• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1034-1035
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• 2015

Watertight 25.8 kV/600 A/12.5 kA fault current limiters (FCLs) have successfully installed in five areas (Incheon, Seoul, Gyeong-gi, Daejeon, Suwon) on KEPCO power distribution line for the purpose of commercial demonstrations. The fault current limiting operation of this FCL, which includes functions of sensing, commutation, and reduction of fault currents, is perfectly completed within 1 cycle immediately after fault occurs. The performance of FCL was verified by short circuit test, impedance test, insulation test, temperature-rise test, and control test, etc at PT&T in LS industrial systems, which is the official certification institute in Korea. In 2013, and also the FCL field test was performed in order to test the protection coordination between conventional relays and FCL, on the 1.5 kA and 5.0 kA faults, which were made by connecting the Artificial Fault Generator (AFG) to the distribution line in test grid at KEPCO Power Testing Center. The next step of this project is to check the FCL conditions caused by real external environment, and acquire the various data from five regions installed with FCL. In this paper, we intend to explain the FCL specifications and performance characteristics, and check the expected effect by application of FCL to power distribution line based on the power system analysis of an application site.

• Journal of the Korea Society of Computer and Information
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• v.23 no.6
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• pp.75-79
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• 2018

The purpose of this paper is to introspect again the role of the criminal law at a time when it is said that numerous criminal and legal discussions are needed to develop the so called "reply manipulation " case that is shaking the nation's political history. The research method considered the literature and precedents discussed in the past, and discussed the issue of subculture abuse caused by the internet, which is a product of convenience and affluence that came with the Forth industrial revolution through criminal law. Through a computer program, a discussion was held on what penalties would be imposed on the criminal law for attempting to manipulate public opinion by manipulating the so-called number of comments or Reaction. Question of whether the criminal law should further emphasize the need for a discussion on the need for a method to strengthen the preventive functions of the criminal law and expand the scope of punishment in order to address new causes of risk that came with the development of science. Without reflecting on whether such as "government-inspired demonstration "would be possible in today's world that was in the public perception of the authoritarian government of the past, it is a problem to see that the political goals of a particular group can be achieved by manipulating comments or creating public opinion on the Internet. The duty of criminal law is to protect the interests of the law. The role of the criminal law should be maintained the self limiting as far as possible in cases of violation or danger of the law. Still, it is a problem that the role of the criminal justice system today is too aggressive and is seen as a top tool rather than a last resort for solving problems. he role of the internet will be expanded further in the Hyper Connected society. To solve these problems, we should look forward to a change in the priority of other laws and policies other than criminal law.

• Microbiology and Biotechnology Letters
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• v.39 no.3
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• pp.189-199
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• 2011

Recently seaweed polysaccharides have been extensively studied due to their various biological functions including antitumor, antiviral, anticoagulant, and anti-inflammatory activities. Although seaweed polysaccharides are known to possess numerous beneficial properties, their industrial applications have been limited due to the low inclusion efficiency and high cost of manufacturing involved in chemical hydrolysis. In addition, the smell of seaweed has been a limiting factor in its application in the food and cosmetic industries. Therefore, novel hydrolysis methods and the deodorization of seaweed are required if the extensive application of seaweed polysaccharides is to be seen. A number of studies have examined various seaweed polysaccharide-degrading enzymes, which have been isolated from marine microorganisms, and enzymatic hydrolysis processes have been investigated for the improvement of production yields and the bioefficacy of seaweed polysaccharides. This review is a synopsis on the properties of seaweed polysaccharides-degrading enzymes from marine microorganisms and their industrial applications. The review reveals the pressing need for more concentrated research on the development of new biological materials from seaweed.

• Tuberculosis and Respiratory Diseases
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• v.78 no.1
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• pp.8-17
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• 2015

Background: AMP-activated protein kinase (AMPK) not only functions as an intracellular energy sensor and regulator, but is also a general sensor of oxidative stress. Furthermore, there is recent evidence that it participates in limiting acute inflammatory reactions, apoptosis and cellular senescence. Thus, it may oppose the development of chronic obstructive pulmonary disease. Methods: To investigate the role of AMPK in cigarette smoke-induced lung inflammation and emphysema we first compared cigarette smoking and polyinosinic-polycytidylic acid [poly(I:C)]-induced lung inflammation and emphysema in $AMPK{\alpha}1$-deficient ($AMPK{\alpha}1$-HT) mice and wild-type mice of the same genetic background. We then investigated the role of AMPK in the induction of interleukin-8 (IL-8) by cigarette smoke extract (CSE) in A549 cells. Results: Cigarette smoking and poly(I:C)-induced lung inflammation and emphysema were elevated in $AMPK{\alpha}1$-HT compared to wild-type mice. CSE increased AMPK activation in a CSE concentration- and time-dependent manner. 5-Aminoimidazole-4-carboxamide-1-${\beta}$-4-ribofuranoside (AICAR), an AMPK activator, decreased CSE-induced IL-8 production while Compound C, an AMPK inhibitor, increased it, as did pretreatment with an $AMPK{\alpha}1$-specific small interfering RNA. Conclusion: $AMPK{\alpha}1$-deficient mice have increased susceptibility to lung inflammation and emphysema when exposed to cigarette smoke, and AMPK appears to reduce lung inflammation and emphysema by lowering IL-8 production.

