• Structural Engineering and Mechanics
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• v.78 no.5
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• pp.637-649
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• 2021

Great efforts have been conducted to investigate the seismic performances of the arch and rectangular underground structures, however, the differences between seismic responses of these two types of underground structures, especially the vault radian influencing the seismic responses of arch structures are not clarified. This paper presents a detailed numerical investigation on the seismic responses of arch underground structures with different vault radians, and aims to illustrate the rule that vault radian affects the seismic responses of underground structures. Five arch underground structures are built for nonlinear soil-structure interaction analysis. The internal forces of the structural components of the underground structures only under gravity are discussed detailedly, and an optimum vault radian for perfect load-carrying functionality of arch underground structures is suggested. Then the structures are analyzed under seven scaled ground motions, amounting to a total of 35 dynamic calculations. The numerical results show that the vault radian can have beneficial effects on the seismic response of the arch structure, compared to the rectangular underground structures, causing the central columns to suffer smaller axial force and horizontal deformation. The conclusions provide some directive suggestions for the seismic design of the arch underground structures.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.5
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• pp.1047-1057
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• 2018

As the number of services offered on the Internet exponentially increases, password managers are increasing popular applications that store several passwords in an encrypted database (or password vault). Browser-integrated password managers or locally-installed password managers store the password vault on the user's device. Although a web-based password manager stores the password vault on the cloud server, a user can store the master password used to sign in the cloud server on her device. An attacker that steals a user's encrypted vault stored in the victim's device can make an offline attack and, if successful, all the passwords in the vault will be exposed to the attacker. This paper investigates the vulnerability of the password vault stored in the device and develops attack programs to verify the vulnerability of the password vault.

• Structural Engineering and Mechanics
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• v.67 no.5
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• pp.481-492
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• 2018

The current experimental study is the reinforcement of the simple curvature vault masonry structures. In this study, we discuss complex structure include vault and rib cover with two radii and actual dimensions under a vertical load. The unreinforced structure data were compared with analysis data. The analysis data are in good agreement with experimental data. In the first experiment, a structure without reinforcement is tested and according to the test results, the second structure was reinforced using the carbon polymer fibers and the same test is done to see the effects of reinforcement. Based on the test results of the first structure, the first cracks are created in the vault. Moreover, the reinforcement with carbon fibers will increase the loading capacity of the structure around 35%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.11
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• pp.2221-2234
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• 2011

The fuzzy vault scheme has emerged as a promising solution to user privacy and fingerprint template security problems. Recently, however, the fuzzy vault scheme has been shown to be susceptible to a correlation attack. This paper proposes a novel scheme for one-time templates for fingerprint authentication based on the fuzzy vault scheme. As in one-time passwords, the suggested method changes templates after each completion of authentication, and thus the compromised templates cannot be reused. Furthermore, a huge number of chaff minutiae can be added by expanding the size of the fingerprint image. Therefore, the proposed method can protect a user's fingerprint minutiae against the correlation attack. In our experiments, the proposed approach can improve the security level of a typical approach against brute-force attack by the factor of $10^{34}$.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.321-322
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• 2006

In this paper, we propose a method that extracts invariant iris codes from user's iris pattern in order to apply these codes to a new cryptographic construct called fuzzy vault. The fuzzy vault, proposed by Juels and Sudan, has been used to manage cryptographic key safely by merging with biometrics. Generally, iris data has intra-variation of iris pattern according to sensed environmental changes, but cryptography requires correctness. Therefore, to combine iris data and fuzzy vault, we have to extract an invariant iris feature from iris pattern. In this paper, we obtain invariant iris codes by clustering iris features extracted by independent component analysis(ICA) transform. From experimental results, we proved that the iris codes extracted by our method are invariant to sensed environmental changes and can be used in fuzzy vault.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.241-242
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• 2007

In this paper, we propose a fuzzy vault system using iris data. The fuzzy vault, proposed by Juels and Sudan, has been used to protect cryptographic key with biometric information. In order to combine the fuzzy vault scheme with iris data, we used iris features extracted by ICA method and clustering technique. From our experimental results, we proved that the propose fuzzy vault system is robust to sensed environmental change.

• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.519-531
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• 2003

The aim of present investigation was to clinically measure the thickness of palatal masticatory mucosa in the hard palate as potential donor site for mucogingival surgery, to determine the relation to shape of palatal vault, form of tooth, gender, and to serve the clinical criteria t o choose the proper surgical technique. 84(mean age:25yrs) systemically and periodontally healthy volunteers participated in this study and 18 standard measurement points were defined in the hard palate, located on 3 lies which ran at different distances parallel to the gingival margin. 6 positions were designated on each of these 3 lines between the level of canine and 2nd molar and a bone sounding technique using a periodontal probe with minimal local anesthesia was utilized to assess the thickness of palatal masticatory mucosa. Student t-test was used to determine the difference in mucosal thickness between 2 groups gender, shape of palatal vault (high palatal vault vs. low palatal vault), tooth form (short-wide vs. long narrow) The result of this study were as follows: 1. Soft tissue thickness progressively increased in sites further away from the gingival margin (p<0.01). 2. Depending on position, in line a and line c the masticatory mucosal thickness increased from Ca to M2(p<0.01), but in line b the thickness increased from Ca to P2, and decreased to M1 and increased again to M2. 3. Gender did not influence the thickness of masticatory mucosa. 4. Palatal vault shape was associated with the thickness of masticatory mucosa. Thickness of low palatal vault group was thicker than high palatal group between P2 and M2 position. 5. Form of tooth did not influence the thickness of masticatory mucosa. In conclusion, palatal vault shape was associated with the thickness of masticatory mucosa. So, mucogingival surgery can be considered as a treatment modality in high palatal vault group. But, Gender and tooth form did not influence the thickness of masticatory mucosa.

