• Journal of the Earthquake Engineering Society of Korea
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• v.25 no.5
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• pp.213-221
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• 2021

Many Korean domestic masonry structures constructed since 1970 have been found to be vulnerable to earthquakes because they lack efficient lateral force resistance. Many studies have shown that the brick and mortar suddenly experience brittle fracture and out-of-plane collapse when they reach the inelastic range. This study evaluated the seismic retrofitting of non-reinforced masonry with Hybrid Super Coating (HSC) and Cast, manufactured using glass fiber. Four types of specimen original specimen (BR-OR), one layered HSC (BR-HS-O), two-layered HSC (BR-HS-B), one layered HSC, and Cast (BR-CT-HS-O) were constructed and analyzed using compression, flexural tensile, diagonal compression, and triplet tests. The specimen responses were presented and discussed in load-displacement curves, maximum strength, and crack propagation. The compressive strength of the retrofit specimens slightly increased, while the flexural tensile strength of the retrofit specimens increased significantly. In addition, the HSC and Cast also produced a considerable increase in the ductile response of specimens before failure. Diagonal compression test results showed that HSC delayed brittle cracks between the mortar and bricks and resulted in larger displacement before failure than the original brick. The triplet test results confirmed that the bonding strength of the retrofit specimens also increased. The application of HSC and Cast was found to restrain the occurrence of brittle failure effectively and delayed the collapse of masonry wall structures.

• Journal of Korean Neurosurgical Society
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• v.61 no.1
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• pp.19-27
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• 2018

Objective : The objectives of this study were to evaluate the immediate and long-term efficacy and safety of coil embolization for large or giant aneurysms. Methods : One hundred and fifty large or giant aneurysm cases treated with endovascular coil embolization between January 2005 and February 2014 at a single institute were included in this study. Medical records and imaging findings were reviewed. Statistical analysis was performed to evaluate prognostic factors associated with major recurrence (major recanalization or rupture) and delayed thromboembolism after selective coil embolization. Results : Procedure-related symptomatic complications occurred in five (3.3%) patients. The mean clinical and radiological follow-up periods were 38 months (range, 2-110) and 26 months (range, 6-108), respectively. During the follow-up period, the estimated recurrence rate was 4.6% per year. Multivariate analysis using Cox regression showed the degree of occlusion to be the only factor associated with recurrence (p=0.008, hazard ratio 3.15, 95% confidence interval 1.34-7.41). The patient's history of rupture in addition to the size and location of the aneurysm were not associated with recurrence in this study. Delayed infarction occurred in eight cases, and all were incompletely occluded. Conclusion : Although immediate postprocedural safety profiles were reasonable, longterm results showed recanalization and thromboembolic events to occur continuously, especially in patients with incomplete occlusion. In addition, incomplete occlusion was associated with delayed thromboembolic complications. Patients with incomplete occlusions should be followed carefully for delayed recurrence or delayed thromboembolic events.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.2
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• pp.127-134
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• 2017

Delayed eruption disorders caused by systemic or local conditions are mostly found during childhood and can be treated with orthodontic forced eruption. When the disorder is not found nor treated during childhood, however, orthodontic eruption might become a difficult option while prosthodontic restoration can be considered as an another option. Considerations for the prosthodontic treatment plan include the extent of tooth loss, interdental mesio-distal space and interarch space, and age of the patient. In this case report, oral rehabilitation of the patient with delayed eruption disorder through zirconia partial fixed prostheses for both maxilla and mandible was performed.

