Digital Media and Communication

This chapter presents a step-by-step approach to the design, implementation and management of a Data-Intensive Web Site (DIWS). The approach introduces five data formulation and manipulation graphs that are presented analytically. The core concept behind the modeling approach is that of "Web fragments," that is an information decomposition technique that aids design, implementation and management of DIWS. We then present the steps that must be followed in order to "build" a DIWS based on Web fragments. Finally, we show how our approach can be used to ensure the basic DIWS user requirements of personalization, integrity and performance.

The modern communication networks, apart from the specialized applications that they offer depending on the nature of their target groups, they support a set of general purpose elementary network services, that provide some essential communication facilities to the end users. Regarding an educational network, these facilities include collaboration, navigation into the information resources, as well as interpersonal communication, to the members of the Education Society. In the sequel the major principles on providing these elementary network services are presented. On-lline/off-line contact over an alternative means of communication among the members of the trans-European Education Society could be an adequate reason for the deployment of an educational communication network. This category of services will offer the members of the Education Society the ability of exchanging opinions on educational and social matters, as well as interpersonal messages, and collaborating. These facilities should be provided by already existing network services, enhanced where necessary by supporting multimedia information exchange (mostly off-line). In the latter case external media players of attachment viewers may be used for the presentation of the multiple media of information.

Web developers have been concerned with the issues of Web latency and Web data consistency for many years. These issues have become more important in our days since the accurate and imminent dissemination of information is vital to businesses and individuals that rely on the Web. In this paper, we evaluate different run-time management policies against real Web site data. We first define the meaning of data intensive Web sites and categorize them according to their hit patterns. Our research relies on real world Web data collected from various popular Web sites and proxy log files. We propose a Web site run-time management policy that may apply to various real Web site hit patterns and Web data update frequencies.

The rapid increase of World Wide Web users and the development of services with high bandwidth requirements have caused the substantial increase of response times for users on the Internet. Web latency would be significantly reduced, if browser, proxy or Web server software could make predictions about the pages that a user is most likely to request next, while the user is viewing the current page, and prefetch their content. In this paper we study Predictive Prefetching on a totally new Web system architecture. This is a system that provides two levels of caching before information reaches the clients. This work analyses prefetching on a Wide Area Network with the above mentioned characteristics. We first provide a structured overview of predictive prefetching and show its wide applicability to various computer systems. The WAN that we refer to is the GRNET academic network in Greece. We rely on log files collected at the network's Transparent cache (primary caching point), located at GRNET's edge connection to the Internet. We present the parameters that are most important for prefetching on GRNET's architecture and provide preliminary results of an experimental study, quantifying the benefits of prefetching on the WAN. Our experimental study includes the evaluation of two prediction algorithms: an "n most popular document" algorithm and a variation of the PPM (Prediction by Partial Matching) prediction algorithm. Our analysis clearly shows that Predictive prefetching can improve Web response times inside the GRNET WAN without substantial increase in network traffic due to prefetching.

The field of Virtual Environments (VEs) is rapidly evolving into a new means of communication and accessing information, likely to overcome many existent technologies. However, being a new field makes the design and implementation of educational VEs an important aspect for scientific research in their educational potentials and the exploitation of existent technologies. New technologies in the field of VEs have appeared the establishment and combination of which, is yet to be investigated. This paper makes an effort to approach the issue of developing educational VEs introducing new aspects in the issues of interface, interaction with the user and functionality.

In this paper we show that users move from page to page, in the WWW, by following similar browsing patterns when they have similar browsing experience. Similar browsing patterns do not absolutely imply that the same URL's are visited. They only mean that users react in similar ways to similar web sites and follow almost foreseen routes. In order to prove this conclusion we introduce the Navigation Graph technique to trace users' web browsing patterns. We also categorize sites according to their structure by using a commercial tool. Having done these, we analyze the results of the navigation graphs and present them, pointing out the problems that users may encounter. Finally, in order to answer to these problems, we propose enhancements that can improve the performance of web browsers and web servers.

Although real time data processing consumes a significant portion of computing resources worldwide, we are moving rapidly from the age of "real time" towards the era of "next time". The term "next time" characterizes the combination of real time data flows from collective sources with massive computing power with the aim of predicting the future. In other words, if you can compute "fast enough" using real time data sets then you can accurately predict what happens next. Central to this process is the Google Trends service that provides generalized statistics in regard to the popularity of web search terms submitted to Google. The paper combines the conclusions derived from other approaches to the prediction problem with Google Trends data in order to predict the outcome of six national elections races in two countries, Greece and Spain. The results of the proposed model reaffirm our hypothesis that web search terms popularity is directly related to voters decisions in both countries and thus can be used to predict the final outcome with great accuracy.