• The Journal of Advanced Prosthodontics
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• v.14 no.5
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• pp.294-304
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• 2022

PURPOSE. The purpose of this study was to evaluate the influence of different palatal vault configurations on the accuracy and scan speed of intraoral scans (IO) of completely edentulous arches. MATERIALS AND METHODS. Three different virtual models of a completely edentulous maxillary arch with different palatal vault heights- Cl I moderate (U-shaped), Cl II deep (steep) and Cl III shallow (flat)-were digitally designed using CAD software (Meshmixer; Autodesk, USA) and 3D-printed using SLA-based 3D-printer (XFAB; DWS, Italy) (n = 30; 10 specimens per group). Each model was scanned using intraoral scanner (Trios 3; 3Shape^TM, Denmark). Scanning time was recorded for all samples. Scanning accuracy (trueness and precision) were evaluated using digital subtraction technique using Geomagic Control X v2020 (Geomagic; 3DSystems, USA). One-way analysis of variance (ANOVA) test was used to detect differences in scanning time, trueness and precision among the test groups. Statistical significance was set at α = .05. RESULTS. The scan process could not be completed for Class II group and manufacturer's recommended technique had to be modified. ANOVA revealed no statistically significant difference in trueness and precision values among the test groups (P=.959 and P=.658, respectively). Deep palatal vault (Cl II) showed significantly longer scan time compared to Cl I and III. CONCLUSION. The selection of scan protocol in complex cases such as deep palatal vault is of utmost importance. The modified, adopted longer path scan protocol of deep vault cases resulted in increased scan time when compared to the other two groups.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.27-27
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• 2023

최근 기후위기 등으로 인해 생물다양성 감소 우려가 높아지고 있으며, 식물유전자원 보존의 강화를 위해 수많은 국제협약이 체결되고 있다. 자국의 생물다양성을 보호하고, 전 세계의 기후위기 취약식물의 보존을 위해 대한민국 산림청은 세계 최초로 지하터널형 야생식물종자 영구저장시설인 '시드볼트(Seed Vault)'를 경상북도 봉화에 설립하였다. 시드볼트는 안전한 종자의 저장을 위해 온도 -20℃, 습도 RH 40% 이하를 유지하며, 환경 변화를 최소화하기 위해 매일 시설 점검을 진행하고 있다. 시드볼트의 미션은 '기후위기 대응 생물다양성 확보'이며, 전 세계 종자저장의 선도기관으로 2022년 12월 기준으로 5,424종 192,625점을 확보하였으며, 2030년까지 1만 종 30만 점을 목표로 하고 있다. 전 세계 식물 종의 보호를 위해 국제기구와 협력하고 있으나, 해외 종자의 저장이 더욱 강화되어야 하며, 향후 시드볼트 종자저장 네트워크 구축에 참고하기 위한 해외 사례를 조사하였다. 아시아에서는 중국이 다량의 식물종을 수집하고 있으나, 해당 자료에 대한 공개는 이루어지지 않고 있으며, 일본은 농업식량 식물자원 중심으로 종자를 보존하고 있으며, 태국, 대만, 싱가포르 및 몽골 및 중앙아시아 국가의 종자수집과 보존은 근래 확대되는 추세이다. FAO의 Plant Genetic Resources for Food And Agriculture 관련 수집 자료에 따르면, 아시아지역 25개 국가에서 984,019점의 식물유전자원을 보고하였다. 본 연구를 바탕으로 아시아지역의 종자보존 네트워크를 구축하여 해외 종자의 안전한 저장을 통해 아시아 야생식물자원 다양성 보전 가치를 통합하는 시설로 성장하고자 한다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2006.06a
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• pp.123-132
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• 2006

Biometric-based authentication can provide strong security guarantee about the identity of users. However, security of biometric data is particularly important as the compromise of the data will be permanent. To protect the biometric data, we need to store it in a non-invertible transformed version. Thus, even if the transformed version is compromised, the actual biometric data remains safe. In this paper, we propose an approach to protect finger-print templates by using the idea of the fuzzy vault. Fuzzy vault is a recently developed cryptographic construct to secure critical data with the fingerprint data in a way that only the authorized user can access the secret by providing the valid fingerprint. We modify the fuzzy vault to protect fingerprint templates and to perform fingerprint verification with the protected template at the same time. This is challenging because the fingerprint verification is performed in the domain of the protected form. Based on the experimental results, we confirm that the proposed approach can perform the fingerprint verification with the protected template.