135,088 research outputs found
Noncommutative Fourier transform for the Lorentz group via the Duflo map
No full textWe defined a non-commutative algebra representation for quantum systems whose phase space is the cotangent bundle of the Lorentz group, and the non-commutative Fourier transform ensuring the unitary equivalence with the standard group representation. Our construction is from first principles in the sense that all structures are derived from the choice of quantization map for the classical system, the Duflo quantization map
Poesie di autori parmigiani per la felicissima venuta in Parma Dell' Altezza Reale ... D. Carlo.
No full textSign.: []\p1\s, *\p4\s, A-C\p8\s, c\p8\s, D-E\p8\s, F\p3\sSign.: []1, *4, A-C8, c8, D8, E8, F
Static and Dynamic Identification of the Mitsubishi RV-5AS-D-S01 Robot
No full textAccurate identification plays a pivotal role in establishing a finely tuned dynamic model for a manipulator, particularly when manufacturers provide limited data. In sophisticated robotics applications, such as minimum time and minimum energy problems, or executing impact-aware tasks, a precise dynamic model becomes essential for designing feasible movements. This paper focuses on the development of an identification procedure of the collaborative robot Mitsubishi RV-5AS-D-S01, together with some preliminary experimental data
REGULARIZED DYNAMIC PARAMETER IDENTIFICATION FOR THE MITSUBISHI RV-5AS-D-S01 ROBOT
No full textThe use of accurate dynamic models plays a role of paramount importance in the development of efficient and accurate robotic applications. Model-based techniques are at the heart of the development of advanced control strategies, and are extremely useful for planning time-efficient or energy efficient tasks, or to control the interaction with humans in a collaborative framework. The availability of accurate dynamic models for industrial robots is however often limited due to the fact that manufacturers rarely disclose sufficient technical data to build a reliable dynamic model, hence the need to use model identification techniques. This paper presents the results of the use of a model identification technique for a serial robot, augmented with a regularization procedure, applied to the Mitsubishi RV-5AS-D-S01 industrial robot
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No full textChild labor handbook
No full textThis paper surveys many aspects and issues of child labor, including its causes and effects as well as policies associated with it. Child labor has come to be considered an expression of poverty, both a cause and an effect of underdevelopment. Child labor cannot be viewed in isolation from educational, health, fertility, and technological issues; and is not necessarily an aberration but a rational household response to an adverse economic environment. With this in mind, the following proposition was supported - that forbidding children to work or making school attendance compulsory without changing the economic environment may, if effectively enforced, leave children worse off. There is a tendency to believe that income redistribution from the rich to the poor is more powerful for reducing child labor than a universal income rise. It is also indicated that child labor cuts across policy boundaries: health, education, labor market, capital security, criminal law, international peace keeping, income growth, and distribution all have a bearing on child labor. Therefore, reducing child labor cannot be regarded as just another policy issue.Child Labor,Street Children,Youth and Governance,Children and Youth,Health Monitoring&Evaluation
FEATURE SELECTION APPLIED TO THE TIME-FREQUENCY REPRESENTATION OF MUSCLE NEAR-INFRARED SPECTROSCOPY (NIRS) SIGNALS: CHARACTERIZATION OF DIABETIC OXYGENATION PATTERNS
No full textDiabetic patients might present peripheral microcirculation impairment and might benefit from physical training. Thirty-nine diabetic patients underwent the monitoring of the tibialis anterior muscle oxygenation during a series of voluntary ankle flexo-extensions by near-infrared spectroscopy (NIRS). NIRS signals were acquired before and after training protocols. Sixteen control subjects were tested with the same protocol. Time-frequency distributions of the Cohen's class were used to process the NIRS signals relative to the concentration changes of oxygenated and reduced hemoglobin. A total of 24 variables were measured for each subject and the most discriminative were selected by using four feature selection algorithms: QuickReduct, Genetic Rough-Set Attribute Reduction, Ant Rough-Set Attribute Reduction, and traditional ANOVA. Artificial neural networks were used to validate the discriminative power of the selected features. Results showed that different algorithms extracted different sets of variables, but all the combinations were discriminative. The best classification accuracy was about 70%. The oxygenation variables were selected when comparing controls to diabetic patients or diabetic patients before and after training. This preliminary study showed the importance of feature selection techniques in NIRS assessment of diabetic peripheral vascular impairmen
Use of interaction domains for a displacement-based design of caisson foundations
No full textCaisson foundations, typically adopted for both onshore and offshore structures, are usually subject to combined loading acting during working conditions and exceptional events such as earthquakes. Assessment of their performance under general loadings is therefore fundamental, for both serviceability and ultimate limit states. In this study, a simplified displacement-based approach, aimed at preliminary designing caisson foundations subjected to combined loading, is presented. Such an approach requires the definition of both interaction domains (IDs) and generalised pushover curves, together with the assumption of an associative flow rule. The IDs and pushover curves are obtained by interpreting the results of a set of 3D finite element nonlinear static analyses, where the response of massive cylindrical onshore caisson foundations, embedded in a layered soil profile and subjected to both centred vertical (N) and combined loads (N–Q–M), is investigated. Following previous works, the influence of initial loading factor and caisson embedment ratio on both IDs shape and size is investigated. Additionally, the effect of soil drainage conditions on the IDs is discussed. Role of load reference point (LRP) is also assessed, since a suitable choice of LRP may strongly simplify the geometrical representation of the ID. Analytical expressions for dimensionless IDs and pushover curves are presented and used at a preliminary design stage to evaluate the maximum generalised load acting on the caisson for a given threshold generalised displacement, so as not to exceed either serviceability or ultimate limit states
Symmetries of quantum spacetime in three dimensions
No full textBy applying loop quantum gravity techniques to 3D gravity with a positive cosmological constant Λ, we show how the local gauge symmetry of the theory, encoded in the constraint algebra, acquires the quantum group structure of soq(4), with q =exp(ih√Λ/2k). By means of an Inonu-Wigner contraction of the quantum group bi-algebra, keeping k finite, we obtain the kappa-Poincaré algebra of the flat quantum spacetime symmetries
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