• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.199-203
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• 2003

Idler of excavator are large product with diameter 500 - 600 mm and parts of a power transmit device. The object of the paper is developed large products by hot closed-die forging. The forging process which is proposed from numerical analysis and various tests is developed a large products with good quality. To estimate the design process parameters such as working load, temperature and flash thickness so on, numerical analysis are used by DEFORM 2D. To obtain a flow stress data and optimal forging temperature is carried out hot compression and tensile test at a various temperature range. Developed product is tested mechanical properties of elongation, hardness and tensile strength so on. Test results are presented excellent mechanical properties.

• Journal of Chest Surgery
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• v.12 no.2
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• pp.127-134
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• 1979

During the 4 years period to be reported, 34 operations were performed on the mitral valve in the department of Thoracic and cardiovascular surgery, Korea University hospital, from Aug. 1975 to April 1979. At the first 1-year period, the closed technique was used in 12 patients. After that, open-heart surgery was used routinely; 8 patients had open mitral commissurotomy and 14 patients had valve replacement. There were 18 men and 16 women with sex ratio of 1.1: 1. The age of the patients varied widely from 18 years of the youngest to 46 years of the oldest-average aged of 32.5 years. All had symptoms and the mean duration of symptoms was 6 years and 1 month. Preoperative atrial fibrillation was 47% and embolizations were in 3 of 34 patients. The operative mortality was none for the closed and 14% for the open technique combined rate of 9 per cent which were valve thrombosis, brain embolism and left pulmonary vein rupture in deauriculization. But surviving patients undergoing open heart surgery enjoyed symptomatic benefits comparable to these of the patients of closed.

• Journal of Chest Surgery
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• v.11 no.4
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• pp.393-403
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• 1978

A total of 54 patients with mitral stenosis were treated in the Dept.of Thoracic and Cardiovascular Surgery. Chonnam National University Hospital, during the 17-year period from Jan., 1962 to June, 1978. There were 35 men and 19 women with sex ratio of 1.8 : 1. The age of the patient varied widely from 15 years of the youngest to 48 years of the oldest. Preoper ative functional levels according to N.Y.H.A. classification were class II in 19% of cases, class III in 69%, and class IV in 12%. 53 patients were underwent closed operations; 43 cases had closed digital mitral commissurotomy and 10 cases had closed dilator mitral commissurotomy, Hospital mortality was I case (1. 9%). Results of operations were good and excellent in 48cases(91%).Most of the survivors left hospital in a good and improved condition.

• Journal of Chest Surgery
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• v.24 no.4
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• pp.390-396
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• 1991

From July 1984 to September 1990, 316 patients of congenital heart diseases were operated and 15 patients died. Hospital mortality was 4.75%. Five patients of 73 PDA had residual shunt after operation: 4 were ligated under support of Dacron patch, 1 was closed through the pulmonary arteriotomy under CPB. 3 patients were reoperated. No patient had residual shunt or reopening among the patients of simple ligation or division and suture. During the ligation of PDA, Dacron patch for protection from tearing may disturb the complete interruption of shunt. If the tissue around the ductus arteriosus looks weak or fragile, division and suture may be more reliable other than ligation with supporting patch. If the septal leaflet of tricuspid valve is adherent around the VSD, remained opening of VSD may be closed with simple suture directly. In these cases, the incidence of postoperative residual shunt is as high as the incidence of more large VSD closed with patch [10.9%: 9.6%]. During the direct closure of remained opening of VSD, another leaking route should be looked for carefully beneath the septal leaflet of tricuspid valve.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.3
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• pp.383-390
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• 2001

It is a relatively common clinical experience to see a impacted maxillary central incisor Most often, the central incisor is impacted labially. The labial impaction has been indicated as the most difficult to manage. The labial impactions have been found to be associated with mucogingival recession, reduced attached gingiva and periodontal pockets. For the successful treatment, clinicians should avoid loss of attached gingiva in surgical exposure. The most common methods of uncovering labially impacted maxillary anterior teeth are gingivectomy, apically positioned flap and closed eruption technique. If gingivectomy will not leave enough attached gingiva, then an apically positioned flap may be the treatment of choice. If the tooth is impacted in the middle of the alveolus or high in the vestibule near the nasal spine, the closed eruption technique may be the treatment of choice. Closed eruption technique was used in one case, apically positioned flap was used in two case. As the result in two cases of impacted maxillary central incisor, apically positioned flap provide the adequate width of attached gingiva. In case of impacted maxillary central incisor, through the clinical and radiologic examination to select correct surgical operation for reduce the complications.

