cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Analyzing Financial Performance of Commercial Banks in Ethiopia: CAMEL Approach
Creators: name: Getahun, Mulualem
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2015

description: The objective of this study was to analyze the financial performance of Ethiopian Commercial Banks using CAMEL approach and rank the banks based on their performance as well as to test the existence of the relationship between the selected CAMEL factor measurements with the profitability measures. The financial performance of Fourteen Commercial Banks examined by using panel data from year 2010 to year 2014.The study used quantitative research approach and secondary financial data are analyzed by using multiple linear regression model for two profitability measures: ROE and ROA. Fixed effect regression model was applied to investigate the impact & relationship of CAMEL factors: Capital adequacy, Asset Quality, Management efficiency, Earning and Liquidity with bank profitability measures separately. The empirical result shows that capital adequacy, Asset Quality and Management efficiency have negative relation whereas earning and liquidity shows positive relationship with both profitability measures with strong statically significance except Capital Adequacy which is insignificant for ROA whereas Asset quality for ROE. The study suggests focusing and reengineering the banks internal drivers could enhance the profitability of commercial banks in Ethiopia. Furthermore the ranking result based showed the first one by capital adequacy, asset quality and liquidity ratio was Bunna International Bank while Commercial Bank of Ethiopia by Management efficiency and Earning ratio and finally Wogagen Bank was the first by the composite rate
Voltage-driven exchange resonance achieving 100\% mechanical efficiency
Creators: name: Tang, Junyu
name: Cheng, Ran
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Magnetic resonances driven by current-induced torques are crucial tools to study magnetic materials but are very limited in frequency and mechanical efficiency. We propose an alternative mechanism, voltage-induced torque, to realize high efficiency in generating high-frequency magnetization dynamics. When a ferromagnet-topological insulator-ferromagnet trilayer heterostructure is operated as an adiabatic quantum motor, voltage-induced torque arises from the adiabatic motion of gapped topological electrons on the two interfaces and act oppositely on the two ferromagnetic layers, which can excite the exchange mode where the two ferromagnetic layers precess with a $π$-phase difference. The exchange mode resonance, bearing a much higher frequency than the ferromagnetic resonance, is accompanied by topological charge pumping, leading to a sharp peak in electrical admittance at the resonance point. Because the output current is purely adiabatic while dissipative current vanishes identically, the proposed voltage-driven exchange resonance entails a remarkably high mechanical efficiency close to unity, which is impossible in any current-driven systems.
An x-ray quantum eraser setup for time-energy complementarity
Creators: name: Gunst, Jonas
name: Pálffy, Adriana
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A new quantum eraser setup exploiting for the first time the time-energy complementarity relation in the x-ray regime is investigated theoretically. Starting point is the interference process between x-ray quanta driving two nuclear hyperfine transitions in a nuclear forward scattering setup. We show that which-way information can be obtained by marking the scattering paths with orthogonal polarization states, thus leading to the disappearance of the interference pattern. In turn, erasure of the which-way information leads to the reappearance of the interference fringes. We put forward two schemes using resonant scattering off nuclear targets and design which-way marking procedures to realize the quantum eraser setup for x-ray quanta.
description: 13 pages, 7 figures
Spectral signatures of symmetry-breaking dynamical phase transitions
Creators: name: Hurtado-Gutiérrez, R.
name: Hurtado, P. I.
name: Pérez-Espigares, C.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: Cellular Automata and Lattice Gases (nlin.CG)
subject: FOS: Physical sciences

description: Large deviation theory provides the framework to study the probability of rare fluctuations of time-averaged observables, opening new avenues of research in nonequilibrium physics. One of the most appealing results within this context are dynamical phase transitions (DPTs), which might occur at the level of trajectories in order to maximize the probability of sustaining a rare event. While the Macroscopic Fluctuation Theory has underpinned much recent progress on the understanding of symmetry-breaking DPTs in driven diffusive systems, their microscopic characterization is still challenging. In this work we shed light on the general spectral mechanism giving rise to continuous DPTs not only for driven diffusive systems, but for any jump process in which a discrete $\mathbb{Z}_n$ symmetry is broken. By means of a symmetry-aided spectral analysis of the Doob-transformed dynamics, we provide the conditions whereby symmetry-breaking DPTs might emerge and how the different dynamical phases arise from the specific structure of the degenerate eigenvectors. We show explicitly how all symmetry-breaking features are encoded in the subleading eigenvectors of the degenerate manifold. Moreover, by partitioning configuration space into equivalence classes according to a proper order parameter, we achieve a substantial dimensional reduction which allows for the quantitative characterization of the spectral fingerprints of DPTs. We illustrate our predictions in three paradigmatic many-body systems: (i) the 1D boundary-driven weakly asymmetric exclusion process (WASEP), which exhibits a particle-hole symmetry-breaking DPT for current fluctuations, (ii) the $3$ and $4$-state Potts model, which displays discrete rotational symmetry-breaking DPT for energy fluctuations, and (iii) the closed WASEP which presents a continuous symmetry-breaking DPT to a time-crystal phase characterized by a rotating condensate.
