10,694 research outputs found

    Helicopter Main Gearbox Planetary Bearing Fault Diagnosis using Vibration Signal Processing Techniques

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    Helicopters are extensively employed as versatile assets for military, transportation, rescue and many other utilities. A healthy and functional Helicopter Main Gearbox (MGB) is critical to ascertain the helicopter’s system reliability and flight airworthiness, i.e. the suitability for safe flight. Therefore, it is of great importance to monitor the health status of the MGB. Currently, Health and Usage Monitoring System (HUMS), has been deployed on all medium and large size civil helicopters to perform MGB health status monitoring in United Kingdom. Nevertheless, HUMS has shown insensitivities and a lack of accuracy to detect planetary bearings-related defects, resulting in unfortunate accidents. Therefore, the successful diagnosis of planetary bearing defects in MGB could contribute profoundly to enhance sensitivity of HUMS against such defect type, thus improving helicopter flight safety, and reducing the overall maintenance costs. This research aims at investigating the diagnosis of planetary bearing faults inside MGB using advanced signal processing techniques, providing diagnostic information that is more accurate and indicative against incipient planetary bearing faults. To fulfil the requirements, experimental work was undertaken on a commercial helicopter MGB to acquire invaluable vibration data. The MGB was operated under various load, speed and fault severities conditions. Diagnosis of the seeded planetary bearing faults was then successfully performed by evaluating and implementing various frequency domain processing techniques. Finally, further evaluation was conducted using another MGB dataset collected from a CH-46E Aft gearbox. The results of this study have shown that applying various frequency domain signal processing techniques can effectively detect incipient planetary bearing faults. The main contributions of this research include acquiring data from a full scale helicopter main gearbox, proposing and evaluating a non-deterministic weak signature analysis scheme for MGB planetary bearings fault detection, and demonstrating using MGB carrier induced sidebands as a novel spectral feature for planetary bearing diagnosis

    Mass Influx and the Dublin System: A Critical Assessment of the EU Response to the Syrian Refugee Crisis

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    The mass influx of asylum seekers in 2015 exposed the Common European Asylum System (CEAS), especially the application of Dublin III Regulation. CEAS was rendered ineffective in the face of large-scale movements of asylum seekers. The bulk of academic explanation available falls short in pointing out tangible mechanisms within the European Union (EU) asylum system on how mass influx of asylum seekers can be effectively managed. This scholarly vacuum runs the danger of leaving serious questions unanswered, especially on how future influxes can be adequately managed. The study therefore examines the Syrian refugees’ experiences with the application of CEAS at the peak of the refugee crisis of 2015. It points out the non-activation of Temporary Protection Directive (TPD) in the face of 2015 refugee crisis and how prima facie approach was not adopted in tackling the refugee crisis. It also acknowledges the growing influence of the far-right movement within the Union, with their antimigrant rhetoric, that can possibly influence the asylum policy formulation at Union and MS levels. It assesses the impact of a mass influx of asylum seekers on the EU frontline states and examines the ineffectiveness of the EU asylum system in the face of a mass influx of asylum seekers. It further assesses the unilateral and collective responses of the EU to the Syrian refugee crisis. The study adopts a qualitative method, and a phenomenological approach, with interview and document analysis as the data collection tools. The data analysis focuses on the interviews conducted with the Syrian refugees in the UK, France, Germany, and Austria as well as European Asylum Support Office (EASO) and Frontex officials. It also reviews relevant jurisprudence; examines the evaluation report on the Dublin III Regulation, reviews the proposed Dublin IV Regulation, and proffers solutions concerning how similar influxes can be effectively managed in future

    Social Networks as the New Frontier of Terrorism

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    Terrorism. Why does this word grab our attention so? Propaganda machines have adopted modern technology as a means to always have their content available. Regardless of the hour or time zone, information is being shared by somebody, somewhere. Social media is a game changer influencing the way in which terror groups are changing their tactics and also how their acts of terror are perceived by the members of the public they intend to influence. This book explores how social media adoption by terrorists interacts with privacy law, freedom of expression, data protection and surveillance legislation through an exploration of the fascinating primary resources themselves, covering everything from the Snowden Leaks, the rise of ISIS to Charlie Hebdo. The book also covers lesser worn paths such as the travel guide that proudly boasts that you can get Bounty and Twix bars mid-conflict, and the best local hair salons for jihadi brides. These vignettes, amongst the many others explored in this volume bring to life the legal, policy and ethical debates considered in this volume, representing an important part in the development of understanding terrorist narratives on social media, by framing the legislative debate. This book represents an invaluable guide for lawyers, government bodies, the defence services, academics, students and businesses

    Terror from behind the keyboard: conceptualising faceless detractors and guarantors of security in cyberspace

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    By reflecting on active public-domain government documents and statements, this article seeks to develop securitisation theory’s articulation of the dichotomy between legitimate and illegitimate violence as it is reflected in British government policy. This dichotomy has (re)developed through a process wherein GCHQ and MI5 are portrayed as ‘faceless guarantors’ of security, in Manichean juxtaposition to the discursively-created phantom cyberterrorists, who are presented as ‘faceless detractors’ of security. It has previously been stated that the terrorism discourse associated with the present ‘War on Terror’ is attributed, in part, to mechanics of fantasy. I argue that, within the securitised discourse of cyberterrorism, the limits of fantasy possesses a murky nuance, which in turn, allows for a deeper - or at least more entrenched - securitisation. The official discourse surrounding the intelligence services’ online surveillance apparatus operates with a similar opaque quality, but this is upheld by securitising actors as a strength to be maintained

