218 research outputs found

    Refractured Well Selection for Multicriteria Group Decision Making by Integrating Fuzzy AHP with Fuzzy TOPSIS Based on Interval-Typed Fuzzy Numbers

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    Multicriteria group decision making (MCGDM) research has rapidly been developed and become a hot topic for solving complex decision problems. Because of incomplete or non-obtainable information, the refractured well-selection problem often exists in complex and vague conditions that the relative importance of the criteria and the impacts of the alternatives on these criteria are difficult to determine precisely. This paper presents a new model for MCGDM by integrating fuzzy analytic hierarchy process (AHP) with fuzzy TOPSIS based on interval-typed fuzzy numbers, to help group decision makers for well-selection during refracturing treatment. The fuzzy AHP is used to analyze the structure of the selection problem and to determine weights of the criteria with triangular fuzzy numbers, and fuzzy TOPSIS with interval-typed triangular fuzzy numbers is proposed to determine final ranking for all the alternatives. Furthermore, the algorithm allows finding the best alternatives. The feasibility of the proposed methodology is also demonstrated by the application of refractured well-selection problem and the method will provide a more effective decision-making tool for MCGDM problems

    On Intuitionistic Fuzzy Context-Free Languages

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    Taking intuitionistic fuzzy sets as the structures of truth values, we propose the notions of intuitionistic fuzzy context-free grammars (IFCFGs, for short) and pushdown automata with final states (IFPDAs). Then we investigate algebraic characterization of intuitionistic fuzzy recognizable languages including decomposition form and representation theorem. By introducing the generalized subset construction method, we show that IFPDAs are equivalent to their simple form, called intuitionistic fuzzy simple pushdown automata (IF-SPDAs), and then prove that intuitionistic fuzzy recognizable step functions are the same as those accepted by IFPDAs. It follows that intuitionistic fuzzy pushdown automata with empty stack and IFPDAs are equivalent by classical automata theory. Additionally, we introduce the concepts of Chomsky normal form grammar (IFCNF) and Greibach normal form grammar (IFGNF) based on intuitionistic fuzzy sets. The results of our study indicate that intuitionistic fuzzy context-free languages generated by IFCFGs are equivalent to those generated by IFGNFs and IFCNFs, respectively, and they are also equivalent to intuitionistic fuzzy recognizable step functions. Then some operations on the family of intuitionistic fuzzy context-free languages are discussed. Finally, pumping lemma for intuitionistic fuzzy context-free languages is investigated

    SubpathwayMiner: a software package for flexible identification of pathways

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    With the development of high-throughput experimental techniques such as microarray, mass spectrometry and large-scale mutagenesis, there is an increasing need to automatically annotate gene sets and identify the involved pathways. Although many pathway analysis tools are developed, new tools are still needed to meet the requirements for flexible or advanced analysis purpose. Here, we developed an R-based software package (SubpathwayMiner) for flexible pathway identification. SubpathwayMiner facilitates subpathway identification of metabolic pathways by using pathway structure information. Additionally, SubpathwayMiner also provides more flexibility in annotating gene sets and identifying the involved pathways (entire pathways and sub-pathways): (i) SubpathwayMiner is able to provide the most up to- date pathway analysis results for users; (ii) SubpathwayMiner supports multiple species (~100 eukaryotes, 714 bacteria and 52 Archaea) and different gene identifiers (Entrez Gene IDs, NCBI-gi IDs, UniProt IDs, PDB IDs, etc.) in the KEGG GENE database; (iii) the system is quite efficient in cooperating with other R-based tools in biology. SubpathwayMiner is freely available at http://cran.r-project.org/web/packages/SubpathwayMiner/

    Role of the ortho-bridge system in the length unstable subtrochanteric femur fracture in school going children: a retrospective clinical study of 19 cases

