An Introduction to Search Engines and Web Navigation
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
The Google File System (GFS)
The Google File System (GFS), as described by Ghemwat, Gobioff, and Leung in 2003, provided the architecture for scalable, fault-tolerant data management within the context of Google. These architectural choices, however, resulted in sub-optimal performance in regard to data trustworthiness (security) and simplicity. Additionally, the application- specific nature of GFS limits the general scalability of the system outside of the specific design considerations within the context of Google. SYSTEM DESIGN: The authors enumerate their specific considerations as: (1) commodity components with high expectation of failure, (2) a system optimized to handle relatively large files, particularly multi-GB files, (3) most writes to the system are concurrent append operations, rather than internally modifying the extant files, and (4) a high rate of sustained bandwidth (Section 1, 2.1). Utilizing these considerations, this paper analyzes the success of GFS’s design in achieving a fault-tolerant, scalable system while also considering the faults of the system with regards to data-trustworthiness and simplicity. Data-trustworthiness: In designing the GFS system, the authors made the conscious decision not prioritize data trustworthiness by allowing applications to access ‘stale’, or not up-to-date, data. In particular, although the system does inform applications of the chunk-server version number, the designers of GFS encouraged user applications to cache chunkserver information, allowing stale data accesses (Section 2.7.2, 4.5). Although possibly troubling -
A Review on GOOGLE File System
International Journal of Computer Science Trends and Technology (IJCST) – Volume 4 Issue 4, Jul - Aug 2016 RESEARCH ARTICLE OPEN ACCESS A Review on Google File System Richa Pandey [1], S.P Sah [2] Department of Computer Science Graphic Era Hill University Uttarakhand – India ABSTRACT Google is an American multinational technology company specializing in Internet-related services and products. A Google file system help in managing the large amount of data which is spread in various databases. A good Google file system is that which have the capability to handle the fault, the replication of data, make the data efficient, memory storage. The large data which is big data must be in the form that it can be managed easily. Many applications like Gmail, Facebook etc. have the file systems which organize the data in relevant format. In conclusion the paper introduces new approaches in distributed file system like spreading file’s data across storage, single master and appends writes etc. Keywords:- GFS, NFS, AFS, HDFS I. INTRODUCTION III. KEY IDEAS The Google file system is designed in such a way that 3.1. Design and Architecture: GFS cluster consist the data which is spread in database must be saved in of single master and multiple chunk servers used by a arrange manner. multiple clients. Since files to be stored in GFS are The arrangement of data is in the way that it can large, processing and transferring such huge files can reduce the overhead load on the server, the consume a lot of bandwidth. To efficiently utilize availability must be increased, throughput should be bandwidth files are divided into large 64 MB size highly aggregated and much more services to make chunks which are identified by unique 64-bit chunk the available data more accurate and reliable. -
Hacking the Master Switch? the Role of Infrastructure in Google's
Hacking the Master Switch? The Role of Infrastructure in Google’s Network Neutrality Strategy in the 2000s by John Harris Stevenson A thesis submitteD in conformity with the requirements for the Degree of Doctor of Philosophy Faculty of Information University of Toronto © Copyright by John Harris Stevenson 2017 Hacking the Master Switch? The Role of Infrastructure in Google’s Network Neutrality Strategy in the 2000s John Harris Stevenson Doctor of Philosophy Faculty of Information University of Toronto 2017 Abstract During most of the decade of the 2000s, global Internet company Google Inc. was one of the most prominent public champions of the notion of network neutrality, the network design principle conceived by Tim Wu that all Internet traffic should be treated equally by network operators. However, in 2010, following a series of joint policy statements on network neutrality with telecommunications giant Verizon, Google fell nearly silent on the issue, despite Wu arguing that a neutral Internet was vital to Google’s survival. During this period, Google engaged in a massive expansion of its services and technical infrastructure. My research examines the influence of Google’s systems and service offerings on the company’s approach to network neutrality policy making. Drawing on documentary evidence and network analysis data, I identify Google’s global proprietary networks and server locations worldwide, including over 1500 Google edge caching servers located at Internet service providers. ii I argue that the affordances provided by its systems allowed Google to mitigate potential retail and transit ISP gatekeeping. Drawing on the work of Latour and Callon in Actor– network theory, I posit the existence of at least one actor-network formed among Google and ISPs, centred on an interest in the utility of Google’s edge caching servers and the success of the Android operating system. -
