cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Evaluation of imputation techniques with varying percentage of missing data
Creators: name: Sangari, Seema
name: Ray, Herman E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Methodology (stat.ME)
subject: Other Statistics (stat.OT)
subject: FOS: Computer and information sciences

description: Missing data is a common problem which has consistently plagued statisticians and applied analytical researchers. While replacement methods like mean-based or hot deck imputation have been well researched, emerging imputation techniques enabled through improved computational resources have had limited formal assessment. This study formally considers five more recently developed imputation methods: Amelia, Mice, mi, Hmisc and missForest - compares their performances using RMSE against actual values and against the well-established mean-based replacement approach. The RMSE measure was consolidated by method using a ranking approach. Our results indicate that the missForest algorithm performed best and the mi algorithm performed worst.
description: 16 pages, 21 figures, 3 tables
Exotic Looped Trajectories of Photons in Three-Slit Interference
Creators: name: Magana-Loaiza, Omar S.
name: De Leon, Israel
name: Mirhosseini, Mohammad
name: Fickler, Robert
name: Safari, Akbar
name: Mick, Uwe
name: McIntyre, Brian
name: Banzer, Peter
name: Rodenburg, Brandon
name: Leuchs, Gerd
name: Boyd, Robert W.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The validity of the superposition principle and of Born's rule are well-accepted tenants of quantum mechanics. Surprisingly, it has recently been predicted that the intensity pattern formed in a three-slit experiment is seemingly in contradiction with the predictions of the most conventional form of the superposition principle when exotic looped trajectories are taken into account. However, the probability of observing such paths is typically very small and thus rendering them extremely difficult to measure. In this work, we confirm the validity of Born's rule and present the first experimental observation of these exotic trajectories as additional paths for the light by directly measuring their contribution to the formation of optical interference fringes. We accomplish this by enhancing the electromagnetic near-fields in the vicinity of the slits through the excitation of surface plasmons. This process effectively increases the probability of occurrence of these exotic trajectories, demonstrating that they are related to the near-field component of the photon's wavefunction.
A finite volume model of aerodynamic noise generation
Creators: name: Jenvey, Peter Lee.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Multi-label Classification of Aircraft Heading Changes Using Neural Network to Resolve Conflicts
Creators: name: Rahman, Md Siddiqur
name: Lapasset, Laurent
name: Mothe, Josiane
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: An aircraft conflict occurs when two or more aircraft cross at a certain distance at the same time. Specific air traffic controllers are assigned to solve such conflicts. A controller needs to consider various types of information in order to solve a conflict. The most common and preliminary information is the coordinate position of the involved aircraft. Additionally, a controller has to take into account more information such as flight planning, weather, restricted territory, etc. The most important challenges a controller has to face are: to think about the issues involved and make a decision in a very short time. Due to the increased number of aircraft, it is crucial to reduce the workload of the controllers and help them make quick decisions. A conflict can be solved in many ways, therefore, we consider this problem as a multi-label classification problem. In doing so, we are proposing a multi-label classification model which provides multiple heading advisories for a given conflict. This model we named CRMLnet is based on a novel application of a multi-layer neural network and helps the controllers in their decisions. When compared to other machine learning models, our CRMLnet has achieved the best results with an accuracy of 98.72% and ROC of 0.999. The simulated data set that we have developed and used in our experiments will be delivered to the research community.
description: This paper has been withdraw by the Authors due to some crucial errors and measurements
The Nexus Between Financial Development and Economic Growth in Ethiopia
Creators: name: Endris, Meron
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2016

