5,108 research outputs found

    The Viability and Potential Consequences of IoT-Based Ransomware

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    With the increased threat of ransomware and the substantial growth of the Internet of Things (IoT) market, there is significant motivation for attackers to carry out IoT-based ransomware campaigns. In this thesis, the viability of such malware is tested. As part of this work, various techniques that could be used by ransomware developers to attack commercial IoT devices were explored. First, methods that attackers could use to communicate with the victim were examined, such that a ransom note was able to be reliably sent to a victim. Next, the viability of using "bricking" as a method of ransom was evaluated, such that devices could be remotely disabled unless the victim makes a payment to the attacker. Research was then performed to ascertain whether it was possible to remotely gain persistence on IoT devices, which would improve the efficacy of existing ransomware methods, and provide opportunities for more advanced ransomware to be created. Finally, after successfully identifying a number of persistence techniques, the viability of privacy-invasion based ransomware was analysed. For each assessed technique, proofs of concept were developed. A range of devices -- with various intended purposes, such as routers, cameras and phones -- were used to test the viability of these proofs of concept. To test communication hijacking, devices' "channels of communication" -- such as web services and embedded screens -- were identified, then hijacked to display custom ransom notes. During the analysis of bricking-based ransomware, a working proof of concept was created, which was then able to remotely brick five IoT devices. After analysing the storage design of an assortment of IoT devices, six different persistence techniques were identified, which were then successfully tested on four devices, such that malicious filesystem modifications would be retained after the device was rebooted. When researching privacy-invasion based ransomware, several methods were created to extract information from data sources that can be commonly found on IoT devices, such as nearby WiFi signals, images from cameras, or audio from microphones. These were successfully implemented in a test environment such that ransomable data could be extracted, processed, and stored for later use to blackmail the victim. Overall, IoT-based ransomware has not only been shown to be viable but also highly damaging to both IoT devices and their users. While the use of IoT-ransomware is still very uncommon "in the wild", the techniques demonstrated within this work highlight an urgent need to improve the security of IoT devices to avoid the risk of IoT-based ransomware causing havoc in our society. Finally, during the development of these proofs of concept, a number of potential countermeasures were identified, which can be used to limit the effectiveness of the attacking techniques discovered in this PhD research

    Anuário científico da Escola Superior de Tecnologia da Saúde de Lisboa - 2021

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    É com grande prazer que apresentamos a mais recente edição (a 11.ª) do Anuário Científico da Escola Superior de Tecnologia da Saúde de Lisboa. Como instituição de ensino superior, temos o compromisso de promover e incentivar a pesquisa científica em todas as áreas do conhecimento que contemplam a nossa missão. Esta publicação tem como objetivo divulgar toda a produção científica desenvolvida pelos Professores, Investigadores, Estudantes e Pessoal não Docente da ESTeSL durante 2021. Este Anuário é, assim, o reflexo do trabalho árduo e dedicado da nossa comunidade, que se empenhou na produção de conteúdo científico de elevada qualidade e partilhada com a Sociedade na forma de livros, capítulos de livros, artigos publicados em revistas nacionais e internacionais, resumos de comunicações orais e pósteres, bem como resultado dos trabalhos de 1º e 2º ciclo. Com isto, o conteúdo desta publicação abrange uma ampla variedade de tópicos, desde temas mais fundamentais até estudos de aplicação prática em contextos específicos de Saúde, refletindo desta forma a pluralidade e diversidade de áreas que definem, e tornam única, a ESTeSL. Acreditamos que a investigação e pesquisa científica é um eixo fundamental para o desenvolvimento da sociedade e é por isso que incentivamos os nossos estudantes a envolverem-se em atividades de pesquisa e prática baseada na evidência desde o início dos seus estudos na ESTeSL. Esta publicação é um exemplo do sucesso desses esforços, sendo a maior de sempre, o que faz com que estejamos muito orgulhosos em partilhar os resultados e descobertas dos nossos investigadores com a comunidade científica e o público em geral. Esperamos que este Anuário inspire e motive outros estudantes, profissionais de saúde, professores e outros colaboradores a continuarem a explorar novas ideias e contribuir para o avanço da ciência e da tecnologia no corpo de conhecimento próprio das áreas que compõe a ESTeSL. Agradecemos a todos os envolvidos na produção deste anuário e desejamos uma leitura inspiradora e agradável.info:eu-repo/semantics/publishedVersio

