• Journal of Chest Surgery
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• v.49 no.4
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• pp.225-231
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• 2016

Throughout its 30-year history, the right gastroepiploic artery (GEA) has been useful for in situ grafts in coronary artery bypass grafting (CABG). The early graft patency rate is high, and the late patency rate has improved by using the skeletonized GEA graft and proper target selection, which involves having a target coronary artery with a tight >90% stenosis. Total arterial revascularization with the internal thoracic artery and GEA grafts is an option for achieving better outcomes from CABG procedures.

• Journal of the Korean earth science society
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• v.26 no.5
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• pp.376-386
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• 2005

This study investigated to describe how the nature of science is revealed in the four natural history museums in Korea. Natural history museums are well considered as informal settings of education, and the nature of science has been one of major topics stressed in science education. Therefore, the revelation of this topic is supposedly reflected in developing museum exhibitions. In each of the four target natural history museum or natural history exhibition, the representative exhibits subtitled by scientific inquiry and cases dealing with history of science were selected for the study. The analyzing exhibits focused on whether exhibitions were labeled with emphasis on declarative description or interpretative one. In analyzing the contents, the focus was on the concerns of scientists, scientific community, social and cultural aspects, uncertainty of scientific knowledge, and providing sufficient evidences. All things considered, it was hard to conclude that every target exhibit clearly considered the nature of science as an essential element, in designing and developing their exhibitions. More deliberate input of nature of science is suggested for worldly renowned natural history museums, because previous researches keep insisting that the nature of science would be more efficiently achieved in an informal educational setting rather than in classrooms.

• Molecules and Cells
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• v.41 no.10
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• pp.889-899
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• 2018

Intrinsically disordered proteins (IDPs) are highly unorthodox proteins that do not form three-dimensional structures under physiological conditions. The discovery of IDPs has destroyed the classical structure-function paradigm in protein science, 3-D structure = function, because IDPs even without well-folded 3-D structures are still capable of performing important biological functions and furthermore are associated with fatal diseases such as cancers, neurodegenerative diseases and viral pandemics. Pre-structured motifs (PreSMos) refer to transient local secondary structural elements present in the target-unbound state of IDPs. During the last two decades PreSMos have been steadily acknowledged as the critical determinants for target binding in dozens of IDPs. To date, the PreSMo concept provides the most convincing structural rationale explaining the IDP-target binding behavior at an atomic resolution. Here we present a brief developmental history of PreSMos and describe their common characteristics. We also provide a list of newly discovered PreSMos along with their functional relevance.

• Journal of The Korean Association For Science Education
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• v.24 no.1
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• pp.63-75
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• 2004

The purpose of this study is to explore characteristics of on-line teaching materials on websites of natural history museums, particularly with regard to educational perspectives and the nature of science. The target resources were selected from the websites of the Natural History Museum in London, the Australian Museum in Sydney, the Field Museum of Natural History in Chicago, and the Smithsonian Museum in Washington D.C.. A total of twelve on-line resources from these museums used in this study were selected as representative informal science teaching materials. For the investigation, this study developed a checklist with a total of nine items that were grounded on mostly reviewing previous literature and articles focusing on educational perspectives of natural history museums and science centers. Exciting and positive results were found in all four museums. The analyses, however, indicated weaknesses as well as strengths in on-line resources regarding their usages as informal science teaching venues.

• Steel and Composite Structures
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• v.36 no.4
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• pp.399-415
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• 2020

Responses of semi-rigid frames having different degrees of semi-rigidity obtained by the nonlinear static analysis (NSA) are evaluated at specific target displacements by comparing them with those obtained by the nonlinear time-history analysis (NTHA) for scaled earthquakes. The peak ground accelerations (PGA) of the earthquakes are scaled such that the obtained peak top story displacements match with the target displacements. Three different types of earthquakes are considered, namely, far-field and near-field earthquakes with directivity and fling-step effects. In order to make the study a comprehensive one, three degrees of semi-rigidity (one fully rigid and the other two semi-rigid), and two frames having different heights are considered. An ensemble of five-time histories of ground motion is included in each type of earthquake. A large number of responses are considered in the study. They include the peak top-story displacement, maximum inter-story drift ratio, peak base shear, total number of plastic hinges, and square root of sum of the squares (SRSS) of the maximum plastic hinge rotations. Results of the study indicate that the nonlinear static analysis provides a fairly good estimate of the peak values of top-story displacements, inter-story drift ratio (for shorter frame), peak base shear and number of plastic hinges; however, the SRSS of maximum plastic hinge rotations in semi-rigid frames are considerably more in the nonlinear static analysis as compared to the nonlinear time history analysis.