description: The paper examined the empirical relationship between economic growth and financial development in Ethiopia over the period 1980–2014. The long-run and short-run parameters were estimated with a use of autoregressive distributed lag (ARDL) bounds testing approach for co integration analysis. To determine the direction of causality, Granger causality analysis was done. Empirical findings indicate,there is long-run associationbetween economic growth and proxy of financial deepening, broad money and private sector credit while proxy of financial widening, trade openness has positive significant relationship with economic growth but financial liberalization has negative significant association with economic growth. The overall result indicates economic growth has a significant positive effect on financial development. The magnitude of the ECT coefficient is -0.8545 justified about 85% of the disequilibrium annually converge towards long run equilibrium in the following year. The Granger causality testis consistent with the co-integration result indicating uni-directional causality between financial development and economic growth in Ethiopia for the period under study.The result supports demand following hypotheses;means that economic growth is leading to the financial sector development in Ethiopia. Hence, confirm the heavy hand of the government in the financial sector. Keywords: financial development, economic growth, ARDL bounds test, cointegration, granger causality
A theoretical and experimental investigation into the microgeometry of ground surfaces in contact - the heat transfer requirements
Creators: name: Idrus, Nirwan.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Lattice Dirac Fermions on a Simplicial Riemannian Manifold
Creators: name: Brower, Richard C.
name: Fleming, George T.
name: Gasbarro, Andrew D.
name: Raben, Timothy G.
name: Tan, Chung-I
name: Weinberg, Evan S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The lattice Dirac equation is formulated on a simplicial complex which approximates a smooth Riemann manifold by introducing a lattice vierbein on each site and a lattice spin connection on each link. Care is taken so the construction applies to any smooth D-dimensional Riemannian manifold that permits a spin connection. It is tested numerically in 2D for the projective sphere ${\mathbb S}^2$ in the limit of an increasingly refined sequence of triangles. The eigenspectrum and eigenvectors are shown to converge rapidly to the exact result in the continuum limit. In addition comparison is made with the continuum Ising conformal field theory on ${\mathbb S}^2$. Convergence is tested for the two point, $\langle ε(x_1) ε(x_2) \rangle$, and the four point, $\langle σ(x_1) ε(x_2) ε(x_3 )σ(x_4) \rangle $, correlators for the energy, $ε(x) = i \bar ψ(x)ψ(x)$, and twist operators, $σ(x)$, respectively.
description: 53 pages, 29 figures
Fredholm Toeplitz operators on doubling Fock spaces
Creators: name: Hu, Zhangjian
name: Virtanen, Jani A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Functional Analysis (math.FA)
subject: Complex Variables (math.CV)
subject: FOS: Mathematics
subject: 47B35, 30H20

description: Recently the authors characterized the Fredholmn properties of Toeplitz operators on weighted Fock spaces when the Laplacian of the weight function is bounded below and above. In the present work the authors extend their characterization to doubling Fock spaces with a subharmonic weight whose Laplacian is a doubling measure. The geometry induced by the Bergman metric for doubling Fock spaces is much more complicated than that of the Euclidean metric used in all the previous cases to study Fredholmness, which leads to considerably more involved calculations.
Revisiting the constraints on annihilating dark matter by radio observational data of M31
Creators: name: Chan, Man Ho
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Recent gamma-ray observations and radio observations put strong constraints on the parameters of dark matter annihilation. In this article, we derive new constraints for six standard model annihilation channels by using the recent radio data of M31 galaxy. The new constraints are generally tighter than the constraints obtained from 6 years of Fermi Large Area Telescope gamma-ray observations of the Milky Way dwarf spheroidal satellite galaxies. The conservative lower limits of dark matter mass annihilating via $b\bar{b}$, $μ^+μ^-$ and $τ^+τ^-$ channels are 90 GeV, 90 GeV and 80 GeV respectively with the canonical thermal relic cross section and the Burkert profile being the dark matter density profile. Hence, our results do not favor the most popular models of the dark matter interpretation of the Milky Way GeV gamma-ray excess.
description: Accepted for publication in Physical Review D
Asymptotic properties of Principal Component Analysis and shrinkage-bias adjustment under the Generalized Spiked Population model
Creators: name: Dey, Rounak
name: Lee, Seunggeun
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistics Theory (math.ST)
subject: Machine Learning (stat.ML)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: Primary 62H25, secondary 15A18

description: With the development of high-throughput technologies, principal component analysis (PCA) in the high-dimensional regime is of great interest. Most of the existing theoretical and methodological results for high-dimensional PCA are based on the spiked population model in which all the population eigenvalues are equal except for a few large ones. Due to the presence of local correlation among features, however, this assumption may not be satisfied in many real-world datasets. To address this issue, we investigated the asymptotic behaviors of PCA under the generalized spiked population model. Based on the theoretical results, we proposed a series of methods for the consistent estimation of population eigenvalues, angles between the sample and population eigenvectors, correlation coefficients between the sample and population principal component (PC) scores, and the shrinkage bias adjustment for the predicted PC scores. Using numerical experiments and real data examples from the genetics literature, we showed that our methods can greatly reduce bias and improve prediction accuracy.
Verified eigenvalue and eigenvector computations using complex moments and the Rayleigh$\unicode{x2013}$Ritz procedure for generalized Hermitian eigenvalue problems
Creators: name: Imakura, Akira
name: Morikuni, Keiichi
name: Takayasu, Akitoshi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65F15, 65G20, 65G50

