• 제목/요약/키워드: optimum weight

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Structural design optimization of racing motor boat based on nonlinear finite element analysis

  • Song, Ha-Cheol;Kim, Tae-Jun;Jang, Chang-Doo
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제2권4호
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    • pp.217-222
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    • 2010
  • Since 1980's, optimum design techniques for ship structural design have been developed to the preliminary design which aims at minimum weight or minimum cost design of mid-ship section based on analytic structural analysis. But the optimum structural design researches about the application for the detail design of local structure based on FEA have been still insufficient. This paper presents optimization technique for the detail design of a racing motor boat. To improve the performance and reduce the damage of a real existing racing boat, direct structural analyses; static and non-linear transient dynamic analyses, were carried out to check the constraints of minimum weight design. As a result, it is shown that the optimum structural design of a racing boat has to be focused on reducing impulse response from pitching motion than static response because the dynamic effect is more dominant. Optimum design algorithm based on nonlinear finite element analysis for a racing motor boat was developed and coded to ANSYS, and its applicability for actual structural design was verifed.

유한요소법에 의한 횡강도부재의 최소중량설계 (Minimum Weiht Design of Transverse Strength Member by Using Finite Element Method)

  • 나승수;민계식;엄항섭;신동희
    • 대한조선학회지
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    • 제22권3호
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    • pp.27-37
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    • 1985
  • The optimum design of the transverse strength member was carried out with respect to the minimum hull weight taken account of the 2-dimensional analysis by using Finite Element Method. The optimum sizes of the member such as web height, web thickness, lower flange breadth, lower flange thickness, radii, were calculated by using Hooke and Jeeves direct search method. The optimum structure satisfies requirements to allowable bending and shear stresses in each strength member. The optimum design results were compared with the practical ship design. The optimum design saves the hull weight than that of practical design amounts to 9.6% of that.

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계란의 란중별영양성분 및 적정가격에 관한 조사연구 (Studies on the Nutrient Contents and Optimum Prices of Eggs in Relation to Egg Weight)

  • 이규호;오봉국;오세정;이상진
    • 한국가금학회지
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    • 제12권1호
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    • pp.39-44
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    • 1985
  • 본 조사연구는 계란의 중량등급별 영양가를 조사하고 적정가격을 검토하기 위하여 600개의 계란을 공시하여 계란의 중량등급별 평균란중, 란황과 란백 및 란각의 구성비, 란황과 란백의 영양성분 분석, 계란의 단백질과 지방함량 조사를 실시하고, 계란의 란중과 단백질함량 및 단백질+지방함량을 기준으로 하는 적정가격을 검토하였는 바 얻어진 결과는 다음과 같다. 1. 평균란중(X, g/10개)의 증가에 따라 란황의 비율(Y, %)은 Y=44.34-0.02X로 감소하고, 란백의 비율(Y, %)은 Y=40.136+0.026X로 증가하였으며, 란각의 비율(Y, %)은 Y=15.358-0.006X로 감소하였다. 2. 란황과 란백의 영양분석은 계란의 중량에 따라 큰 차이나 일정한 경향을 보이지 않았다. 3. 평균란중(X, g/10개)의 증가에 따라 전란의 단백질함량(Y, %)은 Y=11.943-0.00032X로 감소하고, 지방함량(Y, %)은 Y=13.996-0.00614X로 역시 감소하였으며, 단백질+지방함량(Y, %)는 Y=25.939-0.00646X로 감소하였다. 4. 평균란중을 기준으로 하는 적정가는 단백질함량을 기준으로 하는 적정가와 비슷한 경향을 보였으며, 이들 적정가는 단백질+지방함량을 기준으로 하는 적정가보다 특란과 왕란에서는 높게 그리고 경란-중란에서는 낮게 평가되었으며, 시가와 비교할 때 단백질+지방함량기준 적정가가 가장 비슷한 경향을 보였다.

