• International journal of advanced smart convergence
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• v.9 no.2
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• pp.68-75
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• 2020

Non-orthogonal multiple access (NOMA) has gained the significant attention in the fifth generation (5G) mobile communication, which enables the advanced smart convergence of the artificial intelligence (AI), the internet of things (IoT), and many of the state-of-the-art technologies. Recently, correlated superposition coding (SC) has been proposed in NOMA, to achieve the near-perfect successive interference cancellation (SIC) bit-error rate (BER) performance for the stronger channel users, and to mitigate the severe BER performance degradation for the weaker channel users. In the correlated SC NOMA scheme, the stronger channel user BER performance is even better than the perfect SIC BER performance, for some range of the power allocation factor. However, such excessively good BER performance is not good for the user-fairness, i.e., the more power to the weaker channel user and the less power to the stronger channel user, because the excessively good BER performance of the stronger channel user results in the worse BER performance of the weaker channel user. Therefore, in this paper, we propose the power splitting to establish the user-fairness between both users. First, we derive a closed-form expression for the power splitting factor. Then it is shown that in terms of BER performance, the user-fairness is established between the two users. In result, the power splitting scheme could be considered in correlated SC NOMA for the user-fairness.

• International journal of advanced smart convergence
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• v.10 no.1
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• pp.75-81
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• 2021

As the number of connected smart devices and applications increases explosively, the existing orthogonal multiple access (OMA) techniques have become insufficient to accommodate mobile traffic, such as artificial intelligence (AI) and the internet of things (IoT). Fortunately, non-orthogonal multiple access (NOMA) in the fifth generation (5G) mobile networks has been regarded as a promising solution, owing to increased spectral efficiency and massive connectivity. In this paper, we investigate the achievable data rate for non-orthogonal multiple access (NOMA) with negatively-correlated information sources (CIS). For this, based on the linear transformation of independent random variables (RV), we derive the closed-form expressions for the achievable data rates of NOMA with negatively-CIS. Then it is shown that the achievable data rate of the negatively-CIS NOMA increases for the stronger channel user, whereas the achievable data rate of the negatively-CIS NOMA decreases for the weaker channel user, compared to that of the positively-CIS NOMA for the stronger or weaker channel users, respectively. We also show that the sum rate of the negatively-CIS NOMA is larger than that of the positively-CIS NOMA. As a result, the negatively-CIS could be more efficient than the positively-CIS, when we transmit CIS over 5G NOMA networks.

• Journal of Venture Innovation
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• v.2 no.1
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• pp.1-11
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• 2019

Many research or consulting institute refered to Artificial Intelligence, Internet of Things, Blockchain technology and 3D Printing as key driving forces and technologies of 4th industrial revolution. Compared with traditional manufacturing as a subtractive manufacturing(SM), 3D printing technology as an additive manufacturing(AM) will revolutionary impacts on many industries. This study compared 3D printing with traditional manufacturing in the economic, manufacturing, and marketing perspectives. This study also analyzed issues of 3D printing for the purpose of building business ecosystem. Finally agenda for the further research were suggested.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.3
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• pp.473-480
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• 1988

In this study, a method that can realize the effect of residual stresses on fatigue crack propagation has been proposed. This method requires that the relaxation quantities of residual stresses are measured by experimental method according to fatigue cycles and are employed to the experimental results of base materials by introducing the concept of superposition. SS41 material has been analyzed as an example. The results show that the relaxation factor of residual stresses for fatigue cycles is .alpha.$_{i}$= 1/0.6903+0.0380 $a_{I}$ the effective stress ratio for fatigue crack propagation length is ( $R_{eff}$)$_{i}$ = 1/1.1274+0.0118$_{I}$ and the fatigue crack propagation rate for relaxation quantities of residual stresses is (da/dN)$_{t}$ = 0.5 $K_{cf}$ - .DELTA.K/{1-1/1.1274+0.0118$_{ai}$ } $K_{cf}$ - .DELTA. K(da/dN), for stress ratio /R=0.5.io /R=0.5.5.

• Journal of Energy Engineering
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• v.27 no.4
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• pp.86-91
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• 2018

This paper is a review of accounts balancing time in small distributed power trading platform using blockchain technology. First, the national VPP energy management system using the AMI applied to this study is introduced and then the accounts balancing time and process of the cryptocurrency coin payment which based on the power generation of pro-consumer certified by power big data analysis in a test bed environment is discussed. Futhermore the configuration of a power Big Data analysis system with GPU Fast Big Data that applies MapD to current lambda architecture is also introduced.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.101-103
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• 2022

자율운항선박은 센서, IoT, 빅데이터, AI, 플랫폼 등 고도의 ICT 요소 기술이 필요한 미래 유망 산업 분야이다. 특히 선박 내부장치로 부터 수집된 정보와 선박 주변의 해상 데이터가 증가될수록 선박 대 선박 및 선박 대 육상 간 정보 교환 체계인 해상통신망의 중요성은 커질수 밖에 없다. 해양수산부는 2020년 세계 최초로 대한민국 연안으로부터 최대 100km 까지 해역을 LTE(Long Term Evolution) 통신체계로 구축한 바 있다. 본 논문은 초고속 해상무선통신망(LTE-Maritime)이 자율운항선박의 주요 통신 기술로써 활용되기 위해 우선적으로 고려할 사항을 타 해상 무선통신 기술과의 연계, 업링크 및 항내 통신품질의 향상 관점으로 살펴보고자 한다. 이를 위해 LTE-M. 망의 무선설비 다각화 사업으로 추진중인 해양 드론용 송수신기의 실해역 성능 시험을 통해, 선박과 육상 간 정보 교환에 있어 상호운용성 시험의 중요성을 재고해 보고, 해상 무선통신 체계의 신뢰성 및 호환성을 확보하기 위한 무선품질지표, 상호운용성 시험 방법 등을 제시하고자 한다.

