외국인 대학원생의 학술적 언어사용역 인식 양상 연구

최지영 ( Choi¸ Jiyoung ) 국제한국어교육학회 2021 한국어 교육 Vol.32 No.4

The purpose of this study is to examine the awareness of academic register by foreign graduate students in Korea. To investigate this, a questionnaire was created, and differences by academic register item and related variables were analyzed through ANOVA and correlation analysis. As a result of the survey, it was found that international students did not clearly recognize academic register. Specifically, international students were relatively clearly aware of ‘academic vocabulary’, ‘authorial self-mention expressions’, ‘literary-style adverbs’, and ‘literary-style endings’, but they were not aware of ‘complex sentence constructions’, ‘long-form negations’, ‘objective modality’, and ‘hedge expressions’. Regarding related variables, it was confirmed that learning experience and Korean proficiency were somewhat related to the students’ awareness of academic register, but there was no statistical significance. In addition, the difference in scores between Ph.D. and master’s students, the difference in scores by major, and the difference in scores according to the mother tongue were not statistically significant. This study is meaningful in that it is the first discussion to actually examine the awareness of foreign graduate students’ academic register. (Chonnam National University)

Synchronous Cancers of Hepatic Angiosarcoma and Gallbladder Adenocarcinoma, Mimicking Gallbladder Cancer with Hepatic Invasion: a Case Report

Jiyoung Choi,김혁중,Suk Ki Jang,So Ya Paik,Ki Ho Kim 대한자기공명의과학회 2020 Investigative Magnetic Resonance Imaging Vol.24 No.2

Synchronous primary cancers in the liver and gallbladder have been rarely reported. We report a case of synchronous cancers of hepatic angiosarcoma and gallbladder adenocarcinoma, mimicking gallbladder cancer with hepatic invasion. Additionally, the clinical implications, the radiologic features, and the diagnostic difficulties are further discussed.

Chemical Characterization of Atmospheric Aerosols Measured in Seoul and Anmyon-do

Jiyoung Kim,Jae-Cheon Choi,Byoung-Cheol Choi,Sung-Nam Oh 한국기상학회 2002 Korean Journal of the Atmospheric Sciences Vol.5 No.3

Mercury intrusion porosimetry characterization of micropore structures of high-strength cement pastes incorporating high volume ground granulated blast-furnace slag

Choi, Young Cheol,Kim, Jiyoung,Choi, Seongcheol Elsevier 2017 Construction & building materials Vol.137 No.-

<P><B>Abstract</B></P> <P>In this study, we characterized the micropore structures of high-strength cement pastes incorporating high volume ground granulated blast-furnace slag (GGBFS). Using mercury intrusion porosimetry, we measured the pore-size distributions of cement pastes with different GGBFS replacement ratios at ages of 3, 7, 28, and 91d. The test results indicated that the total porosity increased with increasing GGBFS ratio in the specimens at early ages, whereas it decreased at later ages. The replacement ratio of 65% produced the densest pore structure, which was consistent with compressive strength test results.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We experimentally characterized the microstructures of high volume GGBFS-blended high-strength cement pastes. </LI> <LI> The total porosity increased over the GGBFS ratios in the specimens at early ages. </LI> <LI> The total porosity decreased over the GGBFS ratios in the specimens at later ages. </LI> <LI> A GGBFS replacement ratio of 65% produced the densest pore structures. </LI> </UL> </P>

Prognostic factors of non-functioning pancreatic neuroendocrine tumor revisited

Jiyoung Bu,Sangmin Youn,Wooil Kwon,Kee Taek Jang,Sanghyup Han,Sunjong Han,Younghun You,Jin Seok Heo,Seong Ho Choi,Dong Wook Choi 한국간담췌외과학회 2018 Annals of hepato-biliary-pancreatic surgery Vol.22 No.1

