In the paper, we minimize the holding cost of the safety stock held in a supply chain modeled as a general network. By our assumption, the demand is bounded by a concave function. This fact allows us to formulate the problem as a deterministic optimization. We minimize a concave function over a discrete polyhedron. The main goal of the paper is to describe an algorithm to solve the problem without assuming any particular structure of the underlying supply chain. The algorithm is a branch and bound algorithm. / Singapore-MIT Alliance (SMA)

We analyze the notions of monotonicity and complete monotonicity for Markov Chains in continuous-time, taking values in a finite partially ordered set. Similarly to what happens in discrete-time, the two notions are not equivalent.<br> However, we show that there are partially ordered sets for which monotonicity and complete monotonicity coincide in continuous time but not in discrete-time. / Nous étudions les notions de monotonie et de monotonie complète pour les processus de Markov (ou chaînes de Markov à temps continu) prenant leurs valeurs dans un espace partiellement ordonné. Ces deux notions ne sont pas équivalentes, comme c'est le cas lorsque le temps est discret. Cependant, nous établissons que pour certains ensembles partiellement ordonnés, l'équivalence a lieu en temps continu bien que n'étant pas vraie en temps discret.

This paper focuses on the issue of sampling directly from the stationary distribution of Vervaat perpetuities. It improves upon an algorithm for perfect sampling first presented by Fill & Huber by implementing both a faster multigamma coupler and a moving value of Xmax to increase the chance of unification. For beta = 1 we are able to reduce the expected steps for a sample by 22%, and at just beta = 3 we lower the expected time by over 80%. These improvements allow us to sample in reasonable time from perpetuities with much higher values of beta than was previously possible.

Continuous-time Markov chains (CTMC's) form a convenient mathematical framework for analyzing random systems across many different disciplines. A specific research problem that is often of interest is to try to predict maximum probability sequences of state transitions given initial or boundary conditions. This work shows how to solve this problem exactly through an efficient dynamic programming algorithm. We demonstrate our approach through two different applications - ranking mutational pathways of HIV virus based on their probabilities, and determining the most probable failure sequences in complex fault-tolerant engineering systems. Even though CTMC's have been used extensively to realistically model many types of complex processes, it is often a standard practice to eventually simplify the model in order to perform the state evolution analysis. As we show here, simplifying approaches can lead to inaccurate and often misleading solutions. Therefore we expect our algorithm to find a wide range of applications across different domains.

The first generation of agricultural crops developed using biotechnology have offered the primary producers of the crops agronomic benefits. Some consumers have resisted accepting this technology because of concerns with food and environmental safety, and ethical issues that arise from the processes that are involved in developing these products. The second and third generation of agricultural biotechnology are being developed to offer products with direct benefits to consumers. The focus of this thesis is the second generation, which have added health benefits. Specifically, the obstacles to commercialization of functional foods derived through biotechnology are examined. The three factors which have the potential to set back commercial introduction of functional foods derived through biotechnology are government regulatory uncertainty, consumer aversion and brand risk, and gaining access to intellectual property. The regulations governing functional foods are examined to show the regulatory ambiguity that exists in Canada. Comparisons are drawn to other nations. Literature that focuses on consumer aversion to agricultural biotechnology is reviewed, along with consumer preference studies with regards to genetically modified (GM) foods with and without health benefits. Transaction cost economics literature is used to analyse the problems related to gaining access to intellectual property and the resulting supply chain implications. Three separate theoretical models are developed to examine each of the three factors separately. Government regulatory uncertainty is incorporated into an expected profit model to show the effects of increased uncertainty on the expected profit from a new technology. A heterogeneous consumer preference model is used to show the effects of changing consumer preferences on the market share of the firm introducing the GM functional food to the market. Simulation analysis using this model shows the effects of changing variables on the market shares of three products in the market. Finally a stylized model of the vertical market shows the effects of increased transaction costs incurred in gaining access to intellectual property on the rent that is available for distribution throughout the supply chain. The results show that these factors could be an obstacle to commercial development of functional foods derived through biotechnology. When the three factors are combined, the rent available for distribution is important for the success of the supply chain. Multiple bilateral monopoly negotiations cause this rent to be less than optimal. Increased levels of government regulatory uncertainty, consumer aversion and brand risk, and costs gaining of access to intellectual property decrease the expected rent available for distribution. This could be a problem facing developers of functional foods derived through biotechnology.

