133,832 research outputs found
Enhanced Lee model from rough terrain sampling data aspect
No full textThe Lee propagation prediction model has been well recognized by the wireless industry as one of the most accurate propagation prediction models. This paper discusses innovative approaches dealing with rough digital samples of terrain data and enhancements to the Lee model during the validation process. In general, the Lee model is composed of two parts, the impact of man-made structures and the impact of the natural terrain variation [1-6]. There are other papers discuss innovative algorithms on calculating effective antenna gain [7,8] and diffraction loss [7-9] as well as on enhancing the Lee model [12-14]. This paper focuses on the natural (terrain) factor. The new algorithm presented in this paper is quite different than others as it integrates both Line Of Site (LOS) and shadow loss calculation together for the Lee model. First, in the LOS scenario, it addresses the issue of big swing of effective antenna gain due to non-continuous terrain data. Second, in the non-LOS situation, the effective antenna gain is integrated with shadow loss. Both single knife edge and multiple knife edge scenarios are discussed. The new algorithm is developed based on the analysis of measured and predicted (the theoretical shadow loss and effective antenna gain) data. The new algorithm involves more calculation but it improves the accuracy of the predicted value. This algorithm was implemented and verified using field terrain and measurement data from a variety of different environments and different countries including Italy, US, Spain, Japan, South Korea, Taiwan and Romania. ?2010 IEEE.EI
Enhanced lee in-building model
No full textThis paper provides a complete solution for building related propagation, starting by validating the Lee In-building model [1-3] for the single floor scenario. Then how the enhanced Lee In-building model performs in inter-floor and interbuilding cases are discussed. Measurement data were collected from 2.4G WLAN developed systems installed in many different floors in two different buildings which are connected with a corridor. The data are from multiple single floor measurements, inter floor measurement and inter building measurements. The FDTD and Ray Tracing models [4-9] was used to validate the measured with the Lee model. The results show that the Lee model outperforms the FDTD and Ray Tracing models in both speed and accuracy. The propagation environment is quite unique and challenging for this deployment. The Lee model was used to optimize the coverage and minimize the interference while fine tuning radio parameters (antenna types, ERP, down tilt) to improve system performances. The net results were continuous connectivity with smooth roaming and high throughput which provided a different experience for users. Copyright ? 2013 by the Institute of Electrical and Electronic Engineers, Inc.EI
Morphological clocks in palaeontology, and a mid-Cretaceous origin of crown Aves
No full textMichael S.Y. Lee, Andrea Cau, Darren Naish, and Gareth J. Dyk
James Y. Lee
No full textJames Y. Lee, son of John D. Lee and wife Poly Young. Juanita Brooks wrote the biography of John D. Lee and researched his involvement in the Mountain Meadows Massacre, viewing him as a scapegoat of the incident
Possible involvement of phospholipase A(2) in light signal transduction of guard cells of Commelina communis
No full textPolyunsaturated fatty acids induce stomatal opening (Y. Lee, H. Lee, R. C. Crain, A. Lee and S. J. Kern. 1994. Cell Signal. 6: 181-186), but it is not known whether they function as second messengers in guard cells exposed to signals that open stomata. To test the hypothesis that phospholipase A(2)(PLA(2)), which produces fatty acids and lysophospholipids, is involved in light signal transduction in guard cells, we treated epidermal peels of Commelina communis L. with PLA(2) inhibitors and followed the changes in stomatal apertures in response to light. Stomatal opening by white, blue, or red light was inhibited by 2-3 different PLA(2) inhibitors in concentration ranges that have bren reported to inhibit PLA(2) activity. However, the PLA(2), inhibitors could not block stomatal opening induced by a polyunsaturated fatty acid. These results suggest that PLA(2) functions as a signal transducer for both blue and red light in guard cells.X118sciescopu
Quantum teleportation and Bells inequality using single-particle entanglement
No full text©2000 The American Physical Society
URL: http://link.aps.org/abstract/PRA/v63/e012305
DOI: 10.1103/PhysRevA.63.012305
PACS: 03.67.-a, 03.65.Ta, 42.50.-pA single-particle entangled state can be generated by illuminating a beam splitter with a single photon. Quantum teleportation utilizing such a single-particle entangled state can be successfully achieved with a simple setup consisting only of linear optical devices such as beam splitters and phase shifters. Application of the locality assumption to a single-particle entangled state leads to Bell's inequality, a violation of which signifies the nonlocal nature of a single particle.This research was supported by the Brain Korea 21 Project of the Korean Ministry of Education and by the Korea Atomic Energy Research Institute (KAERI). The authors wish to thank Professors K. An, P. Ko, E. K. Lee, S. C. Lee, Y. H. Lee, E. Stewart, and Mr. J. C. Hong for helpful discussions
Lee y diviértete
No full textEste programa trabaja los fonemas g , j , r y rr . Es muy gráfico y tiene muchos archivos de sonido ya que los niños de esta edad se supone que tienen dificultades en la lectura y es mejor que reciban las órdenes por vía oralhabilidad lectoraEnsino Fundamental::Séries Iniciais::Língua Portugues
Lee y diviértete
No full textEste programa trabaja los fonemas g , j , r y rr . Es muy gráfico y tiene muchos archivos de sonido ya que los niños de esta edad se supone que tienen dificultades en la lectura y es mejor que reciban las órdenes por vía oralhabilidad lectoraEnsino Fundamental::Séries Iniciais::Língua Portugues
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