Sungkyunkwan University Research Articles

Association between reproductive lifespan and lung function among postmenopausal women.

Correspondence to: Hye Yun Park, MD, PhD. Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, South Korea. Email: hyeyunpark@skku.edu; Juhee Cho, PhD. Department of Clinical Research Design and Evaluation, SAIHST, Sungkyunkwan University, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, South Korea. Email: Jcho@skku.edu.BackgroundBoth age of menarche and menopause are associated with impaired lung function. However, there is limited data on the association between reproductive lifespan (RL) and lung function. This study aims to evaluate the association between RL and lung function among postmenopausal women.MethodsIn the Korean National Health and Nutrition Examination Survey (2010–2015), an annual cross-sectional survey of a national representative sample of non-institutionalized Korean population, the postmenopausal women aged 40–64 years who underwent spirometry were included. Spirometry was performed according to the recommendations of the American Thoracic Society and European Respiratory Society, and RL (years) was calculated by subtracting the age at menarche from age at menopause.ResultsAmong 3,410 postmenopausal women, the mean RL were 34.91 (standard error 0.07). In spline regression models, shorter RL was associated with reduced predicted forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1), and the associations were linear. In multivariable-adjusted models, the prevalence ratios (95% confidence interval) for abnormal lung function (restrictive or obstructive ventilatory disorder) comparing women with RL ≤30 years and >30 to <39 years to women with RL ≥39 years were 1.83 (1.15, 2.50) and 1.42 (1.01, 1.84), respectively. Women with RL ≤30 years showed a 2.13 (1.28, 3.54) times higher prevalence of restrictive ventilatory disorder than women with RL ≥39 years.ConclusionsIn postmenopausal women, a shorter RL was associated with abnormal lung function, particularly with a restrictive ventilatory disorder.

A Figure of Merit for Flexible Batteries

Dr. Jian Chang received his BEng at Jilin University (2010) and PhD at Sungkyunkwan University (2015). He worked as postdoctoral fellow in Prof. Zheng's group between 2016 and 2019. He is currently research assistant professor at Southern University of Science and Technology. Dr. Qivao Huang received her BA (2014) and PhD (2019) at The Hong Kong Polytechnic University. She is currently postdoctoral fellow in Prof. Zheng's group and will start her research assistant professor position in September 2020 at The Hong Kong Polytechnic University. Dr. Zijian Zheng is currently full professor at The Hong Kong Polytechnic University. His research interests include surface and polymer science, nanolithography, flexible and wearable electronics, and energy. He received his BEng in Chemical Engineering at Tsinghua University in 2003 and PhD in Chemistry at the University of Cambridge in 2007. In 2008 and 2009, he worked as a postdoctoral researcher at Northwestern University. He was elected a Founding Member of The Hong Kong Young Academy of Sciences.

Value of Computed Tomography-Defined Visceral Fat Area as a Risk Factor for Endometrial Cancer

Jaehyun Cho1, Jeong Sig Kim1*, Suyeon Park2 and Woo Young Kim3 Author Affiliations 1Department of Obstetrics and Gynecology, Soonchunhyang University College of Medicine, Seoul, Republic of Korea 2Department of Biostatistics, Soonchunhyang University College of Medicine, Seoul, Republic of Korea 3Department of Obstetrics & Gynecology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea. Received: May 18, 2020 | Published: June 09, 2020 Corresponding author: Jeong Sig Kim, Department of Obstetrics and Gynecology, Soonchunhyang University Hospital Seoul. #59 Daesagwan-ro, Yongsan-gu, Seoul 04401, Republic of Korea DOI: 10.26717/BJSTR.2020.28.004609

남녀의 출산의향, 출산 희망연령과 계획 자녀수의 영향 요인

The purpose of this study was to identify the factors related to the willingness to have a child, parental age at first child’s birth, and the planned number of children. The data came from the Korean General Social Survey from the Survey Research Center at Sung Kyun Kwan University. The sample data set included 488 men and women between the ages of 18 and 49. The major findings are as follows. First, gender, age, satisfaction with family relations, the value of marriage, the value of family succession, and willingness to increase spending on education significantly affected the willingness to have a child among unmarried and married participants without children. Second, among people willing to have a child, the factors that influenced parental age at first child’s birth were gender, education, satisfaction with household economic condition, the value of marriage, and the willingness to increase spending on education. Third, across the sample, the planned number of children was decided by satisfaction of family relations, the value of childbirth, the value of marriage, and home ownership. Overall, the value of marriage was the factor most strongly associated with the three dependent variables. The more a person agree with living with their partner before marriage, the more willing they were to give birth, the younger they were when they became a parent, and the more children they planned to have. The higher satisfaction of family relations, the higher willingness to have a child, and the more children a participant planned to have. In addition, the more a participant was willing to increase spending on education, the higher their willingness was to have a child and the older they were when they became a parent.

