• Korean Journal of Computational Design and Engineering
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• v.18 no.5
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• pp.309-320
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• 2013

Augmented reality (AR) is considered to be an excellent user interface to a 3D information space embedded within physical reality. For this reason, it has been applied to various applications such as design, medical service, interaction, and collaboration. However, there is no formal way of analyzing the research trend and evolution of augmented reality. This paper identifies the research trend and change in augmented reality (AR) via co-citation analysis. The co-citation analysis provides how the AR research has evolved, who are main contributors, and which papers suggest essential and influencing impact. To systematically analyze the cocitation, we have retrieved 1,145 papers from the Web of Science and applied a scientomertric analysis using CiteSpace. Based on the co-citation analysis of authors and documents, it is possible to analyze the evolution of augmented reality, key authors and papers, and breakthroughs. We have also compared the proposed approach with survey papers written by experts so that the result of the co-citation analysis can compromise the qualitative result done by experts, and thus it can provide a different view and insight for visualizing the research on augmented reality.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.5
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• pp.479-488
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• 2003

Dual-band microstrip antenna is designed for industrial-scientific-medical(ISM) band of 2.4 GHz and 5.8 GHz using finite-difference time-domain method(FDTD). Cross patch 130 by aperture in the ground plane of microstrip line is proposed as radiation element of antenna which is 2 rectangular patch is overlapped. To design antenna, change of input impedance is examined by length change of aperture and stub. And center frequency and - 10 dB bandwidth are investigated by change of length and width in radiation element. Measured result about reflection loss confirm that agree well with simulation results of FDTD and IE3D. And 3 dB beam width, front to back ratio and maximum gain is presented by measuring radiation pattern of antenna in frequency 2.43 GHz and 5.79 GHz.

• Journal of electromagnetic engineering and science
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• v.13 no.1
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• pp.28-33
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• 2013

This paper proposes a miniaturized high-isolation diversity antenna for wearable wireless body area network (WBAN) applications. An inverted-F type radiating element is used to reduce the overall dimension of the proposed antenna to $30mm{\times}30mm{\times}2.5mm$. The antenna performance on the human body phantom is analyzed through simulation and the performance of the fabricated antenna is verified by comparing the measured data with that of the simulation when the antenna is placed on a semi-solid flat phantom with equivalent electrical properties of a human body. The fabricated antenna has a 10 dB return loss bandwidth over the Industrial Scientific Medical (ISM) band from 2.35 GHz to 2.71 GHz and isolation is higher than 28 dB at 2.45 GHz. The measured peak gain of antenna elements # 1 and # 2 is -0.43 dBi and -0.54 dBi, respectively. Performance parameters are analyzed, including envelope correlation coefficient (ECC), mean effective gain (MEG), and the MEG ratio. In addition, the specific absorption ratio (SAR) distributions of the proposed antenna are measured for consideration in use.

• Journal of information and communication convergence engineering
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• v.11 no.1
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• pp.45-49
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• 2013

A compact radio frequency (RF) bandpass filter (BPF) in low temperature co-fired ceramic (LTCC) is suggested for WiMAX applications. The center frequency ($f_0$) of the BPF is 5.5 GHz and its pass band or 3-dB bandwidth is 700 MHz to cover all the three major bands, low and middle unlicensed national information infrastructure (U-NII; 5.15-5.35 GHz), World Radiocommunication Conference (5.47-5.725 GHz), and upper U-NII/industrial, scientific, and medical (ISM) (5.725-5.85 GHz), for the WiMAX frequency band. A lumped circuit element design-the 5th order capacitively coupled Chebyshev BPF topology-is adopted. In order to design a compact RF BPF, a very thin ($43.18{\mu}m$) ceramic layer is used in LTCC substrate. An interdigital BPF is also designed in silicon substrate to compare the size and performance of the lumped circuit element BPF. Due to the high relative dielectric constant (${\varepsilon}_r$ = 11.9) of the silicon substrate, the quarter-wavelength resonator of the interdigital BPF can be reduced. In comparison to the 5th order interdigital BPF at $f_0$ = 5.5 GHz, the lumped element design is 24% smaller in volume and has 17 and 7 dB better attenuation characteristics at $f_0{\pm}0.75$ GHz.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.1285-1288
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• 2002

