• Imaging Science in Dentistry
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• v.52 no.2
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• pp.209-217
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• 2022

Purpose: The aim of this study was, firstly, to determine the concordance of ultrasonographic and histopathological diagnoses in patients in whom apical resection was already indicated. Secondly, this study aimed to determine whether lesions were periapical granulomas or cysts, and to compare them after root canal treatment using ultrasonography and periapical radiographs. Materials and Methods: In the first stage of the study, ultrasonographic and histopathologic diagnoses of 10 lesions were compared. Secondly, the periapical radiographs and ultrasonographic images of 44 lesions were measured. The presence of internal vascularity was determined by ultrasonographic color and power Doppler modes. Follow-up examinations of healing after root canal treatment were performed using ultrasonography and periapical radiographs, and these modalities were compared. Results: In the periapical granuloma and cyst groups, the measurement values decreased for all variables. There was no significant difference in the dimensional changes of lesions between the 2 groups, and ultrasonography and periapical radiographs were compatible. The pre-diagnoses were compared with histopathological diagnoses and were found to be compatible. Conclusion: The ultrasonographic color and power Doppler techniques could be an effective method for diagnosing periapical lesions as cysts or granulomas. After root canal treatment of granulomas and cysts, the dimensional shrinkage and healing patterns appear to be similar. Ultrasonography and periapical radiographs were consistent in terms of dimensional comparisons, and ultrasonography may be an alternative method for follow-up of the healing of periapical lesions.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.1
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• pp.121-130
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• 2022

Molar-incisor malformation (MIM) is a newly reported dental anomaly with molar root deformity and incisor crown defects. MIM-affected teeth may cause severe pain with no apparent tooth caries. Since the affected molars clinically appear normal, radiographs are recommended for accurate diagnosis on the first visit. Since MIM-affected patients are in mixed dentition, timely and appropriate interventions are needed to avoid unnecessary pain and complicated clinical issues. This report was written to describe two patients who had MIM in early mixed dentition and report their 2-year follow-ups.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.753-760
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• 2021

This study was carried out to discover suitable packaging methods during the cold or frozen storage of sawtooth oak and Japanese larch seedlings, which are major afforestation tree species in Korea. The weight loss rate of sawtooth oak was lower under frozen storage at -2℃ (maximum, 33.7%) than under cold storage at 2℃ (maximum, 61.0%). A film liner treatment inside the packaging box effectively suppressed the increase in the weight loss rate. For the sawtooth oak containerized seedlings, when stored at -2℃, the rate of weight loss was 17.9 to 25.4% in the untreated group and less than 1% in the film liner treatment group. Similar results were observed with Japanese larch. After two months of freezing at -2℃, both species maintained a low index of 1.0 - 1.1 with regard to the degree of shoot desiccation of containerized seedlings, and there was no significant difference between the treatments. On the other hand, the chlorine dioxide treatment could more effectively reduce the occurrence of mold and shoot desiccation than a PE single treatment in bare-root seedlings. According to these results, it was concluded that frozen storage is generally suitable as a means of long-term storage compared to cold storage of sawtooth oak and Japanese larch. A chlorine dioxide treatment at 20 ppm was effective for maintaining seedling quality levels during storage, demonstrating the good effect of suppressing the occurrence of shoot desiccation and the occurrence of mold.

• Restorative Dentistry and Endodontics
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• v.45 no.4
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• pp.50.1-50.11
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• 2020