description: 30 pages, 17 figures
Federated Learning with Partial Model Personalization
Creators: name: Pillutla, Krishna
name: Malik, Kshitiz
name: Mohamed, Abdelrahman
name: Rabbat, Michael
name: Sanjabi, Maziar
name: Xiao, Lin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: Optimization and Control (math.OC)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: We consider two federated learning algorithms for training partially personalized models, where the shared and personal parameters are updated either simultaneously or alternately on the devices. Both algorithms have been proposed in the literature, but their convergence properties are not fully understood, especially for the alternating variant. We provide convergence analyses of both algorithms in the general nonconvex setting with partial participation and delineate the regime where one dominates the other. Our experiments on real-world image, text, and speech datasets demonstrate that (a) partial personalization can obtain most of the benefits of full model personalization with a small fraction of personal parameters, and, (b) the alternating update algorithm often outperforms the simultaneous update algorithm by a small but consistent margin.
Calibration of rubber hardness testers
Creators: name: Sieker, Horst Winfried.
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.
The superadditivity effects of quantum capacity decrease with the dimension for qudit depolarizing channels
Creators: name: Martinez, Josu Etxezarreta
name: iOlius, Antonio deMarti
name: Crespo, Pedro M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: Information Theory (cs.IT)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Quantum channel capacity is a fundamental quantity in order to understand how good can quantum information be transmitted or corrected when subjected to noise. However, it is generally not known how to compute such quantities, since the quantum channel coherent information is not additive for all channels, implying that it must be maximized over an unbounded number of channel uses. This leads to the phenomenon known as superadditivity, which refers to the fact that the regularized coherent information of $n$ channel uses exceeds one-shot coherent information. In this article, we study how the gain in quantum capacity of qudit depolarizing channels relates to the dimension of the systems considered. We make use of an argument based on the no-cloning bound in order to proof that the possible superadditive effects decrease as a function of the dimension for such family of channels. In addition, we prove that the capacity of the qudit depolarizing channel coincides with the coherent information when $d\rightarrow\infty$. We also discuss the private classical capacity and obain similar results. We conclude that when high dimensional qudits experiencing depolarizing noise are considered, the coherent information of the channel is not only an achievable rate but essentially the maximum possible rate for any quantum block code.
description: 10 pages, 2 figures
Current Practices, Challenges and Prospects of Using Credit Cards as a Payment Method: the Case of Ethiopian Airlines Enterprise
Creators: name: Getaye, Temesgen
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2015

description: This research paper examined the current practices, challenges, and prospects of using credit cards as a payment method by Ethiopian Airlines and it is done by adopting concurrent mixed research approach. Qualitative methods were employed by means of interviews and review of related documents while quantitative methods were used through survey of sales agents, area managers, officers and senior managers on the area. A total of 65 questionnaires were distributed to officers and managrs and 47 were collected and 6 interviews were conducted with directors and managers of the airline and that of merchant banks. The main findings of the study were that the internal control systems of the airline are not adequate enough to prevent card frauds and mitigate the credit card financial risk. Adequate and recurrent trainings for operational and back office staff on credit card acceptance and fraud prevention and having well-organized credit card desk with skilled and sufficient man power are the main critical success factors that are not either in existence or are not effective. Management of the airline threfore, need to take immediate corrective action to the increasing threat of card fraud by means of provision of awareness and recurrent training for operational and back office staff; implementing the latest fraud screening and fraud prevention tools in all of the airlines' sales cahnnels; establish well-organized credit card desk with well trained and suficient staff; establish clear policies and procedures with clear assignment of responsibilities among operational and support staff; and ensure that there is seamless and integrated system. Key words: Card payment industry; chargeback, card fraud, payment method, merchant, issuing bank, card schemes
Five Planets Transiting a Ninth Magnitude Star
Creators: name: Vanderburg, Andrew
name: Becker, Juliette C.
name: Kristiansen, Martti H.
name: Bieryla, Allyson
name: Duev, Dmitry A.
name: Jensen-Clem, Rebecca
name: Morton, Timothy D.
name: Latham, David W.
name: Adams, Fred C.
