avijit mandal - Academia.edu (original) (raw)

Papers by avijit mandal

Motivated by the classical synchronization problem and emerging applications in bioinformatics, w... more Motivated by the classical synchronization problem and emerging applications in bioinformatics, we study noisy deletion channels in a regime of practical interest: short code length, low decoding complexity and low SNR. Our work is inspired by an important insight from information theory and Markov chains: appropriately parametrized Markov codewords can correct deletions and errors (due to noise) simultaneously. We extend this idea to practice by developing a low complexity decoder for short Markov codes, which displays competitive performance in simulations at low SNRs. Our decoder design combines the sequence prediction capability of recurrent neural networks with the assured performance of maximum a posteriori (MAP) decoders like the BCJR decoder.

DOAJ (DOAJ: Directory of Open Access Journals), 2016

Wegener`s granulomatosis is an autoimmune small vessel necrotising vasculitis associated with bot... more Wegener`s granulomatosis is an autoimmune small vessel necrotising vasculitis associated with both granulomatosis and polyangiitis. While its standard form involves the upper and lower respiratory tracts and kidneys, it may essentially involve any organ. We report a case of a 14 year old girl, admitted with fever, cough, haemoptysis, nose bleeds and following admission developed hoarseness of voice.There was anemia, elevated CRP. Chest X-ray and HRCT chest showed a cavitary consolidation of left upper lobe of the lung. In view of respiratory symptoms, fever, haemoptysis and radiological ndings, the child was started on antitubercular therapy to which she did not respond. Subsequently she developed features of nephtitis and Wegener`s granulomatosis was suspected and conrmed by renal biopsy and positive c-ANCA. She was treated with steroids and cyclophosphamide to which she responded dramatically in our institution. We should suspect Wegener`s granulomatosis in any child presenting with respiratory symptoms, nose bleeds and symptoms of nephritis. Presence of cough, haemoptysis, and fever with obvious consolidation with cavitations may not always be tuberculosis.

In this paper, we describe a static analysis approach to detect potential runtime errors for a pr... more In this paper, we describe a static analysis approach to detect potential runtime errors for a programming language that is used to program industrial robots. The language we deal in this paper is RAPID, a high level programming language for programming ABB industrial robots. The presence of real-time interrupts, exception handlers and complex data-types makes it a difficult language for general purpose static analyzers. The properties of interest include some generic programming errors as well as some domain-specific properties that the robot system must comply with. Generic programming errors include properties like integer overflow, array access out of bounds and division by zero. An example of a domain-specific property is defining boundary limits for robotic arm movement. We have developed a tool to detect these errors successfully in the presence of real-time interrupts.

Software - Practice and Experience, Nov 11, 2022

Newly released robot programming tools have made it feasible for end‐users to program industrial ... more Newly released robot programming tools have made it feasible for end‐users to program industrial robots by combining block‐based languages and lead‐through programming. To use these systems effectively, end‐users, who usually have limited or no programming experience, require training. To train users, tutoring systems are often used for block‐based programming—some even for lead‐through programming—but no tutorial system combines these two types of programming. We present CoBlox Interactive Tutorials (CITs), a novel tutoring approach that teaches how to use both the hardware and software components that comprise a typical end‐user robot programming environment. As users switch between the two programming styles, CITs provide them with extensive scaffolding, give users immediate feedback on missteps, and provide guidance on next steps. To evaluate CITs, we conducted a study with 79 industrial end‐users using a programming environment released by ABB Robotics that compares our approach to training with training videos, the most commonly used training in industry. This study, one of the largest to date on training professional end‐users, found that CIT‐trained users authored more correct programs in less time than video‐trained users. This shows that a tight integration of hardware and software concepts is crucial to training end‐users to program industrial robots.

Software used to monitor and control operations within an automation system is defined using doma... more Software used to monitor and control operations within an automation system is defined using domain-specific languages. Latent errors in the control code, if left undetected, can lead to unexpected system failures compromising the safety and the security of the automation system. Traditional analysis techniques are insufficient to detect such errors as they do not cater specifically to the underlying domain-specific language. However, given the diversity of different automation domains, there is no standard platform for analysis of these languages. This paper proposes a generic static analysis framework for domain-specific languages used in the automation domain. The analysis approach exhaustively detects runtime errors in control code and ensures compliance to good programming practices. These runtime errors and coding violations are checked against abstract syntax trees and control flow graphs derived from the code. Data Flow Analysis (DFA), Abstract interpretation and pattern-based matching techniques are used to identify domain specific errors and coding violations for control languages.

2023 IEEE International Symposium on Information Theory (ISIT)

Monthly Notices of the Royal Astronomical Society: Letters

In this study, we carry out a comprehensive variability analysis of the BL Lac object 4FGL J2202.... more In this study, we carry out a comprehensive variability analysis of the BL Lac object 4FGL J2202.7+4216 detected by the Fermi-LAT, over a period of more than 3 yr, from 2019 April 27 to 2022 August 09. We detect the presence of quasi-periodic fluctuations with a period of ∼100 d with a confidence level exceeding 4σ. We also tentatively detect two other quasi-periodic fluctuations with a period of ∼75 and ∼50 d, which persist over the entire duration of observation. This is the first time such a variability feature pertaining to this source is being reported. We propose that the observed quasi-periodic oscillations may be related to the precession of the blazar jet with a high Lorentz factor or to the motion of a plasma blob through the helical structure of the jet. The harmonicity among the detected periodicities suggests the global p-mode oscillations of the thick disc to be a plausible mechanism as well. For a decisive conclusion on the physical origin of such fluctuation, further...

