Dheeraj Kumar

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Internet-of-Things (IoT) is a concept referring to interconnected people and objects and smart city is one of the many applications of IoT. Wireless Sensor Network (WSN) is a specific technology that helps to create “Smart Cities”. It aims at creating a distributed network of intelligent sensor nodes which can measure various parameters for(More)
Clustering of big data has received much attention recently. In this paper, we present a new clusiVAT algorithm and compare it with four other popular data clustering algorithms. Three of the four comparison methods are based on the well known, classical batch k -means model. Specifically, we use k -means, single pass k -means, online k -means, and(More)
Recent algorithmic and computational improvements have reduced the time it takes to build a minimal spanning tree (MST) for big data sets. In this paper we compare single linkage clustering based on MSTs built with the Filter-Kruskal method to the proposed clusiVAT algorithm, which is based on sampling the data, imaging the sample to estimate the number of(More)
This paper proposes a novel application of Visual Assessment of Tendency (VAT)-based hierarchical clustering algorithms (VAT, iVAT, and clusiVAT) for trajectory analysis. We introduce a new clustering based anomaly detection framework named iVAT+ and clusiVAT+ and use it for trajectory anomaly detection. This approach is based on partitioning the(More)
Spin-wave-based devices promise to usher in an era of low-power computing where information is carried by the precession of the electrons' spin instead of dissipative translation of their charge. This potential is, however, undermined by the need for a bias magnetic field, which must remain powered on to maintain an anisotropic device characteristic. Here,(More)
Wireless sensor networks are often deployed in large numbers, over a large geographical region, in order to monitor the phenomena of interest. Sensors used in the sensor networks often suffer from random or systematic errors such as drift and bias. Even if they are calibrated at the time of deployment, they tend to drift as time progresses. Consequently,(More)
Clustering of a large amount of taxi GPS mobility data helps to understand the spatio-temporal dynamics for the applications of urban planning and transportation. In this paper we cluster the origin-destination pairs of the passenger taxi rides to provide useful insight into the city mobility patterns, urban hot-spots, road network usage and general(More)
Stroke is a major reason for physical immobility and death. For effective treatment of stroke, early diagnosis and aggressive medication in the form of thrombolytic drugs is shown to be essential. In order to provide proper care, the patient should be kept under continuous monitoring during the first few hours after subjecting thrombolytic drugs and based(More)