IET Software最新文献

With the development of artificial intelligence and blockchain technology, the training of deep learning models needs large computing resources. Meanwhile, the Proof of Work (PoW) consensus mechanism in blockchain systems often leads to the wastage of computing resources. This article combines distributed deep learning (DDL) with blockchain technology and proposes a blockchain consensus scheme based on the proof of distributed deep learning work (BCDDL) to reduce the waste of computing resources in blockchain. BCDDL treats DDL training as a mining task and allocates different training data to different nodes based on their computing power to improve the utilization rate of computing resources. In order to balance the demand and supply of computing resources and incentivize nodes to participate in training tasks and consensus, a dynamic incentive mechanism based on task size and computing resources (DIM-TSCR) is proposed. In addition, in order to reduce the impact of malicious nodes on the accuracy of the global model, a model aggregation algorithm based on training data size and model accuracy (MAA-TM) is designed. Experiments demonstrate that BCDDL can significantly increase the utilization rate of computing resources and diminish the impact of malicious nodes on the accuracy of the global model.

Context: As more time has been spent on code comprehension activities during software development, automatic code summarization has received much attention in software engineering research, with the goal of enhancing software comprehensibility. In the meantime, it is prevalently known that a good knowledge about the declaration and the use of method parameters can effectively enhance the understanding of the associated methods. A traditional approach used in software development is to declare the types of method parameters.

Objective: In this work, we advocate parameter-level code summarization and propose a novel approach to automatically generate parameter summaries of a given method. Parameter summarization is considerably challenging, as neither do we know the kind of information of the parameters that can be employed for summarization nor do we know the methods for retrieving such information.

Method: We present paramTrans, which is a novel approach for parameter summarization. paramTrans characterizes the semantic features from parameter-related information based on transformer; it also explores three fusion strategies for absorbing the method-level information to enhance the performance. Moreover, to retrieve parameter-related information, a parameter slicing algorithm (named paramSlice) is proposed, which slices the parameter-related node from the abstract syntax tree (AST) at the statement level.

Results: We conducted experiments to verify the effectiveness of our approach. Experimental results show that our approach possesses an effective ability in summarizing parameters; such ability can be further enhanced by understanding the available summaries about individual methods, through the introduction of three fusion strategies.

Conclusion: We recommend developers employ our approach as well as the fusion strategies to produce parameter summaries to enhance the comprehensibility of code.

Web-based applications are popular in demand and usage. To facilitate the development of web-based applications, the software engineering community developed multiple web application frameworks, one of which is Flask. Flask is a popular web framework that allows developers to speed up and scale the development of web applications. A review of the software engineering literature revealed that the Stack Overflow (SO) website has proven its effectiveness in providing a better understanding of multiple subjects within the software engineering field. This study aims to analyze SO Flask-related questions to gain a better understanding of the stance of Flask on the website. We identified a set of 70,230 Flask-related questions that we further analyzed to estimate how the interest towards the framework evolved over time on the website. Afterward, we utilized the Latent Dirichlet Allocation (LDA) algorithm to identify Flask-related topics that are discussed within the set of the identified questions. Moreover, we leveraged a number of proxy measures to examine the difficulty and popularity of the identified topics. The study found that the interest towards Flask has been generally increasing on the website, with a peak in 2020 and drops in the following years. Moreover, Flask-related questions on SO revolve around 12 topics, where Application Programming Interface (API) can be considered the most popular topic and background tasks can be considered the most difficult one. Software engineering researchers, practitioners, educators, and Flask contributors may find this study useful in guiding their future Flask-related endeavors.

