• PNF and Movement
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• v.13 no.1
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• pp.39-46
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• 2015

Purpose: The accelerometer is a tool for evaluating walking by the displacement of the center of mass (COM) in the body. Recently, smartphones have added an accelerometer app, and it can be used to evaluate outcomemanures in rehabilitation. The purpose of this study was to investigate the COM in the bodies of normal persons and stroke patients using this smartphone application while walking. Methods: Twenty normal persons and twenty-two stroke patients were recruited and had their COM measured using G-walk and the smartphone application, SMAP, during 10 m walking. Subjects repeated the 10 m of walking 3 times, and we used the SMAP, Accelerometer Monitor ver. 1.5.0, to evaluate COM during the walk. To measure the displacement of COM, we used the difference in value between the maximal angle and the minimum anterior-posterior (AP), mediolateral (ML), and rotational angles during the walk. Results: For the normal persons, there was significant correlation between the AP and AP of SMAP, and was also a significant correlation between rotational angle and the ML of SMAP. In the stroke patients, there was significant correlation between AP and ML, and the rotational angle of SMAP. Conclusion: Our research results suggest that if the SMAP system is reinforced in the case of patients who have a greater displacement of COM, it may be used as an evaluation tool during walking.

• Journal of Distribution Science
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• v.12 no.11
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• pp.85-100
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• 2014

Purpose - Recently, the prevalence of high-speed mobile communication technology (4G) and mobile devices (smart phones, tablet PC, etc.) is leading innovative changes across all fields in society as well as business environments. Furthermore, a diversified mobile application service has spread rapidly through mobile devices such as smart phones and tablet PCs. Accordingly, the traditional E-government services paradigm has rapidly changed into mobile intelligence. To identify the influencing factors on the using intention of G4C smart app services, based on previous studies, the variables that influence using G4C smart app services are defined; these are user cognitive factors (perceived usefulness, perceived easiness), user characteristics factors (user innovativeness, self-efficiency, social influence), service quality factors (convenience, interactivity, accessibility), and system quality factors (instant connectivity, safety). Research design, data, and methodology - This is designed not only to collect data with a questionnaire survey (9/22/13~10/23/13) but also to test hypotheses with SEM by SPSS 21.0 and AMOS 21.0 in both Korea and China. All items are used with Likert 5 scales. A total of 643 questionnaires (Korea 318, China 325) are used. Results - The perceived usefulness and perceived easiness in user cognitive factors have positive influence on using intention. The user innovativeness, self-efficiency, and social factors in user characteristics factors have positive influences on using intention. The convenience, interactivity, and accessibility in service quality factors have positive influences on both reliability and using intention. Safety in system quality has positive influence on both reliability and using intention. Reliability has positive influence on using intention. The control variables (Korea and China) affect its control hypothesis. Strategies and implications are suggested to assist the public using the intention of smartphone's e-government services based on the results of the empirical analysis. The mobile application service can be considered a new emergence of the paradigm just like the government's on-line portal websites appeared in the past. Under this prevailing situation of mobile smart devices, to promote the success of e-government mobile APP services, accurate analysis and understanding of users should precede anything, to provide services to grasp and satisfy users' desire properly. Conclusions - This study proposes implications to help E-governmental officers and companies make strategies. First, this is expected to give some information on the understanding and knowledge regarding the process of G4C smart APP service based on the empirical study. Second, this helps to make future policies and ways about E-government G4C smart APP service. Third, it is proved that super speed mobile communication technology and devices including phones will be crucial to change the structure of E-government services in 2-3 years. Fourth, it is necessary to increase the trust and using intention of users. Fifth, considering what type of environment users are placed in, to present proper public information matching their inclination, is important. Finally, various ways of experiencing service to explore potential users and ceaseless public relations are required.

