• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.5
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• pp.484-493
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• 2012

Since the 1980s, there have been many research activities devoted to quantitatively characterizing and imaging human tissues based on sound speed, attenuation coefficient, density, nonlinear B/A parameter, etc., but those efforts have not yet reached the stage of commercialization. However, a new imaging technology termed elastography, which was proposed in the early 1980s, has recently been implemented in commercial clinical ultrasound scanners, and is now being used to diagnose prostates, breasts, thyroids, livers, blood vessels, etc., more quantitatively as a complementary adjunct modality to the conventional B-mode imaging. The purpose of this article is to introduce and review various elastographic algorithms for use in quasistatic or static compression type elasticity imaging modes. Most of the algorithms are based on the crosscorrelation or autocorrelation function methods, and the fundamental difference is that the time shift is estimated by changing the lag variable in the former, while it is directly obtained from the phase shift at a fixed lag in the latter.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.76-76
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• 2021

물정보 중 가뭄 정보가 상대적으로 부족한 원인은 무엇을 가뭄으로 볼 것인지 정의하기 어렵기 때문이다. 특히 우리나라와 같이 댐 및 저수지, 광역상수도 등 수자원시스템 네트워크를 기반으로 물공급이 이루어지는 경우, 개별 요소만을 고려한 기존 가뭄모니터링 및 전망은 현실적이지 못하며, 가뭄 위험도 관리 측면에서도 부족한 부분이 있다. 가뭄 현상의 경우 기상학적 영향인 강수의 부족이 가장 큰 요소로 기여하지만 실질적으로 국민에 필요한 양보다 적은 양의 물이 공급될 때 국민들은 가뭄을 체감한다. 이러한 점을 보완하기 위하여 지역별로 사용하는 수원 및 물수급 시설 등을 세분화하고, 실적기반 분석을 통해 분석대상 지역의 가뭄을 정확히 판단하기 위한 합리적인 물수급 분석 모형 개발이 필요하다. 즉, 공간분석단위를 표준유역 단위 이하의 취방류 시설물을 기준으로 구성하고, 이들 시설물의 운영정보와 수문기상 빅데이터를 연계한 물순환 모형을 구현함으로써 댐, 저수지, 하천 등 다양한 수원을 가지는 유역 내 가용 수자원량을 준실시간 개념으로 평가하는 시스템의 개발이 필요하다. 본 연구에서는 하천을 중심으로 물수급 관련 수요·공급 시설의 위치를 절점으로 부여하고 연결하는 물수급 네트워크 알고리즘을 통해 빅데이터 기반 물수급 분석 모형을 개발하였다. 주요 모니터링 지점 및 모든 이수 시설의 위치를 유역분석 기법을 통하여 점(point), 선(line), 면(shape)으로 구성된 지형공간정보의 위상(topology) 관계를 설정하여 물수급 분석의 계산순서를 선정하고, 시계열 DB를 입력하여 지점별 물수급 분석 결과를 도출하였다. 권역별 주요 수위-유량관측소 1:1 Nash 계수를 검증한 결과 저유량에서 0.8 이상의 높은 재현 성능을 보이는 것으로 나타났다. 이에 따라 본 연구에서 개발된 물수급 분석 모형은 향후 물관련 이슈 지역의 용수공급능력 평가 및 수자원장기종합계획 등 다양한 수자원 정책평가에 활용될 것으로 기대된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1D
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• pp.45-55
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• 2008

The objective of this research was to develop a VEPCD (ViscoElastoPlastic Continuum Damage) Model which is used to predict the behavior of asphalt concrete under various loading and temperature conditions. This paper presents the VEPCD model formulated in a tension mode and its validation using four hot mix asphalt (HMA) mixtures: dense-graded HMA, SBS, CR-TB, and Terpolymer. Modelling approaches consist of two components: the ViscoElastic Continuum Damage (VECD) mechanics and the ViscoPlastic (VP) theory. The VECD model was to describe the time-dependent behavior of HMA with growing damage. The irrecoverable (whether time-dependent or independent) strain has been described by the VP model. Based on the strain decomposition principle, these two models are integrated to form the VEPCD model. For validating the VEPCD model, two types of laboratory tests were performed: 1) a constant crosshead strain rate tension test, 2) a fatigue test with randomly selected load levels and frequencies.

