• Title/Summary/Keyword: resistive

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The Influence of Aerobic Exercise and Resistive Exercise with Hypertension in the Elderly (유산소 운동과 저항성 운동이 노인들의 고혈압에 미치는 영향)

  • Lee, Sang-Yeol;Jung, Hyoun-Sung;Shim, Jae-Myoung;Kim, Eun-Jung;Kim, Seung-Jun
    • Journal of the Korean Society of Physical Medicine
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    • v.3 no.4
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    • pp.261-268
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    • 2008
  • Purpose : This study was to investigate the effects of aerobic exercise and resistive exercise program on hypertension in the elderly. Methods : Subjects were allocated into one of three groups (aerobic exercise group, resistive exercise group, control group). Blood pressure was measured pre- and post-exercise in each exercise group. Data were analyzed with paired t-test and one-way ANOVA to determine blood pressure differences. Results : The results of this study were as follows. 1) The systolic blood pressure of the aerobic exercise group decreased significantly after exercise (p<.05). 2) The diastolic blood pressure of the resistive exercise group decreased significantly after exercise (p<.05). 3) There was a significant decrease in systolic blood pressure of aerobic exercise group compared with control group following the exercise. 4) There was no significant differences in diastolic blood pressure among three groups following the exercise (p>.05). Conclusion : Aerobic exercise and resistive exercise program were effective in reducing systolic blood pressure and diastolic blood pressure of the hypertension in the elderly. Thus, this program can be recommended as an effective intervention for the elderly. Therefore, regular and continued those exercises will be the solution for decreasing systolic blood pressure and diastolic blood pressure.

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A identification of sprayed fire-resistive materials by near-infrared spectroscopy (근적외선 분광 분석법을 이용한 내화뿜칠재 일치성분석)

  • Cho, Nam-Wook;Shin, Hyun-Jun;Cho, Won-Bo;Lee, Seong-Hun;Rie, Dong-Ho;Kim, Hyo-Jin
    • Analytical Science and Technology
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    • v.24 no.2
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    • pp.85-93
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    • 2011
  • To protect the steel structure in a high story buildings from fire, the sprayed fire-resistive materials are applied during the construction. Current standard methods to check the quality of sprayed fire-resistive materials are real fire test in lab, which take a long time (several weeks) and expensive. In this study, a simple analytical method to check the quality of sprayed fire-resistive materials is developed using Near Infrared Spectroscopy (NIR). Total 9 kinds of sprayed fire-resisted materials and 3 kinds of normal sprayed material sets were used for the analysis. Each set of materials was 50 to 100 samples. Samples are grinded and make a fine powder. The spectral data acquisition was carried out using FT-NIR spectrometer with a integrating sphere. NIR methods successfully identify the sprayed fire resistive materials by a principle component analysis (PCA) after a vector normalization (SNV) pretreatment.

Resistive Switching Behavior of Cr-Doped SrZrO3 Perovskite Thin Films by Oxygen Pressure Change (산소 분압의 변화에 따른 Cr-Doped SrZrO3 페로브스카이트 박막의 저항변화 특성)

  • Yang, Min-Kyu;Park, Jae-Wan;Lee, Jeon-Kook
    • Korean Journal of Materials Research
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    • v.20 no.5
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    • pp.257-261
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    • 2010
  • A non-volatile resistive random access memory (RRAM) device with a Cr-doped $SrZrO_3/SrRuO_3$ bottom electrode heterostructure was fabricated on $SrTiO_3$ substrates using pulsed laser deposition. During the deposition process, the substrate temperature was $650^{\circ}C$ and the variable ambient oxygen pressure had a range of 50-250 mTorr. The sensitive dependences of the film structure on the processing oxygen pressure are important in controlling the bistable resistive switching of the Cr-doped $SrZrO_3$ film. Therefore, oxygen pressure plays a crucial role in determining electrical properties and film growth characteristics such as various microstructural defects and crystallization. Inside, the microstructure and crystallinity of the Cr-doped $SrZrO_3$ film by oxygen pressure were strong effects on the set, reset switching voltage of the Cr-doped $SrZrO_3$. The bistable switching is related to the defects and controls their number and structure. Therefore, the relation of defects generated and resistive switching behavior by oxygen pressure change will be discussed. We found that deposition conditions and ambient oxygen pressure highly affect the switching behavior. It is suggested that the interface between the top electrode and Cr-doped $SrZrO_3$ perovskite plays an important role in the resistive switching behavior. From I-V characteristics, a typical ON state resistance of $100-200\;{\Omega}$ and a typical OFF state resistance of $1-2\;k{\Omega}$, were observed. These transition metal-doped perovskite thin films can be used for memory device applications due to their high ON/OFF ratio, simple device structure, and non-volatility.

