• Title/Summary/Keyword: Extreme Point

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The capacity loss of a RCC building under mainshock-aftershock seismic sequences

  • Zhai, Chang-Hai;Zheng, Zhi;Li, Shuang;Pan, Xiaolan
    • Earthquakes and Structures
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    • v.15 no.3
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    • pp.295-306
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    • 2018
  • Reinforced concrete containment (RCC) building has long been considered as the last barrier for keeping the radiation from leaking into the environment. It is important to quantify the performance of these structures and facilities considering extreme conditions. However, the preceding research on evaluating nuclear power plant (NPP) structures, particularly considering mainshock-aftershock seismic sequences, is deficient. Therefore, this manuscript serves to investigate the seismic fragility of a typical RCC building subjected to mainshock-aftershock seismic sequences. The implementation of the fragility assessment has been performed based on the incremental dynamic analysis (IDA) method. A lumped mass RCC model considering the tri-linear skeleton curve and the maximum point-oriented hysteretic rule is employed for IDA analyses. The results indicate that the seismic capacity of the RCC building would be overestimated without taking into account the mainshock-aftershock effects. It is also found that the seismic capacity of the RCC building decreases with the increase of the relative intensity of aftershock ground motions to mainshock ground motions. In addition, the effects of artificial mainshock-aftershock ground motions generated from the repeated and randomized approaches and the polarity of the aftershock with respect to the mainshock on the evaluation of the RCC are also researched, respectively.

Stability and minimum bracing for stepped columns with semirigid connections: Classical elastic approach

  • Aristizabal-Ochoa, J. Dario
    • Structural Engineering and Mechanics
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    • v.5 no.4
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    • pp.415-431
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    • 1997
  • Stability equations that evaluate the elastic critical axial load of stepped columns under extreme and intermediate concentrated axial loads in any type of construction with sidesway totally inhibited, partially inhibited and uninhibited are derived in a classical manner. These equations can be utilized in the stability analysis of framed structures (totally braced, partially braced, and unbraced) with stepped columns with rigid, semirigid, and simple connetions. The proposed column classification and the corresponding stability equations overcome the limitations of current methods which are based on a classification of braced and unbraced columns. The proposed stability equations include the effects of: 1) semirigid connections; 2) step variation in the column cross section at the point of application of the intermediate axial load; and 3) lateral and rotational restraints at the intermediate connection and at the column ends. The proposed method consists in determining the eigenvalue of a $2{\times}2$ matrix for a braced column at the two ends and of a $3{\times}3$ matrix for a partially braced or unbraced column. The stability analysis can be carried out directly with the help of a pocket calculator. The proposed method is general and can be extended to multi-stepped columns. Various examples are include to demonstrate the effectiveness of the proposed method and to verify that the calculated results are exact. Definite minimum bracing criteria for single stepped columns is also presented.

FISS and SDO Observation of a Brightening Event Near a Pore

  • Kang, Juhyeong;Chae, Jongchul
    • The Bulletin of The Korean Astronomical Society
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    • v.42 no.2
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    • pp.61.2-61.2
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    • 2017
  • We report a fine scale transient brightening event near a pore boundary with the Fast Imaging Solar Spectrograph (FISS) of the 1.6m Goode Solar Telescope (GST), the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO), and Helioseismic and Magnetic Imager (HMI) aboard SDO. The event appears in all AIA extreme ultraviolet bands, also in the two FISS lines, $H{\alpha}$ and Ca II $8542{\AA}$, and lasted for a minute. The brightening occurred at a footpoint of a loop. The conjugate brightening occurred at the other foot point outside the FISS field of view. The brightening near the pore exhibit a redshift of 4.3 km s-1 in the $H{\alpha}$ and about 2.3 km s-1 in Ca II line. Differential emission measure derived from 6 AIA EUV passbands and cloud model fitting of the two FISS lines indicate the temperature increase of between 10,000 and 20 MK at the main event. After the brightening, the upward mass motion appears in the AIA images. We discuss the physical implication of this brightening in the context of magnetic reconnection and coronal heating.

