• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.11
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• pp.1545-1550
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• 2014

Fault detection and diagnosis (FDD) of photovoltaic (PV) power systems is one of significant techniques for reducing economic loss due to abnormality occurred in PV modules. This paper presents a new FDD method against PV power systems by using statistical comparison. This comparative approach includes deviation signals between the outputs of two neighboring PV modules. We first define a binary hypothesis testing under such deviation and make use of a generalized likelihood ratio testing (GLRT) theory to derive its FDD algorithm. Additionally, a recursive computational mechanism for our proposed FDD algorithm is presented for improving a computational effectiveness in practice. We carry out a real-time experiment to test reliability of the proposed FDD algorithm by utilizing a lab based PV test-bed system.

• Korean Management Science Review
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• v.10 no.1
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• pp.59-80
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• 1993

Electronic data interchange (EDI) is a new technology of information communication which can make offices paperless. This study develop an EDI system to communicate informations among companies using computer systems. The system consists of five modules-document I/O, translation, system management, communication, and additional modules. The database of EDI documentation standards has been constructed by the table-driven method. The communication module provides three communication modes-RS232C, MODEM, and message handling system (MHS). The system performance has been improved by the method of data compression and data encryption which prevent the communication delay and illegal users. This EDI system can be used as a front-end, back-end, or stand-alone mode.

• Journal of Power Electronics
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• v.2 no.2
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• pp.88-94
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• 2002

The demand for protection of power electronic application has during the last couple of vears increased regarding the high-power IGBT modules. Even with an active protection, a high power IGBT still has a risk of exhibiting a violent rupture in the case of a fault if IGBT Fuses do not protect it. By introducing fuses into the circuit this will increase the circuit inductance and slight inductance over-voltage during the turn-off of the diode and the IGBT. It is therefore vital when using fuses that the added inductance is kept at a minimum. This paper discuss three issues regarding the IGBT Fuse protection of adding inductance of existing High-speed and new Typower Fuse protection. First, the problem of adding inductance of exiting High-speed and new Typower Fuse DC-link circuit is treated, second a short discussion of protection of the IGBT module is done, and finally, the impect of the high frwquency loading on the currying capability of the fuses is presented.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.6
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• pp.496-502
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• 2020

The reliability of a solid-state transformer (SST) is one of the important aspects to consider when replacing a conventional low-frequency passive transformer with SST for urban railway vehicles. Lifetime evaluation of SST in the design phase is therefore essential in guaranteeing a certain SST reliability. In this study, a lifetime evaluation of power semiconductor devices in SST is performed with respect to temperature stress. For a case study, a 3 MW SST with three kinds of power modules (one IGBT module and two SiC-MOSFET modules) is used for the lifetime estimation under the operation profile of urban railway vehicles.

• The KIPS Transactions:PartD
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• v.9D no.6
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• pp.1127-1136
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• 2002

In the medical field. the desire of the hospital information system based on the advanced computer technology has been increased because hospital staffs wanted to provide better medical services to their patients by using it. So, the electronic medical records have emerged to share and exchange medical and healthcare information stored in database. In this paper. we developed an electronic medical record system using XML. This system includes four modules : data repository. document structure manager, document writter and XML automatic generator. For the purpose of evaluating the usability of the electronic medical records of our system, we also applied it to out-patient medical records in the department of orthopedic surgery.

• Journal of the Semiconductor & Display Technology
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• v.18 no.4
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• pp.149-153
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• 2019

The technology of electronic packaging among semiconductor technologies is evolving as an axis of the market in its own field beyond the simple assembly process of the past. In the field of electronic packaging technology, the packaging of power modules plays an important role for green electric vehicles. In this power module packaging, the thermal reliability is an important factor, and silicon nitride plays an important part of package substrates, Silicon nitride is a compound that is not found in nature and is made by chemical reaction between silicon and nitrogen. In this study, this core material, silicon nitride, was fabricated by reaction bonded silicon nitride. The fabricated silicon nitride was studied for thermo-mechanical properties, and through this, the structure of power module packaging was made using reaction bonded silicon nitride. And the characteristics of stress were evaluated using finite element analysis conditions. Through this, it was confirmed that reaction bonded silicon nitride could replace the silicon nitride as a package substrate.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.35 no.6
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• pp.568-575
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• 2022

This paper is a study on frequency analysis and electronic noise reduction of energy storage system (ESS). We acquired 4 necessary data for about 2 minutes and 4 seconds using a sampling frequency of 10,000 Hz in ESS. Fast Fourier transform (FFT) was used for electronic noise analysis from the acquired data. As a result, it was confirmed that DC component, fundamental wave, second and higher harmonic component exist. For the attenuation of harmonics, low-pass filter (LPF) was applied. We confirmed that an attenuation of approximately 59.3% appears from the second harmonic. The presence of many harmonic components in the data of the ESS was expected to occur due to the insufficiency of optimization among the modules inside the ESS. Therefore, we propose that a national certification system for ESS should be introduced to settle down the issue properly.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.543-546
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• 2001

So far, the design methods of quartz crystal resonator have been developed. Recently, as the electronic package and semiconductor modules become smaller, the need to minimize the sizes of crystal components grows larger. but Minimizing crystal plate sizes has limitations because its temperature-frequency characteristics is worse and unwanted resonances occur. so appropriate design of electrode size and crystal plates is necessary. In this palter, Two-dimensional governing equations for electroded piezoelectric crystal plates with general symmetry have been solved from deduced equations from three-dimensional equations of linear piezoelectricity in most cases. In practice, electroded piezoelectric crystal plates have three-dimensional geometry, so simplified 2-dimensional equations and 2-D modeling are insufficient for explaining its resonance modes and characteristics. So, three-dimensional FEM(finite element method) analysis is done and its effectiveness is verified from analyzing practical crystal resonator model.

• Journal of IKEEE
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• v.21 no.2
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• pp.162-165
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• 2017

CAN (controller area network) is a standard real-time serial communication protocol, and it was developed to control various in-vehicle electronic modules. In this paper, a CAN controller was designed in Verilog HDL, based on CAN ver. 2.0A and 2.0B. The designed CAN controller was implemented in FPGA, and it was verified its operation by connecting commercial chips. Its size is about 7,800 gates when synthesized in 0.18um technology.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.871-873
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• 1999

According to the reports about the failure mode analysis of modules and systems, It is said that there are many early failure of system. To remove latent defects which causes early failures like that, It is necessary that screening test is performed. ESS is often used fur screening electronic equipments, and is proposed by the most powerful tool for removing latent defects of electronic equipments. [1][2] In this report, the procedure of the environmental stress screening which uses the temperature cycling stress is proposed. It is considered about environmental conditions of distributed control system(DCS) to be tested, design specifications of the system, recommended conditions of relative IEC-STD and applied conditions of similar company. ESS test was applied at the DCS to be installed in power plant. As the results of analyzing discovered problems. It was found that almost latent defects of electronic control systems was discovered early.