이종접합 Gate 구조를 갖는 수평형 NiO/Ga₂O₃ FET의 전기적 특성 연구

이건희 ( Geon-hee Lee ),문수영 ( Soo-young Moon ),이형진 ( Hyung-jin Lee ),신명철 ( Myeong-cheol Shin ),김예진 ( Ye-jin Kim ),전가연 ( Ga-yeon Jeon ),오종민 ( Jong-min Oh ),신원호 ( Weon-ho Shin ),김민경 ( Min-kyung Kim ),박철환 ( 한국전기전자재료학회 2023 전기전자재료학회논문지 Vol.36 No.4

Gallium Oxide (Ga₂O₃) is preferred as a material for next generation power semiconductors. The Ga₂O₃ should solve the disadvantages of low thermal resistance characteristics and difficulty in forming an inversion layer through p-type ion implantation. However, Ga₂O₃ is difficult to inject p-type ions, so it is being studied in a heterojunction structure using p-type oxides, such as NiO, SnO, and Cu₂O. Research the lateral-type FET structure of NiO/Ga₂O₃ heterojunction under the Gate contact using the Sentaurus TCAD simulation. At this time, the VG-ID and VD-ID curves were identified by the thickness of the Epi-region (channel) and the doping concentration of NiO of 1 × 10¹⁷ to 1 × 10¹⁹ cm^-3. The increase in Epi region thickness has a lower threshold voltage from -4.4 V to -9.3 V at I_D = 1 × 10^-8 mA/mm, as current does not flow only when the depletion of the PN junction extends to the Epi/Sub interface. As an increase of NiO doping concentration, increases the depletion area in Ga₂O₃ region and a high electric field distribution on PN junction, and thus the breakdown voltage increases from 512 V to 636 V at I_D =1 × 10^-3 A/mm.

Identification of Ellagitannins in Black Raspberry Seeds and Optimization of Accelerated Solvent Extraction of Ellagitannins Using Artificial Neural Network Coupled with Genetic Algorithm

Ga Eun Lee,Ryun Hee Kim,Taehwan Lim,Jaecheol Kim,Suna Kim,Keum Taek Hwang 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10

This study aimed to identify ellagitannins in black raspberry (Rubus occidentalis) seeds (BS) and to optimize accelerated solvent extraction of ellagitannins using artificial neural network (ANN) coupled with genetic algorithm (GA). Ellagitannins were fractionated using Amberlite XAD-16N and Sephadex LH-20 resins. The ellagitannin fraction was qualitatively analyzed by HPLC-Q-TOF-MS/MS. BS had mainly monomeric and dimeric ellagitannins such as pedunculagin, castalagin, acutissimin A, sanguiin H-10, casuarictin, sanguiin H-2, sanguiin H-6, and sanguiin H-6 without a gallic moiety. For ANN modeling, extraction time (3-9 min), extraction temperature (40-70°C), and solvent concentration (50-100% acetone) were set as independent input variables, and total ellagitannin content was set as output variable. The ANN of this study had an input layer with three neurons, a hidden layer with ten neurons, and an output layer with one neuron. The optimal extraction conditions of the total ellagitannin content were predicted by the trained ANN coupled with GA. This study is the first attempt to analyze ellagitannin content in BS.

Raping Translation in Translating Rape: A Case Study of The Bluest Eye

( Kim¸ Ga-hee ) 동국대학교 영어권문화연구소 2015 영어권문화연구 Vol.8 No.2

What this paper deals with is that how it would be then if a male translator happens to deal with rape of women in a woman writer's text that is written from a feminist perspective and if he would possibly, consciously or not, distort the feminist rape narrative in various ways because of his male identity. These research questions are brought from Chen's research, and this paper substantiates them by the analysis and comparison of the Korean translated texts. The recent studies in translation studies, including feminist translation theory, indicate male translators are influenced by gender awareness. Therefore this paper studying the translated texts of two male translators in terms of translating ‘rape’ and ‘incest’ in The Bluest Eye is considered worthwhile. The Bluest Eye written by Tony Morrison and its two different male translators' Korean versions are subject to the comparative analysis of this study.

