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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Supply chain strategies and practices: an exploratory study. / CUHK electronic theses & dissertations collection

January 2006 (has links)
Keywords. Competitive strategy, Supply chain strategy, Leanness, Agility, Environmental uncertainty, Moderator, Cumulative model. / Supply chain management has become one of the most popular approaches to enhance the global competitiveness of business corporations today. Thus, it has received more and more attention from practitioners and the academia. However, how to effectively manage the flow of materials from supply sources to the ultimate customer represents a major challenge for today's managers. From the viewpoint of business competition, Porter (1980) identified three general types of strategies, i.e., overall cost leadership, differentiation, and focus. This research tries to make an extension of this typology from an angle of supply chain management. Two general supply chain strategies including leanness and agility are identified in this study. / This research is composed of three studies. Study 1 makes a contribution to investigate the moderating effect of environmental uncertainty on the relationship between competitive strategy and supply chain strategy, and between supply chain strategy and financial performance. The findings prove that environmental uncertainty works as a homologizer in the proposed framework. Using multiple group structural equation analysis, the different strengths of the impact of competitive strategy on supply chain strategy and that of supply chain strategy on financial performance are identified. Study 2 tests the validity of the matrix proposed by Fisher (1997) and Christopher (2000) in which the relationship between product characteristics and supply chain structure is proposed. The findings show that the functional product needs a higher level of the use of the lean supply chain, while innovative products need a higher level of the use of the agile or leagile supply chain. The regression results demonstrate that the match between product characteristics and supply chain strategy indeed lead to higher performance. Finally, study 3 identifies several supply chain management practices through a thorough literature review of about 300 academic papers and classifies them into eight bundles. Based on Ferdows and De Meyer (1990)'s cumulative model, we propose that lean manufacturers should focus on such practices that help them build lean capabilities, and agile manufacturers need to build lean capabilities first before pursuing agility. / Qi Yinan. / "May 2006." / Adviser: Xiande Zhao. / Source: Dissertation Abstracts International, Volume: 68-02, Section: A, page: 0644. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 175-187). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.
42

The effects and detection of collinearity in an analysis of covariance

Giacomini, Jo Jane January 2011 (has links)
Typescript (photocopy). / Digitized by Kansas Correctional Industries
43

Behavior of an ion in a bubble in the ground state

Oh, Joung Hoon 01 January 1991 (has links)
Deuterons might be trapped in a bubble embryo which occur s due to statistical fluctuation in heavy water. The size of the bubble embryo is expected to be an order of a small molecule. The ground state energy level which the deuteron may occupy in the bubble is calculated by solving the Schroedinger equation, and by considering the interaction between the trapped deuteron by a spherical bubble and the surrounding polarized liquid medium (heavy water). From the dependence of the energy eigenvalue of the ground state on the bubble radius, the pressure exerted on the bubble wall is obtained. It is found that the pressure is negatively very large if the bubble radius is about the molecular size (3 to 7 Å). From extrapolating this result to larger sizes, we expect that a bubble would quickly collapse if enough energy is supplied and never grows to a stable bubble when the deuteron is trapped in the ground state.
44

Development of a mathematical N-line model for simulation of beach changes

Dang, Van To, Civil & Environmental Engineering, Faculty of Engineering, UNSW January 2006 (has links)
The development of a new N-Line model, which provides a practical tool for simulating regional beach changes induced by short and long-term processes, is described in this thesis. The new N-Line model consists of four main modules that together describe the hydrodynamic and morphological responses. The four constituent modules have been integrated based on a wide range of research including the utility and function of commercial or freeware models. They are RCPWAVE wave module, time-averaged and depth-integrated current module, sediment transport module based on Bailard (1981) and contour change morphological module. Two different time-scales and two staggered grid systems for hydrodynamic and morphological simulations were adopted alternatively. For short-term 2D profile changes, new N-Line model applicability has been examined using data from the laboratory to the field. For ideal beaches, new N-Line can simulate an offshore storm bar generation or an onshore accretion due to high or low energy waves. For SUPERTANK large-scale flume data, the predicted profile matched the measured profile well, especially the bar height and position. For beach profile data from the Gold Coast, storm-induced variations of barred profiles were reasonably modelled. The new N-Line model compared well with other commonly used cross-shore models such as SBEACH and UNIBEST. A new schematisation for a non-monotonic profile and DUNED inclusion were introduced. Sensitivity tests on cross-shore sediment coefficient (Kq), smoothing parameter (??s) and water level fluctuations were performed. For long-term 3D beach changes, the new N-Line model applicability has been tested with various boundary conditions using idealized and real field data. Two periods, 17 and 16 months, of beach changes before and after a major bypass plant commenced operation in 2001 at Letitia Spit were simulated. The profile and shoreline changes were predicted reasonably well. Empirical model parameters were determined after a range of sensitivity and calibration testing. The new N-Line model showed its better performance compared to one-line models. It can handle various boundary conditions, especially bypass conditions. The N-Line model is not only capable of modelling planform variations but also cross-shore profile changes.
45