description: We propose a verified computation method for eigenvalues in a region and the corresponding eigenvectors of generalized Hermitian eigenvalue problems. The proposed method uses complex moments to extract the eigencomponents of interest from a random matrix and uses the Rayleigh$\unicode{x2013}$Ritz procedure to project a given eigenvalue problem into a reduced eigenvalue problem. The complex moment is given by contour integral and approximated using numerical quadrature. We split the error in the complex moment into the truncation error of the quadrature and rounding errors and evaluate each. This idea for error evaluation inherits our previous Hankel matrix approach, whereas the proposed method enables verification of eigenvectors and requires half the number of quadrature points for the previous approach to reduce the truncation error to the same order. Moreover, the Rayleigh$\unicode{x2013}$Ritz procedure approach forms a transformation matrix that enables verification of the eigenvectors. Numerical experiments show that the proposed method is faster than previous methods while maintaining verification performance and works even for nearly singular matrix pencils and in the presence of multiple and nearly multiple eigenvalues.
description: 23 pages, 4 figures
Benchmarking the Graphulo Processing Framework
Creators: name: Weale, Timothy
name: Gadepally, Vijay
name: Hutchison, Dylan
name: Kepner, Jeremy
Publisher: name: arXiv
Year: 2016
Subjects: subject: Databases (cs.DB)
subject: Mathematical Software (cs.MS)
subject: Performance (cs.PF)
subject: FOS: Computer and information sciences

description: Graph algorithms have wide applicablity to a variety of domains and are often used on massive datasets. Recent standardization efforts such as the GraphBLAS specify a set of key computational kernels that hardware and software developers can adhere to. Graphulo is a processing framework that enables GraphBLAS kernels in the Apache Accumulo database. In our previous work, we have demonstrated a core Graphulo operation called \textit{TableMult} that performs large-scale multiplication operations of database tables. In this article, we present the results of scaling the Graphulo engine to larger problems and scalablity when a greater number of resources is used. Specifically, we present two experiments that demonstrate Graphulo scaling performance is linear with the number of available resources. The first experiment demonstrates cluster processing rates through Graphulo's TableMult operator on two large graphs, scaled between $2^{17}$ and $2^{19}$ vertices. The second experiment uses TableMult to extract a random set of rows from a large graph ($2^{19}$ nodes) to simulate a cued graph analytic. These benchmarking results are of relevance to Graphulo users who wish to apply Graphulo to their graph problems.
description: 5 pages, 4 figures, IEEE High Performance Extreme Computing (HPEC) conference 2016
Presented in Partial Fulfillment of the Requirements for the Degree of Master of Science in Accounting and Finance
Creators: name: Getahun, Amano
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2014

description: This study investigated the determinants of commercial banks" lending behavior in the Ethiopian context. The study aimed to test and confirm the effectiveness of the common determinants of commercial banks lending behavior and how it affects the lending behavior of commercial banks in Ethiopia. Balanced fixed effect panel regression was used for the data of eight commercial banks in the sample covered the period from 2001 to 2013. Seven factors affecting banks loan and advance were selected and analyzed. The results of panel data regression analysis showed that volume of deposit and bank size had positive and significant impact on loan and advance. Liquidity ratio and interest rate had negative and significant impact on loan and advance. Cash reserve requirement, and inflation rate had positive and significant impact on loan and advance but the coefficient sign was not as expected. Real GDP growth rate had statistically insignificant impact on bank"s loan and advance. The study then suggests that commercial banks should focus on mobilizing more deposits as this will enhance their lending performance and should formulate critical, realistic and comprehensive strategic and financial plans
Factors Determining Effectiveness of Internal Audit in Ethiopian Commercial Banks
Creators: name: Misganaw, Tadiwos
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2016

