26,412 research outputs found
Chan An Ancient Maya Farming Community
No full textThe farming community of Chan thrived for over twenty centuries, surpassing the longevity of many larger Maya urban centers. Between 800 BC and 1200 AD it was a major food production center, and this collection of essays reveals the important role played by Maya farmers in the development of ancient Maya society. Chan offers a synthesis of compelling and groundbreaking discoveries gathered over ten years of research at this one archaeological site in Belize. The contributors develop three central themes, which structure the book. They examine how sustainable farming practices maintained the surrounding forest, allowing the community to exist for two millennia. They trace the origins of elite Maya state religion to the complex religious belief system developed in small communities such as Chan. Finally, they describe how the group-focused political strategies employed by local leaders differed from the highly hierarchical strategies of the Classic Maya kings in their large cities. In breadth, methodology, and findings, this volume scales new heights in the study of Maya society and culture.Cover -- Title -- Copyright -- Contents -- List of Figures -- List of Tables -- Foreword -- Acknowledgments -- 1. Introducing the Chan Site: Farmers in Complex Societies -- Part 1. Time, Space, and Landscapes -- 2. A Changing Cultural Landscape: Settlement Survey and GIS at Chan -- 3. Ceramics and Chronology at Chan -- 4. Agricultural Practices at Chan: Farming and Political Economy in an Ancient Maya Community -- 5. Agroforestry and Agricultural Production of the Ancient Maya at Chan -- Part 2. Life in a Farming Community Center -- 6. Ritual in a Farming Community -- 7. Nonroyal Governance at Chan's Community Center -- 8. "Empty" Spaces and Public Places: A Microscopic View of Chan's Late Classic West Plaza -- Part 3. Diversity across the Chan Community -- 9. Recognizing Difference in Small-Scale Settings: An Examination of Social Identity Formation at the Northeast Group, Chan -- 10. Organization of Chert Tool Economy during the Late and Terminal Classic Periods at Chan: Preliminary Thoughts Based upon Debitage Analyses -- 11. Limestone Quarrying and Household Organization at Chan -- Part 4. Bodies, Material Culture, and Meaning -- 12. The Chan Community: A Bioarchaeological Perspective -- 13. Creating Community with Shell -- 14. Obsidian Acquisition, Trade, and Regional Interaction at Chan -- 15. Contextualizing Ritual Behavior: Caches, Burials, and Problematical Deposits from Chan's Community Center -- Part 5. Conclusion -- 16. Learning from an Ancient Maya Farming Community -- References -- List of Contributors -- Index -- A -- B -- C -- D -- E -- F -- G -- H -- I -- J -- K -- L -- M -- N -- O -- P -- Q -- R -- S -- T -- V -- W -- X -- YThe farming community of Chan thrived for over twenty centuries, surpassing the longevity of many larger Maya urban centers. Between 800 BC and 1200 AD it was a major food production center, and this collection of essays reveals the important role played by Maya farmers in the development of ancient Maya society. Chan offers a synthesis of compelling and groundbreaking discoveries gathered over ten years of research at this one archaeological site in Belize. The contributors develop three central themes, which structure the book. They examine how sustainable farming practices maintained the surrounding forest, allowing the community to exist for two millennia. They trace the origins of elite Maya state religion to the complex religious belief system developed in small communities such as Chan. Finally, they describe how the group-focused political strategies employed by local leaders differed from the highly hierarchical strategies of the Classic Maya kings in their large cities. In breadth, methodology, and findings, this volume scales new heights in the study of Maya society and culture.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
Elevational range size and climatic variaiblity. Chan et al.
No full textData for reproducing the results published in Chan, W.-P., Chen, I.-C., Colwell, R.K., Liu, W.-C., Huang, C.-y. & Shen, S.-F. (2016) Seasonal and daily climate variation have opposite effects on species elevational range size. Science, 351, 1437-1439
Coulter, Chan L., July 23, 1996 [Interview]
No full textProfessor of Philosophy Chan L. Coulter was interviewed on June 17, 1996, by Michael Birkner and David Hedrick about his career at Gettysburg College, including memorable colleagues, classes, and controversies.Dunn, Seymour B.; Glatfelter, Charles H.; Hanson, C. Arnold; Crapster, Basil L.; Barnes, Robert D.; Baskerville, Edward J.; Mara, Richard T.; Qually, Ingolf; Bugbee, Bruce W.; Richardson, Norman E.; Bolich, Harry F.; Arms, Richard A.; Mason, Francis C.; Taylor, Kathrine Kressmann; Schmidt, Emile O.; Glassick, Charles E.; Potts, David B.Willard S. Paul Years; Carl Arnold Hanson Years; Charles E. Glassick Years; Gordon A. Haaland Year
Helical structure of the waves propagating in a spinning Timoshenko beam
No full textThe aim of the paper is to study the cause of a frequency-splitting phenomenon that occurs in a spinning Timoshenko beam. The associated changes in the structure of the progressive waves are investigated to shed light on the relationship between the wave motion in a spinning beam and the whirling of a shaft. The main result is that travelling bending waves in a beam spinning about its central axis have the topological structure of a revolving helix traced by the centroidal axis with right-handed or left-handed chirality. Each beam element behaves like a gyroscopic disc in precession being rotated at the wave frequency with anticlockwise or clockwise helicity. The gyroscopic effect is identified as the cause of the frequency splitting and is shown to induce a coupling between two interacting travelling waves lying in mutually orthogonal planes. Two revolving waves travelling in the same direction in space appear, one at a higher and one at a lower frequency compared with the pre-split frequency value. With reference to a given spinning speed, taken as clockwise, the higher one revolves clockwise and the lower one has anticlockwise helicity, each wave being represented by a characteristic four-component vector wavefunction.Two factors are identified as important, the shear-deformation factor q and the gyroscopic-coupling phase factor ?. The q-factor is related to the wavenumber and the geometric shape of the helical wave. The ?-factor is related to the wave helicity and has two values, +?/2 and ??/2 corresponding to the anticlockwise and clockwise helicity, respectively. The frequency-splitting phenomenon is addressed by analogy with other physical phenomena such as the Jeffcott whirling shaft and the property of the local energy equality of a travelling wave. The relationship between Euler's formula and the present result relating to the helical properties of the waves is also explored
Gender Differences in Performance of Top Scientists by Field and Country
No full textData and supplementary material for Chan and Torgler (2020). https://link.springer.com/article/10.1007/s11192-020-03733-w.
