Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Physical Sciences and Mathematics (10864)
- Education (3687)
- Engineering (3444)
- Computer Sciences (2696)
- Social and Behavioral Sciences (2402)
-
- Life Sciences (1983)
- Environmental Sciences (1619)
- Chemistry (1436)
- Physics (1398)
- Mathematics (1329)
- Earth Sciences (1252)
- Arts and Humanities (1185)
- Medicine and Health Sciences (1044)
- Electrical and Computer Engineering (987)
- Higher Education (833)
- Science and Mathematics Education (830)
- Computer Engineering (797)
- Law (749)
- Business (631)
- Statistics and Probability (615)
- Mechanical Engineering (614)
- Oceanography and Atmospheric Sciences and Meteorology (605)
- Teacher Education and Professional Development (575)
- Geology (511)
- Educational Assessment, Evaluation, and Research (501)
- Curriculum and Instruction (496)
- Public Affairs, Public Policy and Public Administration (468)
- Civil and Environmental Engineering (449)
- Astrophysics and Astronomy (401)
- Psychology (398)
- Institution
-
- University of Nebraska - Lincoln (1095)
- Purdue University (696)
- TÜBİTAK (665)
- University of South Florida (508)
- Singapore Management University (504)
-
- Utah State University (433)
- University of Kentucky (416)
- Louisiana State University (403)
- Old Dominion University (367)
- City University of New York (CUNY) (359)
- Missouri University of Science and Technology (357)
- Brigham Young University (353)
- Georgia Southern University (332)
- Portland State University (310)
- Walden University (301)
- Nova Southeastern University (298)
- Association of Arab Universities (293)
- Embry-Riddle Aeronautical University (271)
- University of Plymouth (262)
- University of Arkansas, Fayetteville (259)
- University of New Mexico (253)
- University of Texas at El Paso (242)
- Clemson University (239)
- Wayne State University (225)
- University of Central Florida (224)
- University of South Carolina (224)
- Wright State University (218)
- California Polytechnic State University, San Luis Obispo (216)
- University of Texas at Arlington (213)
- West Virginia University (211)
- Keyword
-
- Education (302)
- Mathematics (285)
- Applied sciences (251)
- Pure sciences (137)
- Climate change (109)
-
- Georgia Southern University (102)
- Optimization (102)
- Machine learning (98)
- STEM (97)
- Assessment (96)
- Technology (94)
- Higher education (89)
- Simulation (89)
- Physics (84)
- Chemistry (77)
- Science (76)
- Modeling (73)
- Earth sciences (68)
- Statistics (64)
- Sustainability (64)
- IMSA (62)
- Curriculum (61)
- Illinois Mathematics and Science Academy (61)
- Collaboration (60)
- Professional development (59)
- Social sciences (59)
- Security (58)
- Engineering (57)
- Geology (56)
- Research (56)
- Publication
-
- Theses and Dissertations (1004)
- Electronic Theses and Dissertations (482)
- Research Collection School Of Computing and Information Systems (435)
- Faculty Publications (395)
- Turkish Journal of Electrical Engineering and Computer Sciences (372)
-
- Dissertations (293)
- Walden Dissertations and Doctoral Studies (288)
- Open Access Dissertations (285)
- Applied Mathematics & Information Sciences (245)
- USF Tampa Graduate Theses and Dissertations (198)
- Publications and Research (184)
- Theses (182)
- Masters Theses (155)
- School of Engineering, Computing and Mathematics (155)
- Doctoral Dissertations (151)
- Nebraska Tractor Tests (136)
- Open Access Theses (133)
- Publications (132)
- Graduate Theses and Dissertations (131)
- Honors Theses (125)
- Open Access Theses & Dissertations (123)
- Turkish Journal of Mathematics (120)
- Articles (118)
- LSU Doctoral Dissertations (113)
- Master's Theses (111)
- Dissertations and Theses (110)
- Browse all Theses and Dissertations (109)
- Departmental Technical Reports (CS) (107)
- Dissertations, Theses, and Capstone Projects (107)
- Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions) (105)
- Publication Type
- File Type
Articles 22771 - 22800 of 24390
Full-Text Articles in Entire DC Network
Internal And External Validity Of Sluggish Cognitive Tempo In Young Adolescents With Adhd, Zoe Smith
Internal And External Validity Of Sluggish Cognitive Tempo In Young Adolescents With Adhd, Zoe Smith
Theses and Dissertations
