5. Teaching methods – working in pairs, the prescription writing of drugs for concrete situations; training, defining terms, solving problems, answer questions, working out examples (of the slides, of the handbooks and handouts), MCQs.
1.Katzung B. G., ed. 2001. Basic and Clinical Pharmacology, 8th ed., Lange Medical Books/McGraw-Hill, Appleton and Lange. PP. 107-119, 446-462.
2.Tripathi K.D., ed.1999, Essentials of Medical Pharmacology. 4th ed., New Delhi, India, Jaypee Brothers. PP. 103-114, 148-159.
3.Sharma V.N., ed.1996 Essentials of Pharmacology. 1th ed., New Delhi, India, CBS Publishers & Distributors. PP. 54-58, 69-70, 119-125.
7. Assessment Prescriptions Writing, MCQs, ECQs.
Orthogonal decomposition of signals with limited spectrum range.
As well as the Fourier transform for periodic and non-periodical FIR signals, widely used Kotelnikov decomposition. Let us consider the main features of these expansions.
Orthogonal decomposition of Kotelnikov for continuous signals with bounded spectra can represent them and a pulse sequences. The theoretical basis of the presentation is Kotelnikov theorem (sampling theorem): any continuous function S(t), does not contain frequencies above F, completely determined by the sequence of values in moment you are separated from each other for a while . The total number of samples to signal duration , ie, the same base signal.
For the signal S (t), the spectrum of which is in the interval [0, F] , orthogonal decomposition Kotelnikov
Where - countdown signal at the moment basis set of orthogonal functions with a common — sampling interval equal to the norm of basic function. Functions is call reference functions and values - counts. Graph of samples shown in figure Orthogonality of samples tested by calculating the integral
The sampling interval, as we see, does not exceed half of the highest frequency of the signal.
From Parseval that the energy of a continuous signal with a limited range determined by counting:
Once again it must be emphasized that in nature there are no signals, co-torye have both limited duration and spectrum. In engineering calculations must take into account that part of the spectrum, which are home to 80 ... 95% of the signal energy. So particle of most of the signals are considered as signals with limited spectrum. If there is a signal on the interval , then choose the number of terms (number of samples)
Advantages of an orthogonal decomposition Kotelnikov following: a basic system of orthogonal functions is chosen so that the series is formal, that is, at any point of reference he makes one value the other components of a number of degenerate to zero: coefficients of the series can not compute, and their values are determined by measuring the signal.
Graph of samples:
Or from its analytical form, and knowing the signal duration T and
cut-off frequency F, determine the required number of samples of the signal energy .
At the last features useful in more detail. For this, consider the physical meaning of the Kotelnikov decomposition. Each term of the sum is response of an ideal low-pass filter gk (see Fig.) with a cutoff frequency of F for a very short pulse arriving at the time and space available. Therefore, when a discrete signal transmission S (t) with a limited range to at regular intervals to take instant readings i peny signal and transmit the channel sequence sufficiently short pulses of amplitude at the time selected to the receiver in the selected sequence video pulses passed through a low pass filter, the output of which transmits a continuous signal is restored. Pulse duration τ can be arbitrarily small, but choose it based on the transparency of the link bandwidth. hour- u rate (clock speed) is 2F.