• Title/Summary/Keyword: composition control

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Active vibration control of nonlinear stiffened FG cylindrical shell under periodic loads

  • Ahmadi, Habib;Foroutan, Kamran
    • Smart Structures and Systems
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    • v.25 no.6
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    • pp.643-655
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    • 2020
  • Active control of nonlinear vibration of stiffened functionally graded (SFG) cylindrical shell is studied in this paper. The system is subjected to axial and transverse periodic loads in the presence of thermal uncertainty. The material composition is considered to be continuously graded in the thickness direction, also these properties depend on temperature. The relations of strain-displacement are derived based on the classical shell theory and the von Kármán equations. For modeling the stiffeners on the cylindrical shell surface, the smeared stiffener technique is used. The Galerkin method is used to discretize the partial differential equations of motion. Some comparisons are made to validate the SFG model. For suppression of the nonlinear vibration, the linear and nonlinear control strategies are applied. For control objectives, the piezoelectric actuator is attached to the external surface of the shell and the thin ring piezoelectric sensor is attached to the middle internal surface of shell. The effect of PID, feedback linearization and sliding mode control on the suppression of vibration for SFG cylindrical shell is presented.

A digital aesthetic in music (음악에서의 디지탈 미학)

  • 윤증선
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.130-133
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    • 1996
  • An exploration for an emotional intelligence paradigm has been delineated. Emotional intelligence is investigated in terms of composing machine as a modern abstract art. The system consists of interface, plan and performance modules. Design concepts of the system are modular, open, and user friendly to ensure the overall performance. The exploration of art in the view of intelligence, information and structure will restore the balanced sense of the art and the science seek the happiness of life. The investigations of emotional intelligence will establish the foundations of intelligence, information and control technologies.

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Modeling and controller design for a continuous copolymerization reactor (연속식 공중합 반응기의 모델링 및 제어기 설계)

  • 황우현;이현구
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.788-791
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    • 1996
  • A mathematical model is developed for thermal solution copolymerization of styrene and acrylonitrile in a continuous stirred tank reactor(CSTR). Computational studies are carried out with the continuous copolymerization system model developed in this work to give the monomer conversion, copolymer composition and the average molecular weights of the copolymer. By performing the dynamic analysis of the reaction system, the polymer properties against the changes in the operating conditions are determined quantitatively. The cascade PID and fuzzy controller show satisfactory performances for both set point tracking and disturbance rejection. Especially, the fuzzy controller is superior to the PID controller.

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( Control of Primary Solidification Mode for Improving Solidification Cracking Resistance , Corrosion Resistance and Cryogenic Toughness of Austenitic Stainless Steel (오스테나이트계 스테인리스강의 응고균열저항 내식성 및 극저온 초성 향상을 위한 초정응고 형식의 제어)

  • 정호신
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.28 no.2
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    • pp.208-215
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    • 1992
  • Concept of primary solidification mode control was adopted to obtain optimal solidification crack resistance, hot ductility, corrosion resistance and toughness for austenitic stainless steel. By controlling primary solidification phase as primary $\delta$ and containing no ferrite at room temperature, optimal solidification crack resistance, hot ductility, corrosion resistance and cryogenic toughness could be obtained. The optimum chemical composition of austenitic stainless steel ranges 1.46~1.55(Creq/Nieq ratio) calculated by Schaeffler's equation.

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Effect of nutrient composition, pH and media on growth and flowering in fertigational culture of Lilium and Iris sup. (백합 및 아이리스의 관비재배시 양액조성, pH 및 배양토가 생육과 개화에 미치는 영향)

  • 최영재;손성수;서정근
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 1997.05a
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    • pp.40-45
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    • 1997
  • 백합 및 아이리스는 국내에서 주로 생산되고 있는 주요 구근식물이다 특히 백합은 95년 일본 및 흥콩으로 232만 달러를 수출하였으며, 앞으로도 수출유망작물로 크게 각광 받을 것이다. 또한 아이리스도 국내 10대 절화작물에 속하는 주요 화훼작물이다. 그러나 국내에서 재배되고 있는 백합 및 아이리스 대부분이 시설내 토양에서 재배되고 있어 합리적인 영양관리가 어려우며, (중략)

