Modeling and control of a plastic film manufacturing web process

This paper is concerned with the modelling of aplastic film manufacturing process and the development and implementation of a model-based Cross-Directional (CD) controller. The model is derived from first-principles and some empirical relationships. The final validated nonlinear model could provide a useful off-line platform for developing control and monitoring algorithms.A new controller is designed which has a similar structureto that of Internal Model Control (IMC) with the addition ofan observer whose gain is designed to minimise process andmodel mis-match. The observer gain is obtained by solving amulti-objective optimisation problem through the application of a genetic algorithm. The controller is applied to the nonlinear model and simulation results are presented demonstrating improvements that can be achieved by the proposed controller over two existing CD controllers

Graph Symmetry Detection and Canonical Labeling: Differences and Synergies

Symmetries of combinatorial objects are known to complicate search algorithms, but such obstacles can often be removed by detecting symmetries early and discarding symmetric subproblems. Canonical labeling of combinatorial objects facilitates easy equivalence checking through quick matching. All existing canonical labeling software also finds symmetries, but the fastest symmetry-finding software does not perform canonical labeling. In this work, we contrast the two problems and dissect typical algorithms to identify their similarities and differences. We then develop a novel approach to canonical labeling where symmetries are found first and then used to speed up the canonical labeling algorithms. Empirical results show that this approach outperforms state-of-the-art canonical labelers.Comment: 15 pages, 10 figures, 1 table, Turing-10

Efficiency Improvement of Fault-Tolerant Three-Level Power Converters

Fault-tolerant power converters play a critical role in the transportation electrification. However, fault-tolerant operation, high efficiency, and low cost usually result in design criteria that have conflicting constraints and goals. The majority of the fault-tolerant power converter topologies presented in the literature confirm these conflicts. In this paper, three types of fault-tolerant neutral-point clamped (NPC) converters are investigated. Various modulation strategies are explored to reduce the losses of the redundant phase leg. The simulation and experimental results show that the Switching Frequency Optimal Phase opposition Disposition modulation strategy is the most effective approach in minimizing the losses in the redundant phase leg

Effect of Freezing on Stress–Strain Characteristics of Granular and Cohesive Soils

This is the author accepted manuscript. The final version is available from ASCE via the DOI in this recordTo investigate the stress-strain behavior of frozen soils, a program of triaxial compression tests was designed and carried out on samples of unfrozen and frozen cohesive (CL) and granular (SP) soils and pure ice. The experiments involved study of the influence of freezing, temperature reduction and loading rate on the stress-strain characteristics of the frozen ground. The aim of this study is to assess the possibility of using the Artificial Ground Freezing (AGF) technique in the excavation and tunneling in Line 2 of the Tabriz Subway project. The results show that freezing of the CL soil has no significant effect on the type of soil behavior (strain-hardening), while, freezing of the SP soil changes its strain-hardening behavior to strain-softening. The effect of freezing on the increase in shear strength of the saturated SP soil is much greater than that of the saturated CL soil; however, the rate of increase in the shear strength due to freezing and temperature reduction is much larger for the CL soil. Freezing and reduction in temperature cause an increase in the elastic modulus of all the materials tested in the present study. Also, the shear strength and elastic modulus 26 of these materials increase with loading rate.Ministry of Science of Ira

A new approach to modeling the behavior of frozen soils

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this recordIn this paper a new approach is presented for modeling the behavior of frozen soils. A data-mining technique, Evolutionary Polynomial Regression (EPR), is used for modeling the thermo-mechanical behavior of frozen soils including the effects of confining pressure, strain rate and temperature. EPR enables to create explicit and well-structured equations representing the mechanical and thermal behavior of frozen soil using experimental data. A comprehensive set of triaxial tests were carried out on samples of a frozen soil and the data were used for training and verification of the EPR model. The developed EPR model was also used to simulate the entire stress-strain curve of triaxial tests, the data for which were not used during the training of the EPR model. The results of the EPR model predictions were compared with the actual data and it was shown that the proposed methodology can extract and reproduce the behavior of the frozen soil with a very high accuracy. It was also shown that the EPR model is able to accurately generalize the predictions to unseen cases. A sensitivity analysis revealed that the model developed from raw experimental data is able to extract and effectively represent the underlying mechanics of the behavior of frozen soils. The proposed methodology presents a unified approach to modeling of materials that can also help the user gain a deeper insight into the behavior of the materials. The main advantages of the proposed technique in modeling the complex behavior of frozen soil have been highlighted

