Miracle-dz/UniFAR-FTUs huggingface dataset:
Quality control of risk measures: backtesting VAR models

measures: quality control of risk measures (QCRM). The approach is applied to the problem of backtesting value-at-risk (VAR) models. VAR models are used to predict the maximum likely losses in a bank’s portfolio at a specified confidence level and time horizon. The widely accepted VAR backtesting procedure outlined by the Basel Committee for Banking Supervision controls the probability of rejecting the model when the model is correct. A drawback of the Basel approach is its limited power to control the probability of accepting an incorrect VAR model. By exploiting the binomial structure of the testing problem, QCRM provides a more balanced testing procedure, which results in a uniform reduction of the probability of accepting a wrong model. QCRM consists of three elements: the first is a new hypothesis-testing problem in which the null and alternative hypotheses are exchanged to control the probability of accepting an inaccurate model. The second element is a new approach for comparing the power of the QCRM and Basel tests in terms of the probability of rejecting correct and incorrect models. The third element involves the use of the technique of pivoting the cumulative distribution function to obtain one-sided confidence intervals for the probability of an exception. The use of these confidence intervals results in new acceptance/rejection regions for tests of the VAR model. We compare these to ones commonly used in the financial literature.
Returning home: Case study of travelling for work from Czechoslovakia in times of socialism

Abstract It is not a new concept to live and enjoy family life in one place and work somewhere else. Travelling to get to one´s place of work and living part-time away from one´s place of residence is still a lifestyle many choose. During the Communist era in Czechoslovakia many men were leaving their families to work abroad. The struggle to get to the place of work was incomparable to the way it is now. This article presents the story of a man who had been working abroad (in democratic countries such as Germany and Austria) for years and always chose to return home, to a country full of restrictions (Czechoslovakia). The theoretical part will explain the theory of place attachment and provide a historical context for the empirical part. The empirical part represents an insight into life, travel, and work in the Communist era in Czechoslovakia. The purpose of this article is to provide a psychological point of view to labor migration and most importantly an explanation of a desire to return home despite the socialist regime. The focus is on the place attachment theory and an individual case study relating to international labor migration, put in a historical context.
Development of a Personal Sampler for Evaluating Exposure to Ultrafine Particles

Evaluation of the exposure of humans to ultrafine, airborne particles is an important aspect of health in the workplace, especially in cases where nano-particles are present. However, portable sampling devices for efficiently collecting ultrafine particles in a worker's breathing zone are not readily available. The present study describes the design and development of a portable sampler for collecting particulates in the breathing zone, as a possible tool for this purpose. The design is based on the use of an ”Inertial Filter” to separate various-sized nano-order particles. Inertial filters consisting of SUS fiber felt (fiber diameter 5.6-13.5 μm) placed in circular nozzles (3-6 mm diameter with 4.5 mm length) were used. To achieve the smallest dp50 under the allowable pressure drop of a portable pump, the influence of fiber loading on separation performance and pressure drop were investigated. The influence of particle loading was also examined in relation to pressure drop and separation performance. The smallest dp50 under the allowable pressure drop (5.7 kPa at 6 L/min) for the battery pump employed was ~140 and 200 nm respectively for SUS fibers of 5.6 and 9.8 μm diameter (particle volume fraction ~0.013). The change in separation performance due to particle loading was confirmed to be acceptable for use under the present conditions. Under these conditions, a sufficient amount of particles can be collected for chemical analyses, e.g., particle-bound PAHs after 6-8 hours of sampling. Hence, the developed sampler has the potential for use in evaluating exposure to ultrafine particles in the breathing zone in the workplace.
Evaluation of genetic diversity of okra accessions [Abelmoschus esculentus (L. Moench)] cultivated in Burkina Faso using microsatellite markers

Okra is a traditional vegetable grown throughout Burkina Faso. Despite a food and non-food valorization of all parts of the plant, its genetic diversity is still little known. Thus, 50 accessions of okra from Burkina Faso were characterized using 19 microsatellite markers in order to determine the level and structure of genetic diversity. The results reveal a total of 34 alleles including 3 rare alleles and a number of 2.58 effective alleles. A polymorphic information content (PIC) value between 0.11 and 0.86 and markers polymorphism rate of 42.10% were also obtained. Mean expected heterozygosity and Shannon diversity index were 0.46 and 0.77, respectively. In addition, a structuring of the 50 accessions in three genetic groups with indices of very similar accessions of 88 to 95% between climatic zones and 83 to 95% between ethnic groups were observed. The diversity obtained could be exploited in the program of selection and varietal improvement of okra. Key words: Genetic variability, simple sequence repeats (SSR) markers, varietal selection, valorization, genetic differentiation.
Inductive Inference of LR(0) Grammars

