• Journal of Korean Society of Environmental Engineers
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• v.29 no.7
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• pp.801-809
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• 2007

Fly ash and blast furnace slag are an industrial by-product that can be alkali-activated to yield adhesive and cementitious materials, whose production is less energy-intensive and emits less $CO_2$ than ordinary Portland cement manufacture. A laboratory investigation was carried out to evaluate the effect of alkali-activating conditions on compressive strength of fly ash/slag cement and the acid corrosion resistance of this cement. Two alkali activator solution, NaOH and waterglass + NaOH solutions, were used. Waterglass concentration was the factor that gave the highest compressive strength in all tests. The next significant factor was the NaOH concentration, followed by curing temperature. Acid corrosion resistance of FC(fly ash cement) and FSC(fly ash/slag cement), such as sulfuric$(H_2SO_4)$ and hydrochloric acid(HCl), was for better than Portland cement(PC).

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.1
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• pp.49-57
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• 2011

This paper concentrate on the passengers' perception of risks by analyzing data gathered through a field survey in the South Korean air market. Twenty two Koreans were killed in the accident of PMT Air in the Kingdom of Cambodia on June 25th 2007 and This has caused customers to be more concerned about the safety of airline. Three hundred forty-two samples were collected from field survey at Kimpo International Airport in Seoul and Jeju International Airport on Jeju island and the findings are based on 316 questionnaires. The multiple regression analysis, Analysis of variance (ANOVA), Correlation analysis, T-test were carried out to examine the effect, relationship and difference of data set. The results show that there are differences between passengers' perceived risks in LCC's and those in FSC's. Passengers of LCC's took serious consideration of the type of fleet and feeling physical risk, whereas those of FSC's only took consideration of financial risk.

• Journal of The Korean Society of Grassland and Forage Science
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• v.15 no.4
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• pp.245-252
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• 1995

To select a carrier as Rhizobiwn inoculants for alfalfa, severeal Rhizobium inoculants were produced by adding or not sub-materials($CaCO_3$ and sucrose) to main materials(organic or inorganic materials). The root nodule bacteria, Rhizobium meliloti 1061 distributed from KAIST, and Vemal alfalfa was used in this experiment. The Rhizobium populations and inoculation effects of the Rhizobium inoculants produced in several materials were scrutinized at laboratory and greenhouse in Livestock Experiment Station, RDA from 1993 to 1994. Moisture contents of the caniers were varied from 32 to 50% on dry weight basis according to material characteristics and the pH ranges of these were varied from pH 4.56 to 10.06 according to raw material characteristics and preparations. Initial Rhizobium numbers of the carriers were higher in organic material-inoculants than in inorganic, and among the inoculants, the inoculant made of Bentonite+Vermiculite(l:3 w/w) was excellent because of high rhizobium population($7.8~8.3\times10^8/g$ inoculant) and high rhizobium reappearance of inoculant in severed different production time. The root nodules of the alfalfa inoculated with different inoculants were fast formed in the fermented sawdust with cattle dung (FSC) inoculant, and bentonite(B)+vermiculite(V) than others. Plant length of alfalfa was differentiated on 15 days after inoculation but was not nearly different between higher inoculants than rhizobium number $10^7/g$ inoculant. Total dry matter of alfalfa was yielded by 20.65, 20.34mg per pot in FSC + sucrose 0.5% and B + V + sucrose 1% inoculants respectively that were higher inoculation effect by 17 times compared with non-inoculation, 1.2 mg per pot.

• Korean Chemical Engineering Research
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• v.48 no.4
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• pp.413-416
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• 2010

In this research, root extracts of Nelumbo nucifera was tested to see the possibility for functional cosmetic agent. 70-100% ethanol was used as solvent and nuciferin was confirmed as active component. To test cosmetic effect of root extracts of Nelumbo nucifera, safety effect(MTT assay), anti-wrinkle effect(elastase inhibition assay) and antioxidation effect(DPPH free radical scavenging assay) were measured. When 100% ethanol was used as extracting solvent, cell viability was over 80% at $100{\mu}g/ml$, which indicated that root extract of Nelumbo nucifera was suitable for cosmetic agent. Root extract of Nelumbo nucifera showed 40~50% elastase inhibition at $100{\mu}g/ml$ so that it had good anti-wrinkle characteristics. 50% antioxidation capacity($FSC_{50}$) was $5.0{\sim}38{\mu}g/ml$ and root extract of Nelumbo nucifera showed excellent antioxidation effect. From the research, root extracts of Nelumbo nucifera showed strong possibility for anti-wrinkle functional cosmetic agent.

