Tutkielma ryhmitellyistä konferensseista ja Binary Floor Control Protocol:n toteutuksesta keskitettyyn konferenssijärjestelmään

The introduction of the third generation (3G) in the mobile telecommunication world offers the possibility for a wide range of new applications and services that operators can offer to their customers. One of these services is multimedia conferencing. There is ongoing work to provide conferencing services in the IP Multimedia Subsystem (IMS) environment as one of the most significant services. This thesis focuses on providing a comprehensive overview of conferencing systems, especially of the Binary Floor Control Protocol (BFCP) and cascade conferences. The Master's Thesis consisted of two parts: The first part is a theoretical part, which provides the concepts of the centralized conferencing, known as tightly coupled conferences, and reviews the current specifications stage of the different standardization bodies. In contrast, the study of the applicability of the current centralized conferencing specifications in a cascaded conferencing environment is presented, as well as the strengths and weaknesses of them. The second part is a practical implementation of the Binary Floor Control Protocol (BFCP). BFCP is implemented in MiniSip, an existing secure open-source SIP User Agent (UA), and in Asterisk, an open source Private Branch Exchange (PBX) replacement system. BFCP is built using the specification defined by the XCON working group within the Internet Engineering Task Force (IETF). Finally, BFCP is evaluated and based on this evaluation, some conclusions are given.Kolmannen sukupolven matkapuhelinverkot mahdollistavat laajan uusien ohjelmien ja palveluiden kirjon, joita operaattorit voivat tarjota asiakkailleen. Eräs tämänlainen palvelu on multimedia konferenssi. Tällä hetkellä tehdään työtä, jonka tarkoituksena on mahdollistaa konferenssinpalvelun tarjoaminen IP Multimedia Subsystem (IMS) ympäristössä. Tämä diplomityö keskittyy konferenssijärjestelmän perusteelliseen kuvaukseen, painottuen Binary Floor Control Protocol:aan (BFCP) sekä ryhmiteltyihin konferensseihin. Työ koostuu kahdesta osasta: Ensimmäinen osa keskittyy teoriaan, joka käsittelee keskitettyjä konferenssijärjestelmiä sekä aiheen nykyistä tilaa eri standardointiorganisaatioissa. Vastakohtana tarkastellaan nykyisen keskitetyn konferenssijärjestelmän heikkouksia ja vahvuuksia. Toinen osa käsittelee käytännön toteutusta BFCP:sta, joka on toteutettu MiniSip- sekä Asterisk-ohjelmistoihin. MiniSip on avoimeen lähdekoodiin perustuva SIP käyttäjäagentti, ja Asterisk paikallisvaihdeohjelmiston (PBX) avoin korvaaja. BFCP perustuu spesifikaatioon, jonka on määritellyt XCON työryhmä IETF:ssa. Lopuksi BFCP protokollaa on arvioitu tämän toteutuksen avulla

Prognostic implications of comorbidity patterns in critically ill COVID-19 patients: A multicenter, observational study

Background The clinical heterogeneity of COVID-19 suggests the existence of different phenotypes with prognostic implications. We aimed to analyze comorbidity patterns in critically ill COVID-19 patients and assess their impact on in-hospital outcomes, response to treatment and sequelae. Methods Multicenter prospective/retrospective observational study in intensive care units of 55 Spanish hospitals. 5866 PCR-confirmed COVID-19 patients had comorbidities recorded at hospital admission; clinical and biological parameters, in-hospital procedures and complications throughout the stay; and, clinical complications, persistent symptoms and sequelae at 3 and 6 months. Findings Latent class analysis identified 3 phenotypes using training and test subcohorts: low-morbidity (n=3385; 58%), younger and with few comorbidities; high-morbidity (n=2074; 35%), with high comorbid burden; and renal-morbidity (n=407; 7%), with chronic kidney disease (CKD), high comorbidity burden and the worst oxygenation profile. Renal-morbidity and high-morbidity had more in-hospital complications and higher mortality risk than low-morbidity (adjusted HR (95% CI): 1.57 (1.34-1.84) and 1.16 (1.05-1.28), respectively). Corticosteroids, but not tocilizumab, were associated with lower mortality risk (HR (95% CI) 0.76 (0.63-0.93)), especially in renal-morbidity and high-morbidity. Renal-morbidity and high-morbidity showed the worst lung function throughout the follow-up, with renal-morbidity having the highest risk of infectious complications (6%), emergency visits (29%) or hospital readmissions (14%) at 6 months (p<0.01). Interpretation Comorbidity-based phenotypes were identified and associated with different expression of in-hospital complications, mortality, treatment response, and sequelae, with CKD playing a major role. This could help clinicians in day-to-day decision making including the management of post-discharge COVID-19 sequelae. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd

