A Method Based on Intuitionistic Fuzzy Dependent Aggregation Operators for Supplier Selection

Recently, resolving the decision making problem of evaluation and ranking the potential suppliers have become as a key strategic factor for business firms. In this paper, two new intuitionistic fuzzy aggregation operators are developed: dependent intuitionistic fuzzy ordered weighed averaging (DIFOWA) operator and dependent intuitionistic fuzzy hybrid weighed aggregation (DIFHWA) operator. Some of their main properties are studied. A method based on the DIFHWA operator for intuitionistic fuzzy multiple attribute decision making is presented. Finally, an illustrative example concerning supplier selection is given

Entropy Optimization of Scale-Free Networks Robustness to Random Failures

Many networks are characterized by highly heterogeneous distributions of links, which are called scale-free networks and the degree distributions follow $p(k)\sim ck^{-\alpha}$. We study the robustness of scale-free networks to random failures from the character of their heterogeneity. Entropy of the degree distribution can be an average measure of a network's heterogeneity. Optimization of scale-free network robustness to random failures with average connectivity constant is equivalent to maximize the entropy of the degree distribution. By examining the relationship of entropy of the degree distribution, scaling exponent and the minimal connectivity, we get the optimal design of scale-free network to random failures. We conclude that entropy of the degree distribution is an effective measure of network's resilience to random failures.Comment: 9 pages, 5 figures, accepted by Physica

Development of an FEM-DEM Model to Investigate Preliminary Compaction of Asphalt Pavements

Variations in pavement density have been widely monitored and investigated, both in laboratory and in field experiments, since the compaction of pavement is so critical to its long-term performance quality. In contrast to field testing, laboratory tests are simpler to produce but less accurate. Destructive drilled samples are used to conduct field testing; however, they are limited in their ability to assess density information at specific areas. The use of computationally aided approaches, such as the Finite Element Method (FEM) and the Discrete Element Method (DEM), in research involving asphalt mixtures is increasing, since these methods simulate and evaluate the characteristics of asphalt mixtures at macroscopic and microscopic scales. Individual particle behavior at the microscopic level cannot be fully represented using the FEM alone, and the computing cost of utilizing the DEM approach alone is prohibitively high. The objective of this work is to simulate the pre-compaction process by using the coupled FEM-DEM approach. In order to investigate the impact of the asphalt mixtures’ gradation, a dense-graded asphalt mixture (AC 11) and a gap graded asphalt mixture (PA 11) were simulated. Different paving speeds (4, 5, and 6 m/min) were applied on the preliminary compaction model of AC 11 to study the effect of the paving speeds on the compaction process. By comparing the angular velocity, which worked as a reference of compaction quality, it was demonstrated that the grade AC 11 asphalt mixtures performed better in the preliminary compaction process compared to the grade PA 11 asphalt mixtures. Moreover, since it has an effect on compaction, paving speed was carefully monitored and kept within a reasonable range in order to maximize both pavement quality and project efficiency

The protoliths to the sillimanite gneisses from the Larsemann Hills and geological implication in their formation

The source rock from which the sillimanite gneisses derive mainly was the biotite plagioclase gneiss in the Larsemann Hills. It is the deformation-metamorphism process under special pressure and temperature condition, not the original rock compositions, that controls the presence of sillimanite. To a great degree, the sillimanite gneiss was the mixture of the detaining materials of the migrating felsic melt from the bt-plagioclase gneiss that underwent partial melting and the relics when the melt was removed. In sillimanitization the original rock had been changed substantially in chemical composition. The related metamorphism process severely deviated from the isochemical series, the process was of, therefore, an open system. In addition, the Al2O3 contents of the original rock was an important, but not critical factor for the formation of sillimanite, i. e. , the sillimanite-bearing rock need not be of aluminum rich in composition, and vise contrarily, the aluminum rock may not produce sillimanite. The authors of the present paper postulate that the source rock from which the aluminum rich rock derives need not be of aluminum rich, but sillimanitization is generally the Al2O3 increasing process. The aluminum rich sediments such as clay or shale need not correspond directly to sillimanite-rich gneisses. No argillaceous rock present equals to sillimanite-rich gneiss in chemical composition. The protoliths to the sillimanite gneisses from the Larsemann Hills, east Antarctica, and their adjacent area may be pelite, shale greywacke, sub-greywacke, quartz sandstone and quartz-tourmalinite. If correct, the conclusion will be of significant implication for the determination of the sillimanite gneiss formation process and the reconstruction of the protolith setting

