Starfish: Efficient Concurrency Support for Computer Vision Applications

by Jinyoung Choi on 2015-08-03 15:37:15

* 동영상 강의로 진행됩니다.   Date : 2015. 08. 03. (Tue) 10:30 A.M. Locate : EB5. 533   Title : Starfish: Efficient Concurrency Support for Computer Vision Applications Author : Robert LiKamWa and Lin Zhong   Abstract Emerging wearable devices promise a multitude of computer vision-based applications that serve users without active engagement. However, vision algorithms are known to be resource-hungry; and modern mobile systems do not support concurrent application use of the camera. Toward supporting efficient concurrency of vision applications, we report Starfish, a split-process execution system that supports concurrent vision applications by allowing them to share computation and memory objects in a secure and efficient manner. Starfish splits the vision library from an application into a separate process, called the Core, which centrally serves all vision applications. The Core shares library call results among applications, eliminating redundant ... Continue reading →


Ultrasonic Time Synchronization and Ranging on Smartphones

by Jinse Kwon on 2015-07-27 11:38:51

Date : 2015. 07. 28 (Tue) 10:30 A.M. Locate : EB5. 533 Presenter : Jinse Kwon   Title : Ultrasonic Time Synchronization and Ranging on Smartphones Author : Patrick Lazik   Abstract   In this paper, we present the design and evaluation of a platform that can be used for time synchronization and indoor positioning of mobile devices. The platform uses the Time-Difference-Of-Arrival (TDOA) of multiple ultrasonic chirps broadcast from a network of beacons placed throughout the environment to find an initial location as well as synchronize a receiver’s clock with the infrastructure. These chirps encode identification data and ranging information that can be used to compute the receiver’s location. Once the clocks have been synchronized, the system can continue performing localization directly using Time-of-Flight (TOF) ranging as opposed to TDOA. This provides similar ... Continue reading →


Reducing Energy Consumption of Alarm-induced Wake-ups on Android Smartphones HotMobile'15

by Jemin Lee on 2015-06-28 17:36:35

Date: 2015. 07. 03. (Fri) 10:00 A.M. Locate: EB5. 533 Presenter: jemin lee Seminar title: Reducing Energy Consumption of Alarm-induced Wake-ups on Android Smartphones HotMobile'15 Authors: Sewook Park, Dongwon Kim, Hojung Cha Abstract: Alarms are often used to set smartphones to perform tasks at scheduled times. Many applications use alarm functionality, and devices consequently experience frequent wake-ups and waste energy. In this paper, we analyze alarm-induced wake-ups in the Android platforms in terms of energy consumption. We propose a “Time Critical Alarm”, in which alarms necessarily accompany wake-ups. We then propose, AlarmScope, a scheme to reduce non-critical alarms and thus minimize energy waste. Our evaluation of widely-used applications on Android smartphones shows that the proposed scheme would save between 2.6% and 12.5% of energy use. paper download Continue reading →


Duet: Exploring Joint Interactions on a Smart Phone and a Smart Watch

by Jinyoung Choi on 2015-05-18 10:26:14

Date : 2015.05.22.(Fri) 10:00 A.M. Locate : EB5.533 Presenter : Jinyoung Choi   Title : Duet: Exploring Joint Interactions on a Smart Phone and a Smart Watch Author : Xiang ‘Anthony’ Chen, Tovi Grossman, Daniel Wigdor, George Fitzmaurice   Abstract The emergence of smart devices (e.g., smart watches and smart eyewear) is redefining mobile interaction from the solo performance of a smart phone, to a symphony of multiple devices. In this paper, we present Duet – an interactive system that explores a design space of interactions between a smart phone and a smart watch. Based on the devices’ spatial configurations, Duet coordinates their motion and touch input, and extends their visual and tactile output to one another. This transforms the watch into an active element that enhances a wide range of phone-based interactive tasks, and enables a new class of multi-device gestures and sensing techniques. A technical evaluation ... Continue reading →


The Missing Numerator: Toward a Value Measure for Smartphone Apps

by Jemin Lee on 2015-04-08 10:36:23

Date: 2015. 04. 08. (Fri) 10:00 A.M. Locate: EB5. 533 Presenter: Jemin Lee Seminar title: The Missing Numerator: Toward a Value Measure for Smartphone Apps Authors: Anudipa Maiti and Geoffrey Challen Abstract: While great strides have been made in measuring energy consumption, these measures alone are not sufficient to enable effective energy management on battery-constrained mobile devices. What is urgently needed is a way to put energy consumption into context by measuring the value delivered by mobile apps. While difficult to compute, an accurate value measure would enable cross-app comparison, app improvement, energy inefficient app detection, and effective runtime energy allocation and prioritization. Our paper motivates the problem, describes requirements for a value measure, discusses and evaluates several possible inputs to such a measure, and presents results from a preliminary (unsuccessful) attempt to formulate one.  Download: paper   Continue reading →


