• Journal of Chest Surgery
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• v.11 no.3
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• pp.326-332
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• 1978

There appears some conduction defects frequently after total correction of Tetralogy of Fallot. Common defect is right bundle branch block due to surgical intervention. We experienced complete A-V block which occured 3 months later after total correction of Tetralogy of Fallot in a 8 year old boy. The patient was completely free of any A-V block after the operation for 3 months, and sudden onset of A-V block with coupled premature ventricular contractions resulted him in shock state during the attack of severe bronchopneumonia for 4 days prior to the second visit. Emergency implantation of Cordis demand type temporary pacemaker was necessary to control the complete heart block with bradyarrhythmia and frequent ventricular fibrillation. Permanent cardiac pacemaker was implanted two weeks later as indicated with Cordis Stanicor lambda demand pacemaker, and the patient was discharged uneventfully on the 8th post implantation day with the heart rate of 72/min. Another 3 months after the implantation, the patient was transported to this hospital as dead on arrival after an accidental fall from a 2 meter height, and all possible cardiopulmonary resuscitation was performed for 60 minutes at the emergency room in vain. Autopsy was done to find out the cause of sudden death and the etiology of complete heart block. Microscopic focal infarctions with scar formation were noted along the course of conduction system in the interventricular septum, which might be the main cause of complete heart block during the attack of severe bronchopneumonia complicated with acute bacterial endocarditis. The tip of the pacemaker wire was slipped from the granulation scar at the apex of the right ventricular cavity, and this might be the direct cause of pacing failure and death.

• Archives of Craniofacial Surgery
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• v.14 no.1
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• pp.16-23
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• 2013

Background: Even though degrees of deformation of microform cleft lip are not high, it has to be corrected with various procedures upon conditions and areas since it has various expressions. Many studies have focused on the classifications and procedures, but there are only a few studies on how much these procedures are performed in the actual field. This study aims to analyze the utilization of various procedures upon major correction points. Methods: A total of 52 patients who had been corrected by one surgeon from 1995 to 2011 were enrolled as subjects. Based on the medical records, it was checked whether the incision was made or not along with the correction procedures for alar base and philtral column, Cupid's bow, and vermillion free margin. Results: In case of an incision, full incision (42 times) was conducted most frequently. For alar base and philtral column, muscle re-approximation (25 times) was performed most frequently. However, recently, it was shown that excision on only the affected area and correction with dermis were more likely to be used. For Cupid's bow and vermilion free margin, elliptical excision on the only affected area followed by re-approximation was performed most frequently for 46 times (Cupid's bow) and 44 times (vermilion free margin), respectively. Conclusion: For the correction of microform cleft lip, less invasive procedures are preferred. However, in the actual field, if needed, aggressive procedures consisting of incisions have been conducted to correction. These trends are somewhat changed to utilization of a simple procedure, such as excision on the modified area, followed by a re-approximation rather than complicated procedures using the muscle.

• Asian Spine Journal
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• v.12 no.6
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• pp.1053-1059
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• 2018

Study Design: Retrospective review. Purpose: To detect the effect of cannulated (poly-axial head) and solid (mono-axial head) screws on the local kyphotic angle, vertebral body height, and superior and inferior angles between the screw and the rod in the surgical management of thoracolumbar fractures. Overview of Literature: Biomechanics studies showed that the ultimate load, yield strength, and cycles to failure were significantly lower with cannulated (poly-axial head) pedicle comparing to solid core (mono-axial head). Methods: The medical charts of patients with thoracolumbar fractures who underwent pedicle screw fixation with cannulated or solid pedicle screws were retrospectively reviewed; the subjects were followed up from January 2011 to December 2015. Results: Total 178 patients (average age, $36.1{\pm}12.4years$; men, 142 [84.3%]; women, 28 [15.7%]) with thoracolumbar fractures who underwent surgery and were followed up at Hamad Medical Corporation were classified, based on the screw type as those with cannulated screws and those with solid screws. The most commonly affected level was L1, followed by L2 and D12. Surgical correction of the local kyphotic angle was significantly different in the groups; however, there was no significant difference in the loss of correction of the local kyphotic angle of the groups. Surgical correction of the reduction in the vertebral body height showed statistical significance, while the average loss of correction in the reduction of the vertebral body height was not significantly different. The measurement of the angles made by the screws on the rods was not significantly different between the cannulated (poly-axial head) and solid (mono-axial head) screw groups. Conclusions: Solid screws were superior in terms of providing increased correction of the kyphotic angle and height of the fractured vertebra than the cannulated screws; however, no difference was noted between the screws in the maintenance of the superior and inferior angles of the screw with the rod.

