• Composites Research
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• v.33 no.1
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• pp.13-18
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• 2020

Recently, the fire rescue truck in problem proceed research it for the fast works action and for pass the small road. So we were research for weight reduction. In this study, the (NO. 5) fifth boom of the fire rescue truck have 288 mm(W) × 299 mm(D) × 3,691 mm(L) with a maximum load of 876 kg and the thickness of 3 mm of the Steel Boom. This changing of Steel (STRENX960) to CFRP was weave Carbon Fiber NCF (±45°, 2axis) and then it make the NCF Prepreg. This process was designed based on structural analysis, the effects of NCF Prepreg (±45°) on torsion were identified, and the optimal design was made with Stacking Pattern (b). Stack patterns were optimized for levels equal or higher than existing Steel Boom and CFRP Boom stacked in the UD direction, and finally, the lightening effect on weight of approximately 49.6% of the steel was identified.

• Economic and Environmental Geology
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• v.46 no.6
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• pp.509-520
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• 2013

In this study, heavy metals are removed by soil washing from soils contaminated with Cu, Zn, and Pb, whose maximum concentrations are up to 3350, 1220, and 2240 mg/kg, respectively. Through various soil washing experiments, the optimum conditions, including type and concentration of washing reagent, washing time, mixing ratio of soil and washing reagent, and stirring speed, are derived for effective removal of the heavy metals. It is found that the most effective washing reagent and its concentration are hydrochloric acid and 50 mM, respectively. The most suitable washing time is 30 minutes and the optimal mixing ratio of soil and washing reagent is 1:30 (g/mL). The removal efficiency, on the other hand, is not affected by stirring speed. The removal efficiencies of the heavy metals decrease when washing reagent is reused. Furthermore, the heavy metals are readsorbed onto soil in case of consecutive reuse of washing reagent.

• Journal of Digital Convergence
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• v.13 no.1
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• pp.313-319
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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.

• The Korean Journal of Food And Nutrition
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• v.34 no.1
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• pp.107-113
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• 2021

This study was investigated the contents of total polyphenol, flavonoids and antioxidant and antimicrobial activities of Codonopsis lanceolata extracts according to different steaming times. The contents of total polyphenol and flavonoid proportionally increased from 6.45 mgGAE/g to 18.26 mgGAE/g and 2.01 mgRE/g to 6.12 mgRE/g according to ethanol extracts at EDS7. DPPH radical scavenging activity was found to have been 15.26~65.2% and showed the highest level of antioxidant activity at EDS7 was 65.2%. The activity of ABTS radical scavenging and SOD-like activity were also the same result. DPPH and ABTS radical scavenging activity was related to the number of steaming, and the scavenging activity was increased up to 7 times of steaming. The antimicrobial activity of EDS7 had strong antioxidant activity. Antimicrobial activities were examined against 5 microorganisms related to pathogens and food poisoning. The antimicrobial Activity was different depending on the bacteria, but it was effective at the concentration of 300 mg/mL rather than 150 mg/mL. These results showed that Codonopsis lanceolata extracts with a different number of steaming would be conducted to confirm the possibility of developing antimicrobial and antioxidant. It will be helpful in the study of component analysis of Codonopsis lanceolata extracts processed products.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.333-335
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• 2021

Gallbladder polyps (GBPs) may be a cause of gallbladder cancer. The known risk factors for GBPs are male gender, obesity, metabolic syndrome, and dyslipidemia. Especially, male gender has been known that it strongly affects on the prevalence of GBPs. Therefore, this study aimed to investigate risk factors affecting the prevalence of GBPs among adults on Jeju Island according to genders. We examined 5,574 subjects who visited a single health-screening center in Jeju between January 2015 and December 2019. Univariate and multiple logistic regression analysis were performed to identify risk factors affecting the prevalence of GBPs. The prevalence of GBPs were 8.9% in male subjects and 8.1% in female subjects, respectively. Multivariate analysis revealed that ≥60 year age (odds ratio [OR] 0.659; P=0.027) and aspartate aminotransferase >32 IU/L (OR 0.658; P=0.009) in male subjects and high-density lipoprotein-cholesterol ≥60 mg/dL (OR 0.514; P=0.013) in female subjects were independent factors affecting the prevalence of GBPs. The prevalence of GBPs in men (8.9%) is comparable to that in women (8.1%) on Jeju Island. Age <60 years and the high level of aspartate aminotransferase in men and the greater level of high-density lipoprotein-cholesterol in women were independent risk factors of GBPs on Jeju Island.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.271-282
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• 2019

This study was conducted to evaluate physiological activity of Robinia pseudo-acacia leaf and its skin penetration using polymer micelles and skin penetrating peptide. After extraction with Robinia pseudo-acacia using the ethanol and distilled water, various physiological activities were examined. The total concentration of polyphenol compounds was determined to be 47.42 mg/g (ethanol extract), 56.88 mg/g (hydrothermal extract) and DPPH radical scavenging ability at $1,000{\mu}g/mL$ was 44.24% in ethanol extract and it is higher than value(41.50%) in hydrothermal extract. The elastase inhibitory assay showed concentration dependence and elastase inhibition of Robinia pseudo acacia leaf ethanol extract was 54.09%, which was the highest at $500{\mu}g/mL$. In the SOD-like experiments, the concentration-dependent results were showed and the SOD-like activity of the Robinia pseudo-acacia leaf ethanol extract was higher than that of the Robinia pseudo acacia leaf hydrothermal extract at all concentrations. At a concentration of $500{\mu}g/mL$, Robinia pseudo acacia leaf ethanol extract showed the highest SOD-like activity of 76.41%. The tyrosinase inhibition at $20{\mu}g/mL$ was determined to be 56.47% (ethanol extract), 23.05% (hydrothermal extract). In the antimicrobial experiments, the hydrothermal extract had no effect, but ethanol extract represented maximum clear zone of 11.00 mm in Propionbacterium acnes strain and maximum clear zone of 10.50 mm. in Bacillus subtilis strain. To solve the problem of insolubility and to improve skin penetration, PCL-PEG polymer micelles containing Robinia pseudo-acacia leaf ethanol extracts and 1.0% cell permeable peptide, hexa-D-arginine (R6) were successfully prepared with particle size of 108.23 and 126.47 nm and excellent skin permeation effects could be showed.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.820-829
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• 2020

