• Journal of Environmental Impact Assessment
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• v.29 no.3
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• pp.198-209
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• 2020

In this study, electrospun nanofibers made of PAN (polyacrylonitrile) were activated through a physical method to obtain an optimized pore structure. In particular, to enhance the surface alkalinity, the activated carbon fibers (ANFs) were impregnated with tetraethylenepentamine (TEPA) with the aid of HNO₃. Then, the low level (3,000 ppm) CO₂ adsorption capacity for each ANF sample was evaluated. The specific surface area of ANFs increased from 308.4 ㎡/g to 839.4 ㎡/g and the total pore volume increased from 7.882 ㎤/g to 27.50 ㎤/g. Although the TEPA impregnation reduced the specific surface area and pore volume of the ANFs due to blocking of micropores, the HNO₃ pre-oxidation enhanced the amino groups tethered, increasing the amine content from 6.42% to 17.19%, and finally, increased the adsorption capacity of CO₂. This study showed that the sample 60-ANF-HNO₃-TEPA, which was activated for 60 minutes and was impregnated with HNO₃ and TEPA, had the best adsorption capacity for low level (0.3%) CO₂ (in a binary mixture with N₂).

• Korean Journal of Social Welfare
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• v.50
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• pp.87-108
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• 2002

According to Neo-liberalism, the privatization of social security systems is pivotal for a country's economic growth and the wellbeing of its people, because such systems hinder the full operation of the market, eventually leading the national economy to collapse. The Chilean case of pension privatization is often cited as a good evidence for the Neo-liberal argument. Neo-liberalists say that Chile has experienced a rapid economic growth and retirees have enjoyed a much more pension payment since the national pension system was successfully privatized in 1981. The primary purpose of this article is to provide a critical review on the results of the Chilean pension privatization reform implemented in 1981. This study is intended to give an objective understanding of the reform because the existing evaluations, particularly those from the neo-liberalism, over-emphasize the bright sides of the reform. for this purpose, this article will pay a particular attention to the change in the level of pension payment after the reform. The conclusion of this study is that, contrary to the argument of Neo-liberalism, the pension reform has lowered the level of pension payment and, compared to the old public pension, has made the lives of ordinary retirees less secure. Reorganization of the social security system is more desirable than privatization as a remedy for the current problems of the welfare state.

• Journal of the Korea Institute of Building Construction
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• v.10 no.4
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• pp.41-47
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• 2010

It has been continuously noted that many sewage treatment concrete structures have deteriorated due to sulfur-oxidizing bacteria. There have been many reports on approaches to protecting concrete from this bacteria corrosion. The purpose of this study is to evaluate the inhibition of growth of a sulfur-oxidizing bacterium by a antifungal agent such as $NiSO_4{\cdot}6H_2O$, and the characteristics of polymer cement mortar using nickel type antifungal agent. First, we developed antifungal agents using metal nickel and $NiSO_4{\cdot}6H_2O$ to inhibit the growth of thiobacillus novellus, which is the sulfur-oxidizing bacteria in concrete. Then, ordinary cement mortar and polymer cement mortar using nickel type antifungal agent with various polymer-cement ratios, and antifungal agent content were prepared, and were tested for the antifungal adding effect, compressive and flexural strengths, expansion and leaching of nickel ion. From the test results, it was confirmed that the adding of an antifungal agent has an inhibition effect on the growth of sulfur-oxidizing bacteria at antifungal agent contents of 20 mM or more. In addition, the strengths and expansion of polymer cement mortars are not significantly changed by the addition of an antifungal agent. Therefore, the nickel-type antifungal agent developed in this study can be used to improve the durability of reinforced concrete hume pipe in the construction industry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.90-102
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• 2017

Recently, the number of out-of-school adolescents has been increasing, and problems associated with their careers have become an important issue. This study was conducted to identify the relationship between the career barriers and perceived social support type/support source and to examine whether a sense of alienation mediates the relationship between perceived social support and career barriers among out-of-school adolescents preparing for the qualification examination for their high school degree. To accomplish this, a survey of 207 students from the Youth Support Center for out-of-school adolescents-K-Dream-and Qualification Examination Institute located in five regions (Seoul, Busan, Jeju, Gangwon, and Jeonla province) was conducted. Correlation analysis, regression analysis and the Sobel test were used to verify the relationships between variables and mediation effects. The results showed a significant negative correlation between social support and career barriers and a significant positive correlation between alienation and career barriers. Carrier barriers and alienation were highly correlated with parent support and evaluation support. Moreover, a sense of alienation was found to fully mediate the relationship between parental support/teacher support and career barriers, as well as to partially mediate the relationship between peer support and career barriers. A sense of alienation was found to fully mediate the relationship between information support/evaluation support/emotional support/material support and career barriers. These findings imply that, in out-of-school adolescents, career barriers can be reduced through various kinds of social support provided by peers, parents and teachers as it decreases the sense of alienation.

• Korean Journal of Plant Resources
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• v.28 no.5
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• pp.591-599
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• 2015

Osteoarthritis (OA) is a degenerative disease characterized by the progressive degradation of joint cartilage and is accompanied by secondary inflammation of synovial membranes. The purpose of this study describes a preliminary evaluation of the anti-inflammatory activity on test material of Litsea japonica. fruit (LJTM) Also, this study was to evaluate the effects of LJTM on the joint cartilage of rat with OA induced by monosodium iodoacetate (MIA). To study for anti-inflammatory agents effectively, we first examined the inhibitory effect of the LJTM on the production of pro-inflammatory factors and cytokines stimulated with lipopolysaccharide. We identified anti-nociceptive effects of the LJTM by using in vivo peripheral and central nervous pain models. In addition, the aim of this study was to evaluate the effects on mRNA expression of MMP-2, -3, -7, -9, -13, TIMP-1 and –2 in cartilage of OA. In the LJTM inhibited production of pro-inflammatory mediators (NO and PGE₂) and pro-inflammatory cytokines (TNF-α and IL-6). In cartilage, Expression of MMPs and TIMPs mRNA was suppressed in LJTM treatment group than in the control group. This study suggests that LJTM are potential candidates as anti-inflammation and anti-osteoarthritis agents (painkillers) for the treatment of OA.

