Nearest neighbor search in metric spaces through Content-Addressable Networks

Most of the peer-to-peer search techniques proposed in the recent years have focused on the single-key retrieval. However, similarity search in metric spaces represents an important paradigm for content-based retrieval in many applications. In this paper we introduce an extension of the well-known Content-Addressable Network paradigm to support storage and retrieval of more generic metric space objects. In particular we address the problem of executing the nearest neighbors queries, and propose three different algorithms of query propagation. An extensive experimental study on real-life data sets explores the performance characteristics of the proposed algorithms by showing their advantages and disadvantages.     

Reliability,usefulness and construct validity of the Combined Basketball Skill Test (CBST)

This study aimed to assess the reliability, usefulness and construct validity of the newly developed Combined Basketball Skill Test (CBST). Fifteen recreational (age = 22.8 ± 4.2 y, stature = 184.8 ± 6.5 cm, body mass = 81.6 ± 9.6 kg, training experience = 9.8 ± 5.3 y) and fifteen semiprofessional (age = 18.9 ± 3.3 y, stature = 190.5 ± 8.1 cm, body mass = 84.2 ± 11.2 kg, training experience = 11.1 ± 3.5 y) players volunteered to participate in this study. Test–retest reliability and usefulness were examined for recreational players, while construct validity was evaluated comparing the two player groups. The CBST is composed of 12 trials and its outcome measures include: completion time (sum of the 12 trial times); penalty time (sum of the times from the 12 trials); performance time (completion time + penalty time) and total number of errors. Relative reliability analysis showed acceptable ICC values (i.e. ≥0.70) in all the studied variables. Absolute reliability analysis showed a CV < 5% for completion (1.6%) and performance (2.0%) time, while a CV >5% is reported for the remaining variables. The usefulness of the test was considered “Marginal” and “Good” when comparing TE values with SWC₀₂ and SWC₀₅, respectively for all the studied variables. Likely and very likely differences were shown between recreational and semiprofessional players in all investigated variables. Results showed that the CBST is reliable, useful to detect moderate changes and valid to assess basketball skills.     

Between al-Andalus and Genoa: The “Embriaci Tower” Lustreware

This article examines a set of lustreware pottery discovered in the fill of the tower belonging to the Genoese family, the Embriaci. The finds are datable to the mid-thirteenth century, characterised by decorative patterns which are atypical in lustreware production in al-Andalus, though some comparisons can be drawn with the decorative patterns of the “vasos de la Alhambra” and the pottery known as “nazarí primitive”. The context of the discovery in Genoa will briefly be outlined, including the story of the family settlement (Part 1), the stratigraphic sequence (Part 2), and the stylistic connections to other pottery characterising it (Part 3). The formal and decorative elements characterising the lustreware pottery found in the Embriaci Tower will then be examined and compared (Part 4) with finds from the Upper Tyrrhenian region (Provence, Savona, Pisa). Part 5 will suggest that the finds are a specific type of decorated lustreware produced in the thirteenth century in al-Andalus (Murcia, Málaga and Almería). The concluding part (Part 6) will investigate the meaning of the presence of the set of imported ceramics in the “curia” of the Embriaci family in Genoa.

This type of pottery has only been discovered hitherto in excavation finds and architectural contexts (the so called “bacini”) in Italy and France. The identification of decorative and formal elements characterising this “group” of pottery will allow the identification of examples of this production outside of Italy and France. The publication of the findings will provide new data to develop an archaeological overview of commercial contacts between al-Andalus and the Tyrrhenian area (Provence, Liguria, Tuscany) during the thirteenth century.     

The EUCLIDES methodology and portal An on-line learning environment utilizing PBL and ICT

This paper presents the EUCLIDES （Enhancing the Use of Cooperative Learning to Increase Development of Science Studies） project （134246-LLP-1-2007-1-IT-1-COMENIUS-CMP）, which aims at introducing and pilot-testing an innovative teaching and training methodology, based on the constructivist approach and on problem-based learning （PBL）, through the use of information communication technology （ICT） instruments. This methodology has been developed for the study of science subjects and, is currently used in some European schools of secondary education, involving teachers and students. A moodle platform has been developed to enforce the application and use of the methodology. Through this platform, teachers can monitor the progress of the work of the students and intervene as facilitators when it is necessary to provide further co-ordination, pose questions and suggest problem-based approaches. The use of the platform secures that the teachers remain distant from the students allowing students to work by themselves and find solutions to the problems posed.     

Similarity caching in large-scale image retrieval

Feature-rich data, such as audio-video recordings, digital images, and results of scientific experiments, nowadays constitute the largest fraction of the massive data sets produced daily in the e-society. Content-based similarity search systems working on such data collections are rapidly growing in importance. Unfortunately, similarity search is in general very expensive and hardly scalable.     

