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Ultra-low losses SiC based shunt active power filter for harmonics mitigation and harmonics power recovery in industrial power systems
No full textThe classical method to suppress resonances in power systems is by installing passive dampers in parallel to the loads. However, observations indicate significant power losses due to harmonic currents flowing over passive dampers. Certainly, passive dampers absorb harmonic active power and dissipate this power as heat on their resistive elements leading to energy waste. On the other hand, the passive damper counterpart is the active damper. The latter is also known in technical literature as Voltage driven shunt active power filter (VSAPF). The active damper is a power-electronics-based system that emulates a virtual resistance at harmonic frequencies. Truly, very little was known about the harmonic power absorption on active dampers. Therefore, this dissertation delves into a profound analysis of the capability of an ultra-low losses active damper based on SiC semiconductor technology to process the harmonic power intake and perform harmonic power recovery. Harmonic power recovery in this context is understood as the process of transforming the harmonic active power absorbed into fundamental power that is injected back into the power system. The next topic that is addressed is the reduction in the fundamental power demanded by an industrial facility due to the recovery of harmonic active power. To this end, this dissertation analyzes the power balance flow of a distribution power system (e.g., industrial grid) that includes an ultra-low losses active damper. Arising out of the power balance flow analysis, it was found that the active damper with harmonic recovery function achieves a 1.4% reduction on the fundamental power demanded compared to a passive damper. Naturally, the lower the active damper´s power losses, the higher will be the amount of harmonic active power that can be recovered from the power system. Therefore, during this research work, various power electronics converters topologies are analysed to find the best possible design for the active damper with harmonic power recovery functionality. Arising out of this investigation, it was found that the conventional three-level neutral point piloted converter (3L-TNPC) and the asymmetrical three-level converter (3L-ASYM) are the most suitable power circuit topologies for the ultra-low losses active damper. The former topology, the 3L-TNPC, exhibits the lowest power losses for switching frequencies up to 60 kHz. And then, the 3L-ASYM topology presents the lowest losses among all the studied power circuits for switching frequencies beyond 70 kHz. Furthermore, as an active damper forms a closed loop between harmonic voltages and compensating currents, its stability must be ensured. Thus, a careful design of the VSAPF control system and its inner current controllers is essential. On account of this, this dissertation proposes using the Ragazzini method to design the VSAPF’s inner current controllers.Furthermore, the direct design of the inner current controllers on the discrete domain using the Ragazzini method increases the current controllers’ bandwidth by a factor of three compared to the controllers’ design with conventional methods. Consequently, the increased current controller’s bandwidth achieved through the Ragazzini method pushes the stability limit of the active damper forward compared with traditional current controller designs
LGBTIQ+ migration, accommodation, and mental health in the UK: A critical psychological perspective on the death-worlds and the living dead in detention centres
No full textWhile migration and queer studies are respected and well-established, their intersection as an interdisciplinary alliance deserves further research. This paper is part of the critical psychology project ‘Queering migration, migrating queer studies’ to discuss and address primarily the main challenges LGBTIQ+ migrants face around accommodation and mental health in detention in the UK context. Given the recent anti-immigration bill passed in July 2023 by the British parliament and the escalating difficulties to obtain asylum in this hostile environment, the paper reviews academic literature published between 2017 and 2023 on services LGBTIQ+ refugees and asylum seekers have received or have had access to in the UK. It critically reflects on what accommodation means within detention and removal centres and how the latter affects mental health and service provision questions for the LGBTIQ+ community.Bringing to the fore Achille Mbembe’s conceptual framework of necropolitics in dialogue with Frantz Fanon’s psychosocial analytics of racism, this paper shows how LGBTIQ+ migration walks in between Foucauldian biopolitics and necropolitics as an emerging discourse. By mobilising a case study, the paper focuses first on why necropolitics is a useful framework to shed light, expose and resist existing hegemonies on LGBTIQ+ migration issues, particularly in the UK, and second, shows how ‘deathworlds’, and the living dead can be observed in the lives of LGBTIQ+ refugees and asylum seekers coming from Global South and detained in the UK. Nevertheless, we also understand the role of queerness in challenging misconceptions and resisting hegemonies in detention centres, which is a task for critical psychologist
