Documents published in Scipedia

• Efficient geometric framework for 3D images modeling

  M. Castilla, M. Ordóñez

  Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería (2017).

  
  

  Abstract

  The objective of this paper is exploring implementation of a realistic images reconstruction 3D using geometric algebra (GA). We illustrate the suitability of GA for representing structures and developing algorithms in computer graphics, especially for engineering applications as 3D images modeling. A first consequence is to propose an efficient framework model to be implemented in hardware programmable. The obtained results showed that using GA, the computations are less complex and shows as simple computations geometrical operations. The obtained model to hardware can be implemented as a next step in 3D image reconstruction. We also include the potential of GA for optimizations and highly efficient implementations.

  Abstract
  The objective of this paper is exploring implementation of a realistic images reconstruction 3D using geometric algebra (GA). We illustrate the suitability of GA for representing [...]

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• A shock-capturing method based on shape functions for high order discontinuous Galerkin

  E. Casoni, J. Peraire, A. Huerta

  Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería (2017).

  
  

  Abstract

  This article presents a high-order Discontinuous Galerkin method for compressible flow problems, in which is very frequent the formation of shocks. The stabilization is introduced by a new basis functions. This base has the flexibility to vary locally (within each element) between continuous polynomial functions space and a space of piecewise polynomial functions. Thus, the proposed method provides a bridge between the standard methods of high-order Discontinuous Galerkin and classical Finite Volume methods, maintaining the locality and compactness of the scheme. The variation of basis functions is automatically set according to the regularity of the solution and the stabilization is introduced by the jump operator, standard in Discontinuous Galerkin methods. Unlike the classical methods of slope limiting, the strategy here presented is very local, robust, and applies to any order of approximation. Moreover, the proposed method does not require adaptive mesh refinement techniques and it can be used with any temporal integration scheme. Several applications of the Euler equations are shown, demonstrating the validity and effectiveness of the method, especially for high orders of approximation.

  Abstract
  This article presents a high-order Discontinuous Galerkin method for compressible flow problems, in which is very frequent the formation of shocks. The stabilization is introduced [...]

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• Structural stability in elastoplastic 2D frames

  M. Cacho-Pérez, P. López-Reyes, A. Lorenzana, J. Terán

  Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería (2017).

  
  

  Abstract

  The evaluation of the maximum level of load that any 2D framed structure can undergo, before plastic collapse or buckling, is addressed in this paper. The analytical approach, based on a beam element with elastic behaviour except on its ends, uses an incremental approach to determine when changes appear due to plastic behaviour. When the combination of axial force and bending moment in any cross-section reaches the plastic function, that section is considered to yield suddenly and relative displacements can appear because of the yielding. The model includes the traditional plastic hinge, which only considers relative rotation due to the effect of the bending moment. The sequential loading and yielding reduces the stiffness and stability of the frame, which is computed and compared with the classic plastic methods of analysis.

  Abstract
  The evaluation of the maximum level of load that any 2D framed structure can undergo, before plastic collapse or buckling, is addressed in this paper. The analytical approach, [...]

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• An extension of Nelder-Mead method to nonlinear mixed-integer optimization problems

  E. Brea

  Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería (2017).

  
  

  Abstract

  This article presents a new algorithm based on the Nelder-Mead simplex algorithmic method for identifying a local optimum, at least on unconstrained nonlinear mixed-integer problems. The algorithmic method, Integer Mixed Simplex Algorithm (IMSA), so called by the author, is based on a double simplex structure, which is composed of a real n -dimensional simplex structure (real simplex) and an integer n -dimensional simplex structure (integer simplex). The original Nelder-Mead operations are applied on the real simplex. Meanwhile, a novel group of operations are applied on the integer simplex. This new set of operations, together with the original Nelder-Mead operations, guarantee a new trail point at each IMSA iteration in the search of the local optimum in the integer real mixed 2n -dimensional numerical field ℝn×ℤn without the need of integer to real conversions.

  Abstract
  This article presents a new algorithm based on the Nelder-Mead simplex algorithmic method for identifying a local optimum, at least on unconstrained nonlinear mixed-integer [...]

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• Iber — River modelling simulation tool

  E. Bladé, L. Cea, G. Corestein, E. Escolano, J. Puertas, E. Vázquez-Cendón, J. Dolz, A. Coll

  Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería (2017).

