Matching Items (24)
Description
Regional differences of inventive activity and economic growth are important in economic geography. These differences are generally explained by the theory of localized knowledge spillovers, which argues that geographical proximity among economic actors fosters invention and innovation. However, knowledge production involves an increasing number of actors connecting to non-local partners. The space of knowledge flows is not tightly bounded in a given territory, but functions as a network-based system where knowledge flows circulate around alignments of actors in different and distant places. The purpose of this dissertation is to understand the dynamics of network aspects of knowledge flows in American biotechnology. The first research task assesses both spatial and network-based dependencies of biotechnology co-invention across 150 large U.S. metropolitan areas over four decades (1979, 1989, 1999, and 2009). An integrated methodology including both spatial and social network analyses are explicitly applied and compared. Results show that the network-based proximity better defines the U.S. biotechnology co-invention urban system in recent years. Co-patenting relationships of major biotechnology centers has demonstrated national and regional association since the 1990s. Associations retain features of spatial proximity especially in some Midwestern and Northeastern cities, but these are no longer the strongest features affecting co-inventive links. The second research task examines how biotechnology knowledge flows circulate over space by focusing on the structural properties of intermetropolitan co-invention networks. All analyses in this task are conducted using social network analysis. Evidence shows that the architecture of the U.S. co-invention networks reveals a trend toward more organized structures and less fragmentation over the four years of analysis. Metropolitan areas are increasingly interconnected into a large web of networked environment. Knowledge flows are less likely to be controlled by a small number of intermediaries. San Francisco, New York, Boston, and San Diego monopolize the central positions of the intermetropolitan co-invention network as major American biotechnology concentrations. The overall network-based system comes close to a relational core/periphery structure where core metropolitan areas are strongly connected to one another and to some peripheral areas. Peripheral metropolitan areas are loosely connected or even disconnected with each other. This dissertation provides empirical evidence to support the argument that technological collaboration reveals a network-based system associated with different or even distant geographical places, which is somewhat different from the conventional theory of localized knowledge spillovers that once dominated understanding of the role of geography in technological advance.
ContributorsLee, Der-Shiuan (Author) / Ó Huallacháin, Breandán (Thesis advisor) / Anselin, Luc (Committee member) / Kuby, Michael (Committee member) / Lobo, Jose (Committee member) / Arizona State University (Publisher)
Created2011
Description
This report is the consolidated work of an interdisciplinary course project in CEE494/598, CON598, and SOS598, Urban Infrastructure Anatomy and Sustainable Development. In Fall 2012, the course at Arizona State University used sustainability research frameworks and life-cycle assessment methods to evaluate the comprehensive benefits and costs when transit-oriented development is infilled along the proposed light rail transit line expansion. In each case, and in every variation of possible future scenarios, there were distinct life-cycle benefits from both developing in more dense urban structures and reducing automobile travel in the process.
Results from the report are superseded by our publication in Environmental Science and Technology.
ContributorsChester, Mikhail Vin (Author) / Bosfield, Roberta (Author) / Celoza, Amelia (Author) / Christian, Keith (Author) / Flores, Gilbert (Author) / Francis, Nick (Author) / Fraser, Andrew (Author) / Furcini, Ryan (Author) / Garikapati, Madhav (Author) / Johnson, Sam (Author) / Kaehr, Andrew (Author) / Kimball, Mindy (Author) / Nahlik, Matthew (Author) / Prado, Valentina (Author) / Rostain, Drew (Author) / Xu, Minghao (Author) / Yu, Andy (Author) / Arizona State University. School of Sustainable Engineering and the Built Environment (Contributor) / Arizona State University. Center for Earth Systems Engineering and Management (Contributor)
Created2012-12
Description
In an extreme heat event, people can go to air-conditioned public facilities if residential air-conditioning is not available. Residences that heat slowly may also mitigate health effects, particularly in neighborhoods with social vulnerability. We explored the contributions of social vulnerability and these infrastructures to heat mortality in Maricopa County and whether these relationships are sensitive to temperature. Using Poisson regression modeling with heat-related mortality as the outcome, we assessed the interaction of increasing temperature with social vulnerability, access to publicly available air conditioned space, home air conditioning and the thermal properties of residences. As temperatures increase, mortality from heat-related illness increases less in census tracts with more publicly accessible cooled spaces. Mortality from all internal causes of death did not have this association. Building thermal protection was not associated with mortality. Social vulnerability was still associated with mortality after adjusting for the infrastructure variables. To reduce heat-related mortality, the use of public cooled spaces might be expanded to target the most vulnerable.
