• Journal of the Korean Orthopaedic Association
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• v.54 no.4
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• pp.327-335
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• 2019

Purpose: To investigate the radiological efficacy of polymethylmethacrylate (PMMA) augmentation of pedicle screw operation in osteoporotic vertebral compression fractures (OVCF) patients. Materials and Methods: Twenty OVCF patients, who underwent only posterior fusion using pedicle screws with PMMA augmentation, were included in the study. The mean follow-up period was 15.6 months. The demographic data, bone mineral density (BMD), fusion segments, number of pedicle screws, and amount of PMMA were reviewed as medical records. To analyze the radiological outcomes, the radiologic parameters were measured as the time serial follow-up (preoperation, immediately postoperation, postoperation 6 weeks, 3, 6 months, and 1 year follow-up). Results: A total of 20 patients were examined (16 females [80.0%]; mean age, 69.1±8.9 years). The average BMD was -2.5±0.9 g/cm². The average cement volume per vertebral body was 6.3 ml. The mean preoperative Cobb angle of focal kyphosis was 32.7°±7.0° and was improved significantly to 8.7°±6.9° postoperatively (p<0.001), with maintenance of the correction at the serial follow-up, postoperatively. The Cobb angle of instrumented kyphosis, wedge angle, and sagittal index showed similar patterns. In addition, the anterior part of fractured vertebral body height averaged 11.0±5.0 mm and was improved to 18.5±5.7 mm postoperatively (p=0.006), with maintenance of the improvement at the 3-month, 6-month, and 1-year follow-up. Conclusion: The reinforcement of pedicle screws using PMMA augmentation may be a feasible surgical technique for OVCF. Moreover, it appears to be appropriate for improving the focal thoracolumbar/lumbar kyphosis and is maintained well after surgery.

• Journal of the Korean Orthopaedic Association
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• v.54 no.1
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• pp.37-44
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• 2019

Purpose: Tumor infiltration around the knee joint or skip metastasis, repeated infection sequelae after tumor prosthesis implantation, regional recurrence, and mechanical failure of the megaprosthesis might require combined distal femur and proximal tibia replacement (CFTR). Among the aforementioned situations, there are few reports on the indication, complications, and implant survival of CFTR in temporarily arthrodesed patients who had a massive bony defect on either side of the knee joint to control infection. Materials and Methods: Thirty-four CFTR patients were reviewed retrospectively and 13 temporary arthrodesed cases switched to CFTR were extracted. All 13 cases had undergone a massive bony resection on either side of the knee joint and temporary arthrodesis state to control the repeated infection. This paper describes the diagnosis, tumor location, number of operations until CFTR, duration from the index operation to CFTR, survival of CFTR, complications, and Musculoskeletal Tumor Society (MSTS) score. Results: According to Kaplan-Meier plot, the 5- and 10-year survival of CFTR was 69.0%±12.8%, 46.0%±20.7%, respectively. Six (46.2%) of the 13 cases had major complications. Three cases underwent removal of the prosthesis and were converted to arthrodesis due to infection. Two cases underwent partial change of the implant due to loosening and periprosthetic fracture. The remaining case with a deep infection was resolved after extensive debridement. At the final follow-up, the average MSTS score of 10 cases with CFTR was 24.6 (21-27). In contrast, the MSTS score of 3 arthrodesis cases with failed CFTR was 12.3 (12-13). The average range of motion of the 10 CFTR cases was 67° (0°-100°). The mean extension lag of 10 cases was 48° (20°-80°). Conclusion: Although the complication rates is substantial, conversion of an arthrodesed knee to a mobile joint using CFTR in a patient who had a massive bony defect on either side of the knee joint to control infection should be considered. The patient's functional outcome was different from the arthrodesed one. For successful conversion to a mobile joint, thorough the eradication of scar tissue and creating sufficient space for the tumor prosthesis to flex the knee joint up to 60° to 70° without soft tissue tension.

