Search

Due to today's competitive environment and information boom, companies are concerned about production planning in uncertain conditions. This paper integrates decision-making method with production scheduling model by considering limited resources. In this paper, a new mathematical model is extended for production project scheduling with multiple execution modes. The main aim of the formulation is to plan and schedule real production projects in uncertain environments. A new mixed-integer linear formulation is presented by considering trade-off of cost, time, as well as quality. Cost–time-quality trade-off is extended with the interval information. In the presented model, activity quality could be enhanced by reworking. The interval forms of some parameters, including duration, quality of activities, cost, and total available resources, are obtained by determining weights of experts and aggregating them. The presented group decision-making method is based on a bi-directional projection measure to deal with interval information. Since the mathematical model is multi-objective and some data are interval, a new modified solution method is developed for solving the model. The presented method for both decision-making and mathematical models is investigated by a real-world production project and two datasets to ascertain the accuracy of the model. Finally, an appropriate sensitivity analysis is proposed. [ABSTRACT FROM AUTHOR]

In this paper, the flow of an incompressible fluid is thermally studied. Investigations into the heat transfer process have been conducted in non-Newtonian fluid flows with chemical reactions and heat sources present. The application of this work is the fluid flow around the stretching sheet; fluid flow on a stretching sheet can be applied to polymer extrusion, drawing or plastic films, hot rolling, casting and other engineering problems. The novelty of this paper is that the governing equations have been solved by a new and efficient semi-analytical approach, the Akbari–Ganji method (AGM). In order to investigate the issue, the finite element method (FEM) has also been applied. Comparing the results of problem-solving with the applied methods with the results of the previous research shows a perfect agreement. The results show that the parameters of Hartmann number and interaction improve the velocity profiles. Additionally, for greater Hartmann number values, raising the parameter of interaction decreases the temperature value, but a smaller value has the reverse effect. As the Hartmann number increases, the fluid velocity decreases and it shows that with the increase of electromagnetic force, the velocity of fluid flow decreases. [ABSTRACT FROM AUTHOR]

Interval-Valued Pythagorean Fuzzy Sets (IVPFSs) as an enhanced type of Pythagorean Fuzzy Sets (PFSs) improve the expression of membership, non-membership, and hesitancy degrees, compared to Intuitionistic Fuzzy Sets (IFSs). In order to benefit from the advantages of IVPFSs, the current research proposes a new group decisionmaking method based on Linear Assignment Method (LAM). In this approach, both subjective and objective weights of criteria were taken into account. Moreover, the proposed method applied a new ranking method for IVPFSs. To avoid the shortcomings of the first aggregation methods, the introduced decision-making approach focused on the last aggregation approach. Finally, the method was used in a case study of sustainable project evaluation in order to depict the applicability of this method. [ABSTRACT FROM AUTHOR]

An investigation is performed in this paper to analyze the nonlinear thermo-electro-mechanical response of long sandwich cylindrical shells with functionally graded porous (FGP) core and thin piezoelectric actuator layers. The FGP core of the sandwich shell is assumed to be temperature- and microstructure-dependent. It is assumed that the sandwich shell is subjected to uniform lateral pressure loading in a thermo-electrical environment. The equilibrium equations of the shell with infinite length are established with the aid of the virtual displacement principle and von Kármán kinematic assumptions. The governing equations are obtained in terms of displacement components based on the first-order shear deformation model of shallow cylindrical shells and the modified couple stress theory. These nonlinear differential equations are analytically solved for a sandwich shell having both the simply-supported and clamped–clamped edge conditions by employing a two-step perturbation technique. Analytical closed-form solutions are determined as a relationship including the load parameter and the mid-span deflection. The comparison examples are made with the existing results in the literature for a simple functionally graded shell, where good agreement is obtained. It is shown that the nonlinear response of the sandwich shell is highly dependent upon the temperature variation, power law index, porosity coefficient, couple stress parameter, piezoelectric layers, and geometrical parameters of the shell. [ABSTRACT FROM AUTHOR]

Background and Objective: Aortoenteric fistula (AEF) is a rare but life-threatening condition. Secondary AEF in patients with a history of aortic surgery with symptoms of sudden gastrointestinal bleeding may occur even without evidence in endoscopy and colonoscopy, and delay in diagnosis and lack of timely surgery may lead to the death of the patient, and it is important to consider it. This study introduces a 60-year-old man with a history of aortic surgery who referred to the Golestan Hospital in Ahvaz with a complaint of acute gastrointestinal bleeding and underwent surgery with the diagnosis of secondary AEF. Case Report: The patient is a 60-year-old man who had a history of Aortobifemoral Bypass surgery three years ago, and was hospitalized in the emergency room due to gastrointestinal bleeding (melena). The patient's heart rate was 110 beats per minute, the patient's systolic blood pressure was 90 mm Hg and diastolic blood pressure was 60 mm Hg (positive tilt test) and the patient's hemoglobin (HB) was 6 g/dl. The patient underwent fluid resuscitation by the gastroenterology service, received pantoprazole, blood and antibiotics, endoscopy and colonoscopy, but no pathological findings were found. A surgical consultation was requested for him, and the patient underwent emergency CT angiography of the abdominal vessels. Due to the prolonged bleeding, unstable hemodynamics and drop in hemoglobin, it was decided to operate the patient with the suspicion of AEF. During the operation, the aorta (in the renal part) was fistulated to the intestines (jejunum, 30 cm from Treitz ligament) through a 5 mm long tract, which was repaired. The day after the operation, the patient was conscious and had stable vital signs, and was discharged the following week with a good general condition. The patient was followed up monthly for one week, three weeks, and then up to six months, which showed normal conditions. Conclusion: Based on the results of this study, AEF should be considered as a rare but fatal diagnosis in a patient with a history of aortic surgery and lower gastrointestinal bleeding and should undergo emergency surgery. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Understanding the variation of Water Extent (WE) can provide insights into Wetland conservation and management. In this study, and-inter inner-annual variations of WE were analyzed during 2019–2021 to understand the spatiotemporal changes of the International Shadegan Wetland, Iran. We utilized a thresholding process on Modified Normalized Difference Water Index (MNDWI) to extract the WE quickly and accurately using the Google Earth Engine (GEE) platform. The water surface analysis showed that: (1) WE had a downward trend from 2019 to 2021, with the overall average WE being 1405.23 km2; (2) the water area reached its peak due to the water supply to International Shadegan Wetland through the Jarahi River and upstream reservoirs at the end of 2019 and the beginning of 2020, and the largest water body appeared in Winter 2019, reaching 1953.31 km2. In contrast, the smallest water body appeared in Autumn 2021, reaching 563.56 km2; (3) The WE of the wetland showed predictable seasonal characteristics. The water area in Winter was the largest, with an average value of 1829.1 km2, while it was the smallest in Summer, with an average value of 1100.3 km2; (4) The average water area in 2019 was 1490.5 km2 whereas in 2020 and 2021 decreased by 9% and 25%, respectively, and reached 968.6 km2 and 811.9 km2. Finally, to evaluate the proposed model, its results were compared with the Random Forest (RF) classification results. Accordingly, Histogram Analysis (HA) classification achieved 94.6% of the average overall accuracy and the average Kappa coefficient of 0.93, but the RF method obtained 95.38% of the average overall accuracy and an average Kappa coefficient of 0.94. [ABSTRACT FROM AUTHOR]