Electrical Characteristics Analysis of Resistive Memory using Oxygen Vacancy in V2O5 Thin Film (산소공공을 이용한 V2O5 저항성 메모리의 전기적인 동작특성 해석)

  • Oh, Teresa
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.10
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    • pp.1827-1832
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    • 2017
  • To observe the characteristics to be a resistive memory of $V_2O_5$ deposited by oxygen various gas flows and annealed, the hysteresis curves of $V_2O_5$ were analyzed. The good resistive memory was obtained from the electrical characteristics of $V_2O_5$ films with the Schottky contact as a result of electron-hole pair, and the oxygen vacancy generated from the annealing process contributes the high quality of Schottky contact and the formation of resistive memories. The balanced Schottky contacts owing to the oxygen vacancy effect as the result of an ionic reaction were formed at the $V_2O_5$ film annealed at $150^{\circ}C$ and $200^{\circ}C$ and the balanced Schottky contact with negative to positive voltages enhanced the electrical operation with write/erase states according to the forward or reverse bias voltages for the resistive memory behavior due to the oxygen vacancy.

Effect of Non-lattice Oxygen Concentration on Non-linear Interfacial Resistive Switching Characteristic in Ultra-thin HfO2 Films

  • Kim, Yeong-Jae;Kim, Jong-Gi;Mok, In-Su;Lee, Gyu-Min;Son, Hyeon-Cheol
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.359-360
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    • 2013
  • The effect of electrode and deposition methods on non-linear interfacial resistive switching in HfO2 based $250{\times}250$ nm2 cross-point device was studied. HfO2 based device has the interfacial resistive switching properties of non-linearity and self-compliance current switching. The operating current in HfO2 based device was increased with negatively increasing the heat of formation energy in top electrode. Also, it was investigated that the operating current in HfO2 based device was changed with deposition methods of O3 reactant ALD, H2O reactant ALD and dc reactive sputtering, resulting the magnitude of the operating current and on/off ratio in order of HfO2 films deposited by dc reactive sputtering, H2O reactant ALD, and O3 reactant ALD. To investigate the effect of electrode and deposition methods on operating current of non-linear interfacial resistive switching in the cross-point device, X-ray photoelectron spectroscopy was measured. Through the analysis of O 1s spectra, non-lattice oxygen concentration, which is closely related to oxygen vacancies, was increased in order of Pt, TiN, and Ti top electrodes and in order of O3 reactant ALD, H2O reactant ALD, and O3 reactant ALD, and dc reactive sputtering deposition method. From all results, non-lattice oxygen concentration in ultra-thin HfO2 films play a crucial role in the operating current and memory states (LRS & HRS) in the non-linear interfacial resistive switching.

