64623 research outputs found
Sort by
Unlock Self-Sustainability of Reconfigurable Intelligent Surface in Wireless Powered IoT Networks
Full text link—This article discusses the self-sustainability of recon-figurable intelligent surface (RIS) in wireless powered Internet of Things (IoT) networks. Our vision is that RIS helps improve energy harvesting and data transmission capabilities simultaneously , without the extra utilization of radio frequency (RF) spectrum and energy consumption. The inherent properties of RIS are first discussed to unveil its distinctive features, followed by a broader range of use cases motivated by the RIS as their enabling technology. The focus is on the application of RIS in the wireless powered IoT networks, and its potential to interconnect and support these practical use cases. Such an application is then thoroughly evaluated in a case study of a RIS-assisted wireless powered sensor network (WPSN), with system throughput, energy transmission time consumption, and energy harvesting as the key performance metrics. The comprehensive performance evaluation showcases the self-sustainable property of the RIS being unlocked in the considered scenario, identifying a clear pathway towards the future wireless powered IoT networks. We further pave that pathway by exploring research challenges and open issues related to emerging technological development
Restoring the dignity of indigenous people: Perspectives on tourism employment
No full textThe importance of dignity in tourism employment and the positive impact of Indigenous tourism activities are increasingly acknowledged. Nevertheless, the dignity and well-being of Indigenous people in urban tourism workplaces have received limited attention. Drawing on Indigenous Mexicans as a case study, we use cross-disciplinary concepts of dignity and humanistic management to address this gap by developing recommendations for restoring dignity to Indigenous groups through tourism employment in urban destinations. We explore how tourism employment has resulted in violations of the dignity of Indigenous peoples and illustrate how changes in employment practices across economic, sociocultural, and psychological dimensions can contribute to dignity restoration. By doing so, we advance a conceptual understanding of dignity and guide its practical implementation in tourism employment and management, and policy. Finally, we argue that dignity-restoring practices may also result in improved company performance and reputation as well as contribute to the sustainable development goals.•Poverty, climate change, and other pressures have forced Indigenous people migrate to cities in search of work opportunities•In urban areas, many Indigenous people are trapped in precarious forms of work that violate their dignity•Changes in tourism employment practices can contribute to dignity restoration of Indigenous people•Dignity-restoring employment practices can improve organizational performance while contributing to sustainable development goal
Iodine status of pregnant women from the Republic of Cyprus
Full text linkIodine supply is crucial during pregnancy to ensure the proper thyroid function of mother and baby and support fetal brain development. Little is known about iodine status or its dietary determinants in pregnant women in the Republic of Cyprus. We therefore recruited 128 pregnant women at their first-trimester ultrasound scan to a cross-sectional study. We collected spot-urine samples for the measurement of urinary iodine concentration (UIC, µg/L), and creatinine concentration (Creat, g/L), the latter of which allows us to correct for urine dilution and to compute the iodine-to-creatinine ratio (UI/Creat). Women completed a Food Frequency Questionnaire (FFQ) and a general questionnaire. We used a General Linear model to explore associations between maternal and dietary characteristics with UI/Creat. The median UIC (105 µg/L) indicated iodine deficiency according to the World Health Organisation criterion (threshold for adequacy=150 µg/L) and the UI/Creat was also low at 107 µg/g. Only 32% (n=45) of women reported the use of iodine-containing supplements; users had a higher UI/Creat than non-users (131 µg/g vs. 118 µg/g), though this difference was not significant in the adjusted analysis (P=0.37). Of the dietary components, only egg intake was significantly associated with a higher UI/Creat in adjusted analyses (P=0.018); there was no significant association with milk, dairy products, or fish intake. Our results suggest that pregnant women in Cyprus have inadequate iodine status and are at risk of mild-to-moderate iodine deficiency. Further research on dietary sources in this population is required
Data-independent acquisition mass spectrometry in severe rheumatic heart disease (RHD) identifies a proteomic signature showing ongoing inflammation and effectively classifying RHD cases
No full textA route towards the fabrication of large-scale and high-quality perovskite films for optoelectronic devices
No full textA study of integrable form factors in massless relativistic AdS 3
Full text linkWe show that the massless integrable sector of the AdS3 × S 3 × T 4 superstring theory, which admits a non-trivial relativistic limit, provides a setting where it is possible to determine exact minimal solutions to the form factor axioms, in integral form, based on analyticity considerations, along the same lines of ordinary relativistic integrable models. We construct in full detail the formulas for the two-and three-particle case, and show the similarities as well as the differences with respect to the off-shell Bethe ansatz procedure of Babujian et al. We show that our expressions pass a series of non-trivial consistency checks which are substantially more involved than in the traditional case. We speculate on the problems concerned in a possible generalisation to an arbitrary number of particles, and on a possible connection with the hexagon programme
Evaluation of Insurance Companies Considering Uncertainty: A Multi- Objective Network Data Envelopment Analysis Model with Negative Data and Undesirable Outputs