• Journal of Trauma and Injury
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• v.25 no.4
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• pp.261-266
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• 2012

Purpose: Traumatic pancreatic injury is not common in abdominal trauma injury. However, the morbidity and the mortality rates of patients with pancreatic injury, which are related with difficulties of initial assessment, establishment of diagnosis, and treatment are relatively high. The aim of this study is to review our institution's experience and suggest a diagnosis and therapeutic algorithm for use in cases involving traumatic pancreatic injury. Methods: Eighteen(18) patients with blunt pancreatic injury from January, 2004 to October 2012 were included in this study. We analyzed treatment and diagnosis method, other organ injury, treatment interval, hospital stay and complications retrospectively. Results: Nine patients were treated with conservative medication and another nine patients were treated surgically. Complications occurred in nine patients, and one patient died due to intraventricular hemorrhage and subdural hemorrhage with multiple organ failure. Delayed surgery was performed in three cases. The early and delayed surgery groups showed difference in hospital stay and intensive care unit stay. Delayed surgery was associated with a longer hospital stay (p=0.007) than immediate surgery. Conclusion: In blunt pancreatic trauma, proper early diagnosis and prompt treatment are recommended necessity. Based on this review of our experience, we also suggest the adoption of our institution's algorithm for cases involving traumatic pancreatic injury.

• Journal of Chest Surgery
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• v.28 no.3
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• pp.308-312
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• 1995

A 5-year retrospective study of 14 patients with diaphragmatic injuries revealed 9 blunt and 5 penetrating injuries. In the blunt trauma group, 7 were left and 2 were right side. The penetrating diaphragmatic wound consist of 3 left and 2 right sided. Sex ratio was 11: 3, with male predominanace. Preoperative diagnosis was possible in 9 cases and delayed diagnosis [greater than 24 hours occured in 5 cases.Simple chest X-ray was diagnostic or highly suggestive in 7 cases. 7 cases were diagnosed diaphragmatic injuries by computed tomography, fiuroscopy or by explorative operation. All of the cases had association injury. 11 cases of diaphragmatic ruptures were corrected through thoracotomy and 3 cases needed exploratory laparotomy. One death occured after operation due to associated injuries and respiratory failure. Blunt and penetrating diaphragmatic injuries remain a diagnostic challenge and associated injuries, delayed diagnosis determine the outcome.

• Archives of Reconstructive Microsurgery
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• v.8 no.2
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• pp.115-119
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• 1999

In breast reconstruction with a free flap following mastectomy, the recipient vessels most widely used are in the axillary system, which limits flap movement and flexibility in breast shaping. In addition, scarring and fibrosis can make dissection of the vessels difficult. We have performed 43 breast reconstructions using a free transverse rectus abdominis myocutaneous(TRAM) flap. In 10 cases out of 20 delayed reconstruction, we anastomosed to the internal mammary vessels rather than subscapular system. There has been no flap failure. The surgical techniques, advantages and limitations of the internal mammary system are presented. The internal mammary vessel are compared with the axillary vessels as a recipient vascular system.

• Journal of Periodontal and Implant Science
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• v.44 no.1
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• pp.13-19
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• 2014

Purpose: The purpose of this study was to retrospectively evaluate the survival of periodontally hopeless teeth that were intentionally extracted and replanted after a delay and to compare the radiographic characteristics of the survival group with those of the failure group. Methods: The clinical and radiographic data from patients who underwent delayed intentional replantation between March 2000 and July 2010 were reviewed. Twenty-seven periodontally hopeless teeth were extracted and preserved in medium supplemented with antibiotics for 10-14 days. The teeth were then repositioned in the partially healed extraction socket and followed for 3 to 21 months. The radiographic parameters were analyzed using a paired t test and the cumulative survival rate was analyzed using Kaplan-Meier analysis. Results: Seven replanted teeth failed and the overall cumulative survival rate was 66.4%. In the survival group, the amount of bone loss was reduced from 68.45% to 34.66% three months after replantation. There was radiologic and clinical evidence of ankylosis with 5 teeth. However, no root resorption was found throughout the follow-up period. In the failure group, bone formation occurred from the bottom of the socket. However, a remarkable radiolucent line along the root of a replanted tooth existed. The line lengthened and thickened as time passed. Finally, in each case of failure, the tooth was extracted due to signs of inflammation and increased mobility. Conclusions: Delayed intentional replantation has many advantages compared to immediate intentional replantation and could serve as an alternative treatment for periodontally involved hopeless teeth. However, techniques for maintaining the vitality of periodontal structures on the tooth surface should be developed for improved and predictable results.

