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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Optimization in Industrial Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Shortage,Simulated Annealing,Lot-sizing problem,Safety stock deficit,Production manners
- چکیده:
- چکیده انگلیسی: [1] Corresponding author e-mail: mehdi.foumani@monash.edu
[1] Corresponding author e-mail: mehdi.foumani@monash.edu
Lot-sizing problems (LSPs) belong to the class of production planning problems in which the availability quantities of the production plan are always considered as a decision variable. This paper aims at developing a new mathematical model for the multi-level capacitated LSP with setup times, safety stock deficit, shortage, and different production manners. Since the proposed linear mixed integer programming model is NP-hard, a new version of simulated annealing algorithm (SA) is developed to solve the model named revised SA algorithm (RSA). Since the performance of the meta-heuristics severely depends on their parameters, Taguchi approach is applied to tune the parameters of both SA and RSA. In order to justify the proposed mathematical model, we utilize an exact approach to compare the results. To demonstrate the efficiency of the proposed RSA, first, some test problems are generated; then, the results are statistically and graphically compared with the traditional SA algorithm.- انتشار مقاله: 11-06-1390
- نویسندگان: Esameil Mehdizadeh,Mohammad Reza Mohammadizadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Rehabilitation in Civil Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Numerical investigation,RC Beam,GFRP bars,Flexure behaviour
- چکیده:
- چکیده انگلیسی: Enhancement of the response of reinforced concrete (RC) beams applying fiber-reinforced polymer (FRP) reinforcement bars has become a popular structural technique over the past two decades as a result to the well-known advantages of FRP composites including their high strength-to-weight ratio and excellent corrosion resistance. This study presents numerical investigation of 20 concrete beams internally reinforced with GFRP bars without web reinforcement. The accuracy of the non-linear finite element model in ABAQUS software is first validated against experimental data from the literature. The study presents an investigation into the behaviour of FRP reinforced concrete beams including the evaluation of geometrical properties effects. In particular, the study is focused on the effects of span/depth ratio, the reinforcement ratio and the effective depth of the beam, aiming to correct deficiencies in this area in existing knowledge. It’s been revealed that the finite element model is capable of accurately simulating the flexural behaviour of FRP reinforced beams. It was able to predict, with high accuracy, the force-displacement response the beam. Results manifested that FRP reinforcement is a proper solution in order to boost the ductility of RC beam members. Moreover, although that increasing in the span/depth ratio of the beam decreases beam’s rigidity, however; it also postpones the yielding point in the beam’s flexural response and leads to a higher level of displacement ductility for the beam.
- انتشار مقاله: 13-02-1397
- نویسندگان: Mohammad Morad Shirmardi,Mohammad Reza Mohammadizadeh
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Rehabilitation in Civil Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Steel–Concrete–Steel sandwich structure,Stud bolt shear connector,push-out test,quasi-static loading,interlayer shear behavior
- چکیده:
- چکیده انگلیسی: Steel-concrete-steel (SCS) sandwich panels are composed of two steel plates with low thicknesses and high densities and strengths and one thick layer between both plates with low strength and density known as core that is composed of concrete. Cohesive material-epoxy resin or shear connectors are usually applied in order to connect the plates to the concrete core. SCS sandwich composites are being developed so they can be utilized in offshore structures and buildings. Stud bolt is one of the shear connectors and their interlayer shear behavior is examined in the present study. In order to inspect the effect of parameters on interlayer shear behavior of steel-concrete-steel sandwich structure with stud bolt connectors, push-out test is performed under progressive loading. Pursuant to the tests performed, relations are proposed to predict ultimate shear strength and load-slip behavior of samples with stud bolt shear connectors. Consequently, numerical model of push-out test is presented on the basic component of Steel-Concrete-Steel sandwich structure (SCS) with stud bolt connectors. The results indicated that finite element model is consistent with test results applying mass scaling in Explicit Solver with a suitable analysis speed. Applying the regression analysis on the results of 80 numerical models of push-out test,a relation was proposed for shear strength of push-out samples with stud bolt connectors.
- انتشار مقاله: 17-06-1396
- نویسندگان: Mohammad Golmohammadi,Mansour Ghalehnovi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Rehabilitation in Civil Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Flexural capacity,Strengthening,NSM Method,FRP Bars,RC Beam
- چکیده:
- چکیده انگلیسی: Fiber-reinforced polymer (FRP) material is currently being produced in different configurations and widely applied to strengthening and retrofit concrete structures and bridges. It is also possible to apply other strengthening methods without changing the appearance or the dimensions of the structure. Near Surface Mounted (NSM) is a recent strengthening method using CFRP bars (rods or laminate strips) bonded into pre-cut grooves applied to the concrete cover of the elements to be strengthened. These FRP bars can help increase the flexural and shear capacity of existing concrete members as well. This article aims to present the experimental and numerical results gained separately from un-strengthened and strengthened beams under bending loading. In the experimental part, two large-scale fixed-end support reinforced concrete beams of the same size, and reinforcement characteristic was designed, constructed, and tested under one point concentrated loading system. The first specimen used as a control specimen while the second served as the strengthened applying NSM method with a new proposed hand-made CFRP Bar in the laboratory. Moreover; an extra analytical work was carried out using calibration of the analytical models as per the obtained experimental test results. The results and Photographs taken at the selected stages of loading are indicative of the fact that NSM method with FRP bars can be effectively applied to the existing structures in order to increase their flexural capacity, change their crack pattern and decrease final deflection.