효율적인 군 전직지원체제 정립 방안

정철영,고재관,황원채,윤희철,박가열,김재호,이성식,김동승,표성일,이건남,양안나,최수정,김은석 한국직업능력개발원 2008 직업능력개발연구 Vol.11 No.1

이 연구의 목적은 제대군인에 대한 효율적인 전직지원을 위해서 현행 전직지원 프로세스에 대한 개선 안과 이에 따른 국방부, 국가보훈처 등 제대군인 전직지원관련 기관 간의 역할분담 및 연계방안에 대해서 제안하는 것이다. 연구는 크게 세 가지 과정을 거쳤다. 첫째, 국내 군 전직지원 실태를 분석하여 문제점과 시사점을 도출하였다. 둘째, 이러한 문제점과 시사점, 군 전직지원 선행연구를 종합하여 효율적인 군 전직지원 프로세스 안을 제시하였다. 셋째, 구축한 군 전직지원 프로세스 안에 따라 주요 군 전직지원 관련 기관인 국방부, 국가보훈처의 역할 분담 안을 제안하였다. This study aims to suggest an improvement plan for the support process of effective occupation change for discharged soldiers and then role assignments among related institutions for supporting discharged soldiers such as Ministry of Defense, Ministry of Patriots and Veterans Affairs, Ministry of Labor and the cooperation plan among the institutions. The study was made in three steps. First, after analyzing currents support facts and status for discharged soldiers, it induced its problems and implications. Second, integrating the findings of previous studies related to support plan on occupation changes for the discharged soldiers, Problems and implications mentioned above, it constructed effective occupation change process for discharged soldiers. Then, according to the established process, it suggested role assignments such as Ministry of Defense, Ministry of Patriots and Veterans Affairs, Ministry of Labor.

Effect of Ce and La Substitution on the Microstructure and Magnetic Properties of Hot-deformed Nd-Fe-B Magnets

Ga-Yeong Kim,Hee-Ryoung Cha,Youn-Kyoung Baek,Young-Kuk Kim,Dong-Hwan Kim,Yang-Do Kim,Jung-Goo Lee 한국자기학회 2020 Journal of Magnetics Vol.25 No.2

Nd in hot-deformed Nd-Fe-B magnets was partially substituted by Ce and La for the purpose of reducing the materials cost and balancing the utilization of rare earth resources. Initial melt-spun ribbons with the nominal compositions of (Nd1-xMx)13.6FebalB5.6Ga0.6Co6.6 (x = 0, x = 0.2/M=Ce, x = 0.3/M=Ce, Ce+La, wt.%) were prepared by a single-roller melt-spinning method, and pulverized into powders. The powders were then hot-pressed at 973 K under 100 MPa, and deformed at 973 K until 75 % of height reduction was achieved. The magnetic properties of hot-deformed magnets were decreased with the substitution of Ce for Nd. In addition, simultaneous substitution of Ce and La for Nd resulted in much lower magnetic properties. This tendency was almost the same as initial melt-spun powders. The deterioration on magnetic properties by substation of Ce and La for Nd in hot-deformed Nd-Fe-B magnets could be attributed to not only inferior intrinsic properties of (Ce/La)₂Fe14B to Nd₂Fe14B phase but also the effect of Ce/La substitution on microstructure such as density and grain alignment during hot-deformation. Although the magnetic properties were deteriorated by substitution of Ce and La for Nd in hot-deformed Nd-Fe-B magnets, the cost performance was largely enhanced from 2.32 to 2.62 MGOe×kg/$ by 13 % when increasing the content of Ce substituted for Nd from 0 to 0.3 wt.%.

Biological Affinity and Biodegradability of Poly(propylene carbonate) Prepared from Copolymerization of Carbon Dioxide with Propylene Oxide

Kim, Ga-Hee,Ree, Moon-Hor,Kim, Hee-Soo,Kim, Ik-Jung,Kim, Jung-Ran,Lee, Jong-Im The Polymer Society of Korea 2008 Macromolecular Research Vol.16 No.5

In this study we investigated bacterial and cell adhesion to poly(propylene carbonate) (PPC) films, that had been synthesized by the copolymerization of carbon dioxide (a global warming chemical) with propylene oxide. We also assessed the biocompatibility and biodegradability of the films in vivo, and their oxidative degradation in vitro. The bacteria adhered to the smooth, hydrophobic PPC surface after 4 h incubation. Pseudomonas aeruginosa and Enterococcus faecalis had the highest levels of adhesion, Escherichia coli and Staphylococcus aureus had the lowest levels, and Staphylococcus epidermidis was intermediate. In contrast, there was no adhesion of human cells (cell line HEp-2) to the PPC films, due to the hydrophobicity and dimensional instability of the surface. On the other hand, the PPC films exhibited good biocompatibility in the mouse subcutaneous environment. Moreover, contrary to expectation the PPC films degraded in the mouse subcutaneous environment. This is the first experimental confirmation that PPC can undergo surface erosion biodegradation in vivo. The observed biodegradability of PPC may have resulted from enzymatic hydrolysis and oxidative degradation processes. In contrast, the PPC films showed resistance to oxidative degradation in vitro. Overall, PPC revealed high affinity to bioorganisms and also good bio-degradability.

