Identifying top relevant dates for implicit time sensitive queries

Despite a clear improvement of search and retrieval temporal applications, current search engines are still mostly unaware of the temporal dimension. Indeed, in most cases, systems are limited to offering the user the chance to restrict the search to a particular time period or to simply rely on an explicitly specified time span. If the user is not explicit in his/her search intents (e.g., “philip seymour hoffman”) search engines may likely fail to present an overall historic perspective of the topic. In most such cases, they are limited to retrieving the most recent results. One possible solution to this shortcoming is to understand the different time periods of the query. In this context, most state-of-the-art methodologies consider any occurrence of temporal expressions in web documents and other web data as equally relevant to an implicit time sensitive query. To approach this problem in a more adequate manner, we propose in this paper the detection of relevant temporal expressions to the query. Unlike previous metadata and query log-based approaches, we show how to achieve this goal based on information extracted from document content. However, instead of simply focusing on the detection of the most obvious date we are also interested in retrieving the set of dates that are relevant to the query. Towards this goal, we define a general similarity measure that makes use of co-occurrences of words and years based on corpus statistics and a classification methodology that is able to identify the set of top relevant dates for a given implicit time sensitive query, while filtering out the non-relevant ones. Through extensive experimental evaluation, we mean to demonstrate that our approach offers promising results in the field of temporal information retrieval (T-IR), as demonstrated by the experiments conducted over several baselines on web corpora collections.     

Unveiling the Colours of Cellulose Nitrate Black and White Film-based Negatives in Colonial Photography

ABSTRACT

Aiming at contributing to the preservation of black and white (B&W) film-based negatives held by Portuguese archives, four photographic collections from the first half of the twentieth century were selected for study. During the macro assessment of the collections the preservation condition and hues found in photographic negatives from the Elmano Cunha e Costa (ECC) were noticed, distinguishing this collection from the remaining ones. Additional attention was given considering that the ECC collection was formed in a colonial context in the 1930s, while the others were formed on the Portugal mainland. The ECC collection results from an ethnographic survey of Angolan tribes recorded with B&W film-based negatives. In this collection, sets of negatives with pink, lemon yellow, greenish, orange brownish, and red brownish hues were found. To identify the origin of such hues, the image layer was analysed by microscale energy-dispersive X-ray fluorescence (μ EDXRF) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). Additionally, to assess the base decay and its effect on the formation of hues, the plastic supports were characterized by Fourier transform infrared microscopy (μ FTIR). To complement the assessment of the film-base decay, pH was measured by using combined microelectrodes. The identification of mercury, iodine, chromium, and iron by μ EDXRF allowed correlation of the hues found in the negatives with chemical corrective treatments performed to improve the image quality. SEM-EDX confirmed those results and proved that the elements found were in the photographic emulsion layer. The results obtained are relevant since the hues identified may now be used as markers to indicate the technical work performed on colonial photography. Additionally, the visual and molecular assessment of the negatives’ supports (good to fair condition) allow proposing that the original storage conditions may have had a beneficial contribution to their present condition.     

Educational decentralization policies in Argentina and Brazil: exploring the new trends

This paper compares educational decentralization policies implemented in Argentina and Brazil during the 1990s, focusing on the rationales and contexts of the policies, and through a review of secondary sources and some official documents. The paper argues that school decentralization, the movement toward transferring functions and responsibilities to schools, appears as a new and extended reform that was accompanied by more traditional forms of decentralization, but also by a process of centralization of planning and evaluation at the national level. This new form of centralization/decentralization is seen as linked to the neoliberal restructuring of the state, to pressures from globalization processes and forces, and to various internal demands for improving quality and efficiency in the delivery of education.     

Perceived effects and uses of the national teacher evaluation system in Chilean elementary schools

This paper addresses the perceived consequences of the Chilean national teacher evaluation system. We interviewed 57 school leaders in 30 schools across 10 municipalities about effects and uses of the assessment in their schools. Results show that in the large majority of schools our interviewees observe positive effects such as increased teamwork and internal reflection processes based on the assessment results. Reports about effects at teacher level far outnumber institutional effects, and are mixed. In all schools our interviewees report on teachers’ negative emotions and work overload due to the assessment process, but also about their internalization of the underlying professional standards. The paper analyzes differences among schools and offers suggestions for the development of large-scale standardized teacher evaluation systems.     

