6,194 research outputs found

    Configuration Management of Distributed Systems over Unreliable and Hostile Networks

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    Economic incentives of large criminal profits and the threat of legal consequences have pushed criminals to continuously improve their malware, especially command and control channels. This thesis applied concepts from successful malware command and control to explore the survivability and resilience of benign configuration management systems. This work expands on existing stage models of malware life cycle to contribute a new model for identifying malware concepts applicable to benign configuration management. The Hidden Master architecture is a contribution to master-agent network communication. In the Hidden Master architecture, communication between master and agent is asynchronous and can operate trough intermediate nodes. This protects the master secret key, which gives full control of all computers participating in configuration management. Multiple improvements to idempotent configuration were proposed, including the definition of the minimal base resource dependency model, simplified resource revalidation and the use of imperative general purpose language for defining idempotent configuration. Following the constructive research approach, the improvements to configuration management were designed into two prototypes. This allowed validation in laboratory testing, in two case studies and in expert interviews. In laboratory testing, the Hidden Master prototype was more resilient than leading configuration management tools in high load and low memory conditions, and against packet loss and corruption. Only the research prototype was adaptable to a network without stable topology due to the asynchronous nature of the Hidden Master architecture. The main case study used the research prototype in a complex environment to deploy a multi-room, authenticated audiovisual system for a client of an organization deploying the configuration. The case studies indicated that imperative general purpose language can be used for idempotent configuration in real life, for defining new configurations in unexpected situations using the base resources, and abstracting those using standard language features; and that such a system seems easy to learn. Potential business benefits were identified and evaluated using individual semistructured expert interviews. Respondents agreed that the models and the Hidden Master architecture could reduce costs and risks, improve developer productivity and allow faster time-to-market. Protection of master secret keys and the reduced need for incident response were seen as key drivers for improved security. Low-cost geographic scaling and leveraging file serving capabilities of commodity servers were seen to improve scaling and resiliency. Respondents identified jurisdictional legal limitations to encryption and requirements for cloud operator auditing as factors potentially limiting the full use of some concepts

    UMSL Bulletin 2023-2024

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    The 2023-2024 Bulletin and Course Catalog for the University of Missouri St. Louis.https://irl.umsl.edu/bulletin/1088/thumbnail.jp

    Analysis and Design of Non-Orthogonal Multiple Access (NOMA) Techniques for Next Generation Wireless Communication Systems

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    The current surge in wireless connectivity, anticipated to amplify significantly in future wireless technologies, brings a new wave of users. Given the impracticality of an endlessly expanding bandwidth, there’s a pressing need for communication techniques that efficiently serve this burgeoning user base with limited resources. Multiple Access (MA) techniques, notably Orthogonal Multiple Access (OMA), have long addressed bandwidth constraints. However, with escalating user numbers, OMA’s orthogonality becomes limiting for emerging wireless technologies. Non-Orthogonal Multiple Access (NOMA), employing superposition coding, serves more users within the same bandwidth as OMA by allocating different power levels to users whose signals can then be detected using the gap between them, thus offering superior spectral efficiency and massive connectivity. This thesis examines the integration of NOMA techniques with cooperative relaying, EXtrinsic Information Transfer (EXIT) chart analysis, and deep learning for enhancing 6G and beyond communication systems. The adopted methodology aims to optimize the systems’ performance, spanning from bit-error rate (BER) versus signal to noise ratio (SNR) to overall system efficiency and data rates. The primary focus of this thesis is the investigation of the integration of NOMA with cooperative relaying, EXIT chart analysis, and deep learning techniques. In the cooperative relaying context, NOMA notably improved diversity gains, thereby proving the superiority of combining NOMA with cooperative relaying over just NOMA. With EXIT chart analysis, NOMA achieved low BER at mid-range SNR as well as achieved optimal user fairness in the power allocation stage. Additionally, employing a trained neural network enhanced signal detection for NOMA in the deep learning scenario, thereby producing a simpler signal detection for NOMA which addresses NOMAs’ complex receiver problem

    Effective player guidance in logic puzzles

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    Pen & paper puzzle games are an extremely popular pastime, often enjoyed by demographics normally not considered to be ‘gamers’. They are increasingly used as ‘serious games’ and there has been extensive research into computationally generating and efficiently solving them. However, there have been few academic studies that have focused on the players themselves. Presenting an appropriate level of challenge to a player is essential for both player enjoyment and engagement. Providing appropriate assistance is an essential mechanic for making a game accessible to a variety of players. In this thesis, we investigate how players solve Progressive Pen & Paper Puzzle Games (PPPPs) and how to provide meaningful assistance that allows players to recover from being stuck, while not reducing the challenge to trivial levels. This thesis begins with a qualitative in-person study of Sudoku solving. This study demonstrates that, in contrast to all existing assumptions used to model players, players were unsystematic, idiosyncratic and error-prone. We then designed an entirely new approach to providing assistance in PPPPs, which guides players towards easier deductions rather than, as current systems do, completing the next cell for them. We implemented a novel hint system using our design, with the assessment of the challenge being done using Minimal Unsatisfiable Sets (MUSs). We conducted four studies, using two different PPPPs, that evaluated the efficacy of the novel hint system compared to the current hint approach. The studies demonstrated that our novel hint system was as helpful as the existing system while also improving the player experience and feeling less like cheating. Players also chose to use our novel hint system significantly more often. We have provided a new approach to providing assistance to PPPP players and demonstrated that players prefer it over existing approaches

