A singular limit for an age structured mutation problem

The spread of a particular trait in a cell population often is modelled by an appropriate system of ordinary differential equations describing how the sizes of subpopulations of the cells with the same genome change in time. On the other hand, it is recognized that cells have their own vital dynamics and mutations, leading to changes in their genome, mostly occurring during the cell division at the end of its life cycle. In this context, the process is described by a system of McKendrick type equations which resembles a network transport problem. In this paper we show that, under an appropriate scaling of the latter, these two descriptions are asymptotically equivalent

Semigroup approach to diffusion and transport problems on networks

Models describing transport and diffusion processes occurring along the edges of a graph and interlinked by its vertices have been recently receiving a considerable attention. In this paper we generalize such models and consider a network of transport or diffusion operators defined on one dimensional domains and connected through boundary conditions linking the end-points of these domains in an arbitrary way (not necessarily as the edges of a graph are connected). We prove the existence of $C_0$-semigroups solving such problems and provide conditions fully characterizing when they are positive

Enhanced Modal Solutions for Structural Dynamics in Aerothermoelastic Analysis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90665/1/AIAA-2011-1963-873.pd

Effect of Control Surface-Fuselage Inertial Coupling on Hypersonic Vehicle Flight Dynamics

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90732/1/AIAA-2011-6378-636.pd

Proper Orthogonal Decomposition for Reduced-Order Thermal Solution in Hypersonic Aerothermoelastic Simulations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90633/1/AIAA-54293-921.pd

Enhanced Modal Solutions for Structural Dynamics in Aerothermoelastic Analysis

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/143066/1/1.C034122.pd

Education of IT students in the field of IT management practices and Sofware Asset Management in framework of IT studies at academic level

The aim of this article is to demonstrate the need to include good practises of Software Asset Management in the field of academic IT education of IT professionals. In the article based on the analysis of the Regulation of the Minister of Science and Higher Education of July 12, 2007 on educational standards for individual majors and levels of education, as well as the mode of creating and conditions for the university to conduct inter-departmental studies and macro-studies, research, literature and standards the necessity to familiarize IT students with good IT management practices (Software Asset Management (SAM), COBIT. ITIL, ITAM) was demonstrated and specific ranges of information that can be included as appropriate elements of education in the field was proposed

Calculation of natural frequencies of vibration of thin cylindrical shells of variable thickness

In this thesis the theoretical and experimental work is concerned with cylinders consisting of two sections of different thickness. It is claimed, however, that the method of solution developed is perfectly generally applicable to c:linders with any number of sections.The nature of the method permits it to be considered as nothing more than a good approximation, but the experimental findings illustrate how nearly accurate the calculated results are. It yet has the merit of both simplicity and brevity, and as such is of no small value in practical engineering calculations. Due to the presence of the sudden change of thickness of the cylinder, an exact mathematical solution of the problem would be most difficult and cumbersome, and as a working method would present no real value.The overall average agreement between experimental and calculated values of natural frequencies is to within about 2 per cent., but in most cases it is even closer.It is proposed in the next future to extend the present method of solution to cover the general case of a cylindrical shell consisting of any number of portions of different thickness; special consideration will have to be given to the modified beam analogy part of the method: already the natural frequencies of such a shell, which are higher than the Rayleigh frequency of its thickest portion, can be obtained by the process of "fitting together" successive sine -waves with wavelengths corresponding to the same frequency but different thickness ratios, starting from w = 0 at one end, in such a way as to obtain w = 0 at the other end. In addition to evolving the general method of solution, a comprehensive experimental investigation will have to be carried out