• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.4
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• pp.488-495
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• 2017

In this study, we conducted the kinetic hydration modeling of OPC and the final product according to the substitution ratio of GGBS by using the geochemical code, GEMS, in order to calculate the thermodynamic equilibrium. The thermodynamic data was used by GEMS's 3rd party database, Cemdata18, and the cement hydration model, the Parrot & Killoh model was applied to simulate the hydration process. In OPC modeling, ion concentration of pore solution and hydration products by mass and volume were observed according to time. In the GGBS modeling, as the substitution rate increases, the amount of C-S-H, which contributes the long-term strength, increases, but the amount of Portlandite decreases, which leads to carbonation and steel corrosion. Therefore, it is necessary to establish prevention of some deterioration.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.6
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• pp.566-572
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• 2011

In recent semiconductor and FPD (Flat Panel Display) manufacturing processes, high clean-class delivery operation is required more and more for short working time and better product quality. Traditionally SLIM (Single-sided Linear Induction Motor) is widely used in the liner drive applications because of its simplicity in the rail structure. A magnetically levitated (Maglev) unmanned vehicle with SLIM traction, which is powered by a CPS (Contactless Power Supply) can be a high precision delivery solution for this industry. In this paper unmanned FPD-carrying vehicle, which can levitate without contacting the rail structure, is suggested for high clean-class FPD delivery applications. It can be more acceptable for the complex facilities composed with many processes which require longer rails, because of simple rail structure. The test setup consists of a test vehicle and a rounded rail, in which the vehicle can load and unload products at arbitrary position commanded through wireless communications of host computer. The experimental results show that the suggested vehicle and rail have reasonable traction servo and robust electromagnetic suspensions without any contact. The resolution of point servo errors in the SLIM traction system is accomplished under 1mm. The maximum gap error is ${\pm}0.25mm$ with nominal air gap length of 4.0mm in the electromagnetic suspensions. This type of automated delivery vehicle is expected to have significant role in the clean delivery like FPD glass delivery.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.6
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• pp.60-67
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• 2008

At present, RFID system is highly welcomed as a substitute system with its bar code recognition system and self recognition equipment. Consequently, the system has multi applications and can be complementing to its security. In particular, RFID system is significantly related with electronic transaction equipments : transportation card, ID card in check point, attendance sheet. Based upon these characteristic, the system is becoming extremely popular in the field of logistics, harbor and stock management, animal control and product circulation & distribution. In this dissertation, I would like to present a more efficient and stable remote entry control system with the network-based TCP/IP. It is a simple example of ubiquitous computing function. Above all, approved protocol system should be applied to the remote entry control function. Its efficient function with the applied approval protocol based-remote entry control system should be confirmed. Therefore, a preliminary test should be prerequisite in automatic entrance function with the embedded and TCP/IP-based RFID system.

• Journal of the Korean Society of Safety
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• v.32 no.5
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• pp.149-156
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• 2017

This study investigates fire-retardant performances and combustion/thermal characteristics of fire-retardant treated wood by comparing them with those of fire-retardant untreated wood from the expreimental resutls of cone calorimeter and thermo-gravimetric(TG) analyzer. Hazardousness of combustion product gases for fire-retardant treated wood and untreasted wood were also observed from the results of internal finish material incombustibility test according to the Korea standard code of KS F 2271. In this study, we also tried to improve the fire retardant performance of wood by applying fire-retardant chemical composites, and to secure the fire safety performance in buildings. Red pine (Pinus densiflora) was selected as a test specimen because it is mostly used as a building material in Korea. Fire retardant chemical composites (FRCs) were prepared by mixing boron, phosphorous, and nitrogen species and treated by press-impregnation method. Water-based FRCs were composed of 3% boric acid($H_3BO_3$), 3% borax decahydrate($Na_2B_4O_7$), 8% ammonium carbonate($(NH_4)_2CO_3$), diammonium phosphate ($(NH_4)_2HPO_4$) varied from 10-30% and potassium carbonate($K_2CO_3$) varied from 10-30%. From the test results of cone calorimeter, TG analysis and gas hazard assessments, newly proposed were the optimal composition and production methods of FRCs which can sufficiently meet fire-retardant level 3 based on Korea law of construction. Thus, the FRCs, developed in this study, are anticipated to contribute to the improvement of fire safety and widespread of usage in wood as building materials.

• Fashion & Textile Research Journal
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• v.8 no.2
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• pp.183-190
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• 2006

The purpose of this study was to analyze social, economic and cultural phenomena of the luxury brand in the viewpoint that the consumption system of the modern society stood for the sign consumption and the industrial production of difference as Baudrillard mentioned in the Consumer Society. The result was divided into the two subjects popularization and differentiation of luxury brand. Firstly the meaning of luxury brand was that the personal effects of consumption of king or aristocratic class who did not exist in the modern and were made into the selection and consumption-possible things of exchange value. The popularization of this sign was accelerated through TV drama. Secondly as differentiation strategy of luxury brand, was made by giving meaning to the life style concept of the upper class with advertisement and design, and also the logo of design was used as sign differentiated from people. Also the reason why the producer of the luxury brand gave meaning to such life style was that the awareness of the brand which people have consistently makes them consume more products. The consumption system of the modern society stood for the sign consumption, difference sign mark value which was the desire on a social meaning basis, not the consumption of things as used value. And the consumer could express his personality by selecting and consuming the product of luxury brand model made with this sign. Accordingly the distribution, purchase, sales and acquisition of the things with this difference sign were our verbal activity and linguistic code today, and it was the essential feature of the society, culture and economy of the consumer society.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.2
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• pp.121-126
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• 2018

