CAREER: Harnessing Implementation Flexibility to Enable Runtime Adaptation

智能手机及其运行的应用程序(App)正在改变我们的世界。Web应用程序和软件市场使向任何人和任何地方分发软件变得比以往任何时候都更容易。然而，编写好的智能手机应用程序仍然具有挑战性。开发人员必须预见并适应众多不同的设备和用户，以及移动性导致的不断变化的条件和环境。前一分钟网络还是快速而免费的，下一分钟就变得慢而有表了。适应成功的移动应用程序的重要性是众所周知的。然而，几乎没有语言和系统支持来帮助开发人员创建和改进自适应移动应用程序。这个项目调查了一个支持下一代自适应应用程序的新系统。该方法的核心是一种新的语言构造，它允许开发人员在其源代码中表达灵活性。这使得今天必须在开发过程中做出的决定被推迟，并留下了可以利用的灵活性，以实现适应。要智能地利用开发人员展示的灵活性，需要采用新的方法来自动执行部署前测试和动态适应策略生成。该项目还探讨了如何引导开发人员实现有用的灵活性，以及如何在当前和下一代编程语言中管理和展示灵活性。综合教育计划还探索了如何利用灵活性，但利用它来调整在线课程，使其更有效。该项目从包含重叠和自我强化课程的概念库开始，探索了两种形式的灵活性。课程可以重新排序，以表达不同的先决条件，并且在每节课中，可以为不同的学生使用多个解释。综合测验结果和其他形式的反馈将被用来确定不同方法的成功或失败。这些新的个性化学习技术将应用于调查人员在互联网上创建的现有在线课程。

Smartphones and the applications (apps) that they run are transforming our world. Web apps and software marketplaces have made it easier than ever before to distribute software to anyone and anywhere. However, writing good smartphone apps remains challenging. Developers must anticipate and adapt to numerous different devices and users, and to the changing conditions and environments caused by mobility. One minute the network is fast and free, the next it is slow and metered. The importance of adaptation to successful mobile apps is well understood. However, little language and system support exists to help developers create and improve adaptive mobile apps.This project investigates a new system enabling the next generation of adaptive apps. Central to the approach is a new language construct that allows developers to express flexibility within their source code. This allows decisions that today must be made during development to be deferred, and leaves flexibility that can be harnessed to enable adaptation. Intelligently utilizing flexibility exposed by developers requires novel approaches to automated pre-deployment testing and dynamic adaptation policy generation. The project also explores how to guide developers toward useful flexibility, and how flexibility should be managed and exposed in current and next-generation programming languages.The integrated educational plan also explores how to harness flexibility, but uses it to adapt online courses to make them more effective. Beginning with a concept library containing overlapping and self-reinforcing lessons, the project explores two forms of flexibility. Lessons can be reordered to express different prerequisites, and within each lesson multiple explanations an be used for different students. Integrated quiz results and other forms f feedback will be used to determine the success or failure of different approaches. These new personalized learning techniques will be applied to an existing online course on the internet created by the investigator.