1,632 research outputs found
Stable, finite energy density solutions in the effective theory of non-abelian gauge fields
We consider the gauge fixed partition function of pure gauge theory
in axial gauge following the Halpern's field strength formalism. We integrate
over field strengths using the Bianchi identities and obtain an
effective action of the remaining field strengths in momentum
space. We obtain the static solutions of the equations of motion (EOM) of the
effective theory. The solutions exhibit Gaussian nature in the component of
momentum and are proportional to the delta functions of the remaining
components of momentum. The solutions render a finite energy density of the
system and the parameters are found to be proportional to fourth root of the
gluon condensate. It indicates that the solutions offer a natural mass scale in
the low energy phase of the theory.Comment: 6 pages Minor changes in the manuscript and two figures adde
A Multi-objective Perspective for Operator Scheduling using Fine-grained DVS Architecture
The stringent power budget of fine grained power managed digital integrated
circuits have driven chip designers to optimize power at the cost of area and
delay, which were the traditional cost criteria for circuit optimization. The
emerging scenario motivates us to revisit the classical operator scheduling
problem under the availability of DVFS enabled functional units that can
trade-off cycles with power. We study the design space defined due to this
trade-off and present a branch-and-bound(B/B) algorithm to explore this state
space and report the pareto-optimal front with respect to area and power. The
scheduling also aims at maximum resource sharing and is able to attain
sufficient area and power gains for complex benchmarks when timing constraints
are relaxed by sufficient amount. Experimental results show that the algorithm
that operates without any user constraint(area/power) is able to solve the
problem for most available benchmarks, and the use of power budget or area
budget constraints leads to significant performance gain.Comment: 18 pages, 6 figures, International journal of VLSI design &
Communication Systems (VLSICS
Relay-Linking Models for Prominence and Obsolescence in Evolving Networks
The rate at which nodes in evolving social networks acquire links (friends,
citations) shows complex temporal dynamics. Preferential attachment and link
copying models, while enabling elegant analysis, only capture rich-gets-richer
effects, not aging and decline. Recent aging models are complex and heavily
parameterized; most involve estimating 1-3 parameters per node. These
parameters are intrinsic: they explain decline in terms of events in the past
of the same node, and do not explain, using the network, where the linking
attention might go instead. We argue that traditional characterization of
linking dynamics are insufficient to judge the faithfulness of models. We
propose a new temporal sketch of an evolving graph, and introduce several new
characterizations of a network's temporal dynamics. Then we propose a new
family of frugal aging models with no per-node parameters and only two global
parameters. Our model is based on a surprising inversion or undoing of triangle
completion, where an old node relays a citation to a younger follower in its
immediate vicinity. Despite very few parameters, the new family of models shows
remarkably better fit with real data. Before concluding, we analyze temporal
signatures for various research communities yielding further insights into
their comparative dynamics. To facilitate reproducible research, we shall soon
make all the codes and the processed dataset available in the public domain
Unbounded safety verification for hardware using software analyzers
Demand for scalable hardware verification is ever-increasing. We propose an unbounded safety verification framework for hardware, at the heart of which is a software verifier. To this end, we synthesize Verilog at register transfer level into a software-netlist, represented as a word-level ANSI-C program. The proposed tool flow allows us to leverage the precision and scalability of state-of-the-art software verification techniques. In particular, we evaluate unbounded proof techniques, such as predicate abstraction, k-induction, interpolation, and IC3/PDR; and we compare the performance of verification tools from the hardware and software domains that use these techniques. To the best of our knowledge, this is the first attempt to perform unbounded verification of hardware using software analyzers
MILDSum: A Novel Benchmark Dataset for Multilingual Summarization of Indian Legal Case Judgments
Automatic summarization of legal case judgments is a practically important
problem that has attracted substantial research efforts in many countries. In
the context of the Indian judiciary, there is an additional complexity --
Indian legal case judgments are mostly written in complex English, but a
significant portion of India's population lacks command of the English
language. Hence, it is crucial to summarize the legal documents in Indian
languages to ensure equitable access to justice. While prior research primarily
focuses on summarizing legal case judgments in their source languages, this
study presents a pioneering effort toward cross-lingual summarization of
English legal documents into Hindi, the most frequently spoken Indian language.
We construct the first high-quality legal corpus comprising of 3,122 case
judgments from prominent Indian courts in English, along with their summaries
in both English and Hindi, drafted by legal practitioners. We benchmark the
performance of several diverse summarization approaches on our corpus and
demonstrate the need for further research in cross-lingual summarization in the
legal domain.Comment: Accepted at EMNLP 2023 (Main Conference
CONTRASTE: Supervised Contrastive Pre-training With Aspect-based Prompts For Aspect Sentiment Triplet Extraction
Existing works on Aspect Sentiment Triplet Extraction (ASTE) explicitly focus
on developing more efficient fine-tuning techniques for the task. Instead, our
motivation is to come up with a generic approach that can improve the
downstream performances of multiple ABSA tasks simultaneously. Towards this, we
present CONTRASTE, a novel pre-training strategy using CONTRastive learning to
enhance the ASTE performance. While we primarily focus on ASTE, we also
demonstrate the advantage of our proposed technique on other ABSA tasks such as
ACOS, TASD, and AESC. Given a sentence and its associated (aspect, opinion,
sentiment) triplets, first, we design aspect-based prompts with corresponding
sentiments masked. We then (pre)train an encoder-decoder model by applying
contrastive learning on the decoder-generated aspect-aware sentiment
representations of the masked terms. For fine-tuning the model weights thus
obtained, we then propose a novel multi-task approach where the base
encoder-decoder model is combined with two complementary modules, a
tagging-based Opinion Term Detector, and a regression-based Triplet Count
Estimator. Exhaustive experiments on four benchmark datasets and a detailed
ablation study establish the importance of each of our proposed components as
we achieve new state-of-the-art ASTE results.Comment: Accepted as a Long Paper at EMNLP 2023 (Findings); 16 pages; Codes:
https://github.com/nitkannen/CONTRASTE
Hardware/Software Co-verification Using Path-based Symbolic Execution
Conventional tools for formal hardware/software co-verification use
bounded model checking techniques to construct a single monolithic propositional formula. Formulas generated in this way are extremely complex and contain a great deal of irrelevant logic, hence
are difficult to solve even by the state-of-the-art Satisfiability (SAT)
solvers. In a typical hardware/software co-design the firmware only
exercises a fraction of the hardware state-space, and we can use this
observation to generate simpler and more concise formulas. In this
paper, we present a novel verification algorithm for hardware/software co-designs that identify partitions of the firmware and the hardware logic pertaining to the feasible execution paths by means of
path-based symbolic simulation with custom path-pruning, propertyguided slicing and incremental SAT solving. We have implemented
this approach in our tool COVERIF. We have experimentally compared COVERIF with HW-CBMC, a monolithic BMC based co-verification
tool, and observed an average speed-up of 5× over HW-CBMC for
proving safety properties as well as detecting critical co-design bugs
in an open-source Universal Asynchronous Receiver Transmitter
design and a large SoC design
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