Modelling adult skills in OECD countries

Research in the social sciences has focused extensively on the relationship between family background, educational attainment and social destination, on the one hand, and on the processes of skills creation and skills use, on the other. This paper brings these two branches of the literature together by examining the correlation between a range of social factors. The methodology we adopt provides a comprehensive approach to the study of the channels through which literacy skills are acquired, taking into account the interrelation of family background, educational attainment, and the use of skills at work and at home. We use the Programme of International Assessment of Adult Competences (PIAAC) dataset and apply a structural equation model (SEM). Our results show that family background and education play an important role in the configuration of adult skills and skill practices. Unequal family access to resources has a strong impact at later stages in life and strongly affects educational attainment and skills outcomes. Additionally, skills use has a positive and direct impact on adult skills.     

A conceptual framework to understand student volunteerism

Tertiary Education and Management - This paper develops a conceptual framework to understand the value of an increasing number of university study programmes that send students to the global south...     

Consistent bibliometric rankings of authors and of journals

Rankings of journals and rankings of scientists are usually discussed separately. We argue that a consistent approach to both rankings is desirable because both the quality of a journal and the quality of a scientist depend on the papers it/he publishes. We present a pair of consistent rankings (impact factor for the journals and total number of citations for the authors) and we provide an axiomatic characterization thereof.     

An analysis of question asking on scientific texts explaining natural phenomena

This article relays results of a study focused on questions invoked to correct declarative knowledge deficits while readers process science texts explaining natural phenomena. Firstly, the authors focused on finding out what kind of questions are asked by students who read these texts and, secondly how task demand influences quantity and quality of formulated questions. Two hundred and eighty nine Portuguese students from 8th, 10th, and 12th grade participated in the study. The students were instructed to ask questions on two short science paragraphs that explained natural phenomena. Three task conditions were chosen. Thus, in the “Class” condition, the task was introduced as an activity aimed at developing the capacity to ask questions. In the “Examination” condition, the task was presented as a test on question generation. Finally, in the “Extra‐academic” condition the questioning task was camouflaged as a participation in a research project sponsored by the Ministry of Education and geared at the improvement of science textbooks. The results have shown that students are able to ask many questions when given an opportunity to do so. The study has also proven that students are capable of generating a large volume of causal‐antecedent questions relative to this kind of texts. Finally, no clear effects were found between grade level and/or task demand as defined in the conducted study. © 2000 John Wiley & Sons, Inc. J Res Sci Teach 37: 602–614, 2000     

Effect of the addition of hydroxyl-terminated polydimethylsiloxane to TEOS-based stone consolidants

Hybrid stone consolidants prepared from tetraethoxysilane (TEOS) and α,ω-hydroxyl-terminated polydimethylsiloxane (PDMS-OH) have been considered as one of the most promising approaches to improve the effectiveness of traditional alkoxysilane-based formulations. They have emerged as response to the negative reports commonly found in the literature: the resulting silica gel phase (SiO₂) tends to develop fractures and fissures inside the stone as the gel shrinks during the drying stage. In this work, we employed SEM, solid-state ²⁹Si NMR spectroscopy and compressive tests to characterize SiO₂-PDMS hybrid gels. We report the morphological characteristics exhibited by gels prepared in vitro and in situ. It was found an appreciable reduction of gel fracture for hybrids prepared from 5% w/w of PDMS. As TEOS polycondenses, PDMS-OH is chemically incorporated into the gel matrix via Si-O-Si bonds. The inclusion of these elastic chains provides the necessary flexibility to resist the stress imposed by capillary pressure. Additionally, an important hydrophobic character is imparted to the stone.     

Identifying Temporary and Permanent Gaps in Universal Service

This article examines the nature of the gap in household telephone penetration among Whites, Blacks, and Hispanics. By analyzing historic and current penetration levels of the radio, television, and telephone, it suggests that most information technology gaps are amalgamations of smaller socioeconomic trends and can be discerned and reduced only with careful historical analysis of both technology choices and living patterns. It proposes localized universal service strategies, since the penetration gaps are affected by a complex array of factors more particular to localities than to the country as a whole and as such must be investigated with rigor and caution if progress toward the elimination of penetration gaps is to occur.