Functional failure sequences in traffic accidents

This thesis examines the interactions between road users and the factors that contribute to the occurrence of traffic accidents, and discusses the implications of these interactions with regards to driver behaviour and accident prevention measures. Traffic accident data is collected on a macroscopic level by local police authorities throughout the UK. This data provides a description of accident related factors on a macroscopic level which does not allow for a complete understanding of the interaction between the various road users or the influence of errors made by active road users. Traffic accident data collected on a microscopic level analysis of real world accident data, explaining why and how an accident occurred, can further contribute to a data driven approach to provide safety measures. This data allows for a better understanding of the interaction of factors for all road users within an accident that is not possible with other data collection methods. In the first part of the thesis, a literature review presents relevant research in traffic accident analysis and accident causation research, afterwards three accident causation models used to understand behaviour and factors leading to traffic accidents are introduced. A comparison study of these accident causation coding models that classify road user error was carried out to determine a model that would be best suited to code the accident data according to the thesis aims. Latent class cluster analyses were made of two separate datasets, the UK On the Spot (OTS) in-depth accident investigation study and the STATS19 national accident database. A comparison between microscopic (in-depth) accident data and macroscopic (national) accident data was carried out. This analysis allowed for the interactions between all relevant factors for the road users involved in the accident to be grouped into specific accident segmentations based on the cluster analysis results. First, all of the cases that were collected by the OTS team between the years 2000 to 2003 were analysed. Results suggested that for single vehicle accidents males and females typically made failures related to detection and execution issues, whereas male road users made diagnosis failures with speed as a particularly important factor. In terms of the multiple vehicle accidents the interactions between the first two road users and the subsequent accident sequence were demonstrated. A cluster analysis of all two vehicle accidents in Great Britain in the year 2005 and recorded within the STATS19 accident database was carried out as a comparison to the multiple vehicle accident OTS data. This analysis demonstrated the necessity of in-depth accident causation data in interpreting accident scenarios, as the resulting accident clusters did not provide significant differences between the groups to usefully segment the crash population. Relevant human factors were not coded for these cases and the level of detail in the accident cases did not allow for a discussion of countermeasure implications. An analysis of 428 Powered Two Wheeler accidents that were collected by the OTS team between the years 2000 to 2010 was carried out. Results identified 7 specific scenarios, the main types of which identified two particular looked but did not see accidents and two types of single vehicle PTW accidents. In cases where the PTW lost control, diagnosis failures were more common, for road users other than the PTW rider, detection issues were of particular relevance. In these cases the interaction between all relevant road users was interpreted in relation to one another. The subsequent study analysed 248 Pedestrian accidents that were collected by the OTS team between the years 2000 to 2010. Results identified scenarios related to pedestrians as being in a hurry and making detection errors, impairment due to alcohol, and young children playing in the roadside. For accidents that were initiated by the other road user s behaviour pedestrians were either struck after an accident had already occurred or due to the manoeuvre that a road user was making, older pedestrians were over-represented in this accident type. This thesis concludes by discussing how (1) microscopic in-depth accident data is needed to understand accident mechanisms, (2) a data mining approach using latent class clustering can benefit the understanding of failure mechanisms, (3) accident causation analysis is necessary to understand the types of failures that road users make and (4) accident scenario development helps quantify accidents and allows for accident countermeasure implication discussion. The original contribution to knowledge is the demonstration that when relevant data is available there is a possibility to understand the interactions that are occurring between road users before the crash, that is not possible otherwise. This contribution has been demonstrated by highlighting how latent class cluster analysis combined with accident causation data allows for relevant interactions between road users to be observed. Finally implications for this work and future considerations are outlined

Desertification indicators for the European Mediterranean region: state of the art and possible methodological approaches [= Indicatori di desertificazione per il Mediterraneo europeo: stato dell'arte e proposte di metodo]

The Italian Environment Protection Agency (ANPA), and the Desertification Research Centre at the University of Sassary have worked jointly to provide decision-makers with an in-depth analysis of the state of the art and methodologies applicable to the evaluation of the desertification phenomenon. ANPA has promoted this important research activity, within the wider and more dynamic framework of actions it conducts in the Italian National Committee, providing its support to the definition and start up of the National Plan to Combat Desertification and Drought. The complexity of the phenomena and their causes leads to the individuation of a plurality of “actors” who might take the responsibility to carry out actions aimed at combating Desertification and Drought. Indicators represent a crucial link in the chain that, from knowledge, leads to taking decisions and promoting responsible behaviours: starting from an evaluation of the various, physical, biologic, socio-economic processes that contribute to land degradation and desertification, the goal is to individuate indicators that might prove useful in territorial planning and public information activities, and that might be a suitable answer to the request for direct knowledge of the status and evolution of the phenomenon, as well as the opportunity to take actions aimed at mitigating and, above all, preventing the occurrence of the phenomenon

