Validations of a Numerical Model of Solute Transport in a Snowpack

Jeonghoon Lee(이정훈) 대한자원환경지질학회 2012 자원환경지질 Vol.45 No.5

Snowmelt from seasonal snow covers can be significant in many environments of northern and alpine areas. Water flow and chemical transport resulting from snowmelt have been studied for an understanding of contributions to watersheds or catchments. A Mobile-Immobile water Model (MIM) was developed to describe the movement of ionic tracers through a snowpack by Lee et al. (2008a) and Lee et al. (2008b). To validate the model used in the studies, mass balance calculations of the model were conducted and comparisons were made between model results and analytical solutions in this work. Mass balance was calculated based on the fact that change in total mass within a snowpack with time is equal to sum of any change in the flux of water or ionic tracers into and out of the snowpack. Calculations of both water and ionic mass show almost perfect agreement between changes of two water and solute mass fluxes. Comparisons between model results and analytical solutions including wave velocity and effective saturation show almost perfect agreement. 겨울철동안 쌓여 봄에 놓은 눈 녹은 물(snowmelt), 즉 융설의 유출은 북반구 및 산간지역에서 매우 중요한 것으로 여 겨지고 있다. 이러한 지역에서 융설로 인한 유동 및 이온의 이동에 대한 이해는 매우 중요하며 전세계적으로 꾸준하게 연구되고 있다. Lee et al. (2008a)와 Lee et al. (2008b)연구에서는 대기로부터 수송된 이온 및 오염원이 융설에 의해 눈 속을 이동하는 것을 모사하기 위한 Mobile-Immobile water Model (MIM)을 개발하였다. 이 연구에 사용된 모델을 검증 하기 위해서 물질수지계산(mass balance calculation) 및 해석해(analytical solution)를 이용한 모델결과와의 비교를 수행하 였다. 일정시간동안 눈 속에서의 물질의 질량변화는 눈 표면에서 들어온 물질과 눈 기저부에서 빠져나간 물질의 질량 차 이와 같아야한다는 사실을 이용하여 물질수지를 계산하였다. 파면(wave front)의 이동속도 및 기존문헌에서 알려진 해석 해를 이용하여 모델결과와의 비교도 시도하였다. 모델의 물질수지계산결과 질량 차이가 거의 발생하지 않았으며 모델결 과와 해석해와의 비교 역시 두 결과가 거의 일치하였다.

Validations of a Numerical Model of Solute Transport in a Snowpack

이정훈,Lee, Jeonghoon The Korean Society of Economic and Environmental G 2012 자원환경지질 Vol.45 No.5

겨울철동안 쌓여 봄에 놓은 눈 녹은 물(snowmelt), 즉 융설의 유출은 북반구 및 산간지역에서 매우 중요한 것으로 여겨지고 있다. 이러한 지역에서 융설로 인한 유동 및 이온의 이동에 대한 이해는 매우 중요하며 전세계적으로 꾸준하게 연구되고 있다. Lee et al. (2008a)와 Lee et al. (2008b)연구에서는 대기로부터 수송된 이온 및 오염원이 융설에 의해 눈속을 이동하는 것을 모사하기 위한 Mobile-Immobile water Model (MIM)을 개발하였다. 이 연구에 사용된 모델을 검증하기 위해서 물질수지계산(mass balance calculation) 및 해석해(analytical solution)를 이용한 모델결과와의 비교를 수행하였다. 일정시간동안 눈 속에서의 물질의 질량변화는 눈 표면에서 들어온 물질과 눈 기저부에서 빠져나간 물질의 질량 차이와 같아야한다는 사실을 이용하여 물질수지를 계산하였다. 파면(wave front)의 이동속도 및 기존문헌에서 알려진 해석 해를 이용하여 모델결과와의 비교도 시도하였다. 모델의 물질수지계산결과 질량 차이가 거의 발생하지 않았으며 모델결과와 해석해와의 비교 역시 두 결과가 거의 일치하였다. Snowmelt from seasonal snow covers can be significant in many environments of northern and alpine areas. Water flow and chemical transport resulting from snowmelt have been studied for an understanding of contributions to watersheds or catchments. A Mobile-Immobile water Model (MIM) was developed to describe the movement of ionic tracers through a snowpack by Lee et al. (2008a) and Lee et al. (2008b). To validate the model used in the studies, mass balance calculations of the model were conducted and comparisons were made between model results and analytical solutions in this work. Mass balance was calculated based on the fact that change in total mass within a snowpack with time is equal to sum of any change in the flux of water or ionic tracers into and out of the snowpack. Calculations of both water and ionic mass show almost perfect agreement between changes of two water and solute mass fluxes. Comparisons between model results and analytical solutions including wave velocity and effective saturation show almost perfect agreement.

