• 제목/요약/키워드: F.E.M

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반도체 소자에서의 전자장 수치해석

  • 강영태;김태한;황창규
    • 전기의세계
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    • 제39권3호
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    • pp.39-46
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    • 1990
  • 반도체 내에서의 전자장 해석을 위한 Maxwell방정식의 단순화, 반도체 방정식의 전개, 물리적인 모델링, 수치해석 기법, 응용분야 및 차세대 반도체 기술 개발을 위한 device simulation 기술등을 review하였다. Poisson방정식의 고유한 quasi-static apporximation을 고찰하였으며, Drift 확산식의 유효성 범위를 증가시키기 위하여 각 물리적인 모델들을 review하였다. 반도체 수치해석에서 빈번히 사용해온 F.D.M.F.E.N.및 B.E.M기법의 장단점과 각각으 수치해석 기법을 이용한 Simulation tool들을 언급하였다. 또한 현재의 반도체 기술과 차세대 반도체 memory기술을 위한 Simulation의 응용분야 및 3차원 Simulation에 필요한 기본적인 tool의 조건을 언급하였다.

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유한 요소법에 의한 속응 여자 초전도 발전기의 과도 특성 해석 (Transient Characteristic Analysis of Quick Response Extraction Type Superconducting Generator by Finite Element Method)

  • 김정철;한성진
    • 한국초전도ㆍ저온공학회논문지
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    • 제2권2호
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    • pp.26-31
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    • 2000
  • This paper deals with finite element analysis of 2GVA superconducting generator which has slitted electrothermal shield in d-axis (SES). Three phase fault is considered torque of the S.C.G. Using the result, generator parameters are calculated by F.E.M. The results are compared with superconducting generator having conventional electrothermal shield (CES). The result shows that quick response excitation could be applied to superconducting generator with slitted electrothermal shield.

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T.A.F.E.M (Tunnel-Analysis by F.E.M) Program 소개

  • 조선규
    • 전산구조공학
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    • 제2권4호
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    • pp.27-29
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    • 1989
  • 터널의 굴삭과 지보방법에 대한 개념을 도입한 NATM(New Austrian Tunnelling Method)이 등장한 이후, 이 신공법에 대한 연구와 그 응용작업이 급속히 수행되어 왔으며, 현재는 세계각국에서 이 공법을 널리 사용하고 있는 실정이다. 우리나라에서도 1982년 서울 지하철 건설공사에서 본격적으로 사용하여, 현재는 터널 설계에 있어서 일반적 설계방향으로 정착되어 가고 있다. 이런 추세에 따라, 본 Program이 개발되었으며, 그에 관계된 내용을 이글에서 소개코자 한다.

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유한 요소법을 이용한 속응여자방식 초전도 발전기의 정수 산정 (Parameter Estimation of Quick Response Excitation type Superconducting Synchronous Generator by F.E.M)

  • 김정철;한성진
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 B
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    • pp.600-602
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    • 2000
  • This paper deals with finite element analysis of 2GVA superconducting generator which has slitted electrothermal shield in d-axis. Open emf voltage is calculated and three phase fault is considered to Predict the generator parameters by F.E.M. Results show that quick response excitation could be applied to superconducting generator with slitted electrothermal shield.

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유한 요소법을 이용한 하모닉 모터(Harmonic side drive motor)의 토오크 특성 해석 (Finite Element Analysis of Torque Characteristics of Harmonic Side Drive Motor)

  • 윤서진;이은웅;이동주
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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    • pp.58-60
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    • 1998
  • This paper analyzes the torque characteristics with the structure of harmonic side drive motor using by F.E.M and conformal mapping method. F.E.M and conformal analysis result are almost same. Through the results, we investigate how do design parameters variation affect torque characteristics.

