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See detailThe functional Breuer-Major theorem
Nourdin, Ivan UL; Nualart, David

in Probability Theory and Related Fields (in press)

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See detailOversampled DFT-Modulated Biorthogonal Filter Banks: Perfect Reconstruction Designs and Multiplierless Approximations
Alves Martins, Wallace UL; Shankar, Bhavani UL; Ottersten, Björn UL

in IEEE Transactions on Circuits and Systems. II, Express Briefs (in press)

We propose a novel methodology for designing oversampled discrete Fourier transform-modulated uniform filter banks. The analysis prototype is designed as a Nyquist filter, whereas the synthesis prototype ... [more ▼]

We propose a novel methodology for designing oversampled discrete Fourier transform-modulated uniform filter banks. The analysis prototype is designed as a Nyquist filter, whereas the synthesis prototype is designed to guarantee perfect reconstruction (PR) considering oversampling. The resulting optimization problem fits into the disciplined convex programming framework, as long as some convex objective function is employed, as the minimization of either the stop-band energy or the maximum deviation from a desired response. The methodology also accounts for near-PR multiplierless approximations of the prototype analysis and synthesis filters, whose coefficients are obtained in the sum-of-power-of-two (SOPOT) space. The quantized coefficients are computed using successive approximation of vectors, which is able to yield filters with a reduced number of SOPOT coefficients in a computationally efficient manner. The proposed methodology is especially appealing for supporting actual hardware deployments, such as modern digital transparent processors to be used in next-generation satellite payloads. [less ▲]

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See detailConcentration of the Intrinsic Volumes of a Convex Body
Lotz, Martin; McCoy, Michael B.; Nourdin, Ivan UL et al

in Geometric Aspects of Functional Analysis (in press)

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See detailThe Origins and Contemporary Development of Work-based Higher Education in Germany: Lessons for Anglophone Countries?
Graf, Lukas; Powell, Justin J W UL

in Wheelehan, Leesa; Bathmaker, Ann-Marie; Orr, Kevin (Eds.) et al Higher-level Vocational Education: The Route to High Skills and Productivity as well as Greater Equity? An International Comparative Analysis (in press)

Today, higher education is typically seen as offering the most assured pathways to secure careers and low unemployment rates. Yet, increasingly some groups, not least higher education graduates and their ... [more ▼]

Today, higher education is typically seen as offering the most assured pathways to secure careers and low unemployment rates. Yet, increasingly some groups, not least higher education graduates and their families paying ever-higher tuition fees, question the taken-for-granted contributions higher education makes to individuals and society as a whole. Despite decades of mass higher education expansion, even societies with strong systems continue to struggle to achieve their goal of universalizing participation and equalizing access. While in part this is due to limited public or corporate funding for (affordable) study opportunities, differentiated systems, such as in the US, also lack policy coordination and effective governance, providing a surfeit of options. While participation rates have climbed worldwide, higher education systems continue to produce winners (“insiders”) and losers (“outsiders”), even as the “schooled society” shifts the occupational structure upward. Market-oriented higher education systems face increasing privatization, which also involves financializing university governance. Many states have retrenched investments that had once underwritten universities’ flourishing and their moves toward massification. Tensions have deepened over who should pay for rising costs, exacerbated in an era of increasing status competition via higher education. In the face of such challenges globally, which alternatives exist? A prominent possibility, pioneered in Germany in the 1970s, are “dual study” programs offered by several organizational forms, from vocational academies to universities of applied sciences. Such hybrid programs fully integrate phases of higher education study and paid work in firms. Another potential advantage of apprenticeship training being offered in conjunction with higher education is that this would boost the reputation of apprenticeships overall. The German experience indicates that the attractiveness of the apprenticeship training system as a whole can be bolstered when it offers a viable pathway also for those individuals with a traditional university entrance certificate. If these students seriously consider and choose advanced work-based higher education, this may well increase the standing of apprenticeship training among students, their families, and employers. Thus, dual study programs provide an innovative model for policymaking and implementation. Especially when considering strategies to improve skill formation overall, to reduce the costs individuals must bear in attaining higher education, and to improve the fit between the expectations of employers and potential employees regarding skill formation, dual study programs excel. The origins and contemporary developments in work-based higher education in Germany offer lessons and inspiration for Anglophone countries, with their strong and differentiated higher education systems, to further bolster study programs coordinated with firms. [less ▲]

