• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.173-174
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• 1998

We developed the high power telephone for hearing impaired person (HIP) who can't communicate with others by general telephone. The general telephone can't delivered enough sound for HIP to understand telephone speech. In this study, we developed the method of telephone speech amplification proper to HIP and effective howling suppression which occurred as a side effect of amplification. In our new telephone, speech sound is divieded to 3 band pass filter path, amplified respectively fit to HIP's hearing ability, and monitored howling in time domain. The result of test of our telephone showed that we can amplify the sound as much as 40dB, which is very useful to HIP, and make HIP increase the perception of telephone speech.

• Journal of Powder Materials
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• v.24 no.2
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• pp.153-163
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• 2017

Transparent conducting electrodes (TCEs) are attracting considerable attention as an important component for emerging optoelectronic applications such as liquid crystal displays, touch panels, and solar cells owing to their attractive combination of low resistivity (<$10^{-3}{\Omega}cm$) and high transparency (>80%) in the visible region. The solution-based process has unique properties of an easy fabrication procedure, scalability, and low cost compared to the conventional vacuum-based process and may prove to be a useful process for fabricating TCEs for future optoelectronic applications demanding large scale and flexibility. In this paper, we focus on the introduction of a solution-based process for TCEs. In addition, we consider the powder materials used to fabricate solution-based TCEs and strategies to improve their transparent conducting properties.

• Journal of Power System Engineering
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• v.17 no.5
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• pp.38-43
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• 2013

In order to design a wave energy generating system, a 6-DOF analysis technique is applied to CFD analysis on of a floating body and the behavior is interpreted according to the nature of the incoming waves. A spring constant is adopted to control the motion of multi floating bodies and to calculate the total average power absorption. Three cases of different wavelengths namely 20D, 30D and 40D have been modeled to analyze the total average power absorption. The average power absorption not only varies with the position of the floating body but also varies with wavelength. From the results obtained, it is concluded that the maximum total average power absorption is 9W approximately in wavelength 30D and the minimum total average power absorption is 4.3W approximately in wavelength 40D.

• Journal of the Optical Society of Korea
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• v.13 no.3
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• pp.304-309
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• 2009

We tested the feasibility of measuring fat thickness using a miniaturized chip LED sensor module, testing 12 healthy female subjects. The module consisted of a single detector and four sources at four different source-detector distances (SD). A segmental curve-fitting procedure was applied, using an empirical algorithm obtained by Monte-Carlo simulation, and fat thicknesses were estimated. These thicknesses were compared to computed-tomography (CT) results; the correlation coefficient between CT and optical measurements was 0.932 for bicep sites. The mean percentage error between the two measurements was 13.12%. We conclude that fat thickness can be efficiently measured using the simple sensor module.

• Bulletin of the Korean Chemical Society
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• v.29 no.7
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• pp.1297-1298
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• 2008

• Proceedings of the KOSOMBE Conference
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• v.1993 no.05
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• pp.141-145
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• 1993

To Determine the major factor which causes the accelerated calcification of the severe flexing area of the artificial heart sac, comparative study under well defined in vitro situation were carried out. The results show that the effect of static mechanical stress is not so important. According to the data, change of surface area caused by the applied mechanical stress is one of the important factors of the heavy calcification of the severe flexing area of the artificial heart sac.

• Journal of Microbiology and Biotechnology
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• v.19 no.6
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• pp.556-559
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• 2009

Compounds extracted from Platycodon grandiflorum were evaluated for an activation effect on nuclear factor-kappa B (NF-${\kappa}B$). In its active state, NF-${\kappa}B$ turns on the expression of genes related to cell proliferation or death. NF-${\kappa}B$ activators promote growth of neuron cells and can be used to control neurodegenerative diseases. The biological activity of P. grandiflorum extracts toward NF-${\kappa}B$ had not yet been studied. Although the biological activity of several compounds extracted from P. grandiflorum was evaluated, only three exhibited any significant activation effect on NF-${\kappa}B$.

• Biomedical Science Letters
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• v.9 no.2
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• pp.99-103
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• 2003

Hantavirus are rodent-borne RNA virus that belongs to the family Bunyaviridae. Those viruses persistently infect a variety of rodents, and are transmitted by aerosols of their urine, feces and saliva. Antibody titers of sera obtained from normal laboratory rodents against hantaviruses were investigated by indirect immunofluorscence antibody technique (IFA), Seroconversion rates of normal laboratory rodents showed higher in rats than that from hamster and mongolian (M). gerbil. Theses rates of normal laboratory rodents also showed higher in titers against puumala virus (PUUV) than in hantaan (HTNV) and seoul virus (SEOV). We are concerned about infections caused by hantaviruses, especially by PUUV, occurred in laboratory rodents.

• Annals of Clinical Neurophysiology
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• v.16 no.1
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• pp.1-7
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• 2014

Iron is an important element for brain oxygen transport, myelination, DNA synthesis and neurotransmission. However, excessive iron can generate reactive oxygen species and contribute neurotoxicity. Although brain iron deposition is the natural process with normal aging, excessive iron accumulation is also observed in various neurological disorders such as neurodegeneration with brain iron accumulation, Parkinson's disease, Alzheimer's disease, multiple sclerosis, Friedreich ataxia, and others. Magnetic resonance image (MRI) is a useful method for detecting iron deposits in the brain. It can be a powerful tool for diagnosis and monitoring, while furthering our understanding of the role of iron in the pathophysiology of a disease. In this review, we will introduce the mechanism of iron toxicity and the basics of several iron-related MRI techniques. Also, we will summarize the previous results concerning the clinical application of such MR imagings in various neurological disorders.

• Journal of Information Display
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• v.6 no.4
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• pp.35-39
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• 2005

In this paper, we investigate the oxide cathodes for the development of reliable electron sources. Poisoning in oxide cathodes is one of the serious problems in achieving reliable electron emission. In particular, early poisoning induces poor life performance as will be demonstrated herein. The survivability of electron emission sources is significantly improved by high doping of high-speed activator. The robust oxide cathodes with 0.17 % Mg operating at about 1,050 K are expected to work for very long times (>100,000 hours). We suggest that this key idea will contribute to solving the basic problems in oxide cathodes such as poisoning or ion bombardment for high power or high frequency applications of electron sources.