• Journal of Korean Society for Quality Management
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• v.51 no.4
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• pp.633-642
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• 2023

Purpose: The variation of the internal diameters of gun barrel incurs a lot of reworks in gun barrel manufacturing process and the significant quality problem of gun barrel. And it is likely to stem from the current measurement system for the internal diameter of gun barrel and the related manufacturing process as well. The purpose of this study is to improve the gun barrel manufacturing process through improving measurement system. Methods: The improved measurement system using laser can measure the internal diameters of gun barrel more accurately, and the properly adjusted honing process reduces the variation of internal diameters of gun barrel. Results: Comparing the mean square error of internal diameters for 6 gun barrels measured before and after process improvement shows that the variation of gun barrel internal diameters was significantly reduced after the process improvement. Conclusion: The introduction of improved measurement system for the internal diameters of gun barrel and the adjustment of related honing process results in the reduction of reworks of gun barrels and their internal diameter variations.

• The Journal of Internal Korean Medicine
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• v.42 no.4
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• pp.455-474
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• 2021

The aim of this study was to perform a systematic review and meta-analysis of randomized controlled trials (RCTs) that applied herbal medicine to treat viral hepatitis B and C in order to determine the therapeutic efficacy of herbal medicine. EMBASE, Pubmed, NDSL, KMBASE, KISS, KISTI, Koreamed, Koreantk, and Oasis databases were searched to identify RCTs. The selected studies were assessed by the Cochrane group's risk of bias tool. A total of 15 RCTs were selected, and the hepatitis B virus (HBV) DNA reduction was significantly higher in patients treated with herbal medicine combined with Western medicine than in patients treated with herbal medicine. Herbal medicine combined with Western medicine was also superior to Western medicine alone in achieving hepatitis B e-antigen (HBeAg) and alanine aminotransferase [ALT] reduction. Only herbal medicine alone was not superior to Western medicine treatments in achieving HBV DNA, HBeAg, and ALT reduction.

• Journal of Powder Materials
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• v.25 no.5
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• pp.390-394
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• 2018

Metallic tantalum powder is manufactured by reducing tantalum oxide ($Ta_2O_5$) with magnesium gas at 1,073-1,223 K in a reactor under argon gas. The high thermodynamic stability of magnesium oxide makes the reduction reaction from tantalum oxide into tantalum powder possible. The microstructure after the reduction reaction has the form of a mixture of tantalum and magnesium oxide, and the latter could be entirely eliminated by dissolving in weak hydrochloric acid. The powder size in SEM microstructure for the tantalum powder increases after acid leaching in the range of 50-300 nm, and its internal crystallite sizes are observed to be 11.5 to 24.7 nm with increasing reduction temperatures. Moreover, the optimized reduction temperature is found to be 1,173 K as the minimum oxygen concentration is approximately 1.3 wt.%.

• Clinics in Shoulder and Elbow
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• v.11 no.2
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• pp.123-130
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• 2008

Os acromiale is the rare shoulder disease and its treatment is controversial. Despite conservative treatments for 6 months include medication, exercise, physical therapy and subacromial steroid injections, operative treatment for uncontrolled symptomatic Os acromiale is considered the treatment of choice. Operative treatment includes excision, arthroscopic or open reduction and internal fixation with a bone graft. Open reduction with tension band wiring and a bone graft is now the preferred treatment. We experienced 8 patients with symptomatic Os acromiale from March, 2001 to March, 2006. The average patient's age was 45 years and the man and women ratio were 2: 6. All 8 cases of symptomatic Os acromiale of the mesoacromion were treated with open reduction and internal fixation using tension-band wiring. The preoperative ASES($47.3\pm24.4$) and UCLA ($16.6\pm5.8$)scores were improved to $88.8\pm7.3$ and $31.5\pm1.9$, respectively, at the 2 year follow up. The overall UCLA score showed 1 excellent result and 7 good results. We think that symptomatic Os acromiale is a specific disease entity, and open reduction and internal fixation using tension-band wiring with K-wire is a good treatment modality.

• Journal of Korean Foot and Ankle Society
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• v.7 no.2
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• pp.238-249
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• 2003

Purpose: To report the clinical result of the intraarticular calcaneus fracture after open reduction and internal fixation with plate by lateral approach. Materials and Methods: Thirty-six calcaneal fractures of 33 patients(29 men and 4 women) were treated by open reduction and internal fixation using an lateral approach from March, 1997 to May, 2002 and were followed more than one year. The autogenous iliac bone graft was done in 2 cases but the others didn't. Radiographically B?hler angle and Gissane angle on simple lateral radiograph were measured and in the 15 cases, the step-off(gap) of posterior facet joint on post-operative CT images were followed. The Salama method was used for evaluation of clinical results. Results: According to Sanders classification, 19 cases of the 36 cases were classified as type II. Type III fracture were found in 12 cases and type IV in 5 cases. The following results were obtained: twenty-two cases(61.1%) out of 36 cases were estimated as good or excellent. The good results or more were obtained in 15 cases(78.9%) in type II and 7 cases(58.3%) in type ill, but no case in type IV. B?hler angles were improved from preoperative average 1.6?to postoperative average 23.4?, Gissane angle was improved from preoperative 107.2?to postoperative 122.8?, respectively. Among 36 cases, Computed tomography was carried out in 15 cases. The postoperative step-off (gap) of posterior facet joint on computed tomography was filled with cancellous bone. Satifactory results was obtained in 7 cases with 2mm gap or less and in 6 cases of 2-5mm. There were no satifactory results in 2 cases with 5mm gap or more. Conclusion: Open reduction and internal fixation for intra-articular fracture of calcaneus was thought to be a good treatment modality. It is thought that the lateral approach is one of the good one for surgical treatment, and that accurate reduction of the posterior facet, acceptable recovery of B?hler angle are more important to obtain best results.

