• Title/Summary/Keyword: protection effect

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The Current Trend of Research about Bojungikki-tang (보중익기탕의 최근 연구동향)

  • Seo, Min-Jun;Lee, Kyu-Bong;Park, Jin-Han;Hong, Seung-Heon
    • Korean Journal of Oriental Medicine
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    • v.16 no.2
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    • pp.83-90
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    • 2010
  • Objective : The purpose of this study was to provide the information about Bojungikki-tang by domestic papers and theses. Method : Domestic papers related to Bojungikki-tang were reviewed and analyzed. These papers were classified by year, research method, experimental method, and subject. Result : The following results were obtained in this study. 1. The study of Bojungikki-tang started from 1984 and continued steadily. 2. The domestic papers about Bojungikki-tang were 47 volumes. Among them, there were 26 volumes since 2000. 3. Classified by research method from the year 2000, 20 experimental studies, 4 clinical experiments, and 2 documentary researches. 4. Classified by experimental method from the year 2000, 10 studies used mouse in vivo experiment and 4 studies used rat in vivo experiment and 6 studies used each cell in vitro experiment. 5. Classified by subject from the year 2000, papers related to immune enhancing effect, nerve and mental system, radiation protection effect, anti-allergy, anti-inflammatory, anti-cancer, remedy of diabetes, skin protection and so on. Conclusion : Many papers of experimental studies, clinical experiments and documentary researches related Bojungikki-tang are included in domestic journals. Bojungikki-tang is being researched variously in immune enhancing effect, nerve and mental system, radiation protection effect, anti-allergy, anti-inflammatory, anti-cancer, remedy of diabetes, skin protection and so on. However, more clinical studies on Bojungikki-tang are needed.

Experimental Study on Effect of Water-based Iron(III) Oxide Nanofluid on Minimum Film Boiling Point During Quenching of Highly Heated Test Specimen (고온 시편의 급랭 시 산화철 나노유체가 최소막비등점에 미치는 영향에 대한 실험적 연구)

  • Jeong, Chan Seok;Hwang, Gyeong Seop;Lee, Chi Young
    • Journal of the Korean Society of Safety
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    • v.35 no.5
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    • pp.128-136
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    • 2020
  • In the present experimental study, the effect of water-based iron(III) oxide nanofluid on the MFB(Minimum Film Boiling) point during quenching was investigated. As the highly heated test specimen, the cylindrical stainless steel rod was used, and as the test fluids, the water-based iron(III) oxide nanofluids of 0.001 and 0.01 vol% concentrations were prepared with the pure water. To examine the effect of location in the test specimen, the thermocouples were installed at the bottom and middle of wall, and center in the test specimen. Through a series of experiments, the experimental data about the influences of nanofluid concentrations, the number of repeated experiments, and locations in the test specimen on the reaching time to MFB point, MFBT(Minimum Film Boiling Temperature), and MHF(Minimum Heat Flux) were obtained. As a result, with increasing the concentration of nanofluid and the number of repeated experiments, the reaching time to MFB point was reduced, but the MFBT and MHF were increased. In addition, it was found that the effect of water-based iron(III) oxide nanofluid on the MFB point at the bottom of wall in the test specimen was observed to be greater than that at the middle of wall and center. In the present experimental ranges, as compared with the pure water, the water-based iron(III) oxide nanofluid showed that the maximum reduction of reaching time to MFB point was about 53.6%, and the maximum enhancements of MFBT and MHF were about 31.1% and 73.4%, respectively.

Protection coordination between residual current device and surge protective devices in low-voltage consumer's installations (저압 수용가 설비에서 누전차단기와 서지방호장치 사이의 보호협조)

  • Lee, Bok-Hee;Kim, Hoe-Gu;Park, Hee-Yeoul;Ahn, Chang-Hwan
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.27 no.6
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    • pp.75-81
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    • 2013
  • In this paper, protection coordination between residual current devices and surge protective devices in low-voltage consumer's distribution systems are presented. In the case that a surge protrctive device(SPD) is located on the load side of an residual current device(RCD), when the surge is injected from the source side of the RCD, most of injected surge currents are split into the RCD and the protection coordination between the SPD and RCD is improper, three of 6 specimens experience unintended operation due to test impulse currents. Also when the surges is injected from the load side, a lot of the surge currents is split into the SPD, but a half of test specimens causes nuisance trip. Coordination between SPD and RCD is not valid. When installing SPD, it is important to select SPD after due consideration of the protection voltage level of metal oxide varistor embedded in RCD. It is expected that the results obtained from this work could be useful to improve the protection effects of SPD in low-voltage distribution systems.

