2,875 results
Search Results
2. Participation and Performance on Paper- and Computer-Based Low-Stakes Assessments
- Author
-
Nissen, Jayson M., Jariwala, Manher, Close, Eleanor W., and Van Dusen, Ben
- Abstract
Background: High-stakes assessments, such the Graduate Records Examination, have transitioned from paper to computer administration. Low-stakes research-based assessments (RBAs), such as the Force Concept Inventory, have only recently begun this transition to computer administration with online services. These online services can simplify administering, scoring, and interpreting assessments, thereby reducing barriers to instructors' use of RBAs. By supporting instructors' objective assessment of the efficacy of their courses, these services can stimulate instructors to transform their courses to improve student outcomes. We investigate the extent to which RBAs administered outside of class with the online Learning About STEM Student Outcomes (LASSO) platform provide equivalent data to tests administered on paper in class, in terms of both student participation and performance. We use an experimental design to investigate the differences between these two assessment conditions with 1310 students in 25 sections of 3 college physics courses spanning 2 semesters. Results: Analysis conducted using hierarchical linear models indicates that student performance on low-stakes RBAs is equivalent for online (out-of-class) and paper-and-pencil (in-class) administrations. The models also show differences in participation rates across assessment conditions and student grades, but that instructors can achieve participation rates with online assessments equivalent to paper assessments by offering students credit for participating and by providing multiple reminders to complete the assessment. Conclusions: We conclude that online out-of-class administration of RBAs can save class and instructor time while providing participation rates and performance results equivalent to in-class paper-and-pencil tests.
- Published
- 2018
- Full Text
- View/download PDF
3. Meeting Students Where They Are: Using Rubric-Based Assessment to Modify an Information Literacy Curriculum
- Author
-
Markowski, Brianne, McCartin, Lyda, and Evers, Stephanie
- Abstract
The authors conducted a performance-based assessment of information literacy to determine if students in a first-year experience course were finding relevant sources, using evidence from sources effectively, and attributing sources correctly. A modified AAC&U VALUE rubric was applied to 154 student research papers collected in fall 2015 and fall 2016. Study results indicate that students in the sample were able to find relevant and appropriate sources for their research papers; however, they were not using evidence to effectively support an argument or attributing sources correctly. The authors discuss changes to the library instruction curriculum informed by the assessment results.
- Published
- 2018
4. Notes on Fruit Damage by the European Paper Wasp, Polistes dominula (Christ) (Hymenoptera: Vespidae).
- Author
-
Cranshaw, W. S., Larsen Jr., H. J., and Zimmerman, R. J.
- Subjects
- *
PAPER wasps , *LEPIDOPTERA , *FRUIT diseases & pests , *INSECT populations - Abstract
The European paper wasp, Polistes dominula (Christ), has colonized much of Colorado during the past decade and has emerged as a dominant species of nuisance wasp. It is impacting many types of prey species, particularly larval Lepidoptera. However, in western Colorado it is also a common pest in fruit orchards and can be very damaging to ripening grapes, Vitis vinifera L.; sweet cherries, Prunus avium (L.) L.; and other thin-fleshed stone fruits. This latter habit is unusual for a Polistes species. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
5. Introduction to the special collection of papers on the San Luis Basin Sustainability Metrics Project: A methodology for evaluating regional sustainability
- Author
-
Heberling, Matthew T. and Hopton, Matthew E.
- Subjects
- *
GEOLOGICAL basins , *SUSTAINABILITY , *WATERSHEDS , *ECOLOGICAL impact , *WELFARE economics , *DECISION making in environmental policy , *RESEARCH methodology evaluation - Abstract
This paper introduces a collection of four articles describing the San Luis Basin Sustainability Metrics Project. The Project developed a methodology for evaluating regional sustainability. This introduction provides the necessary background information for the project, description of the region, overview of the methods, and summary of the results. Although there are a multitude of scientifically based sustainability metrics, many are data intensive, difficult to calculate, and fail to capture all aspects of a system. We wanted to see if we could develop an approach that decision-makers could use to understand if their system was moving toward or away from sustainability. The goal was to produce a scientifically defensible, but straightforward and inexpensive methodology to measure and monitor environmental quality within a regional system. We initiated an interdisciplinary pilot project in the San Luis Basin, south-central Colorado, to test the methodology. The objectives were: 1) determine the applicability of using existing datasets to estimate metrics of sustainability at a regional scale; 2) calculate metrics through time from 1980 to 2005; and 3) compare and contrast the results to determine if the system was moving toward or away from sustainability. The sustainability metrics, chosen to represent major components of the system, were: 1) Ecological Footprint to capture the impact and human burden on the system; 2) Green Net Regional Product to represent economic welfare; 3) Emergy to capture the quality-normalized flow of energy through the system; and 4) Fisher information to capture the overall dynamic order and to look for possible regime changes. The methodology, data, and results of each metric are presented in the remaining four papers of the special collection. Based on the results of each metric and our criteria for understanding the sustainability trends, we find that the San Luis Basin is moving away from sustainability. Although we understand there are strengths and limitations of the methodology, we argue that each metric identifies changes to major components of the system. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
- View/download PDF
6. Organizational Training and Relationship Building for Increasing Public Participation in a Public School District
- Author
-
Poynton, John, Makela, Carole, and Haddad, Don
- Abstract
From the early twentieth century to the present, citizen participation in U.S. public institutions--particularly schools--has continually decreased. The trend has been linked to the bureaucratization of public schools and their increasing reliance on expert knowledge for solutions to school- and education-related problems. The purpose of this study was to evaluate the impact of a parent training program designed to increase a school district's capacity for public participation by parents and other citizens. The program--known as Leadership St. Vrain--provided citizens knowledge about school district operations and management (know-how) and relationship-building opportunities with key decision makers (know-who). This article focuses on the experiences and participation of the citizens from a mixed-methods study that collected data using two original survey instruments, follow-up interviews, and archival documents. Of the five domains studied, this paper focuses on findings for the domains of knowledge, relationships, and action, as well as the secondary ripple effect from participants to others who did not participate in the training.
- Published
- 2014
7. PAPERS AND POSTERS.
- Subjects
- *
OPTOMETRY , *POSTER presentations , *ANNUAL meetings , *OPTOMETRISTS , *VISION disorders in children , *AMBLYOPIA , *SOCIETIES - Abstract
The article focuses on various papers and posters which were presented during the 39th Annual Meeting of the College of Optometrists in Vision Development (COVD) in Denver, Colorado in 2009. They include "Long Term Results of Treatment of Convergence Insufficiency in Children," by Mitchell Scheiman, "Detection of Visual Efficiency Problems Using Vera School Screening Software," by Michael Gallaway and G. Lynn Mitchell and "Optometric Remediation of Amblyopia Post Unilateral Cataract Extraction," by Hadassa Rutman.
- Published
- 2009
8. Briefing. What the papers say.
- Author
-
PETER DOYLE
- Subjects
- *
RICHTER scale , *SEISMOLOGISTS , *COAL - Abstract
The article focuses on the papers published in the journal Geology Today. The answer to the question, why do we say 4.7 on the Richter scale and not 4.7 Richters, from the seismologist Roger Musson points out that when Richter designed the magnitude scale he did so by analogy with the magnitude scale used by astronomers for stars. The term "Richter scale" was later coined by Californian journalists and is not a scientific term and no seismologist would use the phrase when talking to another seismologist. The destruction of coal, another kind of underground activity is taking place in Colorado. U.S. where coal is burning uncontrolled, is unusual occurrence.
