• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.10a
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• pp.451-455
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• 1997

This paper presents vibration mode control of a smart plate containing electro-rheological (ER) fluid between elastic face layers. Following the composition of a silicone oil-based ER fluid, the ER fluid-embedded plate partitioned into four sections is constructed. Then, an extensive modal test is experimentally carried out to identify field-dependent modal parameters such as mode shapes and natural frequencies of the structure with respect to different are subjected to electric fields. The distilled results from the experiment exhibit that the ER fluid can be effectively employed in a continuous fashion to tune modal behaviors of the distributed parameter systems,

• Archives of Plastic Surgery
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• v.33 no.2
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• pp.219-224
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• 2006

Augmentation rhinoplasty is one of the most popular aesthetic procedure in Asians. Numerous alloplastic implants have been used until now, but no accurate comparative analysis about the implant materials has been reported yet. This study in animal model was designed to determine the safety and effectiveness of various implant materials in augmentation rhinoplasty. The $15{\times}15{\times}2mm$ sized square shaped plate of $Gore-Tex^{(R)}$, silicone rubber, and $15{\times}15{\times}1.5mm$ sized $Medpor^{(R)}$ were implanted under panniculus carnosus of the abdomen wall of rat. And tissue specimens including the implant and surrounding soft tissue were obtained by en bloc excision in 6 months after implantation. The implants were estimated in weight and volume, and also the specimens were examined grossly and microscopically. The results revealed that increase of average weight 26.9%, decrease of average volume 55.4% in $Gore-Tex^{(R)}$ implant, increase of each average weight and volume 62.6%, 8.7% in $Medpor^{(R)}$ implant and very slight increase of both average weight and volume 4.7%, 1.1% in silicone rubber implant. Grossly, the $Gore-Tex^{(R)}$ was deformed, $Medpor^{(R)}$ was strongly adherent to surrounding soft tissue and the silicone rubber was well encapsulated and easily peeled off. Microscopically, silicone rubber showed foreign body reaction slightly and there were no inflammatory responses in all alloplastic implants. In our study, silicone rubber showed very proper alloplastic features for augmentation rhinoplasty due to causing no inflammatory response, no physical change, and no deformity.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.3
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• pp.574-592
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• 1996

This study investigated the time-dependent dimensional changes of elastomeric impression materials using holographic interferometry. Six commercial impression materials, Permlastic(polysulfide), Xantopren VL (condensation silicone), low and medium viscosity of Exafine, Provil (addition silicone), and Impregum(polyether), were selected. Steel plate was used as custom tray, and each impression specimen was 20 mm in width, 15 mm in length and 3 mm in thickness. Each impression material was evaluated at 30 minutes, 1, 2, 4, 6, 8 and 12 hours after setting using real-time holography. The results were as follow : 1. Xantopren VL and Permlastic showed relatively severe and continuous dimensional changes after setting. Low viscosity of Exafine, Provil, Impregum showed relatively slight dimensional changes with function of time and medium viscosity of Exafine showed almost no dimensional change from 2 hours after setting to 6 hours. 2. On initial dimensional changes within 1 hour, the amount of change in low viscosity of Exafine was the least and Xantopren VL was the largest. 3. On dimensional changes at 4 hours after setting, the amount of change in medium viscosity of Exafine was the least and tile change of Xantopren VL was the largest. 4. In overall dimensional stability during 12 hours, medium viscosity of Exafine was the most stable and Xantopren VL and Permlastic were least stable.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.6
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• pp.176-183
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• 2002

Plasma Display Panel(PDP) is a type of flat panel display utilizing the light emission produced by gas discharge. Barrier Ribs of PDP separating each sub-pixel prevents optical and electrical crosstalks from adjacent sub-pixels. The mold for forming the barrier ribs has been newly researched to overcome the disadvantages of conventional manufacturing processes such as screen printing, sand-blasting and photosensitive glass methods. The mold for PDP barrier ribs have stripes of micro grooves transferring glass-material wall. In this paper , Stripes of grooves of which width 48$\mu$m, depth 124$\mu$m , pitch 274$\mu$m was acquired by machining of single crystal silicon with dicing saw blade. Maximum roughness of the bottom of the grooves was 59.6 nm Ra in grooving Si. Barrier ribs were farmed with silicone rubber mold, which is transferred from grooved Si forming hard mold. Silicone rubber mold has the elasticity, which enable to accommodate the waviness of lower glass plate of PDP. The methods assisted by the microwave and UV was adopted for reducing the forming time of glass paste.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.5
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• pp.171-176
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• 2001

