• Journal of Chest Surgery
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• v.23 no.5
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• pp.916-921
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• 1990

Clinical observations were performed on 17 cases of the traumatic sternal fracture, those were admitted and treated at the department of thoracic and cardiovascular surgery in Chosun University Hospital during the past 6 years 5months period from January 1983 to May 1989. Obtained results were as follows: 1. The frequency was about 4.8% of the nonpenetrating chest trauma. 2. The ratio of male to female was 16: 1 in male predominance and age distribution was from 24 to 62 years old. 3. The common cause were high decelerating injury [impact of the steering column] and falling down[more than 3 m in high]. 4. The most common fracture site was sternal body and next was sternomanubrial junction. 5. Associated intrathoracic organ injuries were cardiac contusion [6 cases], hemopneumothorax[1 Case], mediastinal bleeding[1 case], and thoracic cage and extrathoracic organ injuries were rib fracture, head injuries, thoracic spinal fracture, and long bone fracture. 6. Abnormal EGG findings were sinus bradycardia[1 case], bundle branch block [2 cases], and sinus tachycardia[3 cases]. 7. The operative reduction and fixation was necessary in only one case and the others were treated with conservative treatment.

• Tunnel and Underground Space
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• v.12 no.3
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• pp.198-209
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• 2002

To assess deep geological environment for the research and development of hish-level radioactive waste disposal, six boreholes of 3" in diameter were installed in two granitic areas. An areal extent of the rock block scale in the study sites was estimated by the lineament analysis from satellite images and shaded relief maps. The characterization of fracture system developed in rock block scale was carried out based on the acoustic televiewer logging in deep boreholes. In the Yuseong site, the granite rock mass was divided into the upper and lower zones at around -160m based on the probabilistic distribution characteristics of the geometric parameters such as orientation, fracture frequency, spacing and aperture size. Since the groundwater flow is dependent on the fracture system in a fractured rock mass, the correlation of the fracture frequency and cumulative aperture size to the hydraulic conductivity was also discussed.

• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.6
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• pp.160-169
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• 2001

To predict busting failure in tubular hydroforming, the criteria for ductile fracture proposed by Oyane is combined with the finite element method. From the histories of stress and strain in each element obtained from finite element analysis, the fracture initiation site is predicted by mean of the criterion. The prediction by the ductile fracture criterion is applied to three hydroforming processes such as a tee extrusion, an automobile rear axle housing and lower am. For these products, the ductile fracture integral I is not only affected by the process parameters, but also by preforming processes. All the simulation results show the combination of the finite element analysis and the ductile fracture criteria is useful in the prediction of farming limit in hydroforming processes.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.3
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• pp.94-101
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• 1996

This paper presents an investigation of the ability of the scheme to simultaneously accomplish both prediction of fracture initiation and analysis of deformation in cold forged products. The Cockcroft-Latham criterion which is successfully applied to a variety of loading situations is used in the present investigation to estimate if and where surface and internal fracture occur during the deformation process. The numerical predictions and experimental results of two types of fundamental cold metal forming process taken into account are compared. Finite element simulation combined with fracture criterion has successfully predicted the site of surface or internal fracture initiation and corresponding to level of deformation observed experimentally.

• Journal of radiological science and technology
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• v.9 no.1
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• pp.137-143
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• 1986

This study was undertaken to analyze the changes of radiographical image in avian (chicken) by using scanner and ${\gamma}-camera$ with $Tc^{99m}-MDP$. Experiment was aimed also to observe the changes of calcium, phosphorus and alkaline phosphatase activity in serum after experimental fracture. The results obtained are summerized as follows. 1. 10 chickens grown 6 weeks were scanned within 48 hours after experimental fracture, showed localized increase in uptake. The earlist increased local uptake was observed after 7 hours from experimental fracture at the fracture site. 2. Serum alkaline phosphatase level was increasing continuously during the fracture healing process in comparison with control group and serum alkaline phosphatase activity showed a peak after 2 weeks following the fracture. 3. The change of Ca. amount in serum trended to decrease from 1st day after fracture and it was in the lowest level at the 7 day's group following the fracture. 4. Serum phosphorus level trended to increase after fracture and it was in the highest level at the 7 day's group and showed similar level in comparison with control group.

• The Journal of Engineering Geology
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• v.29 no.1
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• pp.1-12
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• 2019

Earthquake can change underground stress condition around the hypocenter and affect the fracture systems of the rocks. In Korea, the M5.8 Gyeongju earthquake on September 12, 2016 and M5.4 Pohang earthquake on November 15, 2017 occurred inside the Yangsan fault zone and possibly affected the fracture systems in the Yangsan fault zone and nearby rock masses. In this study, the characteristics of the fracture system (fracture orientation, number of the fractures, fracture spacing and aperture, dip angle, fracture density along depth, and relative rock strength) of the rocks in the low/intermediate level radioactive waste repository site located in the coastal area of the East Sea are analyzed by the impact of the Gyeongju and Pohang earthquakes using acoustic televiewer data taken from the boreholes at the radioactive waste repository site in 2005 and 2018. As a result of acoustic televiewer logging analysis, the fracture numbers, fracture aperture, and fracture density along depth overall increased in 2018 comparing to those in 2005. This increase tendency may be due to changes in the fracture system due to the impact of the earthquakes, or due to weathering of the wall of the boreholes for a long period longer than 10 years after the installation of the boreholes in 2005. In the borehole KB-14, on the whole, the orientation of the fractures and the average fracture spacing are slightly different between 2005 and 2018, while dip angle and relative rock strength in 2005 and 2018 are similar each other.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.16 no.1
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• pp.89-98
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• 1994

