• 제목/요약/키워드: 2-D & 3-D Analyses

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열차의 3차원 유한요소해석을 이용한 1차원충돌 동역학 등가 모델링 기법 (Equivalent Modeling Technique for 1-D Collision Dynamics Using 3-D Finite Element Analysis of Rollingstock)

  • 박민영;박영일;구정서
    • 한국철도학회논문집
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    • 제13권2호
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    • pp.139-146
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    • 2010
  • 본 연구에서는 복잡한 3차원 유한요소모델 충돌거동과 등가인 1차원 동역학 모델링 방법을 개발하기 위하여 새로운 1-D 모델링 방법을 제안하였다. 충돌 거동을 잘 일치시키기 위해서는 충돌 시너지를 주로 흡수하는 압괴 구간의 특성을 정확하게 모델링하는 것이 중요하다. KHST 편성차량을 대상으로 3차원 유한요소 모델의 차체단면에 설정한 단면 옵션으로 충돌해석 시 차체 단면에 작용하는 충격하중과 변형을 추출하여 새로운 1차원 충돌동역학 모델의 스프링요소 특성으로 모델링하고, 국내철도차량 안전기준의 열차 대 열차 충돌사고 각본으로 수치해석을 수행하였다. 두 모델의 에너지 흡수량, 충돌 가속도, 충격하중-변형 등을 비교한 결과가 잘 일치하였다.

용담(Gentina scabra var. buergeri)의 잎 절편 배양에서 체세포배발생에 의한 식물체 재분화 (Somatic Embryogenesis and Plant Regeneration in Leaf Explant Cultures of Gentiana scabra var buergeri)

  • 방재욱;이미경;정성현
    • 식물조직배양학회지
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    • 제21권4호
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    • pp.233-237
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    • 1994
  • 용담의 잎 절편 배양을 통하여 유도된 배발생 캘러스로 부터 식물체의 재분화 체계를 확립하였다. 캘러스는 0.5 mg/L2,4-D, 2 mg/L BAP가 첨가된 MS 배지에서 유도되었으며, 이 캘러스를 2 mg/L P-CPA, 0.5 mg/L 2,4-D 및 0.5mg/L kinetin이 첨가된 SH 배지에 옮겼을 때 배발생 캘러스의 유도가 가능하였다. 배발생 캘러스는 SH 기본 배지에 옮겨 슈트의 증식 및 뿌리 발생을 유도하였다. 재분화 식물체는 피트모스, 펄라이트, 버미클라이트가 2:1:1의 비율로 혼합된 인공 토양에서 순화시킨 후 토양에 활착시켰다. 토양에 활착된 재분화 식물체는 키, 줄기의 모양과 수, 개화기등에서 표현형적 변이를 나타냈다. 세포유전적 분석에서 모식물체와 재분화 식물체의 염색체는 2n=26으로 안정성을 보였는데, 이는 본 연구에서 적용된 재분화 체계가 안정하다는 것을 시사한다.

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Analysis of Beauvericin and Unusual Enniatins Co-Produced by Fusarium oxysporum FB1501 (KFCC 11363P)

  • Song Hyuk-Hwan;Ahn Joong-Hoon;Lim Yoong-Ho;Lee Chan
    • Journal of Microbiology and Biotechnology
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    • 제16권7호
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    • pp.1111-1119
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    • 2006
  • Beauvericins and enniatins are cyclohexadepsipeptides exhibiting various biological activities on animal systems, including humans. Fusarium oxysporum FB1501 (KFCC 11363P) that produces four different cyclohexadepsipeptides was isolated from soil in Korea and the structures of the four cyclohexadepsipeptides elucidated by HPLC, MS, IR, and NMR analyses. The molecular weights for compounds 1,2,3, and 4 were determined to be 654.5, 784.5, 668.6, and 682.5, respectively, on the basis of ESI-MS measurements. The IR spectra for all the compounds exhibited absorptions for ester $(1,733-1,743\;cm^{-1})$ and amide $(1,649-1,655\;cm^{-1})$ bonds that were very similar to those for beauvericin and enniatins with ester and amide absorptions. The results of the NMR analysis $(^{1}H,\;^{13}C,\;135-DEPT,\;COSY,\;HMQC,\;and\;HMBC;\;in\;COCl_{3})$ revealed that compounds 1,3, and 4 consisted of $_{L}-N-methyl\;valine$ (N-MeVal), $_{D}-{\alpha}-hydroxyisovaleic\;acid$ (Hiv), and 2-hydroxy-3-methylpentanoic acid (Hmp) residues (compound 1: three N-MeVal residues, two Hiv residues, and one Hmp residue; compound 3: three N-MeVal residues, one Hiv, and two Hmp residues; compound 4: three N-MeVal residues and three Hmp residues). Therefore, the compounds were identified as enniatin H (compound 1), enniatin I (compound 3), and enniatin MK1688 (compound 4). Compound 2 was analyzed as beauvericin according to 1D and 2D NMR analyses. This study is the first report related to the co-production of beauvericin with other unusual enniatins, such as enniatin H, enniatin I, and enniatin MK1688, by Fusarium oxysporum.

