• The Korean Journal of Pain
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• v.31 no.1
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• pp.27-38
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• 2018

Background: Related to escalating health care costs and the questionable effectiveness of multiple interventions including lumbar facet joint interventions, cost effectiveness or cost utility analysis has become the cornerstone of evidence-based medicine influencing coverage decisions. Methods: Cost utility of therapeutic lumbar facet joint nerve blocks in managing chronic low back pain was performed utilizing data from a randomized, double-blind, controlled trial with a 2-year follow-up, with direct payment data from 2016. Based on the data from surgical interventions, utilizing the lowest proportion of direct procedural costs of 60%, total cost utility per quality adjusted life year (QALY) was determined by multiplying the derived direct cost at 1.67. Results: Patients in this trial on average received $5.6{\pm}2.6$ procedures over a period of 2 years, with average relief over a period of 2 years of $82.8{\pm}29.6$ weeks with $19{\pm}18.77$ weeks of improvement per procedure. Procedural cost for one-year improvement in quality of life showed USD $2,654.08. Estimated total costs, including indirect costs and drugs with multiplication of direct costs at 1.67, showed a cost of USD $4,432 per QALY. Conclusions: The analysis of therapeutic lumbar facet joint nerve blocks in the treatment of chronic low back pain shows clinical effectiveness and cost utility at USD $2,654.08 for the direct costs of the procedures, and USD $4,432 for the estimated overall cost per one year of QALY, in chronic persistent low back pain non-responsive to conservative management.

• Steel and Composite Structures
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• v.36 no.4
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• pp.427-446
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• 2020

This paper carries out the progressive collapse analysis of stainless steel composite beam-to-column joint sub-models and moment-resisting frames under column removal scenarios. The static flexural response of composite joint sub-models with damaged columns was initially explored via finite element methods, which was validated by independent experimental results and discussed in terms of moment-rotation relationships, plastic hinge behaviour and catenary actions. Simplified finite element methods were then proposed and applied to the frame analysis which aimed to elaborate the progressive collapse response at the frame level. Nonlinear static and dynamic analysis were employed to evaluate the dynamic increase factor (DIF) for stainless steel composite frames. The results suggest that the catenary action effect plays an important role in preventing the damaged structure from dramatic collapse. The beam-to-column joints could be critical components that influence the capacity of composite frames and dominate the determination of dynamic increase factor. The current design guidance is non-conservative to provide proper DIF for stainless steel composite frames, and thus new DIF curves are expected to be proposed.

• Journal of Veterinary Clinics
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• v.21 no.4
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• pp.406-408
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• 2004

A nine-month-old male Jindo with non weight-bearing on the right forelimb in flexed position, pain and edema of the elbow, and resist elbow extension was brought to the Veterinary Teaching Hospital, Chungbuk National University. Elbow radiographs showed loss of humeroradial joint space and lateral displacement of the radius and ulna. Closed reduction was reported the best therapy in most cases of luxation of the elbow but conservative reduction was impossible. Open reduction of the luxated elbow was performed and ruptured collateral ligaments were identified. Displaced elbow was required bloody surgical operation and gentle reduction to restore elbow joint. Internal reduction of choice for elbow luxation with rupture of collateral ligament in the dog was a double locking-loop suture pattern. To ensure secure grasping of parallel bundles of ligament fibers to transverse bites of each suture were placed superficial to the longitudinal bites. All ligaments were repaired with 3-metric (size 2 USP) monofilament polypropylene suture. No complications have been noted during a five-month follow up.

