• Journal of applied mathematics & informatics
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• v.30 no.3_4
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• pp.365-380
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• 2012

Non-negative matrix factorization (NMF) is a very efficient method to explain the relationship between functions for finding basis information of multivariate nonnegative data. The multiplicative update (MU) algorithm is a popular approach to solve the NMF problem, but it fails to approach a stationary point and has inner iteration and zero divisor. So the elementwisely alternating projected gradient (eAPG) algorithm was proposed to overcome the defects. In this paper, we use the fact that the equilibrium point is stable to prove the convergence of the eAPG algorithm. By using a classic model, the equilibrium point is obtained and the invariant sets are constructed to guarantee the integrity of the stability. Finally, the convergence conditions of the eAPG algorithm are obtained, which can accelerate the convergence. In addition, the conditions, which satisfy that the non-zero equilibrium point exists and is stable, can cause that the algorithm converges to different values. Both of them are confirmed in the experiments. And we give the mathematical proof that the eAPG algorithm can reach the appointed precision at the least iterations compared to the MU algorithm. Thus, we theoretically illustrate the advantages of the eAPG algorithm.

• Journal of Digital Convergence
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• v.13 no.7
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• pp.47-55
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• 2015

In e-learning industry which represents the convergence of IT and education, the standard of e-learning content development cost has been calculated according to the guideline or standard of existing similar industries without considering the characteristics of the industry until today. The absence of contents development cost standard related to e-learning has been recognized as one of the most difficulties in e-learning industry. The calculation of the content development cost without reflecting the characteristics of e-learning industry has bad effects such as the degradation of content quality and development of e-learning industry, and the growth obstruction of them. This paper suggest a standard of development cost for e-learning content development considering the characteristics of e-learning industry. We analyse current problems and the characteristics in e-learning industry, and define the development cost standard. We propose the methodology for developing e-learning industry and for contributing quality improvement of e-learning content.

• Bulletin of the Korean Mathematical Society
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• v.39 no.2
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• pp.269-276
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• 2002

Let E be a real Banach space. Let T : E longrightarrow E be a map with F(T) : = { x $\in$ E : Tx = x} $\neq$ 0 and satisfying the accretive-type condition $\lambda\$\mid$x-Tx\$\mid$^2$, for all $x\inE,\;x^*\inf(T)\;and\;\lambda >0$. We prove some necessary and sufficient conditions for the convergence of the Mann iterative sequence to a fixed point of T.

• Journal of Positioning, Navigation, and Timing
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• v.13 no.1
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• pp.15-23
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• 2024

One of the core keywords in the fourth industrial revolution is convergence, and the convergence of the production, distribution, and consumption processes of services is particularly important. The convergence of user services is underway in various industrial fields including mobile communications, healthcare, mobility, artificial intelligence, etc. In order to offer these converged services efficiently, it is necessary to provide accurate user-centric location information, which can be obtained by employing the global navigation satellite system (GNSS). In addition, as we have entered the post-COVID era, the demand for various fields such as a healthcare, customized tourism services, and aviation services based on accurate location information is exploding. In this paper, we present the results of a case study on the current research trends of GNSS used in telemedicine services and AI & IoT fields, and also analyze these results.

• The Journal of the Korea Contents Association
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• v.19 no.4
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• pp.477-489
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• 2019

Recently, interdisciplinary studies have been receiving attention. Interdisciplinary research, especially in arts and technology, is a very interesting issue. E.A.T. was founded in New York in 1966 by artists and engineers. Based on the E.A.T. case, this study analyzed the period background in which art and technology could be converged, and the characteristics of E.A.T. works. The analysis results of the period background revealed that five factors influenced the organization and development of E.A.T.. Economic factors, artistic factors, technical factors, educational factors, and sponsored cultural factors influenced the convergence of art and technology. E.A.T. works collaborated by artists and engineers generally had three characteristics. Convergence across various fields, multi-sensitivity utilizing different senses, and interaction between the environment and humans appeared in E.A.T. works. This study provides meaningful implications for both artists and engineers who wish to overcome the limitations of artistic expression and develop new technology.

