• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.437-440
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• 2007

Recently embedded system developed a lot. Physically, embedded systems range from portable devices such as digital watches and MP3 players, to large stationary installations like traffic lights, factory controllers, or the systems controlling nuclear power plants. This paper focuses on implementation of portable device which is applicable to the child-kidnap or missing child prevention system in residential area or public area. To be specific, this device is to transmit video data which comes from the camera in the device into the host PC via WLAN. Embedded hardware platform consists of s3c2440 with ARM9 core, WindowsCE OS and other sensors. OS enables the platform to do multitasking jobs which are handling GPS data, taking video, capturing audio via microphone in the device and transfer all kind of realtime data to the host PC.

• Journal of Broadcast Engineering
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• v.22 no.1
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• pp.87-94
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• 2017

This paper presents a prototype for virtual reality operating system (VR OS) concept with head mount display (HMD) and hand gesture recognition technology based on game engine (Unity3D). We have designed and implemented simple multitasking thread mechanism constructed on the realtime environment provided by Unity3D game engine. Our virtual reality operating system receives user input from the hand gesture recognition device (Leap Motion) to simulate mouse and keyboard and provides output via head mount display (Oculus Rift DK2). As a result, our system provides users with more broad and immersive work environment by implementing 360 degree work space.

• Journal of the Korea Society of Computer and Information
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• v.13 no.1
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• pp.29-35
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• 2008

For efficient message passing of Parallel programs, it is required to schedule the involved two processes at the same time which are executed on different nodes, that is called 'co-scheduling' However, each node of cluster systems is built on top of general purpose multitasking OS. which autonomously manages local Processes. Thus it is not so easy to co-schedule two (or more) processes in such computing environment. Our work proposes a co-scheduling scheme for MPI-based parallel programs which exploits message exchange information between two parties. We implement the scheme on Linux cluster which requires slight kernel hacking and MPI library modification. The experiment with NPB parallel suite shows that our scheme results in 33-56% reduction in the execution time compared to the typical scheduling case. and especially better Performance in more communication-bound applications.

• Journal of Information Technology Services
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• v.19 no.6
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• pp.55-82
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• 2020

This study examined the factors that influence the turnover intention, job performance of call center representatives based on the adaptive structuration theory (AST). This study intended to empirically examine how individual characteristics of representative affect the technological and task adaptation, how they affect job performance and turnover intention. On the other hand, this study also explains how rational culture and organization a reputation which are considered as dimensions of organizational characteristics affects organizational commitment, and verifies the relationship between organizational commitment and job performance and turnover intention. Finally this paper aim to provide academic and practical implications. In order to solve the above research problems, this research proposed a model based on the adaptive structuration theory. In order to identify the relationship between the proposed variables and the AST for individual, we conducted an empirical test on the call center representatives. The structural equation model was used to verify the research model and hypotheses. The results of the empirical analysis show that the personal characteristics of counselors, such as communication skills, multitasking abilities, and innovativeness have a positive effect on skill adaptation, and skill adaptation has a positive effect on task adaptation, furthermore, it influences on job performance and turnover intention Respectively. In addition, among the factors of organizational environmental dimensions of the call center, it was found that organizational reputation not only increase continuance commitment but also increase normative commitment. Contrary to our expectations, perceived rational culture didn't have a positive effect on organizational commitment. Also, continuance commitment and normative commitment are valid predictors of job performance, but they have nothing to do with turnover intention. On the contrary, emotional commitment is the only one variable among three dimensions of organizational commitment have a positive effect on turnover intention, but is not a valid predictor of job performance.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.118-128
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• 2021

As interest in the audiobook market is growing, this study examined the influence of audiobook usage on purchase intention. An online survey was conducted in December 2020 targeting those in their 20s to 40s with experience using audiobooks. PLS-SEM was employed and the results are as follows. First, information, relaxation, and convenience motivation of audiobooks had a positive impact on user satisfaction. Second, while innovativeness of users had a positive impact on satisfaction, multitasking did not significantly affect satisfaction. Third, satisfaction had a positive impact on continued use and purchase intention. Finally, the continued use intention positively affected the purchase intention. This study is significant as an early study on the use of audiobooks. It is also meaningful in that it explored the process of evolving books in accordance with changes in technology and market demand.