ContributorsEisenman, David P. (Author) / Wilhalme, Holly (Author) / Tseng, Chi-Hong (Author) / Chester, Mikhail Vin (Author) / English, Paul (Author) / Pincetl, Stephanie Sabine, 1952- (Author) / Fraser, Andrew (Author) / Vangala, Sitaram (Author) / Dhaliwal, Satvinder K. (Author)
Created2016-08-03
Description
Hemcrete is an alternative, environmentally‐friendly building material gaining adherents in Great Britain and other European countries. It is an attractive choice as a building material because it is made from a renewable resource, hemp, a hardy plant that is a close, but non‐hallucinogenic relative of marijuana. This plant is relatively easy to cultivate, requires little in the way of pesticides or fertilizers, and almost all parts can be used for various products from paper to textiles to food.
Hemcrete is made from a mixture of lime, water, and the fibrous outer portion of the hemp plant called the “hurd” or “shive”. When mixed, it is worked and placed much like conventional concrete ‐ hence the name. However, that is where the similarities with concrete end. Hemcrete is not comparable to concrete on a strength basis, and is better described as an alternative insulation product. When built into walls of sufficient thickness, Hemcrete offers high thermal efficiency, and has strong claims to being carbon negative. The purpose of this study
was to evaluate this claim of carbon negativity, and to compare these environmentally friendly qualities against conventional fiberglass batt insulation.
Our model was constructed using two identically sized “walls” measuring eight feet square by one foot in depth, one insulated using Hemcrete, and the other using fiberglass. Our study focused on three areas: water usage, cost, and carbon dioxide emissions. We chose water
usage because we wanted to determine the feasibility of using Hemcrete in the Phoenix metropolitan region where water is a troubled resource. Secondly, we wished to evaluate the claim on carbon negativity, so CO2 equivalents throughout the production process were measured. Finally, we wished to know whether Hemcrete could compete on a cost basis with more conventional insulation methods, so we also built in a price comparison.
Since the cultivation of hemp is currently unlawful in the United States, this study can help determine whether these restrictions should be relaxed in order to allow the construction of buildings insulated with Hemcrete.
ContributorsDolins, Sigma (Author) / Guiley, Keith (Author) / Poletti, Joseph (Author) / Stafford, Nicholas (Author) / Arizona State University. School of Sustainable Engineering and the Built Environment (Contributor) / Arizona State University. Center for Earth Systems Engineering and Management (Contributor)
Created2013-05
Description
Climate change is a well-known global threat to societal systems; however, its effects on
the health of individuals are often less evident. Physicians who aim to properly treat patients
holistically must be educated on the various forms of illness and disease projected to be
exacerbated by climate change. Without this necessary climate education, physicians run the risk of being unable to fulfill the most sacred charge of the Hippocratic oath: Do No Harm. To
ensure that physicians moving forward are prepared to face this new global health threat, the
prevalence of climate change in current medical school curricula must be examined. Content
analysis of publicly available medical school curricula in the Southwest U.S. was done using
ChatGPT to track the frequency of climate health search terms. Medical school curricula
analyzed included mandatory degree programs as well as optional dual degree programs or
pathways for medical student education. Researchers found that medical schools within the
Southwest region of the United States are not sufficiently preparing students to mitigate the
regional effects of climate change on the health of patients. Mandatory medical degree
curriculum does not sufficiently educate on climate health issues, nor is it present in Utah, New
Mexico, or Colorado. Optional degrees and pathways are available to medical students to enroll
in and may be sufficient to educate a medical student, but are not enticing enough to sufficiently
educate all medical students. Some medical schools have recently conducted revisals of their
mandatory curriculum and still show a lack of education available about climate health issues.
The lack of educational resources for future providers could lead to detrimental health outcomes
for patients, and medical schools in development should take the lead in educating their students about climate health issues.
