• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.5
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• pp.502-507
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• 2004

The forward planar transformer, which had power capacity of 300 W, input voltage of 220 V, output voltage of 15 V, and switching frequency of 300 KHz, was designed and manufactured by using the planar core with large effective area and the flat copper leadframes for miniaturization and high efficiency of the switching mode power supply (SMPS). As well as, a forward converter equipped with the above mentioned planar transformer was manufactured and electromagnetic characteristics were investigated. The numerical value of turns for 1st and 2nd winding were 15 and 2 respectively The self inductance of 1st winding was 1.592 mH, very low leakage inductance of 2.7 $\mu$H, and the coupling factor of 0.928 were obtained at switching frequency of 300 KHz. The high efficiency of 88.62 % for the SMPS equipped with planar transformer was obtained at power capacity of 300 W.

• Journal of Power Electronics
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• v.10 no.2
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• pp.125-131
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• 2010

Switched-resonator converters are a new family of soft switching DC-DC converters where the energy is transferred via a resonator. This paper introduces some isolated topologies of this family. The achieved advantages include, load independent soft-switching, self short-circuit protection, and optimization capability due to topology variety. Compared to conventional series-resonant converters, outstanding advantages such as a smaller fewer number of switches and diodes, a smaller transformer, and lower current stresses are achieved. A general synthesis scheme, functional topologies, and essential relations are included. Experimental results from a laboratory prototype confirm the presented theoretical analysis.

• Journal of the Korea Convergence Society
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• v.11 no.1
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• pp.131-139
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• 2020

Gamers switch their games to a new when get bored or encounter more attractive ones. Switching cost varies by gamers and depends on how they are satisfied with their current game. This study evaluates the satisfaction with current games as the miltiple basic psychological need in the self-determination theory and suggests 'needs-costs' causality research model that explain the variety of gamer's switching behavior. As the empirical test to domestic mobile gamers, the autonomy fulfillment to current game affect reversely with those of autonomy and relatedness. Those relationships between need satisfaction and perceptual switching cost vary according to their age and game genre preference. The results would be applied to understand gamers' switching behavior.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.359-360
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• 2013

The effect of electrode and deposition methods on non-linear interfacial resistive switching in HfO2 based $250{\times}250$ nm2 cross-point device was studied. HfO2 based device has the interfacial resistive switching properties of non-linearity and self-compliance current switching. The operating current in HfO2 based device was increased with negatively increasing the heat of formation energy in top electrode. Also, it was investigated that the operating current in HfO2 based device was changed with deposition methods of O3 reactant ALD, H2O reactant ALD and dc reactive sputtering, resulting the magnitude of the operating current and on/off ratio in order of HfO2 films deposited by dc reactive sputtering, H2O reactant ALD, and O3 reactant ALD. To investigate the effect of electrode and deposition methods on operating current of non-linear interfacial resistive switching in the cross-point device, X-ray photoelectron spectroscopy was measured. Through the analysis of O 1s spectra, non-lattice oxygen concentration, which is closely related to oxygen vacancies, was increased in order of Pt, TiN, and Ti top electrodes and in order of O3 reactant ALD, H2O reactant ALD, and O3 reactant ALD, and dc reactive sputtering deposition method. From all results, non-lattice oxygen concentration in ultra-thin HfO2 films play a crucial role in the operating current and memory states (LRS & HRS) in the non-linear interfacial resistive switching.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.7
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• pp.680-695
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• 1991

In this paper, the conditions on the number of required copies of a self-routing network with and without extra stages in back-to-back manner are presented respectively for a nonblocking $Multi-Log_2N$ multiconnection network. Actually the obained results hold regardless of connection patterns, i.e., whether a network deploys on-to-one connections or multiconnections. Thus open problems on the nonblocking condition for a multi $Multi-Log_2N$ multiconnection network are solved. Interestingly some of the given formulas comprise the Benes network and the Canto network as a special case repectively. A novel switching system architecture deploying a distributed calls-distribution algorithm is provided to design a nonblocking $Multi-Log_2N$ photonic switching network using a directional coupler. And a directional couplex based call holding demultiplexer is introduced to hold a call until blocking disappears in a switching network and let it enter to a network, provided that the number of switching networks is less than that of required switching networks for a nonblocking $Multi-Log_2N$ network.