Please contact [email protected] for questions and refer to our paper.
Recommended citation: Chan, H. F., & Torgler, B. (2020). Gender differences in performance of top cited scientists by field and country. Scientometrics, in press
Variable structure model for flow-induced tonal noise control with plasma actuators
No full textThe objective of this work was to study the effect of plasma actuators in attenuating low-speed flow-induced cavitytones from a control point of view by employing techniques from classical control. A modification of the existingphysics-based linear model produced a new variable structure model in which a plasma actuator was regarded as alinear gain. The parameters of the overall model working at two operating voltages were identified usingexperimental data. The effects of the plasma actuator control at other various operating voltages were thus able to bepredicted using linear interpolation. The good agreement between the predicted and the measured data supportedthe proposed variable structure model, inside of which plasma actuators affected the damping of cavity pressureoscillations proportionally to the applied voltage to reduce flow-induced tonal noise. With the proposed variablestructure model the system stability controlled by plasma actuators at various operating voltages was ensured, thus aclosed-loop control method could be applied without leading to instability. A simple proportional integral derivativecontroller was implemented. Results show the potential of a closed-loop method by increasing system powerefficiency
“Beauty” Premium for Social Scientists but “Unattractiveness” Premium for Natural Scientists
No full textData and supplementary material for Bi, Chan, and Torgler (2020).
https://www.nature.com/articles/s41599-020-00608-6.
Please contact [email protected] for questions and refer to our paper.
Recommended citation: Bi, W., Chan, H. F., & Torgler, B. (2020). “Beauty” premium for social scientists but “unattractiveness” premium for natural scientists in the public speaking market. Humanities and Social Sciences Communications, 7(1), 1-9
“Beauty” Premium for Social Scientists but “Unattractiveness” Premium for Natural Scientists
No full textData and supplementary material for Bi, Chan, and Torgler (2020).
https://www.nature.com/articles/s41599-020-00608-6.
Please contact [email protected] for questions and refer to our paper.
Recommended citation: Bi, W., Chan, H. F., & Torgler, B. (2020). “Beauty” premium for social scientists but “unattractiveness” premium for natural scientists in the public speaking market. Humanities and Social Sciences Communications, 7(1), 1-9
“Beauty” Premium for Social Scientists but “Unattractiveness” Premium for Natural Scientists
No full textData and supplementary material for Bi, Chan, and Torgler (2020).
https://www.nature.com/articles/s41599-020-00608-6.
Please contact [email protected] for questions and refer to our paper.
Recommended citation: Bi, W., Chan, H. F., & Torgler, B. (2020). “Beauty” premium for social scientists but “unattractiveness” premium for natural scientists in the public speaking market. Humanities and Social Sciences Communications, 7(1), 1-9
Broadband satellite multimedia
No full textThe broadband satellite multimedia (BSM) architecture standardised by ETSI defines a satellite independent service access point (SI-SAP) interface layer that separates the satellite independent features of the upper layers from the satellite dependant features of the lower layers, and provides a mechanism to carry IP-based protocols over these satellite dependent lower layers. This enables interoperability at the IP layer between satellite systems of different physical and link layers technologies that fully comply with the SI-SAP concept. This study reviews past and current standardisation activities including the BSM quality of service (QoS) architecture, security architecture, network management that have been carried out by the ETSI Technical Committee-Satellite Earth Stations and Systems (TC-SES)/BSM working group and looking into the future to extend current SI-SAP functions that can enhance existing QoS provision and security management
capabilities as well as proposing a mobility management architecture that complies with the IEEE 802.21 media independent handover framework to support BSM mobility and to allow integration of satellite networks with fixed and mobile network infrastructures. A service-based network management architecture is also proposed to allow management flexibility and integration of business and operation support functions, paving the way for satellite integration into the Internet of the future
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