name: Baranec, Christoph
name: Berlind, Perry
name: Calkins, Michael L.
name: Esquerdo, Gilbert A.
name: Kulkarni, Shrinivas
name: Law, Nicholas M.
name: Riddle, Reed
name: Salama, Maissa
name: Schmitt, Allan R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The Kepler mission has revealed a great diversity of planetary systems and architectures, but most of the planets discovered by Kepler orbit faint stars. Using new data from the K2 mission, we present the discovery of a five planet system transiting a bright (V = 8.9, K = 7.7) star called HIP 41378. HIP 41378 is a slightly metal-poor late F-type star with moderate rotation (v sin(i) = 7 km/s) and lies at a distance of 116 +/- 18 from Earth. We find that HIP 41378 hosts two sub-Neptune sized planets orbiting 3.5% outside a 2:1 period commensurability in 15.6 and 31.7 day orbits. In addition, we detect three planets which each transit once during the 75 days spanned by K2 observations. One planet is Neptune sized in a likely ~160 day orbit, one is sub-Saturn sized likely in a ~130 day orbit, and one is a Jupiter sized planet in a likely ~1 year orbit. We show that these estimates for the orbital periods can be made more precise by taking into account dynamical stability considerations. We also calculate the distribution of stellar reflex velocities expected for this system, and show that it provides a good target for future radial velocity observations. If a precise orbital period can be determined for the outer Jovian planet through future observations, it will be an excellent candidate for follow-up transit observations to study its atmosphere and measure its oblateness.
description: Accepted by ApJL. 12 pages, 6 figures, 2 tables
Trapping a Free-propagating Single-photon into an Atomic Ensemble as a Quantum Stationary Light Pulse
Creators: name: Kim, U-Shin
name: Ihn, Yong Sup
name: Lee, Chung-Hyun
name: Kim, Yoon-Ho
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Efficient photon-photon interaction is one of the key elements for realizing quantum information processing. The interaction, however, must often be mediated through an atomic medium due to the bosonic nature of photons, and the interaction time, which is critically linked to the efficiency, depends on the properties of the atom-photon interaction. While the electromagnetically induced transparency effect does offer the possibility of photonic quantum memory, it does not enhance the interaction time as it fully maps the photonic state to an atomic state. The stationary light pulse (SLP) effect, on the contrary, traps the photonic state inside an atomic medium with zero group velocity, opening up the possibility of the enhanced interaction time. In this work, we report the first experimental demonstration of trapping a free-propagating single-photon into a cold atomic ensemble via the quantum SLP (QSLP) process. We conclusively show that the quantum properties of the single-photon state are preserved well during the QSLP process. Our work paves the way to new approaches for efficient photon-photon interactions, exotic photonic states, and many-body simulations in photonic systems.
Emergent Geometric Frustration of Artificial Magnetic Skyrmion Crystals
Creators: name: Ma, Fusheng
name: Reichhardt, C.
name: Gan, Weiliang
name: Reichhardt, C. J. Olson
name: Lew, Wen Siang
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Magnetic skyrmions have been receiving growing attention as potential information storage and magnetic logic devices since an increasing number of materials have been identified that support skyrmion phases. Explorations of artificial frustrated systems have led to new insights into controlling and engineering new emergent frustration phenomena in frustrated and disordered systems. Here, we propose a skyrmion spin ice, giving a unifying framework for the study of geometric frustration of skyrmion crystals in a non-frustrated artificial geometrical lattice as a consequence of the structural confinement of skyrmions in magnetic potential wells. The emergent ice rules from the geometrically frustrated skyrmion crystals highlight a novel phenomenon in this skyrmion system: emergent geometrical frustration. We demonstrate how skyrmion crystal topology transitions between a non-frustrated periodic configuration and a frustrated ice-like ordering can also be realized reversibly. The proposed artificial frustrated skyrmion systems can be annealed into different ice phases with an applied current induced spin-transfer torque, including a long range ordered ice rule obeying ground state, as-relaxed random state, biased state and monopole state. The spin-torque reconfigurability of the artificial skyrmion ice states, difficult to achieve in other artificial spin ice systems, is compatible with standard spintronic device fabrication technology, which makes the semiconductor industrial integration straightforward.