A new AI-based approach for rental tax evasion management in Iran (ethical consideration)
No full textIn any nation, some parts of society are unsatisfied with the idea of paying taxes. Some authorities have tried to fill the gaps in law by adopting techniques to discourage tax evasion and tax fraud. In this case, technology, especially big data have been used to enable tax collection and regulation. This paper studied the pivotal role of big data in rental tax evasion management in different countries. In order to solve the issues, this paper investigates tax evasion in the rental era and then applies the GIS approach in describing geo-behaviours, social connections, and the interaction between taxpayers and properties. The idea is to reduce evasion and fraud in Tax Management in Iran by applying the ‘National Licensing Schema’ for landlords, using Tax Profiling System combined with GIS and GraphDB. This is to identify the landlord’s and tenants’ relationship
The economic and social implications of food waste management and its impacts when converted to herald new business opportunities - a case study of Rawalpindi, Pakistan
No full textThe problem of food waste affects not only the economy but also society and the environment. Previous and current studies show that measures have been put in place to combat the recurring social and economic issues caused by the inefficiency of food waste management; however, this is a long way towards achieving global goals. This research aims to bridge the gap by evaluating the importance of efficiently handling urban household food waste and its correlation between economic and social factors.It focuses on Rawalpindi, a metropolitan city in Pakistan. The core theme is value creation–leveraging the benefit of a zero-value resource to achieve social and economic benefits through the operational management of food waste in Pakistan’s crumbling economy.It is observed in the case of Pakistan that there are many risks involved to the environment and the wellbeing of people, such as diseases and negative externalities associated with the improper handling of food waste. A sequential explanatory mixed method was used. Data were collected using a self-completed questionnaire administered to urban households (n=176), in-depth interviews with heads of household (n-21), and five focus groups (n=24).The research revealed a need for more knowledge about the immense potential of food waste; most people are incognizant of converting it into a valuable resource. The research further revealed that social and economic factors were not only concerns but also cultural and behavioural aspects that contribute to the issue of household food waste. Individuals experienced challenges in collecting food waste as it ended up in general waste due to the unavailability of a collection mechanism. Major concerns for the households were electric power cuts and extreme weather conditions.Implementing effective and efficient policies will add value to a valuable resource by minimizing and making the most of food waste. The study further recommends developing a mechanism for collecting and optimizing food waste so this nonvalue resource can be turned into a valuable resource
Homelessness: partnerships and approaches to tackling complex needs
No full textPurpose – This paper – the first of three – aims to explore some of the complex physical and mental health needs of those experiencing homelessness. It will act as a leader to the other articles by establishing the nature of the problem and offer a rationale for carrying out a service user needs assessment as part of a review of local service provision in the North West of England against the backdrop of the current COVID-19 epidemic.Design/methodology/approach – There are a number of complex social and health inequalities often experienced by those who are homeless. Effectively tackling these requires a co-ordinated multi-agency response to both prevent and tackle the harms associated with being and becoming homeless.Findings – Partnership working offers the best opportunity to meet the complex needs of those experiencing homelessness. The current delivery model being actioned in the North West of England highlights the importance of the links between statutory and non-statutory services. An ongoing service user needs assessment will further help to highlight contemporary issues faced by those experiencing homelessness and those providing services in the context of the COVID-19 epidemic.Social implications – Future papers as part of this series of three will consider the implications of social exclusion and barriers to accessing services faced on a day-to-day basis by those experiencing homelessness.Originality/value – The opportunity to reflect on established views in relation to the nature and scope of homelessness. It will consider the implications exclusion from society and service provision that this group face on a day-to-day basis. The paper will describe a contemporary approach to tackling current issues faced by those experiencing homelessness in the current context of the COVID-19 epidemi
Decision-analysis modelling of effectiveness and cost-effectiveness of pharmacological thromboprophylaxis for surgical inpatients, using variable risk assessment models or other strategies
