유기전자소자 적용을 위한 저온 공정용 배리어 박막 연구

Junmo Kim,이동구,이원호,Myungchan An,Youngchan Jang,배형우 한국센서학회 2019 센서학회지 Vol.28 No.6

Recently, semiconducting organic materials have been spotlighted as next-generation electronic materials based on their tunable electrical and optical properties, low-cost process, and flexibility. However, typical organic semiconductor materials are vulnerable to moisture and oxygen. Therefore, an encapsulation layer is essential for application of electronic devices. In this study, SiNx thin films deposited at process temperatures below 150 °C by plasma-enhanced chemical vapor deposition (PECVD) were characterized for application as an encapsulation layer on organic devices. A single structured SiNx thin film was optimized as an organic light-emitting diode (OLED) encapsulation layer at process temperature of 80 °C. The optimized SiNx film exhibited excellent water vapor transmission rate (WVTR) of less than 5 ×10-5g/m2 ·day and transmittance of over 87.3% on the visible region with thickness of 1 µm. Application of the SiNx thin film on the top-emitting OLED showed that the PECVD process did not degrade the electrical properties of the device, and the OLED with SiNx exhibited improved operating lifetime

Effects of Vanadium Carbides on Hydrogen Embrittlement of Tempered Martensitic Steel

Junmo Lee,이태경,Young Jin Kwon,Dong-Jun Mun,Jangyong Yoo,Chong Soo Lee 대한금속·재료학회 2016 METALS AND MATERIALS International Vol.22 No.3

Precipitation of V carbides is known to suppress the hydrogen-embrittlement (HE) phenomenon as well as to increase material strength. Despite increasing attention to V carbides, there have been few systematic and quantitative investigations on their effects on HE resistance. This study reveals the role of V carbides on the HE behavior of tempered martensitic steel while eliminating other factors, such as chemical composition of other elements, mechanical strength, and dislocation density. The amount of trapped hydrogen increased with increasing V content, whereas the best HE resistance was attained at 0.2 wt% V and it decreased with further V addition. V carbide was considered as a non-diffusible hydrogen-trapping site in this study. However, excessive V content led to the formation of large undissolved carbides that gave rise to brittle fracture and decreased HE resistance. This study suggests that improved HE resistance can be achieved by minimizing the size and amount of undissolved V carbides.

Inkjet Printing of Silica Aerogel for Fabrication of 2-D Patterned Thermal Insulation Layers

Junmo Koo,Jun Woo Kim,Minsik Kim,Sungwon Yoon,심준형 한국정밀공학회 2021 International Journal of Precision Engineering and Vol.8 No.2

Aerogels have the lowest thermal conductivity (< 0.2 W m −1 K −1 ) among known materials owing to the presence of pores, which constitute over 90% of the structure. Aerogels have mainly been commercialized for use as a thermal insulation material for building applications, such as walls and pipes. Herein, a silica aerogel thin fi lm was fabricated by using a commercial and cost-effective HP inkjet printer. Next, silica aerogel ink was synthesized by mixing hydrophilic silica aerogel powder, solvent, and other organic additives. The thickness and pattern of the silica aerogel thin films were easily controlled by increasing the number of printing cycles and patterning by using a drawing software. The printed silica aerogel thin fi lm had a smooth surface and thickness with well-distributed ink particles. Further, the aerogel had a unique structure comprising nanopores and nanonetworks. The thermal conductivity of the silica aerogel thin fi lm was approximately 0.05 W m −1 K −1 at 30–300 °C. Inkjet printing of silica aerogels is expected to be a strong candidate for thermal insulating applications in micro-scale systems such as batteries and electronic chips.

