Subarna Bhattacharjee

Mean Residual Life Function, Associated Orderings and Properties

Although the shape of the failure rate function plays an important role in repair and replacement strategies, the mean residual life (mrl) function is more relevant as the latter summarizes the entire residual life function, whereas the former considers only the risk of instantaneous failure. In this paper, we give a review of the different partial ordering results related to mrl order, and proportional mrl model, with some characterization results. Some properties of the shifted mrl order have been developed along with the closure of the shifted mrl order under mixture-type operation. We show that redundancy at the component level is not superior to that at the system level, even when the lifetimes of the original and the spare components are iid, although it is well known that the result holds for usual stochastic order. The shifted mrl order is characterized in terms of the DMRL class. Some other characterizations are also presented here followed by the closure of the order under Poisson shock model.

Cellular-automata-array-based diagnosis of board level faults

A novel scheme for board level fault diagnosis based on cellular automata array (CAA) is presented. In the proposed diagnosis scheme, the output responses of the chips are encoded by applying the strategy of CA-based byte error correcting code. The encoded response symbols for different test vectors are compressed to a signature. The decoding scheme of byte error correcting code is subsequently employed to detect the faulty chips on the board. The CAA-based design for the fault diagnosis strategy results in a simple and modular test structure that is well suited for VLSI implementation. The scheme can be applied for testing and diagnosis of multichip modules (MCMs) as well.

A pipelined architecture algorithm for image compression

Summary form only given. The article reports a pipelined architecture that can support on-line compression/decompression of image data. Spatial and spectral redundancy of an image data file are detected and removed with a simple and elegant scheme that can be easily implemented on a pipelined hardware. The scheme provides the user with the facility of trading off the image quality with the compression ratio. The basic theory of byte error correcting code (ECC) is employed to compress a pixel row with reference to its adjacent row. A simple scheme is developed to encode pixel rows of an image, both monochrome and colour. The compression ratio and quality obtained by this new technique has been compared with JPEG which shows comparable compression ratio with acceptable quality. The scheme is hardware based for both color and monochrome image compression, that can match a high speed communication link, thereby supporting on-line applications.

On Upshifted Reversed Mean Residual Life Order

Recently, the concept of reversed mean residual life order based on the mean of the random variable X t = (t − X | X ≤ t), t > 0, called the reversed residual life, defined for the nonnegative random variable X, has been introduced in the literature. In this paper, a stochastic order based on the shifted version of the reversed mean residual life is proposed, based on the reversed mean residual life function for a random variable X with support (l X , ∞), where l X may be negative infinity, and its properties are studied. Closure under the Poisson shock model and properties for spare allocation are also discussed.

A VLSI architecture for cellular automata based parallel data compression

Analytical study of three neighbourhood two state per cell Cellular Automata (CA) behaviour is a comparatively recent phenomenon. A wide variety of applications have been developed utilizing the elegant structure of group CA. In this paper some of the characterizations of the state transition behaviour of non-group CA are reported. These results are subsequently utilized to develop an efficient parallel scheme for data compression. The experimental results confirms its superiority in terms of compression ratio over UNIX Compress and GZIP packages.

An efficient encoding algorithm for image compression hardware based on cellular automata

Analytical study of three neighbourhood two state per cell Cellular Automata (CA) behaviour is a comparatively recent phenomenon. A wide variety of applications have been developed utilizing the elegant structure of group CA. In this paper some of the characterizations of the state transition behaviour of non-group CA are reported. These results are subsequently utilized to develop an efficient parallel scheme for image compression. The experimental results confirms compression ratio of the CA based scheme is of the same order as that of JPEG coding.

A parallel architecture for video compression

This paper reports a parallel algorithm for compression/decompression of video data files. The algorithm can be easily implemented on a parallel pipelined architecture that can support on-line compression/decompression. The hardware implementing the architecture achieves a throughput of 30 frames per second with frame size of 352/spl times/272 pixels.

An efficient data compression hardware based on cellular automata

Summary form only given. Reports a parallel scheme for text data compression. The scheme utilizes the simple, regular, modular and cascadable structure of cellular automata (CA) with local interconnection structure that ideally suits VLSI technology. The state transition behaviour of a particular class of non-group CA, referred to as TPSA (two predecessor single attractor) CA, has been studied extensively and the results are utilized to develop a parallel scheme for data compression. The state transition diagram of a TPSA CA generates a unique inverted binary tree. This inverted binary tree is a labeled tree whose leaves and internal nodes have a unique pattern generated by the CA in successive cycles. This unique structure can be viewed as a dictionary for text compression. In effect, storage and retrieval of dictionary of conventional data compression techniques get replaced by the autonomous mode operation of the CA that generates the dictionary dynamically with appropriate mapping of dictionary data to CA states wherever necessary.

Study on Posbist Systems

The probability theory, in general, with the help of the dichotomous state develops the theory of reliability. Recently, the fuzzy reliability has been developed based on the concept of possibility distribution and fuzzy-state assumption. In this paper, we derive the possibility distribution function and discuss the properties of a -out-of- () system based on the assumption of the possibility theory and keeping the dichotomous state of the system unchanged when the lifetime distribution is either normal, Cauchy, or exponential. A few results contrary to the conventional reliability theory are obtained.