Diagnostic Trends and Clinical Characteristics of Eosinophilic Esophagitis: A Korean, Single-center Database Study

Ga Hee Kim,정기욱,Hwoon-Yong Jung,Kee Don Choi,JungBok Lee,Young Soo Park,So-Woon Kim,Jeong Hoon Lee,Do Hoon Kim,Ji Yong Ahn,Ho June Song,Gin Hyug Lee,Jin-Ho Kim 대한소화기 기능성질환∙운동학회 2018 Journal of Neurogastroenterology and Motility (JNM Vol.24 No.2

Background/Aims The prevalence of eosinophilic esophagitis (EoE) is reportedly increasing in Western countries. However, its prevalence in Korea remains unknown. We investigated the diagnostic trends and clinical characteristics of EoE in Korea. Methods Using an endoscopic database maintained at a tertiary care center, we retrospectively reviewed the biopsy reports regarding 18 399 biopsy specimens collected from all patients who underwent esophagogastroduodenoscopy and esophageal biopsy at this facility between 2006 and 2014. The presence of more than 15 eosinophils per high-power field with symptoms related to esophageal dysfunction was considered to indicate EoE. Results A total of 37 patients (male:female ratio, 29:8; mean age, 44.0 ± 13.0 years) were diagnosed with EoE. These patients presented with dysphagia (21.6%), epigastric pain (21.6%), heartburn (24.3%), and other symptoms (32.4%). Typical endoscopic appearance of EoE was noted in 33 cases (89.1%) and included linear furrows in 24 cases (64.8%), ringed esophagus in 10 cases (27.0%), and white exudates in 11 cases (29.7%). The median eosinophilic count was 25 per high-power field (interquartile range, 20–70). Notable histopathological findings included eosinophilic microabscesses in 21 cases (56.7%). The diagnosis rate of EoE was found to have increased from 2006 and to 2014 (P-value < 0.001 by the Cochran-Armitage trend test). Conclusions The number of patients with EoE appears to have increased significantly over the 9-year period investigated, while the number of endoscopic investigations increased only marginally. Greater awareness of EoE and the role of esophageal biopsies should be considered.

Incidence, Morbidity, and Mortality of Achalasia: A Nationwide, Population-Based Cohort Study in South Korea

Kim Ga Hee,Park Hyungchul,Jung Kee Wook,Kim Min-Ju,Kim Ye-Jee,Lee Ji Min,Lee Bong Eun,Min Yang Won,Kim Jeong Hwan,Na Hee Kyong,Ahn Ji Yong,Lee Jeong Hoon,Kim Do Hoon,Choi Kee Don,Song Ho June,Lee Gin 거트앤리버 소화기연관학회협의회 2023 Gut and Liver Vol.17 No.6

Background/Aims: Although an association between achalasia and esophageal cancer has been reported, whether achalasia confers a substantial increase in mortality is unknown. Moreover, the causes of death related to achalasia have not been investigated. We performed this nationwide, population-based cohort study on achalasia because no such study has been performed since the introduction of high-resolution manometry in 2008. Methods: This study was performed using data extracted from the Korean National Health Insurance Service database, covering a 9-year period from 2009 to 2017. Control participants without a diagnostic code for achalasia were randomly selected and matched by sex and birth year at a case-to-control ratio of 1:4. Data on the cause of death from Statistics Korea were also analyzed. Results: The overall incidence of achalasia was 0.68 per 100,000 person-years, and the prevalence was 6.46 per 100,000 population. Patients with achalasia (n=3,063) had significantly higher adjusted hazard ratio (aHR) for esophageal cancer (aHR, 3.40; 95% confidence interval [CI], 1.25 to 9.22; p=0.017), pneumonia (aHR, 2.30; 95% CI, 1.89 to 2.81; p<0.001), aspiration pneumonia (aHR, 3.92; 95% CI, 2.38 to 6.48; p<0.001), and mortality (aHR, 1.68; 95% CI, 1.44 to 1.94; p<0.001). Esophageal cancer carried the highest mortality risk (aHR, 8.82; 95% CI, 2.35 to 33.16; p=0.001), while pneumonia had the highest non-cancer mortality risk (aHR, 2.28; 95% CI, 1.31 to 3.96; p=0.004). Conclusions: In this nationwide study, achalasia was associated with increased risk of mortality. Esophageal cancer and pneumonia were the most common comorbidities and the major causes of death in patients with achalasia.

