Effect of Cu Contents on Nanocluster Formation and Two-Step Aging Behavior in Al–Mg–Si Alloys

MinYoung Song,InSu Kim,JaeHwang Kim,SungKil Hong 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6

The effect of Cu contents on nanocluster formation and the two-step aging behavior of Al–Mg–Si alloys was studied based onhardness, DSC and TEM results. The activation energies for the formation of Cluster (1) were 61.6, 70.3 and 92.9 kJ/mol forCu-free, 1Cu (0.1 mass% Cu-added) and 3Cu (0.3 mass% Cu-added), respectively. It was confirmed that hardness increasedslowly with increasing Cu content during natural aging for 3.6 ks. These results suggest that the formation kinetics of Cluster(1) decrease due to the vacancy trapping phenomenon, because of the strong interactions of the Cu-vacancies. Meanwhile,the effect of the formation of nanoclusters by Cu addition on the two-step aging behavior at 170 °C during natural aging wasanalyzed. Hardness at the initial stage of the two-step aging increased with increasing Cu contents. This was caused by thesuppression of Cluster (1) formation during natural aging by the Cu additions. Based on TEM results, at the peak hardnessof the two-step aging, the number density of precipitates was increased by increasing Cu contents, due to the suppression ofnanocluster formation during natural aging.

10–315-MHz Cascaded Hybrid Phase-Locked Loop for Pixel Clock Generation

Minyoung Song,Young-Ho Kwak,Sunghoon Ahn,Hojin Park,Chulwoo Kim IEEE 2013 IEEE transactions on very large scale integration Vol.21 No.11

<P>A cascaded hybrid phase-locked loop (PLL) fabricated in a 65-nm CMOS process consumes 21 mW and occupies 0.4 mm<SUP>2</SUP>. An all-digital PLL (ADPLL) with piecewise linear calibrated hierarchical time-to-digital converter is proposed to achieve a wide operation range, and a charge-pump PLL (CPPLL) with an auxiliary (AUX) charge-pump for low current mismatch is cascaded to filter out the ADPLL output noise. The ADPLL achieves low long-term jitter regardless of the leakage current, and the CPPLL realizes low short-term jitter using a self-biased technique and the AUX charge pump. A phase-selectable divider is also proposed to divide the clock frequency while keeping the relative phase difference constant. The measured peak-to-peak short-term and long-term jitters at an output frequency of 315 MHz are 40 and 70 pspp, respectively, with a multiplication factor of 1024.</P>

Piecewise Linear Modulation Technique for Spread Spectrum Clock Generation

Minyoung Song,Sunghoon Ahn,Inhwa Jung,Yongtae Kim,Chulwoo Kim IEEE 2013 IEEE transactions on very large scale integration Vol.21 No.7

<P>We propose a novel modulation profile for a spread spectrum clock generator (SSCG). The proposed piecewise linear (PWL) modulation profile significantly reduces electromagnetic interference with a simple implementation. Two SSCGs with two- and three-slope-PWL modulation profiles are used. Both SSCGs consist of the proposed spread spectrum control profile generator and a phase-locked loop that includes a high-resolution fractional divider to reduce quantization noise from a delta-sigma modulator. The SSCG with the two-slope-PWL modulation profile was fabricated in a 0.18 μm 1P4M CMOS technology. The measured peak power reduction level of the two-slope-PWL modulation profile is 14.2 dB with 5000 ppm down spreading at 1.5 GHz. The SSCG occupies an active area of 0.49 mm<SUP>2</SUP> and consumes 40 mW of power at 1.5 GHz. The SSCG with the three-slope-PWL modulation profile was fabricated in a 0.13 μm 1P6M CMOS technology. The measured peak power reduction level of the three-slope-PWL modulation profile is 10.3 and 10.52 dB with 5000 ppm down spreading at 162 and 270 MHz, respectively. The SSCG occupies an active area of 0.096 mm<SUP>2</SUP> and dissipates 1 mW of power at 270 MHz.</P>

