• 제목/요약/키워드: resistive

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열분석을 통한 내화 뿜칠재 일치성분석 연구 (A Research for Identification Method of Sprayed Fire-Resistive Material by Thermal Analysis)

  • 조남욱;이동호;신현준
    • 한국화재소방학회논문지
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    • 제25권1호
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    • pp.7-12
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    • 2011
  • 최근 건축물이 고층화 및 대형화됨에 따라 건축물의 주요 구조부 중 기둥과 보를 철근콘크리트가 아닌 철골구조로 많이 시공하고 있다. 건축물의 뼈대가 되는 철골에는 내화피복재를 코팅하여 화재에 견딜 수 있는 구조로 시공한다. 내화시험(실제 규모 화재시험)을 수행하지 않고 현장에 시공된 내화피복재의 성능을 확인할 수 있는 간편한 시험방법의 도입이 필요하다. 본 연구는 내화뿜칠재에 대한 성분분석(기기분석)을 통하여 과학적이며 빠른 분석이 가능한 현장분섭법을 도출하였으며 열분석을 이용하여 내화성능이 확인된 내화뿜칠재의 고유지문영역을 확보하고 이를 표준물질로 Database화하여 현장시공재료에 대한 일치 성분석에 활용 가능함을 실험을 통하여 입증하였다.

2중 유전체층 사이의 저항띠 격자구조에 의한 TM 산란에 관한 연구 (A Study on TM Scattering by a Resistive Strip Grating Between a Double Dielectric Layer)

  • 윤의중
    • 한국인터넷방송통신학회논문지
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    • 제21권1호
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    • pp.49-54
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    • 2021
  • 본 논문에서는 2중 유전체층 사이의 저항띠 격자구조에 의한 E-분극 전자파 산란 문제는 전자파 수치해석방법으로 알려진 PMM(Point Matching method)를 이용하여 해석하였다. 경계조건들은 미지의 계수를 구하기 위하여 이용하였고, 저항띠의 해석을 위해 저항띠 경계조건을 적용하였다. 2중 유전층 사이의 비유전율과 두께 및 저항띠의 저항율에 대해 정규화된 반사전력과 투과전력을 계산하였다. 전반적으로 저항띠의 저항율이 작아지거나 유전체 층의 비유전율이 증가할수록 반사전력은 증가하였으며, 반사전력이 증가하면 투과전력은 상대적으로 감소하였다. 특히, 2중 유전체 층의 비유전율이 증가할수록 반사전력의 변곡점의 최소 값은 격자주기가 작아지는 방향으로 이동하였다. 본 논문의 제안된 구조에 대한 수치결과들은 기존논문의 수치해석 결과들과 비교하여 매우 잘 일치하였다.

수정된 강제유도운동과 탄력밴드를 이용한 가압벨트 저항성 운동이 뇌졸중 환자의 상지 기능에 미치는 효과 (The Effect of Modified Constraint-induced Movement Therapy and Resistive Exercise Using Elastic Band with Pressure Belt on Affected Upper Limb Function in Stroke Patients)

  • 김태곤;김경윤;배세현
    • 대한정형도수물리치료학회지
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    • 제27권3호
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    • pp.25-36
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    • 2021
  • Background: This study aimed to investigate the effect of modified constraint-induced movement therapy (mCIMT) and resistive exercise using elastic band with pressure belt on improving upper extremity function in stroke patients. Methods: Sixteen patients with stroke were randomly assigned to a control group that received mCIMT and resistive exercise using elastic band (n=8) and an experimental group that received mCIMT and resistive exercise using elastic band with pressure belt (n=8). Over the course of four weeks, mCIMT were conducted 60 minute three times per week and resistive exercise using elastic band (with pressure belt) were conducted twice daily, three times per week. The function of the upper extremities were evaluated before, after 2 weeks and 4 weeks using the grip strength test (GST), the box and block test (BBT), and motor activity log (MAL). Results: The values for the GST, the BBT, and MAL increased in both groups as the treatment period progressed. The values for the GST (p<.01), the BBT (p<.001), and MAL (p<.001) were significantly higher in the experimental group than in the control group at 4 weeks after initiating the treatment. Conclusion: We found that mCIMT and wearing a pressure belt during resistive exercise was very useful in improving the function of the upper extremities in patients with stroke.

