• 한국해안·해양공학회논문집
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• 제29권3호
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• pp.154-161
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• 2017

본 연구에서는 침식성 파랑의 내습조건에 대해 인공리프의 길이(Lr), 개구폭(W), 개구부 수의 변화가 인공리프 주변 지형에 미치는 영향을 검토하고자 하였다. 구조물 주변에서의 표사이동 양상은 이동상실험을 통하여 검토하였으며 인공리프의 설치조건과 발생 유속 및 파랑변형, 지형변동과의 관계에 대해 고찰하였다. 실험결과 인공리프의 설치로 인하여 배후 침식량은 감소하였으나 개구부내에서의 세굴은 복수의 개구부를 갖는 구조에 비하여 단일 개구부를 갖는 조건에서 증가되었으며, Lr/W의 변화와 깊은 연관성을 보이는 것으로 확인되었다.

• 방송공학회논문지
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• 제18권3호
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• pp.463-473
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• 2013

본 논문에서는 다시점 영상을 이용한 초고해상도 영상 복원 기법을 제안한다. 구체적으로 $5{\times}5$ 배열로 구성된 다시점 카메라로 25장의 영상을 취득하고, 가운데 카메라에 해당하는 초고해상도 영상을 저해상도 입력 영상과 24장의 저해상도 참조 영상을 활용하여 생성한다. 우선 입력 영상을 중심으로 스테레오 정합 기법을 이용하여 24개의 참조 영상에 대한 변이지도를 각각 추정한다. 그리고 저해상도 영상과 참조 영상에 있는 일치점들을 이용하여 초고해상도 영상을 복원한다. 최종적으로 반복적 균일화를 통해 초고해상도 영상을 보정한다. 실험을 통하여 본 논문에서 제안한 초고해상도 영상 복원 기법의 성능이 우수함을 확인한다.

• 대한조선학회 특별논문집
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• 대한조선학회 2005년도 특별논문집
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• pp.90-96
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• 2005

This paper presents the results of the reliability analysis of PAU (Preliminary Assembly Unit) seat of the floating Production Storage and Off1-loading Unit (FPSO) The main aim of the analysis was to demonstrate that a sufficient safety of structural members is guaranteed against PAU loads, internal and external pressure, and hull girder moments. Topside loads for PAU design are based on owner's request. According to the seat type, topside loads are classified into maximum values of same seat type for design efficiency. Totally, 26 loading cases for each model are used for this analysis with the combination of the reactions of PAU loafing and the hull girder bending moments according to LR offshore (2). The analysis results are evaluated according to the acceptance criteria for yielding given in LR offshore and guidance note (3) and The panel buckling resistance is verified by LR offshore and SDA (4). For 900,000 bbls FPSO, the PAU support foundation analysis using 3-D F.E. model is carried out to verify the structural adequacy of PAU foundation and structure members in way of PAU. The modified structures in way of PAU support are safe against considered load cases and all stresses in way of PAU support are within design criteria.

• 한국통신학회논문지
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• 제36권7B호
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• pp.892-896
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• 2011

본 논문에서는 IEEE 802.15.4a 시스템에 적합한 직렬 검색 비동기 상호 상관(serial search non-coherent correlator)을 이용한 두 단계(two-stage) 방식의 동기 방식(synchronization scheme)을 제안한다. 제안된 방식에서는 다중펄스 신호를 사용하여 단일펄스 신호를 이용하는 기존 방식보다 동기성능을 개선하였고, 적응 임계값(adaptive threshold) 기법을 적용하여 고정 임계값(fixed threshold)을 사용함으로써 생기는 낮은 SNR에서의 성능 열화를 보상하였다. 제안된 기법은 IEEE 802.15.4a 채널 모델에서 기존의 기법과 비교하여 약 0.2~0.3우수한 검출 확률(Detection Probability)을 보였다.