Adolescents with Sluggish Cognitive Tempo (SCT) show symptoms of slowness, mental confusion, excessive daydreaming, low motivation, and drowsiness/sleepiness. Although many symptoms of SCT reflect internalizing states, no study has evaluated the utility of self-report of SCT in an ADHD sample. Further, it remains unclear whether SCT is best conceptualized as a unidimensional or multidimensional construct. In a sample of 262 adolescents comprehensively diagnosed with ADHD, the present study evaluated the dimensionality of a SCT scale and compared CFA and bifactor model fits for parent- and self-report versions. Analyses revealed the three-factor bifactor model to be the best fitting model. In …
A Reused Distance Based Analysis And Optimization For Gpu Cache, Dongwei Wang
A Reused Distance Based Analysis And Optimization For Gpu Cache, Dongwei Wang
Theses and Dissertations
As a throughput-oriented device, Graphics Processing Unit(GPU) has already integrated with cache, which is similar to CPU cores. However, the applications in GPGPU computing exhibit distinct memory access patterns. Normally, the cache, in GPU cores, suffers from threads contention and resources over-utilization, whereas few detailed works excavate the root of this phenomenon. In this work, we adequately analyze the memory accesses from twenty benchmarks based on reuse distance theory and quantify their patterns. Additionally, we discuss the optimization suggestions, and implement a Bypassing Aware(BA) Cache which could intellectually bypass the thrashing-prone candidates.
BA cache is a cost efficient cache design …
Does Koopmans’ Paradigm For 1-Electron Oxidation Always Hold? Breakdown Of Ip/EOx Relationship For P-Hydroquinone Ethers And The Role Of Methoxy Group Rotation, Marat R. Talipov, Anitha Boddeda, Sergey V. Lindeman, Rajendra Rathore
Does Koopmans’ Paradigm For 1-Electron Oxidation Always Hold? Breakdown Of Ip/EOx Relationship For P-Hydroquinone Ethers And The Role Of Methoxy Group Rotation, Marat R. Talipov, Anitha Boddeda, Sergey V. Lindeman, Rajendra Rathore
Chemistry Faculty Research and Publications
Koopmans’ paradigm states that electron loss occurs from HOMO, thus forming the basis for the observed linear relationships between HOMO/IP, HOMO/Eox, and IP/Eox. In cases where a molecule undergoes dramatic structural reorganization upon 1-electron oxidation, the IP/Eoxrelationship does not hold, and the origin of which is not understood. For example, X-ray crystallography of the neutral and cation radicals of bicyclo[2.2.1]heptane-annulated p-hydroquinone ethers (THE and MHE) showed that they undergo electron-transfer-induced conformational reorganization and show breakdown of the IP/Eox relationship. DFT calculations revealed that Koopmans’ paradigm …
Systemic Risk Regulation In Comparative Perspective, Cristie Ford
Systemic Risk Regulation In Comparative Perspective, Cristie Ford
All Faculty Publications
This report succinctly compares, with tables and diagrams, the systemic risk regulatory regimes that have been put in place since 2008 in the US, the UK, the EU and Canada. It describes systemic risk as a problem of a different order from the kinds of investor protection and efficient market concerns that animate day-to-day securities and capital markets regulation. Because contemporary markets operate as systems, characterized by interconnectedness, unpredictability, and fast-moving, multiple-round contagion effects, responding to systemic risk demands a different regulatory structure and a separate set of tools. This report was prepared for the Department of Finance, Government of …
Fine-Scale Change Detection Using Unmanned Aircraft Systems (Uas) To Inform Reproductive Biology In Nesting Waterbirds, Sharon Dulava
Fine-Scale Change Detection Using Unmanned Aircraft Systems (Uas) To Inform Reproductive Biology In Nesting Waterbirds, Sharon Dulava
Cal Poly Humboldt theses and projects
Aerial photographic surveys from manned aircraft are commonly used to estimate the size of bird breeding colonies but are rarely used to evaluate reproductive success. Recent technological advances have spurred interest in the use of unmanned aircraft systems (UAS) for monitoring wildlife. The ability to repeatedly sample and collect imagery at fine-scale spatial and temporal resolutions while minimizing disturbance and safety risks make UAS particularly appealing for monitoring colonial nesting waterbirds. In addition, advances in photogrammetric and GIS software have allowed for more streamlined data processing and analysis. Using UAS imagery collected at Anaho Island National Wildlife Refuge during the …
Differences In Physical Activity Participation, Screen Time, And Body Mass Index For Children With Learning Disabilities And Typically Developing Children, Andrew Q. Pawlick
