• Korean Journal of Environment and Ecology
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• v.21 no.4
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• pp.366-373
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• 2007

This study researched the number of individuals of Roe deer (Capreolus pygarus tianschanicus Satunin), which inhabit Mt. Halla (Hallasan) National Park and its neighboring areas ranging about $270km^2$ areas. The research was done from November(late fall), 1998 to March(early spring), 2001, and additional research was carried out from November 2006 to January 2007. As a result of this, we identified a total of 1,444 deer, and found out the fact that there lived 5.33 deer per $km^2$. By region, we identified a maximum of 270 deer at Donnaeko hiking path and a minimum of 12 deer at the adjacent areas to the second Sanrok-road. The frequency of Roe deer group sighting was higher at the edge of Hallasan National Park than any other surveyed region. Thus, it is estimated that the distribution of Roe deer of Hallasan is more influenced by the quantity and quality of food than human-made interference during wintry season.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.393-393
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• 2012

Optically active nanostructures such as subwavelength moth-eye antireflective structures or surface enhanced Raman spectroscopy (SERS) active structures have been demonstrated to provide the effective suppression of unwanted reflections as in subwavelength structure (SWS) or effective enhancement of selective signals as in SERS. While various nanopatterning techniques such as photolithography, electron-beam lithography, wafer level nanoimprinting lithography, and interference lithography can be employed to fabricate these nanostructures, roll-to-roll (R2R) nanoimprinting is gaining interests due to its low cost, continuous, and scalable process. R2R nanoimprinting requires a master to produce a stamp that can be wrapped around a quartz roller for repeated nanoimprinting process. Among many possibilities, two different types of mask can be employed to fabricate optically active nanostructures. One is self-assembled Au nanoparticles on Si substrate by depositing Au film with sputtering followed by annealing process. The other is monolayer silica particles dissolved in ethanol spread on the wafer by spin-coating method. The process is optimized by considering the density of Au and silica nano particles, depth and shape of the patterns. The depth of the pattern can be controlled with dry etch process using reactive ion etching (RIE) with the mixture of SF6 and CHF3. The resultant nanostructures are characterized for their reflectance using UV-Vis-NIR spectrophotometer (Agilent technology, Cary 5000) and for surface morphology using scanning electron microscope (SEM, JEOL JSM-7100F). Once optimized, these optically active nanostructures can be used to replicate with roll-to-roll process or soft lithography for various applications including displays, solar cells, and biosensors.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.7
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• pp.3-8
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• 2016

We propose a modified form of the decision-directed least mean square (DD LMS) algorithm that is widely used in the optimization of self-adaptive equalizers, and show the modified version greatly improves the initial convergence properties of the conventional algorithm. Existing DD LMS regards the difference between a equalizer output and a quantization value for it as an error, and achieves an optimization of the equalizer based on minimizing the mean squared error cost function for the equalizer coefficients. This error generating method is useful for binary signal or a single-level signals, however, in the case of multi-level signals, it is not effective in the initialization of the equalizer. The modified DD LMS solves this problem by modifying the error generation. We verified the usefulness and performance of the modified DD LMS through experiments with multi-level signals under distortions due to intersymbol interference and additive noise.

• Journal of Oral Medicine and Pain
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• v.45 no.3
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• pp.56-64
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• 2020

Purpose: Temporomandibular disorders (TMD) is a mosaic of clinical signs and symptoms that can be regarded as a set of phenotypes that are affected by various factors including pain sensitivity, pain disability, sleep and psychological functioning. The aims of this study were to evaluate association of pain experience, sleep quality and psychological distress with different phenotypes of TMD patients. Methods: This retrospective study included a cohort (n=1,858; 63.8% for female, mean age=34.9±15.9 years) of patients with TMD. A set of self-administered questionnaires concerning pain interference (Brief Pain Inventory), pain disability (Graded Chronic Pain Scale), sleep quality (Pittsburg Sleep Questionnaire Index), psychological distress (Symptom Checklist-90 revised), and pain catastrophizing (Pain Catastrophizing Scale) were administered to all participants at the first consultation. All TMD patients were classified into four groups including TMD with internal derangement without pain (TMD_ID, n=370), TMD with joint pain (TMD_J, n=571), TMD with muscle pain (TMD_M, n=541) and TMD with muscle-joint combined pain (TMD_MJ, n=376). Results: The female ratio was particularly high in the group with TMD_MJ (p=0.001). The patients with muscle pain and both muscle and joint pain had longer symptom duration (p=0.004) and presented significantly higher scores in pain experience (p<0.001), subjective sleep quality (p<0.001), pain catastrophizing (p<0.001) and psychological distress (p<0.05) except for paranoid-ideation than the groups with only joint problems. Conclusions: The results of this study highlight the importance of multi-dimensional approach that consider pain disability, sleep quality, and psychological functioning in the management of TMD with muscle component. This study would contribute to a better understanding of interaction between heterogeneous TMD and multiple risk factors in order to build tailored treatment based on different phenotypes.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.1
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• pp.52-57
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• 2016

We introduce a hybrid scheduling in a multi-path poor scattering full-duplex (FD) system, which consists of one multi-antenna FD base station and a large number of single-antenna half-duplex mobile stations. Our hybrid scheduling utilizes partial channel state information at the transmitter. In particular, unlike the conventional scheduling method using opportunistic transmission for both uplink and downlink, the proposed scheme combines a random transmit beamforming for downlink and a zero forcing beamforming for uplink. As our main result, via computer simulations, it is shown that the proposed scheme has a superior sum-rate performance than that of the conventional scheduling method beyond a certain signal-to-noise ratio regime.

