Identification Of New States Research Articles

Online Degradation Assessment and Adaptive Fault Detection Using Modified Hidden Markov Model

Online condition monitoring and diagnosis systems play an important role in the modern manufacturing industry. This paper presents a novel method to diagnose the degradation processes of multiple failure modes using a modified hidden Markov model (MHMM) with variable state space. The proposed MHMM is combined with statistical process control to quickly detect the occurrence of an unknown fault. This method allows the state space of a hidden Markov model to be adjusted and updated with the identification of new states. Hence, the online degradation assessment and adaptive fault diagnosis can be simultaneously obtained. Experimental results in a turning process illustrate that the tool wear state can be successfully detected, and previously unknown tool wear processes can be identified at the early stages using the MHMM.

Identification of new states in 26Si using the29Si(3He,6He)26Si reaction and consequences for the 25Al(p,y)26Si reaction rate in explosive hydrogen burning environments

Identification of new states in 26Si using the29Si(3He,6He)26Si reaction and consequences for the 25Al(p,y)26Si reaction rate in explosive hydrogen burning environments

Dispersed laser-induced fluorescence of molecular ions. Identification of new low-lying electronic states of TiCl + and TiF +

The dispersed laser-induced fluorescence technique has been applied for the first time to metallic molecular ions. The TiCl + and TiF + ions were produced by a high-voltage discharge in helium with traces of TiCl 4 or TiF 4. A c.w. dye-laser and a grating plate spectrometer were used to record low-resolution spectra of these species in the visible. This leads to the observation of new low-lying electronic states of these ions: the C 3Π (∼1535 cm −1) state of TiCl +, the B 3Δ (∼2040 cm −1) and C 3Π (∼2200 cm −1) states of TiF +. The identification of these new states contributes to a better characterisation of the first 3000 cm −1 of the energy level diagrams of these molecules. The experimental position of the C 3Π state of TiCl + is in good agreement with theoretical predictions given by a Ligand Field Theory model [C. Focsa, M. Bencheikh, L.G.M. Pettersson, J. Phys. B: At. Mol. Opt. Phys. 31 (1998) 2857]. We have extended these calculations to the TiF + isovalent ion, taking advantage of the new experimental data. Both experimental and theoretical new results presented in this paper are expected to help future investigations on these species.