• 제목/요약/키워드: external magnetic field

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DC Performance of $Nb_3$Sn Cable Joints with multi-interfaces (다수의 접합경계를 갖는 $Nb_3$Sn 케이블 접합부의 직류 저항 특성)

  • 이호진;김기백;연제욱;홍계원;김기만
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.2
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    • pp.170-176
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    • 2000
  • The joints with multi-interfaces was expected to have low DC resistance compared with those with single interface. The small size joint specimens joined with Nb3Sn sub-cables were fabricated to investi-gate the DC performance in the range of 0 to 600A transport current without external magnetic field. The joints with multi-interfaces have a few n-Ohm resistance, which is much lower than that of single lap joint. Because the interfaces between sub-cables of multi-interfaced joint are more complicated than those of single-interfaced joint, the soldering condition between sub-cables is very effective on the joint DC resistance.

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A comparison of the characteristics of External type UHF partial discharge sensor for metal covered barriers in GIS (GIS 스페이서의 에폭시 주입구 장착형 UHF PD 센서의 성능 비교)

  • Hwang, Chul-Min;Kim, Young-No;Lee, Young-Sang;Kwak, Joo-Sik;Park, Ki-Jun
    • Proceedings of the KIEE Conference
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    • 2005.07c
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    • pp.2265-2267
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    • 2005
  • We present detailed studies of externally applicable UHF PD sensors for a metal covered epoxy barrier with a small opening of epoxy injection-hole. The sensors were attached at the surface of injection hole of a metal covered epoxy barrier. 3-Dimensional electro magnetic simulations were performed to analyze electric-field distribution of the GIS and epoxy barrier with injection hole. Sensor structures were designed and analyzed using the 3-D EM simulator then fabricated for experimental verification. Sensor performance was measured in terms of spectral response and detected peak power. Real scale GIS and epoxy barriers were used to test and measure various aspect of performance of the sensors.

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Development of a intelligent suspension displacement sensor for unified chassis control of advanced safety vehicle (고안전 차량의 통합섀시 제어를 위한 지능형 현가시스템 변위 센서 개발)

  • Yun, Duk-Sun;Lee, Chang-Seok;Baek, Seong-Hwan;Kang, Tae-Ho;Boo, Kwang-Suck
    • Journal of Sensor Science and Technology
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    • v.18 no.5
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    • pp.393-401
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    • 2009
  • This paper describes development of a new displacement sensor for intelligent suspension system in which the damping force has been controlled by MR fluid. Most of the current vehicle height sensors have been installed at external place of the damper and connected to that by mechanical linkages so far. The developed sensor has a new mechanism which detects movement of the sensor rod same as connecting rod in the suspension damper by using a GMR Sensor and converts it to the relative displacement from an initial position.

Influence of non-uniform current distribution on transport ac loss in Bi-2223/Ag tapes (불균일 전류분포가 Bi-2223/Ag 초전도선재의 통전손실에 미치는 영향)

  • Choi, S.;Nah, W.;Joo, J.;Kim, J.H.;Ryu, K.W.;Sohn, M.H.;Kwon, Y.K.
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.1240-1242
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    • 2005
  • In this study, we estimate the transport current loss of Bi-2223/Ag tapes with non-uniform current distribution. The conductor was consisted of three Bi-2223/Ag tapes and the each tapes were attached in parallel. The loss of conductor was investigated both numerical and experimental methods. The numerical code to predict ac loss was developed, and finite element method was introduced. It contained intrinsic properties of superconducting tape, which was obtained from nonlinear current voltage relation with external magnetic field and its orientation. Two results were compared and discussed. They showed good agreements with each other.