- Published
- 2003
- Full Text
- View/download PDF
9. A Case Study of Institutional Visioning, Public Good, and the Renewal of Democracy: The Theory and Practice of Public Good Work at the University of Denver
- Author
-
Fretz, Eric, Cutforth, Nick, Nicotera, Nicole, and Thompson, Sheila Summers
- Abstract
In 2001, the University of Denver included language in its vision statement that committed the institution to becoming "a great private university dedicated to the public good." This essay (1) explains how the development of an institutional visioning statement led to the implementation of a series of campus dialogues and action steps designed to forward public good work at the university; (2) presents campus conversations and current literature to offer a theory of public good work within private research universities; and (3) documents challenges and lessons learned through institutional efforts to embrace a culture of engagement. (Contains 6 endnotes.)
- Published
- 2009
10. Administrative metadata for digital images: a real world application of the NISO draft standard1 <FN ID="FN1"><NO>1</NO>This paper is based on the author’s presentation given at the ALA 2002 Midwinter Conference during the Association for Library Collections and Technical Services, Cataloging and Classification Section, Cataloging Norms Discussion Group session.</FN>
- Author
-
Rettig, Patricia J.
- Subjects
- *
METADATA - Abstract
Administrative metadata for digital images is discussed in the context of the International Poster Collection at the Colorado State University Libraries. The decision-making process that resulted in the use of the NISO draft standard “Data Dictionary: Technical Metadata for Digital Still Images” is detailed. The draft standard is discussed, as are the outcomes of its use in the poster project. [Copyright &y& Elsevier]
- Published
- 2002
- Full Text
- View/download PDF
11. A New Approach for Discontinuity Extraction Based on an Improved Naive Bayes Classifier.
- Author
-
Lu, Guangyin, Zhu, Xudong, Cao, Bei, Li, Yani, Tao, Chuanyi, and Yang, Zicheng
- Subjects
NAIVE Bayes classification ,HIERARCHICAL clustering (Cluster analysis) ,RANDOM numbers ,PRINCIPAL components analysis ,POINT cloud ,RANDOM sets ,KNEE - Abstract
An increasing number of methods are being used to extract rock discontinuities from 3D point cloud data of rock surfaces. In this paper, a new method for automatic extraction of rock discontinuity based on an improved Naive Bayes classifier is proposed. The method first uses principal component analysis to find the normal vectors of the points, and then generates a certain number of random point sets around the selected training points for training the classifier. The trained, improved Naive Bayes classifier is based on point normal vectors and is able to automatically remove noise points due to various reasons in conjunction with the knee point algorithm, realizing high-precision extraction of the discontinuity sets. Subsequently, the individual discontinuities are segmented using a hierarchical density-based spatial clustering method with noise application. Finally, the PCA algorithm is used to complete the orientation by plane fitting the individual discontinuities. The method was applied in two cases, Kingston and Colorado, and the reliability and advantages of the new method were verified by comparing the results with those of previous research, and the discussion and analysis determined the optimal values of the relevant parameters in the algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. Publishing a Student Research Journal: A Case Study
- Abstract
Each semester, undergraduate students at the University of Colorado at Colorado Springs produce quality research papers that seldom reach audiences beyond their professors or classrooms. In 2008, Kraemer Family Library launched an open access undergraduate research journal on a trial basis to give faculty a mechanism for highlighting excellent student research. The journal has evolved into a sustainable and popular publishing service at the university. This case study describes the progress and setbacks that were encountered during the first year of the journal's publication, with particular emphasis on management and policy issues. (Contains 3 figures, 1 table and 30 notes.)
- Published
- 2010
- Full Text
- View/download PDF
13. Colorado Mineral Artist Safaa Yu (b. 1985).
- Author
-
Robinson, Susan
- Subjects
MINERALS ,ART & society ,COVID-19 pandemic ,ARTISTS ,ART materials - Abstract
Yu's given name is actually Zhuowei Yu, but most people in the mineral community know her as Safaa Yu. This article presents the colored-pencil artwork of Safaa Yu of Littleton, Colorado. So finally 2020 comes, and for a while I had some time to challenge myself a little by using colored pencils (Prismacolor brand).... As I [progress in my art], I really like to work with them and hopefully will explore more with colored pencils in the future. [Extracted from the article]
- Published
- 2021
- Full Text
- View/download PDF
14. Policy to Practice: A Look at National and State Implementation of School Resource Officer Programs
- Author
-
Cray, Martha and Weiler, Spencer C.
- Abstract
In response to questions related to school safety, in the 1990s the school resource officer (SRO) program gained prominence as an effective intervention strategy. Despite the widespread utilization of SROs in America's public schools, there exists a lack of meaningful research related to practices and effectiveness of SRO programs. A school resource officer is a sworn police officer assigned to a school or a group of schools during the school year. The SRO presence in a school is intended to increase school safety for students, staff, and community members. However, little is actually known about the SRO program and its ability to increase school safety. SRO assignment patterns are documented in this study along with the use of memorandums of understandings (MOU), or other intergovernmental agency agreements, and the role of the MOU in promoting a safe learning environment. School officials interested in increasing school safety through the use of the SRO program are encouraged to develop meaningful MOUs that establish clear guidelines related to the conduct of the sworn police officer in the school building. (Contains 8 tables.)
- Published
- 2011
- Full Text
- View/download PDF
15. WPA as Rhetor: Scholarly Production and the Difference a Discipline Makes
- Author
-
Dew, Debra Frank
- Abstract
This article defines applied rhetorical work as integral to the intellectual work of writing program administration and asks our professional organizations to classify it as such within our position statements. With a specific case, it offers a generative framework for representing and assessing the work's scholarly commons for professional review. (Contains 2 notes.)
- Published
- 2009
16. A Direct Approach for Local Quasi-Geoid Modeling Based on Spherical Radial Basis Functions Using a Noisy Satellite-Only Global Gravity Field Model.
- Author
-
Yu, Haipeng, Chang, Guobin, Yu, Yajie, and Zhang, Shubi
- Subjects
RADIAL basis functions ,ROOT-mean-squares ,DATA distribution ,REFERENCE values ,COVARIANCE matrices - Abstract
The remove–compute–restore (RCR) approach is widely used in local quasi-geoid modeling. However, the classical RCR approach usually does not take into account the noise of the satellite-only global gravity field model (GGM), which may lead to a suboptimal result. This paper presents an approach for local quasi-geoid modeling based on spherical radial basis functions that combines local noisy datasets and a noisy satellite-only GGM. This approach includes an RCR procedure using a satellite-only GGM. This is a direct approach that takes the spherical harmonic coefficients of satellite-only GGM as a noisy dataset and includes the corresponding full-noise covariance matrix in the least-squares estimation, aiming to obtain a statistically optimal local quasi-geoid model. The direct approach goes beyond the indirect approach, which treats the height anomalies generated from the satellite-only GGM as a noisy dataset. However, the generated GGM height anomaly dataset is not an equivalent representation of the satellite-only GGM, which may result in the loss of information from the satellite-only GGM. Through mathematical deduction, we demonstrate the theoretical consistency between the direct approach and the indirect approach. The direct approach also has an advantage over the indirect approach in terms of computational complexity due to the simpler algorithm. We conducted a synthetic closed-loop test with a real data distribution in Colorado, and numerical results demonstrated the advantage of the direct approach in local quasi-geoid modeling. In terms of the root mean square of the differences between the predicted values and the true reference values, the direct approach provided an improvement of approximately 14% compared to the indirect approach. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
17. Elliptic equations involving supercritical Sobolev growth with mixed Dirichlet-Neumann boundary conditions.
- Author
-
de Assis, Heitor R. and Faria, Luiz F. O.
