cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Enough is Enough: Towards Autonomous Uncertainty-driven Stopping Criteria
Creators: name: Placed, Julio A.
name: Castellanos, José A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: Autonomous robotic exploration has long attracted the attention of the robotics community and is a topic of high relevance. Deploying such systems in the real world, however, is still far from being a reality. In part, it can be attributed to the fact that most research is directed towards improving existing algorithms and testing novel formulations in simulation environments rather than addressing practical issues of real-world scenarios. This is the case of the fundamental problem of autonomously deciding when exploration has to be terminated or changed (stopping criteria), which has not received any attention recently. In this paper, we discuss the importance of using appropriate stopping criteria and analyse the behaviour of a novel criterion based on the evolution of optimality criteria in active graph-SLAM.
description: 11th IFAC Symposium on Intelligent Autonomous Vehicles
The effect of bottom friction on unidirectional swell propagation
Creators: name: Moore, K. R. .
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.
Evaluation of Budget Practices of Ethiopia in Comparison with two East African Countries
Creators: name: Yimer, Birhanu
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2011

description: The purpose of this study is to assess similarities and differences between Ethiopia and two east African countries with respect to budget practices and procedures. The study focused on the different phases of budget cycle and cross cutting issues such as budget transparency and participations. To conduct the study qualitative research method was employed. In order to investigate significant insight about budget transparency and participation in Ethiopia the researcher distributed questionnaires to employees of Ministry of Finance and Economic development of Ethiopia, specifically in the budgeting department. The study was based on secondary data sources which were collected on-line on the internet. The study indicates various opportunities which improve budget transparency and participation. The result of the study revealed that the level of transparency with regard to full disclosure of all relevant budget information is very poor in Ethiopia, Kenya and Uganda. Relatively Ethiopia frequently publicizes budget information. It also showed that the need to increase transparency is important in the area which is broadly linked to the different phases of budget cycle so as to increase citizens' participation in the budget decisions. Moreover, public participation in the budget process is very limited in Ethiopia, Kenya and Uganda. This is because of lack of reliable and adequate information. The findings of survey which were carried out with budget experts at the ministry of finance and economic development of Ethiopia disclose that budget information is not available for citizens in accessible, timely and clear and easy to use manner, except very little budget information during budget drafting phase. The major factors that limit citizen participation in the budget process are limited accessibility to budget information, budget language and country population. Key words: Budget transparency & Budget participation
An Introduction to Higher-Form Symmetries
Creators: name: Gomes, Pedro R. S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: These notes are intended to be a pedagogical introduction to higher-form symmetries, which are symmetries whose charged objects are extended operators supported on lines, surfaces, and etc. This subject has been one of the most popular and effervescent topics of theoretical physics in recent years. Gauge theories are central in the study of higher-form symmetries, with Wilson and 't Hooft operators corresponding to the charged objects. Along these notes, we discuss in detail some basic aspects, including Abelian Maxwell and Chern-Simons theories, and $SU(N)$ non-Abelian gauge theories. We also discuss spontaneous breaking of higher-form symmetries.
description: 73 pages, 13 figures, review notes, several typos corrected, references added, comments are welcome!
Flat-band optical phonons in twisted bilayer graphene
Creators: name: Cappelluti, Emmanuele
name: Silva-Guillén, Jose Angel
name: Rostami, Habib
name: Guinea, Francisco
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Twisting bilayer sheets of graphene have been proven to be an efficient way to manipulate the electronic Dirac-like properties, resulting in flat bands at magic angles. Inspired by the electronic model, we develop a continuum model for the lattice dynamics of twisted bilayer graphene and we show that a remarkable band flattening applies to almost all the high-frequency in-plane lattice vibration modes, including the valley Dirac phonon, valley optical phonon, and zone-center optical phonon bands. Utilizing an approximate approach, we estimate small but finite magic angles at which a vanishing phonon bandwidth is expected. In contrast to the electronic case, the existence of a restoring potential prohibits the emergence of a magic angle in a more accurate modeling. The predicted phonon band-flattening is highly tunable by the twist angle and this strong dependence is directly accessible by spectroscopic tools.
