Hybrid User Pairing for Spectral and Energy Efficiencies in Multiuser MISO-NOMA Networks with SWIPT

in IEEE Transactions on Communications (2020), 68(8), 4874-4890

In this paper, we propose a novel hybrid user pairing (HUP) scheme in multiuser multiple-input single-output nonorthogonal multiple access networks with simultaneous wireless information and power ... [more ▼]

In this paper, we propose a novel hybrid user pairing (HUP) scheme in multiuser multiple-input single-output nonorthogonal multiple access networks with simultaneous wireless information and power transfer. In this system, two information users with distinct channel conditions are optimally paired while energy users perform energy harvesting (EH) under non-linearity of the EH circuits. We consider the problem of jointly optimizing user pairing and power allocation to maximize the overall spectral efficiency (SE) and energy efficiency (EE) subject to userspecific quality-of-service and harvested power requirements. A new paradigm for the EE-EH trade-off is then proposed to achieve a good balance of network power consumption. Such design problems are formulated as the maximization of nonconcave functions subject to the class of mixed-integer non-convex constraints, which are very challenging to solve optimally. To address these challenges, we first relax binary pairing variables to be continuous and transform the design problems into equivalent non-convex ones, but with more tractable forms. We then develop low-complexity iterative algorithms to improve the objectives and converge to a local optimum by means of the inner approximation framework. Simulation results show the convergence of proposed algorithms and the SE and EE improvements of the proposed HUP scheme over state-of-the-art designs. In addition, the effects of key parameters such as the number of antennas and dynamic power at the BS, target data rates, and energy threshold, on the system performance are evaluated to show the effectiveness of the proposed schemes in balancing resource utilization. [less ▲]

Hybride Praktiken. Methodologische Überlegungen zu einer erziehungswissenschaftlichen Ethnographie kindermedizinischer Vorsorgeuntersuchungen.

in Hünersdorf, Bettina; Maeder, Christoph; Müller, Burkhard (Eds.) Ethnographie und Erziehungswissenschaft. Methodologische Reflexionen und empirische Annäherungen (2008)

Dieser Beitrag ist methodologischen Fragen nach dem Verhältnis von Ethnographie und Pädagogik gewidmet. Anhand eines empirischen Beispiels aus dem Forschungsprojekt „Kinderkörper in der Praxis“ wird für ... [more ▼]

Dieser Beitrag ist methodologischen Fragen nach dem Verhältnis von Ethnographie und Pädagogik gewidmet. Anhand eines empirischen Beispiels aus dem Forschungsprojekt „Kinderkörper in der Praxis“ wird für einen wissenssoziologisch informierten und praxisanalytisch orientierten Ansatz erziehungswissenschaftlicher Ethnographie plädiert, der sich nicht vorrangig über – ihrem Selbstverständnis nach – pädagogische Handlungsfelder definiert. Vielmehr versteht dieser Ansatz den Begriff des „Feldes“ im Sin-ne einer reflexiven Anthropologie auch und zunächst als einen rekursiven „Modus der Objektkonstruktion“ (Bourdieu/Wacquant 1996, S. 262). Solch ein heuristischer Feldbegriff in Verbindung mit einem formbezogenen Begriff von Pädagogik als Wissensordnung ermöglicht es, einerseits Konstruktionsbedingungen, Funktionen und Verfahrensweisen pädagogischer Praxisformen in vielfältigen Kontexten empirisch zu explorieren und gleichzeitig die je gewählten Forschungsfelder nicht vorgängig durch eine Fokussierung der Fragen auf „das Pädagogische“ weiter künstlich einzugrenzen. [less ▲]

Hybridisierung von Berufs- und Hochschulbildung in Deutschland, Österreich und der Schweiz

in Banscherus, Ulf; Engel, Ole; Mindt, Anne (Eds.) et al Differenzierung im Hochschulsystem: Nationale und internationale Entwicklungen und Herausforderungen (2015)