성인 이러닝 영어 학습자의 개인 특성 및 과목 성취도와 강의 콘텐츠 학습전략의 관계

송민영 ( Song Minyoung ) 한국중등영어교육학회 2023 중등영어교육 Vol.16 No.1

This study aims to examine the relationships of adult e-Learners’ individual characteristics and academic achievements with their English lecture learning strategies. A total of 151 cyber university students responded to a survey which asked how they studied lecture contents and participated in various learning tasks assigned in English lectures. The results were analyzed employing a series of one-way ANOVA and correlation analyses. The main findings are as follows: first, regardless of their individual characteristics, adult e-Learners of English tend to selectively focus on the lecture contents and learning tasks that are directly related to course evaluation, but do not actively participate in learner-teacher interaction activities such as speaking practice with a native speaker and getting feedback on pronunciation. Second, compared to old e-Learners, young e-Learners slightly prefer to study focusing on lecture notes rather than lecture videos. Lastly, novice e-Learners, who do not have much experience in online learning, do not actively prepare for course exams nor study lecture contents without delay. Findings and implications are further discussed in terms of developing online English lecture contents.

포스트 코로나 시대의 카페 가구 디자인에 대한 연구

송민영(Minyoung Song),이선경(Seongyeong Lee),최웅(Choi Woong) 한국디자인학회 2020 한국디자인학회 학술발표대회 논문집 Vol.2020 No.11

제스쳐 기반 인간 인터페이스 장치 Leap Motion을 이용한 보안 시스템 아이디어 설계

송민영(Minyoung Song),조건희(Geonhui Cho),현승권(Seungkwon Hyun),현승민(Seungmin Hyun),홍석현(Seokhyun Hong),박남제(Namje Park) 한국정보과학회 2018 한국정보과학회 학술발표논문집 Vol.2018 No.6

유해화학물질 수송용 차량의 위험기반 최적경로 연구

송민영(Song MinYoung),박명남(Park Myeongnam),김영국(Kim YoungKuk) 한국가스학회 2023 한국가스학회 학술대회논문집 Vol.2023 No.11

무선 단말기용 XML기반 맞춤 서비스 시스템 설계

송민영(Minyoung Song),이기호(Kiho Lee) 한국정보과학회 2001 한국정보과학회 학술발표논문집 Vol.28 No.2Ⅱ

최근 E-Business가 활성화됨에 따라 고객의 특성을 파악해서 고객 개인의 관심에 부합되는 개인화 된 정보나 서비스를 제공할 것이 요구되고 있다. 무선 인터넷을 이용한 서비스가 증가하고 있지만 대부분의 서비스 시스템들은 사용자 개인의 성향은 고려하지 않고 모든 사용자에게 획일적인 서비스를 제공한다. 무선 환경일수록 이러한 무분별한 광고는 오히려 고객의 만족도를 감소시킬 수 있다. 따라서 각각의 고객에게 취향과 관심 분야에 따른 차별화 된 서비스가 필요하다. 기존의 e-mail 시스템들은 모든 사용자들에게 단지 질의한 응답만을 제공하거나 똑같은 광고성 메일을 전달한다. 즉, 개인의 성향은 고려하지 않은 응답 결과를 보여주었다. 이에 본 논문에서는 휴대하기 편리한 이동 단말기의 특성을 이용하여 시,공간적 제약을 극복하고 작은 단말기 액정화면을 통해 정보를 일일이 검색해야 하는 번거로움을 덜어줄 수 있는 XML 기반의 무선단말기용 맞춤 서비스 시스템을 설계하였다. 이를 위해 e-mail 헤더 정보를 이용하여 사용자별로 분류하였고 텍스트마이닝 기법을 적용해 추출된 토픽과 사용자 프로파일 정보를 통해 예측된 사용자의 관심분야에 따른 카테고리를 계산하여 템플릿에 매핑함으로써 맞춤 서비스를 제공하는 시스템을 설계한다. 이로 인해 무선에서 제공하는 서비스의 질을 향상시키고 사용자에게 편리함과 흥미를 유발할 수 있다.