    Placebo scrutiny? Far-right extremism and intelligence accountability in Germany

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    The post-9/11 era has seen a proliferation of special, or one-off parliamentary inquiries into intelligence. This article examines the question of what quality such inquiries can achieve, exploring the scandal surrounding the case of the German far-right terrorist group National Socialist Underground (NSU). The article introduces a theoretical framework, with remit, rigor and reception as the key pillars of analysis. While special inquiries are often seen as a way of overcoming imperfections of the traditional accountability system, they can also create a placebo effect – an illusion of accountability which allows intelligence services to go uncontrolled under a blanket of democracy

    Struggling to strike the right balance between interests at stake:The ‘Yarovaya’, ‘Fake news’ and ‘Disrespect’ laws as examples of ill-conceived legislation in the age of modern technology

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    The article deals with the legislative amendments that have been recently adopted in the Russian Federation, the so-called ‘Yarovaya’ law, the ‘fake news’ law and the ‘disrespect’ law. It explains the essence and problems of implementation of the above-mentioned legal instruments and assesses them from the human rights angle. It is established that the rather complex laws under analysis pose significant threats to the human rights and fundamental freedoms of individuals, including privacy, data protection and freedom of expression, and introduce other additional negative effects to the Russian society and economy. While in the adoption of such legislation it is crucial to give due weight to the involved interests, the used examples indicate that the State’s interests seem to prevail at the cost of the rights and freedoms of those who need to be adequately protected

    National security and the fourth estate in a brave new social media world

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    For those working within security services, or operating as part of the media, whether that be as traditional journalist or broadcaster, or a blogger utilising social media, the myriad of laws and jurisprudence relating to how issues of national security, or terrorist activity, can be reported and disseminated, means navigating this area is both complex and challenging. This chapter aims to provide a road map to help to overcome some of these obstacles. It begins by considering the democratic function of the media, by virtue of its role as the ‘Fourth Estate’. In doing so, it takes a multi-jurisdictional perspective, through recourse to a variety of international laws and jurisprudence. This acts as the foundation for the following sections, which provide analysis of the domestic and international legal principles and framework that the media are subject to, and operates within, when reporting on terrorist activity. Finally, the chapter considers how the print and broadcast media has reported terrorist activity in the past, and some of the problems that this has created. It concludes by analysing the changing media landscape, including the reasons for the demise of the traditional Fourth Estate, and the emergence, and ascendance, of citizen journalism, and an internet-based ‘Fifth Estate’

    Social Networks as the New Frontier of Terrorism

    Get PDF
    Terrorism. Why does this word grab our attention so? Propaganda machines have adopted modern technology as a means to always have their content available. Regardless of the hour or time zone, information is being shared by somebody, somewhere. Social media is a game changer influencing the way in which terror groups are changing their tactics and also how their acts of terror are perceived by the members of the public they intend to influence. This book explores how social media adoption by terrorists interacts with privacy law, freedom of expression, data protection and surveillance legislation through an exploration of the fascinating primary resources themselves, covering everything from the Snowden Leaks, the rise of ISIS to Charlie Hebdo. The book also covers lesser worn paths such as the travel guide that proudly boasts that you can get Bounty and Twix bars mid-conflict, and the best local hair salons for jihadi brides. These vignettes, amongst the many others explored in this volume bring to life the legal, policy and ethical debates considered in this volume, representing an important part in the development of understanding terrorist narratives on social media, by framing the legislative debate. This book represents an invaluable guide for lawyers, government bodies, the defence services, academics, students and businesses

    The Paradox of Source Credibility in Canadian and U.S. Domestic Counterterrorism Communications

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    This article examines the interface of rhetorical theories of credibility and the domestic counterterrorism communications of government and nongovernment actors in Canada and the United States. We track evolving attempts to controvert terrorists’ propaganda through official and unofficial channels. Each country has a comprehensive counterterrorism strategy that employs both deterrence and “soft” approaches, such as diplomacy and engagement. Our focus is the latter. First, we discuss how governments undertook counterterrorism communications following September 2001. Second, we explore attempts to engage credible voices outside of government, such as former violent extremists and religious leaders, in the fight against terrorism. We conclude that although counterterrorism messaging must negotiate the challenge of source credibility, further examination of elements such as context, audience reception, and digital engagement is needed to refine domestic campaigns launched by government and civil society actors

    Citizens’ Support for AI Security Surveillance Systems: A Social Exchange Perspective

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    Artificial intelligence (AI) has tremendously transformed the patterns of security surveillance employed by governments. Although the primary goal of security surveillance is to maintain social order and enhance citizens’ protection, significant privacy concerns were raised for citizens given the unprecedented amount of personal data accessed by various types of AI-powered security surveillance (AISS) systems, such as facial recognition technologies. Nonetheless, policymakers and academia rarely paid attention to the citizens’ views as the main stakeholders of these systems. Motivated by this, in this study, we develop a theoretical model drawing on the assertions of the Social Exchange Theory (SET) to explain the factors and mechanisms that influence citizens’ support for AISS. In particular, we elaborate on the role of privacy-security tradeoff, trust, and power and their interplay in explaining citizens’ supportive attitudes. Potential contributions from this research to theory and practice are also outlined
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