Plasma Display Panel(PDP) is a type of flat panel display utilizing the light emission produced by gas discharge. Barrier Ribs of PDP separating each sub-pixel prevents optical and electrical crosstalks from adjacent sub-pixels. Mold for forming barrier ribs has been newly researched to overcome the disadvantages of conventional manufacturing process such as screen printing, sand-blasting and photosensitive glass methods. Mold for PDP barrier ribs have stripes of micro grooves transferring glass-material wall. In this paper, Stripes of grooves of which width 48${\mu}{\textrm}{m}$ and 270${\mu}{\textrm}{m}$, depth 124${\mu}{\textrm}{m}$, pitch 274${\mu}{\textrm}{m}$ was acquired by machining hard and brittle materials of WC, Silicon, Alumina with dicing saw blade. Maximum roughness of the bottom and sidewall of the grooves was respectively 120nm, 287nm in grooving WC. Maximum tilt angle caused by difference between upper-most width and lower-most width was 2$^{\circ}$. Maximum Radius of bottom curvatures was 7.75${\mu}{\textrm}{m}$. This results satisfies the specification for barrier ribs of 50 inch XGA PDP if the groove form of mold was fully transferred to the barrier ribs. Barrier ribs were formed with Silicone rubber mold, which is transferred from grooved hard materials. Silicone rubber mold has elasticity accommodating the waveness of lower glass plate of PDP.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.6
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• pp.389-395
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• 2009

A specially designed flat plate was mounted vertically over the axial line in the wind tunnel of the Pusan National University. Strain balances were mounted in the trailing part of the plate to measure the skin friction drag over removable insertions of $0.55{\times}0.25m^2$ size. A set of the insertions was designed and manufactured: 3 mm thick polished metal surface and three compliant surfaces. The compliant surfaces were manufactured of a silicone rubber Silastic$^{(R)}$ S2 (Dow Corning company). To modify the viscoelastic properties of the rubber, its composition was varied: 90% rubber + 10% catalyst (standard), 92.5% + 7.5% (weak), 85% + 15% (strong). Modulus of elasticity and the loss factor were measured accurately for these materials in the frequency range from 40 Hz to 3 kHz. The aging of the materials (variation of their properties) for the period of one year was documented as well. Along with the drag measurement using the strain balance, velocity and pressure were measured for different coating. The strong compliant coating achieved 5% drag reduction within a velocity range $20{\sim}40$ m/s while standard and weak coatings increased drag reduction.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.5
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• pp.1-8
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• 2013

Roll-based, nanoimprint lithography (Roll-NIL) is one effective method to produce large-area nanopatterns continuously. Systems and processes for Roll-NIL have been developed and studied for more than 15 years. Since the shapes of the stamp and the substrate for Roll-NIL can be plates, films, and rolls, there exist many concepts to design and implement roll-NIL systems. Combinations and variations of contact-methods for variously shaped stamps and substrates are analyzed in this paper. The contact-area can be changed by using soft materials such as polydimethylsiloxane (PDMS) or silicone rubber. Ultraviolet (UV) sources appropriate for the roll-to-plate or roll-to-roll process are introduced. Finally, two roll-to-plate nanoimprint lithography systems are illustrated.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.6
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• pp.52-64
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• 1996

This paper presents an active position control of a single-rod cylinder system featuring an electrorheological(ER) fluid-based valve. The ER fluid consisting of silicone oil and chemically treated particles is firstly composed and its Bingham property is tested as a function of imposed electric field. A multi-channel plate type of ER valve is then designed and manufactured on the basis of the field-dependent Bingham model. Performance test of the ER valve is undertaken by evaluating pressure drop with respect to the number of electrode as well as the intensity of the electric field. Subsequently, the ER valve-cylinder system is constructed and its governing equation of motion is derived. A neural control scheme for position control of the cylinder is formulated by incorporating proportional-plus-derivative(PD) controller and implemented. Experimental results of both regulating and tracking control responses are presented in order to demonstrate the efficacy of the proposed ER valve-cylinder control system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.246-251
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• 2003

This paper presents an experimental study on the energy dissipation characteristics of viscous damping wall (VDW). VDW is consisted of a plate floating in a thin case made of steel plated filled with highly viscous silicone oil. Because VDW demonstrates both viscous damping and stiffness characteristics, the viscous resisting force can be expressed as the sum of velocity dependant viscous damping force and displacement dependant restoring force. The viscous resisting force and energy absorbing capacity can be easily adjusted by changing three factors, i.e. viscosity of the fluid, gap distance and area of the wall plates. VDW was tested using a series of harmonic (sinusoidal) displacement history having different frequency and amplitude and the force-displacement relationship was recorded. The relationship between dissipated energy with three factors and the influence of exciting frequency on resisting force were Investigated

• Computers and Concrete
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• v.26 no.1
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• pp.21-30
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• 2020

Buckling and post-buckling behaviors of geometrically imperfect annular sector plates made from nanoparticle reinforced composites have been investigated. Two types of nanoparticles are considered including graphene oxide powders (GOPs) and silicone oxide (SiO₂). Nanoparticles are considered to have uniform and functionally graded distributions within the matrix and the material properties are derived using Halpin-Tsai procedure. Annular sector plate is formulated based upon thin shell theory considering geometric nonlinearity and imperfectness. After solving the governing equations via Galerkin's technique, it is showed that the post-buckling curves of annular sector plates rely on the geometric imperfection, nanoparticle type, amount of nanoparticles, sector inner/outer radius and sector open angle.