Which Agenda? Medium of Instruction Policy in Post-1997 Hong Kong

The mandatory use of mother tongue education in Hong Kong after 1997 met strong objections from the local community. While the government put forward a comprehensive educational agenda to justify the implementation of the policy, this paper raises the question of whether the change in language policy was mainly driven by an educational agenda, or whether there were other underlying agendas. To address the question, the history of the medium of instruction in Hong Kong is reviewed, and the experience of three decolonised Asian countries, Malaysia, Singapore and India, is discussed. The paper suggests that the political agenda has always played an important role in language policy formulation and implementation. In view of the important role that language plays in nation building and social reconstruction, it is inevitable that Chinese medium instruction will become more and more important. How the government will balance the need to strengthen the national identity of Hong Kong people and the need to maintain the international out look and economic development of Hong Kong will have a major impact on there view of the new medium of instruction policy in 2001.published_or_final_versio

Global sea level trends in the presence of variable sea level velocities, and variable accelerations

Author name used in this publication: X. L. Ding2013-2014 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Polyaxial figures of the Moon from the lunar reconnaissance orbiter laser altimetry and multi-mission synthesis of the lunar shape

2011-2012 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

A Mobile App Platform for Discovering Learning Profiles and Analytics

published_or_final_versio

Exploring Characteristics of Fine-Grained Behaviors of Learning Mathematics in Tablet-Based E-Learning Activities

Attributes of teaching and learning contexts provide rich information about how students participate in learning activities. By tracking and analyzing snapshots of these attributes captured continuously throughout the duration of the learning activities, teachers can identify individual students who need special attention and apply different pedagogical actions to them. This paper describes the results of the work-in-progress study in exploring characteristics of fine-grained behaviors of learning mathematics in tablet-based e-learning activities. An experimental platform called SkyApp is built. Through SkyApp, teachers can create e-learning activities and track learning records of students after the delivery of the activities. SkyApp supports capturing, storing and analyzing of fine-grained behaviors of students. Pilot tests have been done in two primary schools for eight months. The review of the tests demonstrates the potential in performing learning analytics. By applying clustering algorithms on multiple learning metrics of marks, time and number of attempts for students in solving mathematics questions, classification of students by learning characteristics of performance and engagement can be formulated. [For the complete proceedings, see ED579335.]published_or_final_versio

An improved geometric lunar figure from Chang’E-1 and SELENE laser altimetry

2011-2012 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Orientation of the geometrically best fitting triaxial lunar ellipsoid with respect to the mean earth/polar axis reference frame

Author name used in this publication: X. L. Ding2010-2011 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Understanding Water Level Changes in the Great Lakes by an ICA-Based Merging of Multi-Mission Altimetry Measurements

Accurately monitoring spatio-temporal changes in lake water levels is important for studying the impacts of climate change on freshwater resources, and for predicting natural hazards. In this study, we applied multi-mission radar satellite altimetry data from the Laurentian Great Lakes, North America to optimally reconstruct multi-decadal lake-wide spatio-temporal changes of water level. We used the results to study physical processes such as teleconnections of El Niño and southern oscillation (ENSO) episodes over approximately the past three-and-a-half decades (1985–2018). First, we assessed three reconstruction methods, namely the standard empirical orthogonal function (EOF), complex EOF (CEOF), and complex independent component analysis (CICA), to model the lake-wide changes of water level. The performance of these techniques was evaluated using in-situ gauge data, after correcting the Glacial Isostatic Adjustment (GIA) process using a contemporary GIA forward model. While altimeter-measured water level was much less affected by GIA, the averaged gauge-measured water level was found to have increased up to 14 cm over the three decades. Our results indicate that the CICA-reconstructed 35-year lake level was more accurate than the other two techniques. The correlation coefficients between the CICA reconstruction and the in situ water-level data were 0.96, 0.99, 0.97, 0.97, and 0.95, for Lake Superior, Lake Michigan, Lake Huron, Lake Erie, and Lake Ontario, respectively; ~7% higher than the original altimetry data. The root mean squares of errors (RMSE) were 6.07 cm, 4.89 cm, 9.27 cm, 7.71 cm, and 9.88 cm, respectively, for each of the lakes, and ~44% less than differencing with the original altimetry data. Furthermore, the CICA results indicated that the water-level changes in the Great Lakes were significantly correlated with ENSO, with correlation coefficients of 0.5–0.8. The lake levels were ~25 cm higher (~30 cm lower) than normal during EI Niño (La Niña) events

Oscillatory surface rheotaxis of swimming E. coli bacteria

Bacterial contamination of biological conducts, catheters or water resources is a major threat to public health and can be amplified by the ability of bacteria to swim upstream. The mechanisms of this rheotaxis, the reorientation with respect to flow gradients, often in complex and confined environments, are still poorly understood. Here, we follow individual E. coli bacteria swimming at surfaces under shear flow with two complementary experimental assays, based on 3D Lagrangian tracking and fluorescent flagellar labelling and we develop a theoretical model for their rheotactic motion. Three transitions are identified with increasing shear rate: Above a first critical shear rate, bacteria shift to swimming upstream. After a second threshold, we report the discovery of an oscillatory rheotaxis. Beyond a third transition, we further observe coexistence of rheotaxis along the positive and negative vorticity directions. A full theoretical analysis explains these regimes and predicts the corresponding critical shear rates. The predicted transitions as well as the oscillation dynamics are in good agreement with experimental observations. Our results shed new light on bacterial transport and reveal new strategies for contamination prevention.Comment: 12 pages, 5 figure