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        검색결과 766

        1.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        한반도의 Donacia속에는 2아속에 속하는 6종이 있다(An, 2019). 이 중 Chujo (1941)는 북한 함경북도 웅기에서 채집한 표본을 D. aquatica (Linnaeus, 1758)로 보고하였고, Kimoto and Kawase (1966)는 D. japana로 표기하여 보고하였다. 그리고 Hayashi (2020)는 한국에 기록된 D. japana가 D. aquatica로 오인되었을 수 있다고 밝혔다. 이러한 혼란을 해결하기 위해 본 연구는 한국(포천과 울산)에서 채집한 표본과 D. japana에 대한 기재문, 수컷생식기와 같은 형태적인 부분(Hayashi, 2020), COI 유전자 염기서열을 비교하였다. 그 결과로 한반도에 기록된 D. japana은 D. aquatica로 대체되고, D. japana는 일본 고유종이라고 결론을 내리고자 한다.
        4,000원
        2.
        2024.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to analyze the productivity and economic feasibility of truss-limited tomatoes (Lycopersicon esculentum L.) grown at a high density in Cambodia during the rainy season. During the rainy season in Cambodia, due to excessive rain and very high temperature, tomatoes cannot grow well in an open field, leading to a greatly reduced yield. High density truss-limited cultivation (HDTLC) of tomatoes can shorten the growing season and increase yields. In conventional cultivation (control), tomatoes were transplanted at a spacing of 70×40 cm and harvested up to the 4th fruit cluster. In HDTLC, tomatoes were transplanted at a spacing of 20×20 cm or 25×25 cm and harvested up to the 2nd fruit cluster. Plant heights in HDTLC were higher than those in the control at 22 days after transplanting (DAT). At 39 DAT, plant heights did not differ between 25×25 cm and control. At 60 DAT, plant height, stem diameter, leaf length, and leaf width of the HDTLC were lower than those of the control. Fruit length and width were also lower in HDTLC compared to those of the control. However, sugar content was more than 19% higher in HDTLC compared to that in the control. Yield per plant of the control was the highest, but yields per ha in HDTLCs were 99% (20×20 cm) and 38% (25×25 cm) higher, respectively, compared to that of the control. No pesticides were used for disease control in this experiment. However, to ensure yield, it is recommended to observe the disease status of plants and spray pesticides at the appropriate time. The disease index (1: disease-free; 5: all leaves were disease-infected) of late blight (Phytophthora indestans) was significantly higher for 20×20 cm (4.5) and 25×25 cm (3.6) groups compared to the control (2.0). Income with 20×20 cm (5,668 thousand KRW) and 25×25 cm (1,863 thousand KRW) were 4.9 and 1.6 times higher, respectively, compared to that with the control (1,149 thousand KRW). So, we want to spread the HDTLC technology, which transplanting of tomato seedlings at 20×20 cm intervals and harvests up to 2nd fruit cluster, to Cambodian farmers.
        4,000원
        3.
        2024.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 D도시 소재 A 노인요양시설에서 근무중인 요양보호사를 대 상으로 왜 대부분의 요양보호사는 여성이며, 특히 연령대는 왜 대부분 50~60대인지, 그리고 요양보호사로의 삶에서 나타나는 사회적 문제들은 무엇인지 도출하고자 하였다. 이를 위해 본 연구는 질적 연구 방법 중 하나인 해석적 현상학을 활용하여 요양보호사들의 경험을 심층적으로 탐 구하였다. 이를 통해 본 연구는 최종적으로 4가지 테마를 도출하였다. 1) 대다수가 여성인 이유 2) 요양보호사의 직업적 특성 3) 직업적 현실과 사회적 기대 4) 작업환경과 사회적 인식이 이에 해당한다. 이러한 연구 결과에 기반하여 요양보호사의 근로환경 개선 및 복지향상을 위한 정책 적 지원 방안을 제안하고자 한다.
        7,700원
        4.
