Updated Code Research Articles

Understanding and Analyzing Factors that Affect Merge Conflicts from the Perspective of Software Developers

Merge conflicts are very common in collaborative software development, which is supported mainly by the use of branches that can be potentially merged. In this context, several studies have proposed mechanisms to avoid conflicts whenever possible and some identified factors that lead to conflicts. In this article, we report on an investigation of factors that can lead to conflicts or that can somehow reduce the chances of conflict from the developers’ perspective. To do so, based on related work, we conducted two empirical studies with Brazilian software developers to both understand and analyze factors that affect merge conflicts. Firstly, we conducted survey research with 109 software developers to understand how they use branches, the occurrence of conflicts and the resolution process, and factors that can lead to or avoid conflicts. Results showed that the use of branches is very common and mostly has the purpose of creating a new feature or fixing a bug. According to the participants, in most projects, developers have the autonomy to create new branches and sometimes conflicts happen. The main factors that can lead to conflicts are “the time a branch is isolated” and “lack of communication”. On the other hand, the factors cited as good practices to avoid conflicts were “improve team communication” and “less branching duration”. Secondly, we conducted a field study based on interviews with 15 software developers to analyze those factors to understand better what leads to or avoids conflicts in a merge. Finally, this work allowed us to conclude that communication with the team, checking code updates, shorter branch duration, and management are important for software developers, especially when they think about what increases and decreases merge conflicts.

A review on using inorganic binders in fiber reinforced polymer at different conditions to strengthen reinforced concrete beams

• Previous research on the strengthening of RC beam with FRCM is analyzed. • Failure modes of strengthened beams are highlighted. • The performances of strengthened elements with FRCM at high temperatures are reviewed. Strengthening and rehabilitation of structural element are inevitable and the strengthened concrete structural elements are primarily used to increase the life span of deteriorated structures by complying with the updated design code and regulation. Fiber Reinforced Polymer (FRP) technique is used for repairing and strengthening concrete structures, due to the properties of FRP such as light weight, high strength, corrosion refusal and easy to oversee. The organic binder resins used along with FRP have their own shortcomings due to which inorganic binders like cementitious mortars are used along with FRP as replacement for strengthening the structural members. They are commonly denoted as Fabric Reinforced Cementitious Matrix (FRCM). Inorganic binders consist of cement mortar added with any of the industrial by-products such as fly ash, ground blast-furnace slag, silica fume etc., and relevant polymers are added to increase the bond strength virtues. The FRCM can withstand high thermal conditions and exhibits better compatibility with the concrete surface. This paper aims to provide comprehensive details about the structural strengthening using inorganic bonding agent along with FRP under common practical conditions.

Integrated report content evolution: A case study of the Johannesburg Securities Exchange food and drug retail sector

Background: Since the release of the King III report in 2009, and the adoption of these principles in the Johannesburg Securities Exchange (JSE) listing requirements, there has been a surge in integrated reporting guidelines, including the release of the International Integrated Reporting Council (IIRC) framework and Global Reporting Initiative (GRI) sustainability reporting standards, with an updated code for corporate governance, King IV, subsequently being published. These introductions have simulated a growth in research on integrated reporting; however, the impact of these initiatives on the annual integrated report (AIR) composition or format has not been explored. Aim: The objective of this article is to examine, compare and contrast identified trends in the composition of published AIRs following the release of the aforementioned guidelines. Setting: JSE-listed companies in the food and drug retail sector were analysed from 2009 to 2018. Methods: The study applied both qualitative and quantitative content analysis techniques to analyse the composition of AIRs. Results: The composition of AIRs of companies within the given sector and timespan has shifted, shown through a decrease in the number of pages containing annual financial statements and an increase in governance, strategy and sustainability information. Annual integrated reports have moved to explaining financial results with reference to full financial statements published online, with the other identified shifts coinciding closely with the release of integrated reporting developments. These results suggest that there has been an uptake in application of new reporting initiatives. Contribution: The article revealed that new reporting guidelines had been applied, generating a change in the composition of AIRs over the years, contributing to the body of knowledge on the reporting of economic, environmental and social perspectives. Conclusion: A comprehensive foundational study has been created that has illustrated that AIRs have developed in relation to new reporting initiatives.

