• Title/Summary/Keyword: Reversal Effect

검색결과 239건 처리시간 0.027초

고온초전도 직류 케이블용 절연재료인 PPLP의 직류 및 임펄스 절연 특성 (DC and Impulse Insulation Characteristics of PPLP for HTS DC Cable)

  • 김우진;방만식;김해종;조전욱;김상현
    • 한국전기전자재료학회논문지
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    • 제26권7호
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    • pp.545-549
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    • 2013
  • To realize the high-Tc superconducting (HTS) DC cable system, it is important to study not only high current capacity and low loss of conductor but also optimum electrical insulation at cryogenic temperature. A model HTS DC cable system consists of a HTS conductor, semi-conductor, cooling system and insulating materials. Polypropylene laminated paper (PPLP) has been widely adopted as insulating material for HTS machines. However, the fundamental insulation characteristics of PPLP for the development of HTS DC cable have not been revealed satisfactorily until now. In this paper, we will discuss mainly on the breakdown characteristics of 3 sheets PPLP in liquid nitrogen ($LN_2$). The characteristics of the diameter, location of butt-gap, distance between butt-gap length, pressure effect, polarity effect under DC and impulse voltage were studied. Also, the DC polarity reversal breakdown voltage of mini-model cable was measured in $LN_2$ under 0.4 MPa.

Flumazenil의 투여 방법에 따른 혈장내 농도와 midazolam에 의해 유도된 진정 상태의 환원 효과 (EFFECT OF ADMINSTRATION METHOD OF FLUMAZENIL ON THE PLASMA CONCENTRATION AND THE REVERSAL OF SEDATION INDUCED BY MIDAZOLAM)

  • 박성규;이상호;이창섭;이난영;오유향
    • 대한소아치과학회지
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    • 제32권3호
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    • pp.499-508
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    • 2005
  • Flumazenil의 투여 방법에 따른 혈중 농도와 midazolam에 의해 유도된 진정 상태의 환원 효과를 평가하기 위해 23-25세의 학생을 대상으로 비강으로 midazolam을 투여하여 진정시킨 후 flumazenil을 비강내과 정맥내를 통하여 투여한 다음 액체크로마토그래피(HPLC)를 사용하여 시간 경과에 따른 혈중 농도의 변화와 함께 생징후 및 진정 정도를 측정하여 flumazenil의 길항 효과를 다각적으로 분석, 평가하여 다음과 같은 결과를 얻었다. 1. Midazolam에 의한 진정 상태에서 flumazenil의 투여시 수축기 및 이완기 혈압, 동맥혈 산소포화도 등의 생징후는 변화가 없었으나 맥박은 일시적인 상승이 있었다(P<0.05). 2. Flumazenil은 비강내 투여 및 정맥내 투여 등 투여 방법에 관계없이 midazolam에 의한 진정 상태를 일시적으로 환원시키며 투여 방법에 따른 발현 시간의 차이는 없으나 환원 정도와 지속 시간은 정맥내 투여에서 크게 나타났다(P<0.05). 3. Flumazenil의 비강내 투여는 최고 혈중 농도에 2분, 정맥내 투여는 4분 후에 각각 도달하므로써 흡수 속도는 비강내 투여와 정맥내 투여의 차이가 크지 않았다. 4. Flumazenil의 투여 후 수 분 동안 midazolam의 혈중 농도가 일시적으로 상승하였다(P<0.05). 이상의 결과를 종합하여 보면 flumazenil은 midazolam에 의한 진정 상태에서 생징후의 변화에 영향을 미치지 않으며 진정의 정도를 감소시키는 효과가 있고, 특히 비강내 투여는 정맥내 투여와 발현 시간에 있어서 차이가 없는 것으로 나타나 임상적으로 midazolam에 의한 부작용 발현시 응급 처치법으로 유용하게 사용할 수 있을 것으로 사료된다.

