• Journal of Digital Convergence
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• v.11 no.4
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• pp.243-249
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• 2013

In this paper, GPS(Global Positioning System) that can be used outdoors and GPS(Global Positioning System) is not available for indoor Wi-Fi(Wireless Fidelity) using the Android-based location information system has been designed and implemented. Pedestrians in a room in order to estimate the location of the pedestrian's position, regardless of need to obtain the absolute position and relative position, depending on the movement of pedestrians in a row it is necessary to estimate. In order to estimate the initial position of the pedestrian Wi-Fi Fingerprinting was used. Most existing Wi-Fi Fingerprinting position error small WKNN(Weighted K Nearest Neighbor) algorithm shortcoming EWKNN (Enhanced Weighted K Nearest Neighbor) using the algorithm raised the accuracy of the position. And in order to estimate the relative position of the pedestrian, the smart phone is mounted on the IMUInertial Measurement Unit) because the use did not require additional equipment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.900-902
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• 2015

Doors are to be the most basics of our lives from opening, closing and even keeping our property. Hence, doors have been innovated to blend in and make our daily lives more convenient. However, we find it difficult to open and close the doors manually of offices or tour zones, where they open and close at a precise time everyday. To solve this, we added a dimension of time to previous Door Locks. By this, every door with this specific door lock will open and close at a certain time we want them to open or close. Also, through the application you can control the time or use it to open and close the doors remotely. In order to do this, we systemed the door lock time system based on Java Programing language to make it easy to communicate and open or close the doors through smart phone applications, with the C programming language for the ATmega128 which will open and close the doors.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39B no.12
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• pp.842-855
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• 2014

Recently, the progress of smart phone market has retarded by oversupply therefore wearable computer has been the focus of new growth engine. Wearable computing system is a complex fusion of a variety of technologies such as wireless network, embedded, sensor and new material. Because these technologies involves utilization and mobility in addition to quality characteristic in existing software, application of ISO/IEC 9126 is not perfect when assessing quality of wearable computer. In this study, author suggested new quality assessment model for wearable computer by sorting quality attribute in ISO/IEC 9126 and adding new quality attribute. For this, author investigated features and functional requirements related to wearable computer. and then author suggested quality standard and metrics by identifying quality characteristic. Author confirmed practicality of quality assessment model by using suggested model in scenario and comparing quality assessment of three goods such as company S, L, G. This quality assessment model is expected to use guidelines for assessing quality of wearable computer.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.2
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• pp.28-36
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• 2016

Recently, owing to the development of ICT industry and wide spread of smart phone, the number of people who use car sharing service are increased rapidly. Currently two-way car sharing system with same rental and return locations are mainly operated since this system can be easily implemented and maintained. Currently the demand of one-way car sharing service has increase explosively. But this system have several obstacle in operation, especially, vehicle stock imbalance issues which invoke vehicle relocation. Hence in this study, we present an optimization approach to depot location and relocation policy in one-way car sharing systems. At first, we modelled as mixed-integer programming models whose objective is to maximize the profits of a car sharing organization considering all the revenues and costs involved and several constraints of relocation policy. And to solve this problem efficiently, we proposed a new method based on particle swarm optimization, which is one of powerful meta-heuristic method. The practical usefulness of the approach is illustrated with a case study involving satellite cities in Seoul Metrolitan Area including several candidate area where this kind systems have not been installed yet and already operating area. Our proposed approach produced plausible solutions with rapid computational time and a little deviation from optimal solution obtained by CPLEX Optimizer. Also we can find that particle swarm optimization method can be used as efficient method with various constraints. Hence based on this results, we can grasp a clear insight into the impact of depot location and relocation policy schemes on the profitability of such systems.