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See detailFescher als dein Schatten. Zur Präsenz des Deutschen in Österreich in der Alltagspraxis
Purschke, Christoph UL

in Hundt, Markus; Kleene, Andrea; Plewnia, Albrecht (Eds.) et al Regiolekte – Objektive Sprachdaten und subjektive Wahrnehmung (in press)

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See detailLuxembourg - Recent and Pending CJEU Cases: Fiscal Unity, Taxpayers' fundamental rights and the FIAT case
Pantazatou, Aikaterini UL

in Lang, Michael (Ed.) CJEU: Recent Developments in Direct Taxation 2019 (in press)

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See detailWelfare-Based Income Insecurity in the US and Germany: Evidence from Harmonized Panel Data
d'ambrosio, Conchita UL; Rohde, Nicholas; Tang, Kam Ki et al

in Journal of Economic Behavior and Organization (in press)

This paper develops normative approaches for measuring individual-level income insecurity. Using concepts derived from Expected Utility Theory and Prospect Theory, we build a suite of measures designed to ... [more ▼]

This paper develops normative approaches for measuring individual-level income insecurity. Using concepts derived from Expected Utility Theory and Prospect Theory, we build a suite of measures designed to capture various facets of psychologically distressing income risk. We present an application for the US and Germany from 1993-2013, employing conditionally heteroskedastic fixed-effects models to generate predictive densities for future incomes. Our results reveal much higher levels of income risk in the US relative to Germany, which can be mostly attributed to a higher level of autonomous, time-invariant volatility. State-by-state variations in liberal/conservative political administrations partially explain our results, and we find some evidence that trade exposure is a contributing factor in the US. [less ▲]

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See detailGastric interoception and gastric myoelectrical activity in bulimia nervosa and binge eating disorder
van Dyck, Zoé UL; Schulz, André UL; Blechert, Jens et al

in International Journal of Eating Disorders (in press)

Objective: Identifying factors that control food intake is crucial to the understanding and treatment of eating disorders characterized by binge eating. In healthy individuals, stomach distension plays an ... [more ▼]

Objective: Identifying factors that control food intake is crucial to the understanding and treatment of eating disorders characterized by binge eating. In healthy individuals, stomach distension plays an important role in the development of satiation, but gastric sensations might be overridden in binge eating. The present study investigated the perception of gastric signals (i.e., gastric interoception) and gastric motility in patients experiencing binge eating episodes, i.e. bulimia nervosa (BN) and binge-eating disorder (BED). Method: Twenty-nine patients with BN or BED (ED group) and 32 age-, sex-, and BMI-matched healthy controls (HC group) participated in the study. The onset of satiation and stomach fullness were assessed using a novel 2-step water load test (WLT-II). Gastric myoelectrical activity (GMA) was measured by electrogastrography (EGG) before and after ingestion of non-caloric water. Results: Individuals in the ED group drank significantly more water until reporting satiation during the WLT-II. The percentage of normal gastric myoelectrical power was significantly smaller in the ED group compared to HC, and negatively related to the number of objective binge-eating episodes per week in bulimic patients. Power in the bradygastria range was greater in ED than in HC subjects. Discussion: Patients with EDs have a delayed response to satiation compared to HC participants, together with abnormal GMA. Repeated binge eating episodes may induce disturbances to gastric motor function. [less ▲]

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See detailPatterns of health related gender inequalities – a cluster analysis of 45 countries
Heinz, Andreas UL

in Journal of Adolescent Health (in press), 66(6S), 27-37

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See detailGrenzgeographien der COVID-19-Pandemie
Florian, Weber; Wille, Christian UL

in Weber, Florian; Wille, Christian; Caesar, Beate (Eds.) et al Geographien der Grenze. Räume – Ordnungen – Verflechtungen (in press)

