1,178 research outputs found

    Cross-Paced Representation Learning with Partial Curricula for Sketch-based Image Retrieval

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    In this paper we address the problem of learning robust cross-domain representations for sketch-based image retrieval (SBIR). While most SBIR approaches focus on extracting low- and mid-level descriptors for direct feature matching, recent works have shown the benefit of learning coupled feature representations to describe data from two related sources. However, cross-domain representation learning methods are typically cast into non-convex minimization problems that are difficult to optimize, leading to unsatisfactory performance. Inspired by self-paced learning, a learning methodology designed to overcome convergence issues related to local optima by exploiting the samples in a meaningful order (i.e. easy to hard), we introduce the cross-paced partial curriculum learning (CPPCL) framework. Compared with existing self-paced learning methods which only consider a single modality and cannot deal with prior knowledge, CPPCL is specifically designed to assess the learning pace by jointly handling data from dual sources and modality-specific prior information provided in the form of partial curricula. Additionally, thanks to the learned dictionaries, we demonstrate that the proposed CPPCL embeds robust coupled representations for SBIR. Our approach is extensively evaluated on four publicly available datasets (i.e. CUFS, Flickr15K, QueenMary SBIR and TU-Berlin Extension datasets), showing superior performance over competing SBIR methods

    Potential Errors and Test Assessment in Software Product Line Engineering

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    Software product lines (SPL) are a method for the development of variant-rich software systems. Compared to non-variable systems, testing SPLs is extensive due to an increasingly amount of possible products. Different approaches exist for testing SPLs, but there is less research for assessing the quality of these tests by means of error detection capability. Such test assessment is based on error injection into correct version of the system under test. However to our knowledge, potential errors in SPL engineering have never been systematically identified before. This article presents an overview over existing paradigms for specifying software product lines and the errors that can occur during the respective specification processes. For assessment of test quality, we leverage mutation testing techniques to SPL engineering and implement the identified errors as mutation operators. This allows us to run existing tests against defective products for the purpose of test assessment. From the results, we draw conclusions about the error-proneness of the surveyed SPL design paradigms and how quality of SPL tests can be improved.Comment: In Proceedings MBT 2015, arXiv:1504.0192

    Encoding and analysis of variational ROS computation graphs

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    Dissertação de mestrado integrado em Engenharia InformáticaIn robotic applications, it is common to develop several variants of the same system (also known as a software product line), for example, to support different configurations of a robot. ROS is the most popular framework for developing robotic applications, where each application is implemented as a distributed system of computation nodes that communicate through message passing. HAROS is a framework for static analysis of ROS-based code. It can extract an abstract model of a ROS system’s architecture (called the computation graph) and perform an analysis on that model. However, it can only analyse one configuration at a time. In this thesis, we present three different approaches for encoding various ROS computation graphs in a single variational data structure, which contains the information related to the whole system and not just a configura tion. Additionally, we also define a variational execution algorithm for each approach, along with a small query language, so that we can query and perform some analysis on said data structures. Lastly, we evaluate these algorithms and data structures so that we can reach some conclusions on which approaches work best, and in what conditions.Nas aplicações robóticas, é comum desenvolver diversas variantes do mesmo sistema (também conhecido como uma software product line) para, por exemplo, suportar diferentes configurações de um robot. O ROS é a framework mais popular no que toca ao desenvolvimento de aplicações robóticas, onde cada aplicação é implementada como um sistema distribuído de nós de computação que comunicam entre si através do envio de mensagens. O HAROS é uma framework de análise estática de código ROS. Consegue extrair um modelo abstrato de uma arquitetura de um sistema ROS (chamado grafo de computação) e executar nesse modelo uma análise. Nesta tese, apresentamos três diferentes abordagens para codificar vários grafos de computação ROS numa única estrutura de dados variacional, que contém a informação relativa a todo o sistema e não apenas a uma configuração. Adicionalmente, também definimos um algoritmo de execução variacional para cada abordagem, juntamente com uma pequena linguagem de query, de forma a que possamos analisar e pesquisar nessas estruturas de dados. Por fim, avaliámos estes algoritmos e estruturas de dados de modo a que possamos chegar a algumas conclusões sobre que abordagens funcionam melhor, e em que situações

