510 research outputs found

    The Individual And Their World

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    Measuring the impact of COVID-19 on hospital care pathways

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    Care pathways in hospitals around the world reported significant disruption during the recent COVID-19 pandemic but measuring the actual impact is more problematic. Process mining can be useful for hospital management to measure the conformance of real-life care to what might be considered normal operations. In this study, we aim to demonstrate that process mining can be used to investigate process changes associated with complex disruptive events. We studied perturbations to accident and emergency (A &E) and maternity pathways in a UK public hospital during the COVID-19 pandemic. Co-incidentally the hospital had implemented a Command Centre approach for patient-flow management affording an opportunity to study both the planned improvement and the disruption due to the pandemic. Our study proposes and demonstrates a method for measuring and investigating the impact of such planned and unplanned disruptions affecting hospital care pathways. We found that during the pandemic, both A &E and maternity pathways had measurable reductions in the mean length of stay and a measurable drop in the percentage of pathways conforming to normative models. There were no distinctive patterns of monthly mean values of length of stay nor conformance throughout the phases of the installation of the hospital’s new Command Centre approach. Due to a deficit in the available A &E data, the findings for A &E pathways could not be interpreted

    Towards trustworthy computing on untrustworthy hardware

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    Historically, hardware was thought to be inherently secure and trusted due to its obscurity and the isolated nature of its design and manufacturing. In the last two decades, however, hardware trust and security have emerged as pressing issues. Modern day hardware is surrounded by threats manifested mainly in undesired modifications by untrusted parties in its supply chain, unauthorized and pirated selling, injected faults, and system and microarchitectural level attacks. These threats, if realized, are expected to push hardware to abnormal and unexpected behaviour causing real-life damage and significantly undermining our trust in the electronic and computing systems we use in our daily lives and in safety critical applications. A large number of detective and preventive countermeasures have been proposed in literature. It is a fact, however, that our knowledge of potential consequences to real-life threats to hardware trust is lacking given the limited number of real-life reports and the plethora of ways in which hardware trust could be undermined. With this in mind, run-time monitoring of hardware combined with active mitigation of attacks, referred to as trustworthy computing on untrustworthy hardware, is proposed as the last line of defence. This last line of defence allows us to face the issue of live hardware mistrust rather than turning a blind eye to it or being helpless once it occurs. This thesis proposes three different frameworks towards trustworthy computing on untrustworthy hardware. The presented frameworks are adaptable to different applications, independent of the design of the monitored elements, based on autonomous security elements, and are computationally lightweight. The first framework is concerned with explicit violations and breaches of trust at run-time, with an untrustworthy on-chip communication interconnect presented as a potential offender. The framework is based on the guiding principles of component guarding, data tagging, and event verification. The second framework targets hardware elements with inherently variable and unpredictable operational latency and proposes a machine-learning based characterization of these latencies to infer undesired latency extensions or denial of service attacks. The framework is implemented on a DDR3 DRAM after showing its vulnerability to obscured latency extension attacks. The third framework studies the possibility of the deployment of untrustworthy hardware elements in the analog front end, and the consequent integrity issues that might arise at the analog-digital boundary of system on chips. The framework uses machine learning methods and the unique temporal and arithmetic features of signals at this boundary to monitor their integrity and assess their trust level

    The European Experience: A Multi-Perspective History of Modern Europe, 1500–2000

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    The European Experience brings together the expertise of nearly a hundred historians from eight European universities to internationalise and diversify the study of modern European history, exploring a grand sweep of time from 1500 to 2000. Offering a valuable corrective to the Anglocentric narratives of previous English-language textbooks, scholars from all over Europe have pooled their knowledge on comparative themes such as identities, cultural encounters, power and citizenship, and economic development to reflect the complexity and heterogeneous nature of the European experience. Rather than another grand narrative, the international author teams offer a multifaceted and rich perspective on the history of the continent of the past 500 years. Each major theme is dissected through three chronological sub-chapters, revealing how major social, political and historical trends manifested themselves in different European settings during the early modern (1500–1800), modern (1800–1900) and contemporary period (1900–2000). This resource is of utmost relevance to today’s history students in the light of ongoing internationalisation strategies for higher education curricula, as it delivers one of the first multi-perspective and truly ‘European’ analyses of the continent’s past. Beyond the provision of historical content, this textbook equips students with the intellectual tools to interrogate prevailing accounts of European history, and enables them to seek out additional perspectives in a bid to further enrich the discipline

