• 제목/요약/키워드: RSM

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철도차량 현수장치의 탈선에 대한 민감도 연구 (The Sensitivity Analysis of Derailment in Suspension Elements of Rail Vehicle)

  • 심태웅;박찬경;김기환
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 1999년도 추계학술대회 논문집
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    • pp.566-573
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    • 1999
  • This paper is the result of sensitivity analysis of derailment with respect to the selected suspension elements for the rail vehicle. Derailment phenominon has been explained by the derailment quotient. Thus, the sensitivity of derailment is suggested by a response surface model(RSM) which is a functional relationship between derailment quotient and characteristics of suspension elements. To summarize generation of RSM, we can introduce the procedure of sensitivity analysis as follows. First, to form a RSM, a experiment is performed by a dynamic analysis code, VAMPIRE according to a kind of the design of experiments(DOE). Second, RSM is constructed to a 1$\^$st/ order polynomial and then main effect fators are screened through the stepwise regression. Finally, we can see the sensitivity level through the RSM which only consists of the main effect factors and is expressed by the liner, interaction and quadratic effect terms.

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Decomposable polynomial response surface method and its adaptive order revision around most probable point

  • Zhang, Wentong;Xiao, Yiqing
    • Structural Engineering and Mechanics
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    • 제76권6호
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    • pp.675-685
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    • 2020
  • As the classical response surface method (RSM), the polynomial RSM is so easy-to-apply that it is widely used in reliability analysis. However, the trade-off of accuracy and efficiency is still a challenge and the "curse of dimension" usually confines RSM to low dimension systems. In this paper, based on the univariate decomposition, the polynomial RSM is executed in a new mode, called as DPRSM. The general form of DPRSM is given and its implementation is designed referring to the classical RSM firstly. Then, in order to balance the accuracy and efficiency of DPRSM, its adaptive order revision around the most probable point (MPP) is proposed by introducing the univariate polynomial order analysis, noted as RDPRSM, which can analyze the exact nonlinearity of the limit state surface in the region around MPP. For testing the proposed techniques, several numerical examples are studied in detail, and the results indicate that DPRSM with low order can obtain similar results to the classical RSM, DPRSM with high order can obtain more precision with a large efficiency loss; RDPRSM can perform a good balance between accuracy and efficiency and preserve the good robustness property meanwhile, especially for those problems with high nonlinearity and complex problems; the proposed methods can also give a good performance in the high-dimensional cases.

Tween-Span계 혼합계면활성제를 이용한 Coconut Oil 원료 O/W 유화액의 제조 : CCD-RSM을 이용한 최적화 (Preparation of Coconut Oil in Water Emulsions Using Tween-Span Type Mixed Surfactant : Optimization of CCD-RSM)

  • 유봉호;주카이양;줘청량;이승범
    • 공업화학
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    • 제31권1호
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    • pp.19-24
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    • 2020
  • 본 연구에서는 coconut oil과 Tween-Span계 혼합계면활성제를 사용하여 O/W 유화액을 제조하고 유화안정성을 향상시키기 위한 유화조건을 최적화하였다. 이를 위해 최적화과정은 CCD-RSM (central composite design model-response surface methodology)를 이용하였다. 계량인자로는 HLB (hydrophile-lipophilie balance) value, 혼합계면활성제 첨가량, 유화속도 등을 설정하였으며, 반응치로는 평균액적크기(MDS), 유화액의 유화안정도지수(ESI), 열적 불안정도지수(TII)를 설정하였다. CCD-RSM 분석결과 3가지 반응치를 동시에 만족하는 최적조건으로 HLB value (9.1), 혼합계면활성제 첨가량(8.7 wt.%), 유화속도(6,200.8 rpm)로 산출되었으며, CCD-RSM 분석예상값은 MDS (151.0 nm), 유화액의 ESI (99.86%), TII (3.17%)로 나타났다. 이 조건에서의 실제실험 결과 오차율은 3.5% 이하로 나타나 본 연구에서의 O/W 유화액 제조과정에 CCD-RSM 최적화 분석을 적용할 경우 비교적 높은 유의수준의 결과를 얻을 수 있었다.

난류 부분예혼합 제트화염에 대한 난류 및 연소모델의 예측성능 검토 (Investigation of the Prediction Performance of Turbulence and Combustion Models for the Turbulent Partially-premixed Jet Flame)