description: Internal audit has an important role in helping a firm to achieve its objective when it is implemented, operated, and managed effectively. Organizations which effectively implemented, operated and managed internal auditing were better able to identify their business risks and system inefficiencies for the sake of taking corrective actions and improvement in the process. The overall objective of the study is to identify the factors determining the effectiveness of internal audit in Ethiopian commercial banks. The study used purposive sampling method and covered the head office internal auditors of Ethiopian Commercial Banks. The study adopted mixed research method by employing quantitative and qualitative research methods. The quantitative research method used through 147 usable self administered questionnaires. These questionnaires were constructed in 5-point likert scale, distributed to internal auditors of Ethiopian Commercial Banks, and analyzed using SPSS statistical software. The qualitative research method used through personal interview with internal audit dir ectors of Ethiopian commercial banks and selected documents review. According to the results of the study; independence of internal audit, competence of internal audit team, and management supports were strong and statistically significant effect on the effectiveness of internal audit regarding on value adding role, enhance department performance, and enha nce organizational performance. In this regard, independence of internal audit, competence of internal audit teams and management supports were the factors determining effectiveness of internal audit in Ethiopian commercial banks. The researcher mainly recommended; give attention on the development of certified personnel, top management and IA team work collaboratively in changing audit culture, and to work in using IA softwares. Key words: Internal Audit, Ethiopian Commercial Banks, and Effectiveness of Internal Audit
Electromagnetic 3D subsurface imaging with source sparsity for a synthetic object
Creators: name: Pursiainen, Sampsa
name: Kaasalainen, Mikko
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Mathematical Physics (math-ph)
subject: Medical Physics (physics.med-ph)
subject: FOS: Physical sciences
subject: 65R32, 85A99

