시계열 온실 환경 인자와 딸기 생육 특성간의 상관성 연구

이현규, 정동욱, 이정규, 김수아, 이동훈 忠北大學校 農業科學硏究所 2017 農業科學硏究 Vol.33 No.1

The purpose of this study is to investigate the correlation between the growth conditions of the crops and the environment of the greenhouse according to the variation of temperature inside the greenhouse. The environment sensor (i.e. temperature and humidity sensor) which were installed in the greenhouse were collected as environmental factor. The growth index of strawberry were measured to fruit length, fruit diameter, fruit weight, sugar content and yield according to the average temperature and humidity. The correlation between the environmental factors in the greenhouse and the growth index of strawberry was investigated by simple linear regression. The production of strawberry showed a slight difference in each location, but the production of strawberry was increased in the area close to the heater.

EBM 구축을 위한 쌍화탕의 실험 연구 문헌 분석

이준경(Lee Junkyoung),이남헌(Lee Namhun),하혜경(Ha Hyekyoung),이호영(Lee hoyoung),서창섭(Seo Changsub),정다영(Jung Dayoung),이진아(Lee Jinah),신현규(Shin Hyunkyu) 한국한의학연구원 2008 한국한의학연구원논문집 Vol.14 No.3

Objective: The purpose of this report was to provide the information about activity and safety of Ssanghwa-tang by analyzing domestic papers and theses about Ssanghwa-tang. Methods: Domestic papers and theses related to Ssanghwa-tang were reviewed and analyzed. These papers were then classified by year, experimental method, and activity subject. Results: The following results were obtained in this study. 1. The study of Ssanghwa-tang started from 1981 and continued steadily 1990s and it was decreased 2000s. 2. The paper of Ssanghwatang was entire domestic paper, 20 volumes. 3. In classified by experimental method and animal of Ssanghwa-tang paper, more than a half study used rat in vivo experiment. Furthermore clinical experiments were performed about anti-fatigue effect of Ssanghwa-tang and Ssanghwatang was proved a safety herbal medicine in acute toxicity experiment. 4. Decursin, glycyrrhizin, paeoniflorin were determined in Ssanghwa-tang by using HPLC analysis. 5. As these studies were classified by subject, papers related to anti-fatigue effect were most abundant by 7 papers. Besides there were several papers related to liver funtion, anti-inflammatory, alleviation, smooth muscle relaxation effect and so on. 6. According to experimental data, it is supported that Ssanghwa-tang was safety herbal medicine and it has a several activity about anti-fatigue, anti-inflammatory, alleviation, smooth muscle relaxation. Conclusion : Many study of basic science experiments and clinical experiments were performed and reported on Ssanghwa-tang in domestic journal. Ssanghws-tang is being used in various ways associating with anti-fatigue. anti-inflammatory. alleviation and smooth muscle relaxation. furthermore Ssanghwatang was proved a safety herbal medicine in acute toxicity experiment. However, studies on randomized controlled trials of Ssanghwatang need to be completed at the clinical level.

Impact of collagen-alginate composition from microbead morphological properties to microencapsulated canine adipose tissue-derived mesenchymal stem cell activities

Lee, Hyunkyu,Woo, Heung-Myong,Kang, Byung-Jae Informa UK (TaylorFrancis) 2018 Journal of Biomaterials Science. Polymer Edition Vol. No.

<P>The purpose of this study was to identify the effect of collagen-alginate composition on the size and shape of microbeads and the proliferation and osteogenic properties of microencapsulated canine adipose-derived mesenchymal stem cells (ASCs) in vitro. Canine ASCs were microencapsulated in mixtures of various collagen-alginate compositions using a vibrational technologic encapsulator. The size and shape of the resultant microbeads were measured using a light field microscope and the viability of the microencapsulated canine ASCs was evaluated using a live/dead viability/cytotoxicity kit. Proliferation and osteogenic potentials of microencapsulated canine ASCs were evaluated using an alamarBlue proliferation assay and an alkaline phosphatase assay, respectively. As the collagen ratio increased, the size and size variation of microbeads increased and the shape of microbeads became more irregular. Nonetheless, homogeneous microbeads were created with no significant difference in size and shape, in the range of 0.75% alginate mixed with 0.099% collagen solution in 1.2% alginate solution. There were no significant differences in viability of the ASCs in the various collagen-alginate compositions. Both proliferation and osteogenic properties, in vitro, increased with increasing collagen ratio. Microencapsulation of canine ASCs with appropriate collagen-alginate composition increases cell proliferation and osteogenic properties, in vitro, without significant effects on the shape and size of microbeads and cell viability. Microencapsulation with adequate collagen-alginate composition may produce injectable microbeads that could enhance the therapeutic efficacy of stem cells.</P>

