77 research outputs found

    A Formal Approach to Cyber-Physical Attacks

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    We apply formal methods to lay and streamline theoretical foundations to reason about Cyber-Physical Systems (CPSs) and cyber-physical attacks. We focus on %a formal treatment of both integrity and DoS attacks to sensors and actuators of CPSs, and on the timing aspects of these attacks. Our contributions are threefold: (1) we define a hybrid process calculus to model both CPSs and cyber-physical attacks; (2) we define a threat model of cyber-physical attacks and provide the means to assess attack tolerance/vulnerability with respect to a given attack; (3) we formalise how to estimate the impact of a successful attack on a CPS and investigate possible quantifications of the success chances of an attack. We illustrate definitions and results by means of a non-trivial engineering application

    Rural electrification in central america and east africa, two case studies of sustainable microgrids

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    This paper deals with the electrification of rural villages in developing countries using Sustainable Energy Systems. The rural electrification feasibility study is done using Hybrid Optimization Model for Electric Renewable PRO (HOMER PRO). The HOMER PRO energy modelling software is an optimization software improved by U.S. National Renewable Energy Laboratory. It helps in designing, comparing and optimizing the design of power generation technologies. In this paper, two rural electrification case studies are modelled and analysed using HOMER PRO. Technical and economic evaluation criteria are applied to study the feasibility of a micro-hydro plant in El DĂ­ptamo (Honduras), and a hybrid plant composed of photovoltaic module arrays, Diesel generators, and flow batteries, in a small island on Victoria Lake. For both cases, we show the results of the studies of the daily and yearly loads, of the resources available in the area and the economic evaluation of the chosen plants configuration

    Energy Production Analysis and Optimization of Mini-Grid in Remote Areas: The Case Study of Habaswein, Kenya

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    Rural electrification in remote areas of developing countries has several challenges which hinder energy access to the population. For instance, the extension of the national grid to provide electricity in these areas is largely not viable. The Kenyan Government has put a target to achieve universal energy access by the year 2020. To realize this objective, the focus of the program is being shifted to establishing off-grid power stations in rural areas. Among rural areas to be electrified is Habaswein, which is a settlement in Kenya’s northeastern region without connection to the national power grid, and where Kenya Power installed a stand-alone hybrid mini-grid. Based on field observations, power generation data analysis, evaluation of the potential energy resources and simulations, this research intends to evaluate the performance of the Habaswein mini-grid and optimize the existing hybrid generation system to enhance its reliability and reduce the operation costs. The result will be a suggestion of how Kenyan rural areas could be sustainably electrified by using renewable energy based off-grid power stations. It will contribute to bridge the current research gap in this area, and it will be a vital tool to researchers, implementers and the policy makers in energy sector

    Compensation Committee Quality and Effective Executive Remuneration

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    Grounding in the agency theory, this paper questions whether high quality compensation committee influences the design of executive remuneration towards the alignment of the contrasting interests between managers and shareholders. Relying on a comprehensive approach that captures the compensation committee quality based on different attributes (i.e. independence, interlocking directorates, directors appointed by minorities) we conduct a two-step empirical analysis. First, we illustrate the evolution over time of the stock option plan characteristics and construct an illustrative diagram that shows the linkages between the attributes of the compensation committee quality and the elements of the option plans. Second, we run a probit regression analysis to deeply investigate the picture emerging from the diagram. Our results document that the quality of compensation committee significantly affects the assignment of incentive stock option plans. The paper evidence advances the knowledge in the literature on compensation committee and executive remuneration, by highlighting that structural characteristics of the committee other than independence of its members play a pivotal role in writing effective remuneration contracts for the executives. Our findings are also useful for investors and policymakers

    Rural Electrification in Central America and East Africa, two case studies of sustainable microgrids