    A Decision Support System for Economic Viability and Environmental Impact Assessment of Vertical Farms

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    Vertical farming (VF) is the practice of growing crops or animals using the vertical dimension via multi-tier racks or vertically inclined surfaces. In this thesis, I focus on the emerging industry of plant-specific VF. Vertical plant farming (VPF) is a promising and relatively novel practice that can be conducted in buildings with environmental control and artificial lighting. However, the nascent sector has experienced challenges in economic viability, standardisation, and environmental sustainability. Practitioners and academics call for a comprehensive financial analysis of VPF, but efforts are stifled by a lack of valid and available data. A review of economic estimation and horticultural software identifies a need for a decision support system (DSS) that facilitates risk-empowered business planning for vertical farmers. This thesis proposes an open-source DSS framework to evaluate business sustainability through financial risk and environmental impact assessments. Data from the literature, alongside lessons learned from industry practitioners, would be centralised in the proposed DSS using imprecise data techniques. These techniques have been applied in engineering but are seldom used in financial forecasting. This could benefit complex sectors which only have scarce data to predict business viability. To begin the execution of the DSS framework, VPF practitioners were interviewed using a mixed-methods approach. Learnings from over 19 shuttered and operational VPF projects provide insights into the barriers inhibiting scalability and identifying risks to form a risk taxonomy. Labour was the most commonly reported top challenge. Therefore, research was conducted to explore lean principles to improve productivity. A probabilistic model representing a spectrum of variables and their associated uncertainty was built according to the DSS framework to evaluate the financial risk for VF projects. This enabled flexible computation without precise production or financial data to improve economic estimation accuracy. The model assessed two VPF cases (one in the UK and another in Japan), demonstrating the first risk and uncertainty quantification of VPF business models in the literature. The results highlighted measures to improve economic viability and the viability of the UK and Japan case. The environmental impact assessment model was developed, allowing VPF operators to evaluate their carbon footprint compared to traditional agriculture using life-cycle assessment. I explore strategies for net-zero carbon production through sensitivity analysis. Renewable energies, especially solar, geothermal, and tidal power, show promise for reducing the carbon emissions of indoor VPF. Results show that renewably-powered VPF can reduce carbon emissions compared to field-based agriculture when considering the land-use change. The drivers for DSS adoption have been researched, showing a pathway of compliance and design thinking to overcome the ‘problem of implementation’ and enable commercialisation. Further work is suggested to standardise VF equipment, collect benchmarking data, and characterise risks. This work will reduce risk and uncertainty and accelerate the sector’s emergence

    Epilepsy Mortality: Leading Causes of Death, Co-morbidities, Cardiovascular Risk and Prevention

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    a reuptake inhibitor selectively prevents seizure-induced sudden death in the DBA/1 mouse model of sudden unexpected ... Bilateral lesions of the fastigial nucleus prevent the recovery of blood pressure following hypotension induced by ..

    Investigating the role of R2TP-like co-chaperone complexes during axonemal dynein assembly