    Multidisciplinary perspectives on Artificial Intelligence and the law

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    This open access book presents an interdisciplinary, multi-authored, edited collection of chapters on Artificial Intelligence (‘AI’) and the Law. AI technology has come to play a central role in the modern data economy. Through a combination of increased computing power, the growing availability of data and the advancement of algorithms, AI has now become an umbrella term for some of the most transformational technological breakthroughs of this age. The importance of AI stems from both the opportunities that it offers and the challenges that it entails. While AI applications hold the promise of economic growth and efficiency gains, they also create significant risks and uncertainty. The potential and perils of AI have thus come to dominate modern discussions of technology and ethics – and although AI was initially allowed to largely develop without guidelines or rules, few would deny that the law is set to play a fundamental role in shaping the future of AI. As the debate over AI is far from over, the need for rigorous analysis has never been greater. This book thus brings together contributors from different fields and backgrounds to explore how the law might provide answers to some of the most pressing questions raised by AI. An outcome of the Católica Research Centre for the Future of Law and its interdisciplinary working group on Law and Artificial Intelligence, it includes contributions by leading scholars in the fields of technology, ethics and the law.info:eu-repo/semantics/publishedVersio

    LIPIcs, Volume 251, ITCS 2023, Complete Volume

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    LIPIcs, Volume 251, ITCS 2023, Complete Volum

    UMSL Bulletin 2022-2023

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    The 2022-2023 Bulletin and Course Catalog for the University of Missouri St. Louis.https://irl.umsl.edu/bulletin/1087/thumbnail.jp

    Privacy-preserving artificial intelligence in healthcare: Techniques and applications

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    There has been an increasing interest in translating artificial intelligence (AI) research into clinically-validated applications to improve the performance, capacity, and efficacy of healthcare services. Despite substantial research worldwide, very few AI-based applications have successfully made it to clinics. Key barriers to the widespread adoption of clinically validated AI applications include non-standardized medical records, limited availability of curated datasets, and stringent legal/ethical requirements to preserve patients' privacy. Therefore, there is a pressing need to improvise new data-sharing methods in the age of AI that preserve patient privacy while developing AI-based healthcare applications. In the literature, significant attention has been devoted to developing privacy-preserving techniques and overcoming the issues hampering AI adoption in an actual clinical environment. To this end, this study summarizes the state-of-the-art approaches for preserving privacy in AI-based healthcare applications. Prominent privacy-preserving techniques such as Federated Learning and Hybrid Techniques are elaborated along with potential privacy attacks, security challenges, and future directions. [Abstract copyright: Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.

    Discussion on drivers and proposition of approaches to support the transition of traditional electricity consumers to prosumers