• Journal of Intelligence and Information Systems
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• v.21 no.2
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• pp.1-18
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• 2015

Collaborative filtering(CF) algorithm has been popularly used for recommender systems in both academic and practical applications. A general CF system compares users based on how similar they are, and creates recommendation results with the items favored by other people with similar tastes. Thus, it is very important for CF to measure the similarities between users because the recommendation quality depends on it. In most cases, users' explicit numeric ratings of items(i.e. quantitative information) have only been used to calculate the similarities between users in CF. However, several studies indicated that qualitative information such as user's reviews on the items may contribute to measure these similarities more accurately. Considering that a lot of people are likely to share their honest opinion on the items they purchased recently due to the advent of the Web 2.0, user's reviews can be regarded as the informative source for identifying user's preference with accuracy. Under this background, this study proposes a new hybrid recommender system that combines with users' review mining. Our proposed system is based on conventional memory-based CF, but it is designed to use both user's numeric ratings and his/her text reviews on the items when calculating similarities between users. In specific, our system creates not only user-item rating matrix, but also user-item review term matrix. Then, it calculates rating similarity and review similarity from each matrix, and calculates the final user-to-user similarity based on these two similarities(i.e. rating and review similarities). As the methods for calculating review similarity between users, we proposed two alternatives - one is to use the frequency of the commonly used terms, and the other one is to use the sum of the importance weights of the commonly used terms in users' review. In the case of the importance weights of terms, we proposed the use of average TF-IDF(Term Frequency - Inverse Document Frequency) weights. To validate the applicability of the proposed system, we applied it to the implementation of a recommender system for smartphone applications (hereafter, app). At present, over a million apps are offered in each app stores operated by Google and Apple. Due to this information overload, users have difficulty in selecting proper apps that they really want. Furthermore, app store operators like Google and Apple have cumulated huge amount of users' reviews on apps until now. Thus, we chose smartphone app stores as the application domain of our system. In order to collect the experimental data set, we built and operated a Web-based data collection system for about two weeks. As a result, we could obtain 1,246 valid responses(ratings and reviews) from 78 users. The experimental system was implemented using Microsoft Visual Basic for Applications(VBA) and SAS Text Miner. And, to avoid distortion due to human intervention, we did not adopt any refining works by human during the user's review mining process. To examine the effectiveness of the proposed system, we compared its performance to the performance of conventional CF system. The performances of recommender systems were evaluated by using average MAE(mean absolute error). The experimental results showed that our proposed system(MAE = 0.7867 ~ 0.7881) slightly outperformed a conventional CF system(MAE = 0.7939). Also, they showed that the calculation of review similarity between users based on the TF-IDF weights(MAE = 0.7867) leaded to better recommendation accuracy than the calculation based on the frequency of the commonly used terms in reviews(MAE = 0.7881). The results from paired samples t-test presented that our proposed system with review similarity calculation using the frequency of the commonly used terms outperformed conventional CF system with 10% statistical significance level. Our study sheds a light on the application of users' review information for facilitating electronic commerce by recommending proper items to users.

• Journal of Korea Multimedia Society
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• v.21 no.2
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• pp.261-270
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• 2018

Hearing-impaired people are increasing rapidly due to the global aging trend. Early detection of hearing loss requires an easy-to-use audiometry device for the public. Existing audiometry systems were developed as PC-based, PDA-based, or smartphone apps. These devices were often dependent on specific software platforms and hardware platforms. In this paper, we tried to improve software platform compatibility by using cross platform, and tried to implement IoT-based pure tone audiometry device which does not require sound pressure level correction due to hardware differences. Pure tone audiometry is available in a variety of ways depending on the type of hearing loss and age. Using the IoT-based audiometry device implemented in this paper, it will be possible for an app developer who lacks hardware knowledge to easily develop an app with various scenarios for hearing screening. The results of this study will contribute to overcoming the software and hardware dependency in the development of IoT-based healthcare device.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.6
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• pp.1341-1351
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• 2015

