• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.12 s.354
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• pp.16-23
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• 2006

This paper presents the development of the fast Direction Finder using direct conversion method, which can intercept for short pulse signal of less' than 1 msec. in RF Down Converter, and CVDF(Correlative Vector Direction Finding) algorithm, which estimates DoA (Direction of Arrival). The configuration and characteristics of direction finder using 5-channel equi-spaced circular array antenna are presented and the direct conversion techniques for removing tuning time using I/Q demodulator are described. The CRLB of our model is derived, the principles of 2 kind of CVDF algorithm are explained and their characteristics are compared with CRLB w.r.t the number of samples and spacing ratio. The RF Down Converter prototype using direct conversion method is manufactured, the 2 kind of CVDF algorithm are applied and their performance are analyzed. Finally it is confirmed the LSE based CVDF algorithm is better than correlation-coefficient based except for ambiguity protection capabilities.

• Journal of the Korean Data and Information Science Society
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• v.21 no.6
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• pp.1071-1079
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• 2010

The decathlon is an athletic event consisting of ten track and field events. Events are held over two consecutive days and the winners are determined by the combined performance in all. We considered the best 200 decathletes who competed in the recent Olympics games and World Championship decathlon. We have used correspondence analysis to identify the relationship between ordered individual performance and the overall performance. Canonical correlation analysis of first day events versus second day events could shed light on the change of the level of performance between the two days. Correlation analysis was used to verify relation between cumulative event rank and final decathlon rank. Therefore, we conclude that the decathlon favors those atheletes who do well at the track events to become the best players. The best players in the decathlon performed relatively poorly in the 1,500 metres, but did well in the long jump, the 400 metres and the 110-metre hurdles. Decathletes in this study have a positive correlation between overall performance and maximal excellence in a particular discipline. Thus, to compete successfully at this level, a uniform, relatively high performance in all individual disciplines is required.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.2
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• pp.211-215
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• 1983

Thirty eight varieties with high uniformity and clearance in grain quality among 70 colored soybeans collected from nation-wide provinces were investigated for their seed morphological and agronomic traits. As for seed morphological traits, grain volumetric size, grain weight, grain length, grain thickness, . hilum length and width were studied on the tendency of statistical dispersion and variations. As a result, four groups could be classified on the basis of 100 grains weight, so as small, medium, large, and super large groups, Also, as for agronomic traits, among others, the tendency of setting in flowering date, maturing date, yield components, and stem weight, stem length were studied on the basis of statistical inter-relationships between above mentioned characteristics. From the above, bigger variations were detected in weighing characters of soybean plants than in duration characters. And the flowering and maturing days showed significant relationships to the stem length, stem weight, also stem length and stem weight to the grain yield.

• Korean Journal of Environment and Ecology
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• v.9 no.2
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• pp.147-155
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• 1996

To investigate the structure and the conservation strategy of natural forest at Dongdaesan, Turobong, Sangwangbong Area in Odaesan National Park, 27 plots(20$\times$20m) set up with random sampling method. Three groups were classified by cluster analyses. High positive correlations was proved between Tilia amurensis and Acer pseudo-sieboldianum, Malus faccata and Syringa reticulata var. mandshurica, Prunus padus and Viburnum sargentii, and High negative correlations was proved between Quercus mongolica and pronus padus, Tilia amurensis and Prunus padus, Acer pseudo-sieboldianum and Prunus padus. Species diversity(H') of investigated area was calculated 0.9586~1.1814.

• Korean Journal of Environmental Biology
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• v.30 no.3
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• pp.219-230
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• 2012

