26,625 research outputs found
Comment-based concept location over system dependency graphs
Software maintenance is one of the most expensive phases of software development and understanding a program is one of the most important tasks of software maintenance. Before making the change to the program, software engineers need to find the location, or locations, where the changes will be made, they need to understand the program. Real applications are huge, sometimes old, were written by other person and it is difficult to find the location of the instructions related to a specific problem domain concept. There are various techniques to find these locations minimizing the time spent, but this stage of software development continues to be one of the most expensive and longer. The concept location is a crucial task for program understanding. This paper presents a project whose main objective is to explore and combine two Program Comprehension techniques: visualization of the system dependency graph and concept location over source code comments. The idea is to merge both features in order to perform concept location in system dependency graphs. More than locate a set of hot instructions (based on the associated comments) it will allow to detect the other instructions (the whole method).(undefined
Comment-based Concept Location over System Dependency Graphs
Abstract Software maintenance is one of the most expensive phases of software development and understanding a program is one of the most important tasks of software maintenance. Before making the change to the program, software engineers need to find the location, or locations, where the changes will be made, they need to understand the program. Real applications are huge, sometimes old, were written by other person and it is difficult to find the location of the instructions related to a specific problem domain concept. There are various techniques to find these locations minimizing the time spent, but this stage of software development continues to be one of the most expensive and longer. The concept location is a crucial task for program understanding. This paper presents a project whose main objective is to explore and combine two Program Comprehension techniques: visualization of the system dependency graph and concept location over source code comments. The idea is to merge both features in order to perform concept location in system dependency graphs. More than locate a set of hot instructions (based on the associated comments) it will allow to detect the other instructions (the whole method). ACM Subject Classification D.2.7 Maintenanc
On the Effect of Semantically Enriched Context Models on Software Modularization
Many of the existing approaches for program comprehension rely on the
linguistic information found in source code, such as identifier names and
comments. Semantic clustering is one such technique for modularization of the
system that relies on the informal semantics of the program, encoded in the
vocabulary used in the source code. Treating the source code as a collection of
tokens loses the semantic information embedded within the identifiers. We try
to overcome this problem by introducing context models for source code
identifiers to obtain a semantic kernel, which can be used for both deriving
the topics that run through the system as well as their clustering. In the
first model, we abstract an identifier to its type representation and build on
this notion of context to construct contextual vector representation of the
source code. The second notion of context is defined based on the flow of data
between identifiers to represent a module as a dependency graph where the nodes
correspond to identifiers and the edges represent the data dependencies between
pairs of identifiers. We have applied our approach to 10 medium-sized open
source Java projects, and show that by introducing contexts for identifiers,
the quality of the modularization of the software systems is improved. Both of
the context models give results that are superior to the plain vector
representation of documents. In some cases, the authoritativeness of
decompositions is improved by 67%. Furthermore, a more detailed evaluation of
our approach on JEdit, an open source editor, demonstrates that inferred topics
through performing topic analysis on the contextual representations are more
meaningful compared to the plain representation of the documents. The proposed
approach in introducing a context model for source code identifiers paves the
way for building tools that support developers in program comprehension tasks
such as application and domain concept location, software modularization and
topic analysis
The French research system : which evolution and which borders ?
We analyse the French Research System with the study of the contracts between the CNRS (Centre National de la Recherche Scientifique) and the companies and test the hypothesis of small world in science. Our working material is the data base of the contracts of the units of the CNRS with economic partners, which has been collecting information since 1986 to 2006. This first application of Network methods and tools to the CNRS contracts allows us to obtain some results: at first, the major firmsâs scientific network is not "scale-free" as if competition and strategy between the most large firms dominate the behaviour in R&D investments and management of contracts with public research units. However, in second part, we demonstrate that every discipline network is a "small world", i.e. , that it exists several scientific communities in which the diffusion of information is free and easy, even if its forwards through any actors (some labs or some firms). Probably, there are several "small worlds" in this database as in the scientific collaboration networks. Is seems that the industrial research does not disturb too much the properties of scientific network, as itâs well known in the literature of Sciences Studies
DALiuGE: A Graph Execution Framework for Harnessing the Astronomical Data Deluge
The Data Activated Liu Graph Engine - DALiuGE - is an execution framework for
processing large astronomical datasets at a scale required by the Square
Kilometre Array Phase 1 (SKA1). It includes an interface for expressing complex
data reduction pipelines consisting of both data sets and algorithmic
components and an implementation run-time to execute such pipelines on
distributed resources. By mapping the logical view of a pipeline to its
physical realisation, DALiuGE separates the concerns of multiple stakeholders,
allowing them to collectively optimise large-scale data processing solutions in
a coherent manner. The execution in DALiuGE is data-activated, where each
individual data item autonomously triggers the processing on itself. Such
decentralisation also makes the execution framework very scalable and flexible,
supporting pipeline sizes ranging from less than ten tasks running on a laptop
to tens of millions of concurrent tasks on the second fastest supercomputer in
the world. DALiuGE has been used in production for reducing interferometry data
sets from the Karl E. Jansky Very Large Array and the Mingantu Ultrawide
Spectral Radioheliograph; and is being developed as the execution framework
prototype for the Science Data Processor (SDP) consortium of the Square
Kilometre Array (SKA) telescope. This paper presents a technical overview of
DALiuGE and discusses case studies from the CHILES and MUSER projects that use
DALiuGE to execute production pipelines. In a companion paper, we provide
in-depth analysis of DALiuGE's scalability to very large numbers of tasks on
two supercomputing facilities.Comment: 31 pages, 12 figures, currently under review by Astronomy and
Computin
The sum of edge lengths in random linear arrangements
Spatial networks are networks where nodes are located in a space equipped
with a metric. Typically, the space is two-dimensional and until recently and
traditionally, the metric that was usually considered was the Euclidean
distance. In spatial networks, the cost of a link depends on the edge length,
i.e. the distance between the nodes that define the edge. Hypothesizing that
there is pressure to reduce the length of the edges of a network requires a
null model, e.g., a random layout of the vertices of the network. Here we
investigate the properties of the distribution of the sum of edge lengths in
random linear arrangement of vertices, that has many applications in different
fields. A random linear arrangement consists of an ordering of the elements of
the nodes of a network being all possible orderings equally likely. The
distance between two vertices is one plus the number of intermediate vertices
in the ordering. Compact formulae for the 1st and 2nd moments about zero as
well as the variance of the sum of edge lengths are obtained for arbitrary
graphs and trees. We also analyze the evolution of that variance in Erdos-Renyi
graphs and its scaling in uniformly random trees. Various developments and
applications for future research are suggested
- âŠ