We present two techniques to aid in the retrieval of information from Twitter. First we present a technique to cluster hashtags in meaningful topic groups using a combination of co-occurrence frequency, graph clustering and textual similarity. Second, we present a technique to classify a tweet in terms of these topic groups based on their word content using a combination of PCA dimensionality r...

The Mo- and V-nitrogenases are two homologous members of the nitrogenase family that are distinguished mainly by the presence of different heterometals (Mo or V) at their respective cofactor sites (M- or V-cluster). However, the V-nitrogenase is ~600-fold more active than its Mo counterpart in reducing CO to hydrocarbons at ambient conditions. Here, we expressed an M-cluster-containing, hybrid ...

Clustering-based methods for searching in metric spaces partition the space into a set of disjoint clusters. When solving a query, some clusters are discarded without comparing them with the query object, and clusters that can not be discarded are searched exhaustively. In this paper we propose a new strategy and algorithms for clustering-based methods that avoid the exhaustive search within cl...

High-dimensional data is receiving increasing attention in more and more application fields, but the analysis of such data has shown to be difficult due to the “curse of dimensionality”. Dimension reduction methods have emerged as successful tools to overcome the problem of high-dimensionality. However, even if they are designed to preserve the most important properties of the data, they are ge...

To increase Pt utilization for oxygen reduction reaction (ORR) in fuel cells, reducing particle sizes of Pt is a valid way. However, poisoning or surface oxidation limits the smallest size of Pt particles at 2.6 nm with a low utility of 20%. Here, using density functional theory calculations, we develop a core-shell Al13@Pt42 cluster as a catalyst for ORR. Benefit from alloying with Al in this ...

Network of workstation (NOW) is a coste ective alternative to massively parallel supercomputers. As commercially available o -theshelf processors become cheaper and faster, it is now possible to build a PC or workstation cluster that provides high computing power within a limited budget. However, a cluster may consist of di erent types of processors and this heterogeneity within a cluster compl...

The subject of this research are administrative processes related to a ship’s arrival to seaports, typically attributed to elevated levels of cost of labour required to complete the related administrative tasks. In the previous phases of the research, an average expected cost of the administrative labour cost in traditional seaport clusters in Croatia was identified and quantified on an hourly ...

The ACS Virgo Cluster Survey is a large program to carry out multi-color imaging of 100 early-type members of the Virgo Cluster using the Advanced Camera for Surveys (ACS) on the Hubble Space Telescope. Deep F475W and F850LP images (≈ SDSS g and z) are being used to study the central regions of the program galaxies, their globular cluster systems, and the three-dimensional structure of Virgo it...

Calculating the rooted subtree prune and regraft (rSPR) distance between two rooted binary phylogenetic trees is a frequently applied process in various areas of molecular evolution. However, computing this distance is an NP-hard problem and practical algorithms for computing it exactly are rare. In this paper, a divide-and-conquer approach to calculating the rSPR distance is established. This ...

BACKGROUND AND OBJECTIVES Cardiovascular disease (CVD) and underlying atherosclerosis begin in childhood and are related to CVD risk factors. This study evaluates tools and strategies to enhance adoption of new CVD risk reduction guidelines for children. METHODS Thirty-two practices, recruited and supported by 2 primary care research networks, were cluster randomized to a multifaceted control...