ContributorsGutierrez, Sean (Author) / Jamieson, Ann (Co-author) / Vanos, Jennifer (Thesis director) / Lobo, Jose (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / Historical, Philosophical & Religious Studies, Sch (Contributor)
Created2023-12
Description
Artificial Intelligence (AI) is a rapidly advancing field with the potential to impact every aspect of society, including the inventive practices of science and technology. The creation of new ideas, devices, or methods, commonly known as inventions, is typically viewed as a process of combining existing knowledge. To understand how AI can transform scientific and technological inventions, it is essential to comprehend how such combinatorial inventions have emerged in the development of AI.This dissertation aims to investigate three aspects of combinatorial inventions in AI using data-driven and network analysis methods. Firstly, how knowledge is combined to generate new scientific publications in AI; secondly, how technical com- ponents are combined to create new AI patents; and thirdly, how organizations cre- ate new AI inventions by integrating knowledge within organizational and industrial boundaries. Using an AI publication dataset of nearly 300,000 AI publications and an AI patent dataset of almost 260,000 AI patents granted by the United States Patent and Trademark Office (USPTO), this study found that scientific research related to AI is predominantly driven by combining existing knowledge in highly conventional ways, which also results in the most impactful publications. Similarly, incremental improvements and refinements that rely on existing knowledge rather than radically new ideas are the primary driver of AI patenting. Nonetheless, AI patents combin- ing new components tend to disrupt citation networks and hence future inventive practices more than those that involve only existing components.
To examine AI organizations’ inventive activities, an analytical framework called the Combinatorial Exploitation and Exploration (CEE) framework was developed to measure how much an organization accesses and discovers knowledge while working within organizational and industrial boundaries. With a dataset of nearly 500 AI organizations that have continuously contributed to AI technologies, the research shows that AI organizations favor exploitative over exploratory inventions. However, local exploitation tends to peak within the first five years and remain stable, while exploratory inventions grow gradually over time.
Overall, this dissertation offers empirical evidence regarding how inventions in AI have emerged and provides insights into how combinatorial characteristics relate to AI inventions’ quality. Additionally, the study offers tools to assess inventive outcomes and competence.
ContributorsWang, Jieshu (Author) / Maynard, Andrew (Thesis advisor) / Lobo, Jose (Committee member) / Michael, Katina (Committee member) / Motsch, Sebastien (Committee member) / Arizona State University (Publisher)
Created2023
Description
Climate change is a well-known global threat to societal systems; however, its effects on the health of individuals are often less evident. Physicians who aim to properly treat patients holistically must be educated on the various forms of illness and disease projected to be exacerbated by climate change. Without this necessary climate education, physicians run the risk of being unable to fulfill the most sacred charge of the Hippocratic oath: Do No Harm. To ensure that physicians moving forward are prepared to face this new global health threat, the prevalence of climate change in current medical school curricula must be examined. Content analysis of publicly available medical school curricula in the Southwest U.S. was done using ChatGPT to track the frequency of climate health search terms. Medical school curricula analyzed included mandatory degree programs as well as optional dual degree programs or pathways for medical student education. Researchers found that medical schools within the Southwest region of the United States are not sufficiently preparing students to mitigate the regional effects of climate change on the health of patients. Mandatory medical degree curriculum does not sufficiently educate on climate health issues, nor is it present in Utah, New Mexico, or Colorado. Optional degrees and pathways are available to medical students to enroll in and may be sufficient to educate a medical student, but are not enticing enough to sufficiently educate all medical students. Some medical schools have recently conducted revisals of their mandatory curriculum and still show a lack of education available about climate health issues. The lack of educational resources for future providers could lead to detrimental health outcomes for patients, and medical schools in development should take the lead in educating their students about climate health issues.