    LIPIcs, Volume 261, ICALP 2023, Complete Volume

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    LIPIcs, Volume 261, ICALP 2023, Complete Volum

    Understanding and Mitigating Flaky Software Test Cases

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    A flaky test is a test case that can pass or fail without changes to the test case code or the code under test. They are a wide-spread problem with serious consequences for developers and researchers alike. For developers, flaky tests lead to time wasted debugging spurious failures, tempting them to ignore future failures. While unreliable, flaky tests can still indicate genuine issues in the code under test, so ignoring them can lead to bugs being missed. The non-deterministic behaviour of flaky tests is also a major snag to continuous integration, where a single flaky test can fail an entire build. For researchers, flaky tests challenge the assumption that a test failure implies a bug, an assumption that many fundamental techniques in software engineering research rely upon, including test acceleration, mutation testing, and fault localisation. Despite increasing research interest in the topic, open problems remain. In particular, there has been relatively little attention paid to the views and experiences of developers, despite a considerable body of empirical work. This is essential to guide the focus of research into areas that are most likely to be beneficial to the software engineering industry. Furthermore, previous automated techniques for detecting flaky tests are typically either based on exhaustively rerunning test cases or machine learning classifiers. The prohibitive runtime of the rerunning approach and the demonstrably poor inter-project generalisability of classifiers leaves practitioners with a stark choice when it comes to automatically detecting flaky tests. In response to these challenges, I set two high-level goals for this thesis: (1) to enhance the understanding of the manifestation, causes, and impacts of flaky tests; and (2) to develop and empirically evaluate efficient automated techniques for mitigating flaky tests. In pursuit of these goals, this thesis makes five contributions: (1) a comprehensive systematic literature review of 76 published papers; (2) a literature-guided survey of 170 professional software developers; (3) a new feature set for encoding test cases in machine learning-based flaky test detection; (4) a novel approach for reducing the time cost of rerunning-based techniques for detecting flaky tests by combining them with machine learning classifiers; and (5) an automated technique that detects and classifies existing flaky tests in a project and produces reusable project-specific machine learning classifiers able to provide fast and accurate predictions for future test cases in that project

    MOCAST 2021

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    The 10th International Conference on Modern Circuit and System Technologies on Electronics and Communications (MOCAST 2021) will take place in Thessaloniki, Greece, from July 5th to July 7th, 2021. The MOCAST technical program includes all aspects of circuit and system technologies, from modeling to design, verification, implementation, and application. This Special Issue presents extended versions of top-ranking papers in the conference. The topics of MOCAST include:Analog/RF and mixed signal circuits;Digital circuits and systems design;Nonlinear circuits and systems;Device and circuit modeling;High-performance embedded systems;Systems and applications;Sensors and systems;Machine learning and AI applications;Communication; Network systems;Power management;Imagers, MEMS, medical, and displays;Radiation front ends (nuclear and space application);Education in circuits, systems, and communications

    Quantitative Verification and Synthesis of Resilient Networks

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    Navigating the Soviet Experiment: Travels and Writings of John Dos Passos and Edmund Wilson In Soviet Russia, 1928-1935