지하저장공동에서의 콘크리트 플러그의 역학적 및 수리적 거동에 관한 수치해석적 연구 (Numerical Analysis of the Mechanical and Hydraulic behavior of Concrete Plug in Underground Storage Cavern)

  • 박병기;이희근;전석원;박의섭
    • 터널과지하공간
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    • 제10권3호
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    • pp.344-354
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    • 2000
  • 지하저장공동에 설치되는 콘크리트 플러그는 기능한 모든 하중조건에 대해 안정하게 유지됨은 물론 저장된 유류의 외부 유출과 지하수의 과다 유입을 방지하는 기능을 수행하여야 하므로 지하 유류 비축기지의 건설 및 운영 단계에서 매우 중요한 역할을 한다. 플러그가 시공되고 나면 외부와의 접촉이 모두 차단되게 되므로 플러그가 그 기능을 제대로 발휘하기 위해서는 설계단계에서부터 역학적 및 수리적 고려가 이루어져야 한다. 따라서 본 연구에서는 2차원 및 3 원 유한 차분 프로그램인 FLAC 과 FLA $C^{3D}$를 사용하여 플러그에 대한 역학적 및 수리적 해석을 실시하였다. 먼저 측압계수의 변화, 심도의 변화, 플러그의 형상변화, 암반과 콘크리트 접촉면의 상태변화, 굴착손상권의 발생 등 다양한 조건 하에서 플러그의 거동 변화에 대한 역학적 해석을 실시하였으며, 2차원 해석조건과 동일한 조건을 가진 3차원 모델을 구성하여 그 결과를 2차원 해석과 비교, 검토하였다. 또한 플러그의 쐐기깊이 변화에 따른 수리해석을 실시하여 그 결과를 비교하였다.다.

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Optimum design of steel frames against progressive collapse by guided simulated annealing algorithm

  • Bilal Tayfur;Ayse T. Daloglu
    • Steel and Composite Structures
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    • 제50권5호
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    • pp.583-594
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    • 2024
  • In this paper, a Guided Simulated Annealing (GSA) algorithm is presented to optimize 2D and 3D steel frames against Progressive Collapse. Considering the nature of structural optimization problems, a number of restrictions and improvements have been applied to the decision mechanisms of the algorithm without harming the randomness. With these improvements, the algorithm aims to focus relatively on the flawed variables of the analyzed frame. Besides that, it is intended to be more rational by instituting structural constraints on the sections to be selected as variables. In addition to the LRFD restrictions, the alternate path method with nonlinear dynamic procedure is used to assess the risk of progressive collapse, as specified in the US Department of Defense United Facilities Criteria (UFC) Design of Buildings to Resist Progressive Collapse. The entire optimization procedure was carried out on a C# software that supports parallel processing developed by the authors, and the frames were analyzed in SAP2000 using OAPI. Time history analyses of the removal scenarios are distributed to the processor cores in order to reduce computational time. The GSA produced 3% lighter structure weights than the SA (Simulated Annealing) and 4% lighter structure weights than the GA (Genetic Algorithm) for the 2D steel frame. For the 3D model, the GSA obtained 3% lighter results than the SA. Furthermore, it is clear that the UFC and LRFD requirements differ when the acceptance criteria are examined. It has been observed that the moment capacity of the entire frame is critical when designing according to UFC.

