• 한국산학기술학회논문지
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• 제18권2호
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• pp.14-22
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• 2017

전 세계적으로 지구온난화에 의한 이상기후현상으로 자연재해의 발생빈도와 규모가 증가하고 있는 추세이다. 태풍, 지진, 홍수, 폭우, 가뭄, 폭염, 풍랑, 쓰나미 등과 같은 다양한 자연재해는 현재까지 인간생활에 피해를 주고 있다. 특히, 일본의 대지진, 미국의 허리케인 카트리나, 한국의 태풍 매미 등 세계적으로 자연재해에 의한 피해는 막대하다. 현 단계에서 자연 재해로 인한 피해규모를 정확히 예측하고, 그에 대처하는 것은어려운 실정이다. 그러나 재해대응 차원에서 피해 규모를 예측 할 수 있다면 신속하게 대응하여 피해를 저감할 수 있다고 판단된다. 따라서, 본 연구에서는 여러 가지 자연재해 중 해풍과 파랑에 의해 발생하는 풍랑에 관한 피해예측함수를 개발하였다. 서해 연안지역을 대상으로 국민안전처에서 발간하는 재해연 보('91~'14)의 풍랑 및 태풍피해 이력을 수집하였으며, 물가상승률을 반영하기 위해 2014년 기준으로 피해액을 환산하였다. 또한, 풍랑 및 태풍피해가 발생했을 때 기상청 및 국립해양조사원 홈페이지에서 파고, 풍속, 조위, 파향, 파주기 등의 자료를 수집하였다. 최종적으로, 연안의 지역특성을 반영하여 서해안의 9개 지역의 풍랑 피해예측함수를 개발하였다.

• Clinical and Experimental Pediatrics
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• 제59권6호
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• pp.271-275
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• 2016

Purpose: A limited number of studies have examined the link between F-wave abnormalities and clinical presentation in pediatric Guillain-$Barr{\acute{e}}$ syndrome (GBS). Therefore, this study examined the importance of F-wave abnormalities as a prognostic factor in pediatric GBS patients. Methods: The records and electrodiagnostic studies (EDS) of 70 GBS patients were retrospectively evaluated, and divided into 2 groups according to the results of EDS. Group A (n=33) presented with F-wave abnormalities, and group B (n=26) exhibited normal findings. We compared laboratory reports, clinical features, response to treatment, and prognosis between the 2 groups. Results: Motor weakness was the most frequently observed symptom for either group. Clinically, the incidence of fever and upper respiratory symptoms differed between the 2 groups, while the prevalence of abnormal deep tendon reflex (DTR) was significantly higher in group A than B (P<0.05). Patients diagnosed with GBS had received intravenous immunoglobulin treatment: 94% in group A and 58% in group B. Furthermore, significantly greater numbers of patients in group A showed H-reflex abnormalities and poor prognosis compared with group B (P<0.05). Conclusion: This study demonstrated that F-waves are a clinically important prognostic factor in GBS. F-wave abnormalities were associated with abnormal DTR and poor prognosis in patients. Limited studies have examined the link between F-wave abnormalities and clinical results; therefore, further randomized controlled studies are needed to confirm the clinical characteristics and efficacy of treatments.

• Journal of Genetic Medicine
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• 제21권1호
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• pp.31-35
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• 2024

Allan-Herndon-Dudley syndrome (AHDS) is a rare X-linked neurodevelopmental disorder with abnormal thyroid function caused by mutation in the solute carrier family 16 member 2 (SLC16A2) gene. Clinical manifestations of AHDS are global or axial hypotonia, a variety of movement disorders, severe intellectual disability, quadriplegia or spastic diplegia, growth failure, and seizures. A 10-year-old boy visited our hospital with the chief complaint of newly onset generalized tonic seizures with vocalization of weekly to daily frequency. He showed early infantile hypotonia, severe intellectual disability, and frequent respiratory infections. He could not walk independently and was non-verbal. Electroencephalogram revealed generalized slow spike and waves with multifocal spikes and slow background rhythms. His tonic seizures were controlled with more than two anti-seizure medications (ASMs). At 11 years of age, he was evaluated for thyroid function as part of regular screening for ASM maintenance and was found to have abnormal thyroid function. We performed whole exome sequencing for severe global developmental delay, drug-resistant epilepsy, and abnormal thyroid function. The hemizygous c.940C>T (p.Arg314Ter) variant in the SLC16A2 gene (NM_006517.5) was identified and confirmed based on Sanger sequencing. Herein, we describe a case of an AHDS patient with late-onset drug-resistant epilepsy combined with congenital hypotonia, global developmental delay, and abnormal thyroid function results. To the best of our knowledge, this is the oldest adolescent among AHDS cases reported in Korea. In this report, clinical characteristics of a mid-adolescence patient with AHDS were presented.