• Health Policy and Management
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• v.34 no.2
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• pp.178-184
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• 2024

Background: This study aimed to determine the effectiveness of drug utilization review (DUR) evaluation indicators on safe drug use by comparing the changes in DUR inspection rates and drug duplication prescription prevention rates between the pre- and post-implementation of the DUR evaluation indicators of the Healthcare Quality Evaluation Grant Initiative. Methods: This study used DUR data from the Health Insurance Review and Assessment Service in 2018 (pre-implementation) and the evaluation results of the Healthcare Quality Evaluation Grant Initiative in 2023 (post-implementation). The dependent variables were the DUR evaluation indicators, including DUR inspection rate and drug duplicate prescription prevention rate. The independent variable was the implementation of the DUR evaluation indicators, and the control variables included medical institution characteristics such as type, establishment classification, location, DUR billing software company, and number of beds. Results: The results of the analysis of the difference in the prevention rate of drug duplicate prescriptions between the pre- and post-implementation of the DUR evaluation indicators of the Healthcare Quality Evaluation Grant Initiative showed that the prevention rate of drug duplicate prescriptions increased statistically significantly after the implementation of the DUR evaluation indicators. Conclusion: The policy implications of this study are as follows: First, ongoing evaluation of DUR systems is needed. Second, it is necessary to establish a collaborative partnership between healthcare organizations that utilize DUR system information and the organizations that manage it.

• Journal of Life Science
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• v.34 no.5
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• pp.339-355
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• 2024

The pulmonary system is a highly complex system that can only be understood by integrating its functional and structural aspects. Hence, in vivo animal models are generally used for pathological studies of pulmonary diseases and the evaluation of inhalation toxicity. However, to reduce the number of animals used in experimentation and with the consideration of animal welfare, alternative methods have been extensively developed. Notably, the Organization for Economic Co-operation and Development (OECD) and the United States Environmental Protection Agency (USEPA) have agreed to prohibit animal testing after 2030. Therefore, the latest advances in biotechnology are revolutionizing the approach to developing in vitro inhalation models. For example, lung organ-on-a-chip (OoC) and organoid models have been intensively studied alongside advancements in three-dimensional (3D) bioprinting and microfluidic systems. These modeling systems can more precisely imitate the complex biological environment compared to traditional in vivo animal experiments. This review paper addresses multiple aspects of the recent in vitro modeling systems of lung OoC and organoids. It includes discussions on the use of endothelial cells, epithelial cells, and fibroblasts composed of lung alveoli generated from pluripotent stem cells or cancer cells. Moreover, it covers lung air-liquid interface (ALI) systems, transwell membrane materials, and in silico models using artificial intelligence (AI) for the establishment and evaluation of in vitro pulmonary systems.

• Korean Journal of Remote Sensing
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• v.40 no.4
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• pp.363-375
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• 2024

Waterbody change detection using satellite images has recently been carried out in various regions in South Korea, utilizing multiple types of sensors. This study utilizes optical satellite images from Landsat and Sentinel-2 based on Google Earth Engine (GEE) to analyze long-term surface water area changes in four monitored small and medium-sized water supply dams and agricultural reservoirs in South Korea. The analysis covers 19 years for the water supply dams and 27 years for the agricultural reservoirs. By employing image analysis methods such as normalized difference water index, Canny Edge Detection, and Otsu'sthresholding for waterbody detection, the study reliably extracted water surface areas, allowing for clear annual changes in waterbodies to be observed. When comparing the time series data of surface water areas derived from satellite images to actual measured water levels, a high correlation coefficient above 0.8 was found for the water supply dams. However, the agricultural reservoirs showed a lower correlation, between 0.5 and 0.7, attributed to the characteristics of agricultural reservoir management and the inadequacy of comparative data rather than the satellite image analysis itself. The analysis also revealed several inconsistencies in the results for smaller reservoirs, indicating the need for further studies on these reservoirs. The changes in surface water area, calculated using GEE, provide valuable spatial information on waterbody changes across the entire watershed, which cannot be identified solely by measuring water levels. This highlights the usefulness of efficiently processing extensive long-term satellite imagery data. Based on these findings, it is expected that future research could apply this method to a larger number of dam reservoirs with varying sizes,shapes, and monitoring statuses, potentially yielding additional insights into different reservoir groups.

