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• 41. [Article] A study of single angle compression members

  A study was undertaken to investigate the compressive capacity of a specific group of single angle members. A review of existing literature and techniques was presented. Laboratory compression tests were ...

  Citation × Citation Citation Abstract Copy Title: A study of single angle compression members Author: Callaway, James Robert Year: 1983 A study was undertaken to investigate the compressive capacity of a specific group of single angle members. A review of existing literature and techniques was presented. Laboratory compression tests were performed on 22 angle members of four different sizes and two different lengths. Additional tests were performed to determine the yield strength of the material. The results, normalized with respect to the yield stress, were tabulated and discussed. Two existing analytic models were used to attempt to predict the ultimate capacity of the test members. The first, an elastic method, was based upon the AISC combined stress equation. The second, an inelastic method, was developed by Mueller and Erzurumlu of Portland State University. Comparisons were made with the results of the test program. The results indicate that both analytic models give conservative predictions when pinned end conditions are assumed and unconservative results for fixed end conditions. For the test members with L/r ratios greater than 125, the elastic method results closely paralleled the test results but for the members with L/r ratios less than 125 the correlation was less consistent. The results of the inelastic technique closely paralleled the results of all the member tests. Title: A study of single angle compression members Author: Callaway, James Robert Year: 1983 A study was undertaken to investigate the compressive capacity of a specific group of single angle members. A review of existing literature and techniques was presented. Laboratory compression tests were performed on 22 angle members of four different sizes and two different lengths. Additional tests were performed to determine the yield strength of the material. The results, normalized with respect to the yield stress, were tabulated and discussed. Two existing analytic models were used to attempt to predict the ultimate capacity of the test members. The first, an elastic method, was based upon the AISC combined stress equation. The second, an inelastic method, was developed by Mueller and Erzurumlu of Portland State University. Comparisons were made with the results of the test program. The results indicate that both analytic models give conservative predictions when pinned end conditions are assumed and unconservative results for fixed end conditions. For the test members with L/r ratios greater than 125, the elastic method results closely paralleled the test results but for the members with L/r ratios less than 125 the correlation was less consistent. The results of the inelastic technique closely paralleled the results of all the member tests. Close

• 42. [Article] Characterization of Li-air batteries: Lithium Peroxide Formation in Li-air Electrodes

  Li-air batteries are attractive candidates to be used in electric vehicles (EV) due to their high theoretical capacity, which results in an improved range, a requirement to make EV competitive against ...

  Citation × Citation Citation Abstract Copy Title: Characterization of Li-air batteries: Lithium Peroxide Formation in Li-air Electrodes Author: Garibay, Claudia Torres, Deboever, Jeremiah Year: 2014 Li-air batteries are attractive candidates to be used in electric vehicles (EV) due to their high theoretical capacity, which results in an improved range, a requirement to make EV competitive against fossil fuel powered vehicles. However, Li-air battery technology is considered to be far from commercialization, due to its short lifespan. The decomposition of the electrolyte and its effect on cyclablity has been widely studied, no so much the cathode. This work will make use of recently reported novel adaptation of titration techniques to study cathode degradation in Li-air batteries, along capacity, cyclability, and EIS studies, to characterize the effect of different carbon materials used as cathodes in Li-air batteries. Title: Characterization of Li-air batteries: Lithium Peroxide Formation in Li-air Electrodes Author: Garibay, Claudia Torres, Deboever, Jeremiah Year: 2014 Li-air batteries are attractive candidates to be used in electric vehicles (EV) due to their high theoretical capacity, which results in an improved range, a requirement to make EV competitive against fossil fuel powered vehicles. However, Li-air battery technology is considered to be far from commercialization, due to its short lifespan. The decomposition of the electrolyte and its effect on cyclablity has been widely studied, no so much the cathode. This work will make use of recently reported novel adaptation of titration techniques to study cathode degradation in Li-air batteries, along capacity, cyclability, and EIS studies, to characterize the effect of different carbon materials used as cathodes in Li-air batteries. Close

• 43. [Article] Characterization if Li-Air Batteries Influence of Cathode Degradation: Demonstration of Progress

  Li-air batteries are attractive candidates to be used in electric vehicles (EV) due to their high theoretical capacity, which results in an improved range, a requirement to make EV competitive against ...

