• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.4
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• pp.217-222
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• 2015

Longitudinal transmission-line modal theory is applied to analyze the guiding mode characteristics along 1D & 2D grating patterns of plasmonic grating-assisted directional couplers (P-GADC) based on silicon waveguide. By defining supermodes amenable to rigorous analytical solutions and interference between even and odd modes, the field distributions of TE modes for each grating patterns are evaluated. The numerical result reveals that the field distribution with maximum coupling efficiency occurs at P-GADC composed by square grating pattern. That is, it reveals at a minium gap condition of grating period $d_{min}=8.8{\mu}m$ different from conventional phase-matching condition of GADC.

• Journal of Veterinary Clinics
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• v.37 no.3
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• pp.130-134
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• 2020

This study aimed to confirm the effects that the mobile phone has on Electroretinogram (ERG). The ERG responses of three groups of healthy dogs, five in each group, were studied. ERG test was performed consecutively before and after the mobile phone was carried out. For group A, music was played with the sound on; for group B, music was played but the sound off; and for group C, the phone was set on the airplane mode. In the presence of a mobile phone, the amplitudes of a- and b-wave were increased in all groups. The a- and b-wave amplitudes at the flash intensity of 3,000 mcd·s/㎡ were significantly increased in all groups (p < 0.05). Based on the results, it is recommended to conduct ERG test in the absence of a mobile phone for the accurate evaluation of the retinal function.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.1
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• pp.27-35
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• 2017

In this study, an integrated 2-in-1 transformer for a low-weight and low-cost light-emitting diode lighting power supply is proposed. In the transformer, a power factor correction (PFC) inductor and an LLC resonant transformer are placed and integrated on a single magnetic core. The amount of mutual interference, represented by the coupling coefficient, between magnetic fluxes generated from each magnetic source is minimized by using the new shape core of an integrated 2-in-1 transformer. The design consideration on critical conduction mode PFC converter and LLC resonant converter using the proposed 2-in-1 integrated transformer is described, and the overall performance of the 150 W LED PSU shown through the experiment.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.4 no.3
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• pp.18-29
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• 1993

In single mode fiber optic transmission systems(FOT's) operated at high modulation rates over long fiber spans, chromatic dispersion can produce distortion in the demodulated waveforms, resulting in intersymbol interference(ISI) in the received signal and a reduction of transmission system performance. In this paper, chromatic dispersion limitations for intensity modulation and direct detection(IM-DD) systems are studied by considering the effect of phase modulation to amplitude modulation (PM-AM) conversion noise. Laser phase noise conversion to amplitude noise due to fiber chromatic dispersion is analyzed by deriving the noise power spectral density. We first derive the noise power spectral density of the laser phase noise to intensity noise conver- sion. Next, also evaluate the system power penalty and the transmitter laser linewidth required to avoid PM-AM conversion noise penalties in long-haul nonregenerative transmission system using an external modulator and optical amplifiers. For such system with optical amplifiers, transmission sys- tem length is limited due to fiber chromatic dispersion, even if an ideal external modulator is used.

• Mass Spectrometry Letters
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• v.7 no.2
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• pp.41-44
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• 2016

Secondary ion mass spectrometry (SIMS) is a promising tool to measure isotope ratios of individual uranium particles in environmental samples for nuclear safeguards. However, the analysis requires prior identification of a small number of uranium particles that coexist with a large number of other particles without uranium. In the present study, this identification was performed by scanning electron microscopy - energy dispersive X-ray analysis with automated particle search mode. The analytical results for an environmental sample taken at a nuclear facility indicated that the observation of backscattered electron images with × 1000 magnification was appropriate to efficiently identify uranium particles. Lower magnification (less than × 500) made it difficult to detect smaller particles of approximately 1 μm diameter. After identification, each particle was manipulated and transferred for subsequent isotope ratio analysis by SIMS. Consequently, the isotope ratios of individual uranium particles were successfully determined without any molecular ion interference. It was demonstrated that the proposed technique provides a powerful tool to measure individual particles not only for nuclear safeguards but also for environmental sciences.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.701-704
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• 2005

