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51.
Maghsoud Amiri Mostafa Ekhtiari Mehdi Yazdani 《Expert systems with applications》2011,38(6):7222-7226
In problem of portfolio selection, financial Decision Makers (DMs) explain objectives and investment purposes in the frame of multi-objective mathematic problems which are more consistent with decision making realities. At present, various methods have introduced to optimize such problems. One of the optimization methods is the Compromise Programming (CP) method. Considering increasing importance of investment in financial portfolios, we propose a new method, called Nadir Compromising Programming (NCP) by expanding a CP-based method for optimization of multi-objective problems. In order to illustrate NCP performance and operational capability, we implement a case study by selecting a portfolio with 35 stock indices of Iran stock market. Results of comparing the CP method and proposed method under the same conditions indicate that NCP method results are more consistent with DM purposes. 相似文献
52.
Khraief Chadia Benzarti Faouzi Amiri Hamid 《Multimedia Tools and Applications》2020,79(27-28):19537-19560
Multimedia Tools and Applications - Fall is the biggest threat to seniors, with significant emotional, physical and financial implications. It is the major cause of serious injuries, disabilities,... 相似文献
53.
Noha M. Hamza Ruhul A. Sarker Daryl L. Essam Kalyanmoy Deb Saber M. Elsayed 《工程优选》2014,46(11):1447-1464
Constraint handling is an important aspect of evolutionary constrained optimization. Currently, the mechanism used for constraint handling with evolutionary algorithms mainly assists the selection process, but not the actual search process. In this article, first a genetic algorithm is combined with a class of search methods, known as constraint consensus methods, that assist infeasible individuals to move towards the feasible region. This approach is also integrated with a memetic algorithm. The proposed algorithm is tested and analysed by solving two sets of standard benchmark problems, and the results are compared with other state-of-the-art algorithms. The comparisons show that the proposed algorithm outperforms other similar algorithms. The algorithm has also been applied to solve a practical economic load dispatch problem, where it also shows superior performance over other algorithms. 相似文献
54.
Ramezan Nemati Keshteli Reza Baradaran Kazemzadeh Amirhossein Amiri Rassoul Noorossana 《Quality and Reliability Engineering International》2014,30(5):633-644
Profile is a relation between one response variable and one or more explanatory variables that represent quality of a product or performance of a process. On the other hand, process capability indices are measures to help practitioners in improving the processes to satisfy the customer's expectations. Few researches are done to account for the process capability index in the areas of profile monitoring. All of these researches are focused on process capability index in simple linear profile. In all of these methods, response variables in different levels of explanatory variable are considered, and the relationship in all range of explanatory variable is neglected. In this paper, a functional method is proposed to measure process capability index of circular profiles in all range of explanatory variable. The proposed method follows the traditional definition of process capability indices. The functional method uses reference profile, functional specification limits and functional natural tolerance limits to present a functional form of process capability indices. This functional form results in measuring the process capability in each level of explanatory variable in circular profile as well as a unique value of process capability index for circular profile. The application of the proposed method is illustrated through a real case in automotive industry. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
55.
The flexible job-shop scheduling problem (FJSP) is a generalisation of the classical job-shop scheduling problem which allows an operation of each job to be executed by any machine out of a set of available machines. FJSP consists of two sub-problems which are assigning each operation to a machine out of a set of capable machines (routing sub-problem) and sequencing the assigned operations on the machines (sequencing sub-problem). This paper proposes a variable neighbourhood search (VNS) algorithm that solves the FJSP to minimise makespan. In the process of the presented algorithm, various neighbourhood structures related to assignment and sequencing problems are used for generating neighbouring solutions. To compare our algorithm with previous ones, an extensive computational study on 181 benchmark problems has been conducted. The results obtained from the presented algorithm are quite comparable to those obtained by the best-known algorithms for FJSP. 相似文献
56.
One of the important issues regarding the implementation of cellular manufacturing relates to deciding whether to convert an existing job shop into a cellular manufacturing system comprehensively in a single go, or to convert in stages incrementally wherein the cells are formed one after the other taking the advantage of experiences of implementation. In this paper, a heuristic method based on iterative set partitioning is proposed for incremental cell formation where part operations can be processed on alternative machines. The objective is to minimize cycle time for a given number of workstations. The proposed method is numerically compared with the existing branch and bound technique and another heuristic algorithm based on multistage programming. It is found that the proposed method requires significantly less computational efforts to yield the optimal solution. 相似文献
57.
