Miracle-dz/UniFAR-FTUs huggingface dataset:
Distributionally Robust Neural Networks

Overparameterized neural networks trained to minimize average loss can be highly accurate on average on an i.i. d. test set, yet consistently fail on atypical groups of the data (e.g., by learning spurious correlations that do not hold at test time). Distributionally robust optimization (DRO) provides an approach for learning models that instead minimize worst-case training loss over a set of pre-defined groups. We find, however, that naively applying DRO to overparameterized neural networks fails: these models can perfectly fit the training data, and any model with vanishing average training loss will also already have vanishing worst-case training loss. Instead, the poor worst-case performance of these models arises from poor generalization on some groups. As a solution, we show that increased regularization---e.g., stronger-than-typical weight decay or early stopping---allows DRO models to achieve substantially higher worst-group accuracies, with 10% to 40% improvements over standard models on a natural language inference task and two image tasks, while maintaining high average accuracies. Our results suggest that regularization is critical for worst-group performance in the overparameterized regime, even if it is not needed for average performance. Finally, we introduce and provide convergence guarantees for a stochastic optimizer for this group DRO setting, underpinning the empirical study above.
Belief System: A Barrier to the Use of Modern Contraceptives among the Idoma of Benue State, North Central Nigeria

Despite the benefit of modern contraception, its use remains low in Nigeria. This study examined belief system as a barrier to the use of modern contraceptives among the Idoma of Benue State, North Central Nigeria. Questionnaire (n = 1107), in-depth interview (n = 6) and focus group discussion (n = 52) were used to collect data from three local government areas (LGAs). The results showed high levels of knowledge (88.0%), however, only 37.8% used modern contraceptives. The male condom had the highest percentage use (56.7%). Chi-square results showed that LGA, education and occupation were significantly related to the use of modern contraceptives. Being of greater age increased the likelihood of use, whereas higher levels of education and income decreased the likelihood of modern contraceptive use (p < 0.05). Qualitative data indicated that married women were expected to eschew modern contraceptives due to their belief in Alekwu, the community deity. Designing interventions that are culturally specific could promote use of modern contraceptives among the group.
i-векторов для

The article describes results of applying i-vectors-based (both LID and SID) speech identification methods to define a kind of a distance between languages (in a wide sense of the word – including dialects and any other forms of spoken language). Spontaneous speech recordings of many enough speakers of languages are used on the input of the method. The experiments were carried out at recordings of Latvian and Latgalian dialects, but the method is applicable to any other idioms. Cosine similarity, Euclidean metric, standardized Euclidean metric, Jordan (or Chebyshov) metric and city block (or L 1 ) metric were tried out. Cosine similarity worked well for SID i-vectors, but for unknown reasons was senseless for LID i-vectors. Jordan metric worked well for LID, but was not good enough for SID i-vectors. Standardization of the Euclidean metric does not gave any improvement. Thus, the conclusions are: 1) both SID and LID vectors of full length recordings of spontaneous speech are characterizing and representing languages good enough to be used for detection of a distance between languages; 2) the best metrics for such tasks are Euclidean and L 1 (for arithmetic mean vectors computed from i-vectors of all informants coordinate by coordinate).
Unravelling the nature of hydrogen-poor thermonuclear supernovae

Thermonuclear supernovae take many forms, as demonstrated by the increasing evidence of diversity among type Ia supernovae, particularly at early times, and subclasses of peculiar objects. This thesis presents new observations and modelling tools that explore the diversity of thermonuclear supernovae. We present colour light curves, and optical and near-infrared spectra for SN 2015H, a type Iax supernova, beginning a few days post-explosion. We compare these observations to synthetic light curves and spectra predicted from multi-dimensional explosion models invoking weak deflagrations of Chandrasekhar-mass carbon-oxygen white dwarfs, and find reasonable agreement with a model producing only ∼0.07 M of 56Ni. Our results demonstrate that the observational signatures of this explosion scenario are consistent with type Iax supernovae across a range of luminosities. Our analysis of SN 2015H shows that the strength of the deflagration, and hence amount of 56Ni produced during the explosion, can explain some of the diversity observed among type Iax supernovae. In a subsequent study, we present observations of PS1-12bwh that demonstrate this is not the sole factor affecting the appearance of type Iax supernovae. While the light curve and post-maximum spectra of PS1-12bwh are virtually identical to the prototypical SN 2005hk, the premaximum spectrum of the former does not resemble spectra of the latter at a comparable epoch. We perform spectral modelling and find that the unique pre-maximum appearance of PS1-12bwh is consistent with a lower density in the outer ejecta compared to SN 2005hk. Both objects showed similar light curve peaks and shapes, therefore our analysis indicates that there are additional factors responsible for the diversity of type Iax supernovae apart from the amount of 56Ni produced; hence, type Iax supernovae are not a one-parameter family. The early light curves of type Ia supernovae also display diversity in their colours and shapes. We therefore present a new Monte Carlo radiative transfer code designed for modelling light curves of radioactively driven transients. We perform a parameter study, focusing on the effects of the 56Ni distribution and density profile within the supernova ejecta. Models with 56Ni extending throughout the entire ejecta show brighter and bluer light curves at early times. The density profile also plays a significant role in shaping the early light curve; however, this has been neglected in previous studies. Our models show that comparisons with full colour light curves are necessary to constrain the ejecta properties of type Ia supernovae, such as 56Ni distribution and density profile. ii
Previsão da compra de serviços em seguros de vida usando Data Mining

