iosr-JECE   Volume-1 ~ Issue-1

Abstract : The soft-computing techniques provide us with tools that can be used to calculate the various parameters that cannot be measured easily. In this paper computational study of DNA base Thymine has been carried out using two probe set up. The metal-molecule-metal assembly was realized by inserting Thymine molecule between two gold terminals and analyzed for current-voltage characteristics. The current-voltage characteristics are obtained using Density Functional theory within Non-equilibrium Green's function formalism (NEGF-DFT). Negative differential resistance is exhibited in the characteristics of Thymine. In two probe set-up without using gate, oscillating behavior of current through thymine is observed rendering its use to drive electronic circuits. It is also observed that the current-voltage characteristics of Thymine can be modulated by gating the two probe setup. The analysis shows that Thymine is suitable for use in two and three terminal Nanoelectronic devices.
Keywords: computation, DNA base Thymine, negative differential resistance, resonant tunneling.

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ABTRACTS : In this paper VHDL implementation of 8-bit arithmetic logic unit (ALU) is presented. The design was implemented using VHDL Xilinx Synthesis tool ISE 13.1 and targeted for Spartan device. ALU was designed to perform arithmetic operations such as addition and subtraction using 8-bit fast adder, logical operations such as AND, OR, XOR and NOT operations, 1's and 2's complement operations and compare. ALU consist of two input registers to hold the data during operation, one output register to hold the result of operation, 8-bit fast adder with 2's complement circuit to perform subtraction and logic gates to perform logical operation. The maximum propagation delay is 13.588ns and power dissipation is 38mW. The ALU was designed for controller used in network interface card.
KEYWORDS : ALU, Fast adder, Network interface card, VHDL implementation.

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ABSTRACT: Smart adaptive antenna technology is considered to be the last technology frontier that has the potential of leading to large increases in systems performance. Time domain techniques have been extensively exploited. Space domain techniques, on the other hand, have not been exploited to the same extent. When applied to wireless, the benefits of smart adaptive array a antennas are as follows: (i) increased covered, which is important in the early stages of life cycle, (ii) increased capacity, which is important in the later stages of life cycle, (iii) improved link quality, (iv) reduced costs and increased return on investment, (v) lower handset power consumption, and (vi) assistance in user location by means of direction finding. This paper discusses an experimental neural network based smart antenna capable of performing direction finding and the necessary beam forming. The algorithm operates in two stages. The field of view of the antenna array is divided into spatial sectors ,then each network is trained in the first stage to detect signals emanating from sources in that sector. According to the outputs of the first stage, one or more networks of the second stage can be activated so as to estimate the exact location of the sources. No a priori knowledge is required about the number of sources, and the networks can be designed to arbitrary angular resolution. Some experimental results are shown and compared with other algorithms, such as, the Fourier Transform and the MUSIC algorithm AND ESPRIT variations is done in the proposed research work.
Keywords: DOA ,MUSIC,ESPRIT

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