Financial Management Practice of Church: the Case of the Ethiopian Evangelical Church Mekane Yesus
Creators: name: Matewos, Gemechis
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2018

description: Financial management practices in the faith based areas at large and in the churches specifically is not the recent development. Despite its age, the financial management practice has been challenged in the church because of two main reasons; the first is the source of income arise from volunteers, there is a thought not to monitor the resources with adequate professionals since it is seemed to be holy and the second is the sacred and secular divide the church in which separates the financial management to the secular one and seen as it is a profane. The existence of the aforementioned challenges on one hand and the ever growing resources of the Ethiopian Evangelical Church Mekane Yesus (EECMY) on the other hand are the two paradoxes. The study assessed the financial management practice of the EECMY for administering its financial resources within its structure. Population of the study consists of the 28 church units (synods) and 7 joint programs of the church, total of 35. The study was conducted based on purposively selected 15 church units and 5 joint programs. Non-probability sampling of purposive sampling method was used to draw samples from the population. Questionnaire was distributed to 25 leaders and 25 finance heads and chief accountants of the sampled units; interview was conducted with two higher officials of the church; secondary data such as consolidated financial statements, financial manual, and constitution of the church were used for analysis. The elements of financial management such as accounting records, financial planning, financial policy and organizational philosophy, financial reporting and monitoring and internal control activities were assessed in order to study financial management practice of the EECMY. The data was analyzed by using SPSS through descriptive statistics and the finding of the study indicated that the major challenges of the financial management practice of the EECMY are absence of cash flow statement for reporting, financial policy weakness in using modified cash base instead of following international and nationally accepted financial policies, insufficient number of professional accountants, unclear revenue source and fund uses in the lower level structure, lack of periodical comparison of plan versus actual budget, risk of not audited financial statements, inconsistency with ethical values in few areas, lower risk assessment duties, absence of internal audit activities, and absence of account reconciliations. The study recommends adoption of new financial standards, introduction of cash flow statement, addressing of risk assessment elements of the church, introduction & strengthening of internal audits, and concerned body of religious organizations and financial policy and standard setting bodies in Ethiopia to establish institution that confirms churches are operating with integrity, accountability and transparency
Evidence of suppression of star formation by quasar-driven winds in gas-rich host galaxies at z<1?
Creators: name: Wylezalek, Dominika
name: Zakamska, Nadia L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Feedback from active galactic nuclei (AGN) is widely considered to be the main driver in regulating the growth of massive galaxies through heating or driving gas out of the galaxy, preventing further increase in stellar mass. Observational proof for this scenario has, however, been scarce. We have assembled a sample of 132 radio-quiet type-2 and red AGN at 0.1
description: 18 pages, 10 figures, accepted to MNRAS
Assessment of knowledge and experience of preconception care and associated factors among pregnant mothers with pre existing diabetes mellitus attending diabetic follow up clinic at selected governmental hospitals in Addis Ababa, Ethiopia, 2018.
Creators: name: Kassie, Aychew
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2018

description: Background: Despite improved access and quality of antenatal care, women with pregestational diabetes and their fetuses are at increased risk of developing serious complications compared with the non-diabetic pregnant women; including spontaneous abortion, stillbirth, hypertensive disorders, and delivery by cesarean section. Preconception care is a key to prevent associated fetal and maternal morbidity and mortality. Objective: The aim of this study was to assess the knowledge and experience of preconception care and associated factors among pregnant mothers with pre existing diabetes mellitus attending diabetic clinic at selected governmental hospitals in Addis Ababa. Methods: A facility based both qualitative and quantitative cross-sectional study conducted from March 11 to April 12, 2018. For quantitative part, 142 pregnant mothers and for qualitative part, eight pregnant mothers who visited the clinic during the study period were included. Quantitative data coded and entered to Epi-data version 4.2.0 and exported to SPSS version 25 for analysis. Logistic regression used to identify independent predictor of knowledge and statistical significance considered at p-value <0.05 and 95% CI. Qualitative data analyzed using an open code version 4.02. Result: This study revealed that 67(42.7%) of the study participants had good knowledge on preconception care. Educational level, occupational status and duration of diabetic follow up were factors significantly associated with knowledge of preconception care. Few women experienced anxiety related to their health condition and reproductive needs. All women interviewed had taken preconception folic acid and only few recognize its benefit. Conclusion and recommendation: Women's level of knowledge on preconception care is relatively low. Consequently, establishing formal preconception care clinic that can address all the components of the care and increasing women's knowledge regarding preconception care is important.
