Browsing by Subject "Simulations"

Now showing 1 - 3 of 3

Open Access
Evaluation of mobilization and deployment plan of an armored battalion
(Military Operations Research Society, 2005) Müslüm, S.; Sabuncuoğlu, I.
Being ready for war as soon as possible and with minimum casualties during the crises is the first mission of the troops. Mobilization and deployment plans arise as the most important tools for Army as they cover all the activities that troops must execute to respond against enemy immediately. In this paper, we study the performance of the mobilization and deployment plans of a Turkish armored battalion via simulation. The proposed simulation model is developed for military operation planners to analyse mobilization and deployment operation of troops early in decision process; perform bottleneck analysis and take necessary actions for the main problem areas. The proposed model can also reduce the risk of military operations before conducting them in actual war conditions. Moreover, it is used to identify the significant factors of enemy threat, detect the most hazardous region and the most hazardous factor for each region, and discover the system boundaries. The simulation model is developed using ARENA simulation system. The output of the model is analysed by the experimental design and ranking/selection procedures. A related bibliography is also provided in the paper.
Open Access
Mathematical modelling of bacterial quorum sensing: a review
(Springer, 2016) Pérez-Velázquez, J.; Gölgeli, M.; García-Contreras, R.
Bacterial quorum sensing (QS) refers to the process of cell-to-cell bacterial communication enabled through the production and sensing of the local concentration of small molecules called autoinducers to regulate the production of gene products (e.g. enzymes or virulence factors). Through autoinducers, bacteria interact with individuals of the same species, other bacterial species, and with their host. Among QS-regulated processes mediated through autoinducers are aggregation, biofilm formation, bioluminescence, and sporulation. Autoinducers are therefore “master” regulators of bacterial lifestyles. For over 10ï¿½years, mathematical modelling of QS has sought, in parallel to experimental discoveries, to elucidate the mechanisms regulating this process. In this review, we present the progress in mathematical modelling of QS, highlighting the various theoretical approaches that have been used and discussing some of the insights that have emerged. Modelling of QS has benefited almost from the onset of the involvement of experimentalists, with many of the papers which we review, published in non-mathematical journals. This review therefore attempts to give a broad overview of the topic to the mathematical biology community, as well as the current modelling efforts and future challenges. ï¿½ 2016, Society for Mathematical Biology.
Open Access
Reconfigurable MRI technology for low-SAR imaging of deep brain stimulation at 3T: application in bilateral leads, fully-implanted systems, and surgically modified lead trajectories
(Elsevier, 2019) Kazemivalipour, Ehsan; Keil, B.; Vali, A.; Rajan, S.; Elahi, B.; Atalar, Ergin; Wald, L.; Rosenow, J.; Pilitsis, J.; Golestanirad, L.
Patients with deep brain stimulation devices highly benefit from postoperative MRI exams, however MRI is not readily accessible to these patients due to safety risks associated with RF heating of the implants. Recently we introduced a patient-adjustable reconfigurable coil technology that substantially reduced local SAR at tips of single isolated DBS leads during MRI at 1.5 T in 9 realistic patient models. This contribution extends our work to higher fields by demonstrating the feasibility of scaling the technology to 3T and assessing its performance in patients with bilateral leads as well as fully implanted systems. We developed patient-derived models of bilateral DBS leads and fully implanted DBS systems from postoperative CT images of 13 patients and performed finite element simulations to calculate SAR amplification at electrode contacts during MRI with a reconfigurable rotating coil at 3T. Compared to a conventional quadrature body coil, the reconfigurable coil system reduced the SAR on average by 83% for unilateral leads and by 59% for bilateral leads. A simple surgical modification in trajectory of implanted leads was demonstrated to increase the SAR reduction efficiency of the rotating coil to >90% in a patient with a fully implanted bilateral DBS system. Thermal analysis of temperature-rise around electrode contacts during typical brain exams showed a 15-fold heating reduction using the rotating coil, generating <1C temperature rise during ∼4-min imaging with high-SAR sequences where a conventional CP coil generated >10C temperature rise in the tissue for the same flip angle.