• Journal of Ocean Engineering and Technology
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• v.23 no.1
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• pp.89-95
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• 2009

The purpose of the present study was to evaluate the safety under extreme environmental conditions and the dynamic safety under service environment conditions, of oceanographic buoy mooring systems consisting of a variety of materials, including chain, wire rope, nylon rope, and polypropylene rope. For the static safety assessment of a mooring system, after the calculation of external forces and the division of a mooring system into finite elements, the numerical integral was conducted to yield the elemental static tension until satisfying the geometrical convergence condition. To evaluate the dynamic safety, various processes were considered, including data collection about the anticipated areas for mooring, a determination of the parameters for the interpretation, the interpretation of the dynamic characteristics based on an analytic equation that takes into account the heave motion effect of a buoy hull and a mooring system, and a fatigue analysis of the linear cumulative damage. Based on the analysis results, a supplementary proposal for a wire rope that has a fracture in an actual mooring area was established.

• Archives of Plastic Surgery
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• v.37 no.4
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• pp.504-508
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• 2010

Purpose: Traumatic telecanthus can result from nasoethmoid-orbital fractures. Repair of the medial canthal tendon (MCT) using transnasal wiring is regarded as a choice of method to treat telecanthus, however, is often complicated by incomplete anchoring and drift of canthus, extrusion of wire, in-fracture of orbital bone, and eye damage. The authors introduced oblique transnasal wiring method through the Hiraga's epicanthopalsty incision instead of well-known classical bicoronal approach. Methods: Five patients with traumatic telecanthus were treated with this method. Though the Hiraga's epicanthoplasty incision, we could approach the operative field; the medial orbital wall and detached MCT. Oblique transnasal wiring was performed as following steps. After slit skin incision on the contralateral nasal recession area, drill holes were made from this point to the superior and posterior point of lacrimal sac of deformed eye. A 2-0 wire was double-passed through the holes and MCT. Traction was applied to ensure pulling the MCT and the wires were twisted in the contralateral nose, securing the MCT in the correct position. Results: All patients except 1 person showed improvement and rapid recovery. On average each canthus was moved 5.6 mm medially. In all cases, there were no eyelashes disappear, lacrimal canaliculitis, lacrimal duct injury, or infections. Conclusion: The Hiraga's epicanthoplasty incision could give sufficient operative field to reattach the MCT in traumatic telecanthus patients. And the oblique transnasal wiring technique is effective for the Asians who have flat nose and exophthalmic eye. The authors conclude that this technique could be a simple, safe and scarless method to correct traumatic telecanthus.

• Journal of Chest Surgery
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• v.30 no.7
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• pp.713-718
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• 1997

Fracture of the sternum has been considered as a serious injury and also associated with major complications such as myocardial, major thoracic vascular, and spinal injury. Retrospective datas from blunt trauma victims admitted to our hospital were analyzed to determine significance of sternal fractures and possible associated injures. 101 sternal fractures by blunt trauma were admitted from january, 1986 to december, 1995. Frequency was about 3.51 olo of the nonpenetrating chest trauma. The ratio of male to female was 1.82 versus 1. Most common cause in the stemal fracture was high decelerating injury(73 cases). Most common fracture site was sternal body(75 cases). Average days of adm ssion were 26 days. Abnormal ECG findings were sinus bradycardia(Teases), complete or incomplete RBBB(6 cases), sinus tachycardia(4 cases), specific S-T change(3 cases), 1st degree A-V block(2 cases), LVH(1 case), PVC(1 case), and Low voltage(1 case). CPK-MB was increased about 32.Lolo of sternal fractures. Except of expired 2 patients, patients were treated with conservative treatment(94 cases) and open reductions & steel wire fixations(5 cases). Complication after operation was wound infection(1 case). Causes of death were 1 hypovolemia and 1 acute respiratory distress syndrome. In conclusion, although sternal fracture is less frequent, and mostly treats with conservative treatment, it shoed be carefully observed because of critical associated injuries.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.175-180
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• 2008

