• Korean Journal of Materials Research
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• v.11 no.12
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• pp.1020-1027
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• 2001

Powder type Ag system insert metals were manufactured by mechanical alloying method. Alloying method was the ball milling process using zirconia ball media, and all alloying variables were constant except the milling time. The milling times were selected 24, 48 and 72 hours. The insert metals made by milling method were observed using scanning electron microscope and x-ray analyses. And also, the evaluation of wettability and microstructures of the insert metals were conducted to investigate the characteristics of the brazed joint. The wettability of the insert metals made by milling of 48 hours, was the best condition. And the insert metals contained Cd shows good wettability, however, there was the oxides residue on the brazing test specimen. The microstructures of the manufactured and the commercial insert metals were almost same displaying the Cu- rich proeutectic and Ag-rich eutectic. Further, there were some porosities. The 48 hours alloyed insert metal was exhibited the most sound brazed joint without containing porosity due to the superior wettability and good alloying condition.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.4 s.247
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• pp.435-441
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• 2006

The anterior cruciate ligament(ACL) is an important stabilizer of knee joint. The ACL injury of knee is common and a serious ACL injury leads to ligament reconstruction surgery. Gait analysis is essential to identify knee condition of patients who display abnormal gait. The purpose of this study is to evaluate and classify knee condition of ACL deficient patients using a nonlinear dynamic method. The nonlinear method focuses on understanding how variations in the gait pattern change over time. The experiments were carried out for 17 subjects(l2 healthy subjects and five subjects with unilateral deficiency) walking on a motorized treadmill for 100 seconds. Three dimensional kinematics of the lower extremity were collected by using four cameras and KWON 3D motion analysis system. The largest Lyapunov exponent calculated from knee joint flexion-extension time series was used to quantify knee stability. The results revealed the difference between healthy subjects and patients. The deficient knee was significantly unstable compared with the contralateral knee. This study suggests an evaluation scheme of the severity of injury and the level of recovery. The proposed Lyapunov exponent can be used in rehabilitation and diagnosis of recoverable patients.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.6
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• pp.603-610
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• 2013

Finite element analysis is performed to evaluate stress and deformation of a wrinkle-type dust cover for the ball joints of tie rods of automotive steering system. Results of the analysis for assembly and operation condition show that sealing capability is good and the maximum stress on the body is smaller than the tensile strength. An optimal shape of the dust cover is obtained using the Taguchi method to reduce the maximum stress. The maximum stress of the optimal design under the operation condition is reduced by 22 per cent of that of the initial design. Results of the research show that performance evaluation and design of the dust covers can be effectively done using the proposed method.

• Clinics in Shoulder and Elbow
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• v.17 no.4
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• pp.190-193
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• 2014

Recurrent posterior shoulder instability is a debilitating condition that is relatively uncommon, but its diagnosis in young adults is increasing in frequency. Several predisposing factors for this condition have been identified, such as the presence of an abnormal joint surface orientation, an osteochondral fracture of the humeral head or glenoid cavity, and a postero-inferior capsuloligamentary deficit, but their relative importance remains poorly understood. Whilst, conservative treatment is effective in cases of hyperlaxity or in the absence of bone abnormality, failure of conservative treatment means that open or arthroscopic surgery is required. In general, soft-tissue reconstructions are carried out in cases of capsulolabral lesions in which bone anatomy is normal, whereas bone grafts have been required in cases where posterior bony Bankart lesions, glenoid defects, or posterior glenoid dysplasia are present. However, a consensus on the exact management of posterior shoulder instability is yet to be reached, and published studies are few with weak evidence. In our study, we report the reconstruction of the glenoid using iliac bone graft in a patient suffering recurrent posterior shoulder instability with severe glenoid bone defect.

• Archives of Plastic Surgery
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• v.37 no.5
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• pp.708-711
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• 2010

Purpose: The sheath of tendon is uncommon site of tuberculous involvement as compared to other parts of the body. Especially, tuberculous tenosynovitis affecting flexor tendon of the hand is a rare condition. In recent years, furthermore, the incidence of tuberculosis is increasing in our country. Tuberculous tenosynovitis is a chronic, slowly destructive disease, which is difficult to diagnosis before operation, but can be definitively diagnosed by the pathologic microscopic examination. Early detection and surgical excision combined with antituberculous medication is important. We report a rare case of tuberculous tenosynovitis of the flexor tendon of the hand. Method: A 12-year-old woman presented with a painless, nontender mass on palmar side between distal interphalangeal joint and proximal area of metacarpophalangeal joint of the left third finger. We had surgical excision of the involved flexor tendon sheath and studied histopathologically. Result: The histopathological findings were chronic granulomatous inflammation with caseating necrosis consistent with tuberculosis. We started antituberculous medication. Conclusion: Tuberculous tenosynovitis is a rare condition, especially involving on the flexor tendon of the hand. But because of increasing tendency of tuberculosis, it is important to differentiate it from other tumors of the hand.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.41
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• pp.11.1-11.6
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• 2019

