• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.377-387
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• 2009

Digital signatures not only provide a way of guaranteeing the integrity of data but also establish the identity of the signer. However, basic digital signature format which contains only the signature of the signer does not guarantee the correctness of its creation time, and it can not remain valid over long periods. This paper proposes a system which integrates timestamp service into digital signatures. The system provides online services for the creation and verification of long term digital signatures which can give the guarantee of the correctness of their creation times and can be proved to be valid over long periods. The proposed system can be used in the various areas such as e-commerce contracts, document archival services, and invoice applications, which requires long term digital signatures. The proposed system is tested with the KRISS timestamp service system.

• The Journal of the Korea Contents Association
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• v.5 no.1
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• pp.55-63
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• 2005

In undeniable digital signature scheme, the signature can not be verified without the signer's cooperation. The undeniable signature scheme can be used to computerize many applications which can not be done by a conventional digital signature scheme. In this study, we propose the undeniable digital multi-signature scheme which requires many signers and designated verifier The multi-signature can be verified only in cooperation with all signers. The proposed scheme satisfies undeniable property and it is secure against active attacks such as modification and denial of the multi-signature by signers. We also propose copyright protection method of co-authored digital contents as an application of the proposed scheme.

• Korean Journal of Computational Design and Engineering
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• v.12 no.5
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• pp.382-394
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• 2007

Nowadays, manufacturing industries undergo constantly growing pressures for global competitions, and they must shorten time and cost in product development and production to response varied customers' requirements. Digital virtual manufacturing is a technology that can facilitate effective product development and agile production by using digital models representing the physical and logical schema and the behavior of real manufacturing systems including products, processes, manufacturing resources and plants. For successful applications of this technology, a digital virtual factory as a well-designed and integrated environment is essential. In this paper, we developed a new classification and coding system for effective managements of digital virtual factory objects, and implement a supporting application to verify and apply it. Furthermore, a digital virtual factory layout management system based on the classification and coding system has developed using XML, Visual Basic.NET and FactoryCAD. By some case studies for automotive general assembly shops of a Korean automotive company, efficient management of factory objects and reduction of time and cost in digital virtual factory constructions are possible.

• Journal of Navigation and Port Research
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• v.46 no.5
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• pp.458-470
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• 2022

As the 4th industrial revolution progresses, the application of several cutting-edge technologies such as the Internet of Things, big data, and mixed reality (MR) in relation to autonomous ships is being considered in the maritime logistics field. The aim of this study was to apply the concept of a digital twin model based on Human Machine Interaction (HMI) including a digital twin model and the role of an operator to a ship. The role of the digital twin is divided into information provision, support, decision, and implementation. The role of the operator is divided into operation, decision-making, supervision, and standby. The system constituting the ship was investigated. The digital twin system that could be applied to the ship was also investigated. The cloud-based digital twin system architecture that could apply investigated applications was divided into ship data collection (part 1), cloud system (part 2), analysis system/ application (part 3), and MR/mobile system (part 4). A Mixed Reality device HoloLens was used as an HMI equipment to perform a simulation test of a digital twin system of an 8 m battery-based electric propulsion ship.

• Journal of Information Technology Applications and Management
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• v.30 no.1
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• pp.81-95
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• 2023

As the DT of micro businesses emerges as an important task, the government is also promoting support projects such as policy establishment and micro business education. This study aims to develop a new index (checklist) that can objectively measure the level of digital literacy required for DT in the tertiary industry, which accounts for the largest share of micro business owners. In this study, indicators were derived through review of existing studies and FGI, and the validity and reliability of Likert 5 were measured for decision makers in the tertiary industry. In the field of digital literacy for micro business owners, a total of 22 indicators were developed, largely composed of basic technology environment competency, information utilization competency, information dissemination and production capability, and mind recognition capability. This study has academic significance in that it can contribute to accurately understanding the digital capabilities of micro business owners by developing a digital literacy index for micro business owners, a specific group lacking in research.

• Journal of dental hygiene science
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• v.24 no.3
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• pp.171-180
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• 2024

Background: The Fourth Industrial Revolution highlights the importance of artificial intelligence (AI) and digital literacy in dental hygiene education. However, research on students' attitudes toward AI and their digital literacy levels is limited. Therefore, this study investigated the attitudes of dental hygiene students toward AI and digital literacy levels. Methods: In total, 167 dental hygiene students in Baekseok University participated in the study and provided informed consent. The survey tool included general characteristics, smartphone usage patterns, attitudes toward AI, and digital literacy levels. Attitudes toward AI and digital literacy based on general characteristics and smart device usage were analyzed using t-tests and one-way ANOVA. Correlations among attitudes toward AI, digital literacy awareness, and digital literacy behaviors were analyzed using Pearson's correlation analysis. The impact of AI attitudes and digital literacy awareness on digital literacy behavior was examined using linear regression analysis. Results: Students with higher interest in their major had more positive attitudes toward AI, and those with higher smart device usage showed increased AI attitudes and digital literacy (p<0.05). Simple frequency or duration of smartphone use did not affect digital literacy, but students who perceived their smart device usage positively and believed that they used smart devices effectively in their studies exhibited higher levels of digital literacy (p<0.05). A positive attitude toward AI is associated with higher levels of digital literacy (p<0.05). Digital literacy awareness and attitudes toward AI influenced digital literacy behavior (p<0.05). Conclusion: These results suggest that the qualified utilization and application of digital devices in dental hygiene education are important. Improving the educational curriculum is necessary; as a result, digital technology can be effectively utilized, and various educational programs should be introduced to enhance digital literacy.

• Journal of Service Research and Studies
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• v.12 no.1
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• pp.36-48
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• 2022

As the use of smartphones has rapidly increased due to the development of digital technology, the expansion of smartphones, and the COVID-19 incident, dependence on smartphones and the Internet is emerging as a serious social problem. As one of the solutions to the smartphone overdependence problem, the government and companies are releasing smartphone overdependence prevention applications. However, research on the effectiveness of smartphone overdependence prevention applications is insufficient. Therefore, this study selects 25 applications serviced in Korea as analysis targets and evaluates smartphone overdependence prevention applications in terms of function and service using the FGI survey method to identify problems and propose improvements. In the function evaluation, the functions of blocking illegal/harmful apps/websites, limiting smartphone usage time, and monitoring smartphone usage status are provided in most applications, so satisfaction scores are also highly evaluated. However, functions such as location check, smombie prevention, and body camphishing prevention served by some applications are evaluated low due to poor performance and poor accuracy. Classified by service provider, government-providing applications need to accurately perform functions and improve convenience of use. Mobile-Carrier-providing applications need to improve connectivity with other carriers and compatibility with other smart devices like smartphone, tablet, etc. Other private enterprise-providing applications need to open AS channels such as customer service centre and chatbot to improve service.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.11
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• pp.157-167
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• 2021

The study analyzes the factors affecting the intention and recommendation to use the mobile banking applications of 314 customers from Vietnam. The study analyzes 7 factors affecting the intention and recommendation to use the mobile banking applications of customers from Vietnam, including (i) Perceived risk; (ii) Perceived ease of use; (iii) Perceived usefulness; (iv) Attitude; (v) Perceived trust; (vi) Social image; and (vii) Innovativeness. Besides, the study also analyzes 4 variables that reflect the customer's demographics, including gender, age, education, and occupation, and 6 variables describing the behavior of customers using mobile banking applications. The study findings indicate that the following factors (i) Innovativeness; (ii) Attitude; (iii) Perceived risk; (iv) Perceived ease of use, and (v) Perceived trust have the most significant impact on customers' behavior of using mobile banking applications in emerging markets such as Vietnam in the context of prolonged pandemic and continuous lockdown in many provinces and cities. The study is also of great value to studies on behavior changes among customers using mobile banking applications after the COVID-19 pandemic in Vietnam. The study will provide additional empirical evidence useful to bank administrators in motivating customers to use mobile banking applications, helping develop a digital economy in Vietnam.

• Journal of Digital Convergence
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• v.18 no.11
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• pp.459-464
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• 2020

This study is a study that analyzes the user experience of a virtual makeup application in the beauty industry where color or formulation testing is important. Recently, cases of beauty smart stores and beauty applications using AR and AI are increasing. However, since virtual makeup is different from testing a real product, it is necessary to derive needs through research from the user's side. In order to compare user preferences by using AR and AI cases, six factors based on the emotional interface model were analyzed through a questionnaire to identify items with statistically significant figures. As a result, the user felt comfortable with the virtual makeup function, but showed that it needs to be supplemented in terms of reliability. Since this study focused on the customer experience as a real user and identified the main experience factors and needs of virtual makeup through two types of comparison, it is hoped that this study will be useful as a prior study.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.8
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• pp.1492-1497
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• 2017

In this paper, a design method for a CPW-fed wideband loop antenna for indoor digital TV applications is studied. The proposed loop antenna consists of a square loop and two circular sectors which connect the loop with central feed points, and the CPW feed line is inserted in the lower circular sector. The CPW feed line is designed to match with the 75 ohm port impedance for DTV applications, and the ground slots are etched in order to improve the impedance matching in the middle frequency region. The effects of the gap between the circular sectors and the location and dimension of the ground slots on the input reflection coefficient and gain characteristics are examined to obtain the optimal design parameters. The optimized antenna is fabricated on FR4 substrate, and the experiment results show that it operates in the frequency band of 463-1,280 MHz for a VSWR < 2, which assures the operation in the DTV band.