• Title/Summary/Keyword: Field effect

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Electric Field Optimization using the NURB curve in a Gas-Insulated Switchgear (NURB 곡선을 이용한 가스절연 원통형 관로 내에서의 전계 최적화)

  • Han, In-Su;Kim, Eung-Sik;Min, Suk-Won;Lee, June-Ho;Park, Jong-Keun;Lee, Tae-Hyung;Park, Choon-Soo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.3
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    • pp.548-558
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    • 2009
  • This paper attempts to develop an algorithm which optimizes the electric field through the so-called NURB(Non-Uniform Rational B-spline) curve in order to improve the insulation capacity. In particular, the NURB curve is a kind of interpolation curve that can be expressed by a few variables. The electric field of a conductor is computed by Charge Simulation Method(CSM) while that of a spacer by Surface Charge Method(SCM); this mixed calculation method is adopted for the electric field optimization. For calculation of the initial and optimal shapes, the Gauss-Newton method, which is quite easy to formulate and has slightly faster convergence rate than other optimization techniques, was used. The tangential electric field, the total electric field, and the product of the tangential electric field and area (Area Effect) were chosen as the optimization objective function by the average value of electric field for the determined initial shape.

Effect of Photosensitive Carbon Nanotube Paste on Field Emission Properties (감광성 탄소나노튜브 페이스트의 조성과 열처리가 전계방출 특성에 미치는 영향)

  • Oh, Jeong-Seob;Kim, Dae-Jun;Jeong, Jin-Woo;Song, Yoon-Ho;Cho, Young-Rae
    • Korean Journal of Materials Research
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    • v.16 no.9
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    • pp.550-556
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    • 2006
  • Photosensitive carbon nanotube (CNT) pastes are explored to develop a CNT field emitter for field emission display (FED) application. We formulated a photosensitive paste including multi-walled CNTs (MWNTs) for screen printing. The photosensitive CNT paste was synthesized by mixing of MWNTs, inorganic fillers (nano metal), organic vehicle, monomers and photo initiator. The CNT paste films were patterned by using backside exposure technique. The CNTs were strongly fixed on a cathode by formation of carbon residue during firing process. For the CNT emitters, current-voltage(I-V) characteristics and images of field emission were evaluated. The emission properties of CNT emitters are dependent on the paste composition. A turn-on electric field for the CNT field emitters is measured to be 1 V/$\mu$m. Additionally, the effect of heat treatment parameter on field emission properties was discussed. The newly formulated photosensitive CNT paste can be potentially applicable to highly reliable CNT field emitters.

Effect of Lime Amount and Application Time on Soil pH Change, Yield, and Quality of Leaf Tobacco (석회시용량과 시용시기가 경작지 토양산도 변화와 잎담배 수량 및 품질에 미치는 영향)

  • 정훈채;김용연;황건중
    • Journal of the Korean Society of Tobacco Science
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    • v.22 no.1
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    • pp.61-70
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    • 2000
  • This study was carried out to improve the tobacco field condition and to determine the effect of lime amount and application time on soil pH, yield, and quality of leaf tobacco. Lime was applied to the tobacco field by determined amounts according to different pH level. The changes of soil pH, growth of tobacco, yield, and quality of KF109 and Br21 tobacco were surveyed by time lapse. The target pH value in tobacco field soil can be reached at 6 weeks after lime application, and then the soil pH was lowered slightly after that time. The lime amount needed to reach target pH was decreased 40 % in the same tobacco field after 1 year. Though the initial growth rate of flue-cured tobacco in the field of pH 7.0 was lower than that of conventional tobacco field, the field of pH 7.0 showed the highest yield after the maximum growth stage. The quality of cured leaf tobacco in the field of pH 7.0 applied lime at spring season was slightly lowered compared with that in conventional. This results indicated that the best pH condition in tobacco field for the best tobacco growth was 6.5 and the proper time of lime application was fall season of previous year by application of the whole quantity.

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The Mediating Effect of Professionalism in the Relationship between Clinical Competence and Field Adaptation in Newly Graduated Nurses (신규간호사의 임상수행능력과 현장적응의 관계에서 전문직업성의 매개효과)

  • Kim, Young-Soon;Park, Kyung-Yeon
    • Journal of Korean Academy of Nursing Administration
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    • v.19 no.4
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    • pp.536-543
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    • 2013
  • Purpose: The purpose of this study was to identify the mediating effect of professionalism in the relationship between clinical competence and field adaptation in newly graduated nurses. Methods: The participants in this study were 213 nurses from four tertiary hospitals who had less than 12 months of nursing experience. Data were collected during January and February, 2013. A structured questionnaire was used for data collection and data were analyzed using descriptive statistics, Pearson correlation coefficients, and path analysis with the SPSS/WIN 21.0 and AMOS 21.0 programs. Results: The mean score for clinical competence was $2.85{\pm}0.25$, for professionalism, $3.10{\pm}0.30$, and for field adaptation, $2.79{\pm}0.37$. There was a significant positive relationship between clinical competence and field adaptation. Also, professionalism was positively correlated with field adaptation. Professionalism showed mediating effects between clinical competence and field adaptation. Improvement of clinical competence increased professionalism and the increased professionalism raised the field adaptation. Conclusion: Based on these findings, orientation programs including strategies to increase professionalism, should be established to promote effective field adaptation in newly graduated nurses. These orientation programs can strengthen professionalism, the mediator between clinical competence and field adaptation in newly graduated nurses.