This study was conducted to investigate the anti-oxydant and anti-winkle efficacy as cosmetics ingredient of Lysimachia christinae Hance. Recently, the study of wrinkle improvement of natural products has received continuous interest. so we looked at relationship between reactive oxygen species (ROS) generation and pro-collagen synthesis and matrix metalloproteinases (MMPs) through this study. L. christinae Hance were extracted with 70% ethanol (LcHE) and distilled water (LcHW), respectively, and the experiment was conducted. LcHE had better ROS inhibition effect than LcHW and showed no toxicity up to 250 ㎍/mL concentration as a result of MTT assay in HaCaT cells, so we selected LcHE and conducted the wrinkle improvement material study. We confirmed that the synthesis of type-1 pro-collagen reduced by UVB is activated through pro-collagen synthesis assay. we confirmed that LcHE inhibited the increase in MMP-1 -3 -9 of MMPs induced by UVB in skin cells through western blot and we also performed real-time PCR to confirm the effect of the extract with dependence of concentration at mRNA levels. Therefore, it is expected that Lysimachia christinae Hance is used as a natural material for cosmetics that can effectively prevent wrinkles and skin aging by UVB.

• ALGAE
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• v.32 no.1
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• pp.47-55
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• 2017

We explored feeding by the mixotrophic ciliate Mesodinium rubrum, heterotrophic nanoflagellates (HNFs), and small ciliates (<$30{\mu}m$ in cell length) on natural populations of heterotrophic bacteria in Masan Bay, Keum River Estuary, and in the coastal waters of the Saemankeum area, Korea when M. rubrum red tides occurred. We also measured ingestion rates of M. rubrum on cultured heterotrophic bacteria as a function of bacterial concentration in the laboratory. The ingestion rates of M. rubrum on natural populations of heterotrophic bacteria (2.3-16.8 bacteria $grazer^{-1}h^{-1}$) were comparable to or lower than those of co-occurring HNFs (10.7-41.7 bacteria $grazer^{-1}h^{-1}$), but much lower than those of co-occurring small ciliates (76.0-462.2 bacteria $grazer^{-1}h^{-1}$). However, the maximum grazing coefficient of M. rubrum ($0.245d^{-1}$) on natural populations of heterotrophic bacteria was much higher than that of small ciliates ($0.089d^{-1}}$), and slightly higher than that of HNFs ($0.204d^{-1}$). With increasing bacterial concentrations, ingestion rates of M. rubrum on cultured heterotrophic bacteria continuously increased, but became saturated at higher prey concentrations over $1-5{\times}10^6cells\;mL^{-1}$. The maximum ingestion rate of M. rubrum on cultured heterotrophic bacteria was 34.4 bacteria $grazer^{-1}h^{-1}$. Based on the present study, it is suggested that M. rubrum may be an important grazer of heterotrophic bacteria and sometimes have considerable grazing impact on natural populations of heterotrophic bacteria.

• Resources Recycling
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• v.29 no.2
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• pp.55-61
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• 2020

Selective catalytic reduction (SCR) has been a promising technology to reduce the air pollution caused by nitrogen oxides (NOx) in several industries. The consumption of SCR catalysts increases every year as technology evolves, however those have a limited lifespan and usually end up in landfills after they deactivate. Currently, the most widely used catalyst for and stationary applications is V₂O₅-WO₃/TiO₂ which can contain around 50% wt V₂O₅ and 7-10% wt of WO₃. The vast uses for both vanadium and tungsten and the worldwide interest in recycling methods that allow for the extraction of metals from secondary sources represent the major motivation for this research. The extraction time, pH dependency, extraction concentration studies were carried out using Aliquat 336 in exxol D80 as the extractant. It was determined that to optimize the extraction of both metals 30min of contact time with an organic phase containing 0.5mol/L of Aliquat 336 are needed at a slightly acidic pH (~5.0). In addition, counter McCabe-Thiele studies allowed us to determine that one stage is necessary for the removal of 99% of vanadium while 2 stages are necessary for the extraction of tungsten and counter current simulations proved that the theoretical approach was correct.

• Journal of information and communication convergence engineering
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• v.12 no.1
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• pp.33-38
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• 2014

This paper investigates the shaping operation problem introduced by Callahan et al., namely the k-fragility maximization problem (k-FMP), whose goal is to find a subset of personals within a terrorist group such that the regeneration capability of the residual group without the personals is minimized. To improve the impact of the shaping operation, the degree centrality of the residual graph needs to be maximized. In this paper, we propose a new greedy algorithm for k-FMP. We discover some interesting discrete properties and use this to design a more thorough greedy algorithm for k-FMP. Our simulation result shows that the proposed algorithm outperforms Callahan et al.'s algorithm in terms of maximizing degree centrality. While our algorithm incurs higher running time (factor of k), given that the applications of the problem is expected to allow sufficient amount of time for thorough computation and k is expected to be much smaller than the size of input graph in reality, our algorithm has a better merit in practice.