• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제4권3호
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• pp.127-137
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• 2000

This study presents an analysis of the characteristics of vertical ozone distribution near the surface using ozonesonde data(l995 to 1998), plus surface ozone and meteorological data from the Pohang region. These features were examined in detail using three case studies. The first related to episodes of high surface ozone concentrations during the Spring season when the frontogenesis between the high and low pressure associated with the upper-level jet stream was found to be located near the surface. The second was a 5-day winter period(l3 -17 December, 1997) in the Pohang province when the hourly concentrations exceeded 90 ppb on several occasions owing to low-level jets(LLJs) induced by a nocturnal stable layer. Accordingly, this explains why the high surface ozone concentrations occurred at night as the ozone was transported across the zone by a strong wind speed( over 12.5 ms .1). The third case study was ozone enhancement due to photochemical reactions. In this case, the maximum concentration of ozone exceeded 60 ppb in the summer(23 -28 August, 1997). When an ozone peak appeared within the boundary layer, the occurrence frequency of a low-level jet due to the nocturnal stable layer was about 77%, similarly the occurrence frequency of a near-surface ozone peak relative to the appearance of an LLJ was about 76%. Accordingly, there is clearly a close correlation between the occurrence of LLJs and near-surface ozone peaks.

• 대한한방부인과학회지
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• 제31권1호
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• pp.57-83
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• 2018

Purpose: This research has been carried out to find out correlation between test results of ABR-2000 and other diagnostic equipments to enhance significance of accurate diagnosis and clinical usage of ABR-2000. Methods: Duration of the 31 months from December 2012 to June 2015, records of 564 outpatients at gynecology department have been selected. The 564 patients were tested, using all 3 different test equipments of ABR-2000, DSOM, and 3D Blood Pressure Pulse Analyzer (3D-MAC) without test errors or mis-recordings. Correlation between 3D Blood pressure Pulse Analyzer, DSOM and ABR-2000 were analyzed by frequency & ratio factor of statistic data records of patients groups devided by 8 different disease symptom and by comparison of the groups in the form of Regulation and Graph presented on ABR-2000 equipment. Results: 1. The indicator L in all 1, 2, and 3 quadrant in the graph means the activity and reactivity of the upper body biodynamics detection rate is low and which result is very common symptom among gynecological patients. 2. The portion of patients with hypermenorrhea, endometritis, and menstrual pain symptom among the indicator L group in the reactivity 1-3 quadrantin is significantly high. 3. When 3D Mac analyzer indicates H, diastole decreases while systole increases and tachycardia increases then the blood circulation is expected to increase. In case of indication L, diastole increases and systole decreases then, the blood circulation is expected to decrease.

• 식물조직배양학회지
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• 제25권2호
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• pp.75-80
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• 1998

부정근발생에 관한 도립 및 직립배양의 영향을 구명하기 위하여 6일간 자란 팥의 유경 절편을 사용하였다. $2\times10$^{-4}M$ IAA 용액을 48시간 처리할 때에 절편의 위치를 직립 또는 도립으로 배양 후 96시간 직립으로 배양하였다. 48시간 처리시 직립배양하면 부정근의 형성은 형태학적 기부에서만 발생하지만, 도립 전처리 배양을 하면 유경절편의 양끝에서 부정근이 발생하였다. IAA 전처리는 절편의 방향과 관계없이 부정근 형성을 촉진시켰다. 부정근 발생시기에 유경절편내의 생화학적 변화를 구명하기 위하여 직립배양 및 도립배양을 한 후 부정근 발생 단계별로 24시간, 48시간, 148시간 후 절편을 상부, 중부, 하부로 등분하여 부정근 발생에 수반되는 효소활성, 절편의 길이 신장 및 생중량을 측정하였다. 절편의 길이 신장은 절편의 상부에서 높게 나타났고 생중량은 발근부위에서 높게 나타났다. peroxidase을 catalase 활성은 부정근원기의 형성단계인 24시간에 절편의 발근부위에서 높게 나타났고 이에 비해 IAA oxidase는 양쪽 기부에서 낮았다. 그리고 IAA oxidase와 peroxidase 활성은 48시간 배양인 부정근의 형성동안 발근 부위에서 감소하였다. 도립전처리 유경 절편에 따라서 효소활성의 변화가 일어났으며 peroxidase의 활성은 부정근원기형성과 밀접한 관계를 나타내었다. 따라서 생화학적인 변화는 유경의 발근영역에서 IAA의 수준의 변화와 밀접하게 관련되어 특정부위에서의 부정근 형성을 유도하는 것으로 판단된 것이다.