Reinforcement learning applied to wastewater treatment process control optimization: Approaches, challenges, and path forward
Creators: name: Croll, Henry C.
name: Ikuma, Kaoru
name: Ong, Say Kee
name: Sarkar, Soumik
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Space Science
classificationCode: 69999
subject: Biological Sciences not elsewhere classified
classificationCode: 80699
subject: Information Systems not elsewhere classified
subject: Science Policy
classificationCode: 110309
subject: Infectious Diseases
subject: FOS: Health sciences

description: Wastewater treatment process control optimization is a complex task in a highly nonlinear environment. Reinforcement learning (RL) is a machine learning technique that stands out for its ability to perform better than human operators for certain high-dimensional, complex decision-making problems, making it an ideal candidate for wastewater treatment process control optimization. However, while RL control optimization strategies have shown potential to provide operational cost savings and effluent quality improvements, RL has proven slow to be adopted among environmental engineers. This review provides an overview of existing RL applications for wastewater treatment control optimization found in literature and evaluates five key challenges that must be addressed prior to widespread adoption: practical RL implementation, managing data, integrating existing process models, building trust in empirical control strategies, and bridging gaps in professional training. Finally, this review discusses potential paths forward to addressing each key challenge, including leveraging soft sensing to improve online data collection, working with process engineers to integrate RL programming with existing industry software, utilizing supervised training to build expert knowledge into the RL agent, and focusing research efforts on known scenarios such as the Benchmark Simulation Model No. 1 to build a robust database of RL agent control optimization results.
Higher rank generalization of 11-vertex rational R-matrix: IRF-Vertex relations and associative Yang-Baxter equation
Creators: name: Atalikov, K.
name: Zotov, A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Algebra (math.QA)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We study ${\rm GL}_N$ rational $R$-matrix, which turns into the 11-vertex $R$-matrix in the $N=2$ case. First, we describe its relations to dynamical and semi-dynamical $R$-matrices using the IRF-Vertex type transformations. As a by-product a new explicit form for ${\rm GL}_N$ $R$-matrix is derived. Next, we prove the quantum and the associative Yang-Baxter equations. A set of other $R$-matrix properties and $R$-matrix identities are proved as well.
description: 21 pages
Quantum time reflection and refraction of ultracold atoms
Creators: name: Dong, Zhaoli
name: Li, Hang
name: Wan, Tuo
name: Liang, Qian
name: Yang, Zhaoju
name: Yan, Bo
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Atomic Physics (physics.atom-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Time reflection and refraction are temporal analogies of the spatial boundary effects derived from Fermat's principle. They occur when classical waves strike a time boundary where an abrupt change in the properties of the medium is introduced. The main features of time-reflected and refracted waves are the shift of frequency and conservation of momentum, which offer a new degree of freedom for steering extreme waves and controlling phases of matter. The concept was originally proposed for manipulating optical waves more than five decades ago. However, due to the extreme challenges in the ultrafast engineering of the optical materials, the experimental realization of the time boundary effects remains elusive. Here, we introduce a time boundary into a momentum lattice of ultracold atoms and simultaneously demonstrate the time reflection and refraction experimentally. Through launching a Gaussian-superposed state into the Su-Schrieffer-Heeger (SSH) atomic chain, we observe the time-reflected and refracted waves when the input state strikes a time boundary. Furthermore, we detect a transition from time reflection/refraction to localization with increasing strength of disorder and show that the time boundary effects are robust against considerable disorder. Our work opens a new avenue for future exploration of time boundaries and spatiotemporal lattices, and their interplay with non-Hermiticity and many-body interactions.
description: 6 pages, 4 figures
Evolutionary Approach to Security Games with Signaling
Creators: name: Żychowski, Adam
name: Mańdziuk, Jacek
name: Bondi, Elizabeth
name: Venugopal, Aravind
name: Tambe, Milind
name: Ravindran, Balaraman
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Science and Game Theory (cs.GT)
subject: Neural and Evolutionary Computing (cs.NE)
subject: FOS: Computer and information sciences

description: Green Security Games have become a popular way to model scenarios involving the protection of natural resources, such as wildlife. Sensors (e.g. drones equipped with cameras) have also begun to play a role in these scenarios by providing real-time information. Incorporating both human and sensor defender resources strategically is the subject of recent work on Security Games with Signaling (SGS). However, current methods to solve SGS do not scale well in terms of time or memory. We therefore propose a novel approach to SGS, which, for the first time in this domain, employs an Evolutionary Computation paradigm: EASGS. EASGS effectively searches the huge SGS solution space via suitable solution encoding in a chromosome and a specially-designed set of operators. The operators include three types of mutations, each focusing on a particular aspect of the SGS solution, optimized crossover and a local coverage improvement scheme (a memetic aspect of EASGS). We also introduce a new set of benchmark games, based on dense or locally-dense graphs that reflect real-world SGS settings. In the majority of 342 test game instances, EASGS outperforms state-of-the-art methods, including a reinforcement learning method, in terms of time scalability, nearly constant memory utilization, and quality of the returned defender's strategies (expected payoffs).
