StoryDroid: Automated Generation of Storyboard for Android Apps

Mobile apps are now ubiquitous. Before developing a new app, the development team usually endeavors painstaking efforts to review many existing apps with similar purposes. The review process is crucial in the sense that it reduces market risks and provides inspiration for app development. However, manual exploration of hundreds of existing apps by different roles (e.g., product manager, UI/UX designer, developer) in a development team can be ineffective. For example, it is difficult to completely explore all the functionalities of the app in a short period of time. Inspired by the conception of storyboard in movie production, we propose a system, StoryDroid, to automatically generate the storyboard for Android apps, and assist different roles to review apps efficiently. Specifically, StoryDroid extracts the activity transition graph and leverages static analysis techniques to render UI pages to visualize the storyboard with the rendered pages. The mapping relations between UI pages and the corresponding implementation code (e.g., layout code, activity code, and method hierarchy) are also provided to users. Our comprehensive experiments unveil that StoryDroid is effective and indeed useful to assist app development. The outputs of StoryDroid enable several potential applications, such as the recommendation of UI design and layout code

An optimal full frequency control strategy for the modular multilevel matrix converter based on predictive control

The modular multilevel matrix converter (M3C) is a promising topology for high-voltage high-power applications. Recent researches have proved its significant advantages for adjustable-speed motor drives compared with the back-to-back modular multilevel converter (MMC). However, the branch energy balancing in the M3C presents great challenge especially at critical-frequency points where the output frequency is close to zero or grid-side frequency. Generally, this balancing control depends on the appropriate injection of inner circulating currents and the common-mode voltage (CMV) whereas their values are hard to determine and optimize. In this paper, an optimization based predictive control method is proposed to calculate the required circulating currents and the CMV. The proposed method features a broad-frequency range balancing of capacitor-voltages and no reactive power in the grid side. For operation at critical-frequency points, there is no increase on branch voltage stresses and limited increase on branch current stresses. A downscaled M3C system with 27 cells is designed and experiment results with the R-L load and induction motor load are presented to verify the proposed control method

A branch current reallocation based energy balancing strategy for the modular multilevel matrix converter operating around equal frequency

The Modular multilevel matrix converter (M3C) is a promising topology for medium-voltage, high-power applications. Due to the modular structure, it is scalable, produces high quality output waveforms and can be fault tolerant. However, the M3C suffers from capacitor-voltage fluctuation if the output frequency is similar to the input frequency. This problem could limit the circuit’s application in the adjustable speed drives (ASD). This paper introduces a theoretical analysis in the phasor-domain to find the branch energy equilibrium point of the M3C when operating with equal input and output frequencies. On the basis of this equilibrium point, a branch current reallocation based energy balancing control method is proposed to equalize the energy stored in the nine converter branches. With this novel control method, the M3C can effectively overcome the capacitor voltage fluctuation without using balancing techniques based on common mode voltage or applying reactive power at the input side

Automated and Context-Aware Repair of Color-Related Accessibility Issues for Android Apps

Approximately 15% of the world's population is suffering from various disabilities or impairments. However, many mobile UX designers and developers disregard the significance of accessibility for those with disabilities when developing apps. A large number of studies and some effective tools for detecting accessibility issues have been conducted and proposed to mitigate such a severe problem. However, compared with detection, the repair work is obviously falling behind. Especially for the color-related accessibility issues, which is one of the top issues in apps with a greatly negative impact on vision and user experience. Apps with such issues are difficult to use for people with low vision and the elderly. Unfortunately, such an issue type cannot be directly fixed by existing repair techniques. To this end, we propose Iris, an automated and context-aware repair method to fix the color-related accessibility issues (i.e., the text contrast issues and the image contrast issues) for apps. By leveraging a novel context-aware technique that resolves the optimal colors and a vital phase of attribute-to-repair localization, Iris not only repairs the color contrast issues but also guarantees the consistency of the design style between the original UI page and repaired UI page. Our experiments unveiled that Iris can achieve a 91.38% repair success rate with high effectiveness and efficiency. The usefulness of Iris has also been evaluated by a user study with a high satisfaction rate as well as developers' positive feedback. 9 of 40 submitted pull requests on GitHub repositories have been accepted and merged into the projects by app developers, and another 4 developers are actively discussing with us for further repair. Iris is publicly available to facilitate this new research direction.Comment: 11 pages plus 2 additional pages for reference

