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Highly Enhanced Performance of Network Channel Polysilicon Thin-Film Transistors
Lee, Hojoon,Lee, Junyoung,Baek, Sangwon,Jeong, Woong Hee,Lee, Yongsu,Yang, Taehoon,Lee, Jeong-Soo IEEE 2017 IEEE electron device letters Vol.38 No.2
<P>This letter presents the electrical characteristics of newly proposed network-channel low-temperature polysilicon channel (LTPS) thin-film transistors (TFTs). Due to effective reduction of grain boundary traps and enhanced gate controllability, the network-channel TFTs show better subthreshold slope, lower threshold voltage, and higher ON-OFF current ratio, compared with conventional planar devices. The extracted grain boundary trap density and the interface trap density are significantly reduced in the network-channel devices. In addition, the network-channel devices show higher immunity to hot-carrier stressing, which are confirmed from the low-frequency noise characteristics with various stressing time. These results suggest that the network-channel devices are very promising for next-generation LTPS TFT applications.</P>
( Junyoung Yeo ),( Subeen Lee ),( Hyun Jung Lee ),( Yoon Hee Lee ),( Gun Oh Chong ),( Dae Gy Hong ),( Yoon Soon Lee ) 대한산부인과학회 2020 대한산부인과학회 학술대회 Vol.106 No.-
Objective: This study aimed to compare the surgical outcomes between laparoscopic single port myomectomy (LSPM) and conventional laparoscopic myomectomy (C-LM) by using of a propensity score matching analysis. Methods: Retrospective data of 415 patients who underwent C-LM and 223 patients who underwent LSPM were analyzed. A propensity score matching analysis was performed to control selection bias using age, gravida, parity, body mass index, previous history of pelvic surgery, preoperative hemoglobin level, size, number of myomas, type of myoma, and myoma weights. One hundred and ninety-three patients were selected for each group. Results: The patients characteristics were well balanced between the groups after propensity score matching. Surgical outcomes of the matched LSPM group demonstrated shorter hospital stay (3 d [range, 3-4 d] vs 4 d [range, 3-4 d]; P=.000), shorter operation time (64 min [range, 52-95 min] vs 83 min [range, 64-110 min]; P=.000), and less blood loss (20 ml [range, 10-30 ml] vs 50 ml [range, 25-100 ml]; P=.000). There were no significant changes in hemoglobin drop (1.2 g/dL [range, 0.7-2 g/dL] vs 1.3 g/dL [range, 0.7-2.1 g/dL]; P=.822) and complication rate (3% vs 6 %; P=.134) in the matched LSPM group. Conclusion: Although it was difficult to compare the exact difference owing to the heterogeneity of the disease, the current long-term study demonstrated clinical outcomes of LSPM and C-LM after PS matching analysis, revealing that LSPM had the advantage of shorter hospital stays, shorter operation time, and less blood loss.
MinSoo Byun,Dahyun Yi,JunHo Lee,YoungMin Choe,BoKyung Sohn,JunYoung Lee,HyoJung Choi,Hyewon Baek,YuKyeong Kim,YunSang Lee,ChulHo Sohn,Inhee MookJung,Murim Choi,YuJin Lee,DongWoo Lee,SeungHo Ryu,ShinGy 대한신경정신의학회 2017 PSYCHIATRY INVESTIGATION Vol.14 No.6
Objective-The Korean Brain Aging Study for the Early Diagnosis and Prediction of Alzheimer’s disease (KBASE) aimed to recruit 650 individuals, aged from 20 to 90 years, to search for new biomarkers of Alzheimer’s disease (AD) and to investigate how multi-faceted lifetime experiences and bodily changes contribute to the brain changes or brain pathologies related to the AD process. Methods-All participants received comprehensive clinical and neuropsychological evaluations, multi-modal brain imaging, including magnetic resonance imaging, magnetic resonance angiography, [11C]Pittsburgh compound B-positron emission tomography (PET), and [18F]fluorodeoxyglucose-PET, blood and genetic marker analyses at baseline, and a subset of participants underwent actigraph monitoring and completed a sleep diary. Participants are to be followed annually with clinical and neuropsychological assessments, and biannually with the full KBASE assessment, including neuroimaging and laboratory tests. Results-As of March 2017, in total, 758 individuals had volunteered for this study. Among them, in total, 591 participants-291 cognitively normal (CN) old-aged individuals, 74 CN young- and middle-aged individuals, 139 individuals with mild cognitive impairment (MCI), and 87 individuals with AD dementia (ADD)-were enrolled at baseline, after excluding 162 individuals. A subset of participants (n=275) underwent actigraph monitoring. Conclusion-The KBASE cohort is a prospective, longitudinal cohort study that recruited participants with a wide age range and a wide distribution of cognitive status (CN, MCI, and ADD) and it has several strengths in its design and methodologies. Details of the recruitment, study methodology, and baseline sample characteristics are described in this paper.