Objectives: In this study, we investigated the potential of amoxicillin-loaded polymeric microspheres to be delivered to tooth root infection sites via a bioactive reparative cement. Materials and Methods: Amoxicillin-loaded microspheres were synthesized by a spray-dray method and incorporated at 2.5% and 5% into a mineral trioxide aggregate cement clinically used to induce a mineralized barrier at the root tip of young permanent teeth with incomplete root development and necrotic pulp. The formulations were modified in liquid:powder ratios and in composition by the microspheres. The optimized formulations were evaluated in vitro for physical and mechanical eligibility. The morphology of microspheres was observed under scanning electron microscopy. Results: The optimized cement formulation containing microspheres at 5% exhibited a delayed-release response and maintained its fundamental functional properties. When mixed with amoxicillin-loaded microspheres, the setting times of both test materials significantly increased. The diametral tensile strength of cement containing microspheres at 5% was similar to control. However, phytic acid had no effect on this outcome (p > 0.05). When mixed with modified liquid:powder ratio, the setting time was significantly longer than that original liquid:powder ratio (p < 0.05). Conclusions: Lack of optimal concentrations of antibiotics at anatomical sites of the dental tissues is a hallmark of recurrent endodontic infections. Therefore, targeting the controlled release of broad-spectrum antibiotics may improve the therapeutic outcomes of current treatments. Overall, these results indicate that the carry of amoxicillin by microspheres could provide an alternative strategy for the local delivery of antibiotics for the management of tooth infections.

• The Korean Journal of Pain
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• v.30 no.4
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• pp.287-295
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• 2017

Background: Recently, the use of ultrasound (US) techniques in regional anesthesia and pain medicine has increased significantly. However, the current extent of training in the use of US-guided pain management procedures in Korea remains unknown. The purpose of the present study was to assess the current state of US training provided during Korean Pain Society (KPS) pain fellowship programs through the comparative analysis between training hospitals. Methods: We conducted an anonymous survey of 51 pain physicians who had completed KPS fellowships in 2017. Items pertained to current US practices and education, as well as the types of techniques and amount of experience with US-guided pain management procedures. Responses were compared based on the tier of the training hospital. Results: Among the 51 respondents, 14 received training at first- and second-tier hospitals (Group A), while 37 received training at third-tier hospitals (Group B). The mean total duration of pain training during the 1-year fellowship was 7.4 months in Group A and 8.4 months in Group B. Our analysis revealed that 36% and 40% of respondents in Groups A and B received dedicated US training, respectively. Most respondents underwent US training in patient-care settings under the supervision of attending physicians. Cervical root, stellate ganglion, piriformis, and lumbar plexus blocks were more commonly performed by Group B than by Group A (P < 0.05). Conclusions: Instruction regarding US-guided pain management interventions varied among fellowship training hospitals, highlighting the need for the development of educational standards that mandate a minimum number of US-guided nerve blocks or injections during fellowships in interventional pain management.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.1
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• pp.79-86
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• 2021

In order to increase the probability of success in big data projects, quantified techniques are required to analyze the root cause of risks from complex causes and establish optimal countermeasures. To this end, this study measures risk factors and relationships through SNA analysis and presents a way to respond to risks based on them. In other words, it derives a dependency network matrix by utilizing the results of correlation analysis between risk groups in the big data projects presented in the preliminary study and performs SNA analysis. In order to derive the dependency network matrix, partial correlation is obtained from the correlation between the risk nodes, and activity dependencies are derived by node by calculating the correlation influence and correlation dependency, thereby producing the causal relationship between the risk nodes and the degree of influence between all nodes in correlation. Recognizing the root cause of risks from networks between risk factors derived through SNA between risk factors enables more optimized and efficient risk management. This study is the first to apply SNA analysis techniques in relation to risk management response, and the results of this study are significant in that it not only optimizes the sequence of risk management for major risks in relation to risk management in IT projects but also presents a new risk analysis technique for risk control.

