459 research outputs found

    INDIAN MERCHANTS AS DEPICTED IN THE 17TH CENTURY EUROPEAN TRAVELOGUES

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    Merchants and mercantile communities have been an important part of the Indian commercial economy since ancient times. Wealthy and resourceful merchants were a characteristic feature of the Indian economy during the Mughal period as well. They easily caught the attention of the foreigners who visited India. In this paper a mild attempt has been made to explore the world of the Indian Bania through the lens of the European sources. The paper not only highlights the commercial aspects and activities of the Bania’s  and their arithmetic skills for which they were famous throughout the commercial world but also looks at some of the other important aspects of the Bani’a life as well. There is a brief discussion about the philanthropic activities of the Bania’s. The paper also provides a concise discussion about the position of the Bania’s in the prevailing social structure of India. We also get a sketchy idea about the contemporary European view about the Indian society and economy. &nbsp

    Fault-Tolerant Load Management for Real-Time Distributed Computer Systems

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    This paper presents a fault-tolerant scheme applicable to any decentralized load balancing algorithms used in soft real-time distributed systems. Using the theory of distance-transitive graphs for representing topologies of these systems, the proposed strategy partitions these systems into independent symmetric regions (spheres) centered at some control points. These central points, called fault-control points, provide a two-level task redundancy and efficiently re-distribute the load of failed nodes within their spheres. Using the algebraic characteristics of these topologies, it is shown that the identification of spheres and fault-control points is, in general, is an NP-complete problem. An efficient solution for this problem is presented by making an exclusive use of a combinatorial structure known as the Hadamard matrix. Assuming a realistic failure-repair system environment, the performance of the proposed strategy has been evaluated and compared with no fault environment, through an extensive and detailed simulation. For our fault-tolerant strategy, we propose two measures of goodness, namely, the percentage of re-scheduled tasks which meet their deadlines and the overhead incurred for fault management. It is shown that using the proposed strategy, up to 80% of the tasks can still meet their deadlines. The proposed strategy is general enough to be applicable to many networks, belonging to a number of families of distance transitive graphs. Through simulation, we have analyzed the sensitivity of this strategy to various system parameters and have shown that the performance degradation due to failures does not depend on these parameter. Also, the probability of a task being lost altogether due to multiple failures has been shown to be extremely low

    Novel surface-enhanced raman scattering substrate based on functionalized silicon nanowires

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    This study reports synthesis of a new Surface-Enhanced Raman Scattering (SERS) substrate using Silicon nanowires (SiNW’s) arrays, produced through chemical etching, and functionalized by tailoring their surface chemistry with nitrogen containing groups. From SEM characterization, phenomenon of micro channel formation, porosity and amorphous nature for the as prepared SiNWs was observed. Photoluminescence (PL) spectrum showed that these nanowires have broad emission band in the range of 500-900 nm. Also, change in the surface chemistry of Si nanowires after nitrogen treatment was observed by elemental analysis, EDX and X-ray photoelectron spectroscopy. The data showed that raising the modification temperature also increased the nitrogen content. At high temperature, pyridine and aromatic amines were the dominant functional groups while a small amount of quaternary nitrogen and protonated amide were also present. Methylene blue (MB) was used as a probe molecule to investigate SERS activities of functionalized SiNWs. The enhancement factor was estimated to be 107-109. Interaction of nitrogen containing groups on the surface of SiNWs with MB molecules resulted in high adsorption of MB on the substrate and higher signal detection by SERS

    Semi-Distributed Load Balancing for Massively Parallel Multicomputer Systems

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    This paper presents a semi-distributed approach, for load balancing in large parallel and distributed systems, which is different from the conventional centralized and fully distributed approaches. The proposed strategy uses a two-level hierarchical control by partitioning the interconnection structure of a distributed or multiprocessor system into independent symmetric regions (spheres) centered at some control points. The central points, called schedulers, optimally schedule tasks within their spheres and maintain state information with low overhead. We consider interconnection structures belonging to a number of families of distance transitive graphs for evaluation, and using their algebraic characteristics, show that identification of spheres and their scheduling points is, in general, an NP-complete problem. An efficient solution for this problem is presented by making an exclusive use of a combinatorial structure known as the Hadamard Matrix. Performance of the proposed strategy has been evaluated and compared with an efficient fully distributed strategy, through an extensive simulation study. In addition to yielding high performance in terms of response time and better resource utilization, the proposed strategy incurs less overhead in terms of control messages. It is also shown to be less sensitive to the communication delay of the underlying network

    Modulational instability in binary spin-orbit-coupled Bose-Einstein condensates

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    We study modulation instability (MI) of flat states in two-component spin-orbit-coupled (SOC) Bose-Einstein condensates (BECs) in the framework of coupled Gross-Pitaevskii equations for two components of the pseudospinor wave function. The analysis is performed for equal densities of the components. Effects of the interaction parameters, Rabi coupling, and SOC on the MI are investigated. In particular, the results demonstrate that the SOC strongly alters the commonly known MI (immiscibility) condition, g12>g1g2g_{12} > g_{1} g_{2}, for the binary superfluid with coefficients g1,2g_{1,2} and g12g_{12} of the intra- and interspecies repulsive interactions. In fact, the binary BEC is always subject to the MI under the action of the SOC, which implies that the ground state of the system is plausibly represented by a striped phase
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