45,053 research outputs found
Recommended from our members
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
- …