Numerical Simulation of Asphalt Compaction and Asphalt Performance

Asphalt pavement compaction is important, and it can determine the service quality as well as durability of pavement. In recent years, numerical methods have been extensively used to simulate and study the construction process of asphalt pavement and mechanical properties of asphalt mixtures. In the following sections, the compaction process, considering the interaction between the materials and the equipment, is simulated, and the influence of different compaction methods on the mechanical performance of asphalt mixtures is investigated. To achieve this goal, a pre-compaction model is developed using the Discrete Element Method (DEM), and the models of both materials and the paving machine are generated separately. After the pre-compaction simulation, the theory of bounding surface plasticity is combined with the theory of Finite Element Method (FEM) as well as with a kinematic model of a roller drum to simulate the asphalt mixture behavior during a roller pass. In order to ensure consistency both in the laboratory compaction and in-situ compaction, the Aachen compactor has been developed. The effect of different compaction methods (Field, Aachen and Marshall Compactions) on the asphalt specimens is compared and evaluated using the microscale FEM

Optimization of network structure to random failures

Network's resilience to the malfunction of its components has been of great concern. The goal of this work is to determine the network design guidelines, which maximizes the network efficiency while keeping the cost of the network (that is the average connectivity) constant. With a global optimization method, memory tabu search (MTS), we get the optimal network structure with the approximately best efficiency. We analyze the statistical characters of the network and find that a network with a small quantity of hub nodes, high degree of clustering may be much more resilient to perturbations than a random network and the optimal network is one kind of highly heterogeneous networks. The results strongly suggest that networks with higher efficiency are more robust to random failures. In addition, we propose a simple model to describe the statistical properties of the optimal network and investigate the synchronizability of this model.Comment: 11 pages, 6 figures, accepted by Physica

Clipping and coiling of intracranial aneurysms in the elderly patients: clinical features and treatment outcomes

ObjectiveIn recent years, more and more cases of intracranial aneurysms (IAs) have been found in elderly patients, and neurosurgical interventions have increased, but there is still no consensus on the best treatment strategy for elderly patients. In elderly patients, endovascular coiling (EC) is more popular than surgical clipping (SC) due to its advantages of less trauma and faster recovery. However, SC has made great progress in recent years, significantly improving the prognosis of elderly patients. Therefore, it is necessary to further explore the effects of different treatment modalities on clinical prognosis, hospital stay, and hospital cost of elderly IA patients, and select the most appropriate treatment modalities.MethodsThe authors retrospectively analyzed 767 patients with intracranial aneurysms admitted to the facility between August 2017 and December 2022. Prognostic risk factors and multivariate logistic regression were analyzed for elderly patients treated with EC or SC. The area under the receiver operating characteristic (ROC) curve was used to calculate the predictive power of each independent predictor between the treatment groups.ResultsOur study included 767 patients with aneurysms, of whom 348 (45.4%) were elderly, 176 (22.9%) underwent endovascular coiling, and 172 (22.4%) underwent microsurgical clipping. A comparison of elderly patients treated with EC and SC showed a higher prevalence of hypertension in the EC group (P = 0.011) and a higher Hunt–Hess score on admission in the SC group (P = 0.010). Patients in the EC group had shorter hospital stays but higher costs (P = 0.000 and P = 0.000, respectively). Patients treated with SC had a higher incidence of postoperative cerebral infarction and poor prognosis (P = 0.002 and P = 0.008, respectively). Through multi-factor logistic analysis, it was found that age (OR 1.209, 95% CI 1.047–1.397, P = 0.010), length of stay (LOS) (OR 1.160, 95 CI% 1.041–1.289, P = 0.007), and complications (OR 31.873, 95 CI% 11.677–320.701, P = 0.000) was an independent risk factor for poor prognosis in elderly patients with EC. In elderly patients treated with SC, age (OR 1.105, 95% CI 1.010–1.209, P = 0.029) was an independent risk factor for poor prognosis.ConclusionEC and SC interventions in elderly adults carry higher risks compared to non-older adults, and people should consider these risks and costs when making a decision between intervention and conservative treatment. In elderly patients who received EC or SC treatments, EC showed an advantage in improving outcomes in elderly patients although it increased the economic cost of the patient's hospitalization

Characterising the asphalt concrete fracture performance from X-ray CT Imaging and finite element modelling

© 2018 Informa UK Limited, trading as Taylor & Francis Group. Crack distress causes asphalt pavement failure under repeated traffic loading. The objective of this study is to investigate the fracture properties of asphalt concrete through three dimensional (3D) numerical simulation using finite element method (FEM). The parameters and datum utilised for finite element models were captured from a grey matrix, which can be converted from digital images scanned by an X-ray computed tomography (CT) apparatus. Afterwards, the uniaxial compression test was simulated using FEM and was also conducted in laboratory to study the stress distribution and to evaluate the degree of damage during the loading process. Eighteen cylindrical asphalt concrete specimens were prepared with three different types of gradations: asphalt concrete, stone matrix asphalt and open-graded friction course. The uniaxial compression test was carried out on these specimens. Before and after each step, the specimens were scanned using X-ray CT to analyse the crack growth behaviour inside the asphalt concrete and to investigate the effect of gradation on the fracture characteristics. The degree of fracture can be evaluated by data analysis from the grey intensity histogram. The evaluation on asphalt concrete crack properties based on FEM with X-ray CT imaging was found to be practicable and reproducible. Additionally, the gradation was found to be an influential factor affecting the crack propagation of asphalt concrete