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3D Plasma simulation을 이용한 Cylindrical Rotating Magnetron Sputtering Cathode 개발

  • Cheon, Yong-Hwan;O, Ji-Yeong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.179.1-179.1
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    • 2013
  • Cylindrical Rotating Magnetron Sputtering Cathode (이하 Rotary Cathode)는 기존에 사용 되던 rectangular type 보다 Target 사용 효율이 높다는 큰 이점을 가지고 있다. 높은 Target 사용 효율은 비용 절감 효과와 직접적으로 관련 된다. 이번 연구는 3D Plasma simulation(PIC-MCC)을 통한 Target 사용 효율 80% 이상의 Rotary Cathode 개발을 목적으로 한다. Plasma simulation에 External Magnetic fields를 접목하여 Electron의 이동 궤적을 제어하였고, 생성된 Ion (Ar+)의 밀도 및 속도로 Plasma의 안정성과 Erosion 계산 구간을 선정 하였다. Target Erosion Profile은 Sputtering yield Data와 Target에 충돌한 Ion 정보를 사용하여 산출 하였으며, Sputtered Particles의 Deposition Profile은 계산된 Target Erosion Profile과 The cosine law of emission을 이용하여 계산 하였다. 실험 조건은 Plasma simulation의 초기조건 바탕으로 하여 2G size의 ITO Target을 대상으로 실험 하였다. 비 Erosion 영역 최소화하기 위해 Magnet Length를 변경하여 제작 적용 하였다. Simulation 계산 시간의 제약으로 인하여 simulation에서 생성된 최대 이온 밀도는 일반적으로 알려진 값 보다 적게 계산 되었지만, Simulation으로 예측한 Erosion Profile 및 Deposition Profile은 실험 값과 유사한 형태를 나타났으며, 실험 결과는 Target 사용 효율 80%이상의 결과를 보였다.

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A study on the reduction of ac loss of YBCO coated conductor by a mechanical striation method (기계적으로 분할된 YBCO 선재의 교류손실 감소에 대한 연구)

  • Yoo, Yong-Su;Hong, Gye-Won;Lee, Hee-Gyoun
    • Progress in Superconductivity and Cryogenics
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    • v.11 no.1
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    • pp.9-15
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    • 2009
  • High temperature superconductor (HTS) coated conductors has high hysteretic magnetization loss which is an obstacle for the AC applications of coated conductors. We propose a method to reduce the magnetization loss of the coated conductor. It is the mechanical striation method by load variety using office knife. The magnetization loss measured in the mechanical striated YBCO coated conductor without copper layer was compared with the loss generated by perpendicularly exposed external magnetic filed. The reduction in magnetization loss due to the mechanical striation is clearly shown at higher field and was dependent on the striation number. The mechanical striation method was proven to have additional advantages of a low cost and high fabrication process.

A Survey on the Treatments used in Oriental Obsterics & Gynecology (한방부인과질환에 사용되는 치료방법에 대한 조사연구)

  • Lee, In-Seon;Bae, Kyung-Mi
    • The Journal of Korean Obstetrics and Gynecology
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    • v.22 no.1
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    • pp.203-230
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    • 2009
  • Purpose: In order to know therapies used in the field of Obsterics & Gynecology of Oriental medicine. Methods: This survey investigated papers about clinical study, literature investigation for therapeutic methods and treatment reports published from 1999. 2${\sim}$2008. 11. Results: In the clinical studies, acupuncture is more frequently used than herbal medicine. But in the treatment reports, herbal medicine is most frequently used except some cases. Besides acupuncture and moxibustion was used frequently. In the treatment reports various acupuncture methods were used except vaginal bleeding or abdominal pain cases. Whole body acupuncture was used mainly. Pharmacopuncture, Sa-am Acupuncture, auricular acupuncture was also used frequently. And Dong's acupuncture, Hwa acupuncture was used sometimes. Moxibustion was tend to be used for dysfunctional uterine bleeding, menopausal disorder, urinary incontinence, vaginal bleeding or abdominal pain during pregnancy period, hyperemesis, recurrent miscarriage, postpartum disease, lochiorrhea. Also other treatment methods was used such as external therapy, aromatherapy, herbal retention enema, fumigation, electric lipolysis acupuncture, Chuna manual medicine, obesity management, acupuncture at uterus cervix, magnetic innervation therapy, exercise, cupping and physical therapy. Conclusion: These results suggests that acupuncture, moxibustion and herbal medicine are most frequent therapy in the field of Obsterics & Gynecology of Oriental medicine. And other therapy are used such as external therapy, aromatherapy, herbal retention enema, fumigation and so on.