• Earthquakes and Structures
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• v.16 no.5
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• pp.563-573
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• 2019

When generating spectrum-compatible artificial ground motion in engineering practices, the effect of the variation in fitting parameters on the distribution of the peak ground displacement (PGD) has not yet drawn enough attention. In this study, a method for simulating ground motion matching for multiple targets is developed. In this method, a frequency-dependent amplitude envelope function with statistical parameters is introduced to simulate the nonstationarity of the frequency in earthquake ground motion. Then, several groups of time-history acceleration with different temporal and spectral nonstationarities were generated to analyze the effect of nonstationary parameter variations on the distribution of PGD. The following conclusions are drawn from the results: (1) In the simulation of spectrum-compatible artificial ground motion, if the acceleration time-history is generated with random initial phases, the corresponding PGD distribution is quite discrete and an uncertain number of PGD values lower than the limit value are observed. Nevertheless, the mean values of PGD always meet the requirement in every group. (2) If the nonstationary frequencies of the ground motion are taken into account when fitting the target spectrum, the corresponding PGD values will increase. A correlation analysis shows that the change in the mean and the dispersion values, from before the frequencies are controlled to after, correlates with the modal parameters of the predominant frequencies. (3) Extending the maximum period of the target spectrum will increase the corresponding PGD value and, simultaneously, decrease the PGD dispersion. Finally, in order to control the PGD effectively, the ground motion simulation method suggested in this study was revised to target a specified PGD. This novel method can generate ground motion that satisfies not only the required precision of the target spectrum, peak ground acceleration (PGA), and nonstationarity characteristics of the ground motion but also meets the required limit of the PGD, improving engineering practices.

• The Journal of Korean Medical History
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• v.22 no.1
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• pp.47-55
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• 2009

The Sa-am acupuncture is the acupuncture method created during Chosun Dynasty. It is a unique acupuncture method that was created solely in Korea. Its theories are based on the 69th article of "Classic of Difficult Issues", or Nanjing (難經), which says "tonify its mother when deficiency occurs, and purgate its son when excess occurs" (虛則補其母, 實則瀉其子); the concept of "controlling the viscera which restrains the target" "抑其官" was added to this theory to form the principle of Sa-am acupuncture. It is significant that it turns to the basic principles of the Five Viscera and Six Bowels rather than the 體針 or 阿是針 of the existing acupuncure. Sa-am acupuncture was established in the middle of Chosun Dynasty and was popularized to the practitioners of Korean Medicine through transcripts and printed books. The medical books of at the time of Japanese imperialism that introduced Sa-am acupuncture are "經絡學總論", "舍岩鍼灸訣", "經濟要訣", "靑囊訣", "察病要訣", "濟世寶鑑", "經驗寢具編", and "舍岩 靑囊訣". The magazine that mentions the Sa-am acupuncture is "韓方醫藥". The books on Traditional Medicine that is related to Sa-am acupuncture were of great help in reconstruction of Sa-am acupuncture after the liberation of Korea and explaining the principle of Sa-am acupunture in various angles.

• Structural Engineering and Mechanics
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• v.69 no.3
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• pp.293-306
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• 2019

In current seismic design codes, various elastic design acceleration spectra are defined considering different seismological and soil characteristics and are widely used tool for calculation of seismic loads acting on structures. Response spectrum analyses directly use the elastic design acceleration spectra whereas time history analyses use acceleration records of earthquakes whose acceleration spectra fit the design spectra of seismic codes. Due to the fact that obtaining coherent structural response quantities with the seismic design code considerations is a desired circumstance in dynamic analyses, the response spectra of earthquake records used in time history analyses had better fit to the design acceleration spectra of seismic codes. This paper evaluates structural response distributions of multi-story reinforced concrete frames obtained from nonlinear time history analyses which are performed by using the scaled earthquake records compatible with various elastic design spectra. Time domain scaling procedure is used while processing the response spectrum of real accelerograms to fit the design acceleration spectra. The elastic acceleration design spectra of Turkish Seismic Design Code 2007, Uniform Building Code 1997 and Eurocode 8 are considered as target spectra in the scaling procedure. Soil classes in different seismic codes are appropriately matched up with each other according to $V_{S30}$ values. The maximum roof displacements and the total base shears of considered frame structures are determined from nonlinear time history analyses using the scaled earthquake records and the results are presented by graphs and tables. Coherent structural response quantities reflecting the influence of elastic design spectra of various seismic codes are obtained.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.48.4-49
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• 2017

We aim to trace cosmic mass accretion history of satellites around a dwarf galaxy in Lambda-CDM cosmology frame. Each satellite has a unique mass accretion history due to different environment, potential depth, and different merging events. We perform three different zoom simulations whose target galaxy has a mass of ${\sim}10^{10}Msun$, using ~17 million particles covering a cubic box of $1(Mpc/h)^3$. Here, individual particle masses for dark matter (DM) and gas are $M_{DM}=4.1{\times}10^3Msun$ and $Mgas=7.9{\times}10^2Msun$, respectively, and thus each satellite can be resolved with more than several hundreds of particles.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.3
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• pp.16-24
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• 2007

The high-frequency analysis method of back-scattering cross section spectrum of rotating targets is established. The time history of the back-scattering cross section is calculated using a quasi-stationary approach, based on a physical optics and a physical theory of diffraction, combining an adaptive triangular beam method to consider the shadow effect. And the spectra of back-scattering cross section by the Doppler effect are analyzed applying a simple fast Fourier transform method to its time history. The numerical calculation for rotating targets, such as rotating metal plates and underwater propeller, are carried out. The time history appears to be periodic with respect to the number of wings. The backscattering cross section spectrum level and its frequency shift are dependent on the rotating speed, direction, and the shape of the targets.