• Journal of the Korea Fashion and Costume Design Association
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• v.23 no.4
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• pp.95-103
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• 2021

This study aims to examine the antibacterial effects of cotton and silk fabrics naturally dyed with Artemisia princeps extract on antibiotic-resistant strains of bacteria. The concentrated natural dye of the Artemisia princeps extract was made at the liquor ratio of 1:10 at 40-60℃ for 60 minutes. The concentration of FeSO4·7H2O, Al2(SO4)3, and CuSO4 5H2O mordant was 3% (owf), and the liquor ratio was 1:20. In order to experiment on the antimicrobial activity of the naturally dyed fabrics, Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 33591, was used by breeding it in Brain Heart Infusion Agar (BHA) containing Oxacillin (2㎍/ml), Fungizone (2.5㎍/ml), and Brain Heart Infusion broth (BHI; Detroit, MI, USA). As a result of examining the bacterial growth reduction rate on dyed cotton and silk fabrics against antibiotic-resistant strains, it was found that the copper mordant in cotton fabric shows the highest antibacterial activity with a bacterial growth reduction rate of 99.9%, and the non-mordant cotton fabric shows the lowest antibacterial activity with a reduction rate of 18.6%. In the case of the naturally dyed silk fabric, it indicates the highest reduction rate of strains in the Al mordanting (94.9%), and Cu mordanting (99.9%).

• Journal of Korea Trade
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• v.24 no.8
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• pp.1-18
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• 2020

Purpose - This paper examines how differently output and input tariffs affect domestic employment across industrial characteristics of comparative advantage such as labor quality and capital intensity. Design/methodology - The paper focuses on 453 Korean industries from 2007 to 2014 because Korea is a typical example of a natural resource-scarce open economy and experienced the transition of the export pattern from labor intensity to technology intensity during this period. Findings - The results show that input tariff reduction stimulated total employment, focusing on the early 2010s, while the effects of output tariff reduction were statistically insignificant in general. However, the stimulation effects of output tariff reduction on employment were found in comparative advantage industries with greater labor quality and capital intensity. As for input tariff reduction, its stimulation effects on employment were more prominent in comparative disadvantage industries with lower labor quality and capital intensity. Originality/value - These results provide significant implications for natural resource-scarce open economies which are experiencing the transition of the export pattern from labor intensity to technology intensity and the unequal distribution of income after trade liberalization: imported intermediate inputs has become increasing important, leading to trade effects on employment and alleviation of income inequality.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.6
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• pp.127-137
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• 2015

Recent research has shown that university students experience severe stress and depleted directed attention due to study, social relationships, and economic dependency. Based on the stress reduction theory and the attention restoration theory, this study aims to investigate the effects of natural landscape on university students' stress and cognitive performance through a wide array of measurements including GSR(galvanic skin responsse), IBI(interbeat interval), ZIPERS(Zucherman Inventory of Personal Reactions), and mental arithmetic test. The restorative effects of natural landscape were compared with those of urban landscape. 128 university students participated in the study, and the data of 120 students was analyzed. The results showed that natural landscape was more restorative in relieving psychological stress and in enhancing cognitive performance than urban landscape, which evidenced the restorative effects of natural landscape. Therefore, it could be proposed that natural landscaping of the university campus contributes to students' stress reduction and cognitive enhancement. But such effects were not found in the two physiological measures(both GSR and IBI). Moreover, it was analyzed that urban landscape had a more beneficial effect than natural landscape for IBI, which might resulted from the participants' characteristics and the study landscape. Specifically, the young age span of the participants(average 23.8 years old) and the very natural setting of the university where they were enrolled might lead to the conflicting results in physiological measures. Also, the urban landscape used in the study had a sense of "scope", which is one of the Kaplan and Kaplan's restorative characteristics. Based on this opinion, it was suggested that future study should investigate the impact of the landscape type and contents as well as the participants' characteristics on the restorative effects of natural landscape.

• Korean Journal of Food Science and Technology
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• v.54 no.1
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• pp.1-7
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• 2022

Riboflavin (Rb), in the presence of methionine (Met) under light, generates superoxide radicals that can reduce nitro blue tetrazolium (NBT) to its corresponding formazan. The Rb-Met/NBT system has been used to measure the superoxide dismutase (SOD)-like activities of various antioxidants. However, the reaction mechanisms have not been clearly defined, and the assay conditions are not consistent. In this study, the effects of different photosensitizers and amino acids on NBT reduction in different solvents were investigated. NBT reduction in the Rb-Met/NBT system was more pronounced in phosphate-buffered saline, compared to distilled water or Tris (pH 7.5); histidine (His) instead of Met also led to considerable Rb-induced NBT reduction. Among the photosensitizers, methylene blue with His caused potent NBT reduction in Tris. Rb-induced NBT reduction combined with Met or His was quantitatively inhibited by SOD or gallic acid, but did not affect MB-induced reduction sensitively.

