20 research outputs found

    Competitive Project Portfolio Management

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    Although project portfolio management (PPM) has been an active research area over the past 50 years, budget allocation models that consider competition are sparse. Firms faced with the project portfolio management problem must not only consider their current projections for the returns from their projects’ target markets, but must also anticipate that these returns can depend significantly on the investment decisions made by their competitors. In this thesis, we develop four Competitive PPM (CPPM) models wherein firms allocate resources between multiple projects and project returns are influenced by the actions taken by competitors. In the first two CPPM problems, we assume all-or-nothing project investment decisions where firms fully commit to either a project targeting a mature or an emerging market and the investment amount is fixed (first model) or a decision variable (second model). In the final two CPPM problems, firms have a fixed budget which they allocate in a continuous manner between two markets (third model) or multiple markets (fourth model). The returns each firm obtains from investments into these markets are assumed to follow an s-shaped curve (first model), the Inada (1963) conditions (third model), or are determined based on linear demand functions (second and fourth model). In the first model, two competing firms consider investing into two separate projects targeting a mature and an emerging market. We assume that firms have symmetric investment opportunities for each market and each firm simultaneously decides whether to invest in the mature or the emerging market. The returns from these markets are assumed to follow an s-shaped curve and depend on both firms’ investment decision. We characterize the variety of interactions that may emerge in symmetric environments (e.g., Prisoner’s Dilemma or Game of Chicken). For each game, we outline the CPPM strategy that can offer higher returns by exploiting first-mover advantages, cooperation opportunities and aggressive choices. We also discuss the market conditions that lead to these games. In the second model, a similar CPPM setting is considered where two symmetric firms face two target markets. However, we assume that demand for the emerging market is uncertain and may expand through firms’ market entry (positive diffusion effects), while demand for the mature market is known with certainty and cannot expand. Firms decide when to invest, in which market to invest, and how much to invest into this market. Our analysis reveals that the existence of multiple investment opportunities may induce firms to delay their investment even in the absence of demand uncertainty, and that high diffusion effects coupled with low demand uncertainty can drive firms to invest early even if both firms could increase returns by delaying their investment. We then study the asymmetric case where firms differ with respect to their costs and diffusion effects and show some counter-intuitive results. In the third CPPM problem, we consider continuous budget allocations and prove that while a monopoly firm bases its budget allocation decision solely on the marginal returns of the two markets, duopoly firms also account for their average returns from the two markets. This drives duopoly firms, in particular the firm with the smaller budget, to invest more heavily into the mature market. We show that as a firm’s budget increases, the share of its budget that is invested into the mature market decreases while its competitor’s investment into the mature market increases. This chapter also explores how changes to the market parameters and market uncertainty affect the resource allocation decision of firms under competition. Considering the special case of identical budgets, we prove that as the number of competing firms increases (with a fixed total budget), firms allocate an even greater share of their budget into the mature market. The fourth model considers a general case where a number of budget-constrained firms engage in production decisions for multiple markets under competition. Each firm decides how much to produce for each market, subject to its budget constraint. We prove that firms produce greater quantities for markets with higher than average base demand and that these quantities are increasing in the number of competitors (assuming identical production capacities). With asymmetric production capacities, we numerically illustrate how firms with large production capacities may, instead, increase production into lower than average base demand markets. Furthermore, we characterize the increase in return firms can expect from budget increases and conjecture that if some markets are not served by all firms, the remaining firms reduce their production into those markets where some firms are not producing

    Glosarium Matematika

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    273 p.; 24 cm

    Glosarium Matematika

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    Planning and Optimisation Methods for Lunar In-Situ Resource Utilisation