        2024.07 구독 인증기관 무료, 개인회원 유료
        4,000원
        5.
        2024.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Numerous research institutes have been studying semiconductor devices using two-dimensional materials for several years. However, the findings of these studies have yet to demonstrate the performance of digital devices that could replace silicon devices in the semiconductor industry. Nonetheless, the high carrier mobility and saturation velocity of 2-D materials remain attractive for semiconductor device performance, particularly in analog devices where these features can be utilized. In this research, we fabricated a phase-shift controller, a typical component of analog circuits, using 2-D materials and verified its operational characteristics. Analog circuits do not require large area integration, so we employed graphene, which has relatively simple formation and processing, as the 2-D material. Devices using graphene as a channel exhibit a V-shaped I–V characteristic, allowing for the input voltage to be adjusted to produce various modes of output characteristics. This means that the same devices can generate a phase-shifted output and an output with double the frequency by simply adjusting the input voltage range. This research is particularly meaningful since it demonstrates not only the potential of 2-D materials but also their potential for direct application to the semiconductor industry. These findings will contribute to the development of system IC technology and various applications.
        4,000원
        6.
        2024.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The aggressive scaling of dynamic random-access memory capacitors has increased the need to maintain high capacitance despite the limited physical thickness of electrodes and dielectrics. This makes it essential to use high-k dielectric materials. TiO2 has a large dielectric constant, ranging from 30~75 in the anatase phase to 90~170 in rutile phase. However, it has significant leakage current due to low energy barriers for electron conduction, which is a critical drawback. Suppressing the leakage current while scaling to achieve an equivalent oxide thickness (EOT) below 0.5 nm is necessary to control the influence of interlayers on capacitor performance. For this, Pt and Ru, with their high work function, can be used instead of a conventional TiN substrate to increase the Schottky barrier height. Additionally, forming rutile-TiO2 on RuO2 with excellent lattice compatibility by epitaxial growth can minimize leakage current. Furthermore, plasma-enhanced atomic layer deposition (PEALD) can be used to deposit a uniform thin film with high density and low defects at low temperatures, to reduce the impact of interfacial reactions on electrical properties at high temperatures. In this study, TiO2 was deposited using PEALD, using substrates of Pt and Ru treated with rapid thermal annealing at 500 and 600 °C, to compare structural, chemical, and electrical characteristics with reference to a TiN substrate. As a result, leakage current was suppressed to around 10-6 A/cm2 at 1 V, and an EOT at the 0.5 nm level was achieved.
        4,000원
        7.
        2024.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Ophiopogonin D (OPD) is a steroidal glycoside derived from Ophiopogon japonicus , a traditional Chinese medicine with diverse biological activities, including antithrombosis, anti-inflammation, and antitussive effects. To investigate the cellular effects and mechanisms of OPD on oral squamous cell carcinoma, cell viability was explored, and the effects of OPD on cell cycle regulators, apoptotic marker proteins, and key proteins involved in metastasis and signaling pathways were examined by MTT assay and Western blotting in YD38 cells. OPD strongly inhibited cell proliferation and induced caspase-dependent apoptosis of YD38 cells by suppressing the cell cycle and activating caspase-3 and poly ADP ribose polymerase. Additionally, OPD suppressed the expression of vital proteins regulating metastasis and proliferation within the integrin/matrix metalloproteinases/FAK and AKT/PI3K/mTor pathways. Thus, OPD can be a potential treatment candidate for gingival cancer.
        4,000원
        8.
