• Journal of the Korean Mathematical Society
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• v.55 no.5
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• pp.1045-1061
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• 2018

We investigate the relationship between $C^*$-envelopes and inductive limit of operator systems. Various operator system nuclearity properties of inductive limit for a sequence of operator systems are also discussed.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.173-181
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• 2017

In this paper, the bifurcation criteria for inductive power transfer (IPT) systems is suggested considering the inductive power pad losses. The bifurcation criteria for series-series (SS) and series-parallel (SP) topologies are derived in terms of the main parameters of the IPT system. For deriving precise criteria, power pad resistance is obtained by copper loss calculation and core loss analysis. Utilizing the suggested criteria, possibility of bifurcation occurrence can be predicted in the design process. In order to verify the proposed criteria, 50 W IPT laboratory prototype is fabricated and the feasibilities of the switching frequency and AC load resistance shift to escape from bifurcation are identified.

• 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.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1175-1176
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• 2011

Electric Vehicle Supply Equipment(EVSE) is a system or an equipment to supply electric power for charging the traction batteries on the electric vehicle. EVSEs are classified with a conductive charging system and an inductive charging system by the power transfer method. Inductive charging systems are necessary to use high frequency converters to increase the output power and to reduce the size of the charging systems. In this paper, a 20kHz inverter for inductive charging system has been designed and PSCAD/EMTDC have been used to simulate the output characteristics of the 20kHz inverter.

• 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.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.12a
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• pp.99-102
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• 2001

It has well known that the congestion of traffic and it's distribution. There are very important problems in the traffic control systems. In this paper, we will purpose an ITFS(Intelligent Traffic Forecasting System) which can determine the car classes and transport them to ITS(Intelligent Traffic control System). The system will be used the Inductive Loop Detector(ILD)and the Fuzzy logic and shown the effectiveness by the computer simulation.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.253-255
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• 1997

This paper, which is one of the researches to limit high fault-current, treats the application of an inductive High Tc Superconducting Fault Current Limiter(HTSFCL) to distribution systems. In case that the inductive HTSFCL is applied to distribution systems, this paper presented the usefulness and the commercial possibility of it through computer simulation. If the inductive HTSFCL is established in distribution systems, after fault, it limits fault current effectively within a few millisecond, so it contributes to stability of power distribution system. Especially as the system with the HTSFCL is compared with the system without it, the system is improved in stability.

• Journal of KIISE:Software and Applications
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• v.37 no.9
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• pp.659-668
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• 2010

Collaborative filtering systems grasp behaviors for a new user and need new information for the user in order to recommend interesting items to the user. For the purpose of acquiring the information the collaborative filtering systems learn behaviors for users based on the previous data and can obtain new information from the results. In this paper, we propose an inductive inference method to obtain new information for users and rank items by using the new information in the proposed method. The proposed method clusters users into groups by learning users through NMF among inductive machine learning methods and selects the group features from the groups by using chi-square. Then, the method classifies a new user into a group by using the bayesian probability model as one of inductive inference methods based on the rating values for the new user and the features of groups. Finally, the method decides the ranks of items by applying the Rocchio algorithm to items with the missing values.

• Journal of the Korea Convergence Society
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• v.6 no.2
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• pp.57-64
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• 2015

Inductive Power Transfer (IPT) systems have successfully been developed and used to replace traditional conductive power transfer systems where physical connection is either inconvenient or impossible, such as biomedical implants, undersea vehicles, and contactless battery chargers of robots, for providing power to movable or detachable loads. Inductive Coupling uses magnetic fields to transfer power. There is a primary coil, which generates a magnetic field. Then there is another secondary coil which is composed of a capacitor and a coil, the capacitor creates a circuit with the primary and secondary coils. This paper discusses design method and several implementation alternatives for wireless energy transmission systems. It presents realization examples for these alternatives. Wireless energy transmission is investigated in numerous convergence applications due to its simplicity and advantages.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.1
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• pp.43-52
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• 2018

This paper presents the performance of a Phase Shift Full Bridge (PSFB) converter with inductive load and a new current control scheme to improve dynamic response of output current with various inductive loads. Enhanced dynamic model is used which includes leakage inductance and inductive load. Effect of changing of inductive load was analyzed in detail. Proposed current control scheme is designed based on phase margin specifications. As a result, the proposed current control scheme helps to improve the dynamic response in comparison with the existing current control scheme. The performance of the designed controller is verified by a 500 A PSFB converter. The results will be utilized for high current applications with high inductive load such as superconducting devices.