- Subjects
- *
GALERKIN methods , *ELLIPTIC operators - Abstract
This paper concerns elliptic problems involving supercritical Sobolev growth without the (AR) condition and with a mixed boundary Dirichlet-Neumann type condition. The conditions imposed on the nonlinearity considered here generalizes several previous papers, including that presented in the work that inspired this paper, due to Peral and Colorado, in 2003. Beyond that, we present some complementary results, concerning the non-existence of solutions to a class of elliptic problems and a comparison result inspired by the case of Dirichlet boundary conditions, presented by the work of Ambrosetti, Brezis and Cerami. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
18. "Cowboy up": Gender, labor, and workforce housing in Colorado ski country.
- Author
-
Frydenlund, Shae
- Subjects
HOUSING ,LABOR supply ,GENDER ,COWBOYS ,WOMEN employees - Abstract
Workforce housing does not reproduce all workers equally. So, what kind of workers does "workforce" housing reproduce? Whose reproduction is prioritized, whose is devalued, and how? A case study of housing access and design in three elite Vail Resorts enclaves in Colorado shows that workforce housing prioritizes the reproduction of a young, flexible androcentric workforce who can be cheaply and easily housed. Extending McIntyre and Nast's theorization of racial subsidies, I argue that resort capital awards unearned gendered subsidies to privileged workers and instantiates what Susanne Soederberg calls "displaced survival," or recursive dislocation, for women workers and those with dependents. I detail how twin processes of displaced survival and gendered subsidy emerge in resort communities using data from interviews, survey, ethnographic observation, autoethnography, and municipal records. By attending to the lived experiences of workers in this niche industry, this paper contributes to literature on geographies of exclusion and expands scholarly understandings of how the gendered political economy of labor is sedimented in housing regimes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
19. Generation and Transmission Expansion Planning: Nexus of Resilience, Sustainability, and Equity.
- Author
-
Byles, Dahlia, Kuretich, Patrick, and Mohagheghi, Salman
- Subjects
LIFE cycles (Biology) ,ELECTRIC power distribution grids ,NATURAL disasters ,CAPACITY requirements planning ,ENERGY consumption - Abstract
The problem of power grid capacity expansion focuses on adding or modernizing generation and transmission resources to respond to the rise in demand over a long-term planning period. Traditionally, the problem has been mainly viewed from technical and financial perspectives. However, with the rise in the frequency and severity of natural disasters and their dire impacts on society, it is paramount to consider the problem from a nexus of resilience, sustainability, and equity. This paper presents a novel multi-objective optimization framework to perform power grid capacity planning, while balancing the cost of operation and expansion with the life cycle impacts of various technologies. Further, to ensure equity in grid resilience, a social vulnerability metric is used to weigh the energy not served based on the capabilities (or lack thereof) of communities affected by long-duration power outages. A case study is developed for part of the bulk power system in the state of Colorado. The findings of the study show that, by considering life cycle impacts alongside cost, grid expansion solutions move towards greener alternatives because the benefits of decommissioning fossil-fuel-based generation outweigh the costs associated with deploying new generation resources. Furthermore, an equity-based approach ensures that socially vulnerable populations are less impacted by disaster-induced, long-duration power outages. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
20. When justifications are mistaken for motivations: COVID-related dietary changes at the food-health decision-making nexus.
- Author
-
Carolan, Michael
- Subjects
CONSUMER behavior ,MOTIVATION (Psychology) ,ORGANIC foods ,CONSUMPTION (Economics) ,DECISION making - Abstract
This paper draws from data collected from 500+ surveys, distributed twice from the same respondents (2020 and 2021), and forty-five face-to-face interviews (2022). The location studied is a metropolitan county in Colorado (USA). The research examined the discourses and practices having to do with organic and natural food consumption—note, too, the data were collected at the height of the COVID-19 pandemic. The findings upend conventional understandings of, and frameworks used to explain, consumer behavior. What are often presented as motivations in prior studies are shown, instead, to be justifications; rationalizations after-the-fact. The paper troubles decision-making frameworks that cast motivations, attitudes, and intentions as "antecedents" to consumer behavior. Rather, the findings point to the significance of social networks, and in particular network diversity, for understanding and explaining the sayings (discourses) and doings (practices) of "individual" consumers. Discourses linked to health are also shown to be salient variables, though when situated within social networks those discourses are shown to have politics. Particular attention is devoted to explaining dietary shifts among those who reported the largest increases in the consumption of organic and natural foods between 2020 and 2021/22. The paper concludes discussing what the data mean from the standpoint of envisioning just and inclusive food system futures and agrifood policy that delivers on those ends. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. Contribution of flowering trees to urban atmospheric biogenic volatile organic compound emissions.
- Author
-
Baghi, R., Helmig, D., Guenther, A., Duhl, T., and Daly, R.
- Subjects
FLOWERING trees ,CITIES & towns ,VOLATILE organic compounds & the environment ,AIR sampling ,CRABAPPLES ,PLANT species ,MONOTERPENES - Abstract
Emissions of biogenic volatile organic compounds (BVOC) from urban trees during and after blooming were measured during spring and early summer 2009 in Boulder, Colorado. Air samples were collected onto solid adsorbent cartridges from branch enclosures on the tree species crabapple, horse chestnut, honey locust, and hawthorn. These species constitute 65% of the insect-pollinated fraction of the flowering tree canopy (excluding catkin-producing trees) from the street area managed by the City of Boulder. Samples were analyzed for C
10 -C15 BVOC by thermal desorption and gas chromatography coupled to a flame ionization detector and a mass spectrometer (GC/FID/MS). Identified emissions and emission rates from these four tree species during the flowering phase were found to vary over a wide range. Monoterpene emissions were identified for honey locust, horse chestnut and hawthorn. Sesquiterpene emissions were observed in horse chestnut and hawthorn samples. Crabapple flowers were found to emit significant amounts of benzyl alcohol and benzaldehyde. Floral BVOC emissions increased with temperature, generally exhibiting exponential temper ature dependence. Changes in BVOC speciation during and after the flowering period were observed for every tree studied. Emission rates were significantly higher during the blooming compared to the vegetative state for crabapple and honey locust. Total normalized (30°C) monoterpene emissions from honey locust were higher during flowering (5.26 µg Cg-1 h-1 ) than after flowering (1.23 µg Cg-1 h-1 ). The total normalized BVOC emission rate from crabapple (93 µg Cg-1 h-1 ) during the flowering period is of the same order as isoprene emissions from oak trees, which are among the highest BVOC emissions observed from plants to date. These findings illustrate that during the relatively brief springtime flowering period, floral emissions constitute by far the most significant contribution to the BVOC flux from these tree species, some of which are= leafless at this time. Experimental results were integrated into the MEGAN biogenic emission model and simulations were performed to estimate the contribution of floral BVOC emissions to the total urban BVOC flux during the spring flowering period. The floral BVOC emitted during this three-month simulation are equivalent to 11% of the cumulative monoterpene flux for the Boulder urban area. [ABSTRACT FROM AUTHOR]- Published
- 2012
- Full Text
- View/download PDF
22. A Recap of the 22nd Annual Mid-Year Meeting of the American Taxation Association.
- Author
-
Higgins, Mark
- Subjects
CONFERENCES & conventions ,TAX administration & procedure ,TAXATION -- Study & teaching - Abstract
The article offers information on several papers discussed at the 22nd Annual Mid-Year Meeting of the American Taxation Association held in Denver, Colorado on February 19-20, 2010. The meeting featured Continuing Professional Education (CPE) sessions with papers on tax administration, book-tax difference disclosure and the nature of tax. Presenters and researchers featured in the meeting includes former Internal Revenue Service Commissioner Deborah Nolan, Michael P. Donohoe and John Robinson.
