Kleshchev's decomposition numbers and branching coefficients in the Fock space

10.1090/S0002-9947-07-04202-XTransactions of the American Mathematical Society36031179-119

Calculation of stress intensity factors in an isotropic multicracked plate. Part 1: Theoretical development

An essential part of describing the damage state and predicting the damage growth in a multicracked plate is the accurate calculation of stress intensity factors (SIF's). Here, a methodology and rigorous solution formulation for SIF's of a multicracked plate, with fully interacting cracks, subjected to a far-field arbitrary stress state is presented. The fundamental perturbation problem is derived, and the steps needed to formulate the system of singular integral equations whose solution gives rise to the evaluation of the SIF's are identified. This analytical derivation and numerical solution are obtained by using intelligent application of symbolic computations and automatic FORTRAN generation capabilities (described in the second part of this paper). As a result, a symbolic/FORTRAN package, named SYMFRAC, that is capable of providing accurate SIF's at each crack tip was developed and validated

Hot Electron Effects in the 2D Superconductor-Insulator Transition

The parallel magnetic field tuned two-dimensional superconductor-insulator transition has been investigated in ultrathin films of amorphous Bi. The resistance is found to be independent of temperature on both sides of the transition below approximately 120 mK. Several observations suggest that this regime is not intrinsically "metallic" but results from the failure of the films' electrons to cool. The onset of this temperature-independent regime can be moved to higher temperatures by either increasing the measuring current or the level of electromagnetic noise. Temperature scaling is successful above 120 mK. Electric field scaling can be mapped onto temperature scaling by relating the electric fields to elevated electron temperatures. These results cast doubt on the existence of an intrinsic metallic regime and on the independent determination of the correlation length and dynamical critical exponents obtained by combining the results of electric field and temperature scaling.Comment: 4 pages, 4 figure

Beyond ‘greeting’ and ‘thanking’: politeness in job interviews

Despite the steps taken by Malaysian institutions of higher learning to equip their graduates with the necessary communication skills, local graduates are still failing to create a positive impression on the employers especially during job interviews. Hence this study explored the face-related concept of politeness proposed by Brown and Levinson (1999) at job interviews. Eight final-year undergraduates taking a communication for employment course volunteered for a mock-interview session with a human resource manager from the banking industry. The interviews were audio- and video-recorded and subsequently transcribed. Then a micro-analysis of the data was carried out using Brown and Levinson’s (1999) framework to identify the politeness strategies that the candidates used. Two positive politeness strategies were identified, the first is noticing and attending to interviewer’s interests, wants, needs or goods, and second is raising/asserting common grounds to establish solidarity. One negative politeness strategy was identified which is requesting for clarification or repetition. The pedagogical implications of these findings will be discussed and recommendations for teaching face-related politeness in communication for employment courses will be offered

Calculation of stress intensity factors in an isotropic multicracked plate: Part 2: Symbolic/numeric implementation

Analytical derivations of stress intensity factors (SIF's) of a multicracked plate can be complex and tedious. Recent advances, however, in intelligent application of symbolic computation can overcome these difficulties and provide the means to rigorously and efficiently analyze this class of problems. Here, the symbolic algorithm required to implement the methodology described in Part 1 is presented. The special problem-oriented symbolic functions to derive the fundamental kernels are described, and the associated automatically generated FORTRAN subroutines are given. As a result, a symbolic/FORTRAN package named SYMFRAC, capable of providing accurate SIF's at each crack tip, was developed and validated. Simple illustrative examples using SYMFRAC show the potential of the present approach for predicting the macrocrack propagation path due to existing microcracks in the vicinity of a macrocrack tip, when the influence of the microcrack's location, orientation, size, and interaction are taken into account

Rate distortion functions of countably infinite alphabet memoryless sources

The Shannon lower bound approach to the evaluation of rate distortion functions R(D) for countably infinite alphabet memoryless sources is considered. Sufficient conditions based on the Contraction Mapping Theorem for the existence of the Shannon lower bound RL(D) to R(D) in a region of distortion [0, D1], D1 > 0 are obtained. Sufficient conditions based on the Schauder Fixed Point Theorem for the existence of a Dc > 0 such that R(D) = RL(D) for all D ε [0, Dc] are derived. Explicit evaluation of R(D) is considered for a class of column balanced distortion measures. Other results for distortion measures with no symmetry conditions are also discussed

Comparison Study of Two Different Sun-Tracking Methods in Optical Efficiency of Heliostat Field

There are two sun-tracking methods widely used for the heliostat, which are conventional Azimuth-Elevation and revolutionary Spinning-Elevation methods. Following the previous study to compare the range of motion, a comparison study in optical efficiency of heliostat field for the two methods is further explored in this paper. A special algorithm using ray-tracing technique has also been developed to simulate the optical efficiency of heliostat field for both sun-tracking methods in different latitudes. With the new algorithm, comprehensive analysis to compare the optical efficiency of individual heliostat and the overall heliostat field for the two sun-tracking methods has been carried out