Optimal Control of Vehicular Formations With Nearest Neighbor Interactions

We consider the design of optimal localized feedback gains for one-dimensional formations in which vehicles only use information from their immediate neighbors. The control objective is to enhance coherence of the formation by making it behave like a rigid lattice. For the single-integrator model with symmetric gains, we establish convexity, implying that the globally optimal controller can be computed efficiently. We also identify a class of convex problems for double-integrators by restricting the controller to symmetric position and uniform diagonal velocity gains. To obtain the optimal non-symmetric gains for both the single- and the double-integrator models, we solve a parameterized family of optimal control problems ranging from an easily solvable problem to the problem of interest as the underlying parameter increases. When this parameter is kept small, we employ perturbation analysis to decouple the matrix equations that result from the optimality conditions, thereby rendering the unique optimal feedback gain. This solution is used to initialize a homotopy-based Newton’s method to find the optimal localized gain. To investigate the performance of localized controllers, we examine how the coherence of large-scale stochastically forced formations scales with the number of vehicles. We establish several explicit scaling relationships and show that the best performance is achieved by a localized controller that is both non-symmetric and spatially-varying

Augmented Lagrangian Approach to Design of Structured Optimal State Feedback Gains

We consider the design of optimal state feedback gains subject to structural constraints on the distributed controllers. These constraints are in the form of sparsity requirements for the feedback matrix, implying that each controller has access to information from only a limited number of subsystems. The minimizer of this constrained optimal control problem is sought using the augmented Lagrangian method. Notably, this approach does not require a stabilizing structured gain to initialize the optimization algorithm. Motivated by the structure of the necessary conditions for optimality of the augmented Lagrangian, we develop an alternating descent method to determine the structured optimal gain. We also utilize the sensitivity interpretation of the Lagrange multiplier to identify favorable communication architectures for structured optimal design. Examples are provided to illustrate the effectiveness of the developed method

Determining source code repetitiveness on various types of programming assignments

This study was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia, and these results are parts of the Grant No. 451-03-68/2022-14/200132 with the University of Kragujevac - Faculty of Technical Sciences Čačak.Software projects code duplication and plagiarism are very important in various test cases. The purpose of the work presented in this paper is to observe how various software architectures, project structures, and coding approaches generate different views on code changes. In this paper, code plagiarism -code comparing, in different types of projects has been analyzed through two different approaches. Pythonscript based on the sequence matcher function and the GitLab compare tool are analyzed and compared.Results are presented and discussed in the paper.Publishe

Use of electronic design automation tools in computer engineering courses

The research in this paper is part of the project 451-03-68/2022-14/200132 funded by the Ministry of Education, Science and Technological Development of the Republic of Serbia.Electronic Design Automation (EDA) tools are widely used semiconductor industry to support the ever-growing complexity of computer design, and they became an important skill which is required by computer engineers. In this paper, we present the usage of the EDA Playground web platform for practical exercise in the Digital systems design course at the computer engineering department of the Faculty of technical sciences. This platform was used in process of designing and testing of program counter register of a simple processor.Publishe

Novel Patched 1 mutations in patients with nevoid basal cell carcinoma syndrome - case report

Nevoid basal cell carcinoma syndrome (Gorlin syndrome) is a rare autosomal dominant disorder characterized by numerous basal cell carcinomas, keratocystic odontogenic tumors of the jaws, and diverse developmental defects. This disorder is associated with mutations in tumor suppressor gene Patched 1 (PTCH1). We present two patients with Gorlin syndrome, one sporadic and one familial. Clinical examination, radiological and CT imaging, and mutation screening of PTCH1 gene were performed. Family members, as well as eleven healthy controls were included in the study. Both patients fulfilled the specific criteria for diagnosis of Gorlin syndrome. Molecular analysis of the first patient showed a novel frameshift mutation in exon 6 of PTCH1gene (c.903delT). Additionally, a somatic frameshift mutation in exon 21 (c.3524delT) along with germline mutation in exon 6 was detected in tumor-derived tissue sample of this patient. Analysis of the second patient, as well as two affected family members, revealed a novel nonsense germline mutation in exon 8 (c.1148 C gt A)

