• Convergence Security Journal
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• v.24 no.2
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• pp.71-78
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• 2024

As the rapid development of quantum computing compromises current public key encryption methods, the National Institute of Standards and Technology (NIST) in the United States has initiated the Post-Quantum Cryptography(PQC) project to develop new encryption standards that can withstand quantum computer attacks. This project involves reviewing and evaluating various cryptographic algorithms proposed by researchers worldwide. The initially selected quantum-resistant cryptographic algorithms were developed based on lattices and hash functions. Currently, algorithms offering diverse technical approaches, such as BIKE, Classic McEliece, and HQC, are under review in the fourth round. CRYSTALS-KYBER, CRYSTALS-Dilithium, FALCON, and SPHINCS+ were selected for standardization in the third round. In 2024, a final decision will be made regarding the algorithms selected in the fourth round and those currently under evaluation. Strengthening the security of public key cryptosystems in preparation for the quantum computing era is a crucial step expected to have a significant impact on protecting future digital communication systems from threats. This paper analyzes the security and efficiency of quantum-resistant cryptographic algorithms, presenting trends in this field.

• Journal of Advanced Navigation Technology
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• v.28 no.1
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• pp.136-141
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• 2024

In this paper, a broadband inset-fed microstrip patch antenna operating at 10.525 GHz band was proposed. The proposed broadband inset-fed microstrip patch antenna consists of three narrow rectangular patches. At the center of the center patch, two symmetrical side patches were connected by a strip conductor and were arranged with their centers shifted in a perpendicular direction with respect to the center patch. For performance comparison, a conventional inset-fed square microstrip patch antenna was designed. Experiment results show that the frequency band of the measured input reflection coefficient with a voltage standing wave ratio less than 2 for the broadband inset-fed microstrip patch antenna was 10.036-11.051 GHz (9.63%), whereas that for the conventional inset-fed rectangular microstrip patch antenna was 10.306-10.772 GHz (4.42%). Therefore, the input reflection coefficient frequency bandwidth of the fabricated broadband inset-fed microstrip patch antenna was increased by 2.18 times, compared to the conventional inset-fed square microstrip patch antenna.

• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.815-820
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• 2023

In this paper, the design method of a miniaturized chipless RFID tag using a modified bent H-shaped slot was proposed. The proposed modified bent H-shaped slot was appended on the rectangular conductor plate printed on one side of a 20 mm × 50 mm FR4 substrate with a thickness of 0.8 mm. The resonant dip frequency of the bistatic RCS for the proposed modified bent H-shaped slot was compared with the cases when the H-shaped, U-shaped slot, and bent H-shaped slots were added, respectively, on the conductor plate. The simulated resonant dip frequencies for H-shaped, U-shaped, and bent H-shaped slots were 5.907 GHz, 4.918 GHz, and 4.364 GHz, respectively. When the proposed modified bent H-shaped slot was added, the resonant dip frequency was decreased to 3.741 GHz, and, therefore, the slot length was reduced by 36.7% compared to the H-shaped slot case. Experiment results show that the resonant dip frequency of the fabricated modified bent H-shaped slot was 3.9 GHz.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.105-112
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• 2024

In contemporary society, the expression of emotions and self-reflection are considered pivotal factors with a positive impact on stress management and mental well-being, thereby highlighting the significance of journaling. However, traditional journaling methods have posed challenges for many individuals due to constraints in terms of time and space. Recent rapid advancements in chatbot and emotion analysis technologies have garnered significant attention as essential tools to address these issues. This paper introduces an artificial intelligence chatbot that integrates the GPT-3 model and emotion analysis technology, detailing the development process of a system that automatically generates journals based on users' chat data. Through this system, users can engage in journaling more conveniently and efficiently, fostering a deeper understanding of their emotions and promoting positive emotional experiences.

• Journal of Advanced Navigation Technology
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• v.28 no.3
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• pp.356-361
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• 2024

This paper deals with the design and fabrication of a coplanar waveguide (CPW)-fed super-wideband semicircular-disk-shaped dipole antenna operating in a frequency band of 2.4 GHz or higher. To feed the antenna, a CPW feed line was appended to the center of the lower arm of the semicircular-disk-shaped dipole antenna. For miniaturization, square patches were added to the ends of the two arms of the semicircular-disk-shaped dipole, whereas the slot width of the CPW feed line at the center of the dipole antenna was increased to improve impedance matching in the 5.4-6.3 GHz band. The simulated frequency band of the proposed antenna for a voltage standing wave ratio (VSWR) less than 2 was 2.369-30 GHz(170.7%), whereas the fabricated antenna was maintained VSWR less than 2 in the frequency range of 2.378-20 GHz when measured using a network analyzer operating up to 20 GHz so it can be applied as a super-wideband antenna for next-generation mobile communications.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.6
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• pp.191-199
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• 2023