Kdr allelic variation in a sodium channel gene from a population of South Carolina Heliothis virescens (Fabricius)

Junmo Cho,Sujin Park,Chunkeun Lim,Yong Chul Park,Jang Hyun Hur,Soonsung Hong,Thomas M. Brown,Saeyoull Cho 한국응용곤충학회 2008 Journal of Asia-Pacific Entomology Vol.11 No.3

Mutations at V421M and L1029H in the hscp sodium channel gene are known to contribute to knockdown resistance (kdr) in the Woodrow, Dalzell, and PTJ strains of H. virescens (tobacco budworm) from the cotton fields of South Carolina, USA. In the IS6 region of the sodium channel gene, the frequencies of the mutant allele methionine in the Woodrow and Dalzell strains were 0.07 and 0.1, respectively. For the IIS6 region, the frequencies of the mutant allele histidine in Woodrow and Dalzell strains were 0.175 and 0.263, respectively. In the PTJ strain, the frequencies of methionine and histidine alleles were 0 and 0.1, respectively. The Hpy3 allele, which is strongly linked to the histidine mutant allele, was also found in Woodrow and Dalzell strains. In addition, we found a new allele, which is one nucleotide different from Hpy3, called Hpy3-1, and found that it is also linked to histidine. Mutations at V421M and L1029H in the hscp sodium channel gene are known to contribute to knockdown resistance (kdr) in the Woodrow, Dalzell, and PTJ strains of H. virescens (tobacco budworm) from the cotton fields of South Carolina, USA. In the IS6 region of the sodium channel gene, the frequencies of the mutant allele methionine in the Woodrow and Dalzell strains were 0.07 and 0.1, respectively. For the IIS6 region, the frequencies of the mutant allele histidine in Woodrow and Dalzell strains were 0.175 and 0.263, respectively. In the PTJ strain, the frequencies of methionine and histidine alleles were 0 and 0.1, respectively. The Hpy3 allele, which is strongly linked to the histidine mutant allele, was also found in Woodrow and Dalzell strains. In addition, we found a new allele, which is one nucleotide different from Hpy3, called Hpy3-1, and found that it is also linked to histidine.

One new species of the genus Coleophora (Lepidoptera, Coleophoridae) from Korea

Junmo Koo,Giorgio Baldizzone,Soowon Cho 한국응용곤충학회 2020 한국응용곤충학회 학술대회논문집 Vol.2020 No.05

One unrecorded species of the genus Coleophora (Lepidoptera, Coleophoridae) from Korea

Junmo Koo,Soowon Cho 한국응용곤충학회 2021 한국응용곤충학회 학술대회논문집 Vol.2021 No.04

Outcome Analysis of External Neurolysis in Posture- Induced Compressive Peroneal Neuropathy and the Utility of Magnetic Resonance Imaging in the Treatment Process

Junmo Kim,Jinseo Yang,Yongjun Cho,Sukhyung Kang,Hyukjai Choi,Jinpyeong Jeon 대한신경외과학회 2023 Journal of Korean neurosurgical society Vol.66 No.3

Objective : We aimed to analyze the effectiveness of external neurolysis on the common peroneal nerve (CPN) in patients with posture-induced compressive peroneal neuropathy (PICPNe). Further, we aimed to examine the utility of magnetic resonance imaging (MRI) in assessing the severity of denervation status and predicting the postoperative prognosis. Methods : We included 13 patients (eight males and five females) with foot drop who underwent CPN decompression between 2018 and 2020. We designed a grading system for assessing the postoperative functional outcome. Additionally, we performed MRI to evaluate the denervation status of the affected musculature and its effect on postoperative recovery. Results : The median time to surgery was 3 months. The median preoperative ankle dorsiflexion and eversion grades were both 3, while the average functional grade was 1. Posterior crural intermuscular septum was the most common cause of nerve compression, followed by deep tendinous fascia and anterior crural intermuscular septum. There was a significant postoperative improvement in the median postoperative ankle dorsiflexion and eversion grades and average postoperative functional (4, 5, and 2.38, respectively). Preoperative ankle eversion was significantly correlated with denervation status. Additionally, the devernation status on MRI was positively correlated with the outcome favorability. However, denervation atrophy led to a less favorable outcome. Conclusion : Among patients with intractable PICPNe despite conservative management, surgical intervention could clinically improve motor function and functional ability. Additionally, MRI examination of the affected muscle could help diagnose CPNe and assess the postoperative prognosis.

