• KIISE Transactions on Computing Practices
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• v.21 no.1
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• pp.64-69
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• 2015

Place awareness is an essential for location-based services that are widely provided to smartphone users. However, traditional GPS-based methods are only valid outdoors where the GPS signal is strong and also require symbolic place information of the physical location. In this paper, environmental sounds and images are used to recognize important aspects of each place. The proposed method extracts feature vectors from visual, auditory and location data recorded by a smartphone with built-in camera, microphone and GPS sensors modules. The heterogeneous feature vectors were then learned by an ensemble learning method that learns each group of feature vectors for each classifier respectively and votes to produce the highest weighted result. The proposed method is evaluated for place recognition using a data group of 3000 samples in six places and the experimental results show a remarkably improved recognition accuracy when using all kinds of sensory data comparing to results using data from a single sensor or audio-visual integrated data only.

• KIISE Transactions on Computing Practices
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• v.21 no.2
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• pp.154-159
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• 2015

Over the past few years, user needs in the smartphone application market have been shifted from diversity toward intelligence. Here, we propose a novel cognitive agent that plans the daily routines of users using the lifelog data collected by the smart phones of individuals. The proposed method first employs DPGMM (Dirichlet Process Gaussian Mixture Model) to automatically extract the users' POI (Point of Interest) from the lifelog data. After extraction, the POI and other meaningful features such as GPS, the user's activity label extracted from the log data is then used to learn the patterns of the user's daily routine by POMDP (Partially Observable Markov Decision Process). To determine the significant patterns within the user's time dependent patterns, collaboration was made with the SNS application Foursquare to record the locations visited by the user and the activities that the user had performed. The method was evaluated by predicting the daily routine of seven users with 3300 feedback data. Experimental results showed that daily routine scheduling can be established after seven days of lifelogged data and feedback data have been collected, demonstrating the potential of the new method of place-time-activity coupled daily routine planning systems in the intelligence application market.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.473-481
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• 2015

The flood and environment surveillance network on riverside is a network requiring a way to efficiently manage the information from all kinds of sensors, along with an optical communication device that can deliver high-quality video information at high speed. Since on-site prompt recovery is very important especially for communication problems that occurred due to cut-off or aged network, various researches have been carried out on this. However, because the security against outside hacking or outside intrusion with illegal purposes is very important for environment surveillance network, such as the national backbone network, an efficient network maintenance and repair should be enabled while satisfying security and reliability at the same time. A characteristic of requirement is that when security is improved, the efficiency of maintenance and repair drops as they are conflicting to each other. Therefore, this research proposed a system in order to satisfy the conflicting requirement and improve security, by developing a one-way Bypass TAP and an android-based smartphone app that can enable efficient network maintenance and repair.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.3
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• pp.465-470
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• 2017

This paper designs and implements a smart garden system using probabilistic filter algorithm using SLAM that can be used in apartment or veranda. To do this, we used Arduino and environtal sensors, which are open hardware controllers, and designed to control and observe automatic water supply, lighting, and growth monitoring with three wireless systems (Bluetooth, Ethernet, WiFi). This system has been developed to make it possible to use it in an indoor space such as an apartment, rather than a large-scale cultivation system such as a conventional plant factory which has already been widely used. The developed system collects environmental data by using soil sensor, illuminance sensor, humidity sensor and temperature sensor as well as control through smartphone app, analyzes the collected data, and controls water pump, LED lamp, air ventilation fan and so on. As a wireless remote control method, we implemented Bluetooth, Ethernet and WiFi. Finally, it is designed for users to enable remote control and monitoring when the user is not in the house.

• Journal of Digital Convergence
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• v.13 no.6
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• pp.327-339
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• 2015

The present study explored how 1) individuals' perception about attributes of exercise/fitness apps and 2) their motivation for exercise/fitness behaviors influence perceived usefulness and usage of the apps. A survey of 323 males and females in their 20's and 30's revealed that attributes of apps that satisfy their basic psychological needs are crucial in promoting perceived usefulness and usage of the apps. Participants were more likely to perceive exercise/fitness apps useful as they perceive them having more attributes related to autonomy and competence. The perception regarding relatedness attributes did not have the main effect on perceived usefulness but showed an interaction effect with relative autonomous motivation. This convergence study which examined health apps from the perspectives of psychology and public health provides practical implications to development and evaluation of health apps.