A case for battery charging-aware power management and deferrable task scheduling in smartphones

by Donggeon Han on 2015-04-03 09:56:17

Date: 2015. 04. 03. (Fri) 10:00 A.M. Locate: EB5. 533 Presenter: Donggeon Han Seminar title: A case for battery charging-aware power management and deferrable task scheduling in smartphones Authors: Salma Elmalaki Abstract: Prior battery-aware systems research has focused on discharge power management in order to maximize the usable battery lifetime of a device. In order to achieve the vision of perpetual mobile device operation, we propose that software also needs to carefully consider the process of battery charging. This is because the power consumed by the system when plugged in can influence the rate of battery charging, and hence, the availability of the system to the user. We characterize the charging process of a Nexus 4 smartphone and analyze the charging behaviors of anonymous Nexus 4 users using the Device Analyzer dataset. We find that there is potential for software schedulers to increase ... Continue reading →


Contextual Experience Sampling of Mobile Application Micro-Usage

by Jinyoung Choi on 2015-03-16 16:06:33

Date : 2015. 03. 20. (Fri) 10:00 A.M. Locate : EB5. 533 Presenter : Jinyoung Choi   Seminar title: Contextual Experience Sampling of Mobile Application Micro-Usage Authors Denzil Ferreira, Jorge Goncalves, Vassilis Kostakos, Louise Barkhuus, Anind Dey Abstract Research suggests smartphone users face “application overload”, but literature lacks an in-depth investigation of how users manage their time on smartphones. In a 3-week study we collected smartphone application usage patterns from 21 participants to study how they manage their time interacting with the device. We identified events we term application micro-usage: brief bursts of interaction with applications. While this practice has been reported before, it has not been investigated in terms of the context in which it occurs (e.g., location, time, trigger and social context). In a 2-week follow-up study with 15 participants, we captured participants’ context while micro-using, with a ... Continue reading →


User interaction-based profiling system for Android application tuning

by Jorge Frisancho on 2015-01-27 04:12:26

Date : 2015. 01. 27 (Tue) 01:00 P.M. Locate : EB5. 533 Presenter : Jorge Frisancho Seminar title: User interaction-based profiling system for Android application tuning Authors: Seokjun Lee, Chanmin Yoon, Hojung Cha Abstract Quality improvement in mobile applications should be based on the consideration of several factors, such as users' diversity in spatio-temporal usage, as well as the device's resource usage, including battery life. Although application tuning should consider this practical issue, it is difficult to ensure the success of this process during the development stage due to the lack of information about application usage. This paper proposes a user interaction-based profiling system to overcome the limitations of development-level application debugging. In our system, the analysis of both device behavior and energy consumption is possible with fine-grained process-level application monitoring. By providing fine-grained information, including user ... Continue reading →


BatteryExtender: An Adaptive User-Guided Tool for Power Management of Mobile Devices

by Jemin Lee on 2015-01-19 21:46:21

Date : 2015. 01. 20 (Tue) 01:00 P.M. Locate : EB5. 533 Presenter : Jemin Lee   Title: BatteryExtender: An Adaptive User-Guided Tool for Power Management of Mobile Devices Authors     Grace Metri   Department of Computer Science, Wayne State University Abstract The battery life of mobile devices is one of their most important resources. Much of the literature focuses on accurately profiling the power consumption of device components or enabling application developers to develop energy-efficient applications through fine-grained power profiling. However, there is a lack of tools to enable users to extend battery life on demand. What can users do if they need their device to last for a specific duration in order to perform a specific task? To this extent, we developed BatteryExtender, a user-guided power management tool that enables the reconfiguration of the device’s resources based on ... Continue reading →


