Managers have responsibility for implementing a firm??s executional strategy. An executional strategy is the selection of resources and capabilities and the arrangement of them into a supply chain that puts a firm??s espoused positioning into action (Porter, 1985). Executional strategies are selected to maximize economic rents. Firm resources (Barney, 1991) and the arrangement of supply chains (Chandler, 1962; 1990) are important to rent generation. In turn, the potential arrangement of activities into a supply chain is determined by a firm??s depth of architectural knowledge; this is knowledge of how supply chain elements can be linked (Henderson and Clark, 1990). The study provides a simultaneous test of the impact of resources and supply chain arrangements on the selection of executional strategies. The theoretical model is tested through a discrete choice experiment (Louviere et al., 2000). Findings suggest that resources and cost advantages dominate management decision-making with competition also an influence. Importantly, findings for a sub-sample of subjects whose firms are most impacted by Information technology (IT), confirms that architectural knowledge does play a role in the selection of executional strategies. These ??engaged?? subjects were significantly more experienced with the subject matter and more confident about their responses. These engaged subjects utilized architectural knowledge to select strategies that leveraged their resources more widely and to minimize the influence of transaction costs on their strategic choices.

<p><p>Microstrip structures became very attractive with the development of cost-effective dielectric materials. Among several techniques suitable to the analysis of such structures, the discrete mode matching method (DMM) is a full-wave approach that allows a fast solution to Helmholz equation. Combined with a full-wave equivalent circuit, the DMM allows fast and accurate analysis of microstrips lines on multilayered substrates.</p><p> </p><p>The knowledge of properties like dispersion and electromagnetic fields is essential in the implementation of such transmission lines. For this objective a MATLAB computer code was developed based on the discrete mode matching method (DMM) to perform this analysis.</p><p> </p><p>The principal parameter for the analysis is the utilization of different dielectric profiles with the aim of a reduction in the dispersion in comparison with one-layer cylindrical microstrip line, showing a reduction of almost 50%. The analysis also includes current density distribution and electromagnetic fields representation. Finally, the data is compared with Ansoft HFSS to validate the results.</p></p> / The German Aerospace Center has rights over the thesis work

Cycle-to-cycle control is a method for using feedback to improve product quality for processes that are inaccessible within a single processing cycle. This limitation stems from the impossibility or the prohibitively high cost of placing sensors and actuators that could facilitate control during, or within, the process cycle. Our previous work introduced cycle to cycle control for single input-single output systems, and here it is extended to multiple input-multiple output systems. Gain selection, stability, and process noise amplification results are developed and compared with those obtained by previous researchers, showing good agreement. The limitation of imperfect knowledge of the plant model is then imposed. This is consistent with manufacturing environments where the cost and number of tests to determine a valid process model is desired to be minimal. The implications of this limitation are modes of response that are hidden from the controller. Their effects on system performance and stability are discussed. / Singapore-MIT Alliance (SMA)

Iterative solutions of the Boltzmann transport equation are computationally intensive. Spatial multigrid methods have led to efficient iterative algorithms for solving a variety of partial differential equations; thus, it is natural to explore their application to transport equations. Manteuffel et al. conducted such an exploration in one spatial dimension, using two-cell inversions as the relaxation or smoothing operation, and reported excellent results. In this dissertation we extensively test Manteuffel??s one-dimensional method and our modified versions thereof. We demonstrate that the performance of such spatial multigrid methods can degrade significantly given strong heterogeneities. We also extend Manteuffel??s basic approach to two-dimensional problems, employing four-cell inversions for the relaxation operation. We find that for uniform homogeneous problems the two-dimensional multigrid method is not as rapidly convergent as the one-dimensional method. For strongly heterogeneous problems the performance of the two-dimensional method is much like that of the one-dimensional method, which means it can be slow to converge. We conclude that this approach to spatial multigrid produces a method that converges rapidly for many problems but not for others. That is, this spatial multigrid method is not unconditionally rapidly convergent. However, our analysis of the distribution of eigenvalues of the iteration operators indicates that this spatial multigrid method may work very well as a preconditioner within a Krylov iteration algorithm, because its eigenvalues tend to be relatively well clustered. Further exploration of this promising result appears to be a fruitful area of further research.

Recent innovations in design and construction of architectural buildings has led us to revisit the metrics for discretizing smooth freeform shapes in context with both aesthetics and fabrication. Inspired by the examples of the British Museum Court Roof in Britain and the Beijing Aquatic Centre in China, we propose solutions for generating aesthetic as well as economically viable solutions for tessellating smooth, freeform shapes. For the purpose of generating an aesthetic tessellation, we propose a simple linearized strain based metric to minimize dissimilarity amongst triangles in a local neighborhood. We do so by defining an error function that measures deformation required to map a pair of triangles onto each other. We minimize the error using a global non-linear optimization based framework. We also reduce the complexity associated with prefabricating triangulated panels for a given shape. To do so, we propose a global optimization based framework to approximate any given shape using significantly reduced numbers of unique triangles. By doing so, we leverage the economies of scale as well as simplify the process of physical placement of panels by manual labor.

