Miracle-dz/UniFAR-FTUs huggingface dataset:
Trust : a game of co-evolving beliefs and preferences 14 th May 2012

Trust is often described as an important variable in social interactions, allowing exchanges and potentially influencing economic performance. In the last decades, the understanding of trust antecedents and consequences has deepened. While trust has often been defined as an expectation about a counterpart’s trustworthiness in a situation involving risk, experimental studies point to the social nature of the risk affecting trust-based interaction, and to the relevance of so-called social preferences. In this paper we present a model integrating some recent insights from experimental research. We use a definition of trust based on economic primitives, such as beliefs and preferences. The model extends previous research in that we assume endogeneous preferences and we focus on trust dynamics in a web of social interactions, and on learning as the essential mean for trust evolution and diffusion. We define various settings depending on how buyers update their beliefs and preferences: on one side beliefs are updated either only through direct, or thought direct and indirect experience; on the other side, preferences are updated either considering beliefs evolution, or based on outcomes evaluation. We investigate how the co-evolution of beliefs and preferences influences buyers’ performance in terms of the quality of the selected interactions and of aggregate welfare. We define performance measures in terms of social risk, social loss, welfare, and a synthetic measure of aggregate performance and efficiency. We show that the assumption of preferences endogeneity can have both negative and positive impact on trust dynamics, and on social welfare, depending on the average level of agents’ beliefs, as well as on learning dynamics. In particular, we show that if social learning is fully developed, 1Organization: University of Luxembourg CREA Email: maurizio.cortesi@uni.lu This research is made possible under the financial support of the FNR fellowship project AFR PHD-08-017
Perceptions of E-Learning in Organizations: An Empirical Study on the Effects of Gender Age, Duration of Employment, and Managerial Level

The e-learning industry is predicted by Gartner Group to grow to $33.4 billion by 2005 indicating a phenomenal expansion of market size almost 16 times its current state. The research results reported here are based on a major study involving over 370 e-learners within a large telecommunications company in Australia. Analysis indicates that staff do not prefer e-learning over its traditional face-to-face counterpart and that this is primarily driven by the perception that the disadvantages outweigh the advantages. This research also explores the effect of demographic characteristics on an individual’s preference for e-learning and finds that each of gender, age, time in the workplace and managerial status has an effect on the way it is perceived. The paper concludes by suggesting that the introduction of e-learning into the corporate environment maybe more difficult than short-term cost savings might suggest. It also suggests that management will need to carefully consider the different groups being offered e-learning and tailor the courses with individual characteristics in mind.
Fusion of privileged features for efficient classifier training

Within the supervised machine learning framework, classifier performance is significantly affected by the size of training datasets. One of the ways to improve classification accuracy with small training datasets is to utilize additional knowledge about training data that is not present in testing data. In the Learning Using Privileged Information (LUPI) learning paradigm, this additional knowledge is represented by the privileged feature space, which is fused with the standard feature space during classifier training. In this paper, we study two new algorithmic realization of LUPI, based on knowledge transfer, and compare them with the original SVM+ LUPI algorithm, which is based on similarity control. We apply the algorithms to a wide area aerial video exploitation problem, and measure misclassification error rate and execution time of both algorithms. We use minor area motion imagery (MAMI) dataset, recently released by Air Force Research Laboratory (AFRL). High-resolution imagery is utilized as privileged information for low-resolution imagery. We demonstrate that an ensemble knowledge transfer approach that combines multiple knowledge transfer algorithms outperforms the original SVM+ approach with the error rate reduction of up to 25%. We also show that knowledge transfer approach requires significantly less computational resources, making LUPI algorithms as scalable as SVM.
Computers, talk and learning : using computers to help coach reasoning through talk across the curriculum

