Miracle-dz/UniFAR-FTUs huggingface dataset:
Rate-distortion optimized geometrical image processing

Since geometrical features, like edges, represent one of the most important perceptual information in an image, efficient exploitation of such geometrical information is a key ingredient of many image processing tasks, including compression, denoising and feature extraction. Therefore, the challenge for the image processing community is to design efficient geometrical schemes which can capture the intrinsic geometrical structure of natural images. This thesis focuses on developing computationally efficient tree based algorithms for attaining the optimal rate-distortion (R-D) behavior for certain simple classes of geometrical images, such as piecewise polynomial images with polynomial boundaries. A good approximation of this class allows to develop good approximation and compression schemes for images with strong geometrical features, and as experimental results show, also for real life images. We first investigate both the one dimensional (1-D) and two dimensional (2-D) piecewise polynomials signals. For the 1-D case, our scheme is based on binary tree segmentation of the signal. This scheme approximates the signal segments using polynomial models and utilizes an R-D optimal bit allocation strategy among the different signal segments. The scheme further encodes similar neighbors jointly and is called prune-join algorithm. This allows to achieve the correct exponentially decaying R-D behavior, D(R) 2-cR, thus improving over classical wavelet schemes. We also show that the computational complexity of the scheme is of O(N logN). We then extend this scheme to the 2-D case using a quadtree, which also achieves an exponentially decaying R-D behavior, for the piecewise polynomial image model, with a low computational cost of O(N logN). Again, the key is an R-D optimized prune and join strategy. We further analyze the R-D performance of the proposed tree algorithms for piecewise smooth signals. We show that the proposed algorithms achieve the oracle like polynomially decaying asymptotic R-D behavior for both the 1-D and 2-D scenarios. Theoretical as well as numerical results show that the proposed schemes outperform wavelet based coders in the 2-D case. We then consider two interesting image processing problems, namely denoising and stereo image compression, in the framework of the tree structured segmentation. For the denoising problem, we present a tree based algorithm which performs denoising by compressing the noisy image and achieves improved visual quality by capturing geometrical features, like edges, of images more precisely compared to wavelet based schemes. We then develop a novel rate-distortion optimized disparity based coding scheme for stereo images. The main novelty of the proposed algorithm is that it performs the joint coding of disparity information and the residual image to achieve better R-D performance in comparison to standard block based stereo image coder.
Optimal gauge and gauge invariance in non-perturbative time-dependent calculation of above-threshold ionization

We discuss the problem of the choice of the gauge in which to represent the electromagnetic field in the non-perturbative time-dependent study of the interaction of atoms with intense laser fields. Even though quantum mechanics is gauge invariant, the velocity gauge is more adopted then the length gauge for dynamical reasons. This property is even more severe when the problem is solved by expanding the wavefunction in spherical harmonics. The point is illustrated through the calculation of the above-threshold ionization photoelectron energy spectrum produced by atomic hydrogen under an intense laser pulse.
Mining towns and migration: Comparing three South African cases

Introduction The South African economy has a long history of mining exploration. The first mining operations were recorded in 1852. Literature has expressed the need to continue exploring the implications of internal and cross-border in-migration on the labor market of destination areas. This paper investigates migration patterns in South Africa by focusing on three mining towns (Postmasburg, Rustenburg and Emalahleni) in three different provinces. Methods This paper utilizes survey data from primary sources to investigate the potential link between migration patterns and mining output. The surveys formed part of an interdisciplinary research project under the auspices of the Center of Development Studies (CDS) at the University of the Free State. Results and discussion Postmasburg is the only mining town that experienced recent periods of expansion. This is reflected in the significant increase in the number of migrants moving to Postmasburg during 2011 and 2012, and the shorter average length of stay of migrants in Postmasburg (7.2 years compared to 9.8 years in Emalahleni and 11.0 in Rustenburg). The results resonate with the neo-classical notion of self-interest among younger people as a motivating factor for migration. Migrants in our samples were significantly younger than the locally-born respondents and display higher levels of education. Empirical results confirm this positive return on increased education levels with a positive and highly statistically significant return to every additional year of formal education. In all three towns, the dummy variable included to represent a distinction between mineworkers and non-mineworkers was statically significant. This confirms the general perception that mineworkers in all these communities receive a premium in terms of their monthly earnings-even after controlling for different levels of education. As part of a future research agenda, the role of environmental factors as a driver of migration could also be investigated in depth in Southern Africa.
An estimator for the cumulative co‐volatility of asynchronously observed semimartingales with jumps