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    The travel accounts of Soviet Russia by John Dos Passos (1896-1970) and Edmund Wilson (1895-1972) vividly demonstrate how Western writer-travelers were drawn into Soviet cultural experiments. Only rarely was this process one of literary influence. This thesis focuses on published travel writings by Dos Passos (In All Countries, 1934) and Wilson (Travels In Two Democracies, 1936), as well as journals, letters, and essays, in terms of Soviet cultural developments both writers noted as historically significant in shaping Western views of the Soviet state, and of the methods involved in building socialism and Communism. In the 1920s, Soviet culture emphasized the future through mass or collective production of spectacles involving the observer. This orientation paralleled Marxist teleology toward the post-revolutionary perfection of the fully Communist society. Individuals renounced former class identities and acquired new ones through labor for and participation in mass projects. In the 1930s, as reflected in the advent of Socialist Realism as an artistic doctrine, the emphasis in culture shifted to the exceptional individual, whose activities embodied the message of “socialism achieved” in official party discourse. The popular appeal of using high artistic means to achieve a social end attracted Western writers such as Dos Passos and Wilson. Dos Passos wanted to promote a “revolutionary theater” that could appeal to a mass audience and encourage consciousness of social reform. Wilson sought to glimpse in the Soviet present the material result of Marxist socialism. Official Soviet agencies sought and courted close relationships with Western writers, particularly those perceived through their publications as sympathetic to socialist ideology and its cultural manifestations. Touristic and cultural bureaus directed the curiosity of writers such as Dos Passos and Wilson toward specific Soviet achievements, and also attempted to bring them into closer collaboration with political objectives by appealing to their literary/cultural interests

    Improving data preparation for the application of process mining

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    Immersed in what is already known as the fourth industrial revolution, automation and data exchange are taking on a particularly relevant role in complex environments, such as industrial manufacturing environments or logistics. This digitisation and transition to the Industry 4.0 paradigm is causing experts to start analysing business processes from other perspectives. Consequently, where management and business intelligence used to dominate, process mining appears as a link, trying to build a bridge between both disciplines to unite and improve them. This new perspective on process analysis helps to improve strategic decision making and competitive capabilities. Process mining brings together data and process perspectives in a single discipline that covers the entire spectrum of process management. Through process mining, and based on observations of their actual operations, organisations can understand the state of their operations, detect deviations, and improve their performance based on what they observe. In this way, process mining is an ally, occupying a large part of current academic and industrial research. However, although this discipline is receiving more and more attention, it presents severe application problems when it is implemented in real environments. The variety of input data in terms of form, content, semantics, and levels of abstraction makes the execution of process mining tasks in industry an iterative, tedious, and manual process, requiring multidisciplinary experts with extensive knowledge of the domain, process management, and data processing. Currently, although there are numerous academic proposals, there are no industrial solutions capable of automating these tasks. For this reason, in this thesis by compendium we address the problem of improving business processes in complex environments thanks to the study of the state-of-the-art and a set of proposals that improve relevant aspects in the life cycle of processes, from the creation of logs, log preparation, process quality assessment, and improvement of business processes. Firstly, for this thesis, a systematic study of the literature was carried out in order to gain an in-depth knowledge of the state-of-the-art in this field, as well as the different challenges faced by this discipline. This in-depth analysis has allowed us to detect a number of challenges that have not been addressed or received insufficient attention, of which three have been selected and presented as the objectives of this thesis. The first challenge is related to the assessment of the quality of input data, known as event logs, since the requeriment of the application of techniques for improving the event log must be based on the level of quality of the initial data, which is why this thesis presents a methodology and a set of metrics that support the expert in selecting which technique to apply to the data according to the quality estimation at each moment, another challenge obtained as a result of our analysis of the literature. Likewise, the use of a set of metrics to evaluate the quality of the resulting process models is also proposed, with the aim of assessing whether improvement in the quality of the input data has a direct impact on the final results. The second challenge identified is the need to improve the input data used in the analysis of business processes. As in any data-driven discipline, the quality of the results strongly depends on the quality of the input data, so the second challenge to be addressed is the improvement of the preparation of event logs. The contribution in this area is the application of natural language processing techniques to relabel activities from textual descriptions of process activities, as well as the application of clustering techniques to help simplify the results, generating more understandable models from a human point of view. Finally, the third challenge detected is related to the process optimisation, so we contribute with an approach for the optimisation of resources associated with business processes, which, through the inclusion of decision-making in the creation of flexible processes, enables significant cost reductions. Furthermore, all the proposals made in this thesis are validated and designed in collaboration with experts from different fields of industry and have been evaluated through real case studies in public and private projects in collaboration with the aeronautical industry and the logistics sector
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