Problems and solutions of learning scientific investigation in junior secondary science: a Hong Kong experience

Conference Theme: Building an international platform for exchange between scientists and science educatorsSymposium: no. SS01-3The official Junior Science (Grades 7-9) curriculum and Chemistry curriculum (Grade 10-12) have emphasized the role of scientific investigation for more than a decade. Nevertheless, there are still rooms for improvement in Hong Kong students’ understanding and conducting scientific investigation. For example, Hong Kong students’ performance in TIMSS 2007 revealed that many of them were unable to differentiate observation from conclusion. Also they were weak in writing experimental procedures and interpreting experimental results. An analysis of textbooks for Junior Science level in Hong Kong shows that the way that they frame practical activities are …published_or_final_versio

Affective education in guangzhou, China: A case study

While the affective domain is believed globally to be one of the main areas of human experience and development, affective education is interpreted differently in different countries, and its manifestation varies from region to region. It is argued that affective education is culturally contextualized. The present paper reports a qualitative case study attempting to investigate how affective education is conceptualized and implemented in contemporary China. A middle school in Guangzhou, the biggest city in South China, was chosen as the case school. The study was conducted via semi-structured interviews (both individual and group), analysis of textbooks and school documents, and on-site observations. Findings show that perceived aims and contents of affective education were closely related to character formation, traditional Chinese values and political ideology. Affective education was also interpreted as a response to the rapid social changes in modern China. These findings highlight the influences of Chinese cultural values and political ideology on the conceptualization and interpretation of affective education. Our findings suggest that affective education from the Chinese perspective is 'value-oriented' rather than 'affect-oriented' and it serves as the means to promote the well-being of the collective rather than that of the individual. © Common Ground, Kai Yuen Cheng, Eadaoin K. P. Hui.published_or_final_versio

Live demonstration : a HMM-based real-time sign language recognition system with multiple depth sensors

2014-2015 > Academic research: refereed > Refereed conference paperAccepted ManuscriptPublishe

Hybrid approach for localization in anisotropic sensor networks

In many real-world applications including agricultural, meterological, military applications, etc, localization techniques are widely used to estimate the geographic locations of sensor nodes based on the precision positions of a few anchors equipped with special hardware. Existing localization algorithms mainly try to improve their accuracy in position estimation by using various heuristic-based or mathematical techniques. Every node in the network follows the same technique to find its physical location. However, each individual method with its own strength can only outperform the others in some but not all nodes. Based on this observation, we develop a hybrid approach for the localization problem. Each node collects the same kind of information. By analysing the information, a node can decide what is the best localization algorithm to use. Different nodes can make their own decisions. Our simulation results reveal that the hybrid approach is effective that it outpeforms existing algorithms. To the best of our knowledge, our work presents the first effort in solving the absolute localization problem by adopting a hybrid approach. © 2006 IEEE.published_or_final_versio

Synthesis of ozone from air via a polymer-electrolyte-membrane cell with a doped tin oxide anode

The generation of ozone from air using an electrochemical cell consisting of an air cathode, a polymer-electrolyte-membrane (PEM), and a doped tin oxide anode is reported. This synthesis is environmentally friendly compared to the conventional high-voltage corona discharge process since NOx formation is eliminated; a higher ozone concentration is generated; and lower energy may be required. © The Royal Society of Chemistry 2006.postprin

Molecular diagnostics in tuberculosis

Molecular diagnostics in tuberculosis has enabled rapid detection of Mycobacterium tuberculosis complex in clinical specimens, identification of mycobacterial species, detection of drug resistance, and typing for epidemiological investigation. In the laboratory diagnosis of tuberculosis, the nucleic acid amplification (NAA) test is rapid and specific but not as sensitive as culture of mycobacteria. The primary determinant of successful NAA testing for tuberculosis depends on the shedding of mycobacterial DNA in secretions from caseating granulomas and its dissemination into sterile body fluids or tissue biopsies. In multibacillary diseases with a high mycobacterial load, a positive Ziehl-Neelsen smear with a positive NAA test is diagnostic of active tuberculosis, whereas a positive Ziehl-Neelsen smear with a negative NAA test in the absence of inhibitors would indicate nontuberculous mycobacterial disease. The role of the NAA test is more important in paucibacillary diseases with low mycobacterial loads. The presence of polymerase chain reaction (PCR) inhibitors, however, especially in extrapulmonary specimens, may produce false-negative results. Although this problem can be overcome to some extent by extra extraction steps, the additional processing invariably leads to the loss of mycobacterial DNA. To circumvent this problem, a brief culture augmentation step is carried out before the NAA test is performed, which can enhance the mycobacterial load while concomitantly diluting inhibitors, thereby maintaining the sensitivity of the test without excessively increasing turnaround time. © Springer-Verlag 2005.postprin

Improving localization in wireless sensor networks with an evolutionary algorithm

Wireless sensor networks are highly useful for many location-sensitive applications including environmental monitoring, military applications, disaster management, etc. Localization in wireless sensor networks concerns about the precise estimation of node positions given a relatively small portion as anchor nodes with their absolute positions predetermined. Intrinsically, localization is an unconstrained optimization problem based on various distance/path measures. Most of the existing work focus on increasing the accuracy in position estimation typically by using different heuristic-based or mathematical techniques. On the other hand, there were many complex optimization problems successfully tackled by the nature inspired search algorithms including the ant-based or genetic algorithms. In this paper, we propose to adapt an evolutionary approach, namely a microgenetic algorithm, and integrate as a post-optimizer into some existing localization techniques such as the Ad-hoc Positioning System (APS) to further improve their position estimation. Clearly, our proposed MGA is so adaptable that it can easily be integrated into other localization methods. More importantly, the remarkable improvements obtained by the prototype of our proposed evolutionary optimizer on certain anisotropic topologies of our simulation tests prompt for further investigation. © 2006 IEEE.published_or_final_versio

Concurrent data collection trees for IoT applications

2016-2017 > Academic research: refereed > Publication in refereed journal201804_a bcmaAccepted ManuscriptPublishe

Electrolytic generation of ozone on antimony- And nickel-doped tin oxide electrode

In a recent report, ozone was produced with high efficiency in perchloric acid on an anode coated with antimony-doped tin oxide. We report here that high current efficiency can be enhanced if trace amounts of a second dopant, nickel, is present. The effect of composition of the coating in terms of Ni:Sb:Sn was carefully analyzed. The optimum Ni:Sb:Sn ratio, determined to be 1:8:500, was determined giving a corresponding ozone generation current efficiency of over 30% at room temperature. The highest current efficiency was observed at an optimum operating potential of 2.2 V vs Ag/AgCl. Electrolytic generation of ozone in perchloric acid, sulfuric acid, and phosphoric acid at different concentrations was also studied and compared. In 0.1 M H 2SO 4, the ozone concentration reached 34 mg/L and a current efficiency of 36.3% could be achieved. This is about the highest current efficiency ever reported for electrolytic generation of ozone in an aqueous medium at room temperature. © 2005 The Electrochemical Society. All rights reserved.published_or_final_versio

Trajectory planning for 3D printing : a revisit to traveling salesman problem

2016 2nd International Conference on Control, Automation and Robotics (ICCAR), 28-30 April 20162015-2016 > Academic research: refereed > Refereed conference paperAccepted ManuscriptPublishe