- انتشار مقاله: 02-08-1394
- نویسندگان: Mohammadreza Mohammadian,Mohammad Kazem Sharbatdar
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Rehabilitation in Civil Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Buckling,Transfer Matrix,gap,Crack closing,Contact surface
- چکیده:
- چکیده انگلیسی: In this paper, buckling of simply supported column with an edge crack is investigated numerically and analytically. Four different scenarios of damage severities are applied to a column, open crack assumption and the effect of closing crack in stability of the column which depends on position and size of cracks, are numerically compared. Crack surfaces contact is modeled with GAP element using SAP2000. For analytical solution, transfer matrix method, combined with fundamental solutions of the intact columns is used to obtain the capacity of slender prismatic columns. The stiffness of the cracked section is modeled by a massless rotational spring and governing equations are obtained explicitly for simply supported column from second-order determinant. As expected results show that the effect of a closing crack in presence of compressive load may lead to an increment in buckling load depending on crack depth and position. For the first time, a dimensionless formulation based on numerical results is presented in this study. Proposed formula predicts increment effect of closing crack in buckling results of a notched column.
- انتشار مقاله: 30-07-1391
- نویسندگان: Omid Rezaifar,Mohammad Reza Doostmohammadi,Majid Gholhaki
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Research in Applied Linguistics
- نوع مقاله: Journal Article
- کلمات کلیدی: Ideology,war,vehicle,Recontextualization,Conceptual Metaphor (CM),Territory
- چکیده:
- چکیده انگلیسی: WAR as a vehicle and Sport Is War as a conceptual metaphor (CM) seem inadequate to account metaphorically for SPORT. To cater for an inclusive vehicle/CM, we selected WIN and LOSS lexicon from the news coverage of Brazil’s football team loss to Germany and tested them through the Corpus of Contemporary American English. Then, the data were studied through the 3 stages of metaphor research. In the identification stage, the metaphorical use of the WIN and LOSS lexicon was determined through metaphor identification procedure. In the interpretation stage, the metaphors were revealed to be recontextualized from discourses like war, earthquakes, floods, landslides, and the like. Then, on the basis of a generic source for such discourses, TERRITORY as a vehicle and A Sport Field Is a Territory as a CM were proposed. Finally, in the explanation stage, the ideological implications of the proposed vehicle/CM were argued on the discourse reproduction of Brazil’s problems.
- انتشار مقاله: 08-11-1396
- نویسندگان: Rahim Najjari,Mohammad Mohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Renewable Energy and Environment
- نوع مقاله: Journal Article
- کلمات کلیدی: optimization,Fuel cell,Proton Exchange Membrane,adaptive neuro-fuzzy inference system (ANFIS)
- چکیده:
- چکیده انگلیسی: Fuel cells are potential candidates for storing energy in many applications; however, their implementation is limited due to poor efficiency and high initial and operating costs. The purpose of this research is to find the most influential fuel cell parameters by applying the adaptive neuro-fuzzy inference system (ANFIS). The ANFIS method is implemented to select highly influential parameters for proton exchange membrane (PEM) element of fuel cells. Seven effective input parameters are considered including four parameters of semi-empirical coefficients, parametric coefficient, equivalent contact resistance, and adjustable parameter. Parameters with higher influence are then identified. An optimal combination of the influential parameters is presented and discussed. The ANFIS models used for predicting the most influential parameters in the performance of fuel cells were performed by the well-known statistical indicators of the root-mean-squared error (RMSE) and coefficient of determination (R2). Conventional error statistical indicators, RMSE, r, and R2, were calculated. Values of R2 were calculated as of 1.000, 0.9769, and 0.9652 for three different scenarios, respectively. R2 values showed that the ANFIS could be properly used for yield prediction in this study
- انتشار مقاله: 06-04-1398
- نویسندگان: Ali Mostafaeipour,Mojtaba Qolipour,Hossein Goudarzi,Mehdi Jahangiri,Amir-Mohammad Golmohammadi,Mostafa Rezaei,Alireza Goli,Ladan Sadeghikhorami,Ali Sadeghi Sedeh,Seyad Rashid Khalifeh Soltani
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Renewable Energy and Environment
- نوع مقاله: Journal Article
- کلمات کلیدی: Iran,Geothermal Energy,Hydrogen production,Expanded Entropy Weighting Method
- چکیده:
- چکیده انگلیسی: The present study aimed at ranking and selecting the superior geothermal project for hydrogen production in 14 provinces of Iran using a multi-objective optimization fuzzy hybrid approach through analyzing the ratio (fuzzy Moora) and expanded entropy weighting method. In this research, the extended entropy weighing method and the Fuzzy-Moora approach were utilized to weigh the criteria and project the ranking, respectively. In this research, 13 criteria for ranking the geothermal projects in Iran have been selected for hydrogen production. At first, the technical-economic feasibility of the projects was carried out in Homer software, and then the ranking process was performed with the proposed hybrid approach. The results showed that among 14 studied provinces using geothermal energy, the provinces of Bushehr, Hormozgan, Isfahan, Mazandaran, East Azarbaijan, Fars, Qazvin, Zanjan, Ardebil, Khorasan Razavi, Kerman, Sistan and Baluchestan, South Khorasan and West Azarbaijan were ranked in that order in terms of hydrogen production.