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Lemna gibba $G_3$Salicylic Acid와 Dimethylsulfoxide의 영향 (Influence of Salicylic Acid and Dimethylsulfoxide on Flowering in Lemna gibba $G_3$)

  • 맹주선
    • Journal of Plant Biology
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    • 제27권4호
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    • pp.215-222
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    • 1984
  • The reversal effect of salicylic acid(SA) on inhibition of flowering in Lemna gibba $G_3$ grown on ${NH_4}^+$-free 1/2H medium under continuous light is modified by ${PO_4}^{2-}$- and $Ca^{2+}$ levels. Dimethylsulfoxide(DMSO) either depresses the SA effect in ${NH_4}^{1}$-free 1/2H medium or amplifies it in E medium. The dual action of DMSO determined by relative levels of macro and micronutrient components is discussed.

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전기화학적 기법에 의한 미생물연료전지 내부저항 특성 파악 및 전력관리시스템 연계 전압 변화와 유기물 저감에 미치는 영향 (Identification of Internal Resistance of Microbial Fuel Cell by Electrochemical Technique and Its Effect on Voltage Change and Organic Matter Reduction Associated with Power Management System)

  • 장재경;박혜민;김태영;양윤석;여정진;강석원;백이;권진경
    • 대한의용생체공학회:의공학회지
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    • 제39권5호
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    • pp.220-228
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    • 2018
  • The internal resistance of microbial fuel cell (MFC) using stainless steel skein for oxidizing electrode was investigated and the factors affecting the voltage generation were identified. We also investigated the effect of power management system (PMS) on the usability for MFC and the removal efficiency of organic pollutants. The performance of a stack microbial fuel cell connected with (PMS) or PMS+LED was analyzed by the voltage generation and organic matter reduction. The maximum power density of the unit cells was found to be $5.82W/m^3$ at $200{\Omega}$. The maximum current density was $47.53A/m^3$ without power overshoot even under $1{\Omega}$. The ohmic resistance ($R_s$) and the charge transfer resistance ($R_{ct}$) of the oxidation electrode using stainless steel skein electrode, were $0.56{\Omega}$ and $0.02{\Omega}$, respectively. However, the sum of internal resistance for reduction electrode using graphite felts loaded Pt/C catalyst was $6.64{\Omega}$. Also, in order to understand the internal resistance, the current interruption method was used by changing the external resistance as $50{\Omega}$, $300{\Omega}$, $5k{\Omega}$. It has been shown that the ohm resistance ($R_s$) decreased with the external resistance. In the case of a series-connected microbial fuel cell, the reversal phenomenon occurred even though two cells having the similar performance. However, the output of the PMS constantly remained for 20 hours even when voltage reversal occurred. Also the removal ability of organic pollutants (SCOD) was not reduced. As a result of this study, it was found that buffering effect for a certain period of time when the voltage reversal occurred during the operation of the microbial fuel cell did not have a serious effect on the energy loss or the operation of the microbial fuel cell.

PNF의 안정적 반전과 율동적 안정화 기법이 뇌졸중 환자의 보행 및 균형에 미치는 영향 (The Effect of Stabilizing Reversal and Rhythmic Stabilization in PNF on Walking and Balance in Patients with Stroke)

  • 김진인;강혜원;지민;황상수;맹관철
    • PNF and Movement
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    • 제16권2호
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    • pp.195-205
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    • 2018
  • Purpose: The purpose of this study was to demonstrate the effects of proprioceptive neuromuscular facilitation (PNF) stability techniques on walking speed, trunk stability, and balance in stroke patients. Methods: Ten stroke patients volunteered to participate in the study, and each of subjects was randomly assigned to either the stability technique (ST) group (n=5) or to the treadmill (TM) group (n=5). Each therapeutic exercise program was provided for 30 minutes a day, 5 days per week for 4 weeks. The ST group performed a PNF pattern combined with stabilizing reversal and rhythmic stabilization of the PNF stability technique. Walking speed (measured using a 10-meter walking test), trunk stability (TIS), and balance (BBS, FRT) were evaluated before and after training. All data were analyzed using SPSS version 18.0. The significance level for statistical inspection was set at 0.05. Results: Both groups showed improvements on the 10-meter walking test, the trunk impairment scale, the Berg balance scale, and the functional reaching test. Conclusion: PNF stability techniques are effective for improving trunk stability, balance, and walking speed in stroke patients. For stroke patients, PNF stability techniques are very useful and effective, including in clinical practice.

