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Ashish SabharwalResearch Associate |
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| Links : | Software | Book Chapters | Conference Publications | Journal Articles | Other Work | Tutorials | Non-Academic |
| Curriculum Vitae | : | pdf (extended version) (please click here for shorter CV and further information) |
| Education | : |
2005 - 2008 Postdoctoral Associate in Computer Science,
Cornell University
1998 - 2005 Ph.D. and M.S. at the University of Washington (UW), Seattle [thesis] 1994 - 1998 Bachelor of Technology at the Indian Institute of Technology (IIT), Kanpur |
| Short Bio | : | txt |
| Other Listings | : | DBLP CiteSeerX AI Genealogy Project Math Genealogy Project |
Research
My primary research interest is in Artificial Intelligence, Automated Reasoning, and Theoretical Computer Science, with an emphasis on using insights from proof complexity theory to analyze and improve practical tools for propositional satisfiability (SAT), quantified Boolean formula (QBF), and constraint programming (CP). The recent focus of my research has been on planning and design automation problems, exploitation of structural symmetry in domains, new modeling techniques for QBF, model counting and solution sampling for SAT, and exploration of special constraints.
SampleCount is a SAT model counter, i.e., a tool that computes the number of solutions of a given Boolean formula. It uses solution sampling to cut down the search space in a controlled manner, and is the first tool to provide guaranteed lower bounds on the model count without assuming what-so-ever about the quality of the solution samples. For details, see the paper titled "From Sampling to Model Counting" in IJCAI-07.
Download source code: tgz, tar.bz2, zip, README.
- Includes an enhanced version of Approxcount.
- Includes SampleSat as a command-line option.
Approxcount [Wei and Selman, 2005]. Download stand-alone source code: tgz, tar.bz2, zip, README.
SampleSat [Wei et al. 2004]. Now available as an integrated command-line option in Approxcount/SampleCount. See usage in SampleCount README.
MBound is also a SAT model counter like SampleSat. However, the approach used by it is different. It employs randomly generated parity or XOR constraints for domain-independent streamlining of the input formula, while maintaining a good handle on the solution count of the original formula. It provides probabilistic guarantees on the obtained model count. For details, see the paper titled "Model Counting: A New Strategy for Obtaining Good Bounds" in AAAI-06.
Download simple scripts for adding random XORs to formulas: tgz, tar.bz2, zip, README.
XorSample is a technique for near-uniformly sampling the solutions of a combinatorial problems, specifically, SAT formulas. Like MBound, it uses randomly generated parity or XOR constraints for domain-independent streamlining of the input formula to fewer and fewer solutions. For details, see the paper titled "Near-Uniform Sampling of Combinatorial Spaces Using XOR Constraints" in NIPS-06.
Download simple scripts for adding random XORs to formulas: tgz, tar.bz2, zip, README.
Duaffle is a quantified Boolean formula solver (QBF solver) that uses a split dual CNF-DNF format both internally and for input representation. This facilitates significantly better constraint propagation and avoids other issues that traditional CNF-based QBF solvers run into. Duaffle is implemented as an extension of the QBF solver Quaffle from Princeton. For details, see the paper titled "QBF Modeling: Exploiting Player Symmetry for Simplicity and Efficiency" in SAT-06.
Download source code: tgz, tar.bz2, zip, README.
SymChaff is a propositional satisfiability solver (SAT solver) that implements a new technique to exploit structural symmetry present in a problem instance.
Download source code from the SymChaff webpage.
- Benchmarks
- CNF formulas used in the SampleCount paper for model counting: IJCAI07-suite.tgz (3.5MB)
- CNF formulas used in the XorSample paper for solution sampling: NIPS06-suite.tgz (12KB)
- CNF formulas used in the MBound paper for model counting: AAAI06-suite-v2.tgz (1MB), see note about php formulas
- CNF formulas and SYM files used in the SymChaff paper: AAAI05-suite.tgz (50MB)
- Incomplete Algorithms (for Satisfiability)
[published,
draft pdf]
Henry Kautz, Ashish Sabharwal, Bart Selman
Handbook of Satisfiability, IOS Press. Editors: Armin Biere, Marijn Heule, Hans van Maaren, and Toby Walsh. Chapter 6, pp 185-203, 2009. - Model Counting
[published,
draft pdf]
Carla P. Gomes, Ashish Sabharwal, Bart Selman
Handbook of Satisfiability, IOS Press. Editors: Armin Biere, Marijn Heule, Hans van Maaren, and Toby Walsh. Chapter 20, pp 633-654, 2009. - Exploiting Runtime Variation in Complete
Solvers (for Satisfiability)
[published]
Carla P. Gomes, Ashish Sabharwal
Handbook of Satisfiability, IOS Press. Editors: Armin Biere, Marijn Heule, Hans van Maaren, and Toby Walsh. Chapter 9, pp 271-288, 2009. - Satisfiability Solvers
Carla P. Gomes, Henry Kautz, Ashish Sabharwal, Bart Selman [preprint, bib]
Handbook of Knowledge Representation, in the series Foundations of Artificial Intelligence, vol. 3. Editors: Frank van Harmelen, Vladimir Lifschitz, and Bruce Porter. Elsevier, pp 89-134, 2008.
