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Trajectory Tracking of Tractor-Trailer Wheeled Mobile Robots via Dynamic Feedback Linearization in Forward and Backward Motion
Get PDFOne type of wheeled mobile robot widely used in public transportation and for carrying high payloads is the tractor-trailer wheeled robots (TTWRs). This study considers a differentially-driven tractor under pure rolling conditions, which is subject to nonholonomic constraints. Controlling a TTWR in both backward and forward motion is challenging due to inherent instability. To address this issue and achieve trajectory tracking control for these systems, this paper employs dynamic feedback linearization (DFL) to overcome the limitations of static feedback linearization (SFL). The system’s response will be examined under various trajectories and initial conditions for both forward and backward motion
Striking the Right Notes: Long- and Short-Term Financial Impacts of Musicians’ Charity Advocacy Versus Other Signaling Types
Get PDFBy using multilevel mediation involving 322,589 posts made by 384 musicians over 104 weeks, we simultaneously analyze
the short-term and long-term effects of charity-related signaling on sales, with social media engagement as the mediator.
Specifically, we compare the effects of charity-related signals with those of two other types of signals: mission-related (i.e.,
promoting music and commercial products) and non-mission-related (i.e., other posts that do not relate to the other two
categories). In the short term, the indirect effect of using charity signaling on sales (through engagement) is positive, though
smaller than the effects of mission-related and non-mission related signals. However, in the long term, the indirect effect of
regularly using charity-related signaling on sales (through long-term engagement) is greater than for the effects involving the
other types of signals. We derive from these findings three main implications for the business ethics literature. First, in the
long term, the mutual economic benefits of charity signaling should encourage both entities (i.e., musicians and charities)
to go beyond short-term, transactional philanthropy. Second, because it is profitable for musicians to partner with charities
in the long-term, our research argues that charities have extensive bargaining power in such co-branding decisions. Third,
our research highlights the importance of studying the longitudinal aspects of co-branding decisions involving non-profit
organizations; the financial outlook of such decisions could greatly vary depending on the timeframe (i.e., short vs. long)
Editor’s Notes: Academic Assumptions, Institutional Boundaries and Transformative Education
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The impact of climate entrepreneurship education in higher education institutions: a university-wide climate entrepreneurship programme.
Get PDFScholars are grappling with what educational and pedagogical approaches are needed to create sustainable entrepreneurs able to cope with sustainability challenges. This paper explores the impact of a student-focused climate entrepreneurship education initiative (CEE) in Technological University Dublin (TU Dublin). The paper draws on models and frameworks in the literature that integrate programme objectives and pedagogical methods with impact. The paper addresses two key questions. Firstly, how are students impacted by CEE in terms of the affectedness, skills development and the intention to start a climate enterprise. The second question asks how different types of interventions in CEE influence student impact. The study contributes to the emerging body of literature on sustainability enterprise education (SEE) by firstly, showing interventions needed to embed climate impact into a customer value proposition; secondly, suggesting a simplicity paradox for stronger SEE impact; and thirdly, offering insights for designing CEE programmes for university-wide impact
Computational Efficiency Enhancement of Digital Pre-Distortion for mmWave Hybrid Beamformer Systems
No full textThis research addresses the critical challenge of implementing Digital Pre-Distortion
(DPD) in Hybrid Beamformer (HBF) systems, focusing on the inherent trade-off
between Power Amplifier (PA) efficiency and signal linearity. The study makes
several key contributions, beginning with a novel Genetic Algorithm (GA) designed
to optimise the combined response of the PA array, which yields an accurate DPD
solution and significantly improves the Adjacent Channel Power Ratio (ACPR). A
computationally efficient DPD method is also developed, utilising distinct pre-distorting
coefficients for different signal segments and targeting the most distorted sub-samples
to enhance ACPR with fewer coefficients. Furthermore, the research proposes three
techniques to linearise the PA response and calibrate the RF system by leveraging
signal characteristics, thereby addressing mismatches within the HBF. Finally, an
adaptive Iterative Learning Control (ILC) DPD architecture is presented to rectify
distortion in HBF. Overall, this thesis contributes a suite of efficient DPD techniques
that mitigate PA distortion in HBFs, demonstrating the potential to improve signal
quality and reduce the computational process
Unlocking Enterprise Value: A Comprehensive Review of ArchiMate’s Value Modelling Landscape and Stakeholder Perspectives
Get PDFThere are many attempts to perceive and represent value creation which spans across disciplines. Modelling gives a detailed insight into the areas of value creation and practical applicability in testing its validity. ArchiMate, an internationally recognised standard language for enterprise architecture modelling, offers a structured approach to represent and analyse value within the context of enterprise architecture. Although being predominantly used as an enterprise language and framework, ArchiMate still faces deficiencies in representing the value aspects. Through a comprehensive review of existing literature, this review identifies key challenges, issues, and opportunities in value modelling practices within ArchiMate. The paper aims to improve the value-centric enterprise modelling practice and contributes to ArchiMate’s value representations