• Steel and Composite Structures
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• v.2 no.6
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• pp.411-428
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• 2002

Non-linear large-displacement elasto-plastic finite element analyses are used to propose design recommendations for the eaves bracket of a cold-formed steel portal frame. Owing to the thinness of the sheet steel used for the brackets, such a structural design problem is not trivial as the brackets need to be designed against failure through buckling; without availability of the finite element method, expensive laboratory testing would therefore be required. In this paper, the finite element method is firstly used to predict the plastic moment capacity of the eaves bracket. Parametric studies are then used to propose design recommendations for the eaves bracket against two potential buckling modes of failure: (1) buckling of the stiffened free-edge into one-half sine wave, (2) local plate buckling of the exposed triangular bracket area.The results of full-scale laboratory tests on selected geometries of eaves bracket demonstrate that the proposed design recommendations are conservative. The use of the finite element method in this way exploits modern computational techniques for an otherwise difficult structural design problem.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.36 no.6
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• pp.259-265
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• 2014

Purpose: The purpose of this study is to evaluate the influence of intracapsular fracture lines of the mandibular condyle on the anatomical and functional recovery after non-surgical closed treatment. Methods: Clinical and radiological follow-up of 124 patients with intracapsular fractures of the mandibular condyle was performed after closed treatment between 2005 and 2012. The intracapsular fractures were classified into three categories: type A (medial condylar pole fracture), type B (lateral condylar pole fracture with loss of vertical height) and type M (multiple fragments or comminuted fracture). Results: By radiological finding, fracture types B and M lost up to 24% vertical height of the mandibular condyle compared to the height on the opposite side. In Type M, moderate to severe dysfunction was observed in 33% of the cases. Bilateral fractures were significantly associated with the risk of temporomandibular joint (TMJ) dysfunction in fracture types A and B. Bilateral fracture and TMJ dysfunction were not statistically significantly associated in type M fractures. Conclusion: Most of the mandibular intracapsular condylar fractures recovered acceptably after conservative non-surgical treatment with functional rehabilitation, even with some anatomical shortening of the condylar height. The poor functional recovery encountered in type M fractures, especially in cases with additional fracture sites and bilateral fractures, points up the limitation of closed treatment in such cases.

• Journal of Korean Neurosurgical Society
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• v.62 no.5
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• pp.567-576
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• 2019

Objective : Minimal data exist regarding non-operative management of suspected pseudarthrosis after pedicle subtraction osteotomy (PSO). This study reports radiographic and clinical outcomes of non-operative management for post-PSO pseudarthrosis at a minimum 5 years post-detection. Methods : Nineteen consecutive patients with implant breakage indicating probable pseudarthrosis after PSO surgery (13 women/six men; mean age at surgery, 58 years) without severe pain and disability were treated with non-operative management (mean follow-up, 5.8 years; range, 5-10 years). Non-operative management included medication, intermittent brace wearing and avoidance of excessive back strain. Radiographic and clinical outcomes analysis was performed. Results : Sagittal vertical axis (SVA), proximal junctional angle, thoracic kyphosis achieved by a PSO were maintained after detection of pseudarthrosis through ultimate follow-up. Lumbar lordosis and PSO angle decreased at final follow-up. There was no significant change in Oswestry Disability Index (ODI) scores and Scoliosis Research Society (SRS) total score, or subscales of pain, self-image, function, satisfaction and mental health between detection of pseudarthrosis and ultimate follow-up. SVA greater than 11 cm showed poorer ODI and SRS total score, as well as the pain, self-image, and function subscales (p<0.05). Conclusion : Non-operative management of implant failure of probable pseudarthrosis after PSO offers acceptable outcomes even at 5 years after detection of implant breakage, provided SVA is maintained. As SVA increased, outcome scores decreased in this patient population.

• Steel and Composite Structures
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• v.36 no.1
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• pp.75-86
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• 2020

The grid structures with welded hollow spherical joint (WHSJ) have gained increasing popularity for use in industrial buildings with suspended cranes, and usually welded with steel tube (ST). The fatigue performance of steel tube-welded hollow spherical joint (ST-WHSJ) is however not yet well characterized, and there is little research on fatigue life prediction methods of ST-WHSJ. In this study, based on previous fatigue tests, three series of specimen fatigue data with different design parameters and stress ratios were compared, and two fatigue failure modes were revealed: failure at the weld toe of the ST and the WHSJ respectively. Then, S-N curves of nominal stress were uniformed. Furthermore, a finite element model (FEM) was validated by static test, and was introduced to assess fatigue behavior with the hot spot stress method (HSSM) and the effective notch stress method (ENSM). Both methods could provide conservative predictions, and these two methods had similar results. However, ENSM, especially when using von Mises stress, had a better fit for the series with a non- positive stress ratio. After including the welding residual stress and mean stress, analyses with the local stress method (LSM) and the critical distance method (CDM, including point method and line method) were carried out. It could be seen that the point method of CDM led to more accurate predictions than LSM, and was recommended for series with positive stress ratios.

