• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2005년도 BIOINFO 2005
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• pp.421-426
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• 2005

In this paper, we investigate the nonlinear dynamic behavior of TPP (thiamine pyrophosphate) riboswitches in E. coli (Escherichia coli). TPP riboswitches are highly conserved RNA regulatory elements, embedded within the 5’'untranslated region of three TPP biosynthesis operons. The three operons thiCEFSGH, thiMD, and thiBPQ are involved in the biosynthesis, salvage, and transport of TPP, respectively. TPP riboswitches modulate their expressions in response to changing TPP concentration, without involving protein cofactors. Interestingly, the expression of thiMD is regulated at the translational level, while that of thiCEFSGH at both levels of transcription and translation. We develop a mathematical model of the TPP riboswitch’s regulatory system possessed by thiCEFSGH and thiMD, so as to simulate the time-course experiments of TPP biosynthesis in E. coli. The simulation results are validated against three sets of reported experimental data in order to gain insight into the nature of steady states and the stability of TPP riboswitches, and to explain the biological significance of regulating at level of transcription or translation, or even both. Our findings suggest that in the TPP biosynthesis pathway of E. coli, the biological effect of down-regulating thiCEFSGH operon at the translational level by TPP riboswitch is less prominent than that at the transcriptional level.

• EDISON SW 활용 경진대회 논문집
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• 제3회(2014년)
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• pp.347-358
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• 2014

본 논문에서는 양자 역학적 분자 동역학(Quantum Mechanical/Molecular Mechanical-Molecular Dynamics, QM/MM-MD)을 통해 수용액에 녹아 있는 Potassium Thiocyanate의 dynamics를 연구했다. Umbrella sampling technique을 활용하여 association/dissociation에 해당하는 Free energy surface를 구했다. 두 개의 Free energy minimum이 녹아 있는 두 이온의 center of mass 사이의 거리가 $4{\AA}$일 때와 $5{\sim}6{\AA}$ 부근일 때 나타났으며 $4{\AA}$일 때 더 안정 했다. 본 논문에서는 $4{\AA}$일 때를 Contact Ion Pair(CIP) $6{\AA}$일 때를 Dissociation Ion Pair(DlP)라고 칭했다. 이 minimum들이 무엇인 지를 밝혀 내기 위해 추가 연구를 수행하였다. Free energy 상에서 가장 안정 할 때(CIP) solute인 Potassium thiocyanate의 구조를 살펴 봤더니 Potassium ion은 Thiocyanate ion의 Sulfur보다 Nitrogen side를 선호하였다. 그 원인을 알아보기 위해 salvation shell의 구조를 Radial distribution function을 통해 살펴 봤더니 물 분자가 Nitrogen보다 Sulfur와 더 강한 상호작용을 하고 있었다. 그로 인해 Potassium ion이 Nitrogen을 선호한단 결과가 나온 것이다. 한편, 두 번째 minimum은 물 분자가 Potassium 이온과 Thiocyanate 이온 사이에 flexible하게 bridging을 하는 구조였다. 또한 단순 양자 계산을 통해서도 비슷한 구조를 얻을 수 있었다. 그러나 QM 계산은 0K에서 수행하는 것이기 때문에 엔트로피 효과가 없는 계산이지만 본 연구는 온도 300K로 실제 용매와 가깝게 수행함으로써 고정되어 있는 구조가 아니라 엔트로피와 엔탈피가 균형적으로 존재하는 실제 용액 속에서의 구조를 처음으로 보여주는 것이다.

• Journal of applied mathematics & informatics
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• 제28권5_6호
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• pp.1347-1358
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• 2010

An upright drawing of a planar graph G on k layers is a planar straight-line drawing of G, where the vertices of G are placed on a set of k horizontal lines, called layers and no two adjacent vertices are placed on the same layer. There is a previously known algorithm that decides in linear time whether a planar graph admits an upright drawing on k layers for a fixed value of k. However, the constant factor in the running time of the algorithm increases exponentially with k and makes it impractical even for k = 3. In this paper, we give a linear-time algorithm to examine whether a biconnected planar graph G admits an upright drawing on three layers and to obtain such a drawing if it exists. We also give a necessary and sufficient condition for a tree to have an upright drawing on three layers. Our algorithms in both the cases are much simpler and easier to implement than the previously known algorithms.