ContributorsJamieson, Ann (Author) / Gutierrez, Sean (Co-author) / Vanos, Jennifer (Thesis director) / Lobo, Jose (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / Historical, Philosophical & Religious Studies, Sch (Contributor)
Created2023-12
Description
Sustainable food systems have been studied extensively in recent times and the Food-Energy-Water (FEW) nexus framework has been one of the most common frameworks used. The dissertation intends to examine and quantitatively model the food system interaction with the energy system and the water system. Traditional FEW nexus studies have focused on food production alone. While this approach is informative, it is insufficient since food is extensively traded. Various food miles studies have highlighted the extensive virtual energy and virtual water footprint of food. This highlights the need for transport, and storage needs to be considered as part of the FEW framework. The Life cycle assessment (LCA) framework is the best available option to estimate the net energy and water exchange between the food, energy, and water systems. Climate plays an important role in food production as well as food preservation. Crops are very sensitive to temperature changes and it directly impacts a crop’s productivity. Changing temperatures directly impact crop productivity, and water demand. It is important to explore the feasibility of mitigation measures to keep in check increasing agricultural water demands. Conservation technologies may be able to provide the necessary energy and water savings. Even under varying climates it might be possible to meet demand for food through trade. The complex trade network might have the capacity to compensate for the produce lost due to climate change, and hence needs to be established. Re-visualizing the FEW nexus from the consumption perspective would better inform policy on exchange of constrained resources as well as carbon footprints. This puts the FEW nexus research space a step towards recreating the FEW nexus as a network of networks, that is, FEW-e (FEW exchange) nexus.
ContributorsNatarajan, Mukunth (Author) / Chester, Mikhail (Thesis advisor) / Lobo, Jose (Committee member) / Ruddell, Benjamin (Committee member) / Fraser, Andrew (Committee member) / Arizona State University (Publisher)
Created2019
Description
Contrary to many previous travel demand forecasts there is increasing evidence that vehicle travel in developed countries may be peaking. The underlying causes of this peaking are still under much debate and there has been a mobilization of research, largely focused at the national scale, to study the explanatory drivers but research focused at the metropolitan scale, where transportation policy and planning are frequently decided, is relatively thin. Additionally, a majority of this research has focused on changes within the activity system without considering the impact transportation infrastructure has on overall travel demand. Using Los Angeles County California, we investigate Peak Car and whether the saturation of automobile infrastructure, in addition to societal and economic factors, may be a suppressing factor. After peaking in 2002, vehicle travel in Los Angeles County in 2010 was estimated at 78 billion and was 20.3 billion shy of projections made in 2002. The extent to which infrastructure saturation may contribute to Peak Car is evaluated by analyzing social and economic factors that may have impacted personal automobile usage over the last decade. This includes changing fuel prices, fuel economy, population growth, increased utilization of alternate transportation modes, changes in driver demographics , travel time and income levels. Summation of all assessed factors reveals there is at least some portion of the 20 billion VMT that is unexplained in all but the worst case scenario. We hypothesize that the unexplained remaining VMT may be explained by infrastructure supply constraints that result in suppression of travel. This finding has impacts on how we see the role of hard infrastructure systems in urban growth and we explore these impacts in the research.
ContributorsFraser, Andrew (Author) / Chester, Mikhail V (Thesis advisor) / Pendyala, Ram M. (Committee member) / Seager, Thomas P (Committee member) / Arizona State University (Publisher)
Created2014
Description
Urban scaling analysis has introduced a new scientific paradigm to the study of cities. With it, the notions of size, heterogeneity and structure have taken a leading role. These notions are assumed to be behind the causes for why cities differ from one another, sometimes wildly. However, the mechanisms by which size, heterogeneity and structure shape the general statistical patterns that describe urban economic output are still unclear. Given the rapid rate of urbanization around the globe, we need precise and formal mathematical understandings of these matters. In this context, I perform in this dissertation probabilistic, distributional and computational explorations of (i) how the broadness, or narrowness, of the distribution of individual productivities within cities determines what and how we measure urban systemic output, (ii) how urban scaling may be expressed as a statistical statement when urban metrics display strong stochasticity, (iii) how the processes of aggregation constrain the variability of total urban output, and (iv) how the structure of urban skills diversification within cities induces a multiplicative process in the production of urban output.
ContributorsGómez-Liévano, Andrés (Author) / Lobo, Jose (Thesis advisor) / Muneepeerakul, Rachata (Thesis advisor) / Bettencourt, Luis M. A. (Committee member) / Chowell-Puente, Gerardo (Committee member) / Arizona State University (Publisher)
Created2014