Femtosecond Laser Written Volumetric Diffractive Optical Elements And Their Applications

Since the first demonstration of femtosecond laser written waveguides in 1996, femtosecond laser direct writing (FLDW) has been providing a versatile means to fabricate embedded 3-D microstructures in transparent materials. The key mechanisms are nonlinear absorption processes that occur when a laser beam is tightly focused into a material and the intensity of the focused beam reaches the range creating enough free electrons to induce structural modification. One of the most useful features that can be exploited in fabricating photonic structures is the refractive index change which results from the localized energy deposition. The laser processing system for FLDW can be realized as a compact, desktop station, implemented by a laser source, a 3-D stage and focusing optics. Thus, FLDW can be readily adopted for the fabrication of the photonic devices. For instance, it has been widely employed in various areas of photonic device fabrication such as active and passive waveguides, couplers, gratings, opto-fluidics and similar applications. This dissertation describes the use of FLDW towards the fabrication of custom designed diffractive optical elements (DOE’s). These are important micro-optical elements that are building blocks in integrated optical devices including on-chip sensors and systems. The fabrication and characterization of laser direct written DOEs in different glass materials is investigated. The design and performance of a range of DOE’s is described, especially, laser-written embedded Fresnel zone plates and linear gratings. Their diffractive efficiency as a function of the fabrication parameters is discussed and an optimized fabrication process is realized. The potential of the micro-DOEs and their integration shown in this dissertation will impact on the fabrication of future on-chip devices involving customized iv DOEs that will serve great flexibility and multi-functional capability on sensing, imaging and beam shaping

Individual and parental factors associated with preschool children’s foreign language anxiety in an EFL Setting

The present study aims to examine individual and parental factors that affect young children’s foreign language anxiety (FLA) in an EFL setting. Subjects include 453 mothers of young children aged 3 to 5 years old and of these participants, 217children attended regular kindergarten and 236 children attended English immersion institution. Both individual (child’s age, gender, temperament) and parental (parent’s educational attainment, household income, mother’s beliefs about early English education) factors were collected with mother’s self-report questionnaire. Children’s foreign language anxiety, however, was measured with both mother’s and teacher’s assessment. Results reveal that children’s age and temperament had significant effects on their level of foreign language anxiety. Older children were more prone to having a higher level of foreign language anxiety and children with a higher tendency for impulsiveness and harm avoidance were also more likely to show a higher level of foreign language anxiety. As for the parental factors, children of mothers with more concerns for early English education and stronger beliefs in cognitive benefits of early English education were more likely to show a higher level of foreign language anxiety. Future directions and implications will be discussed

Exhaled Nitric Oxide in Patients with Interstitial Lung Disease: A Pilot Study

Idiopathic pulmonary fibrosis (IPF) and sarcoidosis have an unknown etiology and require, periodic monitoring due to the insidious, unpredictable, and irreversible nature of disease progression. Exhaled nitric oxide (NO) has been used as a non-invasive marker of monitoring airway inflammation in patients with asthma and may have utility in monitoring airway inflammation in patients with IPF and sarcoidosis.The purpose of this pilot study was to explore the utility of exhaled NO in monitoring disease progression and response to therapy in patients with IPF and sarcoidosis. Individuals with IPF (n=15) and sarcoidosis (n=43), and healthy non-smokers (n=20) underwent single breath end-tidal NO (FeNO) measurement at 7 flow-rates (50, 100, 150, 200, 250, 300, & 400 ml/s) using a chemiluminescence analyzer (LR1800; Logan Research, UK) following ATS/ERS guidelines (2005). Alveolar NO concentration (CAlvNO) and airway NO flux (JAWNO) were estimated using the model by Tsoukias, et al. (1998). In individuals with active sarcoidosis, follow-up measurements were performed after being on treatmentThe findings in patients with IPF were: 1) FeNO was not significantly different from that of controls for the 7 flow rates; 2) while there was no significant difference in JAWNO compared with controls, CAlvNO was significantly higher, and 3) CAlvNO showed significant negative correlations with FEV1% and FVC%. In patients with sarcoidosis,: 1) FeNO at a flow rate of 50 ml/sec was lower than that of controls with marginal statistical significance (p=.05); 2) JAWNO , was significantly lower in patients with sarcoidosis compared to controls; there was no significant difference in CAlvNO; 3) CAlvNO showed significant negative correlations with FVC% and DLCO%. The subset of patients with active sarcoidosis (n=8) had significantly lower CAlvNO compared with those with inactive sarcoidosis (n=35), but no significant difference in FeNO and JAWNO. In six patients with active sarcoidosis who completed follow-up at various intervals, exhaled NO (FeNO, CAlvNO and JAWNO) did not change significantly as a result of treatment. Due to a large inter-subject variability in FeNO, confounding from medications used to manage this disease and variable concentrations of ambient NO, exhaled NO does not appear to be effective in detecting changes in airway inflammation in this population

KorNLI and KorSTS: New Benchmark Datasets for Korean Natural Language Understanding

Natural language inference (NLI) and semantic textual similarity (STS) are key tasks in natural language understanding (NLU). Although several benchmark datasets for those tasks have been released in English and a few other languages, there are no publicly available NLI or STS datasets in the Korean language. Motivated by this, we construct and release new datasets for Korean NLI and STS, dubbed KorNLI and KorSTS, respectively. Following previous approaches, we machine-translate existing English training sets and manually translate development and test sets into Korean. To accelerate research on Korean NLU, we also establish baselines on KorNLI and KorSTS. Our datasets are publicly available at https://github.com/kakaobrain/KorNLUDatasets.Comment: Findings of EMNLP 2020. Datasets available at https://github.com/kakaobrain/KorNLUDataset

Effects of a Four-Week Core Stability Exercise on Functional Movement and Balance in People with Mild Lower-limb Discomfort

This study aimed to investigate the effects of a short-term core stability exercise on functional movement and balance in people with mild lower-limb discomfort. Twenty people with mild lower-limb discomfort were randomly assigned to control (CG) and core stability exercise training groups (SG, n=10 each). The SG completed twenty 30-min training sessions consisting of Pilates exercises for four weeks. Functional movement, balance, and discomfort level were assessed before and after core stability exercise, using a functional movement test, balance test and visual analogue scale (VAS), respectively. A mixed ANOVA with repeated measures was performed to determine the differences. SG demonstrated a significant increase in hurdle step (p = 0.024, group × time effect) and shoulder mobility (p = 0.037, group × time effect). The dynamic balance scores were significantly increased from the baseline in both limbs (right, p = 0.007; left, p = 0.011, time effect). Post-hoc pairwise comparisons indicated these increases were significant only in SG. Additionally, ankle pain was significantly reduced in SG (p = 0.023, group × time effect). This study highlights that four weeks of core stability exercise can positively affect the lower limbs’ functional movement and balance in people with mild lower-limb discomfort