• 제목/요약/키워드: mass irregularity

검색결과 56건 처리시간 0.027초

진주지역 아파트 주부들의 식생활 관리실태 조사연구 (A Survey on the Status of the Meal Management Behaviors of Housewives Living in the Apartments of Jinju)

  • 이주희
    • 대한지역사회영양학회지
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    • 제6권5호
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    • pp.755-764
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    • 2001
  • This study was carried out to evaluate meal management behavior of housewives and to improve their behavior by determining what problems exist. The survey was conducted using a questionnaire in Jinju from October to November in 1999. It was shown that 29.1% of housewives didn't plan food budget, whereas only 5.6% of them did. The reasons for not planning food budget were mostly due to not forming a habit(38.8%), irregularity of prices(19.9%) or irregularity of income(13.8%). The characters of planning food budget and the reasons for not planning were not affected by age, education, monthly income, family size or monthly flood cost. Only 17.8% of meal managers recorded their housekeeping in detail and 47.4% of them wrote only the important things. Recording housekeeping records was affected by age and education. It was found that most meal managers(90.8%) didn't set menu planning and they didn't fuel the need for menu planning. The frequency of food shopping was every two days(36.2%), twice a week(20.9%) or randomly(27.4%), and the places for food shopping were supermarket(49.0%) and traditional market(41.3%). Both were affected by education or age. The quality of food was the main reason(54.6%) far the selection of food shopping place. Important consideration for selection of food and meals was preference of family(47.4%) and this character was affected by education. It was shown that the score of nutrition knowledge was 7.36, and it was affected by education. The results of this study suggest that the government, educators and scientists in nutrition make efforts to develop various levels of practical education programs for meal management and nutrition depending on age, education and community using mass media.

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국내 경전철 주행중 이상진동에 대한 시험적 평가 (An Experimental Evaluation for an abnormal vibration on running of the Domestic LRT (Light Rail Transit))

  • 양희주;우관제;이강운;성재호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 춘계학술대회 논문집
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    • pp.1321-1326
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    • 2011
  • THE RAILWAY VEHICLE IS CONSISTS OF CARBODY, BOGIE AND WHEELSETS, EACH OF COMPONENTS IS CONNECTED WITH RIGID MASS, SPRING AND DAMPER. EACH OF COMPONENTS HAS TRANSLATION MOTIONS OF LONGITUDINAL (X AXIS), LATERAL (Y AXIS) AND VERTICAL (Z AXIS) DIRECTIONS, ROTATION MOTIONS OF X, Y, Z AXIS WHICH ARE NAMED ROLLING, PITCHING AND YAWING. THE VIBRATION MODE OF RAILWAY VEHICLE IS DIFFICULT TO FIND THE CHARACTERISTICS OF MOTION DURING THE OPERATION ON THE TRACK BECAUSE THESE HAPPEN TO INDEPENDENCE OR DUPLICATION MOTION CAUSED BY VEHICLE, WHEEL/RAIL AND TRACK IRREGULARITY ETC. IT IS NAMED AN ABNORMAL VIBRATION THAT THE VIBRATION, WHICH WAS PASSED THE PRIMARY AND SECONDARY SUSPENSION, IS AFFECTED TO THE PASSENGER WITHOUT DAMPING. THIS PAPER DESCRIBES AN EXPERIENCE EVALUATION TO FIND THE CAUSE OF AN ABNORMAL VIBRATION WHICH WAS HAPPEN AT OPERATING SPEED 60KPH ZONE DURING THE MAINLINE TEST.

