Computer ARchitecture &
Embedded Systems Laboratory

> Research Area > Smart Devices Optimization

Smart Devices Optimization

1. Motivation

- Smartphones are truly personalized computing devices

- Only one dominant user per smartphone


- As a highly personalized computing device, smartphones present a unique new opportunity for system optimization
- In our own study on the Android app usage profiling of 30 participants

- A single user exhibits very regular usage patterns

- Only a small number of different apps are used

- A small set of distinctive app usage patterns is repeatedly appeared

- Some apps are strongly related to each other

- Different users are quite different in their usage patterns

2. Research goal
​- Collecting and identifying distinctive usage pattern during runtime for personalized optimization

3. POA framework
- Personalized Optimization framework for Android Smartphones (POA)

4. App usage modeling construction
- App Usage Model Module
- Accumulating past app sequence

- Dynamically building a user-specific AUM based on the past app sequence

- An example of building an app usage model​

5. Usage model-based optimization
- Consisting of various optimization-specific sub-modules for personalized optimization
- When each sub-module applies the user-specific AUM , each sub-module requests hints on future app executions from the app usage modeling module

6. Case study: Optimizing restart ratio of apps.

- The Android default app killer

- Limiting the number of the backgrounds apps lower than the predefined maximum number (15)

- Terminating an app which is least recently used (LRU)


- The problem of the default app killer

- Restart ratio of apps is high because it does not recognize the single user's app usage tendency (In our study, most users experience restart ratio more than 10%)


- Optimizing the restart ratio exploiting our proposed AUM


- Improving the performance of Android's app killing/restarting policy

7. International contest

Wook Song, Yeseong Kim, Hakbong Kim, Jehun Lim, Sang-Woo Jun, and Jihong Kim, "Personalized Optimization for Android Smartphones," Android Competition in Embedded Systems Week 2011, Taipei, Taiwan, October 12, 2011