3,133 research outputs found
Antenna technology for advanced mobile communication systems
The onboard antenna front end is the key subsystem conditioning configuration and performance of mobile communication satellites. The objectives of this paper are to demonstrate this key role and to review L-band satellite antenna technology for earth coverage and regional applications. Multibeam arrays are first discussed, then unfurlable and inflatable reflector antennas are described. These technologies are now qualified in Europe for future mobile systems, for which the optimum choice of antenna technology has been found to be the key to efficient use of spectrum and power resources
Evidence for an endogenous rebound effect impacting long-run car use elasticity to fuel price
This paper presents a structural equation model of household fleet fuel efficiency and car use. It allows to weigh the contribution of car equipment changes and car use adjustments to the price elasticity of household demand for fuel. This model is implemented using a panel dataset of 322 households that were present in each annual wave of the French Car Fleet survey from 1999 to 2007. The longitudinal dimension of this dataset enables to assess the short and long-run adjustments at the household level over a period of fuel price increase. The estimated price elasticities of the demand for fuel are fully consistent with the literature: -0.30 in the short run and -0.76 in the long run. Regarding car use elasticities, accounting for an endogenous rebound effect allowed a striking finding: the sensitivity of household car use to fuel price changes is lower on the long run than on the short run. This paper thus not only provides the latest estimations of elasticities for France, in the early 2000's, it also shows that, on the long run, French households have managed to mitigate the impact of increasing fuel prices on their car mobility by using more fuel efficient cars.Elasticity, Fuel Price, Rebound effect, Energy consumption, Energy efficiency, Car use, Household, Panel data
Industrial manufacture of sugar-free chocolates: applicability of alternative sweeteners and carbohydrate polymers as raw materials in product development
Chocolate is dense suspension of solid particles comprising 60-70% sugar and non-fat cocoa solids. Until recently, it was rarely produced as a sugar-free product due to the multi-functional properties of sweetness, bulkiness and textural characteristics that sugar offers to products. Today's consumers are concerned about the high sugar levels, calories and cariogenicity effects in confectionery products, hence increasing popularity of 'light' and 'sugar-free' products. Development of sugar-free chocolates is most challenging since all sugar needs to be replaced. In-depth understanding of the applicability of alternative sweeteners and carbohydrate polymers as ingredients in sugar-free chocolate manufacture would therefore have significant industrial applications
Numerical study of the impact of land use modification on local rainfall over Manila, A
Includes bibliographical references
An Implementation of The Method of Moments on Chemical Systems with Constant and Time-dependent Rates
Among numerical techniques used to facilitate the analysis of biochemical reactions, we can use the method of moments to directly approximate statistics such as the mean numbers of molecules. The method is computationally viable in time and memory, compared to solving the chemical master equation (CME) which is notoriously expensive. In this study, we apply the method of moments to a chemical system with a constant rate representing a vascular endothelial growth factor (VEGF) model, as well as another system with time-dependent propensities representing the susceptible, infected, and recovered (SIR) model with periodic contact rate. We assess the accuracy of the method using comparisons with approximations obtained by the stochastic simulation algorithm (SSA) and the chemical Langevin equation (CLE). The VEGF model is of interest because of the role of VEGF in the growth of cancer and other inflammatory diseases and the potential use of anti-VEGF therapies in the treatment of cancer. The SIR model is a popular epidemiological model used in studying the spread of various infectious diseases in a population
Seawater Dielectric Measurements at L-Band with Latest Improvements
Recently, the dielectric constant of seawater at L-band was determined by employing a resonant cavity technique. A dielectric model function has been developed based on the measurement data and the model function has been used for retrieving the ocean salinity. The results indicate that additional accuracy is still needed to resolve the bias correlated with sea surface temperature. This paper reports the improvements that have been made recently for the development of a more accurate seawater dielectric model function. The additional measurements for the open ocean will be addressed in the paper
Sequential simulation used as a novel educational tool aimed at healthcare managers: a patient-centred approach
Background:
A new challenge for healthcare managers is to improve the patient experience. Simulation is often used for clinical assessment and rarely for those operating outside of direct clinical care. Sequential simulation (SqS) is a form of simulation that re-creates care pathways, widening its potential use.
Local problem Numbers, outcome measures and system profiling are used to inform healthcare decisions. However, none of these captures the personal subtleties of a patient’s experience.
Intervention 56 students attended a teaching module using SqS and facilitated workshops as part of their induction week on an MSc International Health Management course. The workshop was voluntary and was offered as an opportunity for the students to gain an insight into the UK health system through the medium of simulation.
Methods:
An evaluation survey incorporating quantitative and qualitative student feedback was conducted. Descriptive statistics were generated from the quantitative data, and thematic analysis was undertaken for the qualitative data.
Results:
There was strong agreement for the acceptability of the workshop approach in relation to the aims and objectives. Likert scale (1–-5) mean total=4.49. Participants responded enthusiastically (revealed through the qualitative data) with ideas related to perspectives sharing, understanding healthcare management and processes and the consideration of feasibility and practicalities. They also suggested other applications that SqS could be used for.
Conclusion:
The SqS approach has demonstrated that simulation has a wider potential than for clinical assessment alone. Further studies are required to determine its potential uses and affordances beyond its current format
Lightweight Real-time Detection of Components via a Micro Aerial Vehicle with Domain Randomization Towards Structural Health Monitoring
Civil structural component detection plays an integral role in Structural Health Monitoring (SHM) pre and post-construction. Challenges including but not limited to labor-intensiveness, cost, and time constraints associated with traditional methods make it a less opti-mal approach in SHM. Despite the success of deep convolutional neural networks in diverse detection problems, the required computational resources are a challenge. This has led to rendering a chunk of resource-constrained edge nodes less applicable with deep convolutional neural networks. In this paper, a computational-efficient deep convolutional neural network is presented based on Gabor filters and a color Canny edge detector. Generic Gabor filters are generated and used as initializers in the computational-efficient deep convolutional neural network presented, afterward trained on building components data. Next, extensive offline and online experimentation with a resource-constrained edge node is conducted and evaluated using diverse metrics. The computational-efficient detection model demonstrates to be effective in detection and via NVIDIA GPU profiler, we observe conservation of around 30% of computational resources during training. The computational-efficient detection model adduces almost a 3% mean average precision higher than two state-of-the-art detectors and records a promising frame processing rate during the online experimentation
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