• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2017년도 학술발표회
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• pp.334-334
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• 2017

하상재료와 같은 이질적인 토사의 입도 특성을 나타내기 위해서 특정한 비율의 대표입경이 사용된다. 대표입경은 토사의 평균 입경을 나타낼 수 있을 뿐만 아니라 분급(sorting), 왜도, 첨도 등 입도 분포의 다양한 특성을 나타낼 수 있다. 모래와 점토질(실트, 점토)가 포함된 토사의 경우 대표입경은 두 가지 단계를 거쳐 산정된다. 그 하나는 체분석, 비중계 분석 등을 통해 입경별 중량을 구하는 실험적 단계차이며, 그 다음은 입경별 중량 곡선을 그려서 내삽을 통해 대푯값을 찾아내는 과정이다. 그 중에 두 번째 과정은 통상 그래프를 보고 직접 구하는 그래프법이 사용되어 왔다. 그래프법은 단순하고 직관적이기는 하지만 산정해야 할 대표입경이 여러 가지인 경우에 시간이 많이 소요된다는 단점이 있었다. 이에 본 연구에서는 MS Excel을 이용하여 그래프법에 의해 대표입경을 바로 내삽하여 계산하는 프로그램을 제작하였다. 내삽법은 단순 직선에 의한 방법과 대수 곡선을 이용한 방법을 사용하였다. 그래프법에 의해 육안으로 판정한 대표입경과 비교할 때, 단순 직선 내삽은 평균 5.31%, 대수 내삽은 1.29%의 오차를 갖는 것으로 나타났다. 본 연구의 결과를 이용하여 자동으로 대표입경을 계산해 주는 엑셀 프로그램(PDA)을 제작하였다.

• Ocean and Polar Research
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• 제43권3호
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• pp.99-111
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• 2021

Occurrence of epiphytic dinoflagellates (EPDs) in coastal waters off Jeju was first reported in 2011 based on 45 substrate samples from 24 macroalgal species. When re-analyzing, the extreme heterogeneous distribution of whole and genus-specific EPDs was reconfirmed across the sampling stations and substrate macroalgal species, as well as even across substrate samples of the same species. Abundance maximum of an EPD genus (cells g-wwt^-1) at a fixed surface-to-volume ratio (SA/V ratio) of the macroalgal species increased as the SA/V ratio increased up to 500 (cm² cm^-3). However, the abundance maximum of Ostreopsis further increased even in the MG2 (morphological group 2) macroalgae with the SA/V ratios over 500. The number of substrate macroalgal species on the plane of the MG and sampling station was more or less evenly scattered than the average EPD abundance, which was primarily driven by Gambierdiscus and Ostreopsis. Of the total EPD abundance of the five stations, 90.6% were represented by the two most common and abundant genera, Gambierdiscus and Ostreopsis, each accounting for 41.6% and 49.0%. Spatially, 95.9% of the total EPD abundance was found in St. 4 and St. 5, of which St. 4 with higher water temperature had more Ostreopsis spp. (31.8%), and St. 5 with higher salinity had more Gambierdiscus spp. (27.3%). Thus, the environmental transition to favorable T-S condition to MG2, the thin filamentous macroalgal group with very high SA/V ratios, is thus likely to support further success in EPD genera led by Ostreopsis in the coastal waters of Jeju.

• The Journal of Asian Finance, Economics and Business
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• 제8권10호
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• pp.109-117
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• 2021

This study investigates the effects of FDI and other macroeconomic variables on Total Factor Productivity (TFP) in selected ASEAN+3 countries from 1981 till 2016. Total Factor Productivity (TFP) for each ASEAN+3 country was constructed using the Malmquist productivity index method. Then, a panel ARDL framework (dynamic heterogeneous panel), namely Pooled Mean Group (PMG), Mean Group (MG), and Dynamic Fixed Effect (DFE) are employed in examining the effects of FDI and other controlling variables on TFP. The new findings show that FDI has a significant and positive impact on TFP in the long run and the short run in ASEAN+3 countries. Besides, the results also reveal that in the long run, other variables such as the average number of years of schooling and the ratio of high-skilled to low-skilled labor also have a significant and positive effect on TFP. However, economic openness, government expenditure on R&D, and interaction between countries and FDI have a negative and significant impact on TFP. These findings implied that the recipient countries must ensure their political stability and offer various incentives to attract more investors. Furthermore, the influx of foreign investors, especially large ones and lower costs, should be encouraged by each country as FDI inflows can boost their TFP growth.

