• Journal of the Korea Society of Computer and Information
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• v.27 no.4
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• pp.213-221
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• 2022

The purpose of this study is to find methods to prevent and improve smart device over-dependence problems by analyzing differences in school life adaptation and academic performance according to children's dependence on smart devices. For this, the data of fifth grade elementary school students in the 12th year were extracted and utilized from Panel Survey of Korean Children. The data were analyzed using non-hierarchical cluster(K-means) analysis, T-test, one-way ANOVA, and Scheffé tests. The results of this study are as follows. First, It has been shown that dependence on smart devices, school adaptation and academic performance have a negative correlation. Second, students in potential and high-risk groups who are highly dependent on smart devices have significantly lower school adaptation compared to those in the safety group. Third, high-risk students showed significantly lower academic performance compared to those in the potential risk group and general group. Based on these findings, it was suggested that for elementary school students who rely on smart devices, various learning support and national efforts such as counseling for school life adaptation are needed.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.591-597
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• 2021

Recently, as education on the use of smart devices increases, there are many side effects such as dependence on smart devices, addiction, and decline of learning effects. This study analyzed the structural relationship between stress and stress coping to understand why dependence on smart devices occurs. Structural equation modeling using Amos was performed to verify the hypothesis. First, it was found that the higher the perceived stress of university students, the higher the stress coping. Second, the higher the active coping, the lower the dependence on smart devices, and the higher the passive coping, the higher the dependence. Third, it was found that there was a difference in the structural relationship according to mindfulness.

• The Journal of Information Systems
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• v.23 no.1
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• pp.225-246
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• 2014

With the recent establishment of a ubiquitous environment and the paradigm shift to a smart society, the use of mobile devices, such as smart phones and tablet PCs, has become widespread. Thus, the trend is gradually shifting from using Web-based Instant Messenger to using Mobile-based Instant Messenger. Mobile Instant Messenger refers to a service that allows instant messaging as well as data sending and receiving between individuals with exclusive application programs(mobile Apps), which can be used in portable devices-such as smart phones-with wireless Internet access. Korea's portal sites, telecommunication companies, and even big companies have all rushed into the MIM market to join the competition. The reason so many companies are showing interest in the MIM business is because it is rising as a core platform to substitute portal sites in the mobile society, and MIM is perceived as the best means to attract and secure users. The intention to reuse or use continually was considered an important factor in maintaining a dominant position amidst such fierce competition, and consequently, most research thus far has reflected such thought. However, the frequent or long-term use of a system alone cannot indicate the definite success of the system, nor guarantee its dominant position in the market. On the contrary, MIM dependence, which goes beyond simple repetitive use and indicates a state where users actually or emotionally depend on a specific system, can better explain the user action. However, not much research has been conducted on dependence. The research results showed that lively message, concise message, message responsiveness, and social belonging significantly affected perceived usefulness. Message responsiveness, Link, and social belonging significantly affected flow. Flow significantly affected MIM dependence, and perceived usefulness did not affect MIM dependence. This study has proven that lively message, concise message, message responsiveness, Link, social belonging and perceived usefulness are important antecedents and mediating factors of MIM dependence. Moreover, this study is significant in that it explains the overall process of MIM dependence, and expands on the variety and scope of research that can be applied to MIM-related studies.

• Smart Structures and Systems
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• v.24 no.1
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• pp.111-125
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• 2019

Metallic shape memory alloys present fascinating physical properties such as their super-elastic behavior in austenite phase, which can be exploited for providing a structure with both a self-centering capability and an increased ductility. More or less accurate numerical models have been introduced to model their behavior along the last 25 years. This is the reason for which the literature is rich of suggestions/proposals on how to implement this material in devices for passive and semi-active control. Nevertheless, the thermo-mechanical coupling characterizing the first-order martensite phase transformation process results in several macroscopic features affecting the alloy performance. In particular, the effects of day-night and winter-summer temperature excursions require special attention. This aspect might imply that the deployment of some devices should be restricted to indoor solutions. A further aspect is the dependence of the behavior from the geometry one adopts. Two fundamental lacks of symmetry should also be carefully considered when implementing a SMA-based application: the behavior in tension is different from that in compression, and the heating is easy and fast whereas the cooling is not. This manuscript focuses on the passive devices recently proposed in the literature for civil engineering applications. Based on the challenges above identified, their actual feasibility is investigated in detail and their long term performance is discussed with reference to their fatigue life. A few available semi-active solutions are also considered.