Much current literature on women and migration tends to approach the study of migrant domestic workers as victims of global capitalism—or according to Parrenas’s evocative phrase as “servants of globalization”—from one of two vantage points. The first vantage point focuses attention on how the conditions of exit in various sending countries make overseas domestic servitude one of the few employment opportunities available for many women (Parrenas 2001). The second draws attention to the ways in which these migrant women experience stratification—along the lines of gender, race, and class—as part of their settlement experiences in their host countries (Pratt 1998). Both of these vantage points reinforce aspects of the “servants of globalization” discourse in that they pay relatively little attention to the coping practices of migrant domestic workers. In order to extend the thesis beyond the “servants of globalization” discourse, this thesis examines the coping practices that migrant Filipina domestic workers develop in their efforts to create communities of affirmation, care, and belonging.

Much current literature on women and migration tends to approach the study of migrant domestic workers as victims of global capitalism—or according to Parrenas’s evocative phrase as “servants of globalization”—from one of two vantage points. The first vantage point focuses attention on how the conditions of exit in various sending countries make overseas domestic servitude one of the few employment opportunities available for many women (Parrenas 2001). The second draws attention to the ways in which these migrant women experience stratification—along the lines of gender, race, and class—as part of their settlement experiences in their host countries (Pratt 1998). Both of these vantage points reinforce aspects of the “servants of globalization” discourse in that they pay relatively little attention to the coping practices of migrant domestic workers. In order to extend the thesis beyond the “servants of globalization” discourse, this thesis examines the coping practices that migrant Filipina domestic workers develop in their efforts to create communities of affirmation, care, and belonging.

Canada has been recognized as the largest exporter of flax seed in the world. Currently, very little flax straw is further processed, despite its potential as a value added product, with only about 7-10% of Canadian flax seed producers harvesting residual flax straw rather than burning the straw. A traditional use of flax straw has been for the production of fibre for the linen industry. Interest in flax fibre has been rekindled with the impetus to seek out bioproducts that replace non-renewal resources and provide value-added opportunities for agricultural producers. Flax fibre also has a range of potential uses in automotive parts, geotextiles, insulation material, etc. Despite this potential, the Canadian flax fibre sector remains largely underdeveloped, with fledgling supply chains and lack of investment in the necessary processing capacity. This paper develops a framework for analysing the relational exchanges at different stage of the supply chain to determine if the paucity in investment is the result of prohibitively high exchange costs. A number of distinct stages in the flax fibre supply chain can be identified: farmers producing flax seed and/or straw; processors who extract the natural fibre from the straw; and manufacturers who use the fibre in their products. The paper develops a framework that draws together insights from Transaction Cost Economics, Agency Theory and Bargaining Theory. The role of institutions in facilitating quality measurement and providing participants with information is also considered. The theoretical framework identifies asset specificity, agency measurement costs, bargaining power and under-developed institutions as key factors in the development of the flax fibre sector. From the theoretical framework, a set of propositions is developed that examine the anticipated effect of these factors on vertical coordination in the sector. The theoretical propositions are explored through a series of semi-structured interviews with parties at each stage of the supply chain (producers, fibre processors, final manufacturers), as well as with industry experts. Information from the interviews is used to identify the transaction characteristics and the institutional framework characterizing the flax fibre sector in Canada. This is analysed through a comparative case study approach with the flax fibre sector in Europe, and the wool fibre sector in New Zealand as an example of a fully developed and long-standing fibre sector. By also noting the different vertical coordination strategies that are present in these supply chains, a connection is drawn between the presence of certain transaction characteristics and the corresponding cost-minimizing exchange relationships. The case studies are used to investigate the propositions developed from the theoretical framework regarding the impact of transaction characteristics on the optimal vertical coordination strategy and the impediments to development and investment in the sector. The propositions developed in the framework are verified to a great extent by the comparative case study. The uncertainty in the exchange environment regarding the future direction of the flax fibre industry and the high measurement costs due to the absent quality and grading regime in the Canadian flax fibre set the two industries apart from each other. Both of these dimensions impact the exchange costs of a transaction and subsequently, the extent to which the parties are closely coordinated. The case studies verify that using a framework to analyze transactions provides additional insights because of the joint consideration of several features of the transaction.