완전최소자승법과 최소자승법을 이용한 물 안정동위원소의 선형관계식 비교

이다은(Da Eun Lee),이정훈(Jeonghoon Lee),이원상(Won Sang Lee),최혜빈(Hye-Bin Choi),이승구(Seung-Gu Lee) 대한지질학회 2017 대한지질학회 학술대회 Vol.2017 No.10

나노다이아몬드를 첨가한 오일의 트라이볼로지 특성 및 이에 미치는 표면 경도의 영향

이규선(Gyu-Sun Lee),김현수(HyunSoo Kim),이정훈(Jeonghoon Lee),박태희(Tae Hee Park),이정석(Jung Suk Lee),이영제(Young-Ze Lee) 한국트라이볼로지학회 2011 한국윤활학회지(윤활학회지) Vol.27 No.6

Nanodiamond was dispersed in paraffin liquid oil to investigate the effects of nanodiamond at the marginally lubricated condition. Scuffing test and immediate loading sliding wear test were conducted using the fabricated nanodiamond oil. As a result, dispersion of nanodiamond in oil leads to increase in scuffing life, and nanodiamond contents affects the scuffing life. In case of immediate loading sliding wear test, the result was different according to hardness of specimen. If hardness of specimen was low, abrasion of nanodiamond occurred actively. If hardness of specimen was increased, however, nanodiamond can act as a spacer or rolling between contacting surfaces.

Optimal volume of non-point sources management detention considering spatio-temporal variability of land surface moisture condition

Lee, Jeonghoon,Yoon, Jaeyoung,Shin, Hyunsuk,Kim, Sangdan Taylor Francis 2015 Desalination and Water Treatment Vol.53 No.11

Association of serum free thyroxine and glucose homeostasis: Korea National Health and Nutrition Examination Survey

( Jeonghoon Ha ),( Jeongmin Lee ),( Dong-jun Lim ),( Jung-min Lee ),( Sang-ah Chang ),( Moo-il Kang ),( Min-hee Kim ) 대한내과학회 2021 The Korean Journal of Internal Medicine Vol.36 No.0

Background/Aims: Thyroid hormones are involved in wide range of glucose metabolism functions. Overt thyroid dysfunctions are related to altered glucose homeostasis. However, it is not conclusive as to whether subtle changes in thyroid hormones within normal ranges can induce alterations in glucose homeostasis. The aim of this study was to evaluate the association between thyroid hormone and glucose homeostasis parameters in subjects without overt thyroid dysfunction based on nationwide population data. Methods: In the Sixth Korea National Health and Nutrition Examination Survey 2015 (n = 7,380), data were collected from subjects with insulin and thyroid function measurements who were older than 19-years-old. After the exclusion of 5,837 subjects, a total of 1,543 patients were included in the analysis. Subjects were categorized into the quartiles of the free thyroxine (FT4). Fasting glucose, insulin, homeostatic model assessment of insulin resistance and hemoglobin A1c (HbA1c) levels were considered to be glucose homeostasis parameters. Results: Subjects with the highest FT4 quartile showed significantly lower fasting insulin and HbA1c levels. A significant inverse correlation FT4 and HbA1c levels was observed (β = -0.261, p = 0.025). In the logistic regression analysis, the highest quartile of FT4 was demonstrated to lower the risk of HbA1c to a greater degree than the median by approximately 40%, after adjusting for confounders, compared to the lowest quartile (p = 0.028). Conclusions: We demonstrated subjects with a lower FT4 quartile exhibited high risk of HbA1c levels above the median value in a representative Korean population. Subjects with the lowest FT4 quartile should be cautiously managed in terms of altered glucose homeostasis.

