• 제목/요약/키워드: reduced basis design

검색결과 176건 처리시간 0.024초

Wing weight estimation considering constraints of structural strength and stiffness in aircraft conceptual design

  • Bai, Chen;Mingqiang, Luo;Zhong, Shen;Zhe, Wu;Yiming, Man;Lei, Fang
    • International Journal of Aeronautical and Space Sciences
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    • 제15권4호
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    • pp.383-395
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    • 2014
  • According to the requirement of wing weight estimation and frequent adjustments during aircraft conceptual design, a wing weight estimation method considering the constraints of structural strength and stiffness is proposed to help designers make wing weight estimations rapidly and accurately. This method implements weight predictions on the basis of structure weight optimization with stiffness constraints and strength constraints, which include achievement of wing shape parametric modeling, rapid structure layout, finite element (FE) model automated generation, load calculation, structure analysis, weight optimization, and weight computed based on modeling. A software tool is developed with this wing weight estimation method. This software can realize the whole process of wing weight estimation with the method and the workload of wing weight estimation is reduced because much of the work can be completed by the software. Finally, an example is given to illustrate that this weight estimation method is effective.

알루미늄 초경량 차체의 충격 흡수부재 설계 및 충돌 안전도 평가 (Design of the Impact Energy Absorbing Members and Evaluation of the Crashworthiness for Aluminum Intensive Vehicle)

  • 김헌영;김진국;허승진;강혁
    • 한국자동차공학회논문집
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    • 제10권1호
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    • pp.216-233
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    • 2002
  • Due to the environmental problems of fuel consumption and vehicle emission, etc., automotive makers are trying to reduce the weight of vehicles. The most effective way to reduce a vehicle weight is to use lighter materials, such as aluminum and plastics. Aluminum Intensive Vehicle(AIV) has many advantages in the aspects of weight reduction, body stiffness and model change. So, most of automotive manufacturers are attempting to develop AIV using Aluminum Space Frame(ASF). The weight of AIV can be generally reduced to about 30% than that of conventional steel vehicle without the loss of impact energy absorbing capability. And the body stiffness of AIV is higher than that of conventional steel monocoque body. In this study, Aluminum Intensive Vehicle is developed and analyzed on the basis of steel monocoque body. The energy absorbing characteristics of aluminum extrusion components are investigated from the test and simulation results. The crush and crash characteristics of AIV based on the FMVSS 208 regulations are evaluated in comparison with steel monocoque. Using these results, the design concepts of the effective energy absorbing members and the design guide line to improve crashworthiness for AIV are suggested.

H.264 Encoder용 Direct Memory Access (DMA) 제어기 설계 (A Design of Direct Memory Access (DMA) Controller For H.264 Encoder)

  • 송인근
    • 한국정보통신학회논문지
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    • 제14권2호
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    • pp.445-452
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    • 2010
  • 본 논문에서는 Full 하드웨어 기반 베이스라인 프로파일 레벨 3 규격 H.264 인코더 코덱에서 사용할 수 있는 Direct Memory Access (DMA) 제어기를 설계하였다. 설계한 모듈은 CMOS Image Sensor(CIS)로부터 영상을 입력 받아 메모리에 저장한 후 인코더 코덱 모듈의 동작에 맞춰 원영상과 참조영상을 각각 한 매크로블록씩 메모리로부터 읽어서 공급하거나 저장하며, DMA 제어기의 한 매크로블록씩 처리하는데 478 cycle을 소요한다. 설계한 구조를 검증하기 위해 JM 9.4와 호환되는 Reference Encoder C를 개발하였으며, Encoder C로부터 Test Vector를 추출하여 설계한 회로를 검증하였다. 제안한 DMAC 제어기의 Cycle은 Xilinx MIG를 사용한 Cycle 보다 40%의 감소를 나타내었다.

Application of Response Surface Methodology and Plackett Burman Design assisted with Support Vector Machine for the Optimization of Nitrilase Production by Bacillus subtilis AGAB-2

  • Ashish Bhatt;Darshankumar Prajapati;Akshaya Gupte
    • 한국미생물·생명공학회지
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    • 제51권1호
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    • pp.69-82
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    • 2023
  • Nitrilases are a hydrolase group of enzymes that catalyzes nitrile compounds and produce industrially important organic acids. The current objective is to optimize nitrilase production using statistical methods assisted with artificial intelligence (AI) tool from novel nitrile degrading isolate. A nitrile hydrolyzing bacteria Bacillus subtilis AGAB-2 (GenBank Ascension number- MW857547) was isolated from industrial effluent waste through an enrichment culture technique. The culture conditions were optimized by creating an orthogonal design with 7 variables to investigate the effect of the significant factors on nitrilase activity. On the basis of obtained data, an AI-driven support vector machine was used for the fitted regression, which yielded new sets of predicted responses with zero mean error and reduced root mean square error. The results of the above global optimization were regarded as the theoretical optimal function conditions. Nitrilase activity of 9832 ± 15.3 U/ml was obtained under optimized conditions, which is a 5.3-fold increase in compared to unoptimized (1822 ± 18.42 U/ml). The statistical optimization method involving Plackett Burman Design and Response surface methodology in combination with an AI tool created a better response prediction model with a significant improvement in enzyme production.