Differences In Physical Activity Participation, Screen Time, And Body Mass Index For Children With Learning Disabilities And Typically Developing Children, Andrew Q. Pawlick
Cal Poly Humboldt theses and projects
TOPIC: There is a vast body of research revealing low levels of physical activity, excessive use of electronic media, and increasing obesity rates for children in the United States and Europe. This study measures differences in physical activity, screen time, and Body Mass Index (BMI) between typically developing (TD) children and children with learning disabilities (LD). METHODS: The study included 404, thirteen year old Irish children with an LD diagnosis and 440 randomly selected 13 year olds that are typically developing. Children self-reported on how many days in the past two weeks they participated in moderate to vigorous …
Soil Organic Matter Distribution In A Douglas-Fir-Tanoak Forest, Humboldt County, California, Hollie A. Ernest
Soil Organic Matter Distribution In A Douglas-Fir-Tanoak Forest, Humboldt County, California, Hollie A. Ernest
Cal Poly Humboldt theses and projects
Soil carbon (C) affects the active gases in the atmosphere, nutrient cycling, and diversity of flora and fauna. Soil organic matter (SOM) is partially comprised of C, and a widely-accepted ratio of 0.58 organic carbon (OC) to organic matter (OM) is used to measure soil C on a landscape scale. However, this ratio varies according to vegetation, depth, hydrology, and may lead to miscalculations of soil C and SOM estimates. Soil C and SOM are inherently complex and it is not completely understood which environmental factors have the most influence in their formation, which occurs on a time scale of …
Analysis Of Curved Composite Beam, Manish Aggarwal
Analysis Of Curved Composite Beam, Manish Aggarwal
Graduate Theses, Dissertations, and Problem Reports (ETD)
Composite materials are steadily replacing traditional materials in many engineering applications due to several benefits such as high strength to weight ratio and the ability to tailor the material for specific purposes. Over the last several decades the analysis of straight beams has received considerable attention while there is very little focus on curved composite beams.;In the present study, the formulation of the bending of a curved composite beam is based on the bending theory of thick shells. A variational formulation is employed to derive the governing equations. A consistent methodology is applied to reduce the two-dimensional nature of the …
Impact Of Dike Age On Biodiversity And Functional Composition Of Soilmacrofaunal Communities In Poplar Forests In A Reclaimed Coastal Area, Baoming Ge, Daizhen Zhang, Jun Cui, Senhao Jiang, Xuehong Tong, Chunlin Zhou, Boping Tang
Impact Of Dike Age On Biodiversity And Functional Composition Of Soilmacrofaunal Communities In Poplar Forests In A Reclaimed Coastal Area, Baoming Ge, Daizhen Zhang, Jun Cui, Senhao Jiang, Xuehong Tong, Chunlin Zhou, Boping Tang
Turkish Journal of Zoology
Four patches of poplar forest with different dike histories (about 30 to 200 years) were selected from the coastal area of Yancheng, China, for detecting the effect of dike age on soil macrofauna. A total of 825 individuals belonging to 21 taxonomic groups were collected. Omnivorous, phytophagous, predaceous, and saprophagous groups were classified on the basis of diet. Higher biodiversity values were observed in the forests with longer dike histories (100 and 200 years) than in those with shorter dike histories (30 and 50 years). By principal coordinate analysis, the soil macrofaunal communities from the forests were distinguished as three …
The Effect Of Yucca Schidigera Powder Added To Lamb Feed On Fatteningperformance, Some Blood Parameters, The Immune System, And Theantioxidative Metabolism Of The Hepatic Tissue, Recep Gümüş, Hali̇t İmi̇k
The Effect Of Yucca Schidigera Powder Added To Lamb Feed On Fatteningperformance, Some Blood Parameters, The Immune System, And Theantioxidative Metabolism Of The Hepatic Tissue, Recep Gümüş, Hali̇t İmi̇k
Turkish Journal of Veterinary & Animal Sciences
