• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.445-448
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• 2018

In this paper, we design microstrip antenna for GPS / WiFi for broadband mobile communication. The proposed antenna is designed to be used in the FR-4 (er = 4.3), the size is $40mm{\times}50mm$, and it can be used in the GPS frequency band of 1.6GHz and the WiFi frequency band of 5GHz. 2014, and the simulation result shows that the gain is 1.909dB at 1.6GHz and 4.607dB at 5GHz. The S-parameter also showed a result of less than -10dB (WSWR2: 1) in the desired frequency band. Recently, it is expected that GPS navigation system, which is widely used in smart phones and tablet PCs, can be easily and conveniently used by combining and applying GPS with WiFi.

• The Journal of Society for e-Business Studies
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• v.17 no.4
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• pp.197-208
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• 2012

Recently, the development of smart devices such as smart phones and tablet PCs, with mobility, convenience and real-time computing, promotes proliferation and activation of social media. It also causes innovative changes in communication methods. Since 2010, researches in SNS (Social Networking Services) have focused on developing marketing strategies using SNS. On the other hand, the main purpose of this study is to provide a requirement analysis method of smart phone users by using content analysis of SNS. An information systems developed in this study in order to analyze content of SNS automatically because it is very difficult and time consuming to analyze it manually. In addition, this study compares the result of content analysis with that of Kano survey in order to examine consistency between the two results.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.3
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• pp.6-14
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• 2014

Touch panels are widely used in the modern display industry as the cover glass of smart mobile phones and tablet PCs. Glass cutting machines are commonly used to cut the panels into their proper sizes. Vibration of these glass cutting machines is assumed to be the main factor leading to the creation of burrs, notches, cracks, scratches and chips on the cut surfaces, eventually causing defects of the cover glass. In this study, the vibrations of a glass cutting machine used for the shearing of cover glass components were analyzed through an experiment and a computer simulation. The structural properties leading to vibration were also analyzed in an effort to determine design alterations which can suppress these vibrations. Moreover, each design alteration was applied to a computer simulation model to determine the effect of different alteration on suppressing vibration. The results show that simple design alterations can substantially suppress vibrations of glass cutting machines.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.2
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• pp.102-110
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• 2012

ZigBee networks developed for low power and short range communication are being used as home network solution for ubiquitous computing. However, as smart phones and tablet PCs have been widely used, WLANs which use same frequency with ZigBee networks have been increasingly used. Therefore, radio frequency interference causes many problems. To solve radio frequency interference problem among ZigBee networks and WLANs, many researches focus on designing interference minimization schemes in ZigBee networks. However, existing schemes have problems that have waste of resource for detecting interference, and have unnecessary time to avoid interference. In this paper, we propose an interference minimization scheme to solve radio frequency interference in ZigBee networks. The proposed scheme detects interference using ACK mechanism to reduce waste of resource, and avoids interference using table driven channel hopping scheme which is faster than existed schemes. The performance of proposed interference minimization scheme is evaluated by using OPNET simulator. Through the simulation result, we prove that proposed scheme has faster channel hopping than existing schemes.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.111-117
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• 2017

The National Competency Standards (NCS) was designed to implement a competence-based society and solve the problem of inconsistency between the industrial field and education, training, and certification system. This study designed and developed the Korean NCS core vocational competence system, in accordance with the NCS, as an infrastructure to solve fundamental problems such as re-education and the social costs that are incurred in the workplace. Further, this study designed and developed standard indicators to evaluate the technical performance of the system for the global advancement of the Korean NCS core vocational competence system. The NCS core vocational competence system has been developed as an appropriate response type for multiple devices such as computers, tablet PCs, and cellular phones. For the global advancement of the Korean NCS core vocational competence system, this study designed and developed 10 performance evaluation indicators in accordance with 10 global standards, such as linkage-target operating system, interface protocol, packet format, encryption, class component, simultaneous access number, supervisor-to-testtaker response speed, server-to-admin response speed, auto-recovery speed for test answers, and real-time answer transmission speed.

