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        검색결과 98

        1.
        2023.07 구독 인증기관·개인회원 무료
        Over the past decade, in-feed native advertising has become one of the most popular forms of online advertising, attracting attention from both academia and industry. Compared to traditional online ads, in-feed native ads are less intrusive and have more engaging content, effectively reducing users' tendency to avoid ads and improving advertising effectiveness. Despite existing review studies, most of them focus on specific aspects of in-feed native advertising, such as ad identification, disclosure, or regulation, and lack an overview of the relevant literature. Moreover, with the diversified development of digital media forms, the widespread application of AI technologies, and the improvement of consumers' ad literacy, in-feed native ad research faces new issues and practical challenges. Thus, a systematic review of existing research is necessary to identify valuable future research directions.
        2.
        2023.05 구독 인증기관·개인회원 무료
        Some consumer goods containing radioactive substances are in circulation and used in everyday life. In accordance with the Nuclear Safety Act, consumer goods with radioactivity are regulated. However, since most consumer goods distributed in Korea have no information that can confirm the amount of radiation, it is necessary to analyze the radiation for safety regulation. Among these consumer goods, GTLS (Gaseous Tritium Light Source) contains gaseous tritium (tritium, written as 3H or T), which is a radioactive material. The gaseous composition ratio in GTLS was analyzed using a precision gas mass spectrometer (Thermo Fisher, model MAT 271). As a result of GTLS analysis, the H2, HD or H3 +(T) or 3He, HT or D2 or He, DT, and T2, which correspond to the mass-to-charge ratio (m/z) 2 to 6 and the air components were detected. In addition, substances corresponding to m/z=24 and m/z=21 were also detected. These were compared with pure CH4 and those fragmentation patterns. The ratios of CT4 (m/z = 24) to CT3 (m/z = 21) and CH4 (m/z = 16) to CH3 (m/z = 15) were compared and they agree within the measurement uncertainty. We also performed additional experiments to separate the water component in the GTLS samples, considering the possibility that the m/z = 21 to m/z = 24 region is tritium compounds based on H2O. Despite the removal of the water components, peaks were detected at m/z=21 and m/z=24. Therefore, we confirmed that the component of m/z = 24 in the GTLS sample was CT4.
        3.
        2023.05 구독 인증기관·개인회원 무료
        KHNP is carrying out international technical cooperation and joint research projects to decommission Wolsong unit 1 reactor. Construction data of the reactor structures, experience data on the pressure tube replacement projects, and the operation history were reviewed, and the amount of dismantled waste was calculated and waste was classified through activation analysis. By reviewing COG (CANDU owners Group) technical cooperation and experience in refurbishment projects, KHNP’s unique Wolsong unit 1 reactor decommissioning process was established, and basic design of a number of decommissioning equipment was carried out. Based on this, a study is being conducted to estimate the worker dose of dismantling workers. In order to evaluate the dose of external exposure of dismantling workers, detailed preparation and dismantling processes and radiation field evaluation of activated structures are required. The preparation process can be divided into dismantlement of existing facilities that interfere with the reactor dismantling work and construction of various facilities for the dismantlement process. Through process details, the work time, manpower, and location required for each process will be calculated. Radiation field evaluation takes into account changes in the shape of structures by process and calculates millions of areas by process, so integrated scripts are developed and utilized to integrate input text data. If the radiation field evaluation confirms that the radiation risk of workers is high, mutual feedback will be exchanged so that the process can be improved, such as the installation of temporary shields. The results of this study will be used as basic data for the final decommissioning plan for Wolsong unit 1. By reasonably estimating the dose of workers through computer analysis, safety will be the top priority when decommissioning.
        5.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The pitch-based activated carbon fibers (ACFs) were prepared from ethylene tar-derived pitches containing nickelocene (CNi) or nickel nitrate (NiN). The effects of different anions and contents of metal salts on the microstructure and surface chemical properties of fibers were investigated. The results revealed that Ni2+ from CNi mainly remained its pristine molecule in the organometal salt-derived pitch (OP-xCNi), while Ni2+ from NiN occurred complexation reaction with polycyclic aromatic hydrocarbons (PAHs) in the inorganic metal salt-derived pitch (IP-xNiN) due to the weaker binding ability between anions and Ni2+ of CNi than CNi. The XRD and SEM results confirmed that IP-3NiN-ACF contained Ni, NiO, Ni2O3 nanoparticles with different size distributions, while OP-3CNi-ACF only contained more uniformly distributed Ni nanoparticles with small size. Furthermore, OP-3.0CNi-ACF presented higher specific surface area of 1862 m2/ g and a pore volume of 1.69 cm3/ g than those of IP-3.0NiN-ACF due to the formation of pore structure during the in-situ catalytic activation of different metal nanoparticles. Therefore, this work further pointed out that the desired pore structure and surface chemistry of pitch-based ACFs could be obtained through regulating and controlling the interaction of anion species, metal cations and PAHs during the synthesis of pitch precursors.
