• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.8
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• pp.1138-1143
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• 2013

In this paper, we propose a smartphone application based on a wireless fidelity(WiFi) in order to control the charging of electric vehicle(EV) and monitor the charging status together with the vehicle history information. The driver obtains much information on vehicle status through a smartphone application which communicates with the electric vehicle supply equipment(EVSE) management server while the EV also communicates with the EVSE for the authentification through controller area network(CAN). We also implement the simulator for the EV charging control system to verify the functions of the proposed application where the simulator consists of an EV model, an EVSE, and a smartphone. It is shown by the simulator that the proposed smartphone application allows the driver to control and to monitor the charging process of an EV conveniently and, moreover, it can provide the driver with vehicle information stored in the EVSE management server.

• Journal of Korean society of Dental Hygiene
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• v.16 no.5
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• pp.775-782
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• 2016

Objectives: The purpose of the study was to investigate the influence of smart phone addiction on personal relationship in dental hygiene students. Methods: A self-reported questionnaire was completed by 475 dental hygiene students in Gyeonggido and Chungcheongdo from May 9 to June 10, 2016. Except incomplete questionnaire, data were analyzed using SPSS 23.0 program. The instruments consisted of general characteristics of the subjects, smartphone addiction, and personal relationship. Results: The percentage of smart phone was 23.0% in a risk group and 77.0% in a general group. The level of smartphone had a statistically significant difference with personal relationship(p<0.05). Smartphone addiction resulted in bad personal relationship. Conclusions: Smartphone addiction problem interrupts personal relationship. It is very important to reduce smart phone addiction through a variety of solution.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.2
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• pp.723-743
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• 2016

Indoor positioning is considered an enabler for a variety of applications, the demand for an indoor positioning service has also been accelerated. That is because that people spend most of their time indoor environment. Meanwhile, the smartphone integrated powerful camera is an efficient platform for navigation and positioning. However, for high accuracy indoor positioning by using a smartphone, there are two constraints that includes: (1) limited computational and memory resources of smartphone; (2) users' moving in large buildings. To address those issues, this paper uses the TC-OFDM for calculating the coarse positioning information includes horizontal and altitude information for assisting smartphone camera-based positioning. Moreover, a unified representation model of image features under variety of scenarios whose name is FAST-SURF is established for computing the fine location. Finally, an optimization marginalized particle filter is proposed for fusing the positioning information from TC-OFDM and images. The experimental result shows that the wide location detection accuracy is 0.823 m (1σ) at horizontal and 0.5 m at vertical. Comparing to the WiFi-based and ibeacon-based positioning methods, our method is powerful while being easy to be deployed and optimized.

• Current Optics and Photonics
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• v.1 no.2
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• pp.90-94
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• 2017

Visible light identification (VLID) is a user identification system for a door lock application using smartphone that adopts visible light communication (VLC) technology with the objective of high security, small form factor, and cost effectiveness. The user is verified by the identification application program of a smartphone via fingerprint recognition or password entry. If the authentication succeeds, the corresponding encoded visible light signals are transmitted by a light emitting diode (LED) camera flash. Then, only a small size and low cost photodiode as an outdoor interface converts the light signal to the digital data along with a comparator, and runs the authentication process, and releases the lock. VLID can utilize powerful state-of-the-art hardware and software of smartphones. Furthermore, the door lock system is allowed to be easily upgraded with advanced technologies without its modification and replacement. It can be upgraded by just update the software of smartphone application or replacing the smartphone with the latest one. Additionally, wireless connection between a smartphone and a smart home hub is established automatically via Bluetooth for updating the password and controlling the home devices. In this paper, we demonstrate a prototype VLID door lock system that is built up with LEGO blocks, a photodiode, a comparator circuit, Bluetooth module, and FPGA board.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.140-142
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• 2016

Recently, rapid innovation of Smartphone is changing the paradigm of our daily life. Smartphone users, opinion experts more than 99 percent of the economically active population is using, it has reached the saturation past the early stages of formation. Smartphone is equipped with a general purpose OS possible the implementation of high performance environment similar level as a personal computer. Thus, it is a mobile communication terminal scalable which can be removed or installed various applications. Such extensibility, it is possible to use different applications through the Apps store. Also, it is also possible various services which are location based service. In this research, we aim to analyze factors influencing of cloud computing service on reusing intention of smartphone. In addition, we aim to analyze the causal relationship from perceived value to reusing intention. This study suggests practical and theoretical implications based on the results.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.3
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• pp.239-242
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• 2015