In this study, Yucca schidigera powder (YSP) added to lamb feed was investigated for its effects on performance, some blood parameters, the immune system, and the antioxidative metabolism of the hepatic tissue. Throughout a 10-week fattening period, twenty-four 2.5-month-old male Akkaraman lambs were used. Three groups were established, including a control group © and groups YSPI and YSPII, which received a basal ration alone, a basal ration + 100 ppm YSP, and a basal ration + 200 ppm YSP, respectively. The groups did not differ for performance parameters (P > 0.05). While 100 ppm YSP increased serum NH3 levels (P < 0.05), 200 ppm YSP significantly decreased serum cholesterol, HDL, LDL, and Mg levels (P < 0.05). The groups did not differ for antibody titers against the Brucella melitensis vaccine (Rev 1). In groups YSPI and YSPII, hepatic CAT activity and LPO levels were significantly lower than those of Group C (P < 0.01). While the GSH levels of group YSPI were significantly higher than those of groups C and YSPII, the SOD activity of group YSPII was significantly lower than those of groups C and YSPI (P < 0.01). As a result, while YSP did not affect the performance parameters or immune system, it significantly affected NH3 levels, lipid metabolism, and the antioxidant system.
Analysis Of Risk Factors In The Management Of Foot-And-Mouth Disease In Turkey, Berri̇n Şentürk, Cengi̇z Yalçin, Aytaç Akçay
Analysis Of Risk Factors In The Management Of Foot-And-Mouth Disease In Turkey, Berri̇n Şentürk, Cengi̇z Yalçin, Aytaç Akçay
Turkish Journal of Veterinary & Animal Sciences
The aim of this study was to perform a risk analysis of the management of foot-and-mouth disease (FMD) epidemics in Turkey. The relationship between disease outbreaks and risk was analyzed by evaluating 11 disease risk factors related to the input, processing, production, movement, and marketing infrastructure aspects of the animal production chain. A progressive (hierarchical) clustering analysis method was employed to group the quantitative data obtained for each of the risk variables. The total risk scores were grouped in a dendrogram. There was a strong positive relationship (72%) between risk variables and total outbreak numbers (P < 0.01). Results showed the districts in which the FMD risk is high and indicate where the appropriate measures should be taken to eradicate or at least minimize outbreaks.
Outstanding University Lecturers: Ambitious Altruists Or Mavericks Of The Academy?, Sharon Lierse
Outstanding University Lecturers: Ambitious Altruists Or Mavericks Of The Academy?, Sharon Lierse
Australian Journal of Teacher Education
The paper discusses the results of a research study to determine what characteristics outstanding university lecturers have in common. Academic staff and graduate students at an Australian university were invited to participate in a survey questionnaire followed by voluntary interviews. Lecturers who had been identified as outstanding were also interviewed. The five characteristics were expertise, holistic approach to learning, engaging the student, open door policy and ambitious altruists. This study found that outstanding lecturers were unconventional in their work practices and valued student learning often at the sacrifice of their own career paths. Outstanding university lecturers are ambitious altruists who …
Creativity From Two Perspectives: Prospective Mathematics Teachers And Mathematician, Gönül Yazgan-Sağ, Elçin Emre-Akdoğan
Creativity From Two Perspectives: Prospective Mathematics Teachers And Mathematician, Gönül Yazgan-Sağ, Elçin Emre-Akdoğan
Australian Journal of Teacher Education
Although creativity plays a critical role in mathematics, it remains underestimated in the context of a mathematics classroom. This study aims to explore the views and differences creativity displays in prospective teachers and one of their lecturers with respect to the characteristics and practices of creative teachers and the characteristics of creative students. We collected data through interviews with four prospective mathematics teachers and one mathematics lecturer. The study results revealed that their perspectives on creativity varied greatly and were mostly influenced by the characteristics of their diverse backgrounds and teaching practices. The views of the prospective mathematics teachers with …
Next Generation Online Math I Course Evaluation, Jennifer Francis
Next Generation Online Math I Course Evaluation, Jennifer Francis
Graduate Theses, Dissertations, and Problem Reports (ETD)
An evaluation was conducted on the Next Generation Online Math I course implemented at Philip Barbour High School in Philippi, West Virginia. These online math modules are considered a blended learning environment as they incorporate some level of online learning in a face-to-face environment. Current research in blended learning has not shown consistent results in student achievement. Pre- post-test data, benchmark data, and summative yearly assessment data were collected. Results show that students had significant learning gains but did not typically score mastery on unit post-tests. Students in the blended learning environment, with a non-certified teacher, scored similarly to students …