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상호 정보 에너지와 델타함수를 이용한 알고리즘의 충격성 잡음에 대한 강인성 (Robustness to Impulsive Noise of Algorithms based on Cross-Information Potential and Delta Functions)

  • 김남용
    • 인터넷정보학회논문지
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    • 제17권2호
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    • pp.11-17
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    • 2016
  • 이 논문에서는 델타함수와 상호 정보 에너지(cross information-potential with the delta functions, CIPD)에 기반한 블라인드 등화 알고리즘의 최적 가중치를 유도하고 충격성 잡음에 대해 가지는 강인성에 대해 분석하였다. CIPD 알고리즘의 입력에 대한 크기조절 기능이 정상상태 가중치를 충격성 잡음으로부터 안정되게 유지하는 주된 역할을 하는 것으로 분석되었으며 시뮬레이션 결과를 통하여, CIPD 알고리즘의 정상상태 가중치는 MSE 성능기준의 최적해를 가지면서도, 충격성 잡음에서 MSE에 기반한 LMS 알고리즘과 달리, 안정된 값을 유지함을 보였다.

향상된 신호 추정을 위한 안테나 오차 보정 과 수정된 최적 가중치를 이용한 디지털 빔 형성 성능 분석에 관한 연구 (A Study on the Performance Digital Beamforming using Antenna Error Correction and Modified Optimum Weight for Improved Signal Estimation)

  • 조성국;이준동;양길모
    • 디지털산업정보학회논문지
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    • 제10권4호
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    • pp.63-70
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    • 2014
  • Method a target estimation in spatial are mobile wireless communication using network cell and GPS. It have much error that mobile wireless communication depend on cell size. GPS method can't find a target in shadow and inner area. In this paper, we estimate a target as direction of arrival method using adaptive array antenna system. Adaptive array antenna system can obtain desired signal to remove other signal This paper studied digital beamforming method in order to estimation a target. Proposed method is modified optimum weight and antenna error correction to estimation an optimal receive signal. Digital beamforming method decided a signal phase and amplitude from received signal on array antenna element. But if it is not to do error correction of received signal, system performance have decreased. Firstly, we proposed modified optimum weight in order to finding desired target. Secondly, we are error correction of antenna incident signals by optimal weight before digital beamforming method. Thirdly, throughly simulation, we showed that system performance of proposed method compare proposal method with general method. It have improved resolution of estimation target to good performance more proposed method than general method.

탄닌 증량 효과에 따른 견섬유의 염색성과 물성 (Effect of Tannin-weighting Process in Dyeability and Physical Properties of Silk)

  • Kim, In Young
    • 한국염색가공학회지
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    • 제6권4호
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    • pp.62-71
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    • 1994
  • The weighting increase varies with the condition of tannin-weight process and effects dyeability and physical properties of silk. The purpose of this study is to investigate the optimum condition of tannin-weighting process of silk and the effect of tannin-weighting process on dyeability and properties of silk. The methods of this study are first to examine the change according to the variables such as, weight increase of silk, temperature(30, 50, 70, 80, 9$0^{\circ}C$), time(30, 60, 120, 180, 240, 300min), tannin concentration(3, 5, 10, 20, 30g/l) in order to present the optimum condition, sencond to examine the change of the properties such as surface morphology, strength, elongation, mechanical values, dyeing condition, Basic and Acid dye absorption on silk which are tannin-weight processed in the optimum condition.

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Optimum design of steel space frames with composite beams using genetic algorithm

  • Artar, Musa;Daloglu, Ayse T.
    • Steel and Composite Structures
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    • 제19권2호
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    • pp.503-519
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    • 2015
  • This paper presents an optimization process using Genetic Algorithm (GA) for minimum weight by selecting suitable standard sections from a specified list taken from American Institute of Steel Construction (AISC). The stress constraints obeying AISC-LRFD (American Institute of Steel Construction-Load and Resistance Factor Design), lateral displacement constraints being the top and inter-storey drift, mid-span deflection constraints for the beams and geometric constraints are considered for optimum design by using GA that mimics biological processes. Optimum designs for three different space frames taken from the literature are carried out first without considering concrete slab effects in finite element analyses for the constraints above and the results are compared with the ones available in literature. The same optimization procedures are then repeated for the case of space frames with composite (steel and concrete) beams. A program is coded in MATLAB for the optimization processes. Results obtained in the study showed that consideration of the contribution of the concrete on the behavior of the floor beams results with less steel weight and ends up with more economical designs.

