• Smart Media Journal
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• v.12 no.9
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• pp.142-151
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• 2023

This study is a case study on investigating students' learning behavior in the online English reading class of an on-off course. For this purpose, a survey was conducted on a total of 77 students from an English listening and reading course and phone interview with 5 students was implemented. The findings revealed that regularity of learning interval and learning sequence need to be improved through student management in order to increase the effect of online learning. In case of lecture watching, the students are good at utilizing the strengths of taped lecture, such as using pause and repeating watching. However, more research need to be done on how to develop online lecture to enhance students' understanding of the lecture. Regarding the offline review quiz that is supposed to stimulate students into their more positive watching of the lecture, it is suggested that a few of its related elements such as the online learning period and the number of quiz questions be corrected for its better effect.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.193-196
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• 2003

For a power source of usual electronic devices such as PDA, smart phone, UPS and electric vehicle, the battery made of serially connected multiple cells is generally used. In this case, if there are some unbalanced among cell voltages, the total lifetime and the total capacity of the battery are limited to a lower value. To maintain a balanced condition in cells, an effective method of regulating the cell voltage in indispensable. In this paper introduced a method for battery balancing system using dissipation in the resistance.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.3
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• pp.49-55
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• 2012

Recently, with the rapid development of android-based smartphones, it is becomes a major security issue that the case of Android platform is an open platform. so it is easy to be a target of mobile virus penetration and hacking. Even there are a variety of security mechanisms to prevent the vulnerable points of the Android platform but the reason of most of the security mechanisms were designed at application-level that highly vulnerable to the attacks directly to the operating system or attacks using the disadvantages of an application's. It is necessary that the complementary of the android platform kernel blocks the kernel vulnerability and the application vulnerability. In this paper, we proposed a secure system using linux-based android kernel applied to LIDS(Linux Intrusion Detection and Defense System) and applied a smart phone with s5pc110 chip. As a result, the unauthorized alteration of the application was prevented with a proposed secure system.

• Journal of Korean Library and Information Science Society
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• v.42 no.2
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• pp.299-322
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• 2011

The study aims to develop a mobile library model for universities that can be adapted to offer suitable library information and services to smart phone users. To do this, we conducted a case study using four foreign and domestic mobile libraries as well as a user study with 212 participants and questionnaires. In addition, we also administered a survey with 160 librarians. Based on the results of case and user/librarian studies, we proposed a mobile library model in which an access and navigation methods are described and nine key information and services including catalog search, code reader and SNS services are proposed.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.1
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• pp.47-53
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• 2014

LTE-Advanced is the evolved version of LTE which is currently in progress at the 3GPP. At present, as the number of smart phone users is rapidly increasing, the demand for ever more capacity is driven largely by video usage and high quality data communication and so on, this let more researchers study about LTE-A all over the world. LTE-A aims to achieve improved service and communication quality over 3G system at the aspect of throughput, peak data rate, latency, and spectral efficiency. Among various features in LTE-A, the multi-user MIMO(MU-MIMO), in which the base station transmits several streams to multiple receivers, has expected to give better quality for system. In this paper, we investigate performances of various types of downlink receivers with fixed number of antennas. we first review the development process from LTE to LTE-A. Second we introduce TM9 which is adopted in Rel.10 for MU-MIMO system, including the MU-MIMO system model and the explanation on the algorithm used in system. We also have brief introduction about sub-blocking in turbo decoding, finally we compare the performance between the uncoded case and coded case which is using turbo encoding.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.4
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• pp.51-62
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• 2019

Recently, as the number of Smart Phone users increase, the simple payment system has been able to make payments using only card information such as a registered password without extra authorized certificate authentication or input of card information. In this paper, it will examine and analyze simple payment system provided by IT companies and financial institutions and the simple payment system that operates global online payment system by case view of operational direction. Then with this examination, it will study ways to improve the problems with terms of convenience and stability in terms of users. In this paper, it will analyze the inconvenient problem in using the QR code system that recently introduced and will propose solutions. Also, it will propose suggestions to solve inconvenience that caused by system that supports NFC simple payment terminal in Korea is not universalize by analyze case study on the overseas simple payment system. It will also propose opinions on the matters that customer having responsible for event of a small financial accident related to loss or theft when using the simple payment system. Then it will suggest expected requirements to prepare new security technical countermeasures and solve the conditions of meeting expectation satisfaction of users.

• Journal of Digital Contents Society
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• v.13 no.1
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• pp.53-60
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• 2012

While lots of new mobile applications are being developed, applications that provide positional information by using LBS (Location Based Service) have become popular. For instance, smart phones are able to find my location and a destination easily by using GPS, which installed in the instrument, and run the program. However, these existing positional information applications can find the location of only one user at a time. These programs are not able to find out accurate directions from current location to the destination. This paper suggests a case of system development which solved some of the problems in the implementation of existing applications using LBS. The suggested system to solve these issues, having multiple users to share positional information and showing directions, run by AR (Argument Reality). In daily use, this application would be very efficient for location people in the vicinity.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.6
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• pp.1175-1184
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• 2014

Android provides a message-passing mechanism called intent. While it helps easy developments of communications between intra and inter applications, it can be vulnerable to attacks. In particular, implicit intent, differing from explicit intent specifying a receiving component, does not specify a component that receives a message and insecure ways of using implicit intents may allow malicious applications to intercept or forge intents. In this paper, we focus on security vulnerabilities of implicit intent and review researched attacks and solutions. For the case of implicit intent using 'developer-created action', specific attacks and solutions have been published. However, for the case of implicit intent using 'Android standard action', no specific attack has been found and less studied. In this paper, we present a new attack on implicit intent using Android standard action and propose solutions to protect smart phones from this attack.

• Information Systems Review
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• v.12 no.3
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• pp.75-88
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• 2010

Business models in open market systems targeting smart phone users are determined by several important factors. First, by providing developers efficient technical platforms, it contains a setting for developers to learn, apply and improve the skills relating to the product category easily while they stay beyond a corporate boundary. Second, by the first condition, a huge population of talented developers becomes to join a specific open market where will invite more customers to use their applications. Hence it will attract more and more developer participants who will finally give a rise to a persistent market growth. Third, the evaluation system between platform providers and application producers, and one between application producers and application users may underlie the trust relationships between them. The research conducted a multiple embedded case study to test the success factors of open market based business models. It focused on smart phone game communities that have installed user evaluation, and feedback systems. The user innovation empowerment model within the social game networks has highlighted the theories on the roles and characteristics of lead users, and lead user network behaviors for future NPD participations.

• Journal of Digital Contents Society
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• v.15 no.4
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• pp.481-489
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• 2014

In this paper, the automatic standby power blocking socket outlet to reduce standby power by blocking power threshold is implemented. Where, the standby power means a flowing power when a disused power electronic is plugged into the socket outlet. The proposed socket outlet can cut off the standby power by establishing a proper block power threshold electronic device according to each electronic device because it can monitor the amount of power through the smart machines such as the real-time PC or mobile phone and directly control the blocking power threshold. The software is implemented by using Visual Studio software, code vision and SN8 C studio, and the hardware is embodied in ATmega128, SN8F27E93S, USB to UART, and relay etc. Through the simulation, we find that the standby power of the proposed method is similar to that of the conventional method in case of the cellular phone but the standby power of the proposed method is much less than that of the conventional method in case of the computer, air conditioning, and set-top box. Therefore, it is proved that the proposed socket outlet has a superior performance in terms of the standby power.