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

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

Delivering an In-Home Exercise Program via Telerehabilitation: A Pilot Study of Lung Transplant Go (LTGO)

We evaluated the feasibility, safety, system usability, and intervention acceptability of Lung Transplant Go (LTGO), an 8-week in-home exercise intervention for lung transplant recipients using a telerehabilitation platform, and described changes in physical function and physical activity from baseline to post-intervention. The intervention was delivered to lung transplant recipients in their home via the Versatile and Integrated System for TeleRehabilitation (VISYTER). The intervention focused on aerobic and strengthening exercises tailored to baseline physical function. Participants improved walk distance (6-minute walk distance), balance (Berg Balance Scale), lower body strength (30-second chair stand test) and steps walked (SenseWear Armband®). No adverse events were reported. Participants rated the program highly positively in regard to the technology and intervention. The telerehabilitation exercise program was feasible, safe, and acceptable. Our findings provide preliminary support for the LTGO intervention to improve physical function and promote physical activity in lung transplant recipients.

Attention mechanisms and emotion judgment for Korean and American emotional faces: an eye movement study

IntroductionThis study investigates attention mechanisms and the accuracy of emotion judgment among South Korean children by employing Korean and American faces in conjunction with eye-tracking technology.MethodsA total of 42 participants were individually presented with photos featuring either Korean or American children, and their task was to judge the emotions conveyed through the facial expressions in each photo. The participants’ eye movements during picture viewing were meticulously observed using an eye tracker.ResultsThe analysis of the emotion judgment task outcomes revealed that the accuracy scores for discerning emotions of joy, sadness, and anger in Korean emotional faces were found to be significantly higher than those for American children. Conversely, no significant difference in accuracy scores was observed for the recognition of fear emotion between Korean and American faces. Notably, the study also uncovered distinct patterns of fixation duration among children, depending on whether they were viewing Korean or American faces. These patterns predominantly manifested in the three main facial areas of interest, namely the eyes, nose, and mouth.DiscussionThe observed phenomena can be best understood within the framework of the “other-race effect.” Consequently, this prototype formation leads to heightened accuracy in recognizing and interpreting emotional expressions exhibited by faces belonging to the same racial group. The present study contributes to a deeper understanding of how attention mechanisms and other-race effects impact emotion judgment among South Korean children. The utilization of eye-tracking technology enhances the validity and precision of our findings, providing valuable insights for both theoretical models of face processing and practical applications in various fields such as psychology, education, and intercultural communication