• 한국위성정보통신학회논문지
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• 제10권2호
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• pp.109-114
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• 2015

프레임 동기화는 전송 프레임 헤더에 주기적으로 삽입되는 프리엠블(preamble) 패턴과 수신 심볼 간의 상관 연산을 통해 이루어지며 프레임의 시작점 및 구조 검출을 하는 것이 목적이다. 본 논문은 위성 기반 DVB-S2 시스템 요구사항에 부합하는 프레임 구조 획득 방법에 대해 기술하였다. DVB-S2 수신 신호는 매우 낮은 신호 대 잡음비를 가지며 심볼 속도 대비 20%에 상응하는 주파수 오프셋 성분이 포함되어 있다. 또한 규격은 프레임 당 심볼 수가 상이한 16가지의 프레임 구조를 지원하고 있다. 본 논문에서는 위의 환경에서 정확하고 빠른 프레임 동기화를 위해 프레임 헤더의 SOF와 PLSC 정보를 이용하여 상관 열을 발생시키고 상관 값 누적을 통해 프레임 동기 및 구조 검출을 실시하였다 마지막으로 컴퓨터 모의실험을 통해 평균 획득 시간(mean acquisition time), 프레임 구조 검출 오류율에 대한 성능평가를 실시하였다.

• 대한한방부인과학회지
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• 제24권4호
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• pp.95-104
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• 2011

Objectives: The purpose of this study is to investigate the relationship between the degree of menopausal symptom and granulocyte/lymphocyte ratio, and heart rate varibility(HRV). Methods: From 11th April 2011 to 20th May 2011, a total 30 female subjects (age 41-60) was recruited. We evaluated the degree of menopausal symptoms by Kupperman' s index and measured subject's WBC differential count and HRV. The data were analyzed by Kruskal-Wallis test and Spearman correlation test using SPSS/PC ver 13.0 program. Results: 1. There was no statistically significant difference in granulocyte/lymphocyte ratio and HRV among 4 classified groups according to Kupperman's index.- Mild, Moderate, Severe and Urgent. 2. Granulocyte ratio and general symptom score(within Kupperman's index) significantly showed negative correlation coefficient(r=-0.499, p=0.005), and Lymphocyte ratio and general symptom score significantly showed positive correlation coefficient (r=0.374, p=0.042). 3. Granulocyte/lymphocyte ratio and HRV showed no significant correlation. Conclusions: There was no significant relation among the degree of menopausal symptoms and granulocyte/lymphocyte ratio, and HRV. But furthermore large scale study is required.

• Clinical and Experimental Reproductive Medicine
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• 제50권3호
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• pp.206-212
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• 2023

Objective: The aim of the present study was to evaluate the associations between hematologic parameters related to systemic inflammation and insulin resistance-associated metabolic parameters in women with polycystic ovary syndrome (PCOS). Methods: Eighty-two women between the ages of 18 and 35 years who were diagnosed with PCOS were included in this study. A 2-hour 75-g oral glucose tolerance test (OGTT) was administered to all study participants; fasting and postprandial glucose and insulin levels were measured simultaneously during the 2-hour OGTT. Hematologic parameters were derived from a standard complete blood count and a differential count of fasting-state blood samples. The correlations between hematologic parameters and insulin resistance-associated clinical and metabolic parameters were evaluated using the Spearman rank correlation and partial correlation coefficients. Hematologic parameters related to systemic inflammation were compared between the two groups, categorized by the presence or absence of insulin resistance. Results: Significant differences in the absolute neutrophil count, absolute monocyte count, platelet count, and neutrophil-lymphocyte ratio were found between the insulin-resistant group and insulin-nonresistant group. Correlation analysis found that all hematological parameters, except for the platelet-lymphocyte ratio, were associated with at least one insulin resistance-associated metabolic parameter. However, these significant correlations between hematological and metabolic parameters were attenuated after controlling for the effects of other covariates using partial correlation analysis. Conclusion: The association between hematologic parameters indicative of systemic inflammation and insulin resistance-associated metabolic parameters seems to be strongly influenced by other anthropometric covariates in women with PCOS.

