• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.12C
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• pp.1276-1281
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• 2002

Bellare and Rivest proposed the translucent cryptography which was a kind of key recovery system. Translucent cryptography is a system in which the third party can recover encrypted message with the probability p(0$\leq$p$\leq$1). The key recovery agency doesn't need to store the user's private key in advance. The balance between key recovery agency and user can be controlled by the value of p. For example, if p is set to be 0.4 then the key recovery agency can recover 40 out of 100 encrypted messages. In this paper, we show that user can easily deceive the key recovery agency in the translucent cryptography. Then we propose the solution of this problem.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.8
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• pp.2027-2041
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• 2013

In this paper, we propose a novel reversible data hiding scheme in the index tables of the vector quantization (VQ) compressed images based on index set construction strategy. On the sender side, three index sets are constructed, in which the first set and the second set include the indices with greater and less occurrence numbers in the given VQ index table, respectively. The index values in the index table belonging to the second set are added with prefixes from the third set to eliminate the collision with the two derived mapping sets of the first set, and this operation of adding prefixes has data hiding capability additionally. The main data embedding procedure can be achieved easily by mapping the index values in the first set to the corresponding values in the two derived mapping sets. The same three index sets reconstructed on the receiver side ensure the correctness of secret data extraction and the lossless recovery of index table. Experimental results demonstrate the effectiveness of the proposed scheme.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.6
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• pp.606-611
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• 2013

In this study, the regional states of 7 items are analyzed, the regional risks are calculated by using normalized data & analysis hierarchy process to set regional oil recovery capacity. Area on-water oil recovery capacity, $7,500k{\ell}$, is separated and regional on-water oil recovery capacity is determined, based on calculated regional degree of risk. Excessive current oil recovery capacities, setting in Incheon, Gunsan, Mokpo, Busan region, are as a result distributed to the other regions in each area. In case of central region, Daesan is increased as much as $1,475k{\ell}$, Yeosu is increased as much as $375k{\ell}$, Ulsan is increased as much as $475k{\ell}$. The regional on-water oil recovery capacity, considering both the cause of accident aspects and marine environmental & economic aspects, is estimated as more balanced distribution model, compared to current standard of on-water oil recovery capacity.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.4
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• pp.655-667
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• 2014

A disaster is the time-excess case that computerized service can tolerate a failure and financial industry is being set up the disaster recovery system based on the disaster recovery plan and the business continuity plan for preparing these disasters. However, existing system can not guarantee the business continuity when it comes to cyber terror. This paper analyzes the building type and building technology of disaster recovery system for the financial fields. Also this paper explain the type of data backup using online redo log and type of archive log backup using WORM storage. And this paper proposes the model of improved data recovery combining above two types. Lastly this paper confirm the effectiveness and reliability for proposal rocovery model through the implementation of the test environment.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.110-116
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• 2022

Human failure event (HFE) dependency analysis is a part of human reliability analysis (HRA). For efficient HFE dependency analysis, a maximum number of minimal cut sets (MCSs) that have HFE combinations are generated from the fault trees for the probabilistic safety assessment (PSA) of nuclear power plants (NPPs). After collecting potential HFE combinations, dependency levels of subsequent HFEs on the preceding HFEs in each MCS are analyzed and assigned as conditional probabilities. Then, HFE recovery is performed to reflect these conditional probabilities in MCSs by modifying MCSs. Inappropriate HFE dependency analysis and HFE recovery might lead to an inaccurate core damage frequency (CDF). Using the above process, HFE recovery is performed on MCSs that are generated with a non-zero truncation limit, where many MCSs that have HFE combinations are truncated. As a result, the resultant CDF might be underestimated. In this paper, a new method is suggested to incorporate HFE recovery into the MCS generation stage. Compared to the current approach with a separate HFE recovery after MCS generation, this new method can (1) reduce the total time and burden for MCS generation and HFE recovery, (2) prevent the truncation of MCSs that have dependent HFEs, and (3) avoid CDF underestimation. This new method is a simple but very effective means of performing MCS generation and HFE recovery simultaneously and improving CDF accuracy. The effectiveness and strength of the new method are clearly demonstrated and discussed with fault trees and HFE combinations that have joint probabilities.