OEE improvement in a nutraceutical stick-pack packaging line

During the course of this project, the A3 methodology has been rigorously followed in order to improve the original situation, in addition with the different lean tools and principles that have defined the theoretical framework of the project. Thus, the initial scenario has been defined and quantified, and the relevance of the project for the company has been evaluated. It has been observed that one of the biggest areas for improvement, due to its high impact on OEE, was the batch change, so the project has focused on them. Subsequently, some goals have been established to be reached with the improvement project, in order to be able to benchmark the results obtained. Once it was clear, using techniques such as the "5-Why's" and the Ishikawa diagram, a selection of possible causes that affected the problem was successfully identified. To mitigate or eliminate these causes, countermeasures have been developed. These countermeasures have been implemented following a defined roadmap and the results from the final scenario have been monitored. Thanks to the implemented countermeasures, a very positive outcome has been obtained, reducing the batch change time from 72 minutes to 58 minutes, exceeding the nice-to-have target, and the SKU change time from 46,4 minutes to 41,8 minutes, reaching the must-have target. In order to maintain this improvement and to prevent it from reverting to the original situation, some control charts have been designed to identify any out-of-control observation, analyse it, and detect the possible causes. To continue striving for the best, some future development countermeasures have been designed and presented, ready to be implemented in the future by the company

Fault Detection for Cyber-Physical Systems: Smart Grid case

The problem of fault detection and isolation in cyber-physical systems is growing in importance following the trend to have an ubiquitous presence of sensors and actuators with network capabilities in power networks and other areas. In this context, attacks to power systems or other vital components providing basic needs might either present a serious threat or at least cost a lot of resources. In this paper, we tackle the problem of having an intruder corrupting a smart grid in two different scenarios: a centralized detector for a portion of the network and a fully distributed solution that only has limited neighbor information. For both cases, differences in strategies using Set-Valued Observers are discussed and theoretical results regarding a bound on the maximum magnitude of the attacker’s signal are provided. Performance is assessed through simulation, illustrating, in particular, the detection time for various types of faults in IEEE testbed scenarios

ICT aspects of power systems and their security

This report provides a deep description of four complex Attack Scenarios that have as final goal to produce damage to the Electric Power Transmission System. The details about protocols used, vulnerabilities, devices etc. have been for obvious reasons hidden, and the ones presented have to be understood as mere (even if realistic) simplified versions of possible power systems.JRC.DG.G.6-Security technology assessmen

Machine Learning for Software Engineering: A Tertiary Study

Machine learning (ML) techniques increase the effectiveness of software engineering (SE) lifecycle activities. We systematically collected, quality-assessed, summarized, and categorized 83 reviews in ML for SE published between 2009-2022, covering 6,117 primary studies. The SE areas most tackled with ML are software quality and testing, while human-centered areas appear more challenging for ML. We propose a number of ML for SE research challenges and actions including: conducting further empirical validation and industrial studies on ML; reconsidering deficient SE methods; documenting and automating data collection and pipeline processes; reexamining how industrial practitioners distribute their proprietary data; and implementing incremental ML approaches.Comment: 37 pages, 6 figures, 7 tables, journal articl

