• Science of Emotion and Sensibility
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• v.22 no.1
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• pp.89-100
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• 2019

Sleep apnea, a medical condition associated with a variety of complications, is generally monitored by standard sleep polysomnography, which is expensive and uncomfortable. To overcome these limitations, this study proposes an unconstrained wearable monitoring system with stretch-fiber sensors that integrate with the wearer's clothing. The system allows patients to undergo examinations in a familiar environment while minimizing the occurrence of skin allergies caused by adhesive tools. As smart clothing for adult males with sleep apnea, long-sleeved T-shirts embedding fibrous sensors were developed, enabling real-time monitoring of the patients' breathing rate, oxygen saturation, and airflow as sleep apnea diagnostic indicators. The gauge factor was measured as 20.3 in sample 4. The maximum breathing intake, measured during three large breaths, was 2048 ml. the oxygen saturation was measured before and during breath-holding. The oxygen saturation change was 69.45%, showing a minimum measurable oxygen saturation of 70%. After washing the garment, the gauge factor reduced only to 18.0, confirming the durability of the proposed system. The wearable sleep apnea monitoring smart clothes are readily available in the home and can measure three indicators of sleep apnea: respiration rate, breathing flow and oxygen saturation.

• The Journal of the Acoustical Society of Korea
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• v.42 no.6
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• pp.491-499
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• 2023

Scattering by Sea surface roughness occurs due to sea level roughness, communication performance deteriorates by causing frequency spread in communication signals and time variation in communication channels. In order to compare the difference in time variation of underwater acoustic communication channel according to the surface roughness, an experiment was performed in a tank owned by Hanyang University Ocean Acoustics Lab. Artificial surface roughness was created in the tank and communication signals with three bandwidths were used (8 kHz, 16 kHz, 32 kHz). The measured surface roughness was converted into a Rayleigh parameter and used as a roughness parameter, and statistical analysis was performed on the time-varying channel characteristics of the surface path using Doppler spread and correlation time. For the Doppler spread of the surface path, the Weighted Root Mean Square Doppler spread (w_fσ_ν) that corrected the effect of the carrier frequency and bandwidth of the communication signal was used. Using the correlation time of the surface path and the energy ratio of the direct path and the surface path, the correlation of total channels was simulated and compared with the measured correlation time of total channels. In this study, we propose a method for efficient communication signal design in an arbitrary marine environment by using the time-varying characteristics of the sea surface path according to the sea surface roughness.

• Proceeding of EDISON Challenge
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• 2016.11a
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• pp.35-43
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• 2016

본 연구에서는 EDISON의 해석자를 활용하여 선박의 최적 운항 자세 도출과 같은 실용적 문제 해석뿐 만 아니라 자유 수면 및 대칭 경계 조건이 수직한 몰수 익형 주위 유동에 미치는 영향을 분석하는 학술적 연구를 수행하였다. 선박의 자세에 따른 저항 변화를 분석한 결과 0.5m 선수 트림에서 선체 저항이 가장 작은 것으로 나타났으며, 이는 유동 가속에 의한 선수 어깨부의 낮은 압력 및 선미부에서의 압력 회복에 의한 것이다. 반면, 1.0m 선미 트림에서 선체 저항이 가장 큰 것으로 나타났는데, 평형 상태보다 선미부의 압력 회복이 약하기 때문이다. 또한 자유 수면과 대칭 경계 조건이 날개 성능에 미치는 영향을 분석한 결과, 비현실적 대칭경계 조건으로 인해 날개 양력이 13%~16% 크게 나타났으므로 대칭경계조건을 사용할 경우에는 이러한 오차를 감안해야 한다.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.588-592
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• 2016

선박의 최적 운항 자세를 찾기 위해 자유 수면을 포함한 저항 해석을 수행할 경우 많은 격자를 이용한 비정상 해석으로 인해 계산 시간이 오래 소요되는 단점이 있다. 본 연구에서는 이를 개선하여 이중 모형을 이용한 정상 해석을 통해 보다 효율적으로 선박의 최적 운항 자세를 도출하는 방법을 연구하였다. KCS를 대상선으로 선정하여 설계속도(24knots)와 저속(15knots)인 경우에 대하여 평형 상태 및 선수/선미 트림 상태에서 이중 모형 수치해석을 수행하고 기존의 연구결과와 비교하였다. 그 결과 자유수면 유무와 속도에 상관없이 선체 자세에 따른 저항 값은 동일한 경향을 갖는 것을 확인하였다. 하지만 저속일 경우 트림조건에 따른 저항의 변화의 폭에서 차이를 보였으며, 이는 압력저항에 기인한 것이다. 따라서 이중 모형을 이용한 저항 해석은 압력저항의 변동이 큰 경우에는 적용되기 어렵다는 한계점이 있다. 하지만 마찰 저항이 주요한 경우에 적용되어 계산효율을 획기적으로 높일 수 있으며, 정성적인 경향을 제시할 수 있는 타당한 방법이라 사료된다.

