14,554 research outputs found
Sistema de bloqueio de computadores
Mestrado em Engenharia de Computadores e TelemáticaThe use of multiple computing devices per person is increasing more and more. Nowadays is normal that mobile devices like smartphones, tablets and laptops are present in the everyday life of a single person and in many cases people use these devices to perform important operations related with their professional life. This also presents a problem, as these devices come with the user in everyday life and the fact that often they have a high monetary value means that these devices are susceptible to theft. This thesis introduces a computer locking system that distinguishes itself from existing similar systems because (i) it is designed to work independently of the Operating System(s) installed on the laptop or mobile device, (ii) depends on a firrmware driver that implements the lock operation making it resistant to storage device formats or any other attack that uses software operations. It is also explored the operation of a device that has a firrmware that follows the Unified Extensible Firmware Interface (UEFI) specification as well as the development of drivers for this type of firrmware. It was also developed a security protocol and various cryptographic techniques where explored and implemented.O uso de vários dispositivos computacionais por pessoa está a aumentar cada vez mais. Hoje em dia Ă© normal dispositivos mĂłveis como o smartphone, tablet e computador portátil estarem presentes no quotidiano das pessoas e em muitos casos as pessoas necessitam de realizar tarefas na sua vida profissional nestes dispositivos. Isto apresenta tambĂ©m um problema, como estes dispositivos acompanham o utilizador no dia a dia e pelo facto de muitas vezes terem um valor monetário elevado faz com que estes dispositivos sejam suscetĂveis a roubos. Esta tese introduz um sistema de bloqueio de computadores que se distingue dos sistemas similares existentes porque, (i) _e desenhado para funcionar independentemente do(s) sistema(s) operativo(s) instalado(s) no computador portátil ou no dispositivo mĂłvel, (ii) depende de um driver do firrmware que concretiza a operação de bloqueio fazendo com que seja resistente contra formatação do dispositivo de armazenamento ou qualquer outro ataque que tenho por base a utilização de software. É explorado entĂŁo o funcionamento de um dispositivo que tenha um firmware que respeita a especificação Unfied Extensible Firmware Interface (UEFI) assim como a programação de drivers para este tipo de firmware. Foi tambĂ©m desenvolvido um protocolo
de segurança e são exploradas várias técnicas criptográficas passiveis de serem implementadas
The Viability and Potential Consequences of IoT-Based Ransomware
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
Technical Dimensions of Programming Systems
Programming requires much more than just writing code in a programming language. It is usually done in the context of a stateful environment, by interacting with a system through a graphical user interface. Yet, this wide space of possibilities lacks a common structure for navigation. Work on programming systems fails to form a coherent body of research, making it hard to improve on past work and advance the state of the art.
In computer science, much has been said and done to allow comparison of programming languages, yet no similar theory exists for programming systems; we believe that programming systems deserve a theory too.
We present a framework of technical dimensions which capture the underlying characteristics of programming systems and provide a means for conceptualizing and comparing them.
We identify technical dimensions by examining past influential programming systems and reviewing their design principles, technical capabilities, and styles of user interaction. Technical dimensions capture characteristics that may be studied, compared and advanced independently. This makes it possible to talk about programming systems in a way that can be shared and constructively debated rather than relying solely on personal impressions.
Our framework is derived using a qualitative analysis of past programming systems. We outline two concrete ways of using our framework. First, we show how it can analyze a recently developed novel programming system. Then, we use it to identify an interesting unexplored point in the design space of programming systems.
