• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.12
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• pp.39-45
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• 1997

This study presents the first experimental data for the impact of hot-carrier degradtion on the performance of CMOS folded-cascode op-amps. A folded-cascode op-amp which has an NMOS input pair has been designed and fabricated using a 0.8.mu.m single-poly, double-metal CMOS process. After high voltage stress, the degradtion of perfomrance parameters such as open-metal CMOS process. After high voltage stress, the degradation of performance parameters such as open-loop voltage gain, unity-gain frequency and phase margin has been analized and physically explaniend in terms of hot carrier degradation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.61 no.1
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• pp.1-4
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• 2012

In this paper, the planar type modified folded loop antennas for S-DMB band is proposed. The proposed antenna consisted of opened center of a conventional closed loop and folded terminal of microstrip line to inside loop antenna. The sizes proposed antenna was minimized by folding the terminal of the loop. Also, It was minimized reactance value by increasing capacitances between coupled microstrip line. Therefore the proposed antennas compacted about 20% than a conventional loop antenna and increased efficiency of antenna. The proposed antennas got an omni-directional pattern, the antenna gain was 3.67 [dBi] and the bandwidth was 900 MHz (2.6-3.56 GHz) with VSWR${\leq}$2 from the simulated and the measured results. The frequency utilization coefficient was 29.9 %. These properties could satisfy the S-DMB band.

• Journal of the Optical Society of Korea
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• v.9 no.2
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• pp.64-67
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• 2005

A diode-pumped $Nd:YVO_4$ laser is developed. The laser has a closely folded resonator. The laser beam in two arms of the folded resonator passes the same acousto-optic modulator. The laser output power and pulsewidth dependence on a Q-switching frequency were measured. It is found that the newly proposed geometry provides an effective means for reducing the pulsewidth while maintaining almost the same output power compared with the usual folded resonator, where the beam in one arm of the resonator passes the acousto-optic modulator.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.181-182
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• 2006

Photoconductive three-wire folded dipole antennas for terahertz photomixers have been developed. The folded antennas are characterized by a free space time-domain measurement technique, and the measured data are in good agreement with the simulation results. The folded dipole antennas have much higher antenna resistance than other resonant dipole antennas, implying that they can be used for higher output power of THz photomixers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.900-902
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• 2013

In this paper, we propose the CPW antenna with three folded lines for miniaturization. This antenna is consisted of a meander-line on the middle position for LTE band and two folded lines. As widths of three lines are gradually changed to broaden bandwidth, antenna is designed.

• Structural Engineering and Mechanics
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• v.25 no.4
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• pp.405-421
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• 2007

A four-node hybrid stress element for analysing orthotropic folded plate structures is presented. The formulation is based on Hellinger-Reissner variational principle. The element is developed by combining a hybrid plane stress element and a hybrid plate element. The proposed element has six degree of freedom per node and permits an easy connection to other type of elements. An equilibrated stress field in each element and inter element compatible boundary displacement field are assumed independently. Static and free vibration analyses of folded plates are carried out on numerical examples to show that the validity and efficiency of the present element.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.4
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• pp.151-154
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• 2013

In this paper, we will analyze embedding between Folded Hypercube and HFH. We will show Folded Hypercube $FQ_{2n}$ can be embedded into HFH($C_n,C_n$) with dilation 4, expansion $\frac{(C_n)^2}{2^{2n}}$ and HFH($C_d,C_d$) can be embedded into $FQ_{4d-2}$ with dilation O(d).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.84-87
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• 2005

This study is aimed to compare the insertion losses of periodically folded barriers which have same folded width, depth and period of arrangement but different direction of arrangement. One is vortical to the roadside and another is parallel. The pressure levels and the insertion losses at the receiving points behind finite length barriers are measured in an anechoic room by scale model test. The measured insertion losses are compared with calculated insertion losses by 3D BEM models.

• Current Optics and Photonics
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• v.3 no.3
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• pp.227-235
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• 2019

With slimmer, lighter and all-reflective imaging systems in high demand for consumer and military applications, coaxially folded optical image systems are widely considered because they can extend focal length and reduce track length. Most of these systems consist of multiple surfaces, and these surfaces are machined on one element or grouping processing on two elements. In this paper, we report and first experimentally demonstrate an all-aluminum all-reflective optical system which consists of two optical elements, with two high order aspherical surfaces in each element. The coaxially folded system is designed with Seidel aberration theory and advanced optimization with Zemax. The system is made of all-aluminum material processing by single point diamond turning (SPDT). On this basis, we completed the system integration and performed an imaging experiment. The final system has the advantages of short track length and long focal length and broad application prospects in the micro-unmanned aerial vehicle field.

• Proceedings of the Korea Society of Design Studies Conference
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• 2005.05a
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• pp.92-93
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• 2005