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Numerical Study on Heat Transfer Characteristic in Combustor Nozzle (추진기관 노즐의 열전달 특성에 관한 수치적 연구)

  • Namkoung, Hyuck-Joon;Han, Poong-Gyoo;Lee, Kyoung-Hoon;Kim, Young-Soo;Jeong, Hae-Seung
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2007.11a
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    • pp.275-281
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    • 2007
  • For a cooling performance research of the combustor operated in a extreme environment of a high temperature and high pressure, we accomplished a cooling performance analysis. Generally a heat transfer characteristic in cooling passage is known well experimentally and theoretically, however heat flux in the combustion chamber isn't. In this study, fluid flow combined with heat transfer analysis is accomplished about a combustor nozzle. We tried to analyze the cooling performance with a heat transfer characteristic of a gas and coolant side in the view point of quantity on the mass flow rate to be supplied to the cooling channel. And finally, evaluation on the thermal safety of nozzle wall material was accomplished.

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Developing of Exact Tests for Order-Restrictions in Categorical Data (범주형 자료에서 순서화된 대립가설 검정을 위한 정확검정의 개발)

  • Nam, Jusun;Kang, Seung-Ho
    • The Korean Journal of Applied Statistics
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    • v.26 no.4
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    • pp.595-610
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    • 2013
  • Testing of order-restricted alternative hypothesis in $2{\times}k$ contingency tables can be applied to various fields of medicine, sociology, and business administration. Most testing methods have been developed based on a large sample theory. In the case of a small sample size or unbalanced sample size, the Type I error rate of the testing method (based on a large sample theory) is very different from the target point of 5%. In this paper, the exact testing method is introduced in regards to the testing of an order-restricted alternative hypothesis in categorical data (particularly if a small sample size or extreme unbalanced data). Power and exact p-value are calculated, respectively.

글루타치온 생산효소( $\gamma$-Glutamylcysteine Synthetase)와 그 변이효소의 구조분석 및 반응 Kinetics 연구

  • Yang, Hye-Jeong;Gwon, Dae-Yeong
    • Bulletin of Food Technology
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    • v.17 no.4
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    • pp.98-106
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    • 2004
  • Two mutant enzymes of $\gamma$-glutamylcysteine synthetase ($\gamma$-GCS) which catalyzed the synthesis of $\gamma$-glutamylcysteine from L-glutamic acid and L-cysteine in the presence of ATP, were prepared bypoint mutation of $\gamma$-GCS gene with site-directed mutagensis in E. coli. Conformational structuresand catalytic reaction kinetics of mutant enzymes were compared with wild type $\gamma$-GCS afterpurification. The S495F mutant enzyme (serine at 495 residue was substituted with phenylalanine),which had no catalytic activity for $\gamma$-glutamylcysteine synthesis, rarely folded even in neutral pH.However, the mutant A494V (alanine of 494 residue was replaced by valnine) which showed 50 %increase of activity, had a high folding structure. The folding structure of A494V also more stable athigh temperature and extreme pH compared to wild type and S495F. Reaction kinetics of wild typeand A494V were also investigated, Km value of A494V was smaller than that of wild type, while itshowed a little difference at Vmax values. This result evolved that alanine at 494 may be involved inbinding site of substrate rather than catalytic site. In addition, change of catalytic activity by onepoint mutation was highly correlated with the folding structure of enzyme.

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A Case Report on Herpes Zoster (대상포진 환자 치험 1례)

  • Kim, Mi-Rang;Seo, Un-Kyo;Shin, Jeong-In
    • The Journal of Internal Korean Medicine
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    • v.23 no.1
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    • pp.147-152
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    • 2002
  • Clinical symptoms of herpes zoster include red rash, burning pain, tingling or extreme sensitivity in the affected area, usually limited to one side of the body. There might be a fever or a headache. The pain of acute herpes zoster may be severe, but it is usually temporary. Some of old patients are likely to develop postherpetic neuralgia. We treated a 73 year-old male patient who had severe pain and a headache after acute herpes zoster. In the point of Differentiation of Syndromes(辯證), this subject was diasgnosed as wind-heat syndrome(風熱證) and was administered Bangpungtongsung-san. For the purpose of making the pain easier, we used the western medication as well. After six days of treatment, pain and the other symptoms improved. Besides postherpetic neuralgia dissipated. Based on this experience, both oriental medicine and western medicine have a good effect on acute herpes zoster.