  Citation × Citation Citation Abstract Copy Title: Characterization if Li-Air Batteries Influence of Cathode Degradation: Demonstration of Progress Author: Garibay, Claudia Torres, Deboever, Jeremiah Year: 2014 Li-air batteries are attractive candidates to be used in electric vehicles (EV) due to their high theoretical capacity, which results in an improved range, a requirement to make EV competitive against fossil fuel powered vehicles. However, Li-air battery technology is considered to be far from commercialization, due to its short lifespan. The decomposition of the electrolyte and its effect on cyclablity has been widely studied, no so much the cathode. The presence of undesirable reaction by-products at the cathode that affect the battery performance has been quantified through XRD and SEM. This work will make use of recently reported novel adaptation of titration techniques to study cathode degradation in Li-air batteries, along capacity, cyclability, and EIS studies, to characterize the effect of different carbon materials used as cathodes in Li-air batteries. Title: Characterization if Li-Air Batteries Influence of Cathode Degradation: Demonstration of Progress Author: Garibay, Claudia Torres, Deboever, Jeremiah Year: 2014 Li-air batteries are attractive candidates to be used in electric vehicles (EV) due to their high theoretical capacity, which results in an improved range, a requirement to make EV competitive against fossil fuel powered vehicles. However, Li-air battery technology is considered to be far from commercialization, due to its short lifespan. The decomposition of the electrolyte and its effect on cyclablity has been widely studied, no so much the cathode. The presence of undesirable reaction by-products at the cathode that affect the battery performance has been quantified through XRD and SEM. This work will make use of recently reported novel adaptation of titration techniques to study cathode degradation in Li-air batteries, along capacity, cyclability, and EIS studies, to characterize the effect of different carbon materials used as cathodes in Li-air batteries. Close

• 44. [Article] Value of Travel Time Reliability Part II: A Study of Tradeoffs Between Travel Reliability, Congestion Mitigation Strategies and Emissions

  Capacity, demand, and vehicle based emissions reduction strategies are compared for several pollutants employing aggregate US congestion and vehicle fleet condition data. We find that congestion mitigation ...

  Citation × Citation Citation Abstract Copy Title: Value of Travel Time Reliability Part II: A Study of Tradeoffs Between Travel Reliability, Congestion Mitigation Strategies and Emissions Author: Figliozzi, Miguel A., Bigazzi, Alexander Y. Year: 2012 Capacity, demand, and vehicle based emissions reduction strategies are compared for several pollutants employing aggregate US congestion and vehicle fleet condition data. We find that congestion mitigation does not inevitably lead to reduced emissions; the net effect of mitigation depends on the balance of induced travel demand and increased vehicle efficiency that in turn depend on the pollutant, congestion level, and fleet composition. In the long run, capacity-based congestion improvements within certain speed intervals can reasonably be expected to increase emissions of CO2e, CO, and NOx through increased vehicle travel volume. Better opportunities for emissions reductions exist for HC and PM2.5 emissions, and on more heavily congested arterials. Advanced-efficiency vehicles with emissions rates that are less sensitive to congestion than conventional vehicles generate less emissions co-benefits from congestion mitigation. Title: Value of Travel Time Reliability Part II: A Study of Tradeoffs Between Travel Reliability, Congestion Mitigation Strategies and Emissions Author: Figliozzi, Miguel A., Bigazzi, Alexander Y. Year: 2012 Capacity, demand, and vehicle based emissions reduction strategies are compared for several pollutants employing aggregate US congestion and vehicle fleet condition data. We find that congestion mitigation does not inevitably lead to reduced emissions; the net effect of mitigation depends on the balance of induced travel demand and increased vehicle efficiency that in turn depend on the pollutant, congestion level, and fleet composition. In the long run, capacity-based congestion improvements within certain speed intervals can reasonably be expected to increase emissions of CO2e, CO, and NOx through increased vehicle travel volume. Better opportunities for emissions reductions exist for HC and PM2.5 emissions, and on more heavily congested arterials. Advanced-efficiency vehicles with emissions rates that are less sensitive to congestion than conventional vehicles generate less emissions co-benefits from congestion mitigation. Close

• 45. [Article] A GIS Methodology for Assessing the Growth Impacts of Highway Improvements

  This paper presents a methodology to assess the induced land use effects of state highway improvements on urban development patterns. The methodology is applied to the case study City of Hillsboro, Oregon ...