CONFERENCE PUBLICATIONS (refereed and archived)
[2009]
- Integrating Systematic and Local Search
Paradigms: A New Strategy for MaxSAT
[preprint]
Lukas Kroc, Ashish Sabharwal, Carla P. Gomes, Bart Selman
IJCAI-09. 21st International Joint Conference on Artificial Intelligence, Pasadena, CA, July 2009. To appear. - Relaxed DPLL Search for MaxSAT
[preprint]
Lukas Kroc, Ashish Sabharwal, Bart Selman
SAT-09. 12th International Conference on Theory and Applications of Satisfiability Testing, Swansea, Wales, U.K., June 2009. To appear. (short paper). - Backdoors in the Context of Learning
[preprint,
with extended version as a Tech Report]
Bistra Dilkina, Carla P. Gomes, Ashish Sabharwal
SAT-09. 12th International Conference on Theory and Applications of Satisfiability Testing, Swansea, Wales, U.K., June 2009. To appear. (short paper). - Backdoors to Combinatorial Optimization:
Feasibility and Optimality
[draft pdf]
Bistra Dilkina, Carla P. Gomes, Yuri Malitski, Ashish Sabharwal, Meinolf Sellmann
CPAIOR-09. 6th International Conference on Integration of AI and OR Techniques in Constraint Programming for Combinatorial Optimization Problems, Pittsburgh, PA, May 2009. To appear. - Message-Passing and Local Heuristics as
Decimation Strategies for Satisfiability
[preprint,
bib,
slides]
Lukas Kroc, Ashish Sabharwal, Bart Selman
SAC-09. 24th Annual ACM Symposium on Applied Computing, pp 1408-1414, Honolulu, HI, Mar 2009.
[2008]
- Counting Solution Clusters in Graph
Coloring Problems Using Belief Propagation
[published,
preprint,
bib,
spotlight-slide]
Lukas Kroc, Ashish Sabharwal, Bart Selman
NIPS-08. 22nd Annual Conference on Neural Information Processing Systems, pp 873-880, Vancouver, BC, Canada, Dec 2008. - Leveraging Belief Propagation, Backtrack
Search, and Statistics for Model Counting
[published,
preprint,
bib,
slides,
journal version]
Lukas Kroc, Ashish Sabharwal, Bart Selman
CPAIOR-08. 5th International Conference on Integration of AI and OR Techniques in Constraint Programming for Combinatorial Optimization Problems, LNCS volume 5015, pp 127-141, Paris, France, May 2008.
Also at the ISAIM-08 symposium. - Connections in Networks: A Hybrid
Approach
[published,
preprint,
bib,
slides]
Carla P. Gomes, Willem-Jan van Hoeve, Ashish Sabharwal
CPAIOR-08. 5th International Conference on Integration of AI and OR Techniques in Constraint Programming for Combinatorial Optimization Problems, LNCS volume 5015, pp 303-307, Paris, France, May 2008. - Filtering Atmost1 on Pairs of Set
Variables
[published,
bib,
journal version]
Willem-Jan van Hoeve, Ashish Sabharwal
CPAIOR-08. 5th International Conference on Integration of AI and OR Techniques in Constraint Programming for Combinatorial Optimization Problems, LNCS volume 5015, pp 382-386, Paris, France, May 2008.
Also at the ModRef-07 workshop.
[2007]
- Tradeoffs in the Complexity of Backdoor
Detection
[published,
preprint,
bib,
with extended results at ISAIM-08,
journal version]
Bistra Dilkina, Carla P. Gomes, Ashish Sabharwal
CP-07. 13th International Conference on Principles and Practice of Constraint Programming, LNCS volume 4741, pp 256-270, Providence, RI, Sep 2007. - Survey Propagation Revisited
[pdf (revised, see footnote 3),
bib]
Lukas Kroc, Ashish Sabharwal, Bart Selman
UAI-07. 23rd Conference on Uncertainty in Artificial Intelligence, pp 217-226, Vancouver, BC, Canada, July 2007.