• Journal of Crop Science and Biotechnology
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• 제11권3호
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• pp.171-176
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• 2008

The agronomic traits, such as days to flowering and maturity, plant height, 100-seed weight and seed filling period, are quantitatively inherited and important characters in soybean(Glycine max L. Merr.). A total of 126 $F_5$ recombinant inbred lines(RILs) developed from the cross of PI 171451$\times$Hwaeomputkong were used to identify quantitative trait loci(QTLs) for days to flowering(FD), days to maturity(MD), plant height(PH), 100-seed weight(SW), number of branches(NB) and seed filling period(FP). A total of 136 simple sequence repeat(SSR) markers segregated in a RIL population were distributed over 20 linkage groups(LGs), covering 1073.9 cM of the soybean genome with the average distance between adjacent markers of 7.9 cM. Five independent QTLs were identified for FD, three for MD, two for PH, three for SW, one for NB and one for FP. Of these, three QTLs were related to more than two traits of FD, MD, PH, NB and FP and mapped near the same positions on LGs H and O. Thus, these traits could be correlated with biologically controlled major QTLs in this soybean RIL population.

• The Journal of Asian Finance, Economics and Business
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• 제6권1호
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• pp.241-248
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• 2019

The purpose of this study is to investigate empirical evidences of productivity of life insurance institutions in Malaysia. Therefore, this study attempts to explore the productivity of the life insurance institutions in Malaysia. The overall findings show that the total factor productivity (TFP) has progressed by 2.5% per year during the study period from 2012 to 2016 in the Malaysian insurance industry. However, TFP change has declined from 2012 to 2015 and observed a negative growth in 2015-16 (3.3%). The highest productivity progress was documented during 2012-13 at a rate of 11.7% while the minimum productivity progress was during 2014-15 (only 0.2%). The results also indicate that the decomposition of TFP found that overall progress could mainly be attributed to technological change (TC). However, technical efficiency change (TEC) and pure technical efficiency change (PTE) have negative impact on TFP. The findings also show that most of the insurance companies have a steady growth. Therefore, this study will contribute new insights for the policy makers and insurance institutions to take appropriate steps in developing relevant policies for increasing productivity of insurance institutions in Malaysia.

• 대한간호학회지
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• 제46권5호
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• pp.619-629
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• 2016

Purpose: This study was a systematic review to evaluate the effects of aromatherapy on menopausal symptoms, perceived stress and depression in middle aged-women. Methods: Eight databases were searched from their inception September 8, 2015. Two reviewers independently performed the selection of the studies, data abstraction and validations. The risk of bias was assessed using Cochrane criteria. For analysis of the data, a meta-analysis of the studies was performed. Results: From the electronic databases, 73 articles were selected, and 19 removed due to duplication. After two reviewers read the abstracts of 54 studies, 34 studies were selected. Complete papers for 34 s were read and, 12 studies which met selection criteria were reviewed and the effects of aromatherapy on menopausal symptoms, stress and depression analyzed using meta-analysis with RevMan. In the 2 studies which included Randomized Controlled Trials testing of aromatherapy on menopausal symptoms and comparison of control and placebo groups were done. Aromatherapy massage was favorably effective in reducing the menopausal symptoms compared to the control group (n=118, MD=-6.33; 95% CI -11.51 to -1.15), and compared to the placebo group (n=117, MD=-4.14; 95% CI -7.63 to -0.64). Also aromatherapy was effective in reducing stress (n=72, SMD=-0.64; 95% CI -1.12 to -0.17) and depression (n=158, MD=-5.63; 95% CI -10.04 to -1.22). Conclusion: There is limited evidence suggesting that aromatherapy for middle-aged women may be effective in controlling menopausal symptoms, perceived stress and depression.

• 한국수정란이식학회지
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• 제30권1호
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• pp.51-57
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• 2015

This study was aimed to determine the biometry of genital organs, incidence of gynecological disorders and pregnancy loss in Black Bengal goat (Capra hircus). Genitalia of 118 does were collected from local abattoirs. Biometric parameters of genital organs were measured and gross and histopathological examinations were carried out for detection of abnormalities. For gravid uterus, age of the fetus was determined by measuring crown-rump length. There was no significant difference in the length, width and weight of right and left ovaries (P>0.05). However, the number of follicles between left ($5.3{\pm}2.3$) and right ovaries ($7.4{\pm}2.7$) varied significantly (P<0.05). The mean length of right fallopian tube and uterine horn were not varied with those of left fallopian tube and uterine horn. The length of uterine body, cervix and vagina were $1.3{\pm}0.1cm$, $3.3{\pm}0.5cm$ and $6.8{\pm}1.3cm$, respectively. Overall, 29 (24.6%) genitalia had abnormalities. Fifteen genitalia (12.7%) had ovarian abnormalities including ovaro-bursal adhesions (6.8%), parovarian cyst (5.1%) and follicular cyst (0.9%). Uterine abnormalities were found in 12 genitalia (10.2%) and predominant uterine lesion was endometritis (6.8%) followed by adenomyosis (1.7%), hemorrhagic lesion on endometrial surface (0.9%) and cyst in broad ligament (0.9%). In addition, cyst in fallopian tube (0.9%) and vagina (0.9%) were recorded. The proportion of slaughtered pregnant goats was 15.3% (18/118). The pregnancy wastage was highest in the first month (50.0%) followed by second (33.3%) and third (16.7%) month. It can be concluded that ovaro-bursal adhesions, parovarian cyst and endometritis are the gynecological disorders of major concern in Black Bengal goat.