    Specialization of the rostral prefrontal cortex for distinct analogy processes

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    Analogical reasoning is central to learning and abstract thinking. It involves using a more familiar situation (source) to make inferences about a less familiar situation (target). According to the predominant cognitive models, analogical reasoning includes 1) generation of structured mental representations and 2) mapping based on structural similarities between them. This study used functional magnetic resonance imaging to specify the role of rostral prefrontal cortex (PFC) in these distinct processes. An experimental paradigm was designed that enabled differentiation between these processes, by temporal separation of the presentation of the source and the target. Within rostral PFC, a lateral subregion was activated by analogy task both during study of the source (before the source could be compared with a target) and when the target appeared. This may suggest that this subregion supports fundamental analogy processes such as generating structured representations of stimuli but is not specific to one particular processing stage. By contrast, a dorsomedial subregion of rostral PFC showed an interaction between task (analogy vs. control) and period (more activated when the target appeared). We propose that this region is involved in comparison or mapping processes. These results add to the growing evidence for functional differentiation between rostral PFC subregions

    Towards Erlang-based ABS Microservices Framework for Software Product Line Development

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    The current widely used software system can be categorised as a large or very large decentralised control system with various requirements and continuous interchangeable elements. This characteristic leads to a need to control the variability to manage such systems. Software Product Line Engineering (SPLE) is one of the approaches that can manage the variability by developing sets of products. However, there is a need for support tools for development with software product line engineering. One language that supports the SPLE process is Abstract Behavioral Specification (ABS). Some SPLE research has used ABS to create frameworks that support the SPLE process. ABS Microservices is one research that utilises ABS to create a web framework that supports the SPLE process. This framework uses ABS to generate Java-based applications. The research interest in the web application is driven by the fact that it is one of the software types widely used by organisations and serves as the primary support of their business. Microservices are highly interoperable, thus enabling researchers to integrate different technology from other research. However, there is a need for renewal to the ABS Microservices framework. There is a need for more variants of SPLE-enabled frameworks that use more programming language as a specific programming language has its strength and weakness. Deprecation of the Java backend of the ABS opens a new exploration of another web framework that uses other ABS backend languages. We present the ABS microservices web framework based on Erlang OTP. We choose Erlang because it promises more efficient resource usage and the Erlang backend is one of the ABS backends with the most available features. This research aims to create an entry point for ABS Microservices to support more language. This research shows that the Erlang variant of ABS Microservices has less resource usage than the Java variant. Hence, this promises more options to develop product lines using ABS Microservices

    Enhanced software product line (ENSPL) for industrial test applications[QA75].

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    Pendekatan-pendekatan barisan produk perisian masa kini menghasilkan produk perisian yang mempunyai ikatan kuat dengan aset-aset perisian. Current software product lines (SPL) methodologies develop software products in the manner that is tightly coupled to the software assets

    A systematic literature review on the semi-automatic configuration of extended product lines

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    Product line engineering has become essential in mass customisation given its ability to reduce production costs and time to market, and to improve product quality and customer satisfaction. In product line literature, mass customisation is known as product configuration. Currently, there are multiple heterogeneous contributions in the product line configuration domain. However, a secondary study that shows an overview of the progress, trends, and gaps faced by researchers in this domain is still missing. In this context, we provide a comprehensive systematic literature review to discover which approaches exist to support the configuration process of extended product lines and how these approaches perform in practice. Extend product lines consider non-functional properties in the product line modelling. We compare and classify a total of 66 primary studies from 2000 to 2016. Mainly, we give an in-depth view of techniques used by each work, how these techniques are evaluated and their main shortcomings. As main results, our review identified (i) the need to improve the quality of the evaluation of existing approaches, (ii) a lack of hybrid solutions to support multiple configuration constraints, and (iii) a need to improve scalability and performance conditions
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