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- Type:
- Document
- Date Created:
- 2006 July 23-2006 July 27
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- f9377a3ac7b50b1fca5e04fb6d679ec2, 23d738ba88f8333bc39725f9cb5bd0b8, and 32937c7b43e3e015509bb71fd40d2054
- Description:
- Two methods for model behavioural analysis are implemented on a simple 2nd order non-linear model. The results of applying Fords behavioral approach are compared with those obtained using both system-wide and variable-specific loop eigenvalue elasticity analysis. Differences in the division of the time span into analysis intervals are identified as are discrepancies in the outcomes. The effort required for implementation and the necessity for automation also differ substantially. We consider Fords method readily understandable, whereas the mathematically more powerful eigenvalue elasticity analysis poses difficulties in this regard. Future directions for research on model behavioural analysis are identified based on the results of this critical comparison and the learning associated with our development of a prototypical automated model behavioural analysis framework.
-
- Type:
- Document
- Date Created:
- 2006 July 23-2006 July 27
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- f9377a3ac7b50b1fca5e04fb6d679ec2, 23d738ba88f8333bc39725f9cb5bd0b8, and 32937c7b43e3e015509bb71fd40d2054
- Description:
- System Dynamics (SD) is considered a causal modeling approach. Causality is a key and peculiar characteristic of SD: SD models are supposed to contain and represent only causal relationships. However, SD researchers are often not explicit about the notion of causality employed in their work, and there not seem to be a commonly adopted and clear definition of causality in the field. This paper investigates and compares the notions of causality emerging from the work of three major SD authors. The objective is to assess the extent to which a convergence towards a common definition of causality in the field exists, and whether the notion of causality used by the various authors is influenced by the particular field of application. The analysis conduced indicates that the notions of causalities used are similar, and that existing differences could be explained by different fields of application and different backgrounds of the authors.
-
- Type:
- Document
- Date Created:
- 2006 July 23-2006 July 27
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- f9377a3ac7b50b1fca5e04fb6d679ec2, 23d738ba88f8333bc39725f9cb5bd0b8, and 32937c7b43e3e015509bb71fd40d2054
- Description:
- Contamination of a public water supply distribution system would have far-raging public health and economic effects. Emergency response decision-makers need a tool for quickly calculating resources requirement in the aftermath of a contamination incident. A model is needed to describe the potable water distribution system itself and the cascading effects of a disruption of that distribution system on other public institutions such as hospitals, transportation networks, etc. In this paper we present a system dynamics model describing a potable water distribution system that serves an urban area. This model is a component of the Critical Infrastructure Protection Decision Support System (CIP-DSS) project, which models the dynamics of a set of coupled individual infrastructures. We investigate the interdependencies of potable water distribution systems on other critical infrastructures merging our model with other infrastructure models developed under the CIP-DSS project. The main focus of this work is to study the consequences of a disruption on a potable water distribution system. For this purpose we analyze the effects on public health and the economic consequences resulting from contamination of a public water supply.
-
- Type:
- Document
- Date Created:
- 2006 July 23-2006 July 27
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- f9377a3ac7b50b1fca5e04fb6d679ec2, 23d738ba88f8333bc39725f9cb5bd0b8, and 32937c7b43e3e015509bb71fd40d2054
- Description:
- The ability to forecast manpower requirements is crucial for an industry. On the demand side, companies rely on these forecasts to formulate their manpower planning strategies, while, on the supply side, they provide job seekers with a basis to assess the attractiveness of a given sector. Forecasts of supply and demand for manpower also make an important contribution to the governmental policy-making process by serving as pointers, to avoid redundant investments and achieve efficient and balanced growth for an industry. Meanwhile, forecasts based on an inaccurate market analysis can be a cause for imbalances such as undersupply or oversupply of labor. Static and unilateral analyses are the most common culprits for erroneous predictions of supply and demand for manpower. In this paper, we elaborate a model of manpower supply and demand for the information security industry, one of todays fastest-growing sectors, using the system dynamics method. Using this model, we will predict how the labor supply in Koreas information security industry will evolve in the coming years, determine causes for any demand/supply imbalances and propose solutions to resolve these imbalances from a dynamic perspective.
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- Type:
- Document
- Date Created:
- 2006 July 23-2006 July 27
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- f9377a3ac7b50b1fca5e04fb6d679ec2, 23d738ba88f8333bc39725f9cb5bd0b8, and 32937c7b43e3e015509bb71fd40d2054
- Description:
- Following EUs Lisbon strategy development of knowledge-based economy has become one of the headline objectives for the government of Latvia. In this paper we conceptualize driving forces and responses of governments commitment towards this objective. We investigate feedback loops that underlie dynamics of knowledge industry development. Increase in domestic Research and Development (R&D) activities is considered as a prerequisite for sustainable growth of knowledge economy. Dynamics of R&D supply and demand is further analysed and leverage points for different policy measures is identified. Scarce human resources is considered as the main impediment for building domestic R&D capability and impact from mix of policy options is assessed.