We surveyed 23 sites of Jinhae Bay in spring and summer 2010 in order to study the correlation between the variation of environmental factors, including salinity, temperature, and nutrients and the characteristics of phytoplankton community structures in summer stratification. Phytoplankton biomass was high in the surface water in summer; however, it was very low in the bottom water. The results showed a negative correlation between chlorophyll a (chl. a) and nutrients (silicate, nitrate, nitrite, ammonium, and phosphate) or nutrients ratio in summer; however, there was mostly a positive correlation between chl. a and these nutrients in spring. This inconsistent correlation between spring and summer was attributed to the phytoplankton community, because a diverse phytoplankton community has different nutrient uptake abilities. In addition, the results of CCA (canonical correspondence analysis) showed a negative correlation between phosphate and dominant species, including Chaetoceros spp., Skeletonema costatum-like spp., and Pseudo-nitzschia delicatissima in summer, but a strong positive correlation between DIN (dissolved inorganic nitrogen) and the dominant species, including Cryptomonas spp. and Pseudo-nitzschia multistriata in spring. Consistently, the dominant algal species in summer showed a relatively smaller size cells compared with those in spring, suggested that it may have related with the low nutrient levels at surface layer due to strong stratified water column of summer.

• Journal of Applied Biological Chemistry
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• v.62 no.4
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• pp.407-415
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• 2019

The biological half-life of pesticides applied on crops is the key indicator for ensuring the safety of agricultural products. The biological half-life is affected by the several factors like growing conditions of the crop, climate, application method, and physicochemical properties of pesticides. In this study, the biological half-life was calculated and the degradation rates of six triazole fungicides sprayed on perilla leaves were evaluated. Moreover, the statistical analysis confirmed the correlation between the biological half-life and physicochemical properties of six triazole pesticides. The recoveries of the six pesticides were between 84.8-104.9%, which satisfied the residual pesticide analysis criteria. The biological half-life of six pesticides sprayed on perilla leaves, calculated using the first-order kinetics model, ranged between 6.4-15.1 days. When the biological half-life and the physicochemical properties were correlated using the principal component analysis: pKa and Log P, the biological half-life was found to be affected by PC1. The correlation coefficient between biological half-life and physicochemical properties (pKa), calculated by Spearman rank-order correlation, was R² = -0.928 (p <0.01). Biological half-life has been shown to correlate with pKa. In conclusion, it can be used as a database for the relationship between biological half-life and physicochemical properties and will contribute to ensure safe supply of agricultural products.

• Korean Journal of Environment and Ecology
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• v.14 no.4
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• pp.287-295
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• 2001

계룡산국립공원 자연보존지구 천연림의 군집구조를 정확히 파악하여 앞으로의 식생관리에 있어서 기초자료를 마련하고자 34개 방형구(10m$\times$10m)를 설치하여 식생을 조사하였다. Cluster 분석 결과 조사대상지는 활엽수혼효림군집, 신갈나무-쪽동백나무군집 및 신갈나무-소나무군집으로 나뉘어졌다. 수종간의 상관관계에서는 신갈나무와 개옻나무; 까지박달나무와 층층나무; 쪽동백나무와 상수리나무; 비목나무와 느티나무, 고로쇠나무; 느티나무과 고로쇠나무, 참회나무; 쇠물푸레나무와 조록싸리, 노린재나무, 산딸기나무, 굴참나무 및 소나무; 고추나무와 상수리나무, 산뽕나무; 진달래와 개옻나무; 산철쭉과 굴참나무, 소나무, 상수리나무; 굴참나무와 소나무; 상수리나무와 병꽃나무; 고로쇠나무와 산뽕나무; 물푸레나무와 산뽕나무; 바위말발도리와 산뽕나무등의 종들간에는 정의 상관관계가 인정되었고, 신갈나무와 까지박달나무; 신갈나무와 층층나무; 노린재나무와 쪽동백나무등의 종들간에는 부의 상관관계가 인정되었다. 환경인자와 상관에서 쪽동백나무와 진달래는 해발고와 부의 상관이 인정되었으며, 사면의 방위와는 산딸기가 부의 상관이 인정되었다. 본 조사지의 종다양도는 1.4592~1.2917로 비교적 높은 편이었다.