No full textBackgroundSurgical inpatients are at risk of venous thromboembolism (VTE) which can be life-threatening or result in chronic complications. Thromboprophylaxis reduces VTE risk but incurs costs and may increase bleeding risk. Risk assessment models (RAMs) are currently used to target thromboprophylaxis at high-risk patients.Objective To determine the balance of cost, risk, and benefit for different thromboprophylaxis strategies in adult surgical inpatients, excluding major orthopaedic surgery, critical care and pregnant women.Methods Decision analytic modelling to estimate the following outcomes for alternative thromboprophylaxis strategies: thromboprophylaxis usage; VTE incidence and treatment; major bleeding; chronic thromboembolic complications; and overall survival. Strategies compared were: no thromboprophylaxis; thromboprophylaxis for all; and thromboprophylaxis given according to RAMs (Caprini and Pannucci). Thromboprophylaxis is assumed to be given for the duration of hospitalisation. The model evaluates life-time costs and quality-adjusted life-years (QALYs) within England’s health and social care services.Results Thromboprophylaxis for all surgical inpatients had a 70% probability of being the most cost-effective strategy (at a £20,000 per QALY threshold). RAM-based prophylaxis would be the most cost-effective strategy if a RAM with higher sensitivity (99.9%) were available for surgical inpatients. QALY gains were mainly due to reduced post-thrombotic complications. The optimal strategy was sensitive to several other factors including: risk of VTE, bleeding and post thrombotic syndrome; duration of prophylaxis and patient age.Conclusions Thromboprophylaxis for all eligible surgical inpatients appeared to be the most cost-effective strategy. Default recommendations for pharmacological thromboprophylaxis, with the potential to ‘opt-out’, may be superior to a complex risk-based ‘opt-in’ approach
A review of social media marketing on digital savvy brand shoppers
No full textSocial Media (SM) has recently become a platform and a tool for both individuals and companies to communicate in a virtual platform. E-retails is another virtual platform where creates cybernetic communication between brands and customers. Companies create effective marketing strategy through both platforms to influence their customer behavior. On the other hand, digital savvy customers who prefer to take the advantage of saving time and have a convenience shopping experience, buying their desired products through e-shopping is another fact that makes digital marketers to implement new strategies to communicate with their customers. Thus, social media has become an effective tool to create an interaction to influence digital savvy shoppers. The purpose of this paper is to examine different aspects of social media as a tool that can develop marketing strategies and how they influence individuals who prefer to buy products through e-retails. This paper aims to provide a comprehensive review of the impact of social media marketing on digital savvy brand shoppers. The scope of this review encompasses various literature reviews that has been done to illustrate a framework design to represent the impacts that social media has on a specific target audience. The research methodology used for this review involves a systematic literature review of relevant academic and industry publications. The contribution of this paper lies in providing insights into the effectiveness of social media marketing strategies for engaging digital savvy brand shoppers and improving brand loyalty. The findings of this paper represent how social media can influence e-shoppers and have impact on their decision-making process. On the other hand, the findings suggest that social media marketing can enhance brand awareness and influence consumer purchase decision through advertising, user-generated content, and social media influencers. The review also identifies key challenges and limitations of social media marketing for digital savvy brand shoppers
Management and prediction of navigation of industrial robots based on neural network
No full textIn the past, a robotic arm needed to be taught to carry out certain tasks, such as selecting a single object type from a fixed location and orientation. Neural networks have autonomous abilities that are being deployed to aid the development of robots and also improve their navigation accuracy. Maximizing the potentials of neural network as shown in this study enhances the positioning and movement targets of industrial robots. The study adopted an architecture called XBNet (Extremely Boosted Neural Network) trained using a unique optimization approach (Boosted Gradient Descent for Tabular Data (BGDTD) that improves both its interpretability and performance. Based on the analysis of the simulations, the result demonstrates accuracy and precision. The study would contribute significantly to the advancement of robotics and its efficiency
System leadership – emergence and maturity
No full textSince its emergence in the early 2000s, system leadership has been viewed as an important driver for building system capacity required for positive change. System leaders are those Heads or Principals who are willing to shoulder system wide roles in order to support the improvement of other schools as well as their own. The chapter is divided into three sections: the first, outlines the genesis of System Leadership pre-2010; the second, reviews the international literature post 2010 as the concept achieves maturity and is better embedded in policy reforms in many countries; and third, future challenges are identified