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    Motile cilia are specialised cell-types which in humans have important roles in the linings of the airways, the reproductive system and the brain. The movement, required for this type of cilia to function, is facilitated by structures called axonemal dynein motor complexes. These are large, multi-subunit structures, and so it is crucial that they are assembled correctly. In humans, if the motility of these is defective, it can lead to a disorder called Primary Ciliary Dyskinesia, or PCD. This is a heterogeneous, autosomal recessive disorder – symptoms of which include abnormally positioned organs, chronic respiratory infections and infertility. Therefore, the development and structure of the motile cilia is tightly regulated by multiple proteins including chaperones, dynein axonemal assembly factors (DNAAFs), microtubule inner proteins (MIPs), the outer arm docking complex (ODA-DC) and the nexin-dynein regulatory complex (N-DRC). Chaperones work with co-chaperones to regulate their many functions within the cell. One of these co-chaperones is the R2TP complex, which was originally discovered in yeast but is conserved in higher organisms. This multi-protein co-chaperone is involved in the assembly of multi-subunit complexes such as the axonemal dynein motors. Two of the R2TP subunits, Pontin and Reptin, are involved in many cellular functions both in this co-chaperone complex and independently. It is thought that as some DNAAFs share similar protein domains to the components of the R2TP complex, they may form R2TP-like complexes. However, the specific details surrounding the roles of these complexes during the assembly process remains unclear. The structure of motile cilia is highly conserved throughout evolution and Drosophila melanogaster has been shown previously to be an excellent model for furthering understanding into the development and function of these structures as only two cell types in the fly contain axonemal dynein motor complexes. These are the chordotonal neuron, which has a motile ciliated dendrite essential for its mechanosensory function, and the sperm flagellum. In this thesis, I use the Drosophila model to further characterise putative ciliary genes (Wdr16 and Dpcd) identified by a transcriptome analysis previously carried out in the lab. RNAi knockdown experiments as well as expression analysis supported motile cilia functions. The diversity which has been identified regarding the roles of these two putative ciliary genes highlights how proteins can be involved in motile cilia in different ways. I also use this genetically tractable model to further understand the roles of the individual proteins of a previously identified R2TP-like complex (R2DP3). Electron microscopy, proteomics and investigation into how the localisation of dynein subsets was affected in null mutants (generated using CRISPR/Cas9) allowed for the role of this R2TP-like complex in the dynein assembly process to be further specified. Using co-immunoprecipitation and affinity purification, we identified an additional protein complex featuring Pontin and Reptin of the R2TP complex, alongside the DNAAF Heatr2 and the putative DNAAF Dpcd. As well as a role in dynein assembly, both DNAAFs are additionally expressed in the neuroblasts of the CNS, and disruption to their function results in a late larval lethality. Therefore, we have found these genes to not be specific to the dynein assembly process and hypothesise that Dpcd may have an additional function (working with Pontin, Reptin and potentially Heatr2) in the regulation of AKT signalling and therefore impact cell proliferation

    Platform protocol place: a practice-based study of critical media art practice (2007-2020)

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    This practice-based research project focuses on critical media art practices in contemporary digital culture. The theoretical framework employed in this inquiry draws from the work of the Frankfurt School, in particular Theodor Adorno and Max Horkheimer’s The Culture Industry: Enlightenment as Mass Deception. Using Adorno & Horkheimer’s thesis as a theoretical guide, this research project formulates the concept of the digital culture industry - a concept that refers to the contemporary era of networked capitalism, an era defined by the unprecedented extraction, accumulation and manipulation of data and the material and digital infrastructures that facilitate it. This concept is used as a framing mechanism that articulates certain techno-political concerns within networked capitalism and responds to them through practice. The second concept formulated within this research project is Platform Protocol Place. The function of this second concept is to frame and outline the body of practice-based work developed in this study. It is also used to make complex technological issues accessible and to communicate these issues through public exhibition and within this written thesis. The final concept developed in this research project is tactical media archaeology. This concept describes the techniques and approaches employed in the development of the body of practice-based work that are the central focus of this research project. This approach is a synthesis of two subfields of media art practice and theory, tactical media and media archaeology. Through practice, tactical media archaeology critiques the geopolitical machinations and systems beneath the networked devices and interfaces of the digital culture industry

    Channel estimation and beam training with machine learning applications for millimetre-wave communication systems