We present a modification to the LR(0) parsing algorithm, to infer new production rules in (LR(0)) context-free grammars. Given a grammar G and strings w Є L(G), w' 62 L(G), such that w' is an update of w, we propose an algorithm to obtain new grammars (extensions of G) to generate the string w'. We propose the Inductive LR(0) algorithm, to build new LR(0) items, to be added to those of the original grammar. These items will be used to define new production rules, to extend the grammar. Our algorithm generates several solutions. The algorithm can be applied in the context of the schema update for semi-structured data (XML). In that context, we suppose that the data administrator is an expert in the field of application of the schema (grammar) being extended. This data administrator will choose the most adequate solution for their needs.
Nowcasting Thunderstorms: A Status Report

Abstract This paper reviews the status of forecasting convective precipitation for time periods less than a few hours (nowcasting). Techniques for nowcasting thunderstorm location were developed in the 1960s and 1970s by extrapolating radar echoes. The accuracy of these forecasts generally decreases very rapidly during the first 30 min because of the very short lifetime of individual convective cells. Fortunately more organized features like squall lines and supercells can be successfully extrapolated for longer time periods. Physical processes that dictate the initiation and dissipation of convective storms are not necessarily observable in the past history of a particular echo development; rather, they are often controlled by boundary layer convergence features, environmental vertical wind shear, and buoyancy. Thus, successful forecasts of storm initiation depend on accurate specification of the initial thermodynamic and kinematic fields with particular attention to convergence lines. For these reasons .
Simulation of wave propagation in a piecewise homogeneous elastic rod

This article deals with modeling and simulation of the wave propagation phenomenon in a heterogeneous linear elastic rod treated as piecewise homogeneous. Employing a reference configuration approach the piecewise homogeneous elastic rod is mathematically described by a linear hyperbolic system of partial differential equations. Its generalized solution is obtained by connecting intermediate states by contact shocks – thus allowing analytical solutions for some initial value problems even when boundary conditions are considered.
The Effects of Instrumental Marching and Cheerful Music on Women’s Sense of Power, Self-Control, Fear of Childbirth, and Second-Stage Duration During Their Second Stage of Labor

Background: There are few studies regarding ways to promote positive feelings among women in labor. Thus, it would be useful to study the effects of marching music and cheerful music on women in the second stage of labor. Objectives: To examine the effects of marching music and cheerful music on women’s sense of power, self-control, fear of childbirth, and second-stage duration during their second stage of labor. Materials and methods: Randomization was used to assign 145 pregnant women, both primi-parous (67) and multiparous (78), to the control and experimental groups. The women in the experimental group heard marching songs and cheerful music during their second stage of labor. The levels of their sense of power, self-control, and fear of childbirth were measured within two hours after the women gave birth. Measurement was achieved by using the 100 mm Visual Analogue Scale (100 mm VAS), which had test-retest reliabilities of 0.81-0.98. Results: Only 141 of the 145 women were involved in the analysis due to the fact that four women did not have a normal delivery. There were no differences found between the two groups for any of the attributes: sense of power, self-control, and fear of childbirth from data measuring with VAS and duration of second stage labor. However reporting by using questionnaires, most women found that listening to the music was helpful and increased their sense of power at a moderate to high level. Conclusions: Listening to marching music and cheerful music may have little effect on a woman’s sense of power, self-control, fear of childbirth, or second-stage duration. However, the women perceived that there is a benefit to music, and it may be substantial if the music is listened to for a longer period of time than it was in this study. Key words: childbirth, fear, music therapy, self-control, sense of power
Essays in Behavioral Microeconomic Theory Essays in Behavioral Microeconomic Theory

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Collaborative and Self-directed Learning Strategies to Promote Fluent EFL Speakers

Speaking English with fluency is one of the most demanding challenges students and teachers face in many educational communities, and it has been claimed that fluency problems can derive from lack of practice during independent study. This research article reports on a mixed-methods study that analyzed the effects of using collaborative and self-directed learning strategies through speaking tasks aimed at developing oral fluency. This study was carried out with a group of 10 students with a pre-intermediate level (CEFR A2) in English at a Colombian university. Qualitative data from students’ reflections, compiled through a survey, and the teacher’s classroom observations was analyzed through the grounded theory approach. Quantitative analysis was aided by a protocol in which frequency counts of words and hesitations per minute for each speaking task were registered. The results suggest that fluency can be acquired collaboratively when learning from others and by making mistakes. Additionally, working collaboratively increases learners’ confidence not only because they feel they are not being judged but because they learn to see that their mistakes are not just theirs. Thus, collaboration is positively influenced by self-directed learning, in that it encourages students to make personal reflections on their weaknesses and strengths, thereby involving them in decision-making processes that identify what is not working properly and what they should do to succeed.
Stereotype Threat in Higher Education: The Role of Psychological Capital on Student Satisfaction and Commitment

