• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.442-449
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• 2019

Objective : Bone mineral density (BMD) is an important consideration during fusion surgery. Although dual X-ray absorptiometry is considered as the gold standard for assessing BMD, quantitative computed tomography (QCT) provides more accurate data in spine osteoporosis. However, QCT has the disadvantage of additional radiation hazard and cost. The present study was to demonstrate the utility of artificial intelligence and machine learning algorithm for assessing osteoporosis using Hounsfield units (HU) of preoperative lumbar CT coupling with data of QCT. Methods : We reviewed 70 patients undergoing both QCT and conventional lumbar CT for spine surgery. The T-scores of 198 lumbar vertebra was assessed in QCT and the HU of vertebral body at the same level were measured in conventional CT by the picture archiving and communication system (PACS) system. A multiple regression algorithm was applied to predict the T-score using three independent variables (age, sex, and HU of vertebral body on conventional CT) coupling with T-score of QCT. Next, a logistic regression algorithm was applied to predict osteoporotic or non-osteoporotic vertebra. The Tensor flow and Python were used as the machine learning tools. The Tensor flow user interface developed in our institute was used for easy code generation. Results : The predictive model with multiple regression algorithm estimated similar T-scores with data of QCT. HU demonstrates the similar results as QCT without the discordance in only one non-osteoporotic vertebra that indicated osteoporosis. From the training set, the predictive model classified the lumbar vertebra into two groups (osteoporotic vs. non-osteoporotic spine) with 88.0% accuracy. In a test set of 40 vertebrae, classification accuracy was 92.5% when the learning rate was 0.0001 (precision, 0.939; recall, 0.969; F1 score, 0.954; area under the curve, 0.900). Conclusion : This study is a simple machine learning model applicable in the spine research field. The machine learning model can predict the T-score and osteoporotic vertebrae solely by measuring the HU of conventional CT, and this would help spine surgeons not to under-estimate the osteoporotic spine preoperatively. If applied to a bigger data set, we believe the predictive accuracy of our model will further increase. We propose that machine learning is an important modality of the medical research field.

• The Plant Pathology Journal
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• v.35 no.4
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• pp.351-361
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• 2019

In our previous study, pyrrolnitrin produced in Pseudomonas chlororaphis G05 plays more critical role in suppression of mycelial growth of some fungal pathogens that cause plant diseases in agriculture. Although some regulators for pyrrolnitrin biosynthesis were identified, the pyrrolnitrin regulation pathway was not fully constructed. During our screening novel regulator candidates, we obtained a white conjugant G05W02 while transposon mutagenesis was carried out between a fusion mutant $G05{\Delta}phz{\Delta}prn::lacZ$ and E. coli S17-1 (pUT/mini-Tn5Kan). By cloning and sequencing of the transposon-flanking DNA fragment, we found that a vfr gene in the conjugant G05W02 was disrupted with mini-Tn5Kan. In one other previous study on P. fluorescens, however, it was reported that the deletion of the vfr caused increased production of pyrrolnitrin and other antifungal metabolites. To confirm its regulatory function, we constructed the vfr-knockout mutant $G05{\Delta}vfr$ and $G05{\Delta}phz{\Delta}prn::lacZ{\Delta}vfr$. By quantifying ${\beta}-galactosidase$ activities, we found that deletion of the vfr decreased the prn operon expression dramatically. Meanwhile, by quantifying pyrrolnitrin production in the mutant $G05{\Delta}vfr$, we found that deficiency of the Vfr caused decreased pyrrolnitrin production. However, production of phenazine-1-carboxylic acid was same to that in the wild-type strain G05. Taken together, Vfr is required for pyrrolnitrin but not for phenazine-1-carboxylic acid biosynthesis in P. chlororaphis G05.

• Journal of Korean Neurosurgical Society
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• v.62 no.1
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• pp.96-105
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• 2019