A multidisciplinary approach to complex systems design.

Ryan, Alex J. January 2007 (has links)
The design and management of organised systems, comprised of dynamic interdependent collectives of autonomous agents, is the kind of problem that the discipline of complex systems is intended to address. Nevertheless, conventional model-based applications of complex systems may be of limited utility when the problem is also data-poor and soft. In this case, a quantitative model may be at best meaning-less; at worst harmful. Systems approaches, such as soft systems methodologies, have been developed that provide some guidance in this domain. However, these alternatives do not utilise the exact techniques of complex systems, preferring to abandon mathematical representations altogether. It is the aim of this thesis to advance a “conceptual analysis" approach to complex systems design that exploits deep insights from the mathematics of complex systems, without building explicit models of the underlying system. It is argued that this approach can extend the domain of applicability of the discipline of complex systems into situations where quantitative data is unavailable, and human and social factors are significant. Conceptual analysis of complex systems is inherently multidisciplinary, because it is broader than the foundations of any single conventional discipline. This is reflected in the structure of this thesis, which spans the philosophy, theory and application of complex systems. Part I on systems philosophy develops an understanding of representation, which sheds light on the utility and limitations of models. The history of the systems movement is then surveyed, systemism is distinguished from both individualism and holism, and `system' is defined. Complex systems is contrasted with both early systems theory and contemporary systems approaches. Part II on complex systems theory firstly relates the major theoretical concepts within a rigourous information theoretical framework. They include complexity, edge of chaos, self-organisation, emergence, adaptation, evolution and self refer- entiality. The central systems concept - emergence - is then examined in depth beyond its information theoretic interpretation, leading to a concise definition of emergent properties and emergence. A new framework for understanding emergence in terms of scope, resolution and state yields substantial novel insights. It is shown that emergence is coupled to scope, in contrast to the conventional explanation that relates levels of description. Part III applies the preceding philosophical and theoretical framework to real-world problems in the defence and security arena. In the first example, the theory of multi-scale complexity reveals structural impediments to success for conventional force structures in asymmetric warfare, such as Operation Iraqi Freedom. The second example analyses the capability development process, which is responsible for transforming the security needs of Government into equipment purchasing decisions. The analysis produces practical recommendations for improvements that address the underlying complexity of the problem. Reflections in the conclusion of this thesis focus on the interrelations between philosophy, theory and application. As the individual contributions of this thesis are woven into a single tapestry, they demonstrate the utility of a multidisciplinary approach to complex systems design. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1283989 / Thesis(PhD) -- University of Adelaide, School of Mathematical Sciences, 2007
46

Advanced numerical modeling of the Lorentz mixing process

Hager, Michael B. 10 December 1996 (has links)
There are numerous techniques for improving the mixing of fuel and oxidant species. However, many of these methods cannot be applied to combustion systems due to material limitations. A means of mixing the reacting species without physically invading the flow stream is therefore desired. In this work, induced electromagnetic forces known as Lorentz forces are considered as a means of enhancing the combustion of co-flowing reactant streams. To evaluate the effect of various parameters on the mixing process, a non-dimensional description is derived and used to develop a numerical model. Numerical experiments are performed based on a three level Box-Behnken design in which the dimensionless Lorentz force parameter, Reynolds number, and Euler number are varied. The Lorentz force parameter has a large effect on the mixing process. The Reynolds number has a minor effect on mixing, and the Euler number has a negligible effect. Confirmation of these results through experimental work is needed. Approaches that could be used to verify these results experimentally are outlined, and the construction and testing of a burner suitable for further experiments on Lorentz mixing is described. / Graduation date: 1997
47

