Abstract Mobile device applications (apps) are complex because they rely on integrating multiple third-party libraries (TPLs). Yet, TPLs ease app development by offering implementations of specific functionality. For example, app developers often use advertising libraries to generate revenue, integrate social networking libraries to simplify login, or include crash reporting libraries to monitor/report crashes in their apps. However, there are multiple TPLs with similar functionalities from which to choose, and developers often cannot foresee all the consequences of using these libraries in their apps. The sizes of apps grow with the addition and usage of TPLs, and so does the number of required permissions and resource consumption. Thus, TPLs may degrade the quality of apps and developers need help measuring and comparing them. We propose EQuAT, an approach for Evaluating Quality Attributes of TPLs that eases the comparison of TPLs. EQuAT takes as input minimal apps that integrate TPLs and playable scenarios to simulate user interaction while exercising a particular functionality of the included TPL. By collecting quality metrics and comparing them using plots, we provide app developers with a systematic approach to rank TPLs based on their preferences. We show how EQuAT helps developers make informed decisions about which libraries to integrate into their apps by validating them against nine TPLs across three categories.

The performance of population-based multiobjective optimization algorithms is usually evaluated using indicators assessing the quality of the approximation set generated according to convergence, cardinality, spread, and uniformity (the combination of the last two known as diversity). Since not all quality indicators can capture all these properties, we propose to aggregate already-existing indicators into a single measure informing about the algorithm’s performance from a general perspective. To synthesize the desired quality indicators, we build three composite quality indicators (weak, strong, and mixed) based on the reference point approach. This approach enables the use of desirable value ranges for the aggregated quality indicators, defined by aspiration and reservation levels, that allow knowing which algorithms perform better, within, or worse than the desired limits. Each of the composite quality indicators proposed enables a different compensation degree among the aggregated indicators, and their joint use permits a deep insight into the algorithms’ performance. In addition, we show that the weak and mixed composite indicators are Pareto-compliant, and the strong one is weakly Pareto-compliant if at least one of the aggregated indicators is Pareto-compliant. Finally, we demonstrate the benefits of our proposal when comparing many population-based algorithms on three-, five-, and eight-objective optimization problems.

The Internet of Things (IoT) is a network of physical, connected devices providing services through private networks and the Internet. The devices connect through the Internet to Web servers and other devices. One of the popular programming languages for communicating Web pages and Web apps is JavaScript (JS). Hence, the devices would benefit from JS apps. However, porting JS apps to the many IoT devices, e.g., System-on-a-Chip (SoCs) devices (e.g., Arduino Uno), is challenging because of their limited memory, storage, and CPU capabilities. Also, some devices may lack hardware/software capabilities for running JS apps “as is”. Thus, we proposeMoMIT, a multiobjective optimization approach to miniaturize JS apps to run on IoT devices. We implementMoMITusing three different search algorithms. We miniaturize a JS interpreter and measure the characteristics of 23 apps before/after applyingMoMIT. We find reductions of code size, memory usage, and CPU time of 31, 56, and 36 percent, respectively (medians). We show thatMoMITallows apps to run on up to two additional devices in comparison to the original JS interpreter.

Software engineering is vital for IoT systems to design systems that are secure, interoperable, modifiable, and scalable. However, industry and academia are still working on many crucial questions related to software engineering for IoT systems, for example, regarding the best practices for developing IoT systems, how to select the hardware, communication, and software architectures of IoT systems, which communications protocols are the most suitable for a system, and how to guarantee security and privacy when dealing with consumer products often composing IoT systems.

With millions of smartphones sold every year, the development of mobile apps has grown substantially. The battery power limitation of mobile devices has push developers and researchers to search for methods to improve the energy efficiency of mobile apps. We propose a multiobjective refactoring approach to automatically improve the architecture of mobile apps, while controlling for energy efficiency. In this extended abstract we briefly summarize our work.