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    The fifth generation (5G) wireless system will extend the capabilities of the fourth generation (4G) standards to serve more users and provide timely communication. To this end, the carriers of 5G systems will be able to operate at higher frequency bands, such as the millimetre-wave (mmWave) bands that span from 30 GHz to 300 GHz, to obtain greater bandwidths and higher data rates. As a result, the deployment of 5G networks is required to accommodate more antennas and offer pervasive coverage with controlled power consumption. The complexity of 5G systems introduces new challenges to traditional signal processing techniques. To address these challenges, a major step is to integrate machine learning (ML) algorithms into wireless communication systems. ML can learn patterns from datasets to achieve control and optimisation of complex radio frequency (RF) networks. This PhD thesis focuses on developing efficient channel estimation methods and beam training strategies with the application of ML algorithms for mmWave wireless systems. Firstly, the channel estimation and signal detection problem is investigated for orthogonal frequency-division multiplexing (OFDM) systems that operate at mmWave bands. A deep neural network (DNN)-based joint channel estimation and signal detection approach is proposed to achieve multi-user detection in a one-shot process for non-orthogonal multiple access (NOMA) systems. The DNN acts as the receiver, which can recover the transmitted data by learning the channel implicitly from suitable training. The proposed approach can be adapted to work for both single-input and single-output (SISO) systems and multiple-output and multipleoutput (MIMO) systems. This DNN-based approach is shown to provide good performance for OFDM systems that suffer from severe inter-symbol interference or where small numbers of pilot symbols are used. Secondly, the beam training and tracking problem is studied for mmWave channels with receiver mobility. To reduce the signalling overhead caused by frequent beam training, a lowcomplexity beam training strategy is proposed for mobile mmWave channels, which searches a set of selected beams obtained based on the recent beam search results. By searching only the adjacent beams to the one recently used, the proposed beam training strategy can reduce the beam training delay significantly while maintaining high transmission rates. The proposed strategy works effectively for channel datasets generated using either the stochastic or the raytracing channel model. This strategy is shown to approach the performance for an exhaustive beam search while saving up to 92% on the required beam training overhead. Thirdly, the proposed low-complexity beam training strategy is enhanced with the use of deep reinforcement learning (DRL) for mobile mmWave channels. A DRL-based beam training algorithm is proposed, which can intelligently switch between different beam training methods such that the average beam training overhead is minimised while achieving good spectral efficiency or energy efficiency performance. Given the desired performance requirement in the reward function for the DRL model, the spectral efficiency or energy efficiency can be maximised for the current channel condition by controlling the number of activated RF chains. The DRL-based approach can adjust the amount of beam training overhead required according to the dynamics of the environment. This approach can provide a good overhead-performance trade-off and achieve higher data rates in channels with significant levels of signal blockage

    Nonunion of the clavicle: novel use of clinical recovery and ultrasound to improve our ability to predict fracture healing