• Communications for Statistical Applications and Methods
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• v.10 no.3
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• pp.1017-1024
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• 2003

An estimation problem of treatment effect for bivariate censored survival data is considered under location shift model between two sample. The proposed estimator is very intuitive and can be obtained in a closed form. Asymptotic results of the proposed estimator are discussed and simulation studies are performed to show the strength of the proposed estimator.

• 전기의세계
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• v.27 no.3
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• pp.31-35
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• 1978

In this paper, in order to clarify the mature of traps in polymer, the thermally stimulated current (TSC) measurements were mad on high density polyethylene by changing the condition of the high-field treatment such as the strength of the field (Fe), the treatment time (te) and the heating rate (.betha.). In addition, the TSC measured from the HDPE was compared with that from LDPE having different crystallinity. The obtained results can suggest that the trapping proceeds during the high-field treatment and the trap associated with the peak P$_{2}$ may have the closed relation to drystallinity and the release of trapped charge is enhanced by the molecular motion.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.1
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• pp.70-76
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• 2001

Purpose : To evaluate the efficacy of arthrocentesis for treatment of closed lock. Material : 42 patients were diagnosed to closed lock by physical, radiographic examriation and undergone arthrocentesis. All patients have a pain and mouth opening limitation on affected site. Method : Arthrocentesis was done under conscious sedation and local infiltration anesthesia, normal saline and some steroid was injected on upper compartment of tempormandibular joint. After pumping and lavage, manual reduction procedure of anterially displaced disc was done. All the patients wear an anterior repositioning splint just after arthrocentesis. The result of arthrocentesis was assessed by pain and difference of mouth opening. Result : Difference of mouth opening after arthrocentesis was improved to 18.85mm and pain was gradually decreased. All patients were worn stabilization type splint after mean 1.84 months. 6 patients had relapse of mouth opening limitation so done arthrocentesis again and delivered good results.

• Archives of Craniofacial Surgery
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• v.9 no.1
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• pp.8-11
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• 2008

Purpose: The majority of nasal bone fractures have been managed by routine procedure of closed reduction, intranasal packing or intranasal Kirschner wire (K-wire) splinting. But it leaves rooms for many complaints from patients such as pain, rhinorrhea and nasal obstructioon. Another option is, of course, no packing at all. The study was initiated to assess the necessity to pack or splint the nasal bone after routine closed reduction. Methods: We analysed the medical records of 35 patients with nasal bone fracture who were operated by closed reduction in the last 2 years. We evaluated the postoperative CT scan scores and external deviation criterias 1 month after the operation. Results: The postoperative deviation criteria and postoperative CT scan score were favorable and there were no serious complications using this technique. Conclusion: The present study demonstrates that the use of packing or splinting need not be routine in the majority of cases. The risks and discomforts associated with these procedures can often be avoided.

• The Journal of Korean Physical Therapy
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• v.26 no.2
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• pp.68-73
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• 2014

Purpose: The purpose of this study was to investigate the effect of closed kinetic chain exercise using EMG-biofeedback for selective training of the vastus medialis oblique on functional ability and Q-angle in subjects with patellofemoral pain syndrome. Methods: Thirty participants who met the criteria were included in this study. Participants were randomly allocated to the control group (Group I, n=10), closed kinetic chain exercise group (Group II, n=10), and closed kinetic chain exercise using EMG-biofeedback group (Group III, n=10). Intervention was performed in three groups, three times per week, for a period of six weeks. Kujala patellofemoral score and Q-angle were measured before and after the experiment. Results: Some significant differences in kujala patellofemoral score were observed in group II and group III, compared with group I (p<0.01). There was no significant difference on in Q-angle at knee flexion angle $0^{\circ}$. However, some significant differences in Q-angle at knee flexion $60^{\circ}$ were observed in group III, compared with group I (p<0.01). Conclusion: Closed kinetic chain exercise using EMG-biofeedback that provides real-time biometric information on selected muscles in order to increase the efficiency of treatment may be helpful in improvement of functional ability and Q-angle in patellofemoral pain syndrome.