Continuous Fluid Antenna Systems: Modeling and Analysis

Fluid antennas (FAs) is a promising technology for introducing flexibility and reconfigurability in wireless networks. Recent research efforts have highlighted the potential gains that can be achieved in comparison to conventional antennas. These works assume that the FA has a discrete number of positions that the liquid can take. However, from a practical standpoint, the liquid moves in a continuous fashion to any point inside the FA. In this paper, we focus on a continuous FA system (CFAS) and present a general framework for its design and analytical evaluation. In particular, we derive closed-form analytical expressions for the level crossing rate (LCR) and the average fade duration of the continuous signal-to-interference ratio (SIR) process over the FA's length. Then, by leveraging the LCR expression, we characterize the system's outage performance with a bound on the cumulative distribution function of the SIR's supremum. Our results confirm that the CFAS outperforms its discrete counterpart and thus provides the performance limits of FA-based systems.Comment: IEEE Communications Letter

Highlights from the 24th conference on retroviruses and opportunistic infections, 13-16 February 2017, Seattle, Washington, USA

From the 13th to 16th February 2017, researchers from around the world convened for the 24th annual Conference on Retroviruses and Opportunistic Infections (CROI) at the Washington State Convention Center in Seattle, Washington. The conference was organised by the International Antiviral Society-USA (IAS-USA) in partnership with the CROI Foundation. The conference included over 1000 oral and poster presentations of peer-reviewed original research as well as lectures and symposia featuring insights from leading basic, translational and clinical researchers. Highlighted here are key data presented at the conference

Impact of multiangular information on empirical models to estimate canopy nitrogen concentration in mixed forest

Directional effects in remotely sensed reflectance data can influence the retrieval of plant biophysical and biochemical estimates. Previous studies have demonstrated that directional measurements contain added information that may increase the accuracy of estimated plant structural parameters. Because accurate biochemistry mapping is linked to vegetation structure, also models to estimate canopy nitrogen concentration (CN) may be improved indirectly from using multiangular data. Hyperspectral imagery with five different viewing zenith angles was acquired by the spaceborne CHRIS sensor over a forest study site in Switzerland. Fifteen canopy reflectance spectra corresponding to subplots of field-sampled trees were extracted from the preprocessed CHRIS images and subsequently two-term models were developed by regressing CN on four datasets comprising either original or continuum-removed reflectances. Consideration is given to the directional sensitivity of the CN estimation by generating regression models based on various combinations (n=15) of observation angles. The results of this study show that estimating canopy CN with only nadir data is not optimal irrespective of spectral data processing. Moreover adding multiangular information improves significantly the regression model fits and thus the retrieval of forest canopy biochemistry. These findings support the potential of multiangular Earth observations also for application-oriented ecological monitoring

Highlights from the 20th International Symposium on HIV and Emerging Infectious Diseases (ISHEID) 16-18 May 2018, Marseille, France: from HIV and comorbidities to global health.

The 20th International Symposium on HIV and Emerging Infectious Diseases took place in Marseille, France. It had a refreshing European look with reinforced partnerships with the European AIDS Clinical Society and the British HIV Association and with international speakers and participants. Topics included HIV and global health, HIV and hepatitis cure, the microbiome and immunotherapies, clinical research and methodology, as well as chemsex, pre-exposure prophylaxis, sexually transmitted infections and emerging infectious diseases. Novel areas of research were also described, such as electronic technology in order to improve HIV management, and the expert patient

Nadroparine-induced skin necrosis on a patient with essential thrombocythaemia: a case report

Skin necrosis is a rare but serious complication of subcutaneously administered low-molecular-weight heparin. We report a case of a 53-year-old female patient with skin necrosis induced by subcutaneous administration of nadroparine. The patient suffered from essential thrombocythaemia on a background of chronic myeloproliferative disease. She was admitted to our clinic with a subacute ileus due to endometriosis of the rectosigmoid junction. She underwent a high anterior resection and she received pre- and postoperative antithrombotic prophylaxis with subcutaneous nadroparine on a daily basis. On the 6th and 7th postoperative days, two skin necroses occurred at two injection sites

Meta Modeling for Business Process Improvement

Conducting business process improvement (BPI) initiatives is a topic of high priority for today’s companies. However, performing BPI projects has become challenging. This is due to rapidly changing customer requirements and an increase of inter-organizational business processes, which need to be considered from an end-to-end perspective. In addition, traditional BPI approaches are more and more perceived as overly complex and too resource-consuming in practice. Against this background, the paper proposes a BPI roadmap, which is an approach for systematically performing BPI projects and serves practitioners’ needs for manageable BPI methods. Based on this BPI roadmap, a domain-specific conceptual modeling method (DSMM) has been developed. The DSMM supports the efficient documentation and communication of the results that emerge during the application of the roadmap. Thus, conceptual modeling acts as a means for purposefully codifying the outcomes of a BPI project. Furthermore, a corresponding software prototype has been implemented using a meta modeling platform to assess the technical feasibility of the approach. Finally, the usability of the prototype has been empirically evaluated

Incorporating Ecosystems in the Water-Energy-Food Nexus: Current Perspective and Future Directions

Integrated approaches for managing natural resources are needed to meet the increasing demand for freshwater, energy and food, while, in parallel, mitigating and adapting to climate change, maintaining the integrity of ecosystems, and ensuring equitable access to resources. The Water-Energy-Food (WEF) Nexus has been proposed as a cross-sectoral approach to understand, analyse, and manage the complex trade-offs and exploit synergies that arise among these resource sectors. Although not initially included as a component of the Nexus, the importance of ecosystems in supporting water, energy and food security is increasingly recognised by the Nexus community of researchers and practitioners. However, attempts to conceptually integrate Ecosystems into the Nexus have yet to converge into a common framework. A group of natural resources management researchers, system thinkers and ecosystem services experts from the European network COST Action CA20138 NEXUSNET have compiled and investigated the various approaches for integrating ecosystems in the WEF Nexus. By combining literature analysis with interdisciplinary workshops – one of which was held in a hybrid format (in person and online) at the University of Oulu, Finland, in September 2022 – we reveal a multiplicity of concepts utilised to represent, partially or fully, ecosystems in the Nexus, namely “natural environment”, “ecosystem services” and “biodiversity”. Disparity was also found in the role attributed to ecosystems in the Nexus framework, being it an underlying layer from which resources for Nexus sectors are extracted or the pillar of an expanded Nexus system – i.e., the WEF-Ecosystems Nexus. Through this collaborative effort, we present possible advantages and disadvantages of adopting differential WEF-Ecosystems Nexus approaches, highlighting their potential complementarity and integration to support future advancement of Nexus research. In the oral presentation, we will show our preliminary findings and encourage the exchange of ideas and feedback from the different scientific disciplines present at the CEMEPE Conference.Tenth International Conference on Environmental Management, Engineering, Planning and Economics (CEMEPE) & SECOTOX Conference organized by: Division of Hydraulics and Environmental Engineering, Department of Civil Engineering, Aristotle University of Thessaloniki and Society of Ecotoxicology and Environmental Safety (SECOTOX), Skiathos island, Greece, 2023