- Published
- 2010
- Full Text
- View/download PDF
23. Mathematics, its History, and Mathematical Olympiads: A Golden Braid.
- Author
-
Soifer, Alexander
- Subjects
MATHEMATICS contests ,MATHEMATICS ,BRAID group (Knot theory) - Abstract
A beautiful braid of mathematics, history, and mathematical Olympiads will be presented 'in the flesh.' I will convey 4 stories, each featuring a braid of history, old mathematical papers that often contain unnoticed or little noticed treasures that, once dug out, lend themselves to creating new original problems for mathematical Olympiads. Some of these stories have appeared ([3], [5], [6]); others are waiting for an appearance in the new edition [4], and so you will be able to preview some pages of my future book. [ABSTRACT FROM AUTHOR]
- Published
- 2022
24. Mercury dynamics in the Rocky Mountain, Colorado, Snowpack.
- Author
-
Faïn, X., Helmig, D., Hueber, J., Obrist, D., and Williams, M. M.
- Subjects
SNOWPACK augmentation ,ECOLOGICAL research ,LATITUDE ,SOIL depth ,PHOTOCHEMISTRY - Abstract
Gaseous Elemental Mercury (GEM) was monitored at the Niwot Ridge (NWT) longterm ecological research (LTER) site (Colorado, USA, 40°N) from interstitial air extracted from the snowpack at depths ranging from the snow surface to 10 cm above the soil. A highly dynamic cycling of mercury (Hg) in this mid-latitude snowpack was observed. Patterns were driven by both GEM production in surface snow and GEM destruction in the deeper snowpack layers. Thorough mixing and vertical transport processes were observed through the snowpack. GEM was photochemically produced near the snow-air interface leading to enhanced GEM levels in interstitial air of surface snow of up to 8 ngm
-3 . During low wind periods, GEM in surface snow layers remained significantly above ambient air levels at night as well, which may indicate a potential weak GEM production over night. Analysis of vertical GEM gradients in the snowpack show that surface GEM enhancements efficiently propagated down the snowpack, with a temporal lag in peak GEM levels observed with increasing depth. Downward diffusion was responsible for much of these patterns, although vertical advection also contributed to vertical redistribution. Destruction of GEM in the lower snowpack layers was attributed to dark oxidation of GEM. Analysis of vertical GEM/CO2 flux ratios indicated that this GEM destruction occurred in the snow and not in the underlying soil. The strong, diurnal patterns of photochemical GEM production at the surface ultimately lead to re-emission losses of deposited Hg back to the atmosphere. The NWT data show that highest of GEM production and emission occur shortly after fresh snowfall, indicating that fresh snow possibly resupplies photoreducible Hg to the snowpack. [ABSTRACT FROM AUTHOR]- Published
- 2012
- Full Text
- View/download PDF
25. Call for papers.
- Subjects
- *
SOCIAL conditions of women , *CONFERENCES & conventions - Abstract
Announces that the theme `Issues of Women's Status, Families, and Children in Islamic and Judaic Traditions, History, and Contemporary Concerns' will be discussed at a conference co-sponsored by the University of Denver's Institute for Islamic-Judaic Studies, Center for Judaic Studies and the American Jewish Committee to be held on October 23-25, 1994 in Denver, Colorado.
- Published
- 1993
26. Measurements in Firestop Compliance: A Hospital Case Study.
- Author
-
Mulholland, Sean M., Clevenger, Caroline, Bergeman, Paola Figueroa, and Khezri, Maziar
- Subjects
BUILDING maintenance ,PNEUMATICS ,CONSTRUCTION projects ,HOSPITALS ,SMOKE ,BUILT environment ,HAZARD mitigation ,BUILDING-integrated photovoltaic systems - Abstract
Fire/smoke barriers are designed to isolate building spaces into manageable compartments that resist the spread of fire and/or smoke, but there are situations in which these life-safety barriers are purposely compromised. Firestopping is a construction and postconstruction activity used to maintain the integrity of fire/smoke barriers. The activity of firestopping is typically the responsibility of either the contractor(s) that caused the penetration or a designated specialty contractor whose primary project function is to monitor and remediate barrier penetrations. There has been limited research on the classification and/or quantity of penetrations that are typically installed in the built environment. This case study collected data from the construction of two separate healthcare construction projects along Colorado's Front Range. Results of this case study across both buildings showed that the majority of penetrations were the results of electrical/low-voltage scopes of work, followed by plumbing, mechanical, fire, structural, and pneumatic tube system penetrations. Life-safety barriers are common in certain building types, and penetrating these barriers is often necessary. This paper provided a method and classification for penetrations of these barriers. Being able to classify the type of penetration and responsible party allows contractors and designers the ability to manage the mitigation efforts. This process also provides a benchmark for owners and designers to quantify the impact of barrier penetrations on building design and maintenance requirements. This may result in building designs that minimize the number of penetrations and provide access areas for building operators to easily inspect and maintain these penetrations. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
27. Taking Communities into the Groan Zone: Subjective Wellbeing in the Face of Demographic Change, Racial Diversity, and Political Difference☆.
- Author
-
Carolan, Michael
- Subjects
COMMUNITIES ,SUBJECTIVE well-being (Psychology) ,COVID-19 pandemic ,DEMOGRAPHIC change ,STAY-at-home orders ,EMOTIONAL state ,SOCIAL networks - Abstract
This paper draws from a dataset focusing on two rural communities in Colorado (USA). Data collection occurred over two periods: late‐2019 and again during COVID‐19 lockdowns in mid‐2020. The communities differed demographically: one had a growing minoritized population, especially among its youth; the other was overwhelmingly white. The paper troubles the concept of subjective wellbeing (SWB) as it asks about the productive potentials of discomfort, with assistance from such concepts as colorblind ideology, motivated reasoning, and network homophily. While important to think about so‐called positive emotional states in the context of community development, we must also ask questions like, "SWB for who and at whose expense?" How respondents thought about individual‐ and community‐level SWB had much to do with the social networks they were in. I also explore why the community that fared pandemic‐related disruptions, from a SWB standpoint, better than the other performed worse during this same period from an economic (material) standpoint. Sociological factors explain these dynamics, which are leveraged to enhance our understanding of how to conceptualize community development in productive ways. In sum, I argue that certain expressions of discomfort have value and are therefore necessary for creating resilient, flourishing, and, ultimately, just communities. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
28. Lessons Learned from the Colorado Project to Comprehensively Combat Human Trafficking.
- Author
-
Miller, Annie, Laser, Julie, Alejano-Steele, Annjanette, Napolitano, Kara, George, Nevita, Connot, Natcha, and Finger, Amanda
- Subjects
HUMAN trafficking ,COMMUNITY-based participatory research ,SOCIAL movements ,NONPROFIT organizations ,TASK forces ,PUBLIC sector - Abstract
Countering human trafficking at a statewide level requires a combination of knowledge from lived experience, inter-sector collaborations, and evidence-based tools to measure progress. Since 2010, the nonprofit Laboratory to Combat Human Trafficking (LCHT) has collected and analyzed the data on how partners and organizations across the state work toward ending human trafficking. LCHT uses Community-Based Participatory Research (CBPR) to measure and illuminate promising paths toward ending human trafficking. Through CBPR, many collaborative working documents and activities have been created: Colorado Action Plans, Policy Recommendations, a Partnership Toolkit, and Partnership Convenings. This paper provides a single case study analysis of the Colorado Project, from 2013 through 2023, and offers a glimpse into the goals for the Colorado Project 2028. The ideas, strengths, and challenges presented here can guide other local efforts to support data-informed responses to trafficking. The CBPR methodology sheds light on the changes in Colorado's anti-trafficking movement and the actions taken on behalf of partnerships (task forces and coalitions) across the state of Colorado. This paper offers a roadmap for collaborative design and decision-making among academic, nonprofit, and public sector partners seeking to conduct research on social movements utilizing a community-engaged process. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
29. The effect of warm-season precipitation on the diel cycle of the surface energy balance and carbon dioxide at a Colorado subalpine forest site.
