Advanced Materials Research Vols. 403-408

Abstract: The increasing requirement for harnessing nuclear power demands the development of innovative precautionary techniques for protection from radiation. The high energies of the particles emitted have to be moderated before they render damage to any material subjected to them. Besides using simple shielding material, electrostatic shielding by setting up opposing electric fields has been implemented towards charged radiation damping to date. This paper aims at presenting and analyzing a material-efficient protection technique against ionizing radiation by introducing a number of parallel capacitive metal foils in between layers of dielectric shielding material. This is the first paper to present a technique by making use of charged capacitive elements to set neutralization centers for incoming charged radiation in order to minimize the thickness of material used for equivalent radiation shielding. The increase in efficiency of the shielding unit in reducing the net energy of radiation by the introduction of charged capacitive foils is experimentally observed.

Abstract: For consistent remote health monitoring to be realized, power source must be independent of time factor. We require small, inexpensive, ubiquitous sensors to be realized, all constituents of the device, including the power source, must be directly integrable. For long term application the device must be capable of scavenging power from its surrounding environment. An apparent solution lies in conversion of mechanical energy produced by body movements to electrical energy. Here, we propose a health monitoring system utilizing energy scavenging from body movements for signal transmission through wireless antenna.

Abstract: Three technologies can be used for content protection in DVB-H; IPSec, SRTP and ISMACryp. ISMA Encryption and Authentication is one of the three chosen technologies for service protection in DVB-H (Digital Video Broadcasting - Handheld), the TV system for portable handheld devices. This paper deals with modification in ISMACryp. The ISMACryp is encoded with MPEG-4 video and MPEG-4 AAC (advanced audio coding), while leaving all structural data as it is. Two modes of ISMACryp are available; the CTR mode (Counter type) and CBC mode (Cipher Block Chaining) mode. Both modes of ISMACryp is based on 128-bit AES algorithm. AES algorithms are more complex and require larger time with more clock cycles for execution. This paper is being first simulate and implement existing ISMACryp using 128-bit Rijndael algorithm and then modified it with KASUMI algorithm that will be provided lower number of clock pulses with lower execution time. The simulation is done in Matlab and implementation in TMS320C6713 DSP kit.

Abstract: The work presented here uses multiwavelet because of its inherent property to resolve the signal better than all single wavelets. Multiwavelets are based on more than one scaling function. The proposed methodology utilizes an enhanced resolving capability of multiwavelet to recognize power quality events. PQ events classification scheme is performed using multiwavelet transform for feature extraction and fuzzy classifier for classification. In proposed algorithm,statistical features (.i.e. mean, standard deviation, variation etc.) and energy of the signal at different decomposition levels have been considered as feature vectors. The performance of fuzzy classifier has been evaluated by using total 1000 PQ disturbance signals which are generated using the based model. The classification performance of different PQ events using proposed algorithm has been tested. The rate of average correct classification is about 99.95% for the different PQ disturbance signals and noisy disturbances.

Abstract: In this paper a design of controller has been proposed for linear uncertain systems based on multirate output sampling for the purpose of state feedback and nullification of disturbance effect on system response. If certain conditions are satisfied, construction of proposed functional type controller require less number of output samples than any other method based on fast output sampling. The advantage of proposed method is that it can be extended to unobservable systems and avoids the boundedness constraint on disturbance. A numerical exam- ple demonstrates the procedure, superiority in terms number of required output samplings and application to unobservable systems.

Abstract: In this paper we propose a constructive algorithm with adaptive sigmoidal function for designing single hidden layer feedforward neural network (CAASF). The proposed algorithm emphasizes on architectural adaptation and functional adaptation during training. This algorithm is a constructive approach to building single hidden layer neural networks dynamically. The activation functions used at non-linear hidden nodes are belonging to the well-defined sigmoidal class and adapted during training. The algorithm determines not only optimum number of hidden nodes, as also optimum sigmoidal function for the non-linear nodes. One simple variant derived from CAASF is where the sigmoidal function used at the hidden nodes is fixed. Both the variants are compared to each other on five regression functions. Simulation results reveal that adaptive sigmoidal function presents several advantages over traditional fixed sigmoid function, resulting in increased flexibility, smoother learning, better convergence and better generalization performance.

Abstract: This paper proposes a technique for computing a vector linear functional of the system states of a linear time invariant (LTI) system. The concept of multirate output observations has been used to design the observer. The paper also proves that the complete state observability of a system is not a necessary condition for the existence of a functional observer. The proposed technique reduces the computational time and complexity of the hardware and software of the observer system considerably due to static structure of observer as well as involvement of reduced dimension matrices in computation of the functional. The proposed technique has been validated using numerical examples.

Abstract: The Autotrix is an interactive, intelligent, Autonomous Guided Vehicle (AGV) designed to serve in urban environments. Autonomous ground vehicle navigation requires the integration of many technologies such as path planning, odometry, control, obstacle avoidance and situational awareness. The objective of this project is for this prototype to navigate autonomously in an urban environment and reach its destination while detecting and avoiding obstacles on the path .This will be achieved by extracting information from multiple sources of real-time data including digital camera, GPS &ultra sonic sensors, collecting data from this extracted information, processing this data and send controlling instructions to our platform (Autotrix). The significance of this work is in presenting the methods needed for real time navigation; GPS based continuous mapping and obstacle avoidance for intelligent autonomous driving systems.

Abstract: In this paper, Particle swarm optimization (PSO) is utilized to optimize the coefficients of decoupling controllers for a nonlinear process. The optimization criteria considered is the Integral Square Error (ISE) to minimize the tracking error. The controller is tuned at chosen operating points, which are selected to cover the nonlinear range of the process. The optimal PID controller parameters are gain scheduled using Sugeno Fuzzy Gain scheduler. Fuzzy gain scheduling is a special form of model-based fuzzy control that uses linguistic rule fuzzy reasoning to determine the controller parameter transition policy for a dynamic plant subject to large changes in the operating state. The effectiveness of the proposed control scheme has been demonstrated by conducting simulation studies on a Continuous Stirred Tank Reactor (CSTR) which exhibits dynamic nonlinearity.

Abstract: Electromagnetic levitation system (EMLS) is inherently unstable and strongly non-linear in nature. Controllers based on linear model and designed by classical approach for any EMLS have restricted zone of operation. For a small variation of operating air-gap there is sharp degradation of controller performance. But it is essential to design an optimized controller that will stabilize unstable EMLS and will provide satisfactory performance for a wide range of operating air-gap. In this paper a Genetic Algorithm (GA) based optimisation technique for controllers of two actuator based levitation system has been discussed. GA has a highly proven track record of optimisation of parameters for different types of control schemes. Here the work focuses mainly on an optimal control of a proposed two actuator based EMLS scheme, which is composed of a stochastic technique based on Genetic Algorithm (GA).