• Sleep Medicine and Psychophysiology
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• v.28 no.1
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• pp.6-12
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• 2021

Insomnia is one of the most common sleep disorders experienced by modern people, and treatment is often not adequate due to various limitations. Digital therapeutics for insomnia are expected to play a revolutionary role in supplementing and satisfying unmet needs in real-world clinical treatment. Digital therapeutics for insomnia were developed based on cognitive-behavioral therapy for insomnia, which is the first standard treatment for insomnia. The effectiveness of digital therapeutics for insomnia developed by several companies has been proven through well-designed clinical research. Various approaches have been used for practical application of digital therapeutics for insomnia. Thus far, meaningful results have been drawn, but there are areas that need to be improved upon based on real-world evidence. Sleep researchers need to validate the safe and effective application of digital therapeutics for the treatment of insomnia.

• Journal of the Korea Convergence Society
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• v.11 no.1
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• pp.33-39
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• 2020

Specialists have developed pillows that take into account sleep science and ergonomics, such as comfort for lying on your side. This pillow is made of natural latex material, and improved resilience after a certain period of time. A new idea was added to the pillow, which was naturally used for sleep, but could it add additional features for health care. Here, health care targets sleep apnea, which is known to be associated with serious illness. The purpose of this paper is to design a comprehensive service that uses a pressure sensor and a voice sensor to obtain information and to identify abnormal symptoms related to diseases from this information and to refer them to a specialist. It also covers the basic design and implementation to confirm the success of this system. Based on this design, the information obtained will be converted into a DB, and a server system for consultation with a specialist will be completed to upgrade the role of assistive health devices for sleep apnea.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.409-420
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• 2021

The study is a descriptive research to determine high school girls' the status of dysmenorrhea and to look into influencing factors about how relationships between variables: sleep disturbance, stress, anxiety, dietary habit have an effect on dysmenorrhea. Our collected data consisted of 160 high school girls living in B metropolitan city. The study period lasted four weeks, going from Oct 12 to Nov 6, 2020. The resulting data was analyzed with SPSS/WIN 21.0 version to analyze. As a result of this study, The correlated factors of dysmenorrhea included sleep disturbance(r=.531, p<.001), stress(r=.349, p<.001), anxiety(r=.300, p=.003) and dietary habit(r=-.205, p=.041). The prevalent factors influencing dysmenorrhea are sleep disturbance, menstrual periods, menstrual cycles, and anxiety. Therefore, it will be needed to improve the quality of sleep, reduce anxiety, try to regulate menstrual periods and menstrual cycle in order to relieve high school girls' dysmenorrhea.

• Journal of Digital Convergence
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• v.20 no.2
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• pp.553-561
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• 2022

The purpose of this study is to understand the relationship between anxiety, sleep disturbance, and suicide ideation in the elderly using senior welfare centers and to identify factors influencing suicide ideation. Data were collected from January 6 to February 7, 2020 from 206 elders who analyzed using SPSS/Win 25.0 with descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients, multiple regression analysis. anxiety, sleep disturbance, suicide ideation were positively correlated. Meanwhile, factor affecting suicide ideation were anxiety(β=.215, p=.001), sleep disturbance(β=.383, p<.001) and the explanatory power of suicide ideation was 27.3%. Therefore, in order to prevent suicide ideation, it will be necessary to develop an intervention program to maintain qualitative sleep and lower anxiety levels.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.360-360
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• 2019

도시화 및 산업화로 인해 불투수면이 지속적으로 증가하고 있으며, 불투수면 증가로 인해 유역의 물순환 구조가 왜곡되고, 비점오염 배출량이 증가하는 등의 문제가 야기되고 있다. 왜곡된 물순환 체계 회복 및 비점오염 배출 저감 등을 위해 중장기 물순환 개선 목표 수립과 관련된 조항이 물환경보전법 상에 추가되어 2020년 시행예정이며, 광주, 대전, 울산, 안동, 김해시 등은 물순환 선도도시로 선정되어 관리되고 있는 등 물순환 개선을 위한 노력이 높아지고 있다. 본 연구에서는 경안천 중권역을 대상으로 HSPF (Hydrological Simulation Program - FORTRAN) 모형을 이용하여 유출량을 모의하여, 소권역별로 물순환요소를 도출하고, 물순환율을 산정 하고자 한다. 모형의 구동을 위한 기상자료는 기상청으로부터 취득하였으며, 지형자료는 환경부의 소권역도, 국토지리정보원의 수치지형도를 활용하였고, 토지피복도는 국가공간정보포털에서 취득한 연속지적도를 토지피복 분류에 따라 재분류하여 구축하였다. 모형의 보정을 위한 유량자료는 환경부 유량측정망과 수위관측소의 유량자료를 활용하였으며, 2013~2017년은 보정, 2008~2012년은 검정기간으로 활용하였다. 도출된 수문모의 결과를 활용하여 2008년부터 2017년까지 소권역별로 매년 물순환율을 산정하고 비교하였다. 본 연구의 결과는 추후 물순환 현황파악을 위한 기초자료로 활용될 수 있을 것으로 사료된다.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.4
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• pp.391-398
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• 2013

Botulinum toxin has been used for treating strabismus, blepharospasm, cerebral palsy, cervical dystonia, hyperhydrosis, facial wrinkle and chronic migraine under US Food and Drug administration approval. Also it has been tried spasticity-induced pain, post-herpetic neuralgia, myofascial pain and aphthous ulcer as off-label use. In this study, we reviewed recent studies that suggested effects of botulinum toxin on snoring and sleep apnea.