REPUTATION MANAGEMENT ALGORITHMS IN DISTRIBUTED APPLICATIONS

Nowadays, several distributed systems and applications rely on interactions between unknown agents that cooperate in order to exchange resources and services. The distributed nature of these systems, and the consequent lack of a single centralized point of control, let agents to adopt selfish and malicious behaviors in order to maximize their own utility. To address such issue, many applications rely on Reputation Management Systems (RMSs) to estimate the future behavior of unknown agents before establishing actual interactions. The relevance of these systems is even greater if the malicious or selfish behavior exhibited by a few agents may reduce the utility perceived by cooperative agents, leading to a damage to the whole community. RMSs allow to estimate the expected outcome of a given interaction, thus providing relevant information that can be exploited to take decisions about the convenience of interacting with a certain agent. Agents and their behavior are constantly evolving and becoming even more complex, so it is increasingly difficult to successfully develop the RMS, able to resist the threats presented. A possible solution to this problem is the use of agent-based simulation software designed to support researchers in evaluating distributed reputation management systems since the design phase. This dissertation presents the design and the development of a distributed simulation platform based on HPC technologies called DRESS. This solution allows researchers to assess the performance of a generic reputation management system and provides a comprehensive assessment of its ability to withstand security attacks. In the scientific literature, a tool that allows the comparison of distinct RMS and different design choices through a set of defined metrics, also supporting large-scale simulations, is still missing. The effectiveness of the proposed approach is demonstrated by the application scenario of user energy sharing systems within smart-grids and by considering user preferences differently from other work. The platform has proved to be useful for the development of an energy sharing system among users, which with the aim of maximizing the amount of energy transferred has exploited the reputation of users once learned their preferences

Crowdlending: mapping the core literature and research frontiers

[EN] Peer-to-peer (P2P) lending uses two-sided platforms to link borrowers with a crowd of lenders. Despite considerable diversity in crowdlending research, studies in this area typically focus on several common research topics, including information asymmetries, social capital, communication channels, and rating-based models. This young research field is still expanding. However, its importance has increased considerably since 2018. This rise in importance suggests that P2P lending may offer a promising new scientific research field. This paper presents a bibliometric study based on keyword co-occurrence, author and reference co-citations, and bibliographic coupling. The paper thus maps the key features of P2P lending research. Although many of the most cited papers are purely financial, some focus on behavioral finance. The trend in this field is toward innovative finance based on new technologies. The conclusions of this study provide valuable insight for researchers, managers, and policymakers to understand the current and future status of this field. The variables that affect new financial contexts and the strategies that promote technology-based financial environments must be investigated in the future.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.Ribeiro-Navarrete, S.; Piñeiro-Chousa, J.; López-Cabarcos, MÁ.; Palacios Marqués, D. (2022). Crowdlending: mapping the core literature and research frontiers. Review of Managerial Science. 16(8):2381-2411. https://doi.org/10.1007/s11846-021-00491-82381241116

Crowdlending: mapping the core literature and research frontiers

Peer-to-peer (P2P) lending uses two-sided platforms to link borrowers with a crowd of lenders. Despite considerable diversity in crowdlending research, studies in this area typically focus on several common research topics, including information asymmetries, social capital, communication channels, and rating-based models. This young research field is still expanding. However, its importance has increased considerably since 2018. This rise in importance suggests that P2P lending may offer a promising new scientific research field. This paper presents a bibliometric study based on keyword co-occurrence, author and reference co-citations, and bibliographic coupling. The paper thus maps the key features of P2P lending research. Although many of the most cited papers are purely financial, some focus on behavioral finance. The trend in this field is toward innovative finance based on new technologies. The conclusions of this study provide valuable insight for researchers, managers, and policymakers to understand the current and future status of this field. The variables that affect new financial contexts and the strategies that promote technology-based financial environments must be investigated in the futureOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer NatureS

Leveraging Users’ Trust and Reputation in Social Networks

In on line communities, where there is a huge number of users that interact under anonymous identities, it has been observed that e-word of mouth is a very powerful influence tool. So far, this technology is well known in on-line marketplaces, such as Amazon, eBay or travel based platforms like Tripadvisor or Booking. However, these trust based approach can be leverage in other scenarios from e-democracy to trust based recommendations on e-health context and e-learning systems. The purpose of this contribution is to analyse the main existing trust and reputation mechanisms and to point out new research challenges that needs to be accomplished with the objective of fully exploiting these systems in real world on-line communities.The authors would like to acknowledge the financial support from the EU project H2020-MSCA-IF-2016- DeciTrustNET-746398 and FEDER funds provided in the Spanish project TIN2016-75850-P