  • 김유정;오창보
    • 한국화재소방학회논문지
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    • 제28권4호
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    • pp.35-43
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    • 2014
  • 3개의 난류모델과 3개의 연소모델로 구성된 9개의 모델조합을 이용하여 난류 부분예혼합 제트화염 구조에 대한 수치적 예측성능을 검토하였다. 이용된 난류모델은 표준 ${\kappa}-{\varepsilon}$ 모델(SKE), Realizable ${\kappa}-{\varepsilon}$ 모델(RKE) 및 Reynolds 응력모델(RSM)이며 연소모델들은 Eddy Dissipation Concept 모델(EDC), Steady Laminar Flamelet 모델(SLF)와 Unsteady Laminar Flamelet 모델(ULF)이다. 9개 모델조합의 예측성능을 평가하기 위하여 실험결과가 알려진 Sandia D 화염인 난류 부분예혼합 제트화염을 대상으로 수치계산을 수행하였다. 얻어진 결과로서, 화염길이의 예측은 RSM > SKE > RKE순으로 길게 예측하였으며, RKE 난류모델은 화염길이를 너무 과소 예측하는 것을 확인하였다. RSM + SLF과 RSM + ULF의 조합은 화염길이는 비교적 잘 예측하였지만 하류에서의 화염온도를 과대 예측하였다. 반면에 SKE와 연소모델의 조합에서 SLF 또는 ULF 조합은 화염길이 뿐만 아니라 하류에서의 화염온도도 비교적 잘 예측하였는 것을 확인하였다. 반경방향 화염온도 및 화학종 농도분포를 비교해 본 결과 SKE와 연소모델의 조합이 가장 예측성능이 뛰어났으며 SKE + ULF의 조합이 가장 우수한 예측성능을 갖는 것을 확인하였다.

Effects of substitution of soybean meal with rapeseed meal and glutamine supplementation on growth performance, intestinal morphology, and intestinal mucosa barrier of Qiandongnan Xiaoxiang Chicken

  • Zhang, Bolin;Liu, Ning;Hao, Meilin;Xie, Yuxiao;Song, Peiyong
    • Animal Bioscience
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    • 제35권11호
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    • pp.1711-1724
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    • 2022
  • Objective: The present study was to evaluate the effects of different rapeseed meal substitution (RSM) and glutamine (Gln) supplementation on growth performance, intestine morphology, and intestinal mucosa barrier of broilers. Methods: Four hundred and twenty Qiandongnan Xiaoxiang Chicken at 1 day of age with similar weight were chosen and were randomly assigned into 7 groups, consisting of 10 replicates per group and 6 broilers per replicate. Three groups were provided with diets separately containing 0%, 10%, and 20% RSM, and the other four groups were fed with diets separately supplemented with 0.5% and 1% Gln based on the inclusion of 10% and 20% RSM. At 21 and 42 days of age, 10 broilers per group were chosen to collect plasma and intestinal samples for further analysis. Results: The results showed that 10% RSM decreased average daily feed intake (ADFI) and average daily weight gain (ADG) of broilers at 21 days of age (p<0.05). Furthermore, both ADFI and ADG of broilers at 21 and 42 days of age were decreased by 20% RSM, while feed conversion ratio (FCR) was increased (p<0.05). Besides, 10% RSM resulted in lower intestinal villus height and the ratio of villus height to crypt depth, deeper crypt depth (p<0.05), combined with the lower mRNA expressions of occludin, claudin-1, and zonula occludens-1 (ZO-1) in broilers at 21 days of age (p<0.05). Similar results were also observed in broilers at 21 and 42 days of age fed with 20% RSM. However, 1% Gln improved the growth performance of broilers fed with 10% and 20% RSM (p<0.05), ameliorated intestine morphology and elevated mRNA expressions of occludin, claudin-1 and ZO-1 (p<0.05). Conclusion: In conclusion, the increasing inclusion of RSM resulted in more serious effects on broilers, however, 1.0% Gln could reverse the negative effects induced by the inclusion of RSM.

이동최소자승법을 이용한 신뢰성 최적설계 (Reliability Based Design Optimization using Moving Least Squares)

  • 박장원;이오영;임종빈;이수용;박정선
    • 한국항공우주학회지
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    • 제36권5호
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    • pp.438-447
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    • 2008
  • 본 논문에서는 이동최소자승법을 이용한 근사모델을 사용하여 신뢰성 최적설계를 수행하였다. 신뢰성 최적설계의 수행을 위한 반응표면 생성에는 RSM 과 Kriging이 사용될 수 있다. RSM은 계산시간은 빠르나 비선형성이 강한 문제에 약하며 Kriging은 비선형성이 강한 문제에 적용할 수 있으나 계산시간이 오래 걸리는 단점이 있다. 이 두 방법을 보완한 방법인 이동최소자승법(MLSM)을 이용하여 신뢰성 최적설계를 위한 반응표면을 생성하였다. 이동최소자승법을 이용한 신뢰성 최적설계기법은 Rosenbrock function 과 six-hump carmel back function으로 검증하였고 다른 기법과 비교하였다. 이동최소자승법을 이용하여 무인항공기 배기 덕트의 신뢰성 최적설계를 수행하였고 이는 항공우주구조물의 최적설계에 유용할 것으로 보여 진다.