La Sécurité Informatique Edition Livres Pour Tous (
La sécurité informatique Edition Livres pour tous (www.livrespourtous.com) PDF générés en utilisant l’atelier en source ouvert « mwlib ». Voir http://code.pediapress.com/ pour plus d’informations. PDF generated at: Sat, 13 Jul 2013 18:26:11 UTC Contenus Articles 1-Principes généraux 1 Sécurité de l'information 1 Sécurité des systèmes d'information 2 Insécurité du système d'information 12 Politique de sécurité du système d'information 17 Vulnérabilité (informatique) 21 Identité numérique (Internet) 24 2-Attaque, fraude, analyse et cryptanalyse 31 2.1-Application 32 Exploit (informatique) 32 Dépassement de tampon 34 Rétroingénierie 40 Shellcode 44 2.2-Réseau 47 Attaque de l'homme du milieu 47 Attaque de Mitnick 50 Attaque par rebond 54 Balayage de port 55 Attaque par déni de service 57 Empoisonnement du cache DNS 66 Pharming 69 Prise d'empreinte de la pile TCP/IP 70 Usurpation d'adresse IP 71 Wardriving 73 2.3-Système 74 Écran bleu de la mort 74 Fork bomb 82 2.4-Mot de passe 85 Attaque par dictionnaire 85 Attaque par force brute 87 2.5-Site web 90 Cross-site scripting 90 Défacement 93 2.6-Spam/Fishing 95 Bombardement Google 95 Fraude 4-1-9 99 Hameçonnage 102 2.7-Cloud Computing 106 Sécurité du cloud 106 3-Logiciel malveillant 114 Logiciel malveillant 114 Virus informatique 120 Ver informatique 125 Cheval de Troie (informatique) 129 Hacktool 131 Logiciel espion 132 Rootkit 134 Porte dérobée 145 Composeur (logiciel) 149 Charge utile 150 Fichier de test Eicar 151 Virus de boot 152 4-Concepts et mécanismes de sécurité 153 Authentification forte -
Member Directory
D DIRECTORY Member Directory ABOUT THE MOBILE MARKETING ASSOCIATION (MMA) Mobile Marketing Association Member Directory, Spring 2008 The Mobile Marketing Association (MMA) is the premier global non- profit association established to lead the development of mobile Mobile Marketing Association marketing and its associated technologies. The MMA is an action- 1670 Broadway, Suite 850 Denver, CO 80202 oriented organization designed to clear obstacles to market USA development, establish guidelines and best practices for sustainable growth, and evangelize the mobile channel for use by brands and Telephone: +1.303.415.2550 content providers. With more than 600 member companies, Fax: +1.303.499.0952 representing over forty-two countries, our members include agencies, [email protected] advertisers, handheld device manufacturers, carriers and operators, retailers, software providers and service providers, as well as any company focused on the potential of marketing via mobile devices. *Updated as of 31 May, 2008 The MMA is a global organization with regional branches in Asia Pacific (APAC); Europe, Middle East & Africa (EMEA); Latin America (LATAM); and North America (NA). About the MMA Member Directory The MMA Member Directory is the mobile marketing industry’s foremost resource for information on leading companies in the mobile space. It includes MMA members at the global, regional, and national levels. An online version of the Directory is available at http://www.mmaglobal.com/memberdirectory.pdf. The Directory is published twice each year. The materials found in this document are owned, held, or licensed by the Mobile Marketing Association and are available for personal, non-commercial, and educational use, provided that ownership of the materials is properly cited. -
Towards Active SEO 2
JISTEM - Journal of Information Systems and Technology Management Revista de Gestão da Tecnologia e Sistemas de Informação Vol. 9, No. 3, Sept/Dec., 2012, pp. 443-458 ISSN online: 1807-1775 DOI: 10.4301/S1807-17752012000300001 TOWARDS ACTIVE SEO (SEARCH ENGINE OPTIMIZATION) 2.0 Charles-Victor Boutet (im memoriam) Luc Quoniam William Samuel Ravatua Smith South University Toulon-Var - Ingémédia, France ____________________________________________________________________________ ABSTRACT In the age of writable web, new skills and new practices are appearing. In an environment that allows everyone to communicate information globally, internet referencing (or SEO) is a strategic discipline that aims to generate visibility, internet traffic and a maximum exploitation of sites publications. Often misperceived as a fraud, SEO has evolved to be a facilitating tool for anyone who wishes to reference their website with search engines. In this article we show that it is possible to achieve the first rank in search results of keywords that are very competitive. We show methods that are quick, sustainable and legal; while applying the principles of active SEO 2.0. This article also clarifies some working functions of search engines, some advanced referencing techniques (that are completely ethical and legal) and we lay the foundations for an in depth reflection on the qualities and advantages of these techniques. Keywords: Active SEO, Search Engine Optimization, SEO 2.0, search engines 1. INTRODUCTION With the Web 2.0 era and writable internet, opportunities related to internet referencing have increased; everyone can easily create their virtual territory consisting of one to thousands of sites, and practically all 2.0 territories are designed to be participatory so anyone can write and promote their sites. -
