110830 research outputs found
Sort by
Multiple targeted grassland restoration interventions enhance ecosystem service multifunctionality
No full textThe need to combat widespread degradation of grassland ecosystem services makes grassland restoration a global sustainability priority. However, simultaneously enhancing multiple ecosystem services (i.e. ecosystem service multifunctionality) is a major challenge for grassland restoration due to trade-offs among services. We use a long-term multifactor grassland restoration experiment established in 1989 on agriculturally improved, species-poor grassland in northern England, to assess how increasing the number of restoration treatments, including addition of manure, inorganic fertiliser, a seed mixture, and promotion of a nitrogen-fixing legume (Trifolium pratense), affects ecosystem service multifunctionality, based on 26 ecosystem service indicators measured between 2011 and 2014. We find that single interventions usually lead to trade-offs among services and thus have few positive effects on ecosystem service multifunctionality. However, ecosystem service multifunctionality increases with the number of restoration interventions, as trade-offs are reduced. Our findings highlight the significant potential for combined use of multiple targeted interventions to aid the restoration of ecosystem service multifunctionality in degraded grasslands, and potentially, other ecosystems
The Regulation of Personal Insolvency in China : Historical Perspectives, Comparative Insights and Future Directions
Get PDFThis thesis explores the evolution of personal insolvency regulation in China, examining its historical context, comparative insights from established systems, and potential future directions. The research addresses a significant gap in China's legal framework: the absence of a nationwide personal insolvency regime. By investigating the well-established systems in the United Kingdom and the United States, alongside the recent implementation in Shenzhen, this study aims to draw valuable lessons for China's potential nationwide adoption. The research methodology combines doctrinal and comparative approaches. It analyses primary legal texts, including the UK's Insolvency Act 1986, the US Bankruptcy Code, and Shenzhen's Personal Insolvency Regulation. The historical development of personal insolvency laws in these jurisdictions is examined, taking into account cultural influences and legal reforms. Case law review provides crucial insights into practical application and judicial interpretation. Comparative analysis reveals key similarities and differences between the personal insolvency procedures in the UK, US, and Shenzhen, with particular attention to the position of debtors and creditors across these jurisdictions. The research identifies critical issues such as legislative style, pre-bankruptcy debt counselling, discharge mechanisms, and out-of-court procedures. The thesis argues that China's rapid economic growth and evolving market dynamics necessitate the introduction of a personal insolvency regime. It grapples with the challenges of legal transplantation, seeking to balance international best practices with China's unique cultural and economic context. The Shenzhen regulation serves as a valuable case study, offering insights into the potential for nationwide implementation. By synthesising findings from doctrinal and comparative studies, this research contributes to the understanding of personal insolvency law in China and provides insights into its historical context, comparative lessons, and future possibilities. It offers recommendations for establishing a comprehensive Chinese personal insolvency regime, considering both legal and socio-economic factors. The study aims to inform policymakers, legal scholars, and practitioners about the complexities and potential benefits of introducing personal insolvency regulation in China
Coordinated Adaptive Impedance Control of Redundantly Actuated Parallel Manipulators
Get PDFRedundantly actuated parallel mechanisms (RAPMs) have been widely adopted in advanced robotic systems and precision machine tools. It has been demonstrated that redundant actuation can improve the performance of mechatronic systems but introduce challenges with respect to control. One main difficulty is in establishing an accurate dynamic model of the RAPM system. With an inaccurate dynamic model, the torque applied by the actuators will be incorrect, leading to increased antagonistic forces in the system. To solve this problem, a novel coordinated adaptive impedance control approach based on a new adaptive impedance control law is presented here, along with proof of the stability of the closed-loop system. The control algorithm has been validated experimentally by a prototype cable-driven parallel manipulator. It can be seen from the experimental results that the proposed control method is an effective way to correct the antagonistic forces of the system, thus facilitating the improvement of its dynamic performance and its efficacy in different applications
nBn mid-wavelength infrared photodetectors based on bulk InGaAsSb absorbers
Get PDFIn this paper, we demonstrate an nBn mid-wavelength infrared (MWIR) photodetector with a 100% cutoff wavelength over 4.0 µm based on a high-In composition InGaAsSb absorber on GaSb substrate. A thin AlGaAsSb layer is exploited as the barrier layer to suppress the generation-recombination (G-R) current. Both structural and optical properties of the grown InGaAsSb epilayer are investigated by high-resolution X-ray diffraction (HRXRD) and photoluminescence (PL) measurement. Low dark current density down to 9.9 × 10−5 A/cm2 and 6.5 × 10−2 A/cm2 are obtained at −500 mV under 77 K and 300 K, respectively. Moreover, respective peak responsivity of 0.64 A/W and 0.10 A/W at 2.67 µm are achieved at −500 mV under 77 K and 160 K. These correspond to a peak specific detectivity of 1.06 × 1011 cm·Hz1/2/W and 4.23 × 109 cm·Hz1/2/W, respectively
Optimizing with Transaction Costs