단일센서와 시간역전법을 이용한 판에서의 충격위치 결정에 관한 연구 (Determination of Impact Source Location Using a Single Transducer and Time Reversal Technique)

  • 정현조;조성종
    • 비파괴검사학회지
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    • 제32권1호
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    • pp.47-55
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    • 2012
  • 본 논문에서는 단일 센서와 시간역전 원리를 이용하여 간단한 판에서 충격 위치를 결정할 수 있는 탐상법을 다루었다. 수치적인 시뮬레이션과 실험을 통하여 시간역전에 의한 충격위치와 그 주변에서 신호의 집속효과를 관찰하고, 충격위치 결정에 영향을 미칠 수 있는 인자들(가진력의 크기, 신호의 기록시간)에 대해 살펴보았다. 이러한 결과를 기초로 두 가지 다른 충격위치에 대한 실험을 수행하고 그 결과를 가시화하였으며, 실제 충격위치를 정확하게 결정할 수 있음을 확인하였다. 여기서 제안한 방법의 특징은 단일센서를 사용하는 것과 시험체의 형상과 물성을 몰라도 된다는 점이다. 또한 판에서와 같이 분산성의 다중모드 파동이 발생하는 경우에도 특정 모드나 주파수에 의존할 필요가 없다. 따라서 기존의 충격위치 결정법에 비해 많은 장점을 지니고 있다.

PDI Dreamworks와 Pixar 애니메이션에 나타난 아이러니적 특성 연구 -<슈렉 포에버>와 <몬스터대학>을 중심으로 (A Study of Ironic Features in Full-length Animation of PDI Dreamworks and Pixar - Focusing on and )

  • 김윤정
    • 만화애니메이션 연구
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    • 통권36호
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    • pp.1-17
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    • 2014
  • 이 연구는 형식적인 측면으로 쇼트에서의 아이러니적 반전과 내용적인 측면으로 내러티브 구조 안에서 복선으로 인한 아이러니를 살펴보고자 하였다. 미국의 주요 애니메이션 제작사인 PDI Dreamworks, Pixar에서 만들어진 최근 장편 애니메이션에서 아이러니가 어떻게 사용되었는지 고찰해보고자 하였다. 표현된 것과 숨겨진 실제 간의 괴리인 아이러니는 본 연구에서 살펴본 바와 같이 두 가지로 정리된다. 아이러니는 상황설정 후 예상과 암시의 과정을 거쳐 마지막 장면에서 극적으로 나타난다. 주로 극중에 등장하는 캐릭터의 성격묘사나 사건이 일어날 배경의 설정을 위해 사용되어 웃음을 전해준다. 두 번째로 아이러니와 관련하여 애니메이션 초반에 등장한 복선이 극의 중반 또는 후반에 인과관계를 가지고 반전으로 드러났다. 이 아이러니는 극적인 요소를 강화시키며 이야기를 풍성하게 만들어주기 위해 사용되었다. 미국의 주요 제작사에서 제작된 두 편의 장편 애니메이션에서 분석해본 결과, 연속되는 장면에서의 아이러니나 내러티브 안에서 연속되는 등의 다양한 아이러니적 표현의 사용을 찾아볼 수 있었다.

PNF 목 패턴을 이용한 목 운동이 경추척수증 환자의 균형, 양팔의 저린감 및 목의 움직임에 미치는 영향 - 단일 사례 연구 - (The Effects of a Neck Exercise using a PNF Neck Pattern on the Balance and Numbness of Both the Upper Extremities and Neck Motions in Patients with Cervical Myelopathy - Single Subject Design -)