A 1.62 Gb/s–2.7 Gb/s Referenceless Transceiver for DisplayPort v1.1a With Weighted Phase and Frequency Detection

Junyoung Song,Inhwa Jung,Minyoung Song,Young-Ho Kwak,Sewook Hwang,Chulwoo Kim IEEE 2013 IEEE transactions on circuits and systems. a publi Vol.60 No.2

<P>This paper proposes a 2.7 Gb/s referenceless transceiver with weighted PFD for frequency detection of random signals. A single loop referenceless CDR is also proposed to overcome the disadvantages of a dual loop CDR. The ANSI 8b/10b encoder & decoder with the scrambler, the serializer & de-serializer, and the output driver with pre-emphasis are included in the proposed transceiver architecture for DisplayPort v1.1a. The jitter of the generated clock at the Tx PLL is 3.28 ps<SUB>rms</SUB> at 2.7 Gb/s with 1.2 V supply. The eye opening of the transmitter output with 3 m cable is 0.54 UI. The measured jitter of the recovered clock at the CDR is 1.57 ps<SUB>rms</SUB>, and BER is less than 10<SUP>-12</SUP>. The receiver consumes 23 mW at 2.7 Gb/s with 1.2 V supply. The CDR core and transceiver occupy 0.07 mm<SUP>2</SUP> and 0.94 mm<SUP>2</SUP>, respectively, in a 0.13 μm 1P8M CMOS process.</P>

유아교사의 행복감과 유아 또래놀이 상호작용의 관계에서 교사-유아 상호작용의 매개효과

송민영 ( Song Minyoung ),류성연 ( Ryu Sungyeon ),이뿐새 ( Lee Bbeunsae ) 한국유아교육학회 2017 유아교육연구 Vol.37 No.4

본 연구의 목적은 교사의 행복감과 유아 또래놀이 상호작용, 교사의 행복감과 교사-유아 상호작용 간의 관계와 세 요인의 관계에서 교사의 상호작용이 매개적인 역할을 수행하는 지 알아보는 데 있다. 이를 위해 한국아동패널(PSKC) 7차년도 데이터(2014)의 만5세 유아 1,203명과 해당 유아가 다니는 육아지원기관의 교사를 연구대상으로 하였다. 분석은 SPSS 23.0, SPSS macro, AMOS 21.0 프로그램을 활용하였으며, 주 연구결과는 다음과 같다. 교사의 행복감은 유아 또래놀이 상호작용에 직접적인 영향을 미치지는 않았으나, 교사-유아 상호작용에는 직접적인 영향력을 발휘하였다. 또한 교사 행복감과 유아 또래놀이 상호작용 간의 관계에서 교사-유아 상호작용은 매개적인 역할을 하여 본 연구의 구조모형은 완전매개모형임이 검증되었다. 이러한 결과를 통해 교사가 느끼는 행복이라는 감정은 교사의 상호작용이라는 교수활동의 질을 향상시키며, 이는 다시 유아의 사회적 영역에 영향을 미치는 것으로 밝혀진 것이다. 따라서 유아의 사회적 능력 향상을 촉발하기 위해서는 교사의 행복감을 향상시키는 것과 그에 따른 상호작용 질을 높이는 것이 중요하며, 결론에서는 이를 위한 방안에 대해 논의하였다. The purpose of this study was to examine the relationship among teacher-child interactions, teachers` happiness, and child-peer play interaction. For this study, analyzed the seven wave(2014) of Panel Study on Korean Children(PSKC) and the subjects were 1,203 children and their teachers`. Structural equation model (SEM) analysis of data was conducted with SPSS 23.0, AMOS 21.0, SPSS macro. The results were as follows. First, Teachers` happiness did not directly affect the peer play interaction of children, however it had a direct effect on teacher-child interactions. Second, teacher-child interactions mediated the association between teachers` happiness and child-peer play interaction. The results of this study suggest that improve the teachers` happiness and teacher-child interactions in order to boost social skills of children like interaction. Therefore, society should formulate support plan and policies for child-care teachers` emotional happiness, and teachers` should also make efforts to promote happiness, improvements in the quality of interaction.