This paper describes a combined modulation scheme for time-hopping ultra-wideband (TH-UWB) radio systems by using onoff keying (OOK) and pulse-shape modulation (PSM). A set of orthogonal pulses is used to represent bits in a symbol. These orthogonal pulses are transmitted simultaneously in the same pulse repetition interval resulting in a composite pulse. This scheme transmits the same number o...

The knowledge of channel statistics can be very helpful in making sound opportunistic spectrum access decisions. It is therefore desirable to be able to efficiently and accurately estimate channel statistics. In this paper we study the problem of optimally placing sensing/sampling times over a time window so as to get the best estimate on the parameters of an onoff renewal channel. We are parti...

Numerical calculations have been made on the spike-train response of a pair of HodgkinHuxley (HH) neurons coupled by synapses and axons with time delay. The recurrent excitatory-excitatory, inhibitory-inhibitory, excitatory-inhibitory, and inhibitory-excitatory couplings are adopted. The coupled, excitable HH neurons are assumed to receive the two kinds of spike-train inputs: the transient inpu...

The changing of climate directly affects on decreasing agricultural production. Therefore, application of automated system in agriculture activities is potential issue which must be considered. This paper presents error analysis of ON-OFF and ANN controllers which are applied to the automated irrigation system. Controlling of irrigation system used a calculated Penman-Monteith evapotranspiratio...

Chemotaxis during sinusoidal locomotion in nematodes captures in simplified form the general problem of how dynamical interactions between the nervous system, body, and environment are exploited in the generation of adaptive behavior. We used an evolutionary algorithm to generate neural networks that exhibit klinotaxis, a common form of chemotaxis in which the direction of locomotion in a chemi...

0163-6804/97/$10.00 © 1997 IEEE he need for telecommunication networks capable of providing diverse and emerging communication services such as data, voice, and video, motivated the standardization of broadband networks. The need for a flexible design that can accommodate future services and advances in technology led International Consultative Committee for Telephone and Telegraph (CCITT) to a...