• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2001년도 전력전자학술대회 논문집
• /
• pp.183-188
• /
• 2001

In this paper, we have developed a new Force-Display system using tendon-driven method based multiple DC motors. The proposed system is based on the HIR Lab Haptic library, which calculates the real position and renders the reflecting force data to device rapidly. The system is composed of device based tendon- driving method, high-speed controller and Haptic rendering library. The developed system will be used on constructing the dynamical virtual environment. To show the efficiency of our system, we designed simulation program, which an display the moving force (attaching, grabbing, rotating) on two virtual points. As the result of the experiment, our proposed system shows much higher resolution than any others.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.1708-1713
• /
• 1997

In teleoperation of a manipulator, kinesthetic feedback can take an essential role in the sense that it provides an operator with more realistic information. In this paper, in order to implement the concept of kinesthetic feedback, force mapping algorithms based on screw theory have been presented. In the development of such algorithms, the virtual environment has been modeled usign a spring and dampers, and the forces caused by hitting the joint limits of a conrtolled manipulator were considered. Finally, some experimental results of force mapping algorithm have been presented.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2002년도 추계학술대회논문초록집
• /
• pp.373.1-373
• /
• 2002

Impact is the most common type of dynamic loading conditions that give rise to impulsive forces and affects the vibrational characteristics of mechanical systems. Since the impact force and response are measured indirectly through the sensors, it is difficult to predict the impact force and acceleration. In this study, contact force model based on the Hertz law is proposed in order to predict the impact force correctly. (omitted)

• 비파괴검사학회지
• /
• 제32권6호
• /
• pp.669-677
• /
• 2012

This study presents a method to monitor cable force using wireless sensor nodes and piezoelectric sensors. The following approaches are carried out to achieve the objective. Firstly, the principle of piezoelectric materials (e.g., PZT) as strain sensors is reviewed. A cable force estimation method using dynamic features of cables measured by piezoelectric materials is presented. Secondly, the design of an automated cable force monitoring system using the data acquisition sensor-node Imote2/SHM-DAQ is described. The sensor node is originally developed by University of Illinois at Urbana-Champaign and is adopted in this study to monitor strain-induced voltage from PZT sensors. The advantages of the system are cheap, and eligible for wireless communication and automated operation. Finally, the feasibility of the proposed monitoring system is evaluated on a lab-scaled cable.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2007년도 춘계학술대회논문집
• /
• pp.215-218
• /
• 2007

In this paper a dynamic behavior(natural frequency) of a cracked cantilever beam subjected to follower force is presented. In addition, an analysis of the flutter and buckling instability of a cracked cantilever beam subjected to a follower compressive load is presented. Based on the Euler-Bernouli beam theory, the equation of motion can be constructed by using the Lagrange's equation. The vibration analysis on such cracked beam is conducted to identify the critical follower force for flutter insstability based on the variation of the first two resonant frequencies of the beam. Besides, the effect of the crack's intensity and location on the flutter follower force is studied. The crack section is represented by a local flexibility matrix connecting two undamaged beam segments. The crack is assumed to be in the first mode of fracture and to be always opened during the vibrations.

• 한국항해항만학회지
• /
• 제27권6호
• /
• pp.625-630
• /
• 2003

In order to keep the safety of maneuverability under the lateral berthing, it is necessary to estimate the magnitudes and properties of the hydrodynamic forces acting on ship hull quantitatively. In this paper, CFD technique is used to calculate the steady lateral force according to the water depth for Wigley model under the unsteady lateral berthing. The numerical results are analysed into the steady lateral force and the transitional lateral force, and some of reviews for the safety of maneuverability relating to the lateral berthing are discussed based on the computed hydrodynamic forces.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제54권6호
• /
• pp.287-293
• /
• 2005

Equations have been derived for computing electromagnetic forces by using the Continuum Design Sensitivity Analysis based on the Continuum Mechanics and the Virtual Work Principle. The resultant expressions have similar terms relating to the Korteweg-Holmholz force density, Maxwell Stress Tensor and Magnetic Charge Method but numerical implementation of the proposed scheme leads to efficient calculation and improved accuracy. In addition, the method can be easily applied to computing the magnetic force distribution as well as the global force. Results show the aforementioned advantages in comparison with the conventional methods.

• Nuclear Engineering and Technology
• /
• 제52권3호
• /
• pp.654-659
• /
• 2020

The reliability of the spent fuel pool instrument is very important for the security of nuclear power plant, especially during the earthquake. The effect of the fluid force on the vibration characteristics of the flexible tube of the spent fuel pool instrument needs comprehensive analysis. In this paper, based on the potential flow theory, the hydrodynamic pressures acting on the flexible tube were obtained. A mathematical model of a flexible tube was constructed to obtain the dynamic response considering the effects of seismic load and fluid force, and a computer code was written. Based on the mathematical model and computer code, the maximum stresses of the flexible tube in both safe shutdown earthquake and operating basis earthquake events on the spent fuel pool with three typical water levels were calculated, respectively. The results show that the fluid force has an obvious effect on the stress and strain of the flexible tube in both safe shutdown earthquake and operating basis earthquake events.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권3호
• /
• pp.1182-1194
• /
• 2016

The single image dehazing algorithm in existence can satisfy the demand only for improving either the effectiveness or efficiency. In order to solve the problem, a novel variational framework for single image dehazing based on restoration is proposed. Firstly, the initial atmospheric scattering model is transformed to meet the kimmel's Retinex variational model. Then, the green light component of image is considered as an input of the variational framework, which is generated by the sensitivity of green wavelength. Finally, the atmospheric transmission map is achieved by multi-resolution pyramid reduction to improve the visual effect of the results. Experimental results demonstrate that the proposed method can remove haze effectively with less memory consumption.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
• /
• pp.58-65
• /
• 2000

This study is concerned about the verification and the implementation of a mechanical model for the force system in end milling. The model is based on the relationship between the cutting forces and the chip thickness. The components of the model are based on the average cutting forces which are experimentally obtained. And, both instantaneous and average force system characteristics are described as a function of cut geometry and a feed rate. This model employed two specific cutting forces, instantaneous and average specific cutting force, and the models which obtained using two cutting forces were compared and analyzed. In this study, cutter deflection with respect to the center of rotation is considered, which is a major part of the tool run-outs. The effect of run-out on the cutting forces is also discussed. The relationships among the run-out parameters, cutting parameters and the resulting force system characteristics are presented. In all cases, for the down milling with a right hand helix cutter is considered.