Get PDFThis thesis explores the integration of transaction costs into portfolio optimization models, addressing a significant gap in traditional financial theory where such costs are often overlooked or simplified. By treating transaction costs as dynamic and volatile elements, this research enhances the realism and practical applicability of portfolio construction, leading to more efficient and effective investment strategies. The work is structured across three main chapters. Chapter 1 introduces the concept of implementation shortfall variance and integrates transaction cost covariance into the mean-variance utility function. Through statistical modeling and simulations using S&P 500 data, it demonstrates how accounting for transaction cost variance can improve portfolio performance. Chapter 2 extends the analysis to equity factor portfolios, a critical component in asset management. It presents a novel optimization framework that reduces transaction costs while preserving the core characteristics of these portfolios. By applying this methodology to both single and multi-factor portfolios across global markets, the research shows that transaction-cost-optimized portfolios can achieve superior net returns, particularly in less liquid markets. Chapter 3 continues this approach to develop factor-enhanced market portfolios optimized for transaction costs. By integrating these factor strategies within a benchmark-relative context, the research provides actionable insights for asset managers, suggesting that traditional models which overlook or simplify transaction costs may be suboptimal. Overall, this thesis makes significant contributions to the field of finance by emphasizing the importance of transaction costs in portfolio optimization and offering practical tools and models that can enhance portfolio performance in a realistic and cost-effective manner
Reflections on a pedagogy of responsibility
No full textThis chapter combines an interest in pedagogical practices oriented towards evoking and problematising responsibility in management education with an iterative consideration of, and reflection upon, the theoretical concerns and principles that inform such practices. It outlines our evolving pedagogical approach, which seeks to explore and develop the rootedness of learners in their learning experiences through exploring their subject-positioning and related perspectives in contemporary and historical organisational issues. This approach is differentially applied in relation to the immediate situation of personal responsibility, the context of group and organisational responsibility, and the context of societal, global and planetary responsibility, and the interrelatedness of these situations and contexts in lived experience
Interacting dark sector within ETHOS : Cosmological constraints from SPT cluster abundance with DES and HST weak lensing data
No full textWe use galaxy cluster abundance measurements from the South Pole Telescope enhanced by multicomponent matched filter confirmation and complemented with mass information obtained using weak-lensing data from Dark Energy Survey Year 3 (DES Y3) and targeted Hubble Space Telescope observations for probing deviations from the cold dark matter paradigm. Concretely, we consider a class of dark sector models featuring interactions between dark matter (DM) and a dark radiation (DR) component within the framework of the effective theory of structure formation (ETHOS). We focus on scenarios that lead to power suppression over a wide range of scales, and thus can be tested with data sensitive to large scales, as realized, for example, for DM–DR interactions following from an unbroken non-Abelian SU(N) gauge theory (interaction rate with power-law index n=0 within the ETHOS parametrization). Cluster abundance measurements are mostly sensitive to the amount of DR interacting with DM, parametrized by the ratio of DR temperature to the cosmic microwave background (CMB) temperature, ξDR=TDR/TCMB. We find an upper limit ξDR<17% at 95% credibility. When the cluster data are combined with Planck 2018 CMB data along with baryon acoustic oscillation (BAO) measurements we find ξDR<10%, corresponding to a limit on the abundance of interacting DR that is around 3 times tighter than that from CMB + BAO data alone. We also discuss the complementarity of weak lensing informed cluster abundance studies with probes sensitive to smaller scales, explore the impact on our analysis of massive neutrinos, and comment on a slight preference for the presence of a nonzero interacting DR abundance, which enables a physical solution to the S8 tension
Retaining doctors in organisations in socio-economically deprived areas in England : a qualitative study
Get PDFObjectives To identify factors that improve retention in under-doctored areas that experience difficulties in maintaining sufficient medical workforce. Design Qualitative study based on semi-structured interviews, collected as part of a larger study. Setting Four purposely sampled geographic case study sites in England. Three case study sites were selected as areas that struggled to recruit and retain doctors and one as an area that is oversubscribed. This comprised 27 NHS Trusts, plus 1449 GP practices. Participants 100 National Health Service (NHS)-employed doctors (including general practitioners, consultant specialists, specialty and specialist doctors, resident doctors/doctors in postgraduate training and locally employed doctors) were interviewed between December 2022 and March 2024. Findings Participants shared their experiences of organisational levers that impact on decisions about working life and retention in the workforce. Two key themes explained factors influencing retention. First, participants discussed feeling valued by the organisation, both in terms of material circumstances and in relationships with colleagues. Second, the theme of autonomy and opportunity explored why doctors chose to stay in areas that typically experience difficulties in maintaining sufficient staffing. Conclusions Many studies focusing on workforce examine why staff leave, but by focusing on factors that influence retention, greater understanding of specific facets of organisational culture can be used to inform policy and practice