Microstrip structures became very attractive with the development of cost-effective dielectric materials. Among several techniques suitable to the analysis of such structures, the discrete mode matching method (DMM) is a full-wave approach that allows a fast solution to Helmholz equation. Combined with a full-wave equivalent circuit, the DMM allows fast and accurate analysis of microstrips lines on multilayered substrates.   The knowledge of properties like dispersion and electromagnetic fields is essential in the implementation of such transmission lines. For this objective a MATLAB computer code was developed based on the discrete mode matching method (DMM) to perform this analysis.   The principal parameter for the analysis is the utilization of different dielectric profiles with the aim of a reduction in the dispersion in comparison with one-layer cylindrical microstrip line, showing a reduction of almost 50%. The analysis also includes current density distribution and electromagnetic fields representation. Finally, the data is compared with Ansoft HFSS to validate the results. / The German Aerospace Center has rights over the thesis work

The methodology of discrete-event simulation provides a promising alternative to solving complicated construction systems. Given the level of uncertainty that exists in the early estimation phase of mega-projects regarding cost and risk, project simulations have become a central part of decision-making and planning. In this paper, an attempt is made to compare the output generated by a model constructed under the Monte Carlo framework with that of Discrete-Event Simulation to determine the similarities and difference between the two methods. To achieve this, the Simphony modeling (DES) environment is used. The result is then compared to a Monte Carlo simulation conducted by Golder Associates.

The methodology of discrete-event simulation provides a promising alternative to solving complicated construction systems. Given the level of uncertainty that exists in the early estimation phase of mega-projects regarding cost and risk, project simulations have become a central part of decision-making and planning. In this paper, an attempt is made to compare the output generated by a model constructed under the Monte Carlo framework with that of Discrete-Event Simulation to determine the similarities and difference between the two methods. To achieve this, the Simphony modeling (DES) environment is used. The result is then compared to a Monte Carlo simulation conducted by Golder Associates.

In this dissertation, advanced numerical methods for highly forward peaked scattering deterministic calculations are devised, implemented, and assessed. Since electrons interact with the surrounding environment through Coulomb interactions, the scattering kernel is highly forward-peaked. This bears the consequence that, with standard preconditioning, the standard Legendre expansion of the scattering kernel requires too many terms for the discretized equation to be solved efficiently using a deterministic method. The Diffusion Synthetic Acceleration (DSA), usually used to speed up the calculation when the scattering is weakly anisotropic, is inefficient for electron transport. This led Morel and Manteuffel to develop a one-dimensional angular multigrid (ANMG) which has proved to be very effective when the scattering is highly anisotropic. Later, Pautz et al. generalized this scheme to multidimensional geometries, but this method had to be stabilized by a diffusive filter that degrades the overall convergence of the iterative scheme. In this dissertation, we recast the multidimensional angular multigrid method without the filter as a preconditioner for a Krylov solver. This new method is stable independently of the anisotropy of the scattering and is increasingly more effective and efficient as the anisotropy increases compared to DSA preconditioning wrapped inside a Krylov solver. At the coarsest level of ANMG, a DSA step is needed. In this research, we use the Modified Interior Penalty (MIP) DSA. This DSA was shown to be always stable on triangular cells with isotropic scattering. Because this DSA discretization leads to symmetric definite-positive matrices, it is usually solved using a conjugate gradient preconditioned (CG) by SSOR but here, we show that algebraic multigrid methods are vastly superior than more common CG preconditioners such as SSOR. Another important part of this dissertation is dedicated to transport equation and diffusion solves on arbitrary polygonal meshes. The advantages of polygonal cells are that the number of unknowns needed to mesh a domain can be decreased and that adaptive mesh refinement implementation is simplified: rather than handling hanging nodes, the adapted computational mesh includes different types of polygons. Numerical examples are presented for arbitrary quadrilateral and polygonal grids.

One question relating to partially ordered sets (posets) is that of partitioning or dividing the poset's elements into the fewest number of chains that span the poset. In 1950, Dilworth established that the width of the poset - the size of the largest set composed only of incomparable elements - is the minimum number of chains needed to partition that poset. Such a bound in on-line partitioning has been harder to establish, and work has evalutated classes of posets based on their width. This paper reviews the theorems that established val(2)=5 and illustrates them with examples. It also covers some of the work on establishing bounds for on-line partitioning with the Greedy Algorithm. The paper concludes by contributing a bound on incomparable elements in graded, (t+t)-free, finite width posets.