• Journal of the Korea Concrete Institute
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• v.25 no.6
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• pp.631-639
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• 2013

Non-linear finite element analysis for newly developed precast concrete details for beam-to-column connection which can be used in moderate seismic region was carried out in this study. Developed precast system is based on composite structure and which have steel tube in column and steel plate in beam. Improving cracking strength of joint under reversed cyclic loading, joint area was casted with ECC (Engineering Cementitious Composites). Since this newly developed precast system have complex sectional properties and newly developed material, new analysis method should be developed. Using embedded elements and models of non-linear finite element analysis program ABAQUS previously tested specimens were successfully analyzed. Analysis results show comparatively accurate and conservative prediction. Using finite element model, effect of axial load magnitude and flexural strength ratio were investigated. Developed connection have optimized performance under axial load of 10~20% of compressive strength of column. Plastic hinge was successfully developed with flexural strength ratio greater than 1.2.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.25 no.1
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• pp.71-76
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• 2019

Background: An 8-year-old girl had severe neck pain and stiffness after trauma. CT scan showed atlantoaxial rotatory subluxation (AARS). She had conservative treatment because she did not have neurological symptoms and spinal basilar artery dysfunction. Conservative therapy was halter traction twice for 4 weeks. However, pain and stiffness persisted. She had been recommended to have surgery from her physician, but she received manual therapy for non-surgical procedures. Methods: The joint mobilization, muscle energy technique, motor control exercise, and deep neck flexor (DNF) endurance exercise were applied as manual therapy and 10 session for 2weeks. Results: Clinical outcomes were measured at initial baseline, after 2 weeks, and after 6weeks. Active range of motion was completely restored after 6weeks and numeric pain rating scale was completely reduced after 2 weeks. The strength of neck flexor muscle recovered to normal after 2 weeks, and the DNF endurance was improved to 25 seconds after 2 weeks and to 42 seconds after 6weeks. Motor control capacity recovered to 30 ㎜Hg after 2 weeks. Conclusions: This case report describes the immediate and short-term clinical outcomes for a patient presenting with symptoms of neck pain following AARS. Clinical rationale and patient preference aided the decision to incorporate manual therapy as a treatment for this patient. Manual therapy has shown a successful recovery in AARS patients, more research is needed to validate the inference of this case report.

• Journal of the Earthquake Engineering Society of Korea
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• v.23 no.2
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• pp.101-108
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• 2019

The seismic safety of nuclear power plants has always been emphasized by the effects of accidents. In general, the seismic safety evaluation of nuclear power plants carries out a seismic probabilistic safety assessment. The current probabilistic safety assessment assumes that damage to the structure, system, and components (SSCs) occurs independently to each other or perfect dependently to each other. In case of earthquake events, the failure event occurs with the correlation due to the correlation between the seismic response of the SSCs and the seismic performance of the SSCs. In this study, the EEMS (External Event Mensuration System) code is developed which can perform the seismic probabilistic safety assessment considering correlation. The developed code is verified by comparing with the multiplier n, which is for calculating the joint probability of failure, which is proposed by Mankamo. It is analyzed the changes in seismic fragility curves and seismic risks with correlation. As a result, it was confirmed that the seismic fragility curves and seismic risk change according to the failure correlation coefficient. This means that it is important to select an appropriate failure correlation coefficient in order to perform a seismic probabilistic safety assessment. And also, it was confirmed that carrying out the seismic probabilistic safety assessment in consideration of the seismic correlation provides more realistic results, rather than providing conservative or non-conservative results comparing with that damage to the SSCs occurs independently.