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    BackgroundTreating subtrochanteric femur fractures in pediatric patients remains challenging, and an optimal fixation device has yet to be established. This study aimed to asess the clinical and radiological outcomes of Ortho-Bridge System (OBS) treatment for length-unstable subtrochanteric femur fractures in children aged 5–16 years.MethodsWe conducted a retrospective review of pediatric patients with subtrochanteric femur fractures treated with OBS between January 2018 and December 2021. The study included 19 children (12 boys, 7 girls) with an average age of 10.4 ± 2.6 years. Two of the patients had pathological fractures associated with aneurysmal bone cyst. Demographic information, mechanism of accident, fracture type, associated neurovascular injuries, surgical duration and blood loss, were collected from the hospital database. Time to union and postoperative complications were recorded. Clinical and radiological outcomes were assessed using the Harris scoring system at the latest follow-up.ResultsInjuries resulted from vehicle accidents in 10 patients (52.6%), falls over 3 meters in height in 3 patients (15.8%), and sports-related injuries in 6 patients (31.6%). The average patient weight was 41.5 kg (range: 21–78). Of the fractures, 14 (73.7%) were complex, and 5 (26.3%) were spiral. The average surgical duration was 111 min (range: 90–180), and the average surgical blood loss was 134 ml (range: 70–300). The mean time to union was 12.7 weeks (range: 8–16). No cases of infection, malunion, implant failure, or femoral head osteonecrosis were reported. Leg length discrepancy of 10 mm was observed in one patient. All patients achieved excellent results according to the Harris scoring system.ConclusionThis study suggests that the OBS may serve as an effective alternative fixation option for managing length-unstable subtrochanteric femur fractures in school-aged children

    A Simple Brain Storm Optimization Algorithm with a Periodic Quantum Learning Strategy

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    Brain storm optimization (BSO) is a young and promising population-based swarm intelligence algorithm inspired by the human process of brainstorming. The BSO algorithm has been successfully applied to both science and engineering issues. However, thus far, most BSO algorithms are prone to fall into local optima when solving complicated optimization problems. In addition, these algorithms adopt complicated clustering strategies such as K-means clustering, resulting in large computational burdens. The paper proposes a simple BSO algorithm with a periodic quantum learning strategy (SBSO-PQLS), which includes three new strategies developed to improve the defects described above. First, we develop a simple individual clustering (SIC) strategy that sorts individuals according to their fitness values and then allocates all individuals into different clusters. This reduces computational burdens and resists premature convergence. Second, we present a simple individual updating (SIU) strategy by simplifying the individual combinations and improving the step size function to enrich the diversity of newly generated individuals and reduces redundancy in the pattern for generating individuals. Third, a quantum-behaved individual updating with periodic learning (QBIU-PL) strategy is developed by introducing a quantum-behaved mechanism into SBSO-PQLS. QBIU-PL provides new momentum, enabling individuals to escape local optima. With the support of these three strategies, SBSO-PQLS effectively improves its global search capability and computational burdens. SBSO-PQLS is compared with seven other BSO variants, Particle Swarm Optimization (PSO), and Differential Evolution (DE) on CEC2013 benchmark functions. The results show that SBSO-PQLS achieves a better global search performance than do the other nine algorithms

    A Surface Mass-Spring Model with New Flexion Springs and Collision Detection Algorithms Based on Volume Structure for Real-time Soft-tissue Deformation Interaction

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    A critical problem associated with surgical simulation is balancing deformation accuracy with real-time performance. Although the canonical surface mass-spring model (MSM) can provide an excellent real-time performance, it fails to provide effective shape restoration behavior when generating large deformations. This significantly influences its deformation accuracy. To address this problem, this paper proposes a modified surface MSM. In the proposed MSM, a new flexion spring is first developed to oppose bending based on the included angle between the initial position vector and the deformational position vector, improving the shape restoration performance and enhance the deformational accuracy of MSM; then, a new type of surface triangular topological unit is developed for enhancing the computational efficiency and better adapting to the different topological soft tissue deformational models. In addition, to further improve the accuracy of deformational interactions between the soft tissue and surgical instruments, we also propose two new collision detection algorithms. One is the discrete collision detection with the volumetric structure (DCDVS), applying a volumetric structure to extend the effective range of collision detection; the other is the hybrid collision detection with the volumetric structure (HCDVS), introducing the interpolation techniques of the continuous collision detection to DCDVS. Experimental results show that the proposed MSM with DCDVS or HCDVS can achieve accurate and stable shape restoration and show the real-time interactive capability in the virtual artery vessel and heart compared with the canonical surface MSM and new volume MSM

    A Brain Storm Optimization with Multiinformation Interactions for Global Optimization Problems