Macroscopic modelling for screens inside a tuned liquid damper using incompressible smoothed particle hydrodynamics

Liquid sloshing inside a Tuned Liquid Damper (TLD) equipped with screens introduces significant numerical modelling challenges. A 2D Incompressible Smoothed Particle Hydrodynamics (ISPH) model employing a novel macroscopic screen model is presented to capture the complex flow associated with screens and significantly minimize the high computation cost of traditional microscopic screen models. The macroscopic screen model is based on Ergun's equation for pressure drop in porous media. The Sub-Particle Scale (SPS) turbulence model is added to the base code. The modified ISPH code is validated for a hydrostatic case and tank without screens scenario. The predicted sloshing forces and wave heights are validated against experimental data and are compared to numerical results of an existing macroscopic screen model. Findings indicate that the proposed model agrees with experimental results for different fluid depths and under a broad range of excitation amplitudes. The proposed macroscopic screen model and updated ISPH code can more accurately capture the response at small excitation amplitudes and requires less computation time than an existing macroscopic model. The proposed model can be an efficient tool for studying internal tank responses over various excitation amplitudes and frequencies without the need for experimental data to determine the drag coefficient for different screen geometries.

Extending SC-PDSI-PM with neural network regression using GLDAS data and Permutation Feature Importance

The Palmer Drought Severity Index (PDSI) ranges from −10 to 10 and is used for monitoring drought extent and severity. PDSI is a monthly global gridded data set with partial global coverage from 1850 through 1947 and full global coverage from 1948 through 2018. PDSI updates are infrequent. We present a method to extend PDSI using Global Land Data Assimilation System (GLDAS) data. We provide an updated dataset and code for the method. We discuss the accuracy and bias of the method for various regions. We have high accuracy, with 99.5% of the globe exhibiting RMSE values less than 1. Globally our method is unbiased with an average ME of approximately 0. Some regions have slight biases with dryer and wetter regions showing a slight negative and positive biases, respectively. Prediction errors exhibits spatial trends with the highest errors in areas with extreme climate.

BugPre: an intelligent software version-to-version bug prediction system using graph convolutional neural networks

Since defects in software may cause product fault and financial loss, it is essential to conduct software defect prediction (SDP) to identify the potentially defective modules, especially in the early stage of the software development lifecycle. Recently, cross-version defect prediction (CVDP) began to draw increasing research interests, employing the labeled defect data of the prior version within the same project to predict defects in the current version. As software development is a dynamic process, the data distribution (such as defects) during version change may get changed. Recent studies utilize machine learning (ML) techniques to detect software defects. However, due to the close dependencies between the updated and unchanged code, prior ML-based methods fail to model the long and deep dependencies, causing a high false positive. Furthermore, traditional defect detection is performed on the entire project, and the detection efficiency is relatively low, especially on large-scale software projects. To this end, we propose BugPre, a CVDP approach to address these two issues. BugPre is a novel framework that only conducts efficient defect prediction on changed modules in the current version. BugPre utilizes variable propagation tree-based associated analysis method to obtain the changed modules in the current version. Besides, BugPre constructs graph leveraging code context dependences and uses a graph convolutional neural network to learn representative characteristics of code, thereby improving defect prediction capability when version changes occur. Through extensive experiments on open-source Apache projects, the experimental results indicate that our BugPre outperforms three state-of-the-art defect detection approaches, and the F1-score has increased by higher than 16%.

Alcohol and Psoriasis for the Dermatologist: Know, Screen, Intervene.

Psoriasis patients are at increased risk of harmful alcohol use and alcohol dependency with many deleterious effects. Increasing alcohol use is associated with worsening psoriasis severity, is a risk factor for poor response to systemic treatments and may impact on comorbidities such as psoriatic arthritis, cardiovascular disease, cancer and liver disease. Harmful alcohol use and alcohol dependency can be defined by the updated ICD-11 coding system and screening can be completed using many tools including the Cut down, Annoyed, Guilty, Eye-Opener (CAGE), Alcohol Use Disorders Identification Test (AUDIT) and Michigan Alcohol Screening Test (MAST) questionnaires. Dermatologists may be able to complete brief interventions encouraging alcohol reduction in psoriasis patients. Psoriasis patients may respond to messages of gain with reduced psoriasis severity and loss with reduced cardiovascular risk. It is important for dermatologists to discuss alcohol with all psoriasis patients, to be aware of the impact of alcohol in psoriasis and to familiarise themselves with screening tools, brief intervention and local services available to patients who require specialist input for harmful alcohol use or alcohol dependency.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40257-022-00713-z.