Comparison of Two Meta-Analysis Methods: Inverse-Variance-Weighted Average and Weighted Sum of Z-Scores

Lee, Cue Hyunkyu,Cook, Seungho,Lee, Ji Sung,Han, Buhm Korea Genome Organization 2016 Genomics & informatics Vol.14 No.4

The meta-analysis has become a widely used tool for many applications in bioinformatics, including genome-wide association studies. A commonly used approach for meta-analysis is the fixed effects model approach, for which there are two popular methods: the inverse variance-weighted average method and weighted sum of z-scores method. Although previous studies have shown that the two methods perform similarly, their characteristics and their relationship have not been thoroughly investigated. In this paper, we investigate the optimal characteristics of the two methods and show the connection between the two methods. We demonstrate that the each method is optimized for a unique goal, which gives us insight into the optimal weights for the weighted sum of z-scores method. We examine the connection between the two methods both analytically and empirically and show that their resulting statistics become equivalent under certain assumptions. Finally, we apply both methods to the Wellcome Trust Case Control Consortium data and demonstrate that the two methods can give distinct results in certain study designs.

Polarity and threading dislocation dependence of the surface morphology of <i>c</i>-GaN films exposed to HCl vapor

Lee, Hyunkyu,Jang, Dongsoo,Kim, Donghoi,Kim, Hwa Seob,Kim, Chinkyo The Royal Society of Chemistry 2018 Journal of Materials Chemistry C Vol.6 No.23

<P>The polarity and threading dislocation dependence of the surface morphology of <I>c</I>-GaN films exposed to HCl vapor at temperatures of 750 and 810 °C was investigated. For N-polar GaN, some regions were severely etched in such a way that vertically-aligned nanopipes were formed while areas other than those occupied by the nanopipes were barely etched. A cross-sectional transmission electron microscopy analysis revealed that the bottom of the nanopipes was observed to be connected to threading dislocation(s) while no threading-dislocation was observed beneath the unetched surface of N-polar GaN. In comparison, the threading-dislocation-free region in Ga-polar GaN domains was heavily etched, and GaN nanoneedles were formed on a relatively flat surface at temperatures as low as 750 °C. In order to understand the etched surface morphology of Ga-polar GaN (nanoneedles on a relatively flat surface), we proposed a physical model to describe this etching behavior, and a computational simulation based on our proposed model could explain the etched surface morphology of a Ga-polar GaN film exposed to HCl vapor.</P>

A facile method to enhance the uniformity and adhesion properties of water-based ceramic coating layers on hydrophobic polyethylene separators

Lee, Hoogil,Jeon, Hyunkyu,Gong, Seokhyeon,Ryou, Myung-Hyun,Lee, Yong Min Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.427 No.1

<P><B>Abstract</B></P> <P>To enhance the uniformity and adhesion properties of water-based ceramic coating layers on hydrophobic polyethylene (PE) separators, their surfaces were treated with thin and hydrophilic polydopamine layers. As a result, an aqueous ceramic coating slurry consisting of Al<SUB>2</SUB>O<SUB>3</SUB> particles, carboxyl methyl cellulose (CMC) binders, and water solvent was easily spread on the separator surface, and a uniform ceramic layer was formed after solvent drying. Moreover, the ceramic coating layer showed greatly improved adhesion properties to the PE separator surface. Whereas the adhesion strength within the bulk coating layer (<I>F</I> <SUB>mid</SUB>) ranged from 43 to 86Nm<SUP>−1</SUP> depending on the binder content of 1.5–3.0wt%, the adhesion strength at the interface between the ceramic coating layer and PE separator (<I>F</I> <SUB>sepa-Al2O3</SUB>) was 245–360Nm<SUP>−1</SUP>, a value equivalent to an increase of four or five times. Furthermore, an additional ceramic coating layer of approximately 7μm did not degrade the ionic conductivity and electrochemical properties of the bare PE separators. Thus, all the LiMn<SUB>2</SUB>O<SUB>4</SUB>/graphite cells with ceramic-coated separators delivered an improved cycle life and rate capability compared with those of the control cells with bare PE separators.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Polydopamine-treated PE separators were used for ceramic-coated separators (CCSs). </LI> <LI> Polydopamine (PDA) facilitated the uniform water-based ceramic coating layers. </LI> <LI> PDA-PE/CCS improved adhesion strength between PE and ceramic coating layers. </LI> <LI> PDA-PE/CCS improved thermal stability compared to bare PE. </LI> <LI> PDA-PE/CCS improved rate and cycle retention abilities of full cells. </LI> </UL> </P>

