• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.9-12
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• 2004

Presented is a preliminary design concept of the carbon-glass hybrid composite rebars for the application in the construction field. A glass fiber rod with indentation is used for the core of the rebar. Carbon fibers are placed over the glass core by pultrusion. To increase the mechanical locking force and bonding surface, carbon filament windings are added in the hoop direction over the carbon face. Finite element analysis and test were conducted to evaluate the effective stiffness and strength of the rods. The results show that the effective axial stiffness of the rebar with indentation are about $50\%$ of the straight rebar.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1526-1527
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• 2007

This paper presents the design, fabrication and experimental results of an electromagnetic microvalve for drug delivery systems. The microvalve consists of two silicon substrates with a silicone rubber diaphragm and a flow channel, a PDMS layer, and an electromagnetic actuator. Each substrate is fabricated by using the silicon wet etch, SU-8 mold process and $O_2$ plasma bonding.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.479-483
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• 2006

As high-definition television(HDTV) broadcasting were generalized, there have been many researches and developments about large storage capacity and fast data transfer rate in optical disk drives(ODD). Pickup actuators must have high flexible mode frequencies and gain margins. Flexible modes are caused by the flexibility of moving parts in the actuator and a servo bandwidth is limited by them. As a result, the system becomes unstable for high-speed operations in high density reading and recording. In this paper, we suggest improved modeling method that considers the bonding layer. And, flexible mode frequency of actuator is improved by Design of Experiment of lens holder. Magnet circuit is designed considering the relation with moving part. Through improving yoke design, the magnetic flux is changed and DC tilt is reduced. Consequently, we designed actuator which has high flexible mode frequency and gain margins.

• Design & Manufacturing
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• v.14 no.1
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• pp.15-21
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• 2020

Smart systems in different application areas such as automotive, medical and consumer electronics require a novel manufacturing method of electronic, optical and mechanical functions into products. Traditional methods including mechanical assembly, bonding of plastic and electronic circuit cause the problems in large size of products and complicated manufacturing processes. In this study, thermoforming and film insert molding were applied to fabricate a dome shaped plastic part embedded with electronic circuits. The deformation of patterns printed on PET film was predicted by thermoforming simulation using T-SIM, and the results were compared with those by experiment. In order to decrease spring-back after thermoforming, the Taguchi method of design of experiment was used. Through ANOVA analysis, it was found that mold temperature was the most dominant parameter for spring-back. By using flow analysis, gate design was performed to decrease injection pressure. During film insert molding, the wash-out of ink printed on film occurred for Polycarbonate. When the resin was changed to PMMA, the wash-out disappeared due to low melt temperature.

• Journal of the Korean Society of Tobacco Science
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• v.32 no.1
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• pp.12-18
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• 2010

The parcel wrapper for cigarettes has been used as the package and media materials for protection and design of product brands. The design of parcel wrapper has been contributed to the delivery of brand image and motivated consumer to purchase the brand. Therefore, the properties of parcel wrapper have been paid attention to highlight the design image, and increasing opacity of media materials has been one of the effective ways to obtain clear design on the paper surface. This study was carried out to improve the opacity of parcel wrapper for cigarettes. The effects of pulp composition and inorganic fillers in the furnish on the optical and mechanical properties were investigated. The use of hardwood in the stock preparation gave the increased opacity of paper than that of softwood. The application of higher refractive indices of fillers was effective to improve opacity. Brightness, tensile strength and stiffness were affected by the retained filler amount on the paper. Increase of filler contents decrease the tensile strength and stiffness due to the lesser bonding ability of fibers.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.754-758
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• 2002

According to the enlargement of production facilities and structures, the requirements of high-capacity load cells are increased for monitoring the process conditions in many fields. Generally, however, the accuracy of the column-type high-capacity load cells is not enough due to the geometric nonlinearity. It is supposed to result from the fact that the whole spring element is under high-level stress for the uniform strain field. In this paper, a new shape of spring element is developed which utilizes the stress concentration. As a design criterion, an object function which quantifies the degree of nonlinearity is defined and optimized by use of response surface modeling. As a result, the weight of the spring element is reduced shout 50% in comparison to the conventional shape. The bonding positions of stain gages are found. which show theoretically zero geometrical nonlinearity, while the ratio of overload protection is reduced from 130% to 125% Also it is shown that the response surface method is very efficient in the optimization approach by use of FEM.

• Transactions of the Society of Information Storage Systems
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• v.2 no.4
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• pp.240-244
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• 2006

As high-definition television(HDTV) broadcasting becoming more generalized, there have been many researches and developments about a large storage capacity and a fast data transfer rate in optical disk drives (ODD). Pickup actuators must have high flexible mode frequencies and large gain margins. Flexible modes are caused by the flexibility of moving parts in the actuator and a servo bandwidth is limited by them. As a result, the system becomes unstable for high-speed operations in high density reading and recording. In this paper, we suggest improved modeling method in considering of the bonding layer. And, the flexible mode frequency of actuator is improved by Design of Experiments of lens holder. The Magnet circuit is designed considering the relation with the moving part. Through improving the yoke design, the magnetic flux is changed and the DC tilt is reduced. Consequently, we designed an actuator which has a high flexible mode frequency and a large gain margins.

• Structural Engineering and Mechanics
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• v.28 no.6
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• pp.677-694
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• 2008

A vibration power minimization model is developed, based on the mobility matrix method, for a vibration isolation system consisting of a vibrating source placed on an elastic support structure through multiple resilient mounts. This model is applied to investigate the design optimization of an X-Y motion stage-based vibration isolation system used in semiconductor wire-bonding equipment. By varying the stiffness coefficients of the resilient mounts while constraining the dynamic displacement amplitudes of the X-Y motion stage, the total power flow from the X-Y motion stage (the vibrating source) to the equipment table (the elastic support structure) is minimized at each frequency interval in the concerned frequency range for different stiffnesses of the equipment table. The results show that when the equipment table is relatively flexible, the optimal design based on the proposed vibration power inimization model gives significantly little power flow than that obtained using a conventional vibration force minimization model at some critical frequencies. When the equipment table is rigid enough, both models provide almost the same predictions on the total power flow.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.382-386
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• 2011

It has been required to develop a defect detection system to perform defect detection capabilities after the bonding process in the production of RFID tags. However, we are difficult to design a system with understanding the characteristics of RFID tags and design concepts. Also we are difficult to modify even minor changes in features. In this paper, we design the defect RFID detection system using UML and object-oriented design techniques. We suggest the method for apply the UML Diagram to LabVIEW OOP and the technique for redesign the effect detection system's changes.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.12
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• pp.14-20
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• 2020

Currently, the automotive market is intensively researching eco-friendly vehicles such as EV vehicles and hydrogen vehicles. Further, research and developments for the future markets such as autonomous vehicles and the connective cars are coped up continuously along with the rising fuel economy regulations and the emission regulations. In this development, various sensors, batteries, and control devices are fused in order to decrease the weight of the vehicle. Moreover, since the fuel economy regulation is an issue, research on the weight reduction of body parts is underway. Therefore, in this work, a study is conducted to obtain the optimal design of the Dash part that separates the engine room and the passenger seat of the vehicle body by combining lightweight materials with high rigidity materials. The optimal design was obtained using the Finite Element Analysis. Further, AL5083 was used as the lightweight material and ASBC1470 was used for high strength materials. The parts made with this combination of materials had strength equivalent to that of the existing steel and the weight was reduced by 10%.