• Title/Summary/Keyword: Inertia force

Search Result 412, Processing Time 0.031 seconds

구성원들의 학습관성, 폐기학습, 지식통합능력, 혁신행동 간의 관계에 관한 실증연구 (An Empirical Study on the Relationships Among Employees' Learning Inertia, Unlearning, Knowledge Integration Capabilities, and Innovative Behavior)

  • 허명숙;천면중
    • 지식경영연구
    • /
    • 제16권2호
    • /
    • pp.249-278
    • /
    • 2015
  • Employees' knowledge integration capabilities and innovative behavior are still of crucial importance in the effective knowledge management. Recently researchers and practitioners are interested in both the potential benefits of unlearning and the negative aspects of learning inertia. The purpose of this study is to examine the relationships among learning inertia, unlearning, knowledge integration capabilities(knowledge exploitation and knowledge exploration) and innovative behavior. The results of analysis show that learning inertia is employees' psychological obstacle factor affecting knowledge integration capabilities and unlearning, that unlearning of employees is a key factor affecting knowledge integration capabilities, and that knowledge integration capabilities are driving forces leading to innovative behaviors of employees. For theoretical and practical implications, the research presents the grounds for arguments that knowledge integration capabilities are employees' dynamic capabilities from the knowledge management perspective, that unlearning is a driving force of employees' positive behaviors, and that organizations trying to perform the dynamic knowledge management need to identify the causes of employees' psychological resistance to learning. Limitations arisen in the course of the research and suggestions for future research directions are also discussed.

여유자유도/여유구동 인체형 로봇의 임피던스 생성방식 (Impedance modulation of anthropomorphic robots with kinematic and force redundancies)

  • 이병주;김희국;이재훈
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
    • /
    • pp.1289-1292
    • /
    • 1997
  • Typical biomechanical system such as human body and mammals possess abundant muscles which are more than required for motion generation of such systems. We have shown that the excess number of muscles play important roles in spring-like impedance modulation. redundant kinematic structure, which is another feature of biomechanical systems, allows modulations of inertia and damping properties of such systems. In this work, we propose a frequency modulation algorithm which combines the spring-like impedance with inertia impedance. also, a load distribution method for frequency modulation is also introduced. The frequency modulation represents a simulataneous control of force and kinematic redundancies, which has not been addressed in the literature.

  • PDF

변곡점에서 공작기계의 윤곽오차 (Contouring Error of a Machine Tool at Inflection Points)

  • 안일혁;김성수;민경석;최우천;홍대희
    • 한국정밀공학회지
    • /
    • 제20권11호
    • /
    • pp.166-170
    • /
    • 2003
  • Contouring errors are important especially for high speed and precision machining. In this study, contouring errors along contours having inflection points are studied. When a table of a machine tool moves along a circular path, acceleration acts toward the center of the circle. Thus, at inflection points, acceleration as well as inertia force changes its direction abruptly. The effect of inertia force on the contouring error is investigated in this study. It is found that the contouring error at an inflection point is proportional to the acceleration. This result can be useful in determining contouring errors along general paths.

Design of Torsion-typed Smooth Picture Actuator for DLP Projection TV

  • Moon, Yang-Ho
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
    • /
    • pp.564-568
    • /
    • 2006
  • Smooth picture module is operated by vibration to tilt the light from the DMD (digital micro mirror device) of DLP projection TV, which makes the screen of the TV smoother and DMD chip cost lower. To satisfy the vibration characteristics of smooth picture module, it is designed by optimizing moment of inertia, spring constant and damping coefficient, using structural and fluid dynamic simulation that showed a good agreement with experimental data. To reduce the material cost and moment of inertia, engineering plastic is used and the reliability is estimated. A VCM (voice coil motor) type actuator for smooth picture has to satisfy performance requirements such as higher driving force, lower power consumption, and lower cost. The initial design and optimization for VCM was performed using FE analysis. It allowed us to optimize the design of magnetic circuit of the proposed actuator to obtain higher force while maintaining a lower cost.

  • PDF

종동력을 받는 외팔보의 안정성에 관한 이론적 연구 (Theoretical Study on The Stability of the Cantilever Beam Subjected to a Follower Force)

  • 윤한익;손종동;김현수
    • 한국안전학회지
    • /
    • 제13권1호
    • /
    • pp.3-12
    • /
    • 1998
  • On the stability of the cantilever beam subjected to a follower force at the free end, the influences of the translational spring and the moment of inertia of a tip mass at the free end have been studied by numerical methods. The centroid of a tip mass is offset from the free end of a Beam and is located along its extended axis to vary the value of moment of inertia of a tip mass. It is proved that as the constants of a spring supporting the free end are augmented, the critical flutter loads of the above system decrease, whereas they increase without a tip mass.

  • PDF

엔드밀의 정적 강성에 관한 연구 (A Study on the Static Rigidity of the End Mill)

  • 이상규;고성림
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 1996년도 추계학술대회 논문집
    • /
    • pp.9-14
    • /
    • 1996
  • The deflection of an end mill is very important in machining process and cutting simulation because it affects directly workpiece accuracy, cutting force, and chattering. In this study, the deflection of the end mill was studied both experimentally and by using finite element analysis. And the moment of inertia of radial cross sections of tile helical end mill is calculated for the determination of the relation between cross section and rigidity of tile tools. Using tile Bernoulli-Euler beam and and the concept of equivalent diameter, a deflection model is established, which includes most influence from tool geomety parameters. It was found that helix angle attenuates the rigidity of the end mill.

