• Journal of Korea Society of Industrial Information Systems
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• v.12 no.4
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• pp.119-125
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• 2007

In this paper, a miniaturized PCB-integrated antenna is proposed for bluetooth applications. The proposed antenna is a modified form of the printed inverted F antenna where the size reduction is achieved by employing the meander strip for the resonant length part of the radiator. The antenna dimension is optimized using the commercial electromagnetic software MWSTM. The designed antenna is fabricated by the standard photo-etching technique and its performance is measured. The fabricated antenna shows a bandwidth of 125MHz centered at 2.45GHz and a gail of -0.23dBi. The size of the proposed antenna is $9.65mm{\times}5.95mm$ corresponding to the 55 percent of the area of the existing printed inverted F antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.6 s.121
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• pp.674-679
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• 2007

In this paper, the size of the dual-mode microstrip ring resonator is reduced by adding four open stubs, and bandpass filters having 100 MHz bandwidth are designed at the center frequency of 2 GHz. The size of the ring resonator can be controlled by varying the capacitance of the stubs, and the bandpass filter can be designed in two cases, which are two combinations of the stubs. Two bandpass filters are designed and fabricated by using the two-stage bandpass filter circuit model of the proposed structure, and the measured results show good agreement with the simulated results.

• Journal of the Korean GEO-environmental Society
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• v.11 no.12
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• pp.37-45
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• 2010

The particle size of microfine cement(MC) is so small that it can be injected into silt layer. But the more particle size is miniaturized, the more the cohesion increases. This phenomenon results in the decrease of the perviousness of MC. In this study, the grouting effects of microfine cement with superplasticizer to maintain cohesion low and that of normal cement were investigated in rock. To estimate the grouting effects, TCR/RQD test for rock quality, lugeon test, borehole loading test for coefficients of elastic and deformative stress, borehole shear test for shear stress, detection p~q~t(pressure~flow~time) chart tests were carried out. The results using MC show a better permeability, modulus of elasticity, deformation, charge per unit, and recover efficiency of grouting material than those of ordinary portland cement except shear stress.

• ETRI Journal
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• v.35 no.1
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• pp.150-153
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• 2013

In this letter, a compact and fully printed composite right- and left-handed (CRLH) dual-band power divider is proposed. The branches of the conventional Wilkinson power divider are replaced by subwavelength CRLH phase-shift lines having $+90^{\circ}$ for one frequency and $-90^{\circ}$ for another frequency for dual-band and miniaturization performance. Equations are derived for the even- and odd-mode analysis combined with the dual-band CRLH circuit. A PCS and a WLAN band are chosen as the test case and the circuit approach agrees with the CAD simulation and the measurement. Additionally, the CRLH property is shown with the dispersion diagram and the eightfold size reduction is noted.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.793-796
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• 2005

In this paper, we propose a method which can improve uniformity of a miniaturized electron beam array for inspection of very small pattern with high speed using vertical interconnection. This method enables the individual control of columns so that it can reduce the deviation of beam current, beam size, scan range and so on. The test device that used vertical interconnection method was fabricated by multiple wafer bonding and metal reflow. Two silicon and one glass wafers were bonded and metal interconnection by melting of electroplated AuSn was performed. The contact resistance was under $10{\Omega}$.

• ETRI Journal
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• v.37 no.1
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• pp.21-25
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• 2015

A miniaturized triple-band antenna suitable for wireless USB dongle applications is proposed and investigated in this paper. The presented antenna, simply consisting of a circular-arc-shaped stub, an L-shaped stub, a microstrip feed line, and a rectangular ground plane has a compact size of $16mm{\times}38.5mm$ and is capable of generating three separate resonant modes with very good impedance matching. The measurement results show that the antenna has several impedance bandwidths for S11 ${\leq}$ -10 dB of 260 MHz (2.24 GHz to 2.5 GHz), 320 MHz (3.4 GHz to 3.72 GHz), and 990 MHz (5.1 GHz to 6.09 GHz), which can be applied to both 2.4/5.2/5.8 GHz WLAN bands and 3.5/5.5 GHz WiMAX bands. Moreover, nearly-omni-directional radiation patterns and stable gain across the operating bands can be obtained.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.6
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• pp.27-34
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• 2001

There are several electricity applied sterilizers such as using high frequency, ozone, high voltage, and so on. Those sterilizers feature "because of no chemical process and no secondly environmental pollution". At the power conversion part, ZVS and ZCS methods have been used that it results in reduced switching loss, miniaturized size, and lightened weight. Besides, the current in the propose device is smaller than that of existing method. Thus, it is expected that the cost of sterilization process, when quality of the device is measured by power consumption, will be reduce. Therefore, the purpose of this research is to solve the sterilization problems of existing powder with high voltage and field to and more economical and effective way, and to suggest mere improved sterilizer.

• Journal of Navigation and Port Research
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• v.34 no.7
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• pp.543-552
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• 2010

Modified compact combline bandpass filters are proposed based on the miniaturized quarter-wave transmission line which is composed of the parallel coupled line and lumped capacitors. The electrical length of the parallel coupled line in a resonator, which determines the size of combline bandpass filters, is just $5^{\circ}$ or $7^{\circ}$, resulting in a compact circuit area. The designed combline bandpass filter also has a wide upper stopband by suppressing the spurious passbands, not moving. Measured results of two fabricated filters centered at 400MHz show good agreement with the theoretical predications.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.6 s.99
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• pp.660-666
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• 2005

Recently, the need for subminiature storage systems has increased with the diversification of portable devices. An actuator for small optical disk drives has to satisfy performance requirements such as higher access speed, lower power consumption, and smaller size. In this paper, we proposed the miniaturized rotary type VCM actuator that had an effective focusing mechanism and secured sufficient bandwidth for small form factor (SFF) optical disk drive (ODD). Initial model was designed by electromagnetic (EM) and structural analyses. Such a model was improved using design of experiments (DOE) procedure based on a Blu-ray disk (BD) 1x specifications.

• Journal of Information Technology Services
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• v.12 no.3
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• pp.323-330
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• 2013

In this paper, miniaturized patch antenna operating at ISM band has been designed by applying the fractal technique. Various type of antenna structure, microstrip patch antenna and koch curve microstrip patch antenna has been proposed and simulated using Ansoft HFSS (High Frequency Structure Simulator). The area of microstrip patch antenna and koch microstrip patch antenna is 1,058 $mm^2$, and 891 $mm^2$ respectively, showing the size reduction ratio of 16%. The finally made koch curve microstrip patch antenna resonates at 2.45GHz with return loss of 22.69dB, VSWR of 1.2142, and antenna radiation gain of 3.26dBi.