  
  

  Abstract

  The recent requirements of Spanish regulations and directives, on their turn based on European directives, have led to the development of a new two dimensional open channel flow modelling tool. The tool, named Iber, combines a hydrodynamic module, a turbulence module and a sediment transport module, and is based in the finite volume method to solve the involved equations. The simulation code has been integrated in a pre-process and post-process interface based on GiD software, developed by CIMNE. The result is a flow and sediment modelling system for rivers and estuaries that uses advanced numerical schemes, robust and stable, which are especially suitable for discontinuous flows taking place in torrential and hydrologically irregular rivers.

  Abstract
  The recent requirements of Spanish regulations and directives, on their turn based on European directives, have led to the development of a new two dimensional open channel [...]

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• Explicit time integration with large time steps for the heat flow equations

  P. Becker, N. Nigro, S. Idelsohn

  Revista Internacional de Métodos Numéricos para Cálculo y Diseño en Ingeniería (2017).

  
  

  Abstract

  We present a novel fully explicit time integration method that remains stable for large time steps, requires neither matrix inversions nor solving a system of equations and therefore allows for nearly effort-less parallelization. In this first paper the proposed approach is applied to solve conduction heat transfer problems, showing that it is stable for any time step as is the case with implicit methods but with a much lower computation time.

  Abstract
  We present a novel fully explicit time integration method that remains stable for large time steps, requires neither matrix inversions nor solving a system of equations and [...]

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• Effects of two different degrees of lateral-wedge insoles on unilateral lower extremity load-bearing line in patients with medial knee osteoarthritis

  B. Yılmaz, S. Kesikburun, O. Köroğlu, E. Yaşar, A. Göktepe, K. Yazıcıoğlu

  Collection of Acta Orthopaedica et Traumatologica Turcica (2017).

  
  

  Abstract

  The aim of this study is to assess the effect of 5 and 10° lateral-wedge insoles on unilateral lower extremity load carrying line in patients with medial knee osteoarthritis using the L.A.S.A.R. posture alignment system. Twenty subjects (10 females and 10 males, mean age 67.7 ± 5.4 years (range: 58–78) with bilateral medial knee osteoarthritis were included in the study. The laser line projected on the person by the L.A.S.A.R. posture alignment system showed joint load carrying line. The location of the joint load carrying line in static standing with one foot on the force plate was assessed with barefoot, and 5° and 10° lateral-wedge insoles. Displacement of the load carrying line was measured using a ruler placed tangentially to the patella at the level of joint line. The load carrying lines measured with 5° and 10° lateral-wedge insoles were significantly laterally located compared to that without wearing insole (p < 0.001). 10° lateral-wedge insole caused a significant more lateral shifting of the load carrying line than 5° lateral-wedge insole (p < 0.001). Both wedge insoles was effective in moving of the unilateral lower extremity load carrying line to the lateral. Lateral wedged insoles are biomechanically effective and reduce loading of the medial compartment in patients with medial knee osteoarthritis.

  Abstract
  The aim of this study is to assess the effect of 5 and 10° lateral-wedge insoles on unilateral lower extremity load carrying line in patients with medial knee osteoarthritis [...]

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• Cartilage repair strategies in the knee: A survey of Turkish surgeons

  N. Elmalı, R. Tandoğan, M. Demirel, M. Bozkurt, T. Beyzadeoglu

  Collection of Acta Orthopaedica et Traumatologica Turcica (2017).

  
  

  Abstract

  The purpose of this study was to analyze the trends in cartilage repair strategies among Turkish orthopedic surgeons for isolated focal (osteo)chondral lesions of the knee joint. A web-based survey of 21 questions consisting of surgical indications, techniques and time to return to sports was developed to investigate the preferences of members of the TOTBID and the TUSYAD. A total of 147 surgeons answered the questionnaire.70% of the respondents were TUSYAD members. 82% of respondents had at least five years experience in arthroscopy. Half of the surgeons indicated that patient age of 50 was the upper limit for cartilage repair. Irrespective of activity level, microfracture (60–67%) was the most frequently used technique for lesions smaller 2.5 cm2 . In lesions larger than 4 cm2, MACI was the most commonly advocated procedure (67%). In patients with high activity levels, mosaicplasty was the first choice (69%) for lesions between 2.5 and 4 cm2 in size, followed by MACI (27%). Patient age, activity level, BMI and lesion size were important determinants for the choice of treatment of isolated chondral lesions in the knee. These results reflect the choices of experienced knee surgeons in the country. Although not widely performed in Turkey and has limited reimbursement by the health care system, the first choice for defects over 4 cm2 was second generation ACI. Third party payers & health reimbursement authorities should take into account that large defects require methods which are relatively expensive and need high technology. Cross-sectional survey, Level II.