Coupled dynamics of bouys and mooring tethers

Idris, Krisnaldi 19 May 1995 (has links)
Time-domain models were developed to predict the response of a tethered buoy subject to hydrodynamic loadings. A coupled analysis of the interaction of a buoy and its mooring is included and three-dimensional response is assumed. External loadings include hydrodynamic forces, tethers tensions, wind loadings and the weight of both cable and buoy. System nonlinearities include, large rotational and translational motions, and non-conservative fluid loadings. The mooring problem is formulated as a nonlinear two-point-boundary-value-problem. The problem is then converted to a combine initial-value and boundary-value problem to a discrete boundary-value problem at particular time, using a Newmark-like difference formula. At each instant in time the nonlinear boundary-value problem is solved by direct integration and using a successive iterative algorithm, such that boundary conditions are always satisfied. Buoy equations of motion are derived by both a small angle assumption and a large angle assumption. The small angle formulation uses the Eulerian angle for rotational coordinates. Coupling between the buoy and cable is performed by adopting the buoy equations of motion as boundary conditions at one end for the mooring problem. The rotational coordinates for the large angle formulation are represented by Euler parameters. The large angle formulation is solved by a predictor-corrector type of time integration of buoy motions constrained by tether forces. Coupling between the buoy and moorings is then enforced through matching of the velocity of the tether attachment points on the buoy with velocity of the tether ends; the velocities of tether attachment points serve as boundary conditions for the various mooring cables attached. Multiple time steps are used to account for different sizes of integration time step required for stability of solution in the buoy and tether. Numerical examples are provided to contrast the validity and capability of the formulations and solution techniques. Responses of three types of buoy (sphere, spar and disc) are predicted by the present models and compared to results obtained by experiments. Application of the present model to solve a multi-leg/multi-point mooring system is also provided. / Graduation date: 1996
48

Modified limiting dilution analysis : a mathematical model with biological interpretation

Maier, Stefan H. 04 April 1994 (has links)
A mathematical model of Limiting Dilution Analysis for two limiting parameters is presented and investigated. Limiting Dilution Analysis is a microbiological cell assay developed for immunological application. In the given case we deal with the interaction between B lymphocytes, macrophage derived factor and T-independent antigens. The state of the art is that quantitative statements are only possible if one cell type (in general the B cells) is limiting and all others are in excess present. The basis for this thesis is a set of experiments in which B cells and macrophage derived factor are limiting and all other involved cells and factors are in saturating amounts present. It is shown that so far presented suggestions on modeling Limiting Dilution Analysis for two limiting cell-types are not suitable for this problem. Further, a mathematical model based on data is presented and interpreted in immunological terms with the help of a set of partial differential equations. The basis for the interpretation of the model are changes in affinity and saturation effects, both not incorporated in the so far presented models of the assay. In particular the relevance of mathematical interpretation of this process for the identification of new concepts as the saturation effects is stressed. The model of partial differential equations is highly non-linear but offers the possibility of interpreting the highly interrelated processes apart from each other. / Graduation date: 1994
49

Agents' agreement and partial equilibrium pricing in incomplete markets

Anthropelos, Michail, 1980- 25 September 2012 (has links)
We consider two risk-averse financial agents who negotiate the price of an illiquid indivisible contingent claim in an incomplete semimartingale market environment. Under the assumption that the agents are exponential utility maximizers with non-traded random endowments, we provide necessary and sufficient conditions for the negotiation to be successful, i.e., for the trade to occur. We, also, study the asymptotic case where the size of the claim is small compared to the random endowments and give a full characterization in this case. We, then, study a partial-equilibrium problem for a bundle of divisible claims and establish its existence and uniqueness. A number of technical results on conditional indifference prices are provided. Finally, we generalize the notion of partial-equilibrium pricing in the case where the agents' risk preferences are modelled by convex capital requirements. / text
50

Numerical simulation of turbulent flow and microclimate within and above vegetation canopy

Poon, Hao-chi, Cynthia., 潘顥之. January 2010 (has links)
published_or_final_version / Mechanical Engineering / Master / Master of Philosophy

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