        2024.06 구독 인증기관 무료, 개인회원 유료
        이 연구에서는 예비 초등교사들이 금융교육을 통해 무엇을 배우고 싶어하는지를 금융교육 수요로 정의하고, 24개 금융교육 내용 요소에 대한 수요를 조사하였다. 금융교육에 대한 수요가 가장 높은 내용 요소는 ‘저축에 영향을 주는 요인’, ‘예산과 예산관리’, ‘고령사회와 연금’이었으며, 수요가 가장 낮은 내용 요소는 ‘지불 수단’, ‘소득의 결정 원인’, ‘저축의 경 제적 의의’였다. 금융교육에 대한 수요에 나이, 성별, 금융이해력 등이 미치는 영향은 없었 으며, 금융교육의 필요성에 대한 인식만 통계적으로 유의한 영향을 미쳤다. 본 연구는 예비 초등교사인 교육대학 재학생, 특히 신입생을 주요 대상으로 하였기 때문에 보다 다양한 연 령 및 집단을 대상으로 한 후속 연구의 필요성이 제안되었다.
        5,200원
        11.
        2024.04 구독 인증기관·개인회원 무료
        Silk fibroin (SF) from silkworms has special qualities, and these qualities have drawn a lot of interest lately in SF-based hydrogels for a range of biological applications. However, because there is a dearth of naïve silk materials to collect and prepare, research on the SF-based hydrogels isolated from spider silks has been rather limited. Thus, this study compared the microstructural properties of silk fibroin (SF) hydrogel scaffold, which was taken from the cocoon of the insect silkworm Bombyx mori, with those of hydrogel scaffolds derived from two types of woven silk glands in the orb-web spider Trichonephila clavata: the major ampullate gland (MAG) and the tubuliform gland (TG). The SF hydrogel, which is stabilized by connected SF fibers, has a loose top structure, high porosity, and translucency, according to our FESEM investigation. While the TG hydrogel showed greater porosity, ridge-like or wall-like structures, and stable biocapacity generated by physical cross-linking, the MAG hydrogel showed even higher porosity, elongated fibrous structures, and superior mechanical properties. It is anticipated that the unique microstructural properties of MAG and TG hydrogels will be advantageous when choosing customized substrates to support particular cell types for tissue engineering and regenerative medicine applications.
        12.
        2024.04 구독 인증기관·개인회원 무료
        The two sibling species of fruit fly, Drosophila melanogaster and D. simulans (Diptera: Drosophilidae), have long been used as the key model organisms in ecological and evolutionary research. While numerous studies have investigated the thermal responses of these two species, no study has yet systematically compared their response to dietary macronutrient balance. To fill this knowledge gap, we compared how various life-history traits expressed during larval development would response to an array of dietary ratio of protein to carbohydrate (P:C ratio) in these two sibling species. Largely consistent with previous studies, D. melanogaster took longer to complete their larval development and were much larger at adult emergence than D. simulans. For both species, an increase in dietary P:C ratio resulted in improved larval survivorship and faster development. However, the two species showed qualitatively different response to dietary P:C ratio when body mass at adult eclosion was concerned. The body mass of D. melanogaster peaked at an optimal P:C ratio of 1:4, but decreased as the P:C ratio either increased or decreased from this optimum. In marked contrast, the body mass of D. simulans was insensitive to dietary P:C ratio.
        13.
        2024.04 구독 인증기관·개인회원 무료
        This study investigates the phenomenon of task specialization in subterranean termites, focusing on their tunneling behavior. Termites, known for their complex social structure, allocate specific individuals for tunnel construction, rarely switching tasks. To explore this behavior, we developed a simulation model comparing termite groups with and without task shifts. While tunnel orientation showed no significant difference between the two tunnel pattern groups, the absence of task shifts resulted in larger tunnels, indicating enhanced foraging efficiency. This suggests that maintaining a consistent division of labor without task rotation benefits termite foraging. This study sheds light on the ecological advantages of task specialization in social insects, highlighting its role in foraging success and colony survival.
