• Current Optics and Photonics
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• v.3 no.2
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• pp.154-163
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• 2019

In this study, we developed an optical sighting system capable of shooting at a long-distance target by operating a digital gyro mirror composed of a gyro sensor and an FSM. The optical sighting system consists of a reticle part, a digital gyro mirror (FSM), a parallax correction lens, a reticle-ray reflection mirror, and a partial reflection window. In order to obtain the optimal volume and to calculate the leading angle range according to the driving angle of the FSM, a calculation program using Euler rotation angles and a three-dimensional reflection matrix was developed. With this program we have confirmed that the horizontal leading angle of the developed optical sighting system can be implemented under about ${\pm}8^{\circ}$ for the maximum horizontal driving angle (${\beta}={\pm}12.5^{\circ}$) of the current FSM. Also, if the ${\beta}$ horizontal driving angle of the FSM is under about ${\pm}15.5^{\circ}$, it can be confirmed that the horizontal direction leading angle can be under ${\pm}10.0^{\circ}$. If diagonal leading angles are allowed, we confirmed that we can achieve a diagonal leading angle of ${\pm}10.0^{\circ}$ with a vertical driving angle ${\alpha}$ of ${\pm}7.1^{\circ}$ and horizontal driving angle ${\beta}$ of ${\pm}12.5^{\circ}$.

• Journal of The Korean Association of Information Education
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• v.15 no.3
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• pp.425-437
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• 2011

The major functions of the digital textbooks that have been developed recently were focused on electronic whiteboard, learning tools, multimedia. But supporting contents retrieval was not included yet. This study is aimed to develop an elementary digital textbook that supports retrieval function. We surveyed elementary teachers about the requirements for search function and a digital textbook was designed and implemented based on the result of the survey. The distinctive feature of the developed digital textbook, which is written in XML, is that it is enabled to search the units of meaningful phrases. The survey which was carried out after using the new digital textbook showed that more than 90% of the teachers think that it is quite useful in class and they would like to use this textbook in their class. If a retrieval function can be added to the digital textbook which is going to be supplied to elementary schools, it will be a lot helpful for teaching and learning procedure.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.212-219
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• 2010

Modern museum, along with the basic roles of a museum that display to the public through the exhibition of physical evidences that collected, preserved and researched about human environment, it is changing in a way to appropriately fulfill the desire of new culture of the public and to fit the paradigm of the digital era. Diversification of expression method using multimedia played a big role in effective meaning delivery and technology development made possible for interaction-able of digital media build up and application to made possible of interactive communication for visitors. If the main purpose of the past museum exhibition was the delivery of information and knowledge, modern museum's exhibit has been identified as the purpose being diversified through the use of digital media. Exhibition planner, as for museum exhibition that used many characteristics of the digital media as mentioned above, should plan so that past unfamiliar relic can communicate with us living in the modern society. But obsessive usage of the digital media should not shade the interest of the visitors towards the relic in overall exhibition; and what is most important is that other than the exhibition and exhibit, enforcement of translation through systematic coherent approach and its appropriate digital technology and creative application and harmony are more important.

• The KIPS Transactions:PartC
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• v.12C no.1 s.97
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• pp.37-44
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• 2005

As wireless network was developed and Capability of Wireless Phone was increased, M-Commerce was activates In Wireless network environment. User Authentication and Security in E-Commerce Environment is very important, so Authentication Technology, such as WPKI and Hermes System, XML Digital Signature in Wire Network is studying. But if authentication systems was implemented heterogeneous, WPKI is difficult to implement the system, it's not interoperate with authentication system on wire internet, not support XML digital Signature. Hermes system also not interoperate with XML digital signature system. So our paper designed System that can interoperate among digital signature systems and XML document to apply XML digital signature technology on wire network to wireless network, and then implemented system that can XML digital signature to use Java Card.

• Proceedings of the Korea Information Assurance Society Conference
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• 2004.05a
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• pp.303-308
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• 2004

As developed wireless internet and performance of wireless terminal, E-commerce of wire internet move to wireless internet. This I-commerce in wireless internet environment called M-Commerce, recognized user authentication and data security as very important technology such as E-commerce in environment of wire internet. So authentication technology such as WPKI and Hermes system and XML digital signature was studied. But WPKI is difficulty to implement system, if authentication system that consisted in WPKI environment was heterogeneous. And Hermes system is not interoperate to XML digital signature system. So, our paper suggested XML digital signature system based java card to interoperate among the digital signature system, to apply XML digital signature used in wire internet. Our system offer XML digital signature in wireless internet, can interoperate among the XML digital signature systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.2
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• pp.100-108
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• 2014