Exploring the Quantum Frontiers of Generative Adversarial Networks in Chemical Catalysis

Quantum computing and generative Artificial Intelligence (AI) are two burgeoning fields that hold the promise of fundamentally revolutionizing the computational and data science landscapes. While quantum computing is renowned for enabling faster and more efficient calculations through the principles of superposition and entanglement, generative AI models, particularly Generative Adversarial Networks (GANs), are at the forefront of creating novel data and information, paving the way for unprecedented advancements in various domains. The synthesis of these two fields can potentially spearhead a paradigm shift in the realm of generative AI, fostering the development of quantum-inspired generative models that meld the computational prowess of quantum computing with the data generation capabilities of AI. This thesis delineates the current state-of-the-art in both fields and explores their burgeoning intersection, with a keen focus on the infusion of quantum principles in enhancing generative AI models. A critical aspect of this exploration is an in-depth study into the application of GANs in the field of chemical catalysis, a domain where the generation of new data can significantly accelerate the discovery and optimization of catalysts. In particular, this work investigates the potential of using GANs to generate novel chemical catalysis processes, emphasizing the creation and optimization of Copper (Cu) binary catalysts. By leveraging the capabilities of quantum computing, these models can potentially facilitate the discovery of more efficient and effective catalytic processes, opening new opportunities for research and development in the field. The overall aim of this thesis is to unravel the potential advantages and challenges of integrating quantum computing in generative AI, and to pave a road map for future directions in this exciting interdisciplinary domain. Through a meticulous analysis of specific generative AI models, this work endeavors to decipher how quantum principles can augment their capabilities, thereby delineating a promising trajectory for the future of quantum-enhanced generative AI

Making Constrained Things Reachable : A secure IP-agnostic NAT traversal approach for IoT

The widespread adoption of the Internet of Things (IoT) has created a demand for ubiquitous connectivity of IoT devices into the Internet.While end-to-end connectivity for IoT requires in practice IPv6, a vast majority of nodes in Internet are only IPv4-capable. To address this issue, the use of Network Address Translation (NAT) at the IoT network boundary becomes necessary. However, the constrained nature of the IoT devices hinders the integration of traditional NAT traversal architectures through IoT networks. In this article, we introduce a novel transition mechanism that transparently enables IoT devices behind NATs to connect across different network-layer infrastructures. Our mechanism adopts the IoT standards to provide a global connectivity solution in a transparent, secure, and elegant way. Additionally, we revisit the NAT solutions for IoT and describe and evaluate our current implementation.Peer reviewe

Improving the Ubiquitous Capabilities of the Internet of Things

The public defense on 24th April 2020 at 14:00 (2 p.m.) will be organized via remote technology. Link: https://aalto.zoom.us/j/663933727 Zoom Quick Guide: https://www.aalto.fi/en/services/zoom-quick-guideIn recent years, the Internet of Things (IoT) has become a reality in our society. Its digital disruption has spread rapidly to various domains, ranging from home automation to healthcare to industrial manufacturing. One of its most essential aspects resides in its ubiquitous nature; IoT devices are broadly available and fully connected to each other and the Internet. However, despite this obvious benefit, IoT's ubiquitous nature has simultaneously become one of its main challenges. The decentralization of IoT, its heterogeneity in terms of protocols, technologies and communications, and its lack of standards has created several interoperability questions from the perspective of connectivity, management, and data processing. Furthermore, many of those challenges are scattered across the various layers of the Internet protocol stack making it difficult to identify the crucial mechanisms contributing to the cause. This dissertation identifies some of the most significant barriers that prevent IoT from developing to its full potential and proposes solutions to ensure complete adoption of IoT's ubiquitous capabilities. To this end, the contribution of this dissertation can be divided into four specific categories, defined as ubiquitous communication, ubiquitous concurrency control, ubiquitous access control, and ubiquitous semantics. Ubiquitous communication refers to the connectivity-related challenges occurring due to the use of two different versions of Internet Protocols (IP). Ubiquitous concurrency control centers around issues with multiple parties sharing simultaneously a single IoT resource. On the other hand, ubiquitous access control focuses on the scalability related challenges to manage large numbers of IoT resources. Ubiquitous semantics is associated with interpreting the meaning of the heterogeneous IoT data on a universal basis. This dissertation proposes a solution for each category. In addition, the feasibility of the solutions has been evaluated with prototype implementations. In order to validate the implementations, we have performed several experiments and simulations that confirm the suitability of each solution. Lastly, we contributed some of the research results to various international standard organizations

