Clustering Data Set with Categorical attributes using Multidimensional Scaling in Data Mining

Sung_Gi Lee(이성기),Deok_Kyun Yun(윤덕균) 대한산업공학회 2001 대한산업공학회 추계학술대회논문집 Vol.2001 No.11

Effect of Ti Addition on the Microstructure and High-Temperature Oxidation Property of AlCoCrFeNi High-Entropy Alloy

Gi‑Su Ham,Young‑Kyun Kim,Young Sang Na,Kee‑Ahn Lee 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.1

This study investigated the effect of Ti addition on microstructure and high-temperature oxidation property of AlCoCrFeNihigh-entropy alloy. Ti content was controlled at 0 at% and 1 at%. The two alloys were found to have BCC single phase, andthe average grain sizes of Ti0.0 and Ti1.0 were 47.3 μm and 49.7 μm, respectively, showing similarity. The EDS mappingof the inside of grains found that both alloys were characterized to be divided into Al-Ni element rich region and Cr–Feelement rich region. As a result of high-temperature oxidation test at 1100 °C, oxidation weight gains were measured atTi0.0: 0.75 mg/cm2 and Ti1.0: 0.17 mg/cm2, respectively. The results indicate that Ti addition largely improved high temperatureoxidation resistance of AlCoCrFeNi HEA. Ti1.0 alloy, in particular, showed remarkably more excellent 1100 °Chigh-temperature oxidation resistance than other previously reported major ones such as NiCrAl and FeCrAl. In the surfaceand cross-section observations after oxidation tests, both alloys were found to have Al2O3oxides mostly. While the Ti0.0material was observed to have Al2O3spallation macroscopically, the Ti1.0 alloy showed Al2O3spallation only in some localareas. In addition, a unique result was found in AlCoCrFeNiTix(x=0,1) alloy that BCC → FCC phase transformation was accelerated,and FCC phase layer was formed in the surficial area where Al element had been depleted due to high-temperatureoxidation. Moreover, as Ti was added, the thickness of FCC layer induced by high-temperature oxidation decreased. Basedon the results, it was also discussed on how to improve the high-temperature oxidation resistance of AlCoCrFeNiTixHEA.

2단계 집락 조건부 승법 무관양적속성 모형

이기성(Gi-Sung Lee),홍성준(Sung-Joon Hong) 한국자료분석학회 2020 Journal of the Korean Data Analysis Society Vol.22 No.4

Lee, Park(2019)는 덜 민감한 질문 B와 강요질문으로 구축된 확률장치로부터 추출된 질문에 대하여 ‘예’라고 응답한 사람들에게만 민감한 변수, 변환된 응답, 무관한 변수를 포함하고 있는 승법 무관양적속성 확률화응답모형(2016)을 사용하게 하여 민감한 변수에 대한 모평균을 추정할 수 있는 조건부 승법 무관양적속성 모형을 제안하였다. 본 연구에서는 매우 민감한 내용을 조사하는데 있어서 모집단이 집락으로 이루어져 있을 경우, Lee, Park(2019)의 조건부 승법 무관양적 속성 확률화응답모형에 2단계 집락추출법을 응용한 2단계 집락 조건부 승법 무관양적속성 모형을 제안하였다. 그리고 제안한 2단계 집락 조건부 승법 무관양적속성 모형을 이용하여 민감한 변수에 대한 추정과 그 분산을 구하였다. 또한 주어진 비용 하에서 분산을 최소화시키는 1단계 집락의 수와 2단계 조사단위의 수의 최적값을 구하였다. 마지막으로 제안한 2단계 집락 조건부 승법 무관양적속성 모형과 2단계 집락 승법 무관양적속성 확률화응답모형(2017)과의 관계에서 2단계 집락 승법 무관양적속성 확률화응답모형(2017)이 제안한 모형의 특별한 형태임을 확인할 수 있었으며, 두 모형 간의 효율성을 수치적으로 비교하였다. Lee and Park (2019) proposed a conditional multiplicative unrelated quantitative randomized response model to estimate mean of sensitive variable in which only the respondents who answered Yes through the randomization device made up of less sensitive questions and compulsory questions use the multiplicative unrelated quantitative randomized response model proposed by Lee (2016). In this paper, we consider the population of consisted of sensitive clusters and suggest a two stage cluster multiplicative unrelated quantitative attribute randomized response model by applying two stage cluster sampling to Lee and Park (2019)’s model. We also estimate the mean and variance of sensitive variable then calculate the number of PSU and SSU under a given cost to minimize the variance. Finally, we ascertain that the suggested our model is a general case of the two stage cluster multiplicative quantitative attribute randomized response model (2017) and compare numerically the efficiencies between the two models.