description: This paper concerns electromagnetic 3D subsurface imaging in connection with sparsity of signal sources. We explored an imaging approach that can be implemented in situations that allow obtaining a large amount of data over a surface or a set of orbits but at the same time require sparsity of the signal sources. Characteristic to such a tomography scenario is that it necessitates the inversion technique to be genuinely three-dimensional: For example, slicing is not possible due to the low number of sources. Here, we primarily focused on astrophysical subsurface exploration purposes. As an example target of our numerical experiments we used a synthetic small planetary object containing three inclusions, e.g. voids, of the size of the wavelength. A tetrahedral arrangement of source positions was used, it being the simplest symmetric point configuration in 3D. Our results suggest that somewhat reliable inversion results can be produced within the present a priori assumptions, if the data can be recorded at a specific resolution. This is valuable early-stage knowledge especially for design of future planetary missions in which the payload needs to be minimized, and potentially also for the development of other lightweight subsurface inspection systems.
description: 17 pages, 5 figures. This is an author-created, un-copyedited version of an article accepted for publication/published in Inverse Problems. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://doi.org/10.1088/0266-5611/31/12/125004
Finding Strong Gravitational Lenses Through Self-Attention
Creators: name: Thuruthipilly, Hareesh
name: Zadrozny, Adam
name: Pollo, Agnieszka
name: Biesiada, Marek
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: The upcoming large scale surveys like LSST are expected to find approximately $10^5$ strong gravitational lenses by analysing data of many orders of magnitude larger than those in contemporary astronomical surveys. In this case, non-automated techniques will be highly challenging and time-consuming, even if they are possible at all. We propose a new automated architecture based on the principle of self-attention to find strong gravitational lenses. The advantages of self-attention-based encoder models over convolution neural networks are investigated, and ways to optimise the outcome of encoder models are analysed. We constructed and trained 21 self-attention based encoder models and five convolution neural networks to identify gravitational lenses from the Bologna Lens Challenge. Each model was trained separately using 18,000 simulated images, cross-validated using 2,000 images, and then applied to a test set with 100,000 images. We used four different metrics for evaluation: classification accuracy, area under the receiver operating characteristic curve (AUROC), the TPR$_0$ score and the TPR$_{10}$ score. The performances of self-attention-based encoder models and CNNs participating in the challenge are compared. They were able to surpass the CNN models that participated in the Bologna Lens Challenge by a high margin for the TPR$_0$ and TPR_${10}$. Self-Attention based models have clear advantages compared to simpler CNNs. They have highly competing performance in comparison to the currently used residual neural networks. Compared to CNNs, self-attention based models can identify highly confident lensing candidates and will be able to filter out potential candidates from real data. Moreover, introducing the encoder layers can also tackle the over-fitting problem present in the CNNs by acting as effective filters.
description: 18 Pages, 4 tables and 19 Figures
Importance of volume corrections on the net-charge distributions at the RHIC BES energies
Creators: name: Xu, Hao-jie
Publisher: name: arXiv
Year: 2016
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: The paper presents my recent investigations of volume corrections on the cumulant products of net-charge distributions in statistical model, corresponding to the data reported by the STAR collaboration. The corrected statistical expectations, under simple Poisson approximations, can reasonably explain the data measured in experiment. The results indicate that volume corrections play crucial role in event-by-event multiplicity fluctuation studies.
description: 5 pages, 2 figures, contribution to the proceedings of Critical Point and Onset of Deconfinement 2016 (CPOD2016), Wroc{\l}aw, Poland, May 30 - June 4, 2016
The Herschel Exploitation of Local Galaxy Andromeda (HELGA) VII: A SKIRT radiative transfer model and insights on dust heating
Creators: name: Viaene, S.
name: Baes, M.
name: Tamm, A.
name: Tempel, E.
name: Bendo, G.
name: Blommaert, J. A. D. L.
name: Boquien, M.
name: Boselli, A.
name: Camps, P.
name: Cooray, A.
name: De Looze, I.
name: De Vis, P.
name: Fernandez-Ontiveros, J. A.
name: Fritz, J.
name: Galametz, M.
name: Gentile, G.
name: Madden, S.
name: Smith, M. W. L.
name: Spinoglio, L.
name: Verstocken, S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The radiation of stars heats dust grains in the diffuse interstellar medium and in star-forming regions in galaxies. Modelling this interaction provides information on dust in galaxies, a vital ingredient for their evolution. It is not straightforward to identify the stellar populations heating the dust, and to link attenuation to emission on a sub-galactic scale. Radiative transfer models are able to simulate this dust-starlight interaction in a realistic, three-dimensional setting. We investigate the dust heating mechanisms on a local and global galactic scale, using the Andromeda galaxy (M31) as our laboratory. We perform a series of panchromatic radiative transfer simulations of Andromeda with our code SKIRT. The high inclination angle of M31 complicates the 3D modelling and causes projection effects. However, the observed morphology and flux density are reproduced fairly well from UV to sub-millimeter wavelengths. Our model reveals a realistic attenuation curve, compatible with previous, observational estimates. We find that the dust in M31 is mainly (91 % of the absorbed luminosity) heated by the evolved stellar populations. The bright bulge produces a strong radiation field and induces non-local heating up to the main star-forming ring at 10 kpc. The relative contribution of unevolved stellar populations to the dust heating varies strongly with wavelength and with galactocentric distance.The dust heating fraction of unevolved stellar populations correlates strongly with NUV-r colour and specific star formation rate. These two related parameters are promising probes for the dust heating sources at a local scale.
description: 16 pages + appendix, 13 figures, accepted for publication in A&A
Single atom trapping in a metasurface lens optical tweezer
Creators: name: Hsu, Ting-Wei
name: Zhu, Wenqi
name: Thiele, Tobias
name: Brown, Mark O.
name: Papp, Scott B.
name: Agrawal, Amit
name: Regal, Cindy A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Optical metasurfaces of subwavelength pillars have provided new capabilities for the versatile definition of the amplitude, phase, and polarization of light. In this work, we demonstrate that an efficient dielectric metasurface lens can be used to trap and image single neutral atoms with a long working distance from the lens of 3 mm. We characterize the high-numerical-aperture optical tweezers using the trapped atoms and compare with numerical computations of the metasurface lens performance. We predict that future metasurfaces for atom trapping will be able to leverage multiple ongoing developments in metasurface design and enable multifunctional control in complex quantum information experiments with neutral-atoms arrays.
description: 11 pages, 6 figures, Add polarization multiplexed lens result in Appendix
Magnetic flux disorder and superconductor-insulator transition in nanohole thin films
Creators: name: Granato, Enzo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We study the superconductor-insulator transition in nanohole ultrathin films in a transverse magnetic field by numerical simulation of a Josephson-junction array model. Geometrical disorder due to the random location of nanoholes in the film corresponds to random flux in the array model. Monte Carlo simulation in the path-integral representation is used to determine the critical behavior and the universal resistivity at the transition as a function of disorder and average number of flux quanta per cell, $f_o$. The resistivity increases with disorder for noninteger $ f_o$ while it decreases for integer $ f_o$, and reaches a common constant value in a vortex-glass regime above a critical value of the flux disorder $D_f^c$. The estimate of $D_f^c$ and the resistivity increase for noninteger $ f_o$ are consistent with recent experiments on ultrathin superconducting films with positional disordered nanoholes.
description: 5 pages, 2 figures, Phys. Rev. B, rap. comm
Pre Shipment Loan Utilization in Exporting Agricultural Products in Ethiopia
Creators: name: Negash, Mekbib
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2008