벼 뿌리 내생 항균성 Serratia marcescens의 분리 및 동정 (Isolation and Identification of Rice Root Endophytic Antagonistic Serratia marcescens)

  • 이숙경;송완엽;김형무
    • 식물병연구
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    • 제10권1호
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    • pp.63-68
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    • 2004
  • 벼에서 문제시되는 도열병과 잎집무의마름병을 생물학적으로 방제하기 위해 병원균과 생태학적 지위가 비슷한 벼 뿌리에서 내생하는 S. marcescens 23 균주를 분리하였다. 선발 균주들을 공시하여 R. solani와 P. grisea에 대한 길항능력을 검정하여 R. solani와 P. grisea에 각각 83.9%. 88.3%의 높은 억제율을 보인 RSm220 균주를 선발하였다. 선발된 RSm220은 생리ㆍ생화학적 특성 검정결과 S. marcescens type strain과 높은 상관성을 나타내었고. 16S rDNA sequencing에 의한 계통 분석에 의해 S. marcescens의 16S rDNA sequence에 98.2% 유사성을 나타내어 S. marcescens로 동정되었다 내생성 S. marcescens RSm220은 벼 도열병과 잎집무늬마름병에 대한 생물학적 방제제로의 사용이 가능할 것으로 사료된다.

치과위생사와 치위생과 학생의 자기효능감과 방사선안전관리 지식 및 태도에 대한 비교 (Comparing with self-efficacy and knowledge, attitudes about radiation safety management of dental hygienists and students at department of dental hygiene)

  • 윤정애;윤영숙
    • 한국치위생학회지
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    • 제11권5호
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    • pp.729-739
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    • 2011
  • Objectives : It is important to catch individual characteristics by measuring the level of self-efficacy, radiation safety knowledge, attitudes to increase behavior levels in the radiation safety management(RSM) and we consider this should be applied to the professional program development to improve RSM activities of dental hygienist and students at department of dental hygiene. Methods : This study mentioned mainly self-efficacy, radiation safety knowledge, attitudes for dental hygienists and the second & third year students at department of dental hygiene in Pusan area to provide the correct information associated with the use of radiation and to be aid in the development program to increase behavior levels in the RSM in dental care institutions and schools in the future and performed a survey 8 May to 7 Juiy, 2011. The survey results were as follows Results : 1. The results of self-efficacy is $3.53{\pm}0.42$ points for the dental hygienist and $3.32{\pm}0.40$ points for students(p<0.001). 2. According to the knowledge level of RSM, the result is $11.7{\pm}3.12$ points for the dental hygienist and $9.56{\pm}2.72$ points for students(p<0.001). 3. According to the knowledge level of RSM, the result is $4.40{\pm}0.49$ points for the dental hygienist and $4.22{\pm}0.56$ points for students(p<0.001). 4. According to relationship among self-efficacy, radiation safety knowledge and attitudes, the higher the score for knowledge of RSM was, the higher the score for self-efficacy was. The higher the score for attitudes was, the higher the score for self-efficacy and knowledge was(p<0.01). 5. The factors to affect attitudes about RSM were self-efficacy, knowledge(p<0.01).

Apparent Ileal Digestibility of Nutrient in Plant Protein Feedstuffs for Finishing Pigs

  • Han, Y.K.;Kim, I.H.;Hong, J.W.;Kwon, O.S.;Lee, S.H.;Kim, J.H.;Min, B.J.;Lee, W.B.
    • Asian-Australasian Journal of Animal Sciences
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    • 제16권7호
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    • pp.1020-1024
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    • 2003
  • Five barrows (average initial body weight 58.6 kg) were used to determine the apparent ileal digestibilities of amino acids, DM, N and energy in various soybean meal, rapeseed meal and coconut meal in finishing pigs. Dietary treatments included 1) KSBM (Korean soybean meal), 2) CSBM (Chinese soybean meal), 3) ASBM (Argentine soybean meal), 4) RSM (Rapeseed meal), and 5) CNM (Coconut meal). The diets were corn starch-based and formulated so that each protein source provided the same amount of total ME (3,490 kcal/kg), CP (15.70%), lysine (1.00%), Ca (0.80%) and P (0.60%). Protein content of the KSBM was higher than the CSBM and ASBM, with all values similar to those expected, and protein content of the CNM was lower than that of the SBM preparation and RSM. Apparent ileal digestibilities of histidine, lysine, threonine, alanine, asparatic acid, cystine, glutamic acid and serine were greater for the KSBM, CSBM, ASBM and RSM than for the CNM (p<0.05). Also, the apparent ileal digestibilities of methionine, leucine, phenylalanine, valine and tyrosine were greater for the KSBM than for the CSBM, ASBM, RSM and CNM (p<0.05). Overall, the apparent ileal digestibilities of total essential amino acids were greater for the KSBM than for the CSBM, ASBM, RSM and CNM (p<0.05), and the apparent ileal digestibilities of total non essential amino acids were greater for the KSBM, CSBM, ASBM and RSM than for the CNM (p<0.05). No difference (p>0.05) in apparent digestibility of DM at the small intestine was observed among the treatments. However, the apparent digestibility of DM at the total tract was greater for the KSBM than for the CSBM, ASBM, RSM and CNM (p<0.05). Also, apparent digestibilities of N and digestible energy at the small intestine and total tract were greater for the KSBM than for the RSM and CNM (p<0.05). In conclusion, nutrient digestibility values of SBM preparations and RSM were relatively high compared to CNM.