Understanding the Dimensions of Education Inequality in China at Different Geographical Scales

Although education equality has been valued and frequently discussed by scholars from different disciplines, theoretical discussions and empirical studies of education equality from a geographical perspective have been somewhat limited. Since the traditional two-dimensional non-spatial framework for measuring and analysing education inequality is inadequate, the research in this thesis is based on a more comprehensive and flexible three-dimensional framework, in which geography is included as an important dimension. China is used as the case study country to examine education inequalities at different geographical scales. At a regional scale, a multidimensional Index of Regional Education Advantage (IREA), underpinned by Amartya Sen’s capability approach, is introduced to evaluate the effectiveness of policies targeted at reducing regional/provincial educational inequalities in China since 2005. At a local scale, the thesis explores the use of geodemographics as a means of assessing potential inequality in access to compulsory education within urban areas. The thesis argues that applying an area classification, one of the first in China, allows consideration of multi-dimensional, socio-spatial influences which affect school choice within urban areas. The ideas are illustrated through a case study of Central Beijing. At the micro scale, multilevel modelling is used to reveal the influence of contextual factors and confounding individual level socio-economic characteristics on pupils’ travel distance to school in Beijing. The results at the regional scale revealed that education in north-eastern China is better than in the south-west of the country, a pattern which lacks conformity with the eastern, middle and western macro-divisions adopted by Central Government as the basis of policy implementation. Furthermore, the social and spatial disparities in terms of access to education facilities within urban areas were also identified. This research has, for the first time, revealed education inequality in China comprehensively from a geographical perspective, and provides some unique insights and crucial policy implications of education inequalities in China at different geographical scales

Projector calibration method based on optical coaxial camera

This paper presents a novel method to accurately calibrate a DLP projector by using an optical coaxial camera to capture the needed images. A plate beam splitter is used to make imaging axis of the CCD camera and projecting axis of the DLP projector coaxial, so the DLP projector can be treated as a true inverse camera. A plate having discrete markers on the surface will be designed and manufactured to calibrate the DLP projector. By projecting vertical and horizontal sinusoidal fringe patterns on the plate surface from the projector, the absolute phase of each marker’s center can be obtained. The corresponding projector pixel coordinate of each marker is determined from the obtained absolute phase. The internal and external parameters of the DLP projector are calibrated by the corresponding point pair between the projector coordinate and the world coordinate of discrete markers. Experimental results show that the proposed method accurately obtains the parameters of the DLP projector. One advantage of the method is the calibrated internal and external parameters have high accuracy because of uncalibrating the camera. The other is the optical coaxes geometry gives a true inverse camera, so the calibrated parameters are more accurate than that of crossed-optical-axes, especially the principal points and the radial distortion coefficients of the projector lens

Towards Bias Correction of FedAvg over Nonuniform and Time-Varying Communications

Federated learning (FL) is a decentralized learning framework wherein a parameter server (PS) and a collection of clients collaboratively train a model via minimizing a global objective. Communication bandwidth is a scarce resource; in each round, the PS aggregates the updates from a subset of clients only. In this paper, we focus on non-convex minimization that is vulnerable to non-uniform and time-varying communication failures between the PS and the clients. Specifically, in each round $t$, the link between the PS and client $i$ is active with probability $p_i^t$, which is $\textit{unknown}$ to both the PS and the clients. This arises when the channel conditions are heterogeneous across clients and are changing over time. We show that when the $p_i^t$'s are not uniform, $\textit{Federated Average}$ (FedAvg) -- the most widely adopted FL algorithm -- fails to minimize the global objective. Observing this, we propose $\textit{Federated Postponed Broadcast}$ (FedPBC) which is a simple variant of FedAvg. It differs from FedAvg in that the PS postpones broadcasting the global model till the end of each round. We show that FedPBC converges to a stationary point of the original objective. The introduced staleness is mild and there is no noticeable slowdown. Both theoretical analysis and numerical results are provided. On the technical front, postponing the global model broadcasts enables implicit gossiping among the clients with active links at round $t$. Despite $p_i^t$'s are time-varying, we are able to bound the perturbation of the global model dynamics via the techniques of controlling the gossip-type information mixing errors

Measuring and assessing regional education inequalities in China under changing policy regimes

China’s uneven regional economic development and decentralisation of its education system have led to increasing regional education disparities. Here, we introduce a new multidimensional index, the Index of Regional Education Advantage (IREA), underpinned by Amartya Sen’s capability approach, to evaluate the effectiveness of policies targeted at reducing regional/provincial educational inequalities in China since 2005. The analysis of the distribution of IREA scores and the decomposition of the index reveals that education in north-eastern China is better than in the south-west part of the country, a pattern which lacks conformity with the eastern, middle and western macro-divisions adopted by Central Government as the basis of policy implementation. In addition, the education of migrant children and the low transfer rate into high schools are identified as key issues requiring Government attention

Advanced liposome-loaded scaffolds for therapeutic and tissue engineering applications

Liposome is one of the most commonly used drug delivery systems in the world, due to its excellent biocompatibility, satisfactory ability in controlling drug release, and passive targeting capability. However, some drawbacks limit the application of liposomes in clinical, such as problems in transporting, storing, and difficulties in maintaining the drug concentration in the local area. Scaffolds usually are used as implants to supply certain mechanical supporting to the defective area or utilized as diagnosis and imaging methods. But, in general, unmodified scaffolds show limited abilities in promoting tissue regeneration and treating diseases. Therefore, liposome-scaffold composite systems are designed to take advantages of both liposomes’ biocompatibility and scaffolds’ strength to provide a novel system that is more suitable for clinical applications. This review introduces and discusses different types of liposomes and scaffolds, and also the application of liposome-scaffold composite systems in different diseases, such as cancer, diabetes, skin-related diseases, infection and human immunodeficiency virus, and in tissue regeneration like bone, teeth, spinal cord and wound healing.Peer reviewe

Visualizing the elongated vortices in γ\gamma-Ga nanostrips

We study the magnetic response of superconducting $\gamma$-Ga via low temperature scanning tunneling microscopy and spectroscopy. The magnetic vortex cores rely substantially on the Ga geometry, and exhibit an unexpectedly-large axial elongation with aspect ratio up to 40 in rectangular Ga nano-strips (width $l$ $<$ 100 nm). This is in stark contrast with the isotropic circular vortex core in a larger round-shaped Ga island. We suggest that the unusual elongated vortices in Ga nanostrips originate from geometric confinement effect probably via the strong repulsive interaction between the vortices and Meissner screening currents at the sample edge. Our finding provides novel conceptual insights into the geometrical confinement effect on magnetic vortices and forms the basis for the technological applications of superconductors.Comment: published in Phys. Rev. B as a Rapid Communicatio

GPR48-Induced keratinocyte proliferation occurs through HB-EGF mediated EGFR transactivation

AbstractGPR48 can mediate keratinocyte proliferation and migration. Our investigations showed that AG1478, an inhibitor of EGFR tyrosine kinase, could block GPR48-mediated cellular processes. AG1478 treatment of Gpr48+/+ cells also decreased phosphorylation of EGFR, ERK and STAT3. Subsequent screening using conditioned media immunodepleted of EGFR ligands identified HB-EGF as the ligand responsible for phosphorylation of EGFR, ERK and STAT3. HB-EGF was reduced in Gpr48−/− cell culture medium, but its addition restored the phosphorylation of EGFR, ERK, STAT3, as well as cell proliferation. Confirmation that GPR48 mediates EGFR signaling pathway through HB-EGF was subsequently performed using an inhibitor of HB-EGF