Erratum to: Ultra-high current gain tunneling hot-electron transfer amplifier based on vertical van der Waals heterojunctions

The affiliation numbers of the authors were unfortunately misplaced on the first page and the first page of the ESM. Instead of Xu Zhao1,§ (✉), Peng Chen1,2,§, Xingqiang Liu2 (✉), Guoli Li2, Xuming Zou2, Yuan Liu2, Qilong Wu2, Yufang Liu1 (✉), Woo Jong Yu3, and Lei Liao2 1 Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Changsha 410082, China 2 Henan Normal University, School of Physics, Xinxiang 453007, China 3 Department of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea § Xu Zhao and Peng Chen contributed equally to this work. It should read Xu Zhao1,2,§ (✉), Peng Chen1,2,§, Xingqiang Liu1 (✉), Guoli Li1, Xuming Zou1, Yuan Liu1, Qilong Wu1, Yufang Liu2 (✉), Woo Jong Yu3, and Lei Liao1 1 Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education & Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Changsha 410082, China 2 Henan Normal University, School of Physics, Xinxiang 453007, China 3 Department of Electronic and Electrical Engineering, Sungkyunkwan University, Suwon 440-746, Republic of Korea § Xu Zhao and Peng Chen and contributed equally to this work.

한국어 읽기 교재 내 활용을 위한 대학교 학사 공지문 문체 분석 : 중급 수준 학문 목적 한국어 학습자를 대상으로

This study aims to propose the style contents that can be presented by using notices in reading textbooks for intermediate Korean for Academic Purpose(KAP) learners. In doing so, 27 academic notices from the top 3 universities(Kyunghee university, Sungkyunkwan university, Yonsei university) with the most international students were collected and analyzed. The results of the study revealed that, certain

Temporal Trend of Aedes albopictus in Local Urban Parks of the Republic of Korea.

Aedes albopictus (Skuse) was first reported in the Republic of Korea in 1941 (Suwon, Gyeonggi Province). Recently, a mosquito-monitoring program was established in response to the potential development of autochthonous infections of dengue, chikungunya, and Zika viruses, to identify the regional characteristics of Ae. albopictus in Suwon. Daily collections of adult mosquitoes were conducted using Blackhole UV-LED traps and BG-Sentinel traps baited with octenol, carbon dioxide or both at five sites in Suwon (Sungkyunkwan University, Manseok, Seoho, Olympic, and Jungang parks) from 1 July to 1 November 2016. Based on the ecological cycle of mosquitoes, an estimated association between the daily mean temperatures [2 wk prior to the collection date (lag 2 wk)] and relative population abundance were developed using a generalized linear model. The overall proportion of female mosquitoes collected from all traps was 88.3%. Higher female trap indices were observed for mosquitoes collected at BG-Sentinel traps. Additionally, the BG-sentinel trap was more effective collecting Ae. albopictus. Culex pipiens (Coquillett) was the most frequently collected mosquito using UV-LED traps, followed by Ae. vexans nipponii (Theobald), Ochlerotatus koreicus (Edwards), Cx. inatomi (Kamimura and Wada), and members of the Anopheles Hyrcanus Group. Within a certain temperature range, daily mean temperatures 2 wk prior to the collection period was significantly associated with a maximum abundance of Ae. albopictus (P < 0.05) at 26.2°C (95% confidence interval: 24.3-29.4°C). The BG-Sentinel trap is an effective trap for monitoring relative population abundance of Ae. albopictus, and trap catches are significantly correlated with daily mean temperatures.

20-30대 남녀의 결혼제도 인식과 결혼의향

The purpose of this study is to identify the perceptions of and willingness for marriage among people in their 20s and 30s. The data came from the Korean General Social Survey of the Survey Research Center at Sungkyunkwan University. The sample data set included 292 men and women aged 20 to 39. The major findings are as follows. First, gender, satisfaction with oneʼs household economic conditions, and significantly affect the individualsʼ perceptions of marriage. The results show that the menʼs education level, value of family succession, value of gender roles, and value of parentsʼ role are the significant factors that affect their perceptions of marriage. In the case of the womenʼs perceptions of marriage, the significant factors are their household economic conditions, value of family succession, value of gender roles, and value of childbirth. Second, the willingness for marriage among unmarried people is decided by age, education level, whether one has an income or not, satisfaction with oneʼs household economic conditions, and value of oneʼs childbirth. Overall, gender is the most significant factor that affects the perceptions of marriage among all the other variables. However, menʼs and womenʼs values of gender roles and family succession, respectively, both significantly affect their perceptions of marriage but show opposite coefficient directions. Another finding shows that unmarried people who are willing to marry tend not to have children. This implies that they do not perceive the decision on having a child as a necessary factor behind marriage decisions.