Empirical Study on Internet Users' Information Privacy Concerns and Information Protection Behavior (인터넷 사용자의 정보프라이버시 염려와 정보보호 활동에 대한 실증연구)

  • Um, Myoung-Yong;Rhee, Moon-Ki;Kim, Tae-Ung
    • The Journal of Korean Association of Computer Education
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    • v.18 no.1
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    • pp.69-79
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    • 2015
  • This research aims to empirically explore the antecedents that could impact on internet users' information protection behavior. 282 of sample data collected from internet users was used to test the hypotheses. The results of this research reveal that the internet users' information privacy concerns has a significant impact on self-efficacy, perceived usefulness, and information protection behavior. In addition, we found that perceived usefulness and information protection behavior are significantly influenced by self-efficacy. However, contrary to expectations, perceived usefulness has no statistically significant effect on information protection behavior. These findings provide significant implications for online companies and internet uses as well as educational stakeholders that give educations about information protection.

Protection Effects of Summer Fabrics from Cell Toxicity of UVB (직물의 자외선차단과 세포에 미치는 방호효과)

  • An, Ryeong-Mi;Lee, Su-Jin;Song, Myeong-Gyeon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.21 no.4
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    • pp.750-756
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    • 1997
  • The purpose of the study was to investigate a transmittance rate of UVB (Ultraviolet B) through summer fabrics and a protection rate of summer fabric from UVB. The subjects were randomly selected 159 fabrics from Korean common summer fabrics. The protection rates of 159 fabrics from UVB were measured by UVB lamp and UVB sensor, and 14 fabrics among these fabrics were selected for an assay of MTT(3-(4, 5-dimethylthiazol-2-yl) -2, 5 -diphenyltetrazolium). The protection rate of fabrics from cell toxicity of UVB was measured by investigating the difference of the amount of cell toxic substance on between fabrics covered with and without HeLa cell The average protection rate of 159 fabrics from UVB was 95.08%. As result findings, three negative correlations were found between: 1) the transmittance rate of UVB and the amount of MTT on fabrics (y=0.0373+0.O0518 x, r=-0.9323, p<0.001); 2) the air permeability of fabrics and the amount of MTT (r: -0.79, p< 0.01); 3) the air permeability of fabrics and the protection rate of fabrics from UVB (r=0.89, p<0.01). However, there was no effect of thickness of fabrics on the protection rate from UVB and the amount of MTT.

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The Effect Assessment Method of Control and Protection Systems on Transient Stability of Power Systems

  • Miki, Tetsushi;Sugino, Ryuzaburou;Kono, Yoshiyuki
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.736-740
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    • 2004
  • In order to overcome the problems of simulation methods, the power system transient stability assessment method using critical fault clearing time functions has been developed. Using the above method, this paper has developed the new method which can assess accurately and efficiently the effects of control and protection systems on transient stability which is the most important characteristic to assess in power systems. At first, critical fault clearing time functions CCT(W:load) are defined by taking notice of the fact that transient stability is mainly controlled by fault clearing time and load. Next, the method to be enable to assess accurately and efficiently the effects of control and protection systems on transient stability has been newly developed by using the above functions. Finally, it has been applied to the effect assessment in the occurrence of a three-phase fault in a model power system. Results of application have been clarified its effectiveness.

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The verification of the application of grouting in the bottom protection work of sea dikes in the field (그라우팅을 통한 방조제 바닥보호공 차수공법 현장 적용성 검증)

  • Lee, So-Yeal;Choi, Sae-Kyung;Jeong, Il-Han
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09a
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    • pp.29-39
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    • 2010
  • By understanding the construction process of sea dikes and the current state of the thickness and speed of fluid in the bottom layer protection work of final closure gaps, a construction method applicable for the blocking of bottom layer work will be selected. The three construction methods selected will be tested in site through various methods, and the reinforcement of bottom layer protection and impervious effect will be verified. The verification results are as follows: 1) The overall riprap layer were 0.5~1.0m thicker than planned so that the grouting depth and grout input amount increased 2) The applied construction methods permeability of riprap layers were improved from $\alpha{\times}10^{-2}cm/s$ before the construction to $\alpha{\times}10^{-4}cm/s$ after construction. 3) The results of core extraction in order to grossly verify the hardening time and durability allowed the identification of grout injection effect. The amount of filling of the injection was difficult to judge because the slime in many areas made the reading of borehole photography difficult.