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    In recent years, traditional power systems have undergone a significant transition, mainly related to the massive penetration of Renewable Energy Sources (RES). More specifically, the transformation of residential consumers into prosumers has been challenging to the traditional operation of electricity markets. This transition brings new challenges and opportunities to the power system, leading to new Business Model (BM). One widely discussed change is related to a consumer-centric or prosumer-driven approach, promoting increased participation of small consumers in power systems. The present thesis aims at discussing the recent BMs as enablers of the increasing prosumers’ role in the energy market and power system worldwide, deepening the discussion with a holistic view of the Brazilian context. To do so, it defines the main features of prosumers and their general related regulation as well as possible market designs within power systems. Moreover, the work intends to contribute to the knowledge, identification and understanding of the main regulatory barriers and enablers for the development of those BMs in the Brazilian energy market. In addition, it discusses enabling technologies to properly create the conditions that sustain new prosumer-driven markets. Then, it presents a comprehensive review of existing and innovative BMs and a discussion on their future roles in modern power systems and, in the Brazilian regulatory framework seeking to guide the decisions for the country to develop its political and regulatory environment in the future. Moreover, a set of recommendations for promoting these BMs in the power system worldwide is provided along with policy recommendations to promote prosumers aggregation in the Brazilian energy sector. An important conclusion is that, even though economically possible, not all innovative BMs can spread around the world due to regulatory issues. Seeking to further explore one of the prosumer-driven approaches presented and the challenges imposed by this innovative BM, a study of energy and reserve markets based on the Peer-to-Peer (P2P) structure is carried out. This structure is very promising for the prosumers’ promotion but presents some challenges for the network operation. A critical challenge is to ensure that network constraints are not violated due to energy trades between peers and neither due to the use of reserve capacity. Therefore, two methodologies are proposed. First, is proposed a three-step approach (P2PTDF), using Topological Distribution Factors (TDF) to penalize peers responsible for violations that may occur in the network constraints, ensuring a feasible solution. Second, it is proposed a new integrated prosumers-DSO approach applied in P2P energy and reserve tradings that also ensures the feasibility of both energy and reserve transactions under network constraints. The proposed approach includes the estimation of reserve requirements based on the RES uncertain behavior from historical generation data, which allows identifying RES patterns. The proposed models are assessed through a case study that uses a 14-bus system, under the technical and economic criteria. The results show that the approaches can ensure a feasible network operation.Nos últimos anos, os sistemas tradicionais de energia passaram por uma transição significativa, principalmente relacionada à penetração massiva de fontes de energia renováveis (do inglês, Renewable energy sources-RES). Mais especificamente, a transformação de consumidores residenciais em prosumidores tem desafiado a atual operação do mercado de energia elétrica. Essa transição traz novos desafios e oportunidades para o sistema elétrico, levando a novos modelos de negócios (do inglês, Business Models-BM). Uma mudança amplamente discutida está relacionada a uma abordagem centrada no consumidor ou direcionada ao prossumidor, promovendo maior participação de pequenos consumidores nos sistemas de energia. A presente tese tem como objetivo discutir os recentes BMs como facilitadores do crescente papel dos prosumidores no mercado de energia e no sistema elétrico mundial, aprofundando a discussão com uma visão holística do contexto brasileiro. Para tanto, define as principais características dos prosumidores e sua regulamentação geral relacionada, bem como possíveis designs de mercado dentro dos sistemas de energia. Além disso, o trabalho pretende contribuir para o conhecimento, identificação e compreensão das principais barreiras regulatórias e facilitadoras para o desenvolvimento desses BMs no mercado brasileiro de energia. Assim como, discutir as tecnologias importantes para criar adequadamente as condições que sustentam novos mercados orientados ao consumidor final. Em seguida, apresenta uma revisão abrangente dos BMs existentes e inovadores e uma discussão sobre seus papéis futuros nos sistemas de energia modernos e, no quadro regulatório brasileiro, buscando orientar as decisões para que o país desenvolva seu ambiente político e regulatório no futuro. Além disso, um conjunto de recomendações para promover esses BMs no sistema de energia em todo o mundo é fornecido juntamente com recomendações de políticas para promover a agregação de prosumidores no setor de energia brasileiro. Uma conclusão importante é que, mesmo sendo economicamente possível, nem todos os BMs inovadores podem se espalhar pelo mundo devido a obstáculos regulatórias. Buscando explorar ainda mais uma das abordagens orientadas ao prosumidor apresentadas e os desafios impostos por este BM inovador, é realizado um estudo dos mercados de energia e de reserva com base na estrutura ponto a ponto (do inglês, peer-to-peer-P2P). Esta estrutura é muito promissora para a promoção dos prosumidores mas apresenta alguns desafios para o funcionamento da rede. Um desafio crítico é garantir que as restrições da rede não sejam violadas devido a negociações de energia entre pares e nem devido ao uso da capacidade de reserva. Portanto, duas metodologias são propostas. Primeiramente, é proposta uma abordagem em três passos (P2PTDF), utilizando Fatores de Distribuição Topológica (do inglês, Topological Distribution Factors-TDF ) para penalizar os peers responsáveis por violações que possam ocorrer nas restrições da rede, garantindo uma solução viável. Em segundo lugar, é proposta uma nova abordagem integrada de prosumidores-DSO aplicada em transações P2P de energia e reserva que também garante a viabilidade de transações de energia e reserva sob restrições de rede. A abordagem proposta inclui a estimativa dos requisitos de reserva com base no comportamento incerto da RES a partir de dados históricos de geração, o que permite identificar padrões de RES. Os modelos propostos são avaliados através de um estudo de caso que utiliza um sistema de 14 barras, sob os critérios técnico e econômico. Os resultados mostram que as abordagens podem garantir uma operação de rede viável abrangendo energia e mercados de reserva

    Investigating the learning potential of the Second Quantum Revolution: development of an approach for secondary school students

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    In recent years we have witnessed important changes: the Second Quantum Revolution is in the spotlight of many countries, and it is creating a new generation of technologies. To unlock the potential of the Second Quantum Revolution, several countries have launched strategic plans and research programs that finance and set the pace of research and development of these new technologies (like the Quantum Flagship, the National Quantum Initiative Act and so on). The increasing pace of technological changes is also challenging science education and institutional systems, requiring them to help to prepare new generations of experts. This work is placed within physics education research and contributes to the challenge by developing an approach and a course about the Second Quantum Revolution. The aims are to promote quantum literacy and, in particular, to value from a cultural and educational perspective the Second Revolution. The dissertation is articulated in two parts. In the first, we unpack the Second Quantum Revolution from a cultural perspective and shed light on the main revolutionary aspects that are elevated to the rank of principles implemented in the design of a course for secondary school students, prospective and in-service teachers. The design process and the educational reconstruction of the activities are presented as well as the results of a pilot study conducted to investigate the impact of the approach on students' understanding and to gather feedback to refine and improve the instructional materials. The second part consists of the exploration of the Second Quantum Revolution as a context to introduce some basic concepts of quantum physics. We present the results of an implementation with secondary school students to investigate if and to what extent external representations could play any role to promote students’ understanding and acceptance of quantum physics as a personal reliable description of the world
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