• Journal of the Korean Geotechnical Society
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• v.21 no.2
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• pp.127-135
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• 2005

In this paper, a numerical comparison of predictions by limit equilibrium analysis and finite difference analysis is presented for slope/soil-nail system. Special attention is given to the coupled analysis based on the explicit-finite-difference code, FLAC 2D. To this end, an internal routine (FISH) was developed to calculate a factor of safety for a soil nail slope according to shear strength reduction method. The case of coupled analyses was performed for soil nails in slope in which the soil nails response and slope stability are considered simultaneously. In this study, by using these methods, the failure surfaces and factors of safety were compared and analyzed in several cases, such as toe, middle and top of the slope, respectively. Furthermore, the coupled method based on shear strength reduction method was verified by the comparison with other analysis results.

• Journal of the Microelectronics and Packaging Society
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• v.13 no.4
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• pp.9-15
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• 2006

This paper shows the impedance profile of PEEC(Partial Equivalent Electrical Circuit) PDN(Power Distribution Networks) including core and I/O circuit. Through the simulated results, we find that the core power noise having connection with I/O power is affected by I/O switching. Also, using designed $74{\times}5inch$ DLL(Delay Locked Loop) test board, we analyzed the effect of power noise on operation region of chip. Jitter of a DLL measure for frequency of $50{\sim}400MHz$ and compared with impedance obtained result of simulation. Jitter of a DLL are increased near about frequency of 100MHz. It is reason that the resonant peak of PDNs has an impedance of more the 1ohm on 100MHz. we present the impedance profile of a chip and board for the decoupling capacitor reduced the target impedance. Therefore, power supply network design should be considered not only decoupling capacitors but also core switching current and I/O switching current.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.12
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• pp.1053-1058
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• 2016

The eLoran(enhanced Long Range Navigation) transmitting antenna is analyzed for co-location with an AM transmitting antenna in an MF transmitting site. To compensate for the loading effect, the umbrella-type loading is applied for eLoran antenna. The validity of the co-location between the MF antenna and the eLoran antenna is verified through the simulation results of the radiation pattern and the return loss. Also, coupling including antenna matching circuit is analyzed to verify the effect of the transmitting circuit. The coupling between the LF and eLoran antenna is -53.3 dB at 100 kHz and -64.8 dB at 1,053 kHz, respectively.

• Journal of IKEEE
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• v.19 no.3
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• pp.440-446
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• 2015

This study has examined susceptibility of LNA(Low Noise Amplifier) due to Front-Door Coupling under Narrow-Band high power electromagnetic wave. M/DFR(Malfunction/Destruction Failure Rate) was measured to investigate the diagnostic of IC test. In addition, decapsulation analysis was used to understand the inside of the chip state in LNA devices. The experiments is employed as an open-ended waveguide to study the destruction effects of LNA using a 2.45 GHz Magnetron as a high power electromagnetic wave. The susceptibility level of LNA was assessed by electric field strength, and its failure modes were observed. The malfunction of LNA device has showed as the type of self-reset and power-reset. The electric field strength of malfunction threshold is 524 V/m and 1150 V/m respectively. Also, he electric field of destruction threshold is 1530 V/m. Three types of damaged LNA were observed by decapsulation analysis: component, onchipwire, and bondwire destruction. Based on these results, the susceptibility of the LNA can be applied to a database to help elucidate the effects of microwaves on electronic equipment.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.399-404
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• 2004

Novel GHK-conjugated chitosan was prepared by the solid-phase method using $N^{\alpha}-Fmoc$ amino acids/BOP coupling reagent. For this purpose, the chitosan microbeads which had a mean diameter of 70 um were prepared by the W/O emulsion-phase separation method. The GHK was successfully coupled to the chitosan microbeads by stepwise solid-phase method. The result of amino aid analysis was in good agreement with the theoretical values; $Gly_{1.02}\;of\;His_{1.13}\;Lys_{0.96).$. The cell proliferation effect of the GHK-bound chitosan microbeads was measured by MTT assay. We concluded that GHK-bound chitosan microbeads gave higher cell Proliferation effect than chitosan microbeads.