• Journal of Christian Education in Korea
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• v.78
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• pp.21-55
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• 2024

Purpose of study: The purpose of this study is to examine the crisis situation of Christian education experienced by Korean churches and theological education institutions after the COVID-19 pandemic, and to seek new tasks and directions that Korean churches should prepare for the recovery and growth of Christian education. Research Contents and Methods: Before reviewing the current crisis experienced by Korean churches and theological education institutions after the COVID-19 pandemic, the terms and concepts of Christian education are first reflected. In addition, the causes and phenomena of the Korean church and Christian education crisis after the COVID-19 Pandemic are examined through statistics, media, and church field data. The researcher identified the causes of the crisis experienced by Korean churches and theological education institutions as follows: 1. The influence of COVID-19 Pandemic: suspension of faith and educational activities, 2. The age of population cliffs: increase in the elderly vs. decrease in young people, 3. Neoliberalism: marketism, infinite competition, efficiency, winner-take-all, 4. post-religious era: post-Christianity, weakened communitarianism, and reduced number of Christians. The results of this study are four points as follows: 1. Crisis of church education: suspension of operation of Sunday school and feeling of failure, 2. Crisis of faith of young generation: nurturing unstable future church leaders, 3. Faith of adult generation: crisis and hope, 4. The faith of the elderly generation: light and shadow. Conclusion and Recommendations: The new task and direction of Christian education that Korean churches should pursue after the COVID-19 pandemic are as follows: 1. New conversion of Sunday school faith education: From schooling-paradigm education to faith education that integrates family and generation. 2. New conversion of theological education: From knowledge education to spirituality training. 3. Re-ignition of faith education for middle-aged adults: Activation of faith through worship and small groups, 4. New conversion of church elder education: The need to change from caring objects to creative religious life.

• The Korean Journal of Air & Space Law and Policy
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• v.28 no.2
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• pp.3-35
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• 2013

Air transport today is a means of transport that is optimized for exchanges between nations. Around the world, has experienced an increase in operating and the number of airline route expansion that has entered into the international aviation agreements in order to take advantage of the air transport efficient, but the possibility of the occurrence of air transport accidents increased. When compared to the accident of other means of transport, development of air transport accidents, not high, but it leads to catastrophe aviation accident occurs. Air Transport accident many international transportation accident than domestic transportation accident, in the event of an accident, the analysis of the legal responsibility of the shipper or the like is necessary or passenger air carrier. Judgment of the legal order of discipline of air transport accident is a classification of the type of air transport agreement. Depending on the object, air transport agreements are classified into the contract of carriage of aviation of the air passenger transportation contract. For casualties occurs, air passenger transportation accident is a need more discussion of legal discipline for this particular. Korean Commercial Code, it is possible to reflect in accordance with the actual situation of South Korea the contents of the treaty, which is utilized worldwide in international air transport, even on the system, to control land, sea, air transport and welcoming to international standards. However, Korean Commercial Code, the problem of the Montreal Convention has occurred as it is primarily reflecting the Montreal Convention. As a cause of liability for damages, under the Commercial Code of Korea and the contents of the treaty precedent is reflected, the concept of accident is necessary definition of the exact concept for damages of passengers in particular. Cause of personal injury or death of passengers, in the event of an accident to the "working for the elevation" or "aircraft" on, the Montreal Convention is the mother method of Korea Commercial Code, liability for damages of air carrier defines. The Montreal Convention such, continue to be a matter of debate so far in connection with the scope of "working for the lifting of" the concepts defined in the same way from Warsaw Convention "accident". In addition, it is discussed and put to see if you can be included mental damage passenger suffered in air transport in the "personal injury" in the damage of the passenger is in the range of damages. If the operation of aircraft, injury accident, in certain circumstances, compensation for mental damage is possible, in the same way as serious injury, mental damage caused by aviation accidents not be able to live a normal life for the victim it is damage to make. So it is necessary to interpret and what is included in the injury to the body in Korea Commercial Code and related conventions, non-economic damage of passengers, clearly demonstrated from the point of view of prevention of abuse of litigation and reasonable protection of air carrier it must compensate only psychological damage that can be. Since the compensation of delay damages, Warsaw Convention, the Montreal Convention, Korea Commercial Code, there are provisions of the liability of the air carrier due to the delayed arrival of passenger and baggage, but you do not have a reference to delayed arrival, the concept of delay arrangement is necessary. The strict interpretation of the concept of delayed arrival, because it may interfere with safe operation of the air carrier, within the time agreed to the airport of arrival that is described in the aviation contract of carriage of passenger baggage, or, these agreements I think the absence is to be defined as when it is possible to consider this situation, requests the carrier in good faith is not Indian or arrive within a reasonable time is correct. The loss of passenger, according to the international passenger Conditions of Carriage of Korean Air, in addition to the cases prescribed by law and other treaties, loss of airline contracts, resulting in passengers from a service that Korean Air and air transport in question do damage was is, that the fact that Korean Air does not bear the responsibility as a general rule, that was caused by the negligence or intentional negligence of Korean Air is proof, negligence of passengers of the damage has not been interposed bear responsibility only when it is found. It is a clause in the case of damage that is not mandated by law or treaty, and responsible only if the negligence of the airline side has been demonstrated, but of the term negligence "for" intentional or negligent "Korean Air's Terms" I considered judgment of compatibility is required, and that gross negligence is appropriate. The "Korean Air international passenger Conditions of Carriage", airlines about the damage such as electronic equipment that is included in the checked baggage of passengers does not bear the responsibility, but the loss of baggage, international to arrive or depart the U.S. it is not the case of transportation. Therefore, it is intended to discriminate unfairly passengers of international flights arriving or departure to another country passengers of international flights arriving or departure, the United States, airlines will bear the responsibility for the goods in the same way as the contents of the treaty it should be revised in the direction.

