Develmental patterns of Korean EFL learners' English argument structure constructions

The present study aims to explore developmental patterns of constructional knowledge of Korean EFL learners. The study asked120 Korean learners of English to carry out a sentence sorting and a translation task, and investigated how the participants atthree different proficiency levels use their constructional knowledge to comprehend English sentences. The results from thesorting task showed that the learners in the beginner group relied more heavily on verb-centered sorting than the learners in theintermediate group. The results from the translation task revealed that the L2 learners ability to comprehend complexconstructions is highly correlated with their proficiency in the target language. The study suggests that L2 learners' constructionalknowledge is acquired incrementally as their exposure to the target language extends, supporting one of the main premises of theusage-based approach to language and language acquisition.OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000001658/1SEQ:1PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000001658ADJUST_YN:NEMP_ID:A002679DEPT_CD:707CITE_RATE:0FILENAME:developmental patterns of korean efl learners english argument structure constructions.docDEPT_NM:영어교육과EMAIL:[email protected]:

Enhanced efficiency of crystalline Si solar cells based on kerfless-thin wafers with nanohole arrays

Several techniques have been proposed for kerfless wafering of thin Si wafers, which is one of the most essential techniques for reducing Si material loss in conventional wafering methods to lower cell cost. Proton induced exfoliation is one of promising kerfless techniques due to the simplicity of the process of implantation and cleaving. However, for application to high efficiency solar cells, it is necessary to cope with some problems such as implantation damage removal and texturing of (111) oriented wafers. This study analyzes the end-of-range defects at both kerfless and donor wafers and ion cutting sites. Thermal treatment and isotropic etching processes allow nearly complete removal of implantation damages in the cleaved-thin wafers. Combining laser interference lithography and a reactive ion etch process, a facile nanoscale texturing process for the kerfless thin wafers of a (111) crystal orientation has been developed. We demonstrate that the introduction of nanohole array textures with an optimal design and complete damage removal lead to an improved efficiency of 15.2% based on the kerfless wafer of a 48 mu m thickness using the standard architecture of the Al back surface field

Deep Learning-Based Prediction of Resource Block Usage Rate for Spectrum Saturation Diagnosis

Strict restrictions on spectrum utilization and the rapid increases in mobile users have brought fundamental challenges for mobile network operators in securing sufficient spectrum resources. In designing reliable cellular networks, it is essential to predict spectrum saturation events in the future by analyzing the past behavior of base stations, especially their frequency resource block (RB) utilization states. This paper investigates a deep learning-based forecasting strategy of the future RB usage rate (RBUR) status of hundreds of LTE base stations deployed in Seoul, South Korea. The dataset consists of real measurement RBUR samples with a randomly varying number of base stations at each measurement time. This poses a difficulty in handling variable-length RBUR data vectors, which is not trivial for state-of-the-art deep learning estimation models, e.g., recurrent neural networks (RNNs), developed for handling fixed-length inputs. To this end, we propose a two-step RBUR estimation approach. In the first step, we extract a useful feature of the RBUR dataset that accurately approximates the behavior of the top quantile base stations. The feature parameters are carefully designed to be fixed-length vectors regardless of the dimensions of the raw RBUR samples. The fixed-length feature parameter vectors are readily exploited as the training dataset of RNN-based prediction models. Thus, in the second step, we propose a feature estimation strategy where the RNN is trained to predict the future RBUR from the input feature parameter sequences. With the estimated RBUR at hand, we can easily predict the spectrum saturation of the future LTE systems by examining the resource utilization states of the top quantile base stations. Numerical results demonstrate the performance of the proposed RBUR estimation methods with the real measurement dataset

One-Step Peptide Backbone Dissociations in Negative-Ion Free Radical Initiated Peptide Sequencing Mass Spectrometry

Peptide dissociation behavior in TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl)-based FRIPS (free radical initiated peptide sequencing) mass spectrometry was analyzed in both positive- and negative-ion modes for a number of peptides including angiotensin II, kinetensin, glycoprotein IIb fragment (296-306), des-Pro(2)-bradykinin, and ubiquitin tryptic fragment (43-48). In the positive mode, the center dot Bz-C(O)-peptide radical species was produced exclusively at the initial collisional activation of o-TEMPO-Bz-C(O)-peptides, and two consecutive applications of collisional activation were needed to observe peptide backbone fragments. In contrast, in the negative-ion mode, a single application of collisional activation to o-TEMPO-Bz-C(O)-peptides produced extensive peptide backbone fragmentations as well as center dot Bz-C(O)-peptide radical species. This result indicates that the duty cycle in the TEMPO-based FRIPS mass spectrometry can be reduced by one-half in the negative-ion mode. In addition, the fragment ions observed in the negative-ion experiments were mainly of the a-, c-, x-, and z-types, indicating that radical-driven tandem mass spectrometry was mainly responsible for the TEMPO-based FRIPS even with a single application of collisional activation. Furthermore, the survival fraction analysis of o-TEMPO-Bz-C(O)-peptides was made as a function of the applied normalized collision energy (NCE). This helped us to better understand the differences in FRIPS behavior between the positive- and negative-ion modes in terms of dissociation energetics. The duty-cycle improvement made in the present study provides a cornerstone for future research aiming to achieve a single-step FRIPS in the positive-ion mode.X112118sciescopu

[Cu-64]Cu-Albumin Clearance Imaging to Evaluate Lymphatic Efflux of Cerebrospinal Space Fluid in Mouse Model

Purpose Clearance of brain waste in the cerebrospinal fluid (CSF) through the meningeal lymphatic vessels (mLV) has been evaluated mostly through the fluorescent imaging which has inherent limitations in the context of animal physiology and clinical translatability. The study aimed to establish molecular imaging for the evaluation of mLV clearance function. Methods Radionuclide imaging after intrathecal (IT) injection was acquired in C57BL/6 mice of 2-9 months. The distribution of [Tc-99m]Tc-diethylenetriamine pentaacetate (DTPA) and [Cu-64]Cu-human serum albumin (HSA) was comparatively evaluated. Evans Blue and [Cu-64]Cu-HSA were used to evaluate the distribution of tracer under various speed and volume conditions. Results [Tc-99m]Tc-DTPA is not a suitable tracer for evaluation of CSF clearance via mLV as no cervical lymph node uptake was observed while it was cleared from the body. A total volume of 3 to 9 mu L at an infusion rate of 300 to 500 nL/min was not sufficient for the tracer to reach the cranial subarachnoid space and clear throughout the mLV. As a result, whole-body positron emission tomography imaging using [Cu-64]Cu-HSA at 700 nL/min, to deliver 6 mu L of injected volume, was set for characterization of the CSF to mLV clearance. Through this protocol, the mean terminal CSF clearance half-life was measured to be 123.6 min (range 117.0-135.0) in normal mice. Conclusions We established molecular imaging to evaluate CSF drainage through mLV using [Cu-64]Cu-HSA. This imaging method is expected to be extended in animal models of dysfunctional meningeal lymphatic clearance and translational research for disease-modifying therapeutic approaches.N