Anisotropic magnetotransport in the layered antiferromagnet TaFe$_{1.25}$Te$_3$
Creators: name: Chowdhury, Rajeswari Roy
name: DuttaGupta, Samik
name: Patra, Chandan
name: Kataria, Anshu
name: Fukami, Shunsuke
name: Singh, Ravi Prakash
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The discovery of fascinating ways to control and manipulate antiferromagnetic materials have garnered considerable attention as an attractive platform to explore novel spintronic phenomena and functionalities. Layered antiferromagnets (AFMs) exhibiting interesting magnetic structures, can serve as an attractive starting point to establish novel functionalities down to the two-dimensional limit. In this work, we explore the magnetoresistive properties of the spin-ladder AFM TaFe$_{1.25}$Te$_3$. Magnetization studies reveal an anisotropic magnetic behavior resulting in the stabilization of a spin-flop configuration for H $\perp$ (10-1) plane (i.e., out-of-plane direction). Angle-dependent longitudinal and transverse magnetoresistances show an unusual anharmonic behavior. A significant anisotropic enhancement of magnetoresistance when H $\perp$ (10-1) plane compared to H $\parallel$ (10-1) directions has been observed. The present results deepen our understanding of the magnetoresistive properties of low-dimensional layered AFMs, and point towards the possibility of utilizing these novel material systems for antiferromagnetic spintronics.
description: 7 pages, 7 figures
Development of coal preparation flowsheets
Creators: name: Blom, Denis V.
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.
Oscillation-free Quantization for Low-bit Vision Transformers
Creators: name: Liu, Shih-Yang
name: Liu, Zechun
name: Cheng, Kwang-Ting
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: Hardware Architecture (cs.AR)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Weight oscillation is an undesirable side effect of quantization-aware training, in which quantized weights frequently jump between two quantized levels, resulting in training instability and a sub-optimal final model. We discover that the learnable scaling factor, a widely-used $\textit{de facto}$ setting in quantization aggravates weight oscillation. In this study, we investigate the connection between the learnable scaling factor and quantized weight oscillation and use ViT as a case driver to illustrate the findings and remedies. In addition, we also found that the interdependence between quantized weights in $\textit{query}$ and $\textit{key}$ of a self-attention layer makes ViT vulnerable to oscillation. We, therefore, propose three techniques accordingly: statistical weight quantization ($\rm StatsQ$) to improve quantization robustness compared to the prevalent learnable-scale-based method; confidence-guided annealing ($\rm CGA$) that freezes the weights with $\textit{high confidence}$ and calms the oscillating weights; and $\textit{query}$-$\textit{key}$ reparameterization ($\rm QKR$) to resolve the query-key intertwined oscillation and mitigate the resulting gradient misestimation. Extensive experiments demonstrate that these proposed techniques successfully abate weight oscillation and consistently achieve substantial accuracy improvement on ImageNet. Specifically, our 2-bit DeiT-T/DeiT-S algorithms outperform the previous state-of-the-art by 9.8% and 7.7%, respectively. Code and models are available at: https://github.com/nbasyl/OFQ.
description: Proceedings of the 40 th International Conference on Machine Learning, Honolulu, Hawaii, USA. PMLR 202, 2023
Variational waveguide QED simulators
Creators: name: Tabares, Cristian
name: Heras, Alberto Muñoz de las
name: Tagliacozzo, Luca
name: Porras, Diego
name: González-Tudela, Alejandro
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Waveguide QED simulators are analogue quantum simulators made by quantum emitters interacting with one-dimensional photonic band-gap materials. One of their remarkable features is that they can be used to engineer tunable-range emitter interactions. Here, we demonstrate how these interactions can be a resource to develop more efficient variational quantum algorithms for certain problems. In particular, we illustrate their power in creating wavefunction ansätze that capture accurately the ground state of quantum critical spin models (XXZ and Ising) with less gates and optimization parameters than other variational ansätze based on nearest-neighbor or infinite-range entangling gates. Finally, we study the potential advantages of these waveguide ansätze in the presence of noise. Overall, these results evidence the potential of using the interaction range as a variational parameter and place waveguide QED simulators as a promising platform for variational quantum algorithms.
description: 5 pages, 4 figures + Supplementary Material. The codes to reproduce the results are available at: https://github.com/cristiantlopez/Variational-Waveguide-QED-Simulators
Large-scale multi-objective influence maximisation with network downscaling
Creators: name: Cunegatti, Elia
name: Iacca, Giovanni
name: Bucur, Doina
Publisher: name: arXiv
Year: 2022
Subjects: subject: Social and Information Networks (cs.SI)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences

description: Finding the most influential nodes in a network is a computationally hard problem with several possible applications in various kinds of network-based problems. While several methods have been proposed for tackling the influence maximisation (IM) problem, their runtime typically scales poorly when the network size increases. Here, we propose an original method, based on network downscaling, that allows a multi-objective evolutionary algorithm (MOEA) to solve the IM problem on a reduced scale network, while preserving the relevant properties of the original network. The downscaled solution is then upscaled to the original network, using a mechanism based on centrality metrics such as PageRank. Our results on eight large networks (including two with $\sim$50k nodes) demonstrate the effectiveness of the proposed method with a more than 10-fold runtime gain compared to the time needed on the original network, and an up to $82\%$ time reduction compared to CELF.