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A Detection Method of Resistive Leakage Current Flowing through ZnO Arrester Blocks (산화아연 피뢰기소자에 흐르는 저항분 누설전류의 검출기법)

  • 이복희;강성만
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.3
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    • pp.67-73
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    • 2001
  • This paper resents a developed measuring device of resistive leakage current and a fundamental discussion of deterioration diagnosis for Zinc Oxide(ZnO) arrester blocks. We have developed the leakage current detection device for ageing test and durability evaluation for ZnO arrester blocks. The resistive leakage current can be used as an indicator to discriminate whether the ZnO arrester blocks is in good state or in bad. The resistive leakage current measuring system with the compensation circuit was designed and fabricated. The sauce tests for ZnO arrester blocks were investigated by observing the resistive leakage current together with fast Fourier transform analysis. The proposed monitoring systems for the resistive leakage current can effectively be used to investigate the electrophysical properties of ZnO arrester blocks in laboratory and to develop the techniques of forecasting the deterioration of ZnO arresters in electric power systems.

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

  • Yoon, Uei-Joong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.4
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    • pp.21-26
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    • 2019
  • In this paper, TE(transverse electric) scattering problems by a resistive strip grating between a double dielectric layer are analyzed by using the PMM(point matching method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, 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 width and spacing of resistive strip, the relative permittivity and thickness of the double dielectric layers, incident angles, and uniform resisitivity. Typically, the reflected power for the conductive strip increased as the value of the relative dielectric constant increased, the reflected power for the resistive strip with uniform resistivity decreased as the value of the resisvivity increased. The numerical results for the presented structure of this paper are shown in good agreement compared to those of the existing papers.

A Study on H-polarized Electromagnetic Scattering by a Resistive Strip Grating Between a Grounded Double Dielectric Layer (접지된 2중 유전체층 사이의 저항띠 격자구조에 의한 H-polarized 전자파 산란에 관한 연구)

  • Yoon, Uei-Joong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.22 no.1
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    • pp.29-34
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    • 2022
  • In this paper, thr H-polarized scattering problems by a resistive strip grating in a grounded 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, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, and the resistive boundary condition is applied to analysis of the resistive strip. The %error of the convergence of the reflected power according to the relative permittivity of the dielectric layer and the size of the number of rows in the square matrix was compared, as the size of the number of rows in the square matrix increased, the accuracy of the reflected power increased. As the resistivity of the resistive strip decreased, the thickness of the dielectric layers decreased, and the relative permittivity of the dielectric layers increased, the reflected power increased. The numerical results for the presented structure of this paper having a grounded double dielectric layer are shown in good agreement compared to those of the existing papers.

Solution of TE Scattering Applying FGMM for Resistive Strip Grating Between a Grounded Double Dielectric Layer (접지된 2중 유전체층 사이의 저항띠 격자에 대해 FGMM을 적용한 TE 산란 해)

  • Uei-Joong Yoon
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.3
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    • pp.71-76
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    • 2023
  • In this paper, TE(transverse electric) scattering problems by a resistive strip grating between a grounded double dielectric layer are analyzed by applying the FGMM(fourier galerkin moment method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, and the resistive boundary condition is applied to analysis of the resistive strip. Overall, as the resistivity decreased, the magnitude of the current density induced in the resistive strip increased, and the reflected power also increased. In case of uniform resistivity, the reflected power decreased as the relative permittivity of the dielectric layers increased or the thickness of the dielectric layer increased. The numerical results for the presented structure in this paper are shown in good agreement compared to those of the existing papers.

Solution of TE Scattering by a Resistive Strip Grating Between a Double Dielectric Layer Using FGMM (FGMM을 이용한 2중 유전체층 사이의 저항띠 격자구조에 의한 TE 산란 해)

  • Uei-Joong Yoon
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.3
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    • pp.619-624
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    • 2023
  • In this paper, TE(transverse electric) scattering problems by a resistive strip grating between a double dielectric layer are analyzed by using the FGMM(fourier galerkin moment method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, and the resistive boundary condition is applied to analysis of the resistive strip. In order to deal with the problem of the double dielectric layer, numerical calculation was performed only when the thickness and relative permittivity of the dielectric layers had the same value. Overall, as the resistivity of the uniform resistivity increased, the current density induced in the resistive strip decreased, the reflected power decreased, and the transmitted power relatively increased. The numerical results of the structure proposed in this paper are shown in good agreement compared to the results of PMM, a numerical analysis method of the existing paper.