Multi-body model of a bobsleigh: comparison with experimental data

Bobsleigh is a winter sport in which teams make timed runs down narrow, twisting, banked, iced tracks in gravity-powered sleds. To win the race, it is of great importance to have a sled that is optimized from both the sliding and the aerodynamic point of view. However, also typical vehicle parameters, such as the weight distribution and the inclination of the steering axis, play an important role. In fact, being the friction coefficient between skates and ice very small (approx. 0.04), a change in the weight acting on the front skates may significantly modify the steering feedback of the driver thus highlighting his/her driving ability. Better trajectories imply less correction on the steering axis, and thus better performances. The inclination of the steering axis, instead, generates a torque similar to the self-aligning torque produced by road vehicle tires thus stabilizing the front skates and requiring less control actions to the sled driver.     

Computer-aided engineering for sheet metal forming: definition of a springback quality function

Computer-aided engineering methods are extensively applied to sheet metal forming integrated design. The adoption of a new class of materials, the advanced high strength steels, has increased the occurrence of springback, and consequently the request for tools oriented to springback reduction and optimization. This paper presents an approximated formulation to compute the springback field after stamping through the finite element analysis of the process. This can be found assuming that the residual field of nodal forces after stamping produces a springback shape referable to a linear combination of n modes of vibration of the nominal shape of the component. The aim of this formulation is not that of substituting the finite element analysis of the springback but rather to make use of the coefficients of the linear combination, so to define a global quality function for springback. In this way, Robust Design methods or other current optimization procedures to improve the stamping process as for structural defects (such wrinkling, necking and flatness) can be applied also for the reduction of springback. The meaning of these coefficients will be shown through three test cases and the consistency of the formulation will be discussed according to the number of modes of vibration included in the computation.     

An entropy approach to disclosure risk assessment: Lessons from real applications and simulated domains

We live in an increasingly mobile world, which leads to the duplication of information across domains. Though organizations attempt to obscure the identities of their constituents when sharing information for worthwhile purposes, such as basic research, the uncoordinated nature of such environment can lead to privacy vulnerabilities. For instance, disparate healthcare providers can collect information on the same patient. Federal policy requires that such providers share “de-identified” sensitive data, such as biomedical (e.g., clinical and genomic) records. But at the same time, such providers can share identified information, devoid of sensitive biomedical data, for administrative functions. On a provider-by-provider basis, the biomedical and identified records appear unrelated, however, links can be established when multiple providers' databases are studied jointly. The problem, known as trail disclosure, is a generalized phenomenon and occurs because an individual's location access pattern can be matched across the shared databases. Due to technical and legal constraints, it is often difficult to coordinate between providers and thus it is critical to assess the disclosure risk in distributed environments, so that we can develop techniques to mitigate such risks. Research on privacy protection has so far focused on developing technologies to suppress or encrypt identifiers associated with sensitive information. There is a growing body of work on the formal assessment of the disclosure risk of database entries in publicly shared databases, but less attention has been paid to the distributed setting. In this research, we review the trail disclosure problem in several domains with known vulnerabilities and show that disclosure risk is influenced by the distribution of how people visit service providers. Based on empirical evidence, we propose an entropy metric for assessing such risk in shared databases prior to their release. This metric assesses risk by leveraging the statistical characteristics of a visit distribution, as opposed to person-level data. It is computationally efficient and superior to existing risk assessment methods, which rely on ad hoc assessment that are often computationally expensive and unreliable. We evaluate our approach on a range of location access patterns in simulated environments. Our results demonstrate that the approach is effective at estimating trail disclosure risks and the amount of self-information contained in a distributed system is one of the main driving factors.     

The chemistry of silica-supported chromium ions: Calorimetric and spectroscopic study of nitric oxide adsorption

At the surface of CO-reduced, low-loaded (0.5% by weight) chromia/silica samples, four kinds of divalent Cr ions are present. All react with NO eventually yielding linear dinitrosyl species. Differences are found as to the energetic and kinetic behaviour. The most exposed ions (A and B) readily form dinitrosyls, with NO infrared stretching vibrations at 1747–1865 and 1755–1880 cm^?1, respectively. Less reactive Cr ions (designated C1 and C2) form at low coverage stable mononitrosyls (NO stretch at 1810–1815 cm^?1), which change at high NO pressure into A and B dinitrosyls (C1 ions) or to new dinitrosyls (C2 ions: NO stretches at 1765–1987 cm^?1). The different behaviour is explained assuming that A, B, and C ions are, before reaction, respectively 2-, 3-, and 4-coordinate to the surface.     

