Research Statement [ pdf | ps ]
``Modular Software Upgrades for Distributed Systems''
by Sameer Ajmani, Barbara Liskov, and Liuba Shrira.
In European Conference on Object-Oriented Programming (ECOOP), July 2006.
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``Automatic Software Upgrades for Distributed Systems''
by Sameer Ajmani.
Ph.D. dissertation, MIT, Sep. 2004. Also as Technical Report MIT-LCS-TR-1012.
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``Automatic Software Upgrades for Distributed Systems''
by Sameer Ajmani, Barbara Liskov, and Liuba Shrira.
Oct. 2003. Poster presented at the ACM Symposium on Operating Systems Principles (SOSP 19).
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``Scheduling and Simulation: How to Upgrade Distributed Systems''
by Sameer Ajmani, Barbara Liskov, and Liuba Shrira.
In Ninth Workshop on Hot Topics in Operating Systems (HotOS-IX), (Lihue, Hawaii), May 2003, pp. 43-48.
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``Automatic Software Upgrades for Distributed Systems''
by Sameer Ajmani.
Apr. 2003. Ph.D. thesis proposal.
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``The Time Course of Information Integration in Sentence Processing''
by M. Spivey, S. Fitneva, W. Tabor, and S. Ajmani.
In The Lexical Basis of Sentence Processing: Formal, Computational, and Experimental Issues, (P. Merlo and S. Stevenson, eds.), 2002, pp. 207-232.
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``Distributed System Upgrade Scenarios''
by Sameer Ajmani.
Oct. 2002.
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``A Review of Software Upgrade Techniques for Distributed Systems''
by Sameer Ajmani.
Aug. 2002.
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``How to Resolve SDSI Names Without Closure''
by Sameer Ajmani.
June 2002.
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``ConChord: Cooperative SDSI Certificate Storage and Name Resolution''
by Sameer Ajmani, Dwaine E. Clarke, Chuang-Hue Moh, and Steven Richman.
In First International Workshop on Peer-to-Peer Systems (IPTPS), Mar. 2002, pp. 141-154.
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``A Trusted Third-Party Computation Service''
by Sameer Ajmani, Robert Morris, and Barbara Liskov.
MIT technical report MIT-LCS-TR-847, May 2001.
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``A Trusted Execution Platform for Multiparty Computation''
by Sameer Ajmani.
Masters thesis, MIT, Sep. 2000. Also available as MIT technical report MIT-LCS-TR-846.
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Software Engineering TA
MIT Computer Science Teaching Assistant for Professor Srinivasan
Devadas, Fall 2003
TA for 6.170, MIT's undergraduate software engineering course. Taught
weekly section of 16 students. Maintained autograder software.
Pluggable Web Authentication
ArsDigita, Inc., Summer 2001
Designed and implemented Pluggable Authentication Modules (PAMs) for the
ArsDigita Community System. Using the Java Authentication and Authorization
API (JAAS), provided cookie-based and cookie-less web authentication
support.
Software Engineering TA
MIT Computer Science Teaching Assistant for Professor Michael Ernst,
Spring 2001
TA for 6.170, MIT's undergraduate software engineering course. Taught
weekly section of 20 students. Developed autograder software (in Java and
Python) that automatically evaluates student assignments using a
staff-provided test suite.
Content Distribution Networks
Cisco, Inc., Summer and Fall, 2000
With Barbara Liskov, wrote authoritative system architecture document for
Cisco's Content Distribution Network (CDN) software. Designed protocol to
automatically configure Arrowpoint Content Switches for use in the CDN.
Enabled support for automatic failover between content cache replicas.
Thor Network File System
MIT Computer Science Research with Miguel Castro, Fall 1998
Optimized representation of files in an object-oriented database. Tested
system correctness and performance against standard file-system benchmarks.
