SearcharxivSearch

arXiv subjects

Anirban Mitra

Publications and source records attributed to Anirban Mitra.

3 recordsLinked to original sources

On inference for modularity statistics in structured networks

This paper revisits the classical concept of network modularity and its spectral relaxations used throughout graph data analysis. We formulate and study several modularity statistic variants for which we establish asymptotic distributional results in the large-network limit for networks exhibiting nodal community structure. Our work facilitates testing for network differences and can be used in conjunction with existing theoretical guarantees for stochastic blockmodel random graphs. Our results are enabled by recent advances in the study of low-rank truncations of large network adjacency matrices. We provide confirmatory simulation studies and real data analysis pertaining to the network neuroscience study of psychosis, specifically schizophrenia. Collectively, this paper contributes to the limited existing literature to date on statistical inference for modularity-based network analysis. Supplemental materials for this article are available online.

stat.ME

An O(1) algorithm for implementing the LFU cache eviction scheme

Cache eviction algorithms are used widely in operating systems, databases and other systems that use caches to speed up execution by caching data that is used by the application. There are many policies such as MRU (Most Recently Used), MFU (Most Frequently Used), LRU (Least Recently Used) and LFU (Least Frequently Used) which each have their advantages and drawbacks and are hence used in specific scenarios. By far, the most widely used algorithm is LRU, both for its $O(1)$ speed of operation as well as its close resemblance to the kind of behaviour that is expected by most applications. The LFU algorithm also has behaviour desirable by many real world workloads. However, in many places, the LRU algorithm is is preferred over the LFU algorithm because of its lower run time complexity of $O(1)$ versus $O(\log n)$. We present here an LFU cache eviction algorithm that has a runtime complexity of $O(1)$ for all of its operations, which include insertion, access and deletion(eviction).

cs.DS

Structural and Optical Properties of Pulse Laser Deposited Ag_2O Thin Films

We deposited Ag_2O films in PLD system on glass substrate for a fixed partial oxygen gas pressure (70 mili Torr) with the variation of laser energy from 75 to 215 mJ/Pulse. The XRD patterns confirm that the films have well crystallinity and deposited as hexagonal lattice and the crystalline size increases from 26.38 nm to 27.27 nm. The FESEM images show that the particle size of the films increases from 34.84 nm to 65.83 nm. The composition of the films is analyzed from EDX spectra which show that the percentage of oxygen increases from 41.03% to 48.38% with the increment of laser energy. From the optical characterization, it is observed that the optical band gap appears in the visible optical range in an increasing order from 0.87 to 0.98 eV with the increment of laser energy. Our analysis concludes that the Ag_2O thin films, deposited with these parameters, can be considered as a good absorbent layer for solar photovoltaic application.

physics.chem-ph