The main theme of this thesis is the role of computers as a support for reasoning through talk in the classroom. A second, closely linked, theme is the role of reasoning through talk in general intellectual development. In the first part of the thesis the two areas of the teaching of thinking skills and the use of computers as a support for cooperative work in classrooms are explored through critical reviews of the literature and through two empirical studies. The findings of this exploratory research lead to the development of a theoretical framework for the use of computers in classrooms. This theoretical framework consists of the characterisation of a type of talk that is effective in promoting general intellectual development, a model of the structure of educational activities in which groups of children work with computers and a set of principles for the design of software to support reasoned discussion. In the second part of the thesis the theoretical framework is explored and tested through the development and implementation of an intervention programme. A new methodology is developed to evaluate this intervention programme integrating a quasi-experimental method with both qualitative discourse analysis and computer-based discourse analysis. The findings of the evaluation support four key hypotheses which emerge from the theoretical framework. First, that there is a link between the coaching of reasoning through talk and performance on tests of general reasoning ability. Second, that the quality of computer-supported collaborative learning can be enhanced through the off-computer coaching of exploratory talk. Third, that group work at computers can in turn be used effectively to extend an educational programme designed to coach exploratory talk across the curriculum. Fourth, that computer-based collaborative learning can - be used to integrate active peer-learning with directed teaching. These findings have significant implications for educational theory and practice.
Transactions on Ultrasonics , Ferroelectrics and Frequency Control : A New Method for Estimation of Velocity Vectors

The paper describes a new method 1 for determining the velocity vector of a remotely sensed object using either sound or electromagnetic radiat ion. The movement of the object is determined from a field with spatial oscillations in both t he axial direction of the transducer and in one or two directions transverse to the axial dir ection. By using a number of pulse emissions, the inter-pulse movement can be estimated and the velocity found from the estimated movement and the time between pulses. The method i s based on the principle of using transverse spatial modulation for making the receive d signal influenced by transverse motion. Such a transverse modulation can be generated by usi ng apodization on individual transducer array elements together with a special focusing scheme. A method for making such a field is presented along with a suitable two-dimension al velocity estimator. An implementation usable in medical ultrasound is described and simulated results are presented. Simulation results for a flow of 1 m/s in a tube rotated in the im age plane at specific angles (0, 15, 35, 55, 75, 90 degrees) are made and characterized by t he es imated mean value, estimated angle, and the standard deviation in the lateral a nd ongitudinal direction. The average performance of the estimates for all angles is: mean v locity 0.99 m/s, longitudinal std. dev. 0.015 m/s and lateral std. dev. 0.196 m/s. For flow pa rallel to the transducer the results are: mean velocity 0.95 m/s, angle 0.1 , longitudinal std. dev. 0.020 m/s and lateral std. dev. 0.172 m/s.
Constructing a Fully Ranked phylogenetic Constraint Tree using Monophyletic Group, Crown Group and Relative Age Constraints

Phylogenetic research field concerned with the reconstructing of the phylogenetic tree using some information that has evolved from the root to all the descendants. There are many ways to try and find the best tree.If one knows beforehand that a subset of species form a subgroup that are closely related then one can constrain the search algorithm to only look for those trees where this subset of species forms a subtree. Placing such constraints reduces the number of trees that the search algorithm must consider and thus reduces the time spent searching for the best tree. In Bayesian phylogenetic inference we are interested in distributions over a space of trees. When fossil evidence is used in the inference to constrain the tree, new tree spaces arise and counting the number of trees is more difficult. We have constructed a tree using algorithm that is polynomial in the number of sampled individuals for counting of resolutions of a constraint tree assuming that the number of constraints is three.
The Structure of Social Collateral: Embeddedness and Economic Performance in Microfinance

We examine the explicit use of social relationships as collateral against loan default, a core feature of modern microfinance. What structural factors determine whether borrower relationships serve as an effective security? Through a rich combination of data on microfinance clients in Sierra Leone, including ethnographic, affiliation survey, GPS, and loan performance, we explore how a microcredit group's spatial structure affects its embeddedness and the efficacy of social collateral. We posit that group structure determines the salience of alternative social mechanisms underlying cooperation. The effects of group structure on economic performance are statistically tested using a dataset of 5,582 repayment-transactions made by 1,884 microfinance clients in Sierra Leone from 2006-2011. Our findings highlight two structural features of social collateral: (1) A group's spatial concentration improves economic performance up to a certain level; after which, the effect reverses and performance declines. Contrary to predominant expectations in the microfinance literature, groups are significantly at risk of overembeddedness. Though embeddedness enhances the ability to sanction, communicate, and build solidarity, high levels reduce the willingness to enforce the loan. (2) Groups that consist of multiple spatial fragments produce significantly worse economic performance. Socially, such groups are prone to split into factions and hinder overall cooperation.
Robustness of emotional expression recognition under low visibility