  Citation × Citation Citation Abstract Copy Title: A GIS Methodology for Assessing the Growth Impacts of Highway Improvements Author: Sanchez, Thomas W., Dueker, Kenneth Year: 1998 This paper presents a methodology to assess the induced land use effects of state highway improvements on urban development patterns. The methodology is applied to the case study City of Hillsboro, Oregon and illustrates a framework for data management and analysis. A set of temporal land use characteristics and spatial measures are used as predictors of urban development activities resulting from highway accessibility improvements. A multiple regression analysis tests the significance of these variables in predicting rates and locations of urban development. The primary objective of this research is to identify the relationship between capacity increasing highway improvements and changes in urban development. The analysis provides quantifiable indicators that describe the urban development trends associated with the City of Hillsboro. Title: A GIS Methodology for Assessing the Growth Impacts of Highway Improvements Author: Sanchez, Thomas W., Dueker, Kenneth Year: 1998 This paper presents a methodology to assess the induced land use effects of state highway improvements on urban development patterns. The methodology is applied to the case study City of Hillsboro, Oregon and illustrates a framework for data management and analysis. A set of temporal land use characteristics and spatial measures are used as predictors of urban development activities resulting from highway accessibility improvements. A multiple regression analysis tests the significance of these variables in predicting rates and locations of urban development. The primary objective of this research is to identify the relationship between capacity increasing highway improvements and changes in urban development. The analysis provides quantifiable indicators that describe the urban development trends associated with the City of Hillsboro. Close

• 46. [Article] Memory and Information Processing in Recurrent Neural Networks

  Recurrent neural networks (RNN) are simple dynamical systems whose computational power has been attributed to their short-term memory. Short-term memory of RNNs has been previously studied analytically ...

  Citation × Citation Citation Abstract Copy Title: Memory and Information Processing in Recurrent Neural Networks Author: Goudarzi, Alireza, Marzen, Sarah, Banda, Peter, Feldman, Guy, Lakin, Matthew R., Teuscher, Christof, Stefanovic, Darko Year: 2016 Recurrent neural networks (RNN) are simple dynamical systems whose computational power has been attributed to their short-term memory. Short-term memory of RNNs has been previously studied analytically only for the case of orthogonal networks, and only under annealed approximation, and uncorrelated input. Here for the first time, we present an exact solution to the memory capacity and the task-solving performance as a function of the structure of a given network instance, enabling direct determination of the function-structure relation in RNNs. We calculate the memory capacity for arbitrary networks with exponentially correlated input and further related it to the performance of the system on signal processing tasks in a supervised learning setup. We compute the expected error and the worst-case error bound as a function of the spectra of the network and the correlation structure of its inputs and outputs. Our results give an explanation for learning and generalization of task solving using short-term memory, which is crucial for building alternative computer architectures using physical phenomena based on the short-term memory principle. Title: Memory and Information Processing in Recurrent Neural Networks Author: Goudarzi, Alireza, Marzen, Sarah, Banda, Peter, Feldman, Guy, Lakin, Matthew R., Teuscher, Christof, Stefanovic, Darko Year: 2016 Recurrent neural networks (RNN) are simple dynamical systems whose computational power has been attributed to their short-term memory. Short-term memory of RNNs has been previously studied analytically only for the case of orthogonal networks, and only under annealed approximation, and uncorrelated input. Here for the first time, we present an exact solution to the memory capacity and the task-solving performance as a function of the structure of a given network instance, enabling direct determination of the function-structure relation in RNNs. We calculate the memory capacity for arbitrary networks with exponentially correlated input and further related it to the performance of the system on signal processing tasks in a supervised learning setup. We compute the expected error and the worst-case error bound as a function of the spectra of the network and the correlation structure of its inputs and outputs. Our results give an explanation for learning and generalization of task solving using short-term memory, which is crucial for building alternative computer architectures using physical phenomena based on the short-term memory principle. Close

• 47. [Article] Modeling the Response of Dissolved Oxygen to Phosphorus Loading in Lake Spokane

  Mathematical models of hydrodynamics and water quality are often used to determine the assimilative capacity of a waterbody when waterbodies violate state water quality standards. A model of the Spokane ...