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See detailRemoving the saturation assumption in Bank-Weiser error estimator analysis in dimension three
Bulle, Raphaël UL; Chouly, Franz; Hale, Jack UL et al

in Applied Mathematics Letters (in press)

We provide a new argument proving the reliability of the Bank-Weiser estimator for Lagrange piecewise linear finite elements in both dimension two and three. The extension to dimension three constitutes ... [more ▼]

We provide a new argument proving the reliability of the Bank-Weiser estimator for Lagrange piecewise linear finite elements in both dimension two and three. The extension to dimension three constitutes the main novelty of our study. In addition, we present a numerical comparison of the Bank-Weiser and residual estimators for a three-dimensional test case. [less ▲]

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See detailLiving in the Shadow of the Past: Financial Profiles and Well-Being
d'ambrosio, Conchita UL; Clark, Andrew; Zhu, Rong

in Scandinavian Journal of Economics (in press)

We here consider the link between individual financial profiles over time and well-being, as measured by life satisfaction. We in particular look at annual self-reported financial worsening and ... [more ▼]

We here consider the link between individual financial profiles over time and well-being, as measured by life satisfaction. We in particular look at annual self-reported financial worsening and improvement information for over 25,000 individuals in Australian panel data from 2002 to 2017. We first find that satisfaction falls (rises) with a contemporaneous major financial worsening (improvement), with the the largest correlation being with financial worsening. Second, the experience of these financial events in the past continues to be linked to current well-being. Last, only the order of financial-improvement spells relates to well-being: a given number of past years where finances deteriorated has the same association with current well-being whether the deterioration occurred in one continuous spell or was interrupted. We last show that these associations are heterogeneous over the distribution of well-being. [less ▲]

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See detailBeam-inside-beam contact: Mechanical simulations of slender medical instruments inside the human body
Magliulo, Marco UL; Lengiewicz, Jakub UL; Zilian, Andreas UL et al

in Computer Methods and Programs in Biomedicine (in press)

Background and Objective. This contribution presents a rapid computational framework to mechanically simulate the insertion of a slender medical instrument in a tubular structure such as an artery, the ... [more ▼]

Background and Objective. This contribution presents a rapid computational framework to mechanically simulate the insertion of a slender medical instrument in a tubular structure such as an artery, the cochlea or another slender instrument. Methods. Beams are employed to rapidly simulate the mechanical behaviour of the medical instrument and the tubular structure. However, the framework’s novelty is its capability to handle the mechanical contact between an inner beam (representing the medical instrument) embedded in a hollow outer beam (representing the tubular structure). This "beam-insidebeam" contact framework, which forces two beams to remain embedded, is the first of its kind since existing contact frameworks for beams are "beam-to-beam" approaches, i.e. they repel beams from each other. Furthermore, we propose contact kinematics such that not only instruments and tubes with circular cross-sections can be considered, but also those with elliptical cross-sections. This provides flexibility for the optimization of patient-specific instruments. Results. The results demonstrate that the framework’s robustness is substantial, because only a few increments per simulation and a few iterations per increment are required, even though large deformations, large rotations and large curvature changes of both the instrument and tubular structure occur. The stability of the framework remains high even if the modulus of the inner tube is thousand times larger than that of the outer tube. A mesh convergence study furthermore exposes that a relatively small number of elements are required to accurately approach the reference solution. Conclusions. The framework’s high simulation speed originates from the exploitation of the rigidity of the beams’ cross-sections to quantify the exclusion between the inner and the hollow outer beam. This rigidity limits the accuracy of the framework at the same time, but this is unavoidable since simulation accuracy and simulation speed are two competing interests. Hence, the framework is particularly attractive if simulation speed is preferred over accuracy. [less ▲]

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See detailHybrid User Pairing for Spectral and Energy Efficiencies in Multiuser MISO-NOMA Networks with SWIPT
Nguyen, Toan-Van; Nguyen, van Dinh UL; Costa, Daniel Benevides Da et al

in IEEE Transactions on Communications (in press)

In this paper, we propose a novel hybrid user pairing (HUP) scheme in multiuser multiple-input single-output nonorthogonal multiple access networks with simultaneous wireless information and power ... [more ▼]

