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Punching shear failure in slab-column connections is a brittle collapse mode that threatens the safety of flat reinforced concrete (RC) slabs. Conventional design provisions are generally conservative but exhibit inconsistencies across geometric and material variations. This study develops an eXtreme Gradient Boosting (XGBoost) model to predict the ultimate punching shear capacity of flat RC slabs, using a database of experimental results categorized by four different geometric domains, including square slab with square column, circular slab with circular column, square slab with circular column, and circular slab with square column, covering the geometric, materials strength, and reinforcement properties of input parameters. The model achieved high predictive accuracy across the domains with coefficient of determination (R2) values > 0.930 in unseen testing datasets with minimal bias (0.994–1.006) and reduced scatter. Model interpretability, addressed through the SHapley Additive exPlanations analysis, confirmed slab thickness and average effective depth as the most critical predictors of shear capacity, followed by concrete strength and reinforcement parameters, while boundary condition parameters showed negligible influence due to the predominance of interior column cases. These findings demonstrate that XGBoost provides accurate, reliable, and interpretable predictions of punching shear capacity, offering a data-driven alternative to code-based methods and supporting safer and more consistent design of flat RC slabs.
With the rapid development of artificial intelligence technology, robotics, as its core branch, has attracted extensive attention from researchers. This paper designs and develops a robotic arm learning system based on multi-source sensor information fusion, which investigates the autonomous learning capability of robotic arms by closely integrating deep reinforcement learning (DRL) as the core framework for skill acquisition. By incorporating imitation learning as a source of expert prior and leveraging DRL’s intrinsic ability for policy optimization through environmental exploration, the proposed system achieves both rapid learning and robust generalization. Specifically, we introduce the gradient penalty mechanism from Wasserstein generative adversarial networks (WGANs), a technique that improves the stability of adversarial training by penalizing gradients that deviate from a specified norm. This mechanism is incorporated into the soft actor-critic (SAC) algorithm, a widely used off-policy DRL method known for its sample efficiency and robust performance in continuous control tasks. The resulting SAC-GP (SAC-gradient penalty) algorithm benefits from both SAC’s stable policy learning and WGAN’s improved training regularization, leading to superior convergence speed and system stability. Furthermore, this paper proposes a hybrid learning framework by combining generative adversarial imitation learning (GAIL) with SAC-GP, enabling the agent to benefit from both demonstration-based policy initialization and continuous self-improvement via reinforcement learning. Finally, a door-opening experiment is designed to verify the learning and execution capabilities of the system in both virtual and real environments. Experimental results demonstrate that the proposed learning system possesses excellent learning and motion execution abilities in practical applications. This achievement not only provides new insights for research in robot learning but also lays a solid foundation for the future development of robotic technology.
In a time of mass global e-waste production, a re-evaluation of re-purposing and recycling practices feels particularly relevant not only in life but also in art-making processes, especially in temporarily mounted installations, both sonic and visual. What is junk and what is useful material? Can the use of salvaged materials also encourage creativity and innovation? This paper, weaving in theoretical frameworks from sound studies, media archaeology and eco-sonic aesthetics, suggests that using mismatched ‘garbage’ loudspeakers and unconventional loudspeaker arrays can offer sound artists creative opportunities for the exploration of new aural spaces and spatial and timbral possibilities, through the formation of sounding sculptures. Examining Social Sciences and Humanities Research Council-funded sound and art installation Waste Whisperer (2023) as a case study, which involved a bespoke 40 loudspeaker set-up of salvaged ‘trash’, the article also explores the work of artists such as Benoit Maubrey, John Wynne and Nor Tijan Firdaus, who use discarded e-waste as their primary sculptural materials, as well as Paul Rogers’ research around the concept of ‘sonic junk’. In addition, the concepts of transparency and ‘realism’ in the audio medium are discussed, positing critical reflections on prevailing techno-utopian narratives in contemporary audio communities around ‘matching’ loudspeakers and spatialisation conventions.
Hemiplegia, the paralysis of one side of the body, is a common effect of stroke and provides unique challenges for afflicted individuals, including asymmetric body strength and limited mobility, especially in the sit-to-stand (STS) motion. Reducing weight-bearing asymmetry during STS is important for improving mobility outcomes of hemiplegic patients. To address this concern, a semi-wearable STS assistive robot is proposed to provide assistive force and motion guidance during the STS motion. It is a planar 2-DoF assistive robot attached near the hip, designed to reduce weight-bearing asymmetry and facilitate correct execution of the STS motion by guiding the user along a target STS path and constraining pelvic motion in the frontal plane, controlled using a single worn IMU. The method for generating unique target STS paths and assistive robot design is presented. Experiments on healthy test subjects with the motion of one leg constrained were conducted to determine the changes and correlations in force and motion parameters when using the assistive robot during STS. The assistive robot improved rising STS asymmetry in some test subjects and reduced stabilization weight-bearing asymmetry in all test subjects. Motion data showed that the assistive robot facilitated hip translation and tilt toward the test subjects’ constrained side, while a counter trunk tilt toward the unconstrained side was observed. The results of the experiments suggest that more active control of the hip position and tilt and providing real-time feedback during the STS motion could further improve the function of the robot.