The analysis of the high volume of statistics generated by web search engines worldwide on a daily basis, allow researchers to examine the relation between the user's search preferences and future facts. This analysis can be applied to various areas of society such as sales, epidemics, unemployment and elections. The paper investigates whether prediction of election results is possible by analyzing the behavior of potential voters before the date of the elections. In particular, the proposed algorithm is applied on the three more recent German elections. The results of this analysis show that a strong correlation exists between the search preferences of potential voters before the date of the election race and the actual elections results. It also demonstrates the fact that search preferences are influenced by various social events that may take place concurrently to the election race. The effect of such events has to be filtered out as noise in order to arrive at a successful estimation of the final results.

The era of journalism and the participation of the readers on online media websites have changed online journalism. The research interest is now focused on removing the distinction between the publisher/entrepreneur and the journalist/user, with the ultimate goal of actively involving citizens in the journalistic process but also in the web presence of media websites. The evolution of technology, the deep media crisis and the growing dissatisfaction of the citizens, create the conditions for journalism to work with citizens, and in particular through citizen journalism and journalism crowdsourcing. This concept is a form of collective online activity in which a person or a group of people volunteer to engage in work that always involves mutual benefit to both sides. The main research question of this research concerns the analysis of the current situation regarding crowdsourcing, co-creation and UGC and the adoption of best practices such as crowdcreation, comments from the users, c...

This paper examines functional aspects of the internet Web Sites that (re)present Greek Higher
Educational Departments and Institutes and focuses on the promotion and dissemination of
their educational and scientific results. The study conforms to the theoretical guidelines of a
systemic approach that produces an overview of the consistencies and the asymmetries that
define the impact of a Web Site as a communicative system. Web Sites representing Greek
Higher Educational Departments and Institutes are evaluated as communicative systems that
promote certain distinctions (that suggest meanings) in the context of the World Wide Web
(WWW). The relevant evaluation includes five hundred and one (501) Web Sites and was
based on eight (8) criteria. The results of this study hopefully will account for (Greek)
Departments’ Web Sites to be efficient, interactive and provide their readers with appropriate
services.

The aim of this book is to study possible methods that can be applied to media websites in order to reduce power consumption and to educate internet users on environmental issues. Some of the issues that the study addresses are: Whether the servers are powered by renewable sources of energy, the ecological graphic design of the websites, and the existence of energy saving mode, the prevention of printing articles, whether newspapers inform their readers about environmental issues and the interdependence or participation in actions related to environment protection.

This paper discusses the technologicalcharacteristics and tools of web media companies in Greece.The study is comprised of twenty five web sites with the highestrank in Greece according to google rank and alexa.com. Thirtytwo criteria that evaluate the services, the satisfaction of theuser and the quality of the information are being studied. Theresults of the study outline the characteristics and the tools of Greek web media companies and indicate possibleimprovements.

Augmented reality is increasingly applied in
medical education mainly because educators can share
knowledge through virtual objects. This research describes
the development of a web application, which enhances users'
medical knowledge with regards to the anatomy of the
human heart by means of augmented reality. Evaluation is
conducted in two different facets. In the first one, the authors
of this paper evaluate the feasibility of a three-dimensional
human heart module using one investigator under the
supervision of an expert. In the second, evaluation aims at
identifying usability issues by means of the
cognitive walkthrough method. Three medical students
(naive users) are called upon three target tasks in the web
application. Task completion is appreciated in the light of the
standard set of cognitive walkthrough questions. Augmented
reality content miss hits are revealed by means of the first
evaluation in an effort to enhance the educational utility of
the three-dimensional human heart. Cognitive walkthrough
provides further improvement points, which may further
enhance usability in the next software release. The current
piece of work constitutes the pre-pilot evaluation.
Standardized methodologies are utilized in an effort to
improve the application before its wider piloting to proper
student populations. Such evaluations are considered
important in experiential learning methods aiding online
education of anatomy courses.

Climate change has become one of the main challenges that the global village is facing today. Scientists have reached a significant agreement about the origins and magnitude of this process, whose consequences are already evident in many points all over the planet. However, research shows that there is a deficit of media coverage and information on climate change and that its quality and effectiveness is not always suitable.