• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.12
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• pp.5805-5825
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• 2019

Smartphones are important platforms because of their sophisticated computation, communication, and sensing capabilities, which enable a variety of applications in the Internet of Things (IoT) systems. Moreover, advancements in hardware have enabled sensors on smartphones such as environmental and chemical sensors that make sensor data collection readily accessible for a wide range of applications. However, dynamic, opportunistic, and heterogeneous mobility patterns of smartphone users that vary throughout the day, which greatly affects the efficacy of sensor data collection. Therefore, it is necessary to consider phone users mobility patterns to design data collection schedules that can reduce the loss of sensor data. In this paper, we propose a mobility-based weighted adaptive opportunistic scheduling framework that can adaptively adjust to the dynamic, opportunistic, and heterogeneous mobility patterns of smartphone users and provide prioritized scheduling based on various application scenarios, such as velocity, region of interest, and sensor type. The performance of the proposed framework is compared with other scheduling frameworks in various heterogeneous smartphone user mobility scenarios. Simulation results show that the proposed scheduling improves the transmission rate by 8 percent and can also improve the collection of higher-priority sensor data compared with other scheduling approaches.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.149-156
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• 2013

With a rapid growth of smartphone technologies, various applications are developed and diffused actively nowadays. Especially, interesting applications using camera module in a smartphone are developed continuously, mobile users are able to use various useful mobile services in humdrum life. In this paper, we design and implement measurement algorithms which precisely measure the object taken by the camera module in a smartphone. We use 3-axis gyro accelerometer sensor in a smartphone to get the distance, incline and rotation angle in a real time when we take a picture of shooting object and can obtain precise size of it in the picture image. The measurement algorithms proposed in this paper are analyzed and evaluated by a simulation study.

• Journal of Information Technology Applications and Management
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• v.17 no.4
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• pp.83-105
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• 2010

Smartphone services seem to be appealing to people worldwide and show rapid growth in mobile service market. Based on the theoretical framework like attachment theory and self-congruity theory, we developed the research model and proposed six hypotheses. An analysis of 113 smartphone service users found that continued use intention in smartphone services is affected by uses' attachment to the service. We also found that the attachment is significantly increased by self-congruity, customization, and perceived usefulness. Our aim was to gain insight into ways of creating an environment that facilitating continued use intention of smartphone services. This study has important implications for academic researchers and practitioners who seek to understand why smartphone service users continuously use their smart phone services. Other practical implications of these findings and future research implications are also discussed.

• Journal of Korea Society of Digital Industry and Information Management
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• v.9 no.1
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• pp.189-202
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• 2013

Recently, Smartphone is not only used as a communication medium, but also provide mobile service tool enabling game, internet surfing, DMB, navigation services, and so on. A lot of smartphone's applications are using for our daily lives. The purpose of this study was analyze affecting factors such as innovativeness, Self-Efficacy and Social-Influence on adoption behavior of smartphone application. This survey was carried out with university students. Data were obtained from 293 students who have smartphone. To Find difference among variables, exploratory factor analysis, t-test and multiple regression was carried out with collected data. Result shows that the distinction of sex is significantly difference in innovativeness and self-efficacy. And self-efficacy and social influence are significantly affect to smartpjone adoption. Therefore, self-efficacy and social influence are import consider factors to reconsider marketing strategy for smartphone business.