Low-complexity modeling of partially available second-order statistics: theory and an efficient matrix completion algorithm

Non UBCUnreviewedAuthor affiliation: University of MinnesotaFacult

Pleistocene small-vertebrates (amphibians, reptiles, and small mammals) studies in Serbia (Balkan Peninsula, SE Europe): history of research, methodological state of the art, and paleoclimatic and paleoenvironmental reconstructions

Durant el MIS 2, els resultats suggereixen que els Balcans tenien un clima més suau i humit en comparació amb l’Europa central, amb una temperatura mitjana que oscil·lava entre 2,2 i 4,5 ºC inferior a l’actual. Les capes d’holocè no es conserven generalment a causa de la barreja estratigràfica, però en els casos en què és possible distingir les primeres capes d’holocè, aquestes poden contenir informació molt valuosa sobre les espècies que van sobreviure a l’últim màxim glacial o sobre la complexa repoblació de la península dels Balcans per part dels amfibis. i rèptils. En general, no hi va haver canvis ecològics importants durant la transició entre Mousterian i Aurignacian, és a dir, entre els neandertals i els humans anatòmicament moderns. Aquesta conclusió coincideix generalment amb l’opinió comuna que el canvi climàtic no va ser un factor crucial en l’extinció neandertal a la península dels Balcans; en canvi, va tenir un efecte similar a les penínsules Ibèrica i Apenina, on el clima més suau va permetre als neandertals trobar refugi i sobreviure més temps que a la resta d’Europa. MIS 5 es reconstrueix per ser molt més càlid que l'actual, amb temperatures mitjanes de 2,2 ºC superiors a les actuals, cosa que va permetre que les espècies termòfiles prosperessin en aquestes condicions.Durante el MIS 2, los resultados sugieren que los Balcanes tenían un clima más suave y húmedo en comparación con Europa Central, con una temperatura media que oscilaba entre 2,2 y 4,5 ºC por debajo de la actual. Las capas del Holoceno generalmente no se conservan debido a la mezcla estratigráfica, pero en los casos en que es posible distinguir capas del Holoceno temprano, estas pueden contener información muy valiosa sobre las especies que sobrevivieron al Último Máximo Glacial, o la compleja repoblación de la Península Balcánica por anfibios. y reptiles. En general, no hubo cambios ecológicos importantes durante la transición entre los musulmanes y los auriñacienses, es decir, entre los neandertales y los humanos anatómicamente modernos. Esta conclusión coincide en general con la opinión común de que el cambio climático no fue un factor crucial en la extinción de los neandertales en la península de los Balcanes; en cambio, tuvo un efecto similar al de las penínsulas ibérica y de los Apeninos, donde el clima más suave permitió a los neandertales encontrar refugio y sobrevivir más tiempo que en el resto de Europa. MIS 5 está reconstruido para que haya sido mucho más cálido que hoy, con temperaturas promedio de alrededor de 2,2 ºC más altas que las actuales, lo que permitió que las especies termófilas prosperasen en tales condiciones.During the MIS 2, results suggest that the Balkans had milder and humid climate compared to Central Europe, with average temperature ranging from 2.2 to 4.5 ºC lower than presently. Holocene layers are generally not preserved due to stratigraphic mixing, but in cases where it is possible to distinguish early Holocene layers, these might contain very valuable information on the species that survived the Last Glacial Maximum, or the complex repopulating of the Balkan Peninsula by amphibians and reptiles. Overall, there were no important ecological changes during the transition between Mousterian and Aurignacian, i.e. between Neanderthals and Anatomically Modern Humans. This conclusion is generally in line with common opinion that climate change was not a crucial factor in Neanderthal extinction in the Balkan Peninsula; instead it had the effect similar to Iberian and Apennine Peninsulas, where milder climate allowed Neanderthals to find refuge and survive longer than in the rest of the Europe. MIS 5 is reconstructed to have been much warmer than today, with temperatures averaging around 2.2 ºC higher than today, which allowed thermophilic species to thrive in such conditions

Sparsity-promoting optimal control of distributed systems

Non UBCUnreviewedAuthor affiliation: University of MinnesotaFacult