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The Effect of Elastic Band Exercise Training and Detraining on Body Composition and Fitness in the Elder (탄력밴드 운동이 노인의 신체조성과 체력에 미치는 지속적 효과)

  • So, Wi-Young;Song, Misoon;Cho, Be-Long;Park, Yeon-Hwan;Kim, Yeon-Soo;Lim, Jae-Young;Kim, Seon-Ho;Song, Wook
    • 한국노년학
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    • v.29 no.4
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    • pp.1247-1259
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    • 2009
  • Muscle mass is reduced by aging. There seems to be no direct relationship between sarcopenia(muscle loss) and medical cost in the elderly, but lowering muscle mass results in increase risk of fall and decrease of strength, fitness, physical activity, and independent life. This is coupled with physical trouble and chronic degenerative disease such as diabetes, obesity, hyperlipidemia, and hypertension. Thus, sarcopenia is potential risk factor increasing mortality. The purpose of this study was to investigate the effects of elastic band exercise and detraining on sarcopenia prevention related variables, body composition and fitness. The subject of this study was 60~70 aged 14 seniors who participated in exercise program in J-welfare senior center at J-gu in S-city. Elastic band exercise was performed twice per week for 12 weeks. The body composition and fitness variables were measured before 12 weeks of control, after control(before exercise), after 12 weeks of exercise(before detraining), and after 12 weeks of detraining. There was no significant difference in body composition and fitness variables before and after 12 weeks of control, but elastic band exercise before and after 12 weeks has effect on body composition variables such as weight (t=2.978, p=0.001), body mass index (t=3.502, p=0.004), percent body fat (t=2.216, p=0.045), muscle mass (t=-3.837, p=0.002), visceral fat area (t=5.186, p<0.001), and waist-hip ratio (t=3.045, p=0.009) and on fitness variables such as 2-minutes step (t=-6.891 p<0.001), arm curl (t=-4.702, p<0.001), chair stand (t=-4.860, p<0.001), chair sit and reach (t=-5.910, p<0.001), back scratch (t=-3.835, p=0.002), and 8-ft up and go (t=7.560, p<0.001). This exercise effect was continued after 12 weeks of detraining on body composition variables such as weight (t=2.323, p=0.037), body mass index (t=2.503, p=0.026), muscle mass (t=-3.137, p=0.008) and on fitness variables such as 2-minutes step (t=-6.489 p<0.001), chair stand (t=-4.694, p<0.001), chair sit and reach (t=-3.690, p=0.003), and 8-ft up and go (t=7.539, p<0.001). It was found that the elastic band exercise has positive effect on body composition and fitness in the elderly and the effect was maintained over 12 weeks of detraining.

Milk Production, Milk Composition, Live Weight Change and Milk Fatty Acid Composition in Lactating Dairy Cows in Response to Whole Linseed Supplementation

  • Suksombat, Wisitiporn;Meeprom, Chayapol;Mirattanaphrai, Rattakorn
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.8
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    • pp.1111-1118
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    • 2013
  • The objective of this study was to determine the effects of whole linseed supplementation on performances and milk fatty acid composition of dairy cows. Thirty six Holstein Friesian crossbred lactating dairy cows were blocked by milking days first and then stratified random balanced for milk yields and body weight into three groups of 12 cows each. The control group received 300 g of palm oil. The second group was supplemented with 344 g/d of top-dressed whole linseed plus 150 g of palm oil and the third group was supplemented with 688 g/d of top-dressed whole linseed. All cows also received ad libitum grass silage (Brachiaria ruziziensis), had free access to clean water and were individually housed in a free-stall unit and individually fed according to treatments. Residual feeds were collected on 2 consecutive days weekly and at the end of the experiment. Feed samples were pooled to make representative samples for proximate and detergent analyses. Daily milk yields were recorded. Milk samples were collected on 2 consecutive days weekly. Live weights were recorded at the start and at the end of the experiment. Milk samples were taken on d 56 of the experiment and subjected to milk fatty acid composition. The results showed no statistical significant differences in intakes, live weight change, milk yields and milk compositions, however, C18:1, C18:3 and unsaturated FAs were increased while saturated FAs were reduced by whole linseed supplementation. It is recommended that the addition of 300 g/d oil from whole linseed could be beneficial to lactating dairy cows in early lactation.