• The Korean Journal of Air & Space Law and Policy
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• v.27 no.1
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• pp.29-73
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• 2012

Aviation safety is the State and industry's top priority and more scientific approaches for fatigue management should be needed. There are lately various studies and regulation changes for crew fatigue management with ICAO, FAA and EASA. ICAO issued the provisions of fatigue management for flight crew since 1st edition, 1969, of Annex 6 operation of aircraft as a Standards and Recommended practice(SARPs). Unfortunately, there have been few changes and improvement to fatigue management provisions since the time they were first introduced. However the SARPs have been big changed lately. ICAO published guidance materials for development of prescriptive fatigue regulations through amendment 33A of Annex 6 Part 1 as applicable November 19th 2009. And then ICAO introduced additional amendment for using Fatigue Risk Management System (FRMS) with $35^{th}$ amendment in 2011. According to the Annex 6, the State of the operator shall establish a) regulations for flight time, flight duty period, duty period and rest period limitations and b) FRMS regulations. The Operator shall implement one of following 3 provisions a) flight time, flight duty period, duty period and rest period limitations within the prescriptive fatigue management regulations established by the State of the Operator; or b) a FRMS; or c) a combination of a) and b). U.S. FAA recently published several kinds of Advisory Circular about flightcrew fatigue. U.S. passed "Airline Safety and FAA Extension Act of 2010" into law on August 1st, 2010. This mandates all commercial air carriers to develop a FAA-acceptable Fatigue Risk Management Plan(FRMP) by October 31st, 2010. Also, on May 16, 2012, the FAA published a final rule(correction) entitled 'Flightcrew Member Duty and Rest Requirements; correction to amend its existing prescriptive regulations. The new requirements are required to implement same regulations for domestic, flag and supplemental operations from January 4, 2014. EASA introduced a Notice of Proposed Amendment (NPA) 2010-14 entitled "Draft opinion of the European Aviation Safety Agency for a Commission Regulation establishing the implementing rules on Flight and Duty Time Limitations and Rest Requirements for Commercial Air Transport with aeroplanes" on December 10, 2010. The purpose of this NPA is to develop and implement fatigue management for commercial air transport operations. Comparing with Korean and foreign regulations regarding fatigue management, the provisions of ICAO, FAA, EASA are more considering various fatigue factors and conditions. Korea regulations should be needed for some development of insufficiency points. In this thesis, I present the results of the comparative study between domestic and foreign regulations in respect of fatigue management crew member. Also, I suggest legal proposals for amendment of Korea Aviation act and Enforcement Regulations concerning fatigue management for crew members. I hope that this paper is helpful to change korea fatigue regulations, to enhance aviation safety, and to reduce the number of accidents relating to fatigue. Fatigue should be managed at all level such as regulators, experts, operators and pilots. Authority should change surveillance mind-set from regulatory auditor to expert adviser. Operators should identify various fatigue factors and consider to crew scheduling them. Crews should strongly manage both individual and duty-oriented fatigue issues.