Sustainable Building Standards, Codes and Certification Systems: The Status Quo and Future Directions in Saudi Arabia

Sustainable building practices are a response to environmental issues. Businesses and industries are assessing how their activities affect the environment. The architecture, engineering and construction (AEC) industries have significant impacts on the environment and economy, while the industry is considered one of the largest contributors to greenhouse gas (GHG) emissions and has, therefore, been highlighted by researchers as a key area of intervention with a great potential to reduce environmental impacts. This paper critically reviews and evaluates the current state of sustainable building certification systems with the purpose of having a good understanding of the status quo and possibilities for future directions in Saudi Arabia. It reviews the academic literature on Saudi Arabia’s green/sustainable building codes, standards, certification systems, methods and tools. It starts by addressing sustainability in the broadest sense. Then, it investigates sustainability strategies and evaluates the building certification systems in Saudi Arabia, followed by an introduction to the new practice of sustainable healthcare building assessment. Life cycle assessment (LCA) and building information modelling (BIM) techniques have also been investigated. The paper introduces the updated Saudi Building Code (SBC) with further evaluation of the Saudi Green Building Code (SBC 1001-CR). Finally, the paper clearly highlights the key role of sustainable building practices and the need to develop a certification system that considers the new trends and the local context.

Erratum

Erratum

Finding gadgets in incremental code updates for return-oriented programming attacks on resource-constrained devices

Code-reuse attacks pose a threat to embedded devices since they are able to defeat common security defences such as non-executable stacks. To succeed in his code-reuse attack, the attacker has to gain knowledge of some or all of the instructions of the target firmware/software. In case of a bare metal firmware that is protected from being dumped out of a device, it is hard to know the running instructions of the target firmware. This consequently makes code-reuse attacks more difficult to achieve. This paper presents a novel approach how an attacker can gain knowledge of some of these instructions by sniffing unencrypted incremental updates. These updates exist to reduce the radio reception power for resource-constrained devices. It will be demonstrated how a return-oriented programming (ROP) attack can be accomplished on a MSP430 MCU using only the passively sniffed incremental updates. The generated updates of the R3diff and Delta Generator (DG) differencing algorithms will be under assessment. The evaluation reveals that both of them can be exploited by the attacker and how an attacker can maximize his information gain when dealing with more than one update. It also shows that the DG generated updates leak more information than the R3diff generated updates. This stresses the fact that even delta updates need to be protected with encryption. To defend against this attack, different countermeasures that consider different power consumption scenarios are proposed, but yet to be evaluated.

Experimental investigation on shear performance of reinforced concrete beams retrofitted by pre-stressed steel strips

Due to the material deterioration and the update of design codes, some existing reinforced concrete (RC) beams need to be strengthened. The strapping method available in the packaging industry using pre-stressed steel strips can be applied in retrofitting engineering because of its low cost and high confinement effect. To guide the application of steel strips on RC beams under shear, the parameters in this paper are the steel strip spacing, strip layers and chamfer edges. The shear-compression failure and diagonal compression failure of the specimens were observed. The test results indicated that the shear strength of the retrofitted RC beams was enhanced by a maximum of 95%, and the displacement increased by 86% compared with the control specimen. Among the three parameters, the spacing of the steel strips exhibited the most significant effect on the strength and deformability of the retrofitted beams, while the strip layer and chamfer process improved the ductility more than the shear strength. The shear mechanism of the retrofitted RC beams was analyzed on the basis of the softened strut-and-tie model, and the steel strip was considered as a tie model to contribute to the shear strength. A theoretical equation and a design equation considering the parameters of steel strips were proposed to predict the shear capacity of the retrofitted RC beams and then validated by the experimental data.

Response Modification Factors for Multi-Span Reinforced Concrete Bridges in Pakistan

In Pakistan, updated codes covering seismic provisions for reinforced concrete bridges do not exist. The majority of the bridge design uses different versions of AASTHO-LRFD provisions. Response modification factors recommended for usage in these codes are primarily for bridges derived from conditions and bridges in the United States of America. This research focuses on the seismic assessment of three real multi-spans simply supported reinforced concrete bridges in Pakistan having multiple bents. This typology of bridges is very common in Pakistan. Non-linear static pushover analysis is performed to derive seismic capacity curves for these bridges, which were used to compute response modification factors. The study results show that response modification factors vary between 4.50 and 5.0 for the bridges in the longitudinal and transverse directions. The results of this work may serve as input in developing the seismic design code of bridges in Pakistan.