In-depth correlation of separator pore structure and electrochemical performance in lithium-ion batteries

Lee, Yunju,Park, Joonam,Jeon, Hyunkyu,Yeon, Daeyong,Kim, Byung-Hyun,Cho, Kuk Young,Ryou, Myung-Hyun,Lee, Yong Min Elsevier 2016 Journal of Power Sources Vol.325 No.-

<P><B>Abstract</B></P> <P>To establish an accurate correlation between a separator’s pore structure and the electrochemical performance of a lithium-ion battery (LIB), we fabricate well defined polyethylene (PE) separators on the same production line while maintaining most processing variables, except for composition. Four PE separators having different thicknesses and porosities (16 μm/37%, 16 μm/40%, 16 μm/47%, 22 μm/47%, respectively) are physically and electrochemically evaluated in detail. Although thickness and porosity remain good parameters by which to represent the separators’ characteristics, both the normalized Gurley number and ionic conductance are found to have much stronger relationships with the rate capability.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Well-defined polyethylene separators are fabricated with the same raw materials. </LI> <LI> Normalized Gurley number and ionic conductance can predict the cell performance. </LI> <LI> Correlation map on separators’ physical and electrochemical properties is proposed. </LI> </UL> </P>

Plasma-assisted water-based Al₂O₃ ceramic coating for polyethylene-based microporous separators for lithium metal secondary batteries

Jeon, Hyunkyu,Jin, So Yeon,Park, Won Ho,Lee, Hongkyung,Kim, Hee-Tak,Ryou, Myung-Hyun,Lee, Yong Min Elsevier 2016 ELECTROCHIMICA ACTA Vol.212 No.-

<P><B>Abstract</B></P> <P>To meet the high requirements of future lithium secondary batteries based on lithium metal anodes for large-scale applications, we develop a cost-effective and environmentally friendly water-based method to prepare inorganic/polymer composite coating layers on commercial hydrophobic polyolefin-based microporous separators. To this end, we utilize a plasma-treatment technique. After the plasma treatment, the surface of the polyethylene (PE) separators changes from hydrophobic to hydrophilic, and the pore structures of the separators widen. These changes improve the affinity of the PE separators for polar liquid electrolytes and their ionic conductivities compared to those of bare PE and other ceramic-coated control systems. The polar functional groups derived from plasma treatment interact with the hydroxyl groups of water-soluble polymeric binders in the ceramic (Al<SUB>2</SUB>O<SUB>3</SUB>) coating layers, thereby improving the adhesion strength between the PE substrate and the ceramic coating layer. This improvement impedes hydrophobic recovery phenomena. As a result, plasma-treated ceramic-coated separators (plasma CCSs) exhibit superior power capability and cycle performance (plasma CCS maintained 94.7% of the initial discharge capacity up to the 1000th cycle at C/2, whereas bare PE’s remained high only up to the 300th cycle) in unit cells based on lithium metal anodes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Plasma treatment technique realizes a 100% water-based ceramic coating process. </LI> <LI> Plasma treatment enhances the adhesion properties of ceramic coating layer. </LI> <LI> Al<SUB>2</SUB>O<SUB>3</SUB> coating layers impedes hydrophobic recovery after plasma treatment. </LI> <LI> Plasma-treated Al<SUB>2</SUB>O<SUB>3</SUB> layers improves cycle performance and rate capabilities. </LI> </UL> </P>

고령가계의 의료비 부담이 가계경제에 미치는 영향 - 소비지출과 재무안정성을 중심으로

이현규 ( Lee Hyunkyu ),한지형 ( Han Jihyung ),최현자 ( Choe Hyuncha ) 한국소비자학회 2018 소비자학연구 Vol.29 No.6