Integrated Management Of Fruit Flies-Case Studies From Uganda, Brian E. Isabirye, Caroline K. Nankinga, Alex Mayamba, Anne M. Akol, Ivan Rwomushana
Integrated Management Of Fruit Flies-Case Studies From Uganda, Brian E. Isabirye, Caroline K. Nankinga, Alex Mayamba, Anne M. Akol, Ivan Rwomushana
All Peer-Reviewed Publications
Fruit flies (Diptera: Tephritidae) pose a threat to commercialisation of the horticulture industry in Uganda. They impair the quality and quantity of fruits produced, and limit access to lucrative regional and global markets. Here we explore past and present efforts, and future plans for research and management, of fruit flies in Uganda. Early research geared towards collection and identification of fruit flies recognised the pest status of many species and highlighted the need for establishing sustainable management strategies. Subsequently large-scale research initiatives have substantially increased knowledge on the biology and ecology of fruit flies in Uganda. Based on these studies, …
Regulatory Approaches For Cyber Security Of Critical Infrastructures: The Case Of Turkey, Bilge Karabacak, Sevgi Ozkan Yildirim, Nazife Baykal
Regulatory Approaches For Cyber Security Of Critical Infrastructures: The Case Of Turkey, Bilge Karabacak, Sevgi Ozkan Yildirim, Nazife Baykal
All Faculty and Staff Scholarship
Critical infrastructures are vital assets for public safety, economic welfare and/or national security of countries. Today, cyber systems are extensively used to control and monitor critical infrastructures. A considerable amount of the infrastructures are connected to the Internet over corporate networks. Therefore, cyber security is an important item for the national security agendas of several countries. The enforcement of security principles on the critical infrastructure operators through the regulations is a still-debated topic. There are several academic and governmental studies that analyze the possible regulatory approaches for the security of the critical infrastructures. Although most of them favor the market-oriented …
A Vulnerability-Driven Cyber Security Maturity Model For Measuring National Critical Infrastructure Protection Preparedness, Bilge Karabacak, Sevgi Ozkan Yildirim, Nazife Baykal
A Vulnerability-Driven Cyber Security Maturity Model For Measuring National Critical Infrastructure Protection Preparedness, Bilge Karabacak, Sevgi Ozkan Yildirim, Nazife Baykal
All Faculty and Staff Scholarship
Critical infrastructures are vital assets for the public safety, economic welfare and national security of countries. Cyber systems are used extensively to monitor and control critical infrastructures. A number of infrastructures are connected to the Internet via corporate networks. Cyber security is, therefore, an important item of the national security agenda of a country. The intense interest in cyber security has initiated research focusing on national cyber security maturity assessments. However, little, if any, research is dedicated to maturity assessments of national critical infrastructure protection efforts. Instead, the vast majority of studies merely examine diverse national-level security best practices ranging …
An Assessment Model To Improve National Cyber Security Governance, Bilge Karabacak, Unal Tatar, Adrian Gheorghe
An Assessment Model To Improve National Cyber Security Governance, Bilge Karabacak, Unal Tatar, Adrian Gheorghe
All Faculty and Staff Scholarship
Today, cyber space has been embraced by individuals, organizations and nations as an indispensable instrument of daily life. Accordingly, impact of cyber threats has continuously been increasing. Critical infrastructure protection and fighting against cyber threats are crucial elements of national security agendas of governments. In this regard, governments need to assess the roles and responsibilities of public and private organizations to address the problems of current cyber protection postures and to respond with reorganization and reauthorization of these postures. A risk management approach is critical in placing these efforts in an ongoing lifecycle process. In this paper, a model is …
A Thoughtful Faith: Essays On Belief By Mormon Scholars, Philip L. Barlow
A Thoughtful Faith: Essays On Belief By Mormon Scholars, Philip L. Barlow
Books
No abstract provided.
