I am looking for a machine learning research internship for the summer of 2017.
I am a third-year Computer Science Ph.D. student at Carnegie Mellon University. I work with Zico Kolter on machine learning and optimization and am supported by an NSF graduate research fellowship. My research interests include applying theory and statistics to modeling problems in machine learning and computer vision, particularly in deep learning. I am the author of OpenFace, which is an open source face recognition project that uses deep learning.
|Aug 2014 - Present||
Ph.D. in Computer Science
Carnegie Mellon University
|Aug 2014 - May 2016||
M.S. in Computer Science
Carnegie Mellon University
|Aug 2011 - May 2014||
B.S. in Computer Science
|May 2011||Northside High School (Roanoke, Virginia)|
|Apr 2016 - Present||
Carnegie Mellon University, Prof. Zico Kolter
Machine learning and optimization
|Aug 2014 - Apr 2016||
Carnegie Mellon University, Prof. Mahadev Satyanarayanan
Machine learning, computer vision, and mobile computing
|May 2012 - May 2014||
Virginia Tech, Prof. Jules White
Mobile computing, cyber-physical systems, and security
|Jan 2013 - May 2014||
Virginia Tech, Prof. Layne Watson
Scientific computing, global/stochastic optimization, and bioinformatics
|Nov 2012 - Mar 2014||
Virginia Tech, Prof. Binoy Ravindran
Collapsed Variational Inference for Sum-Product Networks
H. Zhao, T. Adel, G. Gordon, and B. Amos
[C1] [abs] [pdf]
Sum-Product Networks (SPNs) are probabilistic inference machines that admit exact inference in linear time in the size of the network. Existing parameter learning approaches for SPNs are largely based on the maximum likelihood principle and hence are subject to overfitting compared to more Bayesian approaches. Exact Bayesian posterior inference for SPNs is computationally intractable. Both standard variational inference and posterior sampling for SPNs are computationally infeasible even for networks of moderate size due to the large number of local latent variables per instance. In this work, we propose a novel deterministic collapsed variational inference algorithm for SPNs that is computationally efficient, easy to implement and at the same time allows us to incorporate prior information into the optimization formulation. Extensive experiments show a significant improvement in accuracy compared with a maximum likelihood based approach.
Applying machine learning classifiers to dynamic Android malware detection at scale
B. Amos, H. Turner, and J. White
[C2] [abs] [pdf] [code]
The widespread adoption and contextually sensitive nature of smartphone devices has increased concerns over smartphone malware. Machine learning classifiers are a current method for detecting malicious applications on smartphone systems. This paper presents the evaluation of a number of existing classifiers, using a dataset containing thousands of real (i.e. not synthetic) applications. We also present our STREAM framework, which was developed to enable rapid large-scale validation of mobile malware machine learning classifiers.
Privacy mediators: helping IoT cross the chasm
N. Davies, N. Taft, M. Satyanarayanan, S. Clinch, and B. Amos
[W1] [abs] [pdf]
Unease over data privacy will retard consumer acceptance of IoT deployments. The primary source of discomfort is a lack of user control over raw data that is streamed directly from sensors to the cloud. This is a direct consequence of the over-centralization of today’s cloud-based IoT hub designs. We propose a solution that interposes a locally-controlled software component called a privacy mediator on every raw sensor stream. Each mediator is in the same administrative domain as the sensors whose data is being collected, and dynamically enforces the current privacy policies of the owners of the sensors or mobile users within the domain. This solution necessitates a logical point of presence for mediators within the administrative boundaries of each organization. Such points of presence are provided by cloudlets, which are small locally-administered data centers at the edge of the Internet that can support code mobility. The use of cloudlet-based mediators aligns well with natural personal and organizational boundaries of trust and responsibility.
Early Implementation Experience with Wearable Cognitive Assistance Applications
Z. Chen, L. Jiang, W. Hu, K. Ha, B. Amos, P. Pillai, A. Hauptmann, and M. Satyanarayanan
[W2] [abs] [pdf]
A cognitive assistance application combines a wearable device such as Google Glass with cloudlet processing to provide step-by-step guidance on a complex task. In this paper, we focus on user assistance for narrow and well-defined tasks that require specialized knowledge and/or skills. We describe proof-of-concept implementations for four different tasks: assembling 2D Lego models, freehand sketching, playing ping-pong, and recommending context-relevant YouTube tutorials. We then reflect on the difficulties we faced in building these applications, and suggest future research that could simplify the creation of similar applications.
