Compute–Forward Multiple Access (CFMA): Practical Implementations

Sula, Erixhen,Zhu, Jingge,Pastore, Adriano,Lim, Sung Hoon,Gastpar, Michael Institute of Electrical and Electronics Engineers 2019 IEEE transactions on communications Vol.67 No.2

<P>We present a practical strategy that aims to attain rate points on the dominant face of the multiple access channel capacity using a standard low complexity decoder. This technique is built upon recent theoretical developments of Zhu and Gastpar on compute–forward multiple access which achieves the capacity of the multiple access channel using a sequential decoder. We illustrate this strategy with off-the-shelf LDPC codes. In the first stage of decoding, the receiver first recovers a linear combination of the transmitted codewords using the sum-product algorithm (SPA). In the second stage, by using the recovered sum-of-codewords as side information, the receiver recovers one of the two codewords using a modified SPA, ultimately recovering both codewords. The main benefit of recovering the sum-of-codewords instead of the codeword itself is that it allows to attain points on the dominant face of the multiple access channel capacity without the need of rate-splitting or time sharing while maintaining a low complexity in the order of a standard point-to-point decoder. This property is also shown to be crucial for some applications, e.g., interference channels. For all the simulations with single-layer binary codes, our proposed practical strategy is shown to be within 1.7 dB of the theoretical limits, without explicit optimization on the off-the-self LDPC codes.</P>

Raise arm_Color Block

한설아(Sula Han) 한국디자인학회 2017 한국디자인학회 국제초대전도록 Vol.2017 No.12

글로벌 디지털 산업 박람회 동향과 미래 산업 시사점: CES, MWC, HM, IFA 리뷰

윤정섭(Jungsub Yoon),진설아(Sula Jin),오윤환(Yoonhwan Oh) 과학기술정책연구원 2022 STEPI Insight Vol.- No.304

Laser welding of cast iron and carburized steel for differential gear

유지영,Taikmin Jung,Sulae Kim,이세헌 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.11

This study concerned laser welding replacing the traditional bolted connection of the ring gear and differential case in the power train of the automobile. Laser welding is necessary to reduce weight and manufacturing cost, since the bolted connection method requires additional parts and space. In the differential gear, however, it is difficult to control the welding processes because cast iron and carburized steel contain high carbon content. To solve these welding problems, laser welding using Ni-base filler metal was used in this work. The results of welding with Ni-base filler metal satisfied the torsional stiffness and durability, but compared to the bolted connection method, noise and hardness problems occurred. Therefore, to solve these problems, penetration depth was decrease from 5mm to 4mm and the carburized layer of the ring gear was cut with 1mm. As well, numerical method was used to evaluate welding deformation, torsional stiffness and fatigue.

오프라인과 온라인 대인관계가 사회자본형성과 주관적 안녕감에 미치는 영향

권정혜(Kwon, Jung-Hye),육설아(Yook, Sula),우성범(Woo, Sungbum),조현(Cho, Hyun) 사이버커뮤니케이션학회 2013 사이버 커뮤니케이션 학보 Vol.30 No.2

인터넷에 기반한 사회네트워크서비스(SNS) 사용이 확산됨에 따라 사람들의 대인관계가 오프라인과 온라인 공간에서 이루어지게 되었다. 본 연구에서는 온라인과 오프라인 대인관계가 사회자본의 형성과 주관적 안녕감에 어떤 영향을 미치는지를 살펴보기 위해, 대인관계를 아주 가까운 사람들(A), 조금 가까운 사람들(B), 알고 지내는 사람들(C)로 나누고, 이 세 부류의 사람들과 오프라인과 온라인에서의 접촉빈도와 관계유지행동(개방성, 긍정성, 호감표현, 네트워크형성)을 평가하였다. 연구대상은 SNS를 가장 많이 사용하는 2?30대를 중심으로 우리나라 인구분포 비율에 맞춰 서울, 경기, 강원, 충청, 전라, 및 경상 지역에서 총 1,051명에게 설문조사를 실시하였다. 설문조사에는 온라인 대인관계 접촉빈도, 관계유지행동, 친밀감, 사회자본, 주관적 안녕감을 측정하는 문항들을 포함하였다. 분석 결과 첫째, A, B, C로 대인관계 영역에 따른 온오프라인의 접촉빈도, 접촉인원수, 관계유지행동의 상호작용이 유의하였다. 둘째. 오프라인 관계행동의 질과 온라인 관계행동의 질이 사회자본 형성과 주관적 안녕감에 미치는 영향은 A, B, C 영역에서 다르게 나타났으며, 유대감 사회자본과 연결망 사회자본은 모두 주관적 안녕감에 정적인 영향을 주는 것으로 나타났다. 마지막으로 본 연구결과의 의의와 제한점, 앞으로의 연구 방향에 대해 논의하였다. The effect of Internet mediated communication on social relationships is still a topic of hot debate. The purpose of this study was to examine the effect of offline and online interpersonal behaviors on the formation of both bonding and bridging social capital and on subjective well-bring. A sample of 1,051 (male: 464, female: 572) individuals aged in 20~39 years old(M: 27.65, SD: 5.70) was recruited via the personal networks. A questionnaire was administered individually in which measures to assess sociodemographic variables, the size of very close (A), close(B), and acquaintant(C) social relationships, the frequencies and quality of relationship-maintaining behaviors in the offline and online contacts, social capital, and subjective well-bring. Results indicated that participants had more offline contacts than online contacts in A, B, and C relationships. It was also shown that the qualities of relationship-maintaining behaviors were higher with A relationships and in the offline contacts. Finally, path analysis showed that both online and offline contacts in A relationships had positive effects in forming both bonding and bridging relationships and offline contacts in B relationships had a positive effects in bonding relationships. However, online contacts in B and C relationships had a negative effects in bonding relationships. Both bonding and bridging relationships had positive relationships on subjective well-bring.

