• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.5
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• pp.809-811
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• 2015

In this paper, for the purpose of providing high data rate services, the multi-hop frame structure is designed for the underwater acoustic (UWA) short-range system which is proposed as a part of ocean surveillance and tracking network (OSTN). Under the measured underwater channel environment, the link-level system performance are also evaluated. Simulation results show not only the packet error rate (PER) comparisons, but the optimal modulation and coding scheme (MCS) levels for the orthogonal frequency division multiplexing (OFDM) based short-range UWA communications network.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.333-344
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• 2018

This proposed paper aims for the high efficiency contactless power transfer in household dc power distribution. A 300 W five-level diode clamped multi-level converter with 300 Vdc input dc link bus is employed for the power transferring task and the output voltage range is controlled at 48 Vdc. The inner and outer solenoid coils are used for inductive power transfer (IPT) transformer with the 200 kHz switching frequency for designed power density. Therefore, to achieve the converter efficiency above 95%, the LLC series resonant with fundamental harmonic analysis (FHA) and the calculated switching angles are used as an optimized tool for designing the system resonant tank. The validations of this approached topology are illustrated in both MATLAB/Simulink simulation and implementation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.743-746
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• 2005

The address selection mechanisms have been suggested under the circumstance occurring link failure already. But this paper proposes various considerations to address selection for load sharing without presenting address selection mechanism clearly. The goal of this document is merely referred various situation that have to consider when we make out address selection mechanism in the context of load sharing.

• Journal of Power Electronics
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• v.14 no.3
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• pp.499-506
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• 2014

This paper proposes a 3 kW single-phase bi-directional multi-level converter for energy storage applications. The proposed topology is based on the H-bridge structure with four switches connected to the DC-link. A simple phase opposition disposition PWM method that requires only one carrier signal is also suggested. The switching sequence to balance the capacitor voltage is considered. The topology can be extended to a nine-level converter or a three-phase system. The operating principle of the proposed converter is verified through a simulation and an experiment.

• Journal of Animal Environmental Science
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• v.13 no.3
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• pp.179-186
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• 2007

The purpose of this study was kinematics analysis of the multi-joint robot manipulator for an automatic milking system. The multi-joint robot manipulator was consisted of one perpendicular link and four revolution links to attach simultaneously four teat cups to four teats of a milking cow. The local coordinates of each joints on the robot manipulator was given for kinematics analysis. The transformation of manipulator was able to be given by kinematics using Denavit-Hatenberg parameters. The value of inverse kinematics which was solved by two geometric solution methods. The kinematics solutions was verified by AutoCAD, MATLAB, simulation program was developed using Visual C++.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.1788-1790
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• 2015

태권도의 승급 및 승단의 경우 심판 및 심사위원의 주관적인 평가에 의존하고 있다. 이러한 주관적인 평가는 판정시비 및 편파 판정과 같은 문제를 야기 시킨다. 제안하는 연구는 이러한 편파 판정의 시비가 발생할 경우 객관적인 입장에서 데이터를 기록하고 확인할 수 있도록 하는 디지털화된 정보를 제공하기 위한 방안을 연구했다. 본 연구에서는 태권도 수련자 및 승급 승단자가 모니터링하고 평가를 할 수 있는 시스템으로 제스처 인식에 사용하는 양안카메라를 제안하고 시스템 운용 방안을 연구했다.

• Earthquakes and Structures
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• v.23 no.6
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• pp.535-547
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• 2022

Handball sport, as its name postulates, is a team sport which highly physical workout. During a handball play, several ball impacts are applied on the hands resulting vibration in the forearm, upper arm, shoulders and in general in whole body. Hand has important role in the handball's game. So, understanding about the dynamics and some issues that improve the stability of the hand is important in the sport engineering field. Ulna and radius are two parallel bones in lower arm of human hand which their ends are located in elbow and wrist joint. The type of the joint provides the capability of rotation of the lower arm. These two bones with their ends conditions in the joints constructs a 4-link frame. The ulna is slightly thinner than radius. So, understanding about hand kinematics in handball's game is an important thing in the engineering field. So, in the current work with the aid of a multi-physics simulation, dynamic stability analysis of the ulna and radius bones will be presented in detail.

• Journal of Advanced Information Technology and Convergence
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• v.9 no.1
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• pp.11-24
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• 2019

This paper investigates the performance comparison of a Terahertz (THz) communications for a single-carrier and a multi-carrier single antenna point-to-point communication system. The multi-carrier system and single carrier system consider the orthogonal frequency division multiplexing (OFDM) and the minimum mean square error linear equalizer (MMSE-LE), respectively. We compare the frame-error-rate (FER) and throughput performance of both the systems for a THz communication environment with the carrier frequency of 300GHz and the tapped delay line (TDL) channel models described in 3GPP. It is observed from the simulation results that the OFDM systems outperform the MMSE-LE for various configurations.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.10033-10038
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• 2014

The aim of this study was to determine the prevalence of tobacco use, beliefs and risk awareness and psychosocial correlates of tobacco use among university students in 24 low, middle and emerging economy countries. Using anonymous questionnaires, data were collected from 16953 undergraduate university students (mean age 20.9, SD=2.9) from 25 universities in 24 countries across Asia, Africa and the Americas. Results indicate that overall 13.3% of the university students were current tobacco users, 22.4% for men and 6.6% for women, ranging from 3.8% in Singapore to 32.5% in Cameroon. The risk awareness of the smoking lung cancer link was 83.6%, while the risk awareness of the smoking heart disease link was 46.5%. Multivariate logistic regression found that older age, male gender, having a wealthy family background, living in a low income country, residing off campus on their own, poor beliefs in the importance not to smoke, awareness of the smoking heart disease link, hit by a sexual partner, depressive symptoms, and substance use (binge drinking and illicit drug use) were associated with current tobacco use.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.592-594
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• 2008

The powers used in the robot drive motor system are mostly DC sources such as batteries. Even AC powers in some systems are generated from DC sources by the inverter. It is can be forecasted that the DC-link communications will be widely used invarious industrial application. In this paper a novel BLDC motor drive system by using DC-link communications is proposed. The characteristic of this system is the communication only needs 2 DC lines. There are not additional lines to translate the reference signals and the reliability of the system is enhanced especially in some badly circumstance. The number of lines can be least when applied in the multi motor control system and the slip ring design can be simplified when applied as rotation machine. The reasonableness of proposed motor system is clarified by the PSIM simulation and the hardware prototype.