30 research outputs found
Monte Carlo Methods for Top-k Personalized PageRank Lists and Name Disambiguation
We study a problem of quick detection of top-k Personalized PageRank lists.
This problem has a number of important applications such as finding local cuts
in large graphs, estimation of similarity distance and name disambiguation. In
particular, we apply our results to construct efficient algorithms for the
person name disambiguation problem. We argue that when finding top-k
Personalized PageRank lists two observations are important. Firstly, it is
crucial that we detect fast the top-k most important neighbours of a node,
while the exact order in the top-k list as well as the exact values of PageRank
are by far not so crucial. Secondly, a little number of wrong elements in top-k
lists do not really degrade the quality of top-k lists, but it can lead to
significant computational saving. Based on these two key observations we
propose Monte Carlo methods for fast detection of top-k Personalized PageRank
lists. We provide performance evaluation of the proposed methods and supply
stopping criteria. Then, we apply the methods to the person name disambiguation
problem. The developed algorithm for the person name disambiguation problem has
achieved the second place in the WePS 2010 competition
Generalized Optimization Framework for Graph-based Semi-supervised Learning
We develop a generalized optimization framework for graph-based
semi-supervised learning. The framework gives as particular cases the Standard
Laplacian, Normalized Laplacian and PageRank based methods. We have also
provided new probabilistic interpretation based on random walks and
characterized the limiting behaviour of the methods. The random walk based
interpretation allows us to explain di erences between the performances of
methods with di erent smoothing kernels. It appears that the PageRank based
method is robust with respect to the choice of the regularization parameter and
the labelled data. We illustrate our theoretical results with two realistic
datasets, characterizing di erent challenges: Les Miserables characters social
network and Wikipedia hyper-link graph. The graph-based semi-supervised
learning classi- es the Wikipedia articles with very good precision and perfect
recall employing only the information about the hyper-text links
Functional status of rowers on kayaks in the process of preliminary selection
Purpose: conduct a comprehensive study of the functional status of athletes specializing in rowing, for the subsequent determination of the prospects in this sport. Material & Methods: students of various sports schools in the age group of 13–14 years were examined, young men – 23 people, girls – 28 people, a total of 51 athletes’. Individual indicators were determined by the method of measuring the effect of the training action developed by us, and visual-motor and auditory-motor reactions, the level of musculo-articular sensitivity and coordination of movements, the power of forced inspiration and exhalation were measured. Results: the conducted studies characterize the functional state and functional capabilities of the body of athletes. The optimal structure of sports activities contributes to their improvement, which, based on the laws of development of physical qualities, in this age period, can not significantly affect the level of sports results, but it has a great impact on the emergence of a corresponding functional basis and maximum realization of individual abilities. Features of the reaction of the body of athletes are a manifestation of effective individual adaptation to intense and complex stimuli of training and competitive activity. Conclusion: proposed tests for measuring the effect of the training action, electromyoreflexometry, pneumotachometry and reverse dynamometry are quite informative in sports practice and allow you to determine and evaluate the individual prerequisites for sports achievements, to identify the individual characteristics of the athlete's body, the possibility of correcting them and managing the training process
Peasant settlers and the ‘civilizing mission’ in Russian Turkestan, 1865-1917
This article provides an introduction to one of the lesser-known examples of European settler colonialism, the settlement of European (mainly Russian and Ukrainian) peasants in Southern Central Asia (Turkestan) in the late nineteenth and early twentieth centuries. It establishes the legal background and demographic impact of peasant settlement, and the role played by the state in organising and encouraging it. It explores official attitudes towards the settlers (which were often very negative), and their relations with the local Kazakh and Kyrgyz population. The article adopts a comparative framework, looking at Turkestan alongside Algeria and Southern Africa, and seeking to establish whether paradigms developed in the study of other settler societies (such as the ‘poor white’) are of any relevance in understanding Slavic peasant settlement in Turkestan. It concludes that there are many close parallels with European settlement in other regions with large indigenous populations, but that racial ideology played a much less important role in the Russian case compared to religious divisions and fears of cultural backsliding. This did not prevent relations between settlers and the ‘native’ population deteriorating markedly in the years before the First World War, resulting in large-scale rebellion in 1916
The James Webb Space Telescope Mission
Twenty-six years ago a small committee report, building on earlier studies,
expounded a compelling and poetic vision for the future of astronomy, calling
for an infrared-optimized space telescope with an aperture of at least .
With the support of their governments in the US, Europe, and Canada, 20,000
people realized that vision as the James Webb Space Telescope. A
generation of astronomers will celebrate their accomplishments for the life of
the mission, potentially as long as 20 years, and beyond. This report and the
scientific discoveries that follow are extended thank-you notes to the 20,000
team members. The telescope is working perfectly, with much better image
quality than expected. In this and accompanying papers, we give a brief
history, describe the observatory, outline its objectives and current observing
program, and discuss the inventions and people who made it possible. We cite
detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space
Telescope Overview, 29 pages, 4 figure
Classification of Content and Users in BitTorrent by Semi-supervised Learning Methods
Best paper awardInternational audienceP2P downloads still represent a large portion of today's Internet traffic. More than 100 million users operate BitTorrent and generate more than 30% of the total Internet traffic. Recently, a significant research effort has been done to develop tools for automatic classification of Internet traffic by application. The purpose of the present work is to provide a framework for subclassification of P2P traffic generated by the BitTorrent protocol. The general intuition is that the users with similar interests download similar contents. This intuition can be rigorously formalized with the help of graph based semi-supervised learning approach. We have chosen to work with a PageRank based semi-supervised learning method, which scales well with very large volumes of data. We provide recommendations for the choice of parameters in the PageRank based semi-supervised learning method. In particular, we show that it is advantageous to choose labelled points with large PageRank score
mtProtEvol: the resource presenting molecular evolution analysis of proteins involved in the function of Vertebrate mitochondria
Abstract Background Heterotachy is the variation in the evolutionary rate of aligned sites in different parts of the phylogenetic tree. It occurs mainly due to epistatic interactions among the substitutions, which are highly complex and make it difficult to study protein evolution. The vast majority of computational evolutionary approaches for studying these epistatic interactions or their evolutionary consequences in proteins require high computational time. However, recently, it has been shown that the evolution of residue solvent accessibility (RSA) is tightly linked with changes in protein fitness and intra-protein epistatic interactions. This provides a computationally fast alternative, based on comparison of evolutionary rates of amino acid replacements with the rates of RSA evolutionary changes in order to recognize any shifts in epistatic interaction. Results Based on RSA information, data randomization and phylogenetic approaches, we constructed a software pipeline, which can be used to analyze the evolutionary consequences of intra-protein epistatic interactions with relatively low computational time. We analyzed the evolution of 512 protein families tightly linked to mitochondrial function in Vertebrates and created “mtProtEvol”, the web resource with data on protein evolution. In strict agreement with lifespan and metabolic rate data, we demonstrated that different functional categories of mitochondria-related proteins subjected to selection on accelerated and decelerated RSA rates in rodents and primates. For example, accelerated RSA evolution in rodents has been shown for Krebs cycle enzymes, respiratory chain and reactive oxygen species metabolism, while in primates these functions are stress-response, translation and mtDNA integrity. Decelerated RSA evolution in rodents has been demonstrated for translational machinery and oxidative stress response components. Conclusions mtProtEvol is an interactive resource focused on evolutionary analysis of epistatic interactions in protein families involved in Vertebrata mitochondria function and available at http://bioinfodbs.kantiana.ru/mtProtEvol/. This resource and the devised software pipeline may be useful tool for researchers in area of protein evolution