• Journal of Ecology and Environment
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• 제47권3호
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• pp.157-167
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• 2023

Background: The most hazardous wastewater sources in the northern part of the Middle Nile Delta, Egypt; receiving a massive amount of agricultural, industrial, and sewage drainage are Kitchener drain which is one of the tallest drainage systems, and Burullus Lake which represents the 2nd largest Egyptian coastal lake. Results: The current work is to determine the abundance and frequency of cyanophytes, chlorophytes, and bacillariophytes and the correlation between them and environmental abiotic components. Among sixty nine microalgal species, 19 species are belong Cyanophyta, 26 belong Chlorophyta and 24 belong Bacillariophyta. Genus Scenedesmus (Chlorophyta) was the most abundant in the study area (13 species), followed by Genus Oscillatoria (9 species) and Genus Navicula (7 species). Nostoc muscorum and Chlorella vulgaris were the most common and recorded in all sites (100% of the locations) under study. The application of the two-way indicator species analysis (TWINSPAN) and detrended correspondence analysis revealed agglomerating of 4 groups (communities) at 4th level of classification and reasonable segregation between these groups. Zinc, cadmium and lead were showed the highest levels (0.26±0.03, 0.26±0.06, and 0.17±0.01 ppm, respectively). Conclusions: The correlation analysis between water and community variables indicated a high negative correlation of total algae richness with nickel (r = -0.936, p < 0.01). Cyanophyta and Bacillariophyta were correlated negatively (r = -0.842, p < 0.01). However, Chlorophyta showed a negative richness with each of Ni and Pb (r = -0.965, -0.873, respectively) on one hand and a high positive correlation was revealed (r = 0.964) with all environmental variables on the other hand.

• Structural Engineering and Mechanics
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• 제42권2호
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• pp.229-245
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• 2012

Bridge vibration displacements have been directly measured by LVDTs (Linear Variable Differential Transformers) or laser equipment and have also been indirectly estimated by an algorithm of integrating measured acceleration. However, LVDT measurement cannot be applied for a bridge crossing over a river or channel and the laser technique cannot be applied when the weather condition is poor. Also, double integration of accelerations may cause serious numerical deviation if the initial condition or a regression process is not carefully controlled. This paper presents an algorithm of estimating bridge vibration displacements using vibration strains measured by FBG (Fiber Bragg Grating) sensors and theoretical mode shapes of a simply supported beam. Since theoretically defined mode shapes are applied, even high modes can be used regardless of the quality of the measured data. In the proposed algorithm, the number of theoretical modes is limited by the number of sensors used for a field test to prevent a mathematical rank deficiency from occurring in computing vibration displacements.89The proposed algorithm has been applied to various types of bridges and its efficacy has been verified. The closeness of the estimated vibration displacements to measured ones has been evaluated by computing the correlation coefficient and by comparing FRFs (Frequency Response Functions) and the maximum displacements.

• Weed & Turfgrass Science
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• 제7권3호
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• pp.239-245
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• 2018

Comparative drought resistances of 11 perennial warm-season turfgrasses were evaluated in the field after withholding irrigation for 48 days in summer I and 57 days in summer II. There were significant variations among the grasses in their drought resistances. From two years study of field shoot recovery from drought stress, the relative rankings among the 11 warm-season turfgrasses was as follows. 'Arizona Common' and 'Texturf 10' bermudagrasses [Cynodon dactylon (L.) Pers.], 'Tifgreen' hybrid bermudagrass [C. dactylon (L.) Pers. ${\times}$ C. transvaalensis Davy], and 'Georgia Common' centipedegrass [Eremochloa ophiuroides (Munro.) Mack.] possessed good drought resistances, whereas 'Texas Common' St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] and 'Tifway' hybrid bermudagrass [Cyndon dactylon (L.) Pers ${\times}$ C. transvaalensis Davy] possessed poor drought resistances. 'Texas Common' buffalograss [Buchloe dactyloides (Nutt.) Engelm.], 'Pensacola' bahiagrass (Paspalum notatum Flugge.), and 'Adalayd' seashore paspalum (Paspalum vaginatum Swartz), 'Meyer' zoysiagrass (Zoysia japonica Steud.), 'Emerald' zoysiagrass (Z. japonica Steud. ${\times}$ Z. tenuifolia Willd. ex Trin.) were found to rank intermediate. Visual leaf firing showed the highest correlation (r=-0.84) to shoot recovery from drought stress. Visual leaf rolling (r=-0.59) and canopy-air temperature differential (r=-0.64) also showed very significant correlations, whereas leaf water potential (r=0.54) showed relatively lower correlation.

