| 1. |
- Gonzalez, Jose M., et al.
(author)
-
Spatial and sectoral benefit distribution in water-energy system design
- 2020
-
In: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 269
-
Journal article (peer-reviewed)abstract
- The design of water and energy systems has traditionally been done independently or considering simplified interdependencies between the two systems. This potentially misses valuable synergies between them and does not consider in detail the distribution of benefits between different sectors or regions. This paper presents a framework to couple integrated water-power network simulators with multi-objective optimisation under uncertainty to explore the implications of explicitly including spatial topology and interdependencies in the design of multi-sector integrated systems. A synthetic case study that incorporates sectoral dependencies in resource allocation, operation of multi-purpose reservoirs and spatially distributed infrastructure selection in both systems is used. The importance of explicitly modelling the distribution of benefits across different sectors and regions is explored by comparing different spatially aggregated and disaggregated multi-objective optimisation formulations. The results show the disaggregated formulation identifies a diverse set of non-dominated portfolios that enables addressing the spatial and sectoral distribution of benefits, whilst the aggregated formulations arbitrarily induce unintended biases. The proposed disaggregated approach allows for detailed spatial design of interlinked water and energy systems considering their complex regional and sectoral trade-offs. The framework is intended to assist planners in real resource systems where diverse stakeholder groups are mindful of receiving their fair share of development benefits.
|
|
| 2. |
- Grasselli, Robert K., et al.
(author)
-
Active centers, catalytic behavior, symbiosis and redox properties of MoV(Nb,Ta)TeO ammoxidation catalysts
- 2006
-
In: Topics in Catalysis. - : Springer Science and Business Media LLC. - 1572-9028 .- 1022-5528. ; 38:1-3, s. 7-16
-
Journal article (peer-reviewed)abstract
- Selective as well as waste forming active centers were defined for MoVNbTeO and MoVTaTeO catalysts in the ammoxidation of propane to acrylonitrile and all catalytic functionalities were assigned to specific elements at the respective active centers. Symbiosis between M1 and M2 phases of these catalysts was observed, with phase cooperation being more extensive in the Nb than Ta containing compositions. The difference in catalytic effectiveness arises most likely because contact and surface area exposure of the two respective, cooperating phase pairs are not equal. The M1 phase of the catalysts is reducible by propane and ammonia in the absence of dioxygen and is regenerable to its original, fully oxidized state by dioxygen (air). No structural collapse is observed even after 120 C3H8 + NH3 reduction pulses. The so induced reduction of the catalyst extends up to 70 layers deep. The product distribution over the first few pulses is very similar to that under catalytic conditions, supporting the concept that lattice oxygen is involved in the catalytic ammoxidation process. Therefore, the ammoxidation of paraffins is a redox process, as is of course the well-known olefin ammoxidation process.
|
|
| 3. |
- McGinn, Steven, et al.
(author)
-
New Technologies for DNA analysis-A review of the READNA Project.
- 2016
-
In: New Biotechnology. - : Elsevier BV. - 1876-4347 .- 1871-6784.
-
Research review (peer-reviewed)abstract
- The REvolutionary Approaches and Devices for Nucleic Acid analysis (READNA) project received funding from the European Commission for 4 1/2 years. The objectives of the project revolved around technological developments in nucleic acid analysis. The project partners have discovered, created and developed a huge body of insights into nucleic acid analysis, ranging from improvements and implementation of current technologies to the most promising sequencing technologies that constitute a 3(rd) and 4(th) generation of sequencing methods with nanopores and in situ sequencing, respectively.
|
|
| 4. |
- Alenaini, Wareed, et al.