- Author
-
Burns, S. P., Blanken, P. D., Turnipseed, A. A., and Monson, R. K.
- Subjects
METEOROLOGICAL precipitation ,SURFACE energy ,CARBON dioxide ,MOUNTAIN plants ,ECOSYSTEMS - Abstract
Precipitation changes the physical and biological characteristics of an ecosystem. Using a precipitation-based conditional sampling technique and a 14 year dataset from a 25 m micrometeorological tower in a high-elevation subalpine forest, we examined how warm-season precipitation affected the above-canopy diel cycle of wind and turbulence, net radiation R
net , ecosystem eddy covariance fluxes (sensible heat H, latent heat LE, and CO2 net ecosystem exchange NEE) and vertical profiles of scalars (air temperature Ta , specific humidity q, and CO2 dry mole fraction χc ). This analysis allowed us to examine how precipitation modified these variables from hourly (i.e., the diel cycle) to multi-day time-scales (i.e., typical of a weather-system frontal passage). During mid-day we found: (i) even though precipitation caused mean changes on the order of 50-70% to Rnet , H, and LE, the surface energy balance (SEB) was relatively insensitive to precipitation with mid-day closure values ranging between 70-80%, and (ii) compared to a typical dry day, a day following a rainy day was characterized by increased ecosystem uptake of CO2 (NEE increased by ≈ 10%), enhanced evaporative cooling (mid-day LE increased by ≈ 30 W m−2 ), and a smaller amount of sensible heat transfer (mid-day H decreased by ≈ 70 W m−2 ). Based on the mean diel cycle, the evaporative contribution to total evapotranspiration was, on average, around 6% in dry conditions and 20% in wet conditions. Furthermore, increased LE lasted at least 18 h following a rain event. At night, precipitation (and accompanying clouds) reduced Rnet and increased LE. Any effect of precipitation on the nocturnal SEB closure and NEE was overshadowed by atmospheric phenomena such as horizontal advection and decoupling that create measurement difficulties. Above-canopy mean χc during wet conditions was found to be about 2-3 μmol mol−1 larger than χc on dry days. This difference was fairly constant over the full diel cycle suggesting that it was due to synoptic weather patterns (different air masses and/or effects of barometric pressure). In the evening hours during wet conditions, weakly stable conditions resulted in smaller vertical χc differences compared to those in dry conditions. Finally, the effect of clouds on the timing and magnitude of daytime ecosystem fluxes is described. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF
30. Passive Treatment of Circumneutral Mine Drainage from the St. Louis Mine Tunnel, Rico CO: Part 2—Vertical Biotreatment Train Pilot Study.
- Author
-
Dean, Daniel M., Fricke, James R., Riese, Arthur C., Moore, Terry J., and Brown, Anthony R.
- Subjects
MINE drainage ,ABANDONED mines ,MINE water ,SETTLING basins ,CARBON dioxide ,ANAEROBIC reactors - Abstract
Copyright of Mine Water & the Environment is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
- View/download PDF
31. Atmospheric deposition as a source of carbon and nutrients to barren, alpine soils of the Colorado Rocky Mountains.
- Author
-
Mladenov, N., Williams, M. W., Schmidt, S. K., and Cawley, K.
- Subjects
ATMOSPHERIC deposition ,MOUNTAIN soils ,BIOGEOCHEMISTRY ,WATER quality ,CARBON compounds ,PLANT nutrients ,DISSOLVED organic matter - Abstract
Many alpine areas are experiencing intense deglaciation, biogeochemical changes driven by temperature rise, and changes in atmospheric deposition. There is mounting evidence that the water quality of alpine streams may be related to these changes, including rising atmospheric deposition of carbon (C) and nutrients. Given that barren alpine soils can be severely C limited, we evaluated the magnitude and chemical quality of atmospheric deposition of C and nutrients to an alpine site, the Green Lake 4 catchment in the Colorado Rocky Mountains. Using a long term dataset (2002-2010) of weekly atmospheric wet deposition and snowpack chemistry, we found that volume weighted mean dissolved organic carbon (DOC) concentrations were approximately 1.0mgL
-1 and weekly concentrations reached peaks as high at 6-10mgL-1 every summer. Total dissolved nitrogen concentration also peaked in the summer, whereas total dissolved phosphorus and calcium concentrations were highest in the spring. Relationships among DOC concentration, dissolved organic matter (DOM) fluorescence properties, and nitrate and sulfate concentrations suggest that pollutants from nearby urban and agricultural sources and organic aerosols derived from subalpine vegetation may influence high summer DOC wet deposition concentrations. Interestingly, high DOC concentrations were also recorded during "dust-in-snow" events in the spring. Detailed chemical and spectroscopic analyses conducted for samples collected in 2010 revealed that the DOM in many late spring and summer samples was less aromatic and polydisperse and of lower molecular weight than that of winter and fall samples and, therefore, likely to be more bioavailable to microbes in barren alpine soils. Bioavailability experiments with different types of atmospheric C sources are needed to better evaluate the substrate quality of atmospheric C inputs. Our C budget estimates for the Green Lake 4 catchment suggest that atmospheric deposition represents an average input of approximately 13 kgCha-1 yr-1 that could be as high as 24 kgCha-1 yr-1 in high dust years and approaches that of autotrophic C fixation in barren soils. [ABSTRACT FROM AUTHOR]- Published
- 2012
- Full Text
- View/download PDF
32. Making the paper: Carolyn Porco.
- Subjects
- *
PLANETARY research , *SATURN (Planet) , *SPACE sciences , *NATURAL satellites , *SPACE vehicles , *IMAGING systems - Abstract
The article reports developments related to research about the planet Saturn at the Space Science Institute (SSI) in Boulder, Colorado. It is stated that the Cassini spacecraft took seven years to reach Saturn. According to Carolyn Porco, who leads the Cassini imaging team at SSI, the images sent back were well worth the wait. She reveals that the most exciting was the finding that one of the planet's moon has the essential ingredients to support life. The spacecraft's images suggest one of the Saturn's moons may host water.
- Published
- 2007
- Full Text
- View/download PDF
33. Assessment of Electronic Reserves Services at the University of Colorado, Boulder.
- Author
-
Austin, Brice and Taylor, Karen
- Subjects
ACADEMIC libraries ,STUDENT attitudes ,LIBRARIES & students ,SURVEYS ,ELECTRONIC reserve collections in libraries - Abstract
Assessment is an important part of any library service, including electronic reserves. This paper describes the assessment of electronic reserves services by means of a survey instrument administered at the University of Colorado, Boulder during the fall semester, 2003. As the University Libraries had moved from a predominately paper reserves environment to an almost completely electronic reserves environment at the beginning of that same semester, the survey offered a unique opportunity to compare student attitudes towards the two formats. We addressed planning for the survey, administering the survey, evaluation of the collected data, and reporting the results to teaching faculty. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
34. Choice Research: A Wealth of Perspectives.
- Author
-
Chakravarti, Dipankar, Sinha, Atanu, and Kim, Jaewhan
- Subjects
CHOICE (Psychology) ,CONSUMER preferences ,DECISION making ,CONFERENCES & conventions ,ADULT education workshops ,NAVIGATION ,SOCIAL sciences - Abstract
This article is a navigation guide to the twenty papers that emerged from the workshops conducted at the Sixth Invitational Choice Symposium (Estes Park, Colorado, June 2004). The papers are categorized into three broad sets that focus respectively on choice modeling issues, on providing interdisciplinary perspectives on choice, and on relating choice research to real world concerns. Within each category, we offer provide brief integrative overviews linking subsets of papers. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