Isolation and Characterization of Antioxidative Compounds from the Aerial Parts of Angelica keiskei

  • Kim, So-Joong;Cho, Jeong-Yong;Wee, Ji-Hyang;Jang, Mi-Young;Kim, Cheol;Rim, Yo-Sup;Shin, Soo-Cheol;Ma, Seung-Jin;Moon, Jae-Hak;Park, Keun-Hyung
    • Food Science and Biotechnology
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    • 제14권1호
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    • pp.58-63
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    • 2005
  • Ethyl acetate-soluble neutral fraction of hot water extracts from the aerial parts of Angelica keiskei showed a 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity. Six antioxidative compounds were purified and isolated by various chromatographic procedures. Based on the analyses of FAB-MS and NMR, the isolated compounds were structurally elucidated as luteolin 7-O-${\beta}$-D-glucopyranoside (1), quercetin 3-O-${\beta}$-D-galactopyranoside (2), quercetin 3-O-${\beta}$-D-glucopyranoside (3), quercetin 3-O-${\alpha}$-D-arabinopyranoside (4), kaempferol 3-O-${\alpha}$-D-arabinopyranoside (5), and luteolin 7-O-rutinoside (6). The glycosides of flavonols and luteolin showed DPPH radical-scavenging activity. One molecule of 2, 3, 4, 6, 1, and 5 scavenged 4.2, 4.2, 4.1, 2.5, 2.2, and 1.4 molecules of DPPH radical, respectively.

4-Hydroxybenzyl alcohol 유도체들의 Tyrosinase 활성 저해에 대한 3D-QSAR 분석 (3D-QSAR Analyses on the Inhibition Activity of 4-Hydroxybenzyl alcohol Analogues Against Tyrosinase)

  • 김상진;성낙도
    • 대한화장품학회지
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    • 제39권4호
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    • pp.329-335
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    • 2013
  • 본 연구에서는 기질 화합물로써 일련의 4-hydroxybenzyl alchol (4-HBA) 유도체들의 치환기($R_1$$R_2$) 변화에 따른 tyrosinase 활성저해에 관한 3차원적인 구조-활성 상관관계(3D-QSARs) 모델을 유도하고 정량적으로 검토하였다. 그 결과, 입체장(S), 정전기장(E), 소수성장(Hy), 수소결합 받게장(HA) 및 수소결합 주게장(HD)의 조합조건에서 통계적으로 양호한 CoMSIA FF 모델(상관성; $r^2$ = 0.858 및 예측성; $q^2$ = 0.951)을 유도하였다. 등고도 분석결과에 의하면 기질분자의 $R_2$-치환기는 입체적으로 작고 음전하를 띄며, 소수성이면서 수소결합 주게장을 선호하지 않는 치환기가 올수록 tyrosinase 활성저해 작용이 용이하다. 그리고 $R_1$-치환기는 수소결합 주게장을 선호하는 치환기 이어서 $R_1$-치환체가 용이하게 탈 양성자화가 일어나야 tyrosinase 활성저해 작용을 용이하게 할 것이라고 예상되며, 이를 위해서는 $R_1$-치환기가 비 치환체(H)이어야 될 것으로 예상되었다.

Pancreatic Fistula after D1+/D2 Radical Gastrectomy according to the Updated International Study Group of Pancreatic Surgery Criteria: Risk Factors and Clinical Consequences. Experience of Surgeons with High Caseloads in a Single Surgical Center in Eastern Europe