SAT2LOD2: A SOFTWARE FOR AUTOMATED LOD-2 BUILDING RECONSTRUCTION FROM SATELLITE-DERIVED ORTHOPHOTO AND DIGITAL SURFACE MODEL

Abstract. Deriving LoD2 models from orthophoto and digital surface models (DSM) reconstructed from satellite images is a challenging task. Existing solutions are mostly system approaches that require complicated step-wise processes, including not only heuristic geometric operations, but also high-level steps such as machine learning-based semantic segmentation and building detection. Here in this paper, we describe an open-source tool, called SAT2LOD2, built based on a minorly modified version of our recently published work. SAT2LoD2 is a fully open-source and GUI (Graphics User Interface) based software, coded in Python, which takes an orthophoto and DSM as inputs, and outputs individual building models, and it can additionally take road network shapefiles, and customized classification maps to further improve the reconstruction results. We further improve the robustness of the method by 1) intergrading building segmentation based on HRNetV2 into our software; and 2) having implemented a decision strategy to identify complex buildings and directly generate mesh to avoid erroneous LoD2 reconstruction from a system point of view. The software can process a moderate level of data (around 5000*5000 size of orthophoto and DSM) using a PC with a graphics card supporting CUDA. Furthermore, the GUI is self-contained and stores the intermediate processing results facilitating researchers to learn the process easily and reuse intermediate files as needed. The updated codes and software are available under this GitHub page: https://github.com/GDAOSU/LOD2BuildingModel.

Transparency and efficiency in building code review. The case of Ontario, Canada

The paper reports findings from a study of building codes and the code change process in Canada. The context is attempts by insurers to change building codes at the national and Province of Ontario levels to make housing more resilient to high winds. The paper focuses on one code update intended to strengthen the roof-to-wall connection in low-rise wood-framed dwellings. The research began with an extensive review of research and government documents followed by discussions and interviews with key stakeholders in the process. The paper concludes that the process of upgrading residential building codes, especially in Ontario, could be more transparent and efficient by incorporating innovations and technology utilized by the International Code Council in the United States.

Application of the multiple sphere superposition solution to large–scale systems of spheres via an accelerated algorithm

The application of an algorithm, based upon an FFT–enabled discrete Fourier convolution, to the multiple sphere superposition solution is presented. As opposed to the NS2 operation count scaling for the standard superposition solution algorithm, where NS is the number of spheres, the accelerated algorithm results in closer to NSlnNS scaling. The new algorithm has been adopted into the Multiple Sphere T Matrix (MSTM) fortran-90 code, and the code has been optimized to allow for rapid calculation of configuration– and/or orientation–averaged radiative properties of large–scale systems of randomly–positioned spheres. Improvement in computational times by more than two orders of magnitude are possible for systems containing in excess of 1000 spheres. Illustrative examples of the application of the updated code are presented.

SOFTVER ESCROW UGOVORI

Because for many companies, continuous operation and maintenance of custom software are crucial, they usually want to ensure that this continues even if the software licenser cannot operate in the future, for example, due to bankruptcy. The easiest way to overcome this for the licensee is to get a copy of the updated source code. Software developers are understandably reluctant to give a copy of their proprietary source code to the customer. The most significant asset of software developers is usually their source code, which can contain valuable trade secrets. One of the ways a software developer can deal with a client that requires access to the source code is to agree to store the source code using a triple escrow agreement. Under the escrow source code agreement, the developer provides a copy of the source code and documentation to a neutral party for safekeeping. The third party will hand over the source code to the buyer only after certain conditions defined by the contract have been met, such as the bankruptcy of software developers. That keeps the developer's source code confidential while, in theory, giving the user access to it if necessary. In this paper, we present the term software escrow contract.