• Journal of Korea Water Resources Association
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• v.44 no.1
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• pp.1-8
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• 2011

This paper addresses the correlation between the flood damage cost and recovery cost. National data (15 regions) for 20 years, panel data, has been analyzed for this test. Model specification of panel data analysis depends on the characteristics of data set and "fixed" or "random" effects model can be used. The results are represented in both models. As we expected all independent variables show positive relationship with recovery cost, except for the number of death and suffers. The damage of public facilities, such as rivers and road are the major factors on the damage and recovery cost, which means that flood damage can not be decreased without decreasing damages of public facilities from floods. Especially, the recovery cost is always higher than the damage cost and investment for flood control. Unlikely, government investment for flood control is the highest and recovery cost is the always lower than da mage cost andinvestment in Japan. Which means that proper investment can reduce economic damage cost of flood and recovery cost.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.391-393
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• 2008

A modified boost converter with magnetic coupling is presented to reduce the reverse recovery loss while maintaining low conduction loss of the rectifiers. By utilizing a coupled inductor and a set of diodes, the current passing the boost rectifier is transferred to an auxiliary loop before turn-off, allowing low di/dt for reduced recovery loss. Moreover, the boost inductor is brought inside the bridge rectifier to reduce conduction loss by decreasing the number of conducting diodes during switch turn-off. Experimental results of a 500W prototype are provided to verify the increase in efficiency and validity of the proposed converter.

• Journal of the Korea Safety Management & Science
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• v.11 no.2
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• pp.159-165
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• 2009

Through the understanding of the change of productivity and the ability of error recovery according to aging and the assessment and analysis of them, we may take this research to contribute to make a design for the road-map to help set up the policy of employment for old generation. For this we have taken an experiment of the coordination tester for 100 person who are chosen randomly and analysed the collected data using SAS, which is one of widely used statistical analysis packages. The main results are as follow: $\circledcirc$ The result of regression between the working speed and the length of the correction of error shows independence. (pr>0.2029). $\circledcirc$ The regression between age and working speed is statistically significant. (pr<0.0001) $\circledcirc$ The relation between age and the length of the correction of error is not significant. (pr>0.9123).

• Speech Sciences
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• v.9 no.3
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• pp.237-250
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• 2002

Linguistically, 'Focus' is the element which includes new or unpresupposed information. It is usually signalled by prosodic prominence called the 'pitch accent'. The purpose of this study is to observe the realization of the focal accent in VP-ellipsis, especially, to affect the meaning recovery of elided VP. Asher (1999) gave evidence that focal stress should be on the higher verb and the AUX in order to recover the elided VP to the lower one. In this paper, the systematic patterning of focal accent to decide the elided meaning in VP-ellipsis is to be observed. The realization of focal accent by English native speakers is set as the criteria for the meaning recovery of the elided VP and is compared to Koreans'. Moreover, the focal accents of Koreans are observed and compared with respect to their English proficiency levels.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.9 s.180
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• pp.2292-2301
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• 2000

We propose an accurate and efficient estimation method of transverse shear stresses for analysis and design of laminated composite structures by 4-node quadrilateral degenerated shell elements. To get proper distributions of transverse shear stresses in each layer, we use 3-dimensional equilibrium equations instead of constitutive equations with shear correction factors which vary diversely according to the shapes of shell sections. Three dimensional equilibrium equations are integrated through the thickness direction with complete polynomial membrane stress fields, which are recovered by REP (Recovery by Equilibrium in Patches) recovery method. The 4-node quadrilateral degenerated shell element used in this paper has drilling degrees of freedom and shear stresses derived from assumed strain fields that are set up at natural coordinate systems. The numerical results demonstrate that the proposed estimation method attains reasonable accuracy and efficiency compared with other methods and FE analysis using 4-node degenerated shell elements.