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.     

Foresight for public procurement and regional innovation policy: The case of Lombardy

Public procurement can be a major source of innovation. The potential benefits of public procurement might be fully exploited through the acquisition not only of appliances which are already available in the market, but also of new appliances which are tailored to the specific needs of the local community and might be exported as well to the international markets. In this way, public procurement might allow to improve the services delivered to the local community and to increase the technological competitiveness of the local industrial and research system. In this context, regional foresight might help identify both long-term societal needs and the patterns of evolution of emerging technologies that can match these needs. The purpose of this paper is to illustrate, trough the recent experience of the regional government of Lombardy, the role of foresight for enhancing public procurement and innovation policy at the regional level.     

Motion analysis of front crawl swimming applying CAST technique by means of automatic tracking

Abstract

Kinematic analysis of swimming is of interest to improve swimming performances. Although the video recordings of underwater swimmers are commonly used, the available methodologies are rarely precise enough to adequately estimate the three dimensional (3D) joint kinematics. This is mainly due to difficulties in obtaining the required kinematic parameters (anatomical landmarks, joint centres and reference frames) in the swimming environment. In this paper we propose a procedure to investigate the right upper limb’s 3D kinematics during front crawl swimming in terms of all elbow and shoulder degrees of freedom (three rotations of the shoulder, two of the elbow). The method is based upon the Calibrated Anatomical Systems Technique (CAST), a technique widely used in clinics, which allows estimation of anatomical landmarks of interest even when they are not directly visible. An automatic tracking technique was adopted. The intra-operator repeatability of the manual tracking was also assessed. The root mean squared difference of three anatomical landmarks, processed five times, is always lower than 8 mm. The mean of the root mean squared difference between trajectories obtained with the different methodologies was found to be lower than 20 mm. Results showed that complete 3D kinematics of at least twice as many frames than without CAST can be reconstructed faster and more precisely.     

Evaluating subtopic retrieval methods: Clustering versus diversification of search results

To address the inability of current ranking systems to support subtopic retrieval, two main post-processing techniques of search results have been investigated: clustering and diversification. In this paper we present a comparative study of their performance, using a set of complementary evaluation measures that can be applied to both partitions and ranked lists, and two specialized test collections focusing on broad and ambiguous queries, respectively. The main finding of our experiments is that diversification of top hits is more useful for quick coverage of distinct subtopics whereas clustering is better for full retrieval of single subtopics, with a better balance in performance achieved through generating multiple subsets of diverse search results. We also found that there is little scope for improvement over the search engine baseline unless we are interested in strict full-subtopic retrieval, and that search results clustering methods do not perform well on queries with low divergence subtopics, mainly due to the difficulty of generating discriminative cluster labels.     

From new imported inputs to new exported products. Firm-level evidence from Sweden

This paper investigates the determinants of the propensity of firms to export new products, and focuses on the role of new imported inputs. Importing offers access to new technologies and better combination of inputs that can lead to new or improved products for the export markets. Based on a sample of more than 14,000 Swedish manufacturing firms over the period 2001–2012, we show that importing new inputs is a key determinant of firms’ propensity to add new products to their export portfolio, even after controlling for multinationality, patenting activity, productivity and a number of other firm characteristics. This is mainly due to the import of new intermediate inputs and it is stronger for smaller firms.     

Skilled migration and innovation in European industries

This paper studies the effects of skilled migration on innovation –proxied by patent citations- in European industries between 1994 and 2005, using the French and the UK Labour Force Surveys and the German Microcensus. Highly-educated migrants have a positive effect on innovation, but the effect differs across industries. It is stronger in industries with low levels of overeducation, high levels of FDIs and openness to trade and, finally, in industries with higher ethnic diversity. The aggregate effect of the skilled immigrant is about one third the one of the skilled natives. We tackle the endogeneity of migrants with a set of external and internal instruments.     

The process toward commitment to running—The role of different motives,involvement, and coaching

The purpose of this investigation was twofold: (a) to explore and describe the relationships between different facets of motivation, involvement, and commitment to running, and (b) to test whether recreational coached runners differ from non-coached runners in their motivation, involvement, and commitment to running. Drawing on the psychological continuum model (PCM), a model was proposed to test relationships among motives, attitudinal and behavioral involvement, and commitment to running as a leisure activity. Results showed that two (enjoyment and health) out of five motives were significant indicators of attitudinal involvement. Attitudinal involvement was a significant predictor of behavioral involvement, which in turn was a significant predictor of commitment. Coached runners differed from non-coached runners in all tested variables. The structural relationships among the variables varied based on the tested group. Implications for theory and practice are presented.