Nominated for the UAI-07 Best Student Paper Award. - The Impact of Network Topology on Pure
Nash Equilibria in Graphical Games
[published,
preprint,
bib]
Bistra Dilkina, Carla P. Gomes, Ashish Sabharwal
AAAI-07. 22nd Conference on Artificial Intelligence, pp 42-49, Vancouver, BC, Canada, July 2007.
Also in NESCAI-07 (preliminary version)
Nominated for the AAAI-07 Best Paper Award. - Counting CSP Solutions Using Generalized
XOR Constraints
[published,
preprint,
bib,
slides]
Carla P. Gomes, Willem-Jan van Hoeve, Ashish Sabharwal, Bart Selman
AAAI-07. 22nd Conference on Artificial Intelligence, 204-209, Vancouver, BC, Canada, July 2007. - Short XORs for Model Counting: From Theory
to Practice
[published,
preprint in color,
preprint in black-and-white,
slides,
bib]
Carla P. Gomes, Joerg Hoffmann, Ashish Sabharwal, Bart Selman
SAT-07. 10th International Conference on Theory and Applications of Satisfiability Testing, LNCS volume 4501, pp 100-106, Lisbon, Portugal, May 2007. (short paper). - Connections in Networks: Hardness of
Feasibility versus Optimality
[published,
preprint,
slides,
bib]
Jon Conrad, Carla P. Gomes, Willem-Jan van Hoeve, Ashish Sabharwal, Jordan Suter
CPAIOR-07. 4th International Conference on Integration of AI and OR Techniques in Constraint Programming for Combinatorial Optimization Problems, LNCS volume 4510, pp 16-28, Brussels, Belgium, May 2007. - [SampleCount paper] From Sampling to Model
Counting
[published,
preprint,
bib]
Carla P. Gomes, Joerg Hoffmann, Ashish Sabharwal, Bart Selman
IJCAI-07. 20th International Joint Conference on Artificial Intelligence, pp 2293-2299, Hyderabad, India, Jan 2007.
Nominated for the IJCAI-07 Best Paper Award.
[2006]
- [XorSample paper] Near-Uniform Sampling of
Combinatorial Spaces Using XOR Constraints
[published,
preprint with appendix,
bib]
Carla P. Gomes, Ashish Sabharwal, Bart Selman
NIPS-06. 20th Annual Conference on Neural Information Processing Systems, pp 481-488, Vancouver, BC, Canada, Dec 2006. - Revisiting the Sequence Constraint
[published,
preprint,
bib,
journal version]
Willem-Jan van Hoeve, Gilles Pesant, Louis-Martin Rousseau, Ashish Sabharwal
CP-06. 12th International Conference on Principles and Practice of Constraint Programming, LNCS volume 4204, pp 620-634, Nantes, France, Sep 2006.
Best Paper Award. - [Duaffle paper] QBF Modeling: Exploiting
Player Symmetry for Simplicity and Efficiency
[published,
preprint,
slides
with the video used,
bib]
Ashish Sabharwal, Carlos Ansotegui, Carla P. Gomes, Justin W. Hart, Bart Selman
SAT-06. 9th International Conference on Theory and Applications of Satisfiability Testing, LNCS volume 4121, pp 382-395, Seattle, WA, Aug 2006. - [MBound paper] Model Counting: A New
Strategy for Obtaining Good Bounds
[published,
preprint,
slides,
bib]
Carla P. Gomes, Ashish Sabharwal, Bart Selman
AAAI-06. 21st National Conference on Artificial Intelligence, pp 54-61, Boston, MA, Jul 2006.
Outstanding Paper Award (two awards out of nearly 800 submissions). - Friends or Foes? An AI Planning
Perspective on Abstraction and Search
[published,
preprint,
bib,
journal version]
Joerg Hoffmann, Ashish Sabharwal, Carmel Domshlak
ICAPS-06. 16th International Conference on Automated Planning and Scheduling, pp 294-303, The English Lake District, UK, June 2006.
Nominated for the ICAPS-06 Best Paper Award.
