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- Type:
- Document
- Date Created:
- 2009 July 26-2009 July 30
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, b3584c6b53c3f58e0202549d7d851f84, and 4818cb531cdd68d6ec6af3f291216fc7
- Description:
- Net migration rate of -3.28 migrants/1000 population ranked Iran 145th in the world. Popular discourse about Iranian immigration focuses on the social and political freedoms associated with relocation. In the current research, the focus is on the authority of the educated people, their impacts on the society, their access to the power and the wealth which seems far negligible. The elites of Iran are no longer the educated people. Based on this assumption, a system dynamics approach is presented to study the long term effects of the emigration on Iranian society. Each emigrant develops themselves in the target country and attracts more emigrants. The success and satisfaction in the target country motivates the young generation to move than to change. The emigrants, when their number increases to millions, form a basement to attract more talented ones from the source country. Emigration of elites is more than a move of people; it has important negative effects on the country to produce wealth, to become industrialized, and to produce more talented
-
- Type:
- Document
- Date Created:
- 2009 July 26-2009 July 30
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, b3584c6b53c3f58e0202549d7d851f84, and 4818cb531cdd68d6ec6af3f291216fc7
- Description:
- The purpose of this study is to illustrate the similarities and differences between discrete event simulation and continuous simulation modeling. A simple M/M/2 queuing system with crowd-dependent arrival rate is used. In the first part, the arrival rate decreases immediately as the number of customers in the system increases. The system is modeled using discrete event and continuous simulation. The results of two simulations are compared with each other and with their analytical solutions. In the second part, the number of customers in the system affects the arrival rate first with a continuous information delay, then with a discrete delay. Discrete and continuous simulations give very similar results in terms of dynamic behaviors of system variables. There are some minor differences in terms of the steady-state values of the variables, particularly the average time spent in system. Finally, increasing proportionately all parameters of the system (arrival rate and number of servers), reduces the discreteness of the system, bringing the discrete and continuous simulation results much closer.
-
- Type:
- Document
- Date Created:
- 2009 July 26-2009 July 30
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, b3584c6b53c3f58e0202549d7d851f84, and 4818cb531cdd68d6ec6af3f291216fc7
- Description:
- This article reports on a theoretical simulation model to investigate effects from policy interventions in the adoption of electronic health records among hospitals, physicians, and patients. The project draws on established system dynamics diffusion theories and provides a conceptual framework to develop and test interventions to promote adoption of electronic medical records. Using data from the Greater Capital Region, Northern New York State, the findings from the simulation experiments suggests that there is no single right intervention but a combination of measures to promote the use of electronic health records not only on the provider side but also among patients.
-
- Type:
- Document
- Date Created:
- 2009 July 26-2009 July 30
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, b3584c6b53c3f58e0202549d7d851f84, and 4818cb531cdd68d6ec6af3f291216fc7
- Description:
- While the System Dynamics modeling process can yield invaluable high level insights, it gives rise to a tremendous amount of detail complexity. In the course of their work, modelers must track successive model versions, the motivation for and assumptions underlying particular what if scenarios, and the implicit relationships between scenarios, model versions and various external artifacts such as spreadsheets, symbolic mathematics calculations, and external documentation. Failure to adequately manage such complexity can reduce the transparency, reliability, and credibility of the modeling process. While adherence to good modeling practices can aid this process, it often falls prey to corner-cutting or human error. This paper describes software that helps manage such complexity, by permitting modelers to easily access and succinctly compare historic versions of a model, by making explicit linkages between scenarios, the model versions and assumptions underlying them, and the motivations for and external files associated with model artifacts.
-
- Type:
- Document
- Date Created:
- 2009 July 26-2009 July 30
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, b3584c6b53c3f58e0202549d7d851f84, and 4818cb531cdd68d6ec6af3f291216fc7
- Description:
- Health policy models have attracted significant offered important insights in to health trends and policy selection. More complete accounting for the cost and health implications of upstream interventions is hindered by the need to consider impact on, and interactions between, multiple comorbidities. Within this paper, we explore several distinct approaches for representing comorbidities, some of them at the aggregate level, and some of them at the individual level. All of these representations have the virtue of being declarative, in that they allow the user to focus on what is to be characterized, rather than how it is to be implemented. Our exploration suggests that while several aggregate representations of comorbidities are possible, they suffer from a variety of shortcomings, ranging from low fidelity to combinatorial blowup. While individual-level representations impose a heavy performance load, greater difficulties in calibration and less rapid analysis, such representations do offer greater transparency, modifiability, scalability, and modularity, and ease of representing transmission and influence networks. With much to recommend each approach, further research is needed to shed additional light on the tradeoffs and identify situations where one representation is preferable to another.
