• Title/Summary/Keyword: Driving forces

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A Study on the Adoption Types and the Utilization of Information Technologies (정보기술도입 유형과 업종별 정보기술 활용에 관한 연구)

  • Yun, Jong-Su;Jeong, In-Geun
    • Asia pacific journal of information systems
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    • v.4 no.2
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    • pp.62-82
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    • 1994
  • The use of information technology (IT) as a competitive weapon has now become a popular cliche. But there is still a lack of understanding of the driving forces that determine particular types of IT adoption in organizations, the activities that supported by ITs, and ITs that organizations are utilizing now and are planning to introduce in the future. Thus, This study investigates the types of IT adoption and organizations' utilization of IT in the value chain now and in the future. Concepts of IT, driving forces for adoption of IT and organizations' activities in the value chain were defined to facilitate the survey.

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Regional Business Cycles in East Asia: Synchronization and its Determinants

  • Park, Young-Joon
    • East Asian Economic Review
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    • v.17 no.2
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    • pp.103-128
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    • 2013
  • This paper analyzes the dynamics and nature of regional business cycle synchronization for East Asian countries in the period of 2000:Q1-2011:Q4. Estimating a dynamic two-factor model extracts the common factor and the nation-specific factor from both the macroeconomic aggregates and plausible driving forces of regional business cycles. Evidence for regional business cycle synchronization is particularly strong for Korea, Malaysia and the Philippines, while Japan shows weak evidence of regional synchronization. On the other hand, Indonesia, Thailand, Singapore and China are decoupling from regional business cycles. The driver of monetary aggregate is the most significant determinant of regional fluctuations of macroeconomic aggregates, whereas oil price and productivity are on average important driving forces of nation-specific fluctuations of real economic activities.

Dynamic Walking Analysis for Biped Robot (이족 로봇을 위한 동적 보행 해석)

  • Park, In-Gyu;Kim, Jin-Geol
    • Proceedings of the KIEE Conference
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    • 2000.07d
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    • pp.2804-2807
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    • 2000
  • This paper suggests a method of the forward dynamic analysis for the computer simulation on the analysis of the dynamic behavior for biped walking robot. The equations f motion of the system or the simulation are constructed by using the Method of the multibody dynamics which is powerful method for modeling of the complex biped system. For the simplicity of simulation, we consider that the sole of the contacting foot is affected by the reaction forces for tree structure system topology instead of the addition or deletion of the kinematic constraints. The ground reaction forces can be modeled using the simple spring and damper model at the three contacting points on the sole of the foot. For minimizing the errors of numerical integration, the number of equations of motion is minimized by adding the driving constraints or a controller instead of the direct driving torques.

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The Logic of Vertical Density: Tall Buildings in the 21st Century City

  • Al-Kodmany, Kheir
    • International Journal of High-Rise Buildings
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    • v.1 no.2
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    • pp.131-148
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    • 2012
  • This paper attempts to summarize recent debates on tall buildings. It first explains the driving forces of constructing tall buildings including population increase, rural-to-urban migration, demographic change, agglomeration, and human aspiration. Next, it discusses disadvantages and challenging factors that are frequently raised in making a case against tall buildings including economics, environmental factors, historic context, public safety, and psychological issues. The paper concludes by affirming that tall buildings will persist in the $21^{st}$ century due to strong commitment to urban sustainability and significant population increase worldwide.

Studies on Analysis of Particle Lumping and Improvement of Driving Characteristics in Charged Particle Type Display (대전입자형 디스플레이에 있어서 입자뭉침의 분석 및 구동특성 개선에 관한 연구)

  • Kim, Young-Cho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.24 no.11
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    • pp.915-919
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    • 2011
  • We analyzed various forces affective to the charged particles in closed space, to explain the image degradation and lifetime-shortening phenomena because of particle lumping which is one of the serious problems in reflective displays. It is possible to predict the quantity of q/m which is the most important parameter in determining the optical and electrical characteristics, by calculating the image force and kinetic energy. For stable driving, the quantity of q/m must be in the defined range but it changes during the fabrication process, so we added the filtering process to solve this problem and obtained the well-defined nonlinear driving voltage coinciding with the threshold voltage. And we obtained the fully-driving property which prevents the particle lumping and decides the image quality and lifetime of panel from the optical characteristics and occupation surface of moving particles.

Inverse Dynamic Analysis for Various Drivings in Kinematic Systems (기구학적 시스템에 있어서 구동방법에 따른 역동역학 해석)

  • Lee, Byung Hoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.9
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    • pp.869-876
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    • 2017
  • Analysis of actuating forces and joint reaction forces are essential to determine the capacity of actuators, to control the mechanical system and to design its components. This paper presents an algorithm that calculates actuating forces(or torques), depending on the various types of driving constraints, in order to produce a given system motion in the joint coordinate space. The joint coordinates are used as the generalized coordinates of a kinematic system. System equations of motion and constraint acceleration equations are transformed from the Cartesian coordinate space to the joint coordinate space using the velocity transformation method. A numerical example is carried out to verify the algorithm proposed.