Brandon Fields Mahsa Amiri Jungyun Lim Julia T. Pürstl Matthew R. Begley Diran Apelian Lorenzo Valdevit 《Advanced Materials Technologies》2024,9(5):2301037
The established approach to materials design for additive manufacturing (AM) consists of attempting to reproduce the uniform structures and properties of conventionally processed materials. While this certainly helped facilitate material certification and the rapid introduction of AM technologies in several industries, the opportunity to exploit unique features of specific AM processes to generate spatially varying microstructures–and hence novel materials, remains largely untapped. This work presents a method for manufacturing materials through laser powder bed fusion (LPBF), in which control over the spatial variation in phase composition and mechanical properties is achieved. This technique is demonstrated using 17-4 precipitation-hardened stainless steel (17-4PH), by controlling spatial modulation of energy densities during printing. This results in local control of ferrite/martensite volume fractions, allowing the fabrication of metal/metal architected composites with hard/brittle regions interspersed with soft/tough regions. Local variations of ~20% in tensile strength and ~150% in elongation are achieved, with a spatial resolution of ~100 microns. The approach is general and robust, fully compatible with commercially available LPBF equipment, and applicable to virtually any multi-phase alloy system. This work shifts the paradigm from attempting to print components with uniform properties to manufacturing alloys with controlled spatial property gradients. 相似文献
58.
Saber Ibrahim;Hager Fahmy;Salah Lotfy; 《应用聚合物科学杂志》2024,141(25):e55529
The treatment or recovery of waste ink constitutes a significant process for the printing and packaging industries, particularly in the flexographic printing of packaging materials. This poses a substantial challenge in the field of waste management science. The application of waste ink recovery, ensuring a safe environment and human health, along with the recovery and sustainability of Earth's resources, has garnered significant global attention. The present research is solely devoted to creating innovative trends without technological barriers for synthesizing a tri-copolymer to be applied as an effective sorption system for waste ink. The Polyethyleneimine-Poly Glycidyl methacrylate-polyethylene glycol diacrylate tri-polymer (PEI-PGMA-PEGDA tri-polymer) was synthesized and thoroughly investigated using FTIR, TGA, and DSC to confirm its chemical structure, thermal stability, and the shift in melting point affected by radiation dose, respectively. SEM analysis showed significant morphological differences in PEI-PGMA-PEGDA tri-polymer samples before and after treatment with flexographic printing ink waste, offering effective strategies for adsorbing waste printing inks from organic solvents. These findings contribute to a comprehensive understanding of the investigated materials and their potential applications. Additionally, the kinetic study of the sorption efficiency of flexographic ink by two sets of tri-copolymers with doses of 20 and 40 kGy indicated that 40 kGy has a more efficient capacity. The highest sorption capacity, approximately 97.6%, was observed for a sample of GMA 15% irradiated by 40 kGy with a sorption amount of 2.5 g L−1. This suggests that the current new treatment strategy can be categorized as highly effective waste ink management and should be advocated for in such domains to ensure a safe environment and preserve Earth's resources. The treatment of printing ink for packaging materials is a crucial step towards achieving green printing technology, which must be supported and advanced through research and industrial application. 相似文献
59.
The magnetorheological elastomers (MREs) are novel multifunctional materials wherein their viscoelastic properties can be varied instantly under an application of applied magnetic field. Due to their field-dependent stiffness and damping properties, MREs are widely used in the development and design of MRE-based adaptive vibration isolators and absorbers and also biomedical engineering. Moreover, MREs due to their inherent magnetostriction effect have enormous potential for the development of soft actuators. The dynamic behavior of MREs is affected by various material parameters (e.g., matrix and particle types, particle concentration, additives) as well as mechanical and magnetic loading parameters (e.g., frequency, amplitude, temperature, magnetic flux density). Understanding and predicting the effect of materials and loading parameters on the response behavior of MREs are of paramount importance for the design of MRE-based adaptive structures and systems. This review paper mainly aims to provide a comprehensive study of material constitutive models to predict the nonlinear magnetomechanical behavior of MREs. Particular emphasis is paid to physics-based models including continuum- and microstructure-based models. Moreover, phenomenological models describing the dynamic magnetoviscoelastic behavior of MREs as well as the effect of temperature on the magnetomechanical behavior of such materials are properly addressed. 相似文献
60.
Monireh Sangi Javad Vasegh Amiri Gholamreza Abdollahzadeh Mehdi Dehestani 《Structural Concrete》2019,20(6):2122-2137
In this study, the effects of fiber orientation within the carbon fiber reinforced (CFRP) sheets, on the fracture mode and crack growth of specimens were investigated by constructing five groups of initially notched self‐consolidating concrete beams, and strengthening them with CFRP sheets in the tensile area. Furthermore, the bearing capacity, strain variation along the sheet, crack mouth opening, and the midspan displacement were recorded by varying the height of the beams and the initial notch lengths. The results indicate that the load‐crack mouth opening curves have two peak load points. First, the applied load increases up to one peak value and then there is a drop in the load‐caring capacity. Afterwards, the applied load is improved to another peak value due to the relatively high cohesive effect of the CFRP sheet. The results show that as the height of the beam section increases, or the initial notch length decreases, the first and the second peak loads increase. By comparing the specimens with different fiber angles in each group, it was observed that the specimen with fiber angle 0° has a higher capacity relative to other angles, yet its failure occurs in a lower displacement. Furthermore, with the help of finite element software and nonlinear static analysis, the behavior of the aforementioned beams including the stress and strain distributions in the CFRP sheet, and the sheet‐to‐concrete bond zone have been examined and compared with the existing experimental results for validation. 相似文献