Female labour force participation, fertility and infant mortality in Australia : some empirical evidence from Granger causality tests

This study applies Granger causality tests within a multivariate error correction framework to examine the relationship between female participation rates, infant mortality rates and fertility rates for Australia using annual data from 1960 to 2000. Decomposition of variance and impulse response functions are also considered. The main findings are twofold. First, in the short run there is unidirectional Granger causality running from the fertility rate to female labour force participation and from the infant mortality rate to female labour force participation while there is neutrality between the fertility rate and infant mortality rate. Second, in the long run both the fertility rate and infant mortality rate Granger cause female labour participation.

Teaching and learning force as a representational issue : insights from a classroom video study

An enormous amount of research in the conceptual change tradition has shown the difficulty of learning fundamental science concepts, yet conceptual change schemes have failed to convincingly demonstrate improvements in supporting significant student learning. Recent work in cognitive science has challenged this purely conceptual view of learning, emphasising the role of languages, and the importance of personal and contextual aspects of  understanding science. The research described in this paper is designed around the notion that learning involves the recognition and development of students’ representational resources. In particular, we argue that difficulties with the concept of force are fundamentally representational in nature. The paper describes the planning and implementation of a classroom sequence in force that focuses on representations and their negotiation, and reports on the effectiveness of this perspective in guiding teaching and learning. Classroom sequences involving three teachers 158 2008 NARST Annual International Conference were videotaped using a combined focus on the teacher and groups of students. Video analysis software was used to code the variety of representations used, and sequences of representational negotiation. Stimulated recall interviews were conducted with teachers and students. The paper will report on the effect of this approach on teacher knowledge and pedagogy, and on student learning of force.

Strategic significance of the island state of Sri Lanka

The study is focused on an analysis of the major diplomatic documents from the mid eighteenth century to the present as regards Sri Lanka, or Ceylon as it was known till 1972. The objectives of the study are to identify the issues underlying these diplomatic documents. These include the political and strategic factors and other subsidiary issues like trade and commerce relevant at the time these treaties, agreements, and proposed treaties were formulated. It is also a geopolitical study as it relates to Sri Lanka's geographical position in the Indian Ocean, and her possession of the Trincomalee Harbour on its east coast, which is one of the great natural harbours of the world. Over the centuries this harbour has had significant strategic value for naval deployments. The case study of the eighteenth and nineteenth centuries studies the diplomatic documents against the political and strategic background for the French Revolution and actions of Napoleon, and the Anglo/French rivalry, spreading from Europe to North America and Asia. In the twentieth century the environment for studying the place of Sri Lanka in the Indian Ocean was created by the Russian Revolution, the failure to keep the peace of Versailles after World War I, the conflict and horrors of World War II which led to the disintegration of European colonial empires in Asia and Africa, and the tensions generated by the Cold War. A study of the documents would reveal that in international relations what matters is the ability of a party to promote its interests, and this depends on its power. This realist approach contrasts to the idealist approach where policies are based on moral and ethical principles. For the realist the states should follow to protect their interests and to survive. To achieve this is to strive for a ‘balance of power’. To do so is to form a favourable alliance system. As the documents examined cover a period from the mid-eighteenth century to the later part of the twentieth century, they reflect the changing technologies that have had an influence on naval and military matters. For example, this period witnessed great changes in technology of energy utilized to propel warships, from wind, to steam, to fuel and finally to nuclear power. These changes had an influence in determining strategic policies involving weapon systems and communications within a global and regional setting. The period covered was the beginning of the process described a ‘globalisation’. Its idea is not unique to this century; there were many attempts, in various times of history, to integrate societies within a global context. Viewed in this light, the Anglo-French rivalry of the eighteenth and nineteenth centuries was the indication of a global naval strategy, in which Sri Lanka was a major factor in the Indian Ocean region. This process was associated with the phenomena called the ‘expansion of Europe’. It covered all the oceans of the world and in the nineteenth and twentieth centuries led to the founding of the largest maritime empire the world has ever seen: The British Empire. After World War I, the British naval strength (the basis of the British Empire) and her consequent position as a great power, was challenged by other powers like the United States of America and Japan. After World War II, the US Navy was supreme: and there was a close alliance between Britain and the USA. The strength of the US/British alliance was based on the navy and its bases, which were spread throughout the globe; to project power, and act as deterrence and balancing force. Sri Lanka, due to her strategic position, was a part of this evolving process, and was tied to a global strategy (with its regional connotations) from the eighteenth century to the present.