This report describes all the work realized throughout the Mathematical Engineering Master Degree’s internship at Msg Life Iberia. The present study’s aim was to develop a model that predicts the purchase of services, using techniques of Data Mining. Initially, to achieve this goal, it was necessary to do a study about the business, the insurance area, and then to perform a study about the data base in order to to know what is the best techniques to apply, what are the most relevant information and the most applicable models. Due to caracteristics of the purchase and not purchase of services it was necessary to apply imbalanced class techniques, such as Oversampling, Downsampling, SMOTE and ROSE in order to have a prediction with less bias. Decision Trees, Random Forest and Support Vector Machine models were compared. For the last model it was necessary to apply Principal Components Analysis to reduce the dimension of the data base. After the application of the predictive models, they were compared and the model with the best results was chosen.
Toxicity modelling of nanomaterials by origin evaluation of their physicochemical descriptors using a combination of principal component analysis and support vector machine methods

In the present study, the performance of physicochemical descriptors of metal oxide nanomaterials on the basis of their origins, including descriptors related to element/ion, the metal oxide in bulk, and metal oxide in the media for toxicity modelling has been evaluated. Three published experimental nanomaterial data sets were selected for the study. The data set was divided into three subsets on the basis of the origin of descriptors; thereafter, each of them was analysed using principal component analysis for visual discrimination of toxic versus nontoxic nanomaterials in the principal component (PC) space. The metal oxide in media‐based descriptor subset results in the best visual clustering of toxicity of nanomaterials compared with the rest two subsets. It was also confirmed with the class separability measures in the PC space and classification accuracy of the support vector machine (SVM) method. PC scores of the metal oxide in media‐related descriptors results in the maximum value of class separability index (J = 0.0049) and the maximum classification accuracy of 96.43% of SVM classifier (sensitivity of 100%). A toxicity classification model of nanomaterials has been established using PC scores of optimal descriptor subset and SVM method.
Um Método Baseado em Grafos para Predição da Utilidade de Opiniões sobre Produtos

Este trabalho apresenta uma nova abordagem para predição da utilidade de opiniões. Usualmente, os trabalhos nessa área usam tabelas do tipo atributo-valor para agregar as caracterı́sticas que representam os textos avaliados. Neste trabalho, essa tarefa é modelada em forma de rede, considerando, dessa forma, as informações de relacionamento entre os objetos da rede (comentários, estrelas e palavras). Uma técnica de regularização de grafos é utilizada para extrair caracterı́sticas relevantes da estrutura do grafo, e, após isso, os comentários são classificados em duas classes: Útil ou Não Útil. Comparou-se a modelagem com um método baseado em lógica fuzzy e a modelagem apresentou resultados promissores, superando-o em 0,13 pontos na medida F1.
What do we mean by ‘pedagogy’ in sustainability education?

ABSTRACT Pedagogy is a term used broadly to refer to both how and why an educator influences learning. Given the importance of quality transformative learning experiences noted in the sustainability education literature, the role of an educator’s values, assumptions and philosophy underpinning their educational capability for the provision of learning experiences are also worthy of further investigation. This necessitates a reflection on what is meant by pedagogy in sustainability education literature to support a clearer understanding of its meaning and how it orients educational practice. The term pedagogy is widely used in sustainability education (and related) literature, and yet rarely is the concept defined or explored in detail. This paper intends to fill this gap by presenting arguments for why explicit reflection on the meaning and role of pedagogy in sustainability education is important and highlight some resulting research implications and avenues for further investigation.
Integral operators commuting with dilations and rotations in generalized Morrey‐type spaces