Sensitization of TRAIL-Induced Cell Death by 20(S)-Ginsenoside Rg₃ via CHOP-Mediated DR5 Upregulation in Human Hepatocellular Carcinoma Cells

Lee, Ju-Yeon,Jung, Kyung Hee,Morgan, Michael J.,Kang, Yi-Rae,Lee, Hee-Seung,Koo, Gi-Bang,Hong, Soon-Sun,Kwon, Sung Won,Kim, You-Sun American Association for Cancer Research 2013 Molecular cancer therapeutics Vol.12 No.3

<P>The TRAIL pathway is a potential therapeutic target for anticancer drugs due to selective cytotoxicity in cancer cells. Despite considerable promise, TRAIL or TRAIL receptor agonists have been used thus far with limited success in multiple clinical trials, in part due to acquired TRAIL resistance during chemotherapeutic treatment. Hepatocellular carcinoma (HCC) is a common solid tumor and the third leading cause of cancer-related death worldwide. Classical chemotherapy is not effective for HCC treatment and targeted therapy is limited to sorafenib. Isolated from <I>Panax ginseng</I> CA Meyer, 20(S)-ginsenoside Rg<SUB>3</SUB> is a steroidal saponin with high pharmacologic activity that has been shown to sensitize cells to some chemotherapeutic agents. We investigated the sensitizing effect of Rg<SUB>3</SUB> on TRAIL-induced cell death in HCC cells. We show Rg<SUB>3</SUB> is capable of promoting TRAIL-induced apoptosis in a number of HCC cell lines, including HepG2, SK-Hep1, Huh-7, and Hep3B, but not in normal HL-7702 hepatocytes, indicating that Rg<SUB>3</SUB> sensitization to TRAIL may be specific to cancer cells. Mechanistically, we found that Rg<SUB>3</SUB> upregulates DR5 expression at the transcriptional level. DR5 upregulation in this case is mediated by C/EBP homology protein (CHOP), an important endoplasmic reticulum stress responsive protein. Furthermore, Rg<SUB>3</SUB> is well tolerated and enhances the therapeutic efficacy of TRAIL in mouse xenograft models, suggesting that chemosensitization also occurs <I>in vivo</I>. Taken together, our study identifies Rg<SUB>3</SUB> as a novel anticancer therapeutic agent and supports the further development of Rg<SUB>3</SUB> as a chemosensitizer in combined therapy with TRAIL. <I>Mol Cancer Ther; 12(3); 274–85. ©2012 AACR</I>.</P>

Development of an AOA Location Method Using Covariance Estimation

Sung-Ho Lee,Gi-Hong Roh,Tae-Kyung Sung 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.1 No.-

In last decades, several linearization methods for the AOA measurements have been proposed, for example, Gauss- Newton method and closed-form solution. Gauss-Newton method can achieve high accuracy, but the convergence of the iterative process is not always ensured if the initial guess is not accurate enough. Closed-form solution provides a non-iterative solution and it is less computational. It does not suffer from convergence problem, but estimation error is somewhat larger. This paper proposes a self-tuning weighted least square AOA algorithm that is a modified version of the conventional closed-form solution. In order to estimate the error covariance matrix as a weight, two-step estimation technique is used. Simulation results show that the proposed method has smaller positioning error compared to the existing methods.

