• Convergence Security Journal
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• v.19 no.5
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• pp.107-118
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• 2019

Based on the Internet of Things technology, one of the core technologies of the fourth industrial revolution, our Ministry of Defense is also pushing to establish M-IoT in defense area to improve management efficiency, innovate military culture and strengthen military power. However, devices connected to the Military Internet of Things can be easily exposed to various of cyber threats as most of them are developed and with a focus on improving sensing and communication skills that collect and transmit data. And it is not easy to uniquely identify the numerous heterogeneous devices, and to establish a secure communication channel between devices or between devices and management servers. In this paper, based on PUF technology, we propose a novel key management scheme that can uniquely identify the various devices, and generate the secret keys needed for the establishment of a secure communication channel using non-replicable information generated by the PUF. We also analyze the efficiency of our proposed scheme through comparison with existing key management scheme and verify the logic and security using BAN Logic.

• Journal of Power System Engineering
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• v.19 no.3
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• pp.16-21
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• 2015

Nitrous oxide($N_2O$) concentration in the atmosphere has been constantly increased by the human activities with industrial growth after the industrial revolution. One of factors to increase $N_2O$ concentration in the atmosphere is the $N_2O$ emission caused by the combustion of marine fuel. Especially, a sulfur component included in marine fuel oils is known as increasing the $N_2O$ formation in diesel combustion. Form this point of view, $N_2O$ emission from a ship is not negligible. On the other hand, Exhaust gas recirculation(EGR) that have thermal, chemical and dilution effect is effective method for reducing the NOx emission. In this study, an author investigated $N_2O$ reduction by using EGR on a direct injection diesel engine. The test engine was a 4-stroke diesel engine with maximum output of 12 kW at 2600rpm, and operating condition of the engine was a fixed load of 75%. The experimental oil was a blend-fuel that were adjusted with sulfur ratio of 3.5%, and EGR ratio of 0%, 10%, 20% and 30%. In conclusion, diesel fuel that contained 3.5% sulfur component increased $SO_2$ emission in exhaust gas, and increment of EGR ratio reduced NO emission. Moreover, $N_2O$ emission was decreased as over 50% at EGR ratio of 10% and reduced 100% at EGR ratio of 30% compared with $N_2O$ emission of 0% EGR ratio.

• Journal of Information Technology Services
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• v.19 no.2
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• pp.109-124
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• 2020

Facing the 4^th Industrial Revolution era, researches on artificial intelligence have become active and attempts have been made to apply machine learning in various fields. In the field of finance, Robo Advisor service, which analyze the market, make investment decisions and allocate assets instead of people, are rapidly expanding. The stock price prediction using the machine learning that has been carried out to date is mainly based on the prediction of the market index such as KOSPI, and utilizes technical data that is fundamental index or price derivative index using financial statement. However, most researches have proceeded without any explicit verification of the prediction rate of the learning data. In this study, we conducted an experiment to determine the degree of market prediction ability of basic indicators, technical indicators, and system risk indicators (AR) used in stock price prediction. First, we set the core parameters for each financial indicator and define the objective function reflecting the return and volatility. Then, an experiment was performed to extract the sample from the distribution of each parameter by the Markov chain Monte Carlo (MCMC) method and to find the optimum value to maximize the objective function. Since Robo Advisor is a commodity that trades financial instruments such as stocks and funds, it can not be utilized only by forecasting the market index. The sample for this experiment is data of 17 years of 1,500 stocks that have been listed in Korea for more than 5 years after listing. As a result of the experiment, it was possible to establish a meaningful trading strategy that exceeds the market return. This study can be utilized as a basis for the development of Robo Advisor products in that it includes a large proportion of listed stocks in Korea, rather than an experiment on a single index, and verifies market predictability of various financial indicators.

• Journal of Digital Contents Society
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• v.19 no.5
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• pp.891-898
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• 2018

Although programming language is a core education area of software that is becoming increasingly important in the age of the fourth industrial revolution, as it requires logical thinking skills, it is recognized as a difficult subject even for SW major students. This difficulty occasionally causes SW major students to lose interest and confidence in their major during the introductory course of a programming language; making them change their majors, or give up their studies. In this study, we designed an instructional model using Scratch for educating C language which is a typical programming introductory language. To do this, we analyzed the concepts that can be trained by Scratch among the programming concepts supported by C language, and developed the examples of Scratch for exercising the concepts. The instructional model supports the progress model of learning first the programming concepts through Scratch and then expand the learning content into C language. We also conducted an experiment on the SW major freshman students of a local private university to verify the effectiveness of the model.

