• Title/Summary/Keyword: 굴곡 효과

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Analysis of Impedance Models on Flexible PCB Transmission Line (연성 PCB 전송라인을 위한 특성 임피던스 모델의 모의 분석)

  • Part, Jong-Kang;Byun, Yong-Ki;Kim, Jong-Tae
    • Proceedings of the KIEE Conference
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    • 2005.07d
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    • pp.3022-3024
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    • 2005
  • 연성 PCB(flexible printed circuit board)는 현재 노트북 PC와 디지털 카메라등에 적용되며, 굴곡성이 강하고 소형화 및 조립에 용이하여 주로 기판 사이나주기판과 외부 커넥터사이에 데이터의 전송매체로써 널리 사용되는 핵심부품이다. 근래에 개발되는 PCB 기반의 고성능 신호처리회로들은 데이터 전송율이 수백 MHz에서 수 GHz에 이르고 있으며, 신호선과 유전체, 접지판의 구조적 특성에 따라서, 반사 효과와 같은 신호무결성 문제들이 파생되어 신호의 최대성능을 제한하게된다. 이에 따라 적절한 임피던스 제어를 통하여 고성능신호들의 왜곡을 상쇄시키는 기술이 중요하게 되었다. 본 논문에서는 연성 PCB 전송라인을 위한 임피던스 모델을 대상으로 각 모델의 주요 특징 및 정확성을 분석하였다. 연성 PCB의 전송라인은 보통 전통적인 마이크로스트립 라인의 특성 임피던스 모델에 비해 신호선의 너비가 크며, 이를 반영한 개선된 수학적 임피던스 모델들이 제안되어 있다. 따라서 본 논문은 기존의 마이크로스트립 전송라인과 연성 PCB 전송라인에 적합한 수학적 모델들을 이용하여 신호 무결성 문제를 모의할 수 있는 CAE(computer-aided engineering) 도구의 임피던스 측정 결과를 비교 및 분석하였다.

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A Study on the Property Changes by Trihydric Alcohol Addition Reaction and Polyurethane Dispersion Synthesis for Buffalo Leather Coatings (Buffalo Leather 코팅에 대한 수분산 폴리우레탄의 합성 및 3가 알콜 첨가에 의한 물성변화 연구)

  • Lee, Joo-Youb
    • Journal of the Korean Applied Science and Technology
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    • v.32 no.4
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    • pp.623-630
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    • 2015
  • Prepared polyurethane resin for buffalo leather coating on surface was synthesized with addition reaction glycerol which had different mole ratio. Mechanical properties of the synthesized polyurethane resin were measured by the SEM, FT-IR, UTM. Growing concerns in the evnironment-friendly polymer resin, we have synthesized low late obtained solvent water dispersion resin to be coating on buffalo leather. The increase of aliphatic trihydric alcohol glycerol mole %, abrasion resistance and tensile strength had demonstrated reduce properties. On the contrary, elongation and flexibility properties had highly increased. In the result of toluene solvent resistance, there was no effect of increased or decreased by the ratio of glycerol mole %.

Mechanical Properties and Synthesis of Polyurethane Dispersion by Glycerol for Vegetable Leather Surface Coatings (Vegetable Leather 표면코팅에 대한 Glycerol을 이용한 수분산 폴리우레탄의 합성 및 기계적 특성)

  • Lee, Joo-Youb
    • Journal of the Korean Applied Science and Technology
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    • v.32 no.1
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    • pp.100-107
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    • 2015
  • Prepared polyurethane resin for vegetable leather coating on surface was synthesized with glycerol which had different mole ratio. Mechanical properties of the synthesized polyurethane resin were measured by the SEM, FT-IR, UTM. Growing concerns in the evnironment-friendly polymer resin, we have synthesized low late obtained solvent water dispersion resin to be coating on vegetable leather. The increase of aliphatic trihydric alcohol glycerol mole %, abrasion resistance and tensile strength had highly stronger in intensity and longer durability. On the contrary, demonstrated reduce properties of elongation and flexibility. In the result of toluene solvent resistance, there was no effect of increased or decreased by the ratio of glycerol mole %.

