Analytical Calculation of Jitter Probability Density at Multistage Output Buffers Due to Supply Voltage Fluctuations

Eunkyeong Park,Hyungsoo Kim,Jongjoo Shim,Yong-Ju Kim,Yun-Saing Kim,Jingook Kim [Institute of Electrical and Electronics Engineers 2015 IEEE transactions on electromagnetic compatibility Vol.57 No.4

<P>The jitter probability density function (PDF) at multistage output buffers due to supply voltage fluctuations is analytically derived. For experimental validation, an integrated circuit (IC) is designed, fabricated, and assembled in a printed circuit board (PCB). The on-chip supply voltage fluctuations are extracted from the simultaneous measurements at the pads on IC and PCB and used to calculate the jitter PDF of the multistage buffers. Also, characteristics of the output channels are measured and modeled with the separately designed channel pattern. Finally, the jitter PDFs for multistage buffers are calculated and compared with the measured jitter histograms.</P>

Developing an English Speaking Placement Test for Low-level College Students

( Eunkyeong Park ),( Jungtae Kim ) 21세기영어영문학회 2016 영어영문학21 Vol.29 No.4

The purpose of the study was to investigate the effectiveness of the Novice Speakers` English Language Test (NSELT) as a placement test in order to place low-level Korean college students into required general English courses at a university. The study also investigated the appropriateness of the current placement method of using the students` English grades on the College Scholastic Aptitude Test (CSAT) and high school English records (HSER). The data from 133 first year students` CSAT and HSER grades were analyzed and the placement results were compared with their satisfaction surveys and English grades. The next semester, native English instructors` decisions were used for the placement compared with the students` English grades as well as their satisfaction survey results. Finally, the NSELT, a face-to-face interview form, was developed based on a needs analysis survey with 133 students. 72 of them took the test. The results indicated that the first placement method was inappropriate and the native instructors` decisions were highly correlated with the NSELT scores. The students were highly satisfied with the test delivery form and results of the new speaking test. Finally, the effectiveness of the NSELT as a placement test was discussed and implications were suggested.

온라인 영어수업에서 학습활동변인과 자기조절학습전략이 학업성취도에 미치는 영향

박은경(Eunkyeong Park),김정태(Jungtae Kim) 한국영어평가학회 2022 영어평가 Vol.17 No.2

This study analyzed the effects of the learning variables and self-regulated learning strategy affecting college learners' achievement in an online general English course. For the study, three learning variables and four self-regulated learning strategies were selected: checking the bulletin board, learning progress, the total number of times students accessed the LMS, cognitive strategy, metacognitive strategy, behavior strategy, and motivational strategy. 106 Korean college students participated in the course. Their data were collected employing the Learning Management System and a self-regulated learning strategy questionnaire. The results were analyzed with the independent T-test and multiple regression analysis. First for the learning variables, checking the bulletin board, the total number of the times students accessed the LMS were closely correlated with their academic achievement. Second, motivational strategy and behavior strategy were closely correlated with their academic achievement. Third, motivational strategy and behavior strategy significantly affected their academic achievement. Fourth, for the high and low groups of motivational strategy and behavior strategy, the data showed a significant mean difference in the variables of checking the bulletin board and the total number of times students accessed the LMS. Some implications and discussions for analyzing learning variables and self-regulated learning strategy affecting academic achievement are illustrated.

Structural basis for recruiting and shuttling of the spliceosomal deubiquitinase USP4 by SART3

Park, Joon Kyu,Das, Tanuza,Song, Eun Joo,Kim, Eunice EunKyeong Oxford University Press 2016 Nucleic acids research Vol.44 No.11

<P><B>Abstract</B></P><P>Squamous cell carcinoma antigen recognized by T-cells 3 (SART3) is a U4/U6 recycling factor as well as a targeting factor of USP4 and USP15. However, the details of how SART3 recognizes these deubiquitinases and how they get subsequently translocated into the nucleus are not known. Here, we present the crystal structures of the SART3 half-a-tetratricopeptide (HAT) repeat domain alone and in complex with the domain present in ubiquitin-specific protease (DUSP)-ubiquitin-like (UBL) domains of ubiquitin specific protease 4 (USP4). The 12 HAT repeats of SART3 are in two sub-domains (HAT-N and HAT-C) forming a dimer through HAT-C. USP4 binds SART3 at the opposite surface of the HAT-C dimer interface utilizing the β-structured linker between the DUSP and the UBL domains. The binding affinities of USP4 and USP15 to SART3 are 0.9 μM and 0.2 μM, respectively. The complex structure of SART3 nuclear localization signal (NLS) and importin-α reveals bipartite binding, and removal of SART3 NLS prevents the entry of USP4 (and USP15) into the nucleus and abrogates the subsequent deubiquitinase activity of USP4.</P>