VIT: A Timer Hypercall to Support Real-time of Guest Operating Systems

by Guest on 2015-01-13 12:35:56

Abstract Guest operating systems running over the virtual machines share a variety of resources. Since CPU is allocated in a time division manner it consequently leads them to having the unknown physical time. It is not regarded as a serious problem in the server virtualization fields. However, it becomes critical in embedded systems because it prevents guest OS from executing real time tasks when it does not occupy CPU. In this paper we propose a hypercall to register a timer service to notify the timer request related real time. It enables hypervisor to schedule a virtual machine which has real time tasks to execute, and allows guest OS to take CPU on time to support real time. The following experiment shows its implementation on Xen-Arm and para-virtualized Linux. We also analyze the real time performance with response time of test application and frames per second of Mplayer. Continue reading →


powerlet:An active battery interface for smartphones

by Donggeon Han on 2015-01-13 12:34:14

Date : 2015. 01. 13 (Tue) 13:00  Locate : EB5. 533 Presenter : Donggeon Han   Title : Powerlet: An Active Battery Interface for Smartphones Authors Wonwoo Jung, Yohan Chon, Dongwon Kim, Hojung Cha (Department of Computer Science, Yonsei university, Seoul, Korea) Abstract A smartphone battery interface should provide ener-gy-related information efficiently with high accuracy be-cause it is the basis for user actions on battery consumption. Previous studies have mainly focused on battery information per se, but the effectiveness of user interaction with the interface has barely been studied. In this paper, we first discuss the results of a survey on different types of ener-gy-related information and features to investigate what users want in terms of battery consumption for smartphones. We then introduce Powerlet, which is a new battery interface that attempts to actively interact with users to provide battery usage information. We validated the efficiency of ... Continue reading →


Common ESL Mistakes in Research Writing

by Jorge Frisancho on 2014-12-24 05:07:18

Title: Common ESL Mistakes in Research Writing By Robert C. Meurant. Date: 2014. 12. 24 (Wed) 10:00 A.M. Locate: EB5. 533 Presenter: Jorge Frisancho   Continue reading →


Efficient Memory Virtualization for Cross-ISA System Mode Emulation

by Sihyeong Park on 2014-12-05 14:00:52

Date : 2015. 01. 06 (Tue) 13:00  Locate : EB5. 533 Presenter : Sihyeong Park   Title : Efficient Memory Virtualization for Cross-ISA System Mode Emulation Authors Chao-Jui Chang    Academia Sinica, Taipei, Taiwan Roc Jan-Jan Wu          Academia Sinica, Taipei, Taiwan Roc Wei-Chung Hsu    National Taiwan University, Taipei, Taiwan Roc Pangfeng Liu         National Taiwan University, Taipei, Taiwan Roc Pen-Chung Yew    University of Minnesota at Twin Cities, Minneapolis, USA   Abstract Cross-ISA system-mode emulation has many important applications. For example, Cross-ISA system-mode emulation helps computer architects and OS developers trace and debug kernel execution-flow efficiently by emulating a slower platform (such as ARM) on a more powerful plat-form (such as an x86 machine). Cross-ISA system-mode emulation also enables workload consolidation in data centers with platforms ... Continue reading →


Android 5.0 Lollipop - New Android Runtime (ART)

by Jemin Lee on 2014-11-26 08:35:08

Date : 2014. 11. 16 (Wed) 10:00 A.M. Locate : EB5. 533 Presenter : Jemin Lee   Android 5.0 Lollipop - new android runtime (ART)   Abstract Android Runtime (ART) is an application runtime environment used by the Android mobile operating system. ART replaces Dalvik, which is the process virtual machine originally used by Android, and performs transformation of the application's bytecode into native instructions that are later executed by the device's runtime environment. Unlike Dalvik, which since Android 2.2 "Froyo" uses just-in-time (JIT) compilation to compile the bytecode every time an application is launched, ART introduces use of ahead-of-time (AOT) compilation by performing it upon the installation of an application. By reducing the overall amount of compilation that needs to be performed across the operation of an application, a mobile device's processor usage is reduced and battery runtime is improved. At the same time, ART brings ... Continue reading →


Caiipa: Automated Large-scale Mobile App Testing through Contextual Fuzzing

by Jemin Lee on 2014-11-14 10:36:20

Date : 2014. 11. 14 (Wed) 10:00 A.M. Locate : EB5. 533 Presenter : Jemin Lee   Caiipa: Automated Large-scale Mobile App Testing through Contextual Fuzzing  Authors     Chieh-Jan Mike Liang    Microsoft Research, Beijing, China Nicholas D. Lane    Microsoft Research, Beijing, China Niels Brouwers    Delft University of Technology, Delft, Netherlands Li Zhang    University of Science and Technology China, Hefei, China Börje F. Karlsson    Microsoft Research, Beijing, China Hao Liu    Tsinghua University, Beijing, China Yan Liu    Shanghai Jiaotong University, Shanghai, China Jun Tang    Harbin Institute of Technology, Harbin, China Xiang Shan    Harbin Institute of Technology, Harbin, China Ranveer Chandra    Microsoft Research, Redmond, USA Feng Zhao    Microsoft Research, Beijing, ... Continue reading →