In this paper, we consider two semimartingales sampled at stopping times in an asynchronous manner. We are interested in estimating their cumulative co‐volatility separately from the sum of their co‐jumps. For this purpose, we combine the Hayashi–Yoshida method (to deal with the asynchronicity) with the threshold technique (to separate the jumps) and consider a class of statistics called the truncated Hayashi–Yoshida estimator. We prove the consistency and the asymptotic mixed normality of the truncated Hayashi–Yoshida estimator under some mild conditions allowing the presence of infinite activity jumps.
Transfer Length vs. Slip of Prestressed Fiber-Reinforced Polymer Reinforcement

A comprehensive analysis of the relationship between transfer length and slip of different types of prestressed fiber reinforced polymer (FRP) reinforcement is provided. The results of the transfer length and slip together with the main influencing parameters of approximately 170 specimens prestressed with different FRP reinforcement were collected. After the analysis of a larger database of transfer length versus slip, new bond shape factors were proposed for carbon fiber composite cable (CFCC) strands (α = 3.5) and carbon fiber reinforced polymer (CFRP) bars (α = 2.5). It was also determined that the type of prestressed reinforcement has an influence on the transfer length of the aramid fiber reinforced polymer (AFRP) bars. Therefore, α = 4.0 and α = 2.1 were proposed for AFRP Arapree bars and AFRP FiBRA and Technora bars, respectively. Moreover, the main theoretical models are discussed together with the comparison of theoretical and experimental transfer length results based on the slip of reinforcement. Additionally, the analysis of the relationship between transfer length and slip and the proposed new values of the bond shape factor α have the potential to be introduced in the production and quality control processes of precast prestressed concrete members and to stimulate additional research that increases the understanding of the transfer length of FRP reinforcement.
Mortality difference from Klebsiella aerogenes vs Enterobacter cloacae bloodstream infections

Members of the order Enterobacterales, including Escherichia coli , Klebsiella species and Enterobacter species, are important pathogens in healthcare-associated infections. Higher mortality has been reported from infections due to Klebsiella pneumoniae than from E. coli , but prior studies comparing Enterobacter aerogenes (recently renamed Klebsiella aerogenes ) bacteraemia and Enterobacter cloacae complex bacteraemia have yielded conflicting results regarding whether clinical outcomes differ. We found bacteraemia with K. aerogenes was independently associated with greater risk of 30-day mortality than bacteraemia with Enterobacter cloacae complex.
Recovery of Intrinsic Heterojunction Bipolar Transistors Profiles by Neural Networks

Due to the shrinking size of devices, the calibration process for TCAD simulators is becoming increasingly complex with time mandatory to run simulations steadily increasing. In this work, we propose a Statistical Learning approach to predict Figures of Merit (FoMs) of a Silicon Germanium Heterojunction bipolar transistor (HBT) from its 1D doping and germanium profile. The surrogate model thus built allows to simulate electrical outputs with high precision much faster than traditional simulations. This model is then used to solve the inverse design problem and recover profiles that match target FoMs.
The mechanisms of potassium loss in acute myocardial ischemia: New insights from computational simulations