Enabling CoAP-Based Communication across Network Boundaries: Challenges and Solutions

The depletion of the pool of unallocated IPv4 addresses has introduced new challenges in the deployment of the Internet of Things across IPv6 and IPv4 networks. In previous work we developed a CoAP-based transition architecture specifically designed to overcome some of these challenges. In this respect, this article extends that work identifying the most common IoT scenarios and their requirements to successfully achieve seamless cross-domain communication in IoT. Furthermore, an analysis of our architecture and the state-of-the-art network transition technologies is conducted on the basis of those requirements. Among other aspects, the analysis provides new insights of the shortcomings of our architecture. Based on these shortcomings, the article proposes new extensions of the architecture in order to achieve seamless communication across the most common IoT scenarios.Peer reviewe

A Framework for Access Coordination in IoT

IoT systems have typically been designed with the assumption that all their resources are available on a concurrent access basis. Conversely, some IoT scenarios only operate correctly if the access to certain resources is given in mutual exclusion fashion and limited to a confined number of nodes. For example, it might not be appropriate that a intrusion detection system prevents a fire suppression service to unlock the doors of a building. This article proposes a service-oriented, resource scheduling framework for IoT systems. The framework is based on the Binary Floor Control Protocol, a protocol designed for managing shared resources in conference systems. The article introduces the design model of the framework and presents an implementation of it. Based on this, the performance of the framework is evaluated and compared with the current state-of-the-art HTTP solutions for references. In addition, the framework is evaluated with respect to its suitability to be used in IoT. The results confirm thatour approach is suitable for IoT environments and achieve good scalability.Peer reviewe

Scalable Access Management in IoT using Blockchain : a Performance Evaluation

The rise of the Internet of Things (IoT) implies new technical challenges such as managing a universally vast number of IoT devices. Despite the fact that there are already a variety of secure management frameworks for IoT, they are based on centralized models, which limits their applicability in scenarios with a large number of IoT devices. In order to overcome those limitations, we have developed a distributed IoT management system based on blockchain. In this paper, we compare the performance of our solution with the existing access management solutions in IoT. We study the delays and the throughput rate associated with the systems and analyze different configurations of our solution to maximize its scalability. The objective of the paper is to find out whether our solution can scale as well as the existing management systems in IoT.Peer reviewe

Semantic Interoperability in the IoT: Extending the Web of Things Architecture

The adoption of the Internet of Things is gradually increasing. However, there remains a significant obstacle that hinders its adoption as a truly ubiquitous technology: the ability of constrained devices to unambiguously exchange data with shared meaning. In this respect, the World Wide Web Consortium has developed the Web of Things architecture to provide semantic data exchange. However, such an architecture does not cover all possible use cases and still has important limitations. This article specifically addresses these issues. In particular, it discusses the design and implementation of a solution that extends the Web of Things architecture to achieve a higher level of semantic interoperability for the Internet of Things. The proposed solution relies on a human-assisted translation process and defines an architecture that enhances the semantic compatibility between components in the World Wide Web Consortium and the Internet Engineering Task Force. The effectiveness of the proposed solution is demonstrated through both a quantitative and a qualitative evaluation, in terms of performance and key properties in comparison with the state of the art.Peer reviewe