• Transactions of Materials Processing
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• v.21 no.1
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• pp.49-57
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• 2012

It is difficult to estimate the properties of multilayered sheet because they are composed of one or more different materials. Plastic deformation behavior of the multilayered sheet is quite different as compared to each material individually. The deformation behavior of multilayered sheet should be investigated in order to prevent forming defects and to predict the properties of the formed part. In this study, the mechanical properties and formability of stainless steel-aluminum-magnesium multilayered sheet were investigated. The multilayered sheet needs to be deformed at an elevated temperature because of its poor formability at room temperature. Uniaxial tensile tests were performed at various temperatures and strain rates. Fracture patterns changed mainly at a temperature of $200^{\circ}C$. Uniform and total elongation of multilayered sheet increased to values greater than those of each material when deformed at $250^{\circ}C$. The limiting drawing ratio (LDR) was obtained using a circular cup deep drawing test to measure the formability of the multilayered sheet. A maximum value for the LDR of about 2 was achieved at $250^{\circ}C$, which is the appropriate forming temperature for the Mg alloy. Fracture patterns on a circular cup and thickness of formed part were predicted by a rigid-viscoplastic FEM analysis. Two kinds of modeling techniques were used to simulate deep drawing process of multilayered sheet. A single-layer FE-model, which combines the three different layers into a macroscopic single layer, predicted well the thickness distribution of the drawn cup. In contrast, the location and the time of fracture were estimated better with a multi-layer FE model, which used different material properties for each of the three layers.

• Korean Journal of Otorhinolaryngology-Head and Neck Surgery
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• v.61 no.11
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• pp.588-592
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• 2018

Background and Objectives The incidence of facial bone fracture is increasing. The zygomatic bone, due to its anatomical prominence, is the second most common site of all facial bone fractures. In this study, we present the clinical experiences of zygomatic arch fracture in a tertiary hospital and introduce the Gillies approach for reduction and its outcome results. Subjects and Method We collected data from retrospective chart reviews of patients who underwent surgeries from 2010 to 2017 for zygomatic arch fractures at Chungbuk National University Hospital. Data were analyzed according to age, gender, cause of trauma, location of trauma, and clinical symptoms including trismus. All surgery was performed under general anesthesia and via the use of Gillies approach. The result of surgery was evaluated by postoperative facial computed tomography. Results Sixteen patients underwent surgery for zygomatic arch fracture. The patients had the average age of 41.3 years, a male predominance of 15:1 and physical assault as the most common cause of trauma. The time lag between injury and surgical reduction was 5.5 days. The surgical outcomes were assessed 'good' in 14 cases and 'moderate' in one case. Patients who had trismus preoperatively were resolved of it in all cases after operation. Postoperative complications were absent. Conclusion The Gillies approach proved to be a relatively easy, safe, and reliable method, and its surgical outcomes was satisfactory in our experiences.

• Journal of Trauma and Injury
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• v.29 no.4
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• pp.201-203
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• 2016

Rectal injury is seen in 1-2% of all pelvic fractures, and lower urinary tract injury occurs in up to 7%. These injuries are rare, but if missed, can lead to a severe septic response. Rectal injury may be suspected by the presence of gross blood on digital rectal examination. However, this classic sign is not always present on physical examination. If an Antero-Posterior Compression type pelvic fracture is seen, we should consider the possibility of rectal and lower urinary tract injury. It is important to define the anatomic location of the rectal injury as it relates to the peritoneal reflection. Trauma to the intraperitoneal rectum should be managed as a colonic injury. Extraperitoneal rectal injury should be managed with fecal diversion regardless of primary repair. We present the case of a 46-year-old man who was referred to our hospital following a major trauma to the pelvis in a pedestrian accident.

• Journal of Welding and Joining
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• v.14 no.5
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• pp.122-133
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• 1996

In order to evaluate the cryogenic fracture characteristics of structural steels for superconducting magnets of fusion reactor, small punch (SP) testing was performed on austenitic stainless steel (JN1 base metal) and its TIG weldments at 293K, 77K and 4K. The mechanical properties with respect to the extracted location of the weld metal, on the effects of welding heat cycle about base metal near fusion line in TIG weldments were investigated. The mechanical property of the weld metal in TIG weldments depends on distance from welding root, root region of weldments having the lowest mechanical property. The base metal near fusion line showed degradation of mechanical property caused by cyclic heating during the TIG welding. Based on the test results, HAZ was found to be up to 5mm from the fusion line. It is shown that SP testing is a useful tool to evaluate the mechanical properties with respect to the microstructures changes such as HAZ as well as weld metal in TIG weldments at cryogenic temperature.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.11 no.1
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• pp.12-20
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• 1989