• Science of Emotion and Sensibility
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• v.23 no.1
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• pp.103-112
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• 2020

Smartphones, now a necessity for modern people, have become more than just an appliance, but an object of obsession for many. This has resulted in smartphone addiction in many modern people. However, the phenomenon of object addiction can lie beyond the problem of the object itself, varying according to the psychological characteristics of the subjects who use it. For this reason, this study aimed to examine adult attachment and covert narcissism as factors influencing smartphone addiction in college students. In order to do this subjects' level of smartphone addiction, adult attachment and covert narcissism needed to be measured on a scale of smartphone addiction, adult attachment and covert narcissism. Regression analysis was conducted with smartphone addiction set as the dependent variable and adult attachment and covert narcissism as independent variables. As a result, we observed anxiety attachment related to adult attachment and hypersensitivity/weakness of covert narcissism played roles in smartphone addiction. These findings suggest that in order to understand smartphone addiction in college students, it is important to know the psychological characteristics of our subjects.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.1
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• pp.89-95
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• 2016

In this paper, we propose a locker system that can remotely control and manage locker. The main features of the proposed system are follows. First, connect the locker with server and then open the locker after passing through the certification process in server. Second, locker manager can more systematically manage a locker by using locker management system based on smart phone. Third, provide an instant locker for temporary using lockers to increase the ease of use. Fourth, unlike traditional analog locker, can support better security by using authentication process and log data. Performance evaluation is performed via simulation by making the dummy model. The results of performance evaluation show the proposed system can support efficiently the locker management.

• Convergence Security Journal
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• v.15 no.4
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• pp.113-119
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• 2015

Recent, cyber violence is increasing in a school and the severity of the problems encountered day by day. In particular, the severity of the cyber force using the smart phone is recognized as a very high and great problems socially. Cyberbullying have long damage degree and a wide range time duration against of existed physical cyber violence. Then student's affects is very seriously. Therefore, we analyzes the relationship and languages in the classroom for students to use to identify signs of cyber violence that may occur between friends in the class. And we support this information to identified parent, classroom teachers and school sheriff for prevent cyberbullying accidents in the school. For this research, we will design and implement a messenger in the cyber classroom. It have many components that are Big-data vocabulary, analyzer, and communication interface. Our proposed messenger can analyze lingual sign and friendship between students using Big-data analysis method such as text mining. It can analysis relationship by per-student, per-classroom.

• Journal of The Korean Association of Information Education
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• v.17 no.1
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• pp.9-21
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• 2013

The purpose of this paper is to develop and implement a mobile application system to improve arithmetical operations for low achievers. The proposed system has the following characteristics. First, the system provides individual study for low achievers based on their different study levels. Second, instant feedback can be provided to students for maintaining study motivation. Third, the system enables students to study arithmetical operations in persistent and repetitive manner. This is due to that, in the literature, arithmetical operation capacity can be increased by persistent and repetitive practices. The proposed system is applied to mathematics low achievers and the following results are obtained. First, interests and intrinsic motivation are increased through use of the proposed system. Second, arithmetical operation speed is increased. Also, accuracy of arithmetical operation is improved. Thus, it is concluded that arithmetical operation capacity of low achievers is improved using the proposed system.

• Journal of Advanced Navigation Technology
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• v.18 no.6
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• pp.594-599
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• 2014

The routinized wireless devices such as smart phone have promoted to expand the use of IEEE 802.11 groups. The challenge environments of the wireless network utilizes effectively and user-oriented seamless services that handover is the most desirable issues under the wireless circumstance. In data center software defined network (SDN) has provided the flow routing to reduce costs and complexities. Flow routing has directly offered control for network administrator and has given to reduce delay for users. Under the circumstance of being short of network facilities, SDNs give the virtualization of network environments and to support out of the isolation traffic conditions. It shows that the mechanism of handover makes sure seamless services for higher density of the network infrastructure which is SDN to support network service re-configurable.

• The Journal of the Korea Contents Association
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• v.7 no.6
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• pp.79-88
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• 2007

As the mobile computers such as Personal Digital Assistants (PDAs) or Smart Phone has been widespread in our daily life, the demand of an extensive data input will gradually be increased. Consequently, many alternative soft keyboards have been proposed to satisfy this requirement. However none of them can provide an absolute solutions for that, the segregated guideline for keyboard arrangement and usage still cause much confusion to the user. Therefore, an integrated guideline is seriously required. In order to come up with the integrated guideline for Korean Soft keyboard GUI, the questionnaire and the experimental test compared with five soft keyboards were conducted in this study. As a result this paper presents five guidelines for improving an input speed of soft keyboard on the mobile computing; following familiarity for effective screen use, using a single key rather than grouping key, considering position of prediction word, considering prompt feedback, finally, considering optimized keyboard size.