Jácome Costa Cunha

Abstract
Although hardware is generally seen as the main culprit for a computer's energy usage, software too has a tremendous impact on the energy spent. Unfortunately, there is still not enough support for software developers so they can make their code more energy-aware. This paper proposes a technique to detect energy inefficient fragments in the source code of a software system. Test cases are executed to obtain energy consumption measurements, and a statistical method, based on spectrum-based fault localization, is introduced to relate energy consumption to the source code. The result of our technique is an energy ranking of source code fragments pointing developers to possible energy leaks in their code. This technique was implemented in the SPELL toolkit. Finally, in order to evaluate our technique, we conducted an empirical study where we asked participants to optimize the energy efficiency of a software system using our tool, while also having two other groups using no tool assistance and a profiler, respectively. We showed statistical evidence that developers using our technique were able to improve the energy efficiency by 43% on average, and even out performing a profiler for energy optimization. © 2019 Elsevier Inc.

Abstract

Abstract
Spreadsheets play a pivotal role in many organizations. They serve to store and manipulate data or forecasting, and they are often used to help in the decision process, thus directly impacting the success, or not, of organizations. As the research community already realized, spreadsheets tend to have the same problems “professional” software contain. Thus, in the past decade many software engineering techniques have been successfully proposed to aid spreadsheet developers and users. However, one of the most used mechanisms to manage software projects is still lacking in spreadsheets: a version control system. A version control system allows for collaborative development, while also allowing individual developers to explore different alternatives without compromising the main project. In this paper we present a version control system, named SheetGit, oriented for end-user programmers. It allows to graphically visualize the history of versions (including branches), to switch between different versions just by pointing and clicking, and to visualize the differences between any two versions in an animated way. To validate our approach/tool we performed an empirical evaluation which shows evidence that SheetGit can aid users when compared to other tools.

Abstract

Abstract