نتایج جستجو برای: layer medium

تعداد نتایج: 509665  

2017
Yishan Su Xiaomei Fu Guangyao Han Naishen Xu Zhigang Jin

In this paper, compressed sensing (CS) theory is utilized in a medium-access control (MAC) scheme for wireless sensor networks (WSNs). We propose a new, cross-layer compressed sensing medium-access control (CL CS-MAC) scheme, combining the physical layer and data link layer, where the wireless transmission in physical layer is considered as a compress process of requested packets in a data link...

2010
Jesús Alonso-Zárate Elli Kartsakli Luis Alonso Christos Verikoukis

Cooperative Automatic Retransmission reQuest (C-ARQ) schemes have become a very active research topic over the last years. C-ARQ schemes constitute a practical way of executing cooperation in wireless networks with already existing equipment. C-ARQ schemes exploit feedback from the receiver, i.e. cooperation is only executed when needed, and thus are sometimes referred to as cooperation on-dema...

1998
Alfred Scharff Goldhaber

At a surface between electromagnetic media the Maxwell equations are consistent with either the usual boundary conditions, or exactly one alternative: continuity of E⊥, H⊥, D‖, B‖. These alternative, classically inexplicable conditions applied to the top and bottom surfaces of an FQH layer capture exactly its unique low-frequency properties. “Magic” in science means not illusion or trickery, bu...

2017
Mehrdad Shahmohammadi Beni Tak Cheong Hau D Krstic D Nikezic K N Yu

Monte Carlo method was used to study the characteristics of neutron interactions with cells underneath a water medium layer with varying thickness. The following results were obtained. (1) The fractions of neutron interaction with 1H, 12C, 14N and 16O nuclei in the cell layer were studied. The fraction with 1H increased with increasing medium thickness, while decreased for 12C, 14N and 16O nucl...

2011
S. Padmaja

we study joint end-to-end congestion control and Per-link medium access control (MAC) in ad-hoc networks. We use a network utility maximization formulation, where the goal is to find optimal end-to-end source rates at the transport layer and per-link persistence probabilities at the medium access control (MAC) layer to maximize the aggregate source utility. Under certain conditions, by applying...

this paper a novel homotopy perturbation method has been presented for forced convection boundary layer problems in a porous medium. Noting the infinite condition, a homotopy form which is similar to the singular perturbation form has been considered. The inner and outer solutions have been achieved and the coincidence of the results has been investigated with a proper matching method. The resu...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - پژوهشکده فنی و مهندسی 1388

asymmetric polyethersulfone (pes) microfiltration flat sheet membranes were composed by the phase inversion method (pim) and were used as supports. composite membranes were fabricated by coating silicone rubber as selective layer. effect of different concentrations of pes and pdms and different solvent such as nmp, dmf and dms effects as pes solvents and support thickness and different coagulat...

In this study, a numerical examination of the significance of rotation and changeable gravitational field on the start of nanofluid convective movement in an anisotropic porous medium layer is shown. A model that accounts for the impact of Brownian diffusion and thermophoresis is used for nanofluid, while Darcy’s law is taken for the porous medium. The porous layer is subjected to uniform rotat...

2001
Anastasios Stamoulis Zhiqiang Liu Georgios B. Giannakis

| In wireless networks, the provision of QoS guarantees needs to address the limited capacity of the physical medium. Such an objective calls for the joint design and integration of the network layer, medium access control, and physical layer. Supporting Integrated Services at the network layer demands a multi-rate transmission scheme at the physical layer, whereas achieving high data throughpu...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید