• Title, Summary, Keyword: Inductive Method

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Inductive Disturbance Reduction Method for Electric Railway (전기철도해서의 유도장해 경감책에 관한 연구)

  • Lee, Kyo-Sung;Kim, Do-Hun;Lee, Yong-Jae;Kim, Yang-Mo
    • Proceedings of the KIEE Conference
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    • pp.369-371
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    • 2002
  • The railway power feeding system is divided into AC power feeding system and DC power feeding system. In downtown area. DC power feeding system is used and AC power feeding system is used in intercity railway system. AC power feeding system raises a inductive disturbance that is divided into electrostatic induction and electromagnetic induction. Especially, it has a bad effect on communication lines. So inductive disturbance reduction method has been adopted in many system. In this paper, we deals with the inductive disturbance reduction method of railway power feeding system and of sides affected by inductive disturbance.

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A Comparative Study of Inductive and Deductive Instructional Effects on the Learning of Population Genetic Concepts (집단유전 개념 학습에서 귀납적 - 연역적인 수업효과 비교)

  • Kim, Wui-Gyeong;Lee, Mi-Sook;Lee, Kil-Jae
    • Journal of The Korean Association For Science Education
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    • v.23 no.2
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    • pp.190-199
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    • 2003
  • The purposes of this study was to investigate the effect of inductive Instructional method and deductive one concerning the learners' population genetic concepts and achievement according to learners' cognitive characteristics. For the study, 180 students were sampled from a boys' high school: 90 students for inductive teaching method and 90 students for deductive teaching method. Group Assessment of Logical Thinking(GALT) and Group Embedded Figure Test (GEFT) were used as the measure of cognitive characteristics. The results of this study were as follows. 1) The inductive instructional method was more effective in the understanding of population genetic concepts and their achievement. 2) Inductive instructional method was more effective than deductive one for the learners in formal operational level and in field independent cognitive style. 3) For the learners in a transitional level and field dependent cognitive style, deductive instructional way was more effective than inductive way on the average, but it was not statistically significant. It was turned out that learners' cognitive level was one of important factors when teachers instruct the concept of population genetics.

Surface-Mountable 10 Gbps Photoreceiver Module Using Inductive Compensation Method

  • Kim, Sung-Il;Hong, Seon-Eui;Lim, Jong-Won;Moon, Jong-Tae
    • ETRI Journal
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    • v.26 no.1
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    • pp.57-60
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    • 2004
  • We propose an inductive compensation method for a surface-mountable 10 Gbps photoreceiver module. Since many typical 10 Gbps photoreceiver modules consist of a photodetector and low-noise pre-amplifier, the impedance mismatch between the photodetector and pre-amplifier, as well as package parasitics, may reduce the frequency bandwidth. In this paper, we inserted an inductive component between the photodetector and pre-amplifier in order to create frequency bandwidth expansion. From the measurement results, we have found that the proposed technique can increase the -3 dB bandwidth about 4.2 GHz wider compared with an uncompensated module. And, from a bit-error rate (BER) test, we observed -15.7 dB sensitivity at $10^{-12}$ BER. This inductive compensation can be implemented easily and is compatible with common manufacturing processes of photoreceiver modules.

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Graphical Design Plane Analysis for Series-Compensated Resonant Energy Links of Inductive Wireless Power Transfer Systems

  • Jeong, Chae-Ho;Choi, Sung-Jin
    • Journal of Power Electronics
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    • v.19 no.6
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    • pp.1440-1448
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    • 2019
  • In wireless power transfer systems, it is important to design resonant energy links in order to increase the power transfer efficiency and to obtain desired system performances. This paper proposes a method for designing and analyzing the resonant energy links in a series-series configured IPT (inductive power transfer) system using the FOM-rd plane. The proposed FOM-rd graphical design plane can analyze and design the voltage gain and the power efficiency of the energy links while considering changes in the misalignment between the coils and the termination load condition. In addition, the region of the bifurcation phenomena, where voltage gain peaks are split over the frequency, can also be distinctly identified on the graphical plane. An example of the design and analysis of a 100 W inductive power transfer system with the proposed method is illustrated. The proposed method is verified by measuring the voltage gain and power efficiency of implemented hardware.

Application of a Textile-based Inductive Sensor for the Vital Sign Monitoring

  • Gi, Sun Ok;Lee, Young Jae;Koo, Hye Ran;Khang, Seonah;Kim, Kyung-Nam;Kang, Seung-Jin;Lee, Joo Hyeon;Lee, Jeong-Whan
    • Journal of Electrical Engineering and Technology
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    • v.10 no.1
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    • pp.364-371
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    • 2015
  • In this study, we developed a feasible structure of a textile-based inductive sensor using a machine embroidery method, and applied it to a non-contact type vital sign sensing device based on the principle of magnetic-induced conductivity. The mechanical heart activity signals acquired through the inductive sensor embroidered with conductive textile on fabric were compared with the Lead II ECG signals and with respiration signals, which were simultaneously measured in every case with five subjects. The analysis result showed that the locations of the R-peak in the ECG signal were highly associated with sharp peaks in the signals obtained through the textile-based inductive sensor (r=0.9681). Based on the results, we determined the feasibility of the developed textile-based inductive sensor as a measurement device for the heart rate and respiration characteristics.

Study on Separation Distance to Protect Radio Service from Inductive System (유도성 시스템으로부터 무선기기 보호를 위한 이격 거리에 관한 연구)

  • Lee, Il-Kyoo;Shim, Yong-Sup;Min, Kyoung-Il;Cha, Jae-Sang;Lee, Kyong-Gun
    • Journal of Satellite, Information and Communications
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    • v.6 no.1
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    • pp.103-108
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    • 2011
  • This paper is related radio interference from inductive system to radio device in home and industrial environment according to increasing the usage of inductive system. In order to analyze interference from magnetic field strength of inductive system, interference model was suggested and explain the method to calculate separation distance by using conversion that from magnetic field strength to magnetic dipole moment based on suggested interference model. Also, scenario that interference occur between inductive system and radio device was shown and the separation distance between inductive system and radio device was calculate with that scenario. The suggested method in this paper will be used to secure the compatibility between inductive system and radio device.

Wireless Power Transmission using Electromagnetic Inductive Coupling and LC Resonant (자기유도방식과 LC공진을 이용한 무선전력전송기기)

  • Lee, Seung-Hwan;Kimm, Hyoen-Min;Kim, Hee-Je;Kim, Su-Weon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.3
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    • pp.349-354
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    • 2013
  • Wireless power transmission introduced by Tesla has instrumented by many scientists of the world. This technique first was utilized as wireless communications such as radio in long range transmission. And contactless transmission using inductive property was used on white goods. In 2007, MIT' lab introduced that new wireless power transmission by magnetic resonance which has about 50% efficiency and 2M transmission distances, it was a chance to refocus a new possibility of wireless power transmission. In this paper, using LC coupling compensate the short distances of contactless transmission, this simple method could transmit about 30cm distances. Using this approach, it can be solved the short transmission distances, a drawback of Electromagnetic inductive coupling method.

A Study on the Voltage Drop and Earth Leakage Current according to Interval of AT in the AT Feeding Method (AT급전방식에서 AT간격에 따른 전압강하 및 대지누설전류에 대한 연구)

  • Kim, Min-Seok;Choe, Seung-Hyuk;Lee, Jong-Woo
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.9
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    • pp.1708-1714
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    • 2011
  • AT feeding system of the electric railway system is installed every about 10km at between the feeder and catenary in parallel and the mid-point of the transformer is connected to the rail The supply voltage of this system is doubled than rolling stock voltage. So the voltage drop is smaller than usual. And the other merit of this system is the decreasing inductive disturbance to the communication line because of the reduced current in rail which runs reversed in a point of view of rolling stock. Also, ATP(Auto Transformer Post) is installed to reduce the voltage drop and to mitigate the inductive disturbance, but still now the proper distance between the ATP and AT feeding system is not established which ranges from 2 to 10[km]. The stable result of simulation(which is set that the end of the line AT is installed) to the voltage drop and inductive disturbance can not analyzes the effect to the supply system due to the ATP. This paper analyzes the effect to the system depending on the location of ATP by forecasting the voltage drop and inductive disturbance.

Protection Distance Calculation Between Inductive Systems and Radiocommunication Services Using Frequency Below 30 MHz (30 MHz 이하에서 무선 서비스와 유도성 시스템 간의 보호 거리 산출)

  • Shim, Yong-Sup;Lee, Il-Kyoo;Park, Seung-Keun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37C no.12
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    • pp.1211-1221
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    • 2012
  • This paper describes separation distance to protect radiocommunication services from the interference of inductive systems using frequencies below 30 MHz for the co-existence between radiocommunication services and inductive systems. For the analysis, the interference scenario model is proposed between inductive system and radiocommunication services. Then the calculation method of protection distance is suggested by comparing the radiation power of inductive system with the allowable interference level of victim services, radiocommunication services, according to the applied propagation model. Also, the protection distance for protecting radiocommunication services in the 30 MHz below is calculated through the interference analysis from RFID(Radio Frequency IDentification) and PDP(Plasma Display Panel) TV based on the suggested method. The proposed calculation method was adopted as ITU-R recommendation in related with resolution 63 at ITU-R SG(Study Group) 1 meeting in June, 2012. It will be available to use for the protection of radiocommunication services from the interference of wireless power transfer system and power line telecommunication system.

A study on design for the $\pi$-junction of a feeder waveguide with an inductive wall using FDTD method (FDTD법을 이용한 유도성벽을 가지는 $\pi$분기 급전도파관의 설계에 관한 연구)

  • 민경식;김광욱;고지원;김동철;임학규
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.143-146
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    • 2000
  • This paper presents a study on design for the k-junction of a feeder waveguide with an inductive wall using FDTD method. The feed structure consists of a single waveguide plated on the same layer as radiating waveguide and is characterized by the unit divider, railed a $\pi$-Junction. This $\pi$-Junction with an inductive wall splits part of the power into two branch waveguide through one coupling window, and can excite densely arrayed waveguide at equal phase and amplitude. The power dividing characteristics of a $\pi$ -Junction obtained by FDTD method are compared with one of Galerkin's method of moments. The scattering matrices a $\pi$ -junction calculated by FDTD method are realized.

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