사람에서 n-3계 불포화지방산이 Serum Lipoprotein과 지질조성에 미치는 영향 (Effect n-3 Polyunsaturated Fatty Acids on Serum Lipoprotein and Lipid Compositions in Human Subjects)

  • 박현서
    • Journal of Nutrition and Health
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    • 제21권1호
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    • pp.61-74
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    • 1988
  • Ten college women were divided into 5 groups and treated in randomized block design for 5 weeks with 1 interval between treatments and subjects serving as their own controls. The experimental diets were corn oil diet as a source of n-6 linoleic acid, perilla oil diet as a source of n-3 $\alpha$-linolenic acid, and fish oil diet as a source of n-3 EPA and DHA. Dietary fat was supplied at 30% Cal and modified to give the total amount of saturated fatty acids and monoenoic acids at constant level. There was no significant effect on serum cholesterol level by different PUFA. However, on a gram-for-gram basis, there was a trend that the decrease in serum cholesterol was proportionate to the degree of fat unsaturation. On the other hand, only fish oil diet significantly decreased TG level but no significant effect on the relative proportion of TG in VLDL. The degree of hypotriglyceridemia did not corrleate with the degree of unsaturation. The relative proportion of CE in LDL was reduced by all PUFA diets but significant only by perilla oil diet. The relative amount of apoprotein in LDL was significantly reduced by n-3 PUFA. HDL-Chol content was significantly increased only in fish oil diet but no change in the relative proportion of its chemical components of HDL.

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Substituting Bakery Waste for Barley Grains in Fattening Diets for Awassi Lambs

  • Hindiyeh, M.Y.;Haddad, S.G.;Haddad, S.K.
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권11호
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    • pp.1547-1551
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    • 2011
  • Bakery waste (BW) is much cheaper than barley (20 to 40% the price of barley). Bakery waste and barley grain have similar chemical composition; they contain 99 and 97% organic matter (OM), 1.1 and 1.8% fat, 18 and 15% neutral detergent fibre (NDF) and 14.0 and 14.5% crude protein (CP), respectively (DM basis). The objectives of this study were to determine the effect of substituting BW for barley grain in high concentrate fattening diets for lambs on nutrient intake, growth and carcass characteristics. Forty Awassi lambs (21.75${\pm}$1 kg) weaned at the age of 65 days were assigned randomly to four experimental fattening diets differing in BW ratio in a completely randomized design. The control diet (CON) contained 20, 60, 11, 7, and 2% (DM basis) wheat straw, barley grain, soybean meal, corn grain, and minerals and vitamin mix, respectively. Bakery waste substituted barley grain by 10, 20 and 30% of the diet DM in the LBW, MBW and HBW diets, respectively. The experiment lasted for 56 days. Dry matter intake (DMI) decreased (p<0.05) in LBW diet compared to the CON diet by approximately 10%. No further reduction in DMI was observed with the higher substitution levels. Metabolizable energy intake for the CON diet (3.6 Mcal/d) was also reduced (p<0.05) compared with LBW, MBW and HBW diets (3.4, 3.4 and 3.3 Mcal/d, respectively). Final body weight for lambs fed the CON diet (34.8 kg) was higher (p<0.05) compared with lambs fed the LBW, MBW and HBW diets (30.6, 32.0 and 31.1 kg, respectively). Growth rate for lambs fed the CON diet (232 g/d) was also higher (p<0.05) compared to lambs fed the LBW, MBW and HBW diets (170, 189, and 167 g/d, respectively). Feed to gain ratio was higher (p<0.05) for lambs fed the LBW, MBW and HBW diets (7.2, 6.6 and 7.3, respectively) compared with lambs that consumed the CON diet (5.7). Body weight gain cost was reduced by approximately 8% by the MBW and HBW diets as compared with the CON diet. Dressing percentage, full gut weight, empty gut weight and liver weights were all unaffected by the BW addition to the diets and averaged 48.9%, 6.8 kg, 2.8 kg and 0.444 kg, respectively. However, fat tail weight was increased (p<0.05) with the higher levels of the BW inclusion. In conclusion, substituting BW for barley grain reduced DMI and growth performance. However, when BW substituted barley grain at the 20 and 30% of the diet DM, body weight gain cost was reduced by approximately 8%.

