Preparing Asian ESOL Teachers to Respond to Student Writing: A Systemic Functional Linguistic Perspective in Action

L2 teachers generally lack the ability to respond to student writing in productive ways, because L2 teacher education has typically not developed teachers’ understanding of how language works in constructing meaningful texts. To address the need for preparing teachers to give meaningful feedback, this study investigates the professional experiences of Asian English language teachers (ELTs) who participated in a professional development program informed by Halliday’s systemic functional linguistics (SFL). This program attempts to apprentice teachers to becoming critical text analysts who are able to analyze the linguistic features of their students’ emergent writing practices and provide informed feedback. The research question guiding this study is: How does coursework in SFL influence Asian ELTs’ approach to responding to student writing? This study uses qualitative case study methods, and focuses on two specific time frames for data collection: 1) over 28 weeks (two semesters) of a SFL-based professional development course; 2) over ELTs’ teaching practicum conducted eight months after the completion of the course. Multiple types of data were collected, including the researcher’s fieldnotes, interviews, ELTs’ course assignments and written responses to student writing samples. The data were analyzed inductively, using multiple layers of coding, theme identification, and relational analysis. The findings indicate that ELTs progressed from offering decontextualized reactions to lexical and syntactic issues (e.g., correcting errors, calling for a wider vocabulary) to providing feedback aimed at strengthening meaning in a text. Specifically, ELTs were able to identify students’ ineffectual register choices for constructing texts relevant to specific genres and writing tasks, and offer linguistically-precise guidance for improvement. However, since ELTs’ uptake of SFL was highly influenced by their exam-oriented, formalism-informed language education and socialization in Asia, they usually addressed the issue of genre stages in student writing prescriptively. They also emphasized students’ language choices in constructing content (ideational meaning) and managing information flow (textual meaning), while overlooking features of voice (interpersonal meaning) in student text. The study contributes to research and practice of L2 writing teacher education by providing empirical information regarding the opportunities and challenges of using SFL to support Asian ELTs’ professional development in responding to student writing

Nuclear matter symmetry energy and the neutron skin thickness of heavy nuclei

Correlations between the thickness of the neutron skin in finite nuclei and the nuclear matter symmetry energy are studied in the Skyrme Hartree-Fock model. From the most recent analysis of the isospin diffusion data in heavy-ion collisions based on an isospin- and momentum-dependent transport model with in-medium nucleon-nucleon cross sections, a value of $L=88\pm 25$ MeV for the slope of the nuclear symmetry energy at saturation density is extracted, and this imposes stringent constraints on both the parameters in the Skyrme effective interactions and the neutron skin thickness of heavy nuclei. Predicted thickness of the neutron skin is $0.22\pm 0.04$ fm for $$Pb, $0.29\pm 0.04$ fm for $^{132}$Sn, and $0.22\pm 0.04$ fm for $$Sn.Comment: 6 pages, 4 figures, 1 table, revised version, to appear in PR

Development of Superplastic Structural Ceramics

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65140/1/j.1151-2916.1990.tb06734.x.pd

Thermodynamical Properties and Quasi-localized Energy of the Stringy Dyonic Black Hole Solution

In this article, we calculate the heat flux passing through the horizon $. {\bf TS}|_{r_h}$ and the difference of energy between the Einstein and M{\o}ller prescription within the region ${\cal M}$, in which is the region between outer horizon ${\cal H}_+$ and inner horizon ${\cal H}_-$, for the modified GHS solution, KLOPP solution and CLH solution. The formula . E_{\rm Einstein}|_{\cal M} = . E_{\rm M{\o}ller}|_{\cal M} - \sum_{\partial {\cal M}} {\bf TS}$ is obeyed for the mGHS solution and the KLOPP solution, but not for the CLH solution. Also, we suggest a RN-like stringy dyonic black hole solution, which comes from the KLOPP solution under a dual transformation, and its thermodynamical properties are the same as the KLOPP solution

Stress-Energy Tensor Induced by Bulk Dirac Spinor in Randall-Sundrum Model

Motivated by the possible extension into a supersymmetric Randall-Sundrum (RS) model, we investigate the properties of the vacuum expectation value (VEV) of the stress-energy tensor for a quantized bulk Dirac spinor field in the RS geometry and compare it with that for a real scalar field. This is carried out via the Green function method based on first principles without invoking the degeneracy factor, whose validity in a warp geometry is a priori unassured. In addition, we investigate the local behavior of the Casimir energy near the two branes. One salient feature we found is that the surface divergences near the two branes have opposite signs. We argue that this is a generic feature of the fermionic Casimir energy density due to its parity transformation in the fifth dimension. Furthermore, we investigate the self-consistency of the RS metric under the quantum correction due to the stress-energy tensor. It is shown that the VEV of the stress-energy tensor and the classical one become comparable near the visible brane if k ~ M ~ M_Pl (the requirement of no hierarchy problem), where k is the curvature of the RS warped geometry and M the 5-dimensional Planck mass. In that case the self-consistency of RS model that includes bulk fields is in doubt. If, however, k <~ M, then an approximate self-consistency of the RS-type metric may still be satisfied.Comment: 7 pages with 2 figure

Mean free paths and in-medium scattering cross sections of energetic nucleons in neutron-rich nucleonic matter within the relativistic impulse approximation

The mean free paths and in-medium scattering cross sections of energetic nucleons in neutron-rich nucleonic matter are investigated using the nucleon optical potential obtained within the relativistic impulse approximation with the empirical nucleon-nucleon scattering amplitudes and the nuclear densities obtained in the relativistic mean field model. It is found that the isospin-splitting of nucleon mean free paths, sensitive to the imaginary part of the symmetry potential, changes its sign at certain high kinetic energy. The in-medium nucleon-nucleon cross sections are analytically and numerically demonstrated to be essentially independent of the isospin asymmetry of the medium and increase linearly with density in the high energy region where the relativistic impulse approximation is applicable.Comment: 13 pages, 6 figure

Superplastic Alumina Ceramics with Grain Growth Inhibitors

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65476/1/j.1151-2916.1991.tb06935.x.pd

Effect of symmetry energy on two-nucleon correlation functions in heavy-ion collisions induced by neutron-rich nuclei

Using an isospin-dependent transport model, we study the effects of nuclear symmetry energy on two-nucleon correlation functions in heavy ion collisions induced by neutron-rich nuclei. We find that the density dependence of the nuclear symmetry energy affects significantly the nucleon emission times in these collisions, leading to larger values of two-nucleon correlation functions for a symmetry energy that has a stronger density dependence. Two-nucleon correlation functions are thus useful tools for extracting information about the nuclear symmetry energy from heavy ion collisions.Comment: Revised version, to appear in Phys. Rev. Let

Fast distributed first-order methods

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 91-94).This thesis provides a systematic framework for the development and analysis of distributed optimization methods for multi-agent networks with time-varying connectivity. The goal is to optimize a global objective function which is the sum of local objective functions privately known to individual agents. In our methods, each agent iteratively updates its estimate of the global optimum by optimizing its local function and exchanging estimates with others in the network. We introduce distributed proximal-gradient methods that enable the use of a gradient-based scheme for non-differentiable functions with a favorable structure. We present a convergence rate analysis that highlights the dependence on the step size rule. We also propose a novel fast distributed method that uses Nesterov-type acceleration techniques and multiple communication steps per iteration. Our method achieves exact convergence at the rate of O(1/t) (where t is the number of communication steps taken), which is superior than the rates of existing gradient or subgradient algorithms, and is confirmed by simulation results.by I-An Chen.S.M