  Citation × Citation Citation Abstract Copy Title: Modeling the Response of Dissolved Oxygen to Phosphorus Loading in Lake Spokane Author: Wells, Scott A., Berger, Chris J. Year: 2016 Mathematical models of hydrodynamics and water quality are often used to determine the assimilative capacity of a waterbody when waterbodies violate state water quality standards. A model of the Spokane River and Lake Spokane in eastern Washington was developed to evaluate the assimilative capacity of the waterbody by setting a total maximum daily load (TMDL). A CE-QUAL-W2 model of this system was developed to establish the TMDL limits for the critical low-flow year of 2001. A recent paper evaluated this model and raised several issues about the validity of this model application as a regulatory tool related to its ability to predict total phosphorus, dissolved oxygen, and chlorophyll a relationships. This paper analyzes the validity of their critiques. For example, the critique used an incorrect formula to calculate total phosphorus inflows into Lake Spokane and used a volume-weighted minimum hypolimnetic dissolved oxygen (DOmin) that was not representative of hypolimnetic conditions. They also assumed incorrectly that the hydrologic, meteorological, operational, and sediment conditions of the 2001 TMDL model would be representative of conditions in other years. Although the water quality model of Lake Spokane can be improved, the critique does not invalidate the model as a tool to evaluate how the lake responds to nutrient environmental controls. Title: Modeling the Response of Dissolved Oxygen to Phosphorus Loading in Lake Spokane Author: Wells, Scott A., Berger, Chris J. Year: 2016 Mathematical models of hydrodynamics and water quality are often used to determine the assimilative capacity of a waterbody when waterbodies violate state water quality standards. A model of the Spokane River and Lake Spokane in eastern Washington was developed to evaluate the assimilative capacity of the waterbody by setting a total maximum daily load (TMDL). A CE-QUAL-W2 model of this system was developed to establish the TMDL limits for the critical low-flow year of 2001. A recent paper evaluated this model and raised several issues about the validity of this model application as a regulatory tool related to its ability to predict total phosphorus, dissolved oxygen, and chlorophyll a relationships. This paper analyzes the validity of their critiques. For example, the critique used an incorrect formula to calculate total phosphorus inflows into Lake Spokane and used a volume-weighted minimum hypolimnetic dissolved oxygen (DOmin) that was not representative of hypolimnetic conditions. They also assumed incorrectly that the hydrologic, meteorological, operational, and sediment conditions of the 2001 TMDL model would be representative of conditions in other years. Although the water quality model of Lake Spokane can be improved, the critique does not invalidate the model as a tool to evaluate how the lake responds to nutrient environmental controls. Close

• 48. [Article] Getting Plant Conservation Right (or Not): The Case of the United States

  Effective plant conservation includes addressing basic needs such as information about species distribution and rarity; research, management, education, and training capacity to mitigate threats facing ...

  Citation × Citation Citation Abstract Copy Title: Getting Plant Conservation Right (or Not): The Case of the United States Author: Havens, Kayri, Kramer, Andrea T., Guerrant, Edward O., Jr. Year: 2014 Effective plant conservation includes addressing basic needs such as information about species distribution and rarity; research, management, education, and training capacity to mitigate threats facing threatened species; policy and funding to support continued capacity and conservation; and, ultimately, a public that understands and supports the importance of plants and the need for their conservation. Coordination of plant conservation efforts is also needed to ensure that resources and expertise are used in a strategic, efficient, and effective manner.We argue that no country is currently getting plant conservation right; plants are becoming increasingly rare around the world. Plants are often not fully protected by policy, their conservation is underfunded, and their importance is underappreciated. However, some countries have progressed further than others. Here we outline areas where the United States is strong and highlight components that need work to meet the country’s plant conservation needs. Title: Getting Plant Conservation Right (or Not): The Case of the United States Author: Havens, Kayri, Kramer, Andrea T., Guerrant, Edward O., Jr. Year: 2014 Effective plant conservation includes addressing basic needs such as information about species distribution and rarity; research, management, education, and training capacity to mitigate threats facing threatened species; policy and funding to support continued capacity and conservation; and, ultimately, a public that understands and supports the importance of plants and the need for their conservation. Coordination of plant conservation efforts is also needed to ensure that resources and expertise are used in a strategic, efficient, and effective manner.We argue that no country is currently getting plant conservation right; plants are becoming increasingly rare around the world. Plants are often not fully protected by policy, their conservation is underfunded, and their importance is underappreciated. However, some countries have progressed further than others. Here we outline areas where the United States is strong and highlight components that need work to meet the country’s plant conservation needs. Close

• 49. [Article] Fuel to the Fire: Natural Disasters and the Duration of Civil Conflict

  Do natural disasters prolong civil conflict? Or are disasters more likely to encourage peace as hostilities diminish when confronting shared hardship or as shifts in the balance of power between insurgents ...