  • PDF

피드백 변화에 따른 건물의 능동제어 실험 (Experimental Study on Active Control of Building Structures by Feedback Variables)

  • 민경원
    • 한국지진공학회:학술대회논문집
    • /
    • 한국지진공학회 1998년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Spring 1998
    • /
    • pp.286-294
    • /
    • 1998
  • This paper presents an experimental study on the performance of the active damper device by feedback variables. The damper is a mass-typed active device, which exerts the inertia control force on the building by AC servo motor. The control performance is experimentally analyzed considering the building response and the control force. It is found that the building response is greatly reduced by mass-typed device under the resonant and earthquake loading. Also, the experimental results show that the velocity feedback reduces the building responses with the smallest amount of control force than any other feedback variables.

  • PDF

Effect of seismic acceleration directions on dynamic earth pressures in retaining structures

  • Nian, Ting-Kai;Liu, Bo;Han, Jie;Huang, Run-Qiu
    • Geomechanics and Engineering
    • /
    • 제7권3호
    • /
    • pp.263-277
    • /
    • 2014
  • In the conventional design of retaining structures in a seismic zone, seismic inertia forces are commonly assumed to act upwards and towards the wall facing to cause a maximum active thrust or act upwards and towards the backfill to cause a minimum passive resistance. However, under certain circumstances this design approach might underestimate the dynamic active thrust or overestimate the dynamic passive resistance acting on a rigid retaining structure. In this study, a new analytical method for dynamic active and passive forces in c-${\phi}$ soils with an infinite slope was proposed based on the Rankine earth pressure theory and the Mohr-Coulomb yield criterion, to investigate the influence of seismic inertia force directions on the total active and passive forces. Four combinations of seismic acceleration with both vertical (upwards or downwards) and horizontal (towards the wall or backfill) directions, were considered. A series of dimensionless dynamic active and passive force charts were developed to evaluate the key influence factors, such as backfill inclination ${\beta}$, dimensionless cohesion $c/{\gamma}H$, friction angle ${\phi}$, horizontal and vertical seismic coefficients, $k _h$ and $k_v$. A comparative study shows that a combination of downward and towards-the-wall seismic inertia forces causes a maximum active thrust while a combination of upward and towards-the-wall seismic inertia forces causes a minimum passive resistance. This finding is recommended for use in the design of retaining structures in a seismic zone.

육상저유탱크 및 육상가옥에 작용하는 지진해일파력의 추정 (Estimation of the Tsunami Force Acting on Onshore Oil Storage Tanks and Houses)

  • 이광호;박보배;김창훈;최낙훈;김도삼
    • 한국해안·해양공학회논문집
    • /
    • 제23권5호
    • /
    • pp.369-382
    • /
    • 2011
  • 본 연구에서는 육상구조물에 작용하는 지진해일파력해석을 위하여 Navier-Stokes slover에 기초한 3차원 혼상류수치해석법을 적용하여 검토하였다. 여기서, 대상구조물을 육상저유탱크와 육상가옥으로 하여 호안과 육상구조물간의 이격거리에 따라 육상구조물에 작용하는 지진해일파력을 검토하였다. 또한 육상구조물에 작용하는 지진해일 파력의 추정을 위하여 항력만을 고려한 방법과 항력 및 관성력을 동시에 고려한 방법을 각각 적용하여 얻은 결과와 수치해석결과 및 설계기준에 의한 결과치를 비교 분석하였다. 이로부터 항력 및 관성력을 동시에 고려하여 추정한 지진해일파력이 항력만을 고려한 경우 보다 수치해석결과에 더 근접하는 것을 확인하였다.

옹벽의 활동에 따른 배면 동적토압의 변화 (Variation of Dynamic Earth Pressure Due to Sliding of Retaining Walls)

  • 윤석재;김성렬;황재익;김명모
    • 한국지반공학회논문집
    • /
    • 제21권8호
    • /
    • pp.55-61
    • /
    • 2005
  • 현재 옹벽의 배면 동적토압을 산정할 때 주로 등가정적해석법인 Mononobe-Okabe 식이 이용되고 있다. 하지만 이식은 벽체와 뒤채움 지반간의 동적상호작용을 고려하지 못한다는 단점이 있다. 본 연구에서는 벽체와 뒤채움 지반간의 동적상호작용을 분석하기 위하여 건조 사질토로 뒤채움한 옹벽에 대하여 진동대 시험을 수행하였다. 벽체 단위중량, 입력가속도의 진폭 그리고 벽체 바닥면 거칠기를 변화시키면서 이들 각 인자가 동적토압에 미치는 영향을 분석하였다. 그 결과 벽체의 활동속도가 작은 경우에는 동적토압과 관성력간은 180도 위상차를 가졌지만 활동속도가 큰 경우에는 동적토압에 관성력과 동일한 위상을 가지는 작은 정점이 발생하였다. 동적토압의 크기는 벽체가속도와 벽체단위중량의 크기에 비례하였다. 또한 Mononobe-Okabe 방법으로 계산된 동적토압은 측정된 동적토압의 상한값으로 나타났다.