(author)
-
Ethnic Differences in Body Fat Deposition and Liver Fat Content in Two UK‐Based Cohorts
- 2020
-
In: Obesity. - : John Wiley & Sons. - 1930-7381 .- 1930-739X. ; 28:11, s. 2142-2152
-
Journal article (peer-reviewed)abstract
- ObjectiveDifferences in the content and distribution of body fat and ectopic lipids may be responsible for ethnic variations in metabolic disease susceptibility. The aim of this study was to examine the ethnic distribution of body fat in two separate UK‐based populations.MethodsAnthropometry and body composition were assessed in two separate UK cohorts: the Hammersmith cohort and the UK Biobank, both comprising individuals of South Asian descent (SA), individuals of Afro‐Caribbean descent (AC), and individuals of European descent (EUR). Regional adipose tissue stores and liver fat were measured by magnetic resonance techniques.ResultsThe Hammersmith cohort (n = 747) had a mean (SD) age of 41.1 (14.5) years (EUR: 374 men, 240 women; SA: 68 men, 22 women; AC: 14 men, 29 women), and the UK Biobank (n = 9,533) had a mean (SD) age of 55.5 (7.5) years (EUR: 4,483 men, 4,873 women; SA: 80 men, 43 women, AC: 31 men, 25 women). Following adjustment for age and BMI, no significant differences in visceral adipose tissue or liver fat were observed between SA and EUR individuals in the either cohort.ConclusionsOur data, consistent across two independent UK‐based cohorts, present a limited number of ethnic differences in the distribution of body fat depots associated with metabolic disease. These results suggest that the ethnic variation in susceptibility to features of the metabolic syndrome may not arise from differences in body fat.
|
|
| 5. |
- Anthony, Richard, et al.
(author)
-
A Middleware Approach to Dynamically Configurable Automotive Embedded Systems
- 2008
-
In: ISVCS 2008. - : EUDL - European Union Digital Library. - 9789639799271
-
Conference paper (peer-reviewed)abstract
- This paper presents an advanced dynamically configurable middleware for automotive embedded systems. The layered architecture of the middleware, and the way in which core and optional services provide transparency and flexible platform independent support for portability, is described. The design of the middleware is positioned with respect to the way it overcomes the specific technical, environmental, performance and safety challenges of the automotive domain. The use of policies to achieve flexible run-time configuration is explained with reference to the core policy technology which has been extended and adapted specifically for this project. The component model is described, focussing on how the configuration logic is distributed throughout the middleware and application components, by inserting ‘decision points’ wherever deferred logic or run-time context-sensitive configuration is required. Included in this discussion are the way in which context information is automatically provided to policies to inform context-aware behaviour; the dynamic wrapper mechanism which isolates policies, provides transparency to software developers and silently handles run-time errors arising during dynamic configuration operations.
|
|
| 6. |
- Brolies, Thomas W., et al.
(author)
-
Rosetta observations of solar wind interaction with the comet 67P/Churyumov-Gerasimenko
- 2015
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 583
-
Journal article (peer-reviewed)abstract
- Context. The Rosetta spacecraft arrived at the comet 67P/Churyumov-Gerasimenko on August 6, 2014, which has made it possible to perform the first study of the solar wind interacting with the coma of a weakly outgassing comet. Aims. It is shown that the solar wind experiences large deflections (>45°) in the weak coma. The average ion velocity slows from the mass loading of newborn cometary ions, which also slows the interplanetary magnetic field (IMF) relative to the solar wind ions and subsequently creates a Lorentz force in the frame of the solar wind. The Lorentz force in the solar wind frame accelerates ions in the opposite direction of cometary pickup ion flow, and is necessary to conserve momentum. Methods. Data from the Ion and Electron Sensor are studied over several intervals of interest when significant solar wind deflection was observed. The deflections for protons and for He++ were compared with the flow of cometary pickup ions using the instrument's frame of reference. We then fit the data with a three-dimensional Maxwellian, and rotated the flow vectors into the Comet Sun Equatorial coordinate system, and compared the flow to the spacecraft's position and to the local IMF conditions. Results. Our observations show that the solar wind may be deflected in excess of 45° from the anti-sunward direction. Furthermore, the deflections change direction on a variable timescale. Solar wind protons are consistently more deflected than the He++. The deflections are not ordered by the spacecraft's position relative to the comet, but large changes in deflection are related to changes in the orthogonal IMF components
|
|
| 7. |
- Ludwig Barbosa, Vinícius, 1990-
(author)
-
On the Ionospheric Influence on GNSS Radio Occultation Signals : Modelling and Assessment
- 2022
-
Doctoral thesis (other academic/artistic)abstract
