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Texture in high-resolution satellite images requires substantial amendment in the conventional segmentation algorithms. A measure is proposed to compute the Hölder exponent (HE) to assess the roughness or smoothness around each pixel of the image. The localized singularity information is incorporated in computing the HE. An optimum window size is evaluated so that HE reacts to localized singularity. A two-step iterative procedure for clustering the transformed HE image is adapted to identify the range of HE, densely occupied in the kernel and to partition Hölder exponents into a cluster that matches with the range. Hölder exponent values (noise or not associated with the other cluster) are clubbed to a nearest possible cluster using the local maximum likelihood analysis.

In this paper we propose a QoS-based routing algorithm for dynamic multicasting. The complexity of the problem can be reduced to a simple shortest path problem by applying a Weighted Fair Queuing (WFQ) service discipline. Using a modified Bellman-Ford algorithm, the proposed routing builds a multicast tree, where a node is added to the existing multicast tree without re-routing and satisfying QoS constraints. With user defined life-time of connection this heuristic algorthm builds multicast tree which is near optimum over the whole duration of session. Simulation results show that tree costs are nearly as good as other dynamic multicast routings that does not consider QoS.

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Device discovery and connection establishment are fundamental to communication between two Bluetooth (BT) devices. In this paper, we give an analytical model of the time it takes for the master in a piconet to discover one slave. We show that, even in the absence of packet interference, the discovery time can be long in some instances. We have simulated the discovery protocol by actually implementing it to validate the analytical model. By means of simulations, we show how discovery time is affected by (i) the presence of multiple potential slaves, and (ii) changes in the maximum backoff limit. Using simulation studies we observed the effectiveness of two proposed improvements to device discovery, namely, (i) avoiding repetitions of the A and B trains before a train switch, and (ii) eliminating the idea of random backoff, or reducing the backoff limit. We show that discovery time can be reduced by avoiding repetitions of the A and B trains before a train switch. However, complete elimination of the random backoff is not a good idea, as discovery time will be too long when the number of BT devices is large. Instead, choosing a small backoff limit of 250-300 slots is highly effective in reducing discovery time even in the presence of a large number (say, 50) of potential slaves.

This paper conducts tests of the export-led growth and the import-compression hypotheses for four less developed countries (LDCs) ± India, Nigeria, Fiji and Papua New Guinea (PNG). Based on Johansen's multiple cointegration test preceded by unit root tests, we test for cointegration between real output, exports and imports. Non-rejection of cointegration between the variables excludes the possibility of Granger non-causality and suggests at least one way Granger causality. Real output, exports and imports are found to be cointegrated in two of the countries and the resulting errorcorrection models suggest that Granger causality runs from exports and imports to real output in these cases. Exogeneity tests are conducted for exports with respect to real output. However, while the assumption of weak exogeneity is validated in two of the countries, the null hypothesis of super exogeneity is rejected. The test results therefore cast doubts on policy recommendations for the LDCs based on the export-led growth hypothesis.