1,362,801 research outputs found
Object learning: Developing a decolonial approach to active learning content
No full textIn this keynote, Atif will take us on a journey through his career from international Sociology doctoral student to Independent Film Producer, Immersive EdTech developer, Lecturer, and Educator. At the core of all his work has been the use of innovative storytelling approaches to inform social change. In the address, Atif will explore some insights in using immersive technologies as a mode of active learning in formal and informal learning settings. Through the example of Millennium Mills: Feeding Edwardian London, Atif will map his “Thinking with History” critical pedagogy in creating immersive content. In particular, Atif will reflect on the underlying principles that have shaped his thinking on the use of immersive technologies - like VR - to deliver East London public history content; and how he aspires to develop more effective active learning and decolonial modes of teaching and thinking
Object learning: A journey towards active learning. An on-line lecture series
No full textIn the address, Atif will explore some insights in using immersive technologies as a mode of active learning in formal and informal learning settings. Through the example of Millennium Mills: Feeding Edwardian London, Atif will map his “Thinking with History” critical pedagogy in creating immersive content. In particular, Atif will reflect on the underlying principles that have shaped his thinking on the use of immersive technologies - like VR - to deliver East London public history content; and how he aspires to develop more effective active learning and decolonial modes of teaching and thinking
Accelerated SVD-based initialization for nonnegative matrix factorization
No full textNonnegative matrix factorization (NMF) is a popular dimensionality reduction technique. NMF is typically cast as a non-convex optimization problem solved via standard iterative schemes, such as coordinate descent methods. Hence the choice of the initialization for the variables is crucial as it will influence the factorization quality and the convergence speed. Different strategies have been proposed in the literature, the most popular ones rely on singular value decomposition (SVD). In particular, Atif et al. (Pattern Recognit Lett 122:53-59, 2019) have introduced a very efficient SVD-based initialization, namely NNSVD-LRC, that overcomes the drawbacks of previous methods, namely, it guarantees that (i) the error decreases as the factorization rank increases, (ii) the initial factors are sparse, and (iii) the computational cost is low. In this paper, we improve upon NNSVD-LRC by using the low-rank structure of the residual matrix; this allows us to obtain NMF initializations with similar quality to NNSVD-LRC (in terms of error and sparsity) while reducing the computational load. We evaluate our proposed solution over other NMF initializations on several real dense and sparse datasets
Photocatalytic hydrogen production with reduced graphene oxide (RGO)-CdZnS nano-composites synthesized by solvothermal decomposition of dimethyl sulfoxide as the sulfur source
No full textIn order to increase photocatalytic activity, to control particle size and to diminish photo-corrosion of CdZnS based photocatalysts, different compositions of Cd((1-x))Zn(x)Sphotocatalysts were decorated on the reduced graphene oxide (RGO). The target photocatalytic composite structures (RGO-Cd(1-x)ZnxS) were firstly prepared by a solvothermal method using dimethyl sulfoxide (DMSO) as the solvent and sulfur source. RGO-Cd((1-x))Zn(x)Snanocomposites were characterized by the x-ray diffraction (XRD), the transmission electron microscopy (TEM), the scanning electron microscopy (SEM), ultraviolet-visible (UV-vis) diffuse reflectance spectra (DRS), photoluminescence (PL) spectra, The transient photocurrent responses, and the energy-dispersive X-ray spectrometry (EDS). Purity, the particle size of 40 nm, the crystallite sizes between 20.8 and 19.1 angstrom and cubic structure of the photocatalysts could be easily achieved by controlled thermal decomposition of DMSO. Decorating the photocatalysts on RGO structure prevented aggregation of Cd(1-x)ZnxS particles, enhanced transfer of photogenerated charge carriers, and increased the electron transfer rate of the photocatalysts, which provided a better photocatalytic activity. Moreover, loading photo-reduced platinum (Pt) nanoparticles on the RGO-Cd((1-x))Zn(x)Snanocomposite showed a significant increase in hydrogen evolution rate. Among the photocatalysts employed herein, RGO-Cd0.6Zn0.4S-Pt (5%) structure showed the highest activity with 184 mu mol h(-1) hydrogen evolution rate and 24.1% apparent quantum efficiency. Presences of RGO in the nanocomposite structure and synthesizing it with solvothermal method by using DMSO apparently increased the stability and activity of the nanocomposites
Resolving Debt Overhang: Political Constraints in the Aftermath of Financial Crises
No full textDebtors bear the brunt of a decline in asset prices associated with financial crises and policies aimed at partial debt relief may be warranted to boost growth in the midst of crises. Drawing on the US experience during the Great Recession of 2008-09 and historical evidence in a large panel of countries, we explore why the political system may fail to deliver such policies. We find that during the Great Recession creditors were able to use the political system more effectively to protect their interests through bailouts. More generally we show that politically countries become more polarized and fractionalized following financial crises. This results in legislative stalemate, making it less likely that crises lead to meaningful macroeconomic reforms.