The Turbulent Origin of Outflow and Spin Misalignment in Multiple Star Systems
Creators: name: Offner, Stella S. R.
name: Dunham, Michael M.
name: Lee, Katherine I.
name: Arce, Hector G.
name: Fielding, Drummond B.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The protostellar outflows of wide-separation forming binaries frequently appear misaligned. We use magneto-hydrodynamic simulations to investigate the alignment of protostellar spin and molecular outflows for forming binary pairs. We show that the protostellar pairs, which form from turbulent fragmentation within a single parent core, have randomly oriented angular momenta. Although the pairs migrate to closer separations, their spins remain partially misaligned. We produce $^{12}$CO(2-1) synthetic observations of the simulations and characterize the outflow orientation in the emission maps. The CO-identified outflows exhibit a similar random distribution and are also statistically consistent with the observed distribution of molecular outflows. We conclude that observed misalignment provides a clear signature of binary formation via turbulent fragmentation. The persistence of misaligned outflows and stellar spins following dynamical evolution may provide a signature of binary origins for more evolved multiple star systems.
description: 6 pages, 4 figures, accepted to ApJL
Transcendence Certificates for D-finite Functions
Creators: name: Kauers, Manuel
name: Koutschan, Christoph
name: Verron, Thibaut
Publisher: name: arXiv
Year: 2023
Subjects: subject: Symbolic Computation (cs.SC)
subject: FOS: Computer and information sciences

description: Although in theory we can decide whether a given D-finite function is transcendental, transcendence proofs remain a challenge in practice. Typically, transcendence is certified by checking certain incomplete sufficient conditions. In this paper we propose an additional such condition which catches some cases on which other tests fail.
description: 9 pages, 1 figure
Variation Of The Tully-Fisher Relation As A Function Of The Magnitude Interval Of A Sample Of Galaxies
Creators: name: Ruelas-Mayorga, A.
name: Sánchez, L. J.
name: Trujillo-Lara, M.
name: Nigoche-Netro, A.
name: Echevarría, J.
name: García, A. M.
name: Ramírez-Vélez, J.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In this paper we carry out a preliminary study of the dependence of the Tully-Fisher Relation (TFR) with the width and intensity level of the absolute magnitude interval of a limited sample of 2411 galaxies taken from Mathewson \& Ford (1996). The galaxies in this sample do not differ significantly in morphological type, and are distributed over an $\sim11$-magnitude interval ($-24.4 < I < -13.0$). We take as directives the papers by Nigoche-Netro et al. (2008, 2009, 2010) in which they study the dependence of the Kormendy (KR), the Fundamental Plane (FPR) and the Faber-Jackson Relations (FJR) with the magnitude interval within which the observed galaxies used to derive these relations are contained. We were able to characterise the behaviour of the TFR coefficients $(α, β)$ with respect to the width of the magnitude interval as well as with the brightness of the galaxies within this magnitude interval. We concluded that the TFR for this specific sample of galaxies depends on observational biases caused by arbitrary magnitude cuts, which in turn depend on the width and intensity of the chosen brightness levels.
description: Accepted to be published in Astrophysics and Space Science, 2016, 17 pages, 41 Figures, 9 Tables
HEATGait: Hop-Extracted Adjacency Technique in Graph Convolution based Gait Recognition
Creators: name: Hasan, Md. Bakhtiar
name: Ahmed, Tasnim
name: Kabir, Md. Hasanul
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Biometric authentication using gait has become a promising field due to its unobtrusive nature. Recent approaches in model-based gait recognition techniques utilize spatio-temporal graphs for the elegant extraction of gait features. However, existing methods often rely on multi-scale operators for extracting long-range relationships among joints resulting in biased weighting. In this paper, we present HEATGait, a gait recognition system that improves the existing multi-scale graph convolution by efficient hop-extraction technique to alleviate the issue. Combined with preprocessing and augmentation techniques, we propose a powerful feature extractor that utilizes ResGCN to achieve state-of-the-art performance in model-based gait recognition on the CASIA-B gait dataset.