The Effect of UG in the L2 Acquisition of Long-Distance Binding

JunMo Cho 한국생성문법학회 2006 생성문법연구 Vol.16 No.2

  This study deals with two theoretical issues relevant to binding, namely argument/adjunct distinction and the finiteness domain effect, by investigating the interlanguage of 44 Korean native speakers learning English. Various types of LD binding were tested to see the effects of the contrasts between argument and adjunct anaphors and between finite and non-finite clause boundaries. The results show that Korean speakers allow LD binding significantly more freely when the anaphor is in an adjunct position, and they also do so when binding takes place over a non-finite clause. These results are rather surprising because in Korean the argument/adjunct distinction does not play a role for binding purposes, and because neither Korean nor English has the finiteness domain effect for LD binding. Accordingly, the result of this experimental study supports the view that interlanguage is UG-constrained.

Formation and Optical Characteristics of Sol-Gel Derived Highly Oriented Ferroelectric (Sr,Ba)Nb2O6 Optical Waveguide Thin Films

Junmo Koo,배병수,Eun-Seok Kang 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.42 No.IV

Highly c-axis oriented SBN thin lms with various compositions were obtained by sol-gel process. The preferential orientation of sol-gel derived lm was enhanced by poling the lm with high dc electric eld, and growing the lm on seeded MgO substrate. The mechanisms of these methods were discussed in this study. For their optical waveguide applications, the optical properties of SBN thin lms were investigated. The anisotropy of refractive indices (no and ne) of the oriented lms decreased certainly as Sr content in the lm composition increased.?

Development of Fuel Quantity Measurement System for Aircraft Supplementary Fuel Tank

Junmo Yang(양준모),Bonggyun Kim(김봉균),Sunghyun Hahn(한성현),Sangchul Lee(이상철) 한국항공우주학회 2020 韓國航空宇宙學會誌 Vol.48 No.11

본 논문에서는 항공기 자세 변화를 고려한 항공기 보조연료탱크 연료량측정시스템을 제시하였다. 개발된 연료량측정시스템은 연료센서, 데이터 처리장치, 계기 및 센서 데이터로부터 연료량을 추정하는 소프트웨어로 구성되었다. 지상에서의 롤 및 피치 자세 변화를 모사하기 위해 모사시험장치가 개발되었다. 모사시험장치를 이용하여 다양한 연료량, 롤 및 피치 각도의 센서 데이터를 자동으로 측정하여 트레이닝 데이터 세트를 획득하였다. 연료량을 추정하는 연료량 측정 소프트웨어를 트레이닝 데이터 세트와 함께 삼선형보간법을 사용하여 개발하였다. 개발된 연료량측정시스템은 참값을 알고 있는 테스트 데이터 세트의 연료 추정 오차를 측정하여 검증하였다. 테스트를 통해 개발된 연료량측정시스템의 오차가 TSO-C55 문서의 기준을 충족하는 것을 확인하였다. This paper presents a fuel quantity measurement system (FQMS) for an aircraft supplementary fuel tank considering the change of aircraft attitude. The developed FQMS consists of fuel sensors, a signal process unit, an indicator and a software to estimate the fuel quantity from the sensor data. To replicate the change of the roll and pitch attitude on the ground, the test simulator is developed in this work. Using the test simulator, the sensor data at various fuel quantities, roll and pitch angles are automatically measured to build a training data set. The data-driven software to estimate the fuel quantity is then developed using a trilinear interpolation method with the training data set. The developed FQMS is verified by investigating the fuel estimation error of the test data set that we know the true values. Through the test, it is confirmed that the error of the developed FQMS system satisfies the criteria of TSO-C55 document.