• Clinics in Shoulder and Elbow
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• v.2 no.2
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• pp.187-198
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• 1999

Purpose: The authors compared the results of Ender nailing for the proximal humerus fractures with those of the conservative methods radiographically. Materials and Method: Nine patients(mean age: 69 years.) received Ender nailing, and the other nine patients, conservative treatments(mean age: 73 years). All fractures were 2 part fractures. The Ender nails were inserted either through posterior elbow approach or transepicondylar approach. A simple Velpeau bandage was applied to the conservative treatment group. The average follow-up was 15 months. Results: The initial status of the anatomical reduction, i.e., the values of the medial shift, overlapping and the varus agulation, were little changed at follow-up radiographs in both the Ender nailing group and the conservative treatment group. There was no significant difference for the status of anatomical reduction between the Ender nailing group and the conservative treatment group. The stability of fixation by Ender nails, i.e., the degree of fanning out of the nails was poor in most cases. Not a few problems/complications happened in cases of Ender nailing group; back­ing out of the nail in three cases, penetration of the nails into the humeral heads in 3, fractures or cracking of the humerus around the nail insertion area in 4 and reduction loss in one. Conclusion: We could not get better results with the use of Ender nail. We use no longer Ender nails for the proximal humerus fractures. Further studies are needed for the better option for the proximal humerus fractures.

• Structural Engineering and Mechanics
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• v.73 no.3
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• pp.331-337
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• 2020

This paper proposes a new approximate analytical solution for highly nonlinear vibration of mechanical systems called Hamiltonian Approach (HA) that can be widely use for structural health monitoring systems. The complete procedure of the HA approach is studied, and the precise application of the presented approach is surveyed by two familiar nonlinear partial differential problems. The nonlinear frequency of the considered systems is obtained. The results of the HA are verified with the numerical solution using Runge-Kutta's [RK] algorithm. It is established the only one iteration of the HA leads us to the high accurateness of the solution.

• Smart Structures and Systems
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• v.15 no.5
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• pp.1311-1327
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• 2015

In this paper, we have applied a new class of approximate analytical methods called Variational Approach (VA) for high nonlinear vibration equations. Three examples have been introduced and discussed. The effects of important parameters on the response of the problems have been considered. Runge-Kutta's algorithm has been used to prepare numerical solutions. The results of variational approach are compared with energy balance method and numerical and exact solutions. It has been established that the method is an easy mathematical tool for solving conservative nonlinear problems. The method doesn't need small perturbation and with only one iteration achieve us to a high accurate solution.

• Earthquakes and Structures
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• v.7 no.1
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• pp.1-15
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• 2014

In this paper we consider three different cases and we apply Variational Approach (VA) to solve the non-natural vibrations and oscillations. The method variational approach does not demand small perturbation and with only one iteration can lead to high accurate solution of the problem. Some patterns are presented for these three different cease to show the accuracy and effectiveness of the method. The results are compared with numerical solution using Runge-kutta's algorithm and another approximate method using energy balance method. It has been established that the variational approach can be an effective mathematical tool for solving conservative nonlinear dynamical equations.

• Nuclear Engineering and Technology
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• v.56 no.1
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• pp.141-146
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• 2024

Station blackout (SBO) risk is one of the most significant contributors to nuclear power plant risk. In this paper, the sequence probability formulas derived by the convolution approach are compared with those derived by the conventional event tree/fault tree (ET/FT) approach for the SBO situation in which emergency diesel generators fail to start. The comparison identifies what makes the ET/FT approach more conservative and raises the issue regarding the mission time of a turbine-driven auxiliary feedwater pump (TDP), which suggests a possible modeling improvement in the ET/FT approach. Monte Carlo simulations with up-to-date component reliability data validate the convolution approach. The sequence probability of an alternative alternating current diesel generator (AAC DG) failing to start and the TDP failing to operate owing to battery depletion contributes most to the SBO risk. The probability overestimation of the scenario in which the AAC DG fails to run and the TDP fails to operate owing to battery depletion contributes most to the SBO risk overestimation determined by the ET/FT approach. The modification of the TDP mission time renders the sequence probabilities determined by the ET/FT approach more consistent with those determined by the convolution approach.

