Tunneling rate fluctuations induced by non-linear resonances: a quantitative treatment based on semiclassical arguments

We investigate the tunneling process between two symmetric stable islands of a forced pendulum Hamiltonian in the weak chaos regime. We show that when the tunneling doublet is quantized over a classical non-linear resonance the tunneling rate strongly deviates from the semiclassical prediction. This mechanism is responsible for the irregular dependence of the tunneling rate on the system parameters. The weak-chaos condition allows us to make a theoretical prediction which agrees very well with the numerical results. This opens up a possible avenue to a general theory on the dependence of quantum tunneling on classical chaos.Comment: 4 pages, 2 figure

Embedded solutions for a class of highly unstable, underactuated and self-balancing robotic systems

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an embedded database technology perspective in cyber physical production systems

Abstract The goal of the paper is the proposition of an enabling technology for the control and optimization of cyber-physical production systems, oriented to the lightweight implementation of performance metrics methodology in a network of distributed devices. The database-centric perspective, applied to distributed devices, supports the adoption of well-known key performance metrics for viable lightweight control policies and optimization of complex scenarios in the factory of the future. An experiment of the technique on a real case data set is presented and analyzed

Financial wealth in the financial accounts and in the Survey of Household Income and Wealth

The Survey on Household Income and Wealth, conducted every two years by the Bank of Italy, and the Italian Financial Accounts, published quarterly, provide information on the wealth of Italian households which are independent and, for the time being, not directly comparable. In this paper we perform a detailed comparison of the estimates of the householdsÂ’ various financial assets and liabilities coming from the two sources, identifying the causes responsible for the observed discrepancies. In general, the outstanding amounts reported in the Financial Accounts are significally larger than those arising from the Survey. Reconciling the data in terms of classification criteria and of valuation methods reduces the differences only to a small extent. Once the variability due to sampling and measurement errors is taken into account, the discrepancies are mainly caused by under-reporting on the survey results; the bias from non-response is less important. As a by-product of the analysis, suggestions for some methodological improvements to both the Survey and the Financial Accounts do also arise, possilby from the joint use of the two sources.Household Wealth, Financial Accounts, sample surveys.

modeling and simulation of the motorcycle s lowside fall

Abstract The deployment of active safety systems enhancing the motorcycle stability and supporting riders in defusing critical and dangerous driving situations is a topic of major concern in the two-wheel research community. In the design and development of safety control systems, setting up an adequate model of the controlled system is a key issue since it should be able to describe adequately the motion of the vehicle in critical situations such as precarious adherence, cornering brake and acceleration, or dangerous falls. In literature, these situations are typically investigated by means of black box approaches, namely by using multibody numerical simulators in which the equations governing the vehicle dynamics are unknown. In this paper, instead, the authors propose an analytical model as alternative to black box approach for the simulation of critical and complex motorcycle's dynamics leading to falls. The model has been presented in author's earlier works, it has a minimum degree of complexity, considers the rear wheel traction/braking and takes into account the interactions between longitudinal and lateral friction forces acting on the tyres. This analytical model has allowed to investigate the lowside phenomenon and the simulation results will be presented

An OSGi-based production process monitoring system for SMEs

The present paper proposes an architecture for a product process monitoring system suitable for SMEs (Small-Medium Enterprises). The monitoring system is the main means by which decision-making systems based on intelligent automation technologies are aware of the state of the system on which they will take decisions. Methods and tools from best-practice and best-effort approaches are proposed in the context of SMEs, where the requirements of low cost, low initial level of digitisation and high production flexibility often coexist and contribute to the complexity of management and control problems in these companies. The paper focuses on the design of the monitoring system using an OSGi framework to meet industry standards and Industry 4.0 requirements, taking into account the peculiarities of SMEs as design constraints. The proposed architecture was first tested using a simulation tool and then implemented on a full-scale production line used for data collection

Execution Time of Optimal Controls in Hard Real Time, a Minimal Execution Time Solution for Nonlinear SDRE

Many engineering fields, such as automotive, aerospace, and the emerging challenges towards industry 4.0, have to deal with Real-Time (RT) or Hard Real Time (HRT) systems, where temporal constraints must be fulfilled, to avoid critical behaviours or unacceptable system failures. For this reason, estimation of code's Worst-Case Execution Time (WCET) has received lots attention because in RT systems a fundamental requirement is to guarantee at least a temporal upper bound of the code execution for avoiding any drawbacks. However, until now there is no approved method to compute extremely tight WCET. Nowadays, indeed, HRT requirements are solved via hardware, using multi-cores embedded boards that allow the computation of the deterministic Execution Time (ET). The availability of these embedded architectures has encouraged the designers to look towards more computationally demanding optimal control techniques for RT scenarios, and to compare and analyze performances also evaluating a tight WCET. However, this area still lacks deep investigations. This paper has the intent of analysing results regarding the choice between three of the most established optimal controls (LQR, MPC, SDRE), providing the first link between WCET analysis and control algorithms performances. Moreover, this work shows how it is also possible to obtain a minimal ET solution for the nonlinear SDRE controller. The results might be useful for future implementations and for coping with Industry 4.0 emerging challenges. Furthermore, this approach can be useful in control system engineering field, especially in the design stage for RT or HRT systems, where temporal bounds have to be fulfilled jointly with all the other application's specifications

Skeletal status in children and adolescents with new-onset type 1 diabetes: a preliminary study based on bone densitometry and quantitative ultrasound

Type 1 diabetes (T1D) represents a risk factor for bone loss and impaired bone quality

The Markov approximation revisited: Inconsistency of the standard quantum Brownian motion model

We revisit the Markov approximation necessary to derive ordinary Brownian motion from a model widely adopted in literature for this specific purpose. We show that this leads to internal inconsistencies, thereby implying that further search for a more satisfactory model is required.Comment: 15 page

Pliocene Diatom Biomarkers in Sabrina Coast. EAIS Continental Marginal Dynamics

PNRA Tytan project, supported by the National Institute of Oceanography and Applied Geophysics (OGS), focused on the advances and retreats dynamics of the ice sheet and on variations in the glacial regime. Unit 2 focused on Diatom biomarkers and assemblages analysis on sediments of core PC03, collected during the IN2017-V01 cruise on the eastern flank of the Minang-a (or Whale) submarine Canyon. The project aims at reconstructing the depositional environment of the continental margin off the Totten Glacier and diatom data remained a key tools to constrain past ice-sheet dynamics and to forecasting future behaviour in a warming world. Preliminary dataset from diatom biostratigraphic tools allows to refer the base of the core to Pliocene while the upper part of the core records more modern EAIS dynamics, indicative of minor sedimentary evolution steps of the continental margin. Diatom assemblage analyses highlight Eocene-Oligocene reworked material and freshwater diatom inputs in Pliocene sequence, strengthening the debate about ice-sheet and paleoceanographic models, WAIS cyclic collapse and suspected Pliocene EAIS retreat into major subglacial Antarctic basins