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        검색결과 1,260

        1.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We aimed to evaluate the effectiveness of ensemble optimal interpolation (EnOI) in improving the analysis of significant wave height (SWH) within wave models using satellite-derived SWH data. Satellite observations revealed higher SWH in mid-latitude regions (30o to 60o in both hemispheres) due to stronger winds, whereas equatorial and coastal areas exhibited lower wave heights, attributed to calmer winds and land interactions. Root mean square error (RMSE) analysis of the control experiment without data assimilation revealed significant discrepancies in high-latitude areas, underscoring the need for enhanced analysis techniques. Data assimilation experiments demonstrated substantial RMSE reductions, particularly in high-latitude regions, underscoring the effectiveness of the technique in enhancing the quality of analysis fields. Sensitivity experiments with varying ensemble sizes showed modest global improvements in analysis fields with larger ensembles. Sensitivity experiments based on different decorrelation length scales demonstrated significant RMSE improvements at larger scales, particularly in the Southern Ocean and Northwest Pacific. However, some areas exhibited slight RMSE increases, suggesting the need for region-specific tuning of assimilation parameters. Reducing the observation error covariance improved analysis quality in certain regions, including the equator, but generally degraded it in others. Rescaling background error covariance (BEC) resulted in overall improvements in analysis fields, though sensitivity to regional variability persisted. These findings underscore the importance of data assimilation, parameter tuning, and BEC rescaling in enhancing the quality and reliability of wave analysis fields, emphasizing the necessity of region-specific adjustments to optimize assimilation performance. These insights are valuable for understanding ocean dynamics, improving navigation, and supporting coastal management practices.
        4,600원
        2.
        2024.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The alternative food market has attracted much attention due to concerns about climate change, increasing consumer awareness of value consumption, and the development of the Food-Tech industry. This study aimed to analyze the factors that drive consumers to purchase alternative food products and identify the mechanisms that can induce consumers to continue buying. We surveyed 1,200 consumers and estimated data using a logit model. The results showed that the presence of vegetarians in the household, environmental concerns, a vegetable-oriented diet, and a mixed diet of meat and vegetables were positively associated with purchasing plant-based alternatives. Of particular interest was the non-linear relationship between respondents’ age and their purchasing experience with plant-based options, with the likelihood of purchasing alternatives increasing with age from the mid-50s onward. These findings suggest that in addition to the growing number of consumers who share the environmental value, which leads to increased interest in and purchase of plant-based alternatives, alternative foods are also health-oriented and meet the needs of older consumers, who are becoming an increasingly important segment of the super-aged society, suggesting the potential for continued growth in the alternative food market.
        4,000원
        3.
        2024.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        많은 연구에 따르면 Tenebrio molitor은 유충 단계에서 플라스틱을 섭취할 수 있다고 보고되었다. 이 연구의 목적은 T. molitor 유충의 성장과 발달에 발포폴리스티렌 섭취가 미치는 영향을 조사하는 것이다. 밀기울을 섭취한 유충의 성장률은 발포폴리스티렌을 섭취한 유충의 성장률보다 더 좋았고(p < 0.001) 발포폴리스티렌을 섭취한 유 충의 번데기로 전환되는 기간은 밀기울을 섭취한 유충의 번데기로 전환되는 기간보다 더 빨랐다(p < 0.001). 하지만 두 처리구간 생존율은 유의미한 차이가 없었다(p = 0.786). 이 결과에 따르면 발포폴리스티렌을 섭취한 유충은 체중 감소와 짧은 발육기간이 특징이지만 생존하는 것에는 문제가 없었다. 따라서 우리는 T. molitor가 플라스틱 폐기물 의 지속 가능하고 친환경적인 제거를 위한 주요 자원이라는 결론을 내렸다.
        4,000원
        5.
        2024.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Carbon fusion is important to understand the late stages in the evolution of a massive star. Astronomically interesting energy ranges for the 12C+12C reactions have been, however, poorly constrained by experiments. Theoretical studies on stellar evolution have relied on reaction rates that are extrapolated from those measured in higher energies. In this work, we update the carbon fusion reaction rates by fitting the astrophysical S-factor data obtained from direct measurements based on the Fowler, Caughlan, & Zimmerman (1975) formula. We examine the evolution of a 20M⊙ star with the updated 12C+12C reaction rates performing simulations with the MESA (Modules for Experiments for Stellar Astrophysics) code. Between 0.5 and 1 GK, the updated reaction rates are 0.35 to 0.5 times less than the rates suggested by Caughlan & Fowler (1988). The updated rates result in the increase of core temperature by about 7% and of the neutrino cooling by about a factor of three. Moreover, the carbon-burning lifetime is reduced by a factor of 2.7. The updated carbon fusion reaction rates lead to some changes in the details of the stellar evolution model, their impact seems relatively minor compared to other uncertain physical factors like convection, overshooting, rotation, and mass-loss history. The astrophysical S-factor measurements in lower energies have large errors below the Coulomb barrier. More precise measurements in lower energies for the carbon burning would be useful to improve our study and to understand the evolution of a massive star.
