Jari Veijalainen

Jari Veijalainen
University of Jyväskylä | JYU · Faculty of Information Technology

Professor

About

133
Publications
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1,685
Citations
Introduction
Social media analytics

Publications

Publications (133)
Article
According to recent estimates, one bitcoin transaction consumes as much energy as 1.5 million Visa transactions. Why is bitcoin using so much energy? Most of the energy is used during the bitcoin mining process, which serves at least two significant purposes: a) distributing new cryptocurrency coins to the cryptoeconomy and b) securing the Bitcoin...
Article
Full-text available
Most recommender systems suggest items that are popular among all users and similar to items a user usually consumes. As a result, the user receives recommendations that she/he is already familiar with or would find anyway, leading to low satisfaction. To overcome this problem, a recommender system should suggest novel, relevant and unexpected i.e....
Article
The “post-Soviet space” consists of countries with a substantial fraction of the world’s population; however, unlike many other regions, its social media network landscape is still somewhat underexplored. This study aims to fill this gap. To this purpose, we use anonymised data on user friendships at VK.com (also known as VKontakte and, informally,...
Article
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We address the feature extraction problem for document ranking in information retrieval. We then propose LifeRank, a Linear feature extraction algorithm for Ranking. In LifeRank, we regard each document collection for ranking as a matrix, referred to as the original matrix. We try to optimize a transformation matrix, so that a new matrix (dataset)...
Conference Paper
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Over the past several years, research in recommender systems has emphasized the importance of serendipity, but there is still no consensus on the definition of this concept and whether serendipitous items should be recommended is still not a well-addressed question. According to the most common definition, serendipity consists of three components:...
Conference Paper
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Cross-domain recommender systems use information from source domains to improve recommendations in a target domain, where the term domain refers to a set of items that share attributes and/or user ratings. Most works on this topic focus on accuracy but disregard other properties of recommender systems. In this paper, we attempt to improve serendipi...
Article
Collaborative filtering (CF) is one of the most effective techniques in recommender systems, which can be either rating oriented or ranking oriented. Ranking-oriented CF algorithms demonstrated significant performance gains in terms of ranking accuracy, being able to estimate a precise preference ranking of items for each user rather than the absol...
Conference Paper
The purpose of this paper is to explore the participation of main actors in Facebook. The engagement shows different degrees of participation that directly affect the brand image and reputation. This research applies Situational Crisis Communication Theory (SCCT) to interaction in the social media. It provides possibilities for decision makers to m...
Article
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in open access available at http://redfame.com/journal/index.php/smc/article/view/1746/1858
Article
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Recommender systems use past behaviors of users to suggest items. Most tend to offer items similar to the items that a target user has indicated as interesting. As a result, users become bored with obvious suggestions that they might have already discovered. To improve user satisfaction, recommender systems should offer serendipitous suggestions: i...
Conference Paper
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Social media sites have appeared during the last 10 years and their use has exploded all over the world. Twitter is a microblogging service that has currently 320 million user profiles and over 100 million daily active users. Many celebrities and leading politicians have a verified profile on Twitter, including Justin Bieber, president Obama, and t...
Conference Paper
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Recently, ranking-oriented collaborative filtering (CF) algorithms have achieved great success in recommender systems. They obtained state-of-the-art performances by estimating a preference ranking of items for each user rather than estimating the absolute ratings on unrated items (as conventional rating-oriented CF algorithms do). In this paper, w...
Conference Paper
Full-text available
Online social networks have become an essential part of our daily life, and an increasing number of users are using multiple online social networks simultaneously. We hypothesize that the integration of data from multiple social networks could boost the performance of recommender systems. In our study, we perform cross-social network collaborative...
Conference Paper
Open standardization seems to be very popular among software developers as it makes the standard's adoption by the software engineering community easier and smoother. Formal specification methods, on the other hand, while very promising, are being adopted by protocol engineers very slowly; the industry seems to have little motivation to move into t...
Conference Paper
Full-text available
In this article, we describe an analysis of social network data set that was collected from the Live Journal (LJ) site during autumn 2013. Initially, we collected 114 politically active LJ user profiles, and friends of their friends using the graph search, i.e. those users who are two hops away from those on the original list. A graph was formed fr...
Conference Paper
Full-text available
The purpose of this paper is to gain understanding of what factors cause rapid issue spread in social media, to help predict issue growth. The frequency graphics of two issues, Arctic Sunrise and U.S. capitol shooting, were compared to investigate rapidity of spread on Twitter. Next, a qualitative model was applied to explain the differences found....