• Journal of Korean Home Economics Education Association
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• v.25 no.1
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• pp.155-172
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• 2013

This study developed smart education programs on clothing in Home Economics education for middle school students and assessed the validity of the programs. To create a self-directed adaptive learning model, 'Textile fibers' was selected as a topic. A digital textbook was developed to provide an adaptive learning experience to each student. The students can learn the contents of the digital textbook via their smart phones or tablet PCs in their Home Economics classes. To create a cooperative learning model for a good communication, 'Recycling clothes' was selected as a topic. Students can cooperate to solve the problems via Google docs and facebook in their Home Economics classes. The programs gained more than 4.5 on a 5-point Likert scale. The results of the assessment indicated that the smart education programs on clothing are appropriate to enhancing the self-directed learning, communication, and cooperation competencies of the students in Home Economics classes.

• Journal of Biosystems Engineering
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• v.39 no.1
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• pp.57-67
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• 2014

Purpose: The modern IT can give enormous impacts on the agricultural production and consumption. However, farmer's ability to use IT devices has been known as one of the critical factors on success of IT in agriculture. This survey study was performed to evaluate the informatization status of farmers and to draw a strategy to develop and distribute a ubiquitous agricultural information system. Methods: A survey questionnaire with 19 questions on the degree of IT devices such as computers and smartphones and their utilization were developed. The survey was questioned 3 groups of farmers in Gyounggi Province and analyzed statistically by the ${\chi}^2$ test. Results: The order of IT devices distribution were computers, smartphones, smart TVs and tablet PCs in all groups. The ratios of ownerships of the devices are 97.7, 78.6%, 31.4%, 17.8% respectively. The active farmers in this survey showed higher informatization level than that of native and the general farmers. Conclusions: The ubiquitous agricultural information system was judged to be developed for the computer because spread and use of it exceeds the other devices. Also, the information system based on the smartphone could be a complementary way if the rapid of the smartphones continues and proper education on use of the phone is provided.

• KIISE Transactions on Computing Practices
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• v.22 no.1
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• pp.38-43
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• 2016

Recent developments regarding transportation technology have positioned travel as a major leisure activity; however, trip-itinerary planning remains a challenging task for tourists due to the need to select Points of Interest (POI) for visits to unfamiliar cities. Meanwhile, due to the GPS functions on mobile devices such as smartphones and tablet PCs, it is now possible to collect a user's position in real time. Based on these circumstances, our research on an automatic itinerary-planning system to simplify the trip-planning process was conducted briskly. The existing studies that include research on itinerary schedules focus on an identification of the shortest path in consideration of cost and time constraints, or a recommendation of the most-popular travel route in the destination area; therefore, we propose a personalized itinerary-recommendation system for which the stay-time preference of the individual user is considered as part of the personalized service.

• The Journal of the Korea Contents Association
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• v.12 no.6
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• pp.48-55
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• 2012

The number of digital content used in mobile devices such as smartphones or tablet PCs has been rapidly increasing along with the development of IT industry. At the same time, studies on digital content management are actively conducted. One of the previous studies defined CTI(Content Tracking Information) for efficient management of the information on digital content usage between mobile devices in an area in which the internet is inaccessible, and suggested ways to deal with CTI management, reduction of the overhead and a technique of collecting as many CTIs as possible within a short time. This paper presents the design and implementation of a simulator capable of verifying the logic and the performance of the CTI management method. This tool simulates a mobile environment where devices move around in the internet inaccessible area and propagates digital contents each other. It shows several advantages including the efficient synchronization of CTI management and overhead reduction.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.7
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• pp.71-79
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• 2012

As advances in computer technology, dissemination of smartphones and tablet PCs has increased and digital media has become easily accessible. The performance of computer hardware is improved and the form of hardware is changed, but basically the change in mechanism was not occurred. Typically, the data used in the program is resident in memory during the operation because of the operating system efficiency. So, these data in memory is accessible through the memory dumps or real-time memory analysis. The user's personal information or confidential data may be leaked by exploiting data; thus, the countermeasures should be provided. In this paper, we proposed the method that minimizes user's data leakage through finding the physical memory address of the process using virtual memory address, and initializing memory data of the process.