• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.774-776
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• 2014

노령층의 증가로 인하여 독거 노인층이 점점 증가하고 있다. 독거 노인은 외부의 침입이나 갑작스런 건강상의 문제로 위험에 처해질 가능성이 매우 높다. 따라서 독거 노인의 의료복지에 대한 관심이 날로 증가하고 있다. 본 연구에서는 독거 노인의 의료 복지에 적용할 수 있는 활동량 모니터링 시스템을 개발하였다. 이 시스템은 저 전력으로 동작하는 지그비 임베드 네트워크와 DTMF(Dual Tone Multi Frequency) 전화 시스템으로 구성되어, U-Health 케어 개념으로 활동량과 혈압 등의 인체 정보를 일상 생활 속에서 병원 및 보호자에게 전송할 수 있다. 또한 본 연구 결과는 미래의 독거 노인 원격진료 시스템에 적용될 수 있다.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.320-321
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• 2019

철도 변전설비를 위한 싸이리스터 듀얼 컨버터 시스템은 기존의 다이오드 정류기로 구성된 변전설비 시스템과는 다르게 전동차 제동 시 발생하는 에너지를 안정적으로 계통(22.9kV)에 전달 가능하다. 본 논문에서는 싸이리스터 듀얼 컨버터의 실증 시험을 통해 기존에 제안된 제어기법을 검증하였다. 실증 시험의 경우 부산 호포 차량기지(전동차 6량 1편성) 시험용 전동차가 기동 시 싸이리스터 듀얼 컨버터에서는 882kW의 에너지를 공급하며, 제동 시 시험용 전동차에서 싸이리스터 듀얼 컨버터로 756kW의 에너지가 회생되는 것을 확인 및 분석하여 본 시스템의 타당성을 검증하였다.

• International Journal of Industrial Entomology and Biomaterials
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• v.39 no.1
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• pp.22-28
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• 2019

We previously isolated 9 clones that show stronger signal compared to Bombyx mori cytoplasmic actin gene (BmA3) by using a dot blot hybridization. In this study, we focused on one clone among these clones which has high amino acid similarity with ${\beta}$-tubulin gene of B. mori. This clone was ubiquitously expressed in all tissues and developmental stage of B. mori. As result of promoter assay using dual luciferase assay system, we found the highest transcription activity region (-750/-1) in the 5'-flanking region of ${\beta}$-tubulin gene, which has about 47 fold more intensive promoter activity than BmA3 promoter. Moreover, the ${\beta}$-tubulin promoter was normally regulated in Bm5, Sf9, and S2 cells. Therefore, we suggest that ${\beta}$-tubulin promoter may be used more powerful and effectively for transgene expression in various insects containing B. mori as a universal promoter.

• Journal of the Korea Society of Computer and Information
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• v.24 no.1
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• pp.167-178
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• 2019

In this paper, we study the multi-objectives vehicle and drone routing problem with time windows, MOVDRPTW for short, which is defined in an urban delivery network. We consider the dual modal delivery system consisting of drones and vehicles. Drones are used as a complement to the vehicle and operate in a point to point manner between the depot and the customer. Customers make various requests. They prefer to receive delivery services within the predetermined time range and some customers require fast delivery. The purpose of this paper is to investigate the effectiveness of the delivery strategy of using drones and vehicles together with a multi-objective measures. As experiment datasets, we use the instances generated based on actual courier delivery data. We propose a hybrid multi-objective evolutionary algorithm for solving MOVDRPTW. Our results confirm that the vehicle-drone mixed strategy has 30% cost advantage over vehicle only strategy.

• ETRI Journal
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• v.43 no.4
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• pp.758-768
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• 2021

In this work, the secrecy of a typical wireless cooperative dual-hop non-orthogonal multiple access (NOMA)-enabled decode-and-forward (DF) relay network is investigated with the impact of collaborative and non-collaborative eavesdropping. The system model consists of a source that broadcasts the multiplexed signal to two NOMA users via a DF relay, and information security against the eavesdropper nodes is provided by a helpful jammer. The performance metric is secrecy rate and ergodic secrecy capacity is approximated analytically. In addition, a differential evolution algorithm-based power allocation scheme is proposed to find the optimal power allocation factors for relay, jammer, and NOMA users by employing different jamming schemes. Furthermore, the secrecy rate analysis is validated at the NOMA users by adopting different jamming schemes such as without jamming (WJ) or conventional relaying, jamming (J), and with control jamming (CJ). Simulation results demonstrate the superiority of CJ over the J and WJ schemes. Finally, the proposed power allocation outperforms the fixed power allocation under all conditions considered in this work.