This study was based on a series of 213 patients with facial bone fractures treated at college of Medicine, Dong-A university from Mar. 1990 to Jun. 1993. The results obtained were as follows : 1. The ratio of male to female was 8.3 : 1 and 3rd decade(34.3%) was the highest age group in incidence. 2. Monthly incidence was the highest in Jan. & Jun.(10.3%) 3. Onset time and daily incidence was the highest in pm. 9:00-12:00(21.4%), Sunday(18.8%). 4. Traffic acidents(38.5%) were the most frequent etiologic factor. 5. The most common site of fracture was zygoma & zygomatic arch(42.3%) and mandible (37.8%), maxilla (10.9%) and nasal bone(9.0%) were next in order of frequency. 6. In mandible fractures, the most frequent site was symphyseal area(43.0%) and IMF & open reduction was major method of treatment. 7. In zygoma & zygomatic arch fractures, zygoma(62.0%) was the most common fracture site and open reduction was the most frequent treatment method. 8. In maxilla fractures, the major fracture type was Le Fort I type (72.4%) and treatment was done by IMF & open reduction primarily. 9. postoperative complications were mal-union, fibrous-union, infection, osteomyelitis etc.

• The Journal of Korean Physical Therapy
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• v.18 no.2
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• pp.47-58
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• 2006

Purpose: The study to pulsed ultrasound effects of diabetes mellitus fracture model in rat. Methods: We used 36 Sprague-Dawely rats which were divided into 3 groups; the animals were divided into group of 4 rats each 4th, 14th and 28th days. All animal was induced diabetes mellitus model to used streptozotocin with 45 mg/kg. Pulsed wave were divided into $50\;mW/cm^2$ and $100\;mW/cm^2$. Results: T-ALP value was significantly change from group II, III on 14th, 28th days (p<0.05). Especially T-ALP value to between groups was significantly change from group II on 14th days (p<0.05). Osteocalcin value was significantly change from group II on 28th days(p<0.05). At fracture site, osteoblast, osteoclast expression was observed from 4th days after treatment and it reached its maximum intensity at 28th days. At fracture site, $TGF-{\beta}_1$ expression was observed from 4th days after treatment and it reached maximum intensity at 14th days. Conclusion: According to this study, diabetes mellitus fracture model to the more effective is divided into $50m\;W/cm^2$ pulsed ultrasound.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.2
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• pp.120-124
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• 2009

The concept of biostimulation of wounds by low-level laser therapy(LLLT) is attracting considerable attention. Although its effect on whole tissues has been studied quite extensively, the biological and cellular mechanisms underlying LLLT have not been clarified. In an experimental radius fracture in rabbits, Tang and Chai reported that LLLT enhanced the activity of red blood cells, macrophages, fibroblasts, chondrocytes, and osteoclasts within the fracture area. The purpose of the present study was to evaluate the effect of LLLT with a GaAlAs diode laser device on bone healing in rabbit mandibular fractures. We use 12 rabbits for this study. All rabbits were fractured mandible angle area using saw in anesthetic condition. In control group(n=6), none treatment was performed at fracture site. In experimental group(n=6), LLLT with a GaAlAs diode laser was radiated at fracture site daily for 7 days. All rabbits were sacrificed at 6 weeks later from performed fracture day. We studied the immunohistochemical staining of CD34 and Vimentin and the histochemical analysis for calcium and phosphorus content. The results were as follows. 1. In the histological and immunohistological staining, after 6week, fibroblasts, osteogenic cells and collgen fibers were observed more in experimental group than in control group. 2. In the histochemical analysis, the amount of calcium and phosphorus contents of the experimental group were more than the control group. From the results obtained, we suggest that the bone healing is stimulated by low-level laser irradiation in bone fractures.

• The Journal of Engineering Geology
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• v.20 no.4
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• pp.425-436
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• 2010

We established a stochastic 3-D fracture network system for fractured rock masses located in Il-Gwang Mine, Busan, to explore the relationship between the acidity of mine drainage and fracture geometry. A field scanline survey and borehole image processing were performed to estimate the best probability distributions of fracture geometry parameters. The stochastic 3-D fracture network system constructed for the rock masses was validated and deemed to be successful. The 3-D fracture network model was suitable for developing conceptual ideas on fluid flow in fractures at a field experimental site. An injection well and three observation wells were drilled at the field experimental site to monitor the acidity of mine drainage induced by the injection of fresh water. The field experiment, which was run for 29 days, yielded a significant relationship (with a high coefficient of determination) between the fracture geometry parameters and the acidity of mine drainage. The results show that pH increased with increasing relative frequency of fracture strike, and decreased with increasing fracture density. The concentration of $SO^{2-}_4$ decreased with increasing relative frequency of fracture strike, and increased with increasing fracture density.