A NOTE ON SPURIOUS REGRESSION IN PANELS WITH CROSS-SECTION DEPENDENCE

This paper analyses regression of two independent stationary panels with cross-sectional dependence. It is shown that the pooling least squares (PLS) estimator converges to zero in probability while the individual OLS estimator converges to a random variable. However, the PLS-based and the OLS-based t-statistics diverge, so the null hypothesis of no correlation tends to be spuriously rejected.Research Methods/ Statistical Methods,

Testing for no autocorrelation using a modified Lobato test

This paper suggests modifying the Lobato test for no autocorrelation by using the bandwidth parameter (M) of the covariance estimator as a fixed proportion of the sample size (T): M=bT, where b (0,1] is a constant. It is shown by means of simulations that the modified test has good control over size regardless the choice of b and a higher testing power can be achieved if a mall b is chosen.

Investigating the interaction effect of democracy and economic freedom on corruption: a cross-country quantile regression analysis

This paper explores the interaction effects of economic freedom and democracy in controlling corruption for 100 countries by using quantile regression technique. The main contribution is to explore the interaction effects throughout conditional distribution of corruption across nations. Our results reinforce some findings in the literature, but also provide new conclusions. The findings suggest a stronger and significant interaction effect in reducing corruption, especially in the most-corrupt countries. However, democratic and economic freedoms alone may not cure corruption effectively in the most-corrupt nations, a sound democratic reform can eliminate corruption substantially only after achieving a threshold level of economic freedom

Oxidation of N,N-Dimethylformamide and N,N-Dimethylacetamide in a photoreactor

Oxidation of N,N-dimethylformamide(DMF) and N,N-dimethylacetamide(DMA) was investigated in a 30 liter semi-batch reactor. Five reaction processes were studied by using UV alone, O3 alone, O2/UV, O2/O3/UV and H2 O2/UV respectively. Mathematical models have been developed to interpret the reaction kinetics. Reaction rate constants and mass transfer coefficients were determined by using Rosenbrock Hillclimb optimization algorithm. The experimental data and the predicted results from the models were compared. The kinetic parameters obtained from the previous semi-batch modes were applied to the continuous stirred tank reactor (CSTR) system. Results of this work show that the laboratory scale investigation using semi-batch reactor has great potential to develop the kinetic parameters required for the large scale CSTR system for the degradation of several aqueous pollutants

A Study of Student Learning through Lectures Based on Information Processing Theory

This study provides an account of a naturalistic research into students' learning through lectures. It documents aspects of students' rating of courses and lecturers, the researcher's participant observation and students' note-taking behaviours during normal lectures in a naturally occurring classroom. Students' opinion about the course and the lecturers involved was collected by using a specially designed questionnaire. Access to students' learning was obtained by using audio-tapes of lectures and students' lecture notes. Analysis of lecture notes and interview data provided insights into the nature of, and factors influencing students' note-taking. It also called into question the value of some conventional wisdom about lecturing. This project described three phases of an extended research study planned to investigate how the effects of lecturers' styles interacted with students' cognitive processing of the corresponding lecture information and thus their note-taking behaviours. The first phase of this study involved an exploratory examination of both lecturing and note-taking at the same time under natural conditions for the purpose of revealing some promising factors for further investigation. It was uncovered that note-taking from lectures under certain conditions was in fact dependent on the lecturing styles. In the second phase of this study, a more complete framework, based on Information Processing Theory, was advanced to investigate both lecturing behaviours and the note-taking behaviours and performance of particular type of learners with different working memory capacity, learning styles and motivational types under various lecturing conditions. The third phase of this study was mainly concerned with testing hypotheses to check the reliability of research findings from the previous phases of this present study and in addition, note-taking behaviours of students in general was also investigated. Based upon Information Processing Theory, this study tried to integrate the research into lecturing and the research into note-taking into a unified framework. Such an attempt has provided a key to a fuller understanding of how lecturing processes (the cognitively oriented stimulus variables) influence students' learning processes (the cognitively orienting response variables) during the lectures. Such study has both theoretical orientations and practical implications for improving lecture effectiveness and students' learning (and note-taking) through lectures. The findings from this research suggest that the approach adopted in this investigation holds promise for improving our understanding of how lecturing could be presented efficiently to maximise the transmission of information, and eventually for improving the lecturing effectiveness by making it more adaptive to the needs, interests and learning styles of students and for improving learning by developing in students the strategies for effective note-taking from lectures. One considerable justification and contribution of this present study is that the research into students' cognitive processes during lectures has pursued purely descriptive studies in naturally occurring classroom settings. Such study could ensure that hypotheses and questions posed are relevant and sensible to the subsequent correlational and experimental research. Constructs and variables used in this research have ecological validity and the research designs have taken account of naturally occurring phenomena and other aspects of university lectures

Conversion of inhomogeneous robin boundary conditions into virtual sources for wave motions and heat conduction

In vibration engineering, the differential equations of wave motions and heat conduction are usually accompanied by inhomogeneous boundary conditions in practice. Boundary inhomogeneity makes the dynamics essentially nonlinear, which prevents Hilbert space from being applied for modal decomposition. To deal with this difficulty, this paper does not treat boundary inhomogeneity as a “condition”, but almost converts it into a virtual source in conjunction with homogeneous boundary. This conversion counts mostly on the Laplace-Galerkin transform, a functional tool developed in previous works. We also explore boundary topology of this virtual-source conversion, and find that its strategy is to zero the environment and simultaneously create a spatially impulsive source on the homogeneous boundary, yielding almost the same solution. In one-dimensional region, such a boundary source takes the form of Dirac delta function usually combined by its derivatives. In a sense, this paper catches how Nature really handles boundary conditions