전이 금속 산화물 기반 Interface-type 저항 변화 특성 향상 연구 동향 (Research Trends on Interface-type Resistive Switching Characteristics in Transition Metal Oxide)

  • 김동은;김건우;김형남;박형호
    • 마이크로전자및패키징학회지
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    • 제30권4호
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    • pp.32-43
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    • 2023
  • 저항 변화 메모리 소자(RRAM)는 저항 변화 특성을 기반으로 빠른 동작 속도, 간단한 소자 구조 및 고집적 구조의 구현을 통해 많은 양의 데이터를 효율적으로 처리할 수 있는 차세대 메모리 소자로 주목받고 있다. RRAM의 작동원리 중 하나로 알려진 interface type의 저항 변화 특성은 forming process를 수반하지 않고 소자 크기를 조절하여 낮은 전류에서 구동이 가능하다는 장점을 갖는다. 그 중에서도 전이 금속 산화물 기반 RRAM 소자의 경우, 정확한 물질의 조성 조절 방법과 소자의 신뢰성 및 안정성과 같은 메모리 특성을 향상시키기 위해 다양한 연구가 진행 중에 있다. 본 논문에서는 이종 원소의 도핑, 다층 박막의 형성, 화학적 조성 조절 및 표면 처리 등의 방법을 이용하여 interface type 저항 변화 특성의 저하를 방지하고 소자 특성을 향상시키기 위한 다양한 방법을 소개하고자 한다. 이를 통해 향상된 저항 변화 특성을 기반으로 한 고효율 차세대 비휘발성 메모리 소자의 구현 가능성을 제시한다.

이중 초음파 검사를 이용한 미숙아의 전 뇌동맥 혈류 측정 (The Measurement of Blood Flow of Anterior Cerebral Artery in Premature Newborns Using Duplex Doppler Ultrasonography)

  • 황미수;배경국;이재교
    • Journal of Yeungnam Medical Science
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    • 제14권1호
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    • pp.77-84
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    • 1997
  • 55명의 미숙아를 대상으로 이중 도플러 초음파 검사를 실시하여 대천문을 통한 전 뇌동맥의 혈류속도 및 혈류형태를 조사하였다. 미숙아에서 뇌 혈류속도 및 pulsatility index는 재태기간, 출생 체중, 및 미숙아의 나이 등의 증가에 따라 비례하여 증가하였으나 resistive index는 감소하였다. 뇌실 출혈이 있는 환아 군에서는 특징적인 resistive index의 증가가 보였지만 혈류속도 및 plusatility index는 불규칙하였다. 정상 미숙아의 뇌혈류 관찰 및 환아 군에서의 뇌혈류 검사에서 이중 도플러 초음파 검사는 비침습적이고 재현성도 뛰어나 선별검사로 유용한 방법이라고 생각한다.

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접지된 유전체층 위에 변하는 저항율을 갖는 저항띠 격자구조에서의 전자파산란 해석 -한쪽 모서리에서 0이고 다른쪽 모서리로 가면서 무한대로 변하는 경우- (Analysis of the Electromagnetic Scattering by a Resistive Strip Grating Tapered Resistivity On a Grounded Dielectric Plane -from Zeores at One Edge to Infinite at the Other Edge-)

  • 윤의중
    • 정보학연구
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    • 제8권2호
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    • pp.77-84
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    • 2005
  • In this paper, electromagnetic scattering problems by a resistive strip grating with tapered resistivity on a grounded dielectric plane according to strip width and spacing, relative permittivity and thickness of dielectric layers, and incident angles of a electric wave are analyzed by applying the Fourier-Galerkin Moment Method known as a numerical procedure. The boundary conditions are applied to obtain the unknown field coefficients and the resistive boundary condition is used for the relationship between the tangential electric field and the electric current density on the strip. The resistivity of resistive strips in this paper varies from zeroes at one edge to infinite at the other edge, then the induced surface current density on the resistive strip is expanded in a series of Jacobi polynomials of the order ${\alpha}=0.2,\;{\beta}=-0.2$ as a orthogonal polynomials. The numerical results of the geometrically normalized reflected power in this paper are compared with those for the existing perfectly conducting strip. The numerical results of the normalized reflected power for conductive strips case with zero resistivity in this paper show in good agreement with those of existing papers.