Improving the prediction of the roll separating force in a hot steel finishing mill

This paper focuses on the development of a hybrid phenomenological/inductive model to improve the current physical setup force model on a five stand industrial hot strip finishing mill. We approached the problem from two directions. In the first approach, the starting point was the output of the current setup force model. A feedforward multilayer perceptron (MLP) model was then used to estimate the true roll separating force using some other available variables as additional inputs to the model.

It was found that it is possible to significantly improve the estimation of a roll separating force from 5.3% error on average with the current setup model to 2.5% error on average with the hybrid model. The corresponding improvements for the first coils are from 7.5% with the current model to 3.8% with the hybrid model. This was achieved by inclusion, in addition to each stand's force from the current model, the contributions from setup forces from the other stands, as well as the contributions from a limited set of additional variables such as: a) aim width; b) setup thickness; c) setup temperature; and d) measured force from the previous coil.

In the second approach, we investigated the correlation between the large errors in the current model and input parameters of the model. The data set was split into two subsets, one representing the "normal" level of error between the current model and the measured force value, while the other set contained the coils with a "large" level of error. Additional set of data with changes in each coil's inputs from the previous coil's inputs was created to investigate the dependency on the previous coil.

The data sets were then analyzed using a C4.5 decision tree. The main findings were that the level of the speed vernier variable is highly correlated with the large errors in the current setup model. Specifically, a high positive speed vernier value often correlated to a large error. Secondly, it has been found that large changes to the model flow stress values between coils are correlated frequently with larger errors in the current setup force model.

Teaching and learning about force with a representational focus : pedagogy and teacher change

A large body of research in the conceptual change tradition has shown the difficulty of learning fundamental science concepts, yet conceptual change schemes have failed to convincingly demonstrate improvements in supporting significant student learning. Recent work in cognitive science has challenged this purely conceptual view of learning, emphasising the role of language, and the importance of personal and contextual aspects of understanding science. The research described in this paper is designed around the notion that learning involves the recognition and development of students’ representational resources. In particular, we argue that conceptual difficulties with the concept of force are fundamentally representational in nature. This paper describes a classroom sequence in force that focuses on representations and their negotiation, and reports on the effectiveness of this perspective in guiding teaching, and in providing insight into student learning. Classroom sequences involving three teachers were videotaped using a combined focus on the teacher and groups of students. Video analysis software was used to capture the variety of representations used, and sequences of representational negotiation. Stimulated recall interviews were conducted with teachers and students. The paper reports on the nature of the pedagogies developed as part of this representational focus, its effectiveness in supporting student learning, and on the pedagogical and epistemological challenges negotiated by teachers in implementing this approach.

Fault tolerance force for redundant manipulators

Fault tolerant manipulators maintain their trajectory even if their joint/s fails. Assuming that the manipulator is fault tolerant on its trajectory, fault tolerant compliance manipulators provide required force at their end-effector even when a joint fails. To achieve this, the contributions of the faulty joints for the force of the end-effector are required to be mapped into the proper compensating joint torques of the healthy joints to maintain the force. This paper addresses the optimal mapping to minimize the force jump due to a fault, which is the maximum effort to maintain the force when a fault occurs. The paper studies the locked joint fault/s of the redundant manipulators and it relates the force jump at the end-effector to the faults within the joints. Adding on a previous study to maintain the trajectory, in here the objective is to providing fault tolerant force at the end-effector of the redundant manipulators. This optimal mapping with minimum force jump is presented using matrix perturbation model. And the force jump is calculated through this model for single and multiple joints fault. The proposed optimal mapping is used in different fault scenarios for a 5-DOF manipulator; also it is deployed to compensate the force at the end-effector for the 5-DOF manipulator through simulation study and the results are presented.

Minimal force jump within human and assistive robot cooperation

When an assistant robotic manipulator cooperatively performs a task with a human and the task is required to be highly reliable, then fault tolerance is essential. To achieve the fault tolerance force within the human robot cooperation, it is required to map the effects of the faulty joint of the robot into the manipulator’s healthy joints’ torque space and the human force. The objective is to optimally maintain the cooperative force within the human robot cooperation. This paper aims to analyze the fault tolerant force within the cooperation and two frameworks are proposed. Then they have been validated through a fault scenario. Finally, the minimum force jump which is the optimal fault tolerance has been achieved.