Solving key design issues for massively multiplayer online games on peer-to-peer architectures

Massively Multiplayer Online Games (MMOGs) are increasing in both popularity and scale on the Internet and are predominantly implemented by Client/Server architectures. While such a classical approach to distributed system design offers many benefits, it suffers from significant technical and commercial drawbacks, primarily reliability and scalability costs. This realisation has sparked recent research interest in adapting MMOGs to Peer-to-Peer (P2P) architectures. This thesis identifies six key design issues to be addressed by P2P MMOGs, namely interest management, event dissemination, task sharing, state persistency, cheating mitigation, and incentive mechanisms. Design alternatives for each issue are systematically compared, and their interrelationships discussed. How well representative P2P MMOG architectures fulfil the design criteria is also evaluated. It is argued that although P2P MMOG architectures are developing rapidly, their support for task sharing and incentive mechanisms still need to be improved. The design of a novel framework for P2P MMOGs, Mediator, is presented. It employs a self-organising super-peer network over a P2P overlay infrastructure, and addresses the six design issues in an integrated system. The Mediator framework is extensible, as it supports flexible policy plug-ins and can accommodate the introduction of new superpeer roles. Key components of this framework have been implemented and evaluated with a simulated P2P MMOG. As the Mediator framework relies on super-peers for computational and administrative tasks, membership management is crucial, e.g. to allow the system to recover from super-peer failures. A new technology for this, namely Membership-Aware Multicast with Bushiness Optimisation (MAMBO), has been designed, implemented and evaluated. It reuses the communication structure of a tree-based application-level multicast to track group membership efficiently. Evaluation of a demonstration application shows i that MAMBO is able to quickly detect and handle peers joining and leaving. Compared to a conventional supervision architecture, MAMBO is more scalable, and yet incurs less communication overheads. Besides MMOGs, MAMBO is suitable for other P2P applications, such as collaborative computing and multimedia streaming. This thesis also presents the design, implementation and evaluation of a novel task mapping infrastructure for heterogeneous P2P environments, Deadline-Driven Auctions (DDA). DDA is primarily designed to support NPC host allocation in P2P MMOGs, and specifically in the Mediator framework. However, it can also support the sharing of computational and interactive tasks with various deadlines in general P2P applications. Experimental and analytical results demonstrate that DDA efficiently allocates computing resources for large numbers of real-time NPC tasks in a simulated P2P MMOG with approximately 1000 players. Furthermore, DDA supports gaming interactivity by keeping the communication latency among NPC hosts and ordinary players low. It also supports flexible matchmaking policies, and can motivate application participants to contribute resources to the system

Blockchain-Based Distributed Trust and Reputation Management Systems: A Survey

Distributed Ledger Technologies (DLTs), like Blockchain, are characterized by features such as transparency, traceability, and security by design. These features make the adoption of Blockchain attractive to enhance information security, privacy, and trustworthiness in very different contexts. This paper provides a comprehensive survey and aims at analyzing and assessing the use of Blockchain in the context of Distributed Trust and Reputation Management Systems (DTRMS). The analysis includes academic research as well as initiatives undertaken in the business domain. The paper defines two taxonomies for both Blockchain and DTRMS and applies a Formal Concept Analysis. Such an approach allowed us to identify the most recurrent and stable features in the current scientific landscape and several important implications among the two taxonomies. The results of the analysis have revealed significant trends and emerging practices in the current implementations that have been distilled into recommendations to guide Blockchain's adoption in DTRMS systems

Access to Knowledge in Egypt

This book is available as open access through the Bloomsbury Open Access programme and is available on www.bloomsburycollections.com. "This book is an important contribution to recovering a nuanced, contextually aware view of access to knowledge and global knowledge governance" Yochaie Benkler, Harvard Law School "This is a 'must read' for scholars and practioners interested in economic devlopment, cultural production and access to knowledge" Susan Sell, George Washington University This volume features five chapters on current issues facing intellectual property, innovation and development policy from the Egyptian perspective. These include: information and communications technology for development, copyright and comparative business models in music, open source software, patent reform and access to medicines, and the role of the Egyptian government in promoting access to knowledge internationally and domestically. Together these chapters offer an overview of the challenges and opportunities facing efforts to promote access to knowledge. Combining both theoretical and empirical approaches, the work will be of interest to scholars and practitioners dealing with intellectual property and innovation property the world over