Traumatic injuries to the primary dentition are commonly encountered problems in dental practice. It is found that 30% of the children had injuries to the primary dentition and 22% to the permanent dentition. The greatest incidence of trauma to the primary dentition occurs at the ages of 2 and 3 as children start to learn motor coordination. Because teeth and alveolar bone are traumatized simultaneously, alveolar bone fractures are likely to occur when multiple teeth are involved in injuries. Dental splints are indicated for the management of maxillofacial fractures. They enable anatomic reduction of fractured segments and help immobilization and maintenance of the fragments after reduction. They also act as a stabilizer during rehabilitation. Various types of dental splints are available. In this case, routine resin-wire splint technique could not be applied because of the child's uncooperative behavior. Oral sedation was not indicated because N.P.O. had not been preceded. Therefore, we decided to use open-cap acrylic splint instead. Stabilization using open cap acrylic splint requires minimum chair time with reduced discomfort to both patient and dentist. It is an effective means of splint for uncooperative children and especially useful when other means of fixation have been failed. Because trauma on the primary dentition can affect the underlying permanent tooth germ, it is important to monitor eruption process of the permanent dentition.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.4
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• pp.440-450
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• 2003

Statement of problem : The joints of removable partial denture alloys have failed frequently after routine usage. Purpose : The purpose of this study was to evaluate the mechanical properties of the laser welded Co-Cr alloys. Material and method : For this study 20 Co-Cr specimens were casted and 10 of them were seperated on the middle area and laser welded with Alpha laser welding machine(Siro Lasertec, Pforzheim, Germany). Rest of them which were as cast, were used as a control group. For the section of the experimental specimens, wire cutting machine was used to make a even gap of the all specimens. Laser welding was done with manufacturer's instrunction and tested each specimen by Instron Machine. Tensile strength, 0.2% yield strength and % elongations were recorded. Fractured surfaces were investigated with SEM. Results : The results were as follows : 1. The tensile strength of the laser welded group(617.7MPa) was about 75% of the as cast group(820.4MPa). It had stastically significant differences(p<0.05). 2. The % elongation of the experimental group was 6.6 which was lower than the control group(14.3). 3. Fracture of the experimental group occured in the welded surface and showed many voids. In contrast, the fracture surface of the control group was showed rough surfaces without any voids. Conclusion : The tensile strengths of the as-cast joints were higher than those for the laser welded joints, and the % elongation of the experimental group was lower than the control group. Porosity was found in laser-welded joints.

• Journal of Trauma and Injury
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• v.34 no.2
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• pp.130-135
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• 2021

Celiac artery compression is a rare condition in which the celiac artery is compressed by the median arcuate ligament. Case reports of compression after trauma are hard to find. Blunt traumatic pericardium rupture is also a rare condition. We report a single patient who experienced both rare conditions from a single blunt injury. An 18-year-old woman was brought to the trauma center after a fatal motorcycle accident, in which she was a passenger. The driver was found dead. Her vital signs were stable, but she complained of mild abdominal pain, chest wall pain, and severe back pain. There were no definite neurologic deficits. Her initial computed tomography (CT) scan revealed multiple rib fractures, moderate lung contusions with hemothorax, moderate liver injury, and severe lumbar spine fracture and dislocation. She was brought to the angiography room to check for active bleeding in the liver, which was not apparent. However, the guide wire was not able to pass through the celiac trunk. A review of the initial CT revealed kinking of the celiac trunk, which was assumed to be due to altered anatomy of the median arcuate ligament caused by spine fractures. Immediate fixation of the vertebrae was performed. During recovery, her hemothorax remained loculated. Suspecting empyema, thoracotomy was performed at 3 weeks after admission, revealing organized hematoma without pus formation, as well as rupture of the pericardium, which was immediately sutured, and decortication was carried out. Five weeks after admission, she had recovered without complications and was discharged home.