• 대한의용생체공학회:의공학회지
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• 제33권3호
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• pp.148-154
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• 2012

Hemorrhagic shock is a primary cause of deaths resulting from injury in the world. Although many studies have tried to diagnose accurately hemorrhagic shock in the early stage, such attempts were not successful due to compensatory mechanisms of humans. The objective of this study was to construct a survival prediction model of rats in acute hemorrhagic shock using a random forest (RF) model. Heart rate (HR), mean arterial pressure (MAP), respiration rate (RR), lactate concentration (LC), and peripheral perfusion (PP) measured in rats were used as input variables for the RF model and its performance was compared with that of a logistic regression (LR) model. Before constructing the models, we performed 5-fold cross validation for RF variable selection, and forward stepwise variable selection for the LR model to examine which variables were important for the models. For the LR model, sensitivity, specificity, accuracy, and area under the receiver operating characteristic curve (ROC-AUC) were 0.83, 0.95, 0.88, and 0.96, respectively. For the RF models, sensitivity, specificity, accuracy, and AUC were 0.97, 0.95, 0.96, and 0.99, respectively. In conclusion, the RF model was superior to the LR model for survival prediction in the rat model.

• Asian Pacific Journal of Cancer Prevention
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• 제13권3호
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• pp.927-930
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• 2012

Background and Objectives: Artificial neural networks (ANNs) are flexible and nonlinear models which can be used by clinical oncologists in medical research as decision making tools. This study aimed to predict distant metastasis (DM) of colorectal cancer (CRC) patients using an ANN model. Methods: The data of this study were gathered from 1219 registered CRC patients at the Research Center for Gastroenterology and Liver Disease of Shahid Beheshti University of Medical Sciences, Tehran, Iran (January 2002 and October 2007). For prediction of DM in CRC patients, neural network (NN) and logistic regression (LR) models were used. Then, the concordance index (C index) and the area under receiver operating characteristic curve (AUROC) were used for comparison of neural network and logistic regression models. Data analysis was performed with R 2.14.1 software. Results: The C indices of ANN and LR models for colon cancer data were calculated to be 0.812 and 0.779, respectively. Based on testing dataset, the AUROC for ANN and LR models were 0.82 and 0.77, respectively. This means that the accuracy of ANN prediction was better than for LR prediction. Conclusion: The ANN model is a suitable method for predicting DM and in that case is suggested as a good classifier that usefulness to treatment goals.

• Environmental Analysis Health and Toxicology
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• 제18권3호
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• pp.209-217
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• 2003

To investigate the effects of low dosed microcystin -LR (MCLR) on the initial stage of subacute hepatotoxicity in vivo, male Sprague-Dawley rats after weanling were divided in four groups. The orally treated group (OG) was administered orally by 1 $\mu\textrm{g}$/kg B.W. at an interval of three days. The free group (FG) has taken the drinking water including 1 $\mu\textrm{g}$/L freely and the control group (CC) was only treated with 0.9％ saline solution All groups were treated for a period of 3 weeks. There was a significant correlation in body growth rate between OG and FC and especially, a deterioration of the growth of spleen was observed in the FG after 5 days. The protein levels were also decreased in OG and FG after 9 days. Level of total fat was increased to the 9th day but again decreased up to the initial level. High hemolysis of the isolated erythrocytes occurred only in OG. Activities of ${\gamma}$-G7 of 0G and FG were higher twice-fold than CG, but the values of OG were already higher at the first treatment day. No significant change in aspartate aminotransferase (AST) activity was shown in all groups, but the activity of alanine aminotransferase (ALT) was slightly increased at the beginning state. There were much similarities in the results of OG and FG. except the growth inhibition of spleen in FG. It may be concluded that long -term effects of the low doses of mycrocystins in animals including human being can lead to serious health problems, especially to liver and spleen.