Association between cataract and cotinine-verified smoking status in 11 435 Korean adults using Korea National Health and Nutrition Examination Survey data from 2008 to 2016.

To investigate the association between cataract and cotinine-verified smoking status. Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, South Korea. Retrospective study. Participants were randomly selected using data collected by the Korea National Health and Nutrition Examination Survey from 2008 to 2016. Participants completed a questionnaire to self-report smoking status and a history of cataract, among other variables. To identify the relationship between cataract and smoking, a new variable was used to define smoking status, survey-cotinine-verified smoking status (SCS)-the combination of self-reported smoking status and cotinine-verified smoking status- and thus identify hidden smokers. In total, 11 435 participants were eligible for final analysis. The study comprised 4925 men and 6510 women; the mean age was 52.86 ± 16.83 years (median: 54 years). Of 2292 SCS smokers, 382 (16.7%) were nonsmokers according to their self-report. Notably, the ratio of the cotinine-verified to self-reported smoking rate of women was greater than that of men, 1.60 and 1.06, respectively. This indicated that female hidden smokers may affect the results of studies based on self-reported questionnaires. Multivariate logistic regression analysis showed that smoking was correlated with cataract (odds ratio [OR], 1.37 [95% CI, 1.07-1.76]; OR, 1.35 [CI, 1.12-1.64]; and OR, 1.36 [CI, 1.10-1.69]) for self-reported, cotinine-verified, and SCS, respectively. No statistically significant sex difference was found. Smoking was associated with cataract, but it did not vary by sex. Female hidden smoking must be considered when investigating the association between smoking and cataract based on self-reported questionnaires.

ACS cohosts forum in Seoul

ACS Publications and South Korea’s Institute for Basic Science (IBS) coorganized the first ACS Publications and IBS Forum, in Seoul, South Korea, Sept. 30–Oct. 1. The forum was hosted by Yonsei University, and the organizing committee included Cindy Burrows from the University of Utah; Jinwoo Cheon, director of the IBS Center for Nanomedicine at Yonsei University; and Peidong Yang from the University of California, Berkeley. The theme of the forum was “Nanomaterials for Energy and Life Sciences.” In addition to Cheon and Yang, the lineup of speakers included Harvard University’s Joanna Aizenberg, the University of Toronto’s Warren Chan, Sungkyunkwan University’s Nam-Gyu Park, and the University of Alberta’s Jillian Buriak, among others. An ACS on Campus event was colocated with the forum, and attendees had the opportunity to hear from American Chemical Society editors about publishing trends and tips on how to become a better writer and reviewer.

Ten-year clinical outcomes after implantation of a posterior chamber phakic intraocular lens for myopia

To report the long-term clinical outcomes, including efficacy and safety, of implantable collamer lens (ICL) implantation to treat myopia. Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea. Retrospective case series. Medical records of patients who had ICL implantation were reviewed. The preoperative and postoperative visual acuity, spherical equivalent (SE), endothelial cell density (ECD), and intraocular pressure (IOP) were analyzed. The postoperative vault and complication rate, including cataract and glaucoma, were evaluated. Patients were placed in the lens opacity group or clear lens group based on whether lens opacity developed postoperatively. One hundred ten eyes (60 patients) were analyzed. The mean preoperative age was 30.3years±8.3 (SD). The mean SE was -12.01±3.70 diopters (D) preoperatively and -0.65±1.09 D 10years postoperatively. The mean vault height was 562.4±175.9μm 6months postoperatively, decreasing to 352.9±171.8μm at 10years. There were no significant changes in the ECD and IOP at any timepoint. Lens opacities developed in 21 eyes (12.1%) during the 10-year follow-up. The mean vault in the lens opacity group was significantly lower than in the clear lens group after 4years. No patient who had ICL implantation when they were 30years or younger developed lens opacity or required phacoemulsification. The results indicate that ICL implantation provided long-term stability and good refractive outcomes. Performing this surgery in young patients, especially those 30years or younger, may be safe in terms of long-term cataract formation.