Much research effort focuses on building programming systems that are easier to use, accessible to non-experts, moldable and/or powerful, but such efforts are disconnected. They are informal, guided by the personal vision of their authors and thus are only evaluable and comparable on the basis of individual experience using them. By providing foundations for more systematic research, we can help programming systems researchers to stand, at last, on the shoulders of giants
Cooking the wild: the role of the Lundayeh of the Ulu Padas, (Sabah, Malaysia) in managing forest foods and shaping the landscape
This thesis provides an account of the Lundayeh subsistence system as found in the villages of Long Pasia and Long Mio, situated in the Ulu Padas, Sabah. The research focuses on Lundayeh food and diet, describing the diversity of resources used and the importance of forest foods. Comparison with studies from elsewhere in Borneo suggests that there are many similarities between Lundayeh practices and those of other highland peoples. These data are used to critically examine the concepts of 'wild' and 'wilderness', considering whether these concepts are meaningful, either analytically or for the Lundayeh. Investigation of the way in which the Lundayeh manipulate and manage their resources suggests that they have had a profound influence on their environment. Consequently, the Ulu Padas cannot be described as a wilderness, nor its resources as wild. The extent to which the Lundayeh themselves construct the categories of 'wild' and 'cultivated' foods is investigated through examining how these resources are owned, and their different roles in the diet. These data suggest that the Lundayeh recognise that there is no simple dichotomy of 'wild' and 'cultivated', but rather, that there is a gradation between these two categories. There is also evidence to suggest that the Lundayeh do not consider any resources as wild, in the sense of being uninfluenced by people. The environmental perceptions of the Lundayeh are also investigated, and how these have been shaped by their particular way of life, history, beliefs and knowledge systems. It is apparent that for the Lundayeh, the Ulu Padas is a cultural landscape. However, this is changing, as a result of recent social and environmental changes. This thesis concludes by examining the impact of changing perceptions on how the Lundayeh are managing their environment, and on their attitudes towards conservation
A productive response to legacy system petrification
Requirements change. The requirements of a legacy information system change, often in unanticipated ways, and at a more rapid pace than the rate at which the information system itself can be evolved to support them. The capabilities of a legacy system progressively fall further and further behind their evolving requirements, in a degrading process termed petrification. As systems petrify, they deliver diminishing business value, hamper business effectiveness, and drain organisational resources. To address legacy systems, the first challenge is to understand how to shed their resistance to tracking requirements change. The second challenge is to ensure that a newly adaptable system never again petrifies into a change resistant legacy system. This thesis addresses both challenges. The approach outlined herein is underpinned by an agile migration process - termed Productive Migration - that homes in upon the specific causes of petrification within each particular legacy system and provides guidance upon how to address them. That guidance comes in part from a personalised catalogue of petrifying patterns, which capture recurring themes underlying petrification. These steer us to the problems actually present in a given legacy system, and lead us to suitable antidote productive patterns via which we can deal with those problems one by one. To prevent newly adaptable systems from again degrading into legacy systems, we appeal to a follow-on process, termed Productive Evolution, which embraces and keeps pace with change rather than resisting and falling behind it. Productive Evolution teaches us to be vigilant against signs of system petrification and helps us to nip them in the bud. The aim is to nurture systems that remain supportive of the business, that are adaptable in step with ongoing requirements change, and that continue to retain their value as significant business assets
AIUCD 2022 - Proceedings
L’undicesima edizione del Convegno Nazionale dell’AIUCD-Associazione di Informatica Umanistica ha per titolo Culture digitali. Intersezioni: filosofia, arti, media. Nel titolo è presente, in maniera esplicita, la richiesta di una riflessione, metodologica e teorica, sull’interrelazione tra tecnologie digitali, scienze dell’informazione, discipline filosofiche, mondo delle arti e cultural studies
Retrieval, analysis and visualization of data from social media
[Abstract] This work is concerned with the development of an application that automates the identification,
tracking, storage and visualization of social media contents, particularly of Twitter
data. It is guided by the requirements of a client requesting such contents with regard to
Vespa velutina, an invasive wasp species that is known to cause death due to severe allergic
reactions.[Resumo] Este traballo trata sobre o desenvolvemento dunha aplicaciĂłn que automatiza a identificaciĂłn,
seguimento, almacenamiento e visualizaciĂłn de contidos de redes sociais, concretamente
de Twitter. Está guiado polos requirimentos dun cliente que precisa contidos sobre a Vespa
velutina, unha especie invasora de avespa que pode causar a morte por reaccións alérxicas
severas.Traballo fin de grao. EnxeñarĂa Informática. Curso 2021/202
Consolidation of Urban Freight Transport – Models and Algorithms
