Lagrangian and Hamiltonian two-scale reduction

Studying high-dimensional Hamiltonian systems with microstructure, it is an important and challenging problem to identify reduced macroscopic models that describe some effective dynamics on large spatial and temporal scales. This paper concerns the question how reasonable macroscopic Lagrangian and Hamiltonian structures can by derived from the microscopic system. In the first part we develop a general approach to this problem by considering non-canonical Hamiltonian structures on the tangent bundle. This approach can be applied to all Hamiltonian lattices (or Hamiltonian PDEs) and involves three building blocks: (i) the embedding of the microscopic system, (ii) an invertible two-scale transformation that encodes the underlying scaling of space and time, (iii) an elementary model reduction that is based on a Principle of Consistent Expansions. In the second part we exemplify the reduction approach and derive various reduced PDE models for the atomic chain. The reduced equations are either related to long wave-length motion or describe the macroscopic modulation of an oscillatory microstructure.Comment: 40 page

Improving instrument recognition in polyphonic music through system integration

A method is proposed for instrument recognition in polyphonic music which combines two independent detector systems. A polyphonic musical instrument recognition system using a missing feature approach and an automatic music transcription system based on shift invariant probabilistic latent component analysis that includes instrument assignment. We propose a method to integrate the two systems by fusing the instrument contributions estimated by the first system onto the transcription system in the form of Dirichlet priors. Both systems, as well as the integrated system are evaluated using a dataset of continuous polyphonic music recordings. Detailed results that highlight a clear improvement in the performance of the integrated system are reported for different training conditions

Boundary effects on the dynamics of chains of coupled oscillators

We study the dynamics of a chain of coupled particles subjected to a restoring force (Klein-Gordon lattice) in the cases of either periodic or Dirichlet boundary conditions. Precisely, we prove that, when the initial data are of small amplitude and have long wavelength, the main part of the solution is interpolated by a solution of the nonlinear Schr\"odinger equation, which in turn has the property that its Fourier coefficients decay exponentially. The first order correction to the solution has Fourier coefficients that decay exponentially in the periodic case, but only as a power in the Dirichlet case. In particular our result allows one to explain the numerical computations of the paper \cite{BMP07}

Unified radio and network control across heterogeneous hardware platforms

Experimentation is an important step in the investigation of techniques for handling spectrum scarcity or the development of new waveforms in future wireless networks. However, it is impractical and not cost effective to construct custom platforms for each future network scenario to be investigated. This problem is addressed by defining Unified Programming Interfaces that allow common access to several platforms for experimentation-based prototyping, research, and development purposes. The design of these interfaces is driven by a diverse set of scenarios that capture the functionality relevant to future network implementations while trying to keep them as generic as possible. Herein, the definition of this set of scenarios is presented as well as the architecture for supporting experimentation-based wireless research over multiple hardware platforms. The proposed architecture for experimentation incorporates both local and global unified interfaces to control any aspect of a wireless system while being completely agnostic to the actual technology incorporated. Control is feasible from the low-level features of individual radios to the entire network stack, including hierarchical control combinations. A testbed to enable the use of the above architecture is utilized that uses a backbone network in order to be able to extract measurements and observe the overall behaviour of the system under test without imposing further communication overhead to the actual experiment. Based on the aforementioned architecture, a system is proposed that is able to support the advancement of intelligent techniques for future networks through experimentation while decoupling promising algorithms and techniques from the capabilities of a specific hardware platform

A unified radio control architecture for prototyping adaptive wireless protocols

Experimental optimization of wireless protocols and validation of novel solutions is often problematic, due to limited configuration space present in commercial wireless interfaces as well as complexity of monolithic driver implementation on SDR-based experimentation platforms. To overcome these limitations a novel software architecture is proposed, called WiSHFUL, devised to allow: i) maximal exploitation of radio functionalities available in current radio chips, and ii) clean separation between the logic for optimizing the radio protocols (i.e. radio control) and the definition of these protocols

Correction : Assessing dimerisation degree and cooperativity in a biomimetic small-molecule model by pulsed EPR

Correction for ‘Assessing dimerisation degree and cooperativity in a biomimetic small-molecule model by pulsed EPR’ by K. Ackermann et al., Chem. Commun., 2015, 51, 5257–5260.Publisher PDFPeer reviewe

Immediate vs non-immediate loading post-extractive implants: A comparative study of Implant Stability Quotient (ISQ)

