• 한국해양공학회지
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• 제33권3호
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• pp.252-258
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• 2019

In this paper, the time history of the surface elevation measured at the Draupner platform in the North Sea in 1995 is used to examine the statistical characteristics of the wave data. The wave statistics for 48 surface measurements, which contain three freak wave occurrences, are summarized. The quartiles, boxplots, correlations, and pair plots of 15 variables, along with the abnormality index, are presented. The kurtosis and skewness of the surface elevation are two variables that are highly correlated with the abnormality index, which defines freak waves. Principal coordinate analysis showed that the direction of the changes in the abnormality index agreed with the changes in the kurtosis and skewness. In addition, various wave heights, except the maximum wave height, showed a similar direction for the height changes, and various wave periods showed a similar direction for the period changes. Based on the correlations and PCA analysis, the kurtosis and skewness of the surface profiles are the two most important variables to predict the abnormality index.

• 한방안이비인후피부과학회지
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• 제30권4호
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• pp.167-175
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• 2017

Objectives : The purpose of this study is to present 3 cases reports of psoriasis treated by Damwi-hwan - focused on lipid metabolic abnomarilty. Methods : We administered Damwi-hwan to three patients who showed psoriasis with lipid metabolic abnormality and evaluated the results by Psoriasis Area and Severity Index(PASI). Results : After the treatment three patients showed improvements in PASI. PASI of patient 1 changed from 15.4 to 0.4; patient 2 from 32.7 to 1.2 ; patient 3 from 7.6 to 0.6. Conclusions : The results suggest that Damwi-hwan can be an effective treatment for psoriasis who has lipid metabolic abnormality.

• 대한핵의학회지
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• 제30권1호
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• pp.47-55
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• 1996

Progressive supranuclear palsy (PSP) is a parkinson-plus syndrome characterized clinically by supranuclear ephthalmoplegia, pseudobulbar palsy, axial rigidity, bradykinesia, postural instability and dementia. Presence of dementia and lack of cortical histopathology suggest the derangement of cortical function by pathological changes in subcortical structures in PSP, which is supported by the pattern of behavioral changes and measurement of brain metabolism using positron emission tomography. This study was done to examine whether there are specific changes of regional cerebral perfusion in PSP and whether there is a correlation between severity of motor abnormality and degree of changes in cerebral perfusion. We measured regional cerebral perfusion indices in 5 cortical and 2 subcortical areas in 6 patients with a clinical diagnosis of PSP and 6 healthy age and sex matched controls using $^{99m}Tc$-HMPAO SPECT. Compared with age and sex matched controls, only superior frontal regional perfusion index was significantly decreased in PSP (p<0.05). There was no correlation between the severity of the motor abnormality and any of the regional cerebral perfusion indices (p>0.05). We affirm the previous reports that perfusion in superior frontal cortex is decreased in PSP. Based on our results that there was no correlation between severity of motor abnormality and cerebral perfusion in the superior frontal cortex, nonmotoric symptoms including dementia needs to be looked at whether there is a correlation with the perfusion abnormality in superior frontal cortex.

• Environmental Analysis Health and Toxicology
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• 제21권1호
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• pp.35-43
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• 2006

Reproduction and organ structure of the pale chub, Zacco platypus in Isa stream were investigated by means of histological methods. The results of the study confirmed reproductive abnormality and histopathological features in the pale chub. The gonadosomatic index (GSI) of the fish showed two peak in April and August. In summer season, GSI of the male was about two times of the female's GSI. Monthly variation of the gonadal development was very irregular. From the histological analysis of the organ structure, epidermal atrophy, necrosis and hyperplasia of pigment cell were observed in the skin. Epithelial layer lifting and clubbing of the lamella and bifurcation of the filament were observed in the gill. Also histological changes as congestion, cytoplasmic degeneration of hepatic cell, degeneration of bile duct, glomerular dilatation, degeneration of renal tubule and pycnosis of interstitial cell were identified in the liver and kidney, respectively.

• 품질경영학회지
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• 제49권3호
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• pp.327-340
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• 2021

Purpose: The purpose of this study is to propose a system predicting whether an electricity distribution system is abnormal by analyzing the temperature of the deteriorated system. Traditional electricity distribution system abnormality diagnosis was mainly limited to post-inspection. This research presents a remote monitoring system for detecting thermal images of the deteriorated electricity distribution system efficiently hereby providing safe and efficient abnormal diagnosis to electricians. Methods: In this study, an object detection algorithm (YOLOv5) is performed using 16,866 thermal images of electricity distribution systems provided by KEPCO(Korea Electric Power Corporation). Abnormality/Normality of the extracted system images from the algorithm are classified via the limit temperature. Each classification model, Random Forest, Support Vector Machine, XGBOOST is performed to explore 463,053 temperature datasets. The process capability index is employed to indicate the quality of the electricity distribution system. Results: This research performs case study with transformers representing the electricity distribution systems. The case study shows the following states: accuracy 100%, precision 100%, recall 100%, F1-score 100%. Also the case study shows the process capability index of the transformers with the following states: steady state 99.47%, caution state 0.16%, and risk state 0.37%. Conclusion: The sum of caution and risk state is 0.53%, which is higher than the actual failure rate. Also most transformer abnormalities can be detected through this monitoring system.