  Abstract
  The purpose of this study was to analyze the trends in cartilage repair strategies among Turkish orthopedic surgeons for isolated focal (osteo)chondral lesions of the knee [...]

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• Influence of patient training on persistence, compliance, and tolerability of different dosing frequency regimens of bisphosphonate therapy: An observational study in Turkish patients with postmenopausal osteoporosis

  Ü. Akarırmak, H. Koçyiğit, N. Eskiyurt, S. Esmaeilzadeh, Ö. Kuru, E. Yalçinkaya, Ö. Peker, A. Ekim, N. Özgirgin, M. Çalış, A. Rezvani, A. Çevikol, S. Eyigör, Ö. Şendur, J. İrdesel

  Collection of Acta Orthopaedica et Traumatologica Turcica (2017).

  
  

  Abstract

  In our study, we aimed to evaluate the influence of training on compliance and persistence with bisphosphonate treatment given on a weekly vs. monthly basis in postmenopausal osteoporosis patients. A total of 979 patients with postmenopausal osteoporosis (mean age: 63.2 ± 7.2 years) were included in this national, multicenter, prospective non-interventional observational cohort registry study. Patients were randomized into training (n = 492, 50.3%, mean age: 63.4 ± 7.2 years) and control (n = 487, 49.7%, mean age: 63.0 ± 7.1 years) groups. Patients in each intervention group were given weekly (44.9% and 44.6% for training and control subjects, respectively) or monthly (55.1% and 55.4%, respectively) bisphosphonate regimens. After the initial visit, patients were followed up at three-month intervals throughout 12 months of treatment for evaluation of persistence, compliance and adverse events. On average, 79.4% of the patients were persistent with the treatment with a mean of 350.4 days of duration during the 12-month follow-up period. The mean compliance in the compliant and fully compliant group remained at an average of 86.6%. No significant difference was detected between the training and control groups in terms of compliance and persistence. Significantly longer persistence (360.0 ± 89.0 vs. 345.0 ± 108.0 days, p = 0.035), higher percentage of persistent patients (83.4% vs. 74.2%, p = 0.012) and higher compliance rates (88.8% vs. 83.3%, p = 0.002) were noted in monthly regimen patients in comparison to those given weekly regimen. Our findings revealed remarkably high rates for persistence and compliance with bisphosphonate treatment in postmenopausal osteoporosis, with no impact of training on compliance and persistence rates. Longer persistence and better compliance rates were achieved with the monthly bisphosphonate regimen when compared to the weekly regimen.

  Abstract
  In our study, we aimed to evaluate the influence of training on compliance and persistence with bisphosphonate treatment given on a weekly vs. monthly basis in postmenopausal [...]

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• A giant clear cell sarcoma on right scapular: A case report

  X. Zhang, C. Hu, L. Cai

  Collection of Acta Orthopaedica et Traumatologica Turcica (2017).

  
  

  Abstract

  Clear-cell sarcoma is a rare and malignant soft tissue tumor most commonly located at the distal end of extremities and rarely at the trunk. Data on the clinical features of the tumor is limited, complicating the analysis of prognosis and establishment of treatment protocols. In our study, we present a case diagnosed with clear-cell sarcoma in his right scapula and treated with tumor resection and chemotherapy, combination of dacarbazine, pharmorubicin and cisplatin. The patient died due to multiple organ failure eight months after operation. Early diagnosis, attentive care, and extended surgical resection combined with adjuvant therapy is of essence in treatment of clear-cell sarcoma.

  Abstract
  Clear-cell sarcoma is a rare and malignant soft tissue tumor most commonly located at the distal end of extremities and rarely at the trunk. Data on the clinical features [...]

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