The technique of software defect prediction aims to assess and predict potential defects in software projects and has made significant progress in recent years within software development. In previous studies, this technique largely relied on supervised learning methods, requiring a substantial amount of labeled historical defect data to train the models. However, obtaining these labeled data often demands significant time and resources. In contrast, software defect prediction based on unsupervised learning does not depend on known labeled data, eliminating the need for large-scale data labeling, thereby saving considerable time and resources while providing a more flexible solution for ensuring software quality. This paper conducts software defect prediction using unsupervised learning methods on data from 16 projects across two public datasets (PROMISE and NASA). During the feature selection step, a chi-squared sparse feature selection method is proposed. This feature selection strategy combines chi-squared tests with sparse principal component analysis (SPCA). Specifically, the chi-squared test is first used to filter out the most statistically significant features, and then the SPCA is applied to reduce the dimensionality of these significant features. In the clustering step, the dot product matrix and Pearson correlation coefficient (PCC) matrix are used to construct weighted adjacency matrices, and a clustering overlap method is proposed. This method integrates spectral clustering, Newman clustering, fluid clustering, and Clauset–Newman–Moore (CNM) clustering through ensemble learning. Experimental results indicate that, in the absence of labeled data, using the chi-squared sparse method for feature selection demonstrates superior performance, and the proposed clustering overlap method outperforms or is comparable to the effectiveness of the four baseline clustering methods.

Software defect prediction (SDP) is a crucial phase preceding the launch of software products. Cross-project defect prediction (CPDP) is introduced for the anticipation of defects in novel projects lacking defect labels. CPDP can use defect information of mature projects to speed up defect prediction for new projects. So that developers can quickly get the defect information of the new project, so that they can test the software project pertinently. At present, the predominant approaches in CPDP rely on deep learning, and the performance of the ultimate model is notably affected by the quality of the training dataset. However, the dataset of CPDP not only has few samples but also has almost no label information in new projects, which makes the general deep-learning-based CPDP model not ideal. In addition, most of the current CPDP models do not fully consider the enrichment of classification boundary samples after cross-domain, leading to suboptimal predictive capabilities of the model. To overcome these obstacles, we present contrastive learning pretraining for CPDP (ConCPDP), a CPDP method integrating contrastive pretraining and category boundary adjustment. We first perform data augmentation on the source and target domain code files and then extract the enhanced data as an abstract syntax tree (AST). The AST is then transformed into an integer sequence using specific mapping rules, serving as input for the subsequent neural network. A neural network based on bidirectional long short-term memory (Bi-LSTM) will receive an integer sequence and output a feature vector. Then, the feature vectors are input into the contrastive module to optimise the feature extraction network. The pretrained feature extractor can be fine-tuned by the maximum mean discrepancy (MMD) between the feature distribution of the source domain and the target domain and the binary classification loss on the source domain. This paper conducts a large number of experiments on the PROMISE dataset, which is commonly used for CPDP, to validate ConCPDP’s efficacy, achieving superior results in terms of F₁ measure, area under curve (AUC), and Matthew’s correlation coefficient (MCC).

The ongoing challenge in the world of blockchain technology is finding a solution to the trilemma that involves balancing decentralization, security, and scalability. This paper introduces a pioneering blockchain architecture designed to transcend this trilemma, uniting advanced cryptographic methods, inventive security protocols, and dynamic decentralization mechanisms. Employing established techniques such as elliptic curve cryptography, Schnorr verifiable random function, and zero-knowledge proof (zk-SNARK), alongside groundbreaking methodologies for stake distribution, anomaly detection, and incentive alignment, our framework sets a new benchmark for secure, scalable, and decentralized blockchain ecosystems. The proposed system surpasses top-tier consensuses by attaining a throughput of 1700+ transactions per second, ensuring robust security against all well-known blockchain attacks without compromising scalability and demonstrating solid decentralization in benchmark analysis alongside 25 other blockchain systems, all achieved with an affordable hardware cost for validators and an average CPU usage of only 16.1%.