• Journal of Korea Game Society
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• v.11 no.4
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• pp.163-174
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• 2011

The purpose of this study was to apply a variety of criteria to analyzing mobile applications for early childhood education, which are now available in application market, and was also to explore how the developmental characteristics and multimedia content characteristics of early childhood could be applied to mobile applications for early childhood education. To meet these purposes, this study targeted total 61 applications for infancy education in terms of mobile applications loaded on online education categories such as iPhone App Store and Android Market. Based on analytic criteria on the foundation of content type by learning type, cognitive load theory and multimedia design principle, this study analyzed those applications for early childhood. As a result, it was found that there were needs to develop a little more various categories of applications, and there were also needs to develop such applications that they can make the best use of smart phone's performance, comply with multimedia design principles but avoid any imprudent use of multimedia.

• Journal of the Korean Society of Clothing and Textiles
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• v.37 no.7
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• pp.1000-1014
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• 2013

This study identifies the determinants that influence attitude toward and the intention to use mobile shopping services through fashion applications (apps) based on the technology acceptance model. In addition, gender and age group differences were examined. Data were collected from subjects who have used smartphone fashion related apps; subsequently, a total of 327 data were analyzed. About 46% of respondents were males, with a mean age of 34.4 years that ranged from 20 to 49 years old. Multiple regression models were developed based on the research model. Perceived usefulness, perceived ease of use, perceived enjoyment, perceived risks (security risk and quality risk), fashion involvement, and fashion app attributes (product attributes and service attributes) were employed as predictors of attitudes towards mobile shopping. Attitudes towards mobile shopping and subjective norms with the aforementioned variables measured the intention to use. Attitudes towards mobile shopping were predicted by perceived enjoyment, perceived usefulness, and service attributes. Attitudes toward mobile shopping and subjective norms were the most important predictors of the intention to use. Gender differences were found in that service attributes were significant for attitudes towards mobile shopping only in the male model. Age differences were also found and perceived usefulness was the most important predictor of attitudes toward mobile shopping among those in their 20's; however, perceived enjoyment was the most important among those in their 30's and 40's. Quality risk was only significant to explain intention to use among those in their 40's. The findings of this study are useful to understand the possibility of the adoption of mobile shopping though fashion apps and provide basic insight into market segmentation.

• The Journal of the Korea Contents Association
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• v.17 no.11
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• pp.9-17
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• 2017

In this paper, we propose a method to develop a multimeter which is used for measuring electric signals in industrial field by using battery and display of smart phone. Most of the multimeters that are linked to existing smartphones are connected to Bluetooth, which is inconvenient for battery use and low in measurement accuracy. To improve this, we developed smart multimeter that can supply power and data at the same time by USB OTG method which can be used by sharing the power of smartphone. We also developed a smart multimeter that can measure resistance, DC voltage, current, AC voltage and current. Developed an Android app with a button that displays measurement data and can select the type of electric signal to be measured, and tests whether the manufactured system is operating normally or not. Respectively.The results of this study confirm that it is possible to fabricate a smart meter that has equal or better performance compared to existing instruments and does not require a separate power source or display, and it is expected to be a reference for the development of various smart instruments in the future.

• Journal of Korean Library and Information Science Society
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• v.47 no.3
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• pp.187-211
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• 2016

The present study investigates the seventh and the eighth graders' perception of Free Learning Semester Programs offered by libraries by developing a survey questionnaire on students' needs for Free Learning Semester Programs of Libraries. The skills that middle school students want to improve in Free Learning Semesters are career exploration skills, and the type of Free Learning Semester that is most intensively implemented is career exploration activities. Programs are often offered in the form of experiential classes. Regarding the activities that the students want to participate during Free Learning Semester, the most preferred activities included field experience activity in the career exploration domain, cooking class in the student choice program, smartphone app development in club activities, design activity in the art domain, the badminton in the physical education domain, and using iPad in the information use skills. In addition, among the library programs in coordination with Free Learning Semester, the students liked the occupational experience program most. Future studies need to include the development and implementation of Free Learning Semester Programs based on students' opinions, and investigate their satisfaction with the Free Learning Semester Programs offered by libraries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6830-6837
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• 2014

Since the advent of global warming and energy depletion, there has been great interest in eco-driving (energy-efficient driving). In this paper, a system is proposed to monitor the idle running of an engine and steady driving for a vehicle equipped with an ISG (Idling Stop & Go system). The system consists of a G/W device to acquire the vehicle operation data, a smartphone app for monitoring eco-driving and a server system. The main contribution of this paper is that it defines the integrated functions, the architecture and operation mechanisms of a system for monitoring eco-driving including the prohibition of running idle. The system enables the users to check the idling stop times, driving speeds, fuel savings, and $CO_2$ emissions, resulting in the driving style for eco-driving. The server system, which is a part of this system, provides OpenAPI-style web services for the storage and retrieval of car operation data, which facilitates the development of applications.