Modeling Attacks in IoT to Assist the Engineering Process

The Internet of Things is the broad name given to technologies that allow for any devices (known in this context as things) to communicate with each other as well as machines, applications, databases, among others in a seamless manner. This allows for devices in an environment such as in a home, a factory or a hospital, to interact with each other and even to autonomously perform actions based on the information they receive. This integration of technology in regular, everyday devices allows for the people that interact or otherwise are affected by them to have a finer degree of control over what is happening around them, allowing for this technology to improve other existing ones by improving their usefulness and efficiency. As a simple example, in the context of a smart home, a user can be able to manually command actions or to set conditions that trigger said actions according to his preferences. This means that things such as controlling room temperature and lighting, opening doors, ordering something when it runs out or turning appliances on, can be automatically performed when the conditions approved by the user are met. In medicine for example, Internet of Things (IoT) systems allow for the creation of more effective patient monitoring and diagnostic systems as well as resource management in general, as patients could potentially carry sensors that allow for constant monitoring thus assisting in diagnostics and in emergency situations. This last example raises an obvious and very important issue with this type of technologies, which is security. If IoT systems are not properly secured, a malicious actor could potentially access or modify private patient or hospital data as well as disable or tamper with the sensors, among other malicious scenarios that could potentially result in harm to equipment or even human lives. Given the speed at which this technology is evolving and new systems are being created and implemented, security is often seen as an afterthought, which results in insufficient or poorly implemented security measures allowing for attackers to easily disrupt the functioning or even to steal sensitive data from the system. Therefore, it is critical to perform an adequate security analysis right from the start of the system design process. By understanding the security requirements relevant to a system, it is possible to implement adequate security measures that prevent attacks or other malicious actions from occurring, thus safeguarding data and allowing for the system to perform as originally intended. The goal of this dissertation is to explore the principles behind system and threat modeling to be able to develop a prototype tool to assist users - even those with limited security knowledge - in the identification of security requirements, threats and good practices. Hopefully, this prototype should prove to be able to assist developers better define security requirements early in the system design stage, as well as including the correct defensive measures in the development stages. This prototype was developed in the context of the S E C U R I o T E S I G N project, as it integrates two other tools created in its context to assist in the identification of the requirements from information provided by the user. This dissertation produced a web application capable of handling the user inputs containing relevant system requirement and recommendations information, and then processing them in order to extrapolate the relevant system and threat modeling information. The validation process for this prototype consisted of comparing a manual system and threat analysis created by an expert, with the results obtained by volunteers using the prototype application, and verifying how correct is the analysis by the tool. The results were satisfying and the proposed objectives were successfully achieved.A Internet das Coisas (Internet of Things, do inglês e abreviado para IoT), é o nome dado às tecnologias que permitem que qualquer dispositivo (que neste contexto é apelidado de coisa) comunique com outro, tal como com máquinas, aplicações, bases de dados, entre outras tecnologias, de maneira direta. Isto permite que dispositivos num dado ambiente interajam uns com os outros e que sejam inclusivamente capazes de tomar decisões de forma autónoma com base nos dados que recebem. Esta integração de novas tecnologias em dispositivos do dia a dia permite que os utilizadores tenham um controlo mais refinado sobre o que cada aparelho é capaz de fazer, aumentando assim a utilidade e eficiência dos mesmos. Alguns exemplos da aplicabilidade deste controlo adicional podem ser observados em casas inteligentes, na qual os utilizadores conseguem controlar remotamente os equipamentos da sua casa, ou até definir o seu controlo de forma automática com base em certos parâmetros determinados pelos equipamentos. Isto significa que tarefas como controlo de temperatura, luminosidade, abertura/fecho de portas, ligar ou desligar eletrodomésticos, ou até mesmo encomendar automaticamente um produto quando este termina podem todas ser efetuadas de maneira automática, quando as condições certas são verificadas. Outro exemplo poderia ser no ramo da Medicina, na qual sistemas baseados na IoT podem permitir a criação de sistemas mais eficientes de monitorização e diagnóstico de pacientes, o que acaba por acarretar benefícios a nível da gestão de recursos hospitalares, visto que os pacientes poderiam simplesmente possuir consigo sensores que faziam a sua monitorização permanente, assistindo nos processos de diagnóstico e em casos de emergência. Contudo, este último exemplo chama à atenção para o problema óbvio e muito importante com estas tecnologias, que é a segurança (ou a falta dela). Casos os sistemas de IoT não cumpram com as medidas de segurança mais adequadas, um atacante poderia potencialmente aceder ou modificar dados dos pacientes, do hospital, ou até mesmo fazer modificações no próprio equipamento. Isto seriam violações gravíssimas da segurança do sistema, que poderiam mesmo provocar prejuízos ao nível de bens materiais ou em casos extremos, de vidas humanas. Dada a velocidade com que estas tecnologias estão a evoluir, e à qual novos sistemas estão a ser desenvolvidos e implementados, a segurança dos sistemas costuma ser algo esquecida a acaba por ser dos últimos aspetos a ser considerado aquando do design dos mesmos. Isto resulta em insuficiências e falhas ao nível de segurança, o que acaba por permitir que atacantes consigam provocar alterações no funcionamento normal ou até mesmo roubar dados do sistema. É extremamente importante efetuar um bom levantamento dos requisitos de segurança que o sistema deve implementar logo desde as fases iniciais de design e planificação da arquitetura. Só quando se compreende na integra os requisitos de segurança é que é possível planear e implementar as medidas de segurança adequadas para o sistema a ser desenhado. O objetivo principal desta dissertação é explorar os princípios por detrás da modelação dos sistemas e das ameaças. Desta forma pretende-se desenvolver um protótipo de uma ferramenta capaz de assistir os utilizadores - mesmo aqueles com conhecimentos limitados na área de segurança - na identificação de requisitos de segurança e ameaças ao sistema, assim como fornecer informação pertinente para colmatar estes aspetos. Esta ferramenta deverá ser capaz de auxiliar os developers, designers e engenheiros de software com os processos de definição de requisitos e medidas de segurança preventivas, desde as etapas iniciais da planificação dos sistemas. Este protótipo foi desenvolvido no contexto do projeto S E C U R I o T E S I G N , o mesmo integra duas outras ferramentas que auxiliam na identificação de requisitos a partir de informações fornecidas pelo utilizador e que vão ser vir de inputs do protótipo aqui desenvolvido. Esta dissertação produziu uma aplicação web capaz de receber os inputs do utilizador contendo a informação com os requisitos e recomendações do sistema e a partir do seu processamento é possível obter a modelação de sistema e de ameaças. O processo de validação do protótipo aqui desenvolvido consistiu em comparar uma análise de modelação de sistema e ameaças produzidas manualmente por um perito, com as análises obtidas por voluntários através do protótipo desta aplicação web, e verificar o quão correta é a análise produzida pelo protótipo. De forma geral os resultados foram satisfatórios, tendo o protótipo sido capaz de alcançar uma análise bastante correta face à produzida pelo perito. Desta forma pode-se concluir que os objetivos desta dissertação foram alcançados com sucesso