The purpose of this study is to examine the impact of ChatGpt's quality on users' satisfaction and intention to continuous use it. For this purpose, a survey was conducted targeting college students in the Busan and Gyeongnam regions, and responses from a total of 155 people were verified using the SPSS 28.0 program. As a result of the study, reliability and stability among ChatGPT quality factors were found to have a positive effect on satisfaction with use and intention to continuous use. Satisfaction with the use of ChatGPT was found to have a positive effect on intention to continuous use.. Satisfaction with use was found to have a positive mediating effect between the reliability and stability of ChatGPT quality and intention to continous use it. As a result of this study, we aim to contribute to suggesting educational and policy directions necessary to promote the use of ChatGPT by presenting factors that affect users' intention to continuous use ChatGPT among the qualities of ChatGPT.

• Journal of Advanced Navigation Technology
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• v.28 no.2
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• pp.232-237
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• 2024

In this paper, a broadband double dipole quasi-Yagi antenna using a 4×2 meander line array structure for maintaining 8 dBi gain was studied. The 4×2 meanderline array structure consists of a unit cell in the shape of a meanderline conductor, and it was placed above the second dipole antenna of the double dipole quasi-Yagi antenna. A double dipole quasi-Yagi antenna with generally used multiple strip directors was designed on an FR4 substrate with the same size, and the input reflection coefficient and gain characteristics were compared. Comparison results showed that the impedance frequency bandwidth increased by 6.3% compared to when using the multiple strip directors, the frequency bandwidth with a gain of 8 dBi or more increased by 10.1%, and average gain also slightly increased. The frequency band of the fabricated antenna for a voltage standing wave ratio less than 2 was 1.548-2.846 GHz(59.1%), and gain was measured to be more than 8 dBi in the 1.6-2.8 GHz band.

• Convergence Security Journal
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• v.24 no.3
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• pp.153-163
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• 2024

Despite the increasing hacking threats and security threats as IT technology advances and many companies adopt security solutions, cyberattacks and threats still persist for years. APT attack is a technique of selecting a specific target and continuing to attack. The threat of an APT attack uses all possible means through the electronic network to perform APT for years. Zero-day attacks, malicious code distribution, and social engineering techniques are performed, and some of them directly invade companies. These techniques have been in effect since 2000, and are similarly used in voice phishing, especially for social engineering techniques. Therefore, it is necessary to study countermeasures against APT attacks. This study analyzes the attack cases of Korean-based APT groups in Korea and suggests the correct method of using intelligence to analyze APT attack groups.

• Journal of the Korean Society for information Management
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• v.41 no.3
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• pp.145-169
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• 2024

This study examined university library services for students, including international students, and the AI-based information services provided by libraries. Additionally, the standards of Korean language education for international students were investigated. Based on the analysis of library services and these standards, a book recommendation system for learning Korean was developed using ChatGPT. The recommendation results from three training datasets were evaluated for recommendation precision. The results of the chatbot's book recommendations based on the 13 test questions were evaluated by recommendation precision. The comparison of the recommendation precision showed that the chatbot using the combined dataset was more successful in recommending all relevant books compared to the individual datasets. This study serves as an example of an effective approach to utilizing artificial intelligence technology for user services in university libraries.

• Journal of Advanced Navigation Technology
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• v.28 no.4
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• pp.538-543
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• 2024

In this paper, the miniaturization of a chipless RFID tag using an interdigital-capacitor-shaped slot was studied. The proposed interdigital-capacitor-shaped slot was appended on the rectangular conductor plate printed on one side of a 20 mm × 50 mm FR4 substrate with a thickness of 0.8 mm. The resonant dip frequency of the bistatic RCS for the proposed interdigital-capacitor-shaped slot was compared with the cases when the H-shaped and modified bent H-shaped slots were added, respectively, on the conductor plate. The simulated resonant dip frequencies for H-shaped and modified bent H-shaped slots were 5.907 GHz and 3.741 GHz, respectively. When the proposed interdigital-capacitor-shaped slot was added, the resonant dip frequency was decreased to 2.889 GHz, and, therefore, the slot length was reduced by 51.1% compared to the H-shaped slot case. Experiment results show that the resonant dip frequency of the fabricated nterdigital-capacitor-shaped slot was 3.07 GHz.