• Journal of Power Electronics
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• v.2 no.4
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• pp.250-257
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• 2002

This paper introduces the Interactive Power Electronics Seminar - iPES - a new software package for teaching of fundamentals of power electronic circuits and systems. iPES is constituted by HTML text with Java applets for interactive animation, circuit design and simulation and visualization of electromagnetic fields and thermal issues in power electronics. It does comprise an easy-to-use self-explaining graphical user interface. The software does need just a standard web-browser, i.e. no installations are required. iPES can be accessed via the World Wide Web or from a CD-ROM in a stand-alone PC by students and professionals. Due to the underlying software technology iPES is very flexible and could be used for on-line learning and could easily be integrated into an e-learning platform. The aim of this paper Is to give an introduction to the iPES-project and to show the different areas covered. The e- learning software is available at no costs at $\underline{www.ipes.ethz.ch}$ in English, German, Japanese, Korean, Chinese and Spanish. The project is still under development and the web page is updated in about 4 weeks intervals.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.773-776
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• 1999

For providing good quality power steadily, it is required that operators manipulate the control system of power plant with the good knowledge of power plant system and the control strategies, and cope with accidents effectively. With those requirements, it is general to train operators in power plant control room using full-scope simulator. A full scope simulator adopts the I&C instruments in the main cotrol room, so has to include I/O interface system to interface the simulation computer with I&C instruments in main control room. In already developed simulators, most of I/O interface systems are closed. vendor-dependent. proprietary systems. so have the many disadvantages in terms of cost and maintenance. In this paper. we suggest the method to configure I/O interface system for Thermal Power Plant Simulator based on standard technology which gives the advantages of ease-of-use. cost effectiveness, and simplicity of maintenanceuse by using off-the-shelf products for system integration.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.337-340
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• 2000

In this paper, I compared some characteristics between HPA and LPA using Feedforward method. Feedforward method is known for best IMD correction. HPA generated 46.5㏈c at 45.5㏈m output power. But, using feedforward linearing method, I could improve IMD to 67.17㏈c at the same output power. IMD could be improved 20.67㏈ at 45.5㏈m output power. I measured average power, IMD, total current, and efficiency of two amplifier at many different power levels. I could get about 70d3c IMD using feedforward method.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.1081-1084
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• 1998

In this paper, we propose the bus coding technique for low power consumption. For CMOS circuit most power is dissipated as dynamic power for charging and discharging node capacitances.Though the I/O and bus are likely to have the very large capacitances associated with them and dissipate much of the power dissipated by an IC, they have little beenthe special target for power reduction. The conventional Bus-Invert coding method can't decrease the peak power dissipation by 50% because the additional invert signal line can invoke a transition at the time when Bus-Invert coding isn't used to code original bus data. The proposed technique always constraints the Hamming distance between data transferred sequentially to be below the half of the bus width, and thus decrease the I/O peak power dissipation and the I/O average power dissipation.

• Nuclear Engineering and Technology
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• v.51 no.3
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• pp.676-682
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• 2019

After the Fukushima Daiichi accident, there has been an increasing preference for passive safety features in the nuclear power industry. Some passive safety systems require limited active components to trigger subsequent passive operation. Under very serious accident conditions, passive safety features could be rendered inoperable or damaged. This study evaluates (i) the performance and effectiveness of the passive safety features of iPOWER (innovative Power Reactor), and (ii) whether a severe accident condition could be reached if the passive safety systems are damaged, namely the case of heat exchanger tube rupture. Analysis results show that the reactor coolant system remains in the hot shutdown condition without operator actions or electricity for over 72 h when the passive auxiliary feedwater systems (PAFSs) are operable without damage. However, heat exchanger tube rupture in the PAFS leads to core damage after about 18 h. Such results demonstrate that, to enhance the safety of iPOWER, maintaining the integrity of the PAFS is critical, and therefore additional protections for PAFS are necessary. To improve the reliability of iPOWER, additional battery sets are necessary for the passive safety systems using limited active components for accident mitigation under such extreme circumstances.

