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        검색결과 55

        4.
        2019.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present the results of near-infrared imaging observations of the galaxy overdensity around the z = 1.44 radio-loud active galactic nucleus (AGN) 6CE1100+3505, which was carried out with the purpose of sampling the redshifted Hα emission from the actively star-forming galaxies that could constitute the overdensity. The existence of the structure around this AGN was spectroscopically confirmed by previous grism observations which are however limited to the central region. Using the CH4Off narrow/medium-band and H broad band filters in the Wide Infrared Camera (WIRCam) on the Canada-France-Hawaii Telescope (CFHT), we constructed a sample of objects that show a flux excess in the CH4Off band due to line emission. The emission line flux is ∼ 4.9 × 10−16 erg s−1 cm−2 , corresponding to a star formation rate (SFR) of ∼ 50 M⊙ yr−1 for galaxies at redshifts z ∼ 1.4. None of the galaxies with medium-band flux excess is located within 1 Mpc from the central AGN, and there is no evidence that the selected galaxies are associated with the proposed cluster. Along with the star formation quenching near the center that was found from the previous grism observations, the lack of extreme starbursts in the structure suggests that at z ∼ 1.4, overdense regions are no longer favorable locations for vigorous star formation.
        4,000원
        5.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study aimed to investigate rapid weight loss (RWL) and consequent physical and psychological challenges among judo athletes at the national athlete training center in 2017. The following results were obtained. Judo athletes used weight loss methods such as “gradually reduce meal portion,” “skip meals,” “limit water intake,” “wear sweat suit for training,” and “use sauna,” and had physical and mental distress from such unhealthy weight management practices. Information about weight loss was obtained from “colleagues or senior athletes,” “Internet,” and “head coach or coach,” and not experts such as nutritionists or physicians. Thus, athletes are recommended to employ healthy weight control methods based on advice from experts, such as nutritionists and physicians
        4,000원
        6.
        2018.04 구독 인증기관·개인회원 무료
        환경부 지정 보호지역인 특정도서는 현재 249개소로 이들을 대상으로 지형․경관, 지질, 식생, 동・식물상 및 해안무척 추동물, 해조류 분류군 대상으로 1차 특정도서기본계획(‘05~’14) 이후 2차 특정기본계획(‘15~’24)에 따라 매년 10~15개 씩 정밀조사가 수행되고 있다. 특정도서의 곤충조사는 2006~2008년 3년간 39개 도서를 제외하고 전무하였다. 특정도서 의 지정사유 중 자연경관․지질의 우수성이 가장 높고 식생이 우수가 다음으로 높아 시간이 지남에 따라 식생과 관련된 해충 및 외래종의 기착지로도 이용될 수 있는 특성을 가지고 있어 2015년부터 곤충에 대한 조사가 이루어지고 있다. 본 연구는 2016년 인천광역시 옹진군 일대 소초지도, 신도, 어평도, 항도, 뭉퉁도, 서만도, 할미염 7개 특정도서에 대한 곤충상 및 군집분석 결과와 각 도서별 과거 2007년 보고된 곤충상을 비교한 결과를 보고하는 바이다.
        7.
        2018.04 구독 인증기관·개인회원 무료
        Until now, 12 subspeceis of Eucarabus (Parhomopterus) sternbergi has been recorded in South Korea and some were described by foreign entomologist without comparative examination. In addition, most of them were not reviewed since the original description. Therefore, based on this study, all subspecies of this group in South Korea were revised taxonomically, and a new subspecific key was provided. As a result, 8 subspecies of Eucarabus (Parhomopterus) sternbergi were confirmed in South Korea and their new synonyms are as follows: Eucarabus (Parhomopterus) sternbergi sternbergi (Roeschke, 1898) = E. (P.) s. gimhwa (Rapuzzi, 2015); E. (P.) s. honamensis (Kwon et Lee, 1984) = E. (P.) s. jindoensis (Rapuzzi, 2015) = E. (P.) s. goheungicus (Rapuzzi, 2015); E. (P.) s. schnelli (Lassalle, 1999) = E. (P.) s. deogyusan (Rapuzzi, 2015).
        8.
        2017.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We study the angular correlation function of bright (Ks ≤ 19.5) Extremely Red Objects (EROs) selected in the Subaru GTO 2 deg2 field. By applying the color selection criteria of R − Ks > 5.0, 5.5, and 6.0, we identify 9055, 4270, and 1777 EROs, respectively. The number density is consistent with similar studies on the optical − NIR color selected red galaxies. The angular correlation functions are derived for EROs with different limiting magnitude and different R −Ks color cut. When we assume that the angular correlation function w() follows a form of a power-law (i.e., w() = A−), the value of the amplitude A was larger for brighter EROs compared to the fainter EROs. The result suggests that the brighter, thus more massive high-redshift galaxies, are clustered more strongly compared to the less massive galaxies. Assuming that EROs have redshift distribution centered at hzi ∼ 1.1 with z = 0.15, the spatial correlation length r0 of the EROs estimated from the observed angular correlation function ranges ∼ 6-10 h−1Mpc. A comparison with the clustering of dark matter halos in numerical simulation suggests that the EROs are located in most massive dark matter halos and could be progenitors of L∗ elliptical galaxies.
        4,000원
        10.
        2017.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Biodegradable epoxy (B-epoxy) was prepared from diglycidyl ether of bisphenol A and epoxidized linseed oil. The mechanical properties of B-epoxy composites reinforced with multi-walled carbon nanotubes (MWCNTs/B-epoxy) were examined by employing dynamic mechanical analysis, critical stress intensity factor (KIC) tests, and impact strength tests. The electromagnetic interference shielding effectiveness (EMI-SE) of the composites was evaluated using reflection and absorption methods. Mechanical properties of MWCNTs/B-epoxy were enhanced with an increase in the MWCNT content, whereas they deteriorated when the MWCNT content was >5 parts per hundred resin (phr). This can likely be attributed to the entanglement of MWCNTs with each other in the B-epoxy due to the presence of an excess amount of MWCNTs. The highest EMI-SE obtained was ~16 dB for the MWCNTs/B-epoxy composites with a MWCNT content of 13 phr at 1.4 GHz. The composites (13 phr) exhibited the minimum EMI-SE (90%) when used as shielding materials at 1.4 GHz. The EMI-SE of the MWCNTs/B-epoxy also increased with an increase in the MWCNT content, which is a key factor affecting the EMI-SE.
        4,000원
        11.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, a finite element analysis approach is proposed to predict the fluid-structure interaction behavior of active materials for lithium-ion batteries (LIBs), which are mainly composed of graphite powder. The porous matrix of graphite powder saturated with fluid electrolyte is considered a representative volume element (RVE) model. Three different RVE models are proposed to consider the uncertainty of the powder shape and the porosity. Pwave modulus from RVE solutions are analyzed based on the microstructure and the interaction between the fluid and the graphite powder matrix. From the results, it is found that the large surface area of the active material results in low mechanical properties of LIB, which leads to poor structural durability when subjected to dynamic loads. The results obtained in this study provide useful information for predicting the mechanical safety of a battery pack.
        4,000원
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