Search results for "Information System"

The generalized method of equal areas for the design of sum-of-cisoids simulators for mobile Rayleigh fading channels with arbitrary Doppler spectra

2011

We present in this paper a generalized version of the method of equal areas (MEA) that is well suited for the design of sum-of-cisoids (SOC) simulators for narrowband mobile Rayleigh fading channels characterized by any type of Doppler power spectral densities (DPSDs). Unlike the original MEA, the generalized MEA (GMEA) can be applied to the simulation of fading channels with asymmetrical DPSDs. This is an important feature because the simulation of such channels is of great interest for the laboratory analysis of mobile communication systems under non-isotropic scattering conditions. We show that irrespective of the underlying DPSD, the GMEA results in a very good approximation to the auto…

Performance of power control in inter-cell interference coordination for frequency reuse

2010

To mitigate inter-cell interference in 3G evolution systems, a novel inter-cell interference coordination scheme called soft fractional frequency reuse is proposed in this article, which enables to improve the data rate in cell-edge. On this basis, an inter-cell power control is presented for the inter-cell interference coordination, and the inter-cell balanced signal to interference plus noise ratio (SINR) among users is established for power allocation, which enables mitigation of inter-cell interference. Especially, the power control is based on a novel exponential kernel equation at higher convergence speed than the traditional arithmetic kernel equations. Numerical results show that th…

Mobile Ontologies

2008

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 only access to Internet are mobile devices, developing high quality services based on them grows in importance. Ontologies are an important ingredient towards more complicated mobile services and wider usage of mobile terminals. In this article, we first discuss ontology and epistemology concepts in general. After that, we review ontologies in the …

Does higher datarate perform better in IEEE 802.11-based multihop ad hoc networks?

2007

Due to the nature that high datarate leads to shorter transmission range, the performance enhancement by high datarate 802.11 WLANs may be degraded when applying high datarate to an 802.11 based multihop ad hoc network. In this paper, we evaluate, through extensive simulations, the performance of multihop ad hoc networks at multiple transmission datarates, in terms of the number of hops between source and destination, throughput, end-to-end delay and packet loss. The study is conducted based on both stationary chain topology and mesh topologies with or without node mobility. From numerical results on network performance based on chain topology, we conclude that there is almost no benefit by…

Channel-dependent load balancing in wireless packet networks

2004

This paper refers to a wireless cellular packet network scenario where fast retransmission of corrupted packets is used to improve the packet error ratio. Since the ‘gross’ packet transmission rate (including retransmission) depends on the channel quality perceived, admitted calls weight unevenly in terms of effective resource consumption. In this paper, we suggest using channel quality information to drive load balancing mechanisms. We propose two novel metrics to determine the best cell to attach to, during handover or new call origination. Extensive simulation results prove the superiority of our proposed schemes with respect to traditional load balancing, which base their operation on t…

User behaviours after critical mobile application incidents: the relationship with situational context

2015

Users occasionally have critical incidents with information systems IS. A critical IS incident is an IS product or service experience that a user considers to be unusually positive or negative. Critical IS incidents are highly influential in terms of users' overall perceptions and customer relationships; thus, they are crucial for IS product and service providers. Therefore, it is important to study user behaviours after such incidents. Within IS, the relationships between the situational context and user behaviours after critical incidents have not been addressed at all. Prior studies on general mobile use as a related research area have recognized the influence of the situational context,…

A tale of two frames : Exploring the role of framing in the use discontinuance of volitionally adopted technology

2022

https://doi.org/10.1111/isj.12355 The discontinuance of volitional IS (i.e., information systems adopted, used and discontinued at will) has recently attracted remarkable attention from academics and practitioners alike. However, most research to date has been ahistorical. Ignoring the temporal progression can be problematic when the phenomenon under investigation is dynamic and evolving. To balance this, we adopt a stage modelling approach to understand the process ending with the technology use being discontinued by users of a popular crowdsourcing platform. Two questions guided our investigation: (1) Why do users discontinue using an IS they have volitionally adopted and used? (2) How do…

Does the law matter? An empirical study on the accessibility of Finnish higher education institutions’ web pages

2022

AbstractInformation and communication technology (ICT) has made higher education available to many students in a new way. The role of online learning in higher education institutions (HEIs) has grown to an unprecedented scale due to the COVID-19 pandemic. The diversity of higher education students has increased, and accessible solutions are needed. New European and national regulations support these trends. The research reported in this paper was conducted in Finland, which is one of the leading European countries in terms of high technology and digitalisation. The aim of this research is to explore the accessibility of all Finnish HEIs’ (N = 38) landing pages based on Web Content Accessibi…

Information Assurance and Advanced Human-Computer Interfaces

2008

On coincidence of feedback and global Stackelberg equilibria in a class of differential games

2021

This paper shows for a class of differential games that the global Stackelberg equilibrium (GSE) coincides with the feedback Stackelberg equilibrium (FSE), although the GSE assumes that the leader/regulator an- nounces at the initial time the regulatory instrument rule she will follow for the rest of the game, while in the FSE, the regulator at any time chooses the optimal level of the regulatory instrument rate. This coincidence is based on the fact that the FSE is calculated using dynamic programming what implies that although the regulator chooses the regulatory instrument rate level that maximizes social welfare, the first-order condition for the maximization of the right-hand side of t…