본 연구는 고령가계의 보유 자원에 따른 의료비 지출 구조와 의료비 부담 차이를 분석하여 의료비 현황과 변화양상을 파악하였으며 의료비 부담으로 인해 가계경제가 어떠한 과정으로 변화하는지 알아보기 위하여 의료비 부담이 가계경제에 미치는 영향력을 밝히고, 의료비 부담의 변화량이 가계경제의 변동 양상에 미치는 영향을 살펴보았다. 이를 위해 본 연구에서는 한국노동패널 17차, 18차 자료를 활용하였고, 자료 중 가구주가 만 55세 이상인 가계를 추출하여 최종적으로 2,835명의 자료를 분석하였다. 분석 방법은 기술통계 분석과 F검정, Scheffe 사후검정, 대응표본 t-test, 이항 로지스틱 회귀분석, 다항 로지스틱 분석을 활용하였다. 연구의 주요 결과는 다음과 같다. 첫째, 고령가계의 평균적인 의료비 지출 규모는 연간 약 95만 원 내외였으며, 비빈곤 가계의 의료비 지출 규모는 약 110만 원으로 가장 크게 나타난 반면, 소득과 자산이 모두 빈곤한 가계는 이의 절반 정도 수준으로 나타났다. 또한 소득자산빈곤 가계와 자산빈곤 가계의 의료비 지출 규모는 각각 전년 대비 35.29%, 20.30%씩 증가했다. 둘째, 고령가계의 의료비 부담의 경우, 전체 고령가계는 약 13%의 의료비 부담 수준을 보였으며 특히, 소득빈곤 가계의 의료비 부담이 약 20% 내외로 다른 가계에 비해 높게 나타났다. 그러나 의료비 부담의 변동성은 유의미하지 않았다. 셋째, 의료비 부담이 소비지출에 미치는 영향을 분석한 결과 의료비 부담이 증가할수록 의료비 외 지출액이 작아졌는데 이는 가계의 의료비 부담이 증가할 경우, 이를 부담할 수 있는 지불 능력이 충분히 상쇄하지 못해 한정된 자원을의료비 외 소비지출로 배분함에서 기인한다고 해석할 수 있다. 한편, 의료비 부담과 재무안정성 충족 여부 간에는 유의미한 인과관계가 존재하지 않는 것으로 나타났다. 넷째, 의료비 부담 변화가 의료비 외 소비지출 변화에 미치는 동태적 영향력을 분석한 결과, 의료비 부담이 급증할수록 의료비 외 소비지출이 감소할 가능성이 높았다. 한편, 의료비 부담 변화가 재무안정성에 미치는 동태적 영향력을 분석한 결과, 의료비 부담의 증가는 가계수지지표의 충족 가능성을 감소시키고, 비상자금지표의 미충족 가능성을 높이는 것으로 나타났다. This study analyzed the medical expenditure structure and burden of poverty type of aged households by analyzing whether there is a difference in the burden of medical expenditure. In addition, we examined the influence of the medical burden on the household economy and investigated the effect of the change in the medical burden on the pattern of change in the household economy. This implies that the mechanism of the elderly bankruptcy process can be clarified and the concept of the burden of medical expenses can be extended. This study analyzed 2,835 households whose household heads were over 55 years old using the 17th and 18th data of Korea Labor & Income Panel Study. The results of the study are as follows. First, the average medical expenditure of aged households is about 950,000 won per year. The expenditure of non - poverty households was the largest at about 1.1 million won, while the households whose income and assets were both poor were about half. In addition, the spending on medical expenses of income poverty households and asset poverty households increased by 35.29% and 20.30% respectively. Second, total aged households showed about 13% of the medical burden. In particular, the burden of medical expenses on income poverty households is about 20%, which is higher than other households. The changes in the burden of medical expenses of the surveyed households showed a not significant change. Third, as a result of cross-sectional analysis between medical expenditure and consumption expenditure, the expenditure of other consumption decreased as the burden of medical expenses increased. This can be interpreted as a result of allocating limited resources to other consumption expenditures because the payment capacity to cover the medical expenses burden of the household increases. On the other hand, cross-sectional analysis between medical burden and financial stability shows that there is no significant causal relationship between absolute size of medical burden and financial stability. Fourth, as a result of analyzing the dynamic influence of changes in medical expenses on changes in other consumption expenditures, it is more likely that other consumption expenditures will decrease as the burden of medical expenses increases. On the other hand, the analysis of the dynamic impact of the change in the medical burden on financial stability shows that the increase in the burden of medical expenses reduces the possibility of meeting the household balance index and increases the possibility of non - matching of the emergency fund index.

무선 센서 네트워크에서 이동 싱크를 지원하기 위한 다중 경로 라우팅 프로토콜

이현규(Hyunkyu Lee),임진혁(Jinhyuk Yim),김회원(Hoewon Kim),이의신(Euisin Lee) 한국통신학회 2016 한국통신학회 학술대회논문집 Vol.2016 No.1