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        검색결과 592

        241.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope (UKIRT), of the Local Group galaxy M33. The main aim was to identify stars in the very nal stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less-evolved giant stars that continue to increase in luminosity. The pulsating giant stars (AGB and red supergiants) are identified and their distributions are used to derive the star formation rate as a function of age. These stars are also important dust factories; we measure their dust production rates from a combination of our data with Spitzer Space Telescope mid-IR photometry. The mass-loss rates are seen to increase with increasing strength of pulsation and with increasing bolometric luminosity. Low-mass stars lose most of their mass through stellar winds, but even super-AGB stars and red superginats lose ~40% of their mass via a dusty stellar wind. We construct a 2-D map of the mass-return rate, showing a radial decline but also local enhancements due to agglomerations of massive stars. By comparing the current star formation rate with total mass input to the ISM, we conclude that the star formation in the central regions of M33 can only be sustained if gas is accreted from further out in the disc or from circum-galactic regions.
        3,000원
        242.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        빅토리아 시대 영국은 변화와 역설의 시기였다. 왜냐하면 과학과 기술과 관련하여 발전과 업적을 이루었지만, 동시에 서로 상반되는 생각들이 공존하는 시기였기 때문이다. 예를 들어 이 당시엔 물질주의와 반물질주의, 세속화와 영성, 과거와 현재 등이 복잡하고 미묘하게 서로 얽여 있는 시대였다. 한편으로 문명과 삶이 계속해서 발전해나갈 것이라는 낙관론이 있었지만, 동시에 퇴보라는 생각도 공존하였다. 특별히 챨스 다윈의 󰡔종의 기원󰡕이라는 책은 아마도 새로운 세상, 그리고 발전과 진보라는 희망을 상징할 것이다. 그러나 사람들은 그러한 희망 안에서 퇴보라는 느낌도 겪어야 했다. 토마스 하디의 󰡔비천한 주드󰡕라는 작품을 보면, 주드와 슈라는 두 등장인물 안에서 그러한 측면을 찾을 수 있을 것이다. 따라서 본 논문은 특별히 이 두 등장인물을 통해서 다뤄지는 종교와 여성의 문제에 관하여 빅토리아 시대의 문맥 안에서 이 작품을 고찰하고자 한다. 두 인물은 교육과 여성성과 관련하여 나름대로의 새로운 정체성을 확립하려고 노력하지만, 결국엔 실패로 돌아간다. 그들의 실패는 하디의 비관론적 차원에서 퇴보를 암시한다.
        5,200원
        243.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In our previous work, we investigated the orbital dynamics of Asteroid 1934 CT (or 1989 AC or 4179 Toutatis) from epoch 2012-Jul-24 (JDE2456132.5) using the Mercury program package. Asteroid 4179 Toutatis has an Earth and Mars crossing orbit with semimajor axis a = 2.5292 AU and eccentricity e = 0.6294, and therefore the perihelion distance is q = 0.9373 AU and the aphelion distance is Q = 4.1211 AU. After more than 300,000 years, asteroid 4179 Toutatis will escape from the Solar System, but during this time, it will have close-encounters with other planets from Venus to Uranus. As a continuation of this project, we investigated its energy changes in each close encounter. We also determine the energy of this asteroid when it escapes from the Solar System. The result is that during its orbital evolution, the energy of this asteroid changes and gives us negative, zero and positive values.
        3,000원
        244.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As a macroscopic research for the interaction of mobile game platform, I have analyzed the differentiation & characteristic of interaction for each platform. ‘Game & Watch’ was the first handheld game console released by Nintendo in 1980, the initial model was merely a combination of clock and game consoles to emphasize mobility. However, ‘Game&Watch:DonkeyKong’ which equipped with Yokoi Gunpei’s cross key provided an opportunity for the development of a full-fledged multi-screen gaming. ‘GameBoy’ was the beginning of a portable game machine in the modern sense. It has brought a lot of changes for the gameplay pattern using the contrast of color, smooth animation, as well as interchangeable cartridge system. Also, ‘NDS(Nintendo DS)’, which had several interaction system such as dual screen, voice input and touch input, had contributed to expanding the emergence of innovative game content and women game users. ‘PSP(Playstation Portable)’ by SONY in 2004 materialized 3D games using high performance and progressed to multimedia platform.
        4,000원
        245.