[2005 and earlier]
- [SymChaff paper] SymChaff: A
Structure-Aware Satisfiability Solver
[published,
preprint,
slides,
bib,
journal version]
Ashish Sabharwal
AAAI-05. 20th National Conference on Artificial Intelligence, pp 467-474, Pittsburgh, PA, July 2005. - Using Problem Structure for Efficient
Clause Learning
[published volume,
preprint,
slides,
bib,
journal version]
Ashish Sabharwal, Paul Beame, Henry Kautz
SAT-03. 6th International Conference on Theory and Applications of Satisfiability Testing, LNCS volume 2919, pp 242-256, Portofino, Italy, May 2003. - Understanding the Power of Clause
Learning
[published,
preprint,
slides,
bib,
journal version]
Paul Beame, Henry Kautz, Ashish Sabharwal
IJCAI-03. 18th International Joint Conference on Artificial Intelligence, pp 1194-1201, Acapulco, Mexico, August 2003. - Bounded-depth Frege Lower Bounds for
Weaker Pigeonhole Principles
[published,
preprint,
bib,
journal version]
Josh Buresh-Oppenheim, Paul Beame, Toniann Pitassi, Ran Raz, Ashish Sabharwal
FOCS-02. 43rd Annual Symposium on Foundations of Computer Science, pp 583-592, Vancouver, BC, Nov 2002. - Resolution Complexity of Independent Sets
in Random Graphs
[published,
preprint,
bib,
journal version]
Paul Beame, Russell Impagliazzo, Ashish Sabharwal
CCC-01. 16th Annual Conference on Computational Complexity, pp 52-68, Chicago, IL, June 2001.
- Backdoors in the Context of Learning for Combinatorial Problems
[draft pdf]
Bistra Dilkina, Carla P. Gomes, Ashish Sabharwal
AMAI (under review). Annals of Mathematics and Artificial Intelligence. - Leveraging
Belief Propagation, Backtrack Search, and Statistics for Model
Counting
[draft pdf]
Lukas Kroc, Ashish Sabharwal, Bart Selman
AOR (under review). Annals of Operations Research. - Bounds
Consistency Filtering for Pair-Atmost1
Willem-Jan van Hoeve, Ashish Sabharwal
AOR (under review). Annals of Operations Research. - Friends or Foes?
An AI Planning Perspective on Abstraction and Search
Carmel Domshlak, Joerg Hoffmann, Ashish Sabharwal
JAIR (under review). Journal of Artificial Intelligence Research. - Towards
Understanding and Harnessing the Potential of Clause Learning
[published,
preprint,
bib]
(see also chapter 4 of my Ph.D. thesis, in particular Corollary 4.2)
Paul Beame, Henry Kautz, Ashish Sabharwal
JAIR-04. Journal of Artificial Intelligence Research, volume 22, pp 319-351, Dec 2004.
Runner-up for the IJCAI-JAIR 2003-2008 Best Paper Prize. - New Filtering
Algorithms for Combinations of Among Constraints
[draft pdf]
Willem-Jan van Hoeve, Gilles Pesant, Louis-Martin Rousseau, Ashish Sabharwal
Constraints journal (under review). - SymChaff:
Exploiting Symmetry in a Structure-Aware Satisfiability Solver
[draft pdf]
Ashish Sabharwal
Constraints journal, special issue on Symmetry. Accepted for publication. - The Resolution
Complexity of Independent Sets and Vertex Covers in Random
Graphs
[published,
preprint,
bib]
Paul Beame, Russell Impagliazzo, Ashish Sabharwal
Computational Complexity journal, volume 16, number 3, pp 245-297, 2007. - Bounded-Depth Frege
Lower Bounds for Weaker Pigeonhole Principles
[published,
preprint,
bib]
Josh Buresh-Oppenheim, Paul Beame, Toniann Pitassi, Ran Raz, Ashish Sabharwal
SICOMP-04. SIAM Journal on Computing, volume 34, number 2, pp 261-276, Dec 2004. - Floodlight
Illumination of Infinite Wedges
[publisher,
draft pdf]
Matthew Cary, Atri Rudra, Ashish Sabharwal, Erik Vee
CGTA-07. Special issue of the journal Computation Geometry: Theory and Applications, 2007. Accepted for publication.
Abstract in the 14th Annual Fall Workshop on Computational Geometry, Boston, MA, Nov 2004.
Preliminary version: Technical Report UW-CSE-2004-10-04, University of Washington, Seattle, Oct 2004.
