Guard Channel
Mostrando 1-12 de 75 artigos, teses e dissertações.
-
1. Low-Overhead Low-Complexity Carrier Phase Recovery Technique for Coherent Multi-Band OFDM-Based Superchannel Systems Enabled by Optical Frequency Combs
Abstract In this paper, we have designed a low-overhead low-complexity carrier phase tracking scheme for OFDM-based superchannel transmission system enabled by optical frequency combs. In this scheme, taking advantage of the broadband phase coherence provided by optical frequency combs among the OFDM-bands, the carrier phase retrieved from pilot-subcarriers
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2021-03
-
2. A parentalidade no contexto da guarda compartilhada.
This research had the objective to analyse the experience of parenthood by divorced and separated couples who chose joint custody to take care their children. The sample was intentional and compounded by six couples. Their are four couples (ex-husbands and ex-wives) and two incomplete couples (only one ex-husband and only a woman), as the total of ten people
Publicado em: 2008
-
3. CONTROLE DE ADMISSÃO E RESERVA DE RECURSOS EM REDES MÓVEIS CELULARES / ADMISSION CONTROL AND RESOURCE RESERVATION IN MOBILE CELLULAR NETWORKS
Esta tese apresenta novos algoritmos para controle de admissão de usuários em redes móveis celulares. É utilizada a técnica de reserva de recursos, também conhecida por uso de canais de guarda, para atingir os graus de qualidade de serviço desejados para cada tipo de usuário. São propostos algoritmos dinâmicos, capazes de se adaptar ao perfil de tr
Publicado em: 2008
-
4. cellular networks; Mobile networks / Controle de admissÃo de chamas e reserva de recursos em redes mÃveis celulares
Handoff in wireless/mobile networks is the mechanism that transfers an ongoing call from the current cell as the mobile station moves through the coverage area of the system. User applications may experience performance degradation due to handoffs from user mobility. If the target cell does not have sufficient available bandwidth, the call will be dropped. F
Publicado em: 2004
-
5. CHANNEL ALLOCATION COMPARATIVE ANALYSIS FOR TDMA TECHNOLOGY / ALOCAÇÃO DE CANAIS ANÁLISE COMPARATIVA PARA TECNOLOGIA TDMA
Fixed channel assignment -FCA- brings to the Cellular Communication Systems stability at the cost of the use of frequency planning, leading to low tolerance to traffic variability. Dynamic channel assignment -DCA- algorithms have been proposed by several authors in order to minimize these problems,incorporating flexibility to the system with respect to chann
Publicado em: 2002
-
6. UNDERWATER ACOUSTIC RECEPTION IN THE PRESENCE OF MULTIPATH / RECEPÇÃO ACÚSTICA SUBMARINA NA PRESENÇA DE MULTIPERCURSOS
A simple, low-cost and robust for the problem of multipath in underwater acoustic communication in deep water, is presented. Initially, a delay profile and noise level characterization, in offshore oil exploitation environments is done, with the objective of defining the communication channel of interest. The modulation techique, considered adequate by means
Publicado em: 1997
-
7. Cloning and electrophysiological analysis of KST1, an inward rectifying K+ channel expressed in potato guard cells.
Potassium uptake by guard cells represents part of the osmotic motor which drives stomatal opening. Patch-clamp measurements have identified inward rectifying K+ channels capable of mediating K+ uptake in guard cells and various other plant cell types. Here we report the molecular cloning and characterization of a voltage-dependent K+ channel (KST1) from pot
-
8. A Cationic Channel in the Guard Cell Tonoplast of Allium cepa.
Stomatal movements depend on an osmoregulation process in which swelling or shrinking of the guard cells opens or closes the stomatal pore. Ions and water fluxes are an essential aspect of guard cell osmoregulation. Thus far, studies of these fluxes have focused on the guard cell plasma membrane. Guard cells, however, are a multi-compartment system that incl
-
9. Dominant Negative Guard Cell K+ Channel Mutants Reduce Inward-Rectifying K+ Currents and Light-Induced Stomatal Opening in Arabidopsis1
Inward-rectifying potassium (K+in) channels in guard cells have been suggested to provide a pathway for K+ uptake into guard cells during stomatal opening. To test the proposed role of guard cell K+in channels in light-induced stomatal opening, transgenic Arabidopsis plants were generated that expressed dominant negative point mutations in the K+in channel s
American Society of Plant Physiologists.
-
10. Expression of a Cs(+)-resistant guard cell K+ channel confers Cs(+)-resistant, light-induced stomatal opening in transgenic arabidopsis.
Inward-rectifying K+ (K+in) channels in the guard cell plasma membrane have been suggested to function as a major pathway for K+ influx into guard cells during stomatal opening. When K+in channels were blocked with external Cs+ in wild-type Arabidopsis guard cells, light-induced stomatal opening was reduced. Transgenic Arabidopsis plants were generated that
-
11. Is ATP Required for K+ Channel Activation in Vicia Guard Cells?
In vivo, K+ entry into guard cells via inward-rectifying K+ channels is indirectly driven by ATP via an H+-ATPase that hyperpolarizes the membrane potential. However, whether activation of the K+ channels of guard cells requires ATP remains unknown. In the present study, both whole-cell and single-channel patch-clamp techniques were used to address this ques
-
12. Identification of High-Affinity Slow Anion Channel Blockers and Evidence for Stomatal Regulation by Slow Anion Channels in Guard Cells.
Slow anion channels in the plasma membrane of guard cells have been suggested to constitute an important control mechanism for long-term ion efflux, which produces stomatal closing. Identification of pharmacological blockers of these slow anion channels is instrumental for understanding plant anion channel function and structure. Patch clamp studies were per