In this paper, we design SSD(simultaneous single band duplex) system using RF(radio frequency) cancellation and digital cancellation. we analyze characteristic of residual self-interference after RF Cancellation signal when error of phase shifter occur in RF cancellation. When phase shifter error of $0^{\circ}$, $0.5^{\circ}$, $1^{\circ}$ and $2^{\circ}$ occur in RF cancellation, residual self-interference signal power after RF cancellation is bigger than desired signal power of distant station. So, it is impossible to receive transmit data of distant station. but we confirm that it is possible to receive transmit data of distant station by digital cancellation with frame structure. Also, in digital cancellation with frame structure, if residual self-interference signal after RF cancellation is too large then LMS algorithm requires more time to estimate self-interference channel. That is, performance degradation occurs because self-interference channel estimation has not completed in estimation frame.

• Journal of the Korea Society of Computer and Information
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• v.12 no.3
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• pp.137-146
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• 2007

Korea's seas have the potentials of dispute against China or Japan due to the overlap of the territorial waters and EEZ. In case of marine accidents, the nature of the sea tends to eliminate much of the track, making it another hardship in evidence adoption in case of an international dispute along with the false entries of fishing vessels' journals. Marine Digital Forensics Protects the functions of computers and IT appliance on vessels and extracts evidence of voyage and accidents to resolve international dispute. The digital evidence, if tampered with its integrity, my lead to the rejection to a critical claim or may even fail to make a case. As a solution, this thesis suggests Marine Digital Forensics as a way to extract evidence and prove a claim. This may be utilized as means of scientific investigation on sea as overseas exchange increases and the vessels digitalize, leading to a solution in international disputes that may occur in the future.

• Journal of Digital Convergence
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• v.18 no.7
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• pp.1-8
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• 2020

This study aimed to develop a self-reporting assessment tool for digital literacy competence to use it as a tool for self-diagnosis or effectiveness verification in educational programs, considering that digital literacy competence is one of the core competencies for the present and future society. Based on the previous research on digital literacy competence, the tool was developed with 45 question items of 2 areas and 8 factors. The results of an exploratory factor analysis and confirmatory factor analysis conducted to determine suitability were generally satisfactory based on the assessment data from about 3,000 middle school students. The assessment tools developed in this study are primarily applicable to primary and secondary school and adult education. In future research, if the system is developed to be accessible to anyone online based on this tool, and the accumulated data provide educational information for each individual's self-development, it will greatly contribute to improving the digital literacy competence of the people.

• KSCI Review
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• v.15 no.1
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• pp.209-217
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• 2007

Korea's seas have the potentials of dispute against China or Japan due to the overlap of the territorial waters and EEZ. In case of marine accidents, the nature of the sea tends to eliminate much of the track, making it another hardship in evidence adoption in case of an international dispute along with the false entries of fishing vessels' journals. Marine Digital Forensics protects the functions of computers and IT appliance on vessels and extracts evidence of voyage and accidents to resolve international dispute. The digital evidence, if tampered with its integrity, may lead to the rejection to a critical claim or may even fail to make a case. As a solution, this thesis suggests Marine Digital Forensics as a way to extract evidence and prove a claim. This may be utilized as means of scientific investigation on sea as overseas exchange increases and the vessels digitalize, leading to a solution in international disputes that may occur in the future.

• Journal of KIBIM
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• v.9 no.4
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• pp.51-61
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• 2019

In the general manufacturing sector, prototyping used to reduce the risks that can arise with new conceptual products. However, in AEC area, it does not mass-produce a building, so the prototype itself becomes a building. Therefore, it is challenging to have prototyping of the same scale as the real thing, and the prototyping process in architecture is very inefficient. The prototyping process in the design stage typically assumes making a scaled model, partial model, or digital model. However, it is difficult for these models to correspond to the actual building and the environment of time and space such as scale, material, environment, load, physical properties and deformation, corrosion, etc., unlike the actual building. When using the digital twin concept in the prototyping process, it is possible to measure performance from the design stage to the operation stage. The digital twin was found by a method for monitoring based on physical twins and real-time linkage in the operation stage. Therefore, if the digital twin concept is applied at the design stage, it is possible to predict performance using not only current performance but also history information using real-time information. In order to apply the digital twin concept to the prototyping design process, we analyze the theoretical considerations and the prototyping design process of the digital twin, analyze the cases and research results where the prototyping design was applied, Provide an applied prototyping design process. The proposed process is tested through a pilot project and analyzed for potential use.