This is a retrospective study on 452 patients with maxillofacial bone fracture. The patients were treated at the Dept. of Oral and Maxillofacial Surgery, WON KWANG UNIV. HOSPITAL from Aug. 1, 1984 to Sept. 30, 1988. The results were as follows. 1. The facial bone fractures occured most frequently in the twenties (35.3%)and male were predominant(75%) than female. 2. The most frequent etiologic factor was traffic accident. 3. The most common location of facial bone fracture was mandible(57%). Zygomatic bone & arch(39.9%) were most common on middle 1/3 of the face and symphysis(37.1%) were most common on the mandible. 4. The time from injury to treatment was variable from under the 1 week (65%) to over the 1 week(35%). In most case of the patients were treated beyond the 3 days(51.5%). 5. The relationship of intermaxillary fixation period and treatment method was an intimate relationship. The IMF period was reduced by the use of plate and screw osteosynthesis. 6. The weight loss was proportioned to intermaxillary fixation period.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.90-95
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• 2004

The probabilistic fracture analysis is used to determine the effects of uncertainties involved in material properties, location and size of flaws, etc, which can not be addressed using a deterministic approach. In this paper the probabilistic fracture analysis is applied for evaluating the RV(Reactor Vessel) under PTS(Pressurised Thermal Shock). A semi-elliptical axial crack is assumed in the inside surface of RV. The selected random parameters are initial crack depth, neutron fluence, chemical composition of material (copper, nickel and phosphorous) and $RT_{NDT}$. The deterministically calculated $K_I$ and crack tip temperature are used for the probabilistic calculation. Using Monte Carlo simulation, the crack initiation probability for fixed flaw and PNNL(Pacific Northwest National Laboratory) flaw distribution is calculated. As the results show initiation probability of fixed flaw is much higher than that of PNNL distribution, the postulated crack sizes of 1/10t in this paper and 1/4t of ASME are evaluated to be very conservative.

• The Korean Journal of Nuclear Medicine
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• v.17 no.2
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• pp.63-69
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• 1983

In order to establish criteria for distinguishing between occult fracture and metastases, we have reviewed 52 records of cancer patients and 24 of rib fracture patients referred for bone scanning. In 52 patients with biopsy-proven malignancy, multiple linear increased uptake of the ribs was found in 32 cases (61.5%), and was the most common finding. In 24 patients with rib fracture, all but 1 had fecal increased uptake of the ribs, and lesions almost always aligned in a row. By analyzing the appearance of rib lesions in total 76 patients, it was concluded that there is a high probability that rib lesions detected by bone scanning are bony metastases if 1) they are multiple linear as opposed to fecal, ad 2) they are not aligned in the same location.

• Journal of Korean Academy of Nursing Administration
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• v.13 no.2
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• pp.199-207
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• 2007

Purpose: Clinical characteristics and medical cost were analyzed according to the surgical procedures for intertrochanteric fracture in aged patients to assess the appropriateness of treatment expense and to find possibility of reducing the medical cost. Method: Variable for the statistical analysis were; the clinical characteristics, medical cost according to the surgical procedures, the treatment success rate, the total medical expense, and the average expense per case. SAS Package Version 8.02. was used to analyze the relevant data. Results: Operative procedures differ significantly according to the gender and by the location of institution. Only significant clinical variables according to the operative procedure were duration of general anesthesia and amount of blood transfusion. Average cost per treatment was the highest in the bipolar hemiarthroplasty followed by the gamma nail and hip compressing screw. Average cost for bipolar hemiarthroplasty was significantly higher than other surgical procedures. Conclusions: The difference in hospital costs for treatment of intertrochanteric fracture originates from the utilized surgical procedures, mostly by the materials used. The method of surgical treatment should be carefully determined by the purpose of the surgery, in order to improve the quality of medical care and also to reduce the hospital cost.

• Steel and Composite Structures
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• v.13 no.4
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• pp.383-396
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• 2012

In order to develop a verification method for extremely low cycle fatigue (ELCF) of steel structures, the initiation mechanism of ductile cracks is investigated in the present study, which is the first step of brittle fracture, occurred in steel bridge piers with thick-walled sections. For this purpose, a total of six steel columns with small width-thickness ratios were tested under cyclic loading. It is found that ductile cracks occurred at the column base in all the specimens regardless of cyclic loading histories subjected. Moreover, strain history near the crack initiation location is illustrated and an index of energy dissipation amount is proposed to evaluate deformation capacity of structures.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.837-843
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• 1998

This paper presents the thermomechanical and fracture mechanics evaluation procedure of thermal striping damage on the secondary piping of LMFR using Green's function method and standard FEM. The thermohydraulic loading conditions used in the present analysis are simplified sinusoidal thermal loads and the random type data thermal load. The thermomechainical fatigue damage was evaluated according to ASME code subsectionNH. The analysis results of fatigue for the sinusoidal and random load cases show that fatigue failure would occur at a geometrically discontinuous location during 90,000 hours of operation The fracture mechanics analysis showed that the crack would be initiated at an early stage of the operation. The fatigue crack was evaluated to propagate up to 5 ㎜ along the thickness direction during the first 944 and 1083 hours of operation for the sinusoidal and the random loading cases, respectively.