Extended Dependency Graph Research Articles

A Novel Model for Vulnerability Analysis through Enhanced Directed Graphs and Quantitative Metrics.

The rapid evolution of industrial components, the paradigm of Industry 4.0, and the new connectivity features introduced by 5G technology all increase the likelihood of cybersecurity incidents. Such incidents are caused by the vulnerabilities present in these components. Designing a secure system is critical, but it is also complex, costly, and an extra factor to manage during the lifespan of the component. This paper presents a model to analyze the known vulnerabilities of industrial components over time. The proposed Extended Dependency Graph (EDG) model is based on two main elements: a directed graph representation of the internal structure of the component, and a set of quantitative metrics based on the Common Vulnerability Scoring System (CVSS). The EDG model can be applied throughout the entire lifespan of a device to track vulnerabilities, identify new requirements, root causes, and test cases. It also helps prioritize patching activities. The model was validated by application to the OpenPLC project. The results reveal that most of the vulnerabilities associated with OpenPLC were related to memory buffer operations and were concentrated in the libssl library. The model was able to determine new requirements and generate test cases from the analysis.

Parallel parameter synthesis algorithm for hybrid CTL

• We deal with parametrised models that appear in various areas of science. • We focus on properties specified in a hybrid extension of CTL. • We provide a novel semi-symbolic parallel parameter synthesis algorithm. Parametrised models of dynamical systems arise in various areas of science. In this work, we focus on models described as parametrised Kripke structures with properties formulated in a hybrid extension of the Computation Tree Logic. Our goal is to identify all the parametrisations under which the given model satisfies the properties. To that end, we propose a novel semi-symbolic parallel parameter synthesis algorithm. The algorithm is built on top of an existing approach that utilises the so-called Extended Dependency Graphs. We extend this approach to deal with parameters. To demonstrate the usefulness of our approach, we show its application to several case studies taken from systems biology.

A Distributed Fixed-Point Algorithm for Extended Dependency Graphs*

A Distributed Fixed-Point Algorithm for Extended Dependency Graphs*

Identifying superword level parallelism with directed graph reachability}{Identifying superword level parallelism with directed graph reachability

SLP (superword level parallelism) is an efficient solution to exploit the parallelism between statements in the basic blocks of SIMD (single instruction multiple data). It has been implemented in almost all the mainstream vectorizing compilers. However, its vectorization ability is limited due to the conservativeness of the parallelism identification process. To solve this problem, this paper proposes an edg (extended dependence graph) approach to identify SLP. First, we extend the adg (array dependence graph) and sdg (statement dependence graph) to construct the edg, which includes both the dependences between each array pair and those between each statement pair. When a statement is represented as an SCC (strong connected component), all of its array references are also constructed in this SCC. We then eliminate the redundant dependence edges between the SCCs from the edg. The dependence information of each statement pair and its SLP vectorization are thus determined by analyzing the reachability between each node pair from the corresponding SCC. We implement this approach to optimize the Open64-5.0 compiler, which improves the compilers identification ability. The evaluation tests on the gcc-vect benchmarks show that the optimized Open64-5.0 compiler can identify more SLP vectorizable loops than the GCC4.9, and that the number of vectorizable loops is comparable to that of ICC14.0. The performance of our generated codes is better than the state-of-the-art for most practical applications.

BioC-compatible full-text passage detection for protein-protein interactions using extended dependency graph.

There has been a large growth in the number of biomedical publications that report experimental results. Many of these results concern detection of protein–protein interactions (PPI). In BioCreative V, we participated in the BioC task and developed a PPI system to detect text passages with PPIs in the full-text articles. By adopting the BioC format, the output of the system can be seamlessly added to the biocuration pipeline with little effort required for the system integration. A distinctive feature of our PPI system is that it utilizes extended dependency graph, an intermediate level of representation that attempts to abstract away syntactic variations in text. As a result, we are able to use only a limited set of rules to extract PPI pairs in the sentences, and additional rules to detect additional passages for PPI pairs. For evaluation, we used the 95 articles that were provided for the BioC annotation task. We retrieved the unique PPIs from the BioGRID database for these articles and show that our system achieves a recall of 83.5%. In order to evaluate the detection of passages with PPIs, we further annotated and Results sections of 20 documents from the dataset and show that an f-value of 80.5% was obtained. To evaluate the generalizability of the system, we also conducted experiments on AIMed, a well-known PPI corpus. We achieved an f-value of 76.1% for sentence detection and an f-value of 64.7% for unique PPI detection.Database URL: http://proteininformationresource.org/iprolink/corpora

System dependence graph construction for aspect oriented C++

This paper proposes an extended system dependence graph called AspectSDG to represent control and data dependences for AspectC++ programs, and presents an approach for the construction of AspectSDG. This approach decomposes aspect-oriented programs into three parts: component codes, aspect codes, and weaving codes. It constructs program dependence graphs (PDGs) for each part, and then connects the PDGs at call sites to form the complete AspectSDG. The AspectSDG can deal with advice precedence correctly, and represent the additional dependences caused by aspect codes. Based on this model, we introduce how to compute a static slice of an AspectC++ program.

Normal forms for answer sets programming

Normal forms for logic programs under stable/answer set semantics are introduced. We argue that these forms can simplify the study of program properties, mainly consistency. The first normal form, called the kernel of the program, is useful for studying existence and number of answer sets. A kernel program is composed of the atoms which are undefined in the Well-founded semantics, which are those that directly affect the existence of answer sets. The body of rules is composed of negative literals only. Thus, the kernel form tends to be significantly more compact than other formulations. Also, it is possible to check consistency of kernel programs in terms of colorings of the Extended Dependency Graph program representation which we previously developed. The second normal form is called 3-kernel. A 3-kernel program is composed of the atoms which are undefined in the Well-founded semantics. Rules in 3-kernel programs have at most two conditions, and each rule either belongs to a cycle, or defines a connection between cycles. 3-kernel programs may have positive conditions. The 3-kernel normal form is very useful for the static analysis of program consistency, i.e. the syntactic characterization of existence of answer sets. This result can be obtained thanks to a novel graph-like representation of programs, called Cycle Graph which presented in the companion article Costantini (2004b).

On the equivalence and range of applicability of graph-based representations of logic programs

Logic programs under Answer Sets semantics can be studied, and actual computation can be carried out, by means of representing them by directed graphs. Several reductions of logic programs to directed graphs are now available. We compare our proposed representation, called Extended Dependency Graph, to the Block Graph representation recently defined by Linke [Proc. IJCAI-2001, 2001, pp. 641–648]. On the relevant fragment of well-founded irreducible programs, extended dependency and block graph turns out to be isomorphic. So, we argue that graph representation of general logic programs should be abandoned in favor of graph representation of well-founded irreducible programs, which are more concise, more uniform in structure while being equally expressive.

Implementation of locking schemes in extended dependency graphs

Concurrency control in deductive databases is an important issue which deserves much attention. In this paper we examine implementation of locking schemes. We adopt a model based on dependency graphs extended with compatibility trees, and describe features related to implementation of locking schemes in this model. Algorithms for read and write locking schemes are provided, and are illustrated by several examples. Although these algorithms are simple, they exemplify what are the unique problems of concurrency control that may be encountered in deductive databases, and how to deal with these problems.