• 한국환경과학회지
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• 제26권12호
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• pp.1363-1374
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• 2017

Global climate change caused by industrialization has caused abnormal weather conditions such as urban temperatures and tropical nights, urban heat waves, heat waves, and heavy rains. Therefore, the study tried to analyze climate conditions and weather conditions in the streets and analyze climate factors and meteorological factors that lead to inconvenience to citizens. In the case of trees, the overall temperature, surface temperature, solar irradiance, and net radiation were measured low, and the temperature was lower in the Pedestrian road than in roads. The dry bulb temperature, the black bulb temperature, and the wet bulb temperature for the thermal evaluation showed the same tendency. In the case of thermal evaluation, there was a similar tendency to temperature in WBGT, MRT, and UTCI, and varied differences between types. Although the correlation between the meteorological environment and the thermal environment showed a statistically significant significance, the difference between the measured items was not significant. The study found that the trees were generally pleasant to weather and thermal climate in the form of trees, and the differences were mostly documented.

• Ocean and Polar Research
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• 제31권4호
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• pp.415-422
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• 2009

The wave observation system in Korea has been established with an emphasis on pointmeasurement based on in situ instrumentations. However, the system cannot fully investigate the coastal wave-related problems that are significantly localized and intensified with three-dimensional regional geometries. Observation technique that can cover local processes with large time and spatial variation needs to be established. Video imaging techniques that can provide continuous monitoring of coastal waves and related phenomena with high spatial and temporal resolutions at minimum cost of instrumentation risks are reviewed together with present status of implementation in Korea. Practical applications of the video imaging techniques are suggested to tackle with various coastal issues of public concern in Korea including, real-time monitoring of wave runup and overtopping of swells on the east coast of Korea, longshore and rip currents, morphological and bathymetric changes, storm surge and tsunami inundation, and abnormal extreme waves in the west coast of Korea, etc.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권4호
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• pp.293-299
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• 2004

This paper is about the extraction of basis function for ECG signal processing. In the first step, it is assumed that ECG signal consists of linearly mixed independent source signals. 12 channel ECG signals, which were sampled at 600sps, were used and the basis function, which can separate and detect source signals - QRS complex, P and T waves, - was found by applying the fast fixed point algorithm, which is one of learning algorithms in independent component analysis(ICA). The possibilities of significant point detection and classification of normal and abnormal ECG, using the basis function, were suggested. Finally, the proposed method showed that it could overcome the difficulty in separating specific frequency in ECG signal processing by wavelet transform. And, it was found that independent component analysis(ICA) could be applied to ECG signal processing for detection of significant points and classification of abnormal beats.

• Progress in Superconductivity
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• 제7권1호
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• pp.28-35
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• 2005

We propose a method to measure atrial arrhythmias (AA) such as atrial fibrillation (Afb) and atrial flutter (Afl) with a SQUID magnetocardiograph (MCG) system. To detect AA is one of challenging topics in MCG. As the AA generally have irregular rhythm and atrio-ventricular conduction, the MCG signal cannot be improved by QRS averaging; therefore a SQUID MCG system having a high SNR is required to measure informative atrial excitation with a single scan. In the case of Afb, diminished f waves are much smaller than normal P waves because the sources are usually located on the posterior wall of the heart. In this study, we utilize an MCG system measuring tangential field components, which is known to be more sensitive to a deeper current source. The average noise spectral density of the whole system in a magnetic shielded room was $10\;fT/{\surd}Hz(a)\;1\;Hz\;and\;5\;fT/{\surd}Hz\;(a)\;100\;Hz$. We measured the MCG signals of patients with chronic Afb and Afl. Before the AA measurement, the comparison between the measurements in supine and prone positions for P waves has been conducted and the experiment gave a result that the supine position is more suitable to measure the atrial excitation. Therefore, the AA was measured in subject's supine position. Clinical potential of AA measurement in MCG is to find an aspect of a reentry circuit and to localize the abnormal stimulation noninvasively. To give useful information about the abnormal excitation, we have developed a method, separative synthetic aperture magnetometry (sSAM). The basic idea of sSAM is to visualize current source distribution corresponding to the atrial excitation, which are separated from the ventricular excitation and the Gaussian sensor noises. By using sSAM, we localized the source of an Afl successfully.