description: Accepted in 2022 4th International Conference on Advances in Computer Technology, Information Science and Communications (CTISC 2022). 6 pages, 4 figures, 2 tables
Abundance analysis of s-process enhanced barium stars
Creators: name: Mahanta, Upakul
name: Karinkuzhi, Drisya
name: Goswami, Aruna
name: Duorah, Kalpana
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Detailed chemical composition studies of stars with enhanced abundances of neutron-capture elements can provide observational constraints for neutron-capture nucleosynthesis studies and clues for understanding their contribution to the Galactic chemical enrichment. We present abundance results from high-resolution spectral analyses of a sample of four chemically peculiar stars characterized by s-process enhancement. High-Resolution spectra (R ~ 42000) of these objects spanning a wavelength range from 4000 to 6800 A, are taken from the ELODIE archive. We have estimated the stellar atmospheric parameters, the effective temperature T_eff, the surface gravity log g, and metallicity [Fe/H] from local thermodynamic equilibrium analysis using model atmospheres. We report estimates of elemental abundances for several neutron-capture elements, Sr, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu and Dy. While HD 49641 and HD 58368 show [Ba/Fe] > 1.16 the other two objects HD 119650 and HD 191010 are found to be mild barium stars with [Ba/Fe] ~ 0.4. The derived abundances of the elements are interpreted on the basis of existing theories for understanding their origin and evolution.
description: 12 pages, 7 figures, accepted for publication in MNRAS
XV Международная научно-практическая конференция «Современные тенденции развития науки и мирового сообщества в эпоху цифровизации»
Creators: name: ООО "Институт развития образования и консалтинга"
Publisher: name: ООО "Институт развития образования и консалтинга"
Year: 2023

description: XV Международная научно-практическая конференция «Современные тенденции развития науки и мирового сообщества в эпоху цифровизации»
Elliptic PDE learning is provably data-efficient
Creators: name: Boullé, Nicolas
name: Halikias, Diana
name: Townsend, Alex
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Numerical Analysis (math.NA)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: PDE learning is an emerging field that combines physics and machine learning to recover unknown physical systems from experimental data. While deep learning models traditionally require copious amounts of training data, recent PDE learning techniques achieve spectacular results with limited data availability. Still, these results are empirical. Our work provides theoretical guarantees on the number of input-output training pairs required in PDE learning. Specifically, we exploit randomized numerical linear algebra and PDE theory to derive a provably data-efficient algorithm that recovers solution operators of 3D uniformly elliptic PDEs from input-output data and achieves an exponential convergence rate of the error with respect to the size of the training dataset with an exceptionally high probability of success.
description: 25 pages, 2 figures
RESISTIRE factsheet: Mental Health Support in Times of Crisis
Creators: name: Aglietti, Claudia
name: Cacace, Marina
name: Rossetti, Federica
name: Charafeddine, Rana
name: Kolasińska, Agnieszka
Publisher: name: Zenodo
Year: 2023
Subjects: COVID-19
Mental health
gender+
Policy Recommendation

description: Mental health was not a priority in the initial management of the COVID-19 crisis. Attention to this problem arose later, and only after the first serious signs of increased psychological distress among the general population became apparent (e.g. a higher prevalence of depression, anxiety, post-traumatic stress, more widespread suicidal thoughts, increased domestic violence). Now that the crisis appears to be over, its impact on people's psychological wellbeing is still difficult to measure, evaluate, and address, but its side effects persist. Moreover, mental health problems have primarily been considered a consequence of the pandemic, but this neglects pre-existing factors that played a role in mitigating or exacerbating the impact the COVID-19 crisis had on the general population. Systematic data collection would provide insights into which groups have been most at risk of developing mental health problems and why, and, in the event of a future crisis, it would help to predict the differential impacts of policy measures. In addition, data collection would provide a basis for developing a prevention-oriented approach at the European level to facilitate the early detection and timely treatment of mental health issues.
Fourier Imager Network (FIN): A deep neural network for hologram reconstruction with superior external generalization
Creators: name: Chen, Hanlong
name: Huang, Luzhe
name: Liu, Tairan
name: Ozcan, Aydogan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: Optics (physics.optics)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Deep learning-based image reconstruction methods have achieved remarkable success in phase recovery and holographic imaging. However, the generalization of their image reconstruction performance to new types of samples never seen by the network remains a challenge. Here we introduce a deep learning framework, termed Fourier Imager Network (FIN), that can perform end-to-end phase recovery and image reconstruction from raw holograms of new types of samples, exhibiting unprecedented success in external generalization. FIN architecture is based on spatial Fourier transform modules that process the spatial frequencies of its inputs using learnable filters and a global receptive field. Compared with existing convolutional deep neural networks used for hologram reconstruction, FIN exhibits superior generalization to new types of samples, while also being much faster in its image inference speed, completing the hologram reconstruction task in ~0.04 s per 1 mm^2 of the sample area. We experimentally validated the performance of FIN by training it using human lung tissue samples and blindly testing it on human prostate, salivary gland tissue and Pap smear samples, proving its superior external generalization and image reconstruction speed. Beyond holographic microscopy and quantitative phase imaging, FIN and the underlying neural network architecture might open up various new opportunities to design broadly generalizable deep learning models in computational imaging and machine vision fields.