Challenges and Strategies for New Industry Promotion in the Post-Covid Era

Jeonghoon Lee 한국콘텐츠학회 2020 한국콘텐츠학회 ICCC 논문집 Vol.2020 No.11

Employee Resistance in the Context of Information Systems Implementation : An Organizational Support Perspective

Lee, Jung Seung,Lee, Jeonghoon Korea Data Strategy Society 2016 Journal of information technology applications & m Vol.23 No.2

When implementing a new information system, the success has been infrequent even though implementing a new IS can bring about various benefits to organizations. Employee resistance has been identified as a critical reason for such failure of implementing and operating a new IS. The vital role of orgazniational support with employee personality traits (e.g., tolerance for ambiguity and openness to expeirence) to reduce employee resistance has been missing when explaining to the failure of impleneting a new IS. The purpose of this study was to test a research model regarding employee resistnace, investigating the relationship bewteen organizational support and employee personality traits in that how organizational support influences employee resistance and also how employee personality traits (e.g., tolerance for ambiguity and openness to expeirence) interact with organizational support to decrease employee resistance the most. The results of this study supported our hypotheses and theoretical and practical implications are discussed.

Component Characteristics of Xanthoceras sorbifolium Seeds for Bioenergy Plant Utilization

Lee, Hyunseok,Yi, Jaeseon,An, Chanhoon,Kim, Minsu,Lee, Jeonghoon Institute of Forest Science 2015 Journal of Forest Science Vol.31 No.4

Xanthoceras sorbifolium is considered as bio-energy crops owing to the high oil content from kernel. This study was performed to analyze calorific value, crude ash content, ultimate ratio, crude lipid and fatty acid composition among seed sources. Calorific values ranged from $4,526.0\;cal\;g^{-1}$ to $7,377.2\;cal\;g^{-1}$ in seeds and kernels showed the highest value. Calorific values and crude ash contents were observed as significant difference among plantations and/or individuals (p>0.05). Kernel from SD-F plantation showed the highest calorific value and lower crude ash content. C content comprised 63.4%, the highest levels was detected from SD-F (64.8%). Crude lipid content in kernel observed as 54.5 g $100\;g^{-1}$ from SD-F. In contrast it was determined the lowest value from LN-JARS as 46.5 g $100\;g^{-1}$. The fatty acid composition of kernel was determined to those of oleic acid (31.3%) and linoleic acid (38.1%) from SD-F and LN-JARS. These results will be offered to useful information for breeding materials selection.

Thymoquinone-Induced Tristetraprolin Inhibits Tumor Growth and Metastasis through Destabilization of MUC4 mRNA

Lee, Se-Ra,Mun, Jeong-Yeon,Jeong, Mi-So,Lee, Hyun-Hee,Roh, Yun-Gil,Kim, Won-Tae,Kim, Min-Hye,Heo, Jeonghoon,Choi, Yung Hyun,Kim, Su Jin,Cha, Hee-Jae,Jun, Mira,Leem, Sun-Hee MDPI AG 2019 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.20 No.11

<P>Tristetraprolin (TTP), a well-characterized AU-rich element (ARE) binding protein, functions as a tumor suppressor gene. The purpose of this study was to investigate whether a bioactive substance derived from a natural medicinal plant affects the induction of TTP and to elucidate its mechanism. We examined the effects of natural bioactive materials including Resveratrol (RSV), thymoquinone (TQ) and curcumin on the expression of TTP in cancer cell. TQ derived from a natural plant Nigella sativa increased the expression levels of TTP mRNA and proteins in a dose-dependent manner in gastric and breast cancer cells. TQ-induced TTP increased the instability of MUC4 mRNA by direct binding of TTP to ARE in the 3′UTR of MUC4 mRNA. The induction of TTP by TQ also reduced the proliferation, migration and invasion of cancer cells. The expression of the epithelial-mesenchymal (EMT)-related genes, which were target genes of TTP, was also decreased by the TQ treatment. In the in vivo experiments using mouse melanoma cells, TQ-induced TTP inhibited metastasis of tumor cells. We have found that TQ-induced TTP might inhibit metastasis by reducing tumor cell migration and invasion through destabilization of MUC4 mRNA, which suggest the MUC4 as a novel target to TTP.</P>