-
- Type:
- Document
- Date Created:
- 2006 July 23-2006 July 27
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- f9377a3ac7b50b1fca5e04fb6d679ec2, 23d738ba88f8333bc39725f9cb5bd0b8, and 32937c7b43e3e015509bb71fd40d2054
- Description:
- The evaluated ELI-P Complex test is a biochemical system for pre-pregnancy/pre-natal screening used to determine the probability of pathology in pregnancy through the evaluation of the immunoregulatory state of fertile females. This work uses system dynamics (SD) as an assessment tool for the given technology and policy analysis. Simulation is designed to run at a relatively high level of aggregation for the time period between 2010 and 2035. It allows the dynamics of the model to be traced at the population (US) level of technology application in order to conduct an integrated policy analysis for prenatal care under various implementation scenarios of the ELI-P Complex. Simulation results clearly point to the benefits of the ELI-P Complex screening which helps to monitor female reproductive health and to achieve noticeable improvements in the overall health status of new generations. This work is the result of collaboration with a well-integrated network of clinicians, microbiologists and system modelers.
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- Type:
- Document
- Date Created:
- 2006 July 23-2006 July 27
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- f9377a3ac7b50b1fca5e04fb6d679ec2, 23d738ba88f8333bc39725f9cb5bd0b8, and 32937c7b43e3e015509bb71fd40d2054
- Description:
- Within recent years, agent-based models have achieved growing prominence in several fields of study. Although powerful and expressive for characterizing the evolution of large populations exhibiting persistent interactions between individuals and high heterogeneity, agent-based methods do not come without tradeoffs. Such methods are burdened by relatively high runtime, lack a formal canonical, declarative, and transparent mathematical semantics, and are often challenging to program, understand, calibrate, generalize and validate. It is therefore important to help modelers recognize modeling contexts requiring the full generality of such models. This paper takes a preliminary step in that direction. Specifically, we built and apply a framework that applies the theory of delay embedding and generic algorithms for intrinsic dimensionality assessment in order to estimate the intrinsic dimensionality of the trajectory of agent-based models. This dimensionality provides a lower bound on the number of state variables required in any model that seeks to reproduce the behavior of these agent based models. Surprisingly, we have found very low dimensional global behavior associated with highly descriptively complex agent-based models. While many caveats apply, we suggest that there may be opportunities for expressing the behavior of many complex agent-based models using system dynamics models of modest size.
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- Type:
- Document
- Date Created:
- 2006 July 23-2006 July 27
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- f9377a3ac7b50b1fca5e04fb6d679ec2, 23d738ba88f8333bc39725f9cb5bd0b8, and 32937c7b43e3e015509bb71fd40d2054
- Description:
- Managing a company requires different tools and methodologies in order to successfully deal with its intangible resources and maintain a competitive advantage. Econometrics, Agent-Based Modelling (ABM) and System Dynamics (SD) are modelling paradigms which allow building dynamic models which is a characteristic of this organisational context. These three paradigms present important differences that could determine their suitability to analyse organisational problems. This paper describes the Econometrics, System Dynamics (SD), Agent-Based Modelling (ABM) modelling paradigms. Next, the paper study how these three paradigms analyse organisational problems by means of a model developed in the three paradigms. Finally, the paper provides a method to validate the assumptions about how the paradigms fit with the requirements to study an organisational problem.
-
- Type:
- Document
- Date Created:
- 2006 July 23-2006 July 27
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- f9377a3ac7b50b1fca5e04fb6d679ec2, 23d738ba88f8333bc39725f9cb5bd0b8, and 32937c7b43e3e015509bb71fd40d2054
- Description:
- The aim of this paper is to build a framework of the motorcycle business in Germany, which can be used to construct a quantitative System Dynamics (SD) simulation model thereof. The problem to be examined is the superannuation and further aging of the motorcycle rider population in Germany and its influence on the whole market. We have chosen to concentrate on Germany the second largest European motorcycle market as it is representative of most other developed motorcycle markets. A Causal Loop Diagram of the problem is developed in a step by step, walkthrough fashion. A discussion of the cohort effect with propose possible levers for change are also introduced.
-
- Type:
- Document
- Date Created:
- 2006 July 23-2006 July 27
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- f9377a3ac7b50b1fca5e04fb6d679ec2, 23d738ba88f8333bc39725f9cb5bd0b8, and 32937c7b43e3e015509bb71fd40d2054
- Description:
- In the Netherlands it can take more then a year to get a verdict in a civil case. This is not desirable from a social and economic point of view. The judiciary has made it one of its top priorities to reduce the processing time in the next couple of years. In order to gain more insight we were asked to use system dynamics to tackle this problem. The only road to success was to make sure that all stakeholders fully supported the model, its outcomes and the drawn conclusions. This paper describes how the civil process at a district court is captured in a model. It shows how we discovered the dynamics of the civil process that were unknown until now. This new insight has lead to a change of the perspective of the decision makers in what are good policies to reduce the processing time. The paper also reveals how a new stakeholder was discovered through the use of system dynamics.