DC Field Effect on Streaming Electrification in Insulating Oil (절연유의 유동대전특성에 미치는 직류전계의 영향에 관한 연구)

  • Chung, K.H.;Kim, Y.W.;Kim, D.S.;Hwang, L.H.;Lim, H.C.;Park, J.Y.;Kim, J.T.;Lee, D.C.
    • Proceedings of the KIEE Conference
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    • 1998.07d
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    • pp.1436-1437
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    • 1998
  • In this paper, the result of experimental investigation into the streaming electrification phenomena of insulating oil under an external dc field effect is described. Energization by positive dc voltage enhanced the streaming electrification. but when the applied voltage was negative, the polarity of streaming current was field strength dependent.

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External Magnetic Field Influence on Exchange Coupling Oscillations in Ultrathin Fe/Au/Tb Film Structures

  • Pogoryelov, Ye.
    • Journal of Magnetics
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    • v.9 no.4
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    • pp.97-100
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    • 2004
  • In the present work exchange coupling between ultrathin Fe ($8{\AA}$) and Tb ($12{\AA}$) layers separated by Au spacer of varied thickness ($3-20{\AA}$) was studied. Anomalous Hall effect measurements showed weakly damped oscillating dependence of the Hall conductivity as a function of Au spacer thickness. Disagreement of the observed damping with the RKKY model of interlayer exchange coupling was explained by the influence of external magnetic field on the behaviour of exchange coupling oscillations. It was confirmed by Hall-like effect measurements at zero applied magnetic field and also illustrated by corresponding estimations.

Study On The Travelling Magnetic Field In The Linear Induction Motor With Its End Effect Taken Into Consideration (유도형 Linear Motor의 단부효과를 고려한 이동자계에 관한 연구)

  • Dal Ho Im
    • 전기의세계
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    • v.21 no.4
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    • pp.7-14
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    • 1972
  • The author has established a general equation for the travelling magnetic field in air gap with the end effect taken into consideration, which constitutes the basics for the analysis of characteristics of linear induction motor. This equation is verified by comparison of the experimental values with the theoretically calculated values. The properties of the travelling wave with attenuation, which is contained in the travelling magnetic field of linear induction motor, have been verified, and consequently the practicable equation is established with these effects taken into consideration. This provides the solid foundation for the theoretical analysis of the characteristics of the linear induction motor.

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Determination of seismic hazard and soil response of a critical region in Turkey considering far-field and near-field earthquake effect

  • Sonmezer, Yetis Bulent;Celiker, Murat
    • Geomechanics and Engineering
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    • v.20 no.2
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    • pp.131-146
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    • 2020
  • Evaluation of earthquake impacts in settlements with a high risk of earthquake occurrence is important for the determination of site-specific dynamic soil parameters and earthquake-resistant structural planning. In this study, dynamic soil properties of Karliova (Bingol) city center, located near to the intersection point of the North Anatolian Fault Zone and the East Anatolian Fault Zone and therefore having a high earthquake risk, were investigated by one-dimensional equivalent linear site response analysis. From ground response analyses, peak ground acceleration, predominant site period, 0.2-sec and 1-sec spectral accelerations and soil amplification maps of the study area were obtained for both near-field and far-field earthquake effects. The average acceleration spectrum obtained from analysis, for a near-field earthquake scenario, was found to exceed the design spectra of the Turkish Earthquake Code and Eurocode 8. Yet, the average acceleration spectrum was found to remain below the respective design spectra of the two codes for the far-field earthquake scenario. According to both near- and far-field earthquake scenarios in the study area, the low-rise buildings with low modal vibration durations are expected to be exposed to high spectral acceleration values and high-rise buildings with high modal vibration durations will be exposed to lower spectral accelerations. While high amplification ratios are observed in the north of the study area for the near-distance earthquake scenario, high amplification ratios are observed in the south of the study area for the long-distance earthquake scenario.

A Study on the Correlation between Shielding Effect of Electromagnetic Field and Immunity of Radiated Radio Frequency (전자파 차폐효과와 방사고주파 내성과의 상관관계에 대한 연구)

  • Park, Chan-Won;An, Hwang-He
    • Proceedings of the KIEE Conference
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    • 1999.07e
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    • pp.2462-2464
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    • 1999
  • All electric and electronic appliances require their own electromagnetic compatibility. So an industrially advanced nations have made many standards for regulation for their profits thus the researches on the electro-magnetic shielding effect(SE) are being increased. But the SE can not proved its effect by a theory alone because of complex-material problems. This study Present the correlation of the SE and immunity of radiated radio frequency of the electromagnetic field. We have analyzed the theory of shielding effect to the shield texture. It has been proved that experimental results showed this effects have intensive relations to the electromagnetic field immunity.

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