  • Martiniuc, Alexandru;Dumitrascu, Traian;Ionescu, Mihnea;Tudor, Stefan;Lacatus, Monica;Herlea, Vlad;Vasilescu, Catalin
    • Journal of Gastric Cancer
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    • 제21권1호
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    • pp.16-29
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    • 2021
  • Purpose: Incidence, risk factors, and clinical consequences of pancreatic fistula (POPF) after D1+/D2 radical gastrectomy have not been well investigated in Western patients, particularly those from Eastern Europe. Materials and Methods: A total of 358 D1+/D2 radical gastrectomies were performed by surgeons with high caseloads in a single surgical center from 2002 to 2017. A retrospective analysis of data that were prospectively gathered in an electronic database was performed. POPF was defined and graded according to the International Study Group for Pancreatic Surgery (ISGPS) criteria. Uni- and multivariate analyses were performed to identify potential predictors of POPF. Additionally, the impact of POPF on early complications and long-term outcomes were investigated. Results: POPF was observed in 20 patients (5.6%), according to the updated ISGPS grading system. Cardiovascular comorbidities emerged as the single independent predictor of POPF formation (risk ratio, 3.051; 95% confidence interval, 1.161-8.019; P=0.024). POPF occurrence was associated with statistically significant increased rates of postoperative hemorrhage requiring re-laparotomy (P=0.029), anastomotic leak (P=0.002), 90-day mortality (P=0.036), and prolonged hospital stay (P<0.001). The long-term survival of patients with gastric adenocarcinoma was not affected by POPF (P=0.661). Conclusions: In this large series of Eastern European patients, the clinically relevant rate of POPF after D1+/D2 radical gastrectomy was low. The presence of co-existing cardiovascular disease favored the occurrence of POPF and was associated with an increased risk of postoperative bleeding, anastomotic leak, 90-day mortality, and prolonged hospital stay. POPF was not found to affect the long-term survival of patients with gastric adenocarcinoma.

이중 유공슬릿 케이슨에 의한 반사특성 (The Reflection Characteristics of a Perforated Slit Caisson with Two Chambers)

  • 허동수;이우동;이현우;김인철
    • 한국해양공학회지
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    • 제24권1호
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    • pp.60-67
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    • 2010
  • Recently, there has been an increase in the construction of various types of coastal structures for efficient wave dissipation, seawater exchange, and so on. Among these, a perforated slit caisson has been widely used to reduce the reflected wave energy and the wave pressure on the structure. Therefore, many studies on the wave force on a caisson, as well as the wave reflection from it, have been carried out with laboratory experiments and numerical analyses, considering it as a 2-D problem. However, because a structure like a perforated slit caisson has a variable 3-D shape, waves forces should be considered as a 3-D problem. Therefore, in this paper, a fully-nonlinear 3-D numerical model (LES-WASS-3D) is proposed to examine the reflection characteristics of a perforated slit caisson with two chambers. The numerical model, LES-WASS-3D, was verified in a 3-D wave field by a comparison with existing experimental data for wave reflection coefficients. Then, using the numerical results, the reflection from a perforated slit caisson with two chambers was examined in relation to wave steepness, chamber width, and the shape/porosity of perforated slit.

관절염질환자의 관절가동범위에 대응한 착탈의 동작평가 (The Motion Evaluation of Arthritis Patients' Dressing and Undressing Corresponding to their Joint Range of Motion)

  • 한승희;최미성
    • 한국의상디자인학회지
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    • 제14권2호
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    • pp.75-87
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    • 2012
  • This study aims at measuring and comparing the joint range of motion(ROM) of the elderly, quantitatively understanding the joint ROM and duration for their dressing and undressing of pants with 3D motion analysis equipment, and thereby providing basic data necessary for the future development of clothes carrying functional designs. The findings are as follows. As for the study method, the 9-item joint ROM measurements were conducted with goniometer, and the questionnaire analyses were carried out for t-test, ANOVA, and regression analysis with spss12.0 program. The 3D motion analyses were handled with 3D Motion Analysis Package Version 3.1 Program. The findings are as follows. First, the ROM was shown to be significantly low, as the arthritis-pain consciousness level was felt higher by the subject than the average one. Seven ROM variables, such as hip flexion, hip adduction, hip internal rotation, hip external rotation, knee flexion, ankle dorsiflexion, and ankle plantar flexion, were shown to significantly affect the discomfort level experienced at the time of dressing or undressing. Second, in the motion of inserting the remaining leg into the pant crotch part(3e), the difference of angles in the hip joint and knee joint was the largest between the women in their 20s and the elderly women with arthritis. Third.

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