The Development,Implementation, and Evaluation of a Problem Solving Heuristic

Problem-solving is one of the main goals in science teaching and is something many students find difficult. This research reports on the development, implementation and evaluation of a problem-solving heuristic. This heuristic intends to help students to understand the steps involved in problem solving (metacognitive tool), and to provide them with an organized approach to tackling problems in a systematic way. This approach guides students by means of logical reasoning to make a qualitative representation of the solution of a problem before undertaking calculations, using a backwards strategy, which thus comprises a cognitive tool. The findings of the study suggest that students found the heuristic useful in setting up and solving quantitative chemical problems, and helped them to understand the phases of the problem solving process. Possible applications of the heuristic in the classroom include its use in formative assessment, to identify and to overcome student alternative conceptions, problem-solving in a cooperative environment, and to reduce the gender gap in science.     

A computational fluid dynamics model for wind simulation: model implementation and experimental validation

To provide physically based wind modelling for wind erosion research at regional scale, a 3D computational fluid dynamics (CFD) wind model was developed. The model was programmed in C language based on the Navier-Stokes equations, and it is freely available as open source. Integrated with the spatial analysis and modelling tool (SAMT), the wind model has convenient input preparation and powerful output visualization. To validate the wind model, a series of experiments was conducted in a wind tunnel. A blocking inflow experiment was designed to test the performance of the model on simulation of basic fluid processes. A round obstacle experiment was designed to check if the model could simulate the influences of the obstacle on wind field. Results show that measured and simulated wind fields have high correlations, and the wind model can simulate both the basic processes of the wind and the influences of the obstacle on the wind field. These results show the high reliability of the wind model. A digital elevation model (DEM) of an area (3800 m long and 1700 m wide) in the Xilingele grassland in Inner Mongolia (autonomous region, China) was applied to the model, and a 3D wind field has been successfully generated. The clear implementation of the model and the adequate validation by wind tunnel experiments laid a solid foundation for the prediction and assessment of wind erosion at regional scale.     

A modified multitarget adaptive array algorithm for wireless CDMA system

The paper presents a modified least squares despread respread multitarget constant modulus algorithm(LS-DRMTCMA). The cost function of the original algorithm was modified by the minimum bit error rate(MBER)criterion.The novel algorithm tries to optimize weight vectors by directly minimizing bit error rate(BER)of code division multiple access(CDMA)mobile communication system. In order to achieve adaptive update of weight vectors,a stochastic gradient adaptive algorithm was developed by a kernel density estimator of possibility density function based on samples. Simulation results showed that the modified algorithm remarkably improves the BER performance,capacity and near-far effect resistance of a given CDMA communication system.     

The constitution of agency in developing lifelong learning ability: the ‘being’ mode

In an age of uncertainty, one of the aims of higher education is to establish lifelong learning abilities in students. However, different authors remain divided on the question of what constitutes ‘lifelong learning ability’. This article proposes the hypothesis that the cultivation of lifelong learning abilities in higher education needs to be conceptualised and sustained through a focus on the constitution and operation of agency. The cultivation of lifelong learning as a set of agent abilities needs to be grounded within the mode of being, a concept inspired by Heidegger, rather than within having or doing. While the importance of developing epistemology by focusing on learning as delivery (having) and interacting (doing) is not denied, this article suggests that higher education also concerns ontological learning. The Heideggerian perspective on being provides a more person-focused approach that is useful for providing balance and congruence between feeling and thought and between mind and body, supplementing the having and doing approaches by inviting students to reflect on their own growth and leading not only to knowledge construction for problem-solving but also to the construction of subjectivity as a means of finding meaning in the learner’s existence in times of uncertainty.