According to the failure characteristics of aircraft structure, a delay-time model is an effective method to optimize maintenance for aircraft structure. To imitate the practical situation as much as possible, imperfe...According to the failure characteristics of aircraft structure, a delay-time model is an effective method to optimize maintenance for aircraft structure. To imitate the practical situation as much as possible, imperfect inspections, thresholds and repeated intervals are concerned in delay-time models. Since the suggestion by the existing delay-time models that the inspections are implemented in an infinite time span lacks practical value, a de- lay-time model with imperfect inspection within a finite time span is proposed. In the model, the nonhomogenous Poisson process is adopted to obtain the renewal probabilities between two different successive inspections on de- fects or failures. An algorithm is applied based on the Nelder-Mead downhill simplex method to solve the model. Finally, a numerical example proves the validity and effectiveness of the model.展开更多
Total hip arthroplasty （THA） for an un- treated acetabular fracture is technically challenging and the long-term result is not so favorable. A 45-year-old fe- male patient with untreated column and comminuted poste-...Total hip arthroplasty （THA） for an un- treated acetabular fracture is technically challenging and the long-term result is not so favorable. A 45-year-old fe- male patient with untreated column and comminuted poste- rior wall fracture of the acetabulum was treated in our insti- tution by reconstruction of the posterior wall using iliac strut autograft and plate stabilization of the posterior col- umn with cancellous grafting and cementless THA in a single stage. At 3 years＇ follow-up, the patient was independently mobile without limb length discrepancy. Radiological evalu-ation showed well integrated components and bone grafts. No evidence of aseptic loosening or osteolysis was found. This report aims to emphasize that bony acetabular recon- struction allows the use of primary hip components, which improves prosthesis longevity and preserves bone stock for a future revision.展开更多
基金Supported by the National Natural Science Foundation of China(61079013)the Natural Science Fund Project in Jiangsu Province(BK2011737)~~
文摘According to the failure characteristics of aircraft structure, a delay-time model is an effective method to optimize maintenance for aircraft structure. To imitate the practical situation as much as possible, imperfect inspections, thresholds and repeated intervals are concerned in delay-time models. Since the suggestion by the existing delay-time models that the inspections are implemented in an infinite time span lacks practical value, a de- lay-time model with imperfect inspection within a finite time span is proposed. In the model, the nonhomogenous Poisson process is adopted to obtain the renewal probabilities between two different successive inspections on de- fects or failures. An algorithm is applied based on the Nelder-Mead downhill simplex method to solve the model. Finally, a numerical example proves the validity and effectiveness of the model.
文摘Total hip arthroplasty （THA） for an un- treated acetabular fracture is technically challenging and the long-term result is not so favorable. A 45-year-old fe- male patient with untreated column and comminuted poste- rior wall fracture of the acetabulum was treated in our insti- tution by reconstruction of the posterior wall using iliac strut autograft and plate stabilization of the posterior col- umn with cancellous grafting and cementless THA in a single stage. At 3 years＇ follow-up, the patient was independently mobile without limb length discrepancy. Radiological evalu-ation showed well integrated components and bone grafts. No evidence of aseptic loosening or osteolysis was found. This report aims to emphasize that bony acetabular recon- struction allows the use of primary hip components, which improves prosthesis longevity and preserves bone stock for a future revision.
