• Structural Engineering and Mechanics
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• v.62 no.1
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• pp.11-20
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• 2017

The base force element method (BFEM) is a new finite element method. In this paper, a degenerated 4-mid-node plane element from concave polygonal element of BFEM was proposed. The performance of this quadrilateral element with 4 mid-edge nodes in the BFEM on complementary energy principle is studied. Four examples of linear elastic analysis for plane frame structure are presented. The influence of aspect ratio of the element is analyzed. The feasibility of the 4 mid-edge node element model of BFEM on complementary energy principles researched for plane frame problems. The results using the BFEM are compared with corresponding analytical solutions and those obtained from the standard displacement finite element method. It is revealed that the BFEM has better performance compared to the displacement model in the case of large aspect ratio.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.32 no.6
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• pp.1113-1120
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• 2022

Recently, the investigation has been difficult due to the emergence of messengers that encrypt and store data for the purpose of protecting personal information and provide services such as end-to-end encryption with a focus on security. Accordingly, the number of crime cases using security messengers is increasing, but research on data decoding for security messengers is needed. Element security messengers provide end-to-end encryption functions so that only conversation participants can check conversation history, but research on decoding them is insufficient. Therefore, in this paper, we analyze the instant messenger Element, which provides end-to-end encryption, and propose a plaintext verification of the history of encrypted secure chat rooms using decryption keys stored in the Windows Credential Manager service without user passwords. In addition, we summarize the results of analyzing significant general and secure chat-related artifacts from a digital forensics investigation perspective.

• Earthquakes and Structures
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• v.9 no.1
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• pp.173-194
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• 2015

Site response analysis is an important topic in earthquake engineering. A time-domain numerical method called as one-dimensional (1D) finite element artificial boundary method is proposed to simulate the homogeneous plane elastic wave propagation in a layered half space subjected to the obliquely incident plane body wave. In this method, an exact artificial boundary condition combining the absorbing boundary condition with the inputting boundary condition is developed to model the wave absorption and input effects of the truncated half space under layer system. The spatially two-dimensional (2D) problem consisting of the layer system with the artificial boundary condition is transformed equivalently into a 1D one along the vertical direction according to Snell's law. The resulting 1D problem is solved by the finite element method with a new explicit time integration algorithm. The 1D finite element artificial boundary method is verified by analyzing two engineering sites in time domain and by comparing with the frequency-domain transfer matrix method with fast Fourier transform.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.4
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• pp.637-659
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• 2021

Since the creation of the first Bitcoin blockchain in 2009, the number of cryptocurrency users has steadily increased. However, the number of hacking attacks targeting assets stored in these users' cryptocurrency wallets is also increasing. Therefore, we evaluate the security of the wallets currently on the market to ensure that they are safe. We first conduct threat modeling to identify threats to cryptocurrency wallets and identify the security requirements. Second, based on the derived security requirements, we utilize attack trees and Bayesian network analysis to quantitatively measure the risks inherent in each wallet and compare them. According to the results, the average total risk in software wallets is 1.22 times greater than that in hardware wallets. In the comparison of different hardware wallets, we found that the total risk inherent to the Trezor One wallet, which has a general-purpose MCU, is 1.11 times greater than that of the Ledger Nano S wallet, which has a secure element. However, use of a secure element in a cryptocurrency wallet has been shown to be less effective at reducing risks.

• Nuclear Engineering and Technology
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• v.51 no.5
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• pp.1355-1364
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• 2019

A recently published nuclear forensics methodology for source discrimination of separated weapons-grade plutonium utilizes intra-element isotope ratios and a maximum likelihood formulation to identify the most likely source reactor-type, fuel burnup and time since irradiation of unknown material. Sensitivity studies performed here on the effects of random measurement error and the uncertainty in intra-element isotope ratio values show that different intra-element isotope ratios have disproportionate contributions to the determination of the reactor parameters. The methodology is robust to individual errors in measured intra-element isotope ratio values and even more so for uniform systematic errors due to competing effects on the predictions from the selected intra-element isotope ratios suite. For a unique sample-model pair, simulation uncertainties of up to 28% are acceptable without impeding successful source-reactor discrimination. However, for a generic sample with multiple plausible sources within the reactor library, uncertainties of 7% or less may be required. The results confirm the critical role of accurate reactor core physics, fuel burnup simulations and experimental measurements in the proposed methodology where increased simulation uncertainty is found to significantly affect the capability to discriminate between the reactors in the library.

• Journal of the Korea Society of Computer and Information
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• v.12 no.4
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• pp.239-248
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• 2007

There's been a difficulty for general corporate to adopt recent incident response study because those studies focus on nation wide CERT Coordination Center or large organization aspect. This study is focus on study and design on security ticket based CERT system through analysis Security management's threat element, attack element, response element and it also help general corporate establish incident response process that is adjusted on IT operation. Confirmed CERT model's effectiveness and effect of quantitative Security incident management way that propose executing Security incident response experiment on the basis of this way. This study which provides general corporate oriented CERT model can be used to improve corporate's capability of responding incident by quantified management technique and select incident response SLA indicator. Already, formation which operate CERT can heighten corporation's information protection level by measure Security incident response result as metrical and analyze and improve problem continuously.

• KSCI Review
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• v.15 no.1
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• pp.141-150
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• 2007

There's been a difficulty for general corporate to adopt recent incident response study because those studies focus on nation wide CERT Coordination Center or large organization aspect. This study is focus on study and design on security ticket based CERT system through analysis Security management's threat element, attack element. response element and it also help general corporate establish incident response process that is adjusted on IT operation. Confirmed CERT model's effectiveness and effect of quantitative Security incident management wav that propose executing Security incident response experiment on the basis of this way. This study which Provides general corporate oriented CERT model can be used to improve corporate's capability of responding incident by quantified management technique and select incident response SLA indicator. Already, formation which operate CERT can heighten corporation's information protection level by measure Security incident response result as metrical and analyze and improve problem continuously.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.1B
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• pp.29-36
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• 2011

Near Field Communication is an emerging short-range wireless connectivity technology that offers proximity and different operating modes. Particularly, NFC technology has the potential to revolutionize mobile applications like payment and ticketing because NFC is more complex and mutual connectivity than RFID as the simple tag reader. Finally, NFC security technology defines the robust security protocols. This paper will specify and analyze the NFC security technology, and study the chance and its beneficial effect of the UICC card as the NFC Secure Element.

• Convergence Security Journal
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• v.9 no.2
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• pp.33-39
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• 2009

The problems of current network security system, separated by a single element is checked. To improve this, this thesis is to find vulnerabilities in the network security systems, and network security systems, security equipment, organic to make sure each works is a comprehensive review. Automation also offers a way to check it, it was implemented.

• Convergence Security Journal
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• v.5 no.2
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• pp.65-74
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• 2005

The hacking accident is increasing repidly according to development of latest computer network and the method becomes various. But, to correspond to hacking, it is lot of difficulties to cope gear and security element between product because most radiant mercuries apply technology between individual digenomic species and It is real condition that great setup, equipment, manpower disturbance are enlarged to apply this. Designed and embody Site-Based executive system that can integrate security element about IDS information between digenomic species to solve these problem and correspond efficiently from hacking.