description: 19 Pages, 5 Figures, 1 Table
A unified scalable framework for causal sweeping strategies for Physics-Informed Neural Networks (PINNs) and their temporal decompositions
Creators: name: Penwarden, Michael
name: Jagtap, Ameya D.
name: Zhe, Shandian
name: Karniadakis, George Em
name: Kirby, Robert M.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Physics-informed neural networks (PINNs) as a means of solving partial differential equations (PDE) have garnered much attention in the Computational Science and Engineering (CS&E) world. However, a recent topic of interest is exploring various training (i.e., optimization) challenges - in particular, arriving at poor local minima in the optimization landscape results in a PINN approximation giving an inferior, and sometimes trivial, solution when solving forward time-dependent PDEs with no data. This problem is also found in, and in some sense more difficult, with domain decomposition strategies such as temporal decomposition using XPINNs. We furnish examples and explanations for different training challenges, their cause, and how they relate to information propagation and temporal decomposition. We then propose a new stacked-decomposition method that bridges the gap between time-marching PINNs and XPINNs. We also introduce significant computational speed-ups by using transfer learning concepts to initialize subnetworks in the domain and loss tolerance-based propagation for the subdomains. Finally, we formulate a new time-sweeping collocation point algorithm inspired by the previous PINNs causality literature, which our framework can still describe, and provides a significant computational speed-up via reduced-cost collocation point segmentation. The proposed methods form our unified framework, which overcomes training challenges in PINNs and XPINNs for time-dependent PDEs by respecting the causality in multiple forms and improving scalability by limiting the computation required per optimization iteration. Finally, we provide numerical results for these methods on baseline PDE problems for which unmodified PINNs and XPINNs struggle to train.
Tax Audit Practice in Ethiopia: the Case of the Federal Government
Creators: name: Mihret, Getaneh
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2011

description: This study examines tax audit practice in Ethiopia (the case of federal government), and investigates key problems in tax audit operation regarding the appropriateness of audit type used, audit rate, aptness of audit case selection methods and audit examination techniques used, and the experience and capability of audit staff resources. The study adopts mixed method approach in order to achieve the research objectives and to answer research questions. Specifically, the techniques used in the study include survey with tax auditors and investigators, in-depth interviews with tax officials and taxpayers, and documentary analysis. With these research methods, the results of the study reveal that tax audit program remains undeveloped with slight range of tax audit activities performed targeting aptly specific risks. The tax audit program is a toddler tool in improving voluntary compliance and increasing future revenue performance through educating and helping taxpayers to understand their tax obligations. The study also shows low audit coverage, the absence of compliance risk-based audit case selection strategy, scarcity of audit resources, tax auditors in particular, and absence of proficient and experienced tax auditors. In the end, the study forwards the possible measures to be taken by the Ethiopian Revenue and Customs Authority to mitigate problems in tax audit operation
Mode-sum regularization of $\left\langle ϕ^{2} \right\rangle$ in the angular-splitting method
Creators: name: Levi, Adam
name: Ori, Amos
Publisher: name: arXiv
Year: 2016
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The computation of the renormalized stress-energy tensor or $\left\langleϕ^{2}\right\rangle_{ren}$ in curved spacetime is a challenging task, at both the conceptual and technical levels. Recently we developed a new approach to compute such renormalized quantities in asymptotically-flat curved spacetimes, based on the point-splitting procedure. Our approach requires the spacetime to admit some symmetry. We already implemented this approach to compute $\left\langle ϕ^{2}\right\rangle _{ren}$ in a stationary spacetime using t-splitting, namely splitting in the time-translation direction. Here we present the angular-splitting version of this approach, aimed for computing renormalized quantities in a general (possibly dynamical) spherically-symmetric spacetime. To illustrate how the angular-splitting method works, we use it here to compute $\left\langle ϕ^{2}\right\rangle _{ren}$ for a quantum massless scalar field in Schwarzschild background, in various quantum states (Boulware, Unruh, and Hartle-Hawking states). We find excellent agreement with the results obtained from the t-splitting variant, and also with other methods. Our main goal in pursuing this new mode-sum approach was to enable the computation of the renormalized stress-energy tensor in a dynamical spherically symmetric background, e.g. an evaporating black hole. The angular-splitting variant presented here is most suitable to this purpose.
description: 34 pages, 12 figures. Submitted to Phys. Rev. D