Deubiquitinating Enzymes: A Critical Regulator of Mitosis

Park, Jinyoung,Cho, Jinhong,Kim, Eunice EunKyeong,Song, Eun Joo MDPI AG 2019 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.20 No.23

<P>Mitosis is a complex and dynamic process that is tightly regulated by a large number of mitotic proteins. Dysregulation of these proteins can generate daughter cells that exhibit genomic instability and aneuploidy, and such cells can transform into tumorigenic cells. Thus, it is important for faithful mitotic progression to regulate mitotic proteins at specific locations in the cells at a given time in each phase of mitosis. Ubiquitin-dependent modifications play critical roles in this process by regulating the degradation, translocation, or signal transduction of mitotic proteins. Here, we review how ubiquitination and deubiquitination regulate the progression of mitosis. In addition, we summarize the substrates and roles of some deubiquitinating enzymes (DUBs) crucial for mitosis and describe how they contribute error correction during mitosis and control the transition between the mitotic phases.</P>

City-wide Pothole Detection with Vision Intelligence

Minwoo Park,Ryong Lee,Jinsol Jang,Eunkyeong Kim,Min-gi Kim,Rae-young Jang 한국콘텐츠학회 2020 한국콘텐츠학회 ICCC 논문집 Vol.2020 No.11

A positive feedback loop of IL-21 signaling provoked by homeostatic CD4+CD25- T cell expansion is essential for the development of arthritis in autoimmune K/BxN mice.

Jang, Eunkyeong,Cho, Sin-Hye,Park, Hyunjoo,Paik, Doo-Jin,Kim, Jung Mogg,Youn, Jeehee Williams Wilkins 2009 JOURNAL OF IMMUNOLOGY Vol.182 No.8

<P>Rheumatoid arthritis is a joint-specific autoimmune inflammatory disease of unknown etiology. The K/BxN mouse is a model of rheumatoid arthritis that is thought to be mainly due to autoantibody-mediated inflammatory responses. We showed previously that homeostatic proliferation of autoreactive CD4(+) T cells is required for disease initiation in the K/BxN mice. In this study, we show that the homeostatically proliferating CD4(+)CD25(-) T cells produce IL-21. We generated IL-21R-deficient (IL-21R(-/-)) K/BxN mice and found that these mice were completely refractory to the development of spontaneous arthritis. They contained fewer CD4(+) T cells with a reduced proportion of homeostatically proliferating cells, fewer follicular Th cells, and, surprisingly, more Th17 cells than their control counterparts. They also failed to develop IgG1(+) memory B cells and autoantigen-specific IgG1 Ab-secreting cells. IL-21 induced expression of receptor activator of NF-kappaB ligand (RANKL) a regulator of osteoclastogenesis, and few RANKL-expressing infiltrates were found in the synovia of IL-21R(-/-) K/BxN mice. Thus, our results demonstrate that IL-21 forms a positive feedback autocrine loop involving homeostatically activated CD4(+) cells and that it plays an essential role in the development of autoimmune arthritis by mechanisms dependent on follicular Th cell development, autoreactive B cell maturation, and RANKL induction but independent of Th17 cell function. Consistent with this, in vivo administration of soluble the IL-21R-Fc fusion protein delayed the onset and progression of arthritis. Our findings suggest that effective targeting of IL-21-mediated processes may be useful in treating autoimmune arthritis.</P>

Stimulus-activatable echogenic maltodextrin nanoparticles as nanotheranostic agents for peripheral arterial disease

Jung, Eunkyeong,Lee, Jeonghun,Jeong, Lipjeong,Park, Sanghun,Lee, Moungyoung,Song, Chulgyu,Lee, Dongwon Elsevier 2019 Biomaterials Vol.192 No.-