• 한국재료학회지
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• 제28권8호
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• pp.478-488
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• 2018

In this study, three kinds of steels are manufactured by varying the rolling conditions, and their microstructures are analyzed. Tensile and Charpy impact tests are performed at room temperature to investigate the correlation between microstructure and mechanical properties. In addition, heat affected zone(HAZ) specimens are fabricated through the simulation of the welding process, and the HAZ microstructure is analyzed. The Charpy impact test of the HAZ specimens is performed at $-40^{\circ}C$ to investigate the low temperature HAZ toughness. The main microstructures of steels are quasi-polygonal ferrite and pearlite with fine grains. Because coarse granular bainite forms with an increasing finish rolling temperature, the strength decreases and elongation increases. In the steel with the lowest reduction ratio, coarse granular bainite forms. In the HAZ specimens, fine acicular ferrites are the main features of the microstructure. The volume fraction of coarse bainitic ferrite and granular bainite increases with an increasing finish rolling temperature. The Charpy impact energy at $-40^{\circ}C$ decreases with an increasing volume fraction of bainitic ferrite and granular bainite. In the HAZ specimen with the lowest reduction ratio, coarse bainitic ferrite and granular bainite forms and the Charpy impact energy at $-40^{\circ}C$ is the lowest.

• 한국토양비료학회지
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• 제22권2호
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• pp.131-137
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• 1989

고수량(高收量) 삼포(蔘圃)에서 인접(隣接)한 대소편삼(大小片蔘)의 근권(根圈)의 화학성(化學性)과 미생물(微生物) 특성(特性)을 조사(調査)하여 근생육(根生育)과의 관계(關係)를 살폈다. $NO_3-N$, $NH_4-N$ 인산이 대편삼(大片蔘)에서 적었고 Ca은 대편삼(大片蔘)에서 높았다. 미량성분(微量成分)은 Cu와 Zn은 지근수(支根數)와 유의정상관(有意正相關)을 보였으나 Fe는 부상관(負相關)이었다. $NH_4-N$, $NO_3-N$는 세근발달(細根發達)과 유의부상관(有意負相關)을 보였다. 유기물특성(有機物特性)에서는 휴민산의 침전비율(PQ)이 유의성은 없으나 대편삼(大片蔘)에서 높은 경향이었다. 근권미생물(根圈微生物)은 세균밀도(細菌密度)가 근중(根重)에 기여하는 방향으로 곰팡이와 방선균(放線菌)은 저해하는 방향이며 세균중(細菌中) 우점세균밀도(優占細菌密度)는 대편삼(大片蔘)에 유의성(有意性)있게 많았다. 세균(細菌)과 곰팡이 또는 방선균(放線菌)의 비율(比率)이 세균발달(細菌發達)과 유의정상관(有意正相關)을 보였다.

• 한국항행학회논문지
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• 제22권4호
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• pp.295-301
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• 2018

최근에 GPS(Global Positioning System) 간섭신호 제거를 위해서 배열안테나 기술 적용이 일반화되고 있으며, 이러한 안테나 기반의 GPS 수신 신호 보호 기술은 지상의 주요 국가 인프라 및 항공분야에서 점진적으로 확대 적용되는 추세이다. 이와 같은 배열안테나 기반의 간섭신호 제거 기술은 지금까지 평면 배열안테나인 2차원 구조가 보편적으로 활용되지만, 상대적으로 높은 고도에서 운용되는 무인기 같은 비행체의 경우 아래쪽에서 여기되는 간섭신호가 안테나 수평면과 대칭되는 위치에 미러 이미지에 의한 추가 널(null) 존(zone)이 발생하며 이로 인하여 수신가능 패턴 영역을 축소시킬 수 있다. 본 논문에서는 평면구조 배열안테나 사용 시 발생하는 간섭신호 미러 이미지 제거를 통해서 20%의 빔 패턴 수신 성능 향상 및 13 dB의 상관 값 성능을 개선하였다.

• 한국초지조사료학회지
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• 제40권4호
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• pp.265-273
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• 2020

We aimed to predict the Italian ryegrass (IRG) productivity change of introduced and domestic varieties based on climate factors and identify suitable areas for IRG cultivation using the RCP 8.5 scenario. The minimum mean air temperature in January showed the highest correlation with productivity. The ratio of possible and low productivity areas was high in Gangwondo, and the ratio of suitable and best suitable areas was relatively high in the central and southern regions in the past 30 years. The change in the IRG cultivation area was found to be 26.9% in the best suitable area between 1981-2010 but increased significantly to 88.9% between 2090s. In the IRG suitability comparison classes between domestic and introduced cultivars, the ratio of suitable and best suitable areas was relatively high in the domestic varieties during the past 30 years. However, there is almost no difference between the IRG domestic and introduced varieties in the IRG suitability classes after the 2050s. These results can predict changes in the IRG suitability classes between domestic and introduced cultivars according to the climate change scenario, but there are limitations in accurately predicting the productivity of IRG because the results may vary depending on other environmental factors.