• ETRI Journal
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• v.25 no.3
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• pp.149-155
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• 2003

A self-pulsating multisection distributed-feedback laser diode (DFB LD) can potentially realize all-optical clock extraction. This device generally consists of three sections, two DFB sections and one waveguide section. The most important variable in this device is detuning, which is the relative spectral position between the stop bands of two DFB sections. We fabricated a novel structure in which two gratings were located one over and one under the active layers. Each grating structure was independently defined in processing so that detuning, which is the prerequisite for self-pulsation, could be easily controlled. Observing various self-pulsating phenomena in these devices under several detuning conditions, we characterized the phenomena as dispersive Q-switching, mode beating, and self-mode-locking.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.339-341
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• 2004

We obtained ultra-short single pulse with an energy of 80 of from self Q-switched Distributed Feedback Dye Laser. Using three stages of amplifiers constructed by two stages of dye amplifiers and one bethune cell amplifier, we obtained high power pulse and second harmonic generation with BBO in ultraviolet region.

• ETRI Journal
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• v.24 no.4
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• pp.311-322
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• 2002

Presently, optical burst switching (OBS) technology is under study as a promising solution for the backbone of the optical Internet in the near future because OBS eliminates the optical buffer problem at the switching node with the help of no optical/electro/optical conversion and guarantees class of service without any buffering. To implement the OBS network, there are a lot of challenging issues to be solved. The edge router, burst offset time management, and burst assembly mechanism are critical issues. In addition, the core router needs data burst and control header packet scheduling, a protection and restoration mechanism, and a contention resolution scheme. In this paper, we focus on the burst assembly mechanism. We present a novel data burst generation algorithm that uses hysteresis characteristics in the queueing model for the ingress edge node in optical burst switching networks. Simulation with Poisson and self-similar traffic models shows that this algorithm adaptively changes the data burst size according to the offered load and offers high average data burst utilization with a lower timer operation. It also reduces the possibility of a continuous blocking problem in the bandwidth reservation request, limits the maximum queueing delay, and minimizes the required burst size by lifting up data burst utilization for bursty input IP traffic.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.39-47
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• 2016

The purpose of this study is to investigate the smartwork use resistance and Non-Class-Related Behavior of attendees in university smartwork class with the perspective of Motivation-Threat-Ability. To do this, this study built a research model and examined how smartwork switching cost, threat and self-efficacy affect Non-Class-Related Behavior through smartwork use resistance. We also examined the relationship between self-efficacy and Non-Class-Related Behavior. The survey method was used for this paper, and data from a total of 80 university students were used for the analysis. And structural equation model was used to analyze the data. The results of this empirical study is summarized as followings. First, switching cost and threat have direct effects on the use resistance of smartwork services. Second, smartwork use resistance has a negative effect on Non-Class-Related Behavior but self-efficacy has a positive effect on it. Further, it will provide meaning suggestion point of the importance of use resistance motivations in establishing the use policy of smartwork services.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.4
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• pp.274-279
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• 2002

ATM packet switching technologies for the purpose of the B-ISDN service are focused on high performance which represents good qualities on throughput, packet loss, and packet delay. ATM switch designs on a class of parallel interconnection network have been researched. But these are based on the self-routing function of it. It leads to conflict with each other, and to lose the packets. Therefore, this paper proposes the method based on Sort-Banyan network should be adopted for optimal routing algorithm. It is difficult to expect good hardware complexity. For good performance, a switch design based on the development of new routing algorithm is required. For the design of switch network, the packet distributor and multiplane are proposed. They prevent each packet from blocking as being transmitted selectively by two step distributed decision algorithm. This switch will be proved to be a good performance switch network that internal blocking caused from self-routing function is removed. Also, it is expected to minimize the packet loss and decrease the packet delay according to packet transmission.