Article
This paper describes a hierarchical, three-level modelling framework for monitoring social media. Immediate social reality is modelled through the first level of the models. They represent various virtual communities at social media sites and adhere to the social world models of the sites, i.e., the "site ontologies". The second-level model is a te...
Article
This paper describes traces of user activity around a alleged online social network profile of a Boston Marathon bombing suspect, after the tragedy occurred. The analyzed data, collected with the help of an automatic social media monitoring software, includes the perpetrator's page saved at the time the bombing suspects' names were made public, and...
Conference Paper
The disparity between healthcare systems in developed countries and underdeveloped countries is huge, particularly due to the fact that the healthcare infrastructure of former is based on a sophisticated technological infrastructure. Efforts are being made worldwide to bridge this disparity and make healthcare services affordable even to the most r...
Article
Full-text available
In this paper, we describe an overall architecture for Internet of Things (IoT) and analyze the known and new threats for the security, privacy and trust (SPT) at different levels of architecture, with attacker centric and system centric approaches. Our strong view is that IoT will be an important part of the global huge ICT infrastructure ("future...
Conference Paper
Nowadays, WWW contains a number of social media sites, which are growing rapidly. One of the main features of social media sites is to allow to its users creation and modification of contents of the site utilizing the offered WWW interfaces. Such contents are referred to as user generated contents and their type varies from site to site. Social med...
Conference Paper
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This paper describes the architecture and a partial implementation of a system designed for the monitoring and analysis of communities at social media sites. The main contribution of the paper is a novel system architecture that facilitates long-term monitoring of diverse social networks existing and emerging at various social media sites. It consi...
Conference Paper
European Union has decided that all emergencies can be reported to authorities by European citizens by calling 112 or sending a text message to 112. Distributing warnings and alerts of authorities to citizens currently happens through national TV and radio channels, but telecom networks are also used now in some countries for this purpose. During t...
Conference Paper
In the developed world health care sector has used for tens of years information systems in their daily activities. Soon after the Internet usage began to spread to the societies mid 1990'ies the sector began to ponder how to offer services over the web to patients. The USA and the EU began to discuss eHealth scenarios, and many services are now of...
Chapter
This chapter serves as a gateway to the subsequent chapters of the book, as it poses the basic ideas and questions concerning transactional support for cooperative work and explains the fundamental decisions taken to tackle the questions. Therefore, this chapter is warmly recommended to any reader of the book.
Chapter
Full-text available
The TRANSCOOP project started with an analysis of different cooperative work scenarios and their underlying computer support. the goal was to found the subsequent specification and transaction model development on a sound basis of requirements which reflect the organization of cooperative work processes in practice and which address the shortcoming...
Chapter
In this chapter we review the earlier research and development work for providing transactional support for cooperative work. In this chapter we review the earlier research and development work for providing transactional support for cooperative work. We start by discussing the fundamental concepts and database transaction modeling ideas developed...
Article
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The advancements in mobile, wireless and positioning technologies have enabled applications and services such as route guiding and emergency call-out assistance. These and other similar services have become known as `location-based services' (LBS). The ...
Article
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In this article we will investigate what kind of regulative bodies within China were formed and how they have acted. This is the principal research question. We use the TD-SCDMA development from standard definition phase to deployment as a beacon that elucidates which Actors came together to oversee regulatory actions and how they influenced the re...
Article
The number of mobile subscribers in the world is soon reaching the three billion mark. According to the newest estimates, majority of the subscribers are already in the developing countries, whereas the number of subscribers in the industrialized countries is about to stagnate around one billion. Because especially in the developing countries the o...
Conference Paper
There are over 300 known school shooting cases in the world and over ten known cases where the perpetrator(s) have been prohibited to perform the attack at the last moment or earlier. Interesting from our point of view is that in many cases the perpetrators have expressed their views in social media or on their web page well in advance, and often a...
Conference Paper
The number of mobile devices has exceeded four billions and is still growing. Especially in developing countries mobile devices are often the only access to Internet and digital services. In the most developed countries laptops, Wi-Fi and faster and faster wireless telecom networks have for long time made mobile access to various digital services p...
Article
Full-text available
Surprisingly cruel mass murders and attacks have been witnessed in the educational institutions of the Western world since the 1970s. These are often referred to as 'school shootings'. There have been over 300 known incidents around the world and the number is growing. Social network sites (SNSs) have enabled the perpetrators to express their views...
Chapter
The number of mobile subscribers in the world is soon reaching the three billion mark. According to the newest estimates, majority of the subscribers are already in the developing countries, whereas the number of subscribers in the industrialized countries is about to stagnate around one billion. Because especially in the developing countries the o...