• Journal of Digital Convergence
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• v.20 no.2
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• pp.415-424
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• 2022

This study is a user experience research on the current usage of TV multiview and evaluating the usability. From traditional TV viewing to connecting laptop or mobile devices, the scope of using TV has expanded and evolved to multipurpose. Utilizing the multiview feature offers new TV experiences, but research on its usability has not been actively conducted yet. In this research, a case study and survey were held prior to usability testing to identify user needs and behavior of TV multiview. After reviewing the results, we ran a task-based usability testing and in-depth interview. As a result, users preferred different ways of accessing and using multiview based on their situation, and the current user interface needed improvement for easier, intuitive use. This study is expected to contribute to the development of improving user experience in TV multiview.

• The Journal of the Korea Contents Association
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• v.22 no.3
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• pp.94-104
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• 2022

As the audio content market grows due to the spread of the AI speaker market and the influence of connected cars, the demand for podcast service is increasing. Therefore, in this study, the behaviors of podcast users were identified and the user types were classified. In the background study, podcast usage motives and user types were studied, and they were referred to when making the questionnaire. In the survey, preferred audio content was identified according to the situation, and in the in-depth interview, the user type and insights were derived by identifying the audio service usage behavior. As a result of the survey, there was little difference between preferred content for single listening and multitasking, but the difference in preferred content according to time period was statistically significant. The three user types derived from the in-depth interview were divided into users who listen alone for the purpose of study, find and listen to useful information quickly while on the go, and multitask and listen to the light and comfortable contents. It is expected that the results of this study will be an important reference for designing an audio content platform to improve user experience.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.2
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• pp.61-66
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• 2023

As the use of smartphones expands to various areas and the level of multitasking increases, the support of swap is becoming increasingly important. However, swap support in smartphones is known to cause excessive storage traffic, resulting in memory thrashing. In this paper, we analyze how the thrashing of swaps that occurred in early smartphones has changed with the advancement of smartphone hardware. As a result of this analysis, we show that the swap thrashing problem can be resolved to some extent when the memory size increases. However, we also show that thrashing still occurs when the number of running apps continues to increase. Based on further analysis, we observe that this thrashing is caused by some hot data and suggest a way to solve this through an NVM-based architecture. Specifically, we show that a small size NVM with judicious management can resolve the performance degradation caused by smartphone swap.

• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.885-890
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• 2024

This study proposes a secure keypad structure that can adapt to screen changes in mobile devices equipped with stretchable display. For this purpose, we compared and analyzed the authentication methods applied to current rigid form factor smartphones with those applied to rollable and bendable display based smartphones, which are the previous stages of stretchable display. Based on the results of this analysis, we identified potential user convenience and security safety issues that may arise in the form factor structure for smart wallets, multitasking, screen expansion and media viewing, and gaming and entertainment applications where stretchable displays will be applied, then proposed a security keypad structure for these form factors. Our keypad structure provides enhanced user convenience and security compared to the structures applied in the smartphone environment based on the conventional rigid display form factor and rollable, bendable display form factor.

• Journal of KIISE:Computer Systems and Theory
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• v.34 no.8
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• pp.367-376
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• 2007

In this paper, we introduce an application-specific and adaptive power management technique for portable systems that support dynamic voltage scaling (DVS). We exploit both the idle time of multitasking systems running soft real-time tasks as well as memory- or CPU-bound code regions. Detailed power and execution time profiles guide an adaptive power manager (APM) that is linked to the operating system. A post-pass optimizer marks candidate regions for DVS by inserting calls to the APM. At runtime, the APM monitors the CPU's performance counters to dynamically determine the affinity of the each marked region. for each region, the APM computes the optimal voltage and frequency setting in terms of energy consumption and switches the CPU to that setting during the execution of the region. Idle time is exploited by monitoring system idle time and switching to the energy-wise most economical setting without prolonging execution. We show that our method is most effective for periodic workloads such as video or audio decoding. We have implemented our method in a multitasking operating system (Microsoft Windows CE) running on an Intel XScale-processor. We achieved up to 9% of total system power savings over the standard power management policy that puts the CPU in a low Power mode during idle periods.