster. Det empiriska materialet till studien samlades in genom två kanaler i huvudsak. Först, genom en djupdykning i tidigare forskning och vetenskapliga artiklar relaterade till hyperlooptekniken, för att generera insikter kring tekniken och dess omgivning. Detta kompletteras med kvalitativa intervjuer för att erhålla material om dynamiken på den svenska transportmarknaden samt för att ge en förståelse av hyperloop i den svenska kontexten. Den empiriska studien kompletterades ytterligare med en översyn av nyhetsartiklar och webbplatser för att kartlägga de senaste framstegen i hyperlooputvecklingen. Genom att analysera det empiriska materialet med hjälp av tre ramverk; Egenskaper för Spridning av Innovation, Perspektiv i Multipla Nivåer (MLP) och Teknisk Mogenhetsnivå (TRL), kunde flertalet intressanta upptäckter och slutsatser dras. Vilka tillsammans pekar mot att hyperloop, om tekniken lyckas uppnå den predikterade prestandan, kommer att ha betydande relativa fördelar och synliga effekter i förhållande till dagens transportsätt. Vidare kan ett märkbart möjlighetsfönster, sprunget ur kapacitetsbrist och tryck mot miljömässig hållbarhet, identifieras på den svenska marknaden. Detta fönster skulle kunna kapitaliseras på och motivera hyperloop i den svenska kontexten. Teknologins nuvarande tillstånd har emellertid konsekvenser, eftersom den hittills inte är tillräcklig för att minska osäkerheten hos potentiella adopterare. Faktorer som sannolikt kommer att förlänga processen att adoptera tekniken i Sverige härstammar från systemets relativa komplexitet, dess begränsade kompatibilitet med befintliga metoder samt teknikens låga mogenhet. Därav är det essentiellt för hyperloopbolagen att bevisa konceptet möjligt och öka mogenheten för att få tillräcklig acceptans och erkännande. Detta arbete bidrar till det akademiska samhället genom att bedöma kompatibiliteten mellan hyperloop och den svenska marknaden, samt om hyperloop kan bli ett genomförbart transportalternativ i Sverige. Arbetet bidrar med insikter i specifika perspektiv på den svenska marknaden, dess krav samt efterfrågan för alternativa transportlösningar. Därav kan denna uppsats anses utgöra både ett analytiskt bidrag genom dess utvärdering av genomförbarheten av disruptiv teknik. Samt ett empiriskt bidrag genom att belysa viktiga insikter för den potentiella spridningen av hyperloop. Insikter som är viktiga för såväl hyperloopaktörer som de dominanta aktörerna på den svenska transportmarknaden.
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Implementation and Analysis of Co-Located Virtual Reality for Scientific Data Visualization

Jordan M McGraw (8803076) 07 May 2020 (has links)
<div>Advancements in virtual reality (VR) technologies have led to overwhelming critique and acclaim in recent years. Academic researchers have already begun to take advantage of these immersive technologies across all manner of settings. Using immersive technologies, educators are able to more easily interpret complex information with students and colleagues. Despite the advantages these technologies bring, some drawbacks still remain. One particular drawback is the difficulty of engaging in immersive environments with others in a shared physical space (i.e., with a shared virtual environment). A common strategy for improving collaborative data exploration has been to use technological substitutions to make distant users feel they are collaborating in the same space. This research, however, is focused on how virtual reality can be used to build upon real-world interactions which take place in the same physical space (i.e., collaborative, co-located, multi-user virtual reality).</div><div><br></div><div>In this study we address two primary dimensions of collaborative data visualization and analysis as follows: [1] we detail the implementation of a novel co-located VR hardware and software system, [2] we conduct a formal user experience study of the novel system using the NASA Task Load Index (Hart, 1986) and introduce the Modified User Experience Inventory, a new user study inventory based upon the Unified User Experience Inventory, (Tcha-Tokey, Christmann, Loup-Escande, Richir, 2016) to empirically observe the dependent measures of Workload, Presence, Engagement, Consequence, and Immersion. A total of 77 participants volunteered to join a demonstration of this technology at Purdue University. In groups ranging from two to four, participants shared a co-located virtual environment built to visualize point cloud measurements of exploded supernovae. This study is not experimental but observational. We found there to be moderately high levels of user experience and moderate levels of workload demand in our results. We describe the implementation of the software platform and present user reactions to the technology that was created. These are described in detail within this manuscript.</div>

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