This thesis proposes an alternative cooperating strategy for cooperative communications through the use of parley algorithm in cooperative communications. When employing parley algorithm in cooperative communications, the relay nodes and the destination node need to disseminate and agree on a common decision throughout the cooperation network via a consensus flooding procedure. In this thesis, a heuristic approach for improving the performance of the parley algorithm is proposed. This heuristic approach is to design power allocation method during each iteration of consensus flooding protocol. Specifically, when distributing the power to each node within the cooperative network, this thesis adopts the criterion of maximum capacity of the broadcast channel used for consensus flooding procedures. The simulation result obtained from the investigation of this thesis shows that the proposed power allocation approach can improve the performance in terms of bit error rate as compared with the parley algorithm with uniform power allocation, and, hence, confirms the proposed idea is useful.

Arterial endothelial cells (ECs) are subjected to pulsatile strain due to pressure changes in the cardiac cycle and this may play a significant role in vascular function in health and disease. Further, ECs differentially respond to different patterns of strain. There is much evidence that cyclic uniaxial strain results in a perpendicular orientation of ECs and their stress fibers, while no such alignment occurs in response to cyclic equaibiaxial stretch. It is unclear how cells and their stress fibers determine their specific response to particular spatiotemporal changes in the matrix, however. Given that ECs located at regions in the arterial tree prone to atherogenesis are non-aglined, while ECs in relatively healthy regions are oriented perpendicular to the principal direction of cyclic stretch, it is important to understand the mechanisms which regulate stretch-induced stress fiber alignment. The focus of this thesis was to develop realistic models to describe the dynamic changes in the organization of stress fibers in response to diverse spatiotemporal patterns of stretch. The model is based on the premise that stress fibers are pre-stressed at a ?homeostatic? level so that stress fibers are extended beyond their unloaded lengths, and that perturbation in stress fiber length from the homeostatic level destabilizes the stress fibers. A deterministic model described experimentally measured time courses of stress fiber reorientation perpendicular to the direction of cyclic uniaxial stretch, as well as the lack of alignment in response to equibiaxial stretch. In the case of cyclic simple elongation with transverse matrix contraction, stress fibers oriented in the direction of least perturbation in stretch. Model analysis indicated the need for a time-dependent stress fiber mechanical property, however. Thus, a stochastic model was developed that incorporated the concept that stress fibers tend to self-adjust to an equilibrium level of extension when they are perturbed from their unload lengths with the turnover of stress fibers. The stochastic model successfully described experimentally measured time courses of stress fiber reorganization over a range of frequencies. At a frequency of 1 Hz, stress fibers predominantly oriented perpendicular to stretch, while at 0.1 Hz the extent of stress fiber alignment was markedly reduced and at 0.01 Hz there was no alignment at all. Both the deterministic and stochastic models accurately described the relationship between stretch magnitude and the extent of stress fiber alignment in endothelial cells subjected to cyclic uniaxial stretch. Parameter sensitivity analyses for each model were used to demonstrate the effects of each parameter on the characteristics of the system response. In summary, the mathematical models were capable of describing stress fiber reorganization in response to diverse temporal and spatial patterns of stretch. These models provide a theoretical framework to elucidate the mechanisms by which adherent cells sense the characteristics of matrix deformation and describe a mechanism by which the cells can then adapt to such deformations to maintain mechanical homeostasis.

Les systèmes de tenségrité sont des structures légères réticulées, formées de barres et de câbles, en état d'autocontrainte stable. Ils sont utilisés pour composer des structures légères, de grande portée, visuellement transparentes et, pour certains cas, déployables. Ces structures sont sujettes à des problèmes de déformations et de vibrations lorsqu'elles sont soumises à des charges externes, d'origine climatique, humaine, ou sismique. On s'intéresse dans cette étude au contrôle des vibrations d'une grille plane de tenségrité. L'objectif est l'amortissement actif des deux premiers modes propres, par commande d'actionneurs intégrés à la structure. Une synthèse de loi de commande robuste est développée afin de minimiser le niveau des vibrations tout en conservant la même efficacité lorsque la rigidité ou la masse varie. En utilisant la simulation, nous proposons une nouvelle structure active de tenségrité avec le même principe de contrôle. / Tensegrity systems are selfstressed reticulate space structure. They are defined as a set of elements maintained in compression inside a continous set of tense components, wich are generally cables. As lightweight frames, they are subject to deformation and vibration issues when faced to external loads, climate, human, or seismic. We are interested in this thesis to the vibration control of a tensegrity plane grid. The objective is the active damping of the first two modes, by controlling actuators integrated into the structure. A robust control law is developed to minimize the vibration level while maintaining the same efficiency when the stiffness or mass varies. Using simulation, new active tensegrity structures that use similaractuation principle can be proposed.