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Effects of Wheel Condition on Solidification Characteristics of Al-Cu Polycrystalline Ribbon (Al-Cu 다결정 리본의 응고거동에 미치는 휠조건의 영향)

  • Kim, Ju-Hyung;Lee, Sang-Mok;Hong, Chun-Pyo
    • Journal of Korea Foundry Society
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    • v.17 no.3
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    • pp.276-285
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    • 1997
  • The effect of wheel surface condition on solidification behavior of Al-Cu ribbon was investigated in order to establish extreme levels of heat extraction. The condition of wheel surface was changed either by heating the wheel surface up to $200^{\circ}C$ or by coating boron nitride(BN) onto the the rim of a wheel. Heating the wheel surface up to $200^{\circ}C$ improved the wetting behavior between the molten metal and the rotating wheel, leading to an increase in the ratio of columnar structure to the entire thickness of Al-4.3wt%Cu and Al-33.2wt%Cu ribbons. For Al-4.3wt%Cu ribbon, assuming one grain as a single heterogeneous nucleation event at the contact point, the nucleation density with the wheel surface heated to $200^{\circ}C$, was $4{\times}10^6/mm^2$, and in the cases of BN coating with thin and thick layers, $10^5/mm^2$ and $5{\times}10^4/mm^2$, respectively. The largest cooling capacity of the wheel corresponded to the heated wheel surface, and as the thickness of BN coating layer increased, the cooling capacity of the wheel gradually decreased.

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Study of Hydrogen Evolution Reaction by Molybdenum Oxide Doped TiO2 Nanotubes (몰리브덴 산화물이 도핑된 티타늄 나노튜브전극의 수소 발생 반응 연구)

  • Oh, Kiseok;Yoo, Hyeonseok;Lee, Gibaek;Choi, Jinsub
    • Journal of the Korean institute of surface engineering
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    • v.49 no.6
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    • pp.521-529
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    • 2016
  • In this study, titanium nanotubes, prepared by anodization method, showing high surface and strong chemical stability in acidic and basic media, have been employed for the application to the electrodes for water splitting in KOH solution. Due to its high polarization resistance of $TiO_2$ itself, proper catalysts are essentially required to reduce overpotentials for water oxidation and reduction. Most of academic literature showed noble metal catalysts for foreign dopants in $TiO_2$ electrodes. From commercialization point of view, screening of low-cost catalyst is important. Herein, we propose molybdenum oxide as low-cost catalysts among various catalysts tested in the experiments, which exhibits the highest performance for hydrogen evolution reaction in highly alkaline solution. We showed that molybdenum oxide doped electrode can be operated in extreme acidic and basic conditions as well.

A Study on the Anti-aesthetic Characteristics of Fashion Show Make-up - based on expressions of shape - (패션쇼 메이크업의 반미학적 특성 연구 - 형태 표현을 중심으로 -)

  • Byun, Young-Hee;Chae, Keum-Seok
    • Journal of the Korean Society of Fashion and Beauty
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    • v.2 no.1 s.1
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    • pp.65-74
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    • 2004
  • The purpose of this study is to investigate the trends and characteristics of the anti-aesthetic shapes have been expressed in Fashion Show Make-up from 1995 to 2003 and to enlarge the possibility of expressions through various formative elements and to anticipate the prospect of the Make-up in the future. Anti-aesthetics means the beginning of criticism that destroy the system of modernism and the anti-aesthetic shapes in Fashion Show Make-up have been distorted, deformed, destroyed through asymmetrical arrangement or abnormal transformation or extreme reduction or omission and so on. It means that is to enlarge the range of expressions through a new interpretation. The anti-aesthetic characteristics in Fashion Show Make-up can be summarized as Avant-garde, Satire, De-construction, Poverty, inhumanity and most of shapes show experimental techniques in unlimited method. The differences at the turning point in 21C is to increase the experimental attempts such as informal and collage and graphic Make-up and so forth.

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