Human beings have the capacity to recognize facial emotions even under conditions of imperfect visual access to the face. We tested for the robustness of this process using different kinds of visual noise simulating occlusion, peripheral or unattended vision, and distant vision. We prepared videos of dynamic faces exhibiting one of six basic emotions. The videos were then degraded with either partial occlusion, low contrast, or low pass spatial frequency filtering, to various degrees. Participants were able to recognize the intended emotion in videos under severe visual noise of all types, showing the most robust recognition of surprised expressions. Additionally, the pattern of confusability of one emotion for another was sustained across different kinds and levels of distortion, suggesting the same perceptual mechanism at work under various levels of noise.
Further confirmation for unknown archaic ancestry in Andaman and South Asia

In a recent paper1, we have derived three main conclusions: i) that all Asian and Pacific populations share a single origin and expansion out of Africa, contradicting an earlier proposal of two independent waves; ii) that populations from South and Southeast Asia harbor a small proportion of ancestry from an unknown extinct hominin – different from the Neanderthal and the Denisovan – which is absent in Europeans; and, iii) that the characteristic distinctive phenotypes (including very short stature) of Andamanese do not reflect an ancient African origin, but have resulted from strong natural selection on genes related to human body size. Although the single wave out of Africa2 and single origin for Asian and Pacific populations have been confirmed3, the existence of admixture with an extinct hominin has been challenged by Skoglund et al.4, as they were unable to replicate our results in their data sets. While we had used a wide variety of statistical methods and data sets from diverse populations to draw our inference, Skoglund et al.4 have used only one method (D-stats5, for the whole genome, not specifically for the relevant genomic regions) and compared only with the Asians, not even with the Europeans. Skoglund et al.4 have alleged that our statistical treatment of the data was faulty and have pointed out some possible sources of error. We have reexamined our data focusing on possible sources of error flagged by Skoglund et al4. We have also performed new analyses. The reexamination and new analyses have bolstered our confidence that our earlier inferences were correct and have resulted in an improved model of introgression of modern humans with a hitherto unknown archaic ancestry. We also propose a possible reason for the inability of Skoglund et al.4 to validate our inference.
The Impact of Exchange Rate on Output Level: Bounds Testing Approach for Pakistan

Currency depreciation has been an influential instrument to boost-up the net export of the developing economies that face the strict conditions of international donors along with elevated trade deficit. The eventual intention behind this channel is to achieve the improved current account status that result in higher output level. But the output growth may be dwindling in long-run that may not allow the traditional channel to work. This study examines the given analysis by utilising the annual data set over the period 1972-2010 for output, nominal exchange rate and price level along with different control variables in case of Pakistan. The findings based on Bound-testing approach to auto-regressive distributive lag model (ARDL) indicates that traditional theories do not work in long-run and currency depreciation may lead to reduction in output while the short-run Error-Correction Model (ECM) results robustly support to the traditional theories of open economy macroeconomics in which currency depreciation increases the output level. The study explores the new dimension of research both for policy-maker and international donors working in developing countries, particularly in South Asian region.
Developing Self-Efficacy in Teaching Mathematics: Pre-Service Teachers’ Perceptions of the Role of Subject Knowledge

ABSTRACT Two major concerns in mathematics teacher education are the role of subject matter knowledge and the development of self-efficacy in pre-service teachers. This article brings these issues together in an exploration of the interaction between pre-service teachers’ perceptions of their subject matter knowledge and their accounts of university and placement experiences as potential sources of self-efficacy. Reporting on a group of ten pre-service teachers in Norway, we explore variations in the ways in which they perceived the role of subject knowledge in relation to experience, particularly “mastery experiences”, over a period of nearly two years. We suggest that recognition of the role of “understanding why” in mathematics is crucial in the experience of mastery, and that there is a need to focus more on the role of subject matter knowledge in all sources of self-efficacy in teaching mathematics.
Real-time Subsurface Scattering for Particle-based fluids using Finite Volume Method

We present a real-time subsurface scattering simulation to perform real-time rendering of translucent particle-based fluids. After particle-based fluid simulation, we immediately build voxelized fluids, ca lled Voronoi fluids, with particle locations and neighbour lists using GPUs. And then, we perform a multiple subsurface scattering simulation over the Voronoi fluids with the diffusion equation (DE). We employ Finite Volume Methods to solve DE efficiently and rapidly with th e voxelized fluids. In our implementation, DE is solved on GPUs with the diffusive source boundary condition and query function for computing the outgoing radiance. We demonstrate a milk demo that show our method can be performed in real-time with CUDA-based fluid simulation.
Raman-assisted DPP-BOTDA sensor employing Simplex coding with sub-meter scale spatial resolution over 93 km standard SMF

