• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.12
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• pp.61-67
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• 2015

Certainly, we are living in a true mobile society. At the end of 2014, approximately 40million 560thousand people are subscribed to smartphone services in Korea, using more than 2000MB of mobile data per a person. The use of smartphone is expected to increase. Moreover, smartphone moves toward becoming a requisite for modern people. Under the circumstances, high-speed communication services such as LTE provide high quality services anywhere and anytime and, furthermore, the development of high performances of the application makes the life patterns of modern people link directly to smartphone. Almost every day, new creative services are being introduced and the demands of on-line streaming services such as high-performance game and YouTube are increasing day after day. However, although smartphones are getting smarter and high quality services are rapidly growing, consumers still complain about the insufficient usage time caused by the capacity of batteries. In order to solve this problem, this thesis suggests EDLC(Electric Double-Layer Capacitor) uses as a supplemental power supply to keep the continuity of work while switching batteries. Through this approach, the running time of smartphone becomes longer as the number of batteries without power off and the purpose of this study is to maximize the convenience of using smartphone by eliminating the initialization of memories and the loss of time of rebooting while batteries are switched.

• Journal of Digital Contents Society
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• v.14 no.2
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• pp.135-142
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• 2013

In this study, I research about extensions and changes of user experience by using smartphone from the point of conceptual metaphor based on embodied cognition and the remediation characteristics. The result of this study is as follow; The first, container schema and path schema as center image schema of the conceptual metaphor are a proper theories to be mapped user experience by using smartphone because of including embodied schema structure by human physical experience. The second, user experience of smartphone in the point of remediation is remediated by smartphone. And physical space is rededicated and interacted to behavior space by the user experience. The third, the conceptual metaphor of smartphone UX activate container chema through implicit interaction and has transparent immediacy to ingenerate existence of media. The forth, path schema that is activated from explicit interaction makes users to experience hypermediacy. Conceptual metaphor and remediation in this study could be used to theoretical framework and to explain new user experience from using smartphone.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.561-569
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• 2016

Purpose : We will clarify the situation of using a smartphone and what kind of factors are currently related when people use a smartphone while doing something else in order to obtain basic information to educate people to prevent the use of smartphone while doing something else. Methods : We conducted an anonymous self-administered questionnaire survey with 885 people who commuted by train to six companies located in Tokyo, Chiba, and Osaka and 550 university students who commuted by train to five universities located in the same areas. The research period was from April to May of 2014. Results : 33% of the subjects used a feature phone and 73% of the subjects used a smartphone. 38% of them listened to music, using their smartphones or feature phones while walking. Binominal logistic regression analysis was done with dependent variables of using a smartphone while walking and independent variables of age, sex, and educational advertisement. The results showed that people in their 20s used a smartphone while walking 4.93 times more than people in their 30s(p <0.00). No significant difference was found in the relationship between sex and educational advertisement(poster, TV, or magazine) and using a smatphone while doing something else.

• Journal of the Korea Safety Management & Science
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• v.20 no.2
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• pp.37-44
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• 2018

The Location Based Service is growing rapidly nowadays due to the universalization of the use for smartphone, and therefore the location determination technology has been placed in a very important position. This study suggests an algorithm that can provide the estimate of users' location by using smartphone sensors. And in doing so we will propose a methodology for the creation and update of indoor map through the more accurate position estimation using smartphone sensors such as acceleration sensor, gyroscope sensor, geomagnetic sensor and rotation sensor.

• Journal of the Semiconductor & Display Technology
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• v.17 no.3
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• pp.108-112
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• 2018

In this paper, a respiration measurement method using FMCW signal for off-the-shelf smartphone is presented and investigated. The proposed algorithm transmits FMCW signal periodically instead of transmitting continuously so that one can reduce the power consumption from speaker in smartphone and the algorithm complexity. In order to eliminate the clicking noise generated when transmitting FMCW signal, Tukey window with ${\alpha}=0.01$ is applied to prevent the noise from being heard. An application program for Android OS which can transmit FMCW signal through speaker and record the reflected signals through MIC has been developed. Since the total duration of the signal transmission is set to 20msec per 1 second for the experiments, the power consumption can be decreased by 80% compared to the continuous transmission. It was confirmed that the clicking noise is inaudible as long as a smartphone is located at more than 10cm from ears. In the experiments on a sleeping child, the breathing signal of about 0.27Hz was measured.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.100-108
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• 2020