Article
The previous section analysed use of software to improve productivity from a general perspective and provided a quick statistical analysis of software usage to the performance of a CSP. Before conducting elaborated statistical analysis on CSP software usage, we need to gain some insight into operator business and understanding on how operators see...
Chapter
The number of mobile subscribers in the world is soon reaching the three billion mark. According to the newest estimates, majority of the subscribers are already in the developing countries, whereas the number of subscribers in the industrialized countries is about to stagnate around one billion. Because especially in the developing countries the o...
Article
The number of mobile subscribers in the world is soon reaching the three billion mark. According to the newest estimates, majority of the subscribers are already in the developing countries, whereas the number of subscribers in the industrialized countries is about to stagnate around one billion. Because especially in the developing countries the o...
Article
Full-text available
It is a fair question to ask whether or not services, ontologies, and mobility all thrown together in one issue will make a strange and somewhat arbitrary mix of themes. As we will demonstrate in this article, this is most definitely not the case. In the contrary, it is our belief that only the combination of ontologies and services will provide an...
Article
Full-text available
Mobile P2P environments are emerging as a result of rapid expansion of portable terminals that are able to establish direct wireless communication links among themselves. These kinds of terminals are under the control of persons and allowing interactions between their terminals is subject to trust between the individuals and their desire to preserv...
Conference Paper
The number of mobile subscribers in the world is soon reaching the three billion mark. According to the newest estimates, majority of the subscribers are already in the developing countries, whereas the number of subscribers in the industrialized countries is about to stagnate around one billion. Because especially in the developing countries the o...
Conference Paper
Full-text available
Mobile P2P environments are emerging as a result of rapid expansion of portable terminals that are able to establish direct wireless communication links among themselves. These kinds of terminals are under the control of persons and allowing interactions between their terminals is subject to trust between the individuals and their desire to preserv...
Conference Paper
Full-text available
Although UDDI does not provide support for semantic search, retrieval and storage, it is already accepted as an industrial standard and a huge number of services already store their service specifications in UDDI. Objective of this paper is to analyze possibilities and ways to use UDDI registry to allow utilization of meta-data encoded according to...
Conference Paper
Full-text available
The number of mobile terminals is continuously increasing in the world, although in many developed countries the market has saturated. Thus, the market can only grow if new service types are offered to the mobile terminals. One emerging technology that might make this possible is semantic web services. At the core of this technology are ontologies...
Article
Full-text available
This paper discusses architectural requirements for an inter-organizational, semantics-based service provisioning platform and presents a generic reference architecture. We deduce essential requirements for such an architecture from the inter-organisational environment and the technology in use. We also analyze the implementation options of the ref...
Article
In this paper, we develop and evaluate an approach to assessing the content quality in a location-based service (LBS). The proposed approach, instead of assessing the quality in absolute terms such as completeness or accuracy, measures the effect that the imperfection of the content is having on the reliability of that specific LBS. We apply the ba...
Article
Purpose – To report the work on the design of an integrated identity verification system architecture aimed at approaching high verification accuracy, continuous security, and user-friendliness. Design/methodology/approach – The reported research corresponds to the building process in the design science research paradigm. The requirements to an ide...
Conference Paper
Mobile phones and other small and powerful portable devices have revolutionized personal communication and affected the lifestyles of the people in the industrialized world. Following credible estimates, in a few years there will over two - billions of such portable devices in use. An emerging trend is the electronic commerce performed using mobile...
Article
Full-text available
In the currently used information system architectures of paper mills there is a huge number of signals generated at the lowest automation level by thousands of hardware sensors and other embedded components. These are accumulated and refined into a manageable number of semantically meaningful events by software layers above the physical and automa...
Conference Paper
The unauthorised use of mobile terminals may result in an abuse of sensitive information kept locally on the terminals or accessible over the network. Therefore, there is a need for security means capable of detecting the cases when the legitimate user of the terminal is substituted. The problem of user substitution detection is considered in the p...
Article
Full-text available
An E-commerce transaction is a means to conduct particular commercial activities using the global digital E-commerce infrastructure. We concentrate here on business to customer (B-to-C) E-commerce transactions. These transactions are based on protocols offered by the global infrastructure, primarily the Internet. Using electronic means to do busine...
Conference Paper
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With the increase in applications for sensor networks, data manipulation and representation have become a crucial component of sensor networks. This paper explores an approach to process and interpret the data gathered by sensor networks. We have built ...
Article
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This document presents the results from the working group “Business Models” (WG 1) discussing the seminar topic under market aspects. Main objectives were developing a shared view of the field (i.e. matching business, technology and research interests), identifying key players and relations between them (including barriers and lessons l...