• Journal of Korean Home Economics Education Association
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• v.31 no.4
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• pp.149-161
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• 2019

At present, we are at the point of change of the 4th industrial revolution era due to the development of artificial intelligence(AI) and rapid technological innovation that no one can predict until now. This study started from the question of 'What role should home economics education play in the era of the Fourth Industrial Revolution?'. The Fourth Industrial Revolution is characterized by AI, cloud computing, Internet of Things(IoT), big data, and Online to Offline(O2O). It will drastically change the social system, science and technology and the structure of the profession. Since the dehumanization of robots and artificial intelligence may occur, the 4th Industrial Revolution Education should be sought to foster future human resources with humanity and citizenship for the future community. In addition, the implication of education in the fourth industrial revolution, which will bring about a change to a super-intelligent and hyper-connected society, is that the role of education should be emphasized so that humans internalize their values as human beings. Character education should be established as a generalized and internalized consciousness with a concept established in the integration of the curriculum, and concrete practical strategies should be prepared. In conclusion, home economics education in the 4th industrial revolution era should play a leading role in the central role of character education, and intrinsic improvement of various human lives. The fourth industrial revolution will change not only what we do, or human mental and physical activities, but also who we are, or human identity. In the information society and digital society, it is important how quickly and accurately it is possible to acquire scattered knowledge. In the information society, it is required to learn how to use knowledge for human beings in rapid change. As such, the fourth industrial revolution seeks to lead the family, organization, and community positively by influencing the systems that shape our lives. Home economics education should take the lead in this role.

• Economic and Environmental Geology
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• v.55 no.4
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• pp.421-428
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• 2022

This study analyzes emerging earthquake and space use technologies from the latest Korean and Japanese scientific and technological foresights in 2022 and 2019, respectively. Unlike the earthquake prediction and early warning technologies presented in the 2017 study, the emerging earthquake technologies in 2022 in Korea was described as an earthquake/complex disaster information technology and public data platform. Many detailed future technologies were presented in Japan's 2019 survey, which includes largescale earthquake prediction, induced earthquake, national liquefaction risk, wide-scale stress measurement; and monitoring by Internet of Things (IoT) or artificial intelligence (AI) observation & analysis. The latest emerging space use technology in Korea and Japan were presented in more detail as robotic mining technology for water/ice, Helium-3, and rare earth metals, and manned station technology that utilizes local resources on the moon and Mars. The technological realization year forecasting in 2019 was delayed by 4-10 years from the prediction in 2015, which could be greater due to the Corona 19 epidemic, the declaration of carbon neutrality in Korea and Japan in 2020 and the Russo-Ukrainian War in 2022. However, it is required to more active research on earthquake and space technologies linked to information technology.

• Journal of Broadcast Engineering
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• v.25 no.2
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• pp.200-207
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• 2020

Recently, deep neural networks such as CNN are showing excellent performance in various fields such as image classification, object recognition, visual quality enhancement, etc. However, as the model size and computational complexity of deep learning models for most applications increases, it is hard to apply neural networks to IoT and mobile environments. Therefore, neural network compression algorithms for reducing the model size while keeping the performance have been being studied. In this paper, we apply few compression methods to CNN models and evaluate their performances in the embedded environment. For evaluate the performance, the classification performance and inference time of the original CNN models and the compressed CNN models on the image inputted by the camera are evaluated in the embedded board equipped with QCS605, which is a customized AI chip. In this paper, a few CNN models of MobileNetV2, ResNet50, and VGG-16 are compressed by applying the methods of pruning and matrix decomposition. The experimental results show that the compressed models give not only the model size reduction of 1.3~11.2 times at a classification performance loss of less than 2% compared to the original model, but also the inference time reduction of 1.2~2.21 times, and the memory reduction of 1.2~3.8 times in the embedded board.

• Journal of the Korea Society of Computer and Information
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• v.24 no.11
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• pp.235-243
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• 2019

Universities are opening related majors and subjects to nurture the problem-solving fusion that businesses want. The time has come when rapid technological. On this thesis, we analyzed three years (2017-2019) of survey result of Women University students in order to figuring out and dealing with the change in 4th industrial revolution and intellectual information technology. It turns out that 1) there was an increase of interest in 4th industrial revolution from 59% in 2017 to 80% in 2019, 2) IoT, ICT, Artificial Intelligence, and Education Research System became top priority in technical strategy, 3)the prime keyword is AI, robot, job, 4)the expectation on increasing of the opportunity and the number of jobs in science technology field was 50%, 5)the importance of universities and companies was 50%, 80% each, 6) the information needed for science technology were educational discipline, change in future science, prospective future information in order, and 7)the most needed education were education on creativity, coding, cross-subject, engineering in order. In the era of the fourth industrial revolution, it is essential to expand the SW manpower base in various fields. University education, which should provide connectivity for super-fusion, should provide curriculum optimized for industrial demands such as, fusion and connected education, creative thinking, self-directed problem solving and etc.