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Seismic assessment of existing r.c. framed structures with in-plan irregularity by nonlinear static methods

  • Bosco, Melina;Ferrara, Giovanna A.F.;Ghersi, Aurelio;Marinoc, Edoardo M.;Rossi, Pier Paolo
    • Earthquakes and Structures
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    • 제8권2호
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    • pp.401-422
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    • 2015
  • This paper evaluates the effectiveness of three nonlinear static methods for the prediction of the dynamic response of in-plan irregular buildings. The methods considered are the method suggested in Eurocode 8, a method previously proposed by some of the authors and based on corrective eccentricities and a new method in which two pushover analyses are considered, one with lateral forces applied to the centres of mass of the floors and the other with only translational response. The numerical analyses are carried out on a set of refined models of reinforced concrete framed buildings. The response predicted by the nonlinear static analyses is compared to that provided by nonlinear dynamic analyses. The effectiveness of the nonlinear static methods is evaluated in terms of absolute and interstorey displacements.

Fractal 차원과 Variogram을 이용한 암반 불연속면의 굴곡도 특성 서술 (Surface Roughness Characterization of Rock Masses Using the Fractal Dimension and the Variogram)

  • 이영훈
    • 자원환경지질
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    • 제27권1호
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    • pp.81-91
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    • 1994
  • There has been considerable research dealing with the influence of surface roughness along surfaces of rock discontinuities in relation to the peak shear strength of rock masses. Concepts accepted recently for measuring such strength include estimation of a roughness coefficient such as developed by Barton's studies. The method for estimation the Joint Roughness Coefficient (JRC) value of a measured roughness profile is subjective. The aim of this research is to estimate the JRC value of the roughness of a surface profile in a rock mass system using an objective method. The study of roughness of surfaces has included measurement of fractal geometric characteristics. Once the irregularity of the surface has been described by the fractal dimension, the spatial variation of the surface irregularities can be described using variogram and drift analysis. An empirical relationships between the roughness profiles of selected JRC ranges and their fractal dimension with variogram and drift were derived. The application of analyses of fractal dimension, variogram and drift was novel for the analysis of roughness profiles. Also, an empirical equation was applied to experimental data.

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Stochastic space vibration analysis of a train-bridge coupling system

  • Li, Xiaozhen;Zhu, Yan
    • Interaction and multiscale mechanics
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    • 제3권4호
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    • pp.333-342
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    • 2010
  • The Pseudo-Excitation Method (PEM) is applied to study the stochastic space vibration responses of train-bridge coupling system. Each vehicle is modeled as a four-wheel mass-spring-damper system with two layers of suspension system possessing 15 degrees-of- freedom. The bridge is modeled as a spatial beam element, and the track irregularity is assumed to be a uniform random process. The motion equations of the vehicle system are established based on the d'Alembertian principle, and the motion equations of the bridge system are established based on the Hamilton variational principle. Separate iteration is applied in the solution of equations. Comparisons with the Monte Carlo simulations show the effectiveness and satisfactory accuracy of the proposed method. The PSD of the 3-span simply-supported girder bridge responses, vehicle responses and wheel/rail forces are obtained. Based on the $3{\sigma}$ rule for Gaussian stochastic processes, the maximum responses of the coupling system are suggested.

비틀림 비정형성을 가진 RC 건물의 설계편심 (Design Eccentricity of RC Building Structures with Torsional Irregularity)

  • 이한선;고동우
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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    • pp.140-143
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    • 2003
  • Recently, many high-rise reinforced concrete (RC) bearing wall structures of multiple occupancy have been constructed, which have the irregularities of weak (or soft) story and torsion at the lower stories simultaneously. The study compared the eccentricity of such a building predicted by design codes, EC 8, IBC 2000 and UBC 97, and by the test results through a series of shaking table tests of 1:12 model. Based on the comparison of the predicted eccentricity and the test result, the conclusions are drawn as follow: Accidental torsion due to the uncertainty on the properties of structure can be reasonably predicted by using the dynamic analysis with the center of mass being shifted by 5 percent of the dimension of the building perpendicular to the direction of the excitations than by using equivalent lateral force procedure

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Ramp장치를 이용한 철도차량 거동모드 주파수에 관한 연구 (A Study for behavior mode frequency of railway vehicle using ramp device)