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A Study on the Method of Alleviating Anxiety for the Sake of performing protection Service (경호업무수행을 위한 불안해소방법에 관한 고찰)

  • Lee, Sang-Chul
    • Korean Security Journal
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    • no.1
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    • pp.263-281
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    • 1997
  • The results of protection service could be different according to, first, the potential ability of protection personnel, second, the training degree and efficiency. Namely, it depends on how to control one's anxiety and tension In order to overcome the unsettled mental state and maximize the effect of the service, the level of anxiety of personnel should be measured and the cause of the anxiety should be found. And then complete training having the proper method of alleviating anxiety could be possible. When the method of alleviating anxiety is applied, one should attend the training with a positive mind to be able to perform one's duty successfully. And by adapting the same methode and procedure used to protection service to both mental process and every situation in the condition that strained muscles relax and all one's energies are concentrated, the same methods for reducing anxiety could be used at the same time. The effect of individual method might be varied according to the personal difference, so no one can say this or that method is more efficient than others. But what is important is to choose one method and adapt it which is most proper to oneself. To use the method of reducing anxiety efficiently needs a lot of time, so one should attend the training with patience.

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The Effect of U.S. Protectionist Trade Policy on Foreign Ownership: A Study of Korea's Data Set

  • Jung, Hyun-Uk;Mun, Tae-Hyoung
    • Journal of Korea Trade
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    • v.23 no.7
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    • pp.83-95
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    • 2019
  • Purpose - This study analyzed the effect of the Trump Government's protectionist trade policies on foreign ownership. Specifically, this study empirically analyzes the hypothesis that foreign ownership will decrease after the Trump Government rather than before the Trump Government. Design/methodology - The hypothesis of this study is based on the expectation that US protection trade policy will negatively affect the profitability of Korean companies. The dependent variable in this study is the foreign ownership ratio, and the independent variable is a dummy variable representing before and after the Trump Government. Multiple regression analysis was performed, including the control variables suggested in previous studies related to foreign ownership. Findings - As a result, foreign ownership increased after the Trump Government rather than before the Trump Government. This study further analyzes whether the main variables affecting foreign investor's decision-making are differences before and after Trump Government. The export ratio, profitability and dividends did not differ before and after Trump Government. However, the level of information asymmetry decreased after the Trump Government than before the Trump Government. This suggests that US protection trade policies do not adversely affect the profitability of Korean companies. However, Korean firms are improving their information environment because US protectionist trade policies can lower profitability and negatively impact capital raising. In this regard, the foreign ownership ratio seems to differ before and after the Trump Government. Originality/value - This study contributes in that it presents data that US protectionist policies can affect Korean corporate governance. This study has implications from the short-term analysis of US protection trade policy.

Incorporation of Montmorillonite/Silica Composite for the Corrosion Protection of an Epoxy Coating on a 2024 Aluminum Alloy Substrate

  • Thai Thu Thuy;Trinh Anh Truc;Pham Gia Vu
    • Corrosion Science and Technology
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    • v.22 no.2
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    • pp.99-107
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    • 2023
  • Layered silicate clay montmorillonite (MMT) has been used in nanocomposite coating to improve corrosion protection by reinforcing the barrier property. The better dispersion of MMT in the coating produces a higher barrier effect. Pretreatment with MMT could favor the delamination of clay platelets, facilitating MMT dispersion in the coating. In the present work, a montmorillonite/silica (MMT/Si) composite was prepared by the in situ sol-gel method. x-ray diffraction measurements and field-emission scanning electron microscopy observations showed silica crystal formation and increased basal spacing between the MMT platelets. Composite MMT/Si particles were introduced in an epoxy resin to reinforce the corrosion protection of the coating applied on the AA2024 surface. Electrochemical impedance spectroscopy (EIS) was performed to characterize the protective property of the coating. The results demonstrated the high barrier effect of the coating containing 5 wt% of MMT/Si. Adhesion evaluation after a salt spray test exhibited a high adherence to the epoxy coating containing MMT/Si.