        4,300원
        6.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: A hip fracture may occur spontaneously prior to the hip impact, due to the muscle pulling force exceeding the strength of the femur. Objects: We conducted falling experiments with humans to measure the activity of the hip muscles, and to examine how this was affected by the fall type. Methods: Eighteen individuals fell and landed sideways on a mat, by mimicking video-captured real-life older adults’ falls. Falling trials were acquired with three fall directions: forward, backward, or sideways, and with three knee positions at the time of hip impact, where the landing side knee was free of constraint, or contacted the mat or the contralateral knee. During falls, the activities of the iliopsoas (Ilio), gluteus medius (Gmed), gluteus maximus (Gmax) and adductor longus (ADDL) muscles were recorded. Outcome variables included the time to onset, activity at the time of hip impact, and timing of the peak activity with respect to the time of hip impact. Results: For Ilio, Gmed, Gmax, and ADDL, respectively, EMG onset averaged 292, 304, 350, and 248 ms after fall initiation. Timing of the peak activity averaged 106, 96, 84, and 180 ms prior to the hip impact, and activity at the time of hip impact averaged 72.3, 45.2, 64.3, and 63.4% of the peak activity. Furthermore, the outcome variables were associated with fall direction and/or knee position in all but the iliopsoas muscle. Conclusion: Our results provide insights on the hip muscle activation during a fall, which may help to understand the potential injury mechanism of the spontaneous hip fracture.
        4,000원
        7.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The oxygen-rich activated carbon (AC) was facilely developed using petroleum coke as a raw material by KOH activation under the rapid heating rate. The porosity and surface chemistry of ACs prepared under different heating rates were characterized and their adsorption properties for methylene blue (MB) were investigated. The results showed that the AC5 prepared under the heating rate of 5 °C min−1 had the highest surface area compared with the AC10, AC15 or AC20, while the AC20 prepared under the heating rate of 20 °C min−1 consisted of the highest oxygen content and most –OH functional group compares with the other ACs. These indicated that rapid heating rate was against the formation of more developed porosity, however, it was beneficial to producing more oxygen functional groups. As to MB adsorption, AC15 exhibited the maximum adsorption capacity for MB of 884 mg g−1 due to high surface area of 2803 m2 g−1 and high oxygen content of 23.27%. Moreover, despite the fact that AC20 had much lower surface area than the AC5, the AC20 showed higher MB adsorption capacity than the AC5. This was because the AC20 has the highest content of –OH, which was a positive impetus for MB adsorption. Therefore, rapid heating rate was an effective and simple approach to preparing the oxygen-rich ACs for improving the adsorption capacity of MB.
        4,000원
        12.
        2020.04 구독 인증기관 무료, 개인회원 유료
        홍콩의 비중국어권 유치원생들은 중국어 학습 과정 중에 많은 어려움을 겪게 된다. 개인적인 이유 외에도 교사와 학교 모두 자원, 교재, 경험 등의 부족으로 이들의 중국어 학습은 도전적 상황에 직면해있다. 최근 홍콩 평등기회위원회(香港平等機會委員會)는 중국어권 학습자와 비중국어권 학습자의 통합교육을 적극적으로 건의하였는데, 본래의 좋은 취지와는 다르게 여러 가지 새로운 문제점들이 제기되는 결과를 가져왔다. 이러한 어려움을 해결하기 위해 홍콩 경마자선기금(香港賽馬會慈善基金)과 관련 협력 기관에서는 큰 규모의 연구를 기획하고 실제 프로그램을 개발하여 비중국어권 유치원 교육을 지원하였다. 다양한 프 로그램 가운데, 본 연구는 언어 학습 이론과 효과적인 교육에 중점을 두고, 수업 현장 관찰, 수업 비디오 녹화, 교장과 교사 인터뷰, 학습자 언어 학습 평가와 같은 연구 방법을 사용하 여 연구를 진행하였다. 본 연구는 비중국어권 유아를 대상으로, 유아반에서 상위반까지의 언어학습 발달과정을 추적 하여 네 차례 언어학습 평가를 진행하였다. 학습자의 3년간의 언어 성적은 뚜렷한 성장을 보였는데, 이를 통해 학습이론과 실제 교육법 사이에 분명한 효과가 있음을 알 수 있었다. 또한 본 연구가 통합 정리한 10종의 언어학습이론은 홍콩의 중국어권 유아와 비중국어권 유아의 통합교육에 매우 적합했고, 본 연구에서 얻어진 여러 실제 사례들은 간단히 실행 가능할 뿐만 아니라 많은 자원이 투입되지 않는다는 사실도 도출해 내었다. 본 연구의 이론과 실제 성과가 학계 및 교육 실무자들에게 참고가 되기를 기대해 본다.