Software defect prediction (SDP) has been a prominent area of research in software engineering. Previous SDP methods often struggled in industrial applications, primarily due to the need for sufficient historical data. Thus, clustering-based unsupervised defect prediction (CUDP) and cross-project defect prediction (CPDP) emerged to address this challenge. However, the former exhibited limitations in capturing semantic and structural features, while the latter encountered constraints due to differences in data distribution across projects. Therefore, we introduce a novel framework called improved clustering with graph-embedding-based features (IC-GraF) for SDP without the reliance on historical data. First, a preprocessing operation is performed to extract program dependence graphs (PDGs) and mark distinct dependency relationships within them. Second, the improved deep graph infomax (IDGI) model, an extension of the DGI model specifically for SDP, is designed to generate graph-level representations of PDGs. Finally, a heuristic-based k-means clustering algorithm is employed to classify the features generated by IDGI. To validate the efficacy of IC-GraF, we conduct experiments based on 24 releases of the PROMISE dataset, using F-measure and G-measure as evaluation criteria. The findings indicate that IC-GraF achieves 5.0%−42.7% higher F-measure, 5%−39.4% higher G-measure, and 2.5%−11.4% higher AUC over existing CUDP methods. Even when compared with eight supervised learning-based SDP methods, IC-GraF maintains a superior competitive edge.

Cross-project defect prediction (CPDP) aims to identify defect-prone software instances in one project (target) using historical data collected from other software projects (source), which can help maintainers allocate limited testing resources reasonably. Unfortunately, the feature distribution discrepancy between the source and target projects makes it challenging to transfer the matching feature representation and severely hinders CPDP performance. Besides, existing CPDP models require an intensively expensive and time-consuming process to tune a lot of parameters. To address the above limitations, we propose an effective CPDP model named IAPCP based on distribution adaptation in this study, which consists of two stages: correlation alignment and intra-domain programming. Correlation alignment first calculates the covariance matrices of the source and target projects and then erases some features of the source project (i.e., whitening operation) and employs the features of the target project (i.e., target covariance) to fill the source project, thereby well aligning the source and target feature distributions and reducing the distribution discrepancy across projects. Intra-domain programming can directly learn a nonparametric linear transfer defect predictor with strong discriminative capacity by solving a probabilistic annotation matrix (PAM) based on the adjusted features of the source project. The model does not require model selection and parameter tuning. Extensive experiments on a total of 82 cross-project pairs from 16 software projects demonstrate that IAPCP can achieve competitive CPDP effectiveness and efficiency compared with multiple state-of-the-art baseline models.

The temporal patterns of code submissions, denoted as work rhythms, provide valuable insight into the work habits and productivity in software development. In this paper, we investigate the work rhythms in software development and their effects on technical performance by analyzing the profiles of developers and projects from 110 international organizations and their commit activities on GitHub. Using clustering, we identify four work rhythms among individual developers and three work rhythms among software projects. Strong correlations are found between work rhythms and work regions, seniority, and collaboration roles. We then define practical measures for technical performance and examine the effects of different work rhythms on them. Our findings suggest that moderate overtime is related to good technical performance, whereas fixed office hours are associated with receiving less attention. Furthermore, we survey 92 developers to understand their experience with working overtime and the reasons behind it. The survey reveals that developers often work longer than required. A positive attitude towards extended working hours is associated with situations that require addressing unexpected issues or when clear incentives are provided. In addition to the insights from our quantitative and qualitative studies, this work sheds light on tangible measures for both software companies and individual developers to improve the recruitment process, project planning, and productivity assessment.

This paper tackles current challenges in network security analysis by proposing an innovative information gain-based feature selection algorithm and leveraging visualization techniques to develop a network security log data visualization system. The system’s key functions include raw data collection for firewall logs and intrusion detection logs, data preprocessing, database management, data manipulation, data logic processing, and data visualization. Through statistical analysis of log data and the construction of visualization models, the system presents analysis results in diverse graphical formats while offering interactive capabilities. Seamlessly integrating data generation, processing, analysis, and display processes, the system demonstrates high accuracy, precision, recall, F1 score, and real-time performance metrics, reaching 98.3%, 92.1%, 97.5%, 98.1%, and 91.2%, respectively, in experimental evaluations. The proposed method significantly enhances real-time prediction capabilities of network security status and monitoring efficiency of network devices, providing a robust security assurance tool.