        2015.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The Horizon Run 4 is a cosmological N-body simulation designed for the study of coupled evolution between galaxies and large-scale structures of the Universe, and for the test of galaxy formation models. Using 63003 gravitating particles in a cubic box of Lbox = 3150 h−1Mpc, we build a dense forest of halo merger trees to trace the halo merger history with a halo mass resolution scale down to Ms = 2.7 × 1011h−1M⊙. We build a set of particle and halo data, which can serve as testbeds for comparison of cosmological models and gravitational theories with observations. We find that the FoF halo mass function shows a substantial deviation from the universal form with tangible redshift evolution of amplitude and shape. At higher redshifts, the amplitude of the mass function is lower, and the functional form is shifted toward larger values of ln(1/σ). We also find that the baryonic acoustic oscillation feature in the two-point correlation function of mock galaxies becomes broader with a peak position moving to smaller scales and the peak amplitude decreasing for increasing directional cosine μ compared to the linear predictions. From the halo merger trees built from halo data at 75 redshifts, we measure the half-mass epoch of halos and find that less massive halos tend to reach half of their current mass at higher redshifts. Simulation outputs including snapshot data, past lightcone space data, and halo merger data are available at http://sdss.kias.re.kr/astro/Horizon-Run4.
        4,900원
        246.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Korea's modern waterworks began with construction of DDukdo water treatment plant in 1908 and has been growing rapidly along with the country’s economic development. As a result, water supply rates have reached 98.5% based on 2013. Despite multilateral efforts for high-quality water supply, such as introduction of advanced water treatment process, expansion of waterworks infrastructure and so on, distrust for drinking tap water has been continuing and domestic consumption rate of tap water is in around 5% level and extremely poor comparing to advanced countries such as the United States(56%), Japan(52%), etc. Recently, the water management has been facing the new phase due to water environmental degradation caused by climate change, aging facilities, etc. Therefore, K-water has converted water management paradigm from the "clean and safe water" to the "healthy water“ and been pushing the Smart Water City(SWC) Pilot Project in order to develop and spread new water supply models for consumers to believe and drink tap water through systematic water quality and quantity management combining ICT in the whole water supply process. The SWC pilot projects in Pa-ju city and Go-ryeong county were an opportunity to check the likelihood of the "smart water management" as the answer to future water management. It is needed to examine the necessity of smart water management introduction and nationwide SWC expansion in order to improve water welfare for people and resolve domestic & foreign water problems.
        4,000원
        247.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        2년마다 실시되는 UN의 전자정부시스템 평가에서 한국의 전자정부 시스템은 2010, 2012, 2014년 3차례 걸쳐 1위로 평가되었다. 1978년 시작되어 이제는 해외로 수출까지 되는 한국 전자정부 시스템의 진화에 있어서 표준의 역할에 대해서는 그다지 알려진 바가 없 다. 한국의 전자정부 시스템 발전에 어떠한 표준들이 어떠한 역할을 수행했으며, 이러한 표 준이 제대로 기능하기 위하여 어떠한 제반 환경이 필요하고, 어떠한 노력이 경주되었는지 사 례 연구를 수행하여 밝히고자 한다. 행위자 연결망 이론(Actor Network Theory)과 구조화 이론(Structuration theory)을 이론적 기반으로 하여, 표준이 행위자 연결망 이론 관점에서 어떠한 역할을 수행해 왔는지를 전자정부 시스템 발전에 직접 관여되었던 행정자치부 전자 정부담당 현/전직 관리자급 공무원, 표준담당관, NIA 표준 담당관, 민간 SI 업체 등 관련 전 문가(관리자급)분들과의 인터뷰와 문헌 연구를 바탕으로 사례 분석을 실시하고자 한다.
        5,800원
        248.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        근대 유럽 지도에 나타난 한국 관련 지리정보는 중국이 「황여전람도(皇輿全覽圖)」를 발간하고 이 지도가 당빌에 의해유럽에 번역‧소개되면서 질적·양적으로 증가하게 된다. 이후 18세기말부터 프랑스, 영국 및 러시아 등에 의한 해안 및 수로조사결과가 반영되면서 한반도 모양을 비롯한 지리정보의 양과 질이 풍부해지는 계기가 된다. 특히 서양 탐사선에 의한 해안선 및도서지역 탐사는 선박의 국적에 따라 그 나라 언어로 지명을 부여하는 것으로 분석되었다. 초기에 중국어 발음으로 표기되던 우리나라와 관련된 지명은 김대건 신부에 의해 한국어 발음의 프랑스어로 제작된 「조선전도」가 유럽으로 전파된 시점을 기해각국의 지도에 반영되기 시작한 것으로 보이며 이는 1872년의 스틸러의 지도에서 대부분 우리나라 발음으로 지명이 표기된 사실을 통해 확인할 수 있다. 영어식 표현의 확산은 일본주재 외교관이었던 어네스트 사토우와 「한반도 산맥도」를 저술한 고토분지로의역할이 컸던 것으로 확인된다.