GO-19 : Synergistic effect of COX-2 inhibitor on paclitaxel-induced apoptosis in the human ovarian cancer cell

( Hee Jung Kim ),( Ga Won Yim ),( Eun Ji Nam ),( Seon Mi Baek ),( Miri Hyun ),( Sunghoon Kim ),( Sang Wun Kim ),( Jae Wook Kim ),( Young Tae Kim ) 대한산부인과학회 2012 대한산부인과학회 학술대회 Vol.99 No.-

In vitro studies have revealed that treatment of various human cancer cell lines with specific cyclooxygenase inhibitor regulates apoptotic cell death. It is currently proposed that the combination of celecoxib (COX-2 inhibitor) with paclitaxel improves the efficacy of cancer treatment. Three ovarian cancer cell lines, OVCAR-3, SKOV3 and A2780, were exposed to paclitaxel and celecoxib. Cell viability was evaluated using a cell counting kit-8 assay. Apoptosis was evaluated using Annexin-V/7-AAD staining and cellular DNA fragmentation ELISA. Caspase-3 was examined by the Caspase-3 Colorimetric Assay kit. Caspase-9 and cleavage of poly ADP-ribose polymerase were determined by western blotting. Expression of nuclear factor-κB was assessed using Trans AM kits and immunofluorescence. Vascular endothelial growth factor and Akt activation were studied by RT-PCR and western blotting. A combination of celecoxib with paclitaxel augments anticancer effects more efficiently than paclitaxel alone as evidenced by decreased cell viability and enhanced apoptosis in OVCAR-3, SKOV3 and A2780 cells. Pretreatment with celecoxib also increased activation of caspase-9, -3 and cleaved PARP following paclitaxel-treatment. NF-κB activity assay revealed that activation of NF-κB induced by paclitaxel is downregulated by celecoxib. We also noted that celecoxib inhibited paclitaxel induced VEGF expression. Furthermore, combining celecoxib and paclitaxel inhibited phosphory-lation of Akt. OVCAR-3 cells were sensitized to paclitaxel-induced apoptosis by celecoxib through downregulation of NF-κB and Akt activation, suggesting that celecoxib may work synergistically with paclitaxel to inhibit different targets and ultimately produce anticancer effects. Combining celecoxib with paclitaxel may represent a anti-ovarian cancer strategy.

Long-term Outcomes and Factors Affecting the Survival of Patients with Mucosal Esophageal Squamous Cell Carcinoma

( Ga Hee Kim ),( Hee Kyong Na ),( Ji Yong Ahn ),( Jeong Hoon Lee ),( Kee Wook Jung ),( Do Hoon Kim ),( Hyeong Ryul Kim ),( Kee Don Choi ),( Ho June Song ),( Yong-hee Kim ),( Gin Hyug Lee ),( Hwoon-yon 대한소화기학회 2021 Gut and Liver Vol.15 No.5

Background/Aims: Data regarding the prognosis of early esophageal cancer are lacking. This study investigated the long-term outcomes and factors affecting the survival of patients with mucosal esophageal squamous cell carcinoma (T1aESCC). Methods: We analyzed the clinical and tumor-specific parameters of 263 patients who received surgical resection (SR; n=63) or endoscopic resection (ER; n=200) for T1aESCC. Underlying comorbidities were scored using the Charlson comorbidity index (CCI). Overall survival (OS) was the primary outcome, and multivariate regression analysis was performed to predict factors for OS. Results: Of the study patients (age, 64.5±8.0 years), the CCI was 1.0±1.4 in the ER group and 0.6±0.9 in the SR group (p=0.107). The 5-year OS rate during follow-up (54.4±20.4 months) was 85.7% (ER group, 86.8%; SR group, 82.4%; p=0.631). The cumulative 5-year incidence of esophageal cancer recurrence was 10.5% in the ER group (vs 0% in the SR group). The overall mortality rate was 12.9% (ER group, 12.0%; SR group, 15.9%; p=0.399). The most common cause of mortality was second primary cancers in the ER group (75%) and organ dysfunction or postoperative complications in the SR group (70%). According to multivariate analysis, only CCI was significantly associated with OS (p< 0.001). The 5-year OS rate in patients with a CCI >2 and in those with a CCI ≤2 was 60.2% and 88.2%, respectively (p<0.001). The treatment method (ER vs SR) was not a significant affecting factor (p=0.238). Conclusions: The long-term prognosis of patients with T1aESCC was significantly associated with underlying comorbidities. (Gut Liver 2021;15:705-712)