• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.1
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• pp.121-126
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• 2019

The radionuclide inventory prediction of a nuclear power plant can help establish decommissioning plan by providing information of radiation environment. Accumulated radionuclides in reactors and related facilities after reactor shutdown can be divided into neutron activated materials and contaminated materials. Among the neutron activated radionuclides, $^{36}Cl$ and $^{41}Ca$ are important from the viewpoint of disposal because of its long half-life and physiochemical characteristics. In this research, we calculated the radionuclides of $^{36}Cl$ and $^{41}Ca$ in bioshielding concrete by estimating the neutron flux and cross section using the MCNPX. And we evaluated the inventories of $^{36}Cl$ and $^{41}Ca$ using the activation calculation code ORIGEN2.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.1
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• pp.55-66
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• 2002

Electronic cash system based on anonymous coins have been invented by David Chaum. However, von Solms and Naccache discovered that such anonymous coins also very well suited to support criminals in Blacoailing. In this paper, we suggest a method that a client informs a bank of the information about blackmailing attack by using Schnorr identification protocol of XTR version at the stage of identification, whenever he is blackmailed. In general, blackmailing is the most serious among the various drawbacks of electronic cash system. Especially, blackmiling to be done when the client is kidnapped brings a fatal result to electronic cash system. But if the Schnorr identification protocol of XTR version is used, we can efficiently defeat blackmailing without assumption required in the existing method to defeat blackmailing.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.25-33
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• 2022

This study developed the black liquor evaporation process models using the multiple-effect-evaporator according to the number of effects to predict steam consumption. The developed models were divided into the black liquor preheating and evaporation processes, and a virtual reboiler was added to predict steam consumption. In simulation results, the steam consumption in the double-effect-evaporator was decreased by 48.9 %, and as the number of effects increased, the steam consumption was decreased. Finally, the steam consumption in the octuple-effect-evaporator was decreased by 61.2 %. Also, this study suggests a strategy for deriving the optimal number of effects in the process by analyzing the latent heat recovered from the saturated vapor produced in the multiple-effect-evaporator and the amount of saturated vapor produced by each effect.

• Journal of the Korean Geotechnical Society
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• v.23 no.8
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• pp.137-147
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• 2007

Isotropic (instant loading) and Ko (gradual increase loading) consolidation tests were conducted in triaxial test equipment using cylindrical sample (5.0 cm in diameter and 10.0 cm in height) on two marine clay deposits. The duration of primary consolidation was estimated by two curve fitting methods using measured strain. A differential equation of consolidation for drainage in the radial and vertical direction was solved by the implicit finite difference scheme. The results of two curve fitting methods were compared with the numerical solutions to evaluate the appropriate axial loading rate of Ko consolidation and the primary consolidation periods. In addition, primary consolidation periods of the samples with a diameter of 35 mm and a height of 70 mm were calculated. The relation of radial and vertical consolidation coefficients is also presented.

• The Journal of the Korea Contents Association
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• v.22 no.5
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• pp.26-36
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• 2022

Recently, studies have been conducted to cluster vehicles and disseminate safety messages in a VANET environment for driver safety and smoothy traffic. This paper proposes cluster management scheme for safety message dissemination through V2V communication and V2I communication in a VANET environment with high vehicle density and mobility. The proposed scheme reduces packet loss by selecting CH considering reception quality, total data owned by vehicles, moving speed, and connected vehicles, and maintaining cluster head candidates, which are the main agents of message dissemination, considering frequent cluster departures and subscriptions. In addition, the proposed scheme reduces duplicate messages by utilizing clusters by collaborating with a Road side unit(RSU). To prove the excellence of the proposed scheme, various performance evaluations are performed in terms of message packet loss and the number of RSU processing requests. As a result of performance evaluation, the cluster management scheme proposed in this paper shows better performance than the existing scheme.