• Journal of Advanced Navigation Technology
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• v.27 no.5
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• pp.580-586
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• 2023

AESA radar is able to instantaneously and adaptively position and control the beam, and this enables to greatly improve multi-target tracking capability with high accuracy in comparison to traditional mechanically-scanned radar system. This paper is primarily concerned with the development of an efficient methodology for multi-target managenent with the context of multi-target environment employing AESA radar. In this paper, targets are stratified into two principal categories: currently displayed targets and non-display targets, predicated upon their relative priority. Displayed targets are subsequently stratified into TOI (target of interest), HPT (high priority target), and SAT (situational awareness target), based on the requisite levels of tracking accuracy. It also suggests rules for determining target priority management, especially in air-to-air mode including interleaved mode. This proposed approach was tested and validated in a SIL (system integration lab) environment, applying it to AESA radars mounted on aircraft.

• The Journal of Korean Philosophical History
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• no.35
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• pp.73-108
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• 2012

Researches about the Horaknonjaeng(湖洛論爭) have succeeded by focusing on the Osangnonbyeon(五常論辨)?Mibalnonbyeon(未發論辨). In a way of these researches, philosophic thought of Gwon Sangha(權尙夏) is dealt in a comparison and in that process his philosophic thought seems to be known. However, these researches are treating several thoughts so it is difficult to find accurately what point describes the position of his thought in the korean confucian thought as origin of Hohak(湖學). In this paper, therefore, I examine Gwon Sangha's theory of mind-nature by focusing on the understanding the concept of mind-nature in Hansujaejib(寒水齋集) and find its position in history of thought as an origin of forming Hohak. Before 1709, Horaknonjaeng don't break out, Gwan Sangha had been formed that Inmulseongsangi(人物性相異) of Osangpyeonjeon(五常偏全) based on the understanding of the fact that ensuring of Bonyeonjiseong(本然之性 性善) in Gijiljiseong(氣質之性) and under this influence scholars of Hohak formed thoughts and insisted Osangpyeonjeon(五常偏全 人物性相異) during Horaknonjaeng. In the point of Simseongilmul(心性一物) focusing on nature, he didn't admit the Jujaeseong(主宰性) of mind. This is the efforts of finishing the controversy of Simseongigi(心性二岐) and the efforts of finding the relation between Simseon(心善). Such thoughts are set before the Horaknonjaeng and basing on these influences, scholars of Hohak formed their thoughts and insisted the Gibulyongsa(氣不用事 未發氣質有善惡).

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.159-168
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• 2022

Catalytic activity in ammonia decomposition reaction was studied on Mo-Al nitride obtained through temperature programmed nitridation of calcined Mo-Al mixed oxide prepared by varying the MoO₃ quantity in the range of 10-50 wt%. N₂ sorption analysis, X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS) and H₂-temperature programmed reduction (H₂-TPR), and transmission electron microscopy (TEM) to investigate the physicochemical properties of the prepared catalyst were performed. After calcination at 600 ℃, the XRD of Mo-Al oxide showed γ-Al₂O₃ and Al₂(MoO₄)₃ phases, and the nitride after nitridation showed an amorphous form. The specific surface area after nitridation by topotactic transformation of MoO₃ to nitride was increased due to the formation of Mo nitride, and the Mo nitride was observed to be supported on γ-Al₂O₃. As for the catalytic activity in the ammonia decomposition reaction, 40 wt% MoO₃ showed the best activity, and as the nitridation time increases, the activity increased, and thus the activation energy decreased.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.1
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• pp.10-21
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• 2009

Muan Bay has extensively undertaken artificial influences through a series of construction of dams and dykes nearby resulting in a substantial increase in highest high water level. To unravel sedimentary responses to the water level rise, we collected a number of surface sediment samples and hydrodynamic data from in-situ observations of tidal currents in Muan Bay in 1998 and 2007. Comparison of the data between 1998 and 2007 shows that the relative content of coarse fractions, sand and gravel, in the sediment samples has increased with a decreased mean size, on average, from 6.2 to 5.8${\phi}$ at the expense of silt contents. Such a coarsening trend, which is more evident around high water level, particularly on the tidal flats of Dongam-ri, Guro-ri and Aphae-do, is most likely attributable to rising water level. On the other hand, an increase of fine fractions locally in the western entrance of the bay can be explained with changes in characteristics of tidal currents imposed by construction of bridges therein, such as decreased velocities and varied direction and phase of the tidal currents.