ES02.02 Management of EGFR LA Disease

ES02.02 Management of EGFR LA Disease

1870년대~1930년대 上海 출판 석인본을 통한 근대적 시각 이미지의 국내 유입 양상 연구

In this study I took a look at the overall picture of the lithographed books published in modern Shanghai and then brought into Korea between 1870s and 1930s, and examined the visual images of those books to analyze the symptoms of the modernity in them. The purpose of this study is to provide a basis for evaluating the effects of these visual images on the formation of new knowledge in modern Korea.BR About three thousand lithographed books published in Shanghai were collected in National Library of Korea, Kyujanggak Korean Studies Institute, SungKyunKwan University Jongyeonggak, Korea University Library, Yonsei University Library, Seoul National University Library, and among them nine hundred sixty eight books (about 69 percent of the total) were published at Saoyeshanfang (掃葉山房), and in Korea the institution that has the largest collection of the lithographed books published in Shanghai was the library of Korea University, which has three hundred seventy two books (about 12.3 percent of the total).BR When categorizing the lithographed books collected in Korea University Library into traditional four categories (sibu 四部), thirty six books belong to Confucian classics part (jingbu 經部), about 9.67 percent of the total, thirty one books belonging to the category of historiography and statecraft (shibu 史部), 8.33 percent of the total, ninety one books belonging to the category of masters and philosophers (zibu 子部), 24.46 percent of the total, and two hundred ten books belong to the category of belles-lettres (jibu 集部), about 56.45 percent of the total. Among the books that belong to the category of belles-lettres, fifty three books(about 14.24% of the total) are books of novels. This suggests that the greatest number of novels were introduced among the books published in Shanghai at that time. BR Next, I divided the modern images contained in the lithographed books introduced to Korea including Manqing Guanchang Baiguailu (滿淸官場百怪錄), Guowen Jiaokeshu (國文敎科書), Xizheng Congshu (西政叢書), etc, into two groups; illustrations that convey knowledge from the West and illustrations containing the material representing modern civilization. By examining these images, we can understand how the modern knowledge like anatomy, world geography and scientific knowledge, and material representing modern civilization like new means of transportation, urban landscape, and brand new living supplies were illustrated and explained, and furthermore we can assume that these images had some effect on the formation of visual knowledge in modern Korea.

In situ Observation of Oxygen Vacancy Order-Disorder Transition in NdBaCo2O5.5 Layered Perovskite Oxide

Journal Article In situ Observation of Oxygen Vacancy Order-Disorder Transition in NdBaCo2O5.5 Layered Perovskite Oxide Get access Ohhun Kwon, Ohhun Kwon Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea Search for other works by this author on: Oxford Academic Google Scholar Yong In Kim, Yong In Kim Department of Energy Science, Sungkyunkwan University (SKKU), Suwon, Republic of Korea Search for other works by this author on: Oxford Academic Google Scholar Jong Chan Kim, Jong Chan Kim School of Materials Science and Engineering, UNIST, Ulsan, Republic of Korea Search for other works by this author on: Oxford Academic Google Scholar Hanbeom Jeong, Hanbeom Jeong Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea Search for other works by this author on: Oxford Academic Google Scholar Guntae Kim, Guntae Kim Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea Search for other works by this author on: Oxford Academic Google Scholar Young-Min Kim, Young-Min Kim Department of Energy Science, Sungkyunkwan University (SKKU), Suwon, Republic of Korea Search for other works by this author on: Oxford Academic Google Scholar Hu Young Jeong Hu Young Jeong UNIST Central Research Facilities (UCRF) and School of Materials Science and Engineering, UNIST, Ulsan, Republic of Korea Corresponding author: hulex@unist.ac.kr Search for other works by this author on: Oxford Academic Google Scholar Microscopy and Microanalysis, Volume 25, Issue S2, 1 August 2019, Pages 1872–1873, https://doi.org/10.1017/S1431927619010092 Published: 01 August 2019

Sungkyunkwan University (Adv. Mater. 34/2019)

Advanced MaterialsVolume 31, Issue 34 1970238 Cover PictureFree Access Sungkyunkwan University (Adv. Mater. 34/2019) First published: 20 August 2019 https://doi.org/10.1002/adma.201970238AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract This special issue features 4 Reviews and 13 Progress Reports by professors at Sungkyunkwan University (SKKU) and covers various topics of great interest in the field of material science. The 17 papers in this special issue comprehensively cover the material science areas led by the SKKU faculty members such as display materials, semiconductors, nanomaterials, biological materials, energy materials, and 2D materials. Volume31, Issue34Special Issue: Materials Research at Sungkyunkwan UniversityAugust 23, 20191970238 RelatedInformation

The automatic frequency control based on artificial intelligence for compact particle accelerator.

