• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.148-153
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• 1998

In order to control thermal deformation of machine origin of machine tools due to internal and external heat sources, the real-time compensation system has been developed. First, GMDH models were constructed to estimate thermal deformation of machine origin for a vertical machining center through the measurement of deformation data and temperature data of specific points on the machine tool. Thermocouples and gap sensors are used respectively for measurement. These models are nonlinear equations with high-order polynomials and implemented in a multilayered perceptron type network structure. Secondly, work origin shift method were developed by implementing digital I/O interface board between CNC controller and IBM-PC. The work origin shift method is to shift the work origin by the compensation amounts which is calculated by pre-established GMDH model. From the experimental result, thermal deformation of machine origin was reduced to below $\pm$5${\mu}{\textrm}{m}$.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.367.1-367
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• 2002

Recently, the noise environmental issue in compound residential areas like apartments becomes a very critical factor fer the building designers. In order to satisfy the customer need to live in a quiet environment, several interior structures for buildings are being introduced. The multi-layered composite floor plate is one of them. This structure is designed to prevent the noise generated by an object collision. (omitted)

• Journal of the Korean Ceramic Society
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• v.48 no.2
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• pp.147-151
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• 2011

In this study, we prepared graphene by using the modified Hummers-Offeman method and then introduced the metals (Pt, Pd and Fe) for dispersion on the surface of the graphene for synthesis of metal-graphene composites. The characterization of the prepared graphene and metal-graphene composites was performed by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and transmission electron microscopy (TEM). According to the results, it can be observed that the prepared graphene consists of thin stacked flakes of shapes having a well-defined multilayered structure at the edge. And the metal particles are dispersed uniformly on the surface of the graphene with an average particle size of 20 nm.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.131-133
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• 2007

The aninmatronics is a technique for representing animals or new kinds of living things like aliens with robots and machines. The motions of cameras and objects can be made complicatedly and finely by using various kinds of actuators. But it needs so many actuators to make complicated motions. To handle difficulty to synchronize actuators and to make a database of motions of actuators, the animatronics system that has layered structure with CAN is proposed. The system is devided by a three layers-PC, microcontrollers and actuators so that the problems which arise from using too many actuators such as management of data and time delay of processing data can be handled.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.184.1-184.1
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• 2014

Nanostructures on Graphene surface receive highly attraction for many applications ranging from sensing technologies to molecular electronics. Recently J. Jasuja et al. reported the electrical property tailoring and Raman enhancement by the implantation and growth of dendritic gold nanostructures on graphene derivatives [ACSNANO, 3, 2358, 2013] Here, we introduced Si vapor on the graphen to induce the nanostructure. The surface property change of graphene by controlling the amount of Si and the thickness of graphene were investigated using high resolution photoemission spectroscopy (HRPES), and atomic force microscopy (AFM). The Si nanostructures on graphene show the thickness dependency of graphene, and the size of Si nano-structure reached to 7 nm and 15 nm on the mono and the multilayered graphene after $30{\AA}$ Si evaporation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.8
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• pp.681-687
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• 2000

Magnetic Characteristics of an InSb hall device of multilayered structures were investigated. For the measurement of electrical properties of the hall device InSb thin films fabricated with series and parallel multilayers wee evaporated. Hall coefficient hall mobility carrier density and hall voltage were measured as a function of the intensity of magnetic field. We found that the XRD analysis of InSb thin film showed good properties at 20$0^{\circ}C$ 60 minutes. Resistance of ohmic contact was increased linearly due to increasing current. Hall voltages at 0.01 T showed 5$\times$10$^{-4}$ [V] and $1.5\times$10$^{-3}$ [V]. Some of device fabrication technique and analysis of magnetic characteristics were discussed.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2884-2888
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• 2010

Two red fluorescent DCJTB derivatives (Red 1 and 2) based on modified pyrans were synthesized and their electroluminescent properties were investigated. Multilayered OLEDs were fabricated with the device structure of ITO/NPB (40 nm)/Red 1, 2 or DCJTB (0.5 or 1%): $Alq_3$ (20 nm)/$Alq_3$ (40 nm)/Liq (2 nm)/Al. All devices exhibited efficient red emissions. In particular, a device containing emitter Red 2 as a dopant in the emitting layer, the maximum luminance was $8737\;cd/m^2$ at 12.0 V, the luminous and power efficiencies were 2.31 cd/A and 1.25 lm/W at $20\;mA/cm^2$, respectively. The peak wavelength of the electroluminescence was 638 nm with the CIE (x,y) coordinates of (0.63, 0.36) at 7.0 V.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.791-793
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• 2009

We have developed novel small molecular materials for solution phosphorescent OLEDs having multilayered device structures. These novel materials are applied as an interlayer which is between a buffer layer (or hole injection layer) and an emitting layer to improve the luminance efficiency of solution green phosphorescent OLEDs. In order to form stable double layers by spincoating process, we take the advantage of solubility differences of interlayer materials and emitting materials. Using CIM3 as an interlayer, we have attained the best luminance efficiency, 36 cd/A at a given constant of 2000cd/$m^2$ in the structure of ITO/PEDOT:PSS/CIM3/CIM6:Ir(mppy)$_3$/BAlq/Alq$_3$/LiF/Al.

• Structural Engineering and Mechanics
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• v.56 no.6
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• pp.1003-1020
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• 2015

In this study, free vibration analysis of an edge cracked multilayered symmetric sandwich beams made of functionally graded materials are investigated. Modelling of the cracked structure is based on the linear elastic fracture mechanics theory. Material properties of the functionally graded beams change in the thickness direction according to the power and exponential laws. To represent functionally graded symmetric sandwich beams more realistic, fifty layered beam is considered. Composition of each layer is different although each layer is isotropic and homogeneous. The considered problem is carried out within the Timoshenko first order shear deformation beam theory by using finite element method. A MATLAB code developed to calculate natural frequencies for clamped and simply supported conditions. The obtained results are compared with published studies and excellent agreement is observed. In the study, the effects of crack location, depth of the crack, power law index and slenderness ratio on the natural frequencies are investigated.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.5
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• pp.869-874
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• 2010

A research for the optimal design of microwave absorbing material featuring for the broadband has been conducted to apply to warship. A multilayered structure was suggested using wave absorbing layers and resistance layer to perform high performance in broadband frequencies. For the optimization of the wave absorbing characteristics, the thickness and permittivities of the absorbing layers as well as the surface resistance of the resistant layer were determined using genetic algorithm. The data base of permittivities related to the density of the dielectric materials and loss materials was obtained by the experiments for the dielectric constants of the absorbing layers, furthermore, the results were numerically expressed and used for the optimization.