1,211 research outputs found
THEORETICAL DESIGN STUDY ON SHAFTING ALIGNMENT CALCULATION FOR HIGH SPEED CRAFT
The design reliability of the theory applied when calculating the sensitivity of shafting alignment must be determined especially at the initial design stage of shafting arrangement and calculation for the vertical static bearing loads (reaction forces) and pressures in order to obtain positive uniform values, which have to comply with the design requirements of the High Speed Craft Code of Classification Society. Any poor design of shafting arrangement for each vertical static bearing location and/or bearing off-set design value may cause a failed shafting alignment calculation and a non-uniform bearing load or over excessive bearing load and pressure on the propulsion shaft stern tube/strut supporting bearing and possible further damage, for example, excessive wastage and/or crack on a damaged aft shaft strut bearing for a high speed craft.
The objective of this study was to find and verify the design reliability of the applied theoretical method for calculating the suitable design values of each vertical static bearing load and pressure on the propulsion shafting system at the initial design stage of shafting arrangement. The design values for each vertical static bearing load and pressure calculated by theoretical design methodologies of the finite element method (FEM) and the three moment equation method (TMEM) were compared with the shipyard original design values for the same design case of propulsion shafting system. The design deviation of the vertical static bearing from the shipyard original design values was determined in order to decide which design methodology (TMEM or FEM) would be adopted and developed for further numerical algorithm design on shafting alignment optimization. According to the obtained results, both the FEM and the TMEM theoretical design accuracy and reliability were well matched with the shipyard original design values. In addition, the TMEM design results for each static bearing load and pressure proved to be more close to the shipyard original design values
THEORETICAL DESIGN STUDY ON SHAFTING ALIGNMENT CALCULATION FOR HIGH SPEED CRAFT
The design reliability of the theory applied when calculating the sensitivity of shafting alignment must be determined especially at the initial design stage of shafting arrangement and calculation for the vertical static bearing loads (reaction forces) and pressures in order to obtain positive uniform values, which have to comply with the design requirements of the High Speed Craft Code of Classification Society. Any poor design of shafting arrangement for each vertical static bearing location and/or bearing off-set design value may cause a failed shafting alignment calculation and a non-uniform bearing load or over excessive bearing load and pressure on the propulsion shaft stern tube/strut supporting bearing and possible further damage, for example, excessive wastage and/or crack on a damaged aft shaft strut bearing for a high speed craft.
The objective of this study was to find and verify the design reliability of the applied theoretical method for calculating the suitable design values of each vertical static bearing load and pressure on the propulsion shafting system at the initial design stage of shafting arrangement. The design values for each vertical static bearing load and pressure calculated by theoretical design methodologies of the finite element method (FEM) and the three moment equation method (TMEM) were compared with the shipyard original design values for the same design case of propulsion shafting system. The design deviation of the vertical static bearing from the shipyard original design values was determined in order to decide which design methodology (TMEM or FEM) would be adopted and developed for further numerical algorithm design on shafting alignment optimization. According to the obtained results, both the FEM and the TMEM theoretical design accuracy and reliability were well matched with the shipyard original design values. In addition, the TMEM design results for each static bearing load and pressure proved to be more close to the shipyard original design values
Quasiparticle dynamics and phonon softening in FeSe superconductors
Quasiparticle dynamics of FeSe single crystals revealed by dual-color
transient reflectivity measurements ({\Delta}R/R) provides unprecedented
information on Fe-based superconductors. The amplitude of fast component in
{\Delta}R/R clearly tells a competing scenario between spin fluctuations and
superconductivity. Together with the transport measurements, the relaxation
time analysis further exhibits anomalous changes at 90 K and 230 K. The former
manifests a structure phase transition as well as the associated phonon
softening. The latter suggests a previously overlooked phase transition or
crossover in FeSe. The electron-phonon coupling constant {\lambda} is found to
be 0.16, identical to the value of theoretical calculations. Such a small
{\lambda} demonstrates an unconventional origin of superconductivity in FeSe.Comment: Final published version; 5 pages; 4 figure
Spatially-resolved relaxation dynamics of photoinduced quasiparticles in underdoped YBaCuO
The spatially-resolved relaxation characteristics of photoinduced
quasiparticles (QPs) in CuO planes of underdoped YBCO are disclosed by
polarized fs time-resolved spectroscopy. The relaxation time (tau) along b axis
diverges at Tc, and appears to be governed by a temperature-dependent gap
Delta(T) at T Tc, a monotonic increase of tau with
decreasing T along the b axis and ab diagonal was observed and can be
attributed to a temperature-independent gap Delta. The results lend
support to recombination dominant scenario of QP dynamics. However, the QP
thermalization may take part along the nodal direction in the highly underdoped
samples.Comment: 16 pages, 4 figures. To be published in Physical Review B, Brief
Repor
Spatial Symmetry of Superconducting Gap in YBa2Cu3O7-\delta Obtained from Femtosecond Spectroscopy
The polarized femtosecond spectroscopies obtained from well characterized
(100) and (110) YBa2Cu3O7-\delta thin films are reported. This bulk-sensitive
spectroscopy, combining with the well-textured samples, serves as an effective
probe to quasiparticle relaxation dynamics in different crystalline
orientations. The significant anisotropy in both the magnitude of the
photoinduced transient reflectivity change and the characteristic relaxation
time indicates that the nature of the relaxation channel is intrinsically
different in various axes and planes. By the orientation-dependent analysis,
d-wave symmetry of the bulk-superconducting gap in cuprate superconductors
emerges naturally.Comment: 8 pages, 4 figures. To be published in Physical Review B, Rapid
Communication
A comparative review of dynamic neural networks and hidden Markov model methods for mobile on-device speech recognition
The adoption of high-accuracy speech recognition algorithms without an effective evaluation of their impact on the target computational resource is impractical for mobile and embedded systems. In this paper, techniques are adopted to minimise the required computational resource for an effective mobile-based speech recognition system. A Dynamic Multi-Layer Perceptron speech recognition technique, capable of running in real time on a state-of-the-art mobile device, has been introduced. Even though a conventional hidden Markov model when applied to the same dataset slightly outperformed our approach, its processing time is much higher. The Dynamic Multi-layer Perceptron presented here has an accuracy level of 96.94% and runs significantly faster than similar techniques
Contribution of the cyclic nucleotide gated channel subunit, CNG-3, to olfactory plasticity in Caenorhabditis elegans.
In Caenorhabditis elegans, the AWC neurons are thought to deploy a cGMP signaling cascade in the detection of and response to AWC sensed odors. Prolonged exposure to an AWC sensed odor in the absence of food leads to reversible decreases in the animal's attraction to that odor. This adaptation exhibits two stages referred to as short-term and long-term adaptation. Previously, the protein kinase G (PKG), EGL-4/PKG-1, was shown necessary for both stages of adaptation and phosphorylation of its target, the beta-type cyclic nucleotide gated (CNG) channel subunit, TAX-2, was implicated in the short term stage. Here we uncover a novel role for the CNG channel subunit, CNG-3, in short term adaptation. We demonstrate that CNG-3 is required in the AWC for adaptation to short (thirty minute) exposures of odor, and contains a candidate PKG phosphorylation site required to tune odor sensitivity. We also provide in vivo data suggesting that CNG-3 forms a complex with both TAX-2 and TAX-4 CNG channel subunits in AWC. Finally, we examine the physiology of different CNG channel subunit combinations
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