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        검색결과 585

        45.
        2022.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 2019년에서 2021년까지, 매년 2월에서 5월 동안 대전광역시 6개 지점(기준지역 1곳 포함)의 기 온 데이터를 바탕으로 COVID-19로 인한 인간 활동의 감소가 대전 지역의 도시열섬강도에 미친 영향에 대하여 분석하 였다. 관측 지점에 따라 차이는 있으나 도시열섬강도는 COVID-19 전인 2019년에 비해 2020년과 2021년에 약 20% 이상 감소되었다. 인간 활동 감소는 야간의 도시열섬을 증가시키고 주간의 도시열섬을 감소시켰다. 그 결과 도시열섬강 도의 일변동 폭은 지점에 관계없이 2019년에 비해 2020년 및 2021년 모두 약 20% 이상 증가하였다. 도시열섬강도 감 소는 풍속과 같은 자연적 요인 및 사회적 거리두기 단계와는 큰 관련성이 없는 것으로 보인다. 반면에 COVID-19 이후 시행된 사회적 거리두기 및 확연히 감소된 대기오염물질과 관계가 있는 것으로 나타났으며, 특히 NO2와 가장 유의미한 상관관계를 보였다.
        4,300원
        46.
        2022.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        화석연료의 사용에 따른 지구 온난화 및 기상 이변으로 인하여 온실가스 저감 문제가 대두되고 있으며, 그에 따 라 에너지 소모 없이 셀프 쿨링이 가능한 소재에 대한 연구가 활발히 진행되고 있다. 그 중에서도 실크는 천연 쿨링 소재로 알려져 있으나, 기존의 혼합 공정에서는 실크를 화학적으로 분말화 시키기 때문에 복사 냉각 효과가 사라지는 문제점이 있어, 복사냉각을 위한 필름 또는 코팅제 형태로 제조하는데 어려움을 겪고 있다. 본 연구에서는 실크 피브로인의 고유구조를 훼손 하지 않는 물리적 분쇄 공정을 거친 실크 분말을 사용하여 다양한 형태의 막을 제조하고, 코팅제로서의 적용가능성을 살펴보 고자 연구를 수행하였다. 이를 위해 실크 피브로인 분말이 도입된 전기방사 복합막 및 평막 형태의 복합막을 제조하였으며, 용액의 점도가 막 제조 및 제조된 막의 물성에 큰 영향을 미치는 것을 관찰하였다.
        4,000원
        47.
        2022.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Powder flowability is critical in additive manufacturing processes, especially for laser powder bed fusion. Many powder features, such as powder size distribution, particle shape, surface roughness, and chemical composition, simultaneously affect the flow properties of a powder; however, the individual effect of each factor on powder flowability has not been comprehensively evaluated. In this study, the impact of particle shape (sphericity) on the rheological properties of Ti-6Al-4V powder is quantified using an FT4 powder rheometer. Dynamic image analysis is conducted on plasma-atomized (PA) and gas-atomized (GA) powders to evaluate their particle sphericity. PA and GA powders exhibit negligible differences in compressibility and permeability tests, but GA powder shows more cohesive behavior, especially in a dynamic state, because lower particle sphericity facilitates interaction between particles during the powder flow. These results provide guidelines for the manufacturing of advanced metal powders with excellent powder flowability for laser powder bed fusion.
        4,200원
        48.
        2022.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근에는 경량화 문제에 대한 합리적인 솔루션을 제공하고 유용한 개념설계를 제공할 수 있는 다중 재료 구조 위상최적화가 더욱 중요해지고 있다. 기존의 MMTO(Multi-Material Topology Optimization)의 경우 후보 물질의 수가 증가할수록 설계변수의 수도 증가 하고, 결과적으로 계산 시간이 크게 증가한다. 따라서 PSM(Phase Section Method)과 같은 단일 설계변수를 갖는 MMTO가 제안되었 다. 본 연구는 조성비가 면적이나 부피비를 나타내지 못하고, 설계변수가 목표치에 충분히 집중되지 않고, 특정 재료가 요구량보다 적 게 생성되는 PSM의 세 가지 주요 제한점을 고려하여 이를 개선하는데 중점을 둔다. 이러한 한계를 극복하기 위해 재정의된 조성비와 더 나은 수렴을 위한 조정된 매개변수를 제안한다. 제안된 수정 사항의 유효성을 2차원 및 3차원 수치 예제를 통해 검증한다.
        4,000원
        50.
        2022.03 구독 인증기관 무료, 개인회원 유료
        Republic of Korea has both criminal penalty and punitive damages as a remedy for willful infringement of patent rights after the revision of the Patent Act in 2018. The statutory sentence for willful patent infringement, especially imprisonment, has been enacted since 1961, and the sentence has increased, but statistics over the past 13 years show that the application from the prosecution stage to the judgment is extremely insignificant. Even in the one case in which the prison sentence was ordered, it was necessary to apply doctrine of equivalent, and it is difficult to show the clarity required by the principle of legality, which shows circumstantial evidence that raises doubts about the necessity and justification of the imprisonment against willful patent infringement. Punitive damages is a system that has a punitive function and a deterrent and preventive function of the infringer’s actions, and can perform the same function as the imprisonment against infringement. The United States, Taiwan, China, Canada, Australia and the Philippines, which have punitive damages, do not have criminal penalties for willful infringement. Republic of Korea is the only country that has both criminal penalties and punitive damages for willful patent infringement. For the development of science and technology and economic development, published patents must be used in various ways throughout society. Due to its nature, it is desirable for the regulation and coordination of the country in the field of science and technology to intervene only to the extent of supplementing it while respecting individual autonomy and creativity as much as possible. The purpose of the Patent Act lies in technological innovation and industrial development, and although it is a willful infringement, punishing patent infringers as imprisonment or threatening them can be an act of cutting off the buds of technological innovation in advance. It would be desirable to perform remedies for patent infringement as compensatory damages, and punishment and prevention for willful infringement through punitive damages.