Gvsu Undergraduate And Graduate Catalog, 2016-2017, Grand Valley State University
Gvsu Undergraduate And Graduate Catalog, 2016-2017, Grand Valley State University
Course Catalogs, 1963 - Current
Grand Valley State University 2016-2017 undergraduate and/or graduate course catalog published annually to provide students with information and guidance for enrollment.
Model Lessons For Math And Geography Activities, Karen Adams, Tyler Sexton, Shawnti Peachey
Model Lessons For Math And Geography Activities, Karen Adams, Tyler Sexton, Shawnti Peachey
Instructional Materials
Model Lessons for Math and Geography Activities to use with The Student Atlas of Oregon.
The Enduring Legacy Of Modern Efficient Market Theory After Halliburton V. John, Mark Klock
The Enduring Legacy Of Modern Efficient Market Theory After Halliburton V. John, Mark Klock
Georgia Law Review
In 1988 the U.S. Supreme Court approved the fraud on the market theory for securities trading in an efficient market thus enabling securities class action plaintiffs to establish their required reliance element of the case through a rebuttable presumption. Basic v. Levinson held that efficient markets incorporate publicly disseminated information and investors who purchased or sold securities in an efficient market therefore relied on any publicly disseminated misinformation. For more than a quarter century since Basic, the efficient market theory has sustained a barrage of assaults from commentators who object to the use of economic theory in legal decision making …
Assessment Of Health And Environmental Effects Of Mango Integrated Fruit Fly Management Strategy In Meru County, Kenya, Chris Mwungu Miyinzi
Assessment Of Health And Environmental Effects Of Mango Integrated Fruit Fly Management Strategy In Meru County, Kenya, Chris Mwungu Miyinzi
All Master’s Theses
Mango is among the three most imperative crops in Kenya in terms production and crop area. However, mango production is limited by a number of issues, among which pests and fungal disease infestation are major. Among the pests, mango fruit fly present a real challenge to producers due to losses incurred at the farm level. Majority of the farmers have decided to use of pesticides which have negative impacts on health and environment. To promote sustainable and environmentally friendly agriculture, International Centre of Insect Physiology and Ecology (icipe) developed and implemented an Integrated Pest Management (IPM) fruit fly control package …
Frequently-Used Discipline And Management Techniques In The Cedar Valley, Gabriel Gedlinske
Frequently-Used Discipline And Management Techniques In The Cedar Valley, Gabriel Gedlinske
Honors Program Theses
The primary goal of this research is to observe frequently-used classroom management techniques in the Cedar Falls Community School District. The observed techniques and the philosophies behind them will then be compared to the methods and philosophies of educational researchers and theorists. Classroom management is an area that is often underrepresented in the plethora of courses required of college undergraduates, as can be observed at the University of Northern Iowa. Of the 120 total credit hours required of an undergraduate student for graduation, exactly three are devoted to classroom management. Furthermore, those three credit hours, or one class, may not …
Macroconstants Of Development: A New Benchmark For The Strategic Development Of Advanced Countries And Firms, Andrey V. Bystrov, Vyacheslav N. Yusim, Tamilla Curtis
Macroconstants Of Development: A New Benchmark For The Strategic Development Of Advanced Countries And Firms, Andrey V. Bystrov, Vyacheslav N. Yusim, Tamilla Curtis
Publications
This research proposed a new indicator of countries’ development called “macroconstants of development”. The literature review indicates that the concept of "macroconstants of development" is not used at the moment in neither the theory nor the practice of industrial policy. Research of longitudinal data of total GDP, GDP per capita and their derivatives for most countries of the world was conducted. An analysis of statistical information has been done by employing econometric analyses.