Google Pagerank and Markov Chains
COMP4121 Lecture Notes The PageRank, Markov chains and the Perron Frobenius theory LiC: Aleks Ignjatovic [email protected] THE UNIVERSITY OF NEW SOUTH WALES School of Computer Science and Engineering The University of New South Wales Sydney 2052, Australia Topic One: the PageRank Please read Chapter 3 of the textbook Networked Life, entitled \How does Google rank webpages?"; other references on the material covered are listed at the end of these lecture notes. 1 Problem: ordering webpages according to their importance Setup: Consider all the webpages on the entire WWW (\World Wide Web") as a directed graph whose nodes are the web pages fPi : Pi 2 WWW g, with a directed edge Pi ! Pj just in case page Pi points to page Pj, i.e. page Pi has a link to page Pj. Problem: Rank all the webpages of the WWW according to their \importance".1 Intuitively, one might feel that if many pages point to a page P0, then P0 should have a high rank, because if one includes on their webpage a link to page P0, then this can be seen as their recommendation of P0. However, this is not a good criterion for several reasons. For example, it can be easily manipulated to increase the rating of any webpage P0, simply by creating a lot of silly web pages which just point to P0; also, if a webpage \generously" points to a very large number of webpages, such \easy to get" recommendation is of dubious value. Thus, we need to refine our strategy how to rank webpages according to their \importance", by doing something which cannot be easily manipulated \locally" (i.e., by any group of people who might collude, even if such a group is sizeable). -
Efficient Focused Web Crawling Approach for Search Engine
Ayar Pranav et al, International Journal of Computer Science and Mobile Computing, Vol.4 Issue.5, May- 2015, pg. 545-551 Available Online at www.ijcsmc.com International Journal of Computer Science and Mobile Computing A Monthly Journal of Computer Science and Information Technology ISSN 2320–088X IJCSMC, Vol. 4, Issue. 5, May 2015, pg.545 – 551 RESEARCH ARTICLE Efficient Focused Web Crawling Approach for Search Engine 1 2 Ayar Pranav , Sandip Chauhan Computer & Science Engineering, Kalol Institute of Technology and Research Canter, Kalol, Gujarat, India 1 [email protected]; 2 [email protected] Abstract— a focused crawler traverses the web, selecting out relevant pages to a predefined topic and neglecting those out of concern. Collecting domain specific documents using focused crawlers has been considered one of most important strategies to find relevant information. While surfing the internet, it is difficult to deal with irrelevant pages and to predict which links lead to quality pages. However most focused crawler use local search algorithm to traverse the web space, but they could easily trapped within limited a sub graph of the web that surrounds the starting URLs also there is problem related to relevant pages that are miss when no links from the starting URLs. There is some relevant pages are miss. To address this problem we design a focused crawler where calculating the frequency of the topic keyword also calculate the synonyms and sub synonyms of the keyword. The weight table is constructed according to the user query. To check the similarity of web pages with respect to topic keywords and priority of extracted link is calculated. -
How to Choose a Search Engine Or Directory
How to Choose a Search Engine or Directory Fields & File Types If you want to search for... Choose... Audio/Music AllTheWeb | AltaVista | Dogpile | Fazzle | FindSounds.com | Lycos Music Downloads | Lycos Multimedia Search | Singingfish Date last modified AllTheWeb Advanced Search | AltaVista Advanced Web Search | Exalead Advanced Search | Google Advanced Search | HotBot Advanced Search | Teoma Advanced Search | Yahoo Advanced Web Search Domain/Site/URL AllTheWeb Advanced Search | AltaVista Advanced Web Search | AOL Advanced Search | Google Advanced Search | Lycos Advanced Search | MSN Search Search Builder | SearchEdu.com | Teoma Advanced Search | Yahoo Advanced Web Search File Format AllTheWeb Advanced Web Search | AltaVista Advanced Web Search | AOL Advanced Search | Exalead Advanced Search | Yahoo Advanced Web Search Geographic location Exalead Advanced Search | HotBot Advanced Search | Lycos Advanced Search | MSN Search Search Builder | Teoma Advanced Search | Yahoo Advanced Web Search Images AllTheWeb | AltaVista | The Amazing Picture Machine | Ditto | Dogpile | Fazzle | Google Image Search | IceRocket | Ixquick | Mamma | Picsearch Language AllTheWeb Advanced Web Search | AOL Advanced Search | Exalead Advanced Search | Google Language Tools | HotBot Advanced Search | iBoogie Advanced Web Search | Lycos Advanced Search | MSN Search Search Builder | Teoma Advanced Search | Yahoo Advanced Web Search Multimedia & video All TheWeb | AltaVista | Dogpile | Fazzle | IceRocket | Singingfish | Yahoo Video Search Page Title/URL AOL Advanced -
View Full Issue