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    Lunar water resources are expected to be used for space exploration and development in the future. These resources can be used for life support and rocket fuel to reduce the risks and costs associated with lunar settlement. There is a notable gap in literature relating to the planning and optimisation of lunar resource extraction. This thesis aims to address the problem by developing tools for planning and optimisation of In-Situ Resource Utilisation (ISRU) on the Moon, with a focus on H2O resources. The multidisciplinary tools currently used in the terrestrial mining industry are examined as possible solutions to fill the gap. However, several issues are identified with the direct transfer of these methods to ISRU. Four foundational areas of mining engineering are then expanded for off-Earth applications. These are geomechanics and modelling, mining system selection, extraction sequence optimisation and project valuation. For geomechanics, the Discrete Element Method (DEM) is used to determine the stability of regolith excavations on the Moon. This method is also extended to the development of ground engaging tools under lunar gravity. Conceptual proofs are shown for two novel mining systems using DEM, the Impact Excavator and Drill and Pull method. With further development, these new rock breakage systems can improve ISRU planning and optimisation by enabling the access of harder, higher grade icy regolith. Within literature, there are also numerous off-Earth mining systems described. A procedure is developed to objectively select a mining system for a range of possible space resource deposit types. The procedure utilises principles of Axiomatic Design to estimate the reliability of systems in the absence of experimental data. These system reliabilities assist in making selections that can be used as inputs for subsequent planning and optimisation activities. Traditional optimisation algorithms, such the Lerchs-Grossman pit optimisation method and other graph-based methods are next examined for their applicability to off-Earth mining. They are found to be incompatible when directly applied to ISRU and a new paradigm is developed based on Reinforcement Learning. This method has advantages over the traditional mine optimisation algorithms and solves many of the issues identified for ISRU. For example, it does not require uncertain financial inputs such as cost estimations or price forecasting. This particular weakness in financial inputs for off-Earth mine planning is also addressed for project valuations. An opportunity cost measure, the Propellant Payback Ratio, is shown to overcome many of the difficult input requirements of the traditional method for the purpose of ISRU project appraisal. It enables ISRU project appraisals to be conducted completely independent of the uncertain financial inputs mentioned. Overall, the thesis contributes to the expansion of the mining engineering discipline into the ISRU domain. Four interconnected areas of mining engineering are developed including: geomechanics, mining system selection, sequence optimisation and project appraisal. These are all part of a multidisciplinary approach to ISRU planning and optimisation. Although ISRU has so far not begun, the methods and tools developed here can be used to improve the future prospect of resource utilisation on the Moon

    Considering stakeholders’ preferences for scheduling slots in capacity constrained airports

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    Airport slot scheduling has attracted the attention of researchers as a capacity management tool at congested airports. Recent research work has employed multi-objective approaches for scheduling slots at coordinated airports. However, the central question on how to select a commonly accepted airport schedule remains. The various participating stakeholders may have multiple and sometimes conflicting objectives stemming from their decision-making needs. This complex decision environment renders the identification of a commonly accepted solution rather difficult. In this presentation, we propose a multi-criteria decision-making technique that incorporates the priorities and preferences of the stakeholders in order to determine the best compromise solution

    Ant colony optimization on runtime reconfigurable architectures

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    MATLAB

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    This excellent book represents the final part of three-volumes regarding MATLAB-based applications in almost every branch of science. The book consists of 19 excellent, insightful articles and the readers will find the results very useful to their work. In particular, the book consists of three parts, the first one is devoted to mathematical methods in the applied sciences by using MATLAB, the second is devoted to MATLAB applications of general interest and the third one discusses MATLAB for educational purposes. This collection of high quality articles, refers to a large range of professional fields and can be used for science as well as for various educational purposes

    Principles of Liberty: A Design-based Research on Liberty as A Priori Constitutive Principle of the Social in the Swiss Nation Story

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    One of the still unsolved problems in liberal anarchism is a definition of social constituency in positive terms. Partially, this had been solved by the advancements of liberal discourse ethics. These approaches, built on praxeology as a universal framework for social formation, are detached from the need of any previous or external authority or rule for the discursive partners. However, the relationship between action, personal identity, and liberty within the process of a community becoming solely generated from the praxeological a priori remains largely disputed. In order to develop a testable constitutional model, this study revises how the “ontological turn” was introduced into liberal theories and redefines the concept of liberty. Liberty is usually understood as a moral goal or measurement for just actions, as the generative principle of all social existence - individual and interpersonal. For this purpose, the function of performative contradiction within the mechanism of interpersonal “encounter”, as part of the co-generative process of the individual becoming and social formation was explored through the production of a game-based narrative historiography grounded on 19th century life writings. This narrative historiography was developed in the context of Swiss history, with a “design-based” research approach, and resulted in a prototype for networked storytelling through which the transformative learning process could be visible and the negotiation of competing individual visions of the future could be re-enacted

    Effects of Complementary use of Organic and Inorganic fertilizers on the growth and yield of Cucumber (Cucumu sativus. L.) on an ultisol

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    A field study was conducted in 2008 and 2009 early cropping seasons to assess the response of cucumber (Cucumus sativus L.) to complementary use of organic and inorganic fertilizers in Uyo agro-ecology. The fertilizer treatments were: NPK (15:15:15) at 100 and 200 kgha-1, poultry manure (PM) at 5 and 10 tha-1 , and complementary application of 100 kgha-1 of NPK + 5 tha-1 of PM, 100 kgha-1 of NPK + 10 tha-1 of PM, 200 kgha1 of NPK +5 tha-1 of PM ,200 kgha-1 of NPK +10 tha-1 of PM and control (no fertilizer). Results showed significant differences (P<0.05) in all the growth and yield parameters considered in both cropping seasons. The combined application of 200 kgha-1 of NPK and 10 tha-1 of PM performed better than sole application of either organic or inorganic fertilizer, with fresh fruit yield of 14.63 and 14.92 tha-1 in 2008 and 2009, respectively and exceeded other treatments by 1 -76% and 1-73% in 2009 and 2010, respectively. This indicates strongly the synergistic benefits of using both organic and inorganic fertilizers even at lower rates
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