한국 화장품 산업 지식네트워크 흐름 분석

이예원(Yewon Lee),정일영(Ilyoung Jung),진설아(Sula Jin),이광호(Kwang-ho Lee) 한국기술혁신학회 2021 기술혁신학회지 Vol.24 No.3

국내 화장품 산업은 한류 콘텐츠의 인기와 지속적인 제품혁신을 기반으로 빠르게 성장하여 차세대 혁신성장동력으로 자리매김하고 있다. 화장품 산업은 변화하는 소비트렌드를 제품에 적극적으로 반영하는 수요견인형 산업으로 지속적인 아이디어 발굴과 지식연계가 혁신원천이 된다. 그러나, 화장품 산업의 성장기반이 되는 혁신원천 관점에서 산업 특성을 분석하는 연구는 부재한 실정이다. 따라서, 본 연구에서는 화장품 산업에 혁신을 가져오는 원천인 혁신주체 간 지식연계 및 흐름을 살펴보고자 1979년부터 2020년까지 화장품 분야 특허 데이터를 수집하여 발명자 네트워크를 분석하였다. 그 결과, 화장품 산업은 브랜드기업이 내부지식을 연계하는 폐쇄적인 형태로 발전하고 있고, 브랜드기업과 타 혁신주체 간 기술격차가 큰 것으로 나타났다. 또한, 기능별로는 기초연구보다 응용기술의 공동발명이 활발하였다. 따라서, 화장품 산업의 지속적인 발전과 경쟁력 제고를 위해서는 다양한 혁신주체 간 지식연계를 활성화할 필요가 있다. 특히, 공공분야 혁신주체의 역량을 보강하고 원천기술에 대한 지식연계를 강화하여 기존의 수요기반 산업에서 과학기술기반 산업으로의 전환을 준비해야 할 것으로 보인다. The Korean cosmetics industry is rapidly growing with the spread of Hallyu content and continuous product innovation. The cosmetics industry has characteristics of the demand-pull in technology innovation which is promptly reflecting fast-changing consumer trends. In general, creative ideas, and knowledge engagement are innovation sources which is a key success factor for sustainable industrial growth. However, few studies have examined the influence of innovation sources on the cosmetic industry. In this study, to examine the emergence and connectivity of knowledge as a source of innovation, the inventor network was analyzed based on Korean patent data of cosmetics from 1979 to 2020. The results show that the inventor network is formed mainly by brand companies and is focused on internal innovation. We also found that co-inventors tend to conduct applied research rather than basic research. Therefore, it is necessary to strengthen the capability and participation of various innovation actors and to transform demand-pull into technology push to maintain competitiveness with constant innovation in the cosmetic industry.

A cytotoxic compound from Moutan Cortex

Chu, BoYeun,Jin, WenYi,Choi, Sula,Myung, PyungKeun,Seong, YeonHee,Song, KyungSik,Bae, KiHwan 충남대학교 형질전환복제돼지연구센터 2004 논문집 Vol. No.8

Reserve Adequacy In Asia Revisited: New Benchmarks Based On The Size And Composition Of Capital Flows

( Jung Sik Kim ),( Jie Li ),( Ramkishen S. Rajan ),( Ozan Sula ),( Thomas D. Willett ) 한국경제학회 2007 The Korean Economic Review Vol.23 No.1

The Influence of Obesity on the Association of Obstructive Sleep Apnea and Atrial Fibrillation

Stafford Patrick L.,Harmon Evan K.,Patel Paras,Walker McCall,Lin Gen-Min,박승정,Chatterjee Neal A.,Mehta Nishaki K.,Mazimba Sula,Bilchick Kenneth,권영훈 대한수면학회 2021 sleep medicine research Vol.12 No.1

Background and Objective The association between obstructive sleep apnea (OSA) and atrial fibrillation (AF) has been closely studied. However, obesity is a powerful confounder in the causal relationship between OSA and cardiovascular disease. The contribution of obesity in the relationship between OSA and AF remains unclear. Methods We recruited 457 consecutive patients equally with and without AF who underwent clinically indicated diagnostic polysomnography at a single academic sleep center. Multivariable logistic regression adjusting for age, sex, hypertension, and heart failure was performed to study the independent association between OSA and AF stratified by obesity. Results A total of 457 patients (male: 56.2%, mean age 63.1 ± 13.3 years) was included. OSA prevalence was similar between those with and without AF (52.6% vs. 47.4%, respectively; p = 0.24). In multivariable analysis, no association was found between AF and OSA regardless of obesity status. When severe OSA (vs. non-severe OSA) was modeled as a dependent variable, AF was associated with a higher likelihood of severe OSA in non-obese patients [odds ratio (OR): 2.29, 95% confidence interval (CI): 1.23–4.35, p = 0.01], but not in obese patients (OR: 0.95, 95% CI: 0.48–1.90, p = 0.89). Conclusions The association of OSA with AF was present only in the non-obese and was limited to severe OSA patients. In contrast, no association was found in obese patients. The association between OSA and AF is partly dependent on the body habitus

과학기술기반 미래연구사업 Ⅸ

박병원(Byeongwon Park),서지영(Jiyoung Suh),홍성주(Sungju Hong),박성원(Seongwon Park),윤정현(Junghyun Yoon),최수민(Sumin Choi),김선지(Sunji Kim),진설아(Sula Jin),홍창의(Chang Ui Hong),정다예(Daye Jeong) 과학기술정책연구원 2017 조사연구 Vol.- No.-