Entangling Quantum Memories via Heralded Photonic Bell Measurement
Creators: name: Dhara, Prajit
name: Englund, Dirk
name: Guha, Saikat
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A common way to entangle quantum memories is via photonic entanglement swaps. Each of two memories, connected by an optical channel, emits a photonic qubit entangled with itself, and the photonic qubits undergo an entanglement swap on a beamsplitter in the middle of the channel. We compare two choices of encoding of the photonic qubit: single rail and dual rail. At low channel loss the dual-rail scheme outperforms the single rail scheme. However, as expected, the high-loss rate asymptote for the dual rail scheme scales quadratically worse with loss compared with single rail. Considering the following non-idealities: imperfect mode matching at the swap, carrier-phase mismatch across the interfered photonic qubits, and detector excess noise, we evaluate the density operator of the heralded two-qubit entangled state. We calculate a lower bound on its distillable entanglement per copy, and its Fidelity (with the ideal Bell state). For both schemes, imperfect swap-visibility results in a constant-factor decrease in the rate, while excess noise results in a dropoff of distillable entanglement beyond a certain total channel loss threshold, to zero. Despite the single-rail scheme's better rate-loss scaling, it is more severely affected by excess noise. The single-rail scheme is adversely affected by stochastic carrier-phase mismatch, which does not affect the dual-rail scheme. We study entanglement distillation on the heralded noisy entangled states for both methods, and outline a suite of quantum networking studies that our work could incite.
description: 8 pages and 9 figures (main text); 4 appendices with 8 figures; Comments are welcome!
A standardised protocol for assessment of relative SARS-CoV-2 variant severity, with application to severity risk for COVID-19 cases infected with Omicron BA.1 compared to Delta variants in six European countries
Creators: name: Nyberg, Tommy
name: Bager, Peter
name: Svalgaard, Ingrid Bech
name: Bejko, Dritan
name: Bundle, Nick
name: Evans, Josie
name: Krause, Tyra Grove
name: McMenamin, Jim
name: Mossong, Joël
name: Mutch, Heather
name: Omokanye, Ajibola
name: Peralta-Santos, André
name: Leite, Pedro Pinto
name: Starrfelt, Jostein
name: Thelwall, Simon
name: Veneti, Lamprini
name: Whittaker, Robert
name: Wood, John
name: Pebody, Richard
name: Presanis, Anne M
Publisher: name: arXiv
Year: 2023
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: FOS: Biological sciences

description: Several SARS-CoV-2 variants that evolved during the COVID-19 pandemic have appeared to differ in severity, based on analyses of single-country datasets. With decreased SARS-CoV-2 testing and sequencing, international collaborative studies will become increasingly important for timely assessment of the severity of newly emerged variants. The Joint WHO Regional Office for Europe and ECDC Infection Severity Working Group was formed to produce and pilot a standardised study protocol to estimate relative variant case-severity in settings with individual-level SARS-CoV-2 testing and COVID-19 outcome data during periods when two variants were co-circulating. To assess feasibility, the study protocol and its associated statistical analysis code was applied by local investigators in Denmark, England, Luxembourg, Norway, Portugal and Scotland to assess the case-severity of Omicron BA.1 relative to Delta cases. After pooling estimates using meta-analysis methods (random effects estimates), the risk of hospital admission (adjusted hazard ratio [aHR]=0.41, 95% CI 0.31-0.54), ICU admission (aHR=0.12, 95% CI 0.05-0.27), and death (aHR=0.31, 95% CI 0.28-0.35) was lower for Omicron BA.1 compared to Delta cases. The aHRs varied by age group and vaccination status. In conclusion, this study has demonstrated the feasibility of conducting variant severity analyses in a multinational collaborative framework. The results add further evidence for the reduced severity of the Omicron BA.1 variant.