• Plant Breeding and Biotechnology
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• 제5권3호
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• pp.192-203
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• 2017

Metabolite profile is a powerful analytical technique to identify the functional characterization of plants. In this study, the phytochemicals and secondary metabolites of lentils (Lens culinaris) were analyzed to compare the anti-oxidative activities according to the different colors. The polar metabolites, fatty acids, carotenoids, flavonoids, anthocyanins, total phenolic acids, DPPH activity were analyzed. Three kind of lentils, French green whole lentil (FG), red whole lentil (LR), and green whole lentil (LG) (ASIA SEED Co., LTD), were used for this study. Fatty acids, phytochemicals, and antioxidative components from each lentil varieties were analyzed by official methods. The contents of lutein in carotenoids were 6-9 times higher than zeaxanthin in all lentils, but were not significantly different among three varieties. The content of carotenoids in FG was lower significantly than those in the LR and LG. Myricetin and luteolin were detected in the only FG. Kaempferol and delphinidin were significantly highest in the FG. Most of the phenolic acids except coumarate were higher in FG and LG than in LR. Also antioxidant effects ($EC_{50}$) were higher in FG and LG than in LR. The analyzed metabolites obtained from lentils showed distinct separation in the PCA results according to the varieties. Also, lentils showed different anti-oxidant profiles according to the colors. FG and LG showing higher contents of phytochemicals showed higher antioxidative activity than LG containing relative low contents of phytochemicals.

• The Journal of Korean Physical Therapy
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• 제35권3호
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• pp.57-63
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• 2023

Purpose: The aim of this study was to conduct a systematic review of randomized controlled studies from 2012 to present that explore the diagnostic accuracy of clinical tests used for diagnosing anterior cruciate ligament (ACL) injury. Methods: Study design: Systematic review. Literature search of the PubMed and Scholar databases was conducted using keywords related to diagnostic accuracy of clinical tests for ACL injury. The PRISMA Guidelines were followed to conduct this study. The Cochrane Risk of Bias Tool was utilized to assess the quality of each included study. Results: As a result, 8 studies were included, and 6 clinical tests used in ACL tears were evaluated for diagnostic accuracy. The pivot shift test was reported as having the highest +LR (29.5) value with a sensitivity of 59% and a specificity of 98%. However, the test with the lowest -LR value was the lever test, and the values were as follows: -LR (0.08), +LR (4.7), specificity (80%), sensitivity (94%). Conclusion: In this study, it was concluded that a single clinical test is not sufficient to determine the presence of ACL injury. Test combinations have a higher diagnostic accuracy than a single test. In this study, the accuracy of the clinical tests was examined without considering the amount of ACL rupture and acute-chronic condition. Further research is required to examine the impact of these two factors on diagnostic accuracy of clinical test.

• 분석과학
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• 제36권3호
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• pp.121-127
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• 2023

범죄 현장에서 혈액을 찾아 식별하는 것은 신원 확인 및 사건 재구성을 하기 위해 중요한 과정이다. 하지만, 혈액은 어둡거나 다양한 색상의 표면에서 육안으로 관찰하기 어려울 수 있다. Acidic hydrogen peroxide (AHP)는 최근에 발표된 혈액 증강 시약으로, 카메라의 장노출 기능을 사용하면 혈액을 높은 감도로 관찰할 수 있다. 그러나 어둡거나 다양한 색상의 표면에서 기존에 알려진 기법과 비교된 바는 없다. 이를 위해, 어둡거나 다양한 색상의 표면 8 종류에 혈흔족적을 남기고 UV나 IR을 비추면서 관찰/촬영하는 방법, alginate 전사법, leuco rhodamine 6G (LR6G), AHP를 적용하여 비교하였다. 그 결과, AHP는 UV 및 IR 촬영법보다 증강한 혈액과 표면의 contrast가 높았고, alginate 전사법과 달리 모든 표면에서 적용이 가능했다. 또한 LR6G와 마찬가지로 AHP 역시 어둡거나 다양한 색상의 표면에 부착된 혈액을 성공적으로 증강하였다.