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        검색결과 789

        1.
        2025.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A new spider species of the genus Pholcus Walckenaer, 1805, Pholcus osaek sp. nov., in the family Pholcidae C.L. Koch, 1850, is described from Korea. This new species belongs to phungiformes-group in the genus. It can be distinguished from its congeners by the shape and structure of genital organs of both males and females. It is found on and between rock walls in mountainous mixed forests. Additionally, the taxonomic status of Pholcus uksuensis Kim & Ye, 2014 is revalidated, re-diagnosed, and redescribed based on specimens collected from the type locality. Considering differences mentioned in the diagnosis through revalidation, P. uksuensis is regarded as a distinct species. Therefore, it should be removed from the synonymy of P. woongil Huber, 2011.
        4,000원
        2.
        2025.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The efficient fabrication of uranium-based liquid fuels and the structural integrity of reactor materials are critical challenges for the deployment of chloride-based molten salt reactors (MSRs). As part of KAERI’s ongoing MSR development, this study investigates an optimized uranium chlorination process and a corrosion assessment of candidate structural materials under conditions more closely resembling actual reactor cores. To enhance process efficiency and scalability, metallic uranium was converted into uranium trihydride (UH3) via hydriding, achieving 34.1% efficiency. UH3 was chlorinated with ammonium chloride (NH4Cl), yielding uranium trichloride (UCl3) with a conversion rate over 98% and purity above 99%, as confirmed by ICP-OES. The UCl3 was used to fabricate various uranium-based liquid fuels for MSR applications. Simultaneously, the corrosion behavior of SS304, SS316, and Hastelloy-N was evaluated using a natural convection loop filled with a NaCl– MgCl2 eutectic salt mixture. The system operated for 500 hours at 500–580°C to replicate MSR conditions. Corrosion analysis revealed that SS304 suffered severe degradation, SS316 showed moderate resistance, and Hastelloy-N demonstrated superior stability, although some cold leg samples experienced mass gain due to corrosion product deposition. These findings provide key insights into optimizing liquid fuel synthesis and selecting corrosion-resistant materials for safe, long-term MSR operation.
        5,400원
        3.
        2025.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Visfatin, an adipokine secreted by cells, is crucial for intracellular nicotinamide adenine dinucleotide+ biosynthesis. Extracellularly, visfatin plays diverse roles in inflammatory conditions, including obesity, which is closely linked to osteoclastogenesis. We previously showed that visfatin enhances receptor activator of nuclear factor kappa-B ligand (RANKL)-induced osteoclastogenesis in bone marrow-derived macrophages. However, its enzymatic activity during this process is poorly understood. Here, we investigated visfatin’s effects on RANKL-induced osteoclast differentiation. Our results demonstrate that visfatin promotes this differentiation, an effect inhibited by FK866, an inhibitor of visfatin’s enzymatic activity. Furthermore, FK866 also inhibited RANKL-induced osteoclast differentiation. These findings suggest that inhibiting visfatin’s enzymatic activity modulates osteoclast differentiation. Thus, visfatin plays an important role in osteoclastogenesis, both intracellularly and extracellularly, and FK866 has therapeutic potential for diseases characterized by imbalanced osteoclast formation, such as osteoporosis and periodontitis.
        4,000원
        4.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigates the effect of machine translation (MT) use on the writing performance of Korean EFL students, focusing on complexity, accuracy, and fluency (CAF). Six participants completed a series of writing tasks in which they first translated their L1 writing into L2 manually and then used MT to revise their L2 drafts. This process was repeated across ten different writing topics. Participants’ drafts were analyzed using CAF measures to assess MT’s impact on their writing performance and observe changes over tasks. The results show that MT significantly improved accuracy and fluency. However, gains in syntactic and lexical complexity were less evident. While group-level analysis showed consistent progress, individual trajectories varied widely, indicating diverse patterns of development. Overall, the findings suggest that MT enhances writing accuracy and fluency among Korean EFL students, although its impact on syntactic and lexical complexity is limited. These results indicate that MT can serve as a valuable tool for self-directed learning, helping students independently improve their writing accuracy and fluency and develop essential self-editing skills. This study highlights the potential of MT as a supplementary tool to support EFL students’ writing development, along with traditional instruction.
