Mobility-based predictive call admission control and resource reservation for next-generation mobile communications networks.

Recently, the need for wireless and mobile communications has grown tremendously and it is expected that the number of users to be supported will increase with high rates in the next few years. Not only the number of users, but also the required bandwidth to support each user is supposed to increase especially with the deploying of the multimedia and the real time applications. This makes the researchers in the filed of mobile and wireless communications more interested in finding efficient solutions to solve the limitations of the available natural radio resources. One of the important things to be considered in the wireless mobile environment is that the user can move from one location to another when there is an ingoing call. Resource reservation ( RR ) schemes are used to reserve the bandwidth ( BW ) required for the handoff calls. This will enable the user to continue his/her call while he/she is moving. Also, call admission control ( CAC ) schemes are used as a provisioning strategy to limit the number of call connections into the network in order to reduce the network congestion and the call dropping. The problem of CAC and RR is one of the most challenging problems in the wireless mobile networks. Also, in the fourth generation ( 4G ) of mobile communication networks, many types of different mobile systems such as wireless local area networks ( WLAN s) and cellular networks will be integrated. The 4G mobile networks will support a broad range of multimedia services with high quality of service.New Call demission control and resource reservation techniques are needed to support the new 4G systems. Our research aims to solve the problems of Call Admission Control (CAC), and resource reservation (RR) in next-generation cellular networks and in the fourth generation (4G) wireless heterogeneous networks. In this dissertation, the problem of CAC and RR in wireless mobile networks is addressed in detail for two different architectures of mobile networks: (1) cellular networks, and (2) wireless heterogeneous networks (WHNs) which integrate cellular networks and wireless local area networks (WLANs). We have designed, implemented, and evaluated new mobility-based predictive call admission control and resource reservation techniques for the next-generation cellular networks and for the 4G wireless heterogeneous networks. These techniques are based on generating the mobility models of the mobile users using one-dimensional and multidimensional sequence mining techniques that have been designed for the wireless mobile environment. The main goal of our techniques is to reduce the call dropping probability and the call blocking probability, and to maximize the bandwidth utilization n the mobile networks. By analyzing the previous movements of the mobile users, we generate local and global mobility profiles for the mobile users, which are utilized effectively in prediction of the future path of the mobile user. Extensive simulation was used to analyze and study the performance of these techniques and to compare its performance with other techniques. Simulation results show that the proposed techniques have a significantly enhanced performance which is comparable to the benchmark techniques

Letters from the War of Ecosystems – An Analysis of Independent Software Vendors in Mobile Application Marketplaces