- انتشار مقاله: 07-04-1397
- نویسندگان: Ali Mostafaeipour,Mohammad Saidi Mehrabad,Mojtaba Qolipour,Mohadese Basirati,Mostafa Rezaei,Amir Mohammad Golmohammadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Patient Safety & Quality Improvement
- نوع مقاله: Journal Article
- کلمات کلیدی: Iran,Rheumatoid arthritis,Customer quality,Patients’ Perspective,Self-management strategies
- چکیده:
- چکیده انگلیسی: Introduction: Customer Quality (CQ) refers to customer’s characteristics and is related to the consumer knowledge, skills and self confidence in active participating in care process and life style improvement. This study was aimed to assess customer quality among people with Rheumatoid Arthritis (RA) according to the patients’ perspective.
Materials and Methods:This cross-sectional study was carried out on 170 patients who received care from specialist clinics of Isfahan University of Medical Sciences in 2013. Customer Quality was assessed using Comprehensive Quality Measurement in Health care questionnaire (CQMH_CQ). Questionnaire content validity was reviewed and confirmed by 10 experts and its reliability was confirmed based on Chronbach's alpha index (α=0.803). SPSS-17 statistical software was used to analyze the data. Independent Samples T test and ANOVA were conducted to compare CQ score between categorical variables.
Results: The average CQ score was 70.25 (13.20). According to self-reported customer quality score, all participants achieved the scores at the level of stage one. Some (9.2%) of participants didn’t reach the action stage (stag three), then 90.8% took action in facing with health related problem and finally only 19.8% of participant achieved highest level of Self-management. Customer Quality score of employed patients (P=0.026) and patient who had active disease
(P =0.030) were significantly. Customer quality scores of illiterate participants were lower than that of the educated (P= 0.001).
Conclusion: According to overall score of customer quality, findings indicate the necessity of patients' involvement in care process and self-thought behavior-change skills for ongoing self-management and enhancing their self care abilities in daily life.- انتشار مقاله: 25-02-1393
- نویسندگان: Azad Shokri,Mohammad Hossein Yarmohammadian,Payman Mottaghi,Saeed Karimi,Najmeh Bahman Ziari,Kamal Gholipour,Jafar Sadegh Tabrizi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Nutrition,Fasting and Health
- نوع مقاله: Journal Article
- کلمات کلیدی: Women,Overweight,Obesity,Appetite,Eating behavior,Food craving,Food Craving Questionnaire (FCQ)
- چکیده:
- چکیده انگلیسی: Introduction: Food Craving Questionnaire (FCQ) is a popular tool in assessing food craving which consisted of a trait (FCQ-T) and state (FCQ-S). The aim of the current study was to provide reliability and validity of the Persian version of FCQ-Trait-reduced (FCQ-T-r 15-items) in overweight and obese women. Material and methods: The subjects were 168 overweight and obese women who were consented to participate. The subjects completed the FCQ-T-r and subsequently, anthropometric, body composition and psychometric assessments performed to assess the inter-correlations and concurrent validity. The confirmatory factor analysis was done to derive the potential factors and internal consistency of the questionnaire was assessed. Two weeks later, FCQ-T-r repeated for 126 subjects to assess test-retest reliability. Results: The confirmatory factor analysis of by varimax rotation, show that three principal components were loaded on expected factors. The Cronbach’s alpha coefficient was 0.90. (0.91, 0.78, and 0.71, for factors). The test–retest analysis shows an acceptable level of reliability ( P=0.001) and Pearson correlation coefficient of 0.92 between the two administrations. In split-half reliability analysis the Cronbach’s alpha coefficient of the part 1 was 0.80 and for the part 2 was 0.86. The correlation coefficient between part 1 and part 2 was 0.81. Conclusion: This preliminary study provides evidences in favor of reliability and validity of the Persian version of the FCQ-T-r. In general, the results showed a high level of internal consistency for FCQ-T-r, and none of the 15 items had to be deleted to improve α.
- انتشار مقاله: 08-07-1397
- نویسندگان: Mohammad Reza Mohammadi,Shahin Akhondzadeh,Seyed-Ali Mostafavi,Seyed Ali Keshavarz,Taranom Ahmadi Motlagh,Mohammad Reza Eshraghian,Saeed Hosseini
- مشاهده