Disjoint Dominating Sets with a Perfect Matching

In this paper, we consider dominating sets $D$ and $D'$ such that $D$ and $D'$ are disjoint and there exists a perfect matching between them. Let $DD_{\textrm{m}}(G)$ denote the cardinality of smallest such sets $D, D'$ in $G$ (provided they exist, otherwise $DD_{\textrm{m}}(G) = \infty$). This concept was introduced in [Klostermeyer et al., Theory and Application of Graphs, 2017] in the context of studying a certain graph protection problem. We characterize the trees $T$ for which $DD_{\textrm{m}}(T)$ equals a certain graph protection parameter and for which $DD_{\textrm{m}}(T) = \alpha(T)$, where $\alpha(G)$ is the independence number of $G$. We also further study this parameter in graph products, e.g., by giving bounds for grid graphs, and in graphs of small independence number

Theoretical advances on Economic Model Predictive Control with time-varying costs

© 2016 Published by Elsevier Ltd on behalf of International Federation of Automatic Control.Economic Model Predictive Control is a technique for optimization of economic revenues arising from controlled dynamical processes that has established itself as a variant of standard Tracking Model Predictive Control. It departs from the latter in that arbitrary cost functions are allowed in the formulation of the stage cost. This paper takes a further step in expanding the applicability of Economic Model Predictive Control by illustrating how the paradigm can be adapted in order to accommodate time-varying or parameter-varying costs

Outer structure of the Galactic warp and flare: explaining the Canis Major over-density

(Abridged) We derive the structure of the Galactic stellar Warp and Flare using 2MASS RC and RGB stars, selected at mean heliocentric distances of 3, 7 and 17 kpc. Our results are: (i) a clear stellar warp signature is derived for the 3 selected rings; (ii) the derived stellar warp is consistent (both in amplitude and phase-angle) with that for the Galactic interstellar dust and HI gas; (iii) the Sun seems not to fall on the line of nodes. The stellar warp phase-angle orientation (+15 degrees) is close to the orientation angle of the Galactic bar and this produces an asymmetric warp for the inner rings; (iv) a Northern/Southern warp symmetry is observed only for the ring at 17 kpc; (v) treating a mixture of thin and thick disk populations we trace the disk flaring and derive a constant scale-height (~0.65 kpc) within R(GC)~15 kpc. Further out, the disk flaring increase gradually reaching a mean scale-height of ~1.5 kpc at R(GC)~23 kpc; and (vi) these results provide further robust evidence that there is no disk radial truncation at R(GC)~14 kpc. In the particular case of the Canis Major over-density we confirm its coincidence with the Southern stellar maximum warp occurring near l=240. We present evidence to conclude that all observed parameters (e.g. number density, radial velocities, proper motion etc) of CMa are consistent with it being a normal Milky Way outer-disk population, thereby leaving no justification for a more complex interpretations of its origin. The present analysis does not provide a conclusive test of the structure or origin of the Monoceros Ring. Nevertheless, we show that a warped flared Milky Way contributes significantly at the locations of the Monoceros Ring.Comment: 25 pages, 22 figures, accepted for publication in A&A. A higher resolution pdf file is available at http://wwwuser.oat.ts.astro.it/zaggia/public_html/warp

Structural properties of a calcium aluminosilicate glass from molecular-dynamics simulations: A finite size effects study

We study a calcium aluminosilicate glass of composition (SiO$_2$)$_{0.67}$-(Al$_2$O$_3$)$_{0.12}$-(CaO)$_{0.21}$ by means of molecular-dynamics (MD) simulations, using a potential made of two-body and three-body interactions. In order to prepare small samples that can subsequently be studied by first-principles, the finite size effects on the liquid dynamics and on the glass structural properties are investigated. We find that finite size effects affect the Si-O-Si and Si-O-Al angular distributions, the first peaks of the Si-O, Al-O and Ca-O pair correlation functions, the Ca coordination and the oxygen atoms environment in the smallest system (100 atoms). We give evidence that these finite size effects can be directly attributed to the use of three-body interactions.Comment: 36 pages, 14 figures. Journal of Chem. Phys., in pres