Based on the analysis of the statistical data, which characterizes the development of large, technologically advanced countries in ordinary conditions, it was identified that the average acceleration …
Emerging Tools For Evaluating Safety Management Systems Effectiveness, T. Brady, A. Stolzer
Emerging Tools For Evaluating Safety Management Systems Effectiveness, T. Brady, A. Stolzer
Publications
Safety Management Systems (SMS) have become prevalent in a host of industries, including aviation, for managing safety, but little research has been performed to-date on measuring the effectiveness of SMS. This research examined the independent application of two related concepts to assess effective- ness: IO/SMS, an Input-Output economics concept applied to SMS, and Data Envelopment Analysis (DEA). Input-Output (IO) is a method for systematically determining the inter-relationships among ele- ments in a system. To determine if IO could be applied to SMS, it was necessary to calculate the relative importance to the system of the four components of SMS. Five …
Intermittency Of Gravity Wave Momentum Flux In The Mesopause Region Observed With An All-Sky Airglow Imager, Bing Cao, Alan Z. Liu
Intermittency Of Gravity Wave Momentum Flux In The Mesopause Region Observed With An All-Sky Airglow Imager, Bing Cao, Alan Z. Liu
Publications
The intermittency of gravity wave momentum flux (MF) near the OH airglow layer (∼87 km) in the mesopause region is investigated for the first time using observation of all-sky airglow imager over Maui, Hawaii (20.7∘N, 156.3∘W), and Cerro Pachón, Chile (30.3∘S, 70.7∘W). At both sites, the probability density function (pdf) of gravity wave MF shows two distinct distributions depending on the magnitude of the MF. For MF smaller (larger) than ∼16 m2 s−2 (0.091 mPa), the pdf follows a lognormal (power law) distribution. The intermittency represented by the Bernoulli proxy and the percentile ratio shows that gravity waves have higher …
First Measurement Of Horizontal Wind And Temperature In The Lower Thermosphere (105–140 Km) With A Na Lidar At Andes Lidar Observatory, Alan Liu, Yafang Guo, Fabia A. Vargas, Gary Swenson,
First Measurement Of Horizontal Wind And Temperature In The Lower Thermosphere (105–140 Km) With A Na Lidar At Andes Lidar Observatory, Alan Liu, Yafang Guo, Fabia A. Vargas, Gary Swenson,
Publications
We report the first measurement of nighttime atmospheric temperature and horizontal wind profiles in the lower thermosphere up to 140 km with the Na lidar at Andes Lidar Observatory in Cerro Pachón, Chile (30.25°S, 70.74°W), when enhanced thermospheric Na was observed. Temperature and horizontal wind were derived up to 140 km using various resolutions, with the lowest resolution of about 2.7 hr and 15 km above 130 km. Thus, the measurements span 60 km in vertical, more than double the traditional 25 km. On the night of 17 April 2015, the horizontal wind magnitude in the thermosphere exceeds 150 ms−1, …
Turbulence And Overturning Gravity Wave Effects Deduced From Mesospheric Na Density Between 100-105 Km At Andes Lidar Observatory, Chile, Alan Z. Liu, Channing P. Philbrick, Gary R. Swenson, Fabio A. Vargas
Turbulence And Overturning Gravity Wave Effects Deduced From Mesospheric Na Density Between 100-105 Km At Andes Lidar Observatory, Chile, Alan Z. Liu, Channing P. Philbrick, Gary R. Swenson, Fabio A. Vargas
Publications
Atmospheric turbulence activity in the mesosphere and lower thermosphere (MLT) region is determined from narrowband Na lidar measurements obtained over 27 nights between 85-105 km altitude at the Andes Lidar Observatory (ALO) in Cerro Pachón, Chile (30.3ºS, 70.7ºW). Photocount perturbations in the applicable spectral subrange are used as a tracer of turbulence activity. Mean altitude profiles reveal a log-scale linear increase in turbulence perturbation amplitude above 95 km. The observed trend is compared against global mean constituent transport profiles derived from SABER and SCIAMACHY satellite borne measurements.
Existence Of Periodic Orbits In Nonlinear Oscillators Of Emden-Fowler Form, S.C. Mancas, Haret C. Rosu
Existence Of Periodic Orbits In Nonlinear Oscillators Of Emden-Fowler Form, S.C. Mancas, Haret C. Rosu
Publications
The nonlinear pseudo-oscillator recently tackled by Gadella and Lara is mapped to an Emden–Fowler (EF) equation that is written as an autonomous two-dimensional ODE system for which we provide the phase-space analysis and the parametric solution. Through an invariant transformation we find periodic solutions to a certain class of EF equations that pass an integrability condition. We show that this condition is necessary to have periodic solutions and via the ODE analysis we also find the sufficient condition for periodic orbits. EF equations that do not pass integrability conditions can be made integrable via an invariant transformation which also allows …