description: 21 pages, 6 figures (excluding supplementary material)
Empirical Analysis of the Contribution of Vat for Economic Development and Social Spending in Ethiopia
Creators: name: Alemu, Dakito
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2011

description: This paper discussed some recent critical literature on value-added tax (VAT) in Ethiopia relating to its contributions for economic development and its impact on the Social Spending in Ethiopia. The study employed the tools of quantitative empirical analysis technique to evaluate the contribution of VAT for the development of Ethiopia economy. The generic central objective is to examine the contribution of VAT for the development of Ethiopia economy and its impact on social spending, equity. The tools of empirical analysis used are multiple regression models as abstractions of the respective sectors considered in the study and also descriptive statistics. The study considered a vector of economic development indicators as dependent variables and regressed each on VAT revenue proceeds and other income (loan, donation, grant, taxes excluding VAT revenue, and others) of Ethiopia State for the study period (1995-2002 E.C. or 2003/04 – 2009/10 G.C.). The state economy is disaggregated into five strategic economic sectors in the development process, and multiple regression models specified to enhance isolated analysis of each sector. Development aspects that are considered development, education sector development, agricultural include infrastructural and natural resource development, health sector development and other development sectors. Moreover, in order to make clear decision and summarize the study, the summation of all capital expenditure on the respective sectors were taken and regressed. The analysis showed that, except education sector, VAT revenue contributed positively for the development of the respective sectors. On the aggregate (model VI), the analysis showed that VAT revenue had a considerable contribution for t h e development of the economy during the period under study. However, the contributions are statistically significant only to health and agricultural and natural resource development sectors. Therefore, it can be said that, the VAT tax revenue was unable to neutralize the regressivity of VAT tax levy in Ethiopia because its unsystematic exemptions, tax structure, and tax system. Thus, the study concludes that various sectors of the economy of Ethiopia are yet to benefit significantly from VAT revenue expenditure of the state government. Consequently, the paper calls for equity in sectoral spending of VAT proceeds in Ethiopia State in order to ensure balanced development and sustainability of the emerging mega city status of the state
Stability Satisfied Numerical Approximates to the Non-analytical Solutions of the Cubic Schrödinger Equation
Creators: name: Korkmaz, Alper
Publisher: name: arXiv
Year: 2016
Subjects: subject: Numerical Analysis (math.NA)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: The time dependent complex Schrödinger equation with cubic nonlinearity is solved by constructing differential quadrature algorithm based on sinc functions. Reduction to a coupled system of real equations enables to approach the space derivative terms by the proposed method. The resulted ordinary differential equation system is integrated with respect to the time variable by using a bunch explicit methods of lower and higher orders. Some initial boundary value problems containing some analytical and non-analytical initial data are solved for experimental illustrations. The computational errors between the analytical and numerical solutions are measured by the discrete maximum error norm in case the analytical solution exists. The two conserved quantities are calculated by using the numerical results in all cases. The matrix stability analysis is implemented to control the time step size.
description: 35 Pages, 38 figures
Evaluating performance and portability of high-level programming models: Julia, Python/Numba, and Kokkos on exascale nodes
Creators: name: Godoy, William F.
name: Valero-Lara, Pedro
name: Dettling, T. Elise
name: Trefftz, Christian
name: Jorquera, Ian
name: Sheehy, Thomas
name: Miller, Ross G.
name: Gonzalez-Tallada, Marc
name: Vetter, Jeffrey S.
name: Churavy, Valentin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: Programming Languages (cs.PL)
subject: FOS: Computer and information sciences

description: We explore the performance and portability of the high-level programming models: the LLVM-based Julia and Python/Numba, and Kokkos on high-performance computing (HPC) nodes: AMD Epyc CPUs and MI250X graphical processing units (GPUs) on Frontier's test bed Crusher system and Ampere's Arm-based CPUs and NVIDIA's A100 GPUs on the Wombat system at the Oak Ridge Leadership Computing Facilities. We compare the default performance of a hand-rolled dense matrix multiplication algorithm on CPUs against vendor-compiled C/OpenMP implementations, and on each GPU against CUDA and HIP. Rather than focusing on the kernel optimization per-se, we select this naive approach to resemble exploratory work in science and as a lower-bound for performance to isolate the effect of each programming model. Julia and Kokkos perform comparably with C/OpenMP on CPUs, while Julia implementations are competitive with CUDA and HIP on GPUs. Performance gaps are identified on NVIDIA A100 GPUs for Julia's single precision and Kokkos, and for Python/Numba in all scenarios. We also comment on half-precision support, productivity, performance portability metrics, and platform readiness. We expect to contribute to the understanding and direction for high-level, high-productivity languages in HPC as the first-generation exascale systems are deployed.
description: Accepted at the 28th HIPS workshop, held in conjunction with IPDPS 2023. 10 pages, 9 figures
Positive-Unlabeled Learning with Adversarial Data Augmentation for Knowledge Graph Completion
Creators: name: Tang, Zhenwei
name: Pei, Shichao
name: Zhang, Zhao
name: Zhu, Yongchun
name: Zhuang, Fuzhen
name: Hoehndorf, Robert
name: Zhang, Xiangliang
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Most real-world knowledge graphs (KG) are far from complete and comprehensive. This problem has motivated efforts in predicting the most plausible missing facts to complete a given KG, i.e., knowledge graph completion (KGC). However, existing KGC methods suffer from two main issues, 1) the false negative issue, i.e., the sampled negative training instances may include potential true facts; and 2) the data sparsity issue, i.e., true facts account for only a tiny part of all possible facts. To this end, we propose positive-unlabeled learning with adversarial data augmentation (PUDA) for KGC. In particular, PUDA tailors positive-unlabeled risk estimator for the KGC task to deal with the false negative issue. Furthermore, to address the data sparsity issue, PUDA achieves a data augmentation strategy by unifying adversarial training and positive-unlabeled learning under the positive-unlabeled minimax game. Extensive experimental results on real-world benchmark datasets demonstrate the effectiveness and compatibility of our proposed method.