• Progress in Medical Physics
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• v.23 no.4
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• pp.252-260
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• 2012

The reduction of radiation dose from x-ray is a main concern in computed tomography (CT) imaging due to the side-effect of the dose on human body. Recently, the various methods for dose reduction have been studied in CT and one of the method is a iterative reconstruction based on total variation (TV) minimization at few-views data. In this paper, we evaluated the image quality between total variation (TV) minimization algorithm and Feldkam-Davis-kress (FDK) algorithm in micro computed tomography (CT). To evaluate the effect of TV minimization algorithm, we produced a cylindrical phantom including contrast media, water, air inserts. We can acquire maximum 400 projection views per rotation of the x-ray tube and detector. 20, 50, 90, 180 projection data were chosen for evaluating the level of image restoration by TV minimization. The phantom and mouse image reconstructed with FDK algorithm at 400 projection data used as a reference image for comparing with TV minimization and FDK algorithm at few-views. Contrast-to-noise ratio (CNR), Universal quality index (UQI) were used as a image evaluation metric. When projection data are not insufficient, our results show that the image quality of reconstructed with TV minimization is similar to reconstructed image with FDK at 400 view. In the cylindrical phantom study, the CNR of TV image was 5.86, FDK image was 5.65 and FDK-reference was 5.98 at 90-views. The CNR of TV image 0.21 higher than FDK image CNR at 90-views. UQI of TV image was 0.99 and FDK image was 0.81 at 90-views. where, the number of projection is 90, the UQI of TV image 0.18 higher than FDK image at 90-views. In the mouse study UQI of TV image was 0.91, FDK was 0.83 at 90-views. the UQI of TV image 0.08 higher than FDK image at 90-views. In cylindrical phantom image and mouse image study, TV minimization algorithm shows the best performance in artifact reduction and preserving edges at few view data. Therefore, TV minimization can potentially be expected to reduce patient dose in clinics.

• Korean Journal of Food Science and Technology
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• v.39 no.2
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• pp.138-145
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• 2007

The effects of amylopectin and hydrocolloid (locust bean gum and guar gum) content on wheat flour dough and noodle properties were investigated. As the amount of amylopectin increased, the water absorption rate (farinograph), the tension (tension test), the gel stability (freeze-thawing treatment), and the springiness and the cohesiveness (TPA) increased, but the pasting temperature (RVA), the lightness and yellowness (color measurement), and the hardness (TPA) tended to decrease. In sensory evaluations, the scores for cohesiveness, springiness, and acceptability of cooked noodle increased as the proportion of amylopectin increased. The proper combination of amylose/amylopectin ratio and hydrocolloids improved the freeze-thaw stability and the sensory acceptability of wheat flour dough and noodle.

• Journal of the Korean Recycled Construction Resources Institute
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• v.5 no.2
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• pp.160-167
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• 2017

The purpose of this study is to identify the possibility of developing the 100% Recycled-resources Absorbent-Pervious Alkali-activated Blocks using both the alkalli-binder and the recycled aggregate. In addition, It established a test method such as Void ratio, compressive strength, coefficient permeability, absorption, and evaporation. As a result, an alkali-activated using recycled aggregate block was able to manufacture an 24 MPa class absorbent-pervious blocks with a liquid type sodium silicate and early high temperature curing. In this case, water-holding capacity, absorption and relative absorption were more effective than the natural aggregates. In conclusion, Absorbent-pervious alkali-activated Block Using recycled aggregate has a surface temperature reducing effect of approximately 10 % compared to ordinary concrete block.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.10
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• pp.1431-1440
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• 2012

The optimum extraction of phenolic compounds from whole Rosa multiflora Thunberg fruits was accomplished using 70% ethanol, which produced extracts that generated a zone of inhibition around Helicobacter pylori of 13 mm when $200{\mu}g/mL$ phenolic compounds were applied. In this study, the quality of white bread baked from dough containing added Rosa multiflora Thunberg extracts was investigated. No deterioration of product quality factors including hydration of wheat flour, formation of dough and internal visual characteristics of dough was observed. However, white bread containing Rosa multiflora Thunberg extracts had a wet texture because of the high moisture level, as well as a high number of irregular bubble holes when compared to the control. Nevertheless, there were no remarkable differences between the sample and the control.

• Journal of Internet Computing and Services
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• v.2 no.1
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• pp.23-30
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• 2001

ILP processors require an accurate branch prediction scheme to achieve higher performance. Two-Level branch predictor has been known to achieve high prediction accuracy. But, when a branch accesses a PHT entry that was, previously updated by other branch, Two-level predictor may cause interferences. Negative interferences among all interferences have a negative effect on performance, since they can cause branch mispredictions. Agree predictor achieve high prediction accuracy by converting negative interferences to positive interferences by adding bias bits to BTB, but negative interferences may occur when bias bit is set incorrectly. This paper presents a new dynamic branch predictor which reduces negative interferences. In the proposed predictor, we attach hit bits to entries in BTB to change bias bit dynamically during the execution time, h a result the proposed scheme improve the accuracy of prediction by reducing negative Interferences effectively, To illustrate the effect of the proposed scheme, we evaluate the performance of this scheme using SPEC92int benchmarks, The results show that the proposed scheme can outperform traditional branch predictors.