The energy consumption of mobile apps is a trending topic and researchers are actively investigating the role of coding practices on energy consumption. Recent studies suggest that design choices can conflict with energy consumption. Therefore, it is important to take into account energy consumption when evolving the design of a mobile app. In this paper, we analyze the impact of eight type of anti-patterns on a testbed of 20 android apps extracted from F-Droid. We propose EARMO, a novel anti-pattern correction approach that accounts for energy consumption when refactoring mobile anti-patterns. We evaluate EARMO using three multiobjective search-based algorithms. The obtained results show that EARMO can generate refactoring recommendations in less than a minute, and remove a median of 84 percent of anti-patterns. Moreover, EARMO extended the battery life of a mobile phone by up to 29 minutes when running in isolation a refactored multimedia app with default settings (no Wi-Fi, no location services, and minimum screen brightness). Finally, we conducted a qualitative study with developers of our studied apps, to assess the refactoring recommendations made by EARMO. Developers found 68 percent of refactorings suggested by EARMO to be very relevant.

The Android market is a place where developers offer paid and-or free apps to users. Free apps can follow the freemium or the ads-business model. While the former offers less features and the user is charged for unlocking additional features, the latter includes ads to allow developers to get a revenue. Free apps are interesting to users because they can try them immediately without incurring a monetary cost. However, free apps often have limited features and-or contain ads when compared to their paid counterparts. Thus, users may eventually need to pay to get additional features and-or remove ads. While paid apps have clear market values, their ads-supported versions are not entirely free because ads have an impact on performance. The hidden costs of ads, and the recent possibility to form family groups in Google Play to share purchased apps, make it difficult for developers and users to balance between visible and hidden costs of paid and ads-supported apps. In this paper, first, we perform an exploratory study about ads-supported and paid apps to understand their differences in terms of implementation and development process. We analyze 40 Android apps and we observe that (i) ads-supported apps are preferred by users although paid apps have a better rating, (ii) developers do not usually offer a paid app without a corresponding free version, (iii) ads-supported apps usually have more releases and are released more often than their corresponding paid versions, (iv) there is no a clear strategy about the way developers set prices of paid apps, (v) paid apps do not usually include more functionalities than their corresponding ads-supported versions, (vi) developers do not always remove ad networks in paid versions of their ads-supported apps, and (vii) paid apps require less permissions than ads-supported apps. Second, we carry out an experimental study to compare the performance of ads-supported and paid apps and we propose four equations to estimate the cost of ads-supported apps. We obtain that (i) ads-supported apps use more resources than their corresponding paid versions with statistically significant differences and (ii) paid apps could be considered a most cost-effective choice for users because their cost can be amortized in a short period of time, depending on their usage.

In this article, we propose a new evolutionary algorithm for multiobjective optimization called Global WASF-GA ( global weighting achievement scalarizing function genetic algorithm), which falls within the aggregation-based evolutionary algorithms. The main purpose of Global WASF-GA is to approximate the whole Pareto optimal front. Its fitness function is defined by an achievement scalarizing function (ASF) based on the Tchebychev distance, in which two reference points are considered (both utopian and nadir objective vectors) and the weight vector used is taken from a set of weight vectors whose inverses are well-distributed. At each iteration, all individuals are classified into different fronts. Each front is formed by the solutions with the lowest values of the ASF for the different weight vectors in the set, using the utopian vector and the nadir vector as reference points simultaneously. Varying the weight vector in the ASF while considering the utopian and the nadir vectors at the same time enables the algorithm to obtain a final set of nondominated solutions that approximate the whole Pareto optimal front. We compared Global WASF-GA to MOEA/D (different versions) and NSGA-II in two-, three-, and five-objective problems. The computational results obtained permit us to conclude that Global WASF-GA gets better performance, regarding the hypervolume metric and the epsilon indicator, than the other two algorithms in many cases, especially in three- and five-objective problems.

In this paper, we present a recommendation system aimed at helping users and developers alike. We help users to choose optimal sets of applications belonging to different categories (eg. browsers, e-mails, cameras) while minimizing energy consumption, transmitted data, and maximizing application rating. We also help developers by showing the relative placement of their application's efficiency with respect to selected others. When the optimal set of applications is computed, it is leveraged to position a given application with respect to the optimal, median and worst application in its category (eg. browsers). Out of eight categories we selected 144 applications, manually defined typical execution scenarios, collected the relevant data, and computed the Pareto optimal front solving a multi-objective optimization problem. We report evidence that, on the one hand, ratings do not correlate with energy efficiency and data frugality. On the other hand, we show that it is possible to help developers understanding how far is a new Android application power consumption and network usage with respect to optimal applications in the same category. From the user perspective, we show that choosing optimal sets of applications, power consumption and network usage can be reduced by 16.61% and 40.17%, respectively, in comparison to choosing the set of applications that maximizes only the rating.