• Journal of Software Assessment and Valuation
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• v.15 no.1
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• pp.11-24
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• 2019

Using cross-platform development frameworks, mobile app developers can easily implement mobile apps for multiple platforms in one step. The frameworks also provides adversaries with the ability to write malicious code once, and then run it anywhere for other platforms. In this paper, we analyze the ratio of benign and malicious apps written by cross-platform development frameworks for Android apps collected from AndroZoo's site. The analysis results show that the percentage of benign apps written in the frameworks continues to increase, accounting for 45% of all benign apps in 2018. The percentage of malicious apps written in the frameworks accounted for 25% of all malicious apps in 2015, but that percentage has declined since then. This study provides useful information to make a suitable choice when app developers face several challenges in cross platform app development.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.26 no.4
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• pp.343-352
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• 2022

We present the user-friendly graphical user interface design and implementation of Monte Carlo simulation (MCS) for computing option price of the four-underlying asset step-down equity linked securities (ELS) using the Android platform. The ELS has been one of the most important and influential financial products in South Korea. Most ELS products are based on one-, two-, and three-underlying assets. However, currently there is a demand for higher coupon payment from ELS products because of the increased interest rate in financial market. In order to allow the investors to have higher coupon payment, it is necessary to design a multi-asset ELS such as four-asset step-down ELS. We conduct the computational experiments to demonstrate the performance of the Android platform for pricing four-asset step-down ELS. Furthermore, we perform a comparison test with a three-asset step-down ELS.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.32 no.2
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• pp.49-67
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• 2021

The school library provides a mobile web service that allows access to the library catalog system, and provides services that reflect the needs of search and consider the characteristics of mobile devices. Therefore, this study conducted a literature review, an analysis of the current status of school library mobile web services, and a survey of the mobile service user experience of students and teachers to find the contents and service plans for school library mobile app services that meet the school library mobile needs. Based on the survey, the contents and design plan of the school library DLS mobile service was prepared. First, the steps were reduced from step 4 to step 3. In the first step, solution of screen clipping errors in registering as a member and various login platforms for accessibility are needed. In the second step, integrated search and detailed search, provision of materials for use and reading education, post-booking activities, guides and announcements on the use of the affiliated school library, inter-loan, and e-books are provided as main menu. In the third step, it was proposed to provide related functions such as reservations as well as the display of the detailed screen of the search results of the collection. This study can be used not only to develop dedicated mobile app services, but also to change current web-based mobile services.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.3
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• pp.245-250
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• 2015

Portable devices, such as smart phones and personal digital assistants (PDAs) play an important role in our everyday life. In this paper, we propose a step count algorithm based on SVM(signal vector magnitude) and a adaptive threshold processing to monitor the physical activity. The algorithm measures a user's step counts using the smart phone's inbuilt accelerometer and g sensor. Experiment results showed the proposed algorithm has good performance in accuracy and adaptability than the app on your smart phone.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.157-164
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• 2024

In this paper, we would like to develop a system that selects the drink you want with an application made with an app inventory for the person who manufactures the drink and manufactures the drink. After combining the drinks to be mixed with the dispenser, the actuator was controlled to accurately move the ball screw to the location of the dispenser by controlling the step motor through Arduino. According to the actuator movement control and the number of times the dispenser is pressed, the amount of drinks to be mixed is extracted in proportion to each other. Finally, we establish a system to replace the labor force of cafes and further suggest directions that the system can be used everywhere.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.2
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• pp.45-49
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• 2006

Electrochemical hydrogenation/dehydrogenation properties were studied for a single particle of a Mm-based(Mm : minh metal) hydrogen storage alloy($MmNi_{3.55}Co_{0.75}Mn_{0.4}Al_{0.3}$) for fuel cell and Ni-MH batteries. A carbon fiber microelectrode was manipulated to make electrical contact with an alloy particle, and the potential-step experiment was carried out to determine the apparent chemical diffusion coefficient of hydrogen atom($D_{app}$) in the alloy. Since the alloy particle we used here was a dense, conductive sphere, the spherical diffusion model was employed for data analysis. $D_{app}$ was found to vary the order between $10^{-9}\;and\;10^{-10}[cm^2/s]$ over the course of hydrogenation and dehydrogenation process. Compared with the conventional composite film electrodes, the single particle measurements using the microelectrode gave more detailed, true information about the hydrogen storage alloy.

• Journal of Convergence for Information Technology
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• v.10 no.2
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• pp.21-31
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• 2020

This study tested the effectiveness of commercialized smartphone apps in improving walking activities among college students. 66 participants were randomized into each of four groups that was used different behavior change strategies: monetary rewards app, goal setting and feedback app, gaming app, and self-monitoring control group. 45 participants who completed the experimentation was included in data analysis. Repeated measures ANOVA resulted in statistically significant time by groups interactions in recorded step counts, self-reported completed plans and self-reported walking activities scores. The Goal-setting and feedback group and the gaming group resulted in increase in both step counts and completed plans. The results were discussed in the framework of behaviorism.

• Journal of Industrial Convergence
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• v.18 no.6
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• pp.147-154
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• 2020

It is difficult to educate the overall operation of public and private blockchains with different characteristics. Recently, most education for blockchain is targeted at public blockchains such as Bitcoin and Ethereum. However, in an actual business environment, a private blockchain such as HyperLedger Fabric is used because access to corporate data is controlled through user authentication. In the case of HLF-based education, it is necessary to understand various components that are not in the public blockchain, such as peers, orderers, and channels. In this paper, a lab framework for HLF is designed for an efficient and systematic understanding of the functions and operations. The framework consists of HLF network, chaincode, and decentralized software control functions. Through the framework, the network configuration, distribution and activation of chaincode, and dApp execution process were checked step by step, and it was very easy to understand the overall flow for blockchain services. In addition, it is expected that a systematic understanding of the overall flow will be possible even in future network expansion.

• Journal of The Korean Association of Information Education
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• v.21 no.1
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• pp.13-22
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• 2017

Recently, the emphasis on education of informatics gifted elementary students is to make creative leader in knowledge-based society. It need the high mental faculties and problem solving ability to solve many problem situations for students. In this paper, we developed App Inventor programming education plan. We taught this plan to gifted elementary students and observed the effects of their problem solving ability, self-efficacy and achievement of programing process. In order to achieve the research goals, we designed the appropriate App Inventor programming plan for gifted elementary students and we changed the Learning Model of Renzulli's three step for gifted students to achieve this research goals. Designed learning program was utilized by twenty informatics gifted elementary students for 15 times during five weeks period. In conclusion, we confirmed that App Inventor programming education for gifted elementary students affected the problem solving ability, self-efficacy and achievement of programing process positively.

• Journal of Digital Convergence
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• v.17 no.11
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• pp.435-440
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• 2019

Recently, many musical instrument mobile apps have been released targeting normal people who can't play musical instrument at all. The reason of developing video system based on step sequencer are as follows; first, users can freely play the musical instruments; second, induce multiple users to play; and third, develop and suggest new step sequencer fused with the video. To resolve issue in video synchronization caused by sync issues when operating multiple step sequencers, the Pocket Operator of Teenage Engineering was used to realize multiply-connected step sequencer and also, the ultimate video system was developed through Mira-Web for multiple participation. In addition, it's required to make the Pocket Operator as software and receive various feedbacks to continue and complement study in order to develop the better video system.