Search results for "communication systems"
showing 10 items of 120 documents
Modeling of Vehicle-to-Vehicle Channels in the Presence of Moving Scatterers
2012
In this paper, we derive a vehicle-to-vehicle~(V2V) channel model assuming a typical propagation scenario in which the local scatterers move with random velocities in random directions. The complex channel gain of the proposed V2V channel model is provided. Subsequently, for different scatterer velocity distributions, the corresponding autocorrelation functions~(ACFs) are derived, illustrated, and compared with the classical ACF derived under the assumption of fixed scatterers. Furthermore, under specific conditions, highly accurate approximations for the ACFs are provided in closed form. Since the proposed V2V channel model covers several communication scenarios as special cases, including…
Streaming for vehicular users via elastic proxy buffer management
2004
In this article we refer to the market of vehicular networks, where groups of customers located in the same public vehicle (e.g., a train or bus) connect to a terrestrial network through a wireless/satellite backbone link. Elastic buffering is a proxy management technique devised to decouple the multimedia information retrieval rate on the network backbone from the playout streaming rate at the user terminal. It has been shown in the past that the application of elastic buffering mechanisms in terrestrial networks brings significant advantages in terms of network effectiveness. We show that elastic buffering is an extremely effective means to reduce, or even eliminate, streaming service out…
Stakeholders, contradictions and salience: An empirical study of a Norwegian G2G effort
2006
Author's version of a chapter in Proceedings of the 39th Annual Hawaii International Conference on Systems Sciences. Also available from the publisher at http://dx.doi.org/10.1109/HICSS.2006.436 Previous studies indicate that the expected effects of e-Government are slower to realize than initially expected. Several authors argue that e-Government involves particularly complex settings, consisting of a variety of stakeholders promoting different and often conflicting objectives. Yet, few studies have explicitly addressed the inherent challenges of this complexity. This study focuses on the extent to which contradictory stakeholder objectives can help explain the relatively slow progress of …
Turning a new “page”: ways to decrease the number of pages after hours without compromising patient care
2020
Pages to house staff after hours, especially overnight, lead to interrupted sleep and fatigue the next day. Although some pages are urgent, others may not need an immediate response. In this study we aimed to identify unwarranted pages and to establish ways to reduce them.Over 2 months, all pages to the Department of Pediatric Urology at the Hospital for Sick Children in Toronto, Canada, during call hours were documented, including the assessment of the responding physicians of their medical necessity. After analyzing the reasons for inappropriate pages, we took several steps to try to reduce them without impairing patient care. One year later, pages were tracked again to evaluate the effic…
Correlation and Spectral Properties of Vehicle-to-Vehicle Channels in the Presence of Moving Scatterers
2013
This paper derives a vehicle-to-vehicle (V2V) channel model assuming a typical propagation scenario in which the local scatterers move with random velocities in random directions. The complex channel gain of the proposed V2V channel model is provided. Subsequently, for different scatterer velocity distributions, the corresponding autocorrelation function (ACF), power spectral density (PSD), and the Doppler spread of the channel are derived, shown, and confirmed by the available measurement data. It is shown that the Gaussian mixture (GM) and the exponential distribution can accurately describe the velocity distribution of relatively fast and slow moving scatterers, respectively. Since the p…
Social capital and the networked public sphere: Implications for political social media sites
2012
Submitted version of a paper from the 45th Hawaii International Conference on System Science (HICSS), 2012. Published version available from IEEE: http://dx.doi.org/10.1109/hicss.2012.535 This paper presents a theoretical lens for research on social media use in eParticipation, along with an example case study. The idea of the public sphere and how it can be applied to eParticipation research is presented. The public sphere is discussed in relation to Castell's notion of the network society as the "networked public sphere", and social capital is introduced as a possible explanation for why some people choose to participate while others refrain from doing so. An example case is presented and…
ERP lifecycle: When to retire your ERP system?
2011
Published version of a chapter in the book: Enterprise information systems, vol 219, part 3, 168-177. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-642-24358-5_17 A lot of research has been undertaken focusing on ERP systems lifecycles, but very little paid attention to retirement. ERP retirement means the replacement of an ERP with another. The aim of this research paper is to investigate why and when should organizations retire their ERP systems. A convenience case study of an SME has been selected from Egypt. The case study under investigation has retired their local ERP system and replaced it with SAP ERP. Results of our analysis indicated that reasons of retirem…
Understanding eParticipation services in indonesian local government
2014
Published version of a chapter in the book: Information and Communication Technology. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-642-55032-4_32 This study aims at understanding how local government from a developing country, in this case Indonesia, implement and manage eParticipation services. In doing so, we combine institutional theory and stakeholder theory to build a sharper analytical lens. From an interpretive case study in the city of Yogyakarta, we reveal the institutionalization process of the services since their inception and identify major stakeholders and their salience. Based on our findings, we propose implications for practice and suggest implicati…
Treating cockroach phobia using a serious game on a mobile phone and augmented reality exposure: A single case study
2011
In vivo exposure has proved its efficacy in the treatment of specific phobias; however, not all patients benefit from it. Communication and information technologies such as Virtual Reality (VR) and Augmented Reality (AR) have improved exposure treatment adherence and acceptance. Serious games (SG) could also be used in order to facilitate exposure treatment. A line of research on SG is emerging which focuses on health issues. We have developed a SG for the treatment of cockroach phobia that uses a mobile phone as the application device. This work examines results of an N = 1 study about whether the use of this mobile game can facilitate treatment of this specific phobia preparing her for th…
Context-aware vehicular cyber-physical systems with cloud support: architecture, challenges, and solutions
2014
[EN] The advances in wireless communication techniques, mobile cloud computing, and context-aware technologies boost a growing interest in the design, development, and deployment of vehicular networks for emerging applications. This leads to an increasing evolutionary tendency to change from vehicular networks toward cloud-assisted context-aware vehicular cyber-physical systems. In this article, we first propose a multi-layered context-aware architecture and introduce two crucial service components, vehicular social networks and context-aware vehicular security. Then we propose an application scenario regarding the context-aware dynamic parking services by illuminating the cloud-assisted ar…