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ON GRAPHS ASSOCIATED WITH MODULES OVER COMMUTATIVE RINGS

  • Pirzada, Shariefuddin;Raja, Rameez
    • 대한수학회지
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    • 제53권5호
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    • pp.1167-1182
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    • 2016
  • Let M be an R-module, where R is a commutative ring with identity 1 and let G(V,E) be a graph. In this paper, we study the graphs associated with modules over commutative rings. We associate three simple graphs $ann_f({\Gamma}(M_R))$, $ann_s({\Gamma}(M_R))$ and $ann_t({\Gamma}(M_R))$ to M called full annihilating, semi-annihilating and star-annihilating graph. When M is finite over R, we investigate metric dimensions in $ann_f({\Gamma}(M_R))$, $ann_s({\Gamma}(M_R))$ and $ann_t({\Gamma}(M_R))$. We show that M over R is finite if and only if the metric dimension of the graph $ann_f({\Gamma}(M_R))$ is finite. We further show that the graphs $ann_f({\Gamma}(M_R))$, $ann_s({\Gamma}(M_R))$ and $ann_t({\Gamma}(M_R))$ are empty if and only if M is a prime-multiplication-like R-module. We investigate the case when M is a free R-module, where R is an integral domain and show that the graphs $ann_f({\Gamma}(M_R))$, $ann_s({\Gamma}(M_R))$ and $ann_t({\Gamma}(M_R))$ are empty if and only if $$M{\sim_=}R$$. Finally, we characterize all the non-simple weakly virtually divisible modules M for which Ann(M) is a prime ideal and Soc(M) = 0.

LINC00174 Facilitates Proliferation and Migration of Colorectal Cancer Cells via MiR-3127-5p/ E2F7 Axis

  • Ma, Yuhong;Li, Yuzhen;Tang, Yuanyuan;Tang, Ning;Wang, Dengke;Li, Xiaofei
    • Journal of Microbiology and Biotechnology
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    • 제31권8호
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    • pp.1098-1108
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    • 2021
  • The literature indicates that LINC00174 promotes the growth of colorectal cancer (CRC) cells, but its research needs to be enriched. We tried to explore the function and mechanism of LINC00174 in CRC cell proliferation and migration. Bioinformatics analysis predicted the binding relationship and expressions of lncRNA, miRNA and mRNA. Clinical study analyzes the relationship between LINC00174 and clinical data characteristics of CRC patients. The expressions of LINC00174, miR-3127-5p and E2F7 were verified by RT-qPCR, and the combination of the two was verified by dual luciferase analysis and RNA immunoprecipitation as needed. Western blot was used to detect the expression of EMT-related protein and E2F7 protein. Functional experiments were used to evaluate the function of the target gene on CRC cells. LINC00174 was up-regulated in CRC clinical samples and cells and was related to the clinical characteristics of CRC patients. High-expression of LINC00174, contrary to the effect of siLINC00174, promoted cell viability, proliferation, migration and invasion, up-regulated the expressions of N-Cadherin, Vimentin, E2F7, and inhibited the expression of E-Cadherin. MiR-3127-5p was one of the targeted miRNAs of LINC00174 and was down-regulated in CRC samples. In addition, miR-3127-5p mimic partially reversed the malignant phenotype of CRC cells induced by LINC00174. Besides, E2F7 was a target gene of miR-3127-5p, and LINC00174 repressed miR-3127-5p to regulate E2F7. Our research reveals that LINC00174 affected the biological characteristics of CRC cells through regulated miR-3127-5p/ E2F7 axis.

자돈 분변 유래 병원성 대장균의 병원성 인자 및 항생제 내성 양상 (Virulence factors and antimicrobial resistance patterns of pathogenic Escherichia coli isolated from fecal samples of piglets)

