• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1981년도 제15차 학술대회연제순서 및 초록
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• pp.12.3-12
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• 1981

비강 및 부비동에 발생하는 반전성유두종은 매우 드문 양성종양으로 1854년에 Ward에 의해 기술되어 여러 학자들에 의해 증례 보고되어 왔으며 수술 후 재발이 잘 되고 드물게 악성으로 변하는 경향이 있으며 계속적인 추적관찰이 필요한 질환이다. 이에 저자들은 약 8년전 개인의원에서 비용으로 진단받아 비용절제술을 받은 바 있는 환자와 약 2년전 역시 같은 진단으로 수술을 받았던 환자에서 조직검사 결과 반전성유두종으로 판명된 2례 경험하였기에 문헌 고찰과 함께 보고하는 바이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.134-136
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• 1993

This paper presents a novel and efficient method to calculate the critical point of voltage collapse. Conjugate gradient and modified Newton-Raphson methods are employed to calculate two pairs of multiple load flow solutions for two operating conditions, i.e., both +mode and -mode voltages for two loading conditions respectively. Then these four voltage magnitude-load data sets of the bus which is most susceptible to voltage collapse, are fitted to third order polynomial using Lagrangian interpolation in order to represent approximate nose curve (P-V curve). This nose curve locates first estimate of the critical point of voltage collapse. The procedure described above is repeated near the critical point and the new estimate will be very close to the critical point. The proposed method is tested for the eleven bus Klos-Kerner system, with good accuracy and fast computation time.

• 한국식품과학회지
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• 제43권3호
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• pp.291-302
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• 2011

제조 조건 및 저장 기간에 따른 유채유의 품질을 측정하기 위하여 전자코로 유채유의 향기패턴을 분석하였고 GC및 GC-MS를 이용하여 휘발성분을 분리 동정하였다. 다양한 조건으로 제조된 유채유는 $17^{\circ}C$ 암소에 저장하여 시료로 이용하였다. GC-MS 분석 결과 hydrocarbon류 4종, furan 및 그 유도체류 1종, ketone류 3종, acid류 1종, benzene류 3종, aldehyde류 12종이 분리 동정되었다. 저장기간이 증가할수록 산패에 의한 화합물인 hexanal, 2-heptenal, 2,4-heptadienal의 양이 증가하였으나 배전조건에 따른 경향은 보이지 않았다. 전자코 분석 결과는 판별함수분석(DFA)을 이용하여 나타내었고 이는 DF1값의 영향을 많이 받았으며 품질 변화가 많이 일어날수록 DF1값이 음의 방향으로 이동하였다. 배전 온도에 의한 영향을 알아보기 위해 $150-240^{\circ}C$에서 20분간 볶은 후 착유한 유채유의 경우 고온일수록 DF1값이 음의 값을 나타내었으며 신선한 유채유뿐 아니라 저장 한 시료도 비슷한 결과를 나타내었다. 배전 시간에 따른 유채유의 향기 변화를 알아보고자 $240^{\circ}C$에서 10-30분간 열처리 하였을 경우 배전 시간이 증가함에 따라 DF1값이 음의 값을 나타내었다. 저장기간이 증가함에 따라 DF1값은 감소하였으며 특히 0일과 2일, 20일과 24일에DF1값의 변화량이 컸다.

• 한국축산식품학회지
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• 제41권6호
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• pp.936-949
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• 2021

This study discriminated fatty acid profile and flavor characteristics of Beijing You Chicken (BYC) as a precious local breed and Dwarf Beijing You Chicken (DBYC) eggs. Fatty acid profile and flavor characteristics were analyzed to identify differences between BYC and DBYC eggs. Four classification algorithms were used to build classification models. Arachidic acid, oleic acid (OA), eicosatrienoic acid, docosapentaenoic acid (DPA), hexadecenoic acid, monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), unsaturated fatty acids (UFA) and 35 volatile compounds had significant differences in fatty acids and volatile compounds by gas chromatography-mass spectrometry (GC-MS) (p<0.05). For fatty acid data, k-nearest neighbor (KNN) and support vector machine (SVM) got 91.7% classification accuracy. SPME-GC-MS data failed in classification models. For electronic nose data, classification accuracy of KNN, linear discriminant analysis (LDA), SVM and decision tree was all 100%. The overall results indicated that BYC and DBYC eggs could be discriminated based on electronic nose with suitable classification algorithms. This research compared the differentiation of the fatty acid profile and volatile compounds of various egg yolks. The results could be applied to evaluate egg nutrition and distinguish avian eggs.

• 한국축산식품학회지
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• 제42권2호
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• pp.240-251
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• 2022

Fat deposition in animal muscles differs according to the genetics and muscle anatomical locations. Moreover, different fat to lean muscle ratios (quality grade, QG) might contribute to aroma development in highly marbled beef. Scientific evidence is required to determine whether the abundance of aroma volatiles is positively correlated with the amount of fat in highly marbled beef. Therefore, this study aims to investigate the effect of QG on beef aroma profile using electronic nose data and a chemometric approach. An electronic nose with metal oxide semiconductors was used, and discrimination was performed using multivariate analysis, including principal component analysis and hierarchical clustering. The M. longissimus lumborum (striploin) of QG 1++, 1+, 1, and 2 of Hanwoo steers (n=6), finished under identical feeding systems on similar farms, were used. In contrast to the proportion of monounsaturated fatty acids (MUFAs), the abundance of volatile compounds and the proportion of polyunsaturated fatty acids (PUFAs) decreased as the QG increased. The aroma profile of striploin from carcasses of different QGs was well-discriminated. QG1++ was close to QG1+, while QG1 and QG2 were within a cluster. In conclusion, aroma development in beef is strongly influenced by fat deposition, particularly the fat-to-lean muscle ratio with regard to the proportion of PUFA. As MUFA slows down the oxidation and release of volatile compounds, leaner beef containing a higher proportion of PUFA produces more volatile compounds than beef with a higher amount of intramuscular fat.