In this paper, we propose a novel hybrid user pairing (HUP) scheme in multiuser multiple-input single-output nonorthogonal multiple access networks with simultaneous wireless information and power transfer. In this system, two information users with distinct channel conditions are optimally paired while energy users perform energy harvesting (EH) under non-linearity of the EH circuits. We consider the problem of jointly optimizing user pairing and power allocation to maximize the overall spectral efficiency (SE) and energy efficiency (EE) subject to userspecific quality-of-service and harvested power requirements. A new paradigm for the EE-EH trade-off is then proposed to achieve a good balance of network power consumption. Such design problems are formulated as the maximization of nonconcave functions subject to the class of mixed-integer non-convex constraints, which are very challenging to solve optimally. To address these challenges, we first relax binary pairing variables to be continuous and transform the design problems into equivalent non-convex ones, but with more tractable forms. We then develop low-complexity iterative algorithms to improve the objectives and converge to a local optimum by means of the inner approximation framework. Simulation results show the convergence of proposed algorithms and the SE and EE improvements of the proposed HUP scheme over state-of-the-art designs. In addition, the effects of key parameters such as the number of antennas and dynamic power at the BS, target data rates, and energy threshold, on the system performance are evaluated to show the effectiveness of the proposed schemes in balancing resource utilization. [less ▲]

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See detailApplication of the DAD method for damage 1 localisation on an existing bridge structure using 2 close-range UAV photogrammetry
Erdenebat, Dolgion; Waldmann, Danièle UL

in Engineering Structures (in press)

A novel damage detection and localisation method, the so-called Deformation Area Difference method for localisation of damages in bridge structures is introduced. The method is based on static load ... [more ▼]

A novel damage detection and localisation method, the so-called Deformation Area Difference method for localisation of damages in bridge structures is introduced. The method is based on static load-deflection experiments with the prerequisite of high precise deflection measurement. This study presents the first experiences of applying the DAD method on a real bridge structure. The investigated structure is a prestressed concrete slab bridge with a span of about 27 m, which was built in 2013. The loading on the bridge is applied using six heavy trucks, each weighing up to 32 t. A wide range of the modern measurement technologies were used to achieve high precision measurements of the bridge deflection along the longitudinal axis, namely the photogrammetry using a big size drone, laser scanner, total station, levelling and displacement sensors. The performed load-deflection test was non-destructive since the maximum deformation did not exceed the serviceability limit state. The exercise of the novel damage detection and localisation method on a real structure initiated further optimisation opportunities of the DAD method and the study of its limits. Several boundary conditions and methodical influence factors related to the applicability of the proposed method were analysed, such as impacts of measurement precision, damage degree, the position of damage, and the number of measurement repetitions. [less ▲]

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See detailMonotonic axial compressive behaviour and confinement mechanism of square CFRP-steel tube confined concrete
Wang, Yanlei; Cai, Gaochuang; Si Larbi, Amir et al

in Engineering Structures (in press)

Steel tube confined concrete (STCC) is widely used in the vertical members of high-rise buildings such as columns. The axial load is not directly resisted by the steel tube in STCC, but is resisted via ... [more ▼]

Steel tube confined concrete (STCC) is widely used in the vertical members of high-rise buildings such as columns. The axial load is not directly resisted by the steel tube in STCC, but is resisted via the interfacial frictional stress between steel tube and concrete core, which is different with that of concrete filled steel tube (CFT) members and would effectively suppress the outward local buckling of steel tube at early stage. Recently, fibre-reinforced polymer (FRP) confined STCC presents a potential to enhance the ductility and durability of such vertical elements. This paper presents an experimental study on monotonic axial compressive behaviour of carbon FRP (CFRP) confined STCC (CFRP- STCC) stub column and an analytical study on the confinement mechanism of and the ultimate axial bearing capacity of the elements. A three-stage confinement mechanism involving the different contributions of the steel tube and the CFRP wrap in CFRP-STCC elements was proposed based on the test results. A prediction model of the ultimate axial bearing capacity of CFRP-STCC stub columns was developed subsequently. Results show that the presence of CFRP wrap enhances effectively the load-bearing capacity and the ductility of steel tube confined plain concrete and reinforced concrete elements, and significantly prevents the local buckling of the steel tubes in the elements. The proposed prediction model of ultimate axial bearing capacity assesses test results with a great agreement. [less ▲]

