• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1736-1739
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• 2002

The advanced in semiconductor, hardware, and software technologies enables the integration of more com- plex systems and the increasing design complexity. As system design complexity becomes more complicated, System-level design based on the If block and processor model is more needed in most of the RTL level or low level. In this paper, we present a novel approach fur the system-level design, which satisfies the various required constraints and an optimization method of image encoder based on codesign of function, algorithm, and architecture. In addition, we show an MPEG-4 encoder as a design case study. The best tradeoffs between algorithm and architecture are necessary to deliver the design with satisfying performance and area constraints. The evaluations provide the effective optimization of motion estimation, which is in charge of an amount of performance in the MPEG-4 encoder module.

• Structural Engineering and Mechanics
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• v.42 no.6
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• pp.783-797
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• 2012

A new hybrid meta-heuristic optimization algorithm is presented for design of structures. The algorithm is based on the concepts of the charged system search (CSS) and the particle swarm optimization (PSO) algorithms. The CSS is inspired by the Coulomb and Gauss's laws of electrostatics in physics, the governing laws of motion from the Newtonian mechanics, and the PSO is based on the swarm intelligence and utilizes the information of the best fitness historically achieved by the particles (local best) and by the best among all the particles (global best). In the new hybrid algorithm, each agent is affected by local and global best positions stored in the charged memory considering the governing laws of electrical physics. Three different types of structures are optimized as the numerical examples with the new algorithm. Comparison of the results of the hybrid algorithm with those of other meta-heuristic algorithms proves the robustness of the new algorithm.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.4
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• pp.434-439
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• 2010

A compliant mechanism is a mechanism that produces its motion by the flexibility of some or all of its members when input force or thermal load is applied. Whereas the topology optimizations based on homogenization and SIMP parameterization have been successfully applied for compliant mechanism design, ESO approach has been hardly considered yet for the optimization of these types of systems. In this paper, traditional ESO method is adopted to achieve the optimum design of a compliant mechanism for thermal load, since AESO method cannot consider the effect of both heat conduction and convection. Sensitivity number, a criterion for element removal in traditional ESO, was newly defined for input thermal loading. The procedure has been tested in numerical applications and compared with the results obtained by other methods to validate these approaches.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.225-226
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• 2007

In this paper, we present our study about the optimization of the block matching algorithm on a VLIW based DSP. The block matching algorithm is well known for its computational burden in motion picture encoding. As supposed to the previous researches where the optimization is achieved by optimizing SAD, the most heavy routine of the block matching, we optimize the block matching algorithm by applying software pipelining technique to the whole routine of the algorithm. Through experiments, the efficiency of the proposed optimization is verified.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.2
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• pp.87-93
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• 2019

This research deals with posture optimization for humanoid robot against external forces using genetic algorithm and neural network. When the robot takes a motion to push an object, the torque of each joint is generated by reaction force at the palm. This study aims to optimize the posture of the humanoid robot that will change this torque. This study finds an optimized posture using a genetic algorithm such that torques are evenly distributed over the all joints. Then, a number of different optimized postures are generated from various the reaction forces at the palm. The data is to be used as training data of MLP(Multi-Layer Perceptron) neural network with BP(Back Propagation) learning algorithm. Humanoid robot can find the optimal posture at different reaction forces in real time using the trained neural network include non-training data.

• The Journal of Korea Robotics Society
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• v.17 no.4
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• pp.493-499
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• 2022

This paper presents the design for the kinematic structure of a system for an automatically moored 6000 ton autonomous ship in a port, and the process and results of optimal design for the link cross-sectional shape. We propose an automatic mooring system with a PPP type serial manipulator structure capable of linear motion in the XYZ axis. The mooring force applied by the mooring system was derived with dynamics simulation tool "ADAMS". The design goal is the minimization of the cross-sectional area of the link. Constrains include compressive stress and shear stress. The optimization problems were solved by using the sequential quadratic programing method implemented in the fmincon package. The shape of the cross section was assumed to be rectangle. Through future research, we plan to manufacture automatic mooring system for 6000ton class autonomous ship.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.209-210
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.979-980
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• 2009

• ETRI Journal
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• v.40 no.2
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• pp.266-274
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• 2018

In error-prone wireless environments, it is difficult to realize video coding systems that are robust to various types of data loss. In this paper, a novel motion-vector refinement approach is presented for video error concealment. A traditional boundary-matching approach is exploited to reduce blocky effects along the block boundary. More specifically, a downhill simplex approach is combined with a boundary-matching approach to fine-tune the motion vectors, reducing the blocky effects along the prediction unit block boundary, and minimizing the computational cost. Extensive simulations are performed, and the results obtained verify the robustness and effectiveness of the proposed approach.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.4
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• pp.446-453
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• 1999

An athlete motion during weightlifting is analyzed based on robotic manipulability, which shows dexterities by changing the position and orientation of the end-effector of robot manipulators arbitrary or along a specified direction. The athlete body is modeled as a highly redundant robot manipulator. The motion of weightlifting is analyzed based on the selected model with a power manipulability. Power manipulability and its geometric characteristics are derived by combining kinematic manipulability and dynamic manipulability. Also, manipulability-based optimal trajectory of weightlifter for given body structure of weightlifter derived through genetic algorithm.