• 한국지구물리탐사학회:학술대회논문집
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• 2000.09a
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• pp.54-69
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• 2000

There are groundwater trouble by high-salinity yield inducing sea-water intrusion in Cheju Island. It is used groundwater-GIS(Well-lnfo) in the maintenance and management of groundwater in Cheju Island to grasp groundwater trouble area and cause of high-salinity yield. For 16 wells certain to yield high-salinity, we logged specific electrical conductivity(EC) and tried to get hold of freshwater and saltwater relationship. As result of distribution of $Cl^-$ by depth, it is showed up groundwater trouble by high-salinity yield in the east coastal area and the partly north coastal area. The reason of high-salinity groundwater yield are low-groundwater level by the structure of geology and low-hydraulic gradient etc. There is necessity for management to development and use of groundwater in the high-salinity area, special management area.

• Archives of design research
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• v.17 no.2
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• pp.311-322
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• 2004

The purpose of this study is to ascertain pattern design element in traditional palaces among those in the neighboring three nations of East Asia, notably Korea, China and Japan. The basic assumption underlying this study is that these northeastern Asian states have been developed a unique inter-cultural ties over long periods of time in history, culminating in their respective design cultures. Undoubtly the ultimate goal to be pursued, by so doing, has to be inquiry into the identical prototype of Korean pattern design element. In the West, the pattern is appreciated by an aesthetic level, but the East Asian pattern is a symbolic alphabet deeply rooted in religious and folk beliefs. The difference of the respective country comes from the expression style of the pattern the Chinese express the magnificent pattern with various color, the Korean do the moderate pattern with harmonious color with the nature and the Japanese do the stylized pattern with the material color. To sum up similarities and dissimilarities among the design element in traditional palaces of Korea, China, and Japan is as the following : It is to be noticed that the mainly common characteristics of the artistic design are 'naturalism', 'harmonious ideas 'and 'confucianism'. But the representation style of the design element is differed from the country.

• The Journal of Korean Philosophical History
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• no.31
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• pp.241-262
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• 2011

In this paper we show how the perception of heavenly principle(天理) and definition of individual desires(私慾) in the five commentaries on Daodejing(道德經) was changed over time. The five commentaries on Daodejing(道德經) composed during $Chos{\breve{o}}n$ are 'Sooneon(醇言) by Lee, Yul-gock (李珥,1536~1584), 'SinJoo-DoDuckKyung (新註道德經) - or New Commentary on Daodejing(道德經) - by Park, Se-dang(朴世堂,1629~1703), 'Dodukjigi(道德指歸)' by Suh, Myoung-euing(徐命膺,1716~1787), 'Chowondamro (椒園談老)' by Lee, Chung-ik(李忠翊,1744~1816), and 'Jungro(訂老)' by Hong, Suk-joo (洪奭周,1774~1842). The course of history in understanding the book, "Daodejing(道德經)," demonstrated that by the late of $Chos{\breve{o}}n$ Dynasty in the 18th century, the notion of 'the moral law for the community' has changed. Neither Suh, Myoung-euing nor Lee, Chung-ik emphasized 'the necessity for the truth of the heavens.'Instead, they focused more on the 'individuals' who followed the moral law than the moral law itself. They did not see the individual desire as the object that had to be discarded. Within the context of this framework, the individual's role had changed from the person who had to be obedient to the law to the subject who judged the moral law all by him/herself. This process of breaking up 'the goodness of the community' led the $Chos{\breve{o}}n$ Dynasty of the 18th century in the transition period to the modern era. In other words, it was the time when the introspection of the 'moral law' prevailed in the $Chos{\breve{o}}n$ Dynasty occurred naturally and spontaneously among the Confucian scholars, which implied the reconceptualization of the 'self-awareness' or 'the point of view on the individual's self-desire' was occurred in the context of academic development during the late $Chos{\breve{o}}n$ Dynasty.