Backgrounds/Aims: Various factors have been reported as prognostic factors of non-functional pancreatic neuroendocrine tumors (NF-pNETs). There remains some controversy as to the factors which might actually serve to successfully prognosticate future manifestation and diagnosis of NF-pNETs. As well, consensus regarding management strategy has never been achieved. The aim of this study is to further investigate potential prognostic factors using a large single-center cohort to help determine the management strategy of NF-pNETs. Methods: During the time period 1995 through 2013, 166 patients with NF-pNETs who underwent surgery in Samsung Medical Center were entered in a prospective database, and those factors thought to represent predictors of prognosis were tested in uni- and multivariate models. Results: The median follow-up time was 46.5 months; there was a maximum follow-up period of 217 months. The five-year overall survival and disease-free survival rates were 88.5% and 77.0%, respectively. The 2010 WHO classification was found to be the only prognostic factor which affects overall survival and disease-free survival in multivariate analysis. Also, pathologic tumor size and preoperative image tumor size correlated strongly with the WHO grades (p<0.001, and p<0.001). Conclusions: Our study demonstrates that 2010 WHO classification represents a valuable prognostic factor of NF-pNETs and tumor size on preoperative image correlated with WHO grade. In view of the foregoing, the preoperative image size is thought to represent a reasonable reference with regard to determination and development of treatment strategy of NF-pNETs.

Effects of Body Postures on Clothing Air Gap in a Protective Suit

Jiyoung Choi,Heejin Kim,Yunja Nam,Min K. Chung,Hyunsook Jung,Haewan Lee 대한인간공학회 2014 대한인간공학회 학술대회논문집 Vol.2014 No.5

Air gaps entrapped in a protective suit play an important role in heat transfer, and it is closely related to the wearer’s safety. The distribution and size of the air gaps depends on body motions. In this study 8 representative body motions (stretching, walking, crawling, crouching, twisting, climbing and reaching, moving weights, and lateral bending) of CBR excercise and 2~4 body postures per each motion were derived. After that, for one male participant, theses postures were scanned with a 3D body scanning technique. Scanning was performed for the nude and the dressed to measure the distribution and size of air gaps between the human body and clothing. As a result, the air gaps varied with the different postures. The results will be basic data to improve the protective performance of current protective suit.

Effects of Body Postures on Clothing Air Gap in a Protective Suit

( Jiyoung Choi ),( Heejin Kim ),( Yunja Nam ),( Min K. Chung ),( Hyunsook Jung ) 한국감성과학회 2014 춘계학술대회 Vol.2014 No.-

Air gaps entrapped in a protective suit play an important role in heat transfer, and it is closely related to the wearer`s safety. The distribution and size of the air gaps depends on body motions. In this study 8 representative body motions (stretching, walking, crawling, crouching, twisting, climbing and reaching, moving weights, and lateral bending) of CBR excercise and 2~4 body postures per each motion were derived. After that, for one male participant, theses postures were scanned with a 3D body scanning technique. Scanning was performed for the nude and the dressed to measure the distribution and size of air gaps between the human body and clothing. As a result, the air gaps varied with the different postures. The results will be basic data to improve the protective performance of current protective suit.

Technical Feasibility of Quantitative Measurement of Various Degrees of Small Bowel Motility Using Cine Magnetic Resonance Imaging

Choi Ji Young,Yun Jihye,Heo Subin,Kim Dong Wook,Choi Sang Hyun,Yoon Jiyoung,Kim Kyuwon,Jung Kee Wook,Myung Seung-Jae 대한영상의학회 2023 Korean Journal of Radiology Vol.24 No.11