There are increasing economic incentives within the chemical process industry towards demand driven operation with product diversification, requiring flexible operation in responsive plants. In continuous processes, this is realized through steady-state transitions but requires consideration of process dynamics arising from operation that is inherently transient in nature. The steady-state economic optimum is typically defined at the intersection of constraints, and requires multivariable control with optimal constraint handling capabilities. Thus, constrained model predictive control is well-suited to realize the profit potential at the economic optimum. In this thesis, feasible and optimal steady-state transitions are achieved using reference management with consideration of the closed-loop dynamics of constrained model predictive control. The supervisory control scheme is used to determine the optimal setpoint trajectory which is subsequently tracked by regulatory control, incorporating feedback for the rejection of high frequency disturbances and eliminating steady-state offset in the presence of model mismatch. The separation of economic and control objectives enables the lower level to be tuned for stability and the upper level to be tuned for performance. The mathematical formulation results in a multi-level optimization problem with an economic objective function at the upper level, and a series of control performance objective functions arising from constrained model predictive control at the lower levels. The solution strategy proposed converts the multi-level optimization problem into a single-level optimization problem using the Karush-Kuhn-Tucker conditions, and solves the resulting complementarity conditions using an interior point approach. Alternative objective formulations are investigated based on maximizing profit during transient operation. The first formulation is typically based on a quadratic objective function minimizing the transition time, indirectly improving economic operation by reducing the amount of off-specification product produced. The second formulation is based on the explicit consideration of economics. The profit calculated during transient operation is based on the difference between the revenue generated by the production of acceptable product within specified univariate product quality bands, and the operational costs of raw materials and utilities. The resulting linear objective function is further extended to incorporate control performance considerations to improve conditioning for gradient based optimization. The proposed methodology is applied to a single-input single-output linear system, demonstrating the potential benefits of simultaneous rather than sequential optimization in terms of computational efficiency and solution reliability. Alternative objective function and constraint formulations are investigated, and the effect on the optimal solution assessed. In particular, the possibility of indeterminacy is shown and handled using hierarchical optimization. The methodology is also demonstrated on additional examples including non-minimum phase systems and multi-input multi-output linear systems. Application to a multi-input multi-output nonlinear system corresponding to styrene polymerization using the proposed methodology is detailed. The set of differential and algebraic equations defining the process is discretized using orthogonal collocation on finite elements. The optimal operation during grade transitions based on explicit consideration of economics is determined, and additional improvements realized by manipulating the production rate. Finally, reference management with online re-optimization is investigated for a single-input single-output linear system based on a bias update, and the improvement in closed-loop performance assessed for output disturbances and model mismatch. The methodology is also demonstrated on a multi-input multi-output system based on a linear model when applied to the nonlinear process. The proposed methodology developed for steady-state transitions may also be applied to batch operation, startups and shutdowns. Future extensions include analysis of closed-loop stability due to the incorporation of feedback within the cascade control scheme, and the explicit consideration of uncertainty. / Thesis / Master of Applied Science (MASc)