• Journal of Power Electronics
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• v.8 no.1
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• pp.1-9
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• 2008

This paper presents the design and analysis of a new input AC current wave shaping AC-DC converter for cost effective harmonic mitigation under varying loads. The proposed converter consists of a delta-polygon connected autotransformer based twelve-pulse AC-DC converter and a small rating passive shunt filter tuned at $11^{th}$ harmonic frequency. The proposed AC-DC converter eliminates the most dominant $5^{th},\;7^{th}$ and $11^{th}$ harmonics and reduces higher order harmonics; thereby, resulting in an improved power quality at AC mains. Moreover, the design of the autotransformer is modified to make it suitable for retrofit applications, where presently a 6-pulse diode bridge rectifier is used. To validate the proposed approach, various power quality indices are presented under varying loads. Experimental results obtained on the developed converter are given to validate the model and design of the proposed converter.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.4
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• pp.602-608
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• 2009

In this thesis, output voltage, current and power of solar module were classified by irradiation from data of overall operating characteristics collected for one year in order to manage efficient photovoltaic generation system and deliver maximum power. In addition, from these data, correlations between irradiation of photovoltaic cell and amount of power given by photovoltaic cell was quantitatively examined to deduce optimization of the design and construction of photovoltaic generation system. As I-V characteristics according to a temperature range of 10~50[$^{\circ}C$], the area of I-V characteristics were increased with an increase in temperature. Since this area corresponds to the power, output power is thought to have increased with temperature. As output power characteristics according to a temperature range of 10~50[$^{\circ}C$], output power was increased with an increase in temperature. Since output power increases with temperature increase, the result corresponds well to the related equation on temperature and output power. As I-V characteristics according to a irradiation range of 100~900 [$W/m^2$], voltage and current were increased with an increase in irradiation. The result is thought of as an increase in output power with increasing irradiation. As output power characteristics according to a irradiation range of 100~900 [$W/m^2$], output power was increased with increasing irradiation. This result corresponds well to the related equation on irradiation and output power.

• Journal of the Microelectronics and Packaging Society
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• v.13 no.4
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• pp.9-15
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• 2006

This paper shows the impedance profile of PEEC(Partial Equivalent Electrical Circuit) PDN(Power Distribution Networks) including core and I/O circuit. Through the simulated results, we find that the core power noise having connection with I/O power is affected by I/O switching. Also, using designed $74{\times}5inch$ DLL(Delay Locked Loop) test board, we analyzed the effect of power noise on operation region of chip. Jitter of a DLL measure for frequency of $50{\sim}400MHz$ and compared with impedance obtained result of simulation. Jitter of a DLL are increased near about frequency of 100MHz. It is reason that the resonant peak of PDNs has an impedance of more the 1ohm on 100MHz. we present the impedance profile of a chip and board for the decoupling capacitor reduced the target impedance. Therefore, power supply network design should be considered not only decoupling capacitors but also core switching current and I/O switching current.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.731-732
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• 2007

This paper presents the final configuration of test field and test items for the application of IEC 60364-4-44 in Korea. IEC 60364-4-44 provides rules for the protection against the effects of conducted and radiated disturbances on electrical installations. Especially this standard deals with the protection of low voltage facility against the ground fault in the high voltage side of power distribution system. Many countries define the regulations on the use of electrical facilities based on their own power system and technical references which are considered to be suitable for them. The background of circuit of IEC 60364-4-44 is based on the ungrounded system as most of European countries. However, domestic electric power distribution system is based on multi-grounding system different from European system. Therefore, it is necessary to evaluate or prove the effect of the IEC 60364-4-44 for introducing and applying it to the domestic grounding system as a national standard. The authors with KEA(Korea Electric Association) carried out a project on the application of IEC 60364-4-44 to Korean electrical installations of buildings sponsored by Korean ministry of commerce, industry and energy for three years(2004.4.1$\sim$2007.3.31). The test field is established in K.E.R.I.(Korea Electrotechnology Research Institute), which is the purpose of evaluating the formula to calculate touch voltage and stress voltage in the IEC standards. This paper presents some considerations and final configuration of test field to evaluate and introduce the IEC 60364-4-44 applicable to domestic rule for the protection against ground fault.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.48 no.11
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• pp.724-729
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• 1999

We developed the correlated color temperature (CCT) control technique for electrodeless sulfur lamp (ESL) by adding a few milligrams of NaI into sulfur discharge bulb. Nal produces intense Na D-line that changes the CCT of the ESL. We can adjustthe CCT in the range of 8,400 K to 3,600 K. Color rendering index can be maintained between 79 and 90 for the adjustable range of the CCT. the NaI helps the ESL dischargeable at below 0.5 kW of forward microwave power into the bulb. We have shown that this technique did not cause reduction of luminance compared to electrodeless elemental sulfur lamp.