• 한국항해항만학회지
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• 제34권1호
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• pp.51-57
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• 2010

항내 정온도를 산정 할 때에는 불규칙파의 회절과 반사가 정확하게 계산되어지는 것이 중요하다. 본 연구에서 수치모형의 기본방정식은 완경사 방정식을 사용하였으며, 이는 파랑 거동에 큰 영향을 미치는 비선선형성을 고려할 수 있는 장점을 가지고 있다. 그리고, 삼각격자망은 유한요소법을 이용하여 생성되었다. 비선형성의 효과를 검증하기 위하여 본 연구에서 개발된 수치모형의 계산결과들은 다른 연구자들의 실험결과 및 수치결과와 비교되어졌다. 그 결과, 비선형성의 파랑을 고려한 경우가 고려하지 않은 경우보다 파랑해석에 더 정확하다는 것을 보여주었다. 본 모형을 적용하기 위하여 해수교환방파제가 설치되어 있는 주문진항에 파고분포가 계산되어졌다. 수치해석결과, 이상 파랑이 해수교환방파제를 통한 유입 시에 항내 파고분포의 결과들이 높게 나타났다. 그러므로, 항내 파고를 낮게 유지하기 위해서는 이상 파랑의 유입을 차단할 수 있는 시설이 필요되어질 것으로 사료된다.

• 대한한방내과학회지
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• 제39권4호
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• pp.732-740
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• 2018

Objective: The aim of this study was to find a correlation between the Nepean Dyspepsia Index (NDI) and electrogastrography (EGG) in clinical practice students. Methods: In total, 28 students were enrolled. NDI and EGG were measured in all students. NDI was classified as abnormal when the score was 11 or more. In EGG, standard 1 was classified as abnormal if the preprandial or postprandial percentage of normal gastric slow waves of Ch3 was less than 70% or if power ratio of Ch3 was less than 1. Standard 2 was classified as abnormal if standard 1 was met or if the percentage of normal gastric slow waves of Ch3 decreased after meals. Results: NDI and EGG had no statistically meaningful correlation when standard 1 was used, but NDI and EGG had statistically meaningful correlation when standard 2 was used. Conclusions: These findings suggest that NDI and EGG are correlated and that EGG can be used to evaluate the degree of dyspepsia.

• 한국지반환경공학회 논문집
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• 제24권4호
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• pp.5-11
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• 2023

수역 인근에서 산사태로 인해 발생되는 충격파는 인명과 주변 기반시설에 치명적인 피해로 이어질 수 있다. 이러한 충격파는 일반적으로 산사태 충격파라고 하며, 특정지역에 국한되지 않고 발생한다. 최근에는 이상기후의 영향으로 국지성 집중호우가 빈번하게 발생하면서 국내에서 발생하는 산사태의 발생빈도와 발생규모 모두 증가하고 있다. 이에 본 연구에서는 산사태 모형의 질량비 변화에 따른 실험을 수행하였으며, 생성되는 충격파의 특성 중 파의 진폭을 중점으로 관측 및 분석하였다. 본 연구에서는 5가지의 산사태 모형의 질량비, 3가지의 수로경사로 15가지의 케이스에 대하여 5회 반복실험하여 총 75회의 실험을 수행하였다. 산사태 모형의 질량비를 달리하며 실험을 해본 결과, 만약 초기 에너지가 동일한 산사태의 경우 순수한 입상, 순수한 블록 형태의 산사태에 의해서 생성되는 충격파의 크기보다 입상형태와 블록형태가 섞여 함께 거동하며 생성하는 충격파의 크기가 더 클 수 있다고 분석된다.