Acute myocardial ischemia induces hyperkalemia (accumulation of extracellular potassium), a major perpetrator of lethal reentrant ventricular arrhythmias. Despite considerable experimental efforts to explain this pathology in the last decades, the intimate mechanisms behind hyperkalemia remain partially unknown. In order to investigate these mechanisms, we developed a novel computational model of acute myocardial ischemia which couples a) an electrophysiologically detailed human cardiomyocyte model that incorporates modifications to account for ischemia-induced changes in transmembrane currents, with b) a model of cardiac tissue and extracellular K + transport. The resulting model is able to reproduce and explain the triphasic time course of extracellular K + concentration within the ischemic zone, with values of [ K + ] o close to 14 mmol/L in the central ischemic zone after 30 min. In addition, the formation of a [ K + ] o border zone of approximately 1.2 cm 15 min after the onset of ischemia is predicted by the model. Our results indicate that the primary rising phase of [ K + ] o is mainly due to the imbalance between K + efflux, that increases slightly, and K + influx, that follows a reduction of the NaK pump activity by more than 50%. The onset of the plateau phase is caused by the appearance of electrical alternans (a novel mechanism identified by the model), which cause an abrupt reduction in the K + efflux. After the plateau, the secondary rising phase of [ K + ] o is caused by a subsequent imbalance between the K + influx, which continues to decrease slowly, and the K + efflux, which remains almost constant. Further, the study shows that the modulation of these mechanisms by the electrotonic coupling is the main responsible for the formation of the ischemic border zone in tissue, with K + transport playing only a minor role. Finally, the results of the model indicate that the injury current established between the healthy and the altered tissue is not sufficient to depolarize non-ischemic cells within the healthy tissue.
Determining Critical Success Factors for an Online Laboratory Learning System Using Delphi Method

To prevent the spread of the Covid-19 pandemic, governments have been forced to stop offering educational services directly on campus. Thus, education has moved towards a new path; homes have been transformed into online educational classes through Learning Management Systems (LMS). Despite the many advantages of LMS such as availability, accessibility, and usability, which helps to monitor student learning and manage synchronous and asynchronous learning tools, there are many challenges facing students of applied disciplines such as sciences, engineering, and technology. Among these challenges are the following: how can laboratory experiments be conducted from a distance? How can students’ achievement be measured while conducting their scientific experiment tasks? The current study aimed to reach design criteria for a new system for managing a virtual learning laboratory system (LLS). The Delphi method was used to obtain the opinions of experts and those interested in the field of e-learning design. The responses of (31) experts were analyzed using NVivo software, then the results were analyzed using statistical methods to rank them according to importance through three rounds. The results revealed that the criteria for applying artificial intelligence mechanisms, content management systems through virtual machine, assessment, and accessibility through cloud computing are among the key criteria for designing LLS for science, engineering, and technology disciplines.
Winter Greenhouse Tomato Cultivation: Matching Leaf Pruning and Supplementary Lighting for Improved Yield and Precocity

Solar radiation entering a high-wire tomato greenhouse is mostly intercepted by the top of the crop canopy, while the role of lower leaves diminishes with age, turning them into sink organs rather than sources. Accordingly, the defoliation of basal leaves is a widely applied agronomic practice in high-wire greenhouse cultivation management. However, the recent increase in the application of supplemental light emitting diode (LED) lighting for high-density tomato production may affect the role of basal leaves, promoting their source role for fruit development and growth. The present research aims to explore the application of supplementary LED lighting on Solanum lycopersicum cv. Siranzo in the Mediterranean area during the cold season in combination with two regimes of basal defoliation. The defoliation factors consisted of the early removal of the leaves (R) right under the developing truss before the fruit turning stage and a non-removal (NR) during the entire cultivation cycle. The lighting factors consisted of an artificial LED lighting treatment with red and blue diodes for 16 h d−1 (h 8-00) with an intensity of 180 µmol s−1 m−2 (RB) and a control cultivated under natural light only (CK). The results demonstrated a great effect of the supplemental LED light, which increased the total yield (+118%), favoring fruit setting (+46%) and faster ripening (+60%) regardless of defoliation regimes, although the increased energy prices hinder the economic viability of the technology. Concerning fruit quality, defoliation significantly reduced the soluble solid content, while it increased the acidity when combined with natural light.
Multiple‐scattering microwave radiative transfer for data assimilation applications

