• Journal of KIISE:Computing Practices and Letters
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• v.11 no.1
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• pp.81-91
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• 2005

Today, mobile phones have become an essential item for man-to-man communication. As more people use mobile phones, various services based on mobile phone networks and high-end devices have been developed. In addition, with the growth of the concept of ubiquitous computing, there are many ongoing studies on novel and useful services in smartphone. In this paper, for personalized service in smartphone we propose an intelligent agent that uses user modeling based on bayesian network and rule based service selection mechanism. It infers the user's status such as his current affect, how he is busy, and how someone is familiar with him from personal information and communication history using bayesian network and Provides appropriate services on the basis of the inferred information. We apply it to some realistic situation to confirm the usefulness our proposed agent.

• Journal of Internet Computing and Services
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• v.15 no.1
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• pp.157-170
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• 2014

As the increase of transaction using mobile banking continues, threat to the mobile financial security is also increasing. Mobile banking service performs the financial transaction using the dedicate application which is made by financial corporation. It provides the same services as the internet banking service. Personal information such as credit card number, which is stored in the mobile banking application can be used to the additional attack caused by a malicious attack or the loss of the mobile devices. Therefore, in this paper, to cope with the mobile financial accident caused by personal information exposure, we suggest outlier detection method which can judge whether the transaction is conducted by the appropriate user or not. This detection method utilizes the user's input patterns and transaction patterns when a user uses the banking service on the mobile devices. User's input and transaction pattern data involves the information which can be used to discern a certain user. Thus, if these data are utilized appropriately, they can be the information to distinguish abnormal transaction from the transaction done by the appropriate user. In this paper, we collect the data of user's input patterns on a smart phone for the experiment. And we use the experiment data which domestic financial corporation uses to detect outlier as the data of transaction pattern. We verify that our proposal can detect the abnormal transaction efficiently, as a result of detection experiment based on the collected input and transaction pattern data.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.197-205
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• 2021

TV home shopping companies are not limited to TV channels and phone-ordering channels, but are making efforts to expand their channels through mobile phones. Beyond its interaction and ubiquity using the web, it is expanding its contact point with consumers through mobile live broadcasting. Interacting, ordering, doing their own broadcasts within mobile App, and interacting and enjoying them are likely to differ depending on consumers' personality, such as playfulness and impulsivity. In this study, the effects of Two-way communication, Synchronicity and Ubiquity, which are the characteristics of mobile home shopping, on consumers' flow, and the effect on consumers' flow on mobile home shopping will vary depending on individual preferences. Interacting, ordering, doing their own broadcasts within mobile devices, and interacting and enjoying them are likely to differ depending on consumers' personal preferences, such as play and impulsive tendencies. As a result of the study, Two-way communication was found to have not significant on flow, and Synchronicity was also found to have no significant effect on flow. It was found that ubiquity had a significant effect on flow. Among the individuality, people with high playfulness have a positive effect on flow, and people with high impulsivity also have a significant effect on flow. Flow has been shown to have a positive effect on the intention to using mobile home shopping.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7853-7857
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• 2015

Background: Mortality from breast cancer is high in low- and middle-income countries, in part because most patients have advanced stage disease when first diagnosed. Case-finding may be one approach to changing this situation. Materials and Methods: We conducted a pilot study to explore the feasibility of population-based case finding for breast cancer by community health workers (CHWs) using different data collection methods and approaches to management of women found to have breast abnormalities. After training 8 CHWs in breast problem recognition, manual paper data collection and operation of a cell-phone software platform for reporting demographic, history and physical finding information, these CHWs visited 3150 women >age 18 and over they could find-- from 2356 households in 8 villages in rural Bangladesh. By 4 random assignments of villages, data were collected manually (Group 1), or with the cell-phone program alone (Group 2) or with management algorithms (Groups 3 and 4), and women adjudged to have a serious breast problem were shown a motivational video (Group 3), or navigated/accompanied to a breast problem center for evaluation (Group 4). Results: Only three visited women refused evaluation. The manual data acquisition group (1) had missing data in 80% of cases, and took an average of 5 minutes longer to acquire, versus no missing data in the cell phone-reporting groups (2,3 and 4). One woman was identified with stage III breast cancer, and was appropriately treated. Conclusions: Among very poor rural Bangladeshi women, there was very limited reluctance to undergo breast evaluation. The estimated rarity of clinical breast cancer is supported by these population-based findings. The feasibility and efficient use of mobile technology in this setting is supported. Successor studies may most appropriately be trials focusing on improving the suggested benefits of motivation and navigation, on increasing the numbers of cases found, and on stage of disease at diagnosis as the primary endpoint.

• Journal of Digital Convergence
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• v.11 no.7
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• pp.255-260
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• 2013

This study was attempted to identify the differences of mental health and media use according to the addiction of communication media. Data collection was surveyed using interview and questionnaires by 250 subjects from March 12 to May 13, 2012. The results were as follows : First, with regard to mobile phone use time for communication in the use of over 2 hrs, subjects replied that addictive group was significantly higher than non-addictive group($X^2$=8.51, p=.00). Secondly, in case often depression, the risk ratio of addictive group was significantly higher 4.0 times than non-addictive group(OR=4.0, 95%, Cl=2.4-36.9). In conclusion, in order to prevent the addictive use of communication media, it is needed to make various environment such as sound life rhythm maintenance, systemic and periodic education.