On your marks, headset, go! Understanding the building blocks of metaverse realms
Get PDFIn 2011, Business Horizons published the social media honeycomb article to help managers and scholars understand what was, then, a new form of media, along with its various platforms and how to engage with and learn to use it. Today, we face similar challenges and opportunities with the metaverse as we try to discover how to attract, enable, serve, and capture value from users in the virtual world. In this article, we introduce the concept of a metaverse realm (i.e., a specific type of metaverse space and community) and present the metaverse honeycomb model to explain the functionalities and affordances for different metaverse realms. We present two applications of the honeycomb model to show how shifting attention to immersive functionalities can characterize various metaverse realms. To conclude, we outline how the model could be used to strategically evaluate metaverse realms in terms of their external fit (i.e., the who-what-how of realms), internal fit (i.e., the trade-offs and synergies of realm functionalities), and life cycles (i.e., roadmapping and directing realm evolution)
Optimal control of wave cycloidal rotors with passively morphing foils: An analytical and numerical study
Get PDFIn this paper we perform an analytical and numerical study of the performance of a wave cycloidal rotor in irregular waves, with passively morphing foils and variable rotational velocity control. The performance is measured in two ways: Mechanical power, and fatigue damage in a sample stress hot spot located at the fixed end of the hydrofoils. We consider different strategies seeking to both maximise power extraction and reduce fatigue damage. To maximise power, we consider both constant and variable rotational speed. To mitigate fatigue damage, we consider, for the first time, morphing foils in the context of a wave cycloidal rotor. By testing these control strategies in isolation and in combination, and with the aid of high performance computations, we find that variable rotational speed, in combination with morphing foils, offers the best compromise to enhance power production with a reduced structural penalty on the sample stress hot spot. Hence, in this work, we demonstrate that novel control strategies, such as those proposed in this work, can hold the key in reducing the levelised cost of energy and accelerate the commercialisation of the next generation of lift-based wave energy converters
Ireland’s Climate Change Assessment 2023. Volume 1: Climate Science-Ireland in a changing World. Summary of Policymakers
Get PDFIreland’s Climate Change Assessment (ICCA) delivers a comprehensive, Ireland-focused, state of scientific knowledge report on our understanding of climate change, its impacts on Ireland, the options to respond to the challenges it poses,and the opportunities from transitions and transformations to a climate-neutral, climate-resilient and sustainable economyand society. This serves to complement and localise the global assessments undertaken by the Intergovernmental Panel on Climate Change (IPCC) reports (see www.ipcc.ch). The findings presented build upon these global assessments and add important local and national context.
Volume 1 focuses on the state of knowledge of the physical science basis of climate change, both globally and nationally. The volume contains information published from the IPCC AR6 WGI report, as well as material from the relevant Special Reports from the IPCC and various state agencies including EPA Ireland, Met Éireann and the Marine Institute. The volume updates and extends the analysis provided in the National State of Knowledge Reports on climate change (2012, 2017), and consolidates the current and ongoing research into climate change in Ireland, the observed changes in the climate system as well as future climate projections for Ireland
The Detection and Removal of Pollutants in Aquatic Environments: Developing Sensitive Electrochemical Sensors and Using Magnetic Adsorbents
Get PDFWith the rapid development of industry and economies across the world, the problem of
environmental pollution in aquatic environments has become one of the key issues
facing the World. Consequently, the development of efficient and sensitive analytical
techniques to determine the levels of organic pollutants in water environments and
cost-effective strategies to remove these pollutants, are now more important than ever
before.
In this thesis, sensitive and selective electrochemical sensors with very good long-term
stability were developed for the detection of 4-chloro-2-methylphenoxyacetic acid
(MCPA), p-nitrophenol (p-NP), metronidazole (MTZ), and levofloxacin (LEVO). Two
strategies were employed in the development of these sensors. Firstly, glassy carbon
electrode (GCE) was activated to generate active sites to enhance the electron-transfer
process. Secondly, binder-free nanocomposites were employed to facilitate the detection
of MCPA, p-NP, MTZ and LEVO. The nanocomposites included graphene, bismuth
and copper nanostructures. These were all formed using electrodeposition, avoiding the
need to use binders that are typically employed with drop casting. Using these
approaches, impressive limits of detection of 8.0 nM, 0.18 nM, 0.9 nM and 11.86 nM
were achieved in the electrochemical detection of (1) MCPA at activated GCE, (2) p-NP
with bismuth dendrites deposited onto activated GCE, (3) MTZ with the sequential
electrodeposition of graphene nanoplatelets (Gr) and bismuth and (4) LEVO with the
sequential electrodeposition of Gr and copper at GCE, respectively. Further, graphene
supported magnetic nanocomposites (Gr/Fe) were fabricated and used as adsorbents for
the potential removal of MCPA, p-NP, MTZ and LEVO from aquatic environments.
Iron nanostructures were employed as the magnetic component. These nanocomposites
not only prevent the aggregation of the graphene sheets, but also can endow graphene
with magnetic properties. This makes the magnetic graphene adsorbents easy to separate
by external magnetic fields, greatly simplifying the recycling process. The adsorption
kinetics and adsorption isotherms were studied, and the reproducibility, selectivity and
reusability of the magnetic Gr/Fe composites were evaluated