Characterization of a Chitinase Gene Exhibiting Antifungal Activity from a Biocontrol Bacterium Bacillus licheniformis N1

Lee, Kwang-Youll,Heo, Kwang-Ryool,Choi, Ki-Hyuck,Kong, Hyun-Gi,Nam, Jae-Sung,Yi, Young-Byung,Park, Seung-Hwan,Lee, Seon-Woo,Moon, Byung-Ju The Korean Society of Plant Pathology 2009 Plant Pathology Journal Vol.25 No.4

A biocontrol bacterium Bacillus licheniformis N1 grown in nutrient broth showed no chitinolytic activity, while its genome contains a gene which encodes a chitinase. The gene for chitinase from B. licheniformis N1 was amplified by PCR and the deduced amino acid sequence analysis revealed that the chitinase exhibited over 95% identity with chitinases from other B. licheniformis strains. Escherichia coli cells carrying the recombinant plasmid displayed chitinase activity as revealed by the formation of a clear zone on chitin containing media, indicating that the gene could be expressed in E. coli cells. Chitinase gene expression in B. licheniformis N1 was not detected by RT-PCR analysis. The protein was over-expressed in E. coli BL21 (DE3) as a glutathione S-transferase fusion protein. The protein could also be produced in B. subtilis 168 strain carrying the chitinase gene of N1 strain. The crude protein extract from E. coli BL21 carrying GST fusion protein or culture supernatant of B. subtilis carrying the chitinase gene exhibited enzyme activity by hydrolyzing chitin analogs, 4-methylumbelliferyl-$\beta$-D-N,N'-diacetylchitobioside and 4-methylumbelliferyl-$\beta$-D-N,N',N"-triacetylchitotrioside. These results indicated that even though the chitinase gene is not expressed in the N1 strain, the coding region is functional and encodes an active chitinase enzyme. Furthermore, B. subtilis 168 transformants expressing the chitinase gene exhibited antifungal activity against Fulvia fulva by suppressing spore germination. Our results suggest that the proper engineering of the expression of the indigenous chitinase gene, which will lead to its expression in the biocontrol strain B. licheniformis N1, may further enhance its biocontrol activity.

Disease-resistant Transgenic Arabidopsis Carrying the expI Gene from Pectobacterium carotovorum subsp. carotovorum SL940

Lee, Joo-Hee,Hong, Ja-Bin,Hong, Sang-Bin,Choi, Min-Seon,Jeong, Ki-Yong,Park, Hyoung-Joon,Hwang, Duk-Ju,Lee, Seung-Don,Ra, Dong-Soo,Heu, Sung-Gi The Korean Society of Plant Pathology 2008 Plant Pathology Journal Vol.24 No.2

Plant-cell-wall-degrading enzymes (PCWDEs) of Pectobacterium carotovorum subsp. carotovorum are the key virulence factor in pathogenesis of soft rot disease of vegetables. The production of PCWDEs is controlled in a cell density dependent manner to avoid the premature production of PCWDEs and subsequent activation of plant defense. N-oxoacyl-homoserine lactone (OHL) is essential for quorum sensing in the soft rot pathogen and the expI gene is responsible for OHL production. The ExpI homolog isolated from P. carotovorum subsp. carotovorum SL940 had 94% identity with ExpI of E. carotovora subsp. carotovora scc3193 and 74% identity with Carl of E. carotovora subsp. atroseptica. The transgenic plants that express exp I uner the control of CaMV35S promoter were able to produce diffusible OHL. Transgenic plants producing OHL were very resistant to the infection of P. carotovorum subsp. carotovorum. Since the PR1 gene was strongly induced and NPR1 and NPR4 were induced weakly in transgenic plants compared to the wild type, salicylic acid-dependent pathways is likely involved in the resistance to the soft rot pathogen P. carotovorum subsp. carotovorum in ExpI transgenic plants.

