Peer-to-peer sharing platforms appear as a valid option to stop excessive consumerism. The success of a peer-to-peer sharing platform at Kungliga Tekniska Högskolan university mostly depends on the capability to comprehend the potential users’ motives for engagement. To investigate the relative significance of consumer motives for and against this platform, a theoretical model based on a comprehensive set of potential consumer motives was developed. The model was validated by employing a survey of325 participants. Findings suggest ecological sustainability, sense of belonging, trust in other users, and familiarity as the four most important drivers and prerequisites of platform attitude and process risk concerns as the main barrier. Moreover, attitude shows the most significant effect on behavioral intention and is slightly influenced by reasons of age, gender, type of participant, and school to which the participant belongs. Services in general and study materials appear as the items with the highest number of potential consumers and suppliers; while the free system proves to be the preferred system. Based on the findings, recommendations for future research and implementation of the peer-to-peer platform are suggested. / Peer-to-peer-delningsplattformar visas som ett giltigt alternativ för att stoppa överdriven konsumtion. Framgången hos en peer-to-peer- delningsplattform vid Kungliga Tekniska Högskolan beror oftast på förmågan att förstå de potentiella användarnas motiv för engagemang. För att undersöka den relativa betydelsen av konsumentmotiv för och mot denna plattform, utvecklades en teoretisk modell baserad på en omfattande uppsättning potentiella konsumentmotiv. Modellen validerades genom att använda en undersökning av 325 deltagare. Resultat tyder på ekologisk hållbarhet, känsla av tillhörighet, förtroende för andra användare och förtrogenhet som de fyra viktigaste drivkrafterna och förutsättningarna för plattformshållning och processriskhänsyn som huvudbarriären. Vidare visar attityden den mest signifikanta effekten på beteendets avsikt och påverkas något av ålder, kön, typ av deltagare och skolan som deltagaren tillhör. Tjänster i allmänhet och läromedel förekommer som föremål med högsta möjliga potentiella konsumenter och leverantörer, medan det fria systemet visar sig vara det föredragna systemet. Baserat på resultaten, rekommenderas rekommendationer för framtida forskning och genomförande av peer-to-peer-plattformen.

[pt] Empréstimos P2P conecta tomadores de crédito a investidores por meio de plataformas online, eliminando a necessidade de um banco comercial como intermediário. Ao assumirem o risco de inadimplência dos tomadores, os investidores dependem do processo de cobrança de dívida. Esse estudo investiga se leis estaduais de cobrança de dívida afetam a capacidade dos cobradores de recuperar dívidas liquidadas. Resultados mostram que regulações maís rígidas estão associadas a taxas de recuperação menores, o que por sua vez leva a expansão de crédito para tomadores mais seguros. / [en] P2P Lending connects borrowers and lenders via an online platform, cutting out traditional banking intermediation. By bearing the risk of borrowers defaulting on their loans, investors rely on the debt collection process. This paper investigates whether state debt collection laws affect the ability of debt collectors to recover charged-off debts. Results show that stricter regulation are linked with lower recovery rates, which in turn leads to extension of credit to safer borrowers.

With the increased popularity of the Internet of Things (IoT) and vehicle tracking, long range communication alternatives become essential for connecting a large number of units in a network.In areas where no coverage from existing technologies is available such as rural areas, the need for a solution presents itself. This thesis aims to examine the validity of using a Peer-to-Peer network structure to send geolocation information among nodes in a network using the Long Range (LoRa) protocol as opposed to using Long Range Wide Area Network (LoRaWAN) structure. The research question that was used was the following: “Can LoRa be used for P2P networking to exchange geolocation messages in rural areas?”By developing two modules using Raspberry Pi and Dragino LoRa/GPS shields, a prototype system could be created in order to test the performance of the network. The modules were tested in a rural area outside of Stockholm, Sweden.Together with field test data from the prototype and existing network loss models the network performance was evaluated. Due to testing conditions a theoretical maximum communication range of around 12 km was established using this data. Therefore using Peer-to-Peer LoRa for geolocation purposes in rural areas was concluded viable. / Sakernas internet och fordonsspårning är två trender som ökar i popularitet i en rasande fart. Med detta ökar kraven på fler kommunikationsalternativ för att koppla upp ett stort antal enheter i ett nätverk med en lång räckvidd.I områden såsom på landsbygden kan täckning av nuvarande teknologier kan vara bristfällande. För att lösa detta problem presenterar detta arbete en föreslagen lösning. Målet med arbetet är att undersöka giltigheten i att använda en Peer-to-Peer nätverksstruktur för att skicka platsinformation inom ett nätverk med hjälp av Long Range (LoRa)-protokollet. I tidigare arbeten har detta mestadels gjorts med hjälp av ett Long Range Wide Area Network (LoRaWAN). Frågan som undersöktes i arbetet var följande: ”Kan LoRa användas för P2P nätverkande för att utbyta platsinformation i landsbygdsområden?”För att undersöka giltigheten av denna idé utvecklades en prototyp i form av två moduler som använder sig av varsin Raspberry Pi och Dragino LoRa/GPS tillägg. Dessa system kunde senare användas för att testas i ett landsbygdsområde utanför Stockholm.Tillsammans med data från fälttester med prototypen och modeller över fädning i ett nätverk utvärderades nätverkets prestanda. På grund av förhållanden i testmiljön bestämdes en teoretisk maximal räckvidd på runt 12 km. Med denna information dras slutsatsen att användandet av Peerto-Peer LoRa för platsinformation i landsbygdsområden är giltigt.