• 한국해양환경ㆍ에너지학회지
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• 제14권2호
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• pp.138-145
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• 2011

이 논문에서는 Monte Carlo method를 이용하여 주어진 파랑스펙트럼에서 위상차를 임의의 수 (random number)를 발생시켜 파형의 시계열 자료를 시뮬레이션하여 freak wave의 발생 특성을 살펴보았다. 여러 가지 상태의 해상상태를 스펙트럼법에서 정의한 유의파고 $H_s$와 유의파첨도 $S_s$의 조합을 이용해서 표시하였다. 유의파첨도가 동일한 경우에는 $H_s$가 커질수록 freak wave 발생 확률이 낮아지며 $H_s$가 동일한 경우 유의파첨도가 커질수록 freak wave 발생확률이 높아진다. 주어진 해상상태에서 최대파고 $H_{max}$의 평균은 $S_s$의 값이 증가함에 따라 조금씩 증가한다. 그러나 freak wave의 평균파고는 $S_s$에 관계없이 일정한 값을 가지며 freak wave 파고의 평균은 $H_s$의 2배가 된다. $S_s$가 일정한 경우 $H_s$가 증가하면 파형의 평균 첨도(kurtosis)가 증가한다. 그러나 $H_s$가 일정한 경우 $S_s$가 증가하면 첨도의 평균은 감소한다. Freak wave 발생 기준인 이상지수(Abnormality index, AI)의 평균값은 $H_s$와 $S_s$에 관계없이 2.11 정도의 값을 가지며 AI의 최대값은 2.5-3.0 사이의 값을 가진다. 따라서 Linear focusing에 의해서 발생한 freak wave의 AI의 상한 값은 3.0 정도라고 추정할 수 있다.

• 한국어류학회지
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• 제18권2호
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• pp.87-96
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• 2006

이사천에서 채집된 칼납자루의 생식과 기관계 구조를 조직학적인 방법에 의하여 조사한 결과는 다음과 같다. 암:수 성비는 1:1로 나타났다. 암컷의 경우 생식소중량지수(GSI)는 12월과 4월에 두 번의 정점을 나타냈으며, 산란관지수(OLI)는 불규칙한 변화 양상을 보였다. 기관계의 조직학적인 관찰 결과, 피부에서는 상피층의 위축과 색소세포의 증가가 확인되었으며, 아가미에서는 새판 상피층의 박리와 새엽의 분지현상이 나타났다. 그리고 간과 신장에서는 울혈 및 간세포의 세포질 변성과 사구체의 팽창, 세뇨관 상피세포의 초자성 변성 및 간질세포의 핵 응축이 관찰되었다.

• 한국지리정보학회지
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• 제22권4호
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• pp.86-101
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• 2019

원격탐사 기술은 플랫폼 개발, 탐사면적 및 탐사기능 등 양적 및 질적 향상의 관점에서 지속적으로 발전되어왔으며 비용절감 및 현장자료보완의 방법으로 유용하게 활용되고 있다. 최근에는 농업분야에서의 활용사례와 관련연구가 증가하는 추세에 있으며 농경지의 상태를 탐지하고 정량화하여 농경지 및 농업환경에 대한 관리방안 수립 및 정책지원이 가능하기 때문에 농작물 생육이상 판별, 시계열 정보에 의한 작황 추정 등 다양한 분야에서 연구되고 있다. 본 연구에서는 다중분광센서를 장착한 UAV를 이용하여 간척지 농경지에 대한 식생지수를 분석하고자 하였다. 한편, UAV를 이용하여 취득한 다중분광영상 자료로부터 산정된 식생지수의 정확도를 평가하기 위해서 현지 조사를 실시하였다. 현지조사에 의한 식생지수와 UAV 다중분광영상으로부터 산정된 식생지수간의 상관성을 평가함으로써 가장 적절한 식생지수를 도출하였으며 대상지역 전체에 대한 식생지수 분석에 활용하고자 하였다.

• 한국해양공학회지
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• 제27권1호
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• pp.102-108
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• 2013

In this paper time series wave data, which were measured at the Draupner platform in the North Sea on 1995, are used to investigate statistical characteristics of nonlinear wave. Various statistical properties based on time and frequency domain are examined. The Gram-Chalier distribution fits the probability of wave elevation better than the Gaussian distribution. The skewness of wave profile is 0.393 and the kurtosis is 4.037 when the freak wave is occurred. The nonlinearity of D1520 data is higher than two adjacent wave data. AI index of the New Year Wave is 2.11 and the wave height is 25.6m. The zero crossing wave period of the New Year Wave is 12.5s which is compared to the average zero up-crossing period 11.3s. The significant steepness of wave data is 0.077 when the freak wave was occurred. H1/3/${\eta}_s$ does not increases as the kurtosis increases and the values is close to 4. The New Year Wave belongs to highly nonlinear wave data packet but the AI index is within linear focusing range.

• Archives of Plastic Surgery
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• 제33권1호
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• pp.124-126
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• 2006

Pachydermodactyly is a rare distinct form of fibromatosis characterized by acquired, asymptomatic dense fibrosis and fibroblastic proliferation around one or more proximal interphalangeal joints. Intralesional triamcinolone injection may be helpful in improving the clinical appearance. A 20-year-old unemployed female patient gave a four years history of progressive swelling of the fingers affecting predominantly the proximal interphalangeal joints of index fingers of left hand and index, middle fingers of right hand. There was no pain and tenderness. Physical examination, complete blood count, antinuclear antibody, rheumatoid factor were unremarkable and radiograph of both hands showed soft tissue swelling only without bony abnormality. We excised the redundant soft tissue from the both sides of proximal interphalangeal joint with longitudinal elliptical fashion. After operation, the fingers of the patient showed marked improvement cosmetically. There were no motor or sensory changes. Pachydermodactyly was first reported in 1996 in Korea. Histologic features include an increased dermal accumulation of collagen and occasionally an increased number of fibroblast. We report for one patient with pachydermodactyly treated with longitudinal elliptical excision and obtained an improvement of clinical appearance.