39,704 research outputs found
Better text compression from fewer lexical n-grams
Word-based context models for text compression have the capacity to outperform more simple character-based models, but are generally unattractive because of inherent problems with exponential model growth and corresponding data sparseness. These ill-effects can be mitigated in an adaptive lossless compression scheme by modelling syntactic and semantic lexical dependencies independently
Better Text Compression Using a Large Language Model
Conventional compression techniques for text are based on typical frequencies of individual letters within the text, independent of higher-level semantics. This disclosure describes a compression scheme for text data in which a conventional coder/decoder (codec) is augmented with an additional semantic codec to achieve greater compression and throughput. The additional semantic codec can be implemented with a pre-trained large language model (LLM). Text data is first input to a semantic coder for semantic-based compression. Codes within the codebook are reranked based on selective erasure by the encoder LLM. Once the codebook is established, portions within the text that can be recovered by a decoder LLM are erased. Such semantically compressed data is encoded as usual via conventional techniques and can be first decoded via conventional techniques to recover the semantically coded text. The semantically coded text is further decoded using a semantic decoder that recovers the original text by inferring, based on semantics, the portions that were erased prior to transmission
Semantic Perceptual Image Compression using Deep Convolution Networks
It has long been considered a significant problem to improve the visual
quality of lossy image and video compression. Recent advances in computing
power together with the availability of large training data sets has increased
interest in the application of deep learning cnns to address image recognition
and image processing tasks. Here, we present a powerful cnn tailored to the
specific task of semantic image understanding to achieve higher visual quality
in lossy compression. A modest increase in complexity is incorporated to the
encoder which allows a standard, off-the-shelf jpeg decoder to be used. While
jpeg encoding may be optimized for generic images, the process is ultimately
unaware of the specific content of the image to be compressed. Our technique
makes jpeg content-aware by designing and training a model to identify multiple
semantic regions in a given image. Unlike object detection techniques, our
model does not require labeling of object positions and is able to identify
objects in a single pass. We present a new cnn architecture directed
specifically to image compression, which generates a map that highlights
semantically-salient regions so that they can be encoded at higher quality as
compared to background regions. By adding a complete set of features for every
class, and then taking a threshold over the sum of all feature activations, we
generate a map that highlights semantically-salient regions so that they can be
encoded at a better quality compared to background regions. Experiments are
presented on the Kodak PhotoCD dataset and the MIT Saliency Benchmark dataset,
in which our algorithm achieves higher visual quality for the same compressed
size.Comment: Accepted to Data Compression Conference, 11 pages, 5 figure
Scalable RDF Data Compression using X10
The Semantic Web comprises enormous volumes of semi-structured data elements.
For interoperability, these elements are represented by long strings. Such
representations are not efficient for the purposes of Semantic Web applications
that perform computations over large volumes of information. A typical method
for alleviating the impact of this problem is through the use of compression
methods that produce more compact representations of the data. The use of
dictionary encoding for this purpose is particularly prevalent in Semantic Web
database systems. However, centralized implementations present performance
bottlenecks, giving rise to the need for scalable, efficient distributed
encoding schemes. In this paper, we describe an encoding implementation based
on the asynchronous partitioned global address space (APGAS) parallel
programming model. We evaluate performance on a cluster of up to 384 cores and
datasets of up to 11 billion triples (1.9 TB). Compared to the state-of-art
MapReduce algorithm, we demonstrate a speedup of 2.6-7.4x and excellent
scalability. These results illustrate the strong potential of the APGAS model
for efficient implementation of dictionary encoding and contributes to the
engineering of larger scale Semantic Web applications
A Multi-task Learning Approach for Improving Product Title Compression with User Search Log Data
It is a challenging and practical research problem to obtain effective
compression of lengthy product titles for E-commerce. This is particularly
important as more and more users browse mobile E-commerce apps and more
merchants make the original product titles redundant and lengthy for Search
Engine Optimization. Traditional text summarization approaches often require a
large amount of preprocessing costs and do not capture the important issue of
conversion rate in E-commerce. This paper proposes a novel multi-task learning
approach for improving product title compression with user search log data. In
particular, a pointer network-based sequence-to-sequence approach is utilized
for title compression with an attentive mechanism as an extractive method and
an attentive encoder-decoder approach is utilized for generating user search
queries. The encoding parameters (i.e., semantic embedding of original titles)
are shared among the two tasks and the attention distributions are jointly
optimized. An extensive set of experiments with both human annotated data and
online deployment demonstrate the advantage of the proposed research for both
compression qualities and online business values.Comment: 8 Pages, accepted at AAAI 201
Joint Task and Data Oriented Semantic Communications: A Deep Separate Source-channel Coding Scheme
Semantic communications are expected to accomplish various semantic tasks
with relatively less spectrum resource by exploiting the semantic feature of
source data. To simultaneously serve both the data transmission and semantic
tasks, joint data compression and semantic analysis has become pivotal issue in
semantic communications. This paper proposes a deep separate source-channel
coding (DSSCC) framework for the joint task and data oriented semantic
communications (JTD-SC) and utilizes the variational autoencoder approach to
solve the rate-distortion problem with semantic distortion. First, by analyzing
the Bayesian model of the DSSCC framework, we derive a novel rate-distortion
optimization problem via the Bayesian inference approach for general data
distributions and semantic tasks. Next, for a typical application of joint
image transmission and classification, we combine the variational autoencoder
approach with a forward adaption scheme to effectively extract image features
and adaptively learn the density information of the obtained features. Finally,
an iterative training algorithm is proposed to tackle the overfitting issue of
deep learning models. Simulation results reveal that the proposed scheme
achieves better coding gain as well as data recovery and classification
performance in most scenarios, compared to the classical compression schemes
and the emerging deep joint source-channel schemes
RDF-TR: Exploiting structural redundancies to boost RDF compression
The number and volume of semantic data have grown impressively over the last decade, promoting compression as an essential tool for RDF preservation, sharing and management. In contrast to universal compressors, RDF compression techniques are able to detect and exploit specific forms of redundancy in RDF data. Thus, state-of-the-art RDF compressors excel at exploiting syntactic and semantic redundancies, i.e., repetitions in the serialization format and information that can be inferred implicitly. However, little attention has been paid to the existence of structural patterns within the RDF dataset; i.e. structural redundancy. In this paper, we analyze structural regularities in real-world datasets, and show three schema-based sources of redundancies that underpin the schema-relaxed nature of RDF. Then, we propose RDF-Tr (RDF Triples Reorganizer), a preprocessing technique that discovers and removes this kind of redundancy before the RDF dataset is effectively compressed. In particular, RDF-Tr groups subjects that are described by the same predicates, and locally re-codes the objects related to these predicates. Finally, we integrate
RDF-Tr with two RDF compressors, HDT and k2-triples. Our experiments show that using RDF-Tr with these compressors improves by up to 2.3 times their original effectiveness, outperforming the most prominent state-of-the-art techniques
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