The popularity of blockchain technologies increases with a significant rise in the price of cryptocurrency in 2017, which drew much attention in the academia and industry to research and implement new application or new blockchain technology. Many new blockchains have emerged over the last year in a broad spectrum of sectors and use cases including IOT, Energy, Finance, Real estate, Entertainment, etc.Despite many exciting research and applications have been done, there are still many areas worth investigating, and implementation of the blockchain based distributed application are still facing much uncertainty and challenging since blockchain is still an emerging technology. Meanwhile, the energy sector is under a transition to be digitalized and more distributed. A global technology revolution has disrupted the conventional centralized power system with distributed resources and technologies, like photovoltaic units (PV), batteries, electric mobilities, etc. The citizens then have control of their generation and consumption profiles.The purpose of this master thesis is to explore existing blockchain technology, and smart contracts such as IOTA, NEO, Ethereum Tobalaba, which can be adapted in the energy sector. Within this thesis, blockchain and the smart contract is proposed as a way of building distributed applications for a p2p transaction use case in the energy asset management platform. A design science research methodology is applied for the artifact development and evaluation for the research result. The design was implemented on Ethereum and tested on Tobalaba public network with ether and GAS. The evaluation shows the artifact for the p2p transaction in energy asset management platform fulfill the completeness, and correctness of the design requirement. The result of the performance test on Tobalaba networks shows a correlation between GAS consumption and transaction time.

published_or_final_version / abstract / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy

The rise of new digital technologies and the Internet has given more people than ever before the ability to copy and share music and video. Even as Japan has adopted stronger copyright protections, the number of Japanese peer-to-peer file sharing network users has multiplied. Though the distribution of copyrighted material online has long been illegal and, as of 2010, the download of copyrighted material is now a criminal act, illegal file sharing continues apace, with the majority of people active on Japan’s most popular file sharing programs remaining unaffected by the new legislation. Clearly the law alone does not work to constrain file sharing behavior in Japan and, in fact, it is not the only way Japan strives to enforce copyright law on the Internet. What strategies are industries and government taking to curb illegal file sharing and are these strategies effective? How is unauthorized peer-to-peer file sharing cast into an act both immoral and worthy of criminal prosecution? Of particular interest are the evolution and growth of architectural and social constraints on online behavior alongside these legal constraints. / text

19th IEEE International Conference on Computational Science and Engineering (CSE 2016), is the event, in a series of highly successful International Conferences on Computational Science and Engineering, held mainly as the International Workshop on High Performance Scientific and Engineering Computing for 11 editions. August 24-26, 2016 - Paris, France / Currently multimedia contents dominate the information exchanged in Internet, particularly through social networks. Each actor on the Internet becomes producer and consumer of contents. Nevertheless, social network and other traditional collaborative environments present limitations regarding content selection, categorization, aggregation, linking and interoperability, and usage control and privacy. In [1], we proposed the architecture (based on a peer-to-peer infrastructure and Semantic Web) of a MultiMedia Digital EcoSystem (MMDES), as a new environment for collaboration and sharing of multimedia resources, multimedia processings, as well as for computing and storage capabilities. In this paper, we describe MMDES framework and functionalities related to managing the collective knowledge and equilibrium in MMDES. We also describe the implementation of MMDES using a mobile platform in order to provide resources’ sharing for the Archivo Nacional de Arte Rupestre (ANAR) in Venezuela