<P><B>Abstract</B></P> <P>Reactive oxygen species (ROS) are closely related with various pathological disorders. Therefore, real-time detection of ROS is essential for understanding the procedure of diseases and diagnosing the accurate lesion sites. Hydrogen peroxide (H<SUB>2</SUB>O<SUB>2</SUB>) accounts for a large portion of ROS and has a longer half-life than other ROS, which makes it a highly promising diagnostic and therapeutic biomarker. In this work, we developed H<SUB>2</SUB>O<SUB>2</SUB>-activatable CO<SUB>2</SUB> bubble generating indocyanine green-loaded boronated maltodextrin (ICG-BM) nanoparticles for imaging and therapy of peripheral arterial disease. ICG-BM nanoparticles displayed increasing fluorescence, ultrasound and photoacoustic signals in H<SUB>2</SUB>O<SUB>2</SUB>-triggered manners and exerted significant anti-inflammatory and proangiogenic effects in H<SUB>2</SUB>O<SUB>2</SUB>-stimulated vascular endothelial cells. In mouse models of hindlimb ischemia, ICG-BM nanoparticles also showed H<SUB>2</SUB>O<SUB>2</SUB>-triggered amplification of fluorescence, ultrasound and photoacoustic signals in the ischemic hindlimb muscles. ICG-BM nanoparticles also significantly reduced the level of overproduced H<SUB>2</SUB>O<SUB>2</SUB> and exerted highly potent anti-inflammatory and proangiogenic activities in the ischemic tissues. We therefore believe that pathological stimulus-activatable echogenic ICG-BM nanoparticles provide a new avenue for imaging and treatment of peripheral arterial disease.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Molecularly Engineered Theranostic Nanoparticles for Thrombosed Vessels: H₂O₂-Activatable Contrast-Enhanced Photoacoustic Imaging and Antithrombotic Therapy

Jung, Eunkyeong,Kang, Changsun,Lee, Jeonghun,Yoo, Donghyuck,Hwang, Do Won,Kim, Dohyun,Park, Seong-Cheol,Lim, Sang Kyoo,Song, Chulgyu,Lee, Dongwon American Chemical Society 2018 ACS NANO Vol.12 No.1

<P>A thrombus (blood clot), composed mainly of activated platelets and fibrin, obstructs arteries or veins, leading to various life-threatening diseases. Inspired by the distinctive physicochemical characteristics of thrombi such as abundant fibrin and an elevated level of hydrogen peroxide (H<SUB>2</SUB>O<SUB>2</SUB>), we developed thrombus-specific theranostic (T-FBM) nanoparticles that could provide H<SUB>2</SUB>O<SUB>2</SUB>-triggered photoacoustic signal amplification and serve as an antithrombotic nanomedicine. T-FBM nanoparticles were designed to target fibrin-rich thrombi and be activated by H<SUB>2</SUB>O<SUB>2</SUB> to generate CO<SUB>2</SUB> bubbles to amplify the photoacoustic signal. In the phantom studies, T-FBM nanoparticles showed significant amplification of ultrasound/photoacoustic signals in a H<SUB>2</SUB>O<SUB>2</SUB>-triggered manner. T-FBM nanoparticles also exerted H<SUB>2</SUB>O<SUB>2</SUB>-activatable antioxidant, anti-inflammatory, and antiplatelet activities on endothelial cells. In mouse models of carotid arterial injury, T-FBM nanoparticles significantly enhanced the photoacoustic contrast specifically in thrombosed vessels and significantly suppressed thrombus formation. We anticipate that T-FBM nanoparticles hold great translational potential as nanotheranostics for H<SUB>2</SUB>O<SUB>2</SUB>-associated cardiovascular diseases.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2018/ancac3.2018.12.issue-1/acsnano.7b06560/production/images/medium/nn-2017-06560s_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn7b06560'>ACS Electronic Supporting Info</A></P>

Temperament and Character of High Suicide Risk Group Among Psychiatric Patients

Kim Kyungwon,Park Yong Chon,Choi Junho,Kim Daeho,Kim Eunkyeong 대한신경정신의학회 2022 PSYCHIATRY INVESTIGATION Vol.19 No.8

Objective The purpose of this study was to classify patients with suicidal tendencies into suicide attempts (SA), suicidal ideation (SI), and non-suicidal self-injury (NSSI) and to identify differences in temperaments and characters of the groups. It also aimed to identify difference between the groups and non-suicidal tendencies.Methods Using psychiatric diagnostic data of 195 patients, temperaments and characters were measured with the Temperament and Character Inventory, and the level of depression was measured with the Beck Depression Inventory. The subjects were classified into SA, SI, NSSI, psychiatric patients without suicidal tendencies (PP), and non-patient (Normal) groups, and multivariate analysis of variance and multinomial logistic regression were conducted.Results The NSSI group had higher novelty seeking compared to the SI group, while having higher harm avoidance, lower persistence, and lower self-directedness compared to the SA group. Furthermore, low persistence was a better predictor for the SA group between SA and NSSI groups, and low novelty seeking was found to be a better predictor for the SI group between the SI and NSSI groups.Conclusion As a result, the group differences in temperaments and characters were found, which would be useful to identify patients with suicidal tendencies and provide appropriate interventions tailored to the temperaments and characters of each group.