• Restorative Dentistry and Endodontics
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• v.36 no.6
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• pp.515-520
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• 2011

One of the most challenging task in closing anterior diastema is avoiding "black triangle" between the teeth. This paper reports a case that the closure of diastema in anterior teeth could be successfully accomplished using direct adhesive restorations and gingival recontouring. The traditional technique using Mylar strip was modified to increase the emergence profile with natural contours at the gingival-tooth interface. Mylar strip was extended out of the sulcus by approximately 1 mm high from the gingival margin, and a small cotton pellet was used to provide the emergence contour. This modified approach is acceptable for the clinical situation.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.13 no.2
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• pp.79-84
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• 2007

Purpose: The data was performed to evaluate the effect of conservative treatment in 30 patients aging from 21 to 71 with lumbar back pain. Methods: The effect of conservative treatment was analyzed with use of pain behavior scale, pain self assessment scale by Million Index in according to age, occupation, duration of symptom, symptom. Results: The occupation were desking job 43.4%, standing job 33.3%, house wife 23.3%. Duration of symptoms in over 2-5 months was 40.0%. The pain in below 1 months, classified by duration of symptoms, was reduced from 2.1 to 3.0 in pain behavior scale, 6.0 to 2.2 in pain self assessment scale(p<0.05). The pain in only lumbar back pain, classified by symptoms, was reduced from 2.0 to 3.0 in pain behavior scale, 6.6 to 2.4 in pain self assessment scale(p<0.05). Conclusion: The pain in over 9 months. classified by duration of physical therapy, was increase 2.0 in pain behavior scale, 4.0 in pain self assessment scale (p<0.05).

• Nuclear Engineering and Technology
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• v.36 no.1
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• pp.36-46
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• 2004

The ISAAC fission product release calculation is based on detailed FPRAT models developed by Jaycor. For volatile fission product release calculations, either the Cubicciotti steam oxidation correlation or the NUREG-0772 correlation is used. In this study, evaluation is carried out for these volatile fission product release models. As a result, in the case of early release, the IDCOR model with an in-vessel Te release option shows the most conservative results and for the late release case, the NUREG-0772 model shows the most conservative results. Considering both early and late release, the IDCOR model with an in-vessel Te bound option is evaluated to show mitigated conservative results. In addition, a sensitivity study on detailed core nodalization is performed. In the study, 380 horizontal fuel channels in the Wolsong plant are nodalized into 12 (6 channels per loop, $3{\times}3$ Core Pass) representative channels and detailed by 16/20/24 channels. For reference accidents, LOAH and large LOCA are selected as representing high and low pressure sequences, respectively. According to the results, the original 12 channel approach with $3{\times}3$ core passes is evaluated to be sufficient as an optimal scheme.

• Ocean Systems Engineering
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• v.12 no.3
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• pp.359-384
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• 2022

We develop in this work a new well-balanced preserving-positivity path-conservative central-upwind scheme for Saint-Venant-Exner (SVE) model. The SVE system (SVEs) under some considerations, is a nonconservative hyperbolic system of nonlinear partial differential equations. This model is widely used in coastal engineering to simulate the interaction of fluid flow with sediment beds. It is well known that SVEs requires a robust treatment of nonconservative terms. Some efficient numerical schemes have been proposed to overcome the difficulties related to these terms. However, the main drawbacks of these schemes are what follows: (i) Lack of robustness, (ii) Generation of non-physical diffusions, (iii) Presence of instabilities within numerical solutions. This collection of drawbacks weakens the efficiency of most numerical methods proposed in the literature. To overcome these drawbacks a reformulation of the central-upwind scheme for SVEs (CU-SVEs for short) in a path-conservative version is presented in this work. We first develop a finite-volume method of the first order and then extend it to the second order via the averaging essentially non oscillatory (AENO) framework. Our numerical approach is shown to be well-balanced positivity-preserving and shock-capturing. The resulting scheme could be seen as a predictor-corrector method. The accuracy and robustness of the proposed scheme are assessed through a carefully selected suite of tests.

• Nuclear Engineering and Technology
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• v.56 no.8
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• pp.3097-3111
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• 2024

Since the level 2 PSA of OPR-1000 was the requirement for regulatory purposes, Cs-137 release estimation was contained as the Nuclear Safety Act of ROK in which the Cs-137 release frequency exceeding 100 TBq was determined to happen less than 1.0E-6 per year after the Fukushima Daiichi Accident. However, Cs-137 release estimation from the conventional level 2 PSA of OPR-1000 provided uncertainty due to dominant accident sequence consideration. Thus, this study aimed to develop systematic methods through the overall framework to quantify realistic uncertainty concerns of radioactive material release using sensitivity and uncertainty analysis methods and apply them to OPR-1000. This framework helped to quantify confidential value for the Cs-137 release under the BEPU approach using both parametric and non-parametric methods to cover both realistic and conservative points. Uncertainty propagation analysis showed the unexpected uncertainty increase of Cs-137 release exceeding 100 TBq. The non-parametric uncertainty analysis provided higher conservative concerns for safety than the realistic concerns in terms of economics when compared with the parametric uncertainty analysis. Wilks' uncertainty analysis showed the importance to consider conservative Cs-137 release in order to reach the higher safety need. Sensitivity analysis showed reasonable relationships between engineering safety parameters with the Cs-137 release.