• The korean journal of orthodontics
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• v.37 no.3 s.122
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• pp.231-240
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• 2007

Objective: The purpose of this study was to investigate the maxillary protraction effects of the Tandem Traction Bow Appliance (TTBA), a new appliance devised several years ago for the treatment of growing skeletal Class III patients. Methods: Participants were 88 Korean children (42 boys, 46 girls) with skeletal Class III malocclusion treated with TTBA at the orthodontic clinic of Ewha Womans University Mokdong Hospital. Mean age at the start of treatment was 7.5 years${\pm}$1.5 years. Mean treatment periods were $13{\pm}3$ months. Pretreatment and posttreatment lateral cephalograms were traced and superimposed by the same investigator and analyzed by modified McNamara analysis and pitchfork analysis. Changes were evaluated with paired t-tests at a significance level of p<0.05. Results: The maxilla and maxillary dentition moved forward. The mandible moved backward, although not significantly; and the mandibular dentition moved forward. The net dental changes combined with the apical base change resulted in a favorable total molar relationship correction. Net dental movement was 26% and the apical base change 74% of the total molar relationship correction. Conclusion: These results suggest that TTBA has a maxillary protraction effect that can be useful in the treatment of growing skeletal Class III malocclusion with maxillary deficiency.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.3
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• pp.175-183
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• 2012

Objectives: This study developed a harmonized method for risk assessment based on the Hazard & Risk Evaluation of Chemicals (HREC) according to the Industrial Safety and Health Act (ISHA). Methods: Three preliminary studies, performed during 2010 and 2011 by the Occupational Safety and Health Research Institute and three academic research groups, were compared. The differences in risk assessment, especially in the dose-response assessment method, were analyzed. A new harmonized method for dose-response assessment was suggested and its applicability for the HREC was examined. Results: Considering the various steps of each dose-response assessment, the equivalent steps in quantitative correction, uncertainty factor 2 (UF2) for intra-species uncertainty, and UF3 for the experimental period in the uncertainty correction were relatively high. Using our new method, the total correction values (quantitative correction plus uncertainty correction) ranged from 72~15,789 to 30~60, and the ratio of the threshold limit value (TLV) to the reference concentration decreased from 12.8~1900 to 5.4~11.8. Furthermore, when we performed risk characterization by our new method, hazard quotient (HQ) values for chloroethylene, epichlorohydrin, and barium sulfate became 3.0, 14.1, and 1.13 respectively, whereas three previous studies reported HQ values of 7.1, 4580, and 87.3 considering reasonable maximum exposure (RME) conditions. HQs of the three chemicals were calculated to be 0.6, 2.4, and 0.1 respectively, when compared to their TLVs. Conclusions: Our new method could be applicable for the HREC because the total correction values and the ratio of TLVs were within reasonable ranges. It is also recommended that additional risk management measures be applied for epichlorohydrin, for which the HQ values were greater than 1 when compared with both reference values and the TLV. Our proposed method could be used to harmonize dose-response assessment methods for the implementation of risk assessment based on the HREC according to ISHA.