A multiple‐scattering radiative transfer model for microwave radiance data assimilation in global numerical weather‐prediction models is presented. The model is part of the RTTOV software package and includes forward, tangent‐linear, adjoint and Jacobian models. The model is based on the Eddington approximation to radiative transfer which produces mean errors of less than 0.5 K at the targeted microwave frequencies between 10 and 200 GHz. The simplified treatment of subgrid‐scale cloud cover may produce biased model calculations that show a maximum at 0.5 cloud cover and may reach several degrees K. These errors may be corrected with a simple bias correction. Linearity tests indicate that, given a screening procedure that excludes situations in which the model responds nonlinearly to input perturbations, channels near 50.3, 19.35, 22.235 and 183.31 GHz may be used in global radiance data assimilation. Copyright © 2006 Royal Meteorological Society.
Anchored in praise? Potential manifestation of the anchoring bias in feedback reception

ABSTRACT Although feedback is one of the most important instructional techniques, strong empirical research on receiving feedback is scarce in comparison to research on feedback provision. In this experimental study, we examined the influence of detailed comments and praise on student motivation and change in performance. 147 university students wrote an essay draft, received feedback (detailed comments, detailed comments and praise, or control) and revised their essay based on feedback. First, we found that students who received detailed comments showed higher motivation and greater improvement compared to their counterparts in the control group. Second, we showed that students who received praise demonstrated lower motivation and reduced improvement, compared to students who did not receive praise in addition to detailed comments. This demonstration of paradoxical effects of praise in higher education is explained in the context of the anchoring bias suggesting that praise should be used wisely.
Sweat the Small Stuff, How Small Incidents of Negative Workplace Behavior Lead to Larger Misconduct

Small losses, measurable incremental negative workplace behaviors that do not align with organizational and societal norms often trigger a dynamic, magnifying process that produces greater undesirable outcomes, which once started, can often result in a downward spiral. Quickly addressing small problems can prevent minor misconduct and wrongdoing from escalating into greater difficulties later that can appear unstoppable. Failure to tackle the small issues and big problems will often follow. Managers should celebrate small victories or wins but also need to address small losses. Just as small wins can result in significant organizational gains, small losses can result in business losses.
Millimeter to X-ray flares from Sagittarius A*

Context. We report on new simultaneous observations and modeling of the millimeter, near-infrared, and X-ray flare emission of the source Sagittarius A* (SgrA*) associated with the super-massive (4 × 10 6 M� ) black hole at the Galactic center. Aims. We study the applicability of the adiabatic synchrotron source expansion model and study physical processes giving rise to the variable emission of SgrA* from the radio to the X-ray domain. Methods. Our observations were carried out on 18 May 2009 using the NACO adaptive optics (AO) instrument at the European Southern Observatory’s Very Large Telescope, the ACIS-I instrument aboard the Chandra X-ray Observatory, the LABOCA bolometer at the Atacama Pathfinder EXperiment (APEX), and the CARMA mm telescope array at Cedar Flat, California. Results. The X-ray flare had an excess 2−8 keV luminosity between 6 and 12×10 33 erg s −1 . The observations reveal flaring activity in all wavelength bands that can be modeled as the signal from an adiabatically expanding synchrotron self-Compton (SSC) component. Modeling of the light curves shows that the sub-mm follows the NIR emission with a delay of about three-quarters of an hour with an expansion velocity of about vexp ∼ 0.009c. We find source component sizes of around one Schwarzschild radius, flux densities of a few Janskys, and spectral indices α of about + 1( S (ν) ∝ ν −α ). At the start of the flare, the spectra of the two main components peak just short of 1 THz. To statistically explain the observed variability of the (sub-)mm spectrum of SgrA*, we use a sample of simultaneous NIR/X-ray flare peaks and model the flares using a synchrotron and SSC mechanism. Conclusions. These parameters suggest that either the adiabatically expanding source components have a bulk motion larger than vexp or the expanding material contributes to a corona or disk, confined to the immediate surroundings of SgrA*. For the bulk of the synchrotron and SSC models, we find synchrotron turnover frequencies in the range of 300−400 GHz. For the pure synchrotron models, this results in densities of relativistic particles of the order of 10 6.5 cm −3 and for the SSC models, the median densities are about one order of magnitude higher. However, to obtain a realistic description of the frequency-dependent variability amplitude of SgrA*, models with higher turnover frequencies and even higher densities are required.
Observations of the [Ne II] 12.8 Micron Emission from Two Ultracompact H II Regions, G29.96–0.02 and W51d

