• Title/Summary/Keyword: External Effect

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Effect of an External AC Magnetic field on Dynamic Resistance and Loss Characteristic in a Bi-2223 Tape (외부 교류자장이 Bi-2223테이프의 동저항 및 손실특성에 미치는 영향)

  • Ryu, Kyung-Woo;Choi, Byoung-Ju
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.18 no.5
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    • pp.473-477
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    • 2005
  • A Bi-2223 tape has been developed for power applications such as a fault current limiter, a power cable and a superconducting magnetic energy storage system. In such applications, the Bi-2223 tape carries time varying transport current and in addition experiences time varying external magnetic field. It is well known that the external magnetic field not only causes magnetization loss in the Bi-2223 tape, but also drastically increases transport loss due to a so-called 'dynamic resistance' We developed an evaluation setup, which can measure transport loss in external at magnetic fields. Using this equipment, we measured the dynamic resistances for various amplitudes and frequencies of an external at magnetic field perpendicular to the face in the tape. Simultaneously we investigated the effect of an external ac field on transport loss with different experimental conditions. This paper describes test results ana discussions on correlation between the dynamic resistance and the transport loss for the Bi-2223 tape.

An effect of using internet health information of University students according to their internal and external health control (일부 대학생들의 내·외적 건강컨트롤에 따른 인터넷 건강정보 이용효과)

  • Kim, Seung-Dae;Kim, Myung-Gwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.3069-3073
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    • 2014
  • It's now time for adopting u-Health according to development of internet. It is judged that it needs to research on effect of using internet health information targeting University students who are the most sensitive of internet health information. So we analyzed effect of using internet health information according to internal and external health control materials with 300 University students. As a result, If a rate of investment to the health is high, an effect of internet health information also increases as B=.004, rate of internal health control is high, it decreases as B=-.027 and rate of external health control is high, it increases as B=.037. For a University student who has steady faith about health and can control their internal health more easily, the effect of using internet health information has decreased. And for a University student who has high inclination of external dependence about health and can control their external health more easily, the effect of using internet health information has increased. So it needs to raise credibility, accuracy and accessibility of internet health information.

An Experiment of Flexural Behavior for the Damaged Low Reinforced Concrete Beams Rehabilitated with External Tendons (손상된 저보강 RC보의 외부 긴장 보강 후 휨거동 실험)

  • Yoo, Sung Won;Suh, Jeong In
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.3
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    • pp.40-47
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    • 2013
  • Most experiments carried out in the previous studies dealt with the highly reinforced concrete beams (RC beams) in case of rehabilitating with external tendon. However, the reinforcing effect of external tendons cannot be clearly analyzed in this kind of RC beams because the rehabilitating tendon quantity for it is too small. By this reason, this study chose the low RC beams rehabilitated with external tendons. Therefore, in this study, 7 test beams were manufactured and flexural behavior tests were performed to assess the reinforcing effect and to find more proper rehabilitating method by external tendon. The reinforcing effect increased according to the quantity of tendons, and was especially added by repairing cracks with epoxy resin. It was shown that the design equations of AASHTO 1994 and ACI-318 did not show a good agreement with test results. The result of this study will be able to be used effectively in finding the more proper rehabilitating method of the damaged RC beams.

Study on the Piezoelectric Direct Effect of PVDF Film (PVDF 필름의 압전정효과에 관한 연구)

  • 이용국;한득영
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.9
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    • pp.786-790
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    • 2000
  • This paper is concerned on the theoretical and experimental approaches of direct piezoelectric effect in the PVDF film. When a cantilever structure of PVDF film is bended by the external force, electric charges are concentrated on the electrode surface of the film due to the direct piezoelectric effect, and output voltage is induced from the terminals of the film. In this paper, a symbolic equation between the external force and the output voltage was introduced. Moreover, the theoretical output voltages were compared with the experimental results by falling balls, which were agreed well each other. This results can be useful in a warning system of abnormal pulse rate and breathing, and in detecting impact force and/or mechanical energy using bending of PVDF film.

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A study on the pressure behaviour during the rupture by gas explosion

  • Kim, Min-Kyu;Oh, Kyu-Hyung;Kim, Hong
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.275-281
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    • 1997
  • The destruction by accident is affected by the blast of explosion. However, there are few of research on the external effect of vented gas explosions. Therefore it is necessary to study the effect of vented explosion. This study aims to find the characteristics of gas explosion, and the effect of vented gas explosion. Using an explosion chamber, we obtained a LPG explosion characteristics according to the vent size and concentration. The result of experiment showed that the explosion pressure effect to external space was much stronger than inner space during the course of a gas explosion. And the external pressure become higher in explosion pressure as the vent diameter become smaller.

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Effect of External Acoustic Excitation on Wake behind a Circular Cylinder (외부 음향여기가 원주 후류 유동에 미치는 효과에 관한 연구)

  • Choi, Jae-Ho;Lee, Sang-Joon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.5
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    • pp.603-609
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    • 1999
  • The effect of an external acoustic excitation on the wake structure behind a circular cylinder was experimentally investigated. The sound wave was excited in the frequency range of the shear layer instability and two sound pressure levels of 114 and 120dB were used in this study. As a result, the acoustic excitation modified the wake structure by increasing the velocity fluctuation energy without changing the vortex shedding frequency. The acoustic excitation enhanced the vortex shedding process and promoted the shear layer instability. Consequently, the acoustic excitation reduced the length of the vortex formation region and decreased the base pressure. In addition, the vortex strength of vortices was increased and the width of the wake was spread out due to the acoustic excitation. When the excitation frequency was identical to the shear layer instability frequency, the effect of the external flow control on the cylinder wake was maximized. In addition, with increasing the sound pressure level, the effect of the external acoustic excitation on the wake structure increased.