Dynamic Model Development and Simulation of Crawler Type Excavator (크롤러형 굴삭기의 동역학적 모델 개발 및 시뮬레이션)

  • Kwon, Soon-Ki
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.18 no.6
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    • pp.642-651
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    • 2009
  • The history of excavator design is not long enough which still causes most of the design considerations to be focused on static analysis or simple functional improvement based on static analysis. However, the real forces experiencing on each component of excavator are highly transient and impulsive. Therefore, the prediction and the evaluation of the movement of the excavator by dynamic load in the early design stage through the dynamic transient analysis of the excavator and ensuring of design technique plays an importance role to reduce development-cost, shorten product-deliver, decrease vehicle-weight and optimize the system design. In this paper, Commercial software DADS and ANSYS help to develop the track model of the crawler type excavator, and to evaluate the performance and the dynamic characteristics of excavator with various simulations. For that reason, the track of crawler type excavator is modelled with DADS Track Vehicle Superelement, and the reaction forces on the track rollers were predicted through the driving simulation. Also, the upper frame and cabin vibration characteristics, at the low RPM idle state, were evaluated with engine rigid body modelling. And flexibility body effects were considered to determine the more accurate joint reaction forces and accelerations under the upper frame swing motion.

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교토 기후변화회의 결과와 개도국의 입장

  • 신성휘
    • 에너지협의회보
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    • s.45
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    • pp.11-21
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    • 1998
  • 이 글의 목적은 의무분담(burden sharing) 문제, 특히 개도국의 의무분담 참여를 위한 해결책을 모색하는데 있다. 이를 위해 교토의정서 검토와 기후변화협상의 주요 인자(driving forces)와 지표(indicators)에 대해서 고찰한뒤 3가지의 의무분담 해결방안과 개도국의 참여형태를 제시한다.

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Favorable driving direction of double shield TBM in deep mixed rock strata: Numerical investigations to reduce shield entrapment

  • Wen, Sen;Zhang, Chunshun;Zhang, Ya
    • Geomechanics and Engineering
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    • v.17 no.3
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    • pp.237-245
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    • 2019
  • In deep mixed rock strata, a double shield TBM (DS-TBM) is easy to be entrapped by a large force during tunneling. In order to reduce the probability of the entrapment, we need to investigate a favorable driving direction, either driving with or against dip, which mainly associates with the angle between the tunneling axis and strike, ${\theta}$, as well as the dip angle of rock strata, ${\alpha}$. We, therefore, establish a 3DEC model to show the changes of displacements and contact forces in mixed rock strata through LDP (longitudinal displacement profile) and LFP (longitudinal contact force profile) curves at four characteristic points on the surrounding rock. This is followed by a series of numerical models to investigate the favorable driving direction. The computational results indicate driving with dip is the favorable tunneling direction to reduce the probability of DS-TBM entrapment, irrespective of ${\theta}$ and ${\alpha}$, which is not in full agreement with the guidelines proposed in RMR. From the favorable driving direction (i.e., driving with dip), the smallest contact force is found when ${\theta}$ is equal to $90^{\circ}$. The present study is therefore beneficial for route selection and construction design in TBM tunneling.

Aeroelastic Behaviour of Aerospace Structural Elements with Follower Force: A Review

  • Datta, P.K.;Biswas, S.
    • International Journal of Aeronautical and Space Sciences
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    • v.12 no.2
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    • pp.134-148
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    • 2011
  • In general, forces acting on aerospace structures can be divided into two categories-a) conservative forces and b) nonconservative forces. Aeroelastic effects occur due to highly flexible nature of the structure, coupled with the unsteady aerodynamic forces, causing unbounded static deflection (divergence) and dynamic oscillations (flutter). Flexible wing panels subjected to jet thrust and missile type of structures under end rocket thrust are nonconservative systems. Here the structural elements are subjected to follower kind of forces; as the end thrust follow the deformed shape of the flexible structure. When a structure is under a constant follower force whose direction changes according to the deformation of the structure, it may undergo static instability (divergence) where transverse natural frequencies merge into zero and dynamic instability (flutter), where two natural frequencies coincide with each other resulting in the amplitude of vibration growing without bound. However, when the follower forces are pulsating in nature, another kind of dynamic instability is also seen. If certain conditions are satisfied between the driving frequency and the transverse natural frequency, then dynamic instability called 'parametric resonance' occurs and the amplitude of transverse vibration increases without bound. The present review paper will discuss the aeroelastic behaviour of aerospace structures under nonconservative forces.