• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.3
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• pp.188-194
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• 2020

This paper presents a high-efficiency Switch Mode Line Transformer (SMLT) composed of load-shared dual modules, which is based on the AC/AC LLC resonant converter. Given that the conventional adaptor is usually composed of two power stages, namely, the PFC and DC/DC converters, its system size can be increased according to the output power. However, given that the proposed SMLT can separate the PFC converter from the adaptor, the size reduction of the system can be achieved. Meanwhile, the SMLT with a single module has the limit of the size reduction because of a high resonant current. Thus, it can be configured with dual or multiple modules to reduce the resonant current. Then, their load sharing can be guaranteed by only the proposed transformer structure without an extra current controller. The validity of the proposed converter is proven through a 850-W prototype.

• Journal of the Korean Society of Propulsion Engineers
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• v.20 no.4
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• pp.19-25
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• 2016

Using a actuator to which the motor and the gear is applied to the I-PD control method and a dual-loop system to carry out precise position control. I-PD control algorithm performs an operation to reduce the overshoot in the transient response. Accordingly, the actuator obtains a precise position tracking result. Also it utilizes two sensors and dual loops. It reduces the adverse effect on the precise position control that may occur by the end play of the gear train. In this paper, we uses the actuator model applying the BLDC motor and gear in order to determine the position tracking result by the dynamic characteristic change. It was verified by the simulation results.

• Nuclear Engineering and Technology
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• v.53 no.4
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• pp.1277-1283
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• 2021

It is important for operators of poly-pipelines in petroleum industry to continuously monitor characteristics of transferred fluid such as its type and amount. To achieve this aim, in this study a dual energy gamma attenuation technique in combination with artificial neural network (ANN) is proposed to simultaneously determine type and amount of four different petroleum by-products. The detection system is composed of a dual energy gamma source, including americium-241 and barium-133 radioisotopes, and one 2.54 cm × 2.54 cm sodium iodide detector for recording the transmitted photons. Two signals recorded in transmission detector, namely the counts under photo peak of Americium-241 with energy of 59.5 keV and the counts under photo peak of Barium-133 with energy of 356 keV, were applied to the ANN as the two inputs and volume percentages of petroleum by-products were assigned as the outputs.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.11
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• pp.32-36
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• 2008

In this paper, we investigate the capacity of CDMA/TDD in the inner zone of multimode scenario with dual-band operation where high frequency band is used for TDD in the inner zone and lower frequency band is utilized for FDD in the outer zone. The effects of various system parameters such as cell radius, date rate, and time slot allocation are analyzed.

• Korean Journal of Veterinary Service
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• v.30 no.4
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• pp.527-532
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• 2007

In present study, we described the reliability of the dual priming oligonucleotide (DPO) multiplex polymerase chain reaction (PCR) for the detection of Mycobacterium tuberculosis complex (MTC) and non-Mycobacterium tuberculosis (NMT) in blood samples of the Korea native cattle, Hanwoo. Among 340 samples 22 (6.5%) were positive in using DPO multiplex PCR, 21 (6.2%) were positive in PCR. The relative agreement between 2 tests was 99.7%, and the agreement quotient (kappa), was 0.95 (excellent). In these results, we demonstrated the successful application of DPO multiplex PCR for the diagnosis of bovine tuberculosis in Hanwoo. Multiplex PCR, using DPO primers, can be useful for the simple diagnosis of bovine tuberculosis in bovine blood samples.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.3
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• pp.488-493
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• 2008

This paper represents a dual-mode type transmission technique for a high reliable narrow-band power line communication(PLC) modem, and its design and implementation of a system-on-chip(SoC). The proposed transmission technique is based on a Chirp modulation for the purpose of overcoming time variations of power line channel environments in the narrow-bandwidth of the frequency range of 95-145.5 kHz. The designed modem is fabricated utilizing a mixed 0.18 ${\mu}m$ CMOS technology. Especially, according to the power line channel environments the data transmission rate can be selectively changed into 2.5 kbps and 480 bps. The total hardware complexity of the implemented chip is about 50,000 gates, the power consumption is about 26mW, and the operating frequency is up to 5.12 MHz.

• Journal of electromagnetic engineering and science
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• v.10 no.2
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• pp.50-55
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• 2010

Orthogonal Frequency Division Multiplexing(OFDM) dual-hop systems can take full advantages of the techniques of both multi-hop communication and OFDM. To achievethis end, we propose a joint subcarrier matching, power allocation and bit loading algorithm operating under a total power constraint and the same Bit Error Rate(BER) threshold over all subcarriers. Simulation results demonstrated system throughput improvement compared to single-hop systems and dual-hop systems with different bit loading algorithms for each relay position, power constraint, and required BER.

• ETRI Journal
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• v.30 no.5
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• pp.674-684
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• 2008

This paper proposes a dual addressing scheme (DAS) for IPv6 over IEEE 802.15.4 wireless sensor networks (WSN). DAS combines a global unicast address to cope with association link changes and node mobility, and it links local addresses to lighten the overhead of the system to save energy and resources. This paper describes DAS address formats, address autoconfiguration, and address translation tables in the gateway. A detailed description of DAS is provided through examples. Simulations are performed to demonstrate the performance improvements of the DAS compared with the IPv6-based WSN, which uses the conventional single address.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.6
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• pp.147-154
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• 2003

Radial Dual Mass Flywheel(RDMF) is designed to reduce torsional vibration and noise occurring in automotive powertrain. In this paper, finite element method is used to evaluate stress level and critical area of the torsional spring box, a major part of RDNF system. In finite element analysis, both static and dynamic loadings are considered and it is found that the most critical spot is the welded zone of spring box. Also, fatigue test is performed and fractured surfaces are examined to find fatigue stress level by experiment.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.3
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• pp.9-18
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• 1995

The substitution of conventional fuel oil by alternative fuels is of immense interest due to liquid oil shortage and requirements of emission control standard. Among the alternative fuels, natural gas may be the most rational fuel, because of its widespread resource and clean est burning. Meanwhile, engine simulation is of great importance in engine development. Hence a zero-dimensional combustion model was developed for dual-fuel system. Natural gas was injected directly into the cylinder and small amount of distillate was used to provide the ignition kernel for natural gas burning. The intake air and exhaust gas flow was modeled by filling and emptying method. Although the single zone approach has an inherent limitation, the model showed promise as a predictive tool for engine performance. Its simulation was also made to see how the engine performance was influenced by the fuel injection timings and amount of each fuel.