Rahul Malik - Academia.edu (original) (raw)
Address: Faridabad, Haryana, India
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A Fiber Optic Pressure Sensor utilizing a Fiber Bragg Grating (FBG) as a sensing element has been... more A Fiber Optic Pressure Sensor utilizing a Fiber Bragg Grating (FBG) as a sensing element has been demonstrated. In the experiment, a broad band LED source with a wavelength range of 1520 nm to 1570 nm was launched into a single mode optical fiber within which the FBG was written. With no applied force, the fiber grating reflects light strongly at a wavelength of 1549.92nm. When the FBG was subjected to a range of forces (from 0.0N to 18.0N), applied perpendicularly to its axis, the reflected light from the FBG was found to be wavelength shifted in proportion to the applied force, but in a non- linear manner. The shift in wavelength is detected using fiber Fabry-Perot interferometric technique. With the FBG embedded in carbon fiber material, the test results showed an excellent linear relationship between the wavelength shift and the applied force (pressure). In addition, force sensing range of up to 60N was obtained with the pressure sensor still remaining in good condition.
High-dimensional indexing has been very popularly used for performing similarity search over vari... more High-dimensional indexing has been very popularly used for performing similarity search over various data types such as multimedia (audio/image/video) databases, document collections, time-series data, sensor data and scientific databases. Because of the curse of dimensionality, it is already known that well-known data structures like kd-tree, R-tree, and M-tree suffer in their performance over high-dimensional data space which is inferior to a brute-force approach linear scan. In this paper, we focus on an approximate nearest neighbor search for two different types of queries: r-Range search and k-NN search. Adapting a novel concept of a ring structure, we define a new index structure MLR-Index (Multi-Layer Ring-based Index) in a metric space and propose time and space efficient algorithms with high accuracy. Evaluations through comprehensive experiments comparing with the best-known high-dimensional indexing method LSH show that our approach is faster for a similar accuracy, and shows higher accuracy for a similar response time than LSH.
International Journal of Adaptive, Resilient and Autonomic Systems, 2011
Abstract In this paper we present (1) EDFS, a simple and semi-centralized efficient distributed f... more Abstract In this paper we present (1) EDFS, a simple and semi-centralized efficient distributed file system (for cloud computing environments) and (2) a load balancing and resource sharing scheme for EDFS. EDFS uses a central front-end server only to distribute keys (hashed filenames or indices) to Namenodes. Each Namenode is then responsible for holding the corresponding file (directory) information such as the i-node (metadata) and pointers to where each block of the file is stored in the cloud. Each node is also ...
A Fiber Optic Pressure Sensor utilizing a Fiber Bragg Grating (FBG) as a sensing element has been... more A Fiber Optic Pressure Sensor utilizing a Fiber Bragg Grating (FBG) as a sensing element has been demonstrated. In the experiment, a broad band LED source with a wavelength range of 1520 nm to 1570 nm was launched into a single mode optical fiber within which the FBG was written. With no applied force, the fiber grating reflects light strongly at a wavelength of 1549.92nm. When the FBG was subjected to a range of forces (from 0.0N to 18.0N), applied perpendicularly to its axis, the reflected light from the FBG was found to be wavelength shifted in proportion to the applied force, but in a non- linear manner. The shift in wavelength is detected using fiber Fabry-Perot interferometric technique. With the FBG embedded in carbon fiber material, the test results showed an excellent linear relationship between the wavelength shift and the applied force (pressure). In addition, force sensing range of up to 60N was obtained with the pressure sensor still remaining in good condition.
High-dimensional indexing has been very popularly used for performing similarity search over vari... more High-dimensional indexing has been very popularly used for performing similarity search over various data types such as multimedia (audio/image/video) databases, document collections, time-series data, sensor data and scientific databases. Because of the curse of dimensionality, it is already known that well-known data structures like kd-tree, R-tree, and M-tree suffer in their performance over high-dimensional data space which is inferior to a brute-force approach linear scan. In this paper, we focus on an approximate nearest neighbor search for two different types of queries: r-Range search and k-NN search. Adapting a novel concept of a ring structure, we define a new index structure MLR-Index (Multi-Layer Ring-based Index) in a metric space and propose time and space efficient algorithms with high accuracy. Evaluations through comprehensive experiments comparing with the best-known high-dimensional indexing method LSH show that our approach is faster for a similar accuracy, and shows higher accuracy for a similar response time than LSH.
International Journal of Adaptive, Resilient and Autonomic Systems, 2011
Abstract In this paper we present (1) EDFS, a simple and semi-centralized efficient distributed f... more Abstract In this paper we present (1) EDFS, a simple and semi-centralized efficient distributed file system (for cloud computing environments) and (2) a load balancing and resource sharing scheme for EDFS. EDFS uses a central front-end server only to distribute keys (hashed filenames or indices) to Namenodes. Each Namenode is then responsible for holding the corresponding file (directory) information such as the i-node (metadata) and pointers to where each block of the file is stored in the cloud. Each node is also ...