• Archives of Plastic Surgery
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• 제50권4호
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• pp.348-353
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• 2023

Doppler ultrasound can be used to detect almost all arteries of the face before injecting the hyaluronic acid (HA) filler. The relatively more dangerous sites of filler injection are the glabellar wrinkle, forehead, temple, nose, and nasolabial fold area, and it is recommended to map the vasculature of these areas by Doppler ultrasound before performing filler injection. The Doppler ultrasound detection method is included as a video. Internal carotid arterial branches, the supratrochlear, supraorbital, and dorsal nasal arteries, and external carotid arterial branches, the superficial temporal and facial arteries, are very important arteries when injecting HA filler; thus, Doppler ultrasound detection is recommended.

• 한국환경보건학회지
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• 제29권3호
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• pp.35-42
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• 2003

Nitric Oxide(NO) is produced in many organs of the body, including the lung and airways, and it is detectable in the exhaled air. The measurement of exhaled NO(eNO) provides a simple non-invasive means for measuring airway inflammation, such as asthma. We measured eNO among adult male workers to examine the distribution of eNO in healthy people and to find factors affecting eNO. We measured eNO in a sample of 921 adult workers who also performed lung function test and skin prick test. Exhaled NO was measured in a sitting posture without using a nose clip and NO free gas. NO was measured at three expiratory rates(l8; 42; 71 $m\ell$/sec) and the flow rate of 71 $m\ell$/sec was used in analysis. The average eNO concentration was 5.29 $\pm$ 2.98 ppb. The level increased with age but not significantly(P=0.0529). Exhaled NO showed positive relations to the height(P=0.0001), pollen 1 (P=0.0124), asthma history(P=0.0212), allergic rhinitis symptom(P=0.0302). Exhaled NO Concentration of smokers( 4.62 ppb) was significantly lower than that of nonsmokers(5.99 ppb; P<0.0001).

• 대한기계학회논문집A
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• 제28권10호
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• pp.1566-1573
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• 2004

When a projectile travels at high speed underwater, supercavitating flow arises, in which a huge cavity is generated behind the projectile so that only the nose, i.e., the cavitator, of the projectile is wetted, while the rest of it should be surrounded by the cavity. In that case, the projectile can achieve very high speed due to the reduced drag. Furthermore if the nose of the body is shaped properly, the attendant pressure drag can be maintained at a very low value, so that the overall drag is also reduced dramatically. In this study, shape optimization technique is employed to determine the optimum cavitator shape for minimum drag, given certain operating conditions. Shape optimization technique is also used to solve the potential flow problem fur any given cavitator, which is a free boundary value problem having the cavity shape as unknown a priori. Analytical sensitivities are derived for various shape parameters in order to implement a gradient-based optimization algorithm. Simultaneous optimization technique is proposed for efficient cavitator shape optimization, in which the cavity and cavitator shape are determined in a single optimization routine.

• Journal of Mechanical Science and Technology
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• 제14권8호
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• pp.867-878
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• 2000

In order to study unsteady aerodynamic loads on high speed trains passing by each other 350km/h, three-dimensional flow fields around trains during the crossing event are numerically simulated using three-dimensional Euler equations. Roe's FDS with MUSCL interpolation is employed to simulate wave phenomena. An efficient moving grid system based on domain decomposition techniques is developed to analyze the unsteady flow field induced by the restricted motion of a train on a rail. Numerical simulations of the trains passing by on the double-track are carried out to study the effect of the train nose-shape, length and the existence of a tunnel on the crossing event. Unsteady aerodynamic loads-a side force and a drag force-acting on the train during the crossing are numerically predicted and analyzed. The side force mainly depends on the nose-shape, and the drag force depends on tunnel existence. Also. a push-pull (i.e.impluse force) force successively acts on each car and acts in different directions between the neighborhood cars. The maximum change of the impulsive force reaches about 3 tons. These aerodynamic force data are absolutely necessary to evaluate the stability of high speed multi-car trains. The results also indicate the effectiveness of the present numerical method for simulating the unsteady flow fields induced by bodies in relative motion.

• Journal of Information Processing Systems
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• 제9권1호
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• pp.173-188
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• 2013

In Facial Expression Recognition Systems (FERS), only particular regions of the face are utilized for discrimination. The areas of the eyes, eyebrows, nose, and mouth are the most important features in any FERS. Applying facial features descriptors such as the local binary pattern (LBP) on such areas results in an effective and efficient FERS. In this paper, we propose an automatic facial expression recognition system. Unlike other systems, it detects and extracts the informative and discriminant regions of the face (i.e., eyes, nose, and mouth areas) using Haar-feature based cascade classifiers and these region-based features are stored into separate image files as a preprocessing step. Then, LBP is applied to these image files for facial texture representation and a feature-vector per subject is obtained by concatenating the resulting LBP histograms of the decomposed region-based features. The one-vs.-rest SVM, which is a popular multi-classification method, is employed with the Radial Basis Function (RBF) for facial expression classification. Experimental results show that this approach yields good performance for both frontal and near-frontal facial images in terms of accuracy and time complexity. Cohn-Kanade and JAFFE, which are benchmark facial expression datasets, are used to evaluate this approach.