Optimization of Polymer Composite Properties Using a Red Clay (황토를 이용한 고분자 복합수지 물성 최적화)

  • Seo, Kyoung-Won;Ji, Ju-Hyeon;Peng, Mei-Mei;Lee, Joo-Bo;Jang, Hyun-Tae
    • Proceedings of the KAIS Fall Conference
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    • 2011.05a
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    • pp.332-335
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    • 2011
  • 원적외선, 음이온 방출과 항균, 탈취, 난연등의 효과를 가지는 황토를 합성수지와 혼합하여 복합소재를 연구하여 환경 친화적인 특징과 원적외선, 음이온의 방출을 이룰 수 있는 복합소재 조성을 연구하였다. PP는 MI가 2~60이고, TPE로 Ethylene계을 사용하였으며, 황토와 PP의 혼련을 도와주기 위하여 MA-g-PP를 첨가하였고, 활제, 분산제 및 산화방지제를 첨가하여 compounding 하였다. 또한 황토의 종류에따라 적황토, 호황토, 홍토, 백토, 흑토등으로 구분되고, 각각의 황토 마다 다양한 종류의 입도를 가지고 있으며, 또한 환경 친화적이며 난연성을 부여하기 위하여 다양한 조성으로 compounding 하였다, 황토의 종류에 따른 복합재료의 물성으로부터 기계적 특성치, 원적외선 방사율, 난연성등을 확인하고, 친환경 난연 복합소재 기술을 연구하였다. 적황토의 경우 황토의 함량이 많을수록 인장강도는 작아지는 경향을 나타냈으며, 입도가 작을수록 인장강도가 커지는 경향을 나타냈다. 파단신율의 경우 적황토(#2000)에서 가장 양호하게 나타났으며, 굴곡강도, 충격강도의 경우 적황토(#5000)에서 MI 의 경우 적황토(#325)에서 양호하게 나타났다.

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Nylon 66 Viscosity Effect on Mechanical Properties of Nylon 66/Cloisite 93A Nanocomposite (Nylon 66/Cloisite 93A 나노복합체의 기계적 성질에 대한 Nylon 66 점도 효과)

  • Park, Sang-Cheol;Kim, Ho-Gyum;Min, Kyung-Eun
    • Polymer(Korea)
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    • v.37 no.1
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    • pp.100-112
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    • 2013
  • It is found that the commercialization of nylon 66/Cloisite 93A nanocomposite by applying melt intercalation is possible in the composite production facilities of the pilot scale which has been generalized today. The strength and modulus under tensile and flexural stress have been improved with the introduction of Cloisite 93A in nylon 66. Furthermore, it is found through the analysis of morphologic and crystallization behavior that the elements such as content of Cloisite 93A, viscosity of nylon 66 and the crystallization behavior have significantly influences on the characteristics of nanocomposite.

The Clinical Study for the Effects of Flexion-Distraction Technique on Patients with Low Back Pain (요통 환자의 굴곡신연기법의 효과에 대한 임상적 연구)

  • Jung, Won-Hee;Seo, Sang-Kyoung;Park, Kuk-Ji;Kang, Jun-Hyuk
    • Journal of Korean Medicine Rehabilitation
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    • v.20 no.3
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    • pp.61-74
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    • 2010
  • Objectives : The purpose of this study is to find out the effects of flexion-distraction technique on low back pain. Methods : The 40 patients were divided into 2 groups: group a was treated except flexion-distraction technique and group B was treated with flexion-distraction technique. Both groups were treated with acupuncture treatment, physical therapy and manipulation. Patients were evaluated by McGill pain questionnaire-short form(SF-MPQ), visual analogue scale(VAS), Oswestry disability index(ODI) and pain disability index(PDI). Results : 1. Both Groups were significantly decreased in VAS and ODI after 3 weeks of treatment. 2. Group B compared with Group A was significantly decreased in SF-MPQ, VAS, ODI and PDI after 3 weeks of treatment. Conclusions : We found out that flexion-distraction technique is considered to be effective and useful on low back pain.

Image Processing for Pig's Head Removal (돼지 머리 제거를 위한 영상 처리)

  • Ahn, Han-Se;Choi, Won-Seok;Lee, Han-Hae-Sol;Chung, Yong-Wha;Park, Dai-Hee
    • Proceedings of the Korea Information Processing Society Conference
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    • 2019.05a
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    • pp.621-624
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    • 2019
  • 돈사에서 돼지의 무게는 돼지의 건강이나 성장 상태, 출하 여부, 사육 환경, 사료 배급을 결정하는 주요 요인 중 하나이다. 이에 따라 돈사에서 돼지의 무게를 측정하는 것은 중요한 문제이다. 돼지의 무게 측정을 위해 Top-view 카메라에서 획득한 영상으로부터 돼지의 픽셀 수를 정확히 측정하기 위해서는 돼지의 머리 부분을 제거할 필요가 있다. 본 논문에서는 Convex-hull을 이용하여 돼지 모양에서의 오목 점과 돼지의 중심으로부터의 거리 정보를 이용함으로써 돼지의 머리를 효과적으로 탐지 및 제거하는 방법을 제안한다. 먼저, 이진화된 돼지의 이미지에서 Convex-hull 알고리즘을 수행 후, 돼지의 중심점 좌표로부터 일정 굴곡 이상의 오목 점 중 가장 가까운 점의 좌표를 획득한다. 이후 앞서 획득한 점의 좌표와 중점의 좌표 사이 일정 길이와 각도를 가지는 또 다른 점의 좌표를 획득하고, 두 점을 기준으로 돼지의 몸통과 머리를 분리하였다. 실험결과, 높은 정확도와 적은 수행시간으로 돼지의 머리를 탐지하고 제거할 수 있음을 확인하였다.

