• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.795-798
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• 2003

In this paper, a CMOS Tx RF/IF single chip for PCS applications is designed. The chip consumes 84mA from a 3V supply and the layout area without pads is 1.6mm$\times$3.5mm. Simulation results show that the RF block composed of a SSB RF block and a driver amplifier exhibits a gain of 14.8dB and an OIP3 of 7dBm. The image and carrier suppressions are 35dBc and 31dBc, respectively. The designed circuits are under fabrication using a 0.35${\mu}{\textrm}{m}$ CMOS process.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.77-81
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• 2002

This paper demonstrates a CMOS downconversion mixer for 2.4GHz ISM band applications. The mixer, implemented in a 0.18um CMOS process, is based on the CMOS Gilbert Cell mixer, With a 2.5GHz local oscillator and a 2.45GHz RF input, the measurement results exhibit power conversion gam of -6dB, IIP3 of -6dBm, input $P_{-1dB}$ of -15 dBm, and power dissipation in mixer core of 2.7 mW with 0㏈m LO power and 1.8V supply voltage.

• Smart Media Journal
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• v.1 no.1
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• pp.64-71
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• 2012

Computer graphics applications such as virtual reality, games, animation begin from 3D modeling. The technology of 3D modeling and deformation has become an active research field in the past few decades from the combination of basic 3D primitives to the realistic modeling and deformation algorithm. In this paper, we introduce recent trends in 3D human modeling and deformation technology.

• Journal of Advanced Navigation Technology
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• v.10 no.4
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• pp.326-332
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• 2006

In this study, the antenna was proposed for the omni-directional characteristic in horizontal plane. Therefore we proposed $1{\times}4$ microstrip patch array on cylindrical surface for studying microstrip patch antennas. This antenna is designed for 2.45GHz ISM band and applications. This antenna can be applied to the base station of wireless microphone and access point of wireless LAN. The length and width of the patch antenna and the width of the feed line were calculated by using the theory of microstrip patch antenna, by using the both the 2.5D and 3D EM simulators the optimized antenna characteristics are obtained. From result of measured, antenna's impedance of coaxial waveguide port was 51.915-j3.688 ${\Omega}$, the return loss was -31dB and VSWR was 1.081.

• Journal of electromagnetic engineering and science
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• v.14 no.3
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• pp.306-313
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• 2014

A Fabry-Perot resonator cavity antenna for Ku-band application is presented in this paper. The Fabry-Perot cavity is formed by a ground plane and a frequency selective surface (FSS) made of a circular hole array. The cavity resonance is excited by a single-feed microstrip patch located inside the cavity. The measured results show that the proposed antenna has an impedance bandwidth of approximately 13% ($VSWR{\leq}2$) and a 3-dB gain bandwidth of approximately 7%. The antenna produces a maximum gain of 18.5 dBi and good radiation patterns over the entire 3-dB gain bandwidth. The antenna's very thin profile, high directivity, and single excitation feed make it promising for use in wireless and satellite communication applications in a Ku-band frequency.

• Journal of the Korea Computer Graphics Society
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• v.13 no.4
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• pp.21-27
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• 2007

The 3D Delaunay triangulation is the most widely used method for the mesh creation via the triangulation of a 3D point cloud. However, the method involves a heavy computational cost and, hence, in many interactive applications, it is not appropriate for surface triangulation. In this paper, we propose an efficient triangulation method to create a surface mesh from a 3D point cloud. We divide a set of object points into multiple subsets and apply the 2D Delaunay triangulation to each subset. A given 3D point cloud is cut into slices with respect to the OBB(Oriented Bounding Box) of the point set. The 2D Delaunay triangulation is applied to each subset producing a partial triangulation. The sum of the partial triangulations constitutes the global mesh. As a postprocessing process, we eliminate false edges introduced in the split steps of the triangulation and improve the results. The proposed method can be effectively applied to various image-based modeling applications.

• Journal of Advanced Navigation Technology
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• v.8 no.2
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• pp.91-97
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• 2004

This paper presents the development of InGaAsP multiple quantum well asymmetric Fabry-Perot modulators(AFPM), which have a vertical structure and high performance and describes measurements of devices operating at 10GHz for next generation broadband wireless communication applications such as picocell systems. Advantages of the AFPM include low drive voltage, which is less than -2V, and -3dB coupling loss, good flatness of the frequency response and simple fiber alignment. A simple link demonstration has been introduced, resulting in 92dB/Hz spurious free dynamic range and 40dB inter-modulation distortion. This modulator could be use for broadband radio over fiber systems such as picocell and multiple RF links.

• Applied Chemistry for Engineering
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• v.26 no.5
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• pp.521-525
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• 2015

Graphene-based electrode materials have been widely explored for supercapacitor applications due to their unique two-dimensional structure and properties. In particular, Three-dimensional (3D) graphene materials are of great importance for preparing electrode materials because they can provide large surface area, efficient and rapid electron and ion transfer, and mechanical stability. Recently, a number of 3D hybrid architecture of graphene/metal oxides have been developed to increase simultaneously energy and power densities of supercapacitors. This review presents the recent progress of 3D nanocomposites based on graphene and metal oxides. Preparation methods and structures of these 3D nanocomposites and their great potential in supercapacitor applications have been summarized.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1311-1313
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• 2006

Stereoscopic/autostereoscopic systems have been developed in order to express true 3D images, but have never had great success in the practical use. In order to apply 3D display to promising applications such as advertisements and games, we've developed a 42" 2D/3D switchable display. It has characteristics that don't require special glasses for 3D images, use multi-view technology for improving 3D viewing characteristics, and has a 2D/3D switching function to express dynamic 3D contents as well as conventional 2D contents.

• ETRI Journal
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• v.36 no.2
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• pp.242-252
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• 2014

Since July of 2012, the 3D video extension of H.264/AVC has been under development to support the multi-view video plus depth format. In 3D video applications such as multi-view and free-view point applications, synthesized views are generated using coded texture video and coded depth video. Such synthesized views can be distorted by quantization noise and inaccuracy of 3D wrapping positions, thus it is important to improve their quality where possible. To achieve this, the relationship among the depth video, texture video, and synthesized view is investigated herein. Based on this investigation, an edge noise suppression filtering process to preserve the edges of the depth video and a method based on a total variation approach to maximum a posteriori probability estimates for reducing the quantization noise of the coded texture video. The experiment results show that the proposed methods improve the peak signal-to-noise ratio and visual quality of a synthesized view compared to a synthesized view without post processing methods.