• Journal of Ginseng Research
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• 제45권6호
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• pp.726-733
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• 2021

Background: Panax notoginseng is a highly valued medicinal herb used widely in China and many Asian countries. Its root and rhizome have long been used for the treatment of cardiovascular and hematological diseases. Imaging the spatial distributions and dynamics of metabolites in heterogeneous plant tissues is significant for characterizing the metabolic networks of Panax notoginseng, and this will also provide a highly informative approach to understand the complex molecular changes in the processing of Panax notoginseng. Methods: Here, a high-sensitive MALDI-MS imaging method was developed and adopted to visualize the spatial distributions and spatiotemporal changes of metabolites in different botanical parts of Panax notoginseng. Results: A wide spectrum of metabolites including notoginsenosides, ginsenosides, amino acids, dencichine, gluconic acid, and low-molecular-weight organic acids were imaged in Panax notoginseng rhizome and root tissues for the first time. Moreover, the spatiotemporal alterations of metabolites during the steaming of Panax notoginseng root were also characterized in this study. And, a series of metabolites such as dencichine, arginine and glutamine that changed with the steaming of Panax notoginseng were successfully screened out and imaged. Conclusion: These spatially-resolved metabolite data not only enhance our understanding of the Panax notoginseng metabolic networks, but also provide direct evidence that a serious of metabolic alterations occurred during the steaming of Panax notoginseng.

• Wind and Structures
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• 제28권2호
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• pp.129-140
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• 2019

Accurately simulating the wind field of large-scale region, for instant urban areas, the locations of large span bridges, wind farms and so on, is very difficult, due to the complicated terrains or land surfaces. Currently, the regional wind field can be simulated through the combination of observation data and numerical model using observation-nudging in the Weather Research and Forecasting model (WRF). However, the main drawback of original observation-nudging method in WRF is the effects of observation on the surrounding field is fully mathematical express in terms of temporal and spatial, and it ignores the effects of terrain, wind direction and atmospheric circulation, while these are physically unreasonable for the turbulence. For these reasons, a spatial correlation-based observation-nudging method, which can take account the influence of complicated terrain, is proposed in the paper. The validation and comparation results show that proposed method can obtain more reasonable and accurate result than original observation-nudging method. Finally, the discussion of wind field along bridge span obtained from the simulation with spatial correlation-based observation-nudging method was carried out.

• The Plant Pathology Journal
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• 제35권5호
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• pp.508-520
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• 2019

Interplay between Cymbidium mosaic virus (CymMV)/Odontoglossum ringspot virus (ORSV) and its host plant Phalaenopsis equestris remain largely unknown, which led to deficiency of effective measures to control disease of P. equestris caused by infecting viruses. In this study, for the first time, we characterized viral small interfering RNAs (vsiRNAs) profiles in P. equestris co-infected with CymMV and ORSV through small RNA sequencing technology. CymMV and ORSV small interfering RNAs (siRNAs) demonstrated several general and specific/new characteristics. vsiRNAs, with A/U bias at the first nucleotide, were predominantly 21-nt long and they were derived predominantly (90%) from viral positive-strand RNA. 21-nt siRNA duplexes with 0-nt overhangs were the most abundant 21-nt duplexes, followed by 2-nt overhangs and then 1-nt overhangs 21-nt duplexes in infected P. equestris. Continuous but heterogeneous distribution and secondary structures prediction implied that vsiRNAs originate predominantly by direct Dicer-like enzymes cleavage of imperfect duplexes in the most folded regions of the positive strand of both viruses RNA molecular. Furthermore, we totally predicted 54 target genes by vsiRNAs with psRNATarget server, including disease/stress response-related genes, RNA interference core components, cytoskeleton-related genes, photosynthesis or energy supply related genes. Gene Ontology classification showed that a majority of the predicted targets were related to cellular components and cellular processes and performed a certain function. All target genes were down-regulated with different degree by vsiRNAs as shown by real-time reverse transcription polymerase chain reaction. Taken together, CymMV and ORSV siRNAs played important roles in interplay with P. equestris by down modulating the expression levels of endogenous genes in host plant.

• 한국콘텐츠학회논문지
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• 제21권6호
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• pp.552-560
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• 2021

새로운 미술품 유통방식의 발달로 미술품의 미적 효용을 넘어 투자재로서 바라보는 시각이 활성화되고 있다. 미술품의 가격은 주식이나 채권 등과 달리 객관적 요소와 주관적 요소들이 모두 반영되어 결정되는 이질적 특성이 있기 때문에 가격 예측에 있어서 그 불확실성이 높다. 본 연구에서는 LSTM(장단기 기억) 순환신경망 딥러닝 모형을 활용하여 낙찰총액 순위 1위부터 10위까지의 한국 작가의 회화 작품을 대상으로 작가의 특성, 작품의 물리적 특성, 판매적 특성 등을 입력으로 하여 경매 낙찰가의 예측을 시도하였다. 연구 결과, 모델에 의한 예측 가격과 실제 낙찰 가격의 차이를 설명하는 RMSE 값이 0.064 수준이었으며 작가별로는 이대원 작가의 예측력이 가장 높았고, 이중섭 작가의 예측력이 가장 낮았다. 투자재로서 미술품 시장이 더욱 활성화되고 경매 낙찰 가격의 예측 수요가 높아지면서 본 연구의 결과가 활용될 수 있을 것이다.

