6 research outputs found

    Developing an Overbooking Fuzzy-Based Mathematical Optimization Model for Multi-Leg Flights

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    Overbooking is one of the most vital revenue management practices that is used in the airline industry. Identification of an overbooking level is a challenging task due to the uncertainties associated with external factors, such as demand for tickets, and inappropriate overbooking levels which may cause revenue losses as well as loss of reputation and customer loyalty. Therefore, the aim of this paper is to propose a fuzzy linear programming model and Genetic Algorithms (GAs) to maximize the overall revenue of a large-scale multi-leg flight network by minimizing the number of empty seats and the number of denied passengers. A fuzzy logic technique is used for modeling the fuzzy demand on overbooking flight tickets and a metaheuristics-based GA technique is adopted to solve large-scale multi-leg flights problem. As part of model verification, the proposed GA is applied to solve a small multi-leg flight linear programming model with a fuzzified demand factor. In addition, experimentation with large-scale problems with different input parameters’ settings such as penalty rate, show-up rate and demand level are also conducted to understand the behavior of the developed model. The validation results show that the proposed GA produces almost identical results to those in a small-scale multi-leg flight problem. In addition, the performance of the large-scale multi-leg flight network represented by a number of KPIs including total booking, denied passengers and net-overbooking profit towards changing these input parameters will also be revealed

    Developing an Overbooking Fuzzy-Based Mathematical Optimization Model for Multi-Leg Flights

    Get PDF
    Overbooking is one of the most vital revenue management practices that is used in the airline industry. Identification of an overbooking level is a challenging task due to the uncertainties associated with external factors, such as demand for tickets, and inappropriate overbooking levels which may cause revenue losses as well as loss of reputation and customer loyalty. Therefore, the aim of this paper is to propose a fuzzy linear programming model and Genetic Algorithms (GAs) to maximize the overall revenue of a large-scale multi-leg flight network by minimizing the number of empty seats and the number of denied passengers. A fuzzy logic technique is used for modeling the fuzzy demand on overbooking flight tickets and a metaheuristics-based GA technique is adopted to solve large-scale multi-leg flights problem. As part of model verification, the proposed GA is applied to solve a small multi-leg flight linear programming model with a fuzzified demand factor. In addition, experimentation with large-scale problems with different input parameters’ settings such as penalty rate, show-up rate and demand level are also conducted to understand the behavior of the developed model. The validation results show that the proposed GA produces almost identical results to those in a small-scale multi-leg flight problem. In addition, the performance of the large-scale multi-leg flight network represented by a number of KPIs including total booking, denied passengers and net-overbooking profit towards changing these input parameters will also be revealed

    Influences of flunixin and tenoxicam on the pharmacokinetics of florfenicol in lipopolysaccharide-induced endotoxemia

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    The purpose of this study was to investigate the influences of flunixin (FM) and tenoxicam (TN) on the pharmacokinetics of florfenicol (FF) after coadministration in lipopolysaccharide (LPS)-induced endotoxemic rabbits. Fifteen male rabbits were used in this study. FF (20 mg/kg), FM (2 mg/kg), and TN (1 mg/kg) were coadministered via intravenous injection to the animals. The concentrations of FF were determined by high-performance liquid chromatography with diode-array detection from 0.08 to 12 h in plasma. The plasma concentration-time profile of FF was described using a noncompartmental open model. In this study, terminal half-life, area under the curve, mean residence time, and volume of distribution at steady state were significantly increased, whereas total body clearance was decreased in coadministered groups. In conclusion, FM and TN have effects on the pharmacokinetics of FF in coadministered endotoxemic rabbits. When FF is coadministered with FM and TN, it can be given at a dose of 20 mg/kg b.w. every 8 h for treatment of infections caused by susceptible pathogens with a minimum inhibitory concentration (MIC) of <= 2 mu g/mL or 12 h for treatment of infections caused by susceptible pathogens with MIC of <= 1 mu g/mL in critically ill rabbits. Further studies are necessary to determine variations in dosage regimens

    Combined Treatment with Interlukin-1 and Tumor Necrosis Factor-Alpha Antagonists Improve Type 2 Diabetes in Rats

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    In the present study, combined treatment with etanercept and anakinra were tested in the streptozotocin-induced diabetic rats. Forty male Wistar albino rats were divided into 5 groups; healthy control (HC), diabetic control (DC), diabetic+anakinra (DAT), diabetic+etanercept (DET), and diabetic+etanercept+anakinra (DEAT). HC and DC groups received subcutaneous (sc.) injection with a saline solution, while DAT and DET groups received anakinra (10 mg/kg/day, sc.) or etanercept (10 mg/kg, twice a week, sc.), and DEAT rats received both anakinra and etanercept treatments for 21 days after diabetes has developed. Anakinra and etanercept treatments significantly increased insulin and homeostatic model assessment-β cell function levels and decreased glucose levels compared to the DC group as single (DAT and DET) and combined treatments (DEAT). The thiobarbituric acid reactive substances level was significantly decreased in DAT group. The combine use of etanercept and anakinra can improve insulin and blood glucose in type 2 diabetic rats. The combined treatment of anakinra and etanercept together was more effective than single treatment and might have a potential new treatment strategy and to reduce the mortality and morbidity resulting from diabetes.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

    Pharmacokinetics of ceftriaxone following single ascending intravenous doses in sheep

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    The objective of this study was to evaluate the pharmacokinetics of CTX following intravenous administration of ascending doses in sheep. In this study, six clinically healthy Akkaraman sheep (2.4 +/- 0.4 years and 50 +/- 3 kg of body weight) were used. CTX was administered intravenously to each sheep at 20, 40, and 80 mg/kg doses in a crossover design with a 15-day washout period. Plasma concentrations of CTX were measured using the high-performance liquid chromatography-UV method. Pharmacokinetic parameters were calculated by non-compartmental analysis. CTX was well tolerated following administration at 20, 40, and 80 mg/kg doses. The elimination half-life following administration of 40 and 80 mg/kg doses were significantly longer than that of 20 mg/kg dose (P 0.05). When compared to 20 mg/kg, dose-normalized AUC(0-infinity) at the 80 mg/kg dose significantly increased (P minimum inhibitory concentration (MIC) of > 40% for the treatment of infections caused by bacteria with MIC values <= 2, <= 4, and <= 16 mu g/mL, respectively. This information may be helpful in adjusting the dosage regimen, but there is a need for future work
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