Thor Home Page
Classifying Instruments by Waveforms
MIT Computer Science Graduate Coursework, Fall 1998
Developed technique for normalizing waveforms against pitch and
amplitude. Used multiple machine learning techniques and neural network
designs to classify instruments from waveform samples. Demonstrated
normalization improved classification performance.
Online Logging and Filtering of Data Streams
Teradyne, Inc., Summer 1998
Extended the system for logging and filtering streams of test
results. Enhanced GUI to support the composition of test filters.
Adaptive Failure Detector for Distributed Systems
Cornell University Computer Science Research
with Professor Sam Toueg and Sebastian Silgardo, Spring 1998
Designed and implemented an adaptive failure detector for distributed
systems. Failure detector monitors keepalives from nodes in the system and
adaptively adjusts its timeouts to account for network variability. Failure
detector is "unreliable": may believe a live node is dead for a finite time.
System allows nodes to execute distributed algorithms, such as consensus, in
an asynchronous system.
Failure Detection Papers by Sam Toueg
Automatic Collage Generation (Constrained Bin Packing)
Cornell University Computer Science Undergraduate Coursework
with Kelly Mayoros, Spring 1998
Developed a system which allows users to "cut out" polygonal segments of
images and add these to a collage. System automatically places new pieces
flush with other pieces using scale, rotation, and translation
transformations. Users may associate costs with transforms to avoid
awkwardly large rotations or scalings. System makes use of a number of
algorithms for making a polygon convex, sorting sets of transformations, and
checking for polygon overlap.
Effect of Cell Phone Use on Simulated Extreme Driving Skill
Cornell University Cognitive Science Undergraduate Coursework, Spring 1998
Designed a simulated "extreme driving" course composed of jersey
barriers on a highway, and studied the effect of cell phone use on
users' simulated driving performance (speed and number of crashes).
Study showed that answering simple questions over a hands-free cell
phone forced users to either slow down or crash.
Implementation of the Domain Name Service Protocol
Cornell University Computer Science Undergraduate Coursework
with Joyce Wang, Fall 1997
Implemented a name server and DNS client according to the RFC
specification. Checked correctness of server implementation against UNIX
nslookup, and checked client against UNIX name daemon.
Serial Protocol Design Language, Compiler, and VM
Teradyne, Inc., with Karl Holland, Summer 1997
Designed language for specifying a restricted set of
industry-specific serial communication protocols. Language allows
simple specification of new protocols. Implemented compiler in C++
using yacc and lex. Compiled program is a set of linked C++ objects; a
"virtual machine" object provides a stack, state variables,
communication links, and limited exception handling. A protocol
compiled into this form can be run over any serial communication medium
which provides appropriate read and write functions.
Fault-tolerant Distributed Web Proxy Cache
Cornell University Computer Science Undergraduate Coursework
with Chad Williams, Spring 1997
Modified the Harvest Object Cache to support dynamic membership in the
cache group. Developed a novel token-ring protocol for detecting and
recovering from failures. System functions correctly over unreliable data
streams.
Normalized Recurrence for Neural Nets and Human Data
Cornell University Psychology Undergraduate Coursework
with Professor Michael Spivey, Spring 1997
Implemented an extended version of Spivey's Normalized Recurrence
algorithm in a neural net. Net simulates human response to ungrammatical
sentences. Various parameters affecting the "response time" of the net
provide insights into the human data and cognitive process.
Run-length De/Compression for PostScript Images
Teradyne, Inc., with Karl Holland, Fall 1996
Developed a run-length compression algorithm for storing images as
PostScript files. Decompression is done in the PostScript stack language so
compressed files may be sent to any PostScript-compatible printer.
Solving Logic Puzzles using the Propositional Calculus
Cornell University Computer Science Research
with David Gries, Spring 1995
Translated logic puzzles from Raymond Smullyan's book What is the
Name of This Book? into Gries' propositional calculus. Demonstrated
that confusing word problems were often easy to solve using propositional
logic.
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