Bluetooth wireless technology is a publicly available specification proposed for Radio Frequency (RF) communication for short-range and point-to- multipoint voice and data transfer. It operates in the 2.4GHz ISM(Industrial, Scientific and Medical) band and offers the potential for low-cost, broadband wireless access for various mobile and portable devices at range of about 10 meters. In this paper, we describe the structure and the test results of the bluetooth baseband module we have developed. This module was developed based on IP reuse. So Interface of each module such as link controller UART, and audio CODEC is designed based on ARM7 comfortable processor. We also considered various interfaces of related external chips. The fully synthesizable baseband module was fabricated in a $0.25{\mu}m$ CMOS technology occupying $2.79{\times}2.8mm^2$ area including the ARM TDMI processor. And a FPGA implementation of this module is tested for file and bit-stream transfers between PCs.

• Journal of Navigation and Port Research
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• v.28 no.1
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• pp.31-36
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• 2004

In this paper, the characteristics of an inverted-F antenna for the 2.4GHz(ISM) Bluetooth system have been analysed in terms of the variation of design parameters. The antenna can be integrated on printed circuit board, and the characteristics in terms of the variation of the gap between feed line and shorting stub, gap between antenna's leg and ground plane, antenna leg's width, substrate's height and dielectric constant are analysed By using these characterization plot of design parameter, the tuning techniques are proposed to design optimum antenna. The designed antenna has 6.3%(150MHz) frequency bandwidth for VSWR under 1.5, and 3dBi gain.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.1
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• pp.123-126
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• 2002

More than three hundred million men in the world are suffering from erectile dysfunction. Korean ancient medical records say that the unmated male silkworm moth is effective in strengthening men's vitality, but no scientific examination has preyed its clinical efficacy. Currently, silkworm moths are not allowed for food-stuff. Thus, we selected silkworm of 14-days-after-metamorphosis, at which external morphology possesses that of pupae, but internal component is that of moths. To obtain the reliable source of unmated male silkworm moth, we used the sex-limited silkworm breed with larval marking. The body marker allows casual separation of sex during larval period, preventing mating right after emergence from cocoon. Using the extract prepared with the pupae of 14-days-after-metamorphosis, we investigated the tonic effect of the extract on the rat fed the extract for three weeks. The results showed that the testosterone levels in serum increased maximum by 19%, that of testicle increased maximum by 200%, and athletic endurance of the rats rose by 6%, suggesting positive tonic effect of the pupae prepared at the stage of 14 days after metamorphosis.

• Journal of the Korea Safety Management & Science
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• v.12 no.2
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• pp.49-54
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• 2010

WMSD occurs by accumulating the visible position and movements. Therefore, it is easier to prevent WMSD from occurring than other diseases when each employee is aware of the factors which cause WMSD. Hence, We need to develop exercise remedy, which can be done without using any exercise equipments and regardless places. The exercise prescription for those for LBP was to do the upper body exercise remedy twice in the morning and another twice in the afternoon and the spinal exercise remedy and the lower body exercise remedy once in the morning and once in the afternoon. We measured their maximum muscular strength every second week using a fitness machine so that we could compare the differences of the muscular strength of the test group and the comparison group. Therefore this research presented the fact that the exercise remedy is effective to prevent and cure LBP through a scientific test. And it confirmed that the exercise remedy by the Ergonomic exercise prescriptions is effective on LBP.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.100-103
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• 2003

In this paper, the characteristics of an inverted-F antenna for the 2.4GHz local wireless communication system have been analysed in terms of the variation of design parameters. The antenna can be integrated on printed circuit board, and the characteristics in terms of the variation of the gap between feed line and shorting stub, gap between antenna's leg and ground plane, antenna leg's width, substrate's height and dielectric constant are analysed. By using these characterization plot of design parameter, the tuning techniques are proposed to design optimum antenna. The designed antenna has 6.4% frequency bandwidth for VSWR under 1.5 and 3dB gain.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.6
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• pp.1103-1108
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• 2003

In this paper, the characteristics of an inverted-F antenna for the 2.4GHz local wireless communication system have been analysed in terms of the variation of design parameters. The antenna can be integrated on printed circuit board, and the characteristics in terms of the variation of the gap between feed line and shorting stub, gap between antenna's leg and ground plane, antenna leg's width, substrate's height and dielectric constant are analysed. By using these characterization plot of design parameter, the tuning techniques are proposed to design optimum antenna. The designed antenna has 6.4 % frequency bandwidth for VSWR under 1.5 and 3dB gain.