Constraint satisfaction techniques under uncertain conditions for fault diagnosis in nonlinear dynamic systems

The speed of fault isolation is crucial for the design and reconfiguration of fault tolerant control (FTC). In this paper the fault isolation problem is stated as a constraint satisfaction problem (CSP) and solved using constraint propagation techniques. The proposed method is based on constraint satisfaction techniques and uncertainty space refining of interval parameters. In comparison with other approaches based on adaptive observers, the major advantage of the presented method is that the isolation speed is fast even taking into account uncertainty in parameters, measurements and model errors and without the monotonicity assumption. In order to illustrate the proposed approach, a case study of a nonlinear dynamic system is presented

Treatment of nonlinear optical properties due to large amplitude anharmonic vibrational motions: umbrella motion in NH3

A general reduced dimensionality finite field nuclear relaxation method for calculating vibrational nonlinear optical properties of molecules with large contributions due to anharmonic motions is introduced. In an initial application to the umbrella (inversion) motion of NH3 it is found that difficulties associated with a conventional single well treatment are overcome and that the particular definition of the inversion coordinate is not important. Future applications are described

Field-induced coordinates for the determination of dynamic vibrational nonlinear optical properties

Three conjugated organic molecules that span a range of polarity and valence-bond/charge transfer characteristics were studied. It was found that dispersion can be insignificant, and that adequate treatment can be achieved with frequency-dependent field-induced vibrational coordinates (FD-FICs)

Nuclear relaxation contribution to static and dynamic (infinite frequency approximation) nonlinear optical properties by means of electrical property expansions: Application to HF, CH4, CF4, and SF6

Electrical property derivative expressions are presented for the nuclear relaxation contribution to static and dynamic (infinite frequency approximation) nonlinear optical properties. For CF4 and SF6, as opposed to HF and CH4, a term that is quadratic in the vibrational anharmonicity (and not previously evaluated for any molecule) makes an important contribution to the static second vibrational hyperpolarizability of CF4 and SF6. A comparison between calculated and experimental values for the difference between the (anisotropic) Kerr effect and electric field induced second-harmonic generation shows that, at the Hartree-Fock level, the nuclear relaxation/infinite frequency approximation gives the correct trend (in the series CH4, CF4, SF6) but is of the order of 50% too small

Variational calculation of static and dynamic vibrational nonlinear optical properties

The vibrational configuration interaction method used to obtain static vibrational (hyper)polarizabilities is extended to dynamic nonlinear optical properties in the infinite optical frequency approximation. Illustrative calculations are carried out on H2 O and N H3. The former molecule is weakly anharmonic while the latter contains a strongly anharmonic umbrella mode. The effect on vibrational (hyper)polarizabilities due to various truncations of the potential energy and property surfaces involved in the calculation are examined

Variational calculation of vibrational linear and nonlinear optical properties

A variational approach for reliably calculating vibrational linear and nonlinear optical properties of molecules with large electrical and/or mechanical anharmonicity is introduced. This approach utilizes a self-consistent solution of the vibrational Schrödinger equation for the complete field-dependent potential-energy surface and, then, adds higher-level vibrational correlation corrections as desired. An initial application is made to static properties for three molecules of widely varying anharmonicity using the lowest-level vibrational correlation treatment (i.e., vibrational Møller-Plesset perturbation theory). Our results indicate when the conventional Bishop-Kirtman perturbation method can be expected to break down and when high-level vibrational correlation methods are likely to be required. Future improvements and extensions are discussed

Basis set and electron correlation effects on initial convergence for vibrational nonlinear optical properties of conjugated organic molecules

The level of ab initio theory which is necessary to compute reliable values for the static and dynamic (hyper)polarizabilities of three medium size π-conjugated organic nonlinear optical (NLO) molecules is investigated. With the employment of field-induced coordinates in combination with a finite field procedure, the calculations were made possible. It is stated that to obtain reasonable values for the various individual contributions to the (hyper)polarizability, it is necessary to include electron correlation. Based on the results, the convergence of the usual perturbation treatment for vibrational anharmonicity was examined

Initial convergence of the perturbation series expansion for vibrational nonlinear optical properties

Initial convergence of the perturbation series expansion for vibrational nonlinear optical (NLO) properties was analyzed. The zero-point vibrational average (ZPVA) was obtained through first-order in mechanical plus electrical anharmonicity. Results indicated that higher-order terms in electrical and mechanical anharmonicity can make substantial contributions to the pure vibrational polarizibility of typical NLO molecules

Variational principles for nonlinear dynamical systems

A variational method for Hamiltonian systems is analyzed. Two different variationalcharacterization for the frequency of nonlinear oscillations is also suppliedfor non-Hamiltonian systems

Multisensor change detection with nonlinear canonical correlation

The analysis of multi-modal and multi-sensor images is nowadays of paramount importance for Earth Observation (EO) applications. There exist a variety of methods that aim at fusing the different sources of information to obtain a compact representation of such datasets. However, for change detection existing methods are often unable to deal with heterogeneous image sources and very few consider possible nonlinearities in the data. Additionally, the availability of labeled information is very limited in change detection applications. For these reasons, we present the use of a semi-supervised kernel-based feature extraction technique. It incorporates a manifold regularization accounting for the geometric distribution and jointly addressing the small sample problem. An exhaustive example using Landsat 5 data illustrates the potential of the method for multi-sensor change detection.