Design of UWB Antenna for the External Receiver of Capsule Endoscopy (캡슐 내시경의 외부 수신기용 UWB 안테나 설계)

  • Kim Hong-Seok;Oh Min-Seok;Cheon Chang-Yul
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.8 s.99
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    • pp.790-796
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    • 2005
  • In order to accomplish a wireless communication of capsule endoscopy, an environment study in the human body and receiving antenna design have been performed. The proposed antenna is the loop antenna designed to minimize the propagation loss in multi-loss layer such as the human body and utilize the magnetic field. Considering the propagation loss in the human body, the frequency range is from 400 MHz to 500 MHz. Acorrrding to the FCC regulations, the permittivity and conductivity for each human tissue were extracted. We set up an equivalent model and make an aqueous solution which is replaced with the human body. Due to movement of capsule in the human body which propagation loss is extremly severe, an array antenna is required. Irrespective of the location of transmission antenna transmitting a signal of 1 mW, we confirme what it is possible for the enough signal detection as the average signal level of array antenna is -60 dBm.

Analysis of Characteristics for Strip Line with a Ferrite Material using Spectral-Domain Method (주파수 영역법을 이용한 페라이트 물질이 포함된 스트립 선로 특성 해석)

  • 박진수;양승인
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.10 no.4
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    • pp.498-505
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    • 1999
  • The ferrite device that has nonreciprocal characteristics has been used as various microwave components. In this paper, the spectral-domain method was used to analyze the characteristics of structure(strip line on multilayer structure with ferrite material) for which no paper has been published yet. It is assumed that an external dc magnetic field is applied perpendicular to the ground conductor. The propagation constant is calculated for each parameter and frequency. Also we considered convergence by increasing the number of basis functions and verified the numerical analysis results. From the results, we could confirm that as the thicknesses of YIG is increased, the cutoff region is widened and the propagation constant is decreased at the frequency of upper cutoff region. For a larger applied dc magnetic field, the frequency of cutoff region is found to be increased. Also the simulation results for strip line show that the cutoff region is widened and the propagation constant is larger than that of microstrip line.

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A Characteristic Analysis of Heater Triggered Persistent Current System with 2G High Tc Superconducting Tape (차세대 고온초전도 선재를 이용한 영구전류시스템의 히터트리거 특성 해석)

  • Park, Dong-Keun;Kang, Hyoung-Ku;Yang, Seong-Eun;Ahn, Min-Cheol;Yoon, Yong-Soo;Yoon, Kyung-Yong;Lee, Sang-Jin;Ko, Tae-Kuk
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.1228-1230
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    • 2005
  • This paper deals with design of heater trigger switching in a persistent current system(PCS) by finite element method(FEM) analysis of YBCO coated conductor(CC) tape. Most promising superconducting wire is YBCO coated conductor tape in these days for its high n value and critical current independency from external magnetic field. It is expected to be used many superconducting application such as fault current limiter and cable etc. The superconducting magnet which is operated in persistent current mode in SMES, NMR, MRI and MAGLEV has many advantages such as a high uniformity of a magnetic field and reducing a thermal loss. A PCS system consists of magnet power supply (MPS) which energized current to a magnet, heater, a coated conductor tape for switching, and superconducting magnet. In this paper, the characteristic of thermal quench of the YBCO CC tape and BSCCO tape by heater trigger analyzed by FEM. And optimal length of heater is calculated by temperature and time analysis. This heater trigger analysis is expected to be a basic concept of PCS application design.

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