        6,900원
        17.
        2019.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Soil acidity or alkalinity are serious limitations for crop production. The purpose of this study was to clarify the negative effects of extreme pH stress (low and high) on alfalfa vegetative growth (VG) and biomass accumulation (BA). Two-week-old alfalfa seedlings were exposed to different pH (4.0, 4.5, 7.0, 8.0 and 8.5, respectively) levels for 72 hours. Alfalfa grown at pH 4.0 and 8.5 significantly reduced VG and BA, wherein as neutral pH (7.0) comparably exhibited better growth and biomass yield. These results indicate that extreme acidic or alkaline level are critical limiting factors for growth and biomass yield in alfalfa.
        4,000원
        18.
        2019.04 구독 인증기관·개인회원 무료
        This study was conducted to evaluate the efficacy of mulberry cake mixed diet on larval growth of Protaetia brevitarsis. As a result of adding mulberry cake to oak fermented sawdust and mulberry fermented sawdust, the survival rate of P. brevitarsis larvae were higher than those of the control when mass rearing larvae. When fed oak fermented sawdust with 3, 5% and 10% of mulberry cake, the cumulative proportion of larvae over 2.5g was 92.9% at 65 days, 90.8% at 55 days, and 96.3% at 45 days after rearing at 25±1℃, respectively. When fed mulberry fermented sawdust with 3%, 5% and 10% of mulberry cake, the cumulative proportion of larvae over 2.5g was 86.2% at 85 days, 90.7% at 75 days, and 91.5% at 75 days after rearing at 25±1℃, respectively.
        19.
        2019.04 구독 인증기관·개인회원 무료
        This study was conducted to evaluate the efficacy of mulberry leaf mixed diet on larval growth of Protaetia brevitarsis. As a result of adding mulberry leaves to oak fermented sawdust, the survival rate of P. brevitarsis larvae were higher than those of the control when mass rearing larvae. When fed oak fermented sawdust with 5%, 10% and 20% of mulberry leaves, the cumulative proportion of larvae over 2.5g was 93.1% at 65 days, 95.6% at 55 days, and 93.9% at 55 days after rearing at 25±1℃, respectively. Also, heavy metals were not detected in larvae of P. brevitarsis fed on mulberry leaves.
        20.
        2019.04 구독 인증기관·개인회원 무료
        전라북도는 곤충사육농가의 77%인 121농가가 흰점박이꽃무지를 사육하고 있고 농가수의 증가가 예상됨에 따라, 생산단가를 절감시키면서 효율적인 사육을 위해서는 사육환경을 최적으로 유지하는 것이 매우 중요하다. 따라서 본 연구에서는 뽕나무발효톱밥을 이용하여 유충사육밀도에 따른 유충발육상황을 조사하였다. 최적 사육밀도 설정을 위하여 전라북도 사육농가에서 가장 많이 사용하는 20L 크기의 사육 상자에 각각 100, 125, 150, 175, 200마리 흰점박이꽃무지 유충을 넣고 뽕나무발효톱밥을 2/3정도 채운 후 사육하면서 유충무게변화, 생존율 등을 조사하였다. 부화 후 95일 흰점박이꽃무지 유충 생존율은 평균 81%로 사육밀도별 큰 차이가 없었다. 유충 무게는 100마리/20L 사육 시 2.219g로 가장 높게 나타났으며, 사육밀도가 증가함에 따라 감소하는 경향으로 나타났다. 유충 영양성분 조사결과 단백질 52.8g/100g, 지방 11.8g/100g이었으며, 중금속은 검출되지 않았다.
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