Objective : The aims in the management of thoracolumbar spinal fractures are not only to restore vertebral column stability, but also to obtain acceptable alignment of the thoracolumbar junction (T-L junction) to prevent complications. However, insufficient surgical correction of the thoracolumbar spine would be likely to cause late progression of abnormal kyphosis. Therefore, we identified the surgical factors that affected unfavorable radiologic outcomes of the thoracolumbar spine after surgery. Methods : This study was conducted in a single institution from January 2007 to December 2013. A total of 98 patients with unstable thoracolumbar spine fracture were included. In these patients, fixation was done through transpedicular screws with rods by three surgical patterns. We reviewed digital radiographs and analyzed the images preoperatively and postoperatively during follow-up visits to compare the change of the thoracolumbar Cobb angle with radiologic parameters and clinical outcomes. The unfavorable radiologic group was defined as the patients who were measured as having greater than 20 degrees of thoracolumbar Cobb angle on the last follow-up, or who underwent kyphotic progression of thoracolumbar Cobb angle greater than 10 degrees from the immediate postoperative state to final follow-up, or who had overt instrument failure with/without additional surgery. We assessed the risk factors that affected the unfavorable radiologic outcomes. Results : We had 43 patients with unfavorable radiologic outcomes, including 35 abnormal thoracolumbar alignments and 14 instrumental failures with/without additional surgery. The multivariate logistic regression test showed that immediate postoperative T-L junction Cobb angle less than 10.5 degrees was a statistically significant risk factor, as well as the presence of osteoporosis (p=0.017 and 0.049, respectively). Conclusion : Insufficient correction of thoracolumbar kyphosis was considered to be a major factor of an unfavorable radiological outcome. The spinal surgeon should consider that having a T-L junction Cobb angle larger than 10.5 degrees immediately after surgery could result in an unfavorable radiological outcome, which is related to a poor clinical outcome.

• Journal of Broadcast Engineering
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• v.26 no.5
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• pp.519-532
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• 2021

Recently, in various fields such as games, movies, and animation, content that uses motion capture to build body models and create characters to express in 3D space is increasing. Studies are underway to generate animations using RGB-D cameras to compensate for problems such as the cost of cinematography in how to place joints by attaching markers, but the problem of pose estimation accuracy or equipment cost still exists. Therefore, in this paper, we propose a system that inputs RGB images into a joint estimation network and converts the results into 3D data to create FBX format animations in order to reduce the equipment cost required for animation creation and increase joint estimation accuracy. First, the two-dimensional joint is estimated for the RGB image, and the three-dimensional coordinates of the joint are estimated using this value. The result is converted to a quaternion, rotated, and an animation in FBX format is created. To measure the accuracy of the proposed method, the system operation was verified by comparing the error between the animation generated based on the 3D position of the marker by attaching a marker to the body and the animation generated by the proposed system.

• Korean Journal of Heritage: History & Science
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• v.54 no.3
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• pp.204-227
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• 2021

This paper proposed the validity and necessity of establishing the Jungwon Historical and Cultural Area by reviewing the historical characteristics of the name Jungwon and its temporal and spatial range. We also explored ways to utilize the Jungwon historical and cultural Area under the Special Act on the Maintenance of Historical and Cultural Areas. Jungwon, which means the center of the country, has strategic value as a key area connecting the Korean Peninsula to the north and south through the Geripryeong and Jukryeong. It also includes Chungju, which connects the Namhan and Bukhan Rivers . From the Mahan period, the areas of Cheongju and Jincheon, the Miho Stream basin to the west, and Chungju to the east were closely connected to each other. Afterwards, Baekje, Koguryo, and Silla engaged in a fierce battle to occupy the Jungwon area. Jungwon culture was born through the negotiation and fusion of the cultures of the three kingdoms. In particular, Silla continued to value the Jungwon area, demonstrated by the installation of Seowongyeong in Cheongju and Bukwongyeong in Wonju, centering on the Jungwongyeong. Since we have a historical view with a focus on ancient kingdoms, we have overlooked the full value of the history and culture of Jungwon. We need to recognize the importance of Jungwon area and think about how to utilize it. Therefore, we suggested in this paper that there be more public information services on the cultural heritage of Jungwon, the historical heritage experience, and the education programs for local residents. The development and operation of Jungwon's history, culture, and tourism contents, as well as the various academic research papers should be used to reveal the identity of the Jungwon historical and cultural area.

• Journal of Korean Foot and Ankle Society
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• v.25 no.3
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• pp.111-116
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• 2021

Purpose: Variations in the preferred conservative and operative treatment methods for ankle arthritis may be observed in the practice of orthopedic surgeons. This study is based on the Korean Foot and Ankle Society (KFAS) member survey and aims to report the current trend and changes in the management of ankle arthritis over the last few decades. Materials and Methods: A web-based questionnaire containing 24 questions was sent to all KFAS members in July 2021. The questions were mainly related to the preferred techniques and clinical experience in osteotomy, arthrodesis, and total ankle arthroplasty (TAA) for patients with ankle arthritis. Results: Sixty-three out of 550 surgeons (11.5%) responded to the survey. The responses to 6 out of the total of 24 questions (25.0%) achieved the levels needed to reflect a tendency. Answers that showed a tendency were related to the following: a surgical approach for arthrodesis (anterior approach), use of auto-bone graft for arthrodesis (iliac bone), a nonunion rate of more than 10% following arthrodesis, main reason related to unsatisfactory results after arthrodesis (nonunion or delayed union), the main reason to change total ankle prosthesis (unstable supply of prosthesis), the unusualness of revision TAA and conversion of fusion to TAA. Diversity was found in several aspects of treatment (degree of experience and satisfaction in supramalleolar osteotomy, fixation method for arthrodesis, preferred TAA prosthesis and longevity, degree of experinece, annual number of TAA operation. Conclusion: This study proposes updated information with regard to the current trends in the management of ankle arthritis in Korea. Both consensus and variations in the approach to patients with ankle arthritis were identified through this survey. With an increasing preference for TAA, the need for the development of a prosthesis optimized for Koreans and a stable supply of prostheses were the suggestions made by the study.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.257-263
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• 2021