        15.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to present a predictive drift model, Jeju National University's training ship was tested for about 11 hours and 40 minutes, and 81 samples that selected one of the entire samples at ten-minute intervals were subjected to regression analysis after verifying outliers and influence points. In the outlier and influence point analysis, although there is a part where the wind direction exceeds 1 in the DFBETAS (difference in Betas) value, the CV (cumulative variable) value is 6%, close to 1. Therefore, it was judged that there would be no problem in conducting multiple regression analyses on samples. The standard regression coefficient showed how much current and wind affect the dependent variable. It showed that current speed and direction were the most important variables for drift speed and direction, with values of 47.1% and 58.1%, respectively. The analysis showed that the statistical values indicated the fit of the model at the significance level of 0.05 for multiple regression analysis. The multiple correlation coefficients indicating the degree of influence on the dependent variable were 83.2% and 89.0%, respectively. The determination of coefficients were 69.3% and 79.3%, and the adjusted determination of coefficients were 67.6% and 78.3%, respectively. In this study, a more quantitative prediction model will be presented because it is performed after identifying outliers and influence points of sample data before multiple regression analysis. Therefore, many studies will be active in the future by combining them.
        4,600원
        16.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The towing distance, which is speed over the ground, and the water flow quantity, which is speed through the water, were used when estimating the amount of Metapenaeus joyneri resources that rose to the surface at night using the swept area method in order to compare and analyze the difference. It was conducted using a shrimp dredge, trial fishing gear for catching Metapenaeus joyneri. Catch during the entire survey period was 188.9 kg. Monthly catch ranged from 3.1 to 109.2 kg, highest in June and lowest in September. The swept volume calculated using the speed over the ground was about 13% higher than using the speed through the water. Metapenaeus joyneri resources estimated using the towing distance ranged from 320.1 to 14,649.8 kg. Resources estimated using the water flow quantity ranged from 278.5 to 12,886.3 kg. Therefore, the amount of Metapenaeus joyneri resources estimated using the speed over the ground was about 14% higher than the method using the speed through the water, indicating that the amount of resources was overestimated.
        4,000원
        17.
        2024.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The combination of the two-dimensional (2D) materials g-C3N4 and MXenes in photocatalysis offers several advantages. The g-C3N4 can serve as a visible light-absorbing material, while MXenes can enhance the charge separation and transfer processes leading to improved photocatalytic efficiency. A critical review of 77 already published articles in the field of photocatalytic reactions using g-C3N4 and MXenes, such as hydrogen evolution, the reduction of carbon dioxide, the degradation of organic compounds, the redox reactions of nitrogen, was conducted. For the purpose of greater objectivity, the published results were analysed by non-parametric Mann–Whitney, Kolmogorov–Smirnov, and Mood´s median tests and visualised by box and whisker plots. It was found that MXenes can significantly improve the photocatalytic activity of g-C3N4. Adding other co-catalysts to the MXene/g-C3N4 composites does not bring a significant improvement in the photocatalytic performance. Promising results were obtained especially in the fields of hydrogen evolution and the reduction of carbon dioxide. Since the MXenes are relatively a new class of materials, there is still a big challenge for finding new photocatalytic applications and for the enhancement of existing photocatalytic systems based on g-C3N4, especially in terms of the MXenes and g-C3N4 surface and in the heterojunction engineering.