• BMB Reports
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• v.33 no.3
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• pp.213-220
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• 2000

A fulminant hepatitis is associated with massive liver cell necrosis and a high mortality rate. But survivors regenerate a normal liver and do not have chronic liver disease. This clinical course suggests that the acutely injured livers release a factor that allows a recovery from chronic hepatitis or cirrhosis. The objective of this study was to isolate and characterize an anti-fibrotic factor from acutely damaged rat livers. The liver cell necrosis was prepared from rat by warm ischemical perfusion and the perfusates were assessed against the growth inhibition of fat-storing cells (FSC). A liver-derived growth inhibitory factor (LDGIF) was purified from ischemically damaged rat livers by chromatographies on Sephacryl S-300, CM Sepharose, hydroxyapatite, and Superose 12. The LDGIF was isolated with an overall purification of 194-fold and 40% recovery. Although LDGIF was identified as the rat liver arginase by Nterminal sequence analysis, LDGIF exists as a monomer and the purified native arginase has a trimer form. Furthermore, LDGIF has a lower enzyme activity on the hydrolysis of L-arginine and a higher inhibitory effect on proliferation of FSC than the normal rat liver arginase. The catalytic activity of LDGIF is ascribed to the monomeric characteristics of the LDGIF. Therefore, the inhibitory action of LDGIF might not be due to the arginine depletion by the catalytic activity of arginase. In conclusion, the presence of the LDGIF could interpret the clinical course that serious fibrosis is not found in the liver of patients recovering from severe hepatic necrosis due to fulminant hepatitis, suggesting that this LDGIF may provide a novel target for the prevention and treatment of hepatic fibrosis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.2
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• pp.115-121
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• 2019

The purpose of this study is to establish the training standards for HF of aviation maintenance reflecting the growing relevance of aviation maintenance technicians' ability to perform their work for the safety and efficiency of airline operation. For this purpose, previous studies on the concept of human factors were examined, and the HF training standards of the advanced international aviation bureaus such as the International Civil Aviation Organization(ICAO), Federal Aviation Administration(FAA) and European Aviation Safety Agency(EASA) were compared with the operational technical standards of Korea Aviation Safety Law. In addition, the actual status of human factors education and training were examined for Korea's two full service carriers (FSC) and four of the low cost carriers (LCC). The study results revealed that Korea's human factors education and training standards were weak compared with international standards, and that most airlines were not able to systematically implement human factors education and training. These results complement the existing problem of training standards for aviation maintenance human factors in Korea and support the development of a standard model of the training course for aviation maintenance human factors which meets international standards.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.2
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• pp.149-157
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• 2020

Today, due to the large amount of data duplication caused by the increase in user data, various deduplication studies have been conducted. However, research on personal storage is relatively poor. Personal storage, unlike high-performance computers, needs to perform deduplication while reducing CPU and memory resource usage. In this paper, we propose an adaptive algorithm that selectively applies fixed size chunking (FSC) and whole file chunking (WFH) according to the file type and size in order to maintain the deduplication rate and reduce the load in personal storage. We propose an algorithm for minimization. The experimental results show that the proposed file system has more than 1.3 times slower at first write operation but less than 3 times reducing in memory usage compare to LessFS and it is 2.5 times faster at rewrite operation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.5
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• pp.83-88
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• 2024

In a grid board with 9 cells of 3×3, the sum clue Sujiko puzzle with 4 fixed sum clues(FSCs) and variable sum clues(VSCs) is an NP-complete problem with no known way to solve the puzzle in polynomial time. To solve this puzzle 9! in all possible cases, a brute-force method should be applied to substitute the number. This paper determined the unique combination number cell by reducing the number of candidates that can enter empty cells. If the only number combination cell no longer exists, this paper proposes a method for determining a common number network with numbers common to the intersection cell of FSC+VSC. Applying the proposed algorithm to 9 benchmarking experimental data showed that puzzles can be solved in polynomial time for all problems.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.3
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• pp.287-294
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• 2015

In this study, we investigated the antioxidative effects of brown seaweed Ecklonia cava extract and its subfractions. All experiments were performed with 50% ethanol extract, ethyl acetate fraction and aglycone fraction of E. cava. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities ($FSC_{50}$) of ethyl acetate fraction ($FSC_{50}=6.98{\mu}g/mL$) and aglycone fraction ($7.03{\mu}g/mL$) are similar to that of (+)-${\alpha}$-tocopherol ($8.98{\mu}g/mL$) which is a reference control. Reactive oxygen species (ROS) scavenging activity (total antioxidant capacity, $OSC_{50}$) of the aglycone fraction ($OSC_{50}=14.48{\mu}g/mL$) on ROS generated in $Fe^{3+}-EDTA/H_2O_2$ system using the luminol-dependent chemiluminescence assay was the strongest among all extract and fractions. However, all samples showed lower antioxidant activities than that of L-ascorbic acid ($6.88{\mu}g/mL$) known as a powerful antioxidant. The protective effect of 50% ethanol extract on the $^1O_2$-induced cellular damage of human erythrocytes was dependent on the concentration from 5 to $50{\mu}g/mL$. Both ethyl acetate fraction and aglycone fraction showed strong cellular protective activities at $10{\mu}g/mL$, where the cellular protective effects (${\tau}_{50}$) of each fraction were recorded 442.0 min and 539.9 min, respectively. Three kinds of extract/fractions of E. cava showed much greater cellular protective activities at $10{\mu}g/mL$ than that of liposoluble antioxidant (+)-${\alpha}$-tocopherol (40.6 min) which is a reference control. These results suggest E. cava extracts and its fractions can be applied as an antioxidant ingredient in a field of cosmetics.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.638-640
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• 1996

This paper presents microprocessor-based Digital Position Detection Unit using the inductive radio line and the antennas in train signaling system. This comprises the Fail-Safe system due to the dual controlled system to drive with safe-side even in events of faults, and designs the FSC(failure safe comparator). And the method of Markov Modeling is described for the reliability evaluation of system.