• Tuberculosis and Respiratory Diseases
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• v.83 no.3
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• pp.175-184
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• 2020

Quantitative sputum cytometry facilitates in assessing the nature of bronchitis associated with exacerbations of chronic obstructive pulmonary disease (COPD). This is not assessed in most clinical trials that evaluate the effectiveness of strategies to prevent or to treat exacerbations. While up to a quarter of exacerbations may be associated with raised eosinophil numbers, the vast majority of exacerbations are associated with neutrophilic bronchitis that may indicate airway infections. While eosinophilia may be a predictor of response to corticosteroids (oral and inhaled), the limited efficacy of anti-interleukin 5 therapies would suggest that eosinophils may not directly contribute to those exacerbations. However, they may contribute to airspace enlargement in patients with COPD through various mechanisms involving the interleukin 13 and matrix metalloprotease pathways. The absence of eosinophils may facilitate in limiting the unnecessary use of corticosteroids. The presence of neutrophiia could prompt an investigation for the specific pathogens in the airway. Additionally, sputum measurements may also provide insight into the mechanisms of susceptibility to airway infections. Iron within sputum macrophages, identified by hemosiderin staining (and by more direct quantification) may impair macrophage functions while the low levels of immunoglobulins in sputum may also contribute to airway infections. The assessment of sputum at the time of exacerbations thus would facilitate in customizing treatment and treat current exacerbations and reduce future risk of exacerbations.

• Publications of The Korean Astronomical Society
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• v.27 no.3
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• pp.95-103
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• 2012

We analyzed the current status of the telescope control system (TCS2) of the 1.8 m telescope in Bohyunsan Optical Astronomy Observatory (BOAO), and suggest a new TCS (TCS3) for the long term development of BOAO. The TCS2 was constructed in 1998 to replace the TCS1 which was installed with the telescope itself at the commencement of BOAO. One of the important parts of TCS is PMAC (Programmable Multi-Axis Controller), which is a general-purpose multi-axis motion controller. PMAC provides the direct interactive communication environment permitting users to command the controller directly with simple operations. This makes the setup, debugging, and diagnostics very easy. The TCS2 was operated stable for a long time, but the hardware and TCS computers have been deteriorated and are out of date now. The new TCS3 needs to be constructed based on a modern computer system. And functions such as pre-calculations of telescope limiting position, interworking with virtual observatory tools, and using GUI, etc should be added. Construction of the TCS3 will be a step creating a better observation environment for the Korean astronomical society.

• Fire Science and Engineering
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• v.20 no.4 s.64
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• pp.72-76
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• 2006

Polymer/clay nanocomposites have generated considerable interests in the past decade because adding just tiny amount of clay to the polymer matrix could produce a dramatic enhancement in physical, thermal and mechanical properties. Smectite clays, such as montmorillonite (MMT), are of great industrial value because of their high aspect ratio, plate morphology, intercalative capacity, natural abundance and low cost. In this study, PE/MMT nanocomposites were directly prepared by melt intercalating PE and the modified clay. The nanostructure was verified by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and their flame retardant properties were measured and discussed by limiting oxygen index (LOI), char yield and smoke mass concentration. And their thermal stabilities were measured by differential thermogravimetric (DTG) and thermogravimetric analysis (TGA). The PE/MMT nanocomposites proved more effective the conventional composites in reinforcement. Two functions in the thermal stability of the PE/MMT nanocomposite, one is the barrier effect to improve the thermal stability, and another is catalysis, leading to a decrease of the thermal stability. The flammability was greatly decreased due to the formation of the clay-enriched protective char during the combustion.