La première partie de cette thèse est dédiée à l’état de l’art sur les réseaux pair-à-pair, la recherche d’information dans de tels réseaux et la problématique de la fouille des données dans le contexte pair-à-pair en se focalisant plus particulièrement sur les méthodes de regroupement (clustering) et les arbres de décision.La seconde partie traite des réseaux où les pairs disposent de leurs propres schémas de données. On y analyse plus particulièrement les fondements et le fonctionnement du système SenPeer. On propose alors une architecture supportant une organisation communautaire des réseaux pair-à-pairs sémantiques. Cela nous permet alors de construire des réseaux pair-à-pair sémantiques structurés en communautés appelés cSON (CommunitySemantic Overlay Network).Ce qui pose alors les questions concernant l’explicitation des communautés et leur exploitation pour améliorer les performances (temps de réponse, nombres de messages, précision et le rappel). Pour construire les communautés, nous étudions deux alternatives différentes : (1) Médiation sémantique : la construction des communautés se base sur les liens sémantiques entre les super-pairs et la confiance qu’ils ont les uns envers les autres et (2) Clustering : un algorithme de clustering basé sur l’analyse des requêtes traitées par les super-pairs est à la base de construction des communautés. Ensuite, nous proposons deux méthodes pour calculer des caractérisations des communautaires en se plaçant dans les deux champs de recherche suivants : (1) Data mining: on cherche à caractériser chaque communauté à l’aide d’une connaissance extraite des requêtes traitées par ses super-pairs d’une même communauté CK (Communauty Knowledge) et (2) Hypergraphes : A l’inverse de la méthode précédente, notre objectif maintenant est de caractériser collectivement les communautés. On formalise ce problème comme la recherche des MCS (minimal covering shortcuts) qui sont des raccourcis, entre les super pairs,minimaux couvrants toutes les communautés. Nous développons ensuite deux méthodes de routages de requêtes CK-rooting et MCS-rooting en utilisant respectivement la connaissance communautaire et les MCS afin d’identifier les super-pairs susceptibles de traiter une requête donnée.Dans la troisième partie, nous présentons le simulateur développé pour supporter l’approche cSON. Nous présentons alors les résultats empiriques résultant de simulations et qui montrent une amélioration significative des performances de l’approche basée uniquement sur la médiation sémantique. Cette partie se termine avec la description d’une application de recherche d’information basée sur le partage de documents scientifiques enrichis. / The first part of this thesis is dedicated to the state of the art on the peer-to-peer networks, the information retrieval in such networks, and the problematic of data mining in the peer-to-peer context more particularly on clustering methods and decision trees.The second part deals with networks where peers have their own data schemas. We examine more particularlythe fundamentals and functioning of the system “SenPeer”. Then, we propose an architecture supporting acommunity organization of semantic peer-to-peer networks. This allows us to build peer-to-peer semantic structured communities called cSON (Communauty Semantic Overlay Network).This raises many questions concerning the explanation of communities and their operating to improve performances (response time, number of messages, precision and recall). To build communities, we study two different alternatives: (1) Semantic Mediation: the building of communities is based on semantic links between super-peers and the confidence that they have between them and (2) Clustering: a clustering algorithm, based onthe analysis of queries processed by the super-peers, is the base of community building. Then, we propose twomethods to calculate the characterizations of communities in the two research fields: (1) Data mining: we try to characterize each community using knowledge extracted from applications processed by his super-peers of the same community CK (Community Knowledge) and (2) Hypergraphs: Unlike the previous method, our goal nowis to characterize the communities collectively. We formalize this problem as the research of the MCS (minimalcovering shortcuts) which are shortcuts between the super-peers, minimum shortcuts covering all communities.Then, we develop two methods of queries routing CK-rooting and MCS-rooting respectively using community knowledge and MCS to identify the super-peers may process a given query.In the third section, we present the simulator developed to support the cSON approach. We present the empirical results representing the simulations and which show a significant improvement of performance of the approachonly based on semantic mediation.This part ends with a description of an application of information retrieval based on sharing enriched scientific documents.

Les schémas de routage locaux basés sur des coordonnées prises dans le plan hyperbolique ont attiré un intérêt croissant depuis quelques années. Cependant, les solutions proposées sont toutes appliquées à des réseaux au topologie aléatoire et au nombre de nœuds limités. Dans le même temps, plusieurs travaux se sont concentrés sur la création de modèle topologique basé sur les lois de la géométrie hyperbolique. Dans ce cas, Il est montré que les graphes ont des topologies semblables à Internet et qu'un routage local hyperbolique atteint une efficacité proche de la perfection. Cependant, ces graphes ne garantissent pas le taux de réussite du routage même si aucune panne ne se produit. Dans cette thèse, l'objectif est de construire un système passant à l'échelle pour la création de réseau recouvrant capable de fournir à ses membres un service d'adressage et de routage résilient dans un environnement dynamique. Ensuite, nous étudions de quelle manière les réseaux P2PTV pourraient supporter un nombre d'utilisateur croissant. Dans cette thèse, nous essayons de répondre à cette question en étudiant les facteurs d'efficacité et de passage à l'échelle dans un système de diffusion vidéo P2P typique. Au travers des données fournies par Zattoo, producteur de réseau P2PTV, nous réalisons des simulations dont les résultats montrent qu'il y a encore des obstacles à surmonter avant que les réseaux P2P de diffusion vidéo puissent dépendre uniquement de leurs utilisateurs. / Local routing schemes based on virtual coordinates taken from the hyperbolic plane have attracted considerable interest in recent years.However, solutions have been applied to ad-hoc and sensor networks having a random topology and a limited number of nodes. In other hand, some research has focused on the creation of network topology models based on hyperbolic geometric laws. In this case, it has been shown that these graphs have an Internet-like topology and that local hyperbolic routing achieves a near perfect efficiency. However, with these graphs, routing success is not guaranteed even if no failures happen. In this thesis, we aim at building a scalable system for creating overlay networks on top of the Internet that would provide reliable addressing and routing service to its members in a dynamic environment.Next, we investigate how well P2PTV networks would support a growing number of users. In this thesis, we try to address this question by studying scalability and efficiency factors in a typical P2P based live streaming network. Through the use of the data provided by Zattoo a production P2PTV network, we carry out simulations whose results show that there are still hurdles to overcome before P2P based live streaming could depend uniquely of their users.