Sumeet Kumar | Massachusetts Institute of Technology (MIT) (original) (raw)

Papers by Sumeet Kumar

2013 IEEE International Conference on Services Computing, 2013

The Internet of Things (IoT) offers the promise of integrating the digital world of the Internet ... more The Internet of Things (IoT) offers the promise of integrating the digital world of the Internet with the physical world in which we live. But realizing this promise necessitates a systematic approach to integrating the sensors, actuators, and information on which they operate into the Internet we know today. This paper reports the design and development of an open community-oriented platform aiming to support federated sensor data as a service, featuring interoperability and reusability of heterogeneous sensor data and data services. The concepts of virtual sensors and virtual devices are identified as central autonomic units to model scalable and context-aware configurable/reconfigurable sensor data and services. The decoupling of the storage and management of sensor data and platform-oriented metadata enables the handling of both discrete and streaming sensor data. A cloud computing-empowered prototyping system has been established as a proof of concept to host smart community-oriented sensor data and services.

IEEE Sensors Journal, 2016

We present a system for collecting and analyzing information on street lighting infrastructure. W... more We present a system for collecting and analyzing information on street lighting infrastructure. We develop a carmounted sensor platform that enables collection and logging of data on street lights during night-time drive-bys. We address several signal processing problems that are key to mapping street illumination levels, identifying street lamps, estimating their heights, and geotagging them. Specifically, we highlight an image recognition algorithm to identify street lamps from the video data collected by the sensor platform and its subsequent use in estimating the heights of street lamps. We also outline a framework to improve vehicle location estimates by combining sensor observations in an extended Kalman filter framework. Our eventual goal is to develop a semi-live virtual 3-D street lighting model at urban scale that enables citizens and decision makers to assess and optimize performance of nighttime street lighting.

Acoustic emissions can be sensed to identify and localize leaks in water pipes. Leak noise correl... more Acoustic emissions can be sensed to identify and localize leaks in water pipes. Leak noise correlators and listening devices have been reported in literature as successful approaches to leak detection but they have practical limitations in terms of cost, sensitivity, reliability and scalability. A possible efficient solution is the development of an in-pipe traveling leak detection system. It has been reported that in-pipe sensing is more accurate and efficient since the sensing element can be very close to the sound source. Currently in-pipe approaches are limited to large leaks and larger diameter pipes. Development of such a system requires clear understanding of acoustic signals generated from leaks and their variation with different pipe loading conditions, leak sizes and surrounding media. This paper discusses the acoustic characterization of leak signals in controlled environments. A lab experimental setup was designed and built in which measurements were taken from inside 4 ...

2011 8th International Conference & Expo on Emerging Technologies for a Smarter World, 2011

Advances in many areas of sensing technologies and the widespread use and greater accuracy of glo... more Advances in many areas of sensing technologies and the widespread use and greater accuracy of global positioning systems offer the prospect of improving agricultural productivity through the intensive use of data. By nature, agriculture is a spatial science characterized by significant variability in terms of yield and concentration of pests and plant diseases. Consequently, precision agriculture seeks to improve the effectiveness of various types of sensing information to give the grower more data and the ability to design the specific treatments for site-specific management of inputs and outputs. The intensive use of data in agriculture is at a relatively early stage and there remains much opportunity to refine modeling approaches and to build information infrastructure. With the overall goal of optimizing inputs to achieve the maximum output in terms of yield, this paper focuses on the application of a clustering algorithm to field data with the goal to identify management zones. We employ two sets of attributes, first yield and second field properties like slope and electrical conductivity to delineate the management zones. By definition, a management zone is a contiguous area defined by one or more features and may take on many different shapes. Building on the established machine learning approach of k-means clustering, we successfully identify a near optimal number of management zones for a cotton field.