Permanent stallion contact hastens onset of mares' cyclicity after winter anoestrus

The species Equus caballus is characterized as a seasonal polyoestrous herd mammal, providing continuous interactions between stallions and mares in feral herds throughout the year. Under domesticated conditions mares and stallions are stabled and kept separated mostly due to hygienic and safety concerns. Managing mares through the spring transitional phase until they show fertile cycles represents a high multifactorial challenge for horse breeders and veterinarians. The goal of this study was to examine the influence of a permanent stallion contact on the onset of cyclicity in anoestrous mares in the transition period.

Implementació d'un contact center per empreses basat en software lliure

El proyecto consiste en la creación de un CRM de contact center con canal de telefonía y correo electrónico. Se ha llevado a cabo utilizando software libre. Se integra con centralita telefónica para permitir la realización de llamadas por Voip.

Multimarket contact externalities: the effect of rival's multimarket contacts on focal firm performance

Given that firms develop their activities in a network of multiple players, interfirm rivalry is not only a matter of direct competitors, but also of indirect competition. In spite of this, the literature on competitive dynamics tends to focus on analyzing rivalry as an exclusive function of the competitive relationship between a focal firm and its direct rivals. In this article, we extend competitive dynamics literature by considering how focal firms are affected by the relationships of their rivals with third-party firms. Specifically, we study the effect that the multimarket contacts of rivals produces on the performance of the focal firm. Additionally, we incorporate the idea that there are different strategic options for operating in an industry that affect the intensity of multimarket contact externalities. Our results show that multimarket contact among firms causes externalities that indirectly affect firms that are not directly involved in this competitive relationship. We find that multimarket contact externalities differ between and within strategic groups.

Pseudophakic Retinal Detachment Surgery by 23 G Vitrectomy using Slit-Lamp and Non-Contact 90 D Lens.

Background: The purpose of this study is to report the anatomic and functional results of primary 23 G vitrectomy using slit-lamp and non-contact 90 D lens for the treatment of pseudophakic rhegmatogenous retinal detachment. Patients and Methods: Pseudophakic eyes were operated by 23 G vitrectomy using slit-lamp and non-contact 90 D lens, internal subretinal fluid drainage, cryopexy and internal gas tamponade. The preoperative and postoperative characteristics were analysed. Main outcome measures were anatomic success rates after initial surgical intervention and after reoperation for primary failures, visual outcome at the last follow-up visit, and complications. Results: 46 pseudophakic eyes were included in this retrospective study (October 2013- January 2014). In 40 cases, sulfur hexafluoride 23 % gastamponade was used, silicone oil in 6 cases (13 %). The retina was reattached successfully after a single surgery in 44 eyes (96 %). Recurrence of retinal detachment occurred in 2 eyes. Final anatomic reattachment was obtained in 100 % after a second operation. Silicone oil was removed in all eyes. Visual acuity improved significantly from logMAR 0 (IQR 0 - 0.9) to logMAR 0 (IQR 0 - 0.2) (p < 0.005). Conclusions: Primary 23 G vitrectomy using slit-lamp and non contact 90 D lens for the treatment of pseudophakic rhegmatogenous retinal detachment provides a high anatomic and functional success rate and is associated with few complications.

Intracellular nanomanipulation by a photonic-force microscope with real-time acquisition of a 3D stiffness matrix.

A traditional photonic-force microscope (PFM) results in huge sets of data, which requires tedious numerical analysis. In this paper, we propose instead an analog signal processor to attain real-time capabilities while retaining the richness of the traditional PFM data. Our system is devoted to intracellular measurements and is fully interactive through the use of a haptic joystick. Using our specialized analog hardware along with a dedicated algorithm, we can extract the full 3D stiffness matrix of the optical trap in real time, including the off-diagonal cross-terms. Our system is also capable of simultaneously recording data for subsequent offline analysis. This allows us to check that a good correlation exists between the classical analysis of stiffness and our real-time measurements. We monitor the PFM beads using an optical microscope. The force-feedback mechanism of the haptic joystick helps us in interactively guiding the bead inside living cells and collecting information from its (possibly anisotropic) environment. The instantaneous stiffness measurements are also displayed in real time on a graphical user interface. The whole system has been built and is operational; here we present early results that confirm the consistency of the real-time measurements with offline computations.