• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.157-162
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• 2009

In this paper, the density, viscosity and solubility are measured to know the physical properties of dye. By changing the concentration of dye solution, the density change of the dye solution was very small and the viscosity of the dye solution was increased. Also, by changing the temperature of dye solution, the density change of the dye solution was increased but the viscosity of the dye solution was decreased. Solubility of dye conducts under the changing the salt and concentration of dye. In 20 wt% of dye and 15 wt% KCl, the amount of dye crystal is maximal. Also, batch salting-out experiments were performed with various conditions to know the optimal operating conditions of dye crystal. Under the various experiments, optimal operating condition was found based on amount of dye; added 15 wt% KCl, $25^{\circ}C$ temperature, 100 RPM, added at once.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.262-264
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• 2002

This paper shows the design standard of KEPCO on the contamination design for 345 kV and 154 kV transmission tower. Up to now, because the design standard of KEPCO on the insulation design contains 154 kV transmission system only, we had investigated the 343 kV system for the revision of design standard, with respect to the contamination design, we have used the same design philosophy which were adopted to the 765 kV transmission tower. In order to determine the number of insulator discs, we had investigated the withstand voltage of discs according to the level of ESDD(Equivalent Salt Deposit Density) and kinds of disc types. The TOV(Power Frequency Temporary Overvoltage) were estimated by EMTP(Electromagnetic Transient Program) for both 154 kV and 345 kV transmission system. The overvoltage level was appeared 1.35 p.u. between phase to ground for both 154 kV and 345 kV transmission system, but finally this factor was not applied to the design standard considering current design standard and economic point of view. With regard to classification of contamination area of 345 kV transmission system, we added the clean area which was not specified in the current design practise.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.1-6
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• 2016

Seawater desalination plants generally have two inherent problems which stem from energy inefficiency and desalination concentrate management. The former has been somewhat resolved thanks to the innovative methods in utilizing new and renewable energy resources whereas the latter still has much issues to be dealt with. This paper introduces the application of a desalting process for the disposal of desalination concentrate (especially, Mg) and to improve its cost effectiveness of a MVR seawater desalination plant built in Jeju. Principal component analysis on the desalination concentrate has revealed a steady reduction of Mg with the application of the desalting process verifying its functional reliability. Also, it was found that our MVR seawater desalination plant is not only energy efficient but also could be effectively applied for the dual purpose of fresh water production and concentrate management.

• Journal of Conservation Science
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• v.26 no.2
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• pp.133-142
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• 2010

This paper focused on desalination method for the underwater archaeological ceramics. The desalination method applied in this study takes additional conditions such as the amount of desalting water, temperature, and agitation conditions and compares the effects of desalt process. The result of efficiency rate appears that the twenty-times of the object weight of desalting water is more effective than that of ten-times one, but shows less economic compared to the cost. In addition, the research shows that the efficiency rate has been improved around 20 to 30 %, yet such improvement is not taken into account as an effective result considering the risk of damage from the physical and chemical impact and the consumption of energy in applying additional method.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.2
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• pp.97-103
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• 2010

In this paper, we propose a new digital watermarking technique. The main idea of the proposed algorithm relies on the assumption that any real number can be expressed as a summation of the exponential form with base of 2 and if only consider the first few summations some numbers can be expressed in the same form. Therefore, we can be sure that some amount of changes does not affect the first few summations. The algorithm decomposes a host image in wavelet domain and intensity of the significant wavelet coefficient is expressed in exponential form with base of 2. Multiple barcode watermarks are then embedded by modifying the parity of the exponent. The proposed scheme is semi-blind and also offers either objective or subjective deteew su as well. From extracted watermarks, more accurate watermark is obtained by merging technique as a final watermark. As a simulation result, the proposed algorithm could resist most cases of salt and pepper noise, Gaussian noise and JPEG compression.

• Korean Chemical Engineering Research
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• v.45 no.4
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• pp.319-327
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• 2007

Incineration has been regarded as the best developed technology available for organically hazardous waste. However, permitting and siting incinerators to treat hazardous waste such as a waste containing PCBs is very difficult due to the public concerns associated with toxic air emissions. Recently, a lot of alternatives to an incineration have been developed and these technologies have the potential of alleviating public concerns by decreasing emissions of hazardous materials such as dioxins and furans. This paper reviews currently available alternative incineration technologies for various hazardous waste streams. Various categories of non-thermal and thermal alternative incineration technologies have been evaluated in terms of their process operating condition, applicability of a waste stream and their emission of secondary waste. Detailed descriptions of operating principles of several technologies are also provided.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.4
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• pp.1876-1883
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• 2011

The TPM is a hardware chip for making a trusted environment on computing system. We previously need a command authorization process to use principal TPM commands. The command authorization is used to verify an user who knows a usage secret to TPM chip. Since the user uses a simple password to compute usage secret, an attacker can retrieve the password by evasdropping messages between user and TPM chip and applying off-line dictionary attack. In this paper, we simulate the off-line dictionary attack in real PC environment adopted a TPM chip and propose a novel countermeasure to defeat this attack. Our proposed method is very efficient due to its simplicity and adaptability without any modification of TPM command structures.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.6
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• pp.619-626
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• 2014

In this paper, it was constructed the halophyte Mesocosm experimental which was used tidal flat and dredged sediment as a substrate material. Depending on the vegetation and substrate material of Mesocosm, Mesocosm A(tidal flat sediment + Salicornia herbacea), Mesocosm B (only dredged sediment), Mesocosm C(dredged sediment + Salicornia herbacea). Monitoring was carried out of Warter quality factots(Chemical Oxygen Demand(COD), Total Nitrogen(T-N), Total Phosphorus(T-P), water temperature, salinity), Sediment factors(Chemical Oxygen Demand(COD), Total Nitrogen(T-N), Total Phosphorus(T-P)) and growth of Salricornia herbacea. Habitat Stability Index of vegetation was calculating by using the monitoring results. HSI of Mesocosm C was calculated from 0.87 to 0.95 as compared to the relatively high HSI in Mesocosm A, it was evaluated to be able to be used in the restoration and construction of the coastal salt marsh with dredged sediment.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.3 no.3
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• pp.201-211
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• 2005

In this study, conventional head-end processes of spent TRISO fuel have been reviewed to develope more effective treatment methods. The main concerns in the TRISO treatment are to effectively separate the carbon and SiC contained in the TRISO particles. The crush-burn scheme which was considered in the early stages of the development has been replaced by the crush-leach process because of $^{14}C$ problems as a second waste being generated during the process. However, there are still many obstacles to overcome in the reported processes. Hence, innovative thermomechanical concepts and a molten salt electrochemical approach to breach the coating layers of the TRISO particle with a minimized amount of second waste are proposed in this paper and their principles are described in detail.

• Journal of Korea Multimedia Society
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• v.13 no.1
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• pp.122-132
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• 2010

The analysis of ocean environment offers us essential information for ocean exploration. But ocean environment has a lot of environmental variables such as the movements of nodes by an ocean current, corrosion by salt water, attenuation of radio wave, occurrences of multi-path and difficulty of sensor nodes' deployment. It is accordingly difficult and complex to gather and process the environmental information through ocean data communication due to these constraints of ocean environment unlike the terrestrial wireless networks. To overcome these problems, we organized ocean communication network for monitoring underwater environment by real experiment in Gyeongpoho similar to ocean environment. Therefore, this paper aims at overcoming major obstacles in ocean environment, effectively deploying sensor nodes for ocean environment monitoring and defining an efficient structure suitable for communication environment by the implementation of ocean environment monitoring system in Gyeongpoho.