• Journal of Convergence for Information Technology
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• v.11 no.4
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• pp.35-45
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• 2021

The e-commerce industry using mobile or web is growing rapidly, and the emergence of various platform services is causing innovative changes in the e-commerce industry. This study aims to identify the attachment types of e-commerce users and to demonstrate the relationship between the PPerceived Usefulness, and Perceived Ease of Use by TAM. In order to empirically verify the research model of this study, a survey was conducted on ordinary people with experience using e-commerce and path analysis was conducted by using PLS to analyze its Internal consistency, Confirmatory factor analysis, Discriminant validity and Goodness-of-fit verification. As a result, a significant relationship between Perceived Stability, Perceived Usefulness, and Perceived Ease of Use was identified, could verify the association with the TAM and Acceptance Intention.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.01a
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• pp.283-284
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• 2022

본 논문은 TTS를 사용해 사용자들에게 E-Book 및 뉴스를 보고 들을 수 있는 기능을 제공한다. 사용자 및 개발자가 직접 녹음한 TTS를 사용해 원하는 목소리, 배속과 같은 기능을 제공한다. 기존 TTS를 사용한 E-Book 사이트들은 광고가 많아 가독성의 문제와 유료 서비스인 반면에 본 논문에서 제안한 웹은 다양한 연령층의 사용자들이 사용하기 쉽게 메뉴의 간편화를 통해 다양한 E-Book 및 뉴스 기능을 제공함으로써 보다 직관적이고 쉽게 전자문서를 읽을 수 있도록 하였다.

• Electronics and Telecommunications Trends
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• v.35 no.3
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• pp.85-97
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• 2020

In the maritime industry, the convergence of information and communication technology (ICT) occurs in two areas. The first one is the convergence of e-navigation technology to apply ICT to the maritime domain. This was led by EU's initiative and is also being promoted in our country. The other one is the convergence of autonomous ship technology to apply various ICT technologies for commercial purposes. This initiative is being led by maritime industries. In this paper, we describe trends of e-navigation and maritime autonomous surface ship technology convergence. Subsequently, we explain the standardization status of performance and technical standard bodies, international standardization organizations, and related standard-developing organizations to provide the interoperability of these technologies. Finally, we examine ongoing projects in Korea and suggest future directions for their R&D and standardization.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.2
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• pp.267-275
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• 2015

In this paper, ZnO films were prepared by atomic layer deposition (ALD) and CdS films were deposited using chemical bath deposition (CBD) to form ZnO/CdS heterojunction. More accurate mapping of band arrangement of the ZnO/CdS heterojunction has been performed by analyzing its electrical and optical characteristics in depth by various methods including transmittance, x-ray photoemission spectroscopy (XPS), and ultraviolet photoemission spectroscopy (UPS). The optical bandgap energies ($E_g$) of ZnO and CdS were 3.27 eV and 2.34 eV, respectively. UPS was capable of extracting the ionization potential energies (IPEs) of the materials, which turned out to be 8.69 eV and 7.30 eV, respectively. The electron affinity (EA) values of ZnO and CdS calculated from IPE and $E_g$ were 5.42 eV and 4.96 eV, respectively. Energy-band structures of the heterojunction could be accurately drawn from these parameters taking the conduction band offset (CBO) into account, which will substantially help acquisition of the full band structures of the thin films in the CIGS solar-cell device and contribute to the optimal device designs.

• Proceedings of the CALSEC Conference
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• 2004.02a
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• pp.89-97
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• 2004

1. Introduction; Fundamental Difference between conventional old commerce and e-commerce？ 2. "Quantity changes into Quality"; Phase transition and Critical phenomena Logarithmic Convergence and Emergence of Quality 3. Networked Small World; Indications from Genomics; Power-Law Ordered Plain Structure of Super-Complex System ⇔ The Structure of e-Biz. 4. Uniquitous Crisis to Ubiquitous Critical Points for the Emergence of Qualified Business with e-strucrure