Rising oil prices have been a concern for both developed and developing countries, especially in more recent years as it tends to have a crippling effect on production and transportation. Many countries have moved towards the development of fossil fuel alternatives as a means of achieving energy independence and achieving environmental targets (for example the Kyoto Protocol). Developments in both these types of energy markets (fossil fuel and renewable fuels) may impact Canadian Prairie agriculture. Most of Canadian prairie crops are exported. The Canadian prairies are land locked to some extent. The closest ocean access to the eastern portion of the prairies is the port of Churchill, but is closed during the winter season. Crops are therefore transported west through the Rocky Mountains or east through the Great Lakes to get to a port. This requires hundreds of kilometres of truck and rail transportation, which is fuel dependent. To a lesser extent, at the micro-level farmers depend on fossil fuels to operate machinery to facilitate efficient crop production. If oil prices continue on an upward trajectory, will farmers cropping behaviour change? Furthermore, the development of the bioethanol industry on the Canadian prairies has given wheat farmers another crop option. As oil prices increase, the price of ethanol increases as well. Also, demand is bolstered by renewable fuel standards and government tax exemptions or subsidies. This study seeks to put forward the notion that as oil prices increase, crop production and transportation costs also increase thereby reducing farmers’ gross margins. Also, ceteris paribus, as oil prices increase there will be an increased demand for, and an increase in the price of biofuels thereby increasing the price of biofuel feedstock. Higher feedstock prices are expected to increase the gross margins of farmers. Therefore higher oil prices drive increased crop competition between traditional cropping (cropping for food exports) and energy cropping. This thesis seeks to ascertain at what level of oil prices would farmers, in general, be willing to switch from producing wheat for traditional (hard/food wheat) purposes to bioenergy (soft/ biofuel wheat) cropping alternatives. Also under varying scenarios of oil price growth and government support to the biofuel industry, this thesis seeks to ascertain the impact of biofuel industry expansion on grain elevator pricing behaviour and the structure of the elevator industry, assuming elevators spatially compete with each other for farmers’ crops. An agent based model (ABM) is employed for this study. The model is selected over other types as the researcher wants to capture the increased complexity stemming from the competition between crops that belong to at least one distribution chain. Agent based networks allow for emergent behaviour that is obtained from the spatial competition of elevators. Finally, the agent based model allows for spatial heterogeneity in location of farmers in terms of soil quality and their proximity to an elevator, which affects crop productivity and transportation costs, respectively. The ABM (also called the FARMCHAIN model) is comprised of over 35000 farmer agents, 176 elevator agents, 6 canola crushing plant agents, 5 ethanol plant agents and 1 biodiesel plant agent located on the 20 census agricultural regions (CARs) of Saskatchewan. Farmers allocate land based on their expected gross margins. Farmers produce and truck crops to the designated distribution chain. Crops move through the chain and at every stage the associated costs are computed and apportioned to the farmer. At the end of the period, gross margins are computed and these gross margins are used in computing the expected gross margins for the subsequent period. It is found that real annual crude prices would have to be greater than $133 before farmers begin to switch to producing biofuel wheat (soft wheat) from food wheat (hard wheat). This would have to be approximately 30% higher than that of 2008 in which crude prices were at record levels. Also, if biofuel support is declining then it would take a considerably higher price to entice farmers, in aggregate, to switch.

In some applications polynomials should be evaluated, e.g., polynomial approximation of elementary function and Farrow filter for arbitrary re-sampling. For polynomial evaluation Horner’s scheme uses the minimum amount of hardware resources, but it is sequential. Many algorithms were developed to introduce parallelism in polynomial evaluation. This parallelism is achieved at the cost of hardware, but ensures evaluation in less time. This work examines the trade-off between hardware cost and the critical path for different level of parallelism for polynomial evaluation. The trade-offs in generating powers in polynomial evaluation using different building blocks(squarers and multipliers) are also discussed. Wordlength requirements of the polynomial evaluation and the effect of power generating schemes on the timing of operations is also discussed. The area requirements are calculated by using Design Analyzer from Synopsys (tool for logic synthesis) and the GLPK (GNU Linear Programming Kit) is used to calculate the bit requirements.