-
- Type:
- Document
- Date Created:
- 2009 July 26-2009 July 30
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, b3584c6b53c3f58e0202549d7d851f84, and 4818cb531cdd68d6ec6af3f291216fc7
- Description:
- Recently sales of physical music media have declined along with music industry revenues â the reasons are complex and poorly understood. We present three models exploring claims made in the conversation over piracy and the music industry's future. We model stakeholder perspectives rather than the full industry to identify their assumptions and the implications of their views, including: (1) Music industry labels claim music piracy directly supplants music sales; (2) Artists claim free music distribution can increase artist revenue through concert sales; and (3) Some academics claim reduced music sales revenue is attributable to other market changes (e.g., increased entertainment competition) rather than piracy. Modeled results suggest that, for each claim respectively: (1) Music labels' mental models are simplistic and do not reflect current research findings; (2) Artists can enhance their concert revenues through piracy as free marketing; and (3) competition with other media explains part of declining music industry revenues.
-
- Type:
- Document
- Date Created:
- 2009 July 26-2009 July 30
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, b3584c6b53c3f58e0202549d7d851f84, and 4818cb531cdd68d6ec6af3f291216fc7
- Description:
- After joining the World Trade Organization, Vietnam attracts more and more foreign investment. Large increase in foreign capital has been led to an overheating economy. Vietnam has been depreciating its currency over the last several years compared to the dollar, making Vietnamâs exports to the U.S. lower-priced. In short run, it helps Vietnam to increase the exports and boost national income. However, in the long run, it is expected to negatively affect the economic growth. Since imports become expensive because of undervalued currency, Vietnam can not afford to update the technology improvements. With the lack of updating on technology improvements, it is impossible to maintain per capita growth. The impacts on technological growth in Vietnam, measured as Total Factor Productivity, can affect the per capita growth of Vietnam. This paper investigates what long term effects on the economy of Vietnam when the Dong currency is undervalued.
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- Type:
- Document
- Date Created:
- 2009 July 26-2009 July 30
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, b3584c6b53c3f58e0202549d7d851f84, and 4818cb531cdd68d6ec6af3f291216fc7
- Description:
- In the U.S., there is progressively more concern about the impact that changes in science, technology, engineering, and math (STEM) skills might have on the future of U.S. prosperity. In parallel with their many STEM initiatives, industry, education, and government are engaged in multi-faceted STEM policy conversations, both among themselves and with the American public. We know of five system dynamics models that have been developed toward the objective of improving these STEM policy conversations. In this session, Boeing, as catalyst for development of three of these five models, will outline the STEM problem, summarize and lightly compare the five models, and present one of the models. The model presented here arose from a reading of the National Academies' report, "Rising Above the Gathering Storm: Energizing and Employing America for a Brighter Economic Future." The model focuses on the reinforcing feedback between U.S. prosperity and the U.S. Science and Technology Enterprise, and concentrates attention on how education, R&D investment, and immigration policies might act to strengthen or weaken that feedback. Thus, this model provides a dynamic conceptual framework within which one can place the other four STEM models to be presented in other sessions at this conference.
-
- Type:
- Document
- Date Created:
- 2009 July 26-2009 July 30
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, b3584c6b53c3f58e0202549d7d851f84, and 4818cb531cdd68d6ec6af3f291216fc7
- Description:
- This paper provides a South African energy model that was developed as a first step towards a comprehensive Threshold 21 model for South Africa. The energy sector consists of five sub-models, which are structured around the supply and demand of electricity, coal, oil, and natural gas in the sector. The model was used to examine a set of policies that the South African government is currently considering, e.g. expansion of nuclear energy production and implementation of more stringent energy efficiency measures. The analyses show that energy efficiency measures are indeed the best option to curb the supply and demand constraints, which the energy sector faces, in the short term. In general, the paper demonstrates how a system dynamics approach can be utilized effectively to support understanding of energy-related issues and clarify the advantages and disadvantages related to the options available to government and the private sector. The paper also highlights potential pitfalls that may be encountered when building such a model. Future developments include extending the model to incorporate the linkages between the energy sector and the economy, society and environment, which would complete the T21 framework for South Africa, and extending the model, with models for other countries in the region, to the Southern African Development Community
-
- Type:
- Document
- Date Created:
- 2009 July 26-2009 July 30
- Collection:
- System Dynamic Society Records
- Collecting Area:
- University Archives
- Collection ID:
- ua435
- Parent Record(s):
- 23d738ba88f8333bc39725f9cb5bd0b8, b3584c6b53c3f58e0202549d7d851f84, and 4818cb531cdd68d6ec6af3f291216fc7
- Description:
- Laboratory experiments of decision making have revealed widespread misperceptions of nonlinear dynamic systems. A possible criticism of these experiments is that participants do not get the advice they may receive in real situations. Here we repeat one previous experiment where we add two conflicting advice. A 'populist' advice reflects typical misperceptions while a second advice represents a near-to-optimal policy. The latter advice is in the wording of an 'activist' in Treatment 1 and in the wording of an 'expert' in systems analysis in Treatment 2. The results suggest that advice, including near-to-optimal ones, may have minor effects in complex systems. Activist wording seems more effective than expert wording, with the possible exception for participants with a certain background in stock and flow reasoning.