3-(4-Biphenyl-1-yl)-3-hydr­oxy-1-phenyl­prop-2-en-1-one

In the title compound, C21H16O2, the six crystallographically independent mol­ecules (Z′ = 6) all exist in the enolized form. Strong intra­molecular hydrogen bonds are observed: one approximate H-atom-centered O⋯H⋯O hydrogen bond, two tautomeric forms O—H⋯O (three mol­ecules) and O⋯H—O (two mol­ecules). Only one weak inter­molecular C—H⋯O hydrogen bond between two neighboring mol­ecules is observed in the crystal structure. In addition, eight very weak non-conventional inter­molecular C—H⋯π hydrogen-bonding contacts between mol­ecules are observed

A branch current reallocation based energy balancing strategy for the modular multilevel matrix converter operating around equal frequency

Modular multilevel matrix converter (M3C) is a promising topology for medium-voltage high-power applications. Due to the modular structure, it features easy scalability, high quality output waveforms and superior fault tolerance. However, M3C suffers serious capacitor-voltage fluctuation if the output frequency gets closer to the input frequency. This limits its use in the adjustable-speed-drive (ASD) applications. This paper introduces a theoretical analysis in phasor-domain to find the branch energy equilibrium point of M3C when operating around equal frequency. On the basis of this equilibrium point, a branch current reallocation based energy balancing control method is proposed to equalize the energy stored in the nine converter branches. With this novel control method, M3C can effectively overcome the capacitor voltage fluctuation with neither using common voltage nor applying reactive power at the input side

Bisleuconothine A potentiates the effect of hyperbaric oxygen therapy against traumatic brain injury by enhancing P2X4 protein expressions

Purpose: To investigate the effect of bisleuconothine A (BA), alone and in combination with hyperbaric oxygen (HO), on traumatic brain injury (TBI) in rats. Methods: Traumatic brain injury (TBI) was induced by dropping a 200-g weight of steel on the left anterior frontal areas of Sprague-Dawley rats. The synergistic effect of BA and HO was determined by assessing neurological score, as well as parameters of oxidative stress and inflammation, expressions of P2X4 protein and other proteins, and levels of reactive oxygen species (ROS) in the brain tissues of TBI rats. Results: Neurological function score, levels of inflammatory mediators and oxidative stress parameters were significantly reduced in rats treated with BA alone, and in those treated with a combination of BA and HO, when compared with untreated TBI rats (p < 0.01). Moreover, treatment with BA alone, and BA-HO combination attenuated the altered protein expressions of P2X4, Akt, PI3K and TLR-4 in the TBI rats, and also upregulated the mRNA expression of P2X4 in the brain tissue, when compared with untreated TBI rats (p < 0.01). Conclusion: These results suggest that BA, when used alone or in combination with HO, reduces neuronal injury through upregulation of the protein expression of P2X4 in rats with traumatic brain injury. Thus, BA may be used clinically with HO therapy for the management of traumatic injury. Keywords: Bisleuconothine A, Hyperbaric oxygen, Neuronal injury, Oxidative stress, Inflammatory mediator

Surface Adsorption-Mediated Ultrahigh Efficient Peptide Encapsulation with a Precise Ratiometric Control for Type 1 and 2 Diabetic Therapy

A surface adsorption strategy is developed to enable the engineering of microcomposites featured with ultrahigh loading capacity and precise ratiometric control of co-encapsulated peptides. In this strategy, peptide molecules (insulin, exenatide, and bivalirudin) are formulated into nanoparticles and their surface is decorated with carrier polymers. This polymer layer blocks the phase transfer of peptide nanoparticles from oil to water and, consequently, realizes ultrahigh peptide loading degree (up to 78.9%). After surface decoration, all three nanoparticles are expected to exhibit the properties of adsorbed polymer materials, which enables the co-encapsulation of insulin, exenatide, and bivalirudin with a precise ratiometric control. After solidification of this adsorbed polymer layer, the release of peptides is synchronously prolonged. With the help of encapsulation, insulin achieves 8 days of glycemic control in type 1 diabetic rats with one single injection. The co-delivery of insulin and exenatide (1:1) efficiently controls the glycemic level in type 2 diabetic rats for 8 days. Weekly administration of insulin and exenatide co-encapsulated microcomposite effectively reduces the weight gain and glycosylated hemoglobin level in type 2 diabetic rats. The surface adsorption strategy sets a new paradigm to improve the pharmacokinetic and pharmacological performance of peptides, especially for the combination of peptides.Peer reviewe