Aquifer Thermal Energy Storage (ATES) can be a cost-effective and renewable geothermal energy source, depending on site-specific and thermohydraulic conditions. To design an effective ATES system having influenced by groundwater movement, understanding of thermo hydraulic processes is necessary. The heat transfer phenomena for an aquifer heat storage are simulated using FEFLOW with the scenario of heat pump operation with pumping and waste water reinjection in a two layered confined aquifer model. Temperature distribution of the aquifer model is generated, and hydraulic heads and temperature variations are monitored at the both wells during 365 days. The average groundwater velocities are determined with two hydraulic gradient sets according to boundary conditions, and the effect of groundwater flow are shown at the generated thermal distributions of three different depth slices. The generated temperature contour lines at the hydraulic gradient of 0.00 1 are shaped circular, and the center is moved less than 5m to the groundwater flow direction in 365 days simulation period. However at the hydraulic gradient of 0.01, the contour center of the temperature are moved to the end of boundary at each slice and the largest movement is at bottom slice. By the analysis of thermal interference data between two wells the efficiency of the heat pump system model is validated, and the variation of heads is monitored at injection, pumping and no operation mode.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.7B
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• pp.1261-1267
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• 1999

Frame relay (FR) service via an FR interface over a common asynchronous transfer mode (ATM) backbone network requires an FR-to-ATM interworking unit (IWU), the functionality of which directly impacts the engineering of the overall network in terms of capacity required, quality of service (QoS), and the interference among different types of services. This paper presents performance analysis of frame relay traffic in IWU. Additionally frame relay traffic policing using leaky bucket algorithm in this traffic model is carried out through computer simulation. Three measurements, the percentage of frames accepted as committed, the percentage of frames that accepted but marked eligible for diacard, and the percentage of frames that accepted that are discarded because of insufficient number of credits, are simulated variously in this paper.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.88-96
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• 2016

In this paper, the GaN FET based phase-shift full-bridge dc-dc converter design is implemented. Switch characteristics of GaN FET were analyzed in detail by comparing state-of-the-art Si MOSFET. Owing to the low conduction resistance and parasitic capacitance, it is expected to GaN FET based power conversion system has improved performance. However, GaN FET is vulnerable to electric interference due to the relatively low threshold voltage and fast switching transient. Therefore, it is necessary to consider PCB layout to design GaN FET based power system because PCB layout is the main reason of stray inductance. To reduce the electric noise, gate voltage of GaN FET is analyzed according to operation mode of phase-shift full-bridge dc-dc converter. Two 600W phase-shifted full-bridge dc-dc converter are designed based on the result to evaluate effects of stray inductance.

• Proceedings of the IEEK Conference
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• 2003.07b
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• pp.791-794
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• 2003

The increasing computational capability of processors is driving the need for high bandwidth links to communicate and store the information that is processed. Such links are often an important part of multi processor interconnection, processor-to-memory interfaces and Serial-network interfaces. This paper describes a 0.11-${\mu}{\textrm}{m}$ CMOS 4 Gbp s/pin 3-Level transceiver using RSL/(Rambus Signaling Logic) for high bandwidth. This system which uses a high-gain windowed integrating receiver with wide common-mode range which was designed in order to improve SNR when operating with the smaller input overdrive of 3-Level. For multi-gigabit/second application, the data rate is limited by Inter-Symbol Interference (ISI) caused by low pass effects of channel, process-limited on-chip clock frequency, and serial link distance. In order to detect the transmited 4Gbps/pin with 3-Level data sucessfully ,the receiver is designed using 3-stage sense amplifier. The proposed transceiver employes multi-level signaling (3-Level Pulse Amplitude Modulation) using clock multi phase, double data rate and Prbs patten generator. The transceiver shows data rate of 3.2 ~ 4.0 Gbps/pin with a 1GHz internal clock.

• Journal of Photoscience
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• v.12 no.3
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• pp.137-141
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• 2005

The chemiluminescence reaction of lophine with $H_2O_2$ in alkaline solution has been investigated for use in determination of $Cu^{2+}$ ions. The observed chemiluminescence intensity is found to be a function of the concentration of $Cu^{2+}$. Under the optimum reagent concentrations such as $4{\times}10^{-4}M$ lophine, 0.8 M KOH, 0.2M $H_2O_2,{\lambda}_{em}$, 533nm, the linear range and the detection limit were found to be 0.048ug/ml-48.32ug/ml (R=0.99897) and 0.005ulg/ml respectively. Relative standard deviation for five determinations of 24.16ug/ml $Cu^{2+}$ is 2.35%. The interference from other species was investigated. The proposed method was applied to the determination of $Cu^{2+}$ in different water samples.