        8,400원
        5.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bearing-shaft systems are essential components in various automated manufacturing processes, primarily designed for the efficient rotation of a main shaft by a motor. Accurate fault detection is critical for operating manufacturing processes, yet challenges remain in sensor selection and optimization regarding types, locations, and positioning. Sound signals present a viable solution for fault detection, as microphones can capture mechanical sounds from remote locations and have been traditionally employed for monitoring machine health. However, recordings in real industrial environments always contain non-negligible ambient noise, which hampers effective fault detection. Utilizing a high-performance microphone for noise cancellation can be cost-prohibitive and impractical in actual manufacturing sites, therefore to address these challenges, we proposed a convolution neural network-based methodology for fault detection that analyzes the mechanical sounds generated from the bearing-shaft system in the form of Log-mel spectrograms. To mitigate the impact of environmental noise in recordings made with commercial microphones, we also developed a denoising autoencoder that operates without requiring any expert knowledge of the system. The proposed DAE-CNN model demonstrates high performance in fault detection regardless of whether environmental noise is included(98.1%) or not(100%). It indicates that the proposed methodology effectively preserves significant signal features while overcoming the negative influence of ambient noise present in the collected datasets in both fault detection and fault type classification.
        4,500원
        6.
        2024.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Calcitonin (CT) and CT gene-related peptide (CGRP) are well known to regulate blood calcium concentration and osmotic pressure in vertebrates. Although lophotrochozoan CT-like peptides and their receptors have been characterized in several model species, the presence of CT-like signaling systems in gastropods remains unknown. In this study, we identified two CT-like peptides, Hdh-CT1 and -CT2, and their receptors (CTRs), namely Hdh-CTR-L and -CTR-S, in Pacific abalone. Transcripts encoding Hdh-CT1 and Hdh-CT2 precursors were expressed mainly in neural ganglia. Molluscan CT-type peptides including Hdh-CT peptides were similar in length and showed highly conserved two Cys residues forming a disulfide bond in their N-terminal regions. A phylogenetic analysis revealed that gastropod CTRs, including Hdh-CTRs, belong to a large molluscan CTR subfamily. A luciferase reporter driven by cAMP responsive element was stimulated by Hdh-CT1 but not by Hdh-CT2 in Hdh-CTR-L-transfected human embryonic kidney 293 cells. In silico docking model using SWISS-MODEL and HPEPDOCK server showed that the N-terminal residues in Hdh-CT1 are deeply inserted into the binding pocket of Hdh-CTR-L. Taken together, the identification of the Hdh-CT system provides a comprehensive insight into the functional CT-type signaling system in marine gastropods.
        4,200원
        7.
        2024.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Si-based anodes are promising alternatives to graphite owing to their high capacities. However, their practical application is hindered by severe volume expansion during cycling. Herein, we propose employing a carbon support to address this challenge and utilize Si-based anode materials for lithium-ion batteries (LIBs). Specifically, carbon supports with various pore structures were prepared through KOH and NaOH activation of the pitch. In addition, Si was deposited into the carbon support pores via SiH4 chemical vapor deposition (CVD), and to enhance the conductivity and mechanical stability, a carbon coating was applied via CH4 CVD. The electrochemical performance of the C/Si/C composites was assessed, providing insights into their capacity retention rates, cycling stability, rate capability, and lithium-ion diffusion coefficients. Notably, the macrostructure of the carbon support differed significantly depending on the activation agent used. More importantly, the macrostructure of the carbon support significantly affected the Si deposition behavior and enhanced the stability by mitigating the volume expansion of the Si particles. This study elucidated the crucial role of the macrostructure of carbon supports in optimizing Si-based anode materials for LIBs, providing valuable guidance for the design and development of high-performance energy-storage systems.
        4,300원
        11.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study describes Philodromus rufus Walckenaer, 1826 with detailed descriptions, taxonomic photographs, distribution map, and proposition of a new synonym. Due to morphological similarity between P. pseudoexilis Paik, 1979 and P. rufus, taxonomic identity of P. pseudoexilis has been doubtful to date. A detailed bibliographic study of types of P. pseudoexilis between P. rufus and examination of specimens from the type locality of P. pseudoexilis with specimens of P. rufus collected across the country showed that P. rufus has all diagnostic characters found in types of P. pseudoexilis. Therefore, P. pseudoexilis Paik, 1979 should be regarded as a new synonym of Philodromus rufus Walckenaer, 1826.
        4,000원
        13.
        2024.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        In this paper, we investigate asteroseismic scaling-relations of evolved stars in star clusters observed by Kepler/K2, aiming to address the issue of whether observed stellar oscillations are influenced by environmental factors, as there are interesting phenomena relating to the stellar pulsations observed in star clusters. Specifically, we compare statistical properties of distributions including Δν, νmax, HGauss, δνenv, and δν02 derived from red giant branch (RGB) and red clump (RC) stars in two pairs of star clusters: NGC 2682 - NGC 6819 and NGC 1817 - NGC 6811. We have found that the slopes of relations between νmax and Δν and between HGauss and νmax associated with RC stars in the more compact star clusters, NGC 2682 and NGC 1817, are in common less steep compared with those for NGC 6819 and NGC 6811. It is also found that the slopes of the relation between δνenv and νmax from RC stars in the more compact star clusters are in common steeper compared with those for the others. For the relation between δν02 and Δν obtained from RGB stars, the slope resulting from NGC 2682 and NGC 6819 is indistinguishable. The Kolmogorov–Smirnov tests conducted on RC stars in the pairs of NGC 2682 and NGC 6819, as well as NGC 1817 and NGC 6811, indicate that all the seismic quantities considered in this paper are drawn from different distributions. We conclude, therefore, that the properties of star clusters should be considered when asteroseismic data obtained from stars within star clusters are interpreted.