description: International trade continues to grow every year as nations expand their global sales and new nations join in. Today, over 225 nations are active in trade resulting in over $9 Trillion dollars in global business every year. Ethiopia, though existing part is small in amount, is one of those nations that incessantly increase their contribution in this global business. However, in Ethiopia, as in some other African countries, the export business is dominated by agricultural products accounting roughly for 70-80 per cent of export earnings. One of the common complaints, from Ethiopian agricultural product Exporters, is that they receive minimal support from their banks for export trade transactions. After spending significant time and resources to develop export sales, they often can not secure the funds they need to complete the orders. Thus a key finance service specifically required by these exporters is a short term working capital loan that is used to fulfill international sales orders. Consequently, the main purpose of this study was assessing the utilization of pre- shipment loan by agricultural product exporters in Ethiopia; focusing on those products which hold the highest fraction in the export business. The result of the study in general suggests that the provision of pre shipment working capital credit is characterized by a continuous increasing trend with annual average growth rate of 147% for three consecutive years from 2004- 2006.Although the provision of pre shipment working capital loan increases more than 100% annually, it still constitute small percentage of the total loan provided by the banks. And also the amount of pre shipment export credit in the study period is found to be very low relative to the total export value in the same period. For this reason the researcher suggests that, in order to satisfy needs of exporters in the country and benefit from the opportunities in the international market by expanding the export business, the disbursement of pre shipment credit should be increased more than what actually exists. This can be achieved through encouraging and supporting commercial banks to provide the loan to small and medium emerging exporters who have little experience and knowledge about the foreign trade; easing the requirements of both the commercial banks and government guarantee schemes; facilitating other export financing mechanisms; enhancing the capacity and experience of emerging agricultural product exporters about the international business; and strengthening and increasing the capability of those sectors which are organized with the aim of expanding the export sector in Ethiopia like Ethiopian export promotion agency
Computing the Probability of a Financial Market Failure: A New Measure of Systemic Risk
Creators: name: Jarrow, Robert
name: Protter, Philip
name: Quintos, Alejandra
Publisher: name: arXiv
Year: 2021
Subjects: subject: Mathematical Finance (q-fin.MF)
subject: Probability (math.PR)
subject: FOS: Economics and business
subject: FOS: Mathematics
subject: 91G40, 91G45, 60G55, 91G15

description: This paper characterizes the probability of a market failure defined as the default of two or more globally systemically important banks (G-SIBs) in a small interval of time. The default probabilities of the G-SIBs are correlated through the possible existence of a market-wide stress event. The characterization employs a multivariate Cox process across the G-SIBs, which allows us to relate our work to the existing literature on intensity-based models. Various theorems related to market failure probabilities are derived, including the probability of a market failure due to two banks defaulting over the next infinitesimal interval, the probability of a catastrophic market failure, the impact of increasing the number of G-SIBs in an economy, and the impact of changing the initial conditions of the economy's state variables. We also show that if there are too many G-SIBs, a market failure is inevitable, i.e., the probability of a market failure tends to 1.
description: Ann Oper Res (2022)
Low frequency noise in the environment and testing for its effect on human performance
Creators: name: Broner, Norman I. A.
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
Painel Pré-evento "O que docentes e pesquisadores precisam saber sobre ciência aberta", EnAnpad 2023.
Creators: name: Mendes-Da-Silva, W.
name: Cheron, Cibele
name: Cavalcanti, G.D.C.
Publisher: name: Zenodo
Year: 2023
Subjects: Open Science

description: Apresentações realizadas (via internet) em Pré-evento do EnAnpad 2023, em 20 de setembro de 20023.
The nonlinear anisotropic model of the Universe with the linear potential
Creators: name: Muharlyamov, Ruslan K.
name: Pankratyeva, Tatiana N.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: In the Bianchi I cosmology some subclasses of the Horndeski theory allow for the non-standard anisotropy behavior. For example, the anisotropy is damped near the initial singularity instead of tending to infinity. In this article, we analyze the nonlinear anisotropic model with the linear potential.We have considered an example of such theory, for which the anisotropy is always finite. The anisotropy reaches its a maximum value at the initial moment. The anisotropy suppression occurs during the inflationary stage, and it approaches zero at later times. This cosmological model does not contain the singular point.
Determinants Of Foreign Direct Investment Inflows in Ethiopia
Creators: name: Demissie, Tadesse
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2016

