38 research outputs found
Combining and Aggregating Environmental Data for Status and Trend Assessments: Challenges and Approaches
Increasingly, natural resource management agencies and nongovernmental organizations are sharing monitoring data across geographic and jurisdictional boundaries. Doing so improves their abilities to assess local-, regional-, and landscape-level environmental conditions, particularly status and trends, and to improve their ability to make short-and long-term management decisions. Status monitoring assesses the current condition of a population or environmental condition across an area. Monitoring for trends aims at monitoring changes in populations or environmental condition through time. We wrote this paper to inform agency and nongovernmental organization managers, analysts, and consultants regarding the kinds of environmental data that can be combined with suitable techniques and statistically aggregated for new assessments. By doing so, they can increase the (1) use of available data and (2) the validity and reliability of the assessments. Increased awareness of the difficulties inherent in combining and aggregating data for local-and regional-level analyses can increase the likelihood that future monitoring efforts will be modified and/or planned to accommodate data from multiple sources
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Parallelizing the Simulation of Shipboard Power Systems
As a result of this research the Navy has a simulation approach for ship power systems that is computationally effective enough to permit efficient simulation. In addition to simulating the basic power system, significant progress has been made in the simulation of the control system.United States Office of Naval ResearchCenter for Electromechanic
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Combining and aggregating environmental data for status and trend assessments: challenges and approaches
Increasingly, natural resource management agencies and nongovernmental organizations are sharing monitoring data across geographic and jurisdictional boundaries. Doing so improves their abilities to assess local-, regional-, and landscape-level environmental conditions, particularly status and trends, and to improve their ability to make short-and long-term management decisions. Status monitoring assesses the current condition of a population or environmental condition across an area. Monitoring for trends aims at monitoring changes in populations or environmental condition through time. We wrote this paper to inform agency and nongovernmental organization managers, analysts, and consultants regarding the kinds of environmental data that can be combined with suitable techniques and statistically aggregated for new assessments. By doing so, they can increase the (1) use of available data and (2) the validity and reliability of the assessments. Increased awareness of the difficulties inherent in combining and aggregating data for local-and regional-level analyses can increase the likelihood that future monitoring efforts will be modified and/or planned to accommodate data from multiple sources.Keywords: Lurking variable, Change of support problem, Simpson's paradox, Modifiable areal unit problem, Data aggregation, Environmental monitorin
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A Review of Urban Water Body Challenges and Approaches: (1) Rehabilitation and Remediation
We review how urbanization alters aquatic ecosystems, as well as actions that managers can take to remediate urban waters. Urbanization affects streams by fundamentally altering longitudinal and lateral processes that in turn alter hydrology, habitat, and water chemistry; these effects create physical and chemical stressors that in turn affect the biota. Urban streams often suffer from multiple stressor effects that have collectively been termed an “urban stream syndrome,” in which no single factor dominates degraded conditions. Resource managers have multiple ways of combating the urban stream syndrome. These approaches range from whole-watershed protection to reach-scale habitat rehabilitation, but the prescription must be matched to the scale of the factors that are causing the problem, and results will likely not be immediate because of lengthy recovery times. Although pristine or reference conditions are far from attainable, urban stream rehabilitation is a worthy goal because appropriate actions can provide ecosystem improvements as well as increased ecosystem service benefits for human society
The Gaseous Electronics Conference radio‐frequency reference cell: A defined parallel‐plate radio‐frequency system for experimental and theoretical studies of plasma‐processing discharges
A ‘‘reference cell’’ for generating radio‐frequency (rf) glow discharges in gases at a frequency of 13.56 MHz is described. The reference cell provides an experimental platform for comparing plasma measurements carried out in a common reactor geometry by different experimental groups, thereby enhancing the transfer of knowledge and insight gained in rf discharge studies. The results of performing ostensibly identical measurements on six of these cells in five different laboratories are analyzed and discussed. Measurements were made of plasma voltage and current characteristics for discharges in pure argon at specified values of applied voltages, gas pressures, and gas flow rates. Data are presented on relevant electrical quantities derived from Fourier analysis of the voltage and current wave forms. Amplitudes, phase shifts, self‐bias voltages, and power dissipation were measured. Each of the cells was characterized in terms of its measured internal reactive components. Comparing results from different cells provides an indication of the degree of precision needed to define the electrical configuration and operating parameters in order to achieve identical performance at various laboratories. The results show, for example, that the external circuit, including the reactive components of the rf power source, can significantly influence the discharge. Results obtained in reference cells with identical rf power sources demonstrate that considerable progress has been made in developing a phenomenological understanding of the conditions needed to obtain reproducible discharge conditions in independent reference cells.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70394/2/RSINAK-65-1-140-1.pd
Web Accessibility for Visually Impaired Users: Extending the Technology Acceptance Model (TAM)
The Technology Acceptance Model (TAM) is one of the most widely used models in the MIS literature. Verified by many studies, TAM asserts that the perceived ease of use and perceived usefulness of an information technology is instrumental in its adoption. While previous research has been valuable in explaining how and why the perception of ease of use and usefulness develops, this research does not include a growing number of users, namely the disabled. The large number of disabled technology users calls for scientific examination of ways to improve technology acceptance and usage in this population. Our study will address this need by extending TAM to include visually disabled users. Moreover, our study will expand TAM by examining information accessibility as a potential key determinant of ease of use and usefulness of web usage for people with and without visual disability
Comprehensive evaluation of algal biofuel production: Experimental and target results
Worldwide, algal biofuel research and development efforts have focused on
increasing the competitiveness of algal biofuels by increasing the energy and financial
return on investments, reducing water intensity and resource requirements, and increasing
algal productivity. In this study, analyses are presented in each of these areas—costs,
resource needs, and productivity—for two cases: (1) an Experimental Case, using mostly
measured data for a lab-scale system, and (2) a theorized Highly Productive Case that
represents an optimized commercial-scale production system, albeit one that relies on
full-price water, nutrients, and carbon dioxide. For both cases, the analysis described herein
concludes that the energy and financial return on investments are less than 1, the water
intensity is greater than that for conventional fuels, and the amounts of required resources at a meaningful scale of production amount to significant fractions of current consumption
(e.g., nitrogen). The analysis and presentation of results highlight critical areas for
advancement and innovation that must occur for sustainable and profitable algal biofuel
production can occur at a scale that yields significant petroleum displacement. To this end,
targets for energy consumption, production cost, water consumption, and nutrient
consumption are presented that would promote sustainable algal biofuel production.
Furthermore, this work demonstrates a procedure and method by which subsequent
advances in technology and biotechnology can be framed to track progress.Mechanical Engineerin
College Housing Fire Safety
This project was sponsored by the U.S. Consumer Product Safety Commission (CPSC) to address the issue of fire safety in college residences and to assist in the achievement of the CPSC's strategic goal of a 20% reduction in fire-related deaths over the period of 1998-2013. We researched and analyzed the causes of fires, fire education programs, and fire detection and suppression. From this, we developed recommendations for the CPSC to address the issue of college housing fire safety