The Case for Offload Shaping
W. Hu, B. Amos, Z. Chen, K. Ha, W. Richter, P. Pillai, B. Gilbert, J. Harkes, and M. Satyanarayanan
[W3] [abs] [pdf]
When offloading computation from a mobile device, we show that it can pay to perform additional on-device work in order to reduce the offloading workload. We call this offload shaping, and demonstrate its application at many different levels of abstraction using a variety of techniques. We show that offload shaping can produce significant reduction in resource demand, with little loss of application-level fidelity
Performance study of Spindle, a web analytics query engine implemented in Spark
B. Amos and D. Tompkins
[W4] [abs] [pdf] [code]
This paper shares our experiences building and benchmarking Spindle as an open source Spark-based web analytics platform. Spindle’s design has been motivated by real-world queries and data requiring concurrent, low latency query execution. We identify a search space of Spark tuning options and study their impact on Spark’s performance. Results from a self-hosted six node cluster with one week of analytics data (13.1GB) indicate tuning options such as proper partitioning can cause a 5x performance improvement.
Global Parameter Estimation for a Eukaryotic Cell Cycle Model in Systems Biology
T. Andrew, B. Amos, D. Easterling, C. Oguz, W. Baumann, J. Tyson, and L. Watson
[W5] [abs] [pdf]
The complicated process by which a yeast cell divides, known as the cell cycle, has been modeled by a system of 26 nonlinear ordinary differential equations (ODEs) with 149 parameters. This model captures the chemical kinetics of the regulatory networks controlling the cell division process in budding yeast cells. Empirical data is discrete and matched against discrete inferences (e.g., whether a particular mutant cell lives or dies) computed from the ODE solution trajectories. The problem of estimating the ODE parameters to best fit the model to the data is a 149-dimensional global optimization problem attacked by the deterministic algorithm VTDIRECT95 and by the nondeterministic algorithms differential evolution, QNSTOP, and simulated annealing, whose performances are compared.
Fortran 95 implementation of QNSTOP for global and stochastic optimization
B. Amos, D. Easterling, L. Watson, B. Castle, M. Trosset, and W. Thacker
SpringSim (HPC) 2014
[W6] [abs] [pdf]
A serial Fortran 95 implementation of the QNSTOP algorithm is presented. QNSTOP is a class of quasi-Newton methods for stochastic optimization with variations for deterministic global optimization. This discussion provides results from testing on various deterministic and stochastic optimization functions.
Edge Analytics in the Internet of Things
M. Satyanarayanan, P. Simoens, Y. Xiao, P. Pillai, Z. Chen, K. Ha, W. Hu, and B. Amos
IEEE Pervasive Computing 2015
[M1] [abs] [pdf]
High-data-rate sensors, such as video cameras, are becoming ubiquitous in the Internet of Things. This article describes GigaSight, an Internet-scale repository of crowd-sourced video content, with strong enforcement of privacy preferences and access controls. The GigaSight architecture is a federated system of VM-based cloudlets that perform video analytics at the edge of the Internet, thus reducing the demand for ingress bandwidth into the cloud. Denaturing, which is an owner-specific reduction in fidelity of video content to preserve privacy, is one form of analytics on cloudlets. Content-based indexing for search is another form of cloudlet-based analytics. This article is part of a special issue on smart spaces.
Bad Parts: Are Our Manufacturing Systems at Risk of Silent Cyberattacks?
H. Turner, J. White, J. Camelio, C. Williams, B. Amos, and R. Parker
IEEE Security & Privacy 2015
[M2] [abs] [pdf]
Recent cyberattacks have highlighted the risk of physical equipment operating outside designed tolerances to produce catastrophic failures. A related threat is cyberattacks that change the design and manufacturing of a machine’s part, such as an automobile brake component, so it no longer functions properly. These risks stem from the lack of cyber-physical models to identify ongoing attacks as well as the lack of rigorous application of known cybersecurity best practices. To protect manufacturing processes in the future, research will be needed on a number of critical cyber-physical manufacturing security topics.