description: The study was carried out to establish the possible factors that determine the inflow of Foreign Direct Investment into Ethiopia. In this study, I used secondary time series data sample from 1992 to 2014. The Ordinary Least Squares (OLS) estimation is used and the time series properties of the variables were examined in the process. It first tests for unit root using the Augmented Dickey Fuller (ADF) test. The ARDL technique was employed to derive the long-run relationship. The ARDL model, however, failed to support any long-term relationships between FDI and each explanatory variable. The result of short run dynamic model shows that financial development and market size significantly and negatively affects the inflow of FDI. Trade openness exert positive relationship with FDI and significant at 10% significant level. Both Inflation and external debit affect FDI negatively but insignificant, and infrastructure development positively affects but insignificant FDI. From a policy point of view, the results suggest that, to promote FDI, Ethiopia should develop and introduce policies that increase the level of trade openness. Key Words: FDI in Ethiopia, OLS, Secondary time series data, Time Series properties, ADF Test, and ARDL Technique
Environmental Taxation practice and Revenue performance in Ethiopia
Creators: name: Melese, Lalu
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2013

description: The study focuses on investigating the environmental taxation practices and their revenue performance in Ethiopia. It adopts a mixed methods research approach to address the broad objective through answering research questions and specifically, it uses quantitative (surveys of structured review of documents), in-depth interview together with documentary analysis. The study statistically analyzes the data elicited from documents. It also supports the result from survey by the results from in-depth interviews and document studies. The results of this study reveal that there is no explicit environmental tax in Ethiopia but there exist environmental tax bases which categorise these taxes as environmental tax. The result also identifies that these tax has revenue contribution for the country also it identifies the percentage of these taxes to the total revenue as well as tax revenue is high. And that there are various activities in Ethiopia in which this taxes could be introduced. Moreover, the result identifies the tax can be used as a source of fund for environmentally beneficiary projects. As a whole, the study suggests that laws need further guiding principle and manuals; strict implementation of prior laws like environmental impact assessment is needed also a series of measures which could be taken by the government policy makers and regulators
Velocity segregation effects in galaxy clusters at 0.4
Creators: name: Barsanti, S.
name: Girardi, M.
name: Biviano, A.
name: Borgani, S.
name: Annunziatella, M.
name: Nonino, M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Our study is meant to extend our knowledge of the galaxy color and luminosity segregation in velocity space (VCS and VLS, resp.), to clusters at intermediate and high redshift. Our sample is a collection of 41 clusters in the 0.4=0.8. For the first time, we detect VLS in non-local clusters and confirm that VLS only affects the very luminous galaxies, with brighter galaxies having lower velocities. The threshold magnitude of VLS is ~m3+0.5, where m3 is the magnitude of the third brightest cluster galaxy, and current data suggest that the threshold value moves to fainter magnitudes at higher redshift. We also detect (marginal) evidence of VLS for blue galaxies. We conclude that the segregation effects, when their study is extended to distant clusters, can be important tracers of the galaxy evolution and cluster assembly and discuss the poor/no evidence of VCS at high redshift.
description: A&A accepted, 12 pages, 10 figures
Magic-angle Twisted Bilayer Systems with Quadratic-Band-Touching: Exactly Flat Bands with High-Chern Number
Creators: name: Li, Ming-Rui
name: He, Ai-Lei
name: Yao, Hong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Studies of twisted moiré systems have been mainly focused on two-dimensional (2D) materials such as graphene with Dirac points and transition-metal-dichalcogenide so far. Here we propose a twisted bilayer of 2D systems which feature stable quadratic-band-touching points and find exotic physics different from previously studied twisted moiré systems. Specifically, we show that exactly flat bands can emerge at magic angles and, more interestingly, each flat band exhibits a high Chern number ($C=\pm 2$). We further consider the effect of Coulomb interactions in such magic-angle twisted systems and find that the ground state supports the quantum anomalous Hall effect with quantized Hall conductivity $2\frac{e^2}{hc}$ at certain filling. Furthermore, the possible physical realization of such twisted bilayer systems will be briefly discussed.
description: 4.6 pages + references + supplemental, 4 figures
Lateral load characteristics of flat plate structures
Creators: name: Allen, F. H. .
Publisher: name: Monash University
Year: 2022

description: This thesis was scanned from the print manuscript for digital preservation and is copyright the author.
 Researchers can access this thesis by asking their local university, institution or public library to
 make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.
On finitely summable Fredholm modules from Smale spaces
Creators: name: Gerontogiannis, D. M.
Publisher: name: arXiv
Year: 2021
Subjects: subject: K-Theory and Homology (math.KT)
subject: Dynamical Systems (math.DS)
subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 37D20, 19K33, 58B34 (primary), 54E15 (secondary)

