Adding Compression to Block Addressing Inverted Indexes

Inverted index compression, block addressing and sequential search on compressed text are three techniques that have been separately developed for efficient, low-overhead text retrieval. Modern text compression techniques can reduce the text to less than 30% of its size and allow searching it directly and faster than the uncompressed text. Inverted index compression obtains significant reduction of its original size at the same processing speed. Block addressing makes the inverted lists point to text blocks instead of exact positions and pay the reduction in space with some sequential text scanning.In this work we combine the three ideas in a single scheme. We present a compressed inverted file that indexes compressed text and uses block addressing. We consider different techniques to compress the index and study their performance with respect to the block size. We compare the index against three separate techniques for varying block sizes, showing that our index is superior to each isolated approach. For instance, with just 4% of extra space overhead the index has to scan less than 12% of the text for exact searches and about 20% allowing one error in the matches.     

‘For older folks like me,these things are over us…’: The challenge of embedding tablet computers in everyday life within a geriatric hospital in Uruguay

ABSTRACT

Much research has focused on the introduction of information and communication technology (ICTs) into the lives of older people, but it has generally understood them as external factors who act as a sort of independent variable that impacts the seniors’ lives. There remains a dearth of empirical research into how aging and technology are co-constructed, namely, research that focuses on older people’s relationship to technology as a socio-technical network. We therefore contribute to this field by analyzing the development and establishment of a network in a geriatric hospital in Montevideo, Uruguay. Uruguay has been developing a one-tablet computer-per low-income-senior policy since 2015. In this research, we deployed a qualitative ethnographic research comprised of semi-structured interviews, jottings, and field notes where we explore the adoption of tablets within the corresponding actor-network. Our findings suggest that objectively, not only was the establishment of the sociotechnical network rife with complexities, disruptions, and fissures, but subjectively, seniors in the hospital were heavily influenced by their self-perception of the potentialities of ICTs.     

Crossed looks: globalisations and curriculum in Guinea-Bissau

This article focuses on education in Guinea-Bissau in the context of globalisations, examining the concept of globalisation and its relation to education and the curriculum. It focuses on the relatively neglected area of national education policies in Guinea-Bissau, comparing differences and common points of interference/influence of multilateral (international and regional) and bilateral organisations in these policies. Data collection was based on content analysis of a corpus of documents – the Education Act, the document of Portuguese Cooperation Programme, the Education Sector Policy Paper, the Education for All National Plan of Action, and Policy n. 3/2007/CM/UEMOA – and field notes collected from 2009 to 2012. The article argues that there is a tendency for the homogenisation of curriculum policies, at least at the macro-level, due to the different types of pressures coming from international/regional organisations.     

Effects of cold water immersion on lower extremity joint biomechanics during running

The purpose of this study was to identify the influence of cryotherapy on lower extremity running biomechanics. Twenty-six healthy male volunteers were randomised into two intervention groups: cold water (cold water at ~11°C) or tepid water (tepid water at ~26°C). They were required to run at 4.0 ± 0.2 m · s^?1 before and after they underwent water immersion for 20 min. Differences between pre- and post-intervention were used to compare the influence of water intervention during running. Peak joint angles, peak joint moments, peak ground reaction forces (GRF) and contact time (CT) were calculated using three-dimensional gait analysis. Independent t-tests were applied with a significant alpha level set at 0.05. Decreased peak propulsive and vertical GRF, decreased plantarflexion moments, increased hip flexion angle and longer CT were observed following cold water immersion. Although cold water immersion (cryotherapy) affected the running movement, none of the alterations have been related to running biomechanical patterns associated with injuries. Therefore, our results indicated that cold water immersion appears safe prior to running activities.     

School Schedules Affect Sleep Timing in Children and Contribute to Partial Sleep Deprivation

Although the environmental light/dark cycle is the main zeitgeber for the human species, the social cues seem to be important in the synchronization of circadian rhythms. In Brazil, the existence of two school schedules—one with only morning classes (MG) and other with only afternoon classes (AG)—allows the investigation of the effect of school activities on light exposure and sleep/wake patterns in children. Forty‐seven children wore wrist actimeters for a week for registration of light and sleep data. MG children presented shorter sleep duration on school days than the children from the AG. The results showed that during school days MG children were exposed to bright light earlier in the morning when compared to AG children. Nevertheless, there were no differences in light exposure after sunset. The results reflect the role of school schedules and artificial light in shaping light exposure, and its association with sleep timing in children.     

Determinants of citizens' intention to engage in government-led electronic participation initiatives through Facebook

The research work on understanding whether citizens will readily accept to engage with governments in e-participation initiatives through social media remains limited. Therefore, this study investigates the factors that are influencing citizens' intention to engage in government-led e-Participation initiatives through Facebook. To that end, the study proposes and validates a citizen-centric acceptance model. The proposed model extends the model primarily established on the theory of planned behavior, by incorporating additional factors that emerged from relevant literature. The research data were collected from a survey of 400 Facebook users in Jordan using a probability sample technique. The results revealed that the factors with the most significant influence on citizens' intention to engage in government-led e-participation initiatives through Facebook are: the citizens' attitude, participation efficacy, and perceived behavior control. Subjective norms and perceived value, however, have no direct effect on citizens' intention to engage in government-led e-participation initiatives through Facebook. Furthermore, the results showed that the citizens' attitude is primarily determined by participation efficacy, perceived usefulness and compatibility of Facebook, and perceived value. In contrast, the factors perceived ease of use of Facebook, citizens' trust in government, and citizens' trust in Facebook, have no significant impact on citizens' attitude. These factors have rarely been empirically tested in the context of e-participation. Consequently, this study paves the way towards a better understanding of the important factors that influence citizens' intention to participate, which, in turn, will inform the design and implementation of e-participation initiatives.