Segmented capacitance tomography electrodes: a design and experimental verifications
No full textA segmented capacitance tomography system for real-time imaging of multiphase flows is developed and pre-sented in this work. The earlier research shows that the electrical tomography (ECT) system is applicable in flow visualization (image reconstruction). The acquired concentration profile ob-tained from capacitance measurements able to imaged liquid and gas mixture in pipelines meanwhile the system development is designed to attach on a vessel. The electrode plates which act as the sensor previously has been assembled and fixed on the pipeline, thus it causes obscurity for the production to have any new process installation in the future. Therefore, a segmented electrode sensor offers a new design and idea on ECT system which is portable to be assembled in different diameter sizes of pipeline, and it is flexible to apply in any number due to different size of pipeline without the need of redesigning the sensing module. The new ap-proach of this sensing module contains the integration intelligent electrode sensing circuit on every each of electrode sensors. A microcontroller unit and data acquisition (DAQ) system has been integrated on the electrode sensing circuit and USB technology was applied into the data acquisition system making the sensor able to work independently. Other than that the driven guard that usually placed between adjacent measuring electrodes and earth screen has been embedded on the segmented electrode sensor plates. This eliminates the cable noise and the electrode, so the signal conditioning board can be expanded according to pipe diameter
Essays on Household Credit Markets and Business Cycles
No full textWhat is the role of household credit markets in the business cycle? Do credit market conditions and household debt positions amplify fluctuations in employment and output, or are they passive reflections of the state of the real economy? Should public policy intervene in credit markets when household leverage grows rapidly, or are credit market outcomes efficient from a macroeconomic perspective? This collection of essays empirically investigates the interplay between household credit markets and the real economy.
Chapter 1, co-authored with Gyozo Gyongyosi, examines the household debt-deflation channel of recessions. The chapter isolates the effect of a sudden increase in real household debt burdens by exploiting variation across individuals and regions in exposure to foreign currency debt during the Hungarian currency crisis of 2008. The sudden revaluation of household debt burdens caused by the exchange rate depreciation translates into an increase in default rates, a collapse in consumption, and a significantly worse local recession. The chapter presents evidence of negative spillover effects on local firms and households that did not borrow in foreign currency, consistent with negative financial externalities of debt financing.
Chapter 2, co-authored with Atif Mian and Amir Sufi, analyzes the consequences of household credit expansions using panel data for 30 mostly advanced economies over the past 40 years. Expansions in household credit are associated with a boom and subsequent reversal in output. The chapter argues that credit supply shocks play an important role in instigating increases in credit, while macroeconomic frictions translate debt-induced declines in spending into declines in output.
Chapter 3, co-authored with Atif Mian and Amir Sufi, investigates how credit supply expansions affect the real economy. The chapter develops a new methodology for distinguishing whether credit expansions operate by increasing production capacity or by boosting aggregate demand. The chapter then explores these channels in the context of two natural experiments for credit supply expansion: banking deregulation in the United States during the 1980s and the introduction of the euro in the 2000s. Evidence from these episodes suggests that credit expansions tend to influence real activity primarily by raising aggregate demand
Phthalocyanine-aniline dyad constructed with click electrochemistry: a novel hybrid electrochromic material
No full textA novel hybrid electrochromic material, dyad of poly 4-azidoaniline (PANI-N-3) and manganese phthalocyanine bearing terminal alkynyl moieties (TA-MnPc), was firstly prepared as an electrochromic anode (ITO/PANI-N-3-TA-MnPc). ITO/PANI-N-3-TA-MnPc was developed to improve the coloration efficiency, switching time, cycle live, and the viability of the phthalocyanine and aniline for the electrochromic applications. Click electrochemistry reaction (CEC) was employed for the binding of TA-MnPc to the electropolymerized PANI-N-3 film on the ITO electrode. Characterization of the constructed electrode was performed with square wave voltammetry (SWV), infra-red spectroscopy (IR), scanning electron microscopy (SEM), and 4-probe conductometer, and then it was tested as a potential electrochromic material. PANI-N-3-TA-MnPc hybrid chromophore provided extraordinary electrochromic responses with improved coloration efficiency, faster switching times, and long cycle live. Color change between green and brown with faster switching times (0.50 s) and longer cycle live (no optical lose with 300 CA cycles) made this hybrid material a possible building blocks for advanced electrochromic devices needing green-brown color change with high optical contrasts and faster response times
Supplemental_Figure_1A – Supplemental material for A Review of MicroRNA Biomarkers in Traumatic Brain Injury
No full textSupplemental material, Supplemental_Figure_1A for A Review of MicroRNA Biomarkers in Traumatic Brain Injury by Hamna Atif and Steven D Hicks in Journal of Experimental Neuroscience</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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