The aims of the Lithuanian Health Programme (1998) are to reduce the death rate in patients following stoke, age younger than 65 years old by 15%, and by 10% in patients at age of 65-74 years old, up to year 2010. While trying to enhance the recovery results following the abovementioned disease it is necessary to erect and renew the effective rehabilitation system. The aim is to estimate the effectiveness of The Constrain – Induce Movement Test on arm functions’ recovery of the post - stroke patients. The were two groups of testees, experimental group and control group, each composed of 30 stroke patients. The methods used while writing this study were as follows: the analysis of the used literature sources, and the testing (the evaluation of movements and the Nine Hole Peg Test). The Constrain – Induce Movement Test applied while carrying out this experiment statistically credibly improved the function of the patients’ arms. The average of the evaluation of shoulders arch movements in the control group is 3,13 ± 0,61 points. In the experimental group the average is 4,53 ± 0,97 points. The margin of 1,4 point is statistically reliable (p<0,05). There was also noticed a significant improvement in hand movements in the experimental group. The average of the evaluation of hand movements in the control group is 3,4 ± 0,67 points, while in the experimental group the average is 5,07 ± 0,87 points. The margin is 1,67 points (p<0,05). Analogous results were drawn while estimating... [to full text]

In this dissertation, we show two significant applications of combinatorial branch-and-bound as an exact solution methodology in combinatorial optimization problems. In the first problem, we propose a set of new group centrality metrics and show their performance in estimating protein importance in protein-protein interaction networks. The centrality metrics introduced here are extensions of well-known nodal metrics (degree, betweenness, and closeness) for a set of nodes which is required to induce a specific pattern. The structures investigated range from the ``stricter'' induced stars and cliques, to a ``looser'' definition of a representative structure. We derive the computational complexity for each of the newly proposed metrics. Then, we provide mixed integer programming formulations to solve the problems exactly; due to the computational complexity of the problem and the sheer size of protein-protein interaction networks, using a commercial solver with the formulations is not always a viable option. Hence, we also propose a combinatorial branch-and-bound approach to solve the problems introduced. Finally, we conclude this work with a presentation of the performance of the proposed centrality metrics in identifying essential proteins in helicobacter pylori. In the second problem, we introduce the asymmetric probabilistic minimum-cost Hamiltonian cycle problem (APMCHCP) where arcs and vertices in the graph are possible to fail. APMCHCP has applications in many emerging areas, such as post-disaster recovery, electronic circuit design, and security maintenance of wireless sensor networks. For each vertex, we define a chance-constraint to guarantee that the probability of arriving at the vertex must be greater than or equal to a given threshold. Four mixed-integer programming (MIP) formulations are proposed for modeling the problem, including two direct formulations and two recursive formulations. A combinatorial branch-and-bound (CBB) algorithm is proposed for solving the APMCHCP, where data preprocessing steps, feasibility rules, and approaches of finding upper and lower bounds are developed. In the numerical experiments, the CBB algorithm is compared with formulations on a test-bed of two popular benchmark instance sets. The results show that the proposed CBB algorithm significantly outperforms Gurobi solver in terms of both the size of optimally solved instances and the computing time.

<p>The Gravity Control for Maya will be extraordinary</p><p>beneficial to an animator trying to create realistic</p><p>animation, by calculating the center of gravity and area</p><p>of balance. This control will provide the animator with</p><p>the ability to rotate around the center of gravity and</p><p>keep the character in a balanced pose. With that ability,</p><p>the animator can easily create accurate poses and</p><p>animation, such as mid-air flips. The system also</p><p>supports a vast number of characters with different</p><p>shapes, sizes and number of limbs.</p>

The Gravity Control for Maya will be extraordinary beneficial to an animator trying to create realistic animation, by calculating the center of gravity and area of balance. This control will provide the animator with the ability to rotate around the center of gravity and keep the character in a balanced pose. With that ability, the animator can easily create accurate poses and animation, such as mid-air flips. The system also supports a vast number of characters with different shapes, sizes and number of limbs.

Der Vortrag zeigt die Neuigkeiten in PTC Creo Simulate 3.0 auf. Zudem werden 10 "Tips & Tricks" erklärt, welche das Arbeiten effizienter machen.

Der Vortrag zeigt die Neuigkeiten in PTC Creo Simulate 3.0 auf. Zudem werden 10 "Tips & Tricks" erklärt, welche das Arbeiten effizienter machen.