1,769 research outputs found
Source File Set Search for Clone-and-Own Reuse Analysis
Clone-and-own approach is a natural way of source code reuse for software
developers. To assess how known bugs and security vulnerabilities of a cloned
component affect an application, developers and security analysts need to
identify an original version of the component and understand how the cloned
component is different from the original one. Although developers may record
the original version information in a version control system and/or directory
names, such information is often either unavailable or incomplete. In this
research, we propose a code search method that takes as input a set of source
files and extracts all the components including similar files from a software
ecosystem (i.e., a collection of existing versions of software packages). Our
method employs an efficient file similarity computation using b-bit minwise
hashing technique. We use an aggregated file similarity for ranking components.
To evaluate the effectiveness of this tool, we analyzed 75 cloned components in
Firefox and Android source code. The tool took about two hours to report the
original components from 10 million files in Debian GNU/Linux packages. Recall
of the top-five components in the extracted lists is 0.907, while recall of a
baseline using SHA-1 file hash is 0.773, according to the ground truth recorded
in the source code repositories.Comment: 14th International Conference on Mining Software Repositorie
ARCHANGEL: Tamper-proofing Video Archives using Temporal Content Hashes on the Blockchain
We present ARCHANGEL; a novel distributed ledger based system for assuring
the long-term integrity of digital video archives. First, we describe a novel
deep network architecture for computing compact temporal content hashes (TCHs)
from audio-visual streams with durations of minutes or hours. Our TCHs are
sensitive to accidental or malicious content modification (tampering) but
invariant to the codec used to encode the video. This is necessary due to the
curatorial requirement for archives to format shift video over time to ensure
future accessibility. Second, we describe how the TCHs (and the models used to
derive them) are secured via a proof-of-authority blockchain distributed across
multiple independent archives. We report on the efficacy of ARCHANGEL within
the context of a trial deployment in which the national government archives of
the United Kingdom, Estonia and Norway participated.Comment: Accepted to CVPR Blockchain Workshop 201
Hardware support for real-time network security and packet classification using field programmable gate arrays
Deep packet inspection and packet classification are the most computationally expensive operations in a Network Intrusion Detection (NID) system. Deep packet inspection involves content matching where the payload of the incoming packets is matched against a set of signatures in the database. Packet classification involves inspection of the packet header fields and is basically a multi-dimensional matching problem. Any matching in software is very slow in comparison to current network speeds. Also, both of these problems need a solution which is scalable and can work at high speeds. Due to the high complexity of these matching problems, only Field-Programmable Gate Array (FPGA) or Application-Specific Integrated Circuit (ASIC) platforms can facilitate efficient designs.
Two novel FPGA-based NID solutions were developed and implemented that not only carry out pattern matching at high speed but also allow changes to the set of stored patterns without resource/hardware reconfiguration; to their advantage, the solutions can easily be adopted by software or ASIC approaches as well. In both solutions, the proposed NID system can run while pattern updates occur. The designs can operate at 2.4 Gbps line rates, and have a memory consumption of around 17 bits per character and a logic cell usage of around 0.05 logic cells per character, which are the smallest compared to any other existing FPGA-based solution.
In addition to these solutions for pattern matching, a novel packet classification algorithm was developed and implemented on a FPGA. The method involves a two-field matching process at a time that then combines the constituent results to identify longer matches involving more header fields. The design can achieve a throughput larger than 9.72 Gbps and has an on-chip memory consumption of around 256Kbytes when dealing with more than 10,000 rules (without using external RAM). This memory consumption is the lowest among all the previously proposed FPGA-based designs for packet classification
The Whole World in Your Hand: Active and Interactive Segmentation
Object segmentation is a fundamental problem
in computer vision and a powerful resource for
development. This paper presents three embodied approaches to the visual segmentation of objects. Each approach to segmentation is aided
by the presence of a hand or arm in the proximity of the object to be segmented. The first
approach is suitable for a robotic system, where
the robot can use its arm to evoke object motion. The second method operates on a wearable system, viewing the world from a human's
perspective, with instrumentation to help detect
and segment objects that are held in the wearer's
hand. The third method operates when observing
a human teacher, locating periodic motion (finger/arm/object waving or tapping) and using it
as a seed for segmentation. We show that object segmentation can serve as a key resource for
development by demonstrating methods that exploit high-quality object segmentations to develop
both low-level vision capabilities (specialized feature detectors) and high-level vision capabilities
(object recognition and localization)
Gabor Barcodes for Medical Image Retrieval
In recent years, advances in medical imaging have led to the emergence of
massive databases, containing images from a diverse range of modalities. This
has significantly heightened the need for automated annotation of the images on
one side, and fast and memory-efficient content-based image retrieval systems
on the other side. Binary descriptors have recently gained more attention as a
potential vehicle to achieve these goals. One of the recently introduced binary
descriptors for tagging of medical images are Radon barcodes (RBCs) that are
driven from Radon transform via local thresholding. Gabor transform is also a
powerful transform to extract texture-based information. Gabor features have
exhibited robustness against rotation, scale, and also photometric
disturbances, such as illumination changes and image noise in many
applications. This paper introduces Gabor Barcodes (GBCs), as a novel framework
for the image annotation. To find the most discriminative GBC for a given query
image, the effects of employing Gabor filters with different parameters, i.e.,
different sets of scales and orientations, are investigated, resulting in
different barcode lengths and retrieval performances. The proposed method has
been evaluated on the IRMA dataset with 193 classes comprising of 12,677 x-ray
images for indexing, and 1,733 x-rays images for testing. A total error score
as low as ( accuracy for the first hit) was achieved.Comment: To appear in proceedings of The 2016 IEEE International Conference on
Image Processing (ICIP 2016), Sep 25-28, 2016, Phoenix, Arizona, US
MinMax Radon Barcodes for Medical Image Retrieval
Content-based medical image retrieval can support diagnostic decisions by
clinical experts. Examining similar images may provide clues to the expert to
remove uncertainties in his/her final diagnosis. Beyond conventional feature
descriptors, binary features in different ways have been recently proposed to
encode the image content. A recent proposal is "Radon barcodes" that employ
binarized Radon projections to tag/annotate medical images with content-based
binary vectors, called barcodes. In this paper, MinMax Radon barcodes are
introduced which are superior to "local thresholding" scheme suggested in the
literature. Using IRMA dataset with 14,410 x-ray images from 193 different
classes, the advantage of using MinMax Radon barcodes over \emph{thresholded}
Radon barcodes are demonstrated. The retrieval error for direct search drops by
more than 15\%. As well, SURF, as a well-established non-binary approach, and
BRISK, as a recent binary method are examined to compare their results with
MinMax Radon barcodes when retrieving images from IRMA dataset. The results
demonstrate that MinMax Radon barcodes are faster and more accurate when
applied on IRMA images.Comment: To appear in proceedings of the 12th International Symposium on
Visual Computing, December 12-14, 2016, Las Vegas, Nevada, US
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