• Journal of Life Science
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• v.14 no.3
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• pp.478-483
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• 2004

In a model reaction using lysyl oxidase purified partilally from bovine aorta, effect of L-ascorbic acid AsA on the oxidative reaction of lysine in collagen was investigated. Addition of Ash to the reaction mixture under aerobic conditions resulted in the decrease of enzymatic activity. In order to examine the specificity of AsA in the oxidative reaction of lysine, other reductants including A derivatives instead of AsA were added to the reaction mixture. Thiol such as glutathione had no effect on the activities of lysyl oxidase. on the other hand, it was observed that erythorbic acid, which was a stereoisomer of AsA, had the same inhibitory effect on this oxidative reaction as AsA. Moreover, by the addition of 3,4-dihydroxybenzoate, which was structural analog of AsA, the activities decreased in a similar manner to that of AsA. These results indicate that the regulatory effect of AsA on lysyl oxidase is attributed to characteristics of the structure. From the determination of Ash remained in the reaction mixture, it is shown that AsA concentration remarkably decreased by lysyl oxidase of the reaction mixture. It is hypothesized that endiol groups reduces the enzyme-bound $Cu^{+2}$ required for further progress of the reaction, and suggests that AsA regulates specifically the reduction of $Cu^{+2}$ required to oxidize lysyl oxidase. This findings support that AsA has an important regulatory role on the oxidative reaction of lysine and on changes of collagen cross-links with aging.

• Journal of the Korean Vacuum Society
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• v.2 no.4
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• pp.424-432
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• 1993

AlGaAs/InGaAs/GaAs pseudomorphic structures have been grown by atmosheric pressure-MOCVD . The Al incorporation efficiency is constant but slightly exceeds the Ga incorporation during the growth of AlGaAs layers at $650^{\circ}C$ . Meanwhile , the In incorporation efficiency is constant but slightly less than the Ga incorporation in InGAAs layers. InGaAs/GaAs QWs were grown and their optical properties were characterized . $\delta$-doped Al0.24Ga0.76As/In0.16 Ga0.84As p-HEMT structures were successfully grown by MOCVD and their transport properties were characterized by Hall effect and SdH measurements. SdH Measurements at 3.7K show clear magnetoresistance oscillations and plateaus in the quantum Hall effect confirming the existence of a two-dimensional electron gas(2DEG) and a parallel conduction through the GaAs buffer layer. The fabricated $1.5\mu\textrm{m}$gatelength p-HEMTs having p-type GaAs in the buffer layer show a high transconductance of 200 mS/mm and a good pinch-off characteristics.

• Applied Science and Convergence Technology
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• v.27 no.3
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• pp.56-60
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• 2018

The optical properties of the digital-alloy $(In_{0.53}Ga_{0.47}As)_{1-z}/(In_{0.52}Al_{0.48}As)_z$ grown by molecular beam epitaxy as a function of composition z (z = 0.4, 0.6, and 0.8) have been studied using temperature-dependent photoluminescence (PL) and time-resolved PL (TRPL) spectroscopy. As the composition z increases from 0.4 to 0.8, the PL peak energy of the digital-alloy $In(Ga_{1-z}Al_z)As$ is blueshifted, which is explained by the enhanced quantization energy due to the reduced well width. The decrease in the PL intensity and the broaden FWHM with increasing z are interpreted as being due to the increased Al contents in the digital-alloy $In(Ga_{1-z}Al_z)As$ because of the intermixing of Ga and Al in interface of InGaAs well and InAlAs barrier. The PL decay time at 10 K decreases with increasing z, which can be explained by the easier carrier escape from InGaAs wells due to the enhanced quantized energies because of the decreased InGaAs well width as z increases. The emission energy and luminescence properties of the digitalalloy $(InGaAs)_{1-z}/(InAlAs)_z$ can be controlled by adjusting composition z.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37B no.10
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• pp.901-911
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• 2012

Over the last decade, the Internet in Korea has developed rapidly. The number of ASes in Korea is 755. However, there has been no significant effort to obtain an accurate picture of the Internet AS-level topology. To construct more complete set of Korea AS-level topology data all the available data sources are critically reviewed and compared. Three data sources, which can be used to infer Korea Internet AS-level topology, are selected; BGP data of UCLA "Internet Topology Collection", IRR data and IXP data. It is known that global Internet AS-level topology follows power-law distribution. In this paper, we also investigate if the Korea Internet AS-level topology follows power-law distribution.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.168-168
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• 2010