• Journal of Industrial and Engineering Chemistry
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• v.68
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• pp.129-139
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• 2018

The effects of N doping concentration and dopant moieties on the electrochemical properties of nanoporous graphene and their dependence on annealing temperature are investigated. Four types of N moieties - amide, amine, graphitic-N, and oxidized-N - are obtained, which transformed into pyridinic-N and pyrrolic-N upon annealing. The diffusion coefficient (D') of the ions in the electrode is the maximum at $400^{\circ}C$ because of a high level of N doping, whereas the second highest D0 value is obtained at $700^{\circ}C$ owing to a high level of reduction and N doping. The highest specific capacitance is obtained for the sample annealed at $400^{\circ}C$.

• Journal of the Korea Society of Computer and Information
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• v.25 no.1
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• pp.221-231
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• 2020

Due to the fourth industrial revolution, people are excessively exposed to smart devices regardless of age, and the dependence is increasing rapidly. In the same context, various problems on information ethics have emerged to infant teachers and children. Therefore, there is a need to present guidelines for infants on the correct use of smart devices. This study proposes means to promote information ethics education in infant education based on a survey on future teachers attending Department of Early Childhood Education. Also, it suggests development of various teaching materials. The main significance of the research is to provide a balanced information ethics education and to develop interactive teaching materials. It also calls for infant teachers, as wells as infants, to understand the need for information ethics education and to provide desirable media education for infants.

• International Journal of Advanced Culture Technology
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• v.7 no.1
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• pp.70-76
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• 2019

IoT technology application has been part of modern people's everyday life. This technology makes people to depend on smart devices. 'Smartphone' is the most typical example. Despite the advantages given by this device, the bad side effects are also notable. This paper presents interactive content on the dependence of smartphone device. The research objective is to make individuals to reduce the use of smartphones by realizing their own problems of smartphone dependency. Research was progressed by analyzing aspects obtained from users participating in the self-developed interactive game contents. As a result of the analysis, approximately 68% of people were aware of the problem through this content. This indicates the potential of using convergence research in interactive contents with other fields furthermore.

• International Journal of Advanced Culture Technology
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• v.11 no.1
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• pp.276-282
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• 2023

IoT technology application has been part of modern people's everyday life. This technology makes people to depend on smart devices. 'Smartphone' is the most typical example. Despite the advantages given by this device, the bad side effects are also notable. This paper presents interactive content on the dependence of smartphone device. The research objective is to make individuals to reduce the use of smartphones by realizing their own problems of smartphone dependency. Research was progressed by analyzing aspects obtained from users participating in the self-developed interactive game contents. As a result of the analysis, approximately 68% of people were aware of the problem through this content. This indicates the potential of using convergence research in interactive contents with other fields furthermore.

• Smart Structures and Systems
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• v.18 no.3
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• pp.449-470
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• 2016

Energy harvesting is an emerging technique that extracts energy from surrounding environments to power low-power devices. For example, it can potentially provide sustainable energy for wireless sensing networks (WSNs) or structural control systems in civil engineering applications. This paper presents a comprehensive study on harvesting energy from earthquake-induced structural vibrations, which is typically of low frequency, to power WSNs. A macroscale pendulum-type electromagnetic harvester (MPEH) is proposed, analyzed and experimentally validated. The presented predictive model describes output power dependence with mass, efficiency and the power spectral density of base acceleration, providing a simple tool to estimate harvested energy. A series of shaking table tests in which a single-storey steel frame model equipped with a MPEH has been carried out under earthquake excitations. Three types of energy harvesting circuits, namely, a resistor circuit, a standard energy harvesting circuit (SEHC) and a voltage-mode controlled buck-boost converter were used for comparative study. In ideal cases, i.e., resistor circuit cases, the maximum electric energy of 8.72 J was harvested with the efficiency of 35.3%. In practical cases, the maximum electric energy of 4.67 J was extracted via the buck-boost converter under the same conditions. The predictive model on output power and harvested energy has been validated by the test data.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.9
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• pp.1158-1164
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• 2020

In Korea, the dependence on imported energy is very high, and research to reduce standby power is being conducted based on Zigbee, a low-power technology, to reduce wasted power and improve power efficiency. However, because Zigbee is not an IoT standard protocol and is not network-based, it is necessary to build a network with a separate gateway, and research on standby power is insufficient because the standards for international power consumption of devices are ambiguous. Therefore, in this paper, we applied the IoT standard protocol MQTT to the existing Zigbee technology to build a network network without a separate gateway, and designed and implemented a standby power reduction system that collects standby power degradation and user patterns. As a result of evaluating with the existing system, it was confirmed that about 7.11% of standby power was consumed compared to the existing system.