        4,000원
        14.
        2024.07 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Much effort has been carried out to calibrate and revise asteroseismic relations, given their importance of relations in asteroseismology in determining fundamental parameters of stars. In this study, we statistically explore asteroseismic relations with partial correlation coefficients to determine the most fundamental parameters, separately analyzing asteroseismic data based on the evolutionary status of stars from main sequence up to core helium-burning red-clump stars. We have found that regardless of the evolutionary status of the sampled stars the surface gravity and density of stars strongly influence the observed correlations. More importantly, it is found that indirect correlations derived considering the influence of confounding parameters are subject to the evolutionary status. For example, the observed correlation of the large frequency separation Δν with the central frequency νmax is influenced by the stellar mass, radius, and luminosity only for main sequence stars. The observed correlation of the width of the Gaussian envelope δνenv with νmax is influenced by the stellar mass, effective temperature, radius, and luminosity for main-sequence and subgiant stars. The observed relation between Δν and the small frequency separation δν02 is influenced by the stellar mass, radius, and luminosity for main-sequence and subgiant stars. In contrast, effective temperature, metallicity, and age do not seem to significantly affect the observed correlations. Finally, we conclude by discussing implication of our findings.
        4,000원
        15.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A poorly known spider, Pholcus kwangkyosanensis Kim & Park, 2009 is redescribed with diagnosis, detailed descriptions, and taxonomic photographs of diagnostic characters. P. kwangkyosanensis is similar in appearance to P. kwanaksanensis Namkung & Kim, 1990, in terms of the shape of the genital organ and body, but it can be easily distinguished from the latter by the shape of the cheliceral apophysis, uncus, and procursus in males, as well as the shape of the epigynum and pore plates in females. The specimens of this spider were collected at the type locality (Mt. Gwanggyosan, Suwon), specifically under the bridge on a local stream in an agricultural landscape surrounded by rice fields, upland fields, or horticultural greenhouses.
        3,000원
        16.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Zooplankton biomass is essential for understanding the quantitative structure of lake food webs and for the functional assessment of biotic interactions. In this study, we aimed to propose a biomass (dry weight) estimation method using the body length of cyclopoid copepods. These copepods play an important role as omnivores in lake zooplankton communities and contribute significantly to biomass. We validated several previously proposed estimation equations against direct measurements and compared the suitability of prosomal length versus total length of copepods to suggest a more appropriate estimation equation. After comparing the regression analysis results of various candidate equations with the actual values measured on a microbalance-using the coefficient of variation, mean absolute error, and coefficient of determination-it was determined that the Total Length-DW exponential regression equation [W=0.7775×e2.0183L; W (μg), L (mm)] could be used to calculate biomass with higher accuracy. However, considering practical issues such as the morphological similarity between species and genera of copepods and the limitations of classifying copepodid stages, we derived a general regression equation for the pooled copepod community rather than a species-specific regression equation.
        4,300원
        17.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        넷플릭스의 앤솔로지 애니메이션 시리즈인 <러브, 데스 + 로봇>(Love, Death + Robot) 시즌 3의 에피소드 중 하나이자 알베르토 미엘고 감독이 연출한 단편 애니메이션 <히바로>(Jibaro) 는 공개 당시 작품의 굉장한 몰입감과 사실감으로 화제가 되었다. 그렇지만 <히바로>가 포토 리얼리스틱(Photo-realistic)한 이미지 구현을 목표로 한 작품이라고 보기는 어렵다. 감독의 개성이 애니메이션 매체의 자유로운 표현력을 통해 작품 곳곳에서 드러나기 때문이다. 본 연 구는 <히바로>가 놀라운 사실감을 보여주면서도 초현실적, 환상적 이미지 역시 동시에 담아내 는 독특한 성취를 이룬 작품이며 이를 이루고 있는 구성 요소들을 분석해 볼 필요성이 있다는 판단 아래 진행되었다. 또한, <히바로>에 대한 연구가 국내에서 거의 이뤄지지 않은 상황이기 때문에 본 논문이 더욱 가치를 가질 것으로 기대한다. 본 연구에서는 우선 볼터와 그루신의 재매개 이론에 대해 살펴본 후, 재매개 이론에서 설명하고 있는 재매개의 형태와 방향에 관해 서술하였다. 이후에는 <히바로>의 구성 요소들을 재매개 이론을 바탕으로 분석하며 <히바로> 가 사실성과 환상성을 결합한 방식을 분석해 보았다.
        4,200원
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