35. Photovoltaic power prediction based on sky images and tokens-to-token vision transformer.
- Author
-
Qiangsheng Dai, Xuesong Hou, Dawei Su, and Zhiwei Cui
- Subjects
DEEP learning ,TRANSFORMER models ,COMPUTER vision ,SOLAR energy - Abstract
Photovoltaic (PV) power generation has high uncertainties due to the randomness and imbalance nature of solar energy and meteorological parameters. Hence, accurate PV power forecasts are essential in the operation of PV power plants (PVPP) for short-term dispatches and power generation schedules. In this paper, a new deep neural network structure based on vision transformer is proposed to combine sky images and Tokens-To-Token(T2T) for photovoltaic power prediction. The method uses an incremental tokenization module to aggregate neighboring image patches into tokens, which capture the local structural information of the clouds. Then, an efficient T2T-ViT backbone network is used to extract the global attentional relationships of the tokens for power prediction. In order to evaluate the performance of the proposed model, the method was compared with several deep learning architectures such as ResNet and GoogleNet on a dataset collected by the National Renewable Energy Laboratory in Colorado, USA. The results of power prediction were analysed using training loss, prediction error, and linear regression, and they show that the proposed method achieves higher prediction accuracy and lower error compared to the existing methods, especially in short- and ultra-short-term prediction. The paper demonstrates the potential of applying Transformer models to computer vision tasks for renewable energy forecasting. The results show that the proposed method achieves higher prediction accuracy and lower error than several deep learning architectures, such as ResNet and GoogleNet, especially in short- and ultra-short-term prediction. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
36. Redemption vs. #MeToo: How Journalists Addressed Kobe Bryant's Rape Case in Crafting His Memory.
- Author
-
Walters, Patrick
- Subjects
FEMINISM ,WOMEN'S basketball ,METOO movement ,JOURNALISTS ,FEMINIST theory ,RAPE ,BASKETBALL fans - Abstract
This paper examines how journalists addressed Kobe Bryant's 2003 rape case as they constructed the basketball star's memory through coverage of his death. Bryant, who died in a helicopter crash on Jan. 26, 2020, was accused of raping a hotel clerk in Colorado; charges were dropped when the woman refused to testify, but the parties reached a civil settlement. This textual analysis examines 488 news stories about Bryant's death, content produced by 18 U.S. news organizations (12 newspapers, two magazines, three online-only publications and a cable broadcast outlet) between Jan. 26 and Oct. 31, 2020. It finds that coverage created a field of discourse that mainly celebrated Bryant for his athletic greatness, as a family man, cultural icon and supporter of women's basketball. The paper argues that, despite the influence of social media and the #MeToo movement, journalists continue to oversimplify and cleanse the narratives of famous men with problematic pasts. The paper calls on journalists to draw from feminist theory and utilize triangulated reporting methods to incorporate marginalized viewpoints when memorializing famous men with problematic pasts. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
37. Attribution of Seasonal Wildfire Risk to Changes in Climate: A Statistical Extremes Approach.
- Author
-
Wixson, Troy P. and Cooley, Daniel
- Subjects
CLIMATE extremes ,WILDFIRES ,WILDFIRE risk ,CLIMATE change ,FIRE weather ,WILDFIRE prevention ,EXTREME value theory - Abstract
Wildfire risk is greatest during high winds after sustained periods of dry and hot conditions. This paper is a statistical extreme-event risk attribution study that aims to answer whether extreme wildfire seasons are more likely now than under past climate. This requires modeling temporal dependence at extreme levels. We propose the use of transformed-linear time series models, which are constructed similarly to traditional autoregressive–moving-average (ARMA) models while having a dependence structure that is tied to a widely used framework for extremes (regular variation). We fit the models to the extreme values of the seasonally adjusted fire weather index (FWI) time series to capture the dependence in the upper tail for past and present climate. We simulate 10 000 fire seasons from each fitted model and compare the proportion of simulated high-risk fire seasons to quantify the increase in risk. Our method suggests that the risk of experiencing an extreme wildfire season in Grand Lake, Colorado, under current climate has increased dramatically relative to the risk under the climate of the mid-twentieth century. Our method also finds some evidence of increased risk of extreme wildfire seasons in Quincy, California, but large uncertainties do not allow us to reject a null hypothesis of no change. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
38. Helen Laura Sumner and the Woman Suffrage Movement.
- Author
-
Kapuria-Foreman, Vibha and McCann Jr., Charles R.
- Subjects
WOMEN'S suffrage ,GENDER inequality ,WOMEN'S rights ,SUFFRAGE ,CONSTITUTIONAL amendments ,WOMEN'S education - Abstract
Prior to the passage of the 20th amendment to the US Constitution in 1920, several states had extended the suffrage to women. Helen Laura Sumner (later Woodbury), a student of John R. Commons at Wisconsin, undertook a statistical study of the political, economic, and social impacts of the granting of voting rights to women in the state of Colorado, and subsequently defended the results against numerous attacks. In this paper, we present a brief account of the struggle for women's equality in the extension of the suffrage and examine Sumner's critical analysis of the evidence as to its effects, as well as the counterarguments to which she responded. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
39. An introduction to a special issue and review of the effectiveness of Goodnature A24 self-resetting rat traps.
- Author
-
Shiels, Aaron B., Bogardus, Tyler, Crampton, Lisa H., Gronwald, Markus, Kreuser, Abby M., Baldwin, Roger A., and Lepczyk, Christopher A.
- Subjects
MICE ,RODENT control ,RATTUS rattus ,RAT control ,APODEMUS ,RATS ,FOREST birds - Abstract
Rodent pest species threaten many of the world’s resources, including those in agriculture, urban, and natural environments. Goodnature
® A24 rat+stoat self-resetting traps (A24s) are used extensively for invasive rat control in several countries and environments, especially in island ecosystems. Unlike traditional single-set kill traps, A24s fire and reset up to 24 times per CO2 cartridge, and represent a nontoxic device for rodent pest control. Given the rapid rise in use of A24s as a management tool, our goal was to understand why A24s work in some cases and not others. To address this goal, we briefly review A24 literature, and then we: 1) introduce a special issue of A24 effectiveness and hazard studies, and 2) propose future research needs and recommended uses for A24s including a list of potentially susceptible rodent species for which further A24 testing is required. Most papers in the special issue focus on Rattus rattus control on islands in Hawaii and New Zealand. Additionally, A24 effectiveness was compared to toxic bait use against rats in California agricultural landscapes, and snap-traps against house mice (Mus musculus) in Colorado pens. Behavioral studies in this special issue demonstrated that both rats and mice repeatedly visit and pass by A24s much more frequently than they trigger A24s. Some large-scale trapping grids in Hawaiian forests reduced rat populations, but a few endangered birds were unintentionally killed by A24s, which stimulated research on bird excluder attachments for A24s. Understanding the duration of carcass persistence of rats and birds killed by A24s has helped trap users account for unobserved target and non- target kills. Future research may investigate A24 uses on rodent species other than Rattus, as the types of species potentially vulnerable to A24s range in size from mice (e.g., Apodemus, Mus, Peromyscus, Reithrodontomys; ≥ 14 g) to squirrels (e.g., Otospermophilus, Sciurus; 353–527 g). A24s can be used successfully to control rodent populations of some species in particular environments. Studies that compare A24s with alternative and synergistic rodent management methods will help determine the most effective and efficient rodent control methods that minimize non-target risks. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
40. TPAMI CVPR Special Section.
- Author
-
Felzenszwalb, Pedro F., Forsyth, David A., Fua, Pascal, and Boult, Terrance E.
