Zugl.: Mannheim, Univ., Diss., 2008

Zugl.: Cottbus, Techn. Universiẗat, Diss., 2008.

Zugl.: Mannheim, Univ., Diss., 2010

Bachelor-Arbeit Univ. St. Gallen, 2006.

Bachelor-Arbeit Univ. St. Gallen, 2008.

A spatial-temporal model is developed for modelling the impacts of simulated coastal zone storm surge and flooding using a combined spatial mapping and system dynamics approach. By coupling geographic information systems (GIS) and system dynamics, the interconnecting components of the spatial-temporal model are used with limited historical data to evaluate storm damage. Overlapping cumulative effects layers in GIS (ArcMap) are used for describing the coastal community’s profile, and a system dynamics feedback model (STELLA) is developed to define the interconnecting component relationships of the community. The component-wise changes to the physical environment, community infrastructure, and socioeconomic resources from the storm surge and seal level rise are examined. These changes are used to assess the impacts of the community system as a whole. For the purpose of illustrating this model, the research is applied specifically to the case of Charlottetown, Prince Edward Island, Canada, a vulnerable coastal city subject to considerable impacts from pending sea level rise and more frequent severe storm surge attributed to the changing climate in the coastal zone.

Rising demand for high productivity of machine tools leads to increase of the dynamics of the machine tool. With higher dynamics of the components is produced a free tool vibr ation that can affect the path accuracy of the feed axis and of the tool. In this thesis are examined various parameters of the feed axis, so that the influence of each parameter could be determined. To determine these factors is in this thesis created a structuralmechanical model of the feed axis by means of the finite element method and this thesis presents a connection of the FE model with a control loop of an axis that allows the theoretical study of the influences on the accuracy of the feed axis. The results show succes sful coupling of the FE model with the control loop. Selected parameters are analyzed in this paper.

No description available.

The Hardwood Industry in United States has been challenged by low-cost competition from overseas. Although cost reduction strategies have had minimal success, the proximity of industry to the domestic market has large implications on a more customer-focused strategy. The problem arises that individual companies and supply chains evolved based on the principles of economies of size and not on the flexibility to adapt to customer needs and changing resource constraints. An increased rate at which material and information flows through the hardwood supply chains is the key to the industries' ability to be customer-focused. Information systems may offer benefits for the industry, but changes in material flow of a company or supply chain cannot necessarily be predicted when implementing information systems. It was hypothesized that by understanding the dynamics between information flow and material flow throughout the supply chain, performance improvement would be possible through more effective release and use of information. A case study analysis of a hardwood supply chain was utilized to identify the effect of increased information flow on the material flow of the supply chain. Value Stream Mapping was utilized to benchmark the current state of lead times of information flow and material flow. System Dynamics was utilized to understand the relationships between the information flow and the material flow. Finally, simulations were performed to identify the specific effects on material flow as increased information flow is released through different information strategies. The study showed that increased information flow between supply chain members increased material flow through the supply chain. For a case study supply chain, an increase in information flow, through advanced knowledge of customer demand by a supplier, was found to reduce the inventory buffers throughout the supply chain by up to 38 percent and increase the total material flow through the supply chain by 10 percent. In addition to the increased information flow caused by the advanced knowledge of demand (18 percent), information flow would increase (by an additional 7 percent) based on the reductions in buffer inventory within each company of the supply chain. / Ph. D.

In this research, I study the unintended consequences of implementing information technology. Understanding the causes of these unintended effects is important because information technology is ubiquitous in the modern economy. I used three research protocols to study this phenomenon. The first approach was a literature review to explore and understand what was already written on the subject of implementing information technology. The second approach was an experiment using the beer distribution game to study the implementation of information technology. The third approach I used was a case study in which I used system dynamics modeling to study the information technology in an engineering and architecture firm. I tested the implementation of information technology in the beer distribution game by modifying the play with a change that simulated implementing information technology. I compared the performance of test subjects with control groups that played the game at the same time, without the modification. I also compared the subjects' performance against the performance of trials first published in 1989. I hypothesized that implementing information technology would result in an immediate improvement of the teams' performance. The results of implementing information technology in the beer distribution game were not as expected; implementing information technology did not improve performance. When it became clear that my experimental hypotheses were incorrect, I went back to the literature to see if there was an explanation for this failure that could be derived from the literature on the beer game. I studied the information technology in the case study firm in order to extend the learning from the experimental research. The results of the experiment were not as I expected; I learned a great deal about the effect of information technology in a very controlled experimental setting. By expanding the research to include a case study I was able to explore the behavior in a more realistic environment. The beer distribution game provided me with an unexpected insight into the alignment of users mental models and the structure of the organization. The case study was completed using system dynamics tools to model, and then simulate, the effect of misalignment in a real world organization. Considering the results of the beer distribution game and the case study, I suggest that one explanation for the unintended consequences of implementing information technology is the misalignment of users' mental models with the altered structure of the organization after information technology is implemented. / Ph. D.