A charred body inside a burning car with a garden hose connected to the exhaust pipe: Post-mortem self-immolation, a complex or a complicated suicide after the ingestion of alcohol? The importance of an interdisciplinary approach

The analysis of charred bodies represents a serious challenge for forensic pathologists, and an interdisciplinary approach is often the only way to determine the cause and manner of death. We present an unusual case in which the charred body of a 61-year-old man was found inside his burning vehicle. In order to determine cause and manner of death, an interdisciplinary team was employed, with experts in forensic pathology, forensic radiology, toxicology and fire investigations. Post-mortem computed tomography, autopsy and toxicology ruled out the presence of trauma injury and detected signs of vital exposure to fire and blood alcohol levels. On the other hand, according to fire investigations, the fire started inside the car and partially burned fragments of a garden hose were found along the right side of the car. A suicide could therefore be hypothesized, with the man having attempted to poison himself with the car's exhaust fumes and having set the car on fire. The death was consistent with a complicated suicide in which the victim, in a state of reduced capability, accidentally set his car on fire and was unable to escape. The hypothesis of a complex suicide, with the car having been set deliberately on fire, could not, however, be ruled out

Socio-cultural sustainability of private healthcare providers in an Indian slum setting: A bottom-of-the-pyramid perspective

Delivery of affordable healthcare services to communities is a necessary precondition to poverty alleviation. Co-creation approaches to the development of business models in the healthcare industry proved particularly suitable for improving the health-seeking behavior of BOP patients. However, scant research was conducted to understand BOP consumers’ decision-making process leading to specific healthcare choices in slum settings, and the relative balance of socio-cultural and socio-economic factors underpinning patients’ preferences. This article adopts a mixed-method approach to investigate the determinants of BOP patients’ choice between private and public hospitals. Quantitative analysis of a database, composed of 436 patients from five hospitals in Ahmedabad, India, indicates that BOP patients visit a public hospital significantly more than top-of-the-pyramid (TOP) patients. However, no significant difference emerges between BOP and TOP patients for inpatient or outpatient treatments. Qualitative findings based on 21 interviews with BOP consumers from selected slum areas led to the development of a grounded theory model, which highlights the role of aspirational demand of BOP patients toward private healthcare providers. Overall, healthcare provider choice emerges as the outcome of a collective socio-cultural decision-making process, which often assigns preference for private healthcare services because of the higher perceived quality of private providers, while downplaying affordability concerns. Implications for healthcare providers, social entrepreneurs, and policy-makers are discussed

Scale-up studies for intensified production of biodiesel from used cooking oil

In this paper the effect of channel size on the transesterification of used cooking oil (UCO) with methanol using KOH as catalyst to produce biodiesel was investigated for capillaries with internal diameter ranging from 1 to 3 mm. A T-junction was used as the mixing zone of the two liquid phases. The effects of different parameters such as, internal diameter, methanol-to-oil molar ratio, reaction time, temperature, and catalyst concentration were investigated. Results showed that the conversion efficiency to biodiesel is increased by decreasing the channel size, whilst the interactions of the other variables are also discussed

Application of acoustic techniques to fluid-particle systems – A review

Acoustic methods applied to opaque systems have attracted the attention of researchers in fluid mechanics. In particular, owing to their ability to characterise in real-time, non-transparent and highly concentrated fluid-particle systems, they have been applied to the study of complex multiphase flows such as fluidised beds. This paper gives an overview of the physical principles and typical challenges of ultrasound and acoustic emission AE methods when applied to fluid-particle systems. The principles of ultrasound imaging are explained first. The measurement techniques and signal processing methodologies for obtaining velocity profiles, size distribution of the dispersed phases, and solid volume fraction are then discussed. The techniques are based on the measurement of attenuation, sound speed, frequency shift, and transit time of the propagated sound wave. A description of the acoustic emission technique and applications to fluid-particle systems are then discussed. Finally, extensions and future opportunities of the acoustic techniques are presented