This book explores how social media are used by citizens to frame contentious parades and protests in ‘post-conflict’ Northern Ireland. It provides the first in-depth analysis of how Facebook, Twitter and YouTube were used by citizens to contest the 2013 union flag protests and the Ardoyne parade dispute (2014 and 2015). An essential read for researchers interested in digital mis- and disinformation, it will examine how citizens engaged with false information circulating on these platforms that had the potential to inflame sectarian tensions during these contentious episodes. It also considers the implications of this online activity for efforts to build peace in deeply divided societies such as Northern Ireland.The book uses a qualitative thematic approach to analyse Facebook, Twitter and YouTube content generated during the flag protests and Ardoyne parade dispute between 2012 and 2016. It also draws on semi-structured interviews with key stakeholders including bloggers, political commentators and communication officers from the main political parties, as well as the results of a qualitative content analysis of newspaper coverage of these contentious public demonstrations.
The decision by the Northern Ireland Parades Commission in July 2013 to re-route the return leg of an annual Orange Order parade away from the nationalist Ardoyne district in North Belfast sparked four consecutive nights of violent clashes between loyalist rioters and the PSNI. Fears of a repeat of this violence were not realised in July 2014, despite the failure of representatives from both sides to broker a solution to the impasse. July 2015 saw a return to violence as loyalist protesters attacked PSNI officers enforcing the Parades Commission’s determination to prevent the return leg from returning home via its traditional route. Chapter 6 explores what role, if any, tweeters played in escalating and de-escalating tensions surrounding the contentious parade in 2014 and 2015. The lifespan of misinformation and disinformation about the dispute shared on the microblogging site will be examined to assess the reach and potential impact of content that had the potential to generate violence between loyalists and the Ardoyne residents. It will also examine the ways in which tweeters framed the dispute from a rights perspective and whether there was any evidence of Mouffe’s ‘conflictual consensus’ emerging on the platform during this period. A critical thematic analysis of 7,388 #Ardoyne tweets, collected in July 2014 and July 2015, was conducted in order to investigate these issues. These will be contextualised through a content analysis of 44 articles published in Northern Irish and Irish newspapers during the Twelfth week across both years.
Memes and parody accounts are examples of the ‘silly citizenship’ theorised by Hartley (2010) to capture citizens’ ‘playful’ engagement with political issues online. In terms of the latter, these are often deployed to satirise and hold politicians and authority figures to account for their public statements and actions. In the case of Northern Ireland, self-styled non-sectarian ‘parody group’ Loyalists Against Democracy (LAD) emerged as one of the most vocal critics of the flag protests in December 2012. Its supporters argued that the group articulated the views of the ‘silent majority’ by highlighting the bigotry and sectarianism of loyalists on pages such as LPPU. Conversely, critics accused the group of peddling negative stereotypes of working-class loyalists by shaming them for their poor spelling and grammar in their social media comments. Chapter 5 explores the role of LAD in contentious politics in Northern Ireland between December 2012 and November 2013. It presents the results of the first empirical study of content posted on the group’s Facebook and Twitter profiles, with a view to exploring whether such content could persuasively be framed as satire. It will also examine the extent to which loyalists were represented as ‘social abjects’ akin to the ‘chav’ stereotype used to demonise white working-class communities in England (Tyler, 2013). The role of the group in campaigns such as #givepootstheboot will be explored in order to assess its evolving role within the Northern Irish information ecosystem as a focal point for the contestation of contentious political issues.
In Chapter 1, the evolving relationship between social media, contentious politics and social movements is explored. The role of digital media in social movements since 2011 is analysed, using exemplars such as Occupy Wall Street and the popular uprisings in the Middle East and North Africa later labelled the ‘Arab Spring’. The chapter moves on to explore the evolving role of digital media in contentious politics in Northern Ireland. Data from organisations such as OfCom are used to empirically investigate the news consumption practices of citizens and the levels of public trust in professional news media and political institutions in the social media era. Finally, the results of interviews conducted with key stakeholders (N=14) between October 2009 and September 2013 are elaborated, in order to critically evaluate the impact of Web 2.0 on political participation in the deeply divided society prior to the flag protests.
Chapter 2 focuses specifically on the role of social media in the flag protests between December 2012 and March 2013. Speaking at an event on social media and Northern Irish politics held at the University of Ulster in December 2013, loyalist activist Jamie Bryson would claim that social media “hadn’t helped us [the flag protesters] in the slightest”. This chapter empirically investigates this claim by providing the first qualitative study of Loyalist Peaceful Protest Updater (LPPU). This public Facebook page was used by loyalists to coordinate the protests and was suspended in January 2013 after an emergency injunction filed on behalf of an unidentified Catholic man who had been threatened on the page. The results of a thematic analysis of 24,244 comments posted on LPPU and its backup page during January 2013 are presented in order to assess the type of mobilising information provided on the page, and whether there was much evidence of ‘trolling’ by critics of the protests. The chapter contextualises these results through a content analysis of coverage of the flag protests in the three most widely read newspapers in the region, the Belfast Telegraph, the Irish News, and the News Letter between 3rd December 2012 and 28 February 2013 (N=347).
The final chapter summarises the main contributions of the book to contemporary debates about the role of social media in contentious politics within divided societies such as Northern Ireland. It considers whether the use of online platforms to spread misinformation and disinformation during contentious public demonstrations is evidence of the information crisis seen in other nation states, or a symptom of the democratic dysfunction in Northern Ireland’s power-sharing institutions. Finally, it explores the implications of citizens’ use of social media during such incidents for promoting peace and reconciliation in the deeply divided society.