- Radio Occultation (RO) is a well-established remote sensing technique that uses Global Navigation Satellite System (GNSS) signals to sound the Earth’s atmosphere. GNSS-RO measurements provide high-resolution, vertical profiles of physical parameters from the lower atmosphere (troposphere and stratosphere), e.g., refractivity, dry temperature, pressure, and water vapour, with primary application in weather forecasting and climatology models. The upper atmosphere (ionosphere) is also sounded during measurements, in which information about total electron content, electron density profiles, and scintillation indices compose the RO ionospheric data product.The ionosphere is a dispersive medium composed of ionized particles. It is extensively conditioned by Solar activity and shows seasonal, geographical, and day- and night-time variation. Despite the benefit of the upper atmospheric data, the ionosphere influences the retrievals in the lower atmosphere by (i) adding an inherent systematic bias in bending angles, i.e., residual ionospheric error (RIE), and (ii) disturbing the signal amplitude and phase, i.e., scintillation, in the presence of irregularities regions on the electron density along the ray path, e.g., equatorial plasma bubbles. In this dissertation, both aspects are investigated by modelling the equatorial ionosphere, and its small-scale irregularities in simulations of occultation events to (i) reproduce the effects observed in measurements and (ii) assess methods that can extract information about the ionosphere and support its monitoring and modelling.The multiple phase screen method was applied to model the GNSS signal propagation through quiet and disturbed ionospheric conditions. The small-scale irregularities in the F-region were modelled by a single slope power law to yield moderate to strong scintillation in the signals. Results were assessed according to the amplitude and phase scintillation indices, RIE, the standard deviation of the retrieved bending angles, and power spectral density (PSD). A subset of these parameters was taken as features to train a classifier based on the support vector machine algorithm. The purpose of this model was to detect RO measurements affected by ionospheric scintillation. Specifically, those in which PSD could provide further information about the irregularities according to the scintillation theory. Additionally, the back propagation (BP) method and its capability to estimate the mean distance between the receiver and irregularities were evaluated.Applying spectral analysis techniques to RO measurements may contribute to the characterization of small-scale irregularities in equatorial plasma bubbles. The results from simulations applying the single-slope power law to model the irregularities showed a good agreement with the selected cases. The automatic detection of occultations affected by ionospheric irregularities has achieved similar performance to models trained with ground-based measurements. Furthermore, the BP method can add the estimation of the mean location to the spectral analysis information. Such tools can enlarge the amount of ionospheric data retrieved -- especially for occultations with extended vertical range and when combined with other sounding techniques.
|
|
| 8. |
- Sandberg, Sara, et al.
(author)
-
Performance of LDPC coded spread OFDM with clipping
- 2005
-
In: Proceedings of the 8th International Symposium on Communication Theory and Applications. ; , s. 156-161
-
Conference paper (peer-reviewed)abstract
- We present the performance of OFDM systems with coding, spreading, and clipping. Low-Density Parity-Check (LDPC) codes give coding gains and spreading by the Walsh Hadamard transform gives gains in terms of increased frequency diversity as well as reduced peak-toaverage power ratio (PAPR) of the transmitted OFDM signal. By evaluating both the IFFT transform (OFDM) and the Walsh Hadamard transform in a single step, the number of operations needed for the spread OFDM system is actually less than for the conventional OFDM system. Reducing than for the conventional OFDM system. Reducing the PAPR is important in systems with clipping since it is related to the probability of clips. Each clip introduces clipping noise to the system which reduces the performance. Results of a clipped OFDM system with LDPC coding and spreading for an ETSI indoor wireless channel model are presented and compared with other systems. It is shown that there is a gain by spreading for LDPC coded OFDM systems, and especially for systems with clipping.
|
|
| 9. |
- Uysal, Elif, et al.
(author)
-
Semantic Communications in Networked Systems : A Data Significance Perspective
- 2022
-
In: IEEE Network. - : Institute of Electrical and Electronics Engineers (IEEE). - 0890-8044 .- 1558-156X. ; 36:4, s. 233-240
-
Journal article (peer-reviewed)abstract
- We present our vision for a departure from the established way of architecting and assessing communication networks, by incorporating the semantics of information, defined not necessarily as the meaning of the messages, but as their significance, possibly within a real-time constraint, relative to the purpose of the data exchange. We argue that research efforts must focus on laying the theoretical foundations of a redesign of the entire process of information generation, transmission, and usage for networked systems in unison by developing advanced semantic metrics for communications and control systems; an optimal sampling theory combining signal sparsity and timeliness, for real-time prediction/reconstruction/control under communication constraints and delays; temporally effective compressed sensing techniques for decision making and inference directly in the compressed domain; and semantic-aware data generation, channel coding, packetization, feedback, and multiple and random access schemes that reduce the volume of data and the energy consumption, increasing the number of supportable devices. This paradigm shift targets jointly optimal information gathering, information dissemination, and decision making policies in networked systems.
|
|