A Publication of The Science and Information Organization A Publication of The Science and Information Organization (IJACSA) International Journal of Advanced Computer Science and Applications, Vol. 2, No. 5, 2011 IJACSA Editorial From the Desk of Managing Editor… It is a pleasure to present our readers with the May 2011 Issue of International Journal of Advanced Computer Science and Applications (IJACSA). With monthly feature peer-reviewed articles and technical contributions, the Journal's content is dynamic, innovative, thought- provoking and directly beneficial to the readers in their work. The number of submissions have increased dramatically over the last issues. Our ability to accommodate this growth is due in large part to the terrific work of our Editorial Board. Some of the papers have an introductory character, some of them access highly desired extensions for a particular method, and some of them even introduce completely new approaches to computer science research in a very efficient manner. This diversity was strongly desired and should contribute to evoke a picture of this field at large. As a consequence only 29% of the received articles have been finally accepted for publication. With respect to all the contributions, we are happy to have assembled researchers whose names are linked to the particular manuscript they are discussing. Therefore, this issue may not just be used by the reader to get an introduction to the methods but also to the people behind that have been pivotal in the promotion of the respective research. By having in mind such future issues, we hope to establish a regular outlet for contributions and new findings in the field of Computer science and applications. -
Runtime Repair and Enhancement of Mobile App Accessibility
Runtime Repair and Enhancement of Mobile App Accessibility Xiaoyi Zhang A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy University of Washington 2018 Reading Committee: James Fogarty, Chair Jacob O. Wobbrock Jennifer Mankoff Program Authorized to Offer Degree: Computer Science & Engineering © Copyright 2018 Xiaoyi Zhang University of Washington Abstract Runtime Repair and Enhancement of Mobile App Accessibility Xiaoyi Zhang Chair of the Supervisory Committee: Professor James Fogarty Computer Science & Engineering Mobile devices and applications (apps) have become ubiquitous in daily life. Ensuring full access to the wealth of information and services they provide is a matter of social justice. Unfortunately, many capabilities and services offered by apps today remain inaccessible for people with disabilities. Built-in accessibility tools rely on correct app implementation, but app developers often fail to implement accessibility guidelines. In addition, the absence of tactile cues makes mobile touchscreens difficult to navigate for people with visual impairments. This dissertation describes the research I have done in runtime repair and enhancement of mobile app accessibility. First, I explored a design space of interaction re-mapping, which provided examples of re-mapping existing inaccessible interactions into new accessible interactions. I also implemented interaction proxies, a strategy to modify an interaction at runtime without rooting the phone or accessing app source code. This strategy enables third-party developers and researchers to repair and enhance mobile app accessibility. Second, I developed a system for robust annotations on mobile app interfaces to make the accessibility repairs reliable and scalable. Third, I built Interactiles, a low-cost, portable, and unpowered system to enhance tactile interaction on touchscreen phones for people with visual impairments. -
Analysis and Evaluation of the Link and Content Based Focused Treasure-Crawler Ali Seyfi 1,2
Analysis and Evaluation of the Link and Content Based Focused Treasure-Crawler Ali Seyfi 1,2 1Department of Computer Science School of Engineering and Applied Sciences The George Washington University Washington, DC, USA. 2Centre of Software Technology and Management (SOFTAM) School of Computer Science Faculty of Information Science and Technology Universiti Kebangsaan Malaysia (UKM) Kuala Lumpur, Malaysia [email protected] Abstract— Indexing the Web is becoming a laborious task for search engines as the Web exponentially grows in size and distribution. Presently, the most effective known approach to overcome this problem is the use of focused crawlers. A focused crawler applies a proper algorithm in order to detect the pages on the Web that relate to its topic of interest. For this purpose we proposed a custom method that uses specific HTML elements of a page to predict the topical focus of all the pages that have an unvisited link within the current page. These recognized on-topic pages have to be sorted later based on their relevance to the main topic of the crawler for further actual downloads. In the Treasure-Crawler, we use a hierarchical structure called the T-Graph which is an exemplary guide to assign appropriate priority score to each unvisited link. These URLs will later be downloaded based on this priority. This paper outlines the architectural design and embodies the implementation, test results and performance evaluation of the Treasure-Crawler system. The Treasure-Crawler is evaluated in terms of information retrieval criteria such as recall and precision, both with values close to 0.5. Gaining such outcome asserts the significance of the proposed approach.