• 제목/요약/키워드: Formula-based method

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마찰감쇠기가 설치된 비선형 단자유도 건물의 등가감쇠비 (Equivalent Damping Ratio of the Inelastic SDOF Structures with Friction Damper)

  • 김형섭;민경원;이상현;박지훈;문병욱
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2004년도 가을 학술발표회 논문집
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    • pp.492-499
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    • 2004
  • The purpose of this paper is to present a design procedure of coulomb friction dampers for controlling elastic and inelastic responses of building structures. The equivalent damping and frequency increased by the friction damper are estimated using ATC-40 and ATC-55 procedures which provide equivalent linear system for bilinear one, and then a design formula to achieve target performance response level by friction damper is presented. It is identified that there exists error between the responses obtained by this formula and by performing nonlinear analysis and the features of the error vary according to the hardening ratio, yield strength ratio, and structural period. Equations for compensating this er개r are reposed based on the least square method, and the results from numerical analyses indicate that the error is significantly reduced, and the proposed formula can be used without much error for designing coulomb friction damper for retrofitting a structure showing elastic or inelastic behavior.

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교량구조물의 비탄성변위응답 평가를 위한 연성도감소계수 산정식 제안 (Propositions of the Ductility Reduction Factor for Estimating Inelastic Displacement Responses of Bridge Structures)

  • 송종걸;김학수
    • 산업기술연구
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    • 제26권A호
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    • pp.153-161
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    • 2006
  • The main objective of this study was to derive a formula of ductility reduction factor, expressed as $R_{\mu}$. To attain this objective, a study comprised reduction factors computed for stiffness degrading systems undergoing different levels of ductility and to investigate an accuracy of the formula. Based on this study, the main conclusions can be summarized :(1) The ductility reduction factor is primarily affected by the period of the system and the displacement ductility ratio. (2) The proposed formula is simpler and the inelastic deformations of bridge structures are better than those by the others formulas we used before.

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컴퓨터 프로그램을 이용한 접지설계 (Grounding Grid Design Using Computer Program)

  • 최종기;안용호;정길조
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 일렉트렛트 및 응용기술
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    • pp.165-169
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    • 2002
  • Grounding grid design of substation and power generating plant has been conducted based on IEEE Std 80 or 665, which provides simple formula to estimate grounding performance such as grounding resistance, max. step and touch voltage. Although these formula are applicable for many situations, they contains many assumptions and consequent limits of application. This paper shows the limits of IEEE formula and the virtue of estimating grounding performance of grid using numerical method or computer program.

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제로터 유압 모터의 용량에 관한 연구 (An Analysis on Volumetric Displacement of Hydraulic Gerotor Motor)

  • 김대명;함영복;김성동
    • 유공압시스템학회:학술대회논문집
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    • 유공압시스템학회 2010년도 춘계학술대회
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    • pp.39-43
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    • 2010
  • It is hard and complex to analytically derive a volumetric displacement formula of a gerotor hydraulic motor because geometric shape of its rotors is complicate. An analytical method about the volumetric displacement is proposed in this work, which is relatively easy and based upon two physical concepts. The first one is energy conservation between hydraulic input energy of the motor and mechanical output energy. The second concept is torque equilibrium with respect to inner and outer rotors. The proposed formula about the volumetric displacement is verified by comparing an analytical displacement and a numerical displacement for an example specification of the motor. The numerical displacement is calculated through a kind of CAD technology. The analytical formula can be utilized in analysis and design of hydraulic gerotor motors.

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선체 박판구조의 용접변형 제어에 관한 연구(II) (On the Weld-Induced Deformation Control of Ship's Thin Plate Block (II))

  • 이주성;김철호
    • 대한조선학회논문집
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    • 제44권5호
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    • pp.504-508
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    • 2007
  • In the case of thin plate blocks, buckling deformation due to longitudinal shrinkage is the most important weld-induced deformation. This paper is concerned with developing the formula to predict the longitudinal shrinkage due to welding, in which mechanical tension effect in welding direction is accounted for. For this purpose, bead on plate welding test has been carried out for the 27 thin plate specimens with varying welding conditions and magnitude of tensile load. Empirical formula of predicting the longitudinal shrinkage has been derived based on the results of welding test, in which effect of mechanical tension is included. The derived formula can be usefully used in predicting the level of tensile load to reduce the longitudinal shrinkage.

신뢰성이론에 의한 말뚝기초의 안정해석 및 설계규준 (Reliability Based Stability Analysis and Design Criteria for pile Foundation)

  • 이증빈;김영인;박철수;이정식;신형우
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1991년도 가을 학술발표회 논문집
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    • pp.102-107
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    • 1991
  • This study a reliability based design criteria for the Pile foundation, Which is common type of bridge founfation, and also proposes the theoretical bases limit state equations of stalbility analvsis of Pile foundation and the uncertainty measuring algorithms of each equation are also derived by MFOSM using the pile reations of displacement method, Terzaghi's bearing capacity formula, and chang's lateral load formula. The Level of uncertainties comesponding to these algorithms are proposed approprite values considering our actuality. It may be asserted that the proposed LRFD reliability based design criteria for the pile foundation may have to be incorporated in to the current Highway Bridge Design codes as a design provision corresponding to the USD(or LFD) provisions of the current Highway Bridge Design Code.