In this paper, we propose a walking assisting system for blind people using Android smartphone and Arduino board. In our proposed system, we use an Android smartphone case and an external ultrasonic sensor to detect the obstacles ahead. In this manner, blind people is able to aware unexpected objects by smartphone speakers or vibration functionality. In addition, the walking assisting system is also designed a notice system which will be triggered by built-in smartphone camera flash when blind people walk in some darkness place. The experimental results from real experiments on blind people have demonstrated the applicability of our walking assisting system, when it not only efficiently helps blind people avoid obstacles ahead but also possible traffic collisions in darkness condition.

• Women's Health Nursing
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• v.24 no.1
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• pp.1-13
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• 2018

Purpose: To develop educational material about nutrition during antepartum period for women pregnant with twins by using smartphone applications. Methods: A series of steps according to ADDIE model, including Analysis, Design, Development, Implementation, and Evaluation were used to develop smartphone application of antepartum nutrition care for women pregnant with twins. Results: Based on experts' evaluation, the average score was $4.6{\pm}0.39$ in total. Content score was $4.7{\pm}0.40$. Interface design score was $4.5{\pm}0.55$. Content score was higher than interface design score. User evaluation was conducted in the form of interview. Results of interviews revealed that users generally responded positively to the accuracy, understanding, and objectivity for content items of the smartphone app. As for the evaluation of consistency for the evaluation item of interface design, users answered "ordinary" or "generally yes". For design suitability and accuracy of vocabulary, they answered 'generally suitable'. Conclusion: The smartphone app developed through this study is expected to aid antepartum care for women pregnant with twins. It will also contribute to health promotion of both pregnant women and twin fetus.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.24 no.1
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• pp.60-71
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• 2017

Purpose: The purpose of this study was to develop video assisted education on bowel preparation for colonoscopy (VEBPC) and use a snartphone to evaluate effects of the VEBPC. Methods: Adult patients who were scheduled for colonoscopy were recruited from a university general hospital and randomly assigned to three groups. Group 1 (n=30) watched the video using a computer set in the endoscope consulting room. Group 2 (n=29) watched it using a smartphone, and group 3, the control group (n=29) received education with existing instructions at the reservation-reception desk. Participants were evaluated on knowledge on taking bowel preparation agents and diet, compliance on taking bowel preparation agents and diet, satisfaction with education, and actual level of bowel preparation. Results: Group 1 and 2 showed significantly (p<.001) higher scores for knowledge, compliance, and satisfaction compared to the control group. However, in post-hoc test analyses there were no significant differences in these variables between group 1 and 2. No significant difference was found in the actual level of bowel preparation among the three groups. Conclusion: Findings from this study show that VEBPC using smartphone is a better option than existing educational methods. However, replication studies are necessary to confirm these findings.

• KIPS Transactions on Software and Data Engineering
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• v.3 no.2
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• pp.87-92
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• 2014

In this paper, we present a two-phase activity recognition system using smartphone's accelerometers. To consider the unique temporal pattern of accelerometer data for each activity, our system executes the decision-tree(DT) learning in the first phase, and then, in the second phase, executes the hidden Markov model(HMM) learning based on the sequences of classification results of the first phase classifier. Moreover, to build a robust recognizer for each activity, we trained our system using a large amount of data collected from different users, different positions and orientations of smartphone. Through experiments using 6720 examples collected for 6 different indoor activities, our system showed high performance based on its novel design.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.8
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• pp.1165-1171
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• 2022

Human behavior recognition using an accelerometer has been applied to various fields. As smartphones have become used commonly, a method for human behavior recognition using the acceleration sensor built into the smartphone is being studied. In the case of the elderly, falling often leads to serious injuries, and falls are one of the major causes of accidents at construction fields. In this article, we proposed recognition method for human falling direction using built-in acceleration sensor and orientation sensor in the smartphone. In the past, it was a common method to use the magnitude of the acceleration vector to recognize human behavior. These days, deep learning has been actively studied and applied to various areas. In this article, we propose a method for recognizing the direction of human falling by applying the deep learning multilayer technique, which has been widely used recently.