• Korean Journal of Remote Sensing
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• v.39 no.5_2
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• pp.849-858
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• 2023

Investigating disaster sites such as earthquakes and landslides involves significant risks due to potential secondary disasters like facility collapse. In situations where direct access is challenging, there is a need to develop methods for safely acquiring high-precision 3D disaster information using light detection and ranging (LiDAR) equipped drone survey systems. In this study, the feasibility of using drone LiDAR in disaster scenarios was examined, focusing on the collapse accident at Jeongja Bridge in Bundang-gu, Seongnam City, in April 2023. High-density point clouds for the accident bridge were collected, and the bridge's 3D terrain information was reconstructed and compared to the measurement performance of 10 ground control points. The results showed horizontal and vertical root mean square error values of 0.032 m and 0.055 m, respectively. Additionally, when compared to a point cloud generated using ground LiDAR for the same target area, a vertical difference of approximately 0.08 m was observed, but overall shapes showed minimal discrepancies. Moreover, in terms of overall data acquisition and processing time, drone LiDAR was found to be more efficient than ground LiDAR. Therefore, the use of drone LiDAR in disaster sites with significant risks allows for safe and rapid onsite investigations.

• Journal of Advanced Navigation Technology
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• v.26 no.6
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• pp.434-440
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• 2022

The ICAO (International civil aviation organization)recommended the implementation of the GANP (global air navigation plan) for strategic decision-making and air traffic management evaluation. In this study, we proposed a new method for finding the route distance from KPI (key performance indicator) 05 actual route extension presented for air traffic management evaluation. For this purpose, we collected trajectory data for one month and calculated the en-route distances using the methods presented in ICAO and the methods presented by this author. In the ICAO method, the intersection point must be estimated through the equation of a circle for radius 40 NM and the equation of a straight line for an inner and outer point close to a circle in the track data, and four flight distances are calculated to calculate the en-route distance. In the method presented in this study, two flight distances are calculated without estimating the intersection point to calculate the en-route distance. To determine the error between the two methods, we used the performance evaluation index RMSE (root mean square error) and the determination factor R² of the regression model.

• Korean Journal of Environment and Ecology
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• v.25 no.1
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• pp.31-36
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• 2011

To provide the basic information about slope stability analysis, tensile force and strength of tree roots like Pinus koraiensis, Larix leptolepis, Pinus densiflora, Quercus mongolica, and Alnus japonica were measured and analyzed. As a result, tensile force increases in forms of involution of root diameter. The mean tensile strength of roots like P. koraiensis, L. leptolepis, P. densiflora, A. japonica and Q. mongolica were calculated as $165.38kgf/cm^2$, $172.78kgf/cm^2$, $176.25kgf/cm^2$, $214.29kgf/cm^2$ and $224.19kgf/cm^2$ respectively. It was shown that tensile strength decreasing tendency as root diameter increases. Also, recalculated soil shear strength by tensile strength of the roots like P. koraiensis, L. leptolepis, P. densiflora, A. japonica and Q. mongolica were $0.099kgf/cm^2$, $0.104kgf/cm^2$, $0.106kgf/cm^2$, $0.129kgf/cm^2$ and $0.135kgf/cm^2$ respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.1
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• pp.82-87
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• 2001

A feeding trial was conducted to evaluate the effects of replacing fish meal (FM) with ensiled shrimp by-product (ESB) in a cassava root meal and rice bran-based diet on the performance and carcass characteristics of growing pigs. Thirty six crossbred (Large White$\times$Mong Cai) pigs, with an average initial BW of 19.4 kg, were randomly allocated to one of three different dietary treatments in which the crude protein of the FM was replaced with 0, 50 or 100% ESB. The animals were fed restrictedly and at the end of the experiment at a BW of about 90 kg, 6 representative animals in each treatment group were slaughtered for carcass quality evaluation. Animal growth performance and daily feed intake were significantly reduced (p<0.05) by the inclusion of shrimp by-products in the diets, whereas feed conversion ratios and carcass measurements were not significantly affected (p>0.05). Daily weight gains of the pigs fed the 100% FM diet and 50% ESB diet were significantly (p<0.05) higher than those of pigs fed the 100% ESB diet. In conclusion, from an economical as well as performance point of view, ESB can replace 50% of the crude protein of FM in cassava root meal and rice bran-based diets for growing pigs with a low genetic growth potential.