• Journal of Korean society of Dental Hygiene
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• v.12 no.6
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• pp.1128-1137
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• 2012

Objectives : The purpose of this study was to identify the factors that affect working environment related musculoskeletal subjective symptoms among dental hygienists. Methods : The subjects in this study were 232 dental hygienists working at dental clinics and general hospitals in Daegu. The data has collected through the self-questionnaire survey from July 9th 2012 to July 31th. Results : 1. Musculoskeletal subjective symptoms were 85.3% in shoulder(right), 81.9% in neck, 74.6% in shoulder(left), 65.5% in wrist(right), 56.5% in lower leg(right). 2. Pain frequency of musculoskeletal subjective symptoms were the highest 24.7% in neck. Seeing the severity pain was the highest 9.0% in foot(left). The investigation of work interference related to substantially pain showed the highest 18.5% in wrist(right). 3. Musculoskeletal subjective symptoms correlated with general characteristics such as age, marital status, regular exercise and medical check-up(p<.05). 4. Musculoskeletal subjective symptoms correlated with working environments such as working career, the night treatment, the average daily number of patients handled, the average daily standing work hours, the regular rest, the major job in work place and physical burden(p<.05). Conclusions : The education or program on wrong working habits and bad postures of dental hygienists is needed to prevent musculoskeletal disorder.

• Journal of the Korean Magnetics Society
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• v.13 no.2
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• pp.59-63
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• 2003

Superparamagnetic properties of self-aggregated cobalt nanoparticles in the perfluorinated ion-exchange polymeric membrane (MF-4SK) prepared by ion-exchange and recovery methods were investigated by transmission electron microscopy (TEM) and superconducting quantum interference device (SQUID) magnetometer at various temperatures. Our experimental results show that cobalt nanoparticles in MF-4SK for the concentration of $7.8{\times}10^{19}$ atoms per 1 g of polymer membrane exhibit superparamagnetic properties above the average blocking temperature ($T_{B}$), which is determined to be around 185 K at applied field of 500 Oe. The average particle radius of 4.0 nm achieved from Langevin function fit is in good agreement with TEM observations. This experimental evidence suggests that cobalt nanoparticles in polymer film obey a single domain theory. The results are discussed in the light of current theory for the superparamagnetic behavior of magnetic nanoparticles.

• Journal of dental hygiene science
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• v.17 no.5
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• pp.447-453
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• 2017

The purpose of this study was to analyze the relationship between objective oral health status determined by dentists, self-perceived subjective oral health status, and oral health related quality of life (OHRQoL) in the elderly. The related factors affecting OHRQoL in the elderly were also surveyed. Four hundred and thirty elderly individuals who visited the three public health centers and four dental clinics in Busan were selected by convenience sampling. Twelve dental hygienists investigated the subjective oral health status and OHRQoL using the 14-item Oral Health Impact Profile (OHIP-14) and twentyone dentists examined the objective oral health status, including healthy remaining teeth, treated remaining teeth, functional remaining teeth, missing teeth, and non-treated missing teeth. Data were analyzed using SPSS ver. 12.0. OHRQoL was higher when oral and periodontal status was perceived as healthy, when there was no toothache, no interference in mastication, and when study subjects had the ability of food softening. It was also higher when study subjects had ${\geq}20$ remaining teeth and <9 missing teeth, and were wearing denture. The related factors affecting OHRQoL of the elderly were the type of medical insurance, toothache, ability of food softening, perception of periodontal status, and the number of healthy remaining teeth. There was a significant relationship between the subjective-objective oral health status and OHRQoL in the elderly. A continuous oral health care system aimed at retaining ${\geq}20$ healthy remaining teeth is needed to improve oral health and OHRQoL for the elderly, especially for the elderly receiving medical aid.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.43-46
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• 2015

Recently, full-duplex communications has been considered as one of the most promising techniques for net-generation mobile communication system. In this paper, we propose a compressed sensing based signal detection technique for full-duplex generalized spatial modulation (FD-GSM) systems. In FD-GSM systems, some antennas are used for signal transmission according to input data and the otehrs are used for detecting signals received over the same frequency band. The self-interference (SI) is assumed to be completely removed by help for the recently proposed SI cancellation techniques. The proposed signal detection technique significantly outperforms the conventional ones in terms of symbol error rate (SER). We will investigate the optimal number of used antennas in FD-GSM systems.

• Korean Journal of Optics and Photonics
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• v.17 no.1
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• pp.54-59
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• 2006

Biophotonic sensors based on polymer waveguide with Bragg reflection grating are demonstrated in this work. Waveguide Bragg reflectors were designed by using the effective index method and the transmission matrix method. The grating pattern was formed by exposing the laser interference pattern on a photoresist. On top of the inverted rib waveguide, the Bragg reflection grating was inscribed by the O2 plasma etching. In order to perform the bio-molecule detection experiment, a calixarene molecule was self-assembled on top of thin Au film deposited on the waveguide Bragg reflector. To measure the response of the sensor, several PBS solutions with different concentrations of potassium ion from 1 pM to $100\;{\mu}M$ were dropped on the sensor surface. The shift of Bragg reflection wavelength was observed from the fabricated sensor device, which was proportional to the concentration of potassium ion ranging from 1 pM to 108 pM.