• 정보보호학회논문지
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• 제12권4호
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• pp.55-66
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• 2002

HAVAL은 Zheng 등이 제안한 MD-계열의 해쉬 함수로서, 임의의 길이의 메시지를 입력으로 하며, 128, 160, 192, 224, 256 비트 길이의 해쉬값를 출력하는 해쉬 함수이다. HAVAL은 입력 메시지의 1024 비트 블록을 처리하는 회수에 따라 3-pass HAVAL, 4-pass HAVAL, 그리고, 5-pass HAVAL로 구분된다. 본 논문에서는 3-pass HAVAL의 축소 라운드의 충돌쌍을 찾는 방법을 제안한다. 본 논문에서 제안하는 방법에 의하여 3-pass HAVAL의 처음 두 라운드와 마지막 두 라운드에 대한 충돌쌍을 찾을 수 있다.

• Membrane and Water Treatment
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• 제13권5호
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• pp.235-243
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• 2022

The paper presents the effect of operating temperatures and flow rates on the distillate flux that can be obtained from a hydrophobic membrane having the characteristics: pore size of 0.15 ㎛; thickness of 130 ㎛; and 85% porosity. That membrane in the present investigation could be the direct contact (DCMD) or the air-gap membrane distillation (AGMD). To model numerically the membrane distillation processes, the two-dimensional computational fluid dynamic (CFD) is used for the DCMD and AGMD cases here. In this work, DCMD and AGMD models have been validated with the experimental data using different flows (Parallel and Counter-current flows) in non-steady-state situations. A good agreement is obtained between the present results and those of the experimental data in the literature. The new approach in the present numerical modeling has allowed examining effects of the nature of materials (Polyvinylidene fluoride (PVDF) polymers, copolymers, and blends) used on thermal properties. Moreover, the effect of the area surface of the membrane (0.021 to 3.15 ㎡) is investigated to explore both the laminar and the turbulent flow regimes. The obtained results found that copolymer P(VDF-TrFE) (80/20) is more effective than the other materials of membrane distillation (MD). The mass flux and thermal efficiency reach 193.5 (g/㎡s), and 83.29 % using turbulent flow and an effective area of 3.1 ㎡, respectively. The increase of feed inlet temperatures and its flow rate, with the reduction of cold temperatures and its flow rate are very effective for increasing distillate water flow in MD applications.

• 농약과학회지
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• 제5권4호
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• pp.33-39
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• 2001

물달개비에 병을 일으키는 Pythium myriotylum 균주를 2000년 충청남도 유성 지역에서 수집한 시료로부터 분리하였으며, 실험실과 온실에서 생물학적 방제제로서의 가능성을 조사하였다. 이 곰팡이는 넓은 온도 범위에서 잘 자랐으며 특히 생장적온은 $35^{\circ}C$ 이었다. 또한 $30{\sim}35^{\circ}C$에서 물달개비에 강한 병원성을 나타냈다. 여뀌바늘, 알방동사니, 사마귀풀, 올챙이고랭이 등의 논잡초에는 병원성이 강하였으나, 강피에는 병을 일으키지 못하였다. 벼에 대한 생육시기별 및 품종에 따른 병 발생을 조사한 결과, 발아 직후의 벼는 생육에 저해를 받았으나 1엽기 이상의 벼는 영향을 받지 않았다. 또한 12 품종의 $3{\sim}4$엽기 벼도 MD2에 의하여 영향을 받지 않았다. 그리고 배추, 옥수수, 콩 등 12종의 작물에 대한 병원성 실험을 실시하였는데, 밀을 제외한 11종의 작물은 영향이 없었다. 이상의 결과로부터 Pythium myriotylum MD2는 1엽기 이상의 벼에 대하여 선택성이 있으며, 물달개비뿐만 아니라 여러 종류의 일년생 논잡초에 대하여 강한 병원성을 보이고 또한 작물에 대한 영향도 적어서 생물적 방제제로서 가능하리라 생각되었다.