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상한론에 근거하여 소화기 이상을 동반한 지루성 피부염 환자에 대한 적석지우여량탕 치험 1례 (A Case Report of Seborrheic Dermatitis With a Gastrointestinal Symptom Treated by Jeokseokji-uyeoryang-tang Based on Shanghanlun)

  • 이성준;윤혜지;이숭인
    • 대한한의학방제학회지
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    • 제24권1호
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    • pp.45-52
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    • 2016
  • objective The purpose of this case report is to review the possibility of utilizing Jeokseokji-uyeoryang-tang as a therapy of seborrheic dermatitis, and to consider clinical using possibility of Shanghanlun.method Patient's Diagnosis and progress of seborrheic dermatitis was evaluated based on the patient's chart and picture. And diagnosis based on Shanghanlun was organized by table.results When analyzing the patient's history and symptoms, it can be found in article No. 159 in Shanghanlun. The area and intentsiy of erythema were reduced when viewed photos findings, so diagnosis and therapies used in this case showed valid results in seborrheic dermatitis.conclusion Jeokseokji-uyeoryang-tang is efficient to patient of this case report as a treatment.

상한론에 근거하여 오수유탕을 이용하여 호전된 건선 치험 1례 (A Case Report of Psoriasis Treated by Osuyu-tang Based on Shanghanlun)

  • 이성준;서희애;이숭인
    • 대한한의학방제학회지
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    • 제24권1호
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    • pp.53-61
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    • 2016
  • Objective The object of this case report is to evaluate the possibility of utilizing Osuyu-tang as a new therapy of psoriasis.Method Diagnosis and Psoriasis' progress was evaluated based on the patient's chart and picture. Diagnosis based on Sanghanlun was organized by graph. The severity of psoriasis' progress was evaluated by Psoriasis Area Severity Index(PASI) and visually analyzed through picture.Results On PASI and picture, we could confirm psoriasis’s area was decreased from hairline to middle of forehead and redness, thickness, scale of psoriasis also got better.Conclusion Osuyu-tang is efficient to patient of this case report as a treatment.

여대생의 1일 보행수, 활동계수, 신체조성, 휴식대사량 및 에너지 소비량의 평가 (Assessment of Daily steps, Activity coefficient, Body composition, Resting Energy Expenditure and Daily Energy Expenditure in Female University Students)

  • 최현정;송주미;김은경
    • 대한영양사협회학술지
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    • 제11권2호
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    • pp.159-169
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    • 2005
  • The purpose of this study was to assess the energy expenditure and investigate the relationship between related variables in 70 female university students. Resting energy expenditure estimated by Harris-Benedict formula, WHO/NAO/FAO formula and various formulas based on body weight and body surface area were 1366.9$\pm$74.4kcal/day, 1287.8$\pm$106.6kcal/day, 1171.4$\pm$155.8kcal/day and 1342.0$\pm$97.4kcal/day. Measured resting energy expenditure by indirect calorimetry(Model : Metavine and TrueOne2400) were 1582.0$\pm$150.1kcal/day and 1268.2$\pm$152.9kcal/day, respectively. Average step number per day was 11981.2$\pm$3014.4 steps and average step number per hour was 746.1$\pm$198.0 steps/hr. Daily energy expenditure by using Harris-Benedict formula, body weight formula, body surface area formula, WHO/NAO.FAO formula and 15-min check list formula were 2374.7$\pm$249.6kcal, 2033.5$\pm$313.2kcal, 2331.2$\pm$266.0kcal, 2240.8$\pm$185.5kcal and 2195.5$\pm$398.3kcal. Meanwhile energy intake of subjects was 1714.9$\pm$551.2 kcal. Daily energy expenditure has positive correlation(r=0.262) with daily step number. And there was significant positive correlations(r=0.35-0.68) between various daily energy expenditures and muscle mass. These results suggested that increase of daily step number by using pedometer is good method to increase daily energy expenditure. In particular, increase in step number can reinforce the amounts of muscle.

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Transiting test method for galloping of iced conductor using wind generated by a moving vehicle

  • Guo, Pan;Wang, Dongwei;Li, Shengli;Liu, Lulu;Wang, Xidong
    • Wind and Structures
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    • 제28권3호
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    • pp.155-170
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    • 2019
  • This paper presents a novel test method for the galloping of iced conductor using wind generated by a moving vehicle which can produce relative wind field. The theoretical formula of transiting test is developed based on theoretical derivation and field test. The test devices of transiting test method for aerodynamic coefficient and galloping of an iced conductor are designed and assembled, respectively. The test method is then used to measure the aerodynamic coefficient and galloping of iced conductor which has been performed in the relevant literatures. Experimental results reveal that the theoretical formula of transiting test method for aerodynamic coefficient of iced conductor is accurate. Moreover, the driving wind speed measured by Pitot tube pressure sensors, as well as the lift and drag forces measured by dynamometer in the transiting test are stable and accurate. Vehicle vibration slightly influences the aerodynamic coefficients of the transiting test during driving in ideal conditions. Results of transiting test show that the tendencies of the aerodynamic coefficient curve are generally consistent with those of the wind tunnel tests in related studies. Meanwhile, the galloping is fairly consistent with that obtained through the wind tunnel test in the related literature. These studies validate the feasibility and effectiveness of the transiting test method. The present study on the transiting test method provides a novel testing method for research on the wind-resistance of iced conductor.