The recent emergence of a new generation of mobile application marketplaces has changed the business in the mobile ecosystems. The marketplaces have gathered over a million applications by hundreds of thousands of application developers and publishers. Thus, software ecosystems—consisting of developers, consumers and the orchestrator—have emerged as a part of the mobile ecosystem. This dissertation addresses the new challenges faced by mobile application developers in the new ecosystems through empirical methods. By using the theories of two-sided markets and business ecosystems as the basis, the thesis assesses monetization and value creation in the market as well as the impact of electronic Word-of-Mouth (eWOM) and developer multihoming— i. e. contributing for more than one platform—in the ecosystems. The data for the study was collected with web crawling from the three biggest marketplaces: Apple App Store, Google Play and Windows Phone Store. The dissertation consists of six individual articles. The results of the studies show a gap in monetization among the studied applications, while a majority of applications are produced by small or micro-enterprises. The study finds only weak support for the impact of eWOM on the sales of an application in the studied ecosystem. Finally, the study reveals a clear difference in the multi-homing rates between the top application developers and the rest. This has, as discussed in the thesis, an impact on the future market analyses—it seems that the smart device market can sustain several parallel application marketplaces.Muutama vuosi sitten julkistetut uuden sukupolven mobiilisovellusten kauppapaikat ovat muuttaneet mobiiliekosysteemien liiketoimintadynamiikkaa. Nämä uudet markkinapaikat ovat jo onnistuneet houkuttelemaan yli miljoona sovellusta sadoilta tuhansilta ohjelmistokehittäjiltä. Nämä kehittäjät yhdessä markkinapaikan organisoijan sekä loppukäyttäjien kanssa ovat muodostaneet ohjelmistoekosysteemin osaksi laajempaa mobiiliekosysteemiä. Tässä väitöskirjassa tarkastellaan mobiilisovellusten kehittäjien uudenlaisilla kauppapaikoilla kohtaamia haasteita empiiristen tutkimusmenetelmien kautta. Väitöskirjassa arvioidaan sovellusten monetisaatiota ja arvonluontia sekä verkon asiakasarviointien (engl. electronicWord-of-Mouth, eWOM) ja kehittäjien moniliittymisen (engl. multi-homing) — kehittäjä on sitoutunut useammalle kuin yhdelle ekosysteemille — vaikutuksia ekosysteemissä. Työn teoreettinen tausta rakentuu kaksipuolisten markkinapaikkojen ja liiketoimintaekosysteemien päälle. Tutkimuksen aineisto on kerätty kolmelta suurimmalta mobiilisovellusmarkkinapaikalta: Apple App Storesta, Google Playstä ja Windows Phone Storesta. Tämä artikkeliväitöskirja koostuu kuudesta itsenäisestä tutkimuskäsikirjoituksesta. Artikkelien tulokset osoittavat puutteita monetisaatiossa tutkittujen sovellusten joukossa. Merkittävä osa tarkastelluista sovelluksista on pienten yritysten tai yksittäisten kehittäjien julkaisemia. Tutkimuksessa löydettiin vain heikkoa tukea eWOM:in positiiviselle vaikutukselle sovellusten myyntimäärissä. Työssä myös osoitetaan merkittävä ero menestyneimpien sovelluskehittäjien sekä muiden kehittäjien moniliittymiskäyttäytymisen välillä. Tällä havainnolla on merkitystä tuleville markkina-analyyseille ja sen vaikutuksia on käsitelty työssä. Tulokset esimerkiksi viittaavat siihen, että markkinat pystyisivät ylläpitämään useita kilpailevia kauppapaikkoja.Siirretty Doriast

Letters from the War of Ecosystems – An Analysis of Independent Software Vendors in Mobile Application Marketplaces

