State space representation of flexible structure dynamics in air flow

Recently [1] (Balakrishnan, 2000) it was shown that the linearized dynamics of the response of a flexible structure in inviscid incompressible airflow can be modeled as a convolution/evolution equation in a separable Hilbert space H

(1)     

Diagnostic efficiency of amylase and type IV collagen in predicting chronic pancreatitis

Chronic pancreatitis, an irreversible inflammatory disease of the pancreas, is associated with the replacement of the destroyed parenchyma by extended development of fibrosis. Despite marked progress in diagnostic tools, no consensus has been reached in diagnosis of chronic pancreatitis. In this study we examined the hematological and biochemical parameters among 40 chronic pancreatitis patients within 18 to 67 yrs. ESR level and ALP activity was elevated in 40% cases. Serum amylase activity increased in 32 patients and it showed significant correlation with ALP (r=0.458, p=0.003), CA-19.9 (r=0.556, p<0.001), and calcium level (r=−0.472, p=0.002). Type IV collagen level in chronic pancreatitis also elevated (164.4 ± 55.5 ng/ml) and showed negative significant correlation with calcium level (r= −0.505, p=0.001). However, no significant correlation was observed between amylase activity and type IV collagen (r=0.289, p= 0.07).     

A simple relation between the Leimkuhler curve and the mean residual life

In this paper, a simple relation between the Leimkuhler curve and the mean residual life is established. The result is illustrated with several models commonly used in informetrics, such as exponential, Pareto and lognormal. Finally, relationships with some other reliability concepts are also presented.     

Symmetries and conservation laws in classical and quantum mechanics 1. Classical mechanics

We describe the connection between continuous symmetries and conservation laws in classical mechanics. This is done at successively more sophisticated levels, bringing out important features at each level: the Newtonian, the Euler-Lagrange, and the Hamiltonian phase-space forms of mechanics. The role of the Action Principle is emphasised, and many examples are given.     

Ehrenfest’s theorem and nonclassical states of light 1. Ehrenfest’s theorem in quantum mechanics

When it was first enunciated, Ehrenfest’s Theorem provided a necessary and important link between classical mechanics and quantum mechanics. Today, the content of the theorem is understood to be a natural and immediate consequence of the equation of motion for operators when quantum mechanics is formulated in the Heisenberg picture. Nevertheless, the theorem leads to useful approximations when systems with Hamiltonians of higher than quadratic order in the dynamical variables are considered. In this two-part article, we use it to provide a convenient illustration of the differences between so-called classical and nonclassical states of radiation.     

A comparative study on real lab and simulation lab in communication engineering from students’ perspectives

Over the years, rapid development in computer technology has engendered simulation-based laboratory (lab) in addition to the traditional hands-on (physical) lab. Many higher education institutions adopt simulation lab, replacing some existing physical lab experiments. The creation of new systems for conducting engineering lab activities has raised concerns among educators on the merits and shortcomings of both physical and simulation labs; at the same time, many arguments have been raised on the differences of both labs. Investigating the effectiveness of both labs is complicated, as there are multiple factors that should be considered. In view of this challenge, a study on students’ perspectives on their experience related to key aspects on engineering laboratory exercise was conducted. In this study, the Visual Auditory Read and Kinetic model was utilised to measure the students’ cognitive styles. The investigation was done through a survey among participants from Multimedia University, Malaysia. The findings revealed that there are significant differences for most of the aspects in physical and simulation labs.     

What can the answer be?

A very useful approach in tackling scientific problems is to ask what the answer could possibly be, under the constraints of the given problem. In the first part of this series, this approach is illustrated with some examples from elementary vector analysis.     

What can the answer be?

A very useful approach in tackling scientific problems is to ask what the answer could possibly be, under the constraints of the given problem. In the first part of this series, this approach is illustrated with some examples from elementary vector analysis.     

Om： One tool for many （Indian） languages

INTRODUCTION India is a nation with pluralistic culture, a large number of cultures, ethnicities, languages and relig- ions coexisting with each other. While the culture and faith unify the country under one umbrella either by similarity or by tolerance, the language is what separates them. In the 1951 census, the first census after India attained independence, 845 languages (dialects) were identified, of which 60 were spoken by at least 100000 people each. The Indian constitu- tion iden…