- Subjects
CONFERENCES & conventions ,COMPUTER vision ,PATTERN recognition systems - Abstract
The articles in this special issue include papers from the CVPR'11 conference which was held in Colorado Spring, CO, June 2011. [ABSTRACT FROM PUBLISHER]
- Published
- 2013
- Full Text
- View/download PDF
41. Sequence in Hybridization of Statistical and Intelligent Models in Time Series Forecasting.
- Author
-
Hajirahimi, Zahra and Khashei, Mehdi
- Subjects
TIME series analysis ,STATISTICAL models ,FORECASTING ,MULTILAYER perceptrons ,BOX-Jenkins forecasting ,LYNX - Abstract
With the importance of forecasting with a high degree of accuracy, the increasing attention has been evolved to combine individual models, especially statistical and intelligent ones. The main aim of such that hybrid models is to extract unique modeling strengths in linear and nonlinear pattern recognition, respectively. Therefore, different hybridization methods are proposed in recent literature for time series forecasting. One of the most widely-used combination strategies applied for numerous forecasting problems to yield more accurate results is the series hybrid strategy. In this hybridization methodology, components of a time series are separated and then modeled sequentially by choosing appropriate single models. However, the most accurate series hybrid model developed by determining the proper arrangement of single models. Thus, one of the critical issues in constructing series hybrid models is how to choose the appropriate sequence of individual models in a sequential modeling procedure. Although it is critically affecting on obtaining more accurate forecasting results, it has not been appropriately discussed in the literature of time series forecasting. Thus, in this paper, the performance of two possible sequence modeling procedures, including linear–nonlinear and nonlinear–linear, are evaluated. For this purpose, autoregressive integrated moving average (ARIMA), support vector machines (SVM), and multilayer perceptrons (MLP) models are chosen due to the popularity of these approaches for developing statistical/intelligent series hybrid models. Five well-known real data sets, e.g., Wolf's Sunspot, Canadian Lynx, British pound/US dollar exchange rate, Nikkei 225 stock price, and the Colorado wind speed, are considered to distinguish better sequences. In this way, the main objective of this paper is to response this unanswered question in the literature that which sequence of single models can lead to obtain much better accuracy in constructing bi-component series hybrid models. Empirical results indicate that choosing the nonlinear intelligent model as first component in sequential modeling procedure can lead to yield more accurate results. Both SVM–ARIMA and MLP–ARIMA models can improve the performance of the ARIMA–SVM and ARIMA–MLP, respectively. Therefore, it can be concluded that the nonlinear–linear series hybrid models may produce more accurate results than linear–nonlinear hybrid models for time series forecasting. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
42. Evaluation of side forces for gauge cutters through LS-DYNA 3D numerical simulations.
- Author
-
Farrokh, Ebrahim, Rokhy, Hamid, and Lotfi, Davood
- Subjects
COMPUTER simulation ,MATHEMATICAL sequences ,STATISTICAL models ,MILLING cutters ,SIMULATION methods & models ,GRANITE - Abstract
This paper presents the outcomes of a sequence of three-dimensional numerical simulation models conducted in linear cutting mode, employing the LS-DYNA software. The primary objective was to scrutinize the side force values exerted on the gauge cutters. To accomplish this, an assortment of simulation models was meticulously constructed and executed, employing the Lagrange and SPG computational algorithms, along with the JHC and RHT constitutive material models. By comparing the outcomes of these models with the linear cutting experiments documented in the literature, specifically concerning the Colorado red Granite, it was determined that the SPG computational algorithm and the RHT constitutive material model proved to be the most suitable for simulating rock-cutting scenarios. Building upon the chosen computational algorithm and constitutive material model, a series of numerical models was then crafted to simulate the penetration of gauge cutters in both longitudinal and transverse orientations relative to their tips. Subsequently, the applied side forces were extracted, and a statistical model was developed to accurately predict the side forces experienced by the gauge cutters, yielding a coefficient of determination of 93%. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. Assessing Spatial Stationarity and Segmenting Spatial Processes into Stationary Components.
- Author
-
Tzeng, ShengLi, Chen, Bo-Yu, and Huang, Hsin-Cheng
- Subjects
- *
STATIONARY processes , *EXPONENTIAL functions , *GEOLOGICAL statistics - Abstract
In this research, we propose a novel technique for visualizing nonstationarity in geostatistics, particularly when confronted with a single realization of data at irregularly spaced locations. Our method hinges on formulating a statistic that tracks a stable microergodic parameter of the exponential covariance function, allowing us to address the intricate challenges of nonstationary processes that lack repeated measurements. We implement the fused lasso technique to elucidate nonstationary patterns at various resolutions. For prediction purposes, we segment the spatial domain into stationary sub-regions via Voronoi tessellations. Additionally, we devise a robust test for stationarity based on contrasting the sample means of our proposed statistics between two selected Voronoi subregions. The effectiveness of our method is demonstrated through simulation studies and its application to a precipitation dataset in Colorado. Supplementary materials accompanying this paper appear online. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. The Colorado Delta, 1771–1776: Rereading Francisco Garcés: Part II: Peoples, Practices, and Implications.
- Author
-
Whiteley, Peter M.
- Subjects
- *
ETHNOLINGUISTIC groups , *DEMOGRAPHY , *RURAL population , *AGRICULTURAL productivity , *AGRICULTURE , *ETHNOHISTORY - Abstract
The ethnohistory of the Colorado River delta has been substantively misunderstood, owing to the widespread neglect and/or misinterpretations of the writings of Francisco Garcés. In 1771, 1774, and 1775–1776, Garcés undertook three entradas into the delta, and wrote a series of valuable ethnographic accounts. Not only have Garcés's locations and routes frequently been misidentified by earlier scholars, his observations on agricultural production and population size have been ignored or marginalized, enabling misconceptions about delta historical demography and adaptation to flourish. The present paper seeks to restore Garcés's accounts, making his locations and ethnographic observation intelligible and interpretable, and to show how these can help resolve extant misconceptions. Part I focuses on some key texts, tying his locations to a master map. Part II focuses on ethnolinguistic groups and settlement sites, discusses the implications for a better understanding of historical demography and agricultural adaptation in the delta. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. Semi-automatic Identification of Tunnel Discontinuity Based on 3D Laser Scanning.
- Author
-
Chen, Na, Xiao, Ao, Li, Lihua, and Xiao, Henglin
- Subjects
OPTICAL scanners ,ROCK slopes ,POINT cloud ,GEOLOGICAL surveys ,LASERS - Abstract
Obtaining accurate discontinuity information on a tunnel is essential for tunnel stability assessment, and usually requires geological surveys on the tunnel surface. However, traditional manual measurement methods are time-consuming, labor-intensive, and provide limited data, particularly when dealing with complex tunnel rock masses. To address this problem, this paper proposes a method to quickly obtain the point cloud model of the tunnel surface and semi-automatically identify discontinuity using 3D laser scanner. The method is centered on an improved Regional Growth (RG) algorithm, with key principles and processing flow encompassing: (1) Voxel filtering; (2) Normal calculation for point clouds; (3) Improved RG algorithm; (4) Calculation of discontinuity orientation. An analysis of parametric sensitivity which proved its good robustness was carried out to assess the performance of the method. To ascertain the effectiveness of the method in semi-automatically identifying tunnel discontinuities, three sets of test data (standard cube, rock slope in Colorado, and Xulong hydroelectric station tunnel) were chosen. By comparing the analysis results of the proposed method with those of alternative methods (DSE and CloudCompare), the validation of its efficacy in tunnel discontinuity detection was achieved. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. News from the Chapters.