        4,500원
        249.
        2015.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this study, nitrogen ions were implanted into STS 316L austenitic stainless steel by plasma immersion ion implantation (PIII) to improve the corrosion resistance. The implantation of nitrogen ions was performed with bias voltages of −5, −10, −15, and −20 kV. The implantation time was 240 min and the implantation temperature was kept at room temperature. With nitrogen implantation, the corrosion resistance of 316 L improved in comparison with that of the bare steel. The effects of nitrogen ion implantation on the electrochemical corrosion behavior of the specimen were investigated by the potentiodynamic polarization test, which was conducted in a 0.5 M H2SO4 solution at 70 oC. The phase evolution and texture caused by the nitrogen ion implantation were analyzed by an X-ray diffractometer. It was demonstrated that the samples implanted at lower bias voltages, i.e., 5 kV and 10 kV, showed an expanded austenite phase, γN, and strong (111) texture morphology. Those samples exhibited a better corrosion resistance.
        4,000원
        250.
        2015.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study is about the change of multi-storied buildings in Hanyang, the capital city of Joseon Dynasty. The changes are divided into 3 phases in the viewpoint of architectural types and building types. The first phase is from the early Joseon Dynasty to the time of Japanese invasion to Korea and Sungryemun remains until now. The second phase is from 1592 to the the first half of the 18th century. Many multi-storied Buddhist halls were rebuilt at that time. In the final phase, many multi-storied gate buildings and multi-storied main buildings of palaces were rebuilt. And there are differences between the Buddhist buildings and the main buildings of palaces. By the way the change that architectural style of the Buddhist buildings and the main buildings of pal were switched and mixed occurred. For example, Anguksa Daeungjeon adopted the style of multi-storied gates and Injeongjeon adopted the style of multi-storied Buddhist halls. These phenomenon was result from periodical situation the monk carpenter and his disciple took part in governmental construction like Janganmun.
        4,500원
        251.
        2015.05 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In-situ neutron diffraction has been employed to examine the effect of strain path on lattice strain evolution during monotonic and cyclic tension in an extruded Mg-8.5wt.%Al alloy. In the cyclic tension test, the maximum applied stress increased with cycle number. Lattice strain data were acquired for three grain orientations, characterized by the plane normal to the stress axis. The lattice strain in the hard {10.0} orientation, which is unfavorably oriented for both basal slip and {10.2} extension twinning, evolved linearly throughout both tests during loading and unloading. The {00.2} orientation exhibited significant relaxation associated with {10.2} extension twinning. Coupled with a linear lattice strain unloading behavior, this relaxation led to increasingly compressive residual strains in the {00.2} orientation with increasing cycle number. The {10.1} orientation is favorably oriented for basal slip, and thus showed a soft grain behavior. Microyielding occurred in the monotonic tension test and in all cycles of the cyclic test at an applied stress of ~50 MPa, indicating that strain hardening in this orientation was not completely stable from one cycle to the next. The lattice strain unloading behavior was linear in the {10.1} orientation, leading to a compressive residual strain after every cycle, which, however, did not increase systematically from one cycle to the next as in the {00.2} orientation.
        4,000원
        252.
        2015.05 구독 인증기관·개인회원 무료
        Currently there are two main categories of soft contact lens materials available in the market namely hydrogels and silicone hydrogels. This article provides a summary of the pros and cons of these materials and suggests a new type of material that could be a new direction for material development moving forward. Hydrogel lenses are biocompatible, hydrophilic, comfortable to wear, and have excellent optical properties. However, the oxygen transmissibility (Dk/t) of hydrogel lenses is limited by its water content and the lens thickness. A higher percentage of water will provide greater oxygen transmissibility but high water content materials are also more prone to dehydration. Silicone hydrogels (Si-hys) were first introduced in 1999. Silicone was added to hydrogel to increase the oxygen permeability and eye care professionals had hoped that this material can resolve most of the issues related to contact lens wear. Si-hys have offered multiple times increase in Dk/t over hydrogels, but they have not reduced the incidence of microbial keratitis nor contact lens drop-out rate. In addition, si-hys are not perfect for every patient, they are generally stiffer (with higher modulus) and are more likely to induce ocular complications due to its mechanical properties. Si-hy lenses are also associated with lens surface issues and an increased risk of infiltrative events. The addition of silicone does not seem to be without problems. Si-hy is an important step, but not a big leap and definitely not the only choice for our patients. A new material called Hypergel was developed using the concept of bio-inspiration. Scientists have learnt from the eye and applied three bio-inspired features to make the material works like the eye. Firstly, hypergel has 78% of water content and that matches the water content of the cornea. Secondly, it meets the oxygen level the open eye needs to maintain healthy white eyes. Thirdly, it mimics the lipid layer of the tear film to prevent dehydration. Without the addition of silicone, this material can meet the oxygen need of the open eye and can resist dehydration.