• 한국의류산업학회지
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• 제12권2호
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• pp.214-218
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• 2010

This research was to judge on the gathered skirt's shape by visual images that was from the different gathered skirts according to different sewing conditions; fabrics(cotton, mixed-wool, polyester), ratio of gathers(1.5T, 2.0T, 2.5T). Questionnaire consists of 33 semantic differential scale expressing gathered skirt's image, and 10 items of the shape were measured by 3D measurements method. The data were analyzes by factor analysis, correlation analysis, ANOVA. The image of gathered skirts was composed of the five factors of activities, attraction, grace, softness, and ordinary and it was showed that these five factors occupied 68.4% of the total variance. The shape of gathered skirts was composed of the two factors of the side and the front, and it was showed that these two factors occupied 93.6% of the total variance. According to correlation analysis of visual shape, the front was significant in activities, attraction and ordinary, and the side was significant in activities, grace and ordinary. As a result of ANOVA, the visual images were significant in ratio of gathers. 2.5 ratio of gathered skirts were perceived to be more active and attractive, and 1.5 ratio of gathered skirts were more ordinary and graceful.

• 대한기계학회논문집B
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• 제28권5호
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• pp.526-534
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• 2004

A new second-moment closure model for turbulent heat fluxes is proposed on the basis of the elliptic equation. The new model satisfies the near-wall balance between viscous diffusion, viscous dissipation and temperature-pressure gradient correlation, and also has the characteristics of approaching its respective conventional high Reynolds number model far away from the wall. The predictions of turbulent heat transfer in a channel flow have been carried out with constant wall heat flux and constant wall temperature difference boundary conditions respectively. The velocity field variables are supplied from the DNS data and the differential equations only fur the mean temperature and the scalar flux are solved by the present calculations. The present model is tested by direct comparisons with the DNS to validate the performance of the model predictions. The prediction results show that the behavior of the turbulent heat fluxes in the whole region is well captured by the present model.

• 융합신호처리학회 학술대회논문집
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• 한국신호처리시스템학회 2001년도 하계 학술대회 논문집(KISPS SUMMER CONFERENCE 2001
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• pp.213-216
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• 2001

H.263부호기의 화면내 부호화(intraframe coding)를 위한 부가 부호기법인 Annex I는 기존의 JPEG, MPEG-1, -2 부호기들의 화면내 부호방법들과는 달리 부호화하고자 하는 현재 블록의DCT 계수를 기부호화된 블록들의 DCT 계수들을 이용하여 예측부호화 (Differential Pulse Coded Modulation; DPCM)를 행하고, 이를 통한 부호화 이득의 향상을 얻고 있다. 본 논문에서는 이런 H.263 Annex I의 예측기법을 공간영역에서의 물리적인 의미를 유도한다. 이를 통해서 H.263 Annex I의 예측기법의 비효율성을 지적하고, 영상신호의 통계적 특성에 맞게 예측방식을 수정한다. 제안된 DCT 계수 예측 방식과 기존의 H:263 Annex I 방식의 이론적인 예측성능을 평가하고, H.263 부호기에 적용하여 제안방식의 효율성을 검증한다.

• ETRI Journal
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• 제32권1호
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• pp.102-111
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• 2010

Recently power attacks on RSA cryptosystems have been widely investigated, and various countermeasures have been proposed. One of the most efficient and secure countermeasures is the message blinding method, which includes the RSA derivative of the binary-with-random-initial-point algorithm on elliptical curve cryptosystems. It is known to be secure against first-order differential power analysis (DPA); however, it is susceptible to second-order DPA. Although second-order DPA gives some solutions for defeating message blinding methods, this kind of attack still has the practical difficulty of how to find the points of interest, that is, the exact moments when intermediate values are being manipulated. In this paper, we propose a practical second-order correlation power analysis (SOCPA). Our attack can easily find points of interest in a power trace and find the private key with a small number of power traces. We also propose an efficient countermeasure which is secure against the proposed SOCPA as well as existing power attacks.