• Structural Engineering and Mechanics
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• v.59 no.6
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• pp.1121-1137
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• 2016

A large number of structure in the world were build with poor seismic details, with or without any lateral load resisting system like concentrically braced frames and steel plate shear walls. These structures can reveal deteriorating hysteretic behaviors with stiffness and strength degradation. Therefore, seismic retrofitting of such structures for drift control has vital importance. In this study a retrofit methodology has been developed, which involves diagonal bracing of steel frames with different cable arrangements. In the experimental and numerical program 5 different lateral load resisting system were tested and results compared with each other. The results indicated that multi-cable arrangements suggested in this study showed stable ductile behavior without any sudden decrease in strength. Due to the usage of more than one diagonal cable, fracture of any cable did not significantly affect the overall strength and deformation capacity of the system. In cable braced systems damages concentrated in the boundary zones of the cables and beams. That is why boundary zone must have enough stiffness and strength to resist tension field action of cables.

• Journal of Chest Surgery
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• v.10 no.1
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• pp.38-43
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• 1977

With the adevance of widespread mechanization and high-speed era, the incidence of traumatic rupture of the tracheobronchial tree has been increased considerably. We have experienced these diseased of the 3 cases in our department. The first case was a 25 year old male who was severe dyspneic and subcutaneous emphysema, hemoptysis, and hemopneumothorax of both side were noted. During tracheostomy, it was found that the 2net ring of the trachea was ruptured. No definitive procedure was made on admission. Corrective surgery was performed with end-to-end anastomosis on 31 post-traumatic day. The second case was a 43 year old female who received multiple stab wounds on the anterior neck and it was found that the cricoid cartilage was transected partially. The injured cartilage was approximated with interrupted suture of No. 600 wire. The third case was a 19 year old male who had sustained a compression chest injury without external wound or rib fracture. At five days after trauma, he had suffered from dyspnea, and obstruction of the left main bronchus due to traumatic bronchial rupture was confirmed by means of bronchoscopy and bronchography at two weeks after the trauma. End-to-end anastomosis of the bronchus was performed and the left lung was aerated well. Mild postoperative stenosis of trachea was remained in the first case. Others were uneventful.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.57-60
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• 2005

The objective of this paper is to investigate and analyze the behaviour of prestressed I section structural members constructed with ultra high perfomance steel fiber reinforced cementitious concrete (SFR-UHPC). This material is known as reactive powder concrete (RPC) mixed with domestic materials and its compressive strength is over 150MP. The parameters of test specimens were span to depth ratio, prestressing force, prestressing wire placement and web width. Most influential parameter to determine the failure mode between shear and flexural action was proved to be shear span ratio. The characteristics of ultra high-strength concrete is basically brittle, but due to the steel fiber reinforcement behaviour of this structure member became ductile after the peak load. As a result of the test, the stress block of compressive zone should be redefined. The proposed analytical calculation of internal force capacity based by plastic analysis gave a good prediction for the shear and flexural strength of specimens. The numerical verification of the finite element model which constitutive law developed for Mode I fracture of fiber reinforced concrete correctly captured the overall behaviour of the specimens tested.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.969-972
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• 1997

Ultrasonic machining technology has been developed over recent years for he manufacture of cost-effective and quality-assured precision parts for several industrial application such as optics, semiconductors, aerospace, and automobile application. The past decade has seen a tremendous in the use of ceramic in structural application. The excellent thermal, chemical and wear resistance of these material can be realized because of recent improvement in the overall strength and uniformity of advanced ceramics. Ultrasonic machining, in which abrasive particles in slurry with water are presented to the work surface in the presence of an ultrasonic-vibrating tool, is process which should be of considerable interest, as its potential is not limited by he electrical or chemical characteristics of the work material, making it suitable for application to ceramics. In order to improve the currently used ultrasonic machining using ultrasonic energy, technical accumulation is needed steadily through development of exciting device of ultrasonic machine composed of piezoelectric vibrator and horn. This paper intends to further the understanding of the basic mechanism of ultrasonic machining for brittle material and ultrasonic machining of ceramics based in the fracture-mechanic concept has been analyzed.