• 한국수자원학회논문집
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• 제53권12호
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• pp.1059-1070
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• 2020

하천단면 계측자료는 하천관리를 위한 유량산정 및 홍수 예·경보 방안 등 수리·수문 모델링 관련 연구에서 가장 중요한 입력자료 중 하나이다. 그러나 불규칙한 기하학적 구조로 이어지는 하천의 정확하고 연속적인 단면자료의 취득은 시간과 비용적 측면에서 큰 제약이 따른다. 이러한 관점에서 본 연구의 목적은 연속적인 하천특성의 공간분포를 시간과 비용, 인력의 투입을 최소화하여 계측할 수 있는 방법론을 개발하는 것이다. 따라서 RGB기반 항공 이미지와 실측 자료를 이용한 다중 선형 회귀 분석을 통해 각 단면별로 수심을 추정하고 연속적인 단면 추정 가능성과 정확도를 검토하고자 하였다. 실측 자료와 비교검증을 통해 공간적으로 이질적인 관계를 포착할 수 있는 수심 약 2 m 내외에서 수심을 정확하게 추정할 수 있음을 확인하였으며 이를 통해 정확하고 연속적인 하천 단면 취득에 기여할 수 있을 것으로 기대한다.

• 자원ㆍ환경경제연구
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• 제30권4호
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• pp.535-555
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• 2021

본 연구는 국내 주식시장 변동성에 대한 국제유가의 영향을 실증적으로 분석한다. 분석을 위해 사용된 자료는 2015년 1월 2일부터 2021년 7월 30일까지 KOSPI 지수와 WTI 선물가격의 10분 주기 고빈도 자료이다. 이를 사용하기 위해서는 이질적 자기회귀(HAR) 모형을 사용하였다. 분석 모형에서는 고빈도 자료의 장점을 살려 국제유가의 영향을 수익률뿐 아니라 실현 변동성, 실현 왜도 및 첨도를 통해 확인한다. 추정에는 큰 왜도를 갖는 실현 변동성 분포를 감안하여 Box-Cox 변환을 적용하였다. 추정 결과, WTI 가격의 일간 수익률 변동은 KOSPI 수익률의 변동성에 통계적으로 유의한 양(+)의 영향을 미치는 것으로 나타났다. 하지만 WTI 수익률의 변동성, 왜도, 첨도는 KOSPI 수익률의 변동성에 영향을 주지 않는 것으로 나타났다. 이와 같은 결과는 KOSPI 수익률의 변동성이 거래 시간의 시차를 갖는 WTI 수익률의 일간 변화는 반영하지만 투자자의 일중 거래 행태까지는 반영하지 않기 때문으로 판단된다.

• 대한임상검사과학회지
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• 제54권4호
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• pp.316-324
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• 2022

Polycystic ovary syndrome (PCOS) is a complex endocrinopathy in women of reproductive age. The genetics of PCOS is heterogeneous with the involvement of number of genes in the steroid synthesis pathway. The CYP11B2 encodes aldosterone synthase and the genetic variants might increase aldosterone secretion in PCOS cases. CYP1A1 is known to enhance the intraovarian catechol estrogen production and thus the propensity for PCOS. The present case-control study analyzed a total of 619 females for CYP11B2 (rs1799998) and CYP1A1 (rs4646903) polymorphisms. Obesity was examined according to body mass index (BMI) and waist hip ratio (WHR) categorization. Biochemical (lipid profile) analysis was performed in PCOS females. BMI (P=0.0001) and WHR (P=0.0001) revealed a statistically significant difference between PCOS cases and controls. The overall levels of triglycerides were higher in PCOS females. The genotype frequency distribution of CYP11B2 (rs1799998) polymorphism revealed statistically significant difference between PCOS cases and controls (P=0.017). However, CYP1A1 (rs4646903) polymorphism did not showed any association with PCOS. The present case-control association analysis is first from our region for CYP1A1 and CYP11B2 polymorphisms and is suggestive of genetic predisposition of steroidogenic genes among PCOS patients in the North-Indian Punjabi females.