WORKSHOPS, INVITED TALKS, OTHER WORK
- Domain Filtering for the Intersection of
Set Variables
Willem-Jan van Hoeve (presenter), Ashish Sabharwal
EURO-09. 23rd European Conference on Operational Research, Bonn, Germany, Jul 2009. - Solution Counting Methods for
Combinatorial Problems
[slides]
Carla P. Gomes, Willem-Jan van Hoeve, Lukas Kroc, Ashish Sabharwal (presenter), Bart Selman
INFORMS-08. INFORMS Annual Meeting, Washington, DC, Oct 2008. - Hidden Structure in Constraint Reasoning
Problems
[slides]
Bistra Dilkina, Carla P. Gomes, Ashish Sabharwal (presenter)
INFORMS-08. INFORMS Annual Meeting, Washington, DC, Oct 2008. - Counting CSP Solutions Using Generalized
XOR Constraints
Carla P. Gomes, Willem-Jan van Hoeve (presenter), Ashish Sabharwal, Bart Selman
INFORMS-08. INFORMS Annual Meeting, Washington, DC, Oct 2008. - Optimal Corridor Design for Grizzly Bear
in the U.S. Northern Rockies
Jordan F. Suter (presenter), Jon Conrad, Carla P. Gomes, Willem-Jan van Hoeve, Ashish Sabharwal
AAEA-08. American Agricultural Economics Association Annual Meeting, Orlando, FL, Jul 2008. - Leveraging Belief Propagation, Backtrack
Search, and Statistics for Model Counting
[pdf,
bib]
Lukas Kroc (presenter), Ashish Sabharwal, and Bart Selman
ISAIM-08. 10th International Symposium on Artificial Intelligence and Mathematics, Fort Lauderdale, FL, Jan 2008. - Tradeoffs in Backdoors: Inconsistency
Detection, Dynamic Simplification, and Preprocessing
[pdf,
bib,
slides]
Bistra Dilkina, Carla Gomes, Ashish Sabharwal (presenter)
ISAIM-08. 10th International Symposium on Artificial Intelligence and Mathematics, Fort Lauderdale, FL, Jan 2008. - Hidden Structure in Combinatorial
Problems
[Please refer to slides for the ISAIM-08 paper on Backdoors]
Carla P. Gomes, Ashish Sabharwal (presenter)
INFORMS-07. INFORMS Annual Meeting, Seattle, WA, Nov 2007. - Filtering Algorithms for the Sequence
Constraint
Willem-Jan van Hoeve (presenter), Gilles Pesant, Louis-Martin Rousseau, Ashish Sabharwal
INFORMS-07. INFORMS Annual Meeting, Seattle, WA, Nov 2007. - Two Set Constraints for Modeling and
Efficiency
[pdf,
bib,
slides]
Willem-Jan van Hoeve, Ashish Sabharwal (presenter)
ModRef-07 at CP-07. 6th International Workshop on Constraint Modelling and Reformulation, Providence, RI, September 2007. In conjunction with the CP-07 conference. - Sampling and Soundness: Can We Have
Both?
Carla P. Gomes, Joerg Hoffmann, Ashish Sabharwal, Bart Selman
ISWC-07. 6th International Semantic Web Conference, Busan, Korea, Nov 2007. - Empirical Validation of the Relationship
Between Survey Propagation and Covers in Random 3-SAT
[slides]
Lukas Kroc (presenter), Ashish Sabharwal, Bart Selman
AISP-07. Workshop on Algorithms, Inference, & Statistical Physics, Santa Fe, NM, May 2007. - Sparse Message Passing Algorithms for
Weighted Maximum Satisfiability
[pdf]
Aron Culotta, Andrew McCallum, Bart Selman, Ashish Sabharwal
NESCAI-07. 2nd North East Student Colloquium on Artificial Intelligence, Ithaca, NY, Apr 2007. - Streamlining Reasoning for Solution
Finding and Counting
Carla P. Gomes (presenter), Ashish Sabharwal, Meinolf Sellmann, Bart Selman
INFORMS-06. INFORMS Annual Meeting, Pittsburgh, PA, Nov 2006.
-
Algorithmic Applications of Propositional
Proof Complexity
[bib]
PH.D. THESIS, University of Washington, Seattle, 2005
Advisors: Profs. Paul Beame and Henry Kautz[ abstract, full pdf (single spaced, 1.3MB) ]
[ chapters, single-spaced: titlepage, abstract, contents, ch1, ch2, ch3, ch4, ch5, ch6, ch7 ] - Model Checking: Two Decades of Novel
Techniques and Trends
[pdf]
General Examination Report, University of Washington, Seattle, May 2002.