In-situ adaptive thermal simulation method for predicting and avoiding hotspots in material extrusion processes

PurposeThis study aims to design a novel strategy to avoid thermal defects in three-dimensional (3D) printing processes. A combination of subroutines and utility routines allows for in situ variations of the key process parameters (KPP) in the thermal simulation and produces by post-processing the output an updated machine code for enhanced quality of the printed part in a single iteration.Design/methodology/approachThe input data for the thermal simulation were obtained by characterising an acrylonitrile butadiene styrene filament and calibrating an Ultimaker S5 printer. Abaqus subroutines were used to accurately simulate the continuous deposition of molten material. A utility routine extracted the nodal temperatures during simulation and detected regions that were prone to overheating. We developed a method, enabling the introduction of variable process parameters in the thermal simulation and validated it by printing several test geometries.FindingsThe results of the thermal simulation indicate that decreasing the print speed enhances the amount of heat dissipated to the environment. Therefore, it is an efficient way to avoid overheating of the printed geometry. The validation geometries showed improvements when adapting the print speed.Originality/valueThis approach is the first to demonstrate the potential of variable process parameters using implemented routines in the thermal process simulation. Here, the focus is on predicting and avoiding thermal hotspots. However, more potential can be obtained by enabling the prediction and adaptation of KPP to ensure mechanical performance. This would be an alternative way to tackle the cost- and time-inefficient post-processing of 3D-printed parts.

Large‐scale semi‐automated migration of legacy C/C++ test code

AbstractThis is an industrial experience report on a large semi‐automated migration of legacy test code in C and C++. The particular migration was enabled by automating most of the maintenance steps. Without automation this particular large‐scale migration would not have been conducted, due to the risks involved in manual maintenance (risk of introducing errors, risk of unexpected rework, and loss of productivity). We describe and evaluate the method of automation we used on this real‐world case. The benefits were that by automating analysis, we could make sure that we understand all the relevant details for the envisioned maintenance, without having to manually read and check our theories. Furthermore, by automating transformations we could reiterate and improve over complex and large scale source code updates, until they were “just right.” The drawbacks were that, first, we have had to learn new metaprogramming skills. Second, our automation scripts are not readily reusable for other contexts; they were necessarily developed for this ad‐hoc maintenance task. Our analysis shows that automated software maintenance as compared to the (hypothetical) manual alternative method seems to be better both in terms of avoiding mistakes and avoiding rework because of such mistakes. It seems that necessary and beneficial source code maintenance need not to be avoided, if software engineers are enabled to create bespoke (and ad‐hoc) analysis and transformation tools to support it.

Development of a one-dimensional code for the initial design of a micro gas turbine mixed flow compressor stage

Abstract The use of micro gas turbines (MGTs) for once-off and unique applications means that a rapid turnaround design process is required. The development of a MATLAB® application-based program for the initial design and performance analysis of radial and mixed flow compressors is discussed. The program code is based on one dimensional (1D) mean line flow and loss model theory. For verification, 18 test compressors were developed, covering a wide range of design velocities, mass flow rates and meridional exit angles. Predicted performance results were verified using Numeca/FINE™ Turbo software. Initial comparisons between 1D and Computational Fluid Dynamics (CFD) results did not match well. The 1D software over-predicted compressor performance and provided poor choke prediction. Consequently, empirical models to correct these deviations were derived and implemented into the 1D Application code. The updated 1D code provided a mean choke prediction difference of 1.59% compared to an initial 14.98% difference at the design point. Mean total-to-total isentropic efficiency and pressure ratio reduced to differences of 0.74 and 1.24% from values of 11.23 and 9.31% respectively.

Leveraging structural properties of source code graphs for just-in-time bug prediction

The most common use of data visualization is to minimize the complexity for proper understanding. A graph is one of the most commonly used representations for understanding relational data. It produces a simplified representation of data that is challenging to comprehend if kept in a textual format. In this study, we propose a methodology to utilize the relational properties of source code in the form of a graph to identify Just-in-Time (JIT) bug prediction in software systems during different revisions of software evolution and maintenance. We presented a method to convert the source codes of commit patches to equivalent graph representations and named it Source Code Graph (SCG). To understand and compare multiple source code graphs, we extracted several structural properties of these .graphs, such as the density, number of cycles, nodes, edges, etc. We then utilized the attribute values of those SCGs to visualize and detect buggy software commits. We process more than 246 K software commits from 12 subject systems in this investigation. Our investigation on these 12 open-source software projects written in C++ and Java programming languages shows that if we combine the features from SCG with conventional features used in similar studies, we will get the increased performance of Machine Learning (ML) based buggy commit detection models. We also find the increase of F1 Scores in predicting buggy and non-buggy commits statistically significant using the Wilcoxon Signed Rank Test. Since SCG-based feature values represent the style or structural properties of source code updates or changes in the software system, it suggests the importance of careful maintenance of source code style or structure for keeping a software system bug-free.