Full text linkUncertainty is an important issue to consider when evaluating entities in both public and private sectors. On the other hand, many operations have more than one stage process when some inputs are fed to the system to produce a number of intermediate measures. The intermediate measures are then transformed into final products in the subsequent stages. The composition method in network data envelopment analysis (NDEA) is a popular method for measuring the efficiency of a two-stage process. The composition method is fractional bi-objective programming that is solved by non-linear programming techniques such as bisection search. In this paper, the two-stage NDEA is extended with negative data and undesirable outputs. First, we propose an alternative linear model based on the goal programming technique to avoid complex non-linear calculations. Then, we use a method to transform negative data into positive and undesirable outputs into desirable ones. Finally, we develop the proposed model using the fuzzy α-cut approach in order to incorporate data uncertainty in the linear goal programming (GP) model. To validate the accuracy of the proposed model, a numerical example is solved. To show the applicability of the proposed model, a real case of 22 insurance companies is examined. We also perform a comparative analysis to specify the benchmark and inefficient companies. Comparative analysis can help managers to recognize where improvement should be investigated with priority
New regularity and uniqueness results in the multidimensional Calculus of Variations
Full text link"In the first part of the Thesis we develop a Regularity Theory for a polyconvex functional in compressible elasticity. In particular, we consider energy minimizers/stationary points of the functional\begin{equation}I(u)=\int\limits_\Om{\frac{1}{2}|\grad u|^2+\rho(\det\grad u)\;dx},\label{eq:SA.1.1}\end{equation}where \Omega\ss\R^2 is open and bounded, u\in W^{1,2}(\Om,\R^2) and \rho:\R\ra\R_0^+ smooth and convex with for all and becomes affine when exceeds some value Additionally, we may impose boundary conditions.\\The first general result we will establish is that every stationary point needs to be locally Hölder-continuous.Secondly, we prove that if the growth of is `small' s.t.\! the integrand is still uniformly convex, then all stationary points have to be in Next, a higher-order regularity result is shown.We show that all stationary points that are additionally of class and whose Jacobian is Hölder-continous are of class In particular, these results show that all stationary points have to be smooth for `small' enough. \\The theory described above works for fairly general domains and boundary conditions.We specify those by restricting to the unit ball, and we consider M-covering maps, which take the unit sphere to itself, covering the image times in the process, on the boundary. Under these circumstance, we construct radial symmetric M-covering stationary points to the functional, as given in \eqref{eq:SA.1.1}, which are at least of class In certain situations, depending mainly on the behaviour of and the stationary point itself, we are even able to guarantee maximal smoothness. \\In the second part, we will concentrate on uniqueness questions in various situations of finite elasticity. Starting in incompressible elasticity, the central point is to showthat for problems with uniformly convex integrands with ""small"" pressure, a unique global minimizer can be guaranteed. We make use of this statement by considering various examples and applications.One such application is the construction of a counterexample to regularity. Indeed, on the unit ball and for smooth boundary conditions we give a non-autonomous uniformly convex functional depending smoothly on however discontinously on where the unique global minimizer is Lipschitz but no better. Then we generalise the main result in various ways, for instance, we show that if the pressure is too large to guarantee uniqueness in the full class of admissible maps, one can still guarantee uniqueness up to the first Fourier-modes.Lastly, we discuss analogous statements for polyconvex integrands in compressible elasticity.
Psychological Determinants of Tourist Satisfaction and Destination Loyalty: The Influence of Perceived Overcrowding and Overtourism
No full textThis study develops and tests an integrative model of destination loyalty to tourist hotspot destinations. The study highlights the role of perceived destination adaptation and psychological reactive behaviors in determining tourist satisfaction and loyalty. The model was tested using data collected from 582 respondents who had recently visited one of the “overcrowded” Mediterranean coastal tourism destinations. Findings suggest that perceived destination adaptation negatively influences tourist satisfaction and positively influences reactive behaviors of approach, avoidance, and tolerance. Approach and avoidance behaviors predict assessed crowding levels and tourist satisfaction. Tourists’ tolerance levels on assessed crowding was insignificant. Assessed crowding levels negatively affect tourist satisfaction and intentions to revisit and recommend the destination while positively influencing objections to revisit and recommend the destination. Concomitantly, overtourism awareness moderated the effect of assessed crowding levels on tourist satisfaction and intentions to revisit and recommend the destination. Theoretical and managerial implications are discussed
Dairy as a Source of Iodine and Protein in the UK: Implications for Human Health Across the Life Course, and Future Policy and Research
Full text linkThis narrative review summarizes key concepts in dairy nutrition for supporting human health throughout the life course. Milk and dairy products have been a staple component of our diet for thousands of years and provide a wide range of important nutrients that are otherwise difficult to obtain from dairy-free diets. In this review, we provide a broad perspective on the nutritional roles of iodine and dairy protein in supporting human health during pregnancy and early life, childhood and adolescence, mid- and later-life. New methodologies to identify biomarkers of dairy intake via high-throughput mass spectrometry are discussed, and new concepts such as the role of the food matrix in dairy nutrition are introduced. Finally, future policy and research related to the consumption of dairy and non-dairy alternatives for health are discussed with a view to improving nutritional status across the lifespan
Data sources:
Access Repository Dashboard
Do you manage University of Surrey? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!