description: IJCAI 2022
Star Formation and Gas Accretion in Nearby Galaxies
Creators: name: Yim, Kijeong
name: van der Hulst, J. M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: In order to quantify the relationship between gas accretion and star formation, we analyse a sample of 29 nearby galaxies from the WHISP survey which contains galaxies with and without evidence for recent gas accretion. We compare combined radial profiles of FUV (GALEX) and IR 24 μm (Spitzer) characterizing distributions of recent star formation with radial profiles of CO (IRAM, BIMA, or CARMA) and HI (WSRT) tracing molecular and atomic gas contents to examine star formation efficiencies in symmetric (quiescent), asymmetric (accreting), and interacting (tidally disturbed) galaxies. In addition, we investigate the relationship between star formation rate and HI in the outer discs for the three groups of galaxies. We confirm the general relationship between gas surface density and star formation surface density, but do not find a significant difference between the three groups of galaxies.
description: Accepted for publication in MNRAS, 18 pages, 9 figures, 1 table
Calculation of the energies of the multideterminant states of the nitrogen vacancy center in diamond with quantum Monte Carlo
Creators: name: Simula, Kristoffer
name: Makkonen, Ilja
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Certain point defects in solids can efficiently be used as qubits for applications in quantum technology. They have spin states that are initializable, readable, robust, and can be manipulated optically. New theoretical methods are needed to find the best host materials and defect configurations. Most methods proposed so far rely either on cluster models or restrict the many-body treatment of the defects to a subspace of single-particle orbitals. We explore best practices and theory for the use of quantum Monte Carlo to predict the excitation spectra for spin defects, by using the negatively charged nitrogen vacancy (NV$^-$) center in diamond as a test system. Quantum Monte Carlo can be used to explicitly simulate electronic correlations with larger systems and sets of orbitals than previous methods due to favourable scaling with respect to system size and computing power. We consider different trial wave functions for variational and diffusion Monte Carlo methods, explore the nodal surface errors of the ground and excited state wave functions and study whether the variational principle holds for the excited states. We compute the vertical excitation energies in different simulation cell sizes and extrapolate to infinite system size, and include backflow corrections to the extrapolated energies. The final results for vertical excitation energies are found to overestimate the experimental estimates, but the triplet-to-triplet and singlet-to-singlet transitions are accurate against experiment. Finally, we list further developments for QMC needed to address the problem of accurately predicting structural and spin properties of the solid-state defects.
The estimation of traffic loads using instrumented highway bridges
Creators: name: Richards, Brian Ernest.
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.
J-PLUS: Support Vector Regression to Measure Stellar Parameters
Creators: name: Wang, Cunshi
name: Bai, Yu
name: Yuan, Haibo
name: Liu, Jifeng
name: Fernández-Ontiveros, J. A.
name: Coelho, Paula R. T.
name: Jiménez-Esteban, F.
name: Galarza, Carlos Andrés
name: Angulo, R. E.
name: Cenarro, A. J.
name: Cristóbal-Hornillos, D.
name: Dupke, R. A.
name: Ederoclite, A.
name: Hernández-Monteagudo, C.
name: López-Sanjuan, C.
name: Marín-Franch, A.
name: Moles, M.
name: Sodré, L.
name: Ramió, H. Vázquez
name: Varela, J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. Stellar parameters are among the most important characteristics in studies of stars, which are based on atmosphere models in traditional methods. However, time cost and brightness limits restrain the efficiency of spectral observations. The J-PLUS is an observational campaign that aims to obtain photometry in 12 bands. Owing to its characteristics, J-PLUS data have become a valuable resource for studies of stars. Machine learning provides powerful tools to efficiently analyse large data sets, such as the one from J-PLUS, and enable us to expand the research domain to stellar parameters. Aims. The main goal of this study is to construct a SVR algorithm to estimate stellar parameters of the stars in the first data release of the J-PLUS observational campaign. Methods. The training data for the parameters regressions is featured with 12-waveband photometry from J-PLUS, and is cross-identified with spectrum-based catalogs. These catalogs are from the LAMOST, the APOGEE, and the SEGUE. We then label them with the stellar effective temperature, the surface gravity and the metallicity. Ten percent of the sample is held out to apply a blind test. We develop a new method, a multi-model approach in order to fully take into account the uncertainties of both the magnitudes and stellar parameters. The method utilizes more than two hundred models to apply the uncertainty analysis. Results. We present a catalog of 2,493,424 stars with the Root Mean Square Error of 160K in the effective temperature regression, 0.35 in the surface gravity regression and 0.25 in the metallicity regression. We also discuss the advantages of this multi-model approach and compare it to other machine-learning methods.