Difference of Physiochemical Characteristics Between Citrus Bacterial Canker Pathotypes and Identification of Korean Isolates with Repetitive Sequence PCRs

Lee, Yong-Hoon,Lee, Seung-Don,Lee, Dong-Hee,Yu, Sang-Mi,Lee, Jung-Hee,Heu, Sung-Gi,Hyun, Jae-Wook,Ra, Dong-Soo,Park, Eun-Woo The Korean Society of Plant Pathology 2008 Plant Pathology Journal Vol.24 No.4

The difference of carbon source utilization and fatty acid composition between the pathotypes of Xanthomonas strains, which causing citrus bacterial canker was compared, and the physiochemical characteristics were used to analyze relationship of the strains for the first time. The pattern of several carbon sources utilization and fatty acids composition reliably discriminated the pathotypes of Xanthomonas strains. The dendrogram which was constructed by 95 carbon source utilization profiles differentiated X. axonopodis pv. citri A, $A^*$ and $A^w$ from the other pathotypes. When the dendrogram was drawn by combined analysis of carbon source utilization pattern and fatty acid composition, X. axonopodis pv. aurantifolii B, C and X. axonopodis pv. citrumelo formed a distinct cluster. The difference of carbon source utilization and fatty acid composition could be used effectively for the identification of pathotypes of citrus bacterial canker. The physiochemical characteristics strongly indicated that the strains isolated in Korea belong to X. axonopodis pv. citri A type. The cluster analysis by the band patterns of ERIC-, BOX- and REP-PCR allowed the discrimination of the pathotypes isolated from Korea. However, the rep-PCRs could not differentiate X. axonopodis pv. citri A types from $A^*$ and $A^w$ types. The overall results of metabolic profiles and rep-PCRs strongly indicated that the Korean isolates are X. axonopodis pv. citri A type.

Photoluminescence properties of Na(Sr,Ca)VO4:Eu(3+) phosphors.

Lee, Dong Gi,Kesavulu, C R,Yi, Soung Soo,Cho, Shinho,Jang, Kiwan,Kim, Sung Hoon,Jeong, Jung Hyun American Scientific Publishers 2014 Journal of Nanoscience and Nanotechnology Vol.14 No.8

<P>Eu3+-activated novel alkaline earth metal (Sr and Ca) vanadate phosphors, Na(Sr0.97-x, Ca-x)VO4:Eu-0.03(3+) (x = 0 to 0.97) has been successfully synthesized using solid state reaction method and characterized by XRD, XPS, FE-SEM, luminescence (PLE, PL and CIE coordinate) and decay rate measurements as a function of Ca ion concentration. Phosphors show a broad excitation band (monitored for D-5(0) -> F-7(2) transition of Eu3+) in the 230-430 nm wavelength regions which make them highly suitable for LED chips. Material gives strong emission of Eu3+ ion (lambda(ex) = 323 nm) and intensity of this emission increases with increase in the doping concentration of Ca ions until a maximum is reached for Na(Sr-0.22, Ca-0.75)VO4:Eu-0.003(3+) (x = 0.75) phase phosphor. The intensity ratio of D-5(0) -> F-7(2) to D-5(0) -> F-7(1) transition (monochromaticity, R) suggest that local symmetry around the Eu3+ ion increases with increase in Ca ion concentration, which is responsible for enhanced emission.</P>

[Free Paper] Incidence and management of postoperative abdominal bleeding after liver transplantation

Sung Won Jung,Shin Hwang,Jung Man Namgoong,Samuel Youn,Chun Soo Park,Yo Han Park,Hyo Joon Lee,Hyung Woo Park,Gil Chun Park,Dong Hwan Jung,Gi Won Song,Tae Yong Ha,Chul Soo Ahn,Ki Hoon Kim,Deok Bog Moon 대한외과학회 2011 대한외과학회 학술대회 초록집 Vol.2011 No.11