59,136 research outputs found
Macros That Work
9 pagesThis paper describes a modified form of Kohlbecker's algorithm
for reliably hygienic (capture-free) macro expansion
in block-structured languages, where macros are source-tos-ource
transformations specified using a high-level pattern
language. Unlike previous algorithms, the modified algorithm
runs in linear instead of quadratic time, copies few
constants, does not assume that syntactic keywords ( e.g. if)
are reserved words, and allows local (scoped) macros to refer
to lexical variables in a referentially transparent manner.
Syntactic closures have been advanced as an alternative
to hygienic macro expansion. The problem with syntactic
closures is that they are inherently low-level and therefore
difficult to use correctly, especially when syntactic keywords
are not reserved. It is impossible to construct a pattern-based,
automatically hygienic macro system on top of syntactic
closures because the pattern interpreter must be able
to determine the syntactic role of an identifier (in order to
close it in the correct syntactic environment) before macro
expansion has made that role apparent.
may be viewed as a book-keeping
technique for deferring such decisions until macro expansion
is locally complete. Building on that insight, this paper unifies
and extends the competing paradigms of hygienic macro
expansion and syntactic closures to obtain an algorithm that
combines the benefits of both .
Several prototypes of a complete macro system for
Scheme have been based on the algorithm presented here
On the Online Generation of Effective Macro-operators
Macro-operator (āmacroā, for short) generation is a
well-known technique that is used to speed-up the
planning process. Most published work on using
macros in automated planning relies on an offline
learning phase where training plans, that is, solutions
of simple problems, are used to generate the
macros. However, there might not always be a place
to accommodate training.
In this paper we propose OMA, an efficient method
for generating useful macros without an offline
learning phase, by utilising lessons learnt from existing
macro learning techniques. Empirical evaluation
with IPC benchmarks demonstrates performance
improvement in a range of state-of-the-art
planning engines, and provides insights into what
macros can be generated without training
Evolving macro-actions for planning
Domain re-engineering through macro-actions (i.e. macros) provides one potential avenue for research into learning for planning. However, most existing work learns macros that are reusable plan fragments and so observable from planner behaviours online or plan characteristics offline. Also, there are learning methods that learn macros from domain analysis. Nevertheless, most of these methods explore restricted macro spaces and exploit specific features of planners or domains. But, the learning examples, especially that are used to acquire previous experiences, might not cover many aspects of the system, or might not always reflect that better choices have been made during the search. Moreover, any specific properties are not likely to be common with many planners or domains. This paper presents an offline evolutionary method that learns macros for arbitrary planners and domains. Our method explores a wider macro space and learns macros that are somehow not observable from the examples. Our method also represents a generalised macro learning framework as it does not discover or utilise any specific structural properties of planners or domains
DREAMPlaceFPGA-MP: An Open-Source GPU-Accelerated Macro Placer for Modern FPGAs with Cascade Shapes and Region Constraints
FPGA macro placement plays a pivotal role in routability and timing closer to
the modern FPGA physical design flow. In modern FPGAs, macros could be subject
to complex cascade shape constraints requiring instances to be placed in
consecutive sites. In addition, in real-world FPGA macro placement scenarios,
designs could have various region constraints that specify boundaries within
which certain design instances and macros should be placed. In this work, we
present DREAMPlaceFPGA-MP, an open-source GPU-accelerated FPGA macro-placer
that efficiently generates legal placements for macros while honoring cascade
shape requirements and region constraints. Treating multiple macros in a
cascade shape as a large single instance and restricting instances to their
respective regions, DREAMPlaceFPGA-MP obtains roughly legal placements. The
macros are legalized in multiple steps to efficiently handle cascade shapes and
region constraints. Our experimental results demonstrate that DREAMPlaceFPGA-MP
is among the top contestants of the MLCAD 2023 FPGA Macro-Placement Contest
Wormholes and Off-Diagonal Solutions in f(R,T), Einstein and Finsler Gravity Theories
The aims of this work are 1) to sketch a proof that there are such
parameterizations of the local frame and canonical connection structures when
the gravitational field equations in f(R,T)-modified gravity, MG, can be
integrated in generic off-diagonal forms with metrics depending on all
spacetime coordinates and 2) to provide some examples of exact solutions.Comment: 4 pages, ERE2012-Proceedings macros, Contribution to the Spanish
Relativity Meeting in Portugal, Guimaraes, September 3-7, 201
Macro actions for structures
It is not surprising that structures underly many of the problems that we find interesting in planning. However, the planners that we develop are not always capable of acting on them as they increase in size. For example, the errors caused through relaxations in a heuristic can grow quickly when acting on a structure. Macro actions can help to compensate for heuristic error; however, researchers have investigated finite length macro actions limiting the benefit when the underlying problem is an arbitrary sized structure. In this work we design a specific set of arbitrary length macros, providing a vocabulary for acting on structures
ROOT - A C++ Framework for Petabyte Data Storage, Statistical Analysis and Visualization
ROOT is an object-oriented C++ framework conceived in the high-energy physics
(HEP) community, designed for storing and analyzing petabytes of data in an
efficient way. Any instance of a C++ class can be stored into a ROOT file in a
machine-independent compressed binary format. In ROOT the TTree object
container is optimized for statistical data analysis over very large data sets
by using vertical data storage techniques. These containers can span a large
number of files on local disks, the web, or a number of different shared file
systems. In order to analyze this data, the user can chose out of a wide set of
mathematical and statistical functions, including linear algebra classes,
numerical algorithms such as integration and minimization, and various methods
for performing regression analysis (fitting). In particular, ROOT offers
packages for complex data modeling and fitting, as well as multivariate
classification based on machine learning techniques. A central piece in these
analysis tools are the histogram classes which provide binning of one- and
multi-dimensional data. Results can be saved in high-quality graphical formats
like Postscript and PDF or in bitmap formats like JPG or GIF. The result can
also be stored into ROOT macros that allow a full recreation and rework of the
graphics. Users typically create their analysis macros step by step, making use
of the interactive C++ interpreter CINT, while running over small data samples.
Once the development is finished, they can run these macros at full compiled
speed over large data sets, using on-the-fly compilation, or by creating a
stand-alone batch program. Finally, if processing farms are available, the user
can reduce the execution time of intrinsically parallel tasks - e.g. data
mining in HEP - by using PROOF, which will take care of optimally distributing
the work over the available resources in a transparent way
More on Chiral-Nonchiral Dual Pairs
Expanding upon earlier work of Pouliot and Strassler, we construct chiral
magnetic duals to nonchiral supersymmetric electric theories based upon SO(7),
SO(8) and SO(9) gauge groups with various numbers of vector and spinor matter
superfields. Anomalies are matched and gauge invariant operators are mapped
within each dual pair. Renormalization group flows along flat directions are
also examined. We find that confining phase quantum constraints in the electric
theories are recovered from semiclassical equations of motion in their magnetic
counterparts when the dual gauge groups are completely Higgsed.Comment: 25 pages, harvmac and tables macros, 1 figur
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