  • 양희주;우관제;성재호
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2010년도 춘계학술대회 논문집
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    • pp.30-35
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    • 2010
  • The railway vehicle is a multi-body system running on the track which consists of carbody, bogie and wheelset, each of components is connected with rigid mass, spring and damper. each of components has translation motions of longitudinal (X axis), lateral(Y axis) and vertical(Z axis) direction, and rotation motions of X, Y, Z axis which are named Rolling, Pitching and Yawing. The vibration mode of railway vehicle is difficult to find the characteristics of motion during the operation on the track because these happen to independence or duplication motion caused by vehicle, wheel/rail and track irregularity etc. This paper presents the result of ramp test to show the bounce, roll, pitch and yaw mode frequency of the railway vehicle.

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Torsion bar spring을 가진 현수장치에 대한 최적조건 해석 (Analysis of optimum condition for the suspension system with torsion bar spring)

  • 손병진;신영철
    • 오토저널
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    • 제4권1호
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    • pp.40-45
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    • 1982
  • The spring constant and damping coefficient are vital factors of ride comfort and driving stability in the vibration of the vehicle which is mainly induced by a variety of the surface irregularity. This paper reviewed the optimum condition of the damping factor derived from the typical model of two mass-two degrees of freedom. Through the evaluation and discussion, it was presented that the spring of the torsion bar type was not effective for the driving stability in the large displacement of the wheel, and also that the damper with progressive performance has to be fundamentally selected to meet the requirement of the driving suability when this kind of spring is used as a suspension system of the vehicle.

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연속용융아연 도금라인의 도금편차 진단 (Diagnosis of Coating Deviation in Continuous Galvanizing Line)

  • 배용환
    • Journal of Advanced Marine Engineering and Technology
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    • 제26권2호
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    • pp.192-199
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    • 2002
  • In continuous galvanizing process, the mass of zinc deposited and its distribution are controlled by the air pressure, effective distance from the air knife nozzle to the steel strip surface and line speed. Coating defects are resulted from the unbalance of these control factors and the inaccuracy of coating equipments. This paper investigates the main cause of coating deviation and a new air knife system for control of coating thickness was developed. We investigate dynamic pressure variation by air knife types. It is found that the coating deviation is caused by the unbalance of dynamic pressure, the irregularity of strip position, and the strip vibration. Formulating a useful coating model by using present working condition, an optimal working condition is suggested. The productivity and coating quality are improved by applying the result of this research at the shop floor.

입체 복합구조물의 하부골조 층수 변화에 따른 비선형 거동특성 (The Nonlinear Behavior Characteristics of the 3D Mixed Building Structures with Variations in the Lower Stories)

  • 강병두;전대한;김재웅
    • 한국지진공학회논문집
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    • 제6권1호
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    • pp.55-62
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    • 2002
  • 상부벽식-하부골조 구조(복합구조)는 일반적으로 전이층을 중심으로 상부는 주거공간의 전단벽식의 고층아파트이고 하부는 상업공간의 보-기등의 골조구조이다. 이러한 구조물은 구조형식의 특성상 강성비정형, 질량비정형, 기하학적 비정형 등 비정형 형태의 특징을 갖고 있다. 본 연구에서는 하부골조 구조물의 층수가 변화할 경우에 대해 복합 구조물의 비선형 거동특성과 내진성능을 파악하였다. 비선형 해석결과로부터 얻은 결론은 다음과 같다. 1) 비선형 정적해석의 최상층변위각과 밑면전 단력계수로부터 하부구조의 층수가 증가할 경우 구조물의 밑면전단력계수는 감소하였으나 최상층변위각은 증가하였다. 2) 하부구조의 층수가 증가할 경우 상부벽식구조의 층간변위각과 소성율은 감소하였으며, 상부벽식은 탄성상태에 가까운 거동을 하였다. 3) 하부구조의 층수가 증가할 경우 하부구조에서 층간변위각이 집중적으로 증가하였다.