IEEE Transactions on Signal Processing, 2000

We introduce an iterative linear estimator (ILE) for estimating a signal from samples having loca... more We introduce an iterative linear estimator (ILE) for estimating a signal from samples having location errors and additive noise. We assume that the signals lie in the span of a finite basis and the location errors and noise are mutually independent and normally distributed. The parameter estimation problem is formulated as obtaining a maximum likelihood (ML) estimate given the observations and an observation model. Using a linearized observation model we derive an approximation to the likelihood function. We then adopt an iterative strategy to develop a computationally efficient estimator, which captures the first order effect of sample location errors on signal estimation. Through numerical simulations we establish the efficacy of the proposed estimator for one-dimensional and two-dimensional parametric signals, comparing the mean squared estimation error against a basic linear estimator. We develop a numerical approximation of the Cramér-Rao lower bound (CRB) and the Expectation-Maximization (EM) algorithm, and for a onedimensional signal compare our algorithm against them. We show that for high location error variance and small noise variance the mean squared error (MSE) with ILE is significantly lower when compared to the baseline linear estimator. When compared to EM, our algorithm provides comparable MSE with a significant reduction in computational time.

Robust, low-cost mobile sensing enables effective monitoring and management of urban environment ... more Robust, low-cost mobile sensing enables effective monitoring and management of urban environment and infrastructure which contributes towards a sustainable future. While mobile sensor systems have attracted significant attention in recent years, a large scale deployment for urban infrastructure monitoring poses many research challenges. One fundamental challenge is dealing with noisy and uncontrolled samples stemming from both noisy sensor measurements and locations, and lack of control on sensor deployment. Such conditions pose difficulties in field estimation and “hot spot” identification from sensor data. My thesis contributions aim to bridge this gap. In this thesis, I designed and developed a mobile sensor system for urban light infrastructure monitoring and studied two problems on field estimation in the presence of noisy and uncontrolled samples with general implications on mobile sensing. As an example system, I designed and successfully tested a city-wide street light scann...

We evaluate the integration of on-board diagnostics (OBD) speed measurements with sparse and/or m... more We evaluate the integration of on-board diagnostics (OBD) speed measurements with sparse and/or missing GPS data for vehicle trajectory estimation using an extended Kalman filter. The suggested framework is relevant to the deployment of low-power, low-cost GPS receivers in the context of mobile and pervasive sensing. Our algorithm is capable of handling sensors at different sampling rates and comprises an accelerometer error model that significantly improves trajectory estimation. Based on field data, we evaluate its performance by simulating deliberately reduced GPS sampling rates, random GPS outages, and varying base sampling rates of the Kalman filter estimation loop. We achieve robust performance in estimating the driven distance and a vehicle trajectory with GPS data downsampled from 10 Hz to 0.02 Hz. We also demonstrate that for random GPS omissions of up to two thirds of the samples, the root mean squared error of position estimates is less than 4 m with GPS data downsampled ...

International Journal of Thermal Sciences

Although microﬂuidics has demonstrated the ability to scale down and automate many laboratory pro... more Although microﬂuidics has demonstrated the ability to scale down and automate many laboratory protocols, a fundamental understanding of the underlying device physics is ultimately critical to design robust devices that can be transitioned from the benchtop to commercial products. For example, the miniaturization of many laboratory protocols such as cell culture and thermocycling requires precise thermal management. As device complexity scales up to include integrated electrical components, including heating elements, thermal chip modeling becomes an increasingly important part of the design process. In this paper, a computationally efﬁcient, three-dimensional thermal ﬂuidic modeling approach is presented to study the heat transport characteristics of a continuous ﬂow microﬂuidic thermocycler for polymerase chain reaction (PCR). A two-step simulation model is developed, consisting of a solid domain modeling of the entire microﬂuidic chip that examines thermal crosstalk due to lateral...

Heat Transfer Engineering

Recent advances in nanotechnology, chemical/physical texturing and thin film coating technology g... more Recent advances in nanotechnology, chemical/physical texturing and thin film coating technology generate definite possibilities for sustaining a dropwise mode of condensation for much longer durations than was previously possible. The availability of superior experimental techniques also leads to deeper understanding of the process parameters controlling the relevant transport phenomena, the distinguishing feature of which is the involvement of a hierarchy of length/time scales, proceeding from nuclei formation, to clusters, all the way to macroscopic droplet ensemble, drop coalescence, and subsequent dynamics. This paper is an attempt to connect and present a holistic framework of modeling and studying dropwise condensation at these multiple scales. After a review of the literature, discussions on the following problems are presented: (i) atomistic modeling of nucleation; (ii) droplet–substrate interaction; (iii) surface preparation; (iv) simulation of fluid motion inside sliding d...