We have observed [Ne II] 12.814 μm line emission from two well-studied ultracompact H II regions, G29.96-0.02 and W51d, and obtained its spatially resolved line images. Spatial distributions of the line emission were compared with the VLA 15 GHz continuum maps to derive the Ne+ abundance, which puts strong constraint on the effective temperature or the spectral type of the ionizing star(s). We show that the total neon abundance of G29.96-0.02 is close to the local interstellar abundance of neon, and the dominant species of neon is Ne+ over the whole H II region. When the ionic ratio derived from observed fluxes of [Ne III] 36.0 μm and [Ne II] 12.8 μm is compared with a theoretical calculation based on the recent model of non-LTE stellar atmosphere, it implies that the ionizing star(s) have an effective temperature of ~34,000 K or spectral type of O9.5 in the main sequence. On the other hand, the derived Ne+ abundance of W51d is significantly lower than the local interstellar abundance of neon. In addition, we found the Ne+ abundance decreases remarkably toward the center of W51d. These results suggest that the dominant species of neon would be Ne++ in W51d, and the ionizing star(s) has significantly high effective temperature (~39,000 K). Alternatively, the [Ne II] line could suffer from enormous extinction due to dust associated with this ultracompact H II region.
Approaches and Quality of Algorithm Evaluation

It is a valuable research task to construct the knowledge body and develop the method of analyzing the quality of an algorithm evaluation process since the invention of algorithms is one of the most important research tasks in information technology. To this end, this paper explores approaches and quality of algorithm evaluation through reviewing the papers involved in new approach of algorithm evaluation. Concretely, it does the following three jobs. First, it identifies four approaches of algorithm evaluation and further explores their features. Second, it builds the brief taxonomy of algorithm evaluation from the literature. Third, it proposes a scheme of analyzing the quality of a performance evaluation process. This study aims to facilitate the algorithm inventors to use the proper and high quality way to evaluate algorithms.
Genetic and Genomic Analysis of Cow Mortality in the Israeli Holstein Population

“Livability” was defined as the inverse of the probability of death. The objectives of this study were to estimate the heritability, genetic and phenotypic trends for the livability of Israeli Holstein cows; estimate the genetic and environmental correlations between livability and the nine traits included in the Israeli breeding index; estimate the effect of the inclusion of livability in the Israeli breeding index on expected genetic gains; and compute a genome-wide association study (GWAS) for livability. Seven data sets were analyzed. All data were derived from the database of the Israeli dairy cattle herd-book. The mean livability for the complete data set of 523,954 cows born from 2000 through 2016 was 89.6%. Pregnancy reduced livability by 15%. Livability generally increased with parity and days in milk within parity. Heritability of livability was 0.0082. Phenotypic and genetic trends over the 14-year period from 2000 through 2013 were −0.42% and −0.22% per year. If livability is included in the Israeli breeding index, accounting for 9% of the index, livability would increase by 1.3% and protein production would decrease by 11 kg over the next decade, as compared to the current index. A marker in proximity to the oxytocin–vasopressin locus had the greatest effect in the GWAS. Oxytocin activity in cattle affects calving-associated pathologies and maternal death. Inclusion of livability in the Israeli breeding index is not recommended.