In this work, an advantage actor critic (A2C) based intelligent automatic frequency control (AFC) system was developed for X-band linear accelerator (LINAC). A2C is one type of reinforcement learning, which indicates how software agents should perform actions in an environment. In this paper, the A2C based AFC algorithm and its environment design, simulation result, and controller hardware and software processes are described. The objective of our design is to match LINAC and magnetron frequency, and it is implemented via reward shaping using comparison with the reflected power in the adjacent time. The simulation with the A2C algorithm was implemented in two modes, namely, periodic and White Gaussian Noise (WGN) waves, for analysis with temperature and random disturbance, respectively. In order to create artificial disturbance in the experiment, the magnetron shaft was shifted randomly every 0.5 s by using WGN with 18° angle of the step motor. The standard deviation of the reflected power was 5.63 kW, and the average power was 130.9 kW. To obtain maximum reward at the beginning of the A2C training, the adjacent frequency is needed. The measured average reflected power and standard deviation were 122.8 kW and 1.75 kW, respectively, after 2000 iterations. The results show that the reflected power and standard deviation of the AFC with A2C were lower compared to open-loop with artificial disturbance. The RF station of a medical X-band LINAC was used as the test bench, and the performance was confirmed by the results of an experiment conducted at Sungkyunkwan University in Korea.

Topography-guided versus wavefront-optimized laser in situ keratomileusis for myopia: Surgical outcomes

To compare the outcomes of topography-guided and wavefront-optimized surgery in patients having laser insitu keratomileusis (LASIK) for myopia. Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, and BALGEUN-EYE21 Operation Center, Gwangju, South Korea. Prospective case study. Patients had topography-guided LASIK in 1 eye and wavefront-optimized LASIK in the contralateral eye using Contoura Vision software and the WaveLight EX500 excimer laser. Refractive and visual outcomes were analyzed 3months postoperatively. The study comprised 43 patients. In both groups, the postoperative uncorrected distance visual acuity (UDVA) was 0.0 logarithm of the minimum angle of resolution or better in 90.7% of eyes and the residual spherical equivalent (SE) refractive error was ±0.75 diopter (D) in 81.4% of eyes. The UDVA, residual SE refractive error, and astigmatism did not differ significantly between the 2 groups. There was significant induction of higher-order aberrations (HOAs) in both groups, although corneal coma and trefoil did not increase and ocular trefoil decreased significantly in the topography-guided group (P=.038). However, in the wavefront-optimized group, corneal coma and trefoil increased significantly (P<.001 and P=.046, respectively) and ocular trefoil did not change significantly. In addition, topography-guided LASIK induced significantly fewer corneal total HOAs (P<.001), coma (P<.001), and trefoil (P=.020) than wavefront-optimized LASIK. Although both topography-guided LASIK and wavefront-optimized LASIK safely and effectively achieved the predicted refractive and visual outcomes, topography-guided LASIK induced fewer HOAs and significantly decreased ocular trefoil, corneal total HOAs, and coma.

한국어 학습자의 말하기 전략 사용 양상에 대한 사례 연구

The purpose of this study is to identify aspects of speaking strategies that can be seen in dialogue of Korean language learners during the process of learning Korean from beginning to advanced levels. According to the research result, learners continuously used the repeating strategy from beginning to advanced levels, and it was identified that learners used a lot of borrowing and asking strategies in the beginning level, asking and stalling strategies in the intermediate level, and paraphrasing and revising strategies in the advanced level. The borrowing strategy that learners frequently used in the beginning level was from learning a foreign language that learners previously learned, which in this case refers to English speaking, but it was identified that communication in Korean is possible as the frequency of using English significantly decreased from intermediate level. This study has significance as a case study that identified how speaking strategies of Korean language learners change within a certain period of time of learning the Korean language. (Sungkyunkwan University)

Meet the First Authors.

Meet the First Authors.

Hairy electronic skin catches the breeze

Designing sensors that mimic those in human skin could lead to more realistic prosthetic limbs, ones that can feel a light touch or the warm sun. But flexible electronic skin so far has not incorporated the small feelers that make mammals unique: hair. Now, by placing microscopic polymer hairs on top of graphene, researchers have made a skin-like sensing device that can feel wind and detect its direction and angle (ACS Appl. Mater. Interfaces 2019, DOI: 10.1021/acsami.9b01427). Changhyun Pang of Sungkyunkwan University and colleagues built an array of sensors by depositing a thin film of graphene nanoflakes on a piece of flexible polyethylene. Applying pressure to the sensors pushes the nanoflakes together, changing the electrical resistance. On top of the array, the researchers placed a poly(dimethylsiloxane) film molded with a forest of microscopic pillars. Airflow bends the pillars and puts pressure on the graphene sensors, changing their output current. To