Full-scale wind tunnel-investigation of the Advanced Technology Light Twin-Engine airplane (ATLIT)

An investigation was conducted to evaluate the aerodynamic performance, stability, and control characteristics of the Advanced Technology Light Twin Engine airplane (ATLIT). Data were measured over an angle of attack range from -4 deg to 20 deg for various angles of sideslip between -5 deg and 15 deg at Reynolds numbers of 0.0000023 and 0.0000035 for various settings of power and flap deflection. Measurements were also made by means of special thrust torque balances to determine the installed propeller characteristics. Part of the investigation was devoted to drag cleanup of the basic airplane and to the evaluation of the effect of winglets on drag and stability

Prediction of service life of polymeric sealant compositions for fuel tanks in aerospace structures from measurements of viscoelastic properties Annual report

Prediction of service life of polymeric sealers for fuel tanks from viscoelastic measurement

Statistical quality control applied to a telemetry system acceptance prodedure Technical report no. 13

Statistical quality control applied to telemetry system acceptance procedur

Low-Speed Measurements of Oscillatory Lateral Stability Derivatives of a 1/7-Scale Model of the North American X-15 Airplane

An investigation to determine the low-speed rolling, yawing, and sideslipping derivatives of a 1/7-scale model which was used to represent the original configuration and a modified configuration of the North American X-15 airplane has been conducted in the Langley free-flight tunnel. The original model was modified to approximately represent the final airplane configuration by reducing the size of the fuselage side fairings and changing the vertical-tail arrangement. The effects of various tail arrangements were determined for both configurations and the effect of small forebody strakes was determined for the modified configuration only

Amplitude dependent frequency, desynchronization, and stabilization in noisy metapopulation dynamics

The enigmatic stability of population oscillations within ecological systems is analyzed. The underlying mechanism is presented in the framework of two interacting species free to migrate between two spatial patches. It is shown that that the combined effects of migration and noise cannot account for the stabilization. The missing ingredient is the dependence of the oscillations' frequency upon their amplitude; with that, noise-induced differences between patches are amplified due to the frequency gradient. Migration among desynchronized regions then stabilizes a "soft" limit cycle in the vicinity of the homogenous manifold. A simple model of diffusively coupled oscillators allows the derivation of quantitative results, like the functional dependence of the desynchronization upon diffusion strength and frequency differences. The oscillations' amplitude is shown to be (almost) noise independent. The results are compared with a numerical integration of the marginally stable Lotka-Volterra equations. An unstable system is extinction-prone for small noise, but stabilizes at larger noise intensity

Accounting education literature review (2017)

This review of the accounting education literature includes 103 articles published during 2017 in six journals: (1) Journal of Accounting Education, (2) Accounting Education, (3) Advances in Accounting Education: Teaching and Curriculum Innovations, (4) Global Perspectives on Accounting Education, (5) Issues in Accounting Education, and (6) The Accounting Educators’ Journal. We update 12 prior accounting education literature reviews by organizing and summarizing contributions to the accounting education literature made during 2017. Articles are categorized into five sections corresponding to traditional knowledge bases: (1) curriculum and instruction, (2) instruction by content area, (3) educational technology, (4) students, and (5) faculty. Research rigor of the empirical articles is discussed and critiqued. Suggestions for research in all areas are presented. Articles classified as instructional resources and cases published in the same six journals during 2017 are listed in appendices categorized by the relevant content area

Executive Summary for The Future of Library Services for and with Teens: A Call to Action

As part of the year-long National Forum on Libraries and Teens effort, YALSA has released a report, "The Future of Library Services for and with Teens: A Call to Action" providing direction on how libraries need to adapt and change to meet the needs of 21st century teens. The report is a call to action for the library community. It provides recommendations on how libraries must address challenges and re-envision their teen services in order to meet the needs of their individual communities and to collectively ensure that the nation's 40+ million teens develop the skills they need to be productive citizens. By acting on this call, the library community can work within their own local communities to create the kind of spaces, services, and opportunities that today's teens need in order to succeed in school and in life

The Future of Library Services for & with Teens: A Call to Action

As part of the year-long National Forum on Libraries and Teens effort, YALSA has released a report, "The Future of Library Services for and with Teens: A Call to Action" providing direction on how libraries need to adapt and change to meet the needs of 21st century teens.The report is a call to action for the library community. It provides recommendations on how libraries must address challenges and re-envision their teen services in order to meet the needs of their individual communities and to collectively ensure that the nation's 40+ million teens develop the skills they need to be productive citizens. By acting on this call, the library community can work within their own local communities to create the kind of spaces, services, and opportunities that today's teens need in order to succeed in school and in life

Evaluating the semantic web: a task-based approach

The increased availability of online knowledge has led to the design of several algorithms that solve a variety of tasks by harvesting the Semantic Web, i.e. by dynamically selecting and exploring a multitude of online ontologies. Our hypothesis is that the performance of such novel algorithms implicity provides an insight into the quality of the used ontologies and thus opens the way to a task-based evaluation of the Semantic Web. We have investigated this hypothesis by studying the lessons learnt about online ontologies when used to solve three tasks: ontology matching, folksonomy enrichment, and word sense disambiguation. Our analysis leads to a suit of conclusions about the status of the Semantic Web, which highlight a number of strengths and weaknesses of the semantic information available online and complement the findings of other analysis of the Semantic Web landscape

Accounting education literature review (2020)

This review of the accounting education literature includes 88 articles published during 2020 in five accounting education journals: (1) Journal of Accounting Education, (2) Accounting Education, (3) Advances in Accounting Education: Teaching and Curriculum Innovations, (4) Issues in Accounting Education, and (5) The Accounting Educators’ Journal. We update 15 prior accounting education literature reviews by organizing and summarizing contributions to the accounting education literature made during 2020. Articles are categorized into five sections corresponding to traditional knowledge bases: (1) curriculum and instruction, (2) instruction by content area, (3) educational technology, (4) students, and (5) faculty. We summarize the research design of the empirical articles. Suggestions for research are presented. Articles classified as cases published in the same five journals during 2020 are tabulated in an appendix categorized by content area