This study investigates the effects of sociality, life stress, and depression on smartphone addiction among nursing college students. In October and November 2019, data was collected from nursing college students situated in certain areas. The data of totally 270 students was finally analyzed by frequency, percentage, t-test, and ANOVA, to examine differences in smartphone addiction according to the general characteristics of the subjects. Major variables and multiple regression analysis was carried out to examine factors influencing smartphone addiction. We determined that hours of using a smartphone (β=0.183, p<0.001), life stress (β=0.369, p<0.001), and depression (β=0.205, p=0.012) significantly affect smartphone addiction, having an explanatory power of 33.5%. Life stress (r=0.50, p<0.001) and depression (r=0.35, p<0.001) have high positive correlations with smartphone addiction, whereas sociality (r=-0.20, p<0.001) is negatively correlated. To summarize, our results indicate that hours of using a smartphone, life stress, and depression have important impacts on smartphone addiction among nursing college students. These findings raise a need to reinforce the development of programs to help nursing college students increase their ability of managing hours of using a smartphone, and reduce their life stress and depression to prevent subsequent smartphone addiction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.192-202
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• 2019

This study was a descriptive study to investigate the factors influencing on self-esteem, ego resilience, impulsivity and life stress on smartphone addiction among college students. The subjects include college students in some areas. Data was collected in November and December, 2018. Total 231 college students were analyzed in the study. Collected data was analyzed in frequency, percentage, and t-test to examine differences in smartphone addiction according to general characteristics. Pearson's correlation was performed to examine correlations between smartphone addiction and main variables, and the factors influencing smartphone addiction were analyzed in multiple regression. The findings show that genera, satisfaction with college life, hours of using a smartphone, hours of using SNS, ego resilience, impulsivity, and life stress had significant effects on smartphone addiction. The study examined relations between general characters and smartphone addiction and found that the level of smartphone addiction was high in female college students, those who were not satisfied with college life, and used a smartphone and SNS for many hours. Ego resilience had negative correlations with smartphone addiction, and impulsivity and life stress had positive correlations with it. Multi-variate regression analysis results show that gender, ego resilience, and life stress were factors that had important influences on the smartphone addiction of college students, having explanatory power of 35.6%. In short, colleges and universities need to develop a school-level program to improve the college life of students and reduce their stress to the minimum and create an environment of encouraging them to grow power of controlling their lives so that they can prevent smartphone addiction.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.51-60
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• 2021

This study is a descriptive research conducted to identify smartphone addiction and influencing factors of high grades of elementary school students. The subjects were 294 elementary school students in the 4th, 5th, and 6th grades at 31 regional children's centers located in C city. Data were collected from May 13, 2019 to June 10, 2019. For data analysis, frequency analysis, 𝑥²-test, and logistic regression analysis were performed using SPSS Win 23.0 program. The result of the study were 16% in the addiction risk group and 84.0% in the general group. Factors influencing smartphone addiction were smartphone usage time on weekdays(95% CI: 1.263~827.849, p=.036), and main usage time of smartphone(95% CI: 1.028~29.574, p=.046). Therefore, in order to prevent smartphone addiction of high grade of elementary school, it is necessary to develop a smartphone addiction prevention education or nursing intervention program by identifying usage time and main usage time of smartphone.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.1
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• pp.207-214
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• 2014

Recently, smartphone spyware resembles various types of virus components in PCs and has trends getting more and more severe. Users do not perceive the risk factors severely even if smartphone security is very vulnerable in spite of the smartphone spyware growth. Thus, this study observes the influence of information security in selecting smartphone based on the personal inclinations and spyware perceptions. The main variables of study model are such as the degree of personal risk-accepting and the risk of smartphone spyware as independent variables and smartphone purchasing intention as a dependent variable. The model is tested using SPSS 21 packages on the effective 200 samples gathered through questionnaire survey on the present smartphone users. As a result, the two main hypotheses which are "the degree of personal risk-accepting will influence on the perceiving risk of smartphone spyware" and "the perceiving risk of smartphone spyware will influence on smartphone purchasing intention" were significant statistically. Therefore, we could find out information security's influence on the selecting smartphone.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.6
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• pp.1477-1484
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• 2015

With the growth of financial industry with smartphone, interest on user authentication using smartphone has been arisen in these days. There are various type of biometric user authentication techniques, but gait recognition using accelerometer sensor in smartphone does not seem to develop remarkably. This paper suggests the method of user authentication using accelerometer sensor embedded in smartphone. Specifically, calibrate the sensor data from smartphone with 3D-transformation, extract features from transformed data and do principle component analysis, and learn model with using gaussian mixture model. Next, authenticate user data with confidence interval of GMM model. As result, proposed method is capable of user authentication with accelerometer sensor on smartphone as a high degree of accuracy(about 96%) even in the situation that environment control and limitation are minimum on the research.