As the popularization of smartphone increases the number of various applications, the number of malicious applications also grows rapidly through the third party App Market or black market. This paper suggests an investigation filter, Androfilter, that detects the fabrication of APK file effectively. Whereas the most of antivirus software uses a separate server to collect, analyze, and update malicious applications, Androfilter assumes Google Play as the trusted party and verifies integrity of an application through a simple query to Google Play. Experiment results show that Androfilter blocks brand new malicious applications that have not been reported yet as well as known malicious applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.749-750
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• 2013

Due to the rapid development of smart phones, smart phone users grew, expanding communication between the service users has been enabled by the application's service. Difficult to find a service that allows you to know the quality of school meals and the expectations of these applications. In addition, the existing application works only with a particular device, it is difficult to compatible devices. Thus, based on the HTML5 hybrid application were developed and this feed can be monitored by the students of the school, the communication can be formed.

• The Journal of the Convergence on Culture Technology
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• v.1 no.4
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• pp.65-69
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• 2015

This study can read register reviews and search read information that users want by musical, drama and movie by using DB by developing App providing the newest culture view and information in android smart phone, when users want to enjoy cultural life. Also, the administrator logins as Administrator-mode and controls cultural information and makes smooth controlling by identifying user's information. In addition, the user logins as User-mode and reads cultural information and can make possible in reading and writing reviews. It makes possible to enjoy leisure activity as cultural activity by identifying reliable performance information via recommendation of friend groups.

• Journal of Information Technology Services
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• v.16 no.4
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• pp.213-222
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• 2017

The advancement of ICT is changing every field of life. It becomes possible with the penetration of personalized devices, that is, smartphone. The boom of IoT will come when there exist diversified and personalized services. In general, we might admit that it is needed that the more privatized services than the overall serviced. Jeju Island is the only one special self-governing province in Republic of Korea and deserves to be proud of the unique culture from its long historical background. One of the very regional culture which performs by women divers, Haenyeo activity or culture, was registered as Intangible Cultural Heritage. When authors were researched Jeju Haenyeo as a worthy reserving service, we recognized that it has never considered to use any point of ICT/IoT yet. Because IoT holds the high potentiality to create any service scenario between interesting groups. We will design a few services for Haenyeo which covers their job territory or daily life, adopts up-to-date technology or method such as sensored network, smart contract and App/Web. In this paper, we intent to show the simplicity and easiness of the application of IoT not to much inconspicuous target. So, we suggest a specialized IoT service for the reservation and promotion of Haenyeo Culture. This service would be composed of sensors, IoT network and App/Web at home and office. This service can be used among interesting groups : Haenyeo, policy maker, manufacturer, service provider and culture consumer.

• Agribusiness and Information Management
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• v.7 no.2
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• pp.19-26
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• 2015

Recently, food delivery apps are seeing rapid growth into a market worth 1 trillion won under a simple but unique business model of connecting nearby restaurants with consumers via smartphone. Though basic similarities with social commerce exists in aspects such as mail-order sales intermediaries, startups, types of services and market competition structure, food delivery apps resemble social commerce in many ways in that they use excessive marketing to secure market dominance, causing a spike in consumer complaints. If the excessive marketing and increase in customer complaints are not rectified, the food delivery app could also see rapid decline as it gradually grows distant from consumers, just like social commerce. Accordingly, this study will identify the factors consumers recognize as important for continuous use vis-a-vis social commerce and food delivery apps to perform an empirical analysis on what areas need improvement. After deriving the four upper factors of product, information system and service along with eight sub-factors by referring to existing literature, the areas with opportunity for improvement were derived through satisfaction level and relative importance evaluation. The results of this study present a strategic direction for maintaining customers of social commerce and food delivery apps.

• The Journal of the Convergence on Culture Technology
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• v.3 no.1
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• pp.19-23
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• 2017

With the increase in the number of smart phone users, smart phones themselves are seeing progress in terms of available functions. Many applications, too, are being developed to increase convenience in daily life. This study issued a list of information on films that the user wishes to see, by using an XML parser to call news articles related to the films in question to the news site RSS. The Android App server was built using Ubuntu and the latest film information was provided through the board that was built. The menu was consisted in a manner so that when the information interested was clicked on, a more detailed set of information became available.