Learning study: Helping teachers to use theory, develop professionally, and produce new knowledge to be shared

The lesson study approach is a systematic process for producing professional knowledge about teaching by teachers, and has spread rapidly and extensively in the United States. The learning study approach is essentially a kind of lesson study with an explicit learning theory-the variation theory of learning. In this paper, we argue that having an explicit learning theory adds value to lesson study, as the variation theory of learning serves as a source of guiding principles for the teachers when they engage in pedagogical design, lesson analysis and evaluation. Through the use of two Hong Kong learning study cases, one from each of the two major ways of conducting learning study, we demonstrate the power of variation theory in explaining and predicting the relationship between what has taken place in the classroom and what the learners learn, and subsequently identifying ways to improve student learning through promoting teacher professional learning in a learning study setting. © 2011 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

On the Emergence and Evolution of Mark-up Middlemen: An Inframarginal Model

This paper is aimed to provide an economic interpretation on the emergence and evolution of the specialised middlemen whose duty is to facilitate the transactions of goods and services in an economy. In a general equilibrium framework, the emergence and evolution of the specialised middlemen conforms to Adam Smith’s insight of deepening specialisation and the division of labour with the improvement in institutions and/or transaction technologies. Consequently, the emergence and the growth of the intermediation sector in both absolute and relative terms, the expansion of the network which provides transaction services, the evolution of market structure from autarky towards division of labour, the improvement in productivity, the reduction in wholesaling-retailing price dispersion, will be realised in concurrencymiddlemen, transaction efficiency, inframarginal economics

3D Stretchable Arch Ribbon Array Fabricated via Grayscale Lithography.

Microstructures with flexible and stretchable properties display tremendous potential applications including integrated systems, wearable devices and bio-sensor electronics. Hence, it is essential to develop an effective method for fabricating curvilinear and flexural microstructures. Despite significant advances in 2D stretchable inorganic structures, large scale fabrication of unique 3D microstructures at a low cost remains challenging. Here, we demonstrate that the 3D microstructures can be achieved by grayscale lithography to produce a curved photoresist (PR) template, where the PR acts as sacrificial layer to form wavelike arched structures. Using plasma-enhanced chemical vapor deposition (PECVD) process at low temperature, the curved PR topography can be transferred to the silicon dioxide layer. Subsequently, plasma etching can be used to fabricate the arched stripe arrays. The wavelike silicon dioxide arch microstructure exhibits Young modulus and fracture strength of 52 GPa and 300 MPa, respectively. The model of stress distribution inside the microstructure was also established, which compares well with the experimental results. This approach of fabricating a wavelike arch structure may become a promising route to produce a variety of stretchable sensors, actuators and circuits, thus providing unique opportunities for emerging classes of robust 3D integrated systems

Experimental Polarization State Tomography using Optimal Polarimeters

We report on the experimental implementation of a polarimeter based on a scheme known to be optimal for obtaining the polarization vector of ensembles of spin-1/2 quantum systems, and the alignment procedure for this polarimeter is discussed. We also show how to use this polarimeter to estimate the polarization state for identically prepared ensembles of single photons and photon pairs and extend the method to obtain the density matrix for generic multi-photon states. State reconstruction and performance of the polarimeter is illustrated by actual measurements on identically prepared ensembles of single photons and polarization entangled photon pairs