• Archives of Craniofacial Surgery
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• v.12 no.2
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• pp.93-96
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• 2011

Purpose: In most cases of nasal bone fracture, closed reduction with internal or external splint fixation approach is selected. However, because of indiscriminate insertion of the internal splint without considering of anatomical difference or deformity, insufficient fixation happens frequently that need additional fixation. Therefore, we suggest a new method for providing adequate support in reduced nasal bone by carving $Merocel^{(R)}$ that is fixed for the anatomical structure. Method: Closed reduction and internal fixation with carved $Merocel^{(R)}$ was performed in 15 nasal bone fracture patients from March, 2010 to July, 2010. Each patient was evaluated by physical examination, facial photographic check, simple X-ray, and computerized tomography. On the first day post-operation, location of packing and amount of reduction were checked by follow up X-ray and computerized tomography. In addition, patients' symptoms were evaluated. During the 3-month post-op follow up at out-patient clinic, operator, 2 doctors in training and one assistant performed the objective evaluations by physical examination on nasal dorsal hump, nasal deviation, nasal depression, nasal breath difficulty, and nasal airway obstruction. A survey of subjective patients' satisfaction in 4-stages was also performed. Results: The results of follow-up computerized tomography of the 15 patients revealed that 11 patients had good reduced state. Three patients with combined maxillary frontal process fracture had over reductions. A survey performed on the first day post-operation showed that 14 of 15 patients answered that their current symptoms were more than tolerable. At the 3-month follow-up physical exam, one case had a dorsal hump. However, there were no nasal deviations, nasal depressions, nasal breath difficulties, or nasal airway obstructions. Twelve of the 15 patients answered more than moderate on the 3-month survey. Conclusion: Intranasal packing after carving the $Merocel^{(R)}$ considering anatomical structure is a new effective method to promote proper-reduction, maintain stability, and minimize patients' symptoms by addition of a simple procedure.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.5
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• pp.474-481
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• 2006

The endoscopic assisted approach for the treatment of condylar fracture is a less invasive alternative treatment modality and is considered to be able to overcome the limited access to the operation field to obtain an accurate reduction and fixation. Six patients with condylar neck and subcondylar fracture underwent the endoscopic assisted open reduction and internal fixation through the transoral approach at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital. The endoscope was inserted through an intraoral incision and the reduction of fracture fragment was performed via a transbuccal approach with two transcutaneous stab incisions. Five patients showed anatomic reduction without any complications. One patient, whose fracture site was fixed with a single plate, showed displacement of fractured condylar segment during the follow up period. No patient had any facial nerve damage.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.3
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• pp.300-304
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• 1991

This is case report of open reduction of condylar fractures with or without discal injury. Many articles described open reduction and internal fixation of condylar fractures emphasize the method of bony reduction and fixation without mention of the position of the disc. So we like to present our cases of open reduction of condylar fractures in conjunction with reconstruction of the disc and associated structures. The pupose of this presentation is to emphasize several well - established principles of trauma management and management of temporomandibular joint injuries, such as 1) in situations of traumatic injury, anatomic restoration is the goal of treatment and, 2) anatomic alignment of the TMJ disc over the condyle is preferable to disc subluxation because the latter may lead to chronic pain, limitation of opening and degenerative arthritis. Although our case is small with short term follow up, we believe that open reduction and internal fixation of condylar fractures in conjunction with disc repair is a biologically sound approach to those fractures indicated for open surgery. Long term follow up will allow better judge the validity of this treatment approach to us.

• Journal of Acupuncture Research
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• v.27 no.5
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• pp.35-42
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• 2010

Objectives : The purpose of this study was to analyze the changes of quality of life after reduction of muscluloskeletal pain treated with Korean traditional medicine. Methods : The authors observed reduction of musculoskeletal pain and recorded pain reduction by VAS. And we surveyed SF-36 twice, admission day and one month later and compared each other. Results : 1. Musculoskeletal pain with Korean traditional medical treatment decresed significantly. 2. As patients' musculoskeletal pain reduced, all parts of quality of life increased. Especially, the improvement of Bodily Pain(BP), Physical Function(PF), Vitality(VT), Mental Health(MH), General Health(GH) were statistically significant. Conclusions : Reduction of muscluloskeletal pain improved patient's physical, mental, emotional and social quality of life. But Social Function(SF) and Role Limitation(RP,RE) were less than others, so we need to develop complementary programs.

• The Journal of Internal Korean Medicine
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• v.28 no.4
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• pp.709-716
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• 2007

Objective : We present reference values of flow velocities of intracranial and extracranial cerebral arteries and relation with change factor. Method : We checked transcranial Doppler ultrasonography on mean velocity, systolic velocity, pulsatility index, and resistance index of 252 patients. We also compared differences of change factor. Result : The result showed a difference by sex and age and relevance between vessels besides mean velocity of vessels related with past history and social history. Conclusion : According to the above results, females showed higher velocity of all vessels. With advancing age, subjects showed reduction in velocity and increase in pulsatility index and resistance index. Anterior cerebral, middle cerebral, and posterior cerebral artery increased in proportion to velocity of internal carotid artery and basilar artery. Vessel velocity correlated with diabetes mellitus, hypertension and hyperlipidemia.