• Journal of Digital Contents Society
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• v.19 no.7
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• pp.1245-1251
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• 2018

Communication skills are emphasized as one of the key competencies of the people who are living in the fourth industrial revolution era. However, it is widely believed that traditional education systems focused on individual learning do not provide sufficient communication opportunities. This paper proposes a method to activate communication using mobile app. In this study, app was developed and used by college students for two days, and then analyzed the communication-related effects through questionnaires. The results showed that both fun and communication were effective. Based on the experimental results, it is expected that the proposed app in this paper will contribute to activation of communication among people, increase of interest among members, and improvement of cooperative thinking ability.

• Journal of Digital Contents Society
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• v.19 no.2
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• pp.229-236
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• 2018

The background fort this study is related to the concept of modern time and space which has been extended from physical space to virtual space in the present times witnessing the advent of the Fourth Industrial Revolution. Based on visual tactility and illusion in virtual reality, we intended to present the possibility of the interactions as realistic as the interactions occurring in reality. Regarding the scope of this study, we analyzed the relationship between illusion in game space and immersion in interactions based on the games used frequently among current virtual reality contents. The results of the study showed that the interactions in virtual reality occurred within the space converging the time and space and that the illusion of digital images had realistic position of reality without original. Research which investigates the interaction in virtual space and media projection method for real space and virtual space will provide useful basis for promoting technological development based on novel methods differentiated from existing image grammar and for identifying the content utilization methods.

• Convergence Security Journal
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• v.19 no.3
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• pp.81-86
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• 2019

This study introduces trends on silver care implemented with the fourth industrial revolution technology, and discusses the use of digital technology for elderly health and rehabilitation by reviewing relevant literature to examine and present directions for future digital-based silver care commercialization. First, health smart home, which is a smart residential service available through digital technology or IT technology that supports independent living in your home, is available. Second, there are technical services using artificial intelligence(AI) and robots. Robots based on advanced intelligence can serve as an assistant for the health and rehabilitation of senior citizens by supporting services that enable the daily lives of senior, checking their health conditions, and high-quality medical care. For the commercialization of these silver care systems, information and services appropriate to the current situation, such as the physical ability and health status of the elderly, should be provided, and it would be desirable to gradually expand the use of essential technology to reflect the needs of the elderly in use so that the digital alienated.

• Journal of Digital Convergence
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• v.19 no.5
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• pp.229-239
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• 2021

For this study, we have extensively analyzed the presentation data of the government's financial-related departments and the data of each financial institution and electronic financial institution.. As a result, In Korea's electronic financial environment, real changes such as first) expansion of non-face-to-face finance, second) teleworking in the financial sector, third) abolition of accredited certification, fourth) advanced voice phishing, fifth) openness of the financial industry and diversification of forms, sixth) the'walletless society'. In addition to the above, however, global changes triggered by the Fourth Industrial Revolution spread to the financial security sector, making it difficult to respond to problems such as artificial intelligence/ deep learning/ user analysis/ deepfake technology. As the proportion of electronic finance is increasing socially, it should be studied in the fields of electronic finance and its environment, and crime and criminal investigation.

• Journal of Digital Convergence
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• v.19 no.12
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• pp.151-156
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• 2021

This study is aim to verify the mediating effect of entrepreneurial spirit on non-financial performance and self-efficacy. In this study, data were collected through a survey to investigate the relationship between variables, and empirical analysis of the research hypothesis was conducted using multiple regression analysis. The results of the study are as follows. First, entrepreneurship has a positive effect on self-efficacy; second, it suggests that the stronger entrepreneurship, the better self-efficacy. In addition, self-efficacy can produce positive results in various aspects, especially through this study, self-efficacy has resulted in improvement of non-financial performance.The results of this study have a positive effect on the various convergence of start-ups and the establishment of a stable start-up culture in the era of the Fourth Industrial Revolution.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.3
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• pp.105-114
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• 2019

As the Industrial Revolution progressed, Big Data technologies were used to develop a system that instantly identified the consequences of older vehicles using mobile devices. First, data from the vehicle was collected using the OBD2 sensor, and the data collected was stored in the raspberry pie, giving it the same situation that the raspberry pie was driving. In the event that vehicle data is generated, the data is collected in real time, stored in multiple nodes, and visualized and printed based on the processed, refined, processed and processed data. We can use Big Data in this process and quickly process vehicle data to identify it effectively through mobile devices.