The Hybridization of Vocational Training and Higher Education in Austria, Germany, and Switzerland

Book published by Budrich UniPress (2013)

Austria, Germany, and Switzerland are increasingly relying on hybridization at the nexus of vocational training and higher education to increase permeability and reform their highly praised systems of ... [more ▼]

Austria, Germany, and Switzerland are increasingly relying on hybridization at the nexus of vocational training and higher education to increase permeability and reform their highly praised systems of collective skill formation. This historical and organizational institutionalist study compares these countries to trace the evolution of their skill regimes from the 1960s to today's era of Europeanization, focusing especially on the impact of the Bologna and Copenhagen processes. [less ▲]

HyCast-Podcast Discovery in Mobile Networks

in Proceedings of the 3rd ACM Workshop on Wireless Multimedia Networking and Performance Modeling (WMuNeP '07) (2007)

Podcasts are a popular way to provide multimedia information about certain topics. A multitude of podcast servers exist in the Internet, allowing people to subscribe to them. Typically, podcasts are ... [more ▼]

Podcasts are a popular way to provide multimedia information about certain topics. A multitude of podcast servers exist in the Internet, allowing people to subscribe to them. Typically, podcasts are downloaded onto desktop computers and copied on mobile devices to be played while being on the move. In this paper, we extend the idea of podcasts, making them available in mobile network environments. In particular, HyCast does not rely on central podcast directories. Instead, HyCast also allows discovering, subscribing to, and downloading podcasts and episodes in the local neighborhood. For the dissemination of podcast information, we introduce and evaluate two different strategies. One is based on peer-to-peer communication between one-hop neighbors. The second one employs clustering to reduce the overhead of the podcast information dissemination. [less ▲]

Hydrodynamic Analysis of Gas-Liquid-Liquid-Solid Reactors using the XDEM Numerical Approach

in Canadian Journal of Chemical Engineering (2018)

Multiphase reactors are abundantly used in many industries. Among them, few reactors deal with four phases called gas-liquid-liquid-solid systems, which received less attention due to their complex ... [more ▼]

Multiphase reactors are abundantly used in many industries. Among them, few reactors deal with four phases called gas-liquid-liquid-solid systems, which received less attention due to their complex situation. Numerical study of such complex systems is not easy and requires loads of computational effort. In this study, a discrete-continuous numerical model known as eXtended discrete element method (XDEM) is proposed to investigate the hydrodynamic behaviour of fluid phases passing through the packed bed of solid particles. This model is applied to the dripping zone of a blast furnace. In this zone, two distinct liquid phases, namely liquid iron and slag, flow through a pile of coke particles while exchanging momentum. In this work, besides the solid-fluid and gas-liquid interactions, the liquid-liquid interactions are also studied and the phases' mutual effects are discussed. In addition, a sensitivity study on the slag viscosity is performed, which shows the importance of liquid phase properties on the system behaviour. The results evaluation shows that the liquid iron accelerates the downward flow of the slag and the slag decelerates the downward flow of the liquid iron phase due to the resistance force caused by their relative velocity. [less ▲]

Hydrogen peroxide-mediated killing of Caenorhabditis elegans by Streptococcus pyogenes.

in Infection and Immunity (2002), 70(9), 5202-7

Caenorhabditis elegans is currently introduced as a new, facile, and cheap model organism to study the pathogenesis of gram-negative bacteria such as Pseudomonas aeruginosa and Salmonella enterica serovar ... [more ▼]