Background: Botulinum toxin injection on the masticatory muscle induces the osteopenic condition on the ipsilateral condyle. Bisphosphonate suppresses bone resorption and is used to treat osteopenic or osteoporotic condition. This study aimed to evaluate the effect of bisphosphonate administration on prevention of condylar resorption and botulinum toxin A-induced disuse osteopenia in rats. Results: The volume of the condyle and bone volume/tissue volume (BV/TV, %) showed a strong tendency towards statistical significance (p = 0.052 and 0.058). Trabecular thickness (Tb.Th, mm) and trabecular number (Tb.N, 1/mm) were significantly smaller in the Botox group than in the other groups (p < 0.05). The volume of the condyle and BV/TV in the bisphosphonate 100 and bisphosphonate 200 groups showed similar values when compared with the control group. Conclusion: Bisphosphonate administration after botulinum toxin A injection in the masticatory muscles appears to prevent condyle resorption and botulinum toxin-induced disuse osteopenia in rats.

• Journal of Korean Medicine Rehabilitation
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• v.19 no.3
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• pp.135-146
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• 2009

Objectives : The purpose of this study is to report the effect of live leech(hirudo medicinalis) therapy with oriental medication on the patient with regional rheumatoid arthritis. The patient had resistant to DMARDs so she was in the debilitating condition and suffered from edema, pain, stiffness of joint and purpura before live leech(hirudo medicinalis) therapy. Methods : The regional rheumatoid arthritis patient had edema, pain, stiffness of joint and purpura on right foot. We treated the patient with live leech(hirudo medicinalis) therapy and oriental medicine. Results : The symptoms of regional rheumatoid arthritis was improved through live leech(hirudo medicinalis) therapy and oriental medicine. The patient maintains her condition with oriental medicine treatment after stopped all DMARDs such as MTX(methotrexate) and NSAIDs. After this treatment the patient's walking difficulty has been improved. Conclusions : This study shows that live leech(hirudo medicinalis) therapy and oriental medicine can elevate the regional rheumatoid arthritis patient's quality of life with continuous health care and treatment for major problem. For more accurate studies, further studies would be needed with more cases.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.11 no.1
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• pp.12-19
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• 2015

As a measure of improving the mechanical properties of a diffusion bonded joint of a ferritic/martensitic steel (FMS), the post-bonding heat treatment (PBHT) is applied. In the temperature range of normalizing condition ($950-1,050^{\circ}C$), diffusion bonding is employed with compressive stress (6 MPa). Due to the martensite structure distributed in the matrix, Vicker's hardness values of the as-bonded are much higher than those of the as-received. Through the PBHT for 1 h at $720^{\circ}C$, hardness values are recovered to as low as those of the as-received condition. Also, tensile properties of PBHT are similar to those of the as-received at up to the test temperature of $550^{\circ}C$, when the diffusion bonding is carried out over $1,000^{\circ}C$. Based on the creep-rupture testing performed at $650^{\circ}C$ in air environment, the joint efficiency of the PBHTed specimens is about 80% in, which is higher than that of the as-bonded specimens.

• Journal of Welding and Joining
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• v.30 no.5
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• pp.22-26
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• 2012

Butt-joints of A6061-T6 and AZ31 plates were successfully manufactured by using a friction stir welding method. Off-set free joints and off-set joints were fabricated to investigate the effect of the tool plunge position on the mechanical properties of the joints. Hardness test, tensile test and charpy impact test was performed to evaluate the mechanical properties of the joints. Off-set condition resulted in increase of mechanical properties of the joints. The variation of the hardness distribution in the SZ was also stabilized in the off-set condition. Tensile strength of the off-set joint was about 85% against to that of the AZ31 base metal. Impact absorption energy by Charpy-Impact-Test of the off-set joint also increased by almost 2 times against to that of the AZ31 base metal.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.1
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• pp.70-78
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• 2020

Under the situation which customer orders are cancelled unless all products in the order are delivered all at once, this paper concentrates on the purchase dependent demands and explores the systematic approach to implant the purchase dependence into the multi-product inventory model. First, by acknowledging that it is a challenging task to formulate a suitable inventory model for the purchase dependence, we derive the optimal solution condition using an EOQ model and extend the optimal solution condition to periodic review models. Then, through the comparison simulation of four inventory policies regarding several degrees of purchase dependence, we demonstrate that the inventory models which consider the purchase dependence generate less total cost than the inventory models which ignore the purchase dependence. In general, the inventory models which consider the purchase dependence reduce the loss of sales by maintaining more inventories, which results in reducing the total cost. Consequently, the simulation result supports the effectiveness of this paper's approach. In addition, this paper uses the individual order period and joint order period obtained from the EOQ model for the multi-product inventory model. Through the in-depth analysis of comparing the two models, we observe that the model of using the joint order period produces less total cost when the degree of purchase dependence is high, but the model of using the individual order period produces less total cost when the degree of purchase dependence is low.