• Asia-Pacific Journal of Business
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• v.13 no.3
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• pp.293-309
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• 2022

Purpose - The purpose of this study is to explore the possibility of predicting the degree of smartphone overdependence based on mobile phone usage patterns. Design/methodology/approach - In this study, a survey conducted by Korea Internet and Security Agency(KISA) called "problematic smartphone use survey" was analyzed. The survey consists of 180 questions, and data were collected from 29,712 participants. Based on the data on the smartphone usage pattern obtained through the questionnaire, the smartphone addiction level was predicted using machine learning techniques. k-NN, gradient boosting, XGBoost, CatBoost, AdaBoost and random forest algorithms were employed. Findings - First, while various factors together influence the smartphone overdependence level, the results show that all machine learning techniques perform well to predict the smartphone overdependence level. Especially, we focus on the features which can be obtained from the smartphone log data (without psychological factors). It means that our results can be a basis for diagnostic programs to detect problematic smartphone use. Second, the results show that information on users' age, marriage and smartphone usage patterns can be used as predictors to determine whether users are addicted to smartphones. Other demographic characteristics such as sex or region did not appear to significantly affect smartphone overdependence levels. Research implications or Originality - While there are some studies that predict smartphone overdependence level using machine learning techniques, but the studies only present algorithm performance based on survey data. In this study, based on the information gain measure, questions that have more influence on the smartphone overdependence level are presented, and the performance of algorithms according to the questions is compared. Through the results of this study, it is shown that smartphone overdependence level can be predicted with less information if questions about smartphone use are given appropriately.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.3
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• pp.579-590
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• 2018

In May 2014, AppCard(Which is a smartphone application designed to register and use a credit card in a mobile phone by credit card company.) was attacked by smshing and a vulnerability which could not obtainable phone number. After that, credit card companies have supplemented and operated by introducing additional authentication methods to supplement the vulnerability. However, The analysis of the authentication environments, purposes and methods is not enough to lower the level of vulnerability and risk from existing accidents. This study analyzes the authentication process of the AppCard in the electronic financial service by applying the NIST's authentication guidelines, identifies the problems and suggests improvement directions. The method analyzed in this study can be applied to the analysis of the authentication method in addition to the application card, so that it will be highly utilized.

• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.271-283
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• 2018

This study aimed to investigate the effect of adolescent development environment including parenting attitude, peer relationship, and school environment on delinquent behavior, and between these relationships, the mediate effect of media environment such as computer and mobile devices. The $6^{th}$ year data from Korean Children & Youth Panel Survey (KCYPS) was used and the subjects were limited to 518 students of $7^{th}$ grade who are in their early adolescence. The result shows that adolescents under more affectionate, over involvement, and abusive parenting attitude will commit delinquent behaviors more frequently, and so does alienated youth from their friends. Parenting inconsistency and communication with friends make them use computer and cell phone more often, and excessive media usage increases adolescent's delinquent behavior. In conclusion, family environment and peer relation have influence on adolescents' delinquent behavior. Therefore, there is necessity to build development environment that prevent adolescents' delinquencies like parent education program or peer communication program for example. Also, proper education program for using computer or cell phone usage can reduce adolescents' delinquent behaviors, especially when its addictive aspect was recently issued.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.7
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• pp.1393-1400
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• 2017

As the number of smartphone users increases, vulnerability to privacy protection is increasing. This is because personal information is stored on various servers connected to the Internet and the user is authenticated using the same ID and password. Authentication methods such as OTP, FIDO, and PIN codes have been introduced to solve traditional authentication methods, but their use is limited for authentication that requires sharing with other users. In this paper, we propose the authentication method that is needed for the management of shared information such as hospitals and corporations. The proposed algorithm is an algorithm that can authenticate users in the same place in real time using smart phone IMEI, QR code, BLE, push message. We propose an authentication algorithm that can perform user authentication through mutual cooperation using a smart phone and can cancel realtime authentication. And we designed and implemented a mutual authentication system using proposed algorithm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.57-57
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• 2007

Aspheric glass lenses have many optical advantages, for glass have superior optical performance and an aspheric form can reduce optical aberrations. Recently, the use of it is rapidly expanding as the mass production becomes possible by glass molding press and so this method is considered as the best method for fabricating an aspheric glass lens, but it is difficult to control many parameters for pressing and cooling process. Design of experiments (DOE) is a very useful tool to design and analyze complicated industrial design problems. This study investigated the pressing conditions to mold aspheric glass lenses for mega pixel phone camera module using DOE method. We have applied fractional factorial design and the response variable was set form accuracy (PV) of aspheric surface of molded lens. The results of analysis indicates that all factors expect for pressing force of each step are available for the form accuracy (PV). It was the optimum condition of the designed pressing conditions for lowering the form accuracy(PV) value of molded lens that all factors were at the low level. The form accuracy (PV) of mold and molded lens under the optimum condition are $0.85\;{\mu}m$ and $0.922\;{\mu}m$ respectively.