        253.
        2015.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We carry out three-dimensional hydrodynamic simulations of the supernova remnants (SNRs) produced inside molecular clouds (MCs) near their surface using the HLL code (Harten et al. 1983). We explore the dynamical evolution and the X-ray morphology of SNRs after breaking through the MC surface for ranges of the explosion depths below the surface and the density ratios of the clouds to the intercloud media (ICM). We find that if an SNR breaks out through an MC surface in its Sedov stage, the outermost dense shell of the remnant is divided into several layers. The divided layers are subject to the Rayleigh-Taylor instability and fragmented. On the other hand, if an SNR breaks through an MC after the remnant enters the snowplow phase, the radiative shell is not divided to layers. We also compare the predictions of previous analytic solutions for the expansion of SNRs in stratified media with our one- dimensional simulations. Moreover, we produce synthetic X-ray surface brightness in order to research the center-bright X-ray morphology shown in thermal composite SNRs. In the late stages, a breakout SNR shows the center-bright X-ray morphology inside an MC in our results. We apply our model to the observational results of the X-ray morphology of the thermal composite SNR 3C 391.
        4,900원
        258.
        2014.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Microstructural evolution in the thickness direction of an oxygen free copper processed by accumulative rollbonding (ARB) is investigated by electron back scatter diffraction (EBSD) measurement. For the ARB, two copper alloy sheets 1 mm thick, 30 mm wide and 300 mm long are first degreased and wire-brushed for sound bonding. The sheets are then stacked and roll-bonded by about 50% reduction rolling without lubrication at an ambient temperature. The bonded sheet is then cut to the two pieces of the same dimensions and the same procedure was repeated on the sheets up to eight cycles. The specimen after 1 cycle showed inhomogeneous microstructure in the thickness direction so that the grains near the surface were finer than those near the center. This inhomogeneity decreased with an increasing number of ARB cycles, and the grain sizes of the specimens after 3 cycles were almost identical. In addition, the aspect ratio of the grains decreased with an increasing number of ARB cycles due to the subdivision of the grains by shear deformation. The fraction of grains with high angle grain boundaries also increased with continuing process of the ARB so that it was higher than that of the low angle grain boundaries in specimens after 3 cycles. A discontinuous dynamic recrystallization occurred partially in specimens after 5 cycles.
        4,000원
        259.
        2014.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        탈추격형 혁신체제가 강조됨에 따라 국가연구개발사업은 기술역량 향상에 초 점을 맞춰온 기존의 방식과 달리 문제해결⋅실용화⋅사회적 영향을 모두 아우른 통합적 접 근을 필요로 한다. 이러한 상황에서는 R&D예산의 효과적⋅효율적 집행과 성과관리가 중요 한 과제이나, 기존의 성과평가제도는 획일적 평가, 양적지표 위주 등으로 인해 한계를 가지 고 있다. 본 연구에서는 이러한 문제점에 대응하기 위해 우리나라의 국가연구개발사업 성과 평가의 진화과정을 조사⋅분석⋅평가 체제와 1,2차 성과평가기본계획 체제 세 시기로 나누 어 제반 법⋅제도, 평가체제 및 내용, 평가의 활용 등의 요소를 비교분석하였다. 성과평가제도는 조사⋅분석⋅평가에서 1차 기본계획, 2차 기본계획으로 이행되면서 R&D자원 투입에 따른 양적 성과관리 위주에서 연구사업의 다각적 측면을 평가하기 위한 수단으로 진화하였다. 그 과정에서 평가인프라, 표준성과지표 등 평가체계의 고도화⋅실효성을 제고하기 위한 제도적 장치가 다수 마련되었다. 1차 기본계획에서는 과학기술행정체 계의 잦은 개편이 성과평가 진화의 일관성에 영향을 미쳤으나, 2차 기본계획 이후 체계가 안정화되면서 성과평가제도는 우리나라 혁신시스템 전환을 뒷받침할 수 있는 방향으로 개 선되고 있다.
        8,100원