This study derives the relative cross-section for the natW(p,xn)176Re nuclear reaction by measuring the gamma rays generated from the nuclear reaction with natural tungsten using a 100 MeV linear accelerator of the Korea Multi-purpose Accelerator Complex in the Korea Atomic Energy Research Institute. In general, research on isotopes with a short half-life always shows a tendency that the intensity of radioactivity decreases rapidly within a short period of time, making it very difficult to measure itself. In particular, 176Re is one of the relatively short radionuclides with a half-life of 5.3 minutes. In this study, 109.08 keV gamma rays generated from the 176Re isotope having such a short half-life were measured using a high-purity Ge detector(HPGe detector). The obtained relative measurements were the results in the 8 to 14 MeV proton energy domain published by Richard G. in 1967, and the TENDL-2019 value, which was the result of A. J. Koning in 2019, which evaluated the nuclear reaction cross-section by calculation based on this comparative analysis was performed. The results of this study are expected to be usefully applied to the design of nuclear fusion reactor which is known as future energy sources, elements ratio for the nuclear synthesis of astrophysics.

• Journal of the Korea Convergence Society
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• v.12 no.4
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• pp.61-68
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• 2021

The purpose of this study was to derive their cognitive, psychological, and behavioral characteristics through a fusion study that analyzed the quantified results of post-homeless people participating in the housing support project after the electroencephalogram test. Participants in this study are 6 people who have lived in temporary homeless facilities or homeless living facilities and have expressed their intention to participate in the housing support project. Electroencephalogram measurements were performed using Brainmaster equipment according to the International 10-20 Law. As a result of the analysis, the study participants showed high levels of Theta wave, Beta wave, and High Beta wave, which show the peculiarity of the emotional aspect, which is a result of showing emotional characteristics such as anger, anxiety, and insomnia in the emotional aspect. Therefore, it is suggested that they provide stress management, counseling, and physical health management services in order to maintain a stable residential life in the community in the future. The results of this study presented a quantitative basis for the cognitive, psychological, and behavioral characteristics of homeless people, and suggests a support system necessary for them to maintain self-reliance in communities in the future.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.9
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• pp.709-719
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• 2021

Recent progress in analysis and flight simulation methods enables wider use of a virtual certification and reduces number of certification flight tests. Aerodynamic database (AeroDB) is one of the most important components for the flight simulation. It is composed of aerodynamic coefficients at a range of flight conditions and control deflections. This paper proposes and efficient method for construction of AeroDB that combines Gaussian Process based Variable Fidelity Modeling with adaptive sampling algorithm. A case study of virtual certification of a F-16 fighter is presented. Four AeroDB were constructed using different number and distribution of high-fidelity data points. The constructed database is then used to simulate gliding, short pitch, and roll response. Compliance with certification regulations is then checked. The case study demonstrates that the proposed method can significantly reduce number of high-fidelity data points while maintaining high accuracy of the simulation.

• Resources Recycling
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• v.29 no.6
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• pp.3-14
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• 2020

This study aims to introduce and review on the recovery technologies of rare earth elements(REEs) from coal ash. Many researchers have been carried out by various beneficiation processes, such as particle size separation, magnetic separation, specific gravity, and flotation to recover rare earth elements from coal ash generated from Pulverized Coal(PC) boiler. Through the beneficiation process, it was confirmed that concentration of rare earth elements was much lower than the 4,700 ppm, and that additional enrichment treatment through wet process was needed for the products recovered after the beneficiation process. It was confirmed that the rare earth elements contained in coal ash were applied to the leaching process after pretreatment such as alkali-fusion to improve leaching efficiency. Although beneficiation and leaching methods have been studied, its optimum recovery technologies for rare earth elements not been confirmed up to now, research on the recovery of rare earth contained in coal ash is reported to continue. In case of Korea, the technology for the recovery of rare earth elements from coal ash and coal by-product could not been confirmed up to present. In these reasons, it is urgent to develop technologies such as beneficiation and leaching process continuously.