• Food Science and Industry
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• v.51 no.1
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• pp.37-44
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• 2018

The prevalence of obesity is continually increasing in South Korea; about 1/3 of adults are diagnosed with obesity and 1/2 of adults are overweight in 2016. Abnormal body fat mass increased the risk factors of metabolic syndrome (including hypertension, type II diabetes, dyslipidemia), chronic kidney failure, osteoarthritis, and cardiovascular disease. Ministry of Food and Drug Safety (MFDS) in Korea established the validation and approval system for "functional food" based on related laws and regulations. According to the guideline of MFDS, the biomarkers for obesity study in vitro, in vivo, and clinical trial are well summarized. The analysis of physical phenotypes is necessary condition to study further molecular phenotypes and pathway analysis in vivo study. Thus, we will review currently available physical phenotype analysis; dual energy X-ray absorptiometry (DEXA) and Oxylet gas analysis will be examined in-depth.

• Coupled systems mechanics
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• v.10 no.1
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• pp.21-38
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• 2021

This work is an attempt to design a dynamic model for a non local bio-thermoelastic medium with diffusion. The system of governing equations are formulated in terms of displacement vector field, chemical potential and the tissue temperature in the context of non local dual phase lag (NL DPL) theories of heat conduction and mass diffusion. Based on this considered model, we study the fundamental solution and propagation of plane harmonic waves in tissues. In order to analyze the behavior of the NL DPL model, we construct basic theorem in the terms of elementary function which determine the existence of three longitudinal and one transverse wave. The effects of various parameters on the characteristics of waves i.e., phase velocity and attenuation coefficients are elaborated by plotting various figures of physical quantities in the later part of the paper.

• Journal of Auto-vehicle Safety Association
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• v.14 no.4
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• pp.6-15
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• 2022

In this study, a traffic light recognition algorithm was implemented and validated for low-speed special purpose vehicles in an urban environment. Real-time image data using a camera and YOLO algorithm were applied. Two methods were presented to increase the accuracy of the traffic light recognition algorithm, and it was confirmed that the second method had the higher accuracy according to the traffic light type. In addition, it was confirmed that the optimal YOLO algorithm was YOLO v5m, which has over 98% mAP values and higher efficiency. In the future, it is thought that the traffic light recognition algorithm can be used as a dual system to secure the platform safety in the traffic information error of C-ITS.

• International Journal of Korean Welding Society
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• v.3 no.2
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• pp.46-52
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• 2003

The refinement of microstructure and phase transformation near the interface of pure copper/carbon steel dissimilar metals joints with various friction welding parameters have been studied in this paper. The microstructure of copper and carbon steel joints were changed to be a finer grain compared to those of the base metals due to the frictional heat and plastic deformation. The microstructure of copper side experienced wide range of deformed region from the weld interface and divided into very fine equaxied grains and elongated grains. Especially, the microstructures near the interface on carbon steel were transformed from ferrite and pearlite dual structure to fine ferrite, grain boundary pearlite and martensite due to the welding thermal cycle and rapid cooling rate after welding. These microstructures were varied with each friction welding parameters. The recrystallization on copper side is reason for softening in copper side and martensite transformation could explain the remarkable hardening region in carbon steel side.

• Journal of Auto-vehicle Safety Association
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• v.15 no.2
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• pp.13-20
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• 2023

This paper presents a fault tolerant control strategy for Steer-by-Wire (SbW) systems. Among many problems to be solved before commercialization of SbW systems, maintaining reliability and fault tolerance in such systems are the most pressing issues. In most previous studies, dual steering motors are used to achieve actuation redundancy. However, relatively few studies have been conducted to introduce fault tolerant control strategies using rear wheel steering system. In this work, an actuator fault in front wheel steering is compensated by active rear wheel steering. The proposed fault tolerant control algorithm consists of disturbance observer and sliding mode control. The fault tolerant control performance of the proposed approach is validated via computer simulation studies with Carsim vehicle dynamics software and MATLAB/Simulink.