Sharif Digital Repository

Efficient utilization of runways, as major bottlenecks at airports, not only minimizes flight delays but also plays a vital role in reducing fuel emissions and mitigating environmental impacts. Aircraft scheduling problem studied in this paper seeks to improve this efficiency through optimally scheduling departure/arrival aircraft on multiple runways. The primary innovation of this study lies in accounting for aircraft taxi times between runways and gates, as well as the landing delay patterns, which have not been simultaneously addressed in the literature. To solve the problem, an enhanced branch-and-price method has been developed, improving upon existing approaches in the literature. It... 

Mathematical modeling and computer simulation are powerful tools to help cancer research because they provide a good insight of cancer progression and an efficient framework to test biological hypothesis. Most of the previous studies ignored many intracellular communication between tumor cells. Gap junction is one of the interaction ways between tumor cells which plays a crucial role in cancer progression. In the first phase of this thesis, a model of intracellular communication through gap junction using evolutionary game theory scoring is proposed. In the second phase of this thesis, cancer is modeled by Markov decision process (MDP). Given that considering nutrient level constant is one... 

X-ray radiation is an ionizing radiation that can be produced under some conditions in an ion implanter and can have significant effects on equipment and personnel health. In this dissertation, we first examine the properties of ionizing radiations and their effects of electronic devices and discuss the general properties of common detectors. Next, Using Silvaco TCAD and GEANT4 we will simulate the interaction of ionzing radiation with energies up to 300 keV with electronic devices including a commercial off the shelf photo diode and a specialized x-ray detector and show that these devices can efficiently reveal informations of a radiation source to the user. Also, it has been shown that... 

Suppose that A is a large subset of N. It is interesting to think about the arithmetic progressions in A.In 1936, Erdos and Turan conjectured that for > 0 and k 2 N, there exists N = N(k; ) that for all subsets A {1; 2; : : : ;N}, if lAl N, A has a nontrivial arithmetic progression of length k. Roth proved the conjecture for k = 3 in 1953. In 1969, Szemeredi proved the case k = 4 and in 1975, he gave a combinatorial proof for the general case. In 1977, using ergodic theory, Furstenberg gave a different proof for the Erdos-Turan conjecture (or Szemeredi Theorem!) and finally Gowers found another proof for the Szemeredi theorem, which was an elegant generalization of the Roth’s proof for k =... 

Smart materials are able to change their physical properties under various environmental conditions. Shape memory alloys (SMA) are relatively new smart materials that can respond to environmental stimuli e.g., heat, electricity, etc. Unique behaviors of SMAs, called shape memory effect and superelasticity, have motivated many applications in various fields of study (aerospace, medical, civil engineering, etc.). Although the behavior of SMAs is complicated, modeling and utilizing these materials have been receiving much attention in the past 20 years. Since a cable tolerate more tension than a wire or rod, the shape memory alloy cables could have a broad range of potential applications....