Disclaimer: This material is
presented to ensure timely dissemination of scholarly and technical
work. Copyright and all rights therein are retained by authors or by
other copyright holders. All persons copying this information are
expected to adhere to the terms and constraints invoked by each
author's copyright. In most cases, these works may not be reposted
without the explicit permission of the copyright holder.
Teaching
- Satisfied by Message Passing:
Probabilistic Techniques for Combinatorial Problems
[webpage,
bib]
Lukas Kroc, Ashish Sabharwal, Bart Selman
AAAI-08. 23rd Conference on Artificial Intelligence, Tutorial Forum, Chicago, IL, July 2008.
Shorter version also at: LION 3, 2009. 3rd Conference on Learning and Intelligent Optimization, Tutorial Forum, Trento, Italy, Jan 2009. - Combinatorial Problems (series of three
lectures)
- Finding Solutions [slides]
- Counting and Sampling Solutions [slides]
- The Next Level of Complexity [slides with the video used]
Ashish Sabharwal, Bart Selman
KITPC-08. 2nd Asian-Pacific School on Statistical Physics and Interdisciplinary Applications, Collective Dynamics and Information Systems Program, Kavli Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing, China, March 2008 - Beyond Traditional SAT Reasoning: QBF,
Model Counting, and Solution Sampling
[webpage,
bib]
Ashish Sabharwal, Bart Selman
AAAI-07. 22nd Conference on Artificial Intelligence, Tutorial Forum, Vancouver, BC, Canada, July 2007 - Quantified Boolean Formula (QBF)
Reasoning
[slides with
videos used]
Bart Selman, Carla Gomes, Ashish Sabharwal
Tutorial prepared for DARPA, Feb 2007
- For the course webpage for CSE 326, Data
Structures, that I taught as a pre-doctoral instructor in Fall
2003 at the University of Washington, please click here.
- Notes on Proof Complexity
[pdf]
Lectures by Paul Beame, scribed by Ashish Sabharwal.
IAS/PCMI Summer School, Princeton, NJ, Aug 2000.
My Other Interests
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Piano
Although piano playing has been on hold for the past many years now, six quarters of piano lessons at the University of Washington greatly increased the appreciation I have for (Western) classical music, performers, and composers. Being mathematically oriented, I found it relatively easy to theoretically digest the concepts of scales, transposition, quarter notes, etc., but bringing it all tegether and training one's mind and body to play even a single note perfectly is an art that will take several years. Luckily for me, my piano teacher knew the secrets!
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Martial Arts
I started practicing Shotokan karate with SKA in January 2000. I became a shodan (first degree black belt) in June 2004. The picture on the right is from my first tournament as a white belt. After moving to Cornell University, I haven't had much opportunity to practice karate with an SKA-affiliated dojo. Instead, I have explored aikido with the Cornell Aikido Club.
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Hiking, Mountaineering, and Rock Climbing
The Pacific Northwest is undoubtedly one of the best places to hike. Some of my mountain climbs and scrambles include Mount Hood (Oregon), Mount Daniel (Cascades), The Brothers (Olympics), Colchuck Peak (Alpine Lakes area), Mount Rainier [unsuccessful], and Mount Adams. I have also begun to explore areas in the central New York region. Indoor rock climbing is another related challenge I enjoy.
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Skiing
My favorite ski place near Seattle is Crystal Mountain, but of all the mountains I have skied down, the best is Whistler-Blackcomb in British Columbia, Canada. The wind can be trecherous, but nothing compares to the powdery snow, the beauty, and the challenges of Whistler. The picture here is of me looking at the Roundhouse lodge half way up Whistler mountain. Recently, I have also begun to explore (not-so-exciting) skiing opportunities in the New York region, with my Head Monster iM77 skis with a built-in 'intelligent chip'.
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Motorcycle Riding
I enjoyed riding a beautiful motorcycle that I bought in 2001 and sold off after four years --- a 1997 Kawasaki Ninja 600R (600 cc). Hours working on it and tuning it for a smooth ride were certainly well spent. In the summer of 2004, I was on the road for a memorable trip with my girlfriend to the Columbia River Gorge, on Highways 7/25/30S, 30/I-84E, 97N, 410W... splendid views, scenary changing from thick forests to open dry lands, and close encounters of the four big mountains in the area: St. Helens, Hood, Adams, and Rainier! |
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