• Journal of information and communication convergence engineering
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• 제14권4호
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• pp.252-257
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• 2016

An edge-located electromagnetic bandgap (EL-EBG) structure using a defected ground structure (DGS) is proposed to suppress resonant modes induced by edge excitation in a two-dimensional planar parallel plate waveguide (PPW). The proposed EL-DGS-EBG PPW significantly mitigates multiple transverse-magnetic (TM) modes in a wideband frequency range corresponding to an EBG stopband. To verify the wideband suppression, test vehicles of a conventional PPW, a PPW with a mushroom-type EBG structure, and an EL-DGS-EBG PPW are fabricated using a commercial process involving printed circuit boards (PCBs). Measurements of the input impedances show that multiple resonant modes of the previous PPWs are significantly excited through an input port located at a PPW edge. In contrast, resonant modes in the EL-DGS-EBG PPW are substantially suppressed over the frequency range of 0.5 GHz to 2 GHz. In addition, we have experimentally demonstrated that the EL-DGS-EBG PPW reduces the radiated emission from -24 dB to -44 dB as compared to the conventional PPW.

• 한국위성정보통신학회논문지
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• 제8권4호
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• pp.124-129
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• 2013

PPS 구조가 삽입된 N형 실리콘 제어 정류기 소자를 마이크로 칩의 고전압 I/O 응용을 위해 연구하였다. 종래의 NSCR_PPS_Std 표준소자는 매우 낮은 스냅백 홀딩 전압을 갖는 전형적인 SCR 특성을 가지고 있어 정상적인 동작 동안 래치업 문제가 나타나는 것으로 보고되고 있다. 그러나 본 연구에서 제안하는 CPS 및 부분적으로 형성된 P-Well(PPW) 구조를 갖는 변형된 NSCR_PPS_CPS_PPW 소자는 높은 래치업 면역과 트리거링 전압의 조절이 용이한 안정한 ESD 보호 성능을 나타내어 고전압 동작용 마이크로 칩의 정전기보호 소자로 적용 가능함을 확인하였다.

• 한국의류산업학회지
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• 제20권5호
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• pp.600-607
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• 2018

Polypropylene fibers, while having many advantages such as light weight, sweat fast drying, water-repellent, drainage, thermal insulation, anti-static property has a drawback in dyeing. In recent years, the development of dyeable polypropylene fibers has expanded its value in the textile market. The purpose of this study is to fabricate composite spun yarns using polypropylene, acrylic, rayon and wool and to analyze tensile properties, uniformity characteristics, bending properties, hairiness, and surface shape according to the degree of fineness and blended ratio. The specimens consisted of 100% polypropylene spun yarn pp30, pp40 and ppa(pp/acrylic), ppr(pp/rayon), ppw(pp/wool), 5 altogether sed in this study. The results of the study are as follows. The breaking strength of polypropylene spun yarn blended with rayon and acrylic was higher than that of 100% polypropylene spun yarn. The polypropylene spun yarn is higher the fineness been shown to decrease the breaking strength and elongation. The bending properties of polypropylene spun yarns were in the order of ppa>ppr>pp40>pp30>ppw. The unevenness of ppw, ppr, and ppa was higher than pp40 and pp30. With the exception of ppw with crimp properties, pp30 and pp40 were found to have a hairiness index greater than ppr, ppa. In the microscopic photographs of polypropylene spun yarn, pp30, which had the highest hairiness index, was found to have a thick yarn and a large number of hairs, and ppw had hairs of 3 mm or more protruding elongated outwardly.

• 대한전자공학회논문지TC
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• 제37권2호
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• pp.68-74
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• 2000

유전체 슬랩으로 덮힌 평행평판 도파관의 좁은 슬릿을 통한 슬랩 위의 도체 스트립과의 전자기적인 결합문제를 평행평판 도파관에 TEM파가 입사되는 경우에 대하여 고려하였다. 슬릿의 접선성분 전계와 도체 스트립에 유기된 전류에 관한 결합 적분방정식을 유도하고 모멘트방법으로 풀었다. 도체 스트립이 결합에 미치는 영향을 보이기 위하여 도파관내에서의 반사 및 투과 전력, 슬릿을 통해 결합된 전력, 슬릿의 등가 어드미턴스, 그리고 복사패턴 등에 대한 수치해석결과를 제시하였다 그 결과 슬릿을 통해 평행평판 도파관 외부로 결합된 전력의 최대치가 도파관 내부 입사전력의 약 50%가 됨을 관찰하였다.

• Journal of Magnetics
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• 제15권4호
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• pp.209-212
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• 2010

Photoplethysmogram (PPG) and pressure pulse waveform (PPW) were compared and evaluated for the efficacy of stimulating knuckles by using the pulsed magnetic field. Both signals were observed simultaneously while the knuckles were exposed for 10 min to the pulsed magnetic field, with maximum field intensity of 0.8 T and transition time of 0.126 msec. After 5 min stimulation of the knuckles, the results showed that the aging indexes calculated from the second derivative of the PPG were increased from -1.913 to 0.072, and that of the PPW from -0.063 to 0.387. However, for the relatively long-term stimulation for 10 min, we found that the values of both the aging indexes of the second derivatives and augmentation index of the PPW returned to the starting level. The changes observed in characteristic factors such as the aging indexes of the second derivatives and augmentation index of the PPW indicate the potential of pulsed magnetic field stimulation as a therapeutic method for the treatment of patients with peripheral vascular disease.