InAs는 0.35eV의 낮은 밴드갭을 가지며 상온에서 약 $30,000cm^2/Vs$의 높은 전자이동도를 보여, GaAs/AlGaAs 및 InGaAs/InP 2DEG HEMT에 이은 차세대 초고속 전자소자의 2DEG용 물질로 각광을 받고 있다. 그러나 InAs의 격자상수는 약 0.61nm로 이에 적절한 반절연기판을 구할수 없어, GaAs상에 Al(Ga)Sb를 이용하여 성장하는 방법으로 2DEG을 실현하고 있다. 상기 방법으로 상온에서 ${\sim}30,000cm^2/Vs$ 전자이동도를 보이는 InAs/AlSb 2DEG HEMT 소자를 여러 연구팀에서 시현하였으나, 실제적으로 응용하기 위해서 etch-stop층 또는 contact층의 제작이 용이치 않아 실제의 회로구현에는 어려움을 격고 있다. 이에 InGaAs/InP 2DEG내에 InAs를 넣어 InAs 2DEG을 제작하는 방법이 NTT[1]에 의해 제안되어, SPINTRONICS등의 InAs 2DEG이 필요한 곳에 응용되고 있다. [2] 본 발표에서는 고품질의 InAs 2DEG을 실현하기 위해, 다양한 성장 변수 (온도, As 분압, 성장 시퀀스, InAs층의 두께등)와 2DEG의 전기적특성간의 관계를 발표한다. 최종적으로 상온전자이동도 ${\sim}12,000cm^2/Vs$의 InAs 2DEG을 제작할수 있었으며, 이를 다양한 전자소자에 차후 응용할 예정이다.

• Cross-Cultural Studies
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• v.28
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• pp.67-86
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• 2012

Metaphors were conceived of as a figure of speech whose role consisted in merely ornamenting the language. However, with their seminal book Metaphors we live by (1980), Lakoff and Johnson have revolutionized the conception of metaphors by placing them as central to human language, thought and action. Cognitive linguists argue that humans tend to conceptualize abstract concepts, such as time, through more experiential and tangible concepts. For instance, it has been observed that the abstract concept of time is conceptualized as space in several unrelated languages. According to the Conceptual Metaphor Theory (CMT), TIME AS SPACE metaphor covers two more specific metaphors: (1) The MOVING TIME metaphor wherein the observer is conceived as a stationary entity, as in The end of the academic year is getting closer; and (2) The TIME AS A LOCATION metaphor wherein times are conceived as stationary points and the observer is conceived as moving relative to these locations, as in We are first approaching the end of the year. This paper aims at probing the validity of the CMT representations of time on the basis of an analysis of time metaphors in two languages: English and French. This analysis is conducted within the framework of CMT. The results corroborate the CMT representations of time, suggesting that in both languages the abstract concept of time is expressed in spatial terms. In English, as in French, time is conceptualized as a moving entity and as having extension in space. In both languages, time can be seen as bounded; therefore, one can perform actions within defined limits of time.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.1-7
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• 1997

The goals of the present study lie in presenting the direction of researches and developments for GaAs based solar cells, as well as in taking a step toward the establishment of GaAs MOCVD technologies. On the other hand, the GaAs on Si substrates has been recognized as a lightweight alternative to pure GaAs substrate for space application, because its density is less than the 7alf of GaAs or Ge. So, GaAs/Si has twofold weight advantage to GaAs monolithic cell. It was concluded that the development the development of MOCVD technologies should be ahead of GaAs solar cells.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.366-370
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• 2002

GaAs has become a very popular material for the fabrication of high frequency, low noise and microwave power devices. GaAs devices are also well suited for high temperature operation because of the large band gap of this material. The standard GaAs technology and device structures have to be modified for stable operation at high temperature. In this paper, AlGaAs/GaAs HBT considering stable ohmic contact at high temperature as well as thermal effect such as self-heating effect are introduced. All the data obtained study will be used as input data for the simulator and the result will be compared with an analytical model available in this study,

• The Journal of the Korean dental association
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• v.11 no.11
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• pp.745-748
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• 1973

The author has studied the effects of pain control by using the Anode-S-3 electro anesthesia in cavity preparations. The electric current value had used 4~10㎂. The results were as follows. 1) The 86 tests in cases of 110 tests as much as 78% of it have showed pain control effects and the 24 of tests as much as 22% had no effects in general. 2) The cases of perfect pain control was only made to 42 tests in cases of 110 tests as much as 38% of it. 3) The pain control with a little inordinary feeilng was 33 tests in 110 of it as much as 30% 4) The slight pain were recorded 22 cases as much as 21% of the tests. 5) The severe pain were recorded 12 cases as much as 11% of the tests. 6) Meanwhlie, the case of increasing pains by using electro-anesthesia was not recorded at all.

• The Journal of Art Theory & Practice
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• no.13
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• pp.157-184
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• 2012

This essay examines Jacques Callot's Les Grandes Mis$\grave{e}$res et Malheurs de la Guerre (1633) as a moral meditation on war as catastrophe. It also uses Callot's Miseries to reflect on the nature of catastrophe as such, particularly as "An event producing a subversion of the order or system of things." As such, catastrophe refers less to nature or the natural gone awry, than it does to the abnegation or suspension of moral aspects of human nature. More than a reflection on war as catastrophe, and catastrophe as fundamentally moral, Callot's Miseries are a timeless meditation on aspects of the human condition; or on human beings in what amounts to state of nature-as evidenced in times of disaster. Such reflection, again, does not by itself imply that all war-even when catastrophic-is unnecessary, let alone necessarily unjust. But it does suggest that artistic engagement with war understood as catastrophic, may yield insights into human nature that are as important to human self-understanding as those represented in artistic subject matter that is more quotidian.