This paper presents a low-cost, fully passive UHF RFID light sensor. We demonstrate how our desig... more This paper presents a low-cost, fully passive UHF RFID light sensor. We demonstrate how our design makes use of off-the-shelf photoresistors and LC components to establish a power frequency dependence which is used for improved sensor precision. Preliminary results show we can successfully identify 4 light intensity states between 0 to 1000 lux.

Proceedings of the American Control Conference

Today's wireless sensor nodes can be easily attached to mobile platforms such as robots, cars... more Today's wireless sensor nodes can be easily attached to mobile platforms such as robots, cars and cell phones enabling pervasive sensing of physical fields (say of temperature, vibrations, air quality and chemicals). We address the sensor arrangement problem, i.e. when and where sensors should take samples to obtain a good estimate of a field using mobile sensors. In particular, we focus on incidentally mobile sensors that move passively under the influence of the environment (e.g. sensors attached to floating buoys, cars and smartphones carried by humans). We model the field as a linear combination of known basis functions. Given the samples, we use a linear estimator to find unknown coefficients of the basis functions. We formulate the sensor arrangement problem as one of finding suitably characterized classes of sensor arrangements that lead to a stable reconstruction of the field. We consider a family of multidimensional #x03B4;-dense sensor arrangements, where any square di...

Heat Transfer: Volume 3, 2008

Polymerase Chain Reaction (PCR) is a molecular biological method for the in vitro amplification o... more Polymerase Chain Reaction (PCR) is a molecular biological method for the in vitro amplification of nucleic acid molecules which has wide applications in the area of genetics, medicine and biochemistry. The typical three step PCR cycle consists of heating the sample to 90-94 ºC to denature doublestranded DNA, cooling down to 50-54 ºC to anneal the specific primers to the single stranded DNA and finally increasing the temperature to 70-75 ºC for extension of the primers with thermostable DNA polymerase. The temperature sensitivity of the reaction requires precise temperature control and proper thermal isolation of these three zones. In this paper we present the design of a continuous flow PCR microfluidic device with the channels fabricated in (poly) dimethylsiloxane (PDMS) and thin film Platinum Resistance Temperature Detector (RTD) elements fabricated on glass substrate to define the three different temperature zones. The fluidic arrangement has a water jacket layer to minimize evaporation from the porous PDMS walls. A detailed thermo fluidic model of the device is presented to predict the performance and efficacy of the proposed design. Numerical simulations are carried out to find the temperature distribution and temperature gradients in the device and a parametric study is done by varying flow rate, heat flux and channel dimensions in order to optimize the design for achieving temperature isolation and sharp temperature gradients between different zones.

Powder Technology, 2013

Lubricants improve the flow of metal powders, reduce friction and extend tool life during the die... more Lubricants improve the flow of metal powders, reduce friction and extend tool life during the die compaction process. Fe-2%Cu-0.5%C powders mixed with various amounts (0-0.8 wt.%) of ethylene-bis-stearamide (EBS) were used to determine the effects of lubricant amount on several green properties of the die-compacted parts in the present study. The green density and green strength for the powder mixed with various amounts of EBS increased with increase in compaction pressure. The effect of lubricant on the green density was found to be marginal at high compaction pressures. The green strength however decreased with the addition of EBS. Regression analysis was carried out to evaluate the applicability of existing models to predict the green strength as well as the compression behavior of the powder mixtures. The green strength models developed by Kawakita, Halldin et al., and German showed reasonable applicability for predicting the strength of compacted powders with varying amounts of EBS. The compression models developed by Kawakita, Heckel and Panelli-Ambrosio Filho were suitable for correlating the variation of compressibility of the powders with increasing amounts of EBS. The compressibility of the powders increased with an increase in the amount of EBS. In situ compression curves were experimentally obtained to determine the compressibility of powders as a function of increasing compaction pressure. The compressibility curves for powder with varying amounts of EBS were fitted to a power law equation. The ejection forces were found to be sensitive to the dimensions of the part as well as the amount of EBS. A new model was developed to estimate the ejection force based on the part dimensions and amount of EBS. The models showed a reasonable agreement with the experimental data. It is anticipated that the models evaluated in the present study will be useful in identifying appropriate amounts of lubricants required to optimize various green properties in die compaction components.

Heat Transfer Engineering, 2012