description: 18 pages, 10 figures, accepted by AA
Determinants of Banks Interest rate Spread: An Empirical Evidence from Ethiopian Commercial Banks
Creators: name: Asmare, Aregu
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2014

description: The banking sector plays a fundamental role in economic growth, as it is the basic element in the channeling of funds from lenders to borrowers. Efficient financial intermediation is an important factor in economic development process as it has implication for effective mobilization of investible resources. A major indicator of banking sector efficiency is interest rate spreads. Thus, this study examines the bank, industry and macro-economic specific factors affecting banks interest rate spread for a total of eight commercial banks in Ethiopia, covering the period of 2004-2013. To this end, the study adopts a mixed research approach by combining document analysis and in-depth interviews. The findings of the study show that credit risk, liquidity risk, , operating cost, concentration, reserve requirement, gross domestic product , interest rate volatility and exchange rate volatility have statistically significant and positive relationship with banks interest rate spread. Conversely return on asset, non interest income and financial development indicator has a negative and statistically significant relationship with banks' interest rate spread. However, the relationship between management quality and inflation is found to be statistically insignificant. The study suggests that banks in Ethiopia should not only be concerned about internal structures and policies, but they should consider both the internal and external environment together in fashioning out strategies to improve their intermediary efficiency. Key words: Interest rate spread, efficient financial intermediation, economic growth, commercial banks.
Loan Provision, Degree of Collectiblity and Reason for Default: A Case Study in Wise Saving and Credit Cooperatives Union for Women
Creators: name: Merkuriaw, Meron
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2008

description: This paper entitled "Loan Provision, Degree of Collectiblity and Reason for Default in case of WISE Saving and Credit Cooperatives Union for Women" examined the loan provision, collection procedures as well as the default rate of this SAC. Today a number of Saving and Credit Cooperatives(SACs) are established to give a saving and loan service to clients and much emphasis is given for those women who wants to run SME. WISE's major clients are women who would have an impact on changing their own life as well as their families. The study attempted to identify and assess the loan provision criteria's, collection procedures, the reason for default, the impact of interest on the cooperatives and clients, and last but not the least the benefits and challenges of the SAC under WISE. Data for the study was collected through questionnaire, interview and discussions with four cooperatives members and credit officers who are situated in Nefas Silk sub-city. Results of the study indicate that in order to give loan to a woman WISE have set criteria's so as to decrease the default rate. A woman has to save money and has to provide a business plan in order to be given the requested loan, after being a member of the SACs. The study revealed that the level of education of the borrowers reduces the default rate in turn facilities heavily the collection procedures. The study also indicates that the interest charged has a great impact on clients which makes them to reduce the amount of loan they want to take
A physical and concise halo model based on the depletion radius
Creators: name: Zhou, Yifeng
name: Han, Jiaxin
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We develop a self-consistent and accurate halo model by partitioning matter according to the depletion radii of haloes. Unlike conventional models that define haloes with the virial radius while relying on a separate exclusion radius or ad-hoc fixes to account for halo exclusion, our model distributes mass across all scales self-consistently and accounts for both the virialized and non-virialized matter distribution around each halo. Using a cosmological simulation, we show that our halo definition leads to very simple and intuitive model components, with the one-halo term given by the Einasto profile with no truncation needed, and the halo-halo correlation function following a universal power-law form down to the halo boundary. The universal halo-halo correlation also allows us to easily model the distribution of unresolved haloes as well as diffuse matter. Convolving the halo profile with the halo-halo correlation function, we obtain a complete description of the halo-matter correlation across all scales, which self-consistently accounts for halo exclusion at the transition scale. Mass conservation is explicitly maintained in our model, and the scale dependence of the classical halo bias is easily reproduced. Our model can successfully reconstruct the halo-matter correlation function within an accuracy of $9\%$ for halo virial masses in the range of $10^{11.5}h^{-1}{\rm M}_{\odot}
description: 19 pages, 19 figures
Gaussian ensemble for quantum integrable dynamics
Creators: name: Kim, Hyungwon
name: Polkovnikov, Anatoli
name: Yuzbashyan, Emil A.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose a Gaussian ensemble as a description of the long-time dynamics of isolated quantum integrable systems. Our approach extends the Generalized Gibbs Ensemble (GGE) by incorporating fluctuations of integrals of motion. It is asymptotically exact in the classical limit irrespective of the system size and, under appropriate conditions, in the thermodynamic limit irrespective of the value of Planck's constant. Moreover, it captures quantum corrections near the classical limit, finite size corrections near the thermodynamic limit, and is valid in the presence of non-local interactions. The Gaussian ensemble bridges the gap between classical integrable systems, where a generalized microcanonical ensemble is exact even for few degrees of freedom and GGE, which requires thermodynamic limit. We illustrate our results with examples of increasing complexity.