Urban freight transport is an indispensable component of economic and social life in cities. Compared to other types of transport, however, it contributes disproportionately to the negative impacts of traffic. As a result, urban freight transport is closely linked to social, environmental, and economic challenges. Managing urban freight transport and addressing these issues poses challenges not only for local city administrations but also for companies, such as logistics service providers (LSPs). Numerous policy measures and company-driven initiatives exist in the area of urban freight transport to overcome these challenges. One central approach is the consolidation of urban freight transport. This dissertation focuses on urban consolidation centers (UCCs) which are a widely studied and applied measure in urban freight transport. The fundamental idea of UCCs is to consolidate freight transport across companies in logistics facilities close to an urban area in order to increase the efficiency of vehicles delivering goods within the urban area. Although the concept has been researched and tested for several decades and it was shown that it can reduce the negative externalities of freight transport in cities, in practice many UCCs struggle with a lack of business participation and financial difficulties. This dissertation is primarily focused on the costs and savings associated with the use of UCCs from the perspective of LSPs. The cost-effectiveness of UCC use, which is also referred to as cost attractiveness, can be seen as a crucial condition for LSPs to be interested in using UCC systems. The overall objective of this dissertation is two-fold. First, it aims to develop models to provide decision support for evaluating the cost-effectiveness of using UCCs. Second, it aims to analyze the impacts of urban freight transport regulations and operational characteristics on the cost attractiveness of using UCCs from the perspective of LSPs. In this context, a distinction is made between UCCs that are jointly operated by a group of LSPs and UCCs that are operated by third parties who offer their urban transport service for a fee. The main body of this dissertation is based on three research papers. The first paper focuses on jointly-operated UCCs that are operated by a group of cooperating LSPs. It presents a simulation model to analyze the financial impacts on LSPs participating in such a scheme. In doing so, a particular focus is placed on urban freight transport regulations. A case study is used to analyze the operation of a jointly-operated UCC for scenarios involving three freight transport regulations. The second and third papers take on a different perspective on UCCs by focusing on third-party operated UCCs. In contrast to the first paper, the second and third papers present an evaluation approach in which the decision to use UCCs is integrated with the vehicle route planning of LSPs. In addition to addressing the basic version of this integrated routing problem, known as the vehicle routing problem with transshipment facilities (VRPTF), the second paper presents problem extensions that incorporate time windows, fleet size and mix decisions, and refined objective functions. To heuristically solve the basic problem and the new problem variants, an adaptive large neighborhood search (ALNS) heuristic with embedded local search heuristic and set partitioning problem (SPP) is presented. Furthermore, various factors influencing the cost attractiveness of UCCs, including time windows and usage fees, are analyzed using a real-world case study. The third paper extends the work of the second paper and incorporates daily and entrance-based city toll schemes and enables multi-trip routing. A mixed-integer linear programming (MILP) formulation of the resulting problem is proposed, as well as an ALNS solution heuristic. Moreover, a real-world case study with three European cities is used to analyze the impact of the two city toll systems in different operational contexts
Chinese Benteng Women’s Participation in Local Development Affairs in Indonesia: Appropriate means for struggle and a pathway to claim citizen’ right?
It had been more than two decades passing by aftermath the devastating Asia’s Financial Crisis in 1997, subsequently followed by Suharto’s step down from his presidential throne which he occupied for more than three decades. The financial turmoil turned to a political disaster furthermore has led to massive looting that severely impacted Indonesians of Chinese descendant, including unresolved mystery of the most atrocious sexual violation against women and covert killings of students and democracy activists in this country. Since then, precisely aftermath May 1998, which publicly known as “Reformasi”1, Indonesia underwent political reform that eventually corresponded positively to its macroeconomic growth. Twenty years later, in 2018, Indonesia captured worldwide attention because it has successfully hosted two internationally renowned events, namely the Asian Games 2018 – the most prestigious sport events in Asia – conducted in Jakarta and Palembang; and the IMF/World Bank Annual Meeting 2018 in Bali. Particularly in the IMF/World Bank Annual Meeting, this event has significantly elevated Indonesia’s credibility and international prestige in the global economic powerplay as one of the nations with promising growth and openness. However, the narrative about poverty and inequality, including increasing racial tension, religious conservatism, and sexual violation against women are superseded by friendly climate for foreign investment and eventually excessive glorification of the nation’s economic growth. By portraying the image of promising new economic power, as rhetorically promised by President Joko Widodo during his presidential terms, Indonesia has swept the growing inequality in this highly stratified society that historically compounded with religious and racial tension under the carpet of digital economy.Arte y Humanidade
Graphical scaffolding for the learning of data wrangling APIs
In order for students across the sciences to avail themselves of modern data streams, they must first know how to wrangle data: how to reshape ill-organised, tabular data into another format, and how to do this programmatically, in languages such as Python and R. Despite the cross-departmental demand and the ubiquity of data wrangling in analytical workflows, the research on how to optimise the instruction of it has been minimal. Although data wrangling as a programming domain presents distinctive challenges - characterised by on-the-fly syntax lookup and code example integration - it also presents opportunities. One such opportunity is how tabular data structures are easily visualised. To leverage the inherent visualisability of data wrangling, this dissertation evaluates three types of graphics that could be employed as scaffolding for novices: subgoal graphics, thumbnail graphics, and parameter graphics. Using a specially built e-learning platform, this dissertation documents a multi-institutional, randomised, and controlled experiment that investigates the pedagogical effects of these. Our results indicate that the graphics are well-received, that subgoal graphics boost the completion rate, and that thumbnail graphics improve navigability within a command menu. We also obtained several non-significant results, and indications that parameter graphics are counter-productive. We will discuss these findings in the context of general scaffolding dilemmas, and how they fit into a wider research programme on data wrangling instruction
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