        4,000원
        6.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We have intended and preparation of hierarchically absorbent materials were covered with a NiMn2O4 and acts as a catalyst for azo dye degradation. The polyaromatic-based (PA) absorbent compounds were initially constructed by bromomethylated aromatic hydrocarbons which undergo self-polymerization in presence of ZnBr as a reagent and cross linker is bromomethyl methyl ether. The absorbent black materials with a 3D network were prepared by direct carbonization and activation of the as-prepared PA. The hydrothermal method was adapted for the preparation of carbon hybrid material C@NiMn2O4 powder's catalytic activity is effective in reducing p-nitrophenol to p-aminophenol and decolorizing carbon-based dyes like methyl orange (MO), methyl yellow (MY), and Congo red (CR) in aqueous media at 25 °C when NaBH4 is added. UV–visible spectroscopy was used to analyze the dyes' breakdown at regular interval.
        4,000원
        7.
        2024.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Because most spent nuclear fuel storage casks have been designed for low burnup fuel, a safety-significant high burnup dry storage cask must be developed for nuclear facilities in Korea to store the increasing high burnup and damaged fuels. More than 20% of fuels generated by PWRs comprise high burnup fuels. This study conducted a structural safety evaluation of the preliminary designs for a high burnup storage cask with 21 spent nuclear fuels and evaluated feasible loading conditions under normal, off-normal, and accident conditions. Two types of metal and concrete storage casks were used in the evaluation. Structural integrity was assessed by comparing load combinations and stress intensity limits under each condition. Evaluation results showed that the storage cask had secured structural integrity as it satisfied the stress intensity limit under normal, off-normal, and accident conditions. These results can be used as baseline data for the detailed design of high burnup storage casks.
        4,000원
        8.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Human bitter taste-sensing type 2 receptors (hTAS2Rs) are expressed in various human tissues and may be associated with various cell signaling pathways, cell progression, and cell physiology in each tissue. hTAS2Rs can be a potential drug target because it is also expressed in some cancer cells. Xanthorrhizol (XNT) has various biological activities, such as anticancer, antimicrobial, anti-inflammatory, and antioxidant. XNT produces a bitter taste, but the specific hTAS2R activated is unknown, and the hTAS2R-mediated effect of XNT on cancer cells has not been studied. This study discovered the target receptor of XNT among 25 hTAS2Rs and confirmed the possibility of the hTAS2R-mediated inhibition of cancer cell proliferation. XNT activated only one receptor, hTAS2R38 (EC50=1.606±0.021 g/mL), and its activity was inhibited by probenecid, a hTAS2R38 antagonist. When HepG2 and MCF-7 cells were treated with XNT or phenylthiocarbamide (PTC), a known hTAS2R38 agonist, both chemicals inhibited cancer cell proliferation. XNT targets the human bitter taste receptor TAS2R38 and inhibits the proliferation of HepG2 and MCF-7 cells mediated by TAS2R38. This suggests that TAS2R38 may be a new target for disease treatment and a potential new factor for drug development.
        4,000원
        9.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 광학 시뮬레이션 프로그램을 통해 Gullstrand 모형안을 입체적으로 설계하여, 정시와 굴절이상을 구현하 였다. 이를 이용하여 망막 상의 해상도 변화를 확인하고 정량적인 분석법을 제시하고자 하였다. 방법 : 3D 광학 시뮬레이션 프로그램인 Ansys SPEOS Ver. 2012(ANSYS Inc., USA)를 이용하여 모형안을 설계하였으며, 각막 전면 곡률반지름을 변화시켜 근시 및 원시의 굴절이상을 구현하였다. 각막 전면에서 우측 24.00, 24.38 및 25.00 mm 떨어진 위치에 탐지기를 설치하여 위치에 따른 상의 변화를 분석하였다. 굴절이상의 정도와 검출기 위치에 따른 상의 겉보기 해상도, 세기 분포, 가시성, 선명도를 확인하였으며 도출하였으며, 최종적 으로 정량적 해상도를 계산하였다. 결과 : 망막 상의 겉보기 해상도는 근시는 망막 앞에, 그리고 원시는 망막 뒤에 결상된 상에서 가장 우수한 결과 를 보였다. 세기 분포는 24.76 mm에서 +1.00과 +2.00 D가 모두 유사하게 높은 것으로 나타나 겉보기 해상도와 일부 차이를 보였다. 가시성은 24.00 mm에서 –2.00과 –1.00 D, 24.38 mm에서 –1.00과 +0.00 D, 24.76 mm에 서 +1.00과 +2.00 D가 높게 측정되었다. 선명도는 24.00 mm에서 –2.00 D, 24.38 mm에서는 -1.00 D, 그리고 24.76 mm에서는 +1.00 D에서 가장 높게 측정되었다. 이로써 가시성과 선명도 값은 위치와 굴절이상도에 따른 서로 다른 결과로 분석되었다. 정량적인 해상도는 24.00 mm에서 –2.00 D, 24.38 mm에서 –1.00과 +0.00 D, 24.76 mm에서 +1.00 D가 가장 우수하게 분석되었으며, 겉보기 해상도와 잘 일치하는 것이 확인되었다. 결론 : 본 연구에서 제안된 망막 상의 정량적 해상도 분석 결과를 통해 상대적으로 비교가 까다로운 망막 상에 대하여 정량적으로 명확한 분석이 가능할 것으로 판단된다.
        4,200원
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