  • 박시은;임우택;문상현
    • PNF and Movement
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    • 제16권3호
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    • pp.333-343
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    • 2018
  • Purpose: The purpose of this study was to investigate the effects of a neck exercise using a proprioceptive neuromuscular facilitation (PNF) neck flexion and extension pattern on body balance in a progressive range of positions (supine, prone on elbow, and sitting), on numbness in the upper extremities, and on neck flexion motions in cervical myelopathy patients. Methods: One participant who was diagnosed with cervical myelopathy participated in this study. A reversal design (A-B-A') was used. The A and A' were the baseline period (no intervention), and B was the intervention period. The intervention used a neck extension pattern with a hold-relax technique and a neck flexion pattern with a combination of isotonic techniques in the supine position. Then, neck flexion and extension patterns were applied together with a reversal technique for stabilization, followed by a neck extension pattern with a combination of isotonic techniques in the prone position on the elbows. Finally, a neck flexion and extension pattern was used with a stabilizing reversal technique, and a neck extension pattern was applied with a combination of isotonic techniques in the sitting position for 60 minutes per day, 3 times per week for 8 weeks. To measure balance, numbness, and neck motion during neck flexion, the one-leg stand test and the visual analogue scale were used. Results: The right and left one-leg stand tests showed increased balance ability in the intervention phase. Upper extremity numbness was decreased in the intervention phase, and neck flexion motion was increased in the intervention phase. These increases were maintained after the intervention (Baseline II). Conclusion: These results suggest that a neck exercise using a PNF neck pattern with additional techniques in a progressive range of positions has a positive effect on cervical myelopathy patients for balance, numbness, and neck motion.

Depth perception enhancement based on chromostereopsis in a 3D display

  • Hong, JiYoung;Lee, HoYoung;Park, DuSik;Kim, ChangYeong
    • Journal of Information Display
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    • 제13권3호
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    • pp.101-106
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    • 2012
  • This study was conducted to enhance the cubic effect by representing an image with a sense of three-dimensional (3D) depth, using chromostereopsis, among the characteristics of human visual perception. An algorithm that enhances the cubic effect, based on the theory that the cubic effect of the chromostereoptic effect and the chromostereoptic reversal effect depends on the lightness of the background, classifies the layers of the 3D image input into the foreground, middle, and background layers according to the depth of the image input. It suits the characteristics of human visual perception because it controls the color factor that was adaptively detected through experiments on each layer; and it can achieve an enhanced cubic effect that is suitable for the characteristics of the image input.

Ionic Dependence and Modulatory Factors of the Background Current Activated by Isoprenaline in Rabbit Ventricular Cells

  • Leem, Chae-Hun;Lee, Suk-Ho;So, In-Suk;Ho, Won-Kyung;Earm, Yung-E
    • The Korean Journal of Physiology
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    • 제26권1호
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    • pp.15-25
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    • 1992
  • In order to elucidate the properties of the background current whole cell patch clamp studies were performed in rabbit ventricular cells. Ramp pulses of ${\pm}80\;mV$ from holding potential of 40 mV(or 20 mV) at the speed of 0.8 V/sec were given every 30 sec(or 10 sec) and current-voltage diagrams(I-V curve) were obtained. For the activation of the background current isoprenaline, adenosine 3',5'-cyclic monophosphate(dBcAMP), guanosine 3',5'-cyclic monophosphate(cGMP), and $N^6$-2'-o-dibutyryladenosine 3',5'-cyclic monophosphate(dBcAMP) were applied after all known current systems were blocked with 2mM Ba, 1 mM Cd ,5 mM Ni, 10 ${\mu}M$ diltiazem, 10 ${\mu}m$ ouabain, and 20 mM tetraethylammonium(TEA). The conductance of background current in control was $0.65{\pm}0.69$ nS at 0 mV, its I-V curves was almost linear and reversed near 50 mV. When there was no taurine in pipette solution, isoprenaline hardly activated the background current but when taurine existed in pipette solution, isoprenaline activated the larger background current. Cyclic AMP or cyclic GMP alone had little effect on the activation of the background current, while cGMP potentiated cGMP effect. When the background current was activated with cGMP and cAMP, isoprenaline could not further increased the background current. The background current activated by isoprenaline depended on extracellular $Cl^-$ concentration and its reversal potential was shifted according to chloride equilibrium potential. The change of extracellular $Na+$ concentration had little effect on reversal potential of the background current activated by isoprenaline.

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