Objective: Cine magnetic resonance imaging (MRI) has emerged as a noninvasive method to quantitatively assess bowel motility. However, its accuracy in measuring various degrees of small bowel motility has not been extensively evaluated. We aimed to draw a quantitative small bowel motility score from cine MRI and evaluate its performance in a population with varying degrees of small bowel motility. Materials and Methods: A total of 174 participants (28.5 ± 7.6 years; 135 males) underwent a 22-second-long cine MRI sequence (2-dimensional balanced turbo-field echo; 0.5 seconds per image) approximately 5 minutes after being intravenously administered 10 mg of scopolamine-N-butyl bromide to deliberately create diverse degrees of small bowel motility. In a manually segmented area of the small bowel, motility was automatically quantified using a nonrigid registration and calculated as a quantitative motility score. The mean value (MV) of motility grades visually assessed by two radiologists was used as a reference standard. The quantitative motility score’s correlation (Spearman’s ρ) with the reference standard and performance (area under the receiver operating characteristics curve [AUROC], sensitivity, and specificity) for diagnosing adynamic small bowel (MV of 1) were evaluated. Results: For the MV of the quantitative motility scores at grades 1, 1.5, 2, 2.5, and 3, the mean ± standard deviation values were 0.019 ± 0.003, 0.027 ± 0.010, 0.033 ± 0.008, 0.032 ± 0.009, and 0.043 ± 0.013, respectively. There was a significant positive correlation between the quantitative motility score and the MV (ρ = 0.531, P < 0.001). The AUROC value for diagnosing a MV of 1 (i.e., adynamic small bowel) was 0.953 (95% confidence interval, 0.923–0.984). Moreover, the optimal cutoff for the quantitative motility score was 0.024, with a sensitivity of 100% (15/15) and specificity of 89.9% (143/159). Conclusion: The quantitative motility score calculated from a cine MRI enables diagnosis of an adynamic small bowel, and potentially discerns various degrees of bowel motility.

Hamamelis virginiana Extract Protects from PM<SUB>2.5</SUB>-induced Inflammation via PAR-2 Signaling

Jiyoung CHOI,Gi-Yeon HAN,Dongki YANG,Joonseok CHA 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.10

Dietary supplements and personal care products to protect from air pollution have been of great interest for decades. Epidemiology demonstrated that particulate matters (PM10 and PM2.5) are an actual threat to public health worldwide, but the detailed processes that these particles attack the cells are not fully understood. Here, we report that measuring intracellular calcium concentration ([Ca<SUP>2+</SUP>]i) in human respiratory or skin cells can illustrate pollutant challenges by triggering Ca<SUP>2+</SUP> influx in these cells. This signal was generated by protease-activated receptor-2 (PAR-2), confirmed by competition analyses, and the extract of Hamamelis virginiana (HVE), a native herb of North America, was able to control the calcium response and the expression of PAR-2. The increase of nuclear factor-kappa B (NF-κB), and the decrease of cell adhesion components could address severe damage status by air pollutants and the protection by HVE. Also, it was confirmed that HVE effectively inhibited ROS induced by UVB. The results presented here should help understand the underlying mechanism of PM insults and the beneficial effect of standardized HVE as a dietary supplement or cosmetical ingredient.

Synthesis and Electro-optical Properties of π-Conjugated Polymer Based on 10-Hexylphenothiazine and Aromatic 1,2,4-Triazole

Jiyoung Choi,Donghan Kim,Bong Lee,Joo Hyun Kim 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.9

New π-conjugated polymer with vinylene linkage, poly((10-hexyl-3,7-phenothiazine)-alt-(4-(4-butyl-phenyl)- 3,5-diphenyl-4H-[1,2,4]triazole)-3,5-vinylene) (PTV-TAZ) was synthesized by the Heck coupling reaction. The photoluminescence (PL) maximum wavelength and the band gap energy of PTV-TAZ film were 555 nm and 2.41 eV, respectively. The HOMO energy level of PTV-TAZ was -4.99 eV, which was slightly lower than that of PTV (-4.89 eV). Electron deficient aromatic 1,2,4-triazole (TAZ) in the polymer backbone does not affect the HOMO energy level significantly. The maximum efficiency and brightness of double layer structured electroluminescent (EL) device (ITO/PEDOT (30 nm)/PTV-TAZ (60 nm)/Al) were 0.247 cd/A and 553 cd/m2, respectively, which were significantly higher than those of the device based PTV (1.65 × 10-4 cd/A and 4.3 cd/m2). This is due to that TAZ unit improves electron transporting ability in the emissive layer. The turn-on voltage (defined as the voltage required to give a luminescence of 1 cd/m2) of brightness of the device based on PTV-TAZ was 12.0 V, which was similar to that the based on PTV (11.5 V). This is due to that the ionization potential of PTV-TAZ is very similar to that of PTV.