        5,200원
        51.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study examines the effects of different cooking methods (stir-frying, steaming, superheated-steaming) on the contents and the true retention of moisture, water-soluble vitamins, and bioactive compounds of ten selected vegetables: broccoli, brussels sprout, cabbage, eggplant, green bean, onion, red cabbage, red onion, squash, and tomato. The total color difference (ΔE) values were decreased after stir-frying the samples, except for eggplant, green bean, and tomato. The true retention of water-soluble vitamins (B1, B2, B3, and C) was increased in most vegetables after superheated-steaming, as compared to steaming and stir-frying. Moreover, compared to the uncooked vegetables, a higher true retention of total polyphenol and flavonoid was obtained for most vegetables subsequent to superheated-steaming. Total anthocyanin content was detected only in eggplant, red cabbage, and red onion, and a smaller loss of anthocyanin was determined after subjecting red cabbage to superheated-steaming. Also, the free radical scavenging activities were higher in superheatedsteaming vegetables, except in eggplant and squash. These results indicate that superheated-steaming induces a positive effect for retaining water-soluble vitamins and functional components of vegetables.
        4,600원
        52.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 2021년 2월부터 7월까지 잡곡 106건을 수거 하여 잔류농약 실태조사를 하였다. 대형, 중소형 및 온라 인 유통매장을 중심으로 국내 잡곡 40건과 수입 잡곡 66 건을 수거하였고, GC/MSMS, GC/ECD, GC/NPD, LC/ MSMS, UPLC/PDA, HPLC/FLD를 이용하여 다종농약 다 성분분석법으로 잔류농약 341종을 분석하였다. 잔류농약 이 검출된 잡곡은 대형유통매장 1건, 중소형 유통매장 2 건, 온라인 유통매장 5건으로 총 8건(7.5%)이었고, 5건 (4.7%)에서는 농약잔류허용기준을 초과하였다. 이들 잡곡 에서는 MGK-264, chlorpyrifos, thiamethoxam, malathion, piperonyl butoxide, pirimiphos-methyl 등 6종의 농약 성분 이 검출되었다. 검출된 잡곡은 강낭콩(1건), 녹두(6건), 수 수(1건)이다. 검출된 잡곡 중 농약잔류허용기준을 초과한 품목은 수입 녹두(5건)로 미얀마산이었고, 초과한 농약 성 분은 thiamethoxam이었다.
        4,000원
        53.
        2021.12 구독 인증기관 무료, 개인회원 유료
        4,000원
        54.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Aster koraiensis Nakai (A. koraiensis) which has been used as a food and medicinal plant in the past, is valuable as functional food material. Therefore, the aim of this study was to determine the antioxidant properties and major phenolics of A. koraiensis extracts with different ethanol concentrations (0, 50, 70, and 100% aqueous ethanol solution). When ethanol concentration in the extraction solvent was increased, extraction yield decreased; 34.2, 23.2, 21.0, and 5.5% in 0, 50, 70, and 100% ethanolic extracts, respectively. Total phenolics content and antioxidant activities of extracts were increased in an ethanol concentration-dependant manner. The major phenolics in the extracts were chlorogenic acid (21.264~58.666 mg/g), isochlorogenic acid A (10.432~145.353 mg/g), and isochlorogenic acid C(0.239~13.148 mg/g), and these phenolic contents were higher in 70 and 100% ethanolic extracts than other extracts. Significant correlations were observed between ethanol concentration of extraction solvent, antioxidant properties, and major phenolics. These results indicated that the optimal ethanol concentration for extraction was 70%.
        4,000원
        55.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This investigation aims to identify the roles of the discourse marker ja in home shopping discourse. In 12 excerpts of home s hopping d iscourse, ja h as been f ound 8 6 times, u sed as a marker o f adding more information, changing a subject, starting a new topic, focusing and suggesting. The analysis showed that the adding more information function, which is the most frequently used one (35 times), and the suggesting one were newly found in this type of discourse and directly related to the characteristic of the discourse: show hosts tend to provide as much information about the product as possible and to justify the consumption by suggesting various reasons. In addition, cases in which ja was used more than two times by one speaker were often found, which is connected to the fact that it is necessary to keep consumers' attention for the purpose of selling products. Also, guests who occasionally appear to help the hosts never used ja, which is because only show hosts have the power to control the discourse. In the process of switching the topic (e.g. price, composition, product features, or rushing comments), ja was used as a subject-changing marker second most frequently (29 times), especially when making rushing comments. These findings turn out to be closely related to the distinctive features of home shopping discourse, demonstrating the importance of studying discourse markers within the context of institutional discourse.
        6,000원
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