We find conditions for the boundedness of integral operators K commuting with dilations and rotations in a local generalized Morrey space. We also show that under the same conditions, these operators preserve the subspace of such Morrey space, known as vanishing Morrey space. We also give necessary conditions for the boundedness when the kernel is non‐negative. In the case of classical Morrey spaces, the obtained sufficient and necessary conditions coincide with each other. In the one‐dimensional case, we also obtain similar results for global Morrey spaces. In the case of radial kernels, we also obtain stronger estimates of Kf via spherical means of f . We demonstrate the efficiency of the obtained conditions for a variety of examples such as weighted Hardy operators, weighted Hilbert operator, their multidimensional versions, and others.
A New Historical Reading of Joseph Conrad’s An Outpost of Progress

This article situates Joseph Conrad's An Outpost of Progress in its socio-historical context to unveil the various subtexts embedded in it. Colonization and surveillance are the subtexts being signified in the story. The panoptical model Michel Foucault (1977) proposed is utilized to understand how knowledge as well as capital leads to omnipotent surveillance and observation. The article questions the aesthetic principle that art is produced for its own sake; it argues that art is entrenched deeply in its historical context. It further questions the extent of Kayerts and Carlier's liberty and sovereignty as colonial agents. The significance of this study stems from its new historical presumption that events of history should be examined as critically as those of fiction. This entails that Conrad's story should be appreciated for its historical and artistic value. New historicism, which repudiates the autonomy of text and history, is the methodology through which the research topic and Conrad's story are approached. The article finds that Kayerts and Carlier are devoid of individuality and agency, considering their exposition to and internalization of the colonial ideology. The enlistment of incompetent agents such as Kayerts and Carlier, it also finds, never undermines the perseverance of the empire to conquer and civilize Africa. In addition to the introduction, the article consists of four sections, the first of which reviews the plot, the second reviews the history of trading posts in Africa, the third reviews literature on Conrad's story, and the fourth discusses the assumptions made in the introduction. The findings and inferences are presented in the conclusion. A list of references is given at the end of the article.
Internationalisation as Institutional Escape for Family Businesses in Conflict Zones: Evidence from Afghanistan

Objective: The objective of this article is to investigate the use of internationalisation to “escape” the institutional voids present in conflict economic systems, through interviews with fifteen Afghan family business leaders who run businesses in Kabul. Research Design & Methods: Relying on grounded theory, we explore the role of internationalisation in providing security and stability for family businesses in conflict zones. In total, fifteen family business leaders were interviewed by three members of the research team working in pairs, after an analysis of transcripts subsequently described over the course of the interview process. Findings: We find that Afghan family business leaders demonstrate interest in internationalisation as a method of escaping institutional voids in the domestic environment, and that their most commonly cited motive in doing so is to obtain legitimacy in foreign markets through the establishment of quality standards. Implications & Recommendations: The appropriate way to proceed with internationalisation is to follow a stepwise process, so that family business leaders can draw upon both strengths inherent in their family and also engage in organisational learning through relationships with family businesses in neighbouring countries with similar cultures. Contribution & Value Added: We contribute to institutional theory by advancing our understanding of how insecurity, lawlessness, and tribalism play a role in the internationalisation of family businesses in conflict zones and to the family business literature by documenting how family business internationalisation is a response to domestic institutional voids. Article type: research article
Phase‐Field Modeling of Reaction‐Driven Cracking: Determining Conditions for Extensive Olivine Serpentinization

The motion of plates leads to cycling of chemically bound water and volatiles through the Earth's interior, having consequences for arc magmatism and seismic activity at subduction zones. Tectonically exhumed peridotite at the Earth's surface provides a substantial sink for water and carbon. The natural chemical disequilibrium that exists between exposed mantle peridotite and the surface waters/atmosphere could potentially be harnessed as a negative carbon emission technology. Understanding this process is therefore critical from both a petrological and environmental perspective. Retrograde metamorphism is physically complex, potentially involving an interplay between positive (cracking) and negative (clogging) feedbacks that may limit, or promote, fluid supply to unreacted minerals. Modeling studies are important in helping to constrain the conditions that control the extent of reaction in ultramafic rocks. This study builds on a previously reported model that describes olivine hydration/carbonation in a poroelastic medium, coupling fluid flow, elastic deformation, and mass transfer between chemically active phases. Here we extend this model to include brittle failure, which is crucial given the widely held hypothesis that reaction‐driven cracking is the dominant positive feedback in these processes. Here we explore the use of phase‐field methods to simulate brittle failure in a poroelastic medium, in the context of hydration (serpentinization) of peridotite. We show that reaction‐driven cracking in this model can generate a positive feedback that, under certain conditions, can lead to 100% transformation of olivine to serpentine.
A search for transient events in Konus-Wind data