The Rise of the Sharing City: Examining Origins and Futures of Urban Sharing

With more than half the world’s population living in ever more economically productive cities, and urbanisation continuing apace, large-scale environmental problems resulting from unsustainable, excessively consumption-focussed life styles are doomed to happen. Meanwhile large amounts of equipment and infrastructure are barely used. The recently emerged Sharing City concept combines the benefits of Sharing Economy and Collaborative Consumption with urban development and community building, and promises to address at least some of those issues. This study seeks to gain a better understanding of the concept, and to offer an insight into its (partial) implementation. A literature analysis, qualitative interviews, and three case studies allow identifying major reasons for and enablers of the Sharing City’s emergence, driving forces, obstacles to implementation, and its potential. Structurally, the underlying changes in the global economy enabled it, as well as the recent economic crisis, changes in attitudes towards consumption and ownership, and the development and improvement of Information and Communication Technology (ICT). Driving forces behind the emergence of the Sharing City are identified in good access to ICT infrastructure, the presence of an energetic civil society and an accommodating city administration. Other drivers include a vibrant sharing business scene (as in San Francisco), an active municipality (like Seoul’s), and a sharing-enthusiastic population (as Berlin’s). Obstacles to the implementation and its dissemination are largely found in the legal frameworks governing four priority sectors for cities: food, transportation, housing, and jobs. Deficits are in both regulation that inhibits sharing but also a lack of regulation specifically for sharing. Sharing Cities can benefit the economic, environmental, social, and democratic dimensions of an urban community. One major criticism is levelled against the commercial expansion of sharing, which may be seen as an excessive marketisation of previously ‘private’ life spheres, subjecting ever-greater areas of life to the logic of commercial exchange

Egypt's Obligation to Respect, Protect and Fulfill the Right to Access to Knowledge, Science, Art and Culture (ICESCR Article 15)

Submitted to the United Nations Committee on Economic, Social and Cultural Rights, Pre-Sessional Working Group 51st Session, 21-24 May 2013, Geneva Switzerland, by the Indiana University Robert H. McKinney School of Law Pro Bono UN Human Rights Reporting Program. Team Members: Eslah Salah Alkathiri, LL.M. candidate; Dr. Mohamed Arafa, S.J.D.; J. Michael Blackwell, J.D. candidate; Ritu Chokshi, J.D. candidate; Sherif Mohamed Mansour, J.D. candidate; Deyana Fatme Unis, J.D. candidate; Qifan Wang, J.D. candidate. Faculty Advisers: Professor Lea Shaver, J.D. and Dr. Ian McIntosh, Ph.D. Founder, Head & Trainer: Perfecto `Boyet´ Caparas, A.B., LL.B., LL.M. American Law, LL.M. Human Rights (Honors); Graduate Studies Program Manager, Indiana University Robert H. McKinney School of Law, 530 W. New York Street, Indianapolis, Indiana USA. This human rights report includes the book titled Access to Knowledge in Egypt - New Research on Intellectual Property, Innovation and Development, edited by Nagla Rizk and Lea Shaver, Bloomsbury Academic, (CC) 2010 by Nagla Rizk, Lea Shaver and the contributors

Access to Knowledge in Egypt

This book is available as open access through the Bloomsbury Open Access programme and is available on www.bloomsburycollections.com. "This book is an important contribution to recovering a nuanced, contextually aware view of access to knowledge and global knowledge governance" Yochaie Benkler, Harvard Law School "This is a 'must read' for scholars and practioners interested in economic devlopment, cultural production and access to knowledge" Susan Sell, George Washington University This volume features five chapters on current issues facing intellectual property, innovation and development policy from the Egyptian perspective. These include: information and communications technology for development, copyright and comparative business models in music, open source software, patent reform and access to medicines, and the role of the Egyptian government in promoting access to knowledge internationally and domestically. Together these chapters offer an overview of the challenges and opportunities facing efforts to promote access to knowledge. Combining both theoretical and empirical approaches, the work will be of interest to scholars and practitioners dealing with intellectual property and innovation property the world over