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    The aim of this thesis was to progress our understanding of clavicle nonunion and the ability to accurately predict fracture healing in order to improve the current management of these injuries. Although only one in seven fractures go onto nonunion, these are challenging to predict. It is unclear if the recent widespread increase in the use of acute plate fixation for displaced fractures is justified on current evidence. It is unknown whether the early accurate prediction of fractures at high risk of nonunion is advantageous. Currently the perceived risk of nonunion is largely based on factors available at time of injury alone. The evaluation of clinical recovery following non-operative management and the novel use of ultrasound may advance our ability to accurately predict fracture healing for these injuries. The cost-effectiveness of acute clavicle plate fixation versus non-operative treatment was estimated from randomized controlled trial data that had been previously published. This was completed prior to the start of this thesis and the author was not involved in the original trial. A large retrospective review of clavicle fracture fixations was undertaken to determine whether delayed clavicle fixation has an increased risk of complications compared to acute operative management. A prospective study of displaced midshaft fractures was carried out over a two-year period to determine the influence of functional recovery on the ability to predict fracture healing. The influence of clavicle fracture management on the early functional recovery was evaluated with data from a randomized controlled trial and second prospective cohort. Finally, the novel use of ultrasound to detect early callus formation and determine whether this allows accurate prediction of fracture healing was evaluated for a cohort of clavicle and tibia fractures. The estimated cost per quality-of-life adjusted year of acute plate fixation over non-operative treatment is £480,309.41/QALY. For a threshold of £20,000/QALY the benefit of acute fixation would need to be present for 24 years to be cost-effective over conservative treatment. Linear regression analysis identified nonunion as the only factor to negatively influence the SF-6D at 12-months (p<0.001). A ten-year cohort of 259 clavicle plate fixations found failed primary surgery requiring revision fixation occurred in 7.7% of all patients. Smoking (p<0.001), presence of a post-operative infection (<0.001), increasing age (p=0.018), and greater time delay from injury to surgery (p=0.015) was identified as significant independent predictors on regression analysis. Receiver operating curve analysis (ROC) revealed that surgery beyond 96 days from injury has an increased rate of major complications and revision surgery. Using a matched case cohort of cases before (n=67) and after the ‘safe window’ (n=77), the risk of post-operative infection increased (Odds ratio (OR) 7.7, p=0.028), fixation failure (OR 3.8, p=0.017) and revision surgery (OR 4.8 p=0.004). A delay to operative fixation beyond 3 months following injury would appear to be associated with an increased risk of major operative complications and revision surgery. A large prospective cohort of 200 patients managed non-operatively with a displaced midshaft clavicle fracture were recruited. Regression modelling found a QuickDASH ≥40 (p=0.001), no callus on radiograph (p=0.004) and fracture movement on examination (p=0.001) were significant predictors of nonunion. If none were present the predicted nonunion risk was 3%, found in 40% of the cohort. Conversely if two or more of the predictors were present, found in 23.5% of the cohort, the predicted nonunion risk was 60%. The delayed assessment nonunion model appeared to have superior accuracy when compared to the estimation of nonunion at time of injury alone healing on ROC curve analysis (Area Under Curve analysis; 87.3% vs 64.8% respectively). Data from a randomized controlled trial was used to compare 86 patients who underwent operative fixation against 76 patients that united with non-operative treatment. The recovery of normal shoulder function, as defined by a DASH score within the predicted 95% confidence interval for each respective patient was similar between each group at six-weeks (operative 26.7% vs non-operative 25.0%, p=0.80), three-months (52.3% vs 44.2%, p=0.77) and six-months post-injury (86.0% vs 90.8%, p=0.35). The mean DASH score and return to work was also comparable at each time point. Regression analysis found no specific patient, injury or fracture predictor was associated with an early return of function following non-operative management at six or twelve weeks. From a pilot study of twenty clavicle fractures, six-week sonographic bridging callus appeared to be the most accurate, and repeatable, predictor of fracture healing with a strong agreement on intra class correlation (ICC) between four reviewers (ICC 0.82, 95% confidence interval 0.68-0.91). In a large prospective study of 112 patients, sonographic bridging callus was detected in 62.5% (n=70/112) of the cohort at six weeks post-injury. If present, union occurred in 98.6% of the fractures (n=69/70). If absent, nonunion developed in 40.5% of cases (n=17/42). The sensitivity to predict union with sonographic bridging callus at six weeks was 73.4% and the specificity was 94.4%. Three-dimensional fracture reconstruction can be created using multiple ultrasound images in order to evaluate the presence of bridging callus. This imaging modality has the potential to enhance the usability and accuracy of identification of fracture healing at an early stage following injury. Nonunion following a displaced midshaft clavicle fractures accounts for the majority of poor functional recovery and impaired quality of life over the first-year post-injury. Prediction of clavicle fracture healing at six weeks following injury maybe a safe and effective strategy to identify patients at greatest risk of nonunion. The use of functional recovery enables a more accurate estimation of nonunion risk compared to conventional prediction at time of injury alone. The use of ultrasound may further refine our ability to predict fracture healing
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