Detection of <Emphasis Type="Italic">Trichinella</Emphasis> Larvae in Meat: Comparison of ISO 18743:2015 with Regulation (EU) 2015/1375

Trichinellosis is a foodborne parasitic zoonosis, caused by nematodes within the genus Trichinella. Pigs and wild animals are known sources of Trichinella infections for humans. The Commission Regulation 2075/2005 of the European Union (EU) established that all Trichinella spp. susceptible animals, which are suitable for human consumption, must be tested for these parasites using approved methodologies. Recently, the ISO 18743:2015 Standard on the detection of Trichinella larvae in animals was published. The purpose of this paper was to compare the method described in the ISO Standard with the reference method established in the Commission Regulation of the EU. The comparison was made by setting each clause of the standard versus the corresponding step of the Regulation. The artificial digestion of pooled muscle samples was recognized by both documents as the main reference method and the procedures described were very similar. The ISO Standard provides the basic principles and properties of the essential steps of the method and highlights the Critical Control Points (CCPs) of the procedure, which can affect the performance of the method, providing detailed instructions aimed at inexperienced analysts. The respective roles of the Standard and of the Regulation are also clarified. International standards are developed to provide agreed upon specifications relating to particular matters, while legislation sets mandatory requirements established by public authorities. Thus, European laboratories officially appointed for the detection of Trichinella in meat are required to apply the methods described in the Regulation, but may also rely on the ISO Standard for detailed steps and CCPs.     

A quantum-implementable neural network model

A quantum-implementable neural network, namely quantum probability neural network (QPNN) model, is proposed in this paper. QPNN can use quantum parallelism to trace all possible network states to improve the result. Due to its unique quantum nature, this model is robust to several quantum noises under certain conditions, which can be efficiently implemented by the qubus quantum computer. Another advantage is that QPNN can be used as memory to retrieve the most relevant data and even to generate new data. The MATLAB experimental results of Iris data classification and MNIST handwriting recognition show that much less neuron resources are required in QPNN to obtain a good result than the classical feedforward neural network. The proposed QPNN model indicates that quantum effects are useful for real-life classification tasks.     

Scientific models and ethical issues in hybrid bionic systems research

Research on hybrid bionic systems (HBSs) is still in its infancy but promising results have already been achieved in laboratories. Experiments on humans and animals show that artificial devices can be controlled by neural signals. These results suggest that HBS technologies can be employed to restore sensorimotor functionalities in disabled and elderly people. At the same time, HBS research raises ethical concerns related to possible exogenous and endogenous limitations to human autonomy and freedom. The analysis of these concerns requires reflecting on the availability of scientific models accounting for key aspects of sensorimotor coordination and plastic adaptation mechanisms in the brain.

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Volatility spillovers, interdependence and comovements: A Markov Switching approach

The transmission mechanisms of volatility between markets can be characterized within a new Markov Switching bivariate model where the state of one variable feeds into the transition probability of the state of the other. A number of model restrictions and hypotheses can be tested to stress the role of one market relative to another (spillover, interdependence, comovement, independence, Granger noncausality). The model is estimated on the weekly high-low range of five Asian markets, assuming a central (but not necessarily dominant) role for Hong Kong. The results show plausible market characterizations over the long run with a spillover from Hong Kong to Korea and Thailand, interdependence with Malaysia and comovement with Singapore.     

A dynamically reconfigurable stereoscopic/panoramic vision mobile robot head controlled from a virtual environment

We have built a mobile robotic platform that features an Active Robotic Head (ARH) with two high-resolution cameras that can be switched during robot operation between two configurations that produce respectively panoramic and stereoscopic images. Image disparity is used for improving the quality of the texture. The robot head switches dynamically, based on robot operation between the stereoscopic configuration and the panoramic configuration.