Caenorhabditis elegans is currently introduced as a new, facile, and cheap model organism to study the pathogenesis of gram-negative bacteria such as Pseudomonas aeruginosa and Salmonella enterica serovar Typhimurium. The mechanisms of killing involve either diffusible exotoxins or infection-like processes. Recently, it was shown that also some gram-positive bacteria kill C. elegans, although the precise mechanisms of killing remained open. We examined C. elegans as a pathogenesis model for the gram-positive bacterium Streptococcus pyogenes, a major human pathogen capable of causing a wide spectrum of diseases. We demonstrate that S. pyogenes kills C. elegans, both on solid and in liquid medium. Unlike P. aeruginosa and S. enterica serovar Typhimurium, the killing by S. pyogenes is solely mediated by hydrogen peroxide. Killing required live streptococci; the killing capacity depends on the amount of hydrogen peroxide produced, and killing can be inhibited by catalase. Major exotoxins of S. pyogenes are not involved in the killing process as confirmed by using specific toxin inhibitors and knockout mutants. Moreover, no accumulation of S. pyogenes in C. elegans is observed, which excludes the involvement of infection-like processes. Preliminary results show that S. pneumoniae can also kill C. elegans by hydrogen peroxide production. Hydrogen peroxide-mediated killing might represent a common mechanism by which gram-positive, catalase-negative pathogens kill C. elegans. [less ▲]

Hydrogeological effects on terrestrial gravity measurements

Scientific Conference (2019, December 10)

For the 20 last years, terrestrial and satellite gravity measurements have reached such a precision that they allow for identification of the signatures from water storage fluctuations. In particular ... [more ▼]

For the 20 last years, terrestrial and satellite gravity measurements have reached such a precision that they allow for identification of the signatures from water storage fluctuations. In particular, hydrogeological effects induce significant time-correlated signature in the gravity time series. Gravity response to rainfall is a complex function of the local geologic and climatic conditions, e.g., rock porosity, vegetation, evaporation, and runoff rates. The gravity signal combines contributions from many geophysical processes, source separation being a major challenge. At the local scale and short-term, the associated gravimetric signatures often exceed the tectonic and GIA effects, and monitoring gravity changes is a source of information on local groundwater mass balance, and contributes to model calibrations. Some aquifer main characteristics can then be inferred by combining continuous gravity, geophysical and hydrogeological measurements. In Membach, Belgium, a superconducting gravimeter has monitored gravity continuously for more than 24 years. This long time series, together with 300 repeated absolute gravity measurements and environmental monitoring, has provided valuable information on the instrumental, metrological, hydrogeological and geophysical points of view. This has allowed separating the signal sources and monitoring partial saturation dynamics in the unsaturated zone, convective precipitation and evapotranspiration at a scale of up to 1 km², for signals smaller than 1 nm/s², equivalent to 2.5 mm of water. Based on this experience, another superconducting gravimeter was installed in 2014 in the karst zone of Rochefort, Belgium. In a karst area, where the vadose zone is usually thicker than in other contexts, combining gravity measurements at the surface and inside accessible caves is a way to separate the contribution from the unsaturated zone lying between the two instruments, from the saturated zone underneath the cave, and the common mode effects from the atmosphere or other regional processes. Those experiments contribute to the assessment of the terrestrial hydrological cycle, which is a major challenge of the geosciences associated with key societal issues: availability of freshwater, mitigation of flood hazards, or measurement of evapotranspiration. [less ▲]

Hydrogeophysical Tools for Investigating Groundwater Storage in the Subsurface of a Karst System

Poster (2014, September 14)

Hydrokinetic Energy for Enlightening the Future of Rural Communities in Uttarakhand

in Proceedings International Conference on Hydropower for Sustainable Development (2015, February 07)

Uttarakhand is a northern state of India located in the foothills of the Himalayan mountain ranges. It is rich in water resources with many perennial rivers originating in the state and has enormous ... [more ▼]

Uttarakhand is a northern state of India located in the foothills of the Himalayan mountain ranges. It is rich in water resources with many perennial rivers originating in the state and has enormous potential for hydropower generation. Despite of this fact the recent floods and agitation on setting up large and small hydropower plants has put a question mark on the future hydropower development and thus future of rural electrification in the state. In this context, the paper presents an idea of using hydrokinetic energy as a viable solution for securing low impact and viable power for rural communities in Uttarakhand. [less ▲]