A drum clutch which is a main part for the automatic transmission of auto-mobiles has been manufactured by grob threading and machining. The tooth shape of the drum clutch manufactured by machining has lower dimensional accuracy than that by pressing and its machining needs the enormous cost at plant investment. Thus, this study was designed to develop cold forging process and to improve the productivity and dimensional accuracy. In this work, variables affecting dimensional accuracy were first determined, then cold forming process design according to each variables was performed by FE simulation. Optimal process was suggested on the basis of analytical results.

Chemical mechanical polishing(CMP) has been widely accepted for the planarization of multi-layer structures n semiconductor fabrication. But a variety of defects such as abrasive contamination, scratch, dishing, erosion md corrosion are occurred during CMP. Especially, dishing and erosion defects increase the metal resistance because they decrease the interconnect section area, and ultimately reduce the life time of the semiconductor. Due to this reason dishing and erosion must be prohibited. The pattern density and size in chip have a significant influence on dishing and erosion occurred by over-polishing. The fixed abrasive pad(FAP) was applied and tested o reduce dishing and erosion in this paper. The abrasive concentration decrease of FAP results in advanced pattern selectivity which can lead the uniform removal in chip and declining over-polishing. Consequently, reduced dishing and erosion was observed in CMP of tungsten pattern wafer with proposed FAP and chemicals.

The sapphire wafer was polished by the implementation of the surface machining technology based on nano-tribology. The removal process has been performed by grinding, lapping and chemical-mechanical polishing. For the chemical mechanical polishing process, the chemical reaction between the slurry and sapphire wafer was investigated in terms of the change of Zeta-potential between two materials. The Zeta-potential was -4.98 ㎷ without the slurry in deionized water and was -37.05 ㎷ for the slurry solution. By including the slurry into the deionized water the Zeta-potential -29.73 ㎷, indicating that the surface atoms of sapphire become more repulsive to be easy to separate. The average roughness of the polished surface of sapphire wafer was ranged to 1-4Å.

In this study, the isolation system for multi-mechanism HIF (high impulsive force) device has been investigated. For this purpose, parameter optimization process has been performed based on the simplified isolation system model under constraints of moving displacement and transmitted force. The design parameters for multi-mechanism HIF device have been derived with respect to HIF system Ⅰ and HIF system Ⅱ, respectively. In order to implement the dynamic absorbing system, the dual stage hydro-pneumatic damper and magnetorheological damper with semi-active control scheme are considered. Finally, the performance of the designed prototype isolation system has been evaluated by experimental works under actual operating conditions.

In electrostatic suspension system of thin plates like a silicon wafer or an aluminum disk for hard disk applications, the lateral restoring force exerted on a suspended object plays an important role since the lateral motion of the suspended object, owing to the inherently stable restoring forces, can be passively stabilized without any active control of it. This paper reports about the measurement apparatus of the lateral restoring force originating from a relative translation of the suspended object with respect to the electrodes-for-suspension. An approximate calculation of the lateral force in disk-shaped objects, the structure of the measurement apparatus, a measurement method, stabilization condition and the guideline in designing the measurement apparatus are described. Experimental results obtained by using a 3.5-inch aluminum disk as a suspended object are presented as well in order to assess the magnitude of lateral force and stiffness, and also verify the usefulness of the measurement apparatus.

In this paper, a novel rotor flux estimation method of an induction motor using support vector regression(SVR) is presented. Two well-known different flux models with respect to voltage and current are necessary to estimate the rotor flux of an induction motor. Training of SVR which the theory of the SVR algorithm leads to a quadratic programming(QP) problem. The proposed SVR rotor flux estimator guarantees the improvement of performance in the transient and steady state in spite of parameter variation circumstance. The validity and the usefulness of proposed algorithm are throughly verified through numerical simulation.

Evaluating the effective properties of materials containing various types of in-homogeneities is an important issue in the analysis of structures composed of those materials. A simple and effective method for the purpose is to impose the periodic displacement boundary conditions on the finite element model of a unit cell. Their theoretical background is explained based on the purely kinematical relations in the regularly spaced in-homogeneity problems, and the strategies to implement them into the analysis and to evaluate the homogenized material constants are introduced. The creep behavior of a thin sheet with square arrayed rectangular voids is characterized, where the orthotropy is induced by the presence of the voids. The homogenization method is validated through the comparison of the analysis of detailed model with that of the simplified one with the effective parameters.

Thin plate correction of forming process that it is nowadays smile change of simple contact surface as it becomes possible that forecast dictionary numerically exactly to analyze comparative big comp displacement real industry spot problems between complicated and abnormal curved line shapes and thin plate and die more reliable and need many efforts yet economical analysis method is required and develops this efficient algorithm. This research analyzes correction of forming and examined possibility and validity of spot application using One-Step Finite Element Method. Its application is being increased especially in the automotive industrial area for the cost reduction, weight saving, and improvement of strength.

A glass transfer robot is used for handling LCDs in the production line of flat panel displays under clean environments. During glass transfer operations of the robot, chattering phenomenon occurs at the robot hand. This deteriorates the accuracy and repeatability of the end-effector of the robot. In this paper, we present the kinematic solution of the robot and then analyze the cause of this chattering phenomenon in view of the mechanism and servo control and propose a practical solution that can reduce the chattering significantly at the robot hand of the glass transfer robot.

The guillotined cutting process for the pipe was studied in this paper. Until now guillotining mechanism can not be practically applied in the industries because of the deformation of sheared section around cutting area, the coarse sheared surface, and the burs. To find optimum shapes of blade, several types of blade were experimentally studied. The cutting force normal to the axial direction of the pipe was compared with the theoretical result based on the cutting energy. The experimental maximum cutting forces were very good agreement with the theoretical results. It also discussed that the design parameters of guillotining system such as the blade shape and the clearance between the blade and the die made effects to the deformation of the cutting cross section area. The results show that the guillotining method can be applicable to the pipe cutting system by optimizing the blade shape and the clearance between the blade and the die of the guillotined cutting system with respect to the sheared pipe material.

A crack emanating from an internal electrode or a conducting damage path in ferroelectric ceramic actuators is analyzed. The boundary of the domain switching zone near the edge of the internal electrode in a ceramic multilayer actuator is determined based on the nonlinear electric theory. The stress intensity factor induced by a ferroelectric domain switching under small scale conditions is numerically obtained for flaws of various sizes near the electrode edge. It is found that stress intensity factor near the crack tip depends on the material property of the electrical nonlinearity.

Effect of transverse electric fields on fracture behavior in ferroelectric ceramics under purely electrical loading is investigated. It is shown that the shape and size of the domain switching zone depend strongly on the ratio of the transverse electric field to the coercive electric field as well as the direction of the applied electric field. Under small-scale conditions, the crack-tip mode Ⅰ and Ⅱ stress intensity factors induced by ferroelectric domain switching are numerically obtained. The crack kinking in ferroelectric ceramics is also discussed.