• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.1
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• pp.45-55
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• 1993

In this paper, a two-stage block matching algorithm (BMA), which can reduce greatly the computational complexity of the conventional BMAs, is proposed, in which the onedimensional distortion measure based on the integral projection is introduced to determine the candidate motion vectors and then among them a final motion vector is detected based on the conventional two-dimensional distortion measure. Due to the one-dimensional calculation of a distortion measure, the proposed algorithm can reduce the computational complexity of the conventional BMA (full search method with a 16$\times$16 block) by a factor of 4, with its performance comparable to those of the conventional ones. Simulation results based on the original and noisy image sequences are shown. Also the simulation of the proposed method combined with the MPEG (Moving Picture Experts Group) SM3 (Simulation Model Three) is presented. Computer simulation shows that the proposed algorithm is fast with its performance comparable to those of the conventional ones.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.777-781
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• 2004

This paper presents a force/displacement sensing system to measure penetration depths and machining forces during pattering operation. This sensing system consists of a leaf spring mechanism and a capacitive sensor, which is mounted on a PZT driven in-feed motion stage with 1nm resolution. The sample is moved by a xy scanning motion stage with 5nm resolution. The constructed system was applied to nano indentation experiments, and the load-displacement curves of silicon(111) and aluminum were obtained. Then, the indentation samples were measured by AFM. Experimental results demonstrated that the developed system has the ability of preforming force/depth sensing indentations

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.42-50
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• 2005

This paper presents an ultra precision machining system using a high sensitive force sensing module to measure machining forces and penetration displacement in a tip-based nanopatterning. The force sensing module utilizes a leaf spring mechanism and a capacitive displacement sensor and it has been designed to provide a measuring range from 80 ${\mu}N$ to 8 N. This force sensing module is mounted on a PZT driven in-feed motion stage with 1 nm resolution. The sample can be moved by X-Y scanning motion stage with 5 nm resolution. In nano indentation experiments and patterning experiments, the machining forces were controlled and monitored by the force sensing module. Then, the patterned samples were measured by AFM. Experimental results demonstrated that the developed system can be used as an effective device in nano indentation and nanopatterning operation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1109-1112
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• 2004

This paper presents a high sensitive force sensing module to measure machining forces for a tip-based nanopatterning instrument. The force sensing module utilizing a leaf spring mechanism and a capacitive displacement sensor has been designed to provide a measuring range from 80$\mu$N to 8N. This force sensing module is mounted on a PZT driven in-feed motion stage with 1 nm resolution. The sample can be moved by a X-Y scanning motion stage with 5 nm resolution. In the patterning experiments, the machining forces were controlled and monitored by the force sensing module. Then, the patterned sample was measured by AFM. Experimental results demonstrated that the developed force sensing module can be used as an effective sensing device in the nanopatterning operation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.11a
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• pp.155-159
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• 1991

This paper is a study on the Inverse dynamics of a one-1ink flexible robot arm which is control led by the transiational base motion. The system is composed of the flexible arm, the mobil stage, a DC servomotor, and a computer. The arm base is shifted so that the tip follows a desired path function. The tip Rotten is measured by the laser displacement sensor. The governing equations are based on the Bernoullie-Euler beam theory and solved by applying the Laplace transform method and then the numerical inversion method to the resulted equations. Tip responses obtained both theoretically and experimentally are in good agreement with the desired trajectory, which shows that the scheme of inverse dynamics is effective for the open-loop endpoint positioning of the flexible am driven by the translation stage.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1717-1722
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• 2003

In this paper we developed flip-chip bonder using XY stage, liner-rotary actuator and vision system. We depicted the major parts of the developed flip-chip bonder. Then we discussed several problems and their solutions such as vision and motion control, pick-up module position accuracy, separation of chip from the blue taped hoop, etc. We used a post guide to improve the horizontal positional accuracy against the long arm. Also, we used an ejector module and synchronization technique for easy chip separation from the blue tape.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.377-382
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• 2005

This paper describes the design of micro machine tools system for mechanical machining of micro/meso scale mechanical parts. The micro machining systems such as $\mu-Late$, $\mu-milling/drilling$ machine and $\mu-grinding$ machine are the basic elements constructing $\mu-factory$ which gains more attention recently because of increasing needs of mico and nano-parts in various industrial and medical area. A miniaturized 3-axis milling machine with VCM stage and air spindle and palm-top size micro-late are designed, and air bearing stage and stepwise linear motion system with PZT are studied for motion system. The micro cutting characteristics are investigated experimentally, and reconfigurable machine structures are also considered.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.5
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• pp.211-217
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• 2007

A nano-imprinting stage has been widely used in various fields of nanotechnology. In this study, an analysis method of a nano-imprinting stage machine using FEM and flexible multi-body kinematics and dynamics has been presented. We have developed a virtual imprinting machine to evaluate the prototype design in the early design stage. The simulation using CAE for the imprinting machine is not only to analyze static and dynamic characteristics of the machine but also to determine design parameters of the components for the imprinting machine, such as dimensions and specifications of actuators and sensors. Structural components as the upper plate, the rotator, the shaft and the translator have been modeled with finite elements to analyze flexibility effects during the precision stage motion. In this paper flexible multi-body dynamic simulation is executed to support robust design of the precision stage mechanism. In addition, we made the 4-axis stage model to compare the dynamic behavior with that of 3-axis stage model.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.4
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• pp.392-397
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• 2014

Recently, there is an increase in the need for precision linear stages with vacuum compatibility in such areas as lithography equipment for wafer or mask manufacturing, mask mastering equipment for optical data storage and electron beam equipment. A simple design, high stiffness and low cost can be achieved by using ball bearings. However, a ball bearing have friction and wear problems just as in ambient air. In order to decrease the friction, a special finish, a diamond-like carbon (DLC) film coating, is applied to the surface of a guide rail by sputtering deposition. This paper presents the result of an experimental investigation on the control performance of a ball bearing-guided linear motion stage under two environmental conditions: in air and vacuum. A comparison between the results with and without the DLC coating was also considered in the experimental investigation.

• Journal of Ship and Ocean Technology
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• v.11 no.1
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• pp.11-24
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• 2007

Better prediction of a ship's manouevrabilty in initial design stage is becoming more, important as IMO manoeuvring criteria has been activated in the year of 2004. In the present study, in order to obtain more exact and reliable results for ship manoeuvrability in the initial design stage, numerical simulation is carried out by use of RANS equation based calculation of hydrodynamic forces exerted upon the ship hull. Other forces such as rudder force and propeller force are estimated by one of the empirical models recommended by MMG Group. Calculated hydrodynamic force coefficients are compared with those obtained by empirical models. Standard manoeuvring simulations such as turning circle and zig-zag are also carried out for a medium size Product Carrier and the results are compared with those of pure empirical models and manoeuvring sea trial. Generally good qualitative agreement is obtained in hydrodynamic forces due to steady oblique motion and steady turning motion between the results of CFD calculation and those of MMG model, which is based on empirical formulas. The results of standard manoeuvring simulation also show good agreement with sea trial results.