Weight 2 blocks of general linear groups and modular Alvis-Curtis duality

We obtain the structure of weight 2 blocks and [2:1]-pairs of q-Schur algebras, and compute explicitly the modular Alvis-Curtis duality for weight 2 blocks of finite general linear groups in non-defining characteristic.Comment: 27 pages; to appear in Int. Math. Res. No

3D ultrasound image reconstruction based on VTK

Three dimensional (3D) ultrasound image reconstruction based on two dimensional (2D) images has become a famous method for analyzing some anatomy related to abnormalities. 3D ultrasound image reconstruction system is required in order to view the specific part of the object and so that it can be used for analysis purpose. In this paper, 2D images were taken by using untracked free-hand system. Few sets of 2D images were taken with different number of slices and after some 2D image processing, 3D reconstruction is done by using surface rendering techniques by implementing marching cubes algorithm in Visual C++ 6.0 with Visualization Toolkit (VTK) toolbox. From the experiment, we can conclude that in order to reconstruct a better 3D image, the aid of tracking sensor is important. Besides, another parameter such as the number of slices of the images and image processing technique will affect the smoothness of the reconstructed 3D image

Impacts of Ageing Population on Monetary and Exchange Rate Managements in Singapore

This paper finds that the ageing of the population in Singapore will cause a reversal of the current net Central Provident Fund (CPF) contribution into a substantial net CPF withdrawal from 2025, with a peak occurring at 2035. The result is qualitatively robust to changes in the underlying assumptions of the projection. The paper then highlights the implications of this change on the exchange rate and monetary managements in Singapore. First, the Monetary Authority of Singapore (MAS)’s ability to influence Singapore’s exchange rate will be greatly hampered. Second, the net CPF withdrawal will mean sustained liquidity injection into (instead of the usual liquidity drain from) the economy. To avoid unnecessary inflation, the MAS has to find a sustainable way to mob up the excess liquidity due to the sustained liquidity injection. As a simple reversal of MAS’s current foreign exchange market operation will result in substantial shrinkage of foreign reserves, the paper proposes the issuance of government bonds to achieve the dual objectives of mobbing up the excess liquidity and avoiding the shrinkage of foreign reserves. This measure will also help the bond market development in Singapore. Finally, the paper proposes two other measures that can help maintain MAS’s influence on Singapore’s exchange rate to a reasonable level in the longer future.Ageing Population, Central Provident Fund, Exchange Rate System, Monetary Policy, Singapore.

Attraction of Culex mosquitoes to aldehydes from human emanations.

Anecdotes related to preferential mosquito bites are very common, but to date there is no complete explanation as to why one out of two people systematically receives more mosquito bites than the other when both are equally accessible. Here we tested the hypothesis that two constituents of skin emanations, 6-methyl-5-heptan-2-one (6-MHO) and geranylacetone (GA), are natural repellents and may account for differential attraction in different ratios. We studied skin emanations from two human subjects, confirmed in behavioral assays that female southern house mosquitoes are significantly more attracted to subject A (attractant) than to subject N (non-attractant), and tested their 6-MHO/GA ratios in a dual-choice olfactometer. Although repelling at high doses, 6-MHO/GA mixtures were not active at the levels emitted by human skin. We found, however, differential attraction elicited by the aldehydes in the ratios produced by subjects A and N. When tested in a dose commensurate with the level released from human skin and in the ratio produced by subject A, the aldehyde mixture significantly attracted mosquitoes. By contrast, an aldehyde mixture at the same ratio released by subject N did not attract mosquitoes. We, therefore, hypothesized that aldehydes may play a role in the commonly observed differential attraction

Statistical uncertainty in quantum optical photodetection measurements

We present a complete statistical analysis of quantum optical measurement schemes based on photodetection. Statistical distributions of quantum observables determined from a finite number of experimental runs are characterized with the help of the generating function, which we derive using the exact statistical description of raw experimental outcomes. We use the developed formalism to point out that the statistical uncertainty results in substantial limitations of the determined information on the quantum state: though a family of observables characterizing the quantum state can be safely evaluated from experimental data, its further use to obtain the expectation value of some operators generates exploding statistical errors. These issues are discussed using the example of phase-insensitive measurements of a single light mode. We study reconstruction of the photon number distribution from photon counting and random phase homodyne detection. We show that utilization of the reconstructed distribution to evaluate a simple well-behaved observable, namely the parity operator, encounters difficulties due to accumulation of statistical errors. As the parity operator yields the Wigner function at the phase space origin, this example also demonstrates that transformation between various experimentally determined representations of the quantum state is a quite delicate matter.Comment: 18 pages REVTeX, 7 figures included using epsf. Few minor corrections made, clarified conclusion

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

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