The purpose of this study was to assess bacteriological hazards in the following 7 kinds of minimally processed shellfish products purchased from Korean seafood retail outlets: raw oysters stored with seawater in polyethylene bags, frozen oysters, raw mussels, frozen mussels, boiled mussels, raw short-necked clam, and frozen short-necked clams, obtained from Korean seafood retail outlets. The total coliform and Escherichia coli counts determined in all samples were detected below regulation limit of the Korean government guidelines (Food Code). In addition, the high-risk bacterial pathogens, Listeria monocytogenes, Salmonella spp., and E. coli O157:H7 were not detected in any samples. Low-risk pathogens such as Staphylococcus aureus and Vibrio parahaemolyticus were detected at levels above $1.0{\times}10^2$ colony forming unit (CFU)/g in some minimally processed shellfish products. Notably, S. aureus was detected in all samples. Raw oysters stored with seawater in polyethylene bags, frozen oysters, and boiled blue mussels are commonly ingested without heating, and therefore these minimally processed shellfish products pose bacteriological hazards. The detection of S. aureus in all shellfish products, an organism indicative of poor personal hygiene, which can grow and multiply during distribution, indicates the necessity of improving the food safety of minimally processed shellfish products.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.1
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• pp.69-74
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• 2010

In a grid connected variable speed wind turbine, the PCC voltage and the wind power fluctuate as the wind velocity changed. And this voltage variation is changed due to location of PCC. This paper calculate the value of PCC voltage variation which is proportional to the product of the line impedance from the ideal generator to the PCC and the wind turbine output current. And to reduce this PCC voltage variation, this paper calculate the required reactive power analytically using the vector diagram method. Output reactive current is changed, if the reactive current is limited by inverter capacity or grid code have the margin of voltage variation. If the grid connected inverter is controlled by proposed algorithm, the PCC voltage variation is minimized though the wind turbine output change at random. To verify calculated voltage variation and required reactive power, this paper utilized Matlab and PSCAD/EMTDC simulation and real small wind turbine and power system in Sapsido, island in the Yellow Sea.

• Natural Product Sciences
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• v.21 no.3
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• pp.210-218
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• 2015

The antioxidant activity of white ginseng was not recorded in Korea Functional Food Code, while its activity of red ginsengs was recorded. The aim of this study was to evaluate the antioxidant and hepato protective effect of different ginsengs in H₂O₂-treated HepG2 cells. White and red ginseng were prepared from longitudinal section of the same fresh ginseng (4-year old). The whole parts of white and red ginsengs were separately extracted with 70% ethanol and distilled water respectively, at 70 ℃ to obtain therapeutic ginseng extracts namely, WDH (distilled water extract of white ginseng), WEH (70% ethanol extract of white ginseng), RDH (distilled water extract of red ginseng) and REH (70% ethanol extract of red ginseng). In this work, we have investigated the DPPH, hydroxyl radical, Fe²⁺-chelating activity, intracellular ROS scavenging capacity and lipid peroxidation of different ginsengs. All these extracts showed a dose dependent free-radical scavenging capacity and a ROS generation as well as lipid peroxidation was significantly reduced by treatment with bioactive extracts of white ginsengs (WDH) than red ginsengs. Additionally, white ginseng extracts (WDH) has dramatically increased intracellular antioxidant enzyme activities like superoxide dismutase and catalase in H₂O₂-treated HepG2 cells. All these results explain that administration of white ginseng is useful as herbal medicine than red ginseng for chemoprevention of liver damage.

• Journal of Energy Engineering
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• v.20 no.4
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• pp.259-266
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• 2011

Following the reactor shutdown, the reactor shutdown cooling system must be designed to supply the coolant sufficiently not only to remove the decay heat but to maintain the adequate cooling rate to protect the reactor equipments. In this study, KDESCENT code for the light water reactor and SOPHT, SDCS codes for the heavy water reactor were compared and analyzed to investigate the cooling capability during the shutdown cooling process. The shutdown cooling system design requirements were satisfied during cooling process for both the SDCP and the HTP modes and the design cooling rate of $2.8^{\circ}C/min$ or below was maintained using the SDC heat exchangers. This study shows that the shutdown cooling system in the Wolsong 2, 3, 4 reactors provides sufficient cooling to maintain the nuclear fuel integrity by removing the decay heat of the nuclear fission product.

• Smart Media Journal
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• v.4 no.4
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• pp.80-85
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• 2015

As the number of applications using the internet the rapidly increasing incidence of cyber attacks made on the internet has been increasing. In the equipment of L3 DDoS attack detection equipment in the world and incomplete detection of application layer based intelligent. Next-generation networks domestic product in high-performance wired and wireless network threat response techniques to meet the diverse requirements of the security solution is to close one performance is insufficient compared to the situation in terms of functionality foreign products, malicious code detection and signature generation research primarily related to has progressed malware detection and analysis of the research center operating in Window OS. In this paper, we describe the current status survey and analysis of the latest variety of new attack techniques and analytical skills with the latest cyber-attack analysis prejudice the security situation.