We present the search for and classification of hard X-ray and soft γ-ray transient events in the archive of continuous (waiting-mode) Konus-Wind observations. We found ∼ 26 000 transient events; among them, ∼ 12 000 are solar flares (∼ 10 times as much as observed in triggered mode); and ∼ 5 000 are gamma-ray bursts (GRBs) or soft gamma repeaters (SGRs) confirmed by other space missions (∼ 2 times as much as detected in triggered mode). The remaining ∼ 9 000 events include Galactic transients, unconfirmed GRBs and possible solar flares. We discuss the application of developed techniques for GRBs accompanied by supernovae, high-energy neutrinos and sources of gravitational waves.
Trajectory Outlier Detection Algorithm for ship AIS Data based on Dynamic Differential Threshold

Trajectory outlier detection is one of the most important branches of data mining topics. Most existing outlier detection algorithms only utilized location of trajectory points and neglected some important factors such as speed, acceleration, and corner. In this paper, we propose a trajectory outlier detection algorithm based on dynamic differential threshold, called TODDT. Considering the influence of target motion information in a period of time, TODDT improves the traditional distance-based algorithm by combining dynamic differential threshold into outlier detection to discover more meaningful trajectory outliers. The experiments with real trajectory data sets in ship AIS (Automatic Identification System) show that TODDT algorithm performs efficiently and effectively when applied to the problem of trajectory outlier detection and the quality of trajectory data is greatly improved.
Smart Wide‐Bandgap Omnidirectional Reflector as an Effective Hole‐Injection Electrode for Deep‐UV Light‐Emitting Diodes

Deep‐ultraviolet light‐emitting diodes (DUV‐LEDs) find widespread applications in various industries and are a focus area in environmental and life science research. However, the quantum efficiency of DUV‐LEDs is still low because of the unbalanced hole injection, high operation voltage, and low reflectivity of the p‐electrode. In this study, a smart wide‐bandgap omnidirectional reflector (ODR), which simultaneously acts as an effective hole‐injection electrode, is demonstrated for a flip‐chip DUV‐LED. The smart ODR is composed of p‐type AlGaN (p‐AlGaN)/Ni:AlN/Al with a high reflectivity of 94.2% at 280 nm, in which AlN with a theoretically calculated thickness of 40 nm is Ni‐doped using the pulsed electrical breakdown (PEBD) method. The smart ODR‐mounted AlGaN‐multiquantum‐well‐based DUV‐LED exhibits a remarkable wall‐plug efficiency (4.8%) and high external quantum efficiency (8.5%) at a low operation voltage of 9.75 V owing to the fused layer of Ni3N and Ga vacancies formed in the interfacial region of the p‐AlGaN and AlN layers, through the mutual diffusion of Ni and Ga during PEBD. The interface‐mediated Ohmic contact leads to an effective hole injection without reducing the reflectivity, yielding increased optical output and electric input powers. The proposed smart ODR can provide an innovative route for the manipulation of DUV light.
Consumers’ Perception of Service Newness and Its Marketing Implications

Abstract Researchers and marketers have spent considerable effort to understand product newness, particularly really-new and incrementally new products, however, the same cannot be said about service newness. To date, there is no study that only focuses on how consumers perceive service newness. This research aims not only to fill this academic vacuum, but also to help the practitioner in framing messages that they send to potential consumers when a new service is being introduced. Furthermore, this study contributes to the services marketing literature by examining how new services in a variety of different industries are perceived by consumers.
Developing a team performance framework utilising Neethling’s thinking style preference instrument

Orientation: This article focuses on the employees and managers’ experience of the effects of Neethling’s thinking style preference instrument on team performance. Research purpose: The purpose of this study was to compile a framework to apply Neethling’s thinking style preferences to team performance. Motivation for the study: Organisations today are aware that they need to increase quality, decrease costs, advance customer service, increase their adaptability to an increasingly competitive environment and decrease the time spent on creating new products. To realise these goals, organisations must convert their work teams into more cohesive and dedicated teams. No or limited research has been conducted on how the application of Neethling’s thinking style preferences may influence team performance. Research approach/design and method: A qualitative exploratory study was conducted with 19 participants working in the Financial and Insurance Department of a sales-driven organisation in Gauteng, South Africa. The data were collected by means of focus group and individual interviews. Main findings: The positive effects of the Neethling’s thinking style preferences on the team were that the participants understood people better, their conflict management skills increased, their self-awareness improved, the communication in the team increased and they experienced an increase in team cohesion. The negative experiences were task avoidance, labelling and wrong assessments of people, but the positive experiences exceeded the negative experiences. Due to the positive experiences, the organisation also benefitted in terms of improved customer service and increased productivity, which could lead to organisational success and a competitive advantage. Practical/managerial implications: When used in teamwork, the Neethling’s thinking style preference instrument shows positive outcomes regarding team performance. Contribution/value-add: The findings of this study contribute new knowledge regarding the application of Neethling’s thinking style preferences in team performance.