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In this study, the adsorption of crystal violet dye from aqueous solution onto montmorillonite was studied and the equilibrium isotherms were determined. Two-parameter equations; the Langmuir, Freundlich, and Temkin isotherms, and three-parameter equations; the Sips, Toth, and Khan isotherms were examined for their ability to model the equilibrium adsorption data. Five error analysis methods were used to determine the optimal isotherm: the sum of the errors squared, a hybrid error function, the average relative error, Marquardt's percent standard deviation, and the sum of absolute errors. The Sips isotherm achieved the best-fit quality with the experimental data and the maximum adsorption capacity was found to be 152.229 mg/g. The sum of the normalized errors showed that the hybrid fractional error function obtained the best overall results. [ABSTRACT FROM AUTHOR]

The multi-resource generalized assignment problem (MRGAP) is the assignment of jobs to agents under capacity constraints to minimize the total assignment. In this problem, each agent has multiple resources, each job is assigned to only one agent, and multiple jobs can be assigned to one agent. In the MRGAP problem, it is essential to distribute the loads in balance to the agents. In the literature, for balancing agent loads, bottleneck MRGAP with the aim of minimizing the maximum agent load, and balanced assignment MRGAP models with the aim of minimizing the difference between the maximum agent load and the minimum agent load have been proposed. In this study, the sum of load squares model has been adapted for MRGAP, as well as a new goal programming MRGAP model and a matheuristic algorithm for the solution of this model are developed. The performances of the proposed model and the algorithm were compared with the models taken from the literature by using randomly derived test problems. The quality of the obtained solutions is determined by considering the maximum load, coefficient of variation and total load criteria. The test results are evaluated in terms of these three criteria. The results obtained revealed the success of the proposed goal programming model and the matheuristic algorithm. [ABSTRACT FROM AUTHOR]

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Ending the global COVID-19 outbreak requires multiple country-wide strategies, such as social isolation, multiple tests, and monitoring people's interactions with each other. Many countries in the world have brought their own restrictions. Many parameters such as hospital capacities, social life and economy were taken into consideration while introducing the restrictions. Some countries, such as Italy, Brazil, and even the United States, have failed to predict the course of the outbreak and did not take more stringent measures, therefore; the outbreak has caused thousands of lives and is still happening. In this study, by considering the number of COVID-19 cases and the measures taken by the government, a model was developed to track the course of the epidemic for 91 days. For modeling, the SIR (Susceptible-InfectedRecovered) model, which is widely used in epidemiology was used. To estimate the parameters in the SIR model, RSS (Residual Sum of Squares) method was utilized. By taking into account the important time intervals, such as closure of the schools, country wide lockdowns and bending the restrictions, the model parameters were estimated for these intervals using the epidemic data given by the Ministry of Health. In addition, simulation results are provided to predict how the course of the epidemic would take place if precautions were not taken at the beginning of the outbreak or if the most recent measures were continued. This model offers authorities a preliminary assessment opportunity to manage the outbreak. [ABSTRACT FROM AUTHOR]

In this study, in the balanced experiments in factorial order, it is planned to compare the power values of the test that will be formed as a result of the use of the sum of commonly used Type 1, type 2 and type 3 squares by creating combinations of different widths in terms of standart deviation between combinations of different sample widths, different distribution, different variance ratios and averages. The material of this thesis work consists of random numbers produced by using the IMSL library of Microsoft Developer Studio. 100 000 simulations for 4 different distributions were made (Z, Chi-Square) by using the sum of Type I-Type II and Type III squares according to 16 subgroup combinations with 2 factors with 3, 5, 10 and 20 observation numbers in balanced trials and each factor is 4 in the number of levels. (T and Beta). In the study, the sum of type 3 squares and the sum of type 2, type 1 squares give similar power values in balanced trials. This situation explains the reason for using the sum of type 3 squares in package programs. However, in this study, it was observed that the sum of type 2 and type 1 squares received slightly higher power values in balanced trial patterns in curve distributions. [ABSTRACT FROM AUTHOR]