description: 10 pages, 4 figures
The decay widths of the $Z_{cs}(3985/4000)$ based on rigorous quark-hadron duality
Creators: name: Wang, Zhi-Gang
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this work, we explore the hadronic coupling constants $G_{ZJ/ψK}$, $G_{Zη_c K^*}$, $G_{ZD^* \bar{D}_s}$ of the exotic states $Z_{cs}(3985/4000)$ both in the pictures of the tetraquark states and molecular states with the tentative assignments $J^{PC}=1^{+-}$ based on the rigorous quark-hadron duality. Then we obtain the total widths $Γ_{Z_{cs}}^T =15.31\pm 2.06\,\rm{MeV}$ and $Γ_{Z_{cs}}^M=83.51\pm21.09\,\rm{MeV}$, which are consistent with the experimental data $13.8^{+8.1}_{-5.2}\pm4.9\,\rm{MeV}$ from the BESIII collaboration and $131 \pm 15 \pm 26\,\rm{MeV}$ from the LHCb collaboration, respectively, and support assigning the $Z_{cs}(3985)$ and $Z_{cs}(4000)$ to be the hidden-charm tetraquark state and molecular state with the $J^{PC}=1^{+-}$, respectively.
description: 13 pages, 2 figures
A spatially constrained QCD colour reconnection in pp, pA, and AA collisions in the PYTHIA8/Angantyr model
Creators: name: Lönnblad, Leif
name: Shah, Harsh
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present an updated version of the QCD-based colour reconnection model in PYTHIA8, where we constrain the range in impact parameter for which reconnections are allowed. In this way, we can introduce more realistic colour reconnections in the Angantyr model for heavy ion collisions, where previously only reconnections within separate nucleon sub-collisions have been allowed. We investigate how the new impact parameter constraint influences final states in pp collisions, and retune parameters of the multi-parton interaction parameters in PYTHIA to compensate so that minimum bias data are reproduced. We also study multiplicity distributions in pA collisions and find that, in order to counteract the loss in multiplicity due to the introduction of global colour reconnections, we need to modify some parameters in the Angantyr model while keeping the parameters tuned to pp fixed. With Angantyr we can then extrapolate to AA collisions without further parameter tuning and retaining a reasonable description of the basic multiplicity distributions.
description: 26 pages, 20 figures, Updated in accordance with the journal version of the article
Reduction and reconstruction of stochastic differential equations via symmetries
Creators: name: De Vecchi, Francesco C.
name: Morando, Paola
name: Ugolini, Stefania
Publisher: name: arXiv
Year: 2016
Subjects: subject: Probability (math.PR)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 60H10, 58D19

description: An algorithmic method to exploit a general class of infinitesimal symmetries for reducing stochastic differential equations is presented and a natural definition of reconstruction, inspired by the classical reconstruction by quadratures, is proposed. As a side result the well-known solution formula for linear one-dimensional stochastic differential equations is obtained within this symmetry approach. The complete procedure is applied to several examples with both theoretical and applied relevance.
Billiard-ball paradox for a quantum wave packet
Creators: name: Bishop, Lachlan G.
name: Ralph, Timothy C.
name: Costa, Fabio
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Past studies of the billiard-ball paradox, a problem involving an object that travels back in time along a closed timelike curve (CTC), typically concern themselves with entirely classical histories, whereby any trajectorial effects associated with quantum mechanics cannot manifest. Here we develop a quantum version of the paradox, wherein a (semiclassical) wave packet evolves through a region containing a wormhole time machine. This is accomplished by mapping all relevant paths on to a quantum circuit, in which the distinction of the various paths is facilitated by representing the billiard particle with a clock state. For this model, we find that Deutsch's prescription (D-CTCs) provides self-consistent solutions in the form of a mixed state composed of terms which represent every possible configuration of the particle's evolution through the circuit. In the equivalent circuit picture (ECP), this reduces to a binomial distribution in the number of loops of time machine. The postselected teleportation prescription (P-CTCs) on the other hand predicts a pure-state solution in which the loop counts have binomial coefficient weights. We then discuss the model in the continuum limit, with a particular focus on the various methods one may employ in order to guarantee convergence in the average number of clock evolutions. Specifically, for D-CTCs, we find that it is necessary to regularise the theory's parameters, while P-CTCs alternatively require more contrived modification.