• Communications for Statistical Applications and Methods
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• v.29 no.4
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• pp.421-439
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• 2022

Phase I dose-finding trials are essential in drug development. By finding the maximum tolerated dose (MTD) of a new drug or treatment, a Phase I trial establishes the recommended doses for later-phase testing. The primary toxicity endpoint of interest is often a binary variable, which describes an event of a patient who experiences dose-limiting toxicity. However, there is a growing interest in dose-finding studies regarding non-binary outcomes, defined by either the weighted sum of rates of various toxicity grades or a continuous outcome. Although several novel methods have been proposed in the literature, accessible software is still lacking to implement these methods. This study introduces a newly developed R package, UnifiedDoseFinding, which implements three phase I dose-finding methods with non-binary outcomes (Quasi- and Robust Quasi-CRM designs by Yuan et al. (2007) and Pan et al. (2014), gBOIN design by Mu et al. (2019), and by a method by Ivanova and Kim (2009)). For each of the methods, UnifiedDoseFinding provides corresponding functions that begin with next that determines the dose for the next cohort of patients, select, which selects the MTD defined by the non-binary toxicity endpoint when the trial is completed, and get oc, which obtains the operating characteristics. Three real examples are provided to help practitioners use these methods. The R package UnifiedDoseFinding, which is accessible in R CRAN, provides a user-friendly tool to facilitate the implementation of innovative dose-finding studies with nonbinary outcomes.

• Journal of Ginseng Research
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• v.48 no.2
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• pp.211-219
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• 2024

Background: Recently, plant-derived exosome-like nanoparticles (PDENs) have been isolated, and active research was focusing on understanding their properties and functions. In this study, the characteristics and molecular properties of ginseng root-derived exosome-like nanoparticles (GrDENs) were examined in terms of skin protection. Methods: HPLC-MS protocols were used to analyze the ginsenoside contents in GrDENs. To investigate the beneficial effect of GrDENs on skin, HaCaT cells were pre-treated with GrDENs (0-2 × 10⁹ particles/mL), and followed by UVB irradiation or H₂O₂ exposure. In addition, the antioxidant activity of GrDENs was measured using a fluorescence microscope or flow cytometry. Finally, molecular mechanisms were examined with immunoblotting analysis. Results: GrDENs contained detectable levels of ginsenosides (Re, Rg1, Rb1, Rf, Rg2 (S), Gyp17, Rd, C-Mc1, C-O, and F2). In UVB-irradiated HaCaT cells, GrDENs protected cells from death and reduced ROS production. GrDENs downregulated the mRNA expression of proapoptotic genes, including BAX, caspase-1, -3, -6, -7, and -8 and the ratio of cleaved caspase-8, -9, and -3 in a dose-dependent manner. In addition, GrDENs reduced the mRNA levels of aging-related genes (MMP2 and 3), proinflammatory genes (COX-2 and IL-6), and cellular senescence biomarker p21, possibly by suppressing activator protein-1 signaling. Conclusions: This study demonstrates the protective effects of GrDENs against skin damage caused by UV and oxidative stress, providing new insights into beneficial uses of ginseng. In particular, our results suggest GrDENs as a potential active ingredient in cosmeceuticals to promote skin health.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.18 no.2
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• pp.348-369
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• 2024

With the advancement of Industry 4.0 and Industrial Internet of Things (IIoT), manufacturing increasingly seeks automation and intelligence. Temperature and vibration monitoring are essential for machinery health. Traditional abnormal state detection methodologies often overlook the intricate frequency characteristics inherent in vibration time series and are susceptible to erroneously reconstructing temperature abnormalities due to the highly similar waveforms. To address these limitations, we introduce synergistic, end-to-end, unsupervised Frequency-Time Domain Memory-Enhanced Autoencoders (FTD-MAE) capable of identifying abnormalities in both temperature and vibration datasets. This model is adept at accommodating time series with variable frequency complexities and mitigates the risk of overgeneralization. Initially, the frequency domain encoder processes the spectrogram generated through Short-Time Fourier Transform (STFT), while the time domain encoder interprets the raw time series. This results in two disparate sets of latent representations. Subsequently, these are subjected to a memory mechanism and a limiting function, which numerically constrain each memory term. These processed terms are then amalgamated to create two unified, novel representations that the decoder leverages to produce reconstructed samples. Furthermore, the model employs Spectral Entropy to dynamically assess the frequency complexity of the time series, which, in turn, calibrates the weightage attributed to the loss functions of the individual branches, thereby generating definitive abnormal scores. Through extensive experiments, FTD-MAE achieved an average ACC and F1 of 0.9826 and 0.9808 on the CMHS and CWRU datasets, respectively. Compared to the best representative model, the ACC increased by 0.2114 and the F1 by 0.1876.