• Resources Recycling
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• v.20 no.6
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• pp.43-49
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• 2011

This study calculated the three indices of Korea's resource productivity (and raw material productivity), material circulation rate and decoupling factor to evaluate the sustainability of domestic economic activities and resource consumption and examine the extent of dematerialization. Korea's resource productivity improved 22% from 1.32 million KRW/ton in 2000 to 1.61 million KRW/ton in 2007, with the annual average growth of resource productivity during the period standing at 2.88%. Raw material inputs accounted for 73-76% of domestic material consumption (DMC); raw material productivity for the year 2007 was 2.11 million KRW/ton, growing 3% on annual average from 2000 through 2007. The wastes released are circulated into the economic system through recycling and energization. Korea's material circulation went up from 10.9% in 2000 to 15.6% in 2007, growing by an annual average of 5.3% during the period. The rate of change in year-on-year growth, however, was found to be on the gradual decrease. This study also showed that Korea's economic activities were decoupled with its resource consumption as the country heads toward dematerialization through sustainable resource management.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.230-231
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• 2011

본 논문은 2011년 제주계통 한림변전소와 금악변환소 사이에 설치 예정인 ${\pm}80kV$ 60MW HVDC 시스템의 DC 가공선로를 기존의 AC 송전 철탑의 AC 선로와 병렬로 추가하여 운영할 때 선로 Coupling에 따른 정상상태 영향을 분석한 내용이다. 한림변전소와 금악변환소 사이 철탑 17개의 데이터를 기반으로 송전선로를 모델링함으로써 실제 데이터에 최대한 근접할 수 있도록 정확성을 도모하였으며, 모델링과 분석에 있어서 전자계과도현상 해석프로그램인 PSCAD를 이용하였다. 특히 AC 병렬 연계 유무에 따른 DC 전류 주파수를 비교함으로써 AC/DC Coupling의 영향을 분석하였으며 최종적으로 이에 따른 기본파 성분 제거에 필요한 DC 필터 설치 유무에 관한 결론을 도출하였다.

• Applied Chemistry for Engineering
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• v.29 no.1
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• pp.37-42
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• 2018

In order to increase the compatibility of polypropylene (PP) and kenaf fiber (KF) felt, PP/KF and PP/KF/polyurethane (PU) felt composites were prepared by treating KF with three kinds of silane coupling agents. The concentration of silane coupling agents was fixed at 1 wt%. The chemical reaction between KF and silane coupling agents was confirmed by the existence of Si-O-Si and Si-O-C functional group bands appeared on FT-IR and X-ray photoelectron spectra (XPS). Thermal properties of PP/KF composites were investigated by DSC and TGA, and the thermal stability of PP/KF composites with treated KF increased. Based on tensile, flexural and impact properties of PP/KF and PP/KF/PU composites, 1-2 wt% of (3-aminopropyl)triethoxysilane (APS) contents were the optimum formulation as a compatibilizer. The tensile and flexural strength of the felt composites treated with the silane coupling agents were improved. This is mainly due to the improvement in the compatibility between PP and KF, which was confirmed by SEM images of the fractured surfaces after tension tests.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4126-4130
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• 2012

In this paper, we proposed planar spiral inductors based on AC coupling for high-frequency wireless signal transmission. Design and characteristics of various structures of the inductor were analyzed. Capacitance between the inductors can be reduced by positioning two thin-film inductors in parallel. So two structures were proposed. First structure is inter-diagonal structure. This structure was made not to overlap the wire part of the paralleled two inductors. Second structure is On-chip type structure that the two thin-film inductors were in parallel but located on diagonal line not to face each other. The resonance in this structure was reduced from twice to once by increasing horizontal distance between the two thin-film inductors, because the capacitance effect between the two thin-film inductors decreases when the distance between the two inductors increases.

• Korean Journal of Construction Engineering and Management
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• v.2 no.4 s.8
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• pp.117-126
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• 2001

The purpose of this study is to present a way of Variation Control in building construction process. The study suggest a way of the application method of shielding, decoupling concept and also Poka-yoke device to control variation that occurs from uncertainty in construction industry with lots of waste factors. The main contents of the study are as follows; (1) It's suggested strategy to apply shielding, decoupling as variation control technique. (2) Current Poka-yoke devices are investigated and analyzed. As a future research, it is required to study continuously on the more effective application method of Poka-yoke device and on existing examples in domestic construction sites for the process improvement.