• IEMEK Journal of Embedded Systems and Applications
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• v.9 no.1
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• pp.43-52
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• 2014

This paper presents a tracking system using images captured from a camera on a moving platform. A camera on an unmanned flying vehicle generally moves and shakes due to external factors such as wind and the ego-motion of the machine itself. This makes it difficult to track a target properly, and sometimes the target cannot be kept in view of the camera. To deal with this problem, we propose a new system for stable tracking of a target under such conditions. The tracking system includes target tracking and 3-axis camera motion compensation. At the same time, we consider the simulation of the motion of flying vehicles for efficient and safe testing. With 3-axis motion compensation, our experimental results show that robustness and stability are improved.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.10 no.3
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• pp.203-209
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• 2010

This paper presents a hierarchical fuzzy motion planner for humanoid robots in 3D uneven environments. First, we define both motion primitives and locomotion primitives of humanoid robots. A high-level planner finds a global path from a global navigation map that is generated based on a combination of 2.5 dimensional maps of the workspace. We use a passage map, an obstacle map and a gradient map of obstacles to distinguish obstacles. A mid-level planner creates subgoals that help the robot efficiently cope with various obstacles using only a small set of locomotion primitives that are useful for stable navigation of the robot. We use a local obstacle map to find the subgoals along the global path. A low-level planner searches for an optimal sequence of locomotion primitives between subgoals by using fuzzy motion planning. We verify our approach on a virtual humanoid robot in a simulated environment. Simulation results show a reduction in planning time and the feasibility of the proposed method.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1996.06b
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• pp.7-12
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• 1996

This research is on an interactive animation prototype which can be used by many users from different computers, that means a network with one server and many clients. In our research, a complete motion is represented by simple motion characteristics. We establish databases which contain all kinds of human motion characteristics. Using flexible connection and appropriate time control, we are able to recompose a sequential serial motion data. Moreover, an interactive application system is needed among the uses with a server from animator. In this research, we also investigate three methods of“connect motion database”. We are planing to use the method of connecting motion database under networks with a client-server application system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.8
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• pp.1444-1456
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• 2011

This paper presents a low-complexity algorithm for an H.264/AVC encoder. The proposed motion estimation scheme determines the best coding mode for a given macroblock (MB) by finding motion-blurred MBs; identifying, before motion estimation, an early selection of MBs; and hence saving processing time for these MBs. It has been observed that human vision is more sensitive to the movement of well-structured objects than to the movement of randomly structured objects. This study analyzed permissible perceptual distortions and assigned a larger inter-mode value to the regions that are perceptually less sensitive to human vision. Simulation results illustrate that the algorithm can reduce the computational complexity of motion estimation by up to 47.16% while maintaining high compression efficiency.

• Journal of the Korea Society of Computer and Information
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• v.20 no.7
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• pp.57-64
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• 2015

In this paper, we propose a design of microwave motion detector using X-band doppler radar sensor to minimize the power consumption. To minimize the power consumption and implement battery operated system, pulse input with 2 KHz, 4% duty cycle is exerted on the doppler radar sensor. In order to simplify the process of working with ATmega2560 microcontroller unit, Arduino compatible board is designed and implemented. Arduino is open source hardware and many library software is published as open source tools. Smartphone app is also proposed and designed as a real-time user interface of the motion detector. The SQLite database on the Android mobile operating system is used for recording raw data of motion detection for post-processing job, such as fast Fourier transform (FFT). Bluetooth interface module is implemented on the motion detection board as a wireless communication interface to the smartphone. The speed of human movement is identified by post-processing FFT.

• Journal of the Ergonomics Society of Korea
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• v.8 no.2
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• pp.19-26
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• 1989

This study, as a part of integrated human-robot ergonomics, improves the robot motion control on the robot task in the TOES/WCS whose purpose is improving the teaching task constructed in the previous study. First, the updated combined fuzzy process using a new membership function with Weber's law is constructed for the purpose of coordinate reading of the end points in the macro motion control. Second, an algorithm using the geometric analysis is desinged in order to calculate position values and posture values of the robot joints. Third, the MGSLM method is designed to remove unnecessary the robot motion control caused by the GSLM method in the micro motion control. Consequently, proposed methods in this study lessen burdcn of a human of an improvement of the robot motion control and reduce the teaching time of a human operator and inaccuracy of the teaching task, which contribute to the integrated human-robot ergonomics.

• Korean Journal of Applied Biomechanics
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• v.17 no.3
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• pp.41-49
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• 2007

This study was to investigate the kinematical analysis using ski simulator. Twelve people(six skilled, six unskilled) participated in the experiment. Each phase of motion time was slight differences between the skilled group and the unskilled group but not significant difference in statistics. In displacement of vertical on COG(Center of Gravity), left and right down motion showed significant difference between group. In velocity of horizontal on COG, both left and right down motion showed significant difference between group, and up motion of between down motion showed significant difference. In displacement of angle on ankle, knee, hip joint almost showed significant difference between group. Almost in body position was lower skilled group than unskilled group.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.7
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• pp.160-166
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• 1998

In this research a 2-dimensional motion generator composed of two linear motors was developed. The inertia, damping and/or stiffness characteristics of the motion generator can be changed on the real-time basis by properly regulating the force generated by the linear motors. That is, active impedance is implemented without actual change in the physical structure of the motion generator. Control of the motor force is carried out by controlling the input currents supplied to the linear motors based on the combination of the PI controller and feedforward controller. This motion generator can be used to measure a kinesthetic sense associated with the human arm and thus to develop the products for which the kinesthetic sense is taken into account.

• Structural Engineering and Mechanics
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• v.75 no.3
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• pp.357-367
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• 2020

The objective of this article is investigation of dynamic response of thick multilayer functionally graded (FG) beam under generalized dynamic forces. The plane stress problem is exploited to describe the constitutive equation of thick FG beam to get realistic and accurate response. Applied dynamic forces are assumed to be sinusoidal harmonic, sinusoidal pulse or triangle in time domain and point load. Equations of motion of deep FG beam are derived based on the Hamilton principle from kinematic relations and constitutive equations of plane stress problem. The numerical finite element procedure is adopted to discretize the space domain of structure and transform partial differential equations of motion to ordinary differential equations in time domain. Numerical time integration method is used to solve the system of equations in time domain and find the time responses. Numerical parametric studies are performed to illustrate effects of force type, graduation parameter, geometrical and stacking sequence of layers on the time response of deep multilayer FG beams.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.12
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• pp.874-880
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• 2015

This paper presents the vibration analysis of a deploying beam with spin when the beam has a time-dependent spinning speed. In the previous studies for the deploying beams with spin, the spinning speed was time-independent. However, it is more reasonable to consider the time-dependent spinning speed. The present study introduces the time-dependent spinning speed in the modeling. The Euler-Bernoulli beam theory and von Karman nonlinear strain theory are used together to derive the equations of motion. After the equations of motion are transformed into the weak forms, the weak forms are discretized. The natural frequency and dynamic response are obtained. The effect of the time-dependent spinning speed on the dynamic response is studied.