• Korean Journal of Plant Taxonomy
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• v.44 no.4
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• pp.250-256
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• 2014

This study was carried out to understand the genetic relationship of three Aloe spp. cultivated in Korea, A. saponaria, A. vera and A. arborescens and a new variant in Korea based on three plastid (matK, trnL-F, rbcL) and one nuclear (ITS regions) DNA barcode markers. A total of 2,420 bp sequence was amplified. Two indels were detected in the trnL region, and also several species specific nucleotide loci were detected in all 29 parsimonious informative sites, and 148 variable sites were detected among four taxa studied while 170 variable and 75 parsimonious sites were detected when other Aloe spp. in worldwide were used. An UPGMA phenogram with 10,000 bootstrap replication showed that the new variant was closest to A. vera. The variant was not morphologically and genetically concurrent with any reported species so far. The clustering of Aloe species were broadly in agreement with previously reported results.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.628-635
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• 1999

Background : Maximal expiratory flow rate is determined by the size of airway, elastic recoil pressure and the collapsibility of airway in the lung. The obstruction of expiratory flow is one of the major functional impairments of emphysema, which represents COPD. Nevertheless, expiratory narrowing of upper airway may be recruited as a mechanism for minimizing airway collapse, and maintaining lung volume and hyperinflation by an endogenous positive end-expiratory pressure in patients with airflow obstruction. We investigated the physiologic role of trachea in respiration in emphysema. Method : We included 20 patients diagnosed as emphysema by radiologic and physiologic criteria from January to August in 1997 at Seoul Municipal Boramae Hospital. Chest roentgenogram, high resolution computed tomography(HRCT), and pulmonary function tests including arterial blood gas analysis and body plethysmography were taken from each patient. Cross-sectional area of trachea was measured according to the respiratory cycle on the level of aortic arch by HRCT and calibrated with body surface area. We compared this corrected area with such parameters of pulmonary function tests as $PaCO_2$, $PaO_2$, airway resistance, lung compliance and so on. Results : Expiratory cross-sectional area of trachea had significant correlation with $PaCO_2$ (r=-0.61, p<0.05), $PaO_2$ (r=0.6, p<0.05), and minute ventilation (r=0.73, p<0.05), but inspiratory cross-sectional area did not (r=-0.22, p>0.05 with $PaCO_2$, r=0.26, p>0.05 with $PaO_2$, and r=0.44, p>0.05 with minute ventilation). Minute ventilation had significant correlation with tidal volume (r=0.45, p<0.05), but it had no significant correlation with respiratory frequency (r=-0.31, p>0.05). Cross-sectional area of trachea had no significant correlation with other parameters of pulmonary function including $FEV_1$, FVC, $FEV_1$/FVC, peak expiratory flow, residual volume, diffusing capacity, airway resistance, and lung compliance, whether the area was expiratory or inspiratory. Conclusion : Cross-sectional area of trachea narrowed during expiration in emphysema, and its expiratory area had significant correlation with $PaCO_2$, $PaO_2$, and minute ventilation.

• Korean Journal of Environment and Ecology
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• v.14 no.1
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• pp.28-37
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• 2000

지리산국립공원의 아고산지대를 중심으로 분포하고 있는 한국특산종 구상나무의 생육현화과 구상나무림의 군집구조를 파악하여 앞으로의 구사나무림 관리의 기초자료를 마련하고자 구상나무가 생육하고 있는 지역에 42개의 방형구(20m$\times$20m)를 설치하여 식생을 조사하였다 분석한 결과 조사대상지는 세 개의 군집인 신갈나무-당단풍군집 구상나무-신갈나무군집 구상나무군집으로 분류되었다 수종간의 상관관계에서는 물들메나무와 함박꽃나무 함박꽃나무와 층층나무 구상나무와 잣나무 거제수나무와 노각나무 물들메나무와 말발도리 거제수나무와 물들메나무 거제수나무와 물갬나무 거제수나무와 함박꽃나무 철쭉과 회나무 주목과 미역줄나무 물갬나무와 노각나무, 잣나무와 마가목, 진달래와 명자순 명자순과 시닥나무, 가문비나무와 마가목 등의 수종들간에는 높은 정의 상관관계가 인정되었고 당단풍과 미역줄나무 등의 수종들간에는 높은 부의 상관관계가 인정되었다 본 조사지의 종다야도는 1.2389-1.2552으로 높게 나타났다 구상나무의 활력은 저조한 것으로 나타났으며 12.92%가 고사목이었다 생육현황표의 점수 평균은 13.88이었다.