• Journal of Intelligence and Information Systems
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• v.23 no.1
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• pp.47-67
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• 2017

Steel plate faults is one of important factors to affect the quality and price of the steel plates. So far many steelmakers generally have used visual inspection method that could be based on an inspector's intuition or experience. Specifically, the inspector checks the steel plate faults by looking the surface of the steel plates. However, the accuracy of this method is critically low that it can cause errors above 30% in judgment. Therefore, accurate steel plate faults diagnosis system has been continuously required in the industry. In order to meet the needs, this study proposed a new steel plate faults diagnosis system using Simultaneous MTS (S-MTS), which is an advanced Mahalanobis Taguchi System (MTS) algorithm, to classify various surface defects of the steel plates. MTS has generally been used to solve binary classification problems in various fields, but MTS was not used for multiclass classification due to its low accuracy. The reason is that only one mahalanobis space is established in the MTS. In contrast, S-MTS is suitable for multi-class classification. That is, S-MTS establishes individual mahalanobis space for each class. 'Simultaneous' implies comparing mahalanobis distances at the same time. The proposed steel plate faults diagnosis system was developed in four main stages. In the first stage, after various reference groups and related variables are defined, data of the steel plate faults is collected and used to establish the individual mahalanobis space per the reference groups and construct the full measurement scale. In the second stage, the mahalanobis distances of test groups is calculated based on the established mahalanobis spaces of the reference groups. Then, appropriateness of the spaces is verified by examining the separability of the mahalanobis diatances. In the third stage, orthogonal arrays and Signal-to-Noise (SN) ratio of dynamic type are applied for variable optimization. Also, Overall SN ratio gain is derived from the SN ratio and SN ratio gain. If the derived overall SN ratio gain is negative, it means that the variable should be removed. However, the variable with the positive gain may be considered as worth keeping. Finally, in the fourth stage, the measurement scale that is composed of selected useful variables is reconstructed. Next, an experimental test should be implemented to verify the ability of multi-class classification and thus the accuracy of the classification is acquired. If the accuracy is acceptable, this diagnosis system can be used for future applications. Also, this study compared the accuracy of the proposed steel plate faults diagnosis system with that of other popular classification algorithms including Decision Tree, Multi Perception Neural Network (MLPNN), Logistic Regression (LR), Support Vector Machine (SVM), Tree Bagger Random Forest, Grid Search (GS), Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). The steel plates faults dataset used in the study is taken from the University of California at Irvine (UCI) machine learning repository. As a result, the proposed steel plate faults diagnosis system based on S-MTS shows 90.79% of classification accuracy. The accuracy of the proposed diagnosis system is 6-27% higher than MLPNN, LR, GS, GA and PSO. Based on the fact that the accuracy of commercial systems is only about 75-80%, it means that the proposed system has enough classification performance to be applied in the industry. In addition, the proposed system can reduce the number of measurement sensors that are installed in the fields because of variable optimization process. These results show that the proposed system not only can have a good ability on the steel plate faults diagnosis but also reduce operation and maintenance cost. For our future work, it will be applied in the fields to validate actual effectiveness of the proposed system and plan to improve the accuracy based on the results.

• Journal of Chest Surgery
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• v.39 no.5 s.262
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• pp.359-365
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• 2006

Background: Arterial grafts have been used to achieve better long-term results for coronary revascularization. Bilateral internal thoracic artery (ITA) grafts have a better results, but it may be not used in some situations such as diabetes and chronic obstructive pulmonary disease (COPD). We evaluated the clinical and angiographic results of composite left internal thoracic artery-radial artery (LITA-RA) Y graft. Material and Method: Between April 2002 and September 2004, 119 patients were enrolled in composite Y graft for coronary bypass surgery. The mean age was $62.6{\pm}8.8$ years old and female was 34.5%. Preoperative cardiac risk factors were as follows: hypertension 43.7%, diabetes 33.6%, smoker 41.2%, and hyperlipidemia 22.7%, There were emergency operation (14), cardiogenic shock (6), left ventricle ejection fraction (LVEF) less than 40% (17), and 17 cases of left main disease. Coronary angiography was done in 35 patients before the hospital discharge. Result: The number of distal anastomoses was $3.1{\pm}0.91$ and three patients (2.52%) died during hospital stay. The off-pump coronary artery bypass (OPCAB) was applied to 79 patients (66.4%). The LITA was anastomosed to left anterior descending system except three cases which was to lateral wall. The radial Y grafts were anastomosed to diagonal branches (4), ramus intermedius (21), obtuse marginal branches (109), posterolateral branches (12), and posterior descending coronary artery (8). Postoperative coronary angiography in 35 patients showed excellent patency rates (LITA 100%, and RA 88.5%; 3 RA grafts which anastomosed to coronary arteries <70% stenosed showed string sign with competitive flow). Conclusion: The LITA-RA Y composite graft provided good early clinical and angiographic results in multivessel coronary revascularization. But it should be cautiously used in selected patients.