description: 18 pages, 9 figures
Stability of the tetragonal phase of BaZrO3 under high pressure
Creators: name: Toulouse, Constance
name: Amoroso, Danila
name: Oliva, Robert
name: Xin, Cong
name: Bouvier, Pierre
name: Fertey, Pierre
name: Veber, Philippe
name: Maglione, Mario
name: Ghosez, Philippe
name: Kreisel, Jens
name: Guennou, Mael
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In this paper, we revisit the high-pressure behavior of BaZrO3 by a combination of first-principle calculations, Raman spectroscopy, and x-ray diffraction under high pressure. We confirm experimentally the cubic-to-tetragonal transition at 10 GPa and find no evidence for any other phase transition up to 45 GPa, the highest pressures investigated, at variance with past reports. We re-investigate phase stability with density functional theory considering not only the known tetragonal (I4/mcm) phase but also other potential antiferrodistortive candidates. This shows that the tetragonal phase becomes progressively more stable upon increasing pressure as compared to phases with more complex tilt systems. The possibility for a second transition to another tilted phase at higher pressures, and in particular to the very common orthorhombic Pnma structure, is therefore ruled out.
Forecasting of time data with using fractional Brownian motion
Creators: name: Bondarenko, Valeria
name: Bondarenko, Victor
name: Truskovsky, Kiryl
name: Taralova, Ina
Publisher: name: arXiv
Year: 2016
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60G22, 62M10, 91B84

description: We investigated the quality of forecasting of fractional Brownian motion, and new method for estimating of Hurst exponent is validated. Stochastic model of the time series in the form of converted fractional Brownian motion is proposed. The method of checking the adequacy of the proposed model is developed and short-term forecasting for temporary data is constructed. The research results are implemented.in software tools for analysis and modeling of time series.
Circulation Statistics and the Mutually Excluding Behavior of Turbulent Vortex Structures
Creators: name: Moriconi, Luca
name: Pereira, Rodrigo M.
name: Valadão, Victor J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences
subject: 76F05, 76F55

description: The small-scale statistical properties of velocity circulation in classical homogeneous and isotropic turbulent flows are assessed through a modeling framework that brings together the multiplicative cascade and the structural descriptions of turbulence. We find that vortex structures exhibit short-distance repulsive correlations, which is evidenced when they are "tomographically" investigated, by means of planar cuts of the flow, as two-dimensional vortex gases. This phenomenon is suggested from model improvements which allow us to obtain an accurate multiscale description of the intermittent fluctuations of circulation. Its crucial new ingredient, the conjectured hard disk behavior of the effective planar vortices, is then found to be strongly supported from a study of their spatial distributions in direct numerical simulations of the Navier-Stokes equations.
A probabalistic study of time delay measurement by cross-correlation estimation
Creators: name: Kenyon, Michael.
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.
Control of light emission of quantum emitters coupled to silicon nanoantenna using cylindrical vector beams
Creators: name: Montagnac, Martin
name: Brûlé, Yoann
name: Cuche, Aurélien
name: Poumirol, Jean-Marie
name: Weber, Sébastien J.
name: Müller, Jonas
name: Larrieu, Guilhem
name: Larrey, Vincent
name: Fournel, Franck
name: Boisron, Olivier
name: Masenelli, Bruno
name: Francs, Gérard Colas des
name: Agez, Gonzague
name: Paillard, Vincent
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Light emission of europium (Eu3+) ions placed in the vicinity of optically resonant nanoantennas is usually controlled by tailoring the local density of photon states (LDOS). We show that the polarization and shape of the excitation beam can also be used to manipulate light emission, as azimuthally or radially polarized cylindrical vector beam offers to spatially shape the electric and magnetic fields, in addition to the effect of silicon nanorings (Si-NRs) used as nanoantennas. The photoluminescence mappings of the Eu3+ transitions and the Si phonon mappings are strongly dependent of both the excitation beam and the Si-NR dimensions. The experimental results of Raman scattering and photoluminescence are confirmed by numerical simulations of the near-field intensity in the Si nanoantenna and in the Eu3+-doped film, respectively. The branching ratios obtained from the experimental PL maps also reveal a redistribution of the electric and magnetic emission channels. Our results show that it is possible to spatially control both electric and magnetic dipolar emission of Eu3+ ions by switching the laser beam polarization, hence the near-field at the excitation wavelength, and the electric and magnetic LDOS at the emission wavelength. This paves the way for optimized geometries taking advantage of both excitation and emission processes.
description: 8 pages, 4 figures