Towards a web-based progressive handwriting recognition environment for mathematical problem solving

The emergence of pen-based mobile devices such as PDAs and tablet PCs provides a new way to input mathematical expressions to computer by using handwriting which is much more natural and efficient for entering mathematics. This paper proposes a web-based handwriting mathematics system, called WebMath, for supporting mathematical problem solving. The proposed WebMath system is based on client-server architecture. It comprises four major components: a standard web server, handwriting mathematical expression editor, computation engine and web browser with Ajax-based communicator. The handwriting mathematical expression editor adopts a progressive recognition approach for dynamic recognition of handwritten mathematical expressions. The computation engine supports mathematical functions such as algebraic simplification and factorization, and integration and differentiation. The web browser provides a user-friendly interface for accessing the system using advanced Ajax-based communication. In this paper, we describe the different components of the WebMath system and its performance analysis.

Greening operations management:an online sustainable procurement course for practitioners

In the Operations Management field, sustainable procurement has emerged as a way to green the purchasing and supply process. This paper explores issues in sustainable procurement training. The authors formed an interdisciplinary team to design, deliver and evaluate a training programme to promote and develop sustainable procurement in the United Kingdom health sector. Particular features of the project were its engagement with evolving and contested understandings of sustainable procurement and of the underlying concept of sustainable development and its recognition that relevant knowledge in the field is both incomplete and widely diffused through the procurement community. Eight practitioner groups worked together on themes to develop their understanding of sustainable procurement using the Blackboard virtual learning environment. Group interviews were conducted upon completion of the course and again three months later to explore qualitatively participants' experience of learning and implementing sustainable procurement. Although the course was delivered to practitioners, it might be modified for undergraduate and graduate students as it comprised the use of online activities in virtual learning environments, case studies and a broad range of literature. The course was also particularly significant in the context of contemporary policy moves in the United Kingdom and elsewhere to promote the role of higher education institutions in delivering workplace-based, high-skills education consistent with strategic policy considerations (see, for example, DIUS, 2008).

Online sensorless position estimation for switched reluctance motors using one current sensor

This paper proposes an online sensorless rotor position estimation technique for switched reluctance motors (SRMs) using just one current sensor. It is achieved by first decoupling the excitation current from the bus current. Two phase-shifted pulse width modulation signals are injected into the relevant lower transistors in the asymmetrical half-bridge converter for short intervals during each current fundamental cycle. Analog-to-digital converters are triggered in the pause middles of the dual pulse to separate the bus current for excitation current recognition. Next, the rotor position is estimated from the excitation current, by a current-rise-time method in the current-chopping-control mode in a low-speed operation and a current-gradient method in the voltage-pulse-control mode in a high-speed operation. The proposed scheme requires only a bus current sensor and a minor change to the converter circuit, without a need for individual phase current sensors or additional detection devices, achieving a more compact and cost-effective drive. The performance of the sensorless SRM drive is fully investigated. The simulation and experiments on a 750-W three-phase 12/8-pole SRM are carried out to verify the effectiveness of the proposed scheme.