• Journal of Korea Port Economic Association
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• v.39 no.2
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• pp.129-141
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• 2023

This study analyzes the dynamic characteristics of daily freight rates of dry bulk and tanker shipping markets and their forecasting accuracy by using the error correction models. In order to calculate the error terms from the co-integrated time series, this study uses the common stochastic trend model (CSTM model) and vector error correction model (VECM model). First, the error correction model using the error term from the CSTM model yields more appropriate results of adjustment speed coefficient than one using the error term from the VECM model. Furthermore, according to the adjusted determination coefficients (adjR²), the error correction model of CSTM-model error term shows more model fitness than that of VECM-model error term. Second, according to the criteria of mean absolute error (MAE) and mean absolute scaled error (MASE) which measure the forecasting accuracy, the results show that the error correction model with CSTM-model error term produces more accurate forecasts than that of VECM-model error term in the 12 cases among the total 15 cases. This study proposes the analysis and forecast tasks 1) using both of the CSTM-model and VECM-model error terms at the same time and 2) incorporating additional data of commodity and energy markets, and 3) differentiating the adjustment speed coefficients based the sign of the error term as the future research topics.

• Korean Journal of Remote Sensing
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• v.39 no.6_2
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• pp.1591-1604
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• 2023

In ocean color remote sensing, atmospheric correction is a vital process for ensuring the accuracy and reliability of ocean color products. Furthermore, in recent years, the remote sensing community has intensified its requirements for understanding errors in satellite data. Accordingly, research is currently addressing errors in remote sensing reflectance (R_rs) resulting from inaccuracies in meteorological variables (total ozone, pressure, wind field, and total precipitable water) used as auxiliary data for atmospheric correction. However, there has been no investigation into the error in R_rs caused by the variability of the water vapor profile, despite it being a recognized error source. In this study, we used the Second Simulation of a Satellite Signal Vector version 2.1 simulation to compute errors in water vapor transmittance arising from variations in the water vapor profile within the GOCI-II observation area. Subsequently, we conducted an analysis of the associated errors in ocean color products. The observed water vapor profile not only exhibited a complex shape but also showed significant variations near the surface, leading to differences of up to 0.007 compared to the US standard 62 water vapor profile used in the GOCI-II atmospheric correction. The resulting variation in water vapor transmittance led to a difference in aerosol reflectance estimation, consequently introducing errors in R_rs across all GOCI-II bands. However, the error of R_rs in the 412-555 nm due to the difference in the water vapor profile band was found to be below 2%, which is lower than the required accuracy. Also, similar errors were shown in other ocean color products such as chlorophyll-a concentration, colored dissolved organic matter, and total suspended matter concentration. The results of this study indicate that the variability in water vapor profiles has minimal impact on the accuracy of atmospheric correction and ocean color products. Therefore, improving the accuracy of the input data related to the water vapor column concentration is even more critical for enhancing the accuracy of ocean color products in terms of water vapor absorption correction.

• Journal of Korean society of Dental Hygiene
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• v.18 no.3
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• pp.269-280
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• 2018

Objectives: The purpose of this study was to investigate the change in the posture of dental hygiene students and clinical dental hygienists when implementing dental scaling before and after posture correction training using the rapid upper limb assessment (RULA) method and 3D motion analysis. Methods: Thirty-two healthy volunteers performed dental scaling to remove artificial calculus on dental manikin. The movement and angle of the joints were verified by RULA and 3D motion analysis during the procedure. The subjects were also photographed for 1 minute during the procedure for 10 minutes while the calculus was removed. After the removal of the calculus, the subject and the instructor checked the video together. Posture correction training was conducted by the instructor so that the subject could perform the calculus removal operation in the correct posture. Artificial calculus of the adjacent teeth was then removed for the same period of time, and the change in posture was reviewed. Results: The total score of the posture change using RULA was $5.72{\pm}0.58$ before training and $4.31{\pm}0.10$ after training, showing a significant decrease after training (p<0.001), and upper arm, lower arm, wrist position, neck and waist position showed significant decrease after training. The three-dimensional motion analysis showed significant differences according to the criteria measured at all measurement sites except the left shoulder (p<0.05) Conclusions: It was confirmed through RULA and 3D motion analysis that postural correction training using calculus removal images was effective, and that correct postural education is essential to preventing musculoskeletal diseases caused by removal of calculus.