        5,400원
        18.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 대한민국 울릉도 특산식물인 추산쑥부쟁이(Aster × chusanensis Y.S.Lim, Hyun, Y.D.Kim & H.C.Shin)의 기내 대량증식체계 확립을 위해 시토키닌 계열 식물생장조절 제를 첨가하여 캘러스 및 신초 형성 조건을 구명하고자 수행 하였다. 실험결과, 추산쑥부쟁이의 줄기 절편체에서 캘러스 와 신초가 형성되었다. 캘러스 형성률은 TDZ 3.0mg·L-1처 리구에서 88.9%로 가장 높았고 BAP 3.0mg·L-1와 Zeatin 3.0mg·L-1 처리구는 66.7%, 2iP 3.0mg·L-1 처리구에서는 11.1%였다. 신초 형성률은 모든 처리구에서 77% 이상이고 특히 TDZ처리구와 Zeatin 처리구에서 100%였다. 그러나 TDZ처리구에서는 형성된 신초가 부풀어 오르거나, 잎에 과수 성이 나타나는 등 형태적 기형이 나타났다. Zeatin처리구에 서 발생한 신초는 정상적인 형태를 나타났다. 잎 절편체에서 는 캘러스, 신초가 발생하지 않았으며 절편체가 탈색하며 고 사하는 것을 확인하였다. 종합적으로 추산쑥부쟁이의 캘러 스 및 신초 형성을 위해서는 줄기 절편체를 배양 재료로 이 용하는 것이 효과적으로 확인되었다. 캘러스 유도에는 TDZ 3.0mg·L-1처리가 가장 효과적이었고, 추후 NAA와 같은 옥신 을 함께 첨가하여 증식 효과를 분석하는 연구가 필요할 것이 다. 또한, 신초 유도에도 TDZ 3.0mg·L-1 처리가 효과적이었 으나 장기간, 고농도로 사용할 경우 형태적인 기형이 발생할 수 있어 정상적인 식물생산에 부적합한 것으로 확인되었다. 따라서 형태적 기형이 발생하지 않은 아데닌 유도체형 시토키 닌인 Zeatin을 활용하는 것을 추천한다. 본 연구는 울릉도 특 산식물인 추산쑥부쟁이의 기내 대량증식과 생태계 유지에 필 요한 종 공급을 위한 대량증식 체계 구축을 위한 자료로 활용 할 수 있을 것이다.
        4,000원
        19.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        웹툰이 2D 애니메이션으로의 매체 전환 창작은 새로운 유행이 되어가 고 있다. 그럼에도 불구하고 현재 이 두 매체 간 전환에 대한 연구는 상 대적으로 적다. 본 논문은 베르너 볼프의 트랜스미디어 변환 이론과 브 루스 블록의 시각 이론을 바탕으로 중국에서 성공한 만화 <대리사일지> 를 애니메이션으로의 변환을 미디어 변환 관점에서 분석 연구하였다. 이 연구는 한국 만화의 각색 및 트랜스미디어 변환과 관련된 학문 분야에 연구 방향을 제공하며 응용 분야에는 제작 관점의 참고 의견을 제공한 다. 우리는 웹툰에서 2D 애니메이션으로의 매체 전환을 영향하는 요인들 을 탐구할 뿐만 아니라 두 매체의 시각적 요소 표현의 차이를 밝힐 것이 다. 웹툰에서 2D 애니메이션으로의 전환 과정에서 시각적인 충격을 강화 하고 현실감을 높이며 흥미를 더하는 방법에 중점을 둘 것이다. 또한, 사 려 깊은 촬영 안내를 통해 관중의 참여도를 더욱 강화하는 방법을 탐구 할 것이다. 이러한 측면을 깊이 연구함으로써 우리는 이러한 매체 전환 과정에서의 기회와 도전을 더 잘 이해할 수 있을 것이다.
        6,700원
        20.
        2023.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        β-Ga2O3 has become the focus of considerable attention as an ultra-wide bandgap semiconductor following the successful development of bulk single crystals using the melt growth method. Accordingly, homoepitaxy studies, where the interface between the substrate and the epilayer is not problematic, have become mainstream and many results have been published. However, because the cost of homo-substrates is high, research is still mainly at the laboratory level and has not yet been scaled up to commercialization. To overcome this problem, many researchers are trying to grow high quality Ga2O3 epilayers on hetero-substrates. We used diluted SiH4 gas to control the doping concentration during the heteroepitaxial growth of β-Ga2O3 on c-plane sapphire using metal organic chemical vapor deposition (MOCVD). Despite the high level of defect density inside the grown β-Ga2O3 epilayer due to the aggregation of random rotated domains, the carrier concentration could be controlled from 1 × 1019 to 1 × 1016 cm-3 by diluting the SiH4 gas concentration. This study indicates that β-Ga2O3 hetero-epitaxy has similar potential to homo-epitaxy and is expected to accelerate the commercialization of β-Ga2O3 applications with the advantage of low substrate cost.
        4,000원
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