• Nutrition Research and Practice
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• 제17권5호
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• pp.827-843
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• 2023

BACKGROUND/OBJECTIVES: Mitochondrial DNA leakage leads to inflammatory responses via endosome activation. This study aims to evaluate whether the perennial grass water extract (Pogonatherum panicum) ameliorate mitochondrial DNA (mtDNA) leakage. MATERIALS/METHODS: The major bioactive constituents of P. paniceum (PPW) were investigated by high-performance liquid chromatography, after which their antioxidant activities were assessed. In addition, RAW 264.7 macrophages were stimulated with lipopolysaccharide, resulting in mitochondrial damage. Quantitative polymerase chain reaction and enzyme-linked immunosorbent assay were used to examine the gene expression and cytokines. RESULTS: Our results showed that PPW extract-treated activated cells significantly decrease reactive oxygen species and nitric oxide levels by reducing the p2^phox and iNOS expression and lowering cytokine-encoding genes, including IL-6, TNF-α, IL-1β, PG-E2 and IFN-γ relative to the lipopolysaccharide (LPS)-activated macrophages. Furthermore, we observed that LPS enhanced the mtDNA leaked into the cytoplasm, increasing the transcription of Tlr9 and signaling both MyD88/Irf7-dependent interferon and MyD88/NF-κb p65-dependent inflammatory cytokine mRNA expression but which was alleviated in the presence of PPW extract. CONCLUSIONS: Our data show that PPW extract has antioxidant and anti-inflammatory activities by facilitating mtDNA leakage and lowering the Tlr9 expression and signaling activation.

• 한국위성정보통신학회논문지
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• 제9권3호
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• pp.15-21
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• 2014

NESCR 구조의 정전기 보호소자가 고전압 동작용 I/O 응용을 위해 분석되었다. 기존의 NESCR 표준소자는 매우 낮은 스냅백 홀딩 전압을 갖는 전형적인 SCR 특성을 나타내므로 정상적인 동작 동안 래치업 문제를 초래한다. 그러나 본 연구에서 제안하는 CPS 및 부분적으로 형성된 P-well 구조를 갖는 NESCR_CPS_PPW 변형소자는 높은 온-저항과 스냅백 홀딩 전압을 나타내어 래치업 면역 능력을 향상시킬 수 있었다.

• 한국기계가공학회지
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• 제15권1호
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• pp.61-67
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• 2016

The airbag is a widely accepted device for occupant protection in the automotive industry. As the injuries induced by airbag deployment have become a critical issue, revisions to Federal Motor Vehicle Safety Standard (FMVSS) 208 were required to create advanced airbags that can protect occupants of varying statures. In this paper, we developed a new low-risk deployment passenger airbag by adding the Passenger Protection Wrap (PPW). The PPW reduces the cushion impact force to the occupant in order to ensure pressure dispersion. A series of tests were conducted by using FMVSS 208 test procedures to demonstrate the proposed system. It was found that the system not only satisfied the injury criteria of FMVSS 208 but was also effective for protecting passengers of all sizes (male, small female, 3-year-old, 6-year-old).

• 한국위성정보통신학회논문지
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• 제10권4호
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• pp.1-5
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• 2015

PPS 소자가 삽입된 부분웰 구조의 N형 실리콘 제어 정류기(NSCR_PPS) 소자에서 정전기 보호 성능의 향상을 위한 CPS 이온주입조건의 최적화에 대해 연구하였다. 종래의 NSCR 표준소자는 on-저항, 스냅백 홀딩 전압 및 열적 브레이크다운 전압이 너무 낮아 정전기 보호소자의 필요조건을 만족시키지 못해 적용이 어려웠으나, 본 연구에서 제안하는 CPS 이온주입과 부분웰 이온주입을 동시에 적용한 변형 설계된 소자의 경우 스냅백 홀딩 전압을 동작전압 이상으로 증가시킬 수 있는 향상된 정전기 보호성능을 나타내어 고전압 동작용 마이크로 칩의 정전기보호 소자로 적용 가능함을 확인하였다.

• 한국산학기술학회논문지
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• 제10권5호
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• pp.992-999
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• 2009

심전도와 맥파를 측정함으로써 구해질 수 있는 맥파전달시간은 심혈관계의 상태를 진단하기 위한 의미 있는 지표가 된다. 그러나 맥파를 측정하는 동안 움직이거나, 측정 시에 가해지는 압력이 부정확할 경우, 잘못된 측정 결과를 얻을 수 있다. 이를 해결하기 위하여 본 논문에서는 심전도, 압력맥파 및 광전용적맥파를 동시에 측정할 수 있는 일체형 센서 시스템과 심전도를 지속적으로 측정할 수 있는 금속 전극을 개발하였으며, 실험을 통해 일체형 센서시스템 및 금속 전극의 유용성을 입증하였다.