Evaluation of the lateral ventricle using MRI in normal micropigs

Choi, Mihyun,Lee, Namsoon,Yi, Kangjae,Kim, Junyoung,Choi, Mincheol The Korean Society of Veterinary Science 2011 大韓獸醫學會誌 Vol.51 No.3

This study was undertaken to assess the lateral ventricle, which was some portion of brain and related to congenital anomalies, from 1, 2, 4, and 8 months of age in healthy micropigs. They were induced general anesthesia and performed magnetic resonance imaging (MRI) with a 0.3 Tesla magnet. Each age group was evaluated by three subjects such as lateral ventricular volume, ventricular volume ratio and asymmetry. T1 weighted transverse images were acquired for calculation of lateral ventricular and corresponding brain parenchyma areas. The ratio of bilateral ventricle areas used to analyze the asymmetry. The mean ventricular volumes of each month were $676.74{\pm}25.58mm^3$ (1 month-old), $630.64{\pm}143.84mm^3$ (2 month-old), $992.12{\pm}106.03mm^3$ (4 month-old) and $1172.62{\pm}237.57mm^3$ (8 month-old), respectively. The ventricular volume ratio was the smallest at 2 month-old and re-increased from that age. The ratio was significantly different between 2 month-old and other age groups (p < 0.05). The value of bilateral area ratio showed within 1.5 in all experimental animals. Consequently the lateral ventricle showed a positive correlation with aging and symmetric shapes in both sides. The developmental pattern of the lateral ventricle provides basic data in micropigs as an experimental animal model for physiological and neurosurgical approach.

Quantitative Doppler echocardiography during Dobutamine stress test in canine mitral regurgitant model

Choi, Hojung,Won, Sungjun,Lee, Kichang,Choi, Mincheol,Yoon, Junghee The Korean Society of Veterinary Science 2004 大韓獸醫學會誌 Vol.44 No.2

This study was performed to evaluate echocardiographic parameters in dogs with experimental mitral regurgitation subjected to dobutamine stress testing. In 8 beagle dogs, a 4-prong grasping forceps was inserted into the left ventricle through the carotid artery with fluoroscopic guidance. The disruption of chordae or mitral valve leaflet was performed. Echocardiographic protocols included quantitative Doppler echocardiography and M-mode measurement for evaluating left ventricle function. After all measurement was obtained at rest, dobutamine was infused incrementally. In stress testing, all measurement also was performed at rest as the same method. In stress Doppler echocardiography, regurgitant fraction and aortic stroke volume was increased significantly (P<0.001). Effective regurgitant orifice and regurgitant volume was not changed. In M-mode examination, fractional shortening was increased significantly at stress test (P<0.001). From the results obtained in this study, it could be suggested that dobutamine stress echocardiography increase left ventricle performance in non-functional mitral regurgitation and quantitative Doppler echocardiography is non-invasive, accurate method in valvular regurgitation.

Synthesis and Characterization of F-incorporated Magadiite

Mincheol Choi(최민철),Man Park(박만) 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.10

Layered Silicate for Removal/retrieval of Harmful Metal Cations

Mincheol Choi,Man Park 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Evaluation of computed tomographic and radiographic myelography in normal miniature pigs

Choi, Mihyun,Lee, Hyeyeon,Kim, Mieun,Kim, Junyoung,Lee, Namsoon,Chang, Jinhwa,Jung, Joohyun,Choi, Mincheol The Korean Society of Veterinary Science 2010 大韓獸醫學會誌 Vol.50 No.1

Evaluation of the myelography was studied in miniature pigs. Radiographs and computed tomographic (CT) images of the whole spine were obtained at clinically healthy twelve miniature pigs of 4 (8.7-10 kg) and 12 (26-31 kg) months. The assessments of the spinal cord were made in accordance with the Pavlov's method and compared area ratio [at spinal cord (SC), vertebral canal (VC) and vertebral body (VB)]. The Pavlov's ratio in the cervical spine was significant larger than that of thoracolumbar in radiographic myelography. On CT myelography, the area of the spinal cord had a significant difference between the cervical and thoracolumbar spine. Among the cervical spine, the ratios of spinal cord and vertebral body (SC : VB), vertebral canal and vertebral body (VC : VB) were minimum at the level of 4th cervical spine in both ages, while maximum at the level of 6th cervical spine in both months. In case of lumbar spine, the ratios of spinal cord and vertebral body (SC : VB) were the largest at the level of 4th lumbar spine in 4 months and at the level of 3rd lumbar spine in 12 months. In addition, the ratio of spinal cord and vertebral body (SC : VB) of the cervical spinal cord was significant lower at 4 months but the lumbar spinal cord showed lower pattern at 12 months old miniature pigs.

