• Journal of The Geomorphological Association of Korea
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• v.17 no.1
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• pp.59-72
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• 2010

This study is based on the observation on the patterned ground found in the northern part of the Baekdusan during two fieldtrips of 2008 summer. The patterned grounds are found in two areas-Dalmun and Socheonji. The patterned ground found around Dalmun are well-sorted, having fine materials in the center and coarse (boulder size) materials in the rim, and stretching in the form of stairs. Meanwhile, the types of patterned ground found around Socheonji are various, including polygon, stripe, and circular patterns. The particle size analysis and morphological analysis of comprising materials are carried out only for the patterned ground of Socheonji. The mean short and long axis of the patterned grounds are 91cm and 163cm, respectively. The distribution pattern of material size from the most samples increase toward the rim, indicating the patterned grounds are well-sorted. The comprising materials are dominated by silt, which is very susceptible for freeze-thaw cycle. The lower ratio of clay (low less than 10%), suggests that physical weathering is more dominant rather than chemical weathering. The involution structure found in the vertical section of the patterned grounds is likely to have formed by active cryoturbation which is one of the dominant geomorphic processes in the periglacial environments like the study area.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.257-267
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• 2021

Constraints on the structure and composition of the active layer are important for understanding permafrost evolution. Soil convection owing to repeated moisture-induced freeze-thaw cycles within the active layer promotes the formation of self-organized patterned ground. Here we present the results of ground penetrating radar (GPR) surveys across a selected sorted circle near King Sejong Station, Antarctica, to better delineate the active layer and its relation to the observed patterned ground structure. We acquire GPR data in both bistatic mode (common mid-points) for precise velocity constraints and monostatic mode (common-offset) for subsurface imaging. Reflections are derived from the active layer-permafrost boundary, organic layer-weathered soil boundary within the active layer, and frozen rock-fracture-filled ice boundary within the permafrost. The base of the imaged sorted circle possesses a convex-down shape in the central silty zone, which is typical for the pattern associated with convection-like soil motion within the active layer. The boundary between the central fine-silty domain and coarse-grained stone border is effectively identified in a radar amplitude contour at the assumed active layer depth, and is further examined in the frequency spectra of the near- and far-offset traces. The far-offset traces and the traces from the lower frequency components dominant on the far-offset traces would be associated with rapid absorption of higher frequency radiowave due to the voids in gravel-rich zone. The presented correlation strategies for analyzing very shallow, thin-layered GPR reflection data can potentially be applied to the various types of patterned ground, particularly for acquiring time-lapse imaging, when electric resistivity tomography is incorporated into the analysis.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.436-439
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• 2007

This paper describes the optimization of PGS(Patterned Ground Shield) of 5.5 turns rectangular spiral inductor using Taguchi's method. PGS is decrease method of parasite component by silicon substrate among dielectric loss reduction method. By using the taguchi's method, each parameter is fixed upon that PGS high poison(A), slot spacing(B), strip width(C) and overlap turn number(D) of PGS design parameter. Then we verified that percentage contribution and design sensitivity analysis of each parameter and level by signal to noise ratio of larger-the-better type. We consider percentage contribution and design sensitivity of each parameter and level, and then verify that model of optimization for PGS is lower inductance decreasing ratio and higher Q-factor increasing ratio by EM simulation.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.6
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• pp.50-56
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• 2000

The integrated circuit interconnection lines are experimented with patterned ground shields (PGS) at microwave frequencies. Measurement results demonstrate that the PGS can significantly reduce the power loss through the interconnect lines over wide frequency ranges as the PGS shields the lossy silicon substrate. The transmission line characteristics of the PGS interconnect lines are analyzed and identified that the PGS reduces the wave length of the interconnect line.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.153-157
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• 2006

본 논문에서는 SoC 공정에 적용 가능한 spiral 인덕터의 특성에 대해 다루었다. 일정한 크기의 인덕터에서 턴 수의 변화에 따른 인덕턴스와 Q-factor의 변화를 보았다. HFSS 프로그램을 사용하여 턴 수와 선로의 폭이 같은 조건하에서 사각형 구조와 팔각형 구조를 갖는 인덕터의 인덕턴스와 Q-factor의 ?냅? 계산하였다. 사각형 구조와 팔각형 구조 모두 선로 폭 보다는 턴 수가 증가할수록 인덕턴스가 증가하였다. 턴 수가 증가할수록 Q-factor의 값은 사각형 구조는 감소한 반면 팔각형 구조는 증가하였다. spiral과 실리콘 사이에 PGS(Patterned Ground Shield)를 삽입하여 인덕턴스 및 Q-factor의 변화를 비교 분석하였다. 그 결과 PGS의 사용으로 사각형 구조와 팔각형 구조에서 턴 수에 따라 Q-factor의 값이 구조에 따라 서로 다른 방향으로 증감하는 것을 확인할 수 있었다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.11
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• pp.1967-1971
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• 2007

In this paper, we verified basic forms and equivalent circuits of spiral inductors and various kinds of parasitics of equivalent circuits by using HFSS and Nexxim program that were 3-D EM analysis tools, and fabrication on-chip spiral inductors using Hynix's 0.25um 1-poly and 5-metal CMOS process. Comparing with PGS(patterned ground shield) and NPGS(non patterned ground shield) of spiral inductors of 3.5 turn, 4.5 turn and 5.5 turn, etc, the application of PGS could improve maximum Q value by 8-12%.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.35-38
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• 2008

In this paper, study noise performance of LNA to enhance Q-factor of input circuit by patterned ground shield is inserted inductor using TSMC 0.18um. Applied LNA technology is cascode method. The input matching circuit was constituted on-chip and wirebonding inductor. Taguchi's method is used for the best suited structure of PGS. We confirmed enhancement of Q-factor by inserted PGS into inductor. The input matching circuit enhanced Q-factor by inductor with PGS improve noise figure of LNA.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.272-273
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• 2007

This paper presents the characteristic of rectangular and octagonal spiral inductor using PGS(Patterned Ground Shield). We investigated variation of inductance and Q-factor with changing of turn number at fixed width, spacing and inner diameter. We confirmed that characteristic of inductance and Q-factor be appled PGS in rectangular and octagonal types spiral inductor by EM simulation tool. Inductance decreased irrespective of structure but Q-factor increased. When PGS not exist, Q-factor of Inductor is analogous at classification frequency but, rectangular is a few larger then octagonal in small turn number. The other side, When PGS is inserted, we confirmed that octagonal lager then rectangular in many turn number. Q-factor is improved in case of octagonal structure and small turn number by PGS effect.

• Journal of Advanced Marine Engineering and Technology
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• v.34 no.2
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• pp.325-331
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• 2010

In this study, highly miniaturized short-wavelength meander line employing eriodically patterned ground structure (PPGS) was developed for application to miniaturized on-chip passive component on GaAs MMIC (monolithic microwave integrated circuit). The meander line employing PPGS showed shorter wavelength and slow-wave characteristic compared with conventional meander line. The wavelength of the meander line employing PPGS structure was 17 % of the conventional meander line on GaAs MMIC. Due to its slow-wave structure, the meander line employing PPGS exhibited large propagation constant than conventional meander line, which resulted in larger phase shift and shunt inductance value. Above results indicate that the meander line employing PPGS is a promising candidate for application to a development of miniaturized on-chip RF components as well as inductor with a high inductance value on GaAs MMIC.

• The Korean Journal of Quaternary Research
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• v.22 no.2
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• pp.42-42
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• 2008