Adaptive Integral Sliding Mode Control With Time-Delay Estimation for Robot Manipulators
Lee, Junyoung,Chang, Pyung Hun,Jin, Maolin Institute of Electrical and Electronics Engineers 2017 IEEE transactions on industrial electronics Vol.64 No.8
<P>This paper presents an adaptive robust controller for robot manipulators using adaptive integral sliding mode control and time-delay estimation (TDE). The proposed controller employs TDE to estimate robot dynamics with uncertainties such as parameter variations and disturbances, an integral sliding surface to eliminate the reaching phase together with the noise-sensitive switching action used in the conventional sliding mode control, and adaptation gain dynamics to achieve the applicable high accuracy. Experimental studies using a programmable universal machine for assembly-type industrial robot manipulator are conducted to verify the effectiveness of the proposed control. The proposed controller is robust, chattering free, and highly accurate.</P>
Junyoung Lee,Sehoon Choi,Goeun Lee,Doyeob Kim,Chan Hyoeng Kim 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.1
During decommissioning of a nuclear power plant, a large amount of radioactive waste is produced, and it is known to cost more than 300 billion won to dispose the waste. To reduce the disposal cost, it is essential to minimize the number of radioactive waste drums, which can be achieved by detecting and removing hotspot contaminations in the radioactive waste drums. Therefore, a Compton CT system for radioactive waste monitoring is under development, which provides the images of both the internal structure of the drum and the radioactive hotspot(s) in the drum. Based on the acquired information, the activity of hotspots can be estimated. The performance of the system is affected by various geometry factors. Therefore, it is essential to determine optimal configuration by evaluating the effects of the factors on the performance of the system. In the present study, we determined the optimum value of the factors and then predicted the performance of the optimized system by using a simulator based on the Geant4 Monte Carlo simulation. For optimization, the factors were evaluated in terms of structural similarity index measure (SSIM) and measurement time. The considered factors were the activity of the CT source, source to object distance (SOD), object to detector distance (ODD), and projection angle. The simulation result showed that the activities of the CT sources were determined as 23 mCi for 137Cs and 9.6 mCi for 60Co. The optimal SOD and ODD were 180 cm and 40 cm, respectively. The optimal projection angle was evaluated as 4° since it achieves the SSIM of 0.95 faster than other projection angles. With the optimized parameters, the performance of the system was evaluated using the IAEA gamma CT standard phantom containing a hotspot of 137Cs (7.02 μCi). The Compton image was reconstructed using the back-projection algorithm, and the CT image was reconstructed using the filtered back-projection algorithm. The result showed that the location of the hotspot in the Compton image was well identified at the true position. The acquired CT image also well represented the internal structure of the phantom, and the estimated mean linear attenuation coefficient value (μ= 0.0789 cm?1) of the phantom was close to the true value (μ= 0.0752 cm?1). In addition, the hotspot activity estimated by combining the information of the Compton image and CT image was 8.06 μCi. Hence, it was found that the Compton CT system provides essential information for radioactive waste drums.
Dental imaging characterization of micropigs
Lee, Hyeyeon,Choi, Mihyun,Chang, Jinhwa,Jung, Joohyun,Kim, Mieun,Lee, Namsoon,Kim, Junyoung,Choi, Mincheol The Korean Society of Veterinary Science 2010 大韓獸醫學會誌 Vol.50 No.4
Recently the micropig has been developed as human disease model. The dental and orofacial region of micropig is similar to that of humans, so it has been used for testing implant materials and techniques. The purpose of this study is on dental image at each age using radiography and computed tomography. Total twenty-two male micropigs, two or three animals of each 1, 3, 5, 7, 9, 12, 18 and 24 months old, were given radiographic examinations. After general anesthesia, extra- and intra-oral radiographic technique and computed tomographic scans were performed to assess the dental characterization of micropigs. The total deciduous dental formula comprised 28 teeth and was depicted as Di 3/3, Dc 1/1, Dp 3/3. The total permanent dental formula comprised 44 teeth and was depicted as I 3/3, C 1/1, P 4/4, M 3/3. Hypodontia of the first premolars was common in the micropig. The permanent teeth erupted from 3 to 24 month after birth. The sequence of eruption of the permanent teeth was M1, P1, I3, C, M2, I1 + P3 + P4, P2, I2, M3. Dental imaging enables visualization of the unerupted teeth and gives more information about the development of the teeth. The growth pattern of the teeth obtained through radiographic and computed tomographic examination provides basic data in the micropig as animal model for dental research.
Development and performance evaluation of large-area hybrid gamma imager (LAHGI)
Lee, Hyun Su,Kim, Jae Hyeon,Lee, Junyoung,Kim, Chan Hyeong Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.8
We report the development of a gamma-ray imaging device, named Large-Area Hybrid Gamma Imager (LAHGI), featuring high imaging sensitivity and good imaging resolution over a broad energy range. A hybrid collimation method, which combines mechanical and electronic collimation, is employed for a stable imaging performance based on large-area scintillation detectors for high imaging sensitivity. The system comprises two monolithic position-sensitive NaI(Tl) scintillation detectors with a crystal area of 27 × 27 cm<sup>2</sup> and a tungsten coded aperture mask with a modified uniformly redundant array (MURA) pattern. The performance of the system was evaluated under several source conditions. The system showed good imaging resolution (i.e., 6.0-8.9° FWHM) for the entire energy range of 59.5-1330 keV considered in the present study. It also showed very high imaging sensitivity, successfully imaging a 253 µCi <sup>137</sup>Cs source located 15 m away in 1 min; this performance is notable considering that the dose rate at the front surface of the system, due to the existence of the <sup>137</sup>Cs source, was only 0.003 µSv/h, which corresponds to ~3% of the background level.