Article
The global mobile environment consists of hundreds of mobile access networks based on telecom air interfaces (GSM(+), PDC, W-CDMA,CDMA(2000), etc.) that facilitate well over one billion subscribers throughout the world. These digital communication systems and other global networks, like Internet, are designed in a cooperative manner by a Global Des...
Article
International Journal of Engineering Intelligent Systems for Electrical Engineering and Communications, Special issue on databases and telecommunications. Fall 1996 Vol.3 Nr.4, 130
Article
Los avances en Internet y redes inaldmbricas y el rapido crecimiento del ntimero de equipos moviles han resultado en el crecimiento acelerado del comercio movil. Consideramos el comercio mévil como un subconjunto del comercio electrénico en el que las transacciones se realizan utilizando un terminal movil y una red inalambrica. El usuario de equipo...
Article
Mobile networks are proliferating currently in the world with a rather high pace. The number of mobile telecom subscribers has already exceeded one billion and the number will exceed two billions before the year 2010. The big investements needed in the telecom infrastructure raise the question, how much revenues can the operators and other players...
Article
Security is paramount to the success of pervasive computing environments. The system presented in this paper provides a communications and security infrastructure that goes far in advancing the goal of anywhere-anytime computing. Our work securely enables ...
Article
The main driving force for the rapid acceptance rate of small sized mobile devices is the capability to perform e-commerce transactions at any time and at any place, especially while on the move. There are, however, also weaknesses of this type of e-commerce, often called mobile e-commerce, or m-commerce. Due to their small size and easy portabilit...
Article
this paper we first present a requirement analysis and then present a wireless terminal-based Transaction Manager (TM) architecture. This architecture is based on the assumption that there is an application that supports certain business transaction(s) and that it uses the TM to store transactional state information and retrieve it after a communic...
Conference Paper
Inductive representation of conditional knowledge means to complete knowledge appropriately and can be looked upon as an instance of quite general representation problem. The crucial problem of discovering relevant conditional relationships in statistical ...
Conference Paper
Full-text available
Advances in Internet and network technology and the rapidly growing number of mobile personal devices result in the fast growth of Mobile E-Commerce, M-Commerce. In this paper we view M-Commerce as activity of conducting E-commerce transactions using mobile terminals over a wireless network. A special case of M-commerce are Location Based Services...
Article
Full-text available
Mobile networks are proliferating currently in the world with a rather high pace. The number of mobile telecom subscribers has already exceeded one billion and the number will exceed two billions before the year 2010. The big investements needed in the telecom infrastructure raise the question, how much revenues can the operators and other players...
Chapter
Our society is becoming increasingly dependent on the rapid access and processing of information. The number of handheld mobile devices with access to the Internet and network-based software and services is exploding. Research indicates [1] that by the end of 2002 there will be over 1 billion mobile phone owners globally with Internet access, and t...
Chapter
Full-text available
Mobile phones and other small and powerful portable devices have revolutionized personal communication and affected the lifestyles of the people in the industrialized world. Following credible estimates, in a few years there will be one billion of such portable devices. An emerging trend is the electronic commerce performed using mobile terminals,...
Chapter
Mobile phones and other small and powerful portable devices have revolutionized personal communication and affected the lifestyles of the people in the industrialized world. Following credible estimates, in a few years there will be one billion of such portable devices. An emerging trend is the electronic commerce performed using mobile terminals,...
Article
Full-text available
A variety of developments combine to highlight the need for respecting order when manipulating relations. For example, new functionality is being added to SQL to support OLAP-style querying in which order is frequently an important aspect. The set- or ...
Conference Paper
Full-text available
Mobile networking is developing and proliferating at a high speed. Many estimates say that the number of mobile telecom subscribers will exceed 1 billion in the year 2003. Among the terminals deployed, there will be hundreds of millions of Internet-enabled ones making Mobile Internet a reality for the big masses. The terminals and/or the mobile net...
Article
Full-text available
Internet E-commerce has been flourishing for the last few years, especially with the advent of World Wide Web. Mobile Electronic Commerce (MEC) has started recently to appear in the scene. It exploits the advantages of Internet, mobile computing and mobile communications in order to provide a large number of advanced services to mobile users. The p...
Conference Paper
Full-text available
With the proliferation of 2G and 3G Telecom and other wireless networks hundred of millions of users will be able to access wireless services with their terminals in only a few years. In this paper we discuss the possibilities and limitations of existing and emerging mobile technologies and methodologies for porting information and functionality fr...