Stereotype threat refers to being at risk or confirming, as self-characteristic, a negative group stereotype about one’s group. Past research has linked stereotype threat to a multitude of detrimental outcomes including decreased test performance, the drainage of cognitive resources, and increased stress levels. However, many of these findings were confined to laboratory settings and focused only on immediate effects. Research on stereotype threat framed as a macro-level product in a non-laboratory setting is limited at this time. In an attempt to bridge this gap, the present study examined the lingering effects of stereotype threat on minority satisfaction / commitment in a university setting. The present research also introduced a potential moderator of stereotype threat and minority student satisfaction / commitment in the form of a higher order positive construct, psychological capital. Contrary to initial expectations, results indicated that while minority students reported significantly higher levels of perceived stereotype threat compared to non-minority students, they remained committed to and satisfied with their university. Furthermore, levels of psychological capital did not seem to act as a buffer for stereotype threat.
LIBS Technique for Fast Impurities Identification in Metallurgic Grade Silicon

Thanks to the rapid growth of the photovoltaic market the silicon demand is continuously increasing. The shortage of purified silicon between 2004 and 2008 induced a strong price increase and trigged a capacity expansion as well as the introduction in ingot production of the so called “upgraded metallurgic grade silicon” (UMG-Si) as a feedstock. However, new solar grade silicon might contain significant higher fractions of impurities. It is well known their impact on the final cell quality but the debate is open about what are the acceptable contamination levels within the purified silicon feedstock also because it is well known that during the growth process and cell manufactory the material quality improves. In the recent period in the market there is an increasing availability of silicon feedstock at lower cost but its quality is not always guaranteed. In this paper we report a new fast in line characterization tools for feedstock analysis based on the Laserinduced breakdown spectroscopy. We applied this technique to the characterization of metallurgic grade silicon feedstock with the aim of valuate the applicability of this technique in the photovoltaic industry as in-line portable characterization tool. Different silicon grade feedstock were analyzed and selectivity and detection limit for the main impurities present in the silicon feedstock were determined.
A global model for the NO released in vegetation fires

Vegetation fires are a major emission source of CO, CO2, NOx, volatile organic compounds and particulates to the atmosphere. To describe the impact of these fires on the environment and to model their pollutant emissions, it is necessary to understand the processes involved in the combustion of vegetation. Likewise, the analysis of combustion kinetics in the gas-phase is decisive for modeling vegetation fires behavior given that the rate and amount of energy released from the fuel are derived from the fundamental chemistry of the fuel and its combustion. In this work, a numerical approach has been used to study the mechanisms of NO formation in vegetation fires at the source level, given that NO plays an important role on the formation of ground-level ozone. The major reaction mechanisms involved in NO chemistry have been identified using reactions path analysis and sensitivity analysis with a detailed kinetic mechanism (GDF-kin ® 3.0). Moreover, a two-step global kinetic mechanism has been proposed herein to account for the conversion of volatile fuelbound nitrogen to NO, considering that the volatile fraction of fuel-bound nitrogen is released as NH3. Data from simulations using the PSR code from CHEMKIN-II package with the detailed kinetic mechanism GDFkin ® 3.0 have been used to formulate reaction rate expressions of the global model under vegetation fires conditions.
How to identify larvae of the protected species: Dioszeghyana schmidtii (Diószeghy 1935), and survey its presence and abundance (Lepidoptera: Noctuidae; Hadeninae)

Abs Tr AcT: Dioszeghyana schmidtii (Dioszeghy 1935), is forest species protected by European Union. Its distribution has been studied essentially by the use of light traps. However, its biology and habitat preferences are not sufficiently known and thus its habitats may be damaged by forest management. We suggest the beating method in order to collect larvae as an useful way to record and to survey D. schmidtii. Larvae of the species can be collected by beating branches of its host plants ( Quercus and Acer species) in the lower canopy (below 3 m). Optimal survey time would be the second half of May and the first half of June. Differences between the larvae of D. schmidtii and 16 similar moth larvae, as well as, Tenthredinidae (Hymenoptera) species living at the same time on the same trees are described and figured in a key to identification. The method described in the paper allows one to identify larvae in the field. Results are discussed.
Have we Made Any Progress in Preventing Sudden Cardiac Death in the Community? A Review on Automatic External Defibrillators