  • 신현숙;김근호;서진성;김영욱;임숙경;정병열
    • 한국동물위생학회지
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    • 제46권1호
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    • pp.35-45
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    • 2023
  • Pathogenic Escherichia coli is the cause of a wide range of diseases in pigs, including diarrhea, edema disease, and septicemia. Diarrhea caused E. coli may result in significant economic losses, making pathogenic E. coli an important pathogen for the swine industry. This study investigated the prevalence of virulence factor genes, antimicrobial resistance phenotypes, and resistance genes in E. coli isolated from feces of piglets in Korea between 2017 and 2020. As a result, 119 pathogenic E. coli isolates were obtained from 601 fecal samples. The F4 adhesin gene and the STb enterotoxin gene were commonly present in E. coli isolated from diarrhea samples. The dominant virulotypes of isolates from diarrhea samples were STb, Stx2e, and F4:LT:STb. More than 80% of the screened isolates were resistant to ampicillin, sulfisoxazole, chloramphenicol, or tetracycline. To confirm the resistance mechanisms for β-lactam or quinolone, we investigated the genotypic factors of resistance. Each of the ceftiofur-resistant E. coli produced an extended-spectrum β-lactamase encoded by blaCTX-M-14, blaCTX-M-27, and blaCTX-M-55. And all ciprofloxacin-resistant E. coli harbored mutations in quinoloneresistance-determining-regions. In addition, some of the ciprofloxacin-resistant E. coli contained the plasmid-mediated-quinolone-resistance genes such as qepA, qnrB1, or qnrD. This study has confirmed that the F4 fimbria and the STb enterotoxin are the most predominant in pathogenic E. coli isolated from piglets with diarrhea in Korea and there is a great need for responsible and prudent use of antimicrobials to treat colibacillosis.

Mechanical and Thermal Behavior of Polyamide-6/Clay Nanocomposite Using Continuum-based Micromechanical Modeling

  • Weon, Jong-Il
    • Macromolecular Research
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    • 제17권10호
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    • pp.797-806
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    • 2009
  • The mechanical and thermal behaviors of polyamide-6/clay nanocomposites were studied using the continuum-based, micromechanical models such as Mori-Tanaka, Halpin-Tsai and shear lag. Mechanic-based model prediction provides a better understanding regarding the dependence of the nanocomposites' reinforcement efficiency on conventional filler structural parameters such as filler aspect ratio ($\alpha$), filler orientation (S), filler weight fraction (${\Psi}_f$), and filler/matrix stiffness ratio ($E_f/E_m$). For an intercalated and exfoliated nanocomposite, an effective, filler-based, micromechanical model that includes effective filler structural parameters, the number of platelets per stack (n) and the silicate inter-layer spacing ($d_{001}$), is proposed to describe the mesoscopic intercalated filler and the nanoscopic exfoliated filler. The proposed model nicely captures the experimental modulus behaviors for both intercalated and exfoliated nanocomposites. In addition, the model prediction of the heat distortion temperature is examined for nanocomposites with different filler aspect ratio. The predicted heat distortion temperature appears to be reasonable compared to the heat distortion temperature obtained by experimental tests. Based on both the experimental results and model prediction, the reinforcement efficiency and heat resistance of the polyamide-6/clay nanocomposites definitely depend on both conventional (${\alpha},\;S,\;{\Psi}_f,\;E_f/E_m$) and effective (n, $d_{001}$) filler structural parameters.

CHARACTERIZATIONS OF THE EXPONENTIAL DISTRIBUTION BY ORDER STATISTICS AND CONDITIONAL

  • Lee, Min-Young;Chang, Se-Kyung;Jung, Kap-Hun
    • 대한수학회논문집
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    • 제17권3호
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    • pp.535-540
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    • 2002
  • Let X$_1$, X$_2$‥‥,X$\_$n/ be n independent and identically distributed random variables with continuous cumulative distribution function F(x). Let us rearrange the X's in the increasing order X$\_$1:n/ $\leq$ X$\_$2:n/ $\leq$ ‥‥ $\leq$ X$\_$n:n/. We call X$\_$k:n/ the k-th order statistic. Then X$\_$n:n/ - X$\_$n-1:n/ and X$\_$n-1:n/ are independent if and only if f(x) = 1-e(equation omitted) with some c > 0. And X$\_$j/ is an upper record value of this sequence lf X$\_$j/ > max(X$_1$, X$_2$,¨¨ ,X$\_$j-1/). We define u(n) = min(j|j > u(n-1),X$\_$j/ > X$\_$u(n-1)/, n $\geq$ 2) with u(1) = 1. Then F(x) = 1 - e(equation omitted), x > 0 if and only if E[X$\_$u(n+3)/ - X$\_$u(n)/ | X$\_$u(m)/ = y] = 3c, or E[X$\_$u(n+4)/ - X$\_$u(n)/|X$\_$u(m)/ = y] = 4c, n m+1.