• The Journal of the Korea Contents Association
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• v.22 no.8
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• pp.81-93
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• 2022

Recently, research on processing a large-capacity graph using GPUs has been conducting. In order to process a large-capacity graph in a GPU with limited memory, the graph must be divided into subgraphs and then processed by scheduling subgraphs. In this paper, we propose an efficient graph algorithm processing scheme in GPU environments with limited memory and performance evaluation. The proposed scheme consists of a graph differential subgraph scheduling method and a graph segmentation method. The bulk graph segmentation method determines how a large-capacity graph can be segmented into subgraphs so that it can be processed efficiently by the GPU. The differential subgraph scheduling method schedule subgraphs processed by GPUs to reduce redundant transmission of the repeatedly used data between HOST-GPUs. It shows the superiority of the proposed scheme by performing various performance evaluations.

• Land and Housing Review
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• v.15 no.2
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• pp.29-37
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• 2024

This study investigates the thermal conductivity and density of expanded polystyrene insulation materials collected from buildings under going energy retrofit projects. Due to the absence of initial thermal conductivity data, determining precise long-term patterns was challenging. Analysis based on design documents revealed that expanded polystyrene insulation maintained consistent performance over ten years. Notably, the thermal conductivity measurements of insulation samples of the same grade and age varied significantly. Additionally, the insulation density was found to be substantially below the standard specified in the design documents. The results of the experiment indicate that performance management during both construction and operation phases is lacking. It is crucial to apply building commissioning, which involves performance verification throughout the building's life cycle, to properly evaluate building energy performance improvements, such as building energy retrofit projects.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.4
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• pp.109-120
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• 2007

In this study, a bridge maintenance system is developed to generate performance-based optimum maintenance strategy by considering the life-cycle cost. A multi-objective combinatorial optimization problem is formulated to generate a tradeoff maintenance scenarios which satisfies the balance among the conflicting objectives such as the performance and cost during the bridge lifetime and a genetic algorithm is applied to the system. By using the developed program, this study proposes a process of optimum maintenance scenario applying to the steel girder bridge of national road. The developed system improves the current methods of establishing the bridge maintenance strategy and can be utilized as an efficient tool to provide the optimum bridge maintenance scenario corresponding to the various constraints and requirements of bridge agency.

• Industry Promotion Research
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• v.5 no.3
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• pp.123-134
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• 2020

This study analyses the Korean successive governments' nuclear strategies after the post-cold war and suggests the future countermeasures as analysing to reciprocally interconnect B. Clinton and G.W.Bush governments' policies and North Korea's nuclear strategy. As the conclusion, this study suggests that the most urgent domestic alternative measure to North Korea's nuclear dismantlement is to prepare the grand strategy with the united whole national consensus and to order the renewed stronger future role by the mutual cooperation of multilateral agreement system and international regimes and lastly to adopt the extended deterrence through the reinforcement of the 5 great joint statements between the South-North Koreas.

• Journal of Digital Convergence
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• v.12 no.2
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• pp.391-396
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• 2014

This study was conducted to be helpful to the expansion and development of hospice and to provide the basic data for Hospice palliative care by identifying the general characteristics of curriculum of hospice perception, level of perception, practice experiences, routes, times, meanings, needs, targets, supply, types, organizations, experiences, use of hospice and physical, emotional, social and spiritual aspects of hospice services. Study tools which were used in this study were composed of three sections. Survey paper is 3-point Likert scale which is composed of 6 questions of general characteristics, nominal scale of 24 questions about hospice perception and hospice service contents. Respondents can reply with 3 answers of Necessary (1), Mediocre (2), and Not necessary (3), in physical, emotional, social and spiritual aspects. Score ranges of this tool are from minimum of 24 points to maximum of 72 points and higher scores mean higher perception of Hospice. Hospice is a behavior to take care of terminal patients who are waiting for death and their family and it should be conducted physically, emotionally, socially and spiritually in order that the patients could meet their last moments of life by maintaining a high quality of life, human dignity and peace for the rest of their lives. Hospice could be mentioned to be a comprehensive care to relieve the pains and grieves of bereaved family.