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See detailThe ABCD of cyclic quadrilaterals
Begalla, Engjell UL; Perucca, Antonella UL

Article for general public (in press)

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See detailTokenization of Sukuk: Ethereum Case Study
Khan, Nida UL; Kchouri, Bilal UL; Yatoo, Nissar Ahmad et al

in Global Finance Journal (in press)

Sukuk is a financial instrument that provides returns similar to conventional bonds. It has served to cater to the capital requirements of big corporations and governments, while circumventing interest to ... [more ▼]

Sukuk is a financial instrument that provides returns similar to conventional bonds. It has served to cater to the capital requirements of big corporations and governments, while circumventing interest to adhere to the Shariah law. Sukuk can be touted as Shariah-compliant bonds that rank amongst the most successful and the fastest growing financial instrument in the Islamic economy. The sukuk research area is marked by a dearth of quantitative literature, compared to qualitative academic work. This paper seeks to fill this existing gap, and introduces a novel, exploratory analysis of sukuk tokenization based on a case study. The funding needs of small and medium enterprises remains largely unmet through sukuk on account of the high costs involved, among other reasons. As we show in this paper, blockchains can aid to lower the cost incurred through the tokenization of sukuk. We highlight some of the key challenges involved in the issuance of sukuk and discuss their resolution using blockchain. We also provide a taxonomy of blockchain applications in finance, with a particular focus on Islamic finance. Our paper reviews different blockchain architectures to assess their viability for tokenization. We conduct a novel case study on sukuk tokenization by implementing a basic smart contract for Sukuk al-Murabaha on Ethereum. The paper concludes by a conceptual analysis of feasibility concerns, based on a comparison of the conducted cost-benefit analysis of conventional sukuk issuance with tokenization. [less ▲]

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See detailNon-problematic and problematic binge-watchers do not differ on prepotent response inhibition: A preregistered pilot experimental study
Flayelle, Maèva; Verbruggen, Frederick; Schiel, Julie et al

in Human Behavior and Emerging Technologies (in press)

Binge‐watching (i.e., watching multiple episodes of a TV series back‐to‐back) has become standard viewing practice. Yet, this phenomenon has recently generated concerns regarding its potential negative ... [more ▼]

Binge‐watching (i.e., watching multiple episodes of a TV series back‐to‐back) has become standard viewing practice. Yet, this phenomenon has recently generated concerns regarding its potential negative outcomes on the long run. The presumed addictive nature of this behavior has also received increasing scientific interest, with preliminary findings reporting associations between binge‐watching, self‐control impairments, and heightened impulsivity. Nevertheless, previous studies only relied on self‐report data. The current preregistered study therefore investigated whether non‐problematic and problematic binge‐watchers differ not only in self‐report but also in experimental measures of behavioral impulsivity. Based on their viewing characteristics, 60 TV series viewers were allocated to one of three predetermined groups: non‐binge‐watchers, trouble‐free binge‐watchers (absence of negative impact) and problematic binge‐watchers (presence of negative impact). Participants performed tasks assessing response inhibition (Stop‐Signal Task) and impulsive reward seeking (Delay Discounting Task), and completed self‐reported questionnaires on sociodemographics, affect, symptoms of problematic binge‐watching, and impulsive personality traits. According to the preregistered analytic plan, one‐way analyses of covariance (ANCOVAs) were computed to compare the predetermined groups. With gender being controlled for, no differences were identified in self‐report impulsivity and response inhibition abilities. Trouble‐free binge‐watchers reported higher rates of delay discounting than non‐binge‐watchers. Although preliminary, our results challenge the notion that problematic binge‐watching is characterized by the same neuropsychological impairments as in addictive disorders as, contrary to our preregistered hypotheses, no differences emerged between non‐problematic and problematic binge‐watchers regarding self‐control variables considered as hallmarks of the latter. These results suggest the need for formulating and testing alternative conceptualizations of problematic binge‐watching. [less ▲]

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