• Tunnel and Underground Space
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• v.24 no.1
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• pp.67-80
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• 2014

Long-term stability and delayed failure of granite were evaluated through the laboratory test based on Wilkins method and Brazilian disc test (BDT) which yields tensile strength, mode I fracture toughness and subcritical crack growth parameters. Then, the long-term strength of granite was estimated by using analytical models and long-term stability of compressed air-energy storage (CAES) pilot cavern pressurized up to 5 ~ 6 MPa was evaluated using numerical code, FRACOD with the determined subcritical crack growth parameters. The results of test and analyses showed that the subcritical crack growth index, n was determined as 29.39 and the inner pressure of 5 ~ 6 MPa had an insignificant effect on the long-term stability of pilot cavern. It was also found that the measurement and analysis of acoustic emission events can describe the accumulation of damage due to subcritical crack growth quantitatively. That is, AE monitoring can provide the current status of rock under loading if we make an identical installation condition in the field with that of the laboratory test.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.6
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• pp.63-73
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• 2014

In this study, the large scale test was performed to investigate the behavior of failure on the embankment and spillway transitional zone by overtopping. The pore water pressure, earth pressure, settlement and failure behaviors according to several reinforcing method were compared and analyzed. The pore water pressure showed a small change in the spillway transition zone and core, indicating that the riprap and geotextile efficiently reinforced the embankment, but non-reinforcement showed a largely change in pore water pressure. The earth pressure by riprap and geotextile at upstream slope and bottom core increased rapidly with the infiltration of the pore water by overtopping. And the earth pressure at crest showed a smally change due to effect of the inclined core. A settlement by riprap showed a small change and the geotextile decreased a rapidly due to failure of crest. The width of failure by riprap at intermediate stage (50 min) showed a largely due to sliding of crest. But, the width and depth of the seepage erosion after the intermediate overtopping period (100 min) were very small due to the effect of riprap than geotextile and non-reinforcement which delayed failure. It has the effect that protect reservoir embankment from erosion in the central part. The pore water pressure at the spillway transition zone due to overtopping increased a rapidly in the case of non-reinforcement, but the reinforced methods by geotextile and riprap showed a smally change. Therefore, the reinforced method by riprap and geotextile was a very effective method to protect permanently and the emergency an embankment due to overtopping, respectively.

• Journal of Chest Surgery
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• v.30 no.12
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• pp.1167-1174
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• 1997

We retrospectively reviewed a series of 20 patients treated with delayed sternal closure during a 5-year period from 1991 to 1996. Of the 2675 patients with cardiovascular su gery 20 underwent this procedure. Male and female ratio was 11:9, mean age was 6.4 months(range 7 days to 5 years). The indications included unstable hemodynamic profiles after open heart surgery due to myocardial edema and poor lung compliance(15), necessity of mechanical ventricular assist device due to weaning failure(3), and hypoxia after PAB(2). Sternum was closed at a mean interval of 102(range 4 to 213) hours after operation. During delayed sternal closure, central venous pressure was elevated(p<0.05). Mediastinitis and other wound problems did not occur. Sepsis developed in 2 patients and microorganism was confirmed in one of the two patients. Five patients died(mortality 25%). And two of 15 discharged patients died during follow-up period. Cumulative survival rate was 65.0% at 12 months and also 65.0% at 24 months.(Standard error was 10.7%) Delayed sternal closure Is considered to be a good method to decompress the hemodynamically compromised heart. Without that, it is not f asible to come off bypass or to decompress the heart. Of course. careful selection of the indication is imperative.