부분방전 패턴인식을 위해 EMC센서를 이용한 최적화된 RBFNNs 분류기 설계 (Design of Optimized Radial Basis Function Neural Networks Classifier Using EMC Sensor for Partial Discharge Pattern Recognition)

  • 정병진;이승철;오성권
    • 전기학회논문지
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    • 제66권9호
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    • pp.1392-1401
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    • 2017
  • In this study, the design methodology of pattern classification is introduced for avoiding faults through partial discharge occurring in the power facilities and local sites. In order to classify some partial discharge types according to the characteristics of each feature, the model is constructed by using the Radial Basis Function Neural Networks(RBFNNs) and Particle Swarm Optimization(PSO). In the input layer of the RBFNNs, the feature vector is searched and the dimension is reduced through Principal Component Analysis(PCA) and PSO. In the hidden layer, the fuzzy coefficients of the fuzzy clustering method(FCM) are tuned using PSO. Raw datasets for partial discharge are obtained through the Motor Insulation Monitoring System(MIMS) instrument using an Epoxy Mica Coupling(EMC) sensor. The preprocessed datasets for partial discharge are acquired through the Phase Resolved Partial Discharge Analysis(PRPDA) preprocessing algorithm to obtain partial discharge types such as void, corona, surface, and slot discharges. Also, when the amplitude size is considered as two types of both the maximum value and the average value in the process for extracting the preprocessed datasets, two different kinds of feature datasets are produced. In this study, the classification ratio between the proposed RBFNNs model and other classifiers is shown by using the two different kinds of feature datasets, and also we demonstrate the proposed model shows superiority from the viewpoint of classification performance.

Force-based seismic design of steel haunch retrofit for RC frames

  • Ahmad, Naveed
    • Earthquakes and Structures
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    • 제20권2호
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    • pp.133-148
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    • 2021
  • The paper presents a simplified force-based seismic design procedure for the preliminary design of steel haunch retrofitting for the seismic upgrade of deficient RC frames. The procedure involved constructing a site-specific seismic design spectrum for the site, which is transformed into seismic base shear coefficient demand, using an applicable response modification factor, that defines base shear force for seismic analysis of the structure. Recent experimental campaign; involving shake table testing of ten (10), and quasi-static cyclic testing of two (02), 1:3 reduced scale RC frame models, carried out for the seismic performance assessment of both deficient and retrofitted structures has provided the basis to calculate retrofit-specific response modification factor Rretrofitted. The haunch retrofitting technique enhanced the structural stiffness, strength, and ductility, hence, increased the structural response modification factor, which is mainly dependent on the applied retrofit scheme. An additional retrofit effectiveness factor (ΩR) is proposed for the deficient structure's response modification factor Rdeficient, representing the retrofit effectiveness (ΩR=Rretrofitted /Rdeficient), to calculate components' moment and shear demands for the retrofitted structure. The experimental campaign revealed that regardless of the deficient structures' characteristics, the ΩR factor remains fairly the unchanged, which is encouraging to generalize the design procedure. Haunch configuration is finalized that avoid brittle hinging of beam-column joints and ensure ductile beam yielding. Example case study for the seismic retrofit designs of RC frames are presented, which were validated through equivalent lateral load analysis using elastic model and response history analysis of finite-element based inelastic model, showing reasonable performance of the proposed design procedure. The proposed design has the advantage to provide a seismic zone-specific design solution, and also, to suggest if any additional measure is required to enhance the strength/deformability of beams and columns.

중년 남성 정장 슬림 핏 팬츠 패턴 개발에 관한 연구 (Development of the Slim-fit Formal Pants Pattern for Middle-aged Men)

  • 양정은
    • 한국의류학회지
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    • 제35권1호
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    • pp.26-36
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    • 2011
  • The study analyzes the development of slim-fit formal pants patterns for middle-aged men. This study suggests a new pattern that complements the problems of the existing fit on the basis of the standard nude size for middle-aged men with lower garments through the analyses of one-tuck pants patterns from 5 popular brands. As a result, the waistline is lowered by 0.8cm out of consideration for the waist circumference. The crotch extension is reduced by 1.5cm, the back crotch length is revised, the center back waist point is raised by 0.9cm, and the hip line is straightened. The slim-fit is perfected of the new lines from the thigh to knee-line.

사업장폐기물의 순산소 소각기술 (Polymer Waste Incineration by Oxygen Enriched Combustion)

  • 한인호;최광호;정진우
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2000년도 제21회 KOSCO SYMPOSIUM 논문집
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    • pp.132-139
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    • 2000
  • Oxygen enriched incineration can increase the incineration capacity for wastes and dramatically reduce air pollutant emissions such as CO and dioxine by the allowing complete combustion of wastes in incinerator. Furthermore, this technology is proven to have many benefits including an energy-saving, cost-effective, and versatile application for diverse wastes compared with the conventional air incineration technology. The reduced pollutant emissions in flue gas and higher incineration efficiency are also available when the oxygen enriched air is used for the high temperature incineration systems. On the basis of the experimental results the oxygen enrichment system is successfully applied to the rotary kiln incinerator for industrial wastes. The oxygen enriched incineration system could be allowed more compact design of incinerator and flue gas treatment system due to both increasing incineration capacity and reducing flue gas volume. Therefore, oxygen enriched incineration technology is becoming highlighted in the waste incinerator which strongly require more stable efficiency and environmentally friendly and safe operationPut Abstract text here.

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