IntoNews: Online news retrieval using closed captions

We present IntoNews, a system to match online news articles with spoken news from a television newscasts represented by closed captions. We formalize the news matching problem as two independent tasks: closed captions segmentation and news retrieval. The system segments closed captions by using a windowing scheme: sliding or tumbling window. Next, it uses each segment to build a query by extracting representative terms. The query is used to retrieve previously indexed news articles from a search engine. To detect when a new article should be surfaced, the system compares the set of retrieved articles with the previously retrieved one. The intuition is that if the difference between these sets is large enough, it is likely that the topic of the newscast currently on air has changed and a new article should be displayed to the user. In order to evaluate IntoNews, we build a test collection using data coming from a second screen application and a major online news aggregator. The dataset is manually segmented and annotated by expert assessors, and used as our ground truth. It is freely available for download through the Webscope program.¹ Our evaluation is based on a set of novel time-relevance metrics that take into account three different aspects of the problem at hand: precision, timeliness and coverage. We compare our algorithms against the best method previously proposed in literature for this problem. Experiments show the trade-offs involved among precision, timeliness and coverage of the airing news. Our best method is four times more accurate than the baseline.     

NEWS AND INFORMATION

The purpose of the investigation was to determine whether and how the quality of students’ explanations of chemical phenomena was affected by changing the method of giving the question and answer, respectively, between the spoken and written formats. It also focused on these effects for different questions and different students. Two experiments used the same population of first‐year university students who attempted the same set of questions, variously presented and answered in each of the four different ways of combining these two methods of questioning and answering. From the results, it was concluded that, for these students and questions, there was no observable difference between the performance of the students using any of these combinations of formats.

     

Learning mathematics in mainstream secondary schools: experiences of students with Down’s syndrome

The key questions are: is it true that persons with Down’s syndrome can study mathematics only at a very elementary level? Might it be possible that their difficulties are mainly restricted to some fields, such as numeracy and mental computation, but do not encompass the entire domain of mathematics? Is the use of a calculator recommended? Is non-elementary mathematics accessible at most for the brightest students with Down’s syndrome? Our experience with about 30 students with Down’s syndrome, attending Italian mainstream secondary schools, is that these students can solve mathematical problems, using simple algebraic equations, though they may have very poor numeracy skills and need to use the calculator even with the simplest computations. Moreover, a familiarity with more advanced topics, as algebraic computation and analytic geometry, can help to raise their self-esteem and improve their numeracy too. Surprisingly, these students can learn and apply mathematical procedures in a variety of other different contexts. For instance, Francesca, an Italian student attending a secondary mainstream school, with a mild impairment in numeracy and relatively good linguistic skills, started with algebra and then learned to solve problems in the areas of nutritional science and of business administration. In the same way, Martina, a student in a mainstream secondary school with severe linguistic and numerical impairments, learned to work with Cartesian coordinates and formulas in analytic geometry. She began connecting points on a Cartesian plane, given their coordinates, and colouring in the shapes, such as flowers and animals, that they define. Applying the two points distance formula and verifying the result, she learned to measure the distance of two points with a ruler and to understand the concept of ‘millimetres’. The role of the inclusion in mainstream Italian schools of every disabled student, regardless the severity of the disability, has been crucial for these results.     

Oral anatomy laboratory examinations in a physical therapy program

The process of creating and administering traditional tagged anatomy laboratory examinations is time consuming for instructors and limits laboratory access for students. Depending on class size and the number of class, sections, creating, administering, and breaking down a tagged laboratory examination may involve one to two eight‐hour days. During the time that a tagged examination is being created, student productivity may be reduced as the anatomy laboratory is inaccessible to students. Further, the type of questions that can be asked in a tagged laboratory examination may limit student assessment to lower level cognitive abilities and may limit the instructors' ability to assess the students' understanding of anatomical and clinical concepts. Anatomy is a foundational science in the Physical Therapy curriculum and a thorough understanding of anatomy is necessary to progress through the subsequent clinical courses. Physical therapy curricula have evolved to reflect the changing role of physical therapists to primary caregivers by introducing a greater scope of clinical courses earlier in the curriculum. Physical therapy students must have a thorough understanding of clinical anatomy early in the education process. However, traditional anatomy examination methods may not be reflective of the clinical thought processes required of physical therapy students. Traditional laboratory examination methods also reduce student productivity by limiting access during examination set‐up and breakdown. To provide a greater complexity of questions and reduced overall laboratory time required for examinations, the Physical Therapy Program at Mercer University has introduced oral laboratory examinations for the gross anatomy course series. Anat Sci Educ 6: 271–276. © 2012 American Association of Anatomists.     

Post-Knowledge of Results Delay: Effects of Interpolated Activity on Learning and Performance

Abstract

The present experiment investigated the effects of interpolated processing activity (IPA) during the post knowledge of results (KR) interval. The study attempted to correct some of the problems inherent in previous research by using a ballistic timing criterion task and assessing the effects of interpolated processing activity (IPA) on both acquisition and No KR transfer trials. To insure that the efficacy of the IPA manipulation, a paced task was used and performance was assessed. Two levels of post-KR delay (5 and 10 s) were factorially combined with two levels of IPA (IPA or No IPA) to yield four experimental groups. Each subject completed 30 KR acquisition trials and 20 No KR transfer trials. Interresponse interval was held constant. In contrast to many previous studies, IPA interfered with the subjects' ability to learn and perform the criterion movement time of 150 ms. Both the memory trace and the perceptual trace were similarly affected. The detrimental effects of IPA on absolute error and objective-subjective error differences found during acquisition persisted during KR withdrawal.