412 research outputs found

    Percepcija faktora koji doprinose školskom neuspehu od strane budućih nastavnika i njihova povezanost sa prethodnim ličnim iskustvom uspeha u školi

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    Factors that pre-service class and subject teachers perceive as significant in explaining the occurrence of school failure were examined using mixed methods strategy. The qualitative phase of the study (N = 74) revealed that pre-service teachers recognize a wide range of causes for school failure (16 distinctive categories). The relative significance of the causes was established in the subsequent quantitative phase. The Scale of school failure causes was constructed, applied to 408 pre-service teachers and subjected to exploratory factor analysis, which pointed to the three latent groups of causes explaining 43% of variance. The lack of ability and motivation in students (1st factor) and the lack of educational support (2nd factor) were perceived as highly contributing to school failure, while moderate importance was attributed to the causes related to family and social context (3rd factor). Compared to pre-service subject teachers, pre-service class teachers were more willing to recognize the teachers' responsibility for the occurrence of school failure. Pre-service teachers' perceptions of different factors were related to prior experiences of school success.Faktori koje budući nastavnici razredne i predmetne nastave opažaju kao značajne za pojavu školskog neuspeha su proučavani pomoću miks metodske strategije. U kvalitativnoj fazi istraživanja (N = 74) se pokazalo da budući nastavnici razredne i predmetne nastave prepoznaju brojne uzroke školskog neuspeha (16 različitih kategorija). Relativni značaj ovih uzroka je ispitan u narednoj, kvantitativnoj fazi. Konstruisana je skala uzroka školskog neuspeha i zadata uzorku od 408 budućih nastavnika razredne i predmetne nastave, a zatim su eksplorativnom faktorskom analizom identifikovana tri latentna faktora koji objašnjavaju 43 % varijanse. Nedostatak sposobnosti i motivacije (1. faktor) i nedostatak obrazovne podrške (2. faktor) su opaženi kao faktori koji najviše doprinose školskom neuspehu, dok se umereni značaj pridaje razlozima koji su povezani sa porodičnim i socijalnim kontekstom (3. faktor). U poređenju sa budućim nastavnicima predmetne nastave, budući nastavnici razredne nastave pokazuju veću spremnost da prepoznaju odgovornost nastavnika za školski neuspeh. Percepcija značaja različitih faktora od strane budućih nastavnika je povezana sa njihovim ranijim iskustvima školskog uspeha

    Precise subtyping for synchronous multiparty sessions

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    The notion of subtyping has gained an important role both in theoretical and applicative domains: in lambda and concurrent calculi as well as in programming languages. The soundness and the completeness, together referred to as the preciseness of subtyping, can be considered from two different points of view: operational and denotational. The former preciseness has been recently developed with respect to type safety, i.e. the safe replacement of a term of a smaller type when a term of a bigger type is expected. The latter preciseness is based on the denotation of a type which is a mathematical object that describes the meaning of the type in accordance with the denotations of other expressions from the language. The result of this paper is the operational and denotational preciseness of the subtyping for a synchronous multiparty session calculus. The novelty of this paper is the introduction of characteristic global types to prove the operational completeness

    Oblique surface waves at an interface of metal-dielectric superlattice and isotropic dielectric

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    We investigate the existence and the dispersion characteristics of surface waves that propagate at an interface between metal-dielectric superlattice and isotropic dielectric. Within the long wavelength limit, when the effective-medium approximation is valid, the superlattice behaves like a uniaxial plasmonic crystal with the main optical axes perpendicular to the metal-dielectric interfaces. We demonstrate that if such a semi-infinite plasmonic crystal is cut normally to the layer interfaces and brought into the contact with semi-infinite dielectric, a new type of surface modes can appear. The propagation of such modes obliquely to the optical axes occurs under favorable conditions that regard thicknesses of the layers, as well as the proper choice of dielectric permittivity of the constituent materials. We show that losses within the metallic layers can be substantially reduced by making the layers sufficiently thin. At the same time, a dramatic enlargement of the range of angles for oblique propagation of the new surface modes is observed. This can lead, however, to the field non-locality and consequently to the failure of the effective-medium approximation.Comment: 4 pages, 3 figure

    A simplified analytical approach to calculation of the electromagnetic behavior of left-handed metamaterials with a graded refractive index profile

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    We investigated the spectral properties of a new class of nanostructured artificial composite materials with tailored electromagnetic response, i.e. negative refractive index materials, also known as "left-handed" metamaterials. We analyzed structures incorporating both ordinary positive index media and negative refractive index metamaterials where the interface may be graded to an arbitrary degree. Utilizing a modified version of the Rosen-Morse function, we derived analytical expressions for the field intensity and spectral reflection and transmission through a graded interface between positive and negative index materials. We compared our results to numerical solutions obtained using the transfer matrix technique.