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    The original BSO fails to consider some potential information interactions in its individual update pattern, causing the premature convergence for complex problems. To address this problem, we propose a BSO algorithm with multi-information interactions (MIIBSO). First, a multi-information interaction (MII) strategy is developed, thoroughly considering various information interactions among individuals. Specially, this strategy contains three new MII patterns. The first two patterns aim to reinforce information interaction capability between individuals. The third pattern provides interactions between the corresponding dimensions of different individuals. The collaboration of the above three patterns is established by an individual stagnation feedback (ISF) mechanism, contributing to preserve the diversity of the population and enhance the global search capability for MIIBSO. Second, a random grouping (RG) strategy is introduced to replace both the K-means algorithm and cluster center disruption of the original BSO algorithm, further enhancing the information interaction capability and reducing the computational cost of MIIBSO. Finally, a dynamic difference step-size (DDS), which can offer individual feedback information and improve search range, is designed to achieve an effective balance between global and local search capability for MIIBSO. By combining the MII strategy, RG, and DDS, MIIBSO achieves the effective improvement in the global search ability, convergence speed, and computational cost. MIIBSO is compared with 11 BSO algorithms and five other algorithms on the CEC2013 test suit. The results confirm that MIIBSO obtains the best global search capability and convergence speed amongst the 17 algorithms

    Research on the ablation characteristics of combined lasers for glass fiber reinforced plastic composites

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    Glass fiber reinforced plastic (GFRP) composites have been applied to the manufacture of missile shields and unmanned aerial vehicle (UAV) shells. It is of great significance to explore the ablation characteristics of different lasers for these composites. Currently, most existing studies on the ablation characteristics of lasers for Glass fiber reinforced plastic composites are conducted under a single laser output mode, such as continuous wave (CW) laser or pulsed laser. However, the ablation characteristics of combined lasers for Glass fiber reinforced plastic composites have not been clarified. Therefore, the ablation characteristics of single lasers (continuous wave, millisecond (ms) pulsed, or nanosecond (ns) pulsed laser) and combined laser (CW/ms or CW/ns combined pulsed lasers) were investigated by experimental and simulation methods in this study. Additionally, the ablation mechanisms of Glass fiber reinforced plastic under different laser irradiation conditions were compared and analyzed. The results demonstrated that the ablation rates of single lasers for Glass fiber reinforced plastic composites were all within an order of magnitude of 10 μg/J, which was not significantly correlated with the light source system. The ablation efficiency of the single laser was determined by the incident laser energy. The continuous wave laser was found to be the optimal light source for the ablation and destruction of Glass fiber reinforced plastic composites. Nevertheless, there were some obstacles in the ablation process of continuous wave lasers. Applying pulsed lasers during the irradiation of the continuous wave laser may generate a synergistic effect. Under the conditions in this study, the CW/ns pulsed combined laser increased the ablation efficiency by 53.8%

    Effect of Ultrasonic Treatment on Vitis vinifera L. Cell Wall Pectin Components

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    In order to clarify the content and structural changes of different pectin fractions in grape cell walls under ultrasonic treatment, the grapes were treated with different ultrasonic time and ultrasonic power in this study, and the content of pectin fractions, composition of monosaccharides and structural changes of grape cell walls were analyzed by means of carbazole sulfuric acid method, PMP pre-column derivatization, high-performance liquid gel chromatography , scanning electron microscopy, Fourier transform infrared spectroscopy and circular dichroism. Results showed that the highest and the lowest contents in fresh grape cell walls were alkali-soluble pectin (NSP) and chelate pectin (CSP), respectively, and they were 27.41 mg/g AIR and 8.25 mg/g AIR. The total pectin decreased after ultrasonic treatments, in which the water-soluble pectin (WSP) increased and the CSP and NSP decreased. A total of six monosaccharides were detected in three pectins, and the monosaccharides of different pectin were not the same. The galactose and arabinose were high in WSP, the glucuronic acid was the most abundant of CSP and the rhamnose were the highest in NSP. After ultrasonic treatment, the contents of monosaccharides decreased, while the composition did not change, and the main chain structure of pectin was no change, but the linear structure and the degree of branch chain were changed. With the increase of ultrasonic times and powers, the molecular weight of different pectins declined gradually. And in the microstructure showed a more loose morphology. In addition, ultrasonic treatment had an effect on the structure and chain conformation of CSP and NSP, which made their maximum response values shift, and the effect of ultrasonic power was more significant. In conclusion, ultrasonic treatment could reduce the pectin and monosaccharide contents in grape cell walls, and affect the molecular linear structure and molecular chain conformation of pectin. These results can provide theoretical basis for the quality change of grape products under ultrasonic treatment
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