• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.192-194
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• 1998

This paper proposes a power supply for welding machine of reducing conduction Losses. To improve the conventional Phased-Shift FB DC-DC converter's problems that the copper loss in the high frequency transformer and conduction losses in the 1st terms bridge switch device because the leakage energy in the high frequency transformer and inducing of circulating current. This paper suggested a new topology of FB PWM DC-DC converter for welding machine to minimize a circulating current.

• Korean Journal of Cognitive Science
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• v.27 no.3
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• pp.377-406
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• 2016

Current lists of the Korean emotion words either do not consider word frequency, or only include emotion expression words such as 'joy' while disregarding emotion inducing words like 'heaven'. Also, none of the current lists contains the concreteness level of the emotional words. Therefore, the current study aimed to develop a new Korean affect word list that makes up such limitations of the current lists. To do so, in experiment 1, valence, arousal and concreteness ratings of the 450 Korean emotion expression nouns and emotion inducing nouns were surveyed with 399 participants. In addition, in experiment 2, an emotional stroop task was performed with the newly developed word list to test the usefulness of the list. The results showed clear patterns of the congruency effects between emotional words and emotion expressing faces. Increased response times and more errors were found when the emotion of the words and faces are non-matched, than when they were matched. The result suggested that the newly developed Korean affect word list can be effectively adapted to studies examining the influence of various aspects emotion.

• Proceedings of the KIEE Conference
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• 2006.10d
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• pp.34-36
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• 2006

In this paper, we will treat the diagnosis problem to accurately determine fault types. The judgement of fault types is accomplished by observing the cluster newly formed with faults and clustering the input current waveforms to intrinsically show the conditions with the dignet that is a clustering algorithm. The types of input current waveforms are, however, constrained during normal operation, though it considers the load character. In case of faults. new clusters are generated outside the clusters. which appear during normal operation, because the input current waveforms of the induction motor are generated by the type which is not observed in case of faults. The diagnosis about the types of faults is essential to building a fault tree about the induction motor, and it removes the causes of the faults using a fuzzy logic. We, first, constitute a fault tree, which connects with the parts and the entire system of the induction motor, and investigate fault modes which can be generated from the fault tree and the relationship of the cause and the effect of each part (of the motor). Also, we distinguish the faults of each part by means of inducing the said of fuzzy relation equations encapsulating the relationship of the fault modes and each part.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.2
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• pp.159-164
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• 2016

A wireless communication system is required to be implemented with the low power circuits because it uses a battery having a limited energy. Therefore, the current mode circuit has been studied because it consumes constant power regardless of the frequency change. However, the clock-feedthrough problem is happened by leak of stored energy in memory operation. In this paper, we suggest the current memory circuit to minimize the clock-feedthrough problem and introduce a technique for ultra low power operation by inducing dynamic voltage scaling. The current memory circuit was designed with BSIM3 model of $0.35{\mu}m$ process and was operated in the near-threshold region. From the simulation result, the clock-feedthrough could be minimized when designing the memory MOS Width of $2{\mu}m$, the switch MOS Width of $0.3{\mu}m$ and dummy MOS Width of $13{\mu}m$ in 1MHz switching operation. The power consumption was calculated with $3.7{\mu}W$ at the supply voltage of 1.2 V, near-threshold voltage.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.4
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• pp.47-52
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• 2017

PSC (Prestressed Concrete) structures have been used widely for its engineering advantage with using total concrete area as effective compressive section. However tendon inside is exposed to such a high tensile stress that and more attentions should be paid for corrosion control. This work is for changing corrosion current and ultimate strength in tendon with increasing prestressing force in a constant corrosive condition. With increasing prestressing force, corrosion current, corrosion amount, and ultimate load are changed linearly. When prestressing force increases from 20.0 % to 40.0 %, corrosion current increases to 124.4 % and 168.0 % and ultimate load decreases to 87.8 % and 78.4 %, respectively. With inducing constant electrical potential, increasing corrosion current and reduction of strength are evaluated to be linearly related with increasing prestressing load.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.1
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• pp.85-92
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• 2013