ABSTRACT: Automated External Defibrillators (AEDs) have been recognised lately as an important link in the chain of survival of patients experiencing Sudden Cardiac Arrest (SCA) still remaining a major public health problem in the Western countries, being responsible for more than 250,000 out-of-hospital deaths annually. Due to the fact that survival rates following SCA are still unacceptably poor and that in most of the cases the underlying heart rhythm in out-of-hospital SCA is Ventricular Fibrillation/ pulseless Ventricular Tachycardia, introduction of AEDs seems to open a new prospective. Since the early 1990’s, when first launched, significant improvement has been made in AEDs technology and in many countries Public Access Defibrillation programs are now widespread. After minimal training, lay rescuers and first responder who might not be health professionals effectively provide early defibrillation using AEDs, resulting in many cases in improved survival rates. In the present paper we review the status of AEDs in clinical practice in the year of 2010 emphasizing on their key role for the widespread prevention of sudden cardiac death in the community.
Diversidade, parâmetros estruturais e produtos florestais não madeireiros na reserva florestal de Bonepoupa (Douala, Camarões)

In order to come up with a sustainable use of forest ecosystems in Cameroon, its vegetal diversity has been inventoried; the plant potentials and the structural parameters were studied in the forest reserve of Bonepoupa. Ten non-continuous plots of 200 m² were done and the materialization of the lines was done with a topofil put at the centre of the field with ropes at 5 m each of the topofil. In addition, ninety people were interviewed in order to know the potential use of species in this region. Up to 172 individuals with Diameter at Breast Height (DBH) ≥ 5 cm divided into 27 species, 25 genera and 18 families were inventoried and the coefficient of abundance-dominance was determined. The diversity index of Shannon (H’) was H’1 = 4.17 ± 0.45 with H’1max = 4.75 and the evenness was R1 = 0.88. Taking into account herbaceous species, H’ determined by the coefficient of abundance-dominance was H’2 = 4.74 ± 0.56 with H’2max = 5.70 and the evenness was R2 = 0.83. The total basal area was 19.69 m2/ha and the density was 860 individuals/ha. These results indicate that herbaceous significantly modifies the value of the diversity index and that forest reserve of Bonepoupa is experiencing a problem of conservation which is due to a lack of its appropriate management. The knowledge of non-timber forest products and their use as food as well as medicinal resources by local population might be helpful for the sustainable management of resources in this forest reserve
The Puzzle of Valuation Gaps Between Experimental Auction and Real Choice Experiments: Do Purchase Intention and Price Bargaining Preference Matter?

This article examines the preferences revealed by two non-hypothetical experiments. We found that WTP estimates from real choice experiment are significantly than auction bids. We provide two possible reasons for it: consumers’ purchase intention and aggressiveness in price bargaining. Our results suggest that the discrepancies among experiments can come from the heterogeneity of respondents’ price bargaining aggressiveness, but not from purchase intention differences.
Nature of gum polysaccharide extracted from Moringa oleifera Lam.(Sainjna) plant

Water soluble polysaccharide have been extracted from Moringa oleifera Lam. gum mucilage as L-arabinose and D-galactose in the molar ratio of 1:4 with traces of L-fucose. Hydrolysed gum polysaccharides were separated by paper chromatography and identified by column chromatography. It consumed 8.2 moles of iodine by iodometrically after 110 hrs. Nature of α and β-type linkages were confirmed by IR-Spectra (KBr). Sugars were identified by their specific rotations, melting points and preparation of their suitable crystalline derivatives.
The Physical Chemistry of Pesticides in Soil and Water

Soils are the ultimate examples of physically and chemically irregular mixtures. They are also dynamic. Early investigators consequently did not understand the physical chemistry of pesticides in soil and water. By taking shortcuts instead of trying to understand the physical chemistry, they measured the wrong variables, used the wrong units, calculated the wrong parameters, and totally ignored chemical stoichiometry. Theoretical concepts for the physical chemistry of pesticides in soil have been published during the last quarter century. They are experimentally supported. Yet, chemically incorrect descriptions persist in the literature to this day. That has serious environmental and economic consequences. In particular, government regulators make legally binding pesticide decisions based on computer predictions that are wrong by 1 to 3 orders of magnitude. This needs the attention of scientists, governments, and multinational corporations.
Estimation of Correlation for Continuous Semimartingales

Abstract. In this study we are concerned with inference on the correlation parameter ρ of two Brownian motions, when only high‐frequency observations from two one‐dimensional continuous Itô semimartingales, driven by these particular Brownian motions, are available. Estimators for ρ are constructed in two situations: either when both components are observed (at the same time), or when only one component is observed and the other one represents its volatility process and thus has to be estimated from the data as well. In the first case it is shown that our estimator has the same asymptotic behaviour as the standard one for i.i. d. normal observations, whereas a feasible estimator can still be defined in the second framework, but with a slower rate of convergence.