Differential pulse-width-pair BOTDA technique is combined with bi-directional Raman amplification and Simplex coding to achieve sub-meter spatial resolution over very long sensing distances. Numerical simulations are used to optimize the power levels of the Raman pumps, avoiding nonlinear effects and pump depletion. Distortions in the Brillouin gain spectrum due to acoustic-wave pre-excitation are also avoided by numerical optimization of the pulse width and duty cycle of return-to-zero Simplex coding, providing significant SNR enhancement. We demonstrate 50 cm spatial resolution over 93 km of standard SMF with a strain/temperature accuracy of 34με/1.7 °C, respectively.
Silver Nanoparticles Modified by Gelatin with Extraordinary pH Stability and Long-Term Antibacterial Activity

The potential for application of any nanoparticles, including silver nanoparticles (AgNPs), is strongly dependent on their stability against aggregation. Therefore, improvement of this parameter is a key task, especially in the case of AgNPs, because a correlation between size and biological activity has been demonstrated. In the present work, a natural stabilizer, gelatin, was investigated for the stabilization of AgNPs in an aqueous dispersion. The particles were prepared via a modified Tollens process, and the gelatin modifier was added prior to the reducing agent. The stability against aggregation of the AgNPs prepared by this method was more than one order of magnitude higher (on the basis of the critical coagulation concentration (CCC)) than that of AgNPs prepared via a similar method but without the assistance of gelatin. Their high stability against aggregation was confirmed over wide pH range (from 2 to 13) in which the particles did not exhibit rapid aggregation; such stability has not been previously reported for AgNPs. Additionally, gelatin not only fulfills the role of a unique stabilizer but also positively influences the modified Tollens process used to prepare the AgNPs. The diameter of the gelatin-modified AgNPs was substantially smaller in comparison to those prepared without gelatin. The polydispersity of the dispersion significantly narrowed. Moreover, the gelatin-stabilized AgNPs exhibited long-term stability against aggregation and maintained high antibacterial activity when stored for several months under ambient conditions.
Anthropometry, physical activity, and endometrial cancer risk: results from the Netherlands Cohort Study.

Although obesity is an established risk factor for endometrial cancer, evidence linking risk to height, weight change since age 20, and physical activity is limited. In this case-cohort study, 62 573 women from The Netherlands Cohort Study on Diet and Cancer were followed up from 1986 to 1995, and 226 endometrial cancer case patients were identified. In Cox proportional hazards analyses, women 175 cm or taller had an increased risk of endometrial cancer compared with those less than 160 cm (rate ratio [RR] = 2.57, 95% confidence interval [CI] = 1.32 to 4.99). Compared with women with a body mass index (BMI; kg/m2) between 20 and 22.9, women with a BMI of 30 or greater had a higher risk (RR = 4.50, 95% CI = 2.62 to 7.72; P(trend)<. 001). Moreover, BMI at age 20 and BMI gain since age 20 were positively associated with endometrial cancer risk (P(trend) = . 02 and <. 001, respectively). Women who spent 90 minutes per day or more doing nonoccupational physical activities had a lower risk (RR = 0.54, 95% CI = 0.34 to 0.85; P(trend) = . 002) compared with those who spent less than 30 minutes per day. High BMI and low physical activity were strong and independent risk factors for endometrial cancer.
Konrad-zuse-zentrum Für Informationstechnik Berlin Efficient Projection and Deformation of Volumetric Intensity Models for Accurate Simulation of X-ray Images Efficient Projection and Deformation of Volumetric Intensity Models for Accurate Simulation of X-ray Images

We present an efficient GPU-based method to generate virtual X-ray images from tetrahedral meshes which are associated with attenuation values. In addition, a novel approach is proposed that performs the model deformation on the GPU. The tetrahedral grids are derived from volumetric statistical shape and intensity models (SSIMs) and describe anatomical structures. Our research targets at reconstructing 3D anatomical shapes by comparing virtual X-ray images generated using our novel approach with clinical data while varying the shape and density of the SSIM in an optimization process. We assume that a deformed SSIM adequately represents an anatomy of interest when the similarity between the virtual and the clinical X-ray image is maximized. The OpenGL implementation presented here generates accurate (virtual) X-ray images at interactive rates, thus qualifying it for its use in the reconstruction process.