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    This paper deals with the electrification of rural villages in developing countries using Sustainable Energy Systems. The rural electrification feasibility study is done using Hybrid Optimization Model for Electric Renewable PRO (HOMER PRO). The HOMER PRO energy modelling software is an optimization software improved by U.S. National Renewable Energy Laboratory. It helps in designing, comparing and optimizing the design of power generation technologies. In this paper, two rural electrification case studies are modelled and analysed using HOMER PRO. Technical and economic evaluation criteria are applied to study the feasibility of a micro-hydro plant in El DĂ­ptamo (Honduras), and a hybrid plant composed of photovoltaic module arrays, Diesel generators, and flow batteries, in a small island on Victoria Lake. For both cases, we show the results of the studies of the daily and yearly loads, of the resources available in the area and the economic evaluation of the chosen plants configuration

    Formal Verification of Security Protocol Implementations: A Survey

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    Automated formal verification of security protocols has been mostly focused on analyzing high-level abstract models which, however, are significantly different from real protocol implementations written in programming languages. Recently, some researchers have started investigating techniques that bring automated formal proofs closer to real implementations. This paper surveys these attempts, focusing on approaches that target the application code that implements protocol logic, rather than the libraries that implement cryptography. According to these approaches, libraries are assumed to correctly implement some models. The aim is to derive formal proofs that, under this assumption, give assurance about the application code that implements the protocol logic. The two main approaches of model extraction and code generation are presented, along with the main techniques adopted for each approac

    Results and complications of bilateral limb lengthening in achondroplasia: a retrospective analysis

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    BackgroundAchondroplasia is one of the main causes of disharmonic dwarfism. Patients with achondroplasia might have physical and psychological limitations due to their disproportionate stature. Surgical limb lengthening is the only practical option available to achieve a stature comparable to normal population range. The purpose of this study is to analyze results and complications of our lengthening protocol.MethodsA retrospective analysis was performed on 33 patients with achondroplasia (21 females and 12 males) undergoing simultaneous bilateral tibia or femur lengthening in four surgical stages from 2017 to 2021 (46 lengthening procedures, with a total of 56 tibias and 36 femurs). For each patient, patients’ characteristics and antero-posterior and lateral radiographs were obtained. The following parameters were analyzed: duration of lengthening with external fixator, amount of lengthening, complications or events that influenced outcomes and the healing index (HI).ResultsThe average tibial and femoral gain was 7.9 cm and 6.9 cm, respectively. The tibiae achieved better results than the femurs (p = 0.005). Nineteen complications were reported for 92 segments (20.7%), and the variables influencing complications were: step (p = 0.002) and fixation duration (p = 0.061).ConclusionsBilateral parallel lower limb lengthening in four surgical steps may be a viable technique in patients with achondroplasia

    Professionals’ digital training for child maltreatment prevention in the COVID-19 era : a pan-European model

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    Funding: This study is part of the ERICA project funded by the European Union’s Rights, Equality and Citizenship Programme (2014–2020). GA 856760.The responsiveness of professionals working with children and families is of key importance for child maltreatment early identification. However, this might be undermined when multifaceted circumstances, such as the COVID-19 pandemic, reduce interdisciplinary educational activities. Thanks to technological developments, digital platforms seem promising in dealing with 30 new challenges for professionals’ trainings. We examined a digital approach to child maltreatment training through the ERICA project experience (Stopping Child Maltreatment through Pan-European Multiprofessional Training Programme). ERICA has been piloted during the pandemic in seven European centers involving interconnected sectors of professionals working with children and families. The training consisted of interactive modules embedded in a digital learning frame-work. Different aspects (i.e., technology, interaction, and organization) were evaluated and trainers’ feedback on digital features was sought. Technical issues were the main barrier. However, these did not significantly disrupt the training. The trainers perceived reduced interaction between participants although distinct factors were uncovered as potential favorable mediators. Based on participants’ subjective experiences and perspectives, digital learning frameworks for professionals working with children and families, like the ERICA model nested in its indispensable adaptation to an e-learning mode, can represent a novel interactive approach to empower trainers and trainees to tackle child maltreatment during critical times like a pandemic and as an alternative to more traditional learning frameworks.Publisher PDFPeer reviewe
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