Many efforts will have to be made on securing the stable supply of the energy due to the worldwide trend of controlling the utilization fossil fuels inducing global climate change. Renewable portfolio standard enforced to power companies over 500 MW capacity from 2012. Tidal current energy is one of the most interesting renewable and clean energy resources that have been less exploited. Especially, Korea has worldwide outstanding tidal current energy resources and it is highly required to develop a tidal current energy conversion system(TECS) in coastal region. So, we examine a tidal in-stream energy using a numerical model and estimate a tidal current potential for commercialization of tidal current power plant in the sea of the Bunamgun-do. Available tidal energy resources is also analytically estimated using a tidal farm method and the annual energy production of an optimal TECS arrays will be calculated with taking into account interference of lateral and longitudinal spacing.

• The Journal of Korean Physical Therapy
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• v.16 no.3
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• pp.9-21
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• 2004

The purpose of study is that we will observe the change of c-fos with the immunohistochemistry method and then we will study the effect of micro current stimulation following the frequency after inducing pain to rats with capsaicin. Rat were classified to SD and they have growed for 8 weeks. We classify to four groups, ordinal group is used in experiment I, the group which we induce pain is used in experiment II, the application group which we induce pain and then the high frequency micro current stimulation is used in experiment III, the application group which we induce pain and then the low frequency micro current stimulation is used in experiment IV, we get the following result. Compare with experiment II, experiment III, and experiment IV from acute pain modal in the immunohistochemistry experiment which has c-fos protein as an antigen, c-fos immunoreactive positive neurons significantly after induced pain for two hours(p<0.001). According to these results, from rats induced pain, micro current stimulation effect to reducing pain, but following frequency micro current stimulation theraphy isn't different from immunoreactive c-fos

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.3
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• pp.266-273
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• 2013

With the worldwide trend of controlling the utilization of fossil fuels inducing global climate change, many efforts will have to be made on securing a sustainable energy supply. Tidal current is a concentrated form of gravitational energy, its resource is significant, but limited locations. To effectively capture tidal current energy from the sea, a group of tidal turbines should be formed and positioned with optimal size and spacing for absorbing from multiple points. Thus, the flow field including turbines becomes a huge domain, a so-called tidal farm. It can be very convenient technically and economically if a whole turbine farm is simulated by means of actuator disc thoery. So, the analysis method using actuator discs coupled with a solution of Reynolds Averaged Navier-Stokes (RANS) equations is adopted for actual tidal turbines. Actuator discs have regions where similar forces imposed by actual turbines are applied to a flow. As working in group formation, turbines naturally have interaction effects on one another. Therefore, the present paper investigate the evaluation on the operating performance of tidal farm in terms of the mutual influence among turbine units with various lateral and longitudinal spacing. Authors expect that results of the present study contribute to the development of tidal farm for the future potential energy.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.276-281
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• 2010

In this paper, an electromagnetic induction on a telecommunication line by the distribution line of a power provision system or a feeder line of an electrified railway system has been verified through experiments. The basic cause of induction occurrence by these practical power provision systems is the returning current through the earth. This principle has been confirmed by the experiments documented in this paper which implemented these mechanisms to incur an induction. Experimental methods were used to produce the returning current through the earth. The experiment to find a relationship between inducing strength and the distance between the two phase lines in a power provision line has also been included to confirm that, when the distance is enlarged, the induction effect increases as the cross-nullification effect of magnetic fluxes decreases. An experiment for the existence of a shielding effect by another conduction length material has been addedas a protection measure against the induction.

• International Journal of Precision Engineering and Manufacturing-Green Technology
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• v.5 no.5
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• pp.613-621
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• 2018

The electrically assisted brazing of a ferritic stainless steel with nickel-based filler metal is experimentally investigated. During electrically assisted brazing of a lap joint, the temperature of the joint is first rapidly increased to a brazing temperature and held nearly constant for a specific period using a pulsed electric current. Microstructural analysis results strongly suggest that the electric current during electrically assisted brazing enhances diffusion between the filler metal and the ferritic stainless steel, thus inducing significantly thicker diffusion zones compared with induction brazing. The mechanical test results show that the strength of the electrically assisted brazing joint is comparable to or even superior to those of the joint fabricated by induction brazing, while the process time of the electrically assisted brazing is significantly shorter than that of induction brazing.