2023 IEEE International Conference on Pervasive Computing and Communications (PerCom)

Proceedings of the 2023 CHI Conference on Human Factors in Computing Systems

arXiv (Cornell University), Jul 11, 2022

Belief propagation (BP) is a classical algorithm that approximates the marginal distribution asso... more Belief propagation (BP) is a classical algorithm that approximates the marginal distribution associated with a factor graph by passing messages between adjacent nodes in the graph. It gained popularity in the 1990's as a powerful decoding algorithm for LDPC codes. In 2016, Renes introduced a belief propagation with quantum messages (BPQM) and described how it could be used to decode classical codes defined by tree factor graphs that are sent over the classical-quantum pure-state channel. In this work, we propose an extension of BPQM to general binary-input symmetric classical-quantum (BSCQ) channels based on the implementation of a symmetric "paired measurement". While this new paired-measurement BPQM (PMBPQM) approach is suboptimal in general, it provides a concrete BPQM decoder that can be implemented with local operations. Finally, we demonstrate that density evolution can be used to analyze the performance of PMBPQM on tree factor graphs. As an application, we compute noise thresholds for some LDPC codes with BPQM decoding for a class of BSCQ channels.

arXiv (Cornell University), Jan 17, 2023

Facial expressions have been considered a metric reflecting a person's engagement with a task. Wh... more Facial expressions have been considered a metric reflecting a person's engagement with a task. While the evolution of expression detection methods is consequential, the foundation remains mostly on image processing techniques that suffer from occlusion, ambient light, and privacy concerns. In this paper, we propose ExpresSense, a lightweight application for standalone smartphones that relies on near-ultrasound acoustic signals for detecting users' facial expressions. ExpresSense has been tested on different users in lab-scaled and large-scale studies for both posed as well as natural expressions. By achieving a classification accuracy of ≈ 75% over various basic expressions, we discuss the potential of a standalone smartphone to sense expressions through acoustic sensing.

2022 IEEE Information Theory Workshop (ITW)

arXiv (Cornell University), Nov 1, 2022

We consider maximizing the long-term average reward in a single server queue, where the reward ob... more We consider maximizing the long-term average reward in a single server queue, where the reward obtained for a job is a non-increasing function of its sojourn time. The motivation behind this work comes from multiple applications, including quantum information processing and multimedia streaming. We introduce a new service discipline, shortest predicted sojourn time (SPST), which, in simulations, performs better than well-known disciplines. We also present some limited analytical guarantees for this highly intricate problem.

Software: Practice and Experience

2019 IEEE 17th International Conference on Industrial Informatics (INDIN)

In recent times, there has been significant interest in collaborative robots where the tasks perf... more In recent times, there has been significant interest in collaborative robots where the tasks performed by a robot are non-repetitive and complex, and humans and robots share an overlapping workspace. In such a case, the robot controller must necessarily be safety-aware. In this paper, we propose a mechanism to evaluate a robot program and compute a safety score for each action that the robot is about to perform. To this end, we have implemented a code analyzer that examines the robot’s Move instructions and assigns a safety score. A subjective logic based approach is used to compute the safety score for each instruction. We have evaluated the approach through ABB’s RobotStudio® simulator. We simulate two scenarios: First, where two robots share a workspace and second, where a robot moves along a path with an obstacle. The simulations show that using our code analyzer and safety score formalism; it is possible to evaluate the application code for safety and enable avoidance of potentially unsafe behavior.

2022 14th International Conference on COMmunication Systems & NETworkS (COMSNETS), 2022

This paper considers a multiuser downlink scheduling problem with access to the channel state inf... more This paper considers a multiuser downlink scheduling problem with access to the channel state information at the transmitter (CSIT) to minimize the Age-of-Information (AoI) in a non-stationary environment. The non-stationary environment is modelled using a novel adversarial framework. In this setting, we propose a greedy scheduling policy, called MA-CSIT, that takes into account the current channel state information. We establish a finite upper bound on the competitive ratio achieved by the MA-CSIT policy for a small number of users and show that the proposed policy has a better performance guarantee than a recently proposed greedy scheduler that operates without CSIT. In particular, we show that access to the additional channel state information improves the competitive ratio from 8 to 2 in the two-user case and from 18 to 8 /3 in the three-user case. Finally, we carry out extensive numerical simulations to quantify the advantage of knowing CSIT in order to minimize the Age-of-Information for an arbitrary number of users.

2018 International Symposium on Devices, Circuits and Systems (ISDCS), 2018

CCD is one of the important components in digital imaging. In this paper we analyzed the Charged ... more CCD is one of the important components in digital imaging. In this paper we analyzed the Charged Coupled Device (CCD) which is going to be used in a LASER INDUCED BREAKDOWN SPECTROGRAPHY (LIBS). Here this LIBS instrument is used for getting the knowledge of the soil mineral composition in agricultural purposes. We provide a total android device controlled platform to drive the total system. Now the main impediment in LIBS is that CCD is driven by FPGA. If we want to optimize the cost we must avoid the FPGA. So we drove the CCD is by ARM Microcontroller that is used in ARDUINO due Board. In this paper for the very first time we present a method to drive TCD1201D CCD image sensor with ARM based microcontroller and also incorporated method of control by android device. Now to drive that CCD we need 6 clock signals (SH, ICG, PHI1, PHI2, RS, BT) that will give the output OS & DOS. We gave the 2 outputs to a difference amplifier whose output is now fed to the OP484 for amplification. The ...

2017 IEEE International Symposium on Software Reliability Engineering Workshops (ISSREW), 2017