• Title/Summary/Keyword: resistive

Search Result 1,185, Processing Time 0.031 seconds

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

  • Cho, Nam-Wook;Rie, Dong-Ho;Shin, Hyun-Jun
    • Fire Science and Engineering
    • /
    • v.25 no.1
    • /
    • pp.7-12
    • /
    • 2011
  • As recent buildings are getting more high-rise and larger, steel structures, not a reinforced concrete structure, for columns and beams among the main structural members in a building are being widely used. Steels used for the main members of a building are constructed with a fire-resistive structure by applying them with fire-resistive coatings. The introduction of a simple test method that can verify the performance of fire-resistive material constructed on a site without conducting a fire-resistant test(real scale fire test) is needed and this study derived a site analysis method possible to make a rapid and scientific analysis through the analysis of components (instrumental analysis) concerning tire-resistive materials. the possibility of application of it in analyzing congruence over site construction materials by recognizing it as a standard material after securing an inherent fingerprint area of tire-resistive materials of which performance was verified in the concrete through thermal analysis was proved through experiments. This research result can be minimize of casualties, who is harmed to building collapse according to structures fire.

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

  • Yoon, Uei-Joong
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.21 no.1
    • /
    • pp.49-54
    • /
    • 2021
  • In this paper, n this paper, E-polarized electromagnetic scattering problems by a resistive strip grating between a double dielectric layer are analyzed by applying the PMM(Point Matching Method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, and the resistive boundary condition is applied to analysis of the resistive strip. The numerical results for the normalized reflected and transmitted power are analyzed by according as the relative permittivity and thickness of the double dielectric layers, and the resistivity of resistive strip. Overall, when the resistivity of the resistive strip decreased or the relative permittivity of the dielectric layer increased, the reflected power increased, and as the reflected power increased, the transmitted power decreased relatively. Especially, as the relative permittivity of double dielectric layer increases, the minimum value of the variation curve of the reflected power shifted in the direction that the grating period decreased. The numerical results for the presented structure of this paper are shown in good agreement compared to those of the existing papers.

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 (수정된 강제유도운동과 탄력밴드를 이용한 가압벨트 저항성 운동이 뇌졸중 환자의 상지 기능에 미치는 효과)

  • Kim, Tae-gon;Kim, Kyung-yoon;Bae, Sea-hyun
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
    • /
    • v.27 no.3
    • /
    • pp.25-36
    • /
    • 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.

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

  • Dong-eun Kim;Geonwoo Kim;Hyung Nam Kim;Hyung-Ho Park
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.30 no.4
    • /
    • pp.32-43
    • /
    • 2023
  • Resistive Random Access Memory (RRAM), based on resistive switching characteristics, is emerging as a next-generation memory device capable of efficiently processing large amounts of data through its fast operation speed, simple device structure, and high-density implementation. Interface type resistive switching offer the advantage of low operation currents without the need for a forming process. Especially, for RRAM devices based on transition metal oxides, various studies are underway to enhance the memory characteristics, including precise material composition control and improving the reliability and stability of the device. In this paper, we introduce various methods, such as doping of heterogeneous elements, formation of multilayer films, chemical composition adjustment, and surface treatment to prevent degradation of interface type resistive switching properties and enhance the device characteristics. Through these approaches, we propose the feasibility of implementing high-efficient next-generation non-volatile memory devices based on improved resistive switching properties.

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

  • Hwang, Mi-Soo;Bae, Kyeung-Kug;Lee, Jae-Kyo
    • Journal of Yeungnam Medical Science
    • /
    • v.14 no.1
    • /
    • pp.77-84
    • /
    • 1997
  • We measured the blood flow velocity of the anterior cerebral artery via anterior fontanelle approach of fifty five preterm neonates with duplex Doppler sonography and analyzed the waveform and calculated pulsatility index, resistive index. Intracranial velocities and pulsatility indexes were increased with increasing gestational age, birth weight, and age of the neonate, but resistive indices decreased. In sick babies, characteristic resistive index increment were seen in patients with intraventricular hemorrhage, but no statistical difference was seen in patients with respiratory distress syndrome. Our results suggest that duplex Doppler sonography is a useful noninvasive means of monitoring cerebrohemodynamics in normal preterm neonates and flow change of sick babies.

  • PDF

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- (접지된 유전체층 위에 변하는 저항율을 갖는 저항띠 격자구조에서의 전자파산란 해석 -한쪽 모서리에서 0이고 다른쪽 모서리로 가면서 무한대로 변하는 경우-)

  • Yoon, Uei-Joong
    • The Journal of Information Technology
    • /
    • v.8 no.2
    • /
    • pp.77-84
    • /
    • 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.

  • PDF

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

  • Nam, Ki-Hyun;Kim, Jang-Han;Chung, Hong-Bay
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.29 no.7
    • /
    • pp.400-403
    • /
    • 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
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.16 no.12S
    • /
    • pp.1286-1291
    • /
    • 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.

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

  • Kim, Jae-Hyun;Lim, Young-Bea;Lee, Sang-Ick;Kim, Dong-Woo
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.27 no.9
    • /
    • pp.90-99
    • /
    • 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
    • Journal of the Korean Society of Physical Medicine
    • /
    • v.14 no.1
    • /
    • pp.25-33
    • /
    • 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.