CHARACTERIZATION OF UNDERLYING LAYER STABILIZATION MATERIAL FOR MECHANISTIC-EMPIRICAL DESIGN OF RIGID PAVEMENTS

The Mechanistic-Empirical Pavement Design Guide (MEPDG) is applied to calculate pavement responses against the cumulative damage over time, taking into account the general properties of materials, traffic, environmental conditions and pavement structure. The procedure described in the guide was used in this paper to provide appropriate design alternatives for the existing conditions. The two most common types of rigid pavements for highways, Continuously Reinforced Concrete Pavement (CRCP) and Jointed Plain Concrete Pavement (JPCP) were considered in the design. The base layer material was chosen in such a way that a reasonable design life and distress level can be obtained. For each type of chemical stabilization techniques of the underlying layers, the satisfactory design cases were proposed based on the M-E design procedure. For CRCP, the results were also compared with those obtained from the procedure suggested by Texas Department of Transportation (TxDOT) pavement design manual

Effects of blackberry (Morus nigra L.) consumption on serum concentration of lipoproteins, apo A-I, apo B, and high-sensitivity-C-reactive protein and blood pressure in dyslipidemic patients

This study investigated blackberry (Persian mulberry) effects on apo A-I, apo B, high-sensitivity-C-reactive protein (hs-CRP), and systolic blood pressure (SBP) and diastolic blood pressure (DBP) in dyslipidemic patients. Materials and Methods: In this 8-week randomized clinical trial, 72 dyslipidemic patients were randomly divided into two groups: Intervention (300 mL/day blackberry juice with pulp) and control group (usual diets). Before and after the intervention, fasting blood samples were taken from both groups and serum concentration of lipoprotein, apo A-I and apo B, serum lipids (total cholesterol, low-density lipoprotein, highdensity lipoprotein HDL, and triglyceride), hs-CRP were measured. Blood pressure before and after the study was measured with a mercury manometer. Results: At week 8 in the intervention group, apo A-I and HDL increased significantly (P = 0.015, P = 0.001, respectively), apo B and hs-CRP decreased significantly (P = 0.044, P = 0.04, respectively). Mean changes in apo A-I and HDL and apo B/apo A-I ratio were significant between the groups (P = 0.005, P = 0.014, and P = 0.009, respectively). After 8 weeks, there was a significant difference between hs-CRP mean values (P = 0.01) of the groups. At week 8, SBP decreased significantly (P = 0.005) in the intervention group with no significant differences for SBP mean values between the groups. No significant changes were observed in other lipid parameters and DBP in the intervention group and between the groups. Conclusion: Blackberry consumption may exert beneficial effects on apolipoproteins, blood pressure, and inflammatory markers in individuals with lipid disorders. © 2015 Journal of Research in Medical Sciences

Experimental Study of the Mechanical Behavior of Frozen Soils - A Case Study of Tabriz Subway

This is the final version. Available on open access from Budapest University of Technology and Economics via the DOI in this recordThe mechanical properties of frozen ground are key parameters in design and implementation of artificial ground freezing (AGF) in underground projects. Soil samples were obtained from the urban underground railway project site in Tabriz, Iran. The specimens were classified as SP and CL according to the USCS. The specimens were remolded in accordance with the site conditions. Over 120 triaxial compression tests were conducted on the frozen samples at different temperatures, confining pressures and strain rates. The results show that the frozen SP and CL soils exhibit strain-softening and strain-hardening behaviour, respectively. In all cases, Young’s modulus increases with decreasing temperature and increasing strain rate and confining pressure. Also, the shear strength increases with decreasing temperature and increasing strain rate. In all tests, the Young’s modulus and shear strength of the SP soil are greater than the CL soil. Based on the results of this research, the application of artificial ground freezing was recommended for coarse-grained and non-cohesive soils like SP in the Tabriz underground railway project.Iran’s Ministry of Science