arXiv subjects

Arindam Karmakar

Publications and source records attributed to Arindam Karmakar.

5 recordsLinked to original sources

arXiv2026

NI-ORCA: A Parallel Algorithm for Counting the Orbits of Non-Induced Graphlets up to K4

Counting the orbits of graphlets in a network is a vital tool for understanding the structural roles of vertices in various graph analytics tasks. While existing algorithms efficiently compute orbits of induced graphlets, many real-world applications require non-induced orbit counts. However, no current method offers exact, scalable, and parallel support for non-induced orbit counting. This paper presents NI-ORCA, a parallel algorithm to efficiently compute the orbits of non-induced graphlets up to size four (4-clique). NI-ORCA extends the ORCA framework for non-induced orbit counting by reformulating a system of linear equations. The algorithm consists of three stages: triangle counting, 4-clique enumeration, and orbit solving. We design and implement stage-specific parallelisation strategies using thread and vertex-local memory models and data structures, minimising contention and balancing workload. We further analyse the impact of scheduling policies, chunk sizes, and affinity strategies on performance. Experimental analysis on eight real-world datasets and a series of synthetic Erddos-Renyi graphs demonstrates that a mixed mode combining stage-specific data structure, with dynamic scheduling with small chunk sizes, delivers consistent speedup and effective load balancing. Our results show that NI-ORCA significantly outperforms state-of-the-art sequential algorithms, achieving up to 30x speedups.

cs.DC↗

arXiv2019

Computation of Spatial Skyline Points

We discuss a method of finding skyline or non-dominated sites in a set $P$ of $n$ point sites with respect to a set $S$ of $m$ points. A site $p \in P$ is non-dominated if and only if for each $q \in P \setminus \{p\}$, there exists at least one point $s \in S$ that is closer to $p$ than to $q$. We reduce this problem of determining non-dominated sites to the problem of finding sites that have non-empty cells in an additively weighted Voronoi diagram under a convex distance function. The weights of said Voronoi diagram are derived from the coordinates of the sites of $P$, while the convex distance function is derived from $S$. In the two-dimensional plane, this reduction gives an $O((n + m) \log (n + m))$-time algorithm to find the non-dominated points.

cs.CG↗

arXiv2016

Problems on One Way Road Networks

Let $OWRN = \left\langle W_x,W_y \right\rangle$ be a One Way Road Network where $W_x$ and $W_y$ are the sets of directed horizontal and vertical roads respectively. $OWRN$ can be considered as a variation of directed grid graph. The intersections of the horizontal and vertical roads are the vertices of $OWRN$ and any two consecutive vertices on a road are connected by an edge. In this work, we analyze the problem of collision free traffic configuration in a $OWRN$. A traffic configuration is a two-tuple $TC=\left\langle OWRN, C\right\rangle$, where $C$ is a set of cars travelling on a pre-defined path. We prove that finding a maximum cardinality subset $C_{sub}\subseteq C$ such that $TC=\left\langle OWRN, C_{sub}\right\rangle$ is collision-free, is NP-hard. Lastly we investigate the properties of connectedness, shortest paths in a $OWRN$.

cs.CG↗

arXiv2014

Designing Path Planning Algorithms for Mobile Anchor towards Range-Free Localization

Localization is one of the most important factor in wireless sensor networks as many applications demand position information of sensors. Recently there is an increasing interest on the use of mobile anchors for localizing sensors. Most of the works available in the literature either looks into the aspect of reducing path length of mobile anchor or tries to increase localization accuracy. The challenge is to design a movement strategy for a mobile anchor that reduces path length while meeting the requirements of a good range-free localization technique. In this paper we propose two cost-effective movement strategies i.e., path planning for a mobile anchor so that localization can be done using the localization scheme \cite{Lee2009}. In one strategy we use a hexagonal movement pattern for the mobile anchor to localize all sensors inside a bounded rectangular region with lesser movement compared to the existing works in literature. In other strategy we consider a connected network in an unbounded region where the mobile anchor moves in the hexagonal pattern to localize the sensors. In this approach, we guarantee localization of all sensors within $r/2$ error-bound where $r$ is the communication range of the mobile anchor and sensors. Our simulation results support theoretical results along with localization accuracy.

cs.DC↗

arXiv2014

Analysis of IEEE 802.15.4 MAC under low duty cycle

In this Letter, a discrete-time Markov Chain model is developed to study performance of IEEE 802.15.4 under low duty cycle. The performance is measured in terms of aggregate throughput and average power consumption per packet. The proposed analytical model is verified through ns2 simulations.

cs.NI↗