- Subjects
ASSOCIATIONS, institutions, etc. ,RELIGIOUS institutions - Abstract
This section offers news briefs about several chapters of the Theta Alpha Kappa (TAK) Fraternity. Three new chapters of TAK in Orange, California, Honolulu, Hawaii and Colorado Springs, Colorado were created. Alpha Theta Epsilon Chapter in Newport News, Virigina held its 14th annual John Hoaglund Phlosophy and Religious Student Conference on March 15-16, 2013. Two TAK students presented papers at the Student Symposia sponsored by tahe Alpha Zeta Pi chapter in Siloam Springs, Arkansas.
- Published
- 2013
47. Identification of aquifer pollution's point sources with the reciprocity principle.
- Author
-
Bouhlila, Rachida and Hariga, Nejla T.
- Subjects
AQUIFER pollution ,RECIPROCITY theorems ,ELASTIC structures (Mechanics) ,POINT sources (Pollution) ,TRANSPORT equation ,WATER masses - Abstract
The principle of reciprocity, called Maxwell–Betti theorem, initially used in mechanics in an elastic structure, establishes a relation of equality between two distinct strains under different loads. In this paper, we extend and apply this principle to flow and solute transport equations in porous media, in order to perform the pollution sources identification in aquifers. We developed general 2D expressions of the reciprocity principle for transient transport problems. This model leads to a linear equations set, with point sources coordinates, concentrations and associated water fluxes as unknowns The proposed model is then applied to the Rocky Mountain Arsenal aquifer (Konikow in Modeling Chloride Movement in the Alluvial Aquifer at the Rocky Mountain Arsenal, Colorado. Technical Report Water-Supply Paper 2044, USGS, 1979), where polluted water is injected into a well in the domain. The used inverse technique successfully recovered the position and the pollutant concentration in addition to the associated water flux. In addition, we developed and implemented the inverse method for different knowledge levels of the degrees of the aquifer contamination, i.e. more or less data available in the field. Multiple pollution point sources and noisy data situations are also developed and tested with high efficiency. The proposed method would be easy and useful to be implemented in the modeling software now widely used by researchers and groundwater managers. It can thus be applied in real case studies, to help authorities and regulators to efficiently identify the polluters and the contamination process, i.e. its location, onset, duration and the associated mass and water fluxes. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
48. Measuring Art Markets: The Colorado Art Market in 2017.
- Author
-
Taylor, Jeffrey, Cardenas, Mayela, and Edwards, Stephanie
- Subjects
ART industry ,ARTS endowments ,NONPROFIT sector ,ECONOMIC sectors ,ECONOMIC activity - Abstract
The art market represents a sector of economic activity that is highly entrepreneurial and comprised of many small businesses and individuals. Since the bulk of production and sales takes place through these micro-enterprises, there are numerous problems present for the researcher seeking to measure it. Unlike the nonprofit sector of the visual arts, the for-profit art market mostly has no public reporting requirements. The art market's activity remains largely opaque as it is difficult to gather an accurate field representation or total measurements from such a large number of small enterprises. This paper represents the first stage in the development of new tools for the measuring of the art market by making use of US government data derived from tax and labor statistics, and by measuring the Colorado art market for the year 2017. The data in this paper is used to illustrate the connection between arts and entrepreneurship and how this sector serves to support the wider Colorado economy. It also establishes the methodology for measuring the entire US art market for the year 2018. The National Endowment for the Arts (NEA) Research: Art Works grant will fund the report and release it in early 2020. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
49. THE SYMBIOSIS OF LICHENOMETRY AND RADIOCARBON DATING: A BAYESIAN CHRONOLOGY OF ALPINE HUNTING IN COLORADO'S SOUTHERN ROCKY MOUNTAINS, USA.
- Author
-
Meyer, Kelton A
- Subjects
RADIOCARBON dating ,HISTORICAL chronology ,STONE ,ARCHAEOLOGICAL dating ,GEOCHRONOMETRY - Abstract
Archaeologists keep a limited arsenal of methods for dating stone features at alpine sites. Radiocarbon (
14 C) dating is rarely possible, and it is common that dates do not accurately represent the activity of interest (stone feature construction). In this paper I review a legacy set of 8914 C dates for stone driveline sites built by hunter-gatherers in Colorado's Southern Rocky Mountains. I amend the sample of dates using chronometric hygiene and focus on dates with direct association to hunting features. I then present a newly calibrated set of 29 lichenometric dates for rock features at these sites and use hygiene protocols to remove inaccurate dates. Size-frequency lichenometry, though poorly known in archaeology, provides a way to date stone features indirectly by measuring the growth of long-lived lichens that colonize rock surfaces after construction events. Bayesian modeling of the combined set of dates suggests that the tradition of alpine game driving spans over 6000 years BP, with abundant use over the last 2000 years. Archaeologists must use multiple methods for dating stone features in alpine environments. This Bayesian analysis is a formal effort to combine lichenometry and14 C dating for archaeological interpretation. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
50. Were Wildfires Responsible for the Unusually High Surface Ozone in Colorado During 2021?
- Author
-
Langford, Andrew O., Senff, Christoph J., Alvarez, Raul J., Aikin, Ken C., Ahmadov, Ravan, Angevine, Wayne M., Baidar, Sunil, Brewer, W. Alan, Brown, Steven S., James, Eric P., McCarty, Brandi J., Sandberg, Scott P., and Zucker, Michael L.
- Subjects
WILDFIRE prevention ,OZONE ,THUNDERSTORMS ,WILDFIRES ,AIR quality standards ,AIR quality ,METROPOLITAN areas - Abstract
Ground‐level ozone (O3) was unusually high in northern Colorado in the summer of 2021 with maximum daily 8‐hr average (MDA8) concentrations 6 to 8 parts‐per‐billion by volume (ppbv) higher than in 2019, 2020, or 2022. One or more of the monitors on the Colorado Front Range exceeded the 2015 U.S. National Ambient Air Quality Standard (NAAQS) of 70 ppbv on 66 of the 122 days from 1 June to 30 September, and this record number of exceedances coincided with the near daily presence of dispersed smoke haze from wildfires in Arizona, California, and the Pacific Northwest. In this paper, we use regulatory and non‐regulatory surface O3 and PM2.5 measurements in conjunction with ground‐based lidar observations to estimate how much O3 was associated with the wildfire smoke. Analyses of the surface measurements suggest that pyrogenic O3 transported to northern Colorado with the smoke increased the surface concentrations in northern Colorado by an average of 8 ppbv in July, 3 ppbv in August, and 2 ppbv in September. Analysis of the lidar measurements showed these contributions to be as large as 12 ppbv on some days. Production of O3 from reactions of pyrogenic VOCs and locally emitted NOx appears to have been minimal (<3 ppbv) in the Boulder area, but may have been much larger in the suburbs southwest of downtown Denver. Plain Language Summary: Northern Colorado experienced unusually poor air quality in the summer of 2021 with frequent high ozone (O3) episodes and hazy skies caused by smoke from wildfires in Arizona, California, and the Pacific Northwest. In this study, we use surface and lidar measurements to explore the connection between the two. Our analysis suggests that the unusually high O3 was caused primarily by a combination of O3 transported to Colorado with the wildfire smoke and enhancement of local photochemical production by unusually clear skies and warm temperatures coupled with weak winds that led to localized O3 accumulations and fewer than normal thunderstorms that might otherwise have dispersed the O3. Production of O3 by reactions of locally emitted NOx with VOCs in the wildfire smoke may also have been significant in Southwest Denver. Key Points: The impacts of the 2021 western wildfires on ozone in the Denver metropolitan area and rural northern Colorado in 2021 are examinedOzone transported in the smoke from distant wildfires increased the 8‐hr concentrations in northern Colorado by an average of 8 ppbv in JulyUnusual meteorology, including fewer thunderstorms, allowed ozone produced locally to accumulate along the foothills west of Denver [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.