• Journal of the Korean Society of Safety
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• v.28 no.1
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• pp.24-28
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• 2013

This article evaluates the accuracy of noise measurements for 37 noise measurement applications for iPhone 4 and iPhone 3Gs. Noise levels were measured using simultaneously a precision sound level meter and iPhones installed noise measurement applications at the levels of 70 dB, 80 dB and 90 dB at 1,000 Hz. Measurement errors were estimated by subtracting two measurements between iPhone and sound level meter. It was found that measurement errors of 34 applications(89.2%) were greater than ${\pm}2$ dB which is the maximum allowable error range for the Type II sound level meter. It was only 4 applications that measurement errors lie within ${\pm}2$ dB error range. There was no significant differences among measurements with four iPhone 4s. However, there were significant differences between the measurements with iPhone 4 and iPhone 3Gs using the same application. It was due to the different hardware specifications such as microphone. Therefore, noise measurement applications, for example, which has to utilize hardware of the smartphone, should be programmed to identify hardware specifications and to adopt appropriate correction factors upon hardware specifications. In conclusion, it is necessary to check accuracy and validity before using the noise measurement applications for iPhones. Also, it was suggested that it should develop an evaluation guideline or protocol on accuracy testing for the measurement applications using a smartphone.

• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.325-335
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• 2018

We aimed to construct and test a structural equation model to analyze the convergence effect of utilizing smartphone technology for Therapeutic Lifestyle Change(TLC) among people with mental illness. A survey using a structured self-questionnaire was conducted from 549 male and 357 female subjects. The data was analyzed by SPSS 23.0 and AMOS 21.0. The model fit for the modified hypothetical model was shown: Q(${\chi}^2/df$)=3.241, AGFI=0.968, CFI=0.970, RMSEA=0.050(95% CI=0.035, 0.065), SRMR=0.048. In modified model from hypothetical model, the opinions about smartphone use affect the willingness to use smartphone applications. And the willingness to use smartphone applications affect dietary and living habits. The result of this study suggests that a convergent study using various delivery systems such as smartphone technology is necessary to implement TLC, which can facilitate the prevention of the metabolic syndrome among people with schizophrenia.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.295-298
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• 2011

This paper is to analyze an app curriculum using smartphone authoring solution for the education of smartphone applications with optimized effectiveness by reducing time period of development. In addition, The best goal will find the effective training methodology for developers to develop application program running on smartphones with quick and easy way. The final goal of the paper is to find the best way on how to develop business application programs using an authoring solution for smartphone application. In conclusion, this paper covers the best solution and education of an high-tech authoring solution design for the effective smartphone applications to be used by experienced developers with perfect knowledge of the field for practical on-site.

• Journal of KIISE
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• v.42 no.3
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• pp.295-306
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• 2015

MOnCa2 is a framework for building intelligent smartphone applications based on smartphone sensors and ontology reasoning. In previous studies, MOnCa determined and inferred user situations based on sensor values represented by ontology instances. When this approach is applied, recognizing user space information or objects in user surroundings is possible, whereas determining the user's physical context (travel behavior, travel destination) is impossible. In this paper, MOnCa2 is used to build recognition models for travel behavior and routes using smartphone sensors to analyze the user's physical context, infer basic context regarding the user's travel behavior and routes by adapting these models, and generate high-level context by applying ontology reasoning to the basic context for creating intelligent applications. This paper is focused on approaches that are able to recognize the user's travel behavior using smartphone accelerometers, predict personal routes and destinations using GPS signals, and infer high-level context by applying realization.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.213-223
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• 2021

In this study, a smartphone utilization system was designed to explore ways to use smartphones owned by more than 95% of Korean teenagers in school classes. First, the necessary functions were selected based on the factors related to adolescents and the factors of distraction, dependence, motivation, and cooperation in the preceding studies on the use of smartphone classes, and then three versions of the application were composed according to the educational roles of students, teachers, and parents. By using these applications, students can learn self-study, motivate learning, and actively interact, teachers can be more closely with students and facilitate lessons while giving detailed feedback, and parents can check the student's safe learning using smartphones. It is hoped that this measure will help to increase the educational effect by activating the use of smartphones in school classes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.642-643
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• 2013

Recently there are many smartphone applications. People who live in these days interest in health but there are not many smartphone applications that deal with healthcare. In this work, we will introduce healthcare application which introduce exercise methods and user can be seen their consuming calories and eating calories using calender.