The Physical Properties of Ethylene Vinylacetate Emulsion Mixed with SBR, Urethane, Epoxy and Acryl Latex (아크릴, 에폭시, 우레탄 및 SBR계 라텍스를 혼합한 에틸렌 비닐아세테이트계 에멀젼 수지의 물리적 특성)

  • Suh, Won-Dong
    • Elastomers and Composites
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    • v.35 no.3
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    • pp.196-204
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    • 2000
  • SBR, polyurethane, acryl and epoxy latex were separately mixed with ethylene -vinylacetate emulsion(EVA) in the range of $0{\sim}50wt%$. For the mixtures, the various physical properties such as defoamerability, mechanical property, and water resistance were experimentally examined. The excellent defoamer was BYK-021 and the appropriate use of it was 0.3 phr for the total components. The shrinkage of compounds was influenced by the compatability of resins and the formation of voids. The mechanical properties was related to the cohesive force of resin particles, the coagulation of cement particles and the co-bonding of resin particles with cement particles. Mixing latex separately showed better properties then non-mixing in the shrinkage ratio, flexural strength, adhesive strength, and impact strength. The water resistance of composites mixed with cement was worse than that of EVA resin.

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The Effect of Anti-flexion Taping at the Proximal Interphalangeal Joints on the Gait in Stroke Patients with Clawing Toe (갈고리 발가락에 대한 근위지절관절 굴곡 방지 테이프가 뇌졸중 환자의 보행에 미치는 효과)

  • Kim, Min-Suk;Goo, Bong-Oh
    • PNF and Movement
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    • v.9 no.3
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    • pp.25-29
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    • 2011
  • Purpose : We investigated the effect of anti-flexion taping at the proximal interphalangeal joints on the gait in stroke patients with clawing toe. Methods : Nineteen patients (mean age $63.26{\pm}9.16$ years) with clawing toe were studied. Gait performance was measured under two different conditions : (1) non-tape (2) application of tape. Gait velocity, step time and stride length were examined with the GAITRite system Results : Compared to the non-tape control condition, step time of the hemiparetic side increased significantly after the application of tape(p=0.03). There was no significant mean differences between the taped and control conditions for stride length of the hemiparetic side and velocity. Conclusion : Whilst the anti-flexion tape at the proximal interphalangeal joints changed the walking by providing significant step time effect, positive changes were noted in stride length of the hemiparetic side after tape application. These findings indicate that anti-flexion tape procedures do not significantly alter stride length of the hemiparetic side and velocity.

The Effects of Sling Exercise on Fall Risk Score, Ankle Dorsiflexion and Balance in Community-Dwelling Elderly Women (슬링운동이 여성노인의 낙상위험도, 족관절배측굴곡력 및 균형에 미치는 효과)

  • Hahm, Kyoung-Lim;Lee, Wan-Hee
    • Journal of muscle and joint health
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    • v.16 no.2
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    • pp.165-173
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    • 2009
  • Purpose: The aim of this study was to examine the effects of sling exercise on fall risk score, ankle dorsiflexion and balance in community-dwelling elderly women. Method: A 6-week prospective study was conducted to examine the effects of sling exercise. Participants were required to attend their assigned exercise classes three times a week for 6 weeks. Result: After the 6 week study period, PPA fall-risk scores were reduced by 0.90 for the exercise group, which was a significant change (p<.001). Dorsiflexion strength increased significantly (p<.01) by 1.56 kg after the sling exercise. There was a 2.0 cm-increase (p<.05) in FRT and 0.38 second-improvement (p<.01) in TUGT. A 7.88 second-increase in One-leg standing with Eyes Open and a 3.12 second-increase in One-leg standing with Eyes Closed were reported during the 6-week intervention period. Conclusion: The 6-week sling exercise reduced falls risk score significantly (p<=.001) in community-dwelling elderly women by improving fall risk related factors such as reaction time, balance and strength.