The recent emergence of a new generation of mobile application marketplaces has changed the business in the mobile ecosystems. The marketplaces have gathered over a million applications by hundreds of thousands of application developers and publishers. Thus, software ecosystems&mdash;consisting of developers, consumers and the orchestrator&mdash;have emerged as a part of the mobile ecosystem.&nbsp; This dissertation addresses the new challenges faced by mobile application developers in the new ecosystems through empirical methods. By using the theories of two-sided markets and business ecosystems as the basis, the thesis assesses monetization and value creation in the market as well as the impact of electronic Word-of-Mouth (eWOM) and developer multihoming&mdash; i. e. contributing for more than one platform&mdash;in the ecosystems. The data for the study was collected with web crawling from the three biggest marketplaces: Apple App Store, Google Play and Windows Phone Store.&nbsp; The dissertation consists of six individual articles. The results of the studies show a gap in monetization among the studied applications, while a majority of applications are produced by small or micro-enterprises. The study finds only weak support for the impact of eWOM on the sales of an application in the studied ecosystem. Finally, the study reveals a clear difference in the multi-homing rates between the top application developers and the rest. This has, as discussed in the thesis, an impact on the future market analyses&mdash;it seems that the smart device market can sustain several parallel application marketplaces. - - - - - Muutama vuosi sitten julkistetut uuden sukupolven mobiilisovellusten kauppapaikat ovat muuttaneet mobiiliekosysteemien liiketoimintadynamiikkaa. N&auml;m&auml; uudet markkinapaikat ovat jo onnistuneet houkuttelemaan yli miljoona sovellusta sadoilta tuhansilta ohjelmistokehitt&auml;jilt&auml;. N&auml;m&auml; kehitt&auml;j&auml;t yhdess&auml; markkinapaikan organisoijan sek&auml; loppuk&auml;ytt&auml;jien kanssa ovat muodostaneet ohjelmistoekosysteemin osaksi laajempaa mobiiliekosysteemi&auml;.&nbsp; T&auml;ss&auml; v&auml;it&ouml;skirjassa tarkastellaan mobiilisovellusten kehitt&auml;jien uudenlaisilla kauppapaikoilla kohtaamia haasteita empiiristen tutkimusmenetelmien kautta. V&auml;it&ouml;skirjassa arvioidaan sovellusten monetisaatiota ja arvonluontia sek&auml; verkon asiakasarviointien (engl. electronicWord-of-Mouth, eWOM) ja kehitt&auml;jien moniliittymisen (engl. multi-homing) &mdash; kehitt&auml;j&auml; on sitoutunut useammalle kuin yhdelle ekosysteemille &mdash; vaikutuksia ekosysteemiss&auml;. Ty&ouml;n teoreettinen tausta rakentuu kaksipuolisten markkinapaikkojen ja liiketoimintaekosysteemien p&auml;&auml;lle. Tutkimuksen aineisto on ker&auml;tty kolmelta suurimmalta mobiilisovellusmarkkinapaikalta: Apple App Storesta, Google Playst&auml; ja Windows Phone Storesta.&nbsp; T&auml;m&auml; artikkeliv&auml;it&ouml;skirja koostuu kuudesta itsen&auml;isest&auml; tutkimusk&auml;sikirjoituksesta. Artikkelien tulokset osoittavat puutteita monetisaatiossa tutkittujen sovellusten joukossa. Merkitt&auml;v&auml; osa tarkastelluista sovelluksista on pienten yritysten tai yksitt&auml;isten kehitt&auml;jien julkaisemia. Tutkimuksessa l&ouml;ydettiin vain heikkoa tukea eWOM:in positiiviselle vaikutukselle sovellusten myyntim&auml;&auml;riss&auml;. Ty&ouml;ss&auml; my&ouml;s osoitetaan merkitt&auml;v&auml; ero menestyneimpien sovelluskehitt&auml;jien sek&auml; muiden kehitt&auml;jien moniliittymisk&auml;ytt&auml;ytymisen v&auml;lill&auml;. T&auml;ll&auml; havainnolla on merkityst&auml; tuleville markkina-analyyseille ja sen vaikutuksia on k&auml;sitelty ty&ouml;ss&auml;. Tulokset esimerkiksi viittaavat siihen, ett&auml; markkinat pystyisiv&auml;t yll&auml;pit&auml;m&auml;&auml;n useita kilpailevia kauppapaikkoja.</p

Front-Line Physicians' Satisfaction with Information Systems in Hospitals

Day-to-day operations management in hospital units is difficult due to continuously varying situations, several actors involved and a vast number of information systems in use. The aim of this study was to describe front-line physicians' satisfaction with existing information systems needed to support the day-to-day operations management in hospitals. A cross-sectional survey was used and data chosen with stratified random sampling were collected in nine hospitals. Data were analyzed with descriptive and inferential statistical methods. The response rate was 65 % (n = 111). The physicians reported that information systems support their decision making to some extent, but they do not improve access to information nor are they tailored for physicians. The respondents also reported that they need to use several information systems to support decision making and that they would prefer one information system to access important information. Improved information access would better support physicians' decision making and has the potential to improve the quality of decisions and speed up the decision making process.Peer reviewe

Proceedings of the Conference on Production Systems and Logistics: CPSL 2022

[no abstract available

An evaluation of the challenges of Multilingualism in Data Warehouse development

In this paper we discuss Business Intelligence and define what is meant by support for Multilingualism in a Business Intelligence reporting context. We identify support for Multilingualism as a challenging issue which has implications for data warehouse design and reporting performance. Data warehouses are a core component of most Business Intelligence systems and the star schema is the approach most widely used to develop data warehouses and dimensional Data Marts. We discuss the way in which Multilingualism can be supported in the Star Schema and identify that current approaches have serious limitations which include data redundancy and data manipulation, performance and maintenance issues. We propose a new approach to enable the optimal application of multilingualism in Business Intelligence. The proposed approach was found to produce satisfactory results when used in a proof-of-concept environment. Future work will include testing the approach in an enterprise environmen

Safety and Reliability - Safe Societies in a Changing World

The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk managemen