• Journal of Electrical Engineering and Technology
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• v.11 no.2
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• pp.377-382
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• 2016

In this paper, influence of vibration on cogging torque and Radial Magnetic Force(RMF) imbalance was investigated in the IPM type BLDC motor. Design of cogging torque reduction and the RMF equilibrium was proceed applied to Design of Experiment(DOE). Vibration test results, the RMF imbalance was confirmed that a significant impact of vibration.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.3
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• pp.107-113
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• 1997

This paper presents the active control of a flexible cantilever beam vibration. The cantilever beam was excitied by a steady-state harmonic and white noise point force and the control was performed by one piezo ceramic actuator bonded to the surface of the beam. An adaptive controller based on filtered-x LMS algorithm was used and the controller was defined by minimizing the square of the response of error sensor. In the experiment, gap sensor was used as an error sensor while the sinusoidal or white noise was applied as a disturbance. In the case of sinusoidal input, more than 20 dB of vibration reduction was achieved over all range of the natural frequencies and it takes 5 seconds to control the vibration at first natural frequency and 1 second at other natural frequencies. In the case of white noise input, 7 dB of vibration reduction was achieved at the first natural frequency and good control performance was achieved in the considered whole frequency range. Results indicate that the vibration of a flexible cantilever beam could be controlled effectively when the piezo ceramic actuator was used with filtered-x LMS algorithm.

• International Journal of Computer Science & Network Security
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• v.22 no.7
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• pp.65-74
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• 2022

In natural language processing, commonly used words such as prepositions are referred to as stop-words; they have no inherent meaning and are therefore ignored in indexing and retrieval tasks. The removal of stop-words from Arabic text has a significant impact in terms of reducing the size of a cor- pus text, which leads to an improvement in the effectiveness and performance of Arabic-language processing systems. This study investigated the effectiveness of applying a stop-word lists elimination with normalization as a preprocessing step. The idea was to merge statistical method with the linguistic method to attain the best efficacy, and comparing the effects of this two-pronged approach in reducing corpus size for Ara- bic natural language processing systems. Three stop-word lists were considered: an Arabic Text Lookup Stop-list, Frequency- based Stop-list using Zipf's law, and Combined Stop-list. An experiment was conducted using a selected file from the Arabic Newswire data set. In the experiment, the size of the cor- pus was compared after removing the words contained in each list. The results showed that the best reduction in size was achieved by using the Combined Stop-list with normalization, with a word count reduction of 452930 and a compression rate of 30%.

• Journal of the Korean Chemical Society
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• v.31 no.5
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• pp.444-451
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• 1987

The dependence of polarographic parameters on the pressure for the reduction of copper(II), cadmium(II), and zinc(II) complex ions with ethylenediamine, propylenediamine, and diethylenetriamine has been studied. In this study the dropping mercury electrode, the mercury pool electrode, and helix type of platinum wire were used as the working, the reference, and the auxilary electrode, respectively. With increasing the pressure from 1 atmosphere to 1,500 atmospheres, the reduction half-wave potentials of metal complex ions are shifted to the negative values and the diffusion currents become considerably larger, in keeping with the theory on the change of the physical properties of the electrolytic solution such as the density, the viscosity, the dielectric constant, and the electrical conductance, etc. The slope values of the logarithmic plot are increased with increasing the pressure, which indicates the more irreversible reduction. The temperature coefficients of diffusion current observed over the range of the temperature from 25$^{\circ}$C to 35$^{\circ}$C are about two percentage with increasing the pressure, therefore the polarographic reduction under the high pressure is controlled by diffusion. The linear relationships between diffusion current and concentration of metal complex ions are established over all pressure range.

• Clean Technology
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• v.2 no.1
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• pp.60-68
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• 1996

The oxidation of carbon monoxide of low concentration on the natural manganese dioxide (NMD) has been investigated in a fixed bed reactor. The experimental variables were concentration of oxygen (500ppm~99.8%) and carbon monoxide (500ppm~10000ppm) and catalyst temperature ($50{\sim}750^{\circ}C$). The NMD(Natural Manganese Dioxide) has been characterized by temperature - program reduction(TPR) using 2.4% $CO/H_2$ as a reducing agent, thermogravimetric analysis (TGA), and reduction of NMD by 2.4% $CO/H_2$. It was found that the NMD catalyst activity on the unit area was greater than the $MnO_2$ catalyst for oxidation of CO at the same temperature. The thermal stability of oxidation activity was considered to be maintained when the NMD was heated to $750^{\circ}C$. The TGA, reduction by CO, and TPR of the NMD showed that the NMD had active lattice oxygen which was easily liberated on heating in the absence and low concentration of oxygen. The reaction order in CO is 0.701 between 500~3500ppm and almost zero between 3500~10000ppm of CO.

• Journal of Environmental Health Sciences
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• v.43 no.2
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• pp.122-129
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• 2017

Objectives: Most of the $PM_{10}$ in subway stations is spread by the train-induced wind from the tunnels. Therefore, in order to improve air quality in subway stations, it is important to remove the $PM_{10}$ from the tunnels. After the installation of PSD (platform screen doors), the influence of train-induced wind and $PM_{10}$ at the platform has decreased, but is estimated to have increased in subway tunnels. This study was conducted to investigate the control of $PM_{10}$ in subway tunnels by applying a 500-fold diluted solution mixed with a humectant using a natural polymer. Methods: For this purpose, we tested the dust reduction effect in a laboratory and corrosion test and water pollution using fish and aquatic plants for the natural dust collecting agent. In the tunnel of a subway station, we used the natural dust collecting agent over 15 days. The study was carried out on $PM_{10}$ control during operation, which accounts for more than 70% of subway dust. Results: As results, the natural dust collecting agent exhibited an excellent dust control effect, and it was safe for water quality and soil. It showed the effect of controlling $PM_{10}$ in the subway tunnel by 49.5- 64.7% over 15 days. The use of the dust collecting agent for the control of $PM_{10}$ could be confirmed in the subway. Conclusion: It is necessary to clearly explain the major portions of chemical components contained in $PM_{10}$ to figure out the characteristics of $PM_{10}$ and to develop effective reduction measures to decrease the adverse effects of $PM_{10}$ in the subway.