Isolation and Characterization of Purple Non-Sulfur Bacteria, Afifella marina, Producing Large Amount of Carotenoids from Mangrove Microhabitats

  • Soon, Tan Kar;Al-Azad, Sujjat;Ransangan, Julian
    • Journal of Microbiology and Biotechnology
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    • 제24권8호
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    • pp.1034-1043
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    • 2014
  • This study determined the effect of light intensity and photoperiod on the dry cell weight and total amount of carotenoids in four isolates of purple non-sulfur bacteria obtained from shaded and exposed microhabitats of a mangrove ecosystem in Kota Kinabalu, Sabah, Malaysia. The initial isolation of the bacteria was carried out using synthetic 112 medium under anaerobic conditions (2.5 klx) at $30{\pm}2^{\circ}C$. On the basis of colony appearance, cell morphology, gram staining, motility test, and 16S rRNA gene sequencing analyses, all four bacteria were identified as Afifella marina. One of the bacterial isolates, designated as Af. marina strain ME, which was extracted from an exposed mud habitat within the mangrove ecosystem, showed the highest yield in dry cell weight ($4.32{\pm}0.03g/l$) as well as total carotenoids ($0.783{\pm}0.002mg/g$ dry cell weight). These values were significantly higher than those for dry cell weight ($3.77{\pm}0.02g/l$) and total carotenoid content ($0.706{\pm}0.008mg/g$) produced by the isolates from shaded habitats. Further analysis of the effect of 10 levels of light intensity on the growth characteristics of Af. marina strain ME showed that the optimum production of dry cell weight and total carotenoids was achieved at different light intensities and incubation periods. The bacterium produced the highest dry cell weight of 4.98 g/l at 3 klx in 72 h incubation, but the carotenoid production of 0.783 mg/g was achieved at 2.5 klx in 48 h incubation. Subsequent analysis of the effect of photoperiod on the production of dry cell weight and total carotenoids at optimum light intensities (3 and 2.5 klx, respectively) revealed that 18 and 24 h were the optimum photoperiods for the production of dry cell weight and total carotenoids, respectively. The unique growth characteristics of the Af. marina strain ME can be exploited for biotechnology applications.

유전 알고리즘을 이용한 고속 금형센터의 구조설계 최적화 (Structural Design Optimization of a High Speed Machining Center by Using a Simple Genetic Algorithm)

  • 최영휴;박선균;배병태;이재윤;김태형;박보선
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2000년도 추계학술대회 논문집
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    • pp.1006-1009
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    • 2000
  • In this study, a multi-step optimization technique combined with a simple genetic algorithm is introduced in order to minimize the static compliance, the dynamic compliance, and the weight of a high speed machining center simultaneously. Dimensional thicknesses of the eight structural members on the static force loop are adopted as design variables. The first optimization step is a static design optimization, in which the static compliance and the weight are minimized under some dimensional and safety constraints. The second step is a dynamic design optimization, where the dynamic compliance and the weight are minimized under the same constraints. After optimization, the weight of the moving body only was reduced to 57.75% and the weight of the whole machining center was reduced to 46.2% of the initial design respectively. Both static and dynamic compliances of the optimum design are also in the feasible range even though they were slightly increased than before.

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선박용 갑판크레인의 지브의 경량화설계 (Weight Reduction Design for a JIB of Deck Crane for Shipment)

  • 한동섭;이문재;한근조
    • 대한기계학회논문집A
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    • 제33권4호
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    • pp.396-400
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    • 2009
  • The demand of JIB crane to handle a container or a bulk in a vessel is increasingly because of the growth of the scale of trade through the sea. This deck crane such as JIB crane is required the weight reduction design because it is installed in the deck of a vessel due to the environment regulation. In this study first we carry out the structural analysis of JIB with respect to the luffing angle of it to calculate the maximum equivalent stress of JIB, and next the optimum design for the weight reduction design of JIB. The thickness in a cross section of JIB is adopted as the design variable, the weight of JIB as the objective function, and the von mises stress as the constraint condition for the optimum design of JIB using the ANSYS 10.0.