INSTITUTIONAL ECONOMICS AND THE EMERGENCE OF E-COMMERCE IN AGRIBUSINESS

The emergence of E-commerce in the 1990s heralded the arrival of the New Economy. However, the failure of numerous dotcoms since early 2001 has led to a debate regarding the future direction of E-commerce and its potential relevance for agribusiness. This study examines the economic implications of E-commerce for agribusiness within the framework of New Institutional Economics. The New Institutional Economics implies that E-commerce has the potential to reduce direct transactions costs in agricultural markets, but that it also may add additional indirect transactions costs. Depending upon the tradeoff between these costs, an institutional innovation which reduces the transactions costs may provide the impetus for an alternative marketing channel for agricultural output. Two models of institutional change are explored. The North model of changes in the rules of the game is found to be more consistent with the advent of E-commerce than the model of technological change suggested by Schumpeter.E-commerce, marketing channels, New Institutional Economics, Schumpeter, Agribusiness, Institutional and Behavioral Economics,

Quantum Walks: Theory, Application, And Implementation

The quantum walk is a method for conceptualizing and designing quantum computing algorithms and it comes in two forms: the continuous-time and discrete-time quantum walk. The thesis is organized into three parts, each of which looks to develop the concept and uses of the quantum walk. The first part is the theory of the quantum walk. This includes definitions and considerations for the various incarnations of the discrete-time quantum walk and a discussion on the general method for connecting the continuous-time and discrete-time versions. As a result, it is shown that most versions of the discrete-time quantum walk can be put into a general form and this can be used to simulate any continuous-time quantum walk. The second part uses these results for a hypothetical application. The application presented is a search algorithm that appears to scale in the time for completion independent of the size of the search space. This behavior is then elaborated upon and shown to have general qualitative agreement with simulations to within the approximations that are made. The third part introduces a method of implementation. Given a universal quantum computer, the method is discussed and shown to simulate an arbitrary discrete-time quantum walk. Some of the benefits of this method are that half the unitary evolution can be achieved without the use of any gates and there may be some possibility for error detection. The three parts combined suggest a possible experiment, given a quantum computing scheme of sufficient robustness

Relationship of landscape structure to ring-necked pheasant population dynamics in northern Iowa

I studied demographic processes that operate on individual animals as a means to understand the relationship of landscape structure to population size and survival. I applied the idea of risk-sensitivity to habitat selection by examining the demographic effects on an animal population in which individuals select from two habitats that have similar mean values for reproductive output but differ in the variance of reproductive output. I conducted simulations using a source-sink population model to show that population size increased with increased variation in habitat quality. I then looked at how landscape heterogeneity was related to ring-necked pheasant (Phasianus colchicus) demography. Although wildlife ecologists suggest that the period of settling movements during spring is a time of high mortality, there are few data to quantify the impact on demographics. Most often, the proximate cause of mortality is predation. However, ecologists presume that landscape pattern is strongly correlated with survival. I used radio-tracking data from April-May 1992 and 1993 on hen pheasants in an agricultural landscape in northern Iowa to determine factors related to survival. I measured covariates to quantify habitat selection, individual movement rates, and landscape patterns, and evaluated these using Cox\u27s proportional hazards model. I used a geographical information system to map hen use of habitat, calculated movement rates, and quantified landscape patterns within areas selected by hens. Edge density (m/ha) was predictive of mortality whereas movement rates were not. I linked this landscape factor to pheasant population dynamics by developing a spatially-explicit, individually-based model. I examined both parametric and nonparametric means of specifying the underlying instantaneous hazard, and simulated time- and location-specific survival as a function of landscape features, including edge density. Modeling the distribution of settling movements including habitat selection, and the predicted effects on mortality, enabled me to combine activities and fates of individual animals and to simulate population-wide demographic responses to landscape attributes. I conducted a simulation experiment that tested the effect of changes in the configuration (edge density) and composition (% grassland) of the landscapes used as input for the simulations. Simulated population survival was lowest in landscapes with low proportions of grassland and high measures of edge density

Dynamics of liquid-solid fluidized bed expansion

LD2668 .T4 1962 S3

Influence of atmospheric circulation on turbulent air-sea heat fluxes over the Mediterranean Sea during winter

The influence of the winter atmospheric circulation on the turbulent variables of the air-sea boundary layer in the Mediterranean Sea is investigated. We examine the effects of several climatic indices and the corresponding large scale atmospheric patterns on the above variables by using a correlation analysis. The spatial characteristics and the behavior of the turbulent variables are also examined based on standard deviation and EOF analysis. Two main types of response to the index-specified atmospheric patterns have been identified: (1) A relatively uniform response of the entire basin associated with the influence of the East Atlantic pattern and (2) opposite responses in the western and eastern sub-basins linked mainly to the intrabasin SLP. The latter is a combined effect of the first four modes of atmospheric variability in the North Atlantic/Eurasia region, the North Atlantic Oscillation (NAO), the East Atlantic Pattern (EA), the Scandinavian Pattern (SCAND), and the East Atlantic-West Russia Pattern (EAWR). The two identified responses of the Mediterranean Sea to the atmospheric forcing are also in accordance with the primary modes of variability of the turbulent variables that result in the EOF analysis. All of the statistically independent indices (NAO, EA, SCAND, EAWR) have to be considered in order to fully account for the modulation of the turbulent variables in the Mediterranean Sea. As an example we refer to the mechanism through which, independent modes of atmospheric variability contributed to the Eastern Mediterranean Transient event between 1987 and 1995. © 2012 by the American Geophysical Union.Peer Reviewe