• 한국환경농학회지
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• 제41권2호
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• pp.101-107
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• 2022

BACKGROUND: Soil amendment was necessary applied for the sand that had been used to root zone of green ground in golf course because of its low water retention power and cation exchangeable capacity. This study was conducted to evaluate the effect of the mixed ratio of peat moss and coconut coir as soil amendment materials on the soil physicochemical properties applied to rootzone based on sand. METHODS AND RESULTS: The soil amendments were blended at 0, 3, 5, 7 and 10% by soil volume. The pH in the peat moss treatment was lower than that of control (0% soil amendment), and pH and electrical conductivity (EC) in the coconut coir were higher. The blending ratio of peat moss was negatively correlated with pH of rootzone soil (p<0.01), and that of coconut coir positively with EC (p<0.01). As compared with control, capillary porosity, the physical factors such as air-filled porosity, total porosity, and hydraulic conductivity of rootzone soil were increased by applying peat moss and coconut coir. For correlation coefficients between percentage of soil amendments and soil physical factors, peat moss and coconut coir were positively correlated with porosity and hydraulic conductivity (p<0.01). CONCLUSION(S): These results indicated that the application of peat moss and coconut coir affected on the change of physicochemical properties of rootzone soil, and improved soil porosity and hydraulic conductivity.

• Ocean and Polar Research
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• 제30권3호
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• pp.215-224
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• 2008

A piston core (MR06-04 PC23A) collected from the northern continental slope in the central Bering Sea has recorded the high-resolution millennial-scale variation of calcium carbonate ($CaCO3$) content during the last 65 kyr. An estimation of the age of the core sediments was carried out by using the lithologic correlation of the deglacial laminated layers with a neighboring core (HLY02023JPC), complementing the last appearance datum of both Lychnocanoma nipponica sakaii (54 kyr) and Amphimelissa setosa (85 kyr). The probable age of core MR06-04 PC23A was approximately younger than 65 kyr. Two distinct events of a significant increase of $CaCO3$ in the deglacial laminated sediments clearly correspond to MWP1A and MWP1B in the Bering Sea (Gorbarenko et al. 2005) and to T1ANP and T1BNP in the North Pacific (Gorbarenko 1996). These pronounced peaks of $CaCO3$ contents result from the elevated carbonate production in the surface water and the subsequent weakened dilution due to terrestrial input, along with an enhanced oxygen minimum zone. The $CaCO3$ contents are low (${\sim}2%$) during the last glacial period mainly because of a low carbonate production caused by an expanded sea-ice cover and an increased dilution by terrigenous particles due to their closer distance to the continent during the sea-level low stand. The occurrence of seven distinct $CaCO3$ peaks in core MR06-04 PC23A is remarkable during MIS 3 and MIS 4, and they most likely correlate to the short-term millennial Dansgaard-Oeschger events.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.325-325
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• 2020

Low impact development (LID) is a widely used technology that aims to reduce the peak flow volume and amount of pollutants in stormwater runoff while introducing physicochemical, biological or a combination of both mechanisms in order to improve water quality. This research aimed to determine the effect of hydrologic factors in removing the pollutants on stormwater runoff by an LID facility. Monitored storm events from 2010-2018 were analysed to evaluate the hydraulic and hydrological performance of a small constructed wetland (SCW). Standard methods for the examination water and wastewater were employed to assess the water quality of the collected samples (APHA et al, 1992). Primary hydrologic data were obtained from the Korea Meteorological Administration. The recorded average rainfall intensity and antecedent dry days (ADD) of SCW were 5.26 mm/hr and 7 days respectively. During the highest rainfall event (27 mm/hr), the removal efficiency of SCW for all the pollutants was ranging from 67% to 91%. While on the lowest rainfall event (0.7 mm/hr), the removal efficiency was ranging from -36% to 62%. Rainfall intensity has a significant effect to the removal efficiencies of each facility due to its dilution factor. In addition to that, there was no significant correlation of ADD to the mean concentrations of pollutants. Generally, stormwater runoff contains significant amount of pollutants that can cause harmful effects to the environment if not treated. Also, the component of this LID facility such as pre-treatment zone, media filters and vegetation contributed to the effectivity of the LID facilities in reducing the amounts of pollutants present in stormwater runof.