산업 인공지능의 기술경쟁력과 정책 시사점

최민철(Mincheol Choi),김한흰,조재한,경희권,김용 산업연구원 2022 연구보고서 Vol.- No.-

Worldwide competition for securing leadership in Artificial Intelligence(AI) technology, which is considered the key to industrial digital transformation and new growth momentum, is getting intense. However, Korea’s competitiveness in AI technology is found to be generally lagging behind that of major countries, and the fact that the introduction and utilization of AI in the industry and industrial digital transformation are generally sluggish is evidenced through several sources. Even though it is essential to find ways to enhance the technological competitiveness of industrial AI, which is AI with the purpose of use in the manufacturing industry, necessary empirical evidence is extremely insufficient in Korea. The aim of this study is to provide empirical evidence of the current status regarding the development of industrial AI in Korea and the factors affecting the technological competitiveness of industrial AI, thereby providing several policy implications. First of all, we constructed a dataset consisting of AI patents, which include industrial AI patents, applied between 2007 and 2019 and finally registered (as of July 2022) by linking patent data, government R&D project data, and corporate financial data. Then we using the dataset analyzed the status of industrial AI development, regarding government support, and the determinants of the technological competitiveness of industrial AI and found the following. First, domestic AI technology development and government support are focused on AI for general purposes rather than industrial AI. Second, the Korean government is focusing its support for AI technology development including industrial AI in terms of basic research stage rather than applied research or development stage. Third, it is necessary to expand government R&D support in terms of the development stage in order to enhance the overall competitiveness of industrial AI technology. Fourth, the need for government support centered on the development stage for industrial AI is more pronounced for small and medium enterprises. Finally, it can be effective in enhancing the technological competitiveness of industrial AI to activate technology transactions between firms in manufacturing sector and those in ICT sectors. This study comprehensively provides information and policy implications on the current status of domestic industrial AI and the determinants of its technological competitiveness by utilizing the advantages of patent data including details and potentials for linking to various sources of data. However, the results of this study depend mainly on patent data, and hence, it can be followed by studies based on comprehensively various other data sources including surveys in the future.

Simulation을 이용한 JIT 재고모형과 (s,S) 재고모형의 비교

최민철(Mincheol Choi),박준철(Junchul Park),송한식(Hansik Song) 동아대학교 경영문제연구소 2007 經營論叢 Vol.28 No.-

Current production systems changing from mass production to small quantity production with advantages of production equipments, Accordingly, the inventories of the system has the larger effect on the operations of the systems, Therefore it is interesting to compare inventory models in accordance with business system"s environment, Fazel[l988] studied the relative in advantages of inventory polices by comparing the differences of the total cost of EOQ system and JIT system. This study compared (S, S) inventory model with JIT inventory model. The total cost of (S, S) inventory model with probabilistic demand was computed by Arena Simulation and the total cost of JIT inventory model was compared and analyzed according to the changes of the demand and leadtime. This study also compared JIT and (s, S) policy with varing unit prices when demand is increasing and leadtime is increasing.

Placental growth factor (PlGF) is linked to inflammation and metabolic disorders in mice with diet-induced obesity

Kang, Mincheol,Jeong, Jain,Lee, Jinhee,Park, Song,Sung, Yonghun,Choi, Minjee,Kwon, Wookbong,Jang, Soyoung,Choi, Kwang Shik,Choo, Yeon Sik,Yoon, Duhak,Kim, Myoung Ok,Ryoo, Zae Young Japan Endocrine Society 2018 Endocrine journal Vol.65 No.4

Synthesis and Characterization of Different MnO2 Morphologies for Lithium-Air Batteries

Hyun-A Choi,Hyuk Jang,Hyein Hwang,Mincheol Choi,Dongwook Lim,심상은,백성현 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.5

Manganese dioxide (MnO2) was synthesized in the forms of nanorods, nanoparticles, and mesoporous structures and the characteristics of these materials were investigated. Crystallinities were studied by x-ray diffraction and morphologies by scanning and transmission electron microscopy. Average pore sizes and specific surface areas were analyzed using the Barret-Joyner-Halenda and Brunauer-Emmett-Teller methods, respectively. Samples were also studied by cyclic voltammetry using 1M aqueous KOH solution saturated with either O2 or N2 as electrolytes to investigate their ORR (oxygen reduction reaction) and OER (oxygen evolution reaction) activities. Of the samples produced, mesoporous MnO2 exhibited the highest ORR and OER catalytic activities. Mesoporous MnO2 supported on a gas diffusion layer was also used as a catalyst on the air electrode (cathode) of a lithium-air battery in organic electrolyte. The charge-discharge behavior of mesoporous MnO2 was investigated at a current density 0.2 mAcm−2 in a pure oxygen environment. Mesoporous MnO2 electrodes showed stable cycleability up to 65 cycles at a cell capacity of 700 mAhg−1.

Analysis of Condition for Integral Floating Display Inducing Proper Accommodation Responses

Choi, Ki-Hong,Won, Myoung Ju,Whang, Mincheol,Min, Sung-Wook IEEE 2016 Journal of display technology Vol.12 No.11

<P>The condition for the integral floating display is analyzed and evaluated, which elicits the distinguished accommodation responses to different axial locations of targets. The analysis is carried out to derive condition which helps to devise such a system. And measurements of accommodation response from four subjects are conducted to confirm the agreements with the analytical results, by using the auto-refractometer. The two sample Kolmogorov-Smirnov test is applied to evaluate the measurement results qualitatively. The robust agreements between the analysis and the empirical results are observed. This research can be applied in the optimization of augmented reality or virtual reality devices to provide effective three-dimensional depth cues and relieve viewing discomforts.</P>