A Study of Carbon Nanotube Channel Field-Effect Devices (탄소 나노튜브 채널을 이용한 전계효과 이온-전송 소자 연구)

  • Lee, Jun-Ha;Lee, Hoong-Joo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.2
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    • pp.168-174
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    • 2006
  • We investigated field-effect ion-transport devices based on carbon nanotubes by using classical molecular dynamics simulations under applied external force fields, and we present model schematics that can be applied to the nanoscale data storage devices and unipolar ionic field-effect transistors. As the applied external force field is increased, potassium ions rapidly flow through the nanochannel. Under low external force fields, thermal fluctuations of the nanochannels affect tunneling of the potassium ions whereas the effects of thermal fluctuations are negligible under high external force fields. Since the electric current conductivity increases when potassium ions are inserted into fullerenes or carbon nanotubes, the field effect due to the gate, which can modify the position of the potassium ions, changes the tunneling current between the drain and the source.

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Convergence Held technology commercialization Effects on Performance (융복합 보유기술이 사업화성과에 미치는 영향)

  • Jeon, In-Oh
    • Journal of Digital Convergence
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    • v.13 no.8
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    • pp.101-112
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    • 2015
  • The company's technical reserves in accordance with the internal skills and external technology commercialization capacity and to analyze the impact on the performance of technology commercialization and financial performance of the company. External technology funding, internal and external technologies marketing, internal and external technologies production, outside of the external Technology Commercialization technique was investigated to affect the financial performance. Financing, marketing capability, and the production base is completely mediated effect acting from within the technology business technical achievement, but funding and the regulation of full-mediated effects on the financial performance in the external action, technical marketing skills and capacity of external technology in part mediated effect was investigated by the effect on financial performance.

The Effect of External Divalent Cations on Intestinal Pacemaking Activity

  • Kim, Byung-Joo;Kim, Ki-Whan
    • The Korean Journal of Physiology and Pharmacology
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    • v.9 no.4
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    • pp.203-207
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    • 2005
  • Electrical rhythmicity in the gastrointestinal (GI) muscles is generated by pacemaker cells, known as interstitial cells of Cajal (ICC). In the present study, we investigated the effect of external divalent cations on pacemaking activity in cultured ICC from murine small intestine by using whole-cell patch clamp techniques. ICC generated pacemaker currents under a voltage clamp or electrical pacemaker potentials under a current clamp, and showed a mean amplitude of $-500{\pm}50$ pA or $30{\pm}1$ mV and the frequency of $18{\pm}2$ cycles/min. Treatments of the cells with external 0 mM $Ca^{2+}$ stopped pacemaking activity of ICC. In the presence of 2 mM $Ca^{2+}$, 0 mM external $Mg^{2+}$ depolarized the resting membrane potential, and there was no change in the frequency of pacemaking activity. However, 10 mM external $Mg^{2+}$ decreased the frequency of pacemaking activity ($6.75{\pm}1$ cycles/min, n=5). We replaced external 2 mM $Ca^{2+}$ with equimolar $Ba^{2+}$, $Mn^{2+}$ and $Sr^{2+}$, and they all developed inward current in the sequence of $Ba^{2+}$>$Mn^{2+}$>$Sr^{2+}$. Also the frequency of the pacemaking activity was stopped or irregulated. We investigated the effect of 10 mM $Ba^{2+}$, $Mn^{2+}$ and $Sr^{2+}$ on pacemaking activity of ICC in the presence of external 0 mM $Mg^{2+}$, and found that 10 mM $Ba^{2+}$ and $Mn^{2+}$ induced large inward current and stopped the pacemaking activity of ICC (n=5). Interestingly, 10 mM $Sr^{2+}$ induced small inward current and potentiated the amplitude of pacemaking activity of ICC (n=5). These results indicate that extracellular $Ca^{2+}$ and $Mg^{2+}$ are requisite for the pacemaking activity of ICC.

A Comparative Study of the Effect of External Ultrasound with Power Assisted Liposuction(PAL) (Power Assisted Liposuction(PAL)과 병용한 외부 초음파의 효과에 대한 비교 연구)

  • Song, In Soo;Park, Jun;Yoo, Young Cheun;Yang, Won Yong;Kim, Jin Young
    • Archives of Plastic Surgery
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    • v.32 no.4
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    • pp.496-502
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    • 2005
  • This study was performed to compare the effect of external ultrasound assisted PAL(power assisted liposuction) with that of PAL alone. We performed 17 cases of liposuction from January 2003 to June 2003. For comparing both systems, we treated the right side(study group) with external ultrasound assisted PAL and the left side(control group) with PAL alone. To evaluate the difference in results between two groups, we surveyed three objective and four subjective items. Objectives were categorized as "Reduction rate of postoperative swelling", "Efficiency of suction" and "Histologic finding of aspirated fat tissue". Subjectives were also filed as "Degree of postoperative bruising", "Cannula resistance that operator felt", "Degree of postoperative pain" and "Patient's satisfaction". We assessed by questionnaire three times at 1day, 7 days and 30 days after operation. There were statistically significant differences in two of the subjective items; "Degree of postoperative pain at postoperative 1 day" and "Cannula resistance that operator felt". This study concludes that external ultrasound PAL is more effective high mobility of fat tissue and low tension of surrounding tissue. External ultrasound PAL will be more useful in case of large volume liposuction and revision procedures.