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금속-절연층-실리콘 구조에서의 비정질 GeSe 기반 Resistive Random Access Memory의 동작 특성 (Operating Characteristics of Amorphous GeSe-based Resistive Random Access Memory at Metal-Insulator-Silicon Structure)

  • 남기현;김장한;정홍배
    • 한국전기전자재료학회논문지
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    • 제29권7호
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    • pp.400-403
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    • 2016
  • The resistive memory switching characteristics of resistive random access memory (ReRAM) using the amorphous GeSe thin film have been demonstrated at Al/Ti/GeSe/$n^+$ poly Si structure. This ReRAM indicated bipolar resistive memory switching characteristics. The generation and the recombination of chalcogen cations and anions were suitable to explain the bipolar switching operation. Space charge limited current (SCLC) model and Poole-Frenkel emission is applied to explain the formation of conductive filament in the amorphous GeSe thin film. The results showed characteristics of stable switching and excellent reliability. Through the annealing condition of $400^{\circ}C$, the possibility of low temperature process was established. Very low operation current level (set current: ~ ${\mu}A$, reset current: ~ nA) was showed the possibility of low power consumption. Particularly, $n^+$ poly Si based GeSe ReRAM could be applied directly to thin film transistor (TFT).

Operating Properties of Resistive Superconducting fault Current Limiters with Various Pattern Shapes

  • Park, Hyo-Sang
    • 한국전기전자재료학회논문지
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    • 제16권12S호
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    • pp.1286-1291
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    • 2003
  • Quench behavior of resistive superconducting fault current limiters (SFCLS) with various pattern shapes was investigated. The pattern shapes employed were meander, bi-spiral, and spital shapes of identical line width, gap and margin. SFCLS were fabricated from YBCO thin films grown on two-inch diameter Al$_2$O$_3$ substrates under the same conditions. The total length of current limiting paths was the shortest at the spital shape due to its larger useless space. Inductance component of SFCLs with the spiral shape was around two times as high as those of other two shapes. This is not desirable since impedance characteristics of existing power systems can be changed. Resistance rise of current limiting elements was low at a spiral shape before the whole quench completion, which may act as a disadvantage for simultaneous quench in serial connection between current limiting elements, but the temperature tended to have similar values at higher voltages. On the other hand, hi-spital shape was severe at insulation level between current limiting lines. When these aspects were considered, we concluded that a meander shape was appropriate to design for a resistive SFCL based on thin films except the concentration of electric field at edge areas of strip lines.

인체 통전전류 위상 분석을 통한 저항성 누설전류 감시의 유효성 분석 (The Effectiveness Analysis of the Resistive Leakage Current Monitoring by Analyzing the Phase of the Body Current)

  • 김재현;임용배;이상익;김동우
    • 조명전기설비학회논문지
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    • 제27권9호
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    • pp.90-99
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    • 2013
  • To analyze the effectiveness of the resistive leakage current monitoring as a technology preventing electrical accidents, in this paper, we have estimated the phase of the body impedance by using the body impedance model and the body impedance data from IEC. We also have analyzed the phase of the electric body current in the case of 60Hz/220V. From these results, we concluded that deliberate researches about the phase of the electrical body current and related regulations must be carried out before the resistive leakage current monitoring unit is used to protect electric shock. And we concluded that the resistive leakage current monitoring unit can be utilized to prevent electrical fires caused by electric leakage current without unwanted circuit break due to capacitive leakage current flowing from line filter capacitors to the earth.

Effects of different Diaphragm Breathing Methods on the Diaphragm Thickening Ratio and Pulmonary Function in Young Adults

  • Ha, Tae-Won;Lee, Myung-Mo
    • 대한물리의학회지
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    • 제14권1호
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    • pp.25-33
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    • 2019
  • PURPOSE: This study examined the effective impact of self and resistive and ultrasound-biofeedback diaphragm breathing on the pulmonary function and diaphragm thickening ratio of young adults. METHODS: Thirty normal adults were assigned randomly to three experimental groups (self- diaphragm breathing (n=9), resistive-diaphragm breathing (n=11), ultrasound-biofeedback diaphragm breathing (n=10)). Each group participated for 15 minutes for times with a two minute rest between two sets. The subjects were assessed using the pre- and post- diaphragm thickening ratio and the pulmonary function (forced vital capacity, forced expiratory volume at one second, maximal voluntary ventilation, and respiratory rate) on the thirty subjects. A paired t-test was to determine the difference between before and after the experiment in each group of diaphragm breathing before and after the exercises. One-way ANOVA was used to determine the differences between the groups. RESULTS: The forced vital capacity and maximal voluntary ventilation measurements revealed a significant difference in the resistive-diaphragm breathing group than the other two groups. On the other hand, there was no significant difference between the self-diaphragm breathing and ultrasound-biofeedback breathing groups. CONCLUSION: The resistive-diaphragm breathing group showed greater improvement in the pulmonary function than the other two groups. Therefore, resistive-diaphragm breathing will improve the pulmonary function on normal young adults.