    Subwavelength hole arrays with nanoapertures fabricated by scanning probe nanolithography

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    Owing to their surface plasmon-based operation, arrays of subwavelength holes show extraordinary electromagnetic transmission and intense field localizations of several orders of magnitude. Thus they were proposed as the basic building blocks for a number of applications utilizing the enhancement of nonlinear optical effects. We designed and simulated nanometer-sized subwavelength holes using an analytical approach. In our experiments we used the scanning probe method for nanolithographic fabrication of subwavelength hole arrays in silver layers sputtered on a positive photoresist substrate. We fabricated ordered nanohole patterns with different shapes, dispositions and proportions. The smallest width was about 60 nm. We characterized the fabricated samples by atomic force microscopy

    Identification of deep trap levels from thermally stimulated current spectra of semi-insulating CdZnTe detector material

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    Deep trap levels in the semi-insulating (SI) CdZnTe detector material were characterized by simultaneous multiple peak analysis based on thermally stimulated current (TSC) measurements. In our TSCs that have been published previously electron hole pairs were created through the use of proton beam irradiation. Charge carriers were captured in deep traps and afterward released by thermal emission, which was recorded in the 90–300 K range. We showed that the obtained TSC spectra could be well fitted with a unique set of 14 different deep traps, which were all simultaneously and completely characterized. The obtained trap data are in good accordance with earlier deep trap characterizations of the other authors obtained on similar SI CdZnTe materials using different methods

    Quantum Hypothesis Testing and Non-Equilibrium Statistical Mechanics

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    We extend the mathematical theory of quantum hypothesis testing to the general WW^*-algebraic setting and explore its relation with recent developments in non-equilibrium quantum statistical mechanics. In particular, we relate the large deviation principle for the full counting statistics of entropy flow to quantum hypothesis testing of the arrow of time.Comment: 60 page

    GENETIC ANALYSIS OF PURE ARABIAN BREEDING IN THE REPUBLIC OF CROATIA

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    Pure arab breeding in the Republic of Croatia has very long tradition. Till the 18th century organized breeding was implemented only in bishop Stud Farm Đakovo. Afterwards pure arab breeding was implemented in many private Stud Farms mostly located in Slavonian and Srijem region. Pure arab, traditional arab and araber (arabrasse) population of horses make together arabian breeding in the Republic of Croatia. Numerical strength of these three populations has increasing trend through out the years. First imports which were ground for foundation of pure arab breeding in Croatia realized in year 1991. Today, population of pure arab breeding count 37 head, from which 28 is imported and 9 born in Croatia. Pedigree depth in 4, 5, 6, 7, 8, 9 and 10 generation show average coefficient of inbreeding of 1.899%, 3.15%, 4.413%, 5.434%, 6.243%, 6.974% and 7.552%. According to genealogy in all pedigree depths, coefficient of inbreeding was higher (P < 0.01) in imported arab horses than in those born in Croatia

    GENETIC ANALYSIS OF PURE ARABIAN BREEDING IN THE REPUBLIC OF CROATIA

    Get PDF
    Pure arab breeding in the Republic of Croatia has very long tradition. Till the 18th century organized breeding was implemented only in bishop Stud Farm Đakovo. Afterwards pure arab breeding was implemented in many private Stud Farms mostly located in Slavonian and Srijem region. Pure arab, traditional arab and araber (arabrasse) population of horses make together arabian breeding in the Republic of Croatia. Numerical strength of these three populations has increasing trend through out the years. First imports which were ground for foundation of pure arab breeding in Croatia realized in year 1991. Today, population of pure arab breeding count 37 head, from which 28 is imported and 9 born in Croatia. Pedigree depth in 4, 5, 6, 7, 8, 9 and 10 generation show average coefficient of inbreeding of 1.899%, 3.15%, 4.413%, 5.434%, 6.243%, 6.974% and 7.552%. According to genealogy in all pedigree depths, coefficient of inbreeding was higher (P < 0.01) in imported arab horses than in those born in Croatia

    How math and language gender stereotypes impact educational outcomes in elementary school children