• Journal of Adhesion and Interface
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• v.5 no.2
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• pp.14-26
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• 2004

For reliable determination of mechanical characteristics of adhesively bonded joints used e.g. as input data for computer-aided design of complex components, the thick-adherend tensile-shear test according to ISO 11003-2 is the most important material testing method. Although the total displacement of the joint is measured across the polymer layer directly in the overlap zone in order to minimize the influence of the stepped adherends, the substrate deformation must be taken into account within the framework of the evaluation of the shear modulus and the maximum shear strain, at least when high-strength adhesives are applied. In the standard ISO 11003-2 version of 1993, it was prescribed to perform the substrate deformation correction by means of testing a one-piece reference specimen. The authors, however, pointed to the excessive demands on the measuring accuracy of the extensometers connected with this technique in industrial practice and alternatively proposed a numerical deformation analysis of a dummy specimen. This idea of a mathematical correction was included in the revised ISO 11003-2 version of 2001 but in the simplified form of an analytical method based on Hooke's law of elasticity for small strains. In the present work, it is shown that both calculation techniques yield considerably discordant results. As experimental assessment would require high-precision distance determination (e.g. laser extensometer), finite element analyses of the deformation behavior of the bonded joint are performed in order to estimate the accuracy of the obtained substrate deformation corrections. These simulations reveal that the numerical correction technique based on the finite element deformation modeling of the reference specimen leads to considerably more realistic results.

• Journal of Chest Surgery
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• v.28 no.6
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• pp.565-570
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• 1995

Seventy-three patients with isolated total anomalous pulmonary venous connection the patients associated with other major cardiac anomalies such as single ventricle, DORV[Double Outlet Right Ventricle and large VSD[Ventricular Septal Defect were excluded were underwent surgical repair from January 1980 through October 1993. There were 45 boys and 28 girls. The mean age at operation was 19.9 months[range 6 days to 24 years and mean body weight was 7.1kg[range 2.6kg to 45kg . The anomalous locations of connection were supracardiac in 38, cardiac in 21, infracardiac in 5, and mixed in 9. In 38 patients[52% , the venous drainage was obstructed. The obstruction ratios according to the connection type were as follows: 53%[28/38 in supracardiac, 52%[11/21 in cardiac, 100%[5/5 in infracardiac, 22%[2/9 in mixed type. The associated cardiac anomalies were persistent left SVC[2 , tricuspid valve regurgitation[3 , cor triatriatum[1 , and mitral cleft[1 . And associated noncardiac anomalies were imperforate anus[1 and Neil Weightman syndrome[1 . The operative mortality was 23%. The causes of death were pulmonary hypertensive crisis, perioperative myocardial failure, pneumonia with sepsis, arrhythmia and etc. The statistically significant factors in postoperative mortality were the pulmonary venous obstruction and age [p<0.01 . The operative mortality was high in groups of age under 1 month and pulmonary venous obstruction. The mean follow-up was 27.1 months. There were two late deaths. The first patient was three months old boy with supracardiac type and severe obstructive symptoms. The postoperative echocardiography was showed anastomotic stenosis and reoperations were performed twice but the patients expired due to pneumonia and sepsis. The second patient was three month old boy with supracardiac type and total correction was done and was doing well postoperatively. Eight years later, he expired suddenly due to arrhythmia. But all the other patients were in NYHA Fc I and received no medications. The 5-year survival rate excluding early expired patients is 97.1 $\pm$ 0.03 %. In conclusion, although the operative mortality of total anomalous pulmonary venous connection was relatively high compared to other major cardiac anomalies, we could expect excellent long-term results by early surgical correction.