Data Mining Practical Machine Learning Tools and Techniques

We will review some of the major results in random graphs and some of the more challenging open problems. We will cover algorithmic and structural questions. We will touch on newer models, including those related to the WWW.

Random graphs

Twitter, a microblogging service less than three years old, commands more than 41 million users as of July 2009 and is growing fast. Twitter users tweet about any topic within the 140-character limit and follow others to receive their tweets. The goal of this paper is to study the topological characteristics of Twitter and its power as a new medium of information sharing.We have crawled the entire Twitter site and obtained 41.7 million user profiles, 1.47 billion social relations, 4,262 trending topics, and 106 million tweets. In its follower-following topology analysis we have found a non-power-law follower distribution, a short effective diameter, and low reciprocity, which all mark a deviation from known characteristics of human social networks [28]. In order to identify influentials on Twitter, we have ranked users by the number of followers and by PageRank and found two rankings to be similar. Ranking by retweets differs from the previous two rankings, indicating a gap in influence inferred from the number of followers and that from the popularity of one's tweets. We have analyzed the tweets of top trending topics and reported on their temporal behavior and user participation. We have classified the trending topics based on the active period and the tweets and show that the majority (over 85%) of topics are headline news or persistent news in nature. A closer look at retweets reveals that any retweeted tweet is to reach an average of 1,000 users no matter what the number of followers is of the original tweet. Once retweeted, a tweet gets retweeted almost instantly on next hops, signifying fast diffusion of information after the 1st retweet.To the best of our knowledge this work is the first quantitative study on the entire Twittersphere and information diffusion on it.

https://ink.library.smu.edu.sg/cgi/viewcontent.cgi?article=7104&context=sis_research

What is Twitter, a social network or a news media?

The term “Linked Data” refers to a set of best practices for publishing and connecting structured data on the Web. These best practices have been adopted by an increasing number of data providers over the last three years, leading to the creation of a global data space containing billions of assertions— the Web of Data. In this article, the authors present the concept and technical principles of Linked Data, and situate these within the broader context of related technological developments. They describe progress to date in publishing Linked Data on the Web, review applications that have been developed to exploit the Web of Data, and map out a research agenda for the Linked Data community as it moves forward.

/pdf/linked-data-the-story-so-far-2a9zvmaysa.pdf

Linked Data - the story so far

Obesity now affects one in five children in the United States. Discrimination against overweight children begins early in childhood and becomes progressively institutionalized. Because obese children tend to be taller than their nonoverweight peers, they are apt to be viewed as more mature. The inappropriate expectations that result may have an adverse effect on their socialization. Many of the cardiovascular consequences that characterize adult-onset obesity are preceded by abnormalities that begin in childhood. Hyperlipidemia, hypertension, and abnormal glucose tolerance occur with increased frequency in obese children and adolescents. The relationship of cardiovascular risk factors to visceral fat independent of total body fat remains unclear. Sleep apnea, pseudotumor cerebri, and Blount's disease represent major sources of morbidity for which rapid and sustained weight reduction is essential. Although several periods of increased risk appear in childhood, it is not clear whether obesity with onset early in childhood carries a greater risk of adult morbidity and mortality. Obesity is now the most prevalent nutritional disease of children and adolescents in the United States. Although obesity-associated morbidities occur more frequently in adults, significant consequences of obesity as well as the antecedents of adult disease occur in obese children and adolescents. In this review, I consider the adverse effects of obesity in children and adolescents and attempt to outline areas for future research. I refer to obesity as a body mass index greater than the 95th percentile for children of the same age and gender.

Health Consequences of Obesity in Youth: Childhood Predictors of Adult Disease

To facilitate permanence and collaboration in web archives, we built Interplanetary Wayback to disseminate the contents of WARC files into the IPFS network. IPFS is a peer-to-peer content-addressable file system that inherently allows deduplication and facilitates opt-in replication. We split the header and payload of WARC response records before disseminating into IPFS to leverage the deduplication, build a CDXJ index, and combine them at the time of replay. From a 1.0 GB sample Archive-It collection of WARCs containing 21,994 mementos, we found that on an average, 570 files can be indexed and disseminated into IPFS per minute. We also found that in our naive prototype implementation, replay took on an average 370 milliseconds per request.

