Phonemic classification using a fuzzy dissimilitude relation

The vocal signal emitted by a human operator is characterized by a high degree of variability. Therefore, the fuzzy-set theory can be successfully applied to vocal patterns the contours of which differ from one speaker to another and even for the same one vary with his state of tiredness and humour, and with many other factors [1].     

Luminescent decay kinetics of malachite green on a picosecond time scale

Luminescence measurements after laser pulse excitation are reported for the dye malachite green in solutions of different viscosity with a time resolution of 10 ps.     

Magnetic after-effect in magnetite below the verwey point

The fractional change in the initial magnetic susceptibility (Δx/x), shows a logarithmic time dependence below the Verwey point (T_V). Isochromes of the form 1n Δx/x=const?15 T/T_V, found just below T_V, suggest a five-parameter electron ordering.     

The Assessment of the Political Risk in the Investment Decision

Political risk has become a major risk of business firms involved in international operations. Hence risk evaluation is a more and more crucial issue to be dealt with by different organisations: private firms, banks and even government agencies.Political risk is composed of diverse, non-independent sources of risk, so that, after an identification of the components, one has to solve a multicriterion problem in order to yield a global evaluation.First, a survey of major evaluation methods is presented.Second, a systematic comparison of those methods is carried out.Third, so as to come to a conclusion, a tentative list of major underlying theoretical difficulties together with main practical implementation problems are evoke.     

Symmetric hydrogen bonds in ice X

Raman measurements on Ice VIII under pressures up to 50 GPa reveal strong line shifts, changes in isotope frequency ratio, intensity decreases, and the appearance of one new line around 38 GPa. These observations are consistent with the formation of symmetric hydrogen bonds and a new phase, Ice X, with cuprit structure.     

Non-empirical CI potential curves for the ground and excited states of PH and its positive ion

A series of calculated potential curves is reported for the low lying valence and (selected) Rydberg states of the PH molecule by employing the multi-reference (single- and) double-excitation CI method. A large AO basis including f functions on phosphorous is chosen for this study and up to twenty main configurations are used to generate a given MRD-CI space in the accompanying theoretical treatment. Very good agreement is obtained between calculation and experiment for a variety of spectroscopic constants and a number of predictions for electronically excited states of PH are made for cases in which no comparable empirical data are yet available. The repulsive ⁵∑^- state is shown to be responsible for the predissociation of several states of the neutral system and is also thought to explain the failure to detect a number of low lying Rydberg states experimentally. Analogous calculations for the PH⁺ molecular ion have also been carried out and spectroscopic constants for this system are reported. In this case the ⁴Π state plays much the same role as the neutral ⁵∑^- species in bringing about predissociation in its electronic spectrum. Finally a comparison is made throughout between the results for PH and PH⁺ and a number of isovalent systems, especially NH and NH⁺ and also SiH.     

Comparison of diffusion anisotropy measurements in combination with the flair-technique.

Fluid-attenuated inversion recovery (FLAIR) technique offers an effective tool to diminish partial-volume averaging effects from cerebrospinal (CSF) signal with in vivo magnetic resonance imaging. CSF-suppressed and unsuppressed direction-dependent diffusion-weighted (DW) images are obtained with a DW spin-echo EPI sequence in a single acquisition scheme. Comparison of unsuppressed and CSF-suppressed apparent diffusion coefficient (ADC) maps yields consistent values for brain tissue in volunteers when no partial-volume effects are expected, but differs considerably at borders of parenchyma to ventricles and sulci. From theory and phantom studies, a corrected anisotropy index is introduced considering differences of statistical fit errors. Anisotropy of white matter is observed in normal brain of volunteers. Anisotropy index maps reveal destruction of fiber tracts in pathologic areas. Results of a preliminary study on 12 patients with intra-axial tumors indicate an improved delineation of tumor boundaries of FLAIR ADC maps against unsuppressed acquisition.     

Computer-based areal surface temperature and local heat transfer measurements with thermochromic liquid crystals (TLC)

The experimental technique presented is designed to obtain detailed local heat transfer data on both stationary as well as rotating disc-cavity surfaces applicable to gas turbines. The method employed utilizes thin coatings of thermochromic liquid crystals (TLC) as surface temperature indicators under aerodynamically steady but thermally transient experimental conditions. The color display of the liquid crystals is monitored by a video camera. The video signals are captured in real time by a computer-based color recognition system to extract areal temperature and heat transfer information. Some typical results are presented and compared with-literature data to illustrate the potential of the system.

List of symbols

Symbols Unit Physical property a m²/s thermal diffusivity - B - blue color signal - G - green color signal - G - rotor/stator spacing ratio z/r _o - Nu _ro - Nusselt number r _o/ - r m radial location - r _o m disc radius - R - red color signal - Re _m - mass flow Reynolds number V/2zv - Re _ro - rotational Reynolds number r _o ²/v - t s time - T _o K initial temperature - T _ref K convecting fluid temperature - T _s K disc surface temperature - U - color difference signal - V - color difference signal - Y - luminance signal - z m rotor/stator spacing - - spectral weight factor - W/m² K local heat transfer coefficient - 1/K volumetric expansion coefficient - - spectral weight factor - - scaling factor - _ij - Kronecker-Delta - - scaling factor - - spectral weight factor - W/m K thermal conductivity - v m²/s fluid kinematic viscosity - kg/m³ fluid density