Purpose. This study aims to evaluate differences in implant stability between post-extractive implants vs immediately placed post-extractive implants by resonance frequency analysis (RFA). Materials and methods. Patients were grouped into two different categories. In Group A 10 patients had an immediate postextractive implant, then a provisional, acrylic resin crown was placed (immediate loading). In Group B (control group) 10 patients only had an immediate post-extractive implant. Both upper and lower premolars were chosen as post-extractive sites. Implant Stability Quotient (ISQ) was measured thanks to RFA measurements (Osstell®). Five intervals were considered: immediately after surgery (T0) and every four weeks, until five months after implant placement (T1, T2, T3, T4,T5). A statistical analysis by means of Student’s T-test (significance set at p<0.05) for independent sample was carried out in order to compare Groups A and B. Results. The ISQ value between the two groups showed a statistically significant difference (p<0.02) at T1. No statistically significant difference in ISQ was assessed at T0, T2, T3, T4 and T5. Conclusions. After clinical assessment it is possible to confirm that provisional and immediate prosthetic surgery in postextraction sites with cone-shaped implants, platform-switching abutment and bioactive surface can facilitate osseointegration, reducing healing time

Sorghum dry biomass yield for solid bio-fuel production affected by different N-fertilization rates

The objective of this study was to examine the effect on the dry biomass yield of two dfferent sorghum hybrids (H1 and H2) under five different N-fertilization levels (0, 70, 140, 210 and 280 kg ha-1 ) in a soil which was formed by lacustrine deposits of Karla Lake and is characterized from the downward movement of calcium carbonate from the surface horizons due to leaching (Fluventic Xerochrept) during 2017. The results demonstrated a significant effect (P < 0.05) of fertilization only for one hybrid. Biomass yield ranged from 22.2 to 37.5 t ha−1. For both hybrids, sorghum accumulated a high amount of biomass in stems. Dry stem/total biomass ratio was rather constant throughout the different fertilization treatments achieving 81.6 and 77.5% for the first (H1) and the second hybrid (H2), respectively. The second hybrid (H2) had a higher percentage of leaf biomass (20.1 vs. 13.8%) than the first (H1), but lagged behind in seed production (2.4 vs. 4.6%). Biomass dry matter partitioning and total dry weight are important selection criteria for energy crops, due to different gross calorific value and ash content but also because of the different economic importance they may have e.g. the seed is also used as animal feed. The above high biomass yields of sorghum, confirming the high potential of this crop, should be taken into serious consideration regarding land use planning, but further investigation for the gross calorific value and the ash content is needed as well as biomass characteristics that are quite important in case to improve the combustion process

Subacute dislocation of the elbow following Galeazzi fracture-dislocation of the radius: A case report

<p>Abstract</p> <p>Introduction</p> <p>The Galeazzi fracture-dislocation was originally described by Sir Astley Cooper in 1822 but was named after Italian surgeon Ricardo Galeazzi in 1934. It is an injury classified as a radial shaft fracture with associated dislocation of the distal radioulnar joint and disruption of the forearm axis joint. The associated distal radioulnar joint injury may be purely ligamentous in nature, tearing the triangular fibrocartilaginous complex, or involve bony tissue (that is, ulnar styloid avulsions) or both. We report this case because of the rare association of posterior dislocation of the elbow along with Galeazzi fracture-dislocation. To the best of our knowledge, this has not been previously reported in the English literature.</p> <p>Case presentation</p> <p>A 26-year-old Caucasian man presented to our department after a fall from a motorbike. He sustained a closed, isolated Galeazzi fracture-dislocation of the right forearm and no associated elbow injuries, and this necessitated open reduction and internal fixation of the radius. Post-operative radiographs films were satisfactory. However, clinical and radiological evidence of ipsilateral elbow dislocation was noted at a five-week follow-up, subsequently requiring open reduction of the joint and collateral ligament repair. Our patient was noted to have full elbow and forearm function at three months.</p> <p>Conclusions</p> <p>Although the Galeazzi fracture-dislocation has been classically described as involving only the distal radioulnar joint, traumatic forces can be transmitted to the elbow via the interosseous membrane of the forearm. This can lead to instability of the elbow joint. Therefore, we recommend that, in every case of forearm fracture, both elbow and wrist joints be assessed clinically as well as radiologically for subluxation or dislocation.</p