OpenFace: A general-purpose face recognition library with mobile applications
B. Amos, B. Ludwiczuk, and M. Satyanarayanan
[T1] [abs] [pdf] [code]
Cameras are becoming ubiquitous in the Internet of Things (IoT) and can use face recognition technology to improve context. There is a large accuracy gap between today’s publicly available face recognition systems and the state-of-the-art private face recognition systems. This paper presents our OpenFace face recognition library that bridges this accuracy gap. We show that OpenFace provides near-human accuracy on the LFW benchmark and present a new classification benchmark for mobile scenarios. This paper is intended for non-experts interested in using OpenFace and provides a light introduction to the deep neural network techniques we use.
We released OpenFace in October 2015 as an open source library under the Apache 2.0 license. It is available at: http://cmusatyalab.github.io/openface/
Are Cloudlets Necessary?
Y. Gao, W. Hu, K. Ha, B. Amos, P. Pillai, and M. Satyanarayanan
[T2] [abs] [pdf]
We present experimental results from Wi-Fi and 4G LTE networks to validate the intuition that low end-to-end latency of cloud services improves application response time and reduces energy consumption on mobile devices. We focus specifically on computational offloading as a cloud service. Using a wide range of applications, and exploring both pre-partitioned and dynamically partitioned approaches, we demonstrate the importance of low latency for cloud offload services. We show the best performance is achieved by offloading to cloudlets, which are small-scale edge-located data centers. Our results show that cloudlets can improve response times 51% and reduce energy consumption in a mobile device by up to 42% compared to cloud offload.
Adaptive VM handoff across cloudlets
K. Ha, Y. Abe, Z. Chen, W. Hu, B. Amos, P. Pillai, and M. Satyanarayanan
[T3] [abs] [pdf]
Cloudlet offload is a valuable technique for ensuring low end-to-end latency of resource-intensive cloud processing for many emerging mobile applications. This paper examines the impact of user mobility on cloudlet offload, and shows that even modest user mobility can result in significant network degradation. We propose VM handoff as a technique for seamlessly transferring VMencapsulated execution to a more optimal offload site as users move. Our approach can perform handoff in roughly a minute even over limited WANs by adaptively reducing data transferred. We present experimental results to validate our implementation and to demonstrate effectiveness of adaptation to changing network conditions and processing capacity
QNSTOP-QuasiNewton Algorithm for Stochastic Optimization
B. Amos, D. Easterling, L. Watson, W. Thacker, B. Castle, and M. Trosset
[T4] [abs] [pdf]
QNSTOP consists of serial and parallel (OpenMP) Fortran 2003 codes for the quasi-Newton stochastic optimization method of Castle and Trosset. For stochastic problems, convergence theory exists for the particular algorithmic choices and parameter values used in QNSTOP. Both the parallel driver subroutine, which offers several parallel decomposition strategies, and the serial driver subroutine can be used for stochastic optimization or deterministic global optimization, based on an input switch. QNSTOP is particularly effective for “noisy” deterministic problems, using only objective function values. Some performance data for computational systems biology problems is given.
Input-Convex Deep Networks
B. Amos and J. Kolter
ICLR Workshop 2016
Face Recognition for Context Sensitive IoT Systems
B. Amos and M. Satyanarayanan
[P2] [pdf] [code]
|S2016||Distributed Systems (CMU 15-440/640), TA|
|S2013||Software Design and Data Structures (VT CS 2114), TA|
|May 2014 - Aug 2014||Adobe Research, Data Scientist Intern|
|Dec 2013 - Jan 2014||Snowplow Analytics, Software Engineer Intern|
|May 2013 - Aug 2013||Qualcomm, Software Engineer Intern|
|May 2012 - Aug 2012||Phoenix Integration, Software Engineer Intern|
|Jan 2011 - Aug 2011||Sunapsys, Network Administrator Intern|
|2016 - 2019||NSF Graduate Research Fellowship|
|2014||1st Place Undergraduate Senior Capstone Award, Virginia Tech Computer Science|
|2014||David Heilman Research Award, Virginia Tech Computer Science|
|2014||Senior Scholar Award, Virginia Tech Computer Science|
|2014||Honorable Mention, CRA Outstanding Undergraduate Researcher Award|
|2011 - 2014||Awarded eight undergraduate merit scholarships|
Akka, Android SDK/NDK, Caffe, Node.js, NumPy, TensorFlow, Torch7, Pandas, SciPy, scikit-learn, Spark, Spray
|Image Completion with Deep Learning in TensorFlow||August 9, 2016|
|OpenFace 0.2.0: Higher accuracy and halved execution time||January 19, 2016|
|Command Line Music Setup with Python and mpv||July 5, 2014|
Last updated on 2016-08-09