/pdf/interplanetary-wayback-the-permanent-web-archive-4upa9q11qb.pdf

InterPlanetary Wayback: The Permanent Web Archive

Web archives do not capture every resource on every page that they attempt to archive. This results in archived pages missing a portion of their embedded resources. These embedded resources have varying historic, utility, and importance values. The proportion of missing embedded resources does not provide an accurate measure of their impact on the Web page; some embedded resources are more important to the utility of a page than others. We propose a method to measure the relative value of embedded resources and assign a damage rating to archived pages as a way to evaluate archival success. In this paper, we show that Web users' perceptions of damage are not accurately estimated by the proportion of missing embedded resources. The proportion of missing embedded resources is a less accurate estimate of resource damage than a random selection. We propose a damage rating algorithm that provides closer alignment to Web user perception, providing an overall improved agreement with users on memento damage by 17% and an improvement by 51% if the mementos are not similarly damaged. We use our algorithm to measure damage in the Internet Archive, showing that it is getting better at mitigating damage over time (going from 0.16 in 1998 to 0.13 in 2013). However, we show that a greater number of important embedded resources (2.05 per memento on average) are missing over time.

/pdf/not-all-mementos-are-created-equal-measuring-the-impact-of-336rmqahig.pdf

Not all mementos are created equal: measuring the impact of missing resources

The Internet Archive's (IA) Wayback Machine is the largest and oldest public web archive and has become a significant repository of our recent history and cultural heritage. Despite its importance, there has been little research about how it is discovered and used. Based on web access logs, we analyze what users are looking for, why they come to IA, where they come from, and how pages link to IA. We find that users request English pages the most, followed by the European languages. Most human users come to web archives because they do not find the requested pages on the live web. About 65% of the requested archived pages no longer exist on the live web. We find that more than 82% of human sessions connect to the Wayback Machine via referrals from other web sites, while only 15% of robots have referrers. Most of the links (86%) from websites are to individual archived pages at specific points in time, and of those 83% no longer exist on the live web.

Who and What Links to the Internet Archive

The Internet Archive's (IA) Wayback Machine is the largest and oldest public Web archive and has become a significant repository of our recent history and cultural heritage. Despite its importance, there has been little research about how it is discovered and used. Based on Web access logs, we analyze what users are looking for, why they come to IA, where they come from, and how pages link to IA. We find that users request English pages the most, followed by the European languages. Most human users come to Web archives because they do not find the requested pages on the live Web. About 65 % of the requested archived pages no longer exist on the live Web. We find that more than 82 % of human sessions connect to the Wayback Machine via referrals from other Web sites, while only 15 % of robots have referrers. Most of the links (86 %) from Websites are to individual archived pages at specific points in time, and of those 83 % no longer exist on the live Web. Finally, we find that users who come from search engines browse more pages than users who come from external Web sites.

/pdf/who-and-what-links-to-the-internet-archive-btog2kv64j.pdf

Who and what links to the Internet Archive

Objective Following an international workshop on developing the evidence base for policy relating to school food held in London, UK, in January 2012, the objectives of the present paper were (i) to outline a rationale for school food research, monitoring and evaluation in relation to policy and (ii) to identify ways forward for future working Design The authors analysed presentations, summaries of evidence, and notes from discussions held at the international workshop in London in 2012 to distil common themes and make recommendations for the development of coherent research programmes relating to food and nutrition in schools Setting International, with an emphasis on middle- and high-income countries Results Overviews of existing school food and nutrition programmes from the UK, Hungary, Sweden, the USA, Australia, Brazil, China, Mexico and other countries were presented, along with information on monitoring, evaluation and other research to demonstrate the impact of school feeding on health, attainment, food sourcing, procurement and finances, in the context of interactions between the evidence base and policy decisions This provided the material which, together with summaries and notes of discussions, was used to develop recommendations for the development and dissemination of robust approaches to sustainable and effective school food and nutrition programmes in middle- and high-income countries, including policy guidelines, standards, cost-effectiveness measures and the terms of political engagement Conclusions School food and nutrition can provide a cohesive core for health, education and agricultural improvement provided: (i) policy is appropriately framed and includes robust monitoring and evaluation; and (ii) all stakeholders are adequately engaged in the process International exchange of information will be used to develop a comprehensive guide to the assessment of the impact of school food and nutrition policy and supporting infrastructure

/pdf/school-food-research-building-the-evidence-base-for-policy-3aqyr7hckb.pdf

Michael L. Nelson

Papers

InterPlanetary Wayback: The Permanent Web Archive

Not all mementos are created equal: measuring the impact of missing resources

Who and What Links to the Internet Archive

Who and what links to the Internet Archive

School food research: building the evidence base for policy.