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    Iako su rodni akademski stereotipi označeni kao ključna psihološka barijera u ostvarenju punog akademskog potencijala žena u tradicionalno maskulinim, a muškaraca u tradicionalno femininim akademsko-karijernim oblastima, empirijski dokazi za ovu pretpostavku nisu konzistentni, dok su istraživanja mehanizama preko kojih bi stereotipi mogli da utiču na postignuća i akademsko-karijerne izbore retka. Stoga smo u ovom radu ispitali da li, u kojoj meri i na koji način implicitni i eksplicitni rodni stereotipi o matematičkoj i jezičkoj sposobnosti nastavnica razredne nastave i učenika/ca koje podučavaju doprinose rodnim razlikama u obrazovnim ishodima. Testirali smo tri pretpostavljena mehanizma uticaja rodnih akademskih stereotipa na postignuća i akademsko-karijerne aspiracije učenika i učenica u oblasti matematike i jezika. Na intrapsihičkom planu učenika/ca testirana je medijatorska uloga matematičkog i jezičkog self-koncepta, dok je u okviru socijalne interakcije između nastavnica i učenika/ca ispitan medijatorski status nastavničkih očekivanja i rodno diferencijalnog tretmana u učionici. U okviru ugnježdenog nacrta, u prvoj fazi studije ispitani su rodni akademski stereotipi 115 nastavnica razredne nastave, a prikupljeni su i podaci o postignuću (ocenama) i očekivanjima od 2295 učenika/ca koje ove nastavnice podučavaju. U drugoj fazi studije, na poduzorku od 16 odeljenja ispitani su rodni akademski stereotipi, akademski self-koncept i objektivno postignuće 412 učenika/ca. Uz to, na 56 časova matematike i srpskog jezika posmatrali smo i analizirali dijadnu interakciju nastavnica i učenika/ca. Rezultati su pokazali da se na osnovu eksplicitnih rodnih akademskih stereotipa učenika/ca mogu predviđati obrazovni ishodi, ali je njihova prediktivna moć mala i pronalazi se samo u onim oblastima u kojima bi se prema sadržaju stereotipa očekivala superiornost različitih rodova (postignuće i aspiracije dečaka u domenu matematike i aspiracije devojčica u domenu jezika). Potvrđeno je da se ovi efekti ostvaruju preko akademskog self-koncepta, iako rodni stereotipi imaju i nezavistan doprinos. I efekti nastavničkih rodnih akademskih stereotipa su veoma mali i moderirani rodom učenika/ca. Eksplicitni stereotipi nastavnica negativno utiču na očekivanja i ocene devojčica u oba akademska domena, ali ne i na njihovo znanje. Ista uverenja pozitivno utiču na znanje i aspiracije dečaka u oblasti matematike. Registrovali smo i rodno pristrasna nastavnička očekivanja i rodno diferencijalni tretman učenika/ca u učionici, ali ne i njihov medijatorski status u odnosu nastavničkih rodnih stereotipa i obrazovnih ishoda učenika/ca. Nalaze smo doveli u vezu sa rezultatima sličnih istraživanja i interpretirali oslanjajući se na postavke Teorije balansiranog identiteta. Iskoristili smo ih da formulišemo preporuke za buduća istraživanja i skiciramo smernice za njihovu primenu u obrazovnoj praksi.Even though academic gender stereotypes have been identified as a key psychological barrier to achieving full potential of women in traditionally masculine and men in traditionally feminine academic-career domains, supportive empirical evidence so far has been mixed, while findings on mechanisms through which stereotypes could influence achievement and academic-career choices have been scarce. This study set out to explore whether, to what extent and through which mechanisms implicit and explicit math and language gender stereotypes in primary school teachers and their students contribute to gender differences in educational outcomes. We tested three hypothesized mediating mechanisms to this relation: at the intrapersonal level, students’ mathematical and linguistic self concept; at the interpersonal level, teachers’ expectations from students and their gender differential treatment in the classroom. In a nested design, during the first phase of the study, we measured gender academic stereotypes of 115 primary school teachers, along with their academic expectations from 2295 students, and these students’ grades. In the second phase, we subsampled 16 classes comprising of 412 students, and measured their gender academic stereotypes, academic self-concept and test achievement. In addition, we observed the dyad interaction between the teachers and students in a total of 56 mathematics and Serbian language classes. We observed that educational outcomes can be predicted based on the explicit gender academic stereotypes of the students, albeit with small predictive and only in domains where the superiority of a specific gender would be expected according to gender stereotype (boys’ achievement and aspirations in the domain of mathematics and girls’ aspirations in the domain of language). These effects were mediated via academic self-concept in the corresponding domain, although a direct effect of gender stereotypes was still observed. The effects of teachers' gender academic stereotypes were also small and moderated by the students’ gender. Explicit stereotypes of teachers negatively affected the expectations and assessments, but not knowledge of girls in both academic domains, and positively affected the knowledge and aspirations of boys in the field of mathematics. Although teachers exhibited gender-biased expectations and gender-differential treatment of students in the classroom, we found no evidence of them mediating the relation between teachers’ gender stereotypes and students’ educational outcomes. We related the findings to similar research and discussed them in Balanced Identity Theory framework. Finally, we articulated guidelines for future research and educational policies
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