  Citation × Citation Citation Abstract Copy Title: Fuel to the Fire: Natural Disasters and the Duration of Civil Conflict Author: Eastin, Joshua Year: 2016 Do natural disasters prolong civil conflict? Or are disasters more likely to encourage peace as hostilities diminish when confronting shared hardship or as shifts in the balance of power between insurgents and the state hasten cessation? To address these questions, this study performs an event history analysis of disasters’ impact on the duration of 224 armed intrastate conflicts occurring in 86 states between 1946 and 2005. I contend that natural disasters increase conflict duration by decreasing the state’s capacity to suppress insurgency, while reinforcing insurgent groups’ ability to evade capture and avoid defeat. First, disasters’ economic impact coupled with state financial outlays for disaster relief and reconstruction, reduce resources available for counterinsurgency and nation building in conflict zones. Second, the military’s role in administering humanitarian assistance can reduce the availability of troops and military hardware for counterinsurgency, prompt temporary ceasefires with insurgents, or both. Third, natural disasters can cause infrastructural damages that disproportionately hinder the state’s capacity to execute counterinsurgency missions, thereby making insurgent forces more difficult to capture and overcome. The combination of these dynamics should encourage longer conflicts in states with higher incidence of disaster. Empirical evidence strongly supports this contention, indicating that states with greater disaster vulnerability fight longer wars. Title: Fuel to the Fire: Natural Disasters and the Duration of Civil Conflict Author: Eastin, Joshua Year: 2016 Do natural disasters prolong civil conflict? Or are disasters more likely to encourage peace as hostilities diminish when confronting shared hardship or as shifts in the balance of power between insurgents and the state hasten cessation? To address these questions, this study performs an event history analysis of disasters’ impact on the duration of 224 armed intrastate conflicts occurring in 86 states between 1946 and 2005. I contend that natural disasters increase conflict duration by decreasing the state’s capacity to suppress insurgency, while reinforcing insurgent groups’ ability to evade capture and avoid defeat. First, disasters’ economic impact coupled with state financial outlays for disaster relief and reconstruction, reduce resources available for counterinsurgency and nation building in conflict zones. Second, the military’s role in administering humanitarian assistance can reduce the availability of troops and military hardware for counterinsurgency, prompt temporary ceasefires with insurgents, or both. Third, natural disasters can cause infrastructural damages that disproportionately hinder the state’s capacity to execute counterinsurgency missions, thereby making insurgent forces more difficult to capture and overcome. The combination of these dynamics should encourage longer conflicts in states with higher incidence of disaster. Empirical evidence strongly supports this contention, indicating that states with greater disaster vulnerability fight longer wars. Close

• 50. [Article] Embedding Parallel Computation in a Stochastic Mesh Network: A Morphogenetic Approach

  Many basic techniques in computer science have been founded on the assumption that physical computing resources are scarce but orderly, and that the cost of effective direct communication between physically ...

  Citation × Citation Citation Abstract Copy Title: Embedding Parallel Computation in a Stochastic Mesh Network: A Morphogenetic Approach Author: OrHai, Max Year: 2011 Many basic techniques in computer science have been founded on the assumption that physical computing resources are scarce but orderly, and that the cost of effective direct communication between physically distant parts of a computer system is affordable. In ubiquitous computing systems such as sensor networks, or in the design of nano-scale systems, these familiar assumptions may not hold. What if we suppose instead that computing capacity is plentiful, but that only local communication is possible, and the exact structure of the communication network is not known in advance? This is the domain of spatial programming. How can we program a locally connected network of randomly placed computing nodes to do a practical computing task, while taking advantage of the inherent parallel processing capacity of the network? We believe that the organization and dynamics of biological processes may offer possibilities for the design of both hardware and software under these new conditions. This algorithm, a variation on insertion sort that is also a simplified abstract model of morphogenetic cell sorting in the development of multicellular organisms, explores how we might compute in this novel environment. Title: Embedding Parallel Computation in a Stochastic Mesh Network: A Morphogenetic Approach Author: OrHai, Max Year: 2011 Many basic techniques in computer science have been founded on the assumption that physical computing resources are scarce but orderly, and that the cost of effective direct communication between physically distant parts of a computer system is affordable. In ubiquitous computing systems such as sensor networks, or in the design of nano-scale systems, these familiar assumptions may not hold. What if we suppose instead that computing capacity is plentiful, but that only local communication is possible, and the exact structure of the communication network is not known in advance? This is the domain of spatial programming. How can we program a locally connected network of randomly placed computing nodes to do a practical computing task, while taking advantage of the inherent parallel processing capacity of the network? We believe that the organization and dynamics of biological processes may offer possibilities for the design of both hardware and software under these new conditions. This algorithm, a variation on insertion sort that is also a simplified abstract model of morphogenetic cell sorting in the development of multicellular organisms, explores how we might compute in this novel environment. Close