description: We prove that all K-homology classes of the stable (and unstable) Ruelle algebra of a Smale space have explicit Fredholm module representatives that are finitely summable on the same smooth subalgebra and with the same degree of summability. The smooth subalgebra is induced by a metric on the underlying Smale space groupoid and fine transversality relations between stable and unstable sets. The degree of summability is related to the fractal dimension of the Smale space. Further, the Fredholm modules are obtained by taking Kasparov products with a fundamental class of the Spanier-Whitehead K-duality between the Ruelle algebras. Finally, we obtain general results on stability under holomorphic functional calculus and construct Lipschitz algebras on étale groupoids.
description: 57 pages, version to appear in Transactions of the American Mathematical Society
Molecular characterisation and evolution of the sensory system inmosquitoes
Creators: name: Devilliers, Julien
Publisher: name: University of Leicester
Year: 2025

description: Mosquitoes are well studied for their human health importance, but the molecular mechanisms driving their behaviours remain poorly understood. In this thesis, we investigated molecular mechanisms driving host-seeking behaviour, blood-feeding and swarming. Blood-feeding behaviour evolved independently multiple times in dipterans, where hematophagy has been selected in females extracting needed energy for oviposition from the blood. Here, using phylogenomic analyses, we identified a convergent expansion of gene families in mosquitoes and sandflies, linked to the emergence of blood feeding behaviour. These gene families included a class of octopamine receptors involved in feeding behaviour, suggesting a common adaptation of those receptor in blood-feeding behaviour. Highlighting the lack of non-vector genomics data in mosquitoes, we then provided new reference genomes for the pitcher-plant mosquito (Wyeomyia smithii) and the Southern African elephant mosquito (Toxorhynchites brevipalpis). To investigate the differential involvement of sensory cues and integration between nonbiting males and biting females, we then performed single-cell RNA-sequencing in the head of the malaria mosquito (Anopheles gambiae). We found differential genes expressed in photoreceptor cells of adult mosquitoes suggesting sexually dimorphic temporal resolution of the visual system, as well as different modulation of auditory neurons. When focusing on the full eye of mosquitoes and comparing gene expression between males and females of a non-biting species and two vector species, we identified differential gene expression of olfactory-related genes. These results suggest that the strong interaction between the senses in mosquitoes might be processed directly in the sensory organs or first neuropils before further integration in the brain. Finally, we investigated the molecular mechanisms initiating swarming behaviour in Aedes aegypti, showing a contrasting involvement of the circadian clock compared to previous results in An. gambiae.
Bounds on Herglotz functions and fundamental limits of broadband passive quasi-static cloaking
Creators: name: Cassier, Maxence
name: Milton, Graeme W.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: Analysis of PDEs (math.AP)
subject: Complex Variables (math.CV)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Using a sum rule, we derive new bounds on Herglotz functions that generalize those given in (Gustafson and Sjöberg 2010) and (Bernland, Luger and Gustafson 2011). These bounds apply to a wide class of linear passive systems such as electromagnetic passive materials. Among these bounds, we describe the optimal ones and also discuss their meaning in various physical situations like in the case of a transparency window, where we exhibit sharp bounds. Then, we apply these bounds in the context of broadband passive cloaking in the quasi-static regime to negatively answer the following challenging question: is it possible to construct a passive cloaking device that cloaks an object over a whole frequency band? Our rigorous approach, although limited to quasi-statics, gives quantitative limitations on the cloaking effect over a finite frequency range by providing inequalities on the polarizabilty tensor associated with the cloaking device. We emphasize that our results hold for a cloak or object of any geometrical shape.
description: 36 pages, 2 figures
Challenges of Customs on Trade Facilitation in Ethiopia: the Case of Customs Clearance in ERCA.
Creators: name: W/gebriel, Teweldeberhan
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2011

description: This study examines the challenges of Customs on trade facilitation, specifically the Customs clearing process in Ethiopia. The study focuses on assessing to identify problems and the reason behind those problems, which have negative contribution on the time length of clearing process The study adopts a mixed method research approach to answer the research questions that come out from the review of the existing literature. Particularly, the study uses survey of employees of the Customs, importers, third parties clearing agents, interview with Customs officials and documentary analysis. The study statistically analysis the data bring forth from the survey. It also analysis the result of the interview with Customs officials' and inspection of documents held by the Customs office. The result of this methodology shows that the Customs clearing time taken for a document is quite long in Ethiopia, which adversely affects the trade facilitation. Moreover, the problems for delays of clearing process and reason behind these problems have also identified. The thesis forwards a series of measures to be taken by the authority (ERCA), importers and clearing agents