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        검색결과 239

        1.
        2025.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The objective of this study was to assess the effects of gypsum application on dry matter yield (DMY), mineral content of alfalfa (Medicago sativa L.), and soil properties in reclaimed tidal land in South Korea. The experiment was conducted in Seokmun, located on the west coast of South Korea, which is reclaimed with approximately 70 cm depth of degraded island soil. Treatments consisted of a control with no gypsum application (G0), 2 ton ha-1 (G2), and 4 ton ha-1 (G4) of gypsum application. The first harvest was carried out when the alfalfa reached 10% flowering, and subsequent harvests were conducted at 35-day intervals. Over the three-year experimental periods (2019-2021), the total DMY of G2 treatment was significantly higher than those of G0 and G4 (p<0.05). Although both G2 and G4 gypsum application treatments lowered soil pH, the G4 treatment increased the electrical conductivity (EC) content of the soil. Additionally, gypsum application affected the mineral contents of alfalfa, resulting in reduced concentration of sodium (Na) and Magnesium (Mg). Therefore, this present study suggests that a gypsum application rate of 2 ton ha-1 is optimal for improving alfalfa dry matter yield and mineral balance, as well as enhancing soil chemical properties in reclaimed tidal land in South Korea.
        4,300원
        2.
        2024.12 구독 인증기관·개인회원 무료
        Efficient and safe maritime navigation in complex and congested coastal regions requires advanced route optimization methods that surpass the limitations of traditional shortest-path algorithms. This study applies Deep Q-Network (DQN) and Proximal Policy Optimization (PPO) reinforcement learning (RL) algorithms to generate and refine optimal ship routes in East Asian waters, focusing on passages from Shanghai to Busan and Ulsan to Daesan. Operating within a grid-based representation of the marine environment and considering constraints such as restricted areas and Traffic Separation Schemes (TSS), both DQN and PPO learn policies prioritizing safety and operational efficiency. Comparative analyses with actual vessel routes demonstrate that RL-based methods yield shorter and safer paths. Among these methods, PPO outperforms DQN, providing more stable and coherent routes. Post-processing with the Douglas-Peucker (DP) algorithm further simplifies the paths for practical navigational use. The findings underscore the potential of RL in enhancing navigational safety, reducing travel distance, and advancing autonomous ship navigation technologies.
        3.
        2024.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This review examines the microstructural and mechanical properties of a Ti-6Al-4V alloy produced by wrought processing and powder metallurgy (PM), specifically laser powder bed fusion (LPBF) and hot isostatic pressing. Wrought methods, such as forging and rolling, create equiaxed alpha (α) and beta (β) grain structures with balanced properties, which are ideal for fatigue resistance. In contrast, PM methods, particularly LPBF, often yield a martensitic α′ structure with high microhardness, enabling complex geometries but requiring post-processing to improve its properties and reduce stress. The study evaluated the effects of processing parameters on grain size, phase distribution, and material characteristics, guiding the choice of fabrication techniques for optimizing Ti-6Al-4V performance in aerospace, biomedical, and automotive applications. The analysis emphasizes tailored processing to meet advanced engineering demands.
        4,000원
        5.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: This study focused on reproductive traits in Hanwoo cattle, specifically the environmental factors affecting gestation length and birth weight. Methods: The records of 1,540 cows calved at the Hanwoo Research Institute from 2015 to 2023 were examined. This study analyzed two populations, linebreeding Hanwoo (LBH) and general Hanwoo (GH), with all cows undergoing estrus synchronization and artificial insemination. The R software was used to compare the differences between the two populations and analyze the environmental factors affecting each trait. Results: The results showed that the average gestation length for LBH was 283.28 ± 5.93 days, which was significantly shorter than that of the GH, which had an average of 285.63 ± 6.21 days (p < 0.001). The average birth weight of LBH calves was 25.10 ± 3.69 kg, significantly lighter than GH calves, which weighed 27.26 ± 4.11 kg on average (p < 0.001). Analysis of environmental factors revealed significant differences in the gestation length of LBH based on dam parity, year, and season of calving. However, no significant differences were observed based on calf sex. For LBH, birth weight showed significant differences based on dam parity, year of calving, and sex of the calf, but not the season of calving. In GH, gestation length varied with dam parity and calving season, but not with calving year or calf sex. The GH birth weight showed differences based on dam parity, year of calving, and calf sex, but not the season of calving. Conclusions: Reproductive traits in the Hanwoo cattle industry are economically vital but are heavily influenced by environmental factors due to their low heritability. An accurate evaluation of the genetic potential of these traits requires an analysis of the environmental factors affecting them. The results of this study serve as foundational data for predicting the potential for genetic improvement in the gestation length and birth weight of Hanwoo cattle.
        4,000원
        6.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        고주파 흡수제(Accusorb MRI)를 이용한 자기공명영상 검사 중 화재가 발생했다. 다행히 환자는 화상을 입지는 않았 지만 스트랩과 4채널 코일의 케이블, Accusorb MRI가 녹아서 탄 흔적이 발견되었다. 자기공명영상 검사에 사용되 는 도구의 안전 지침을 준수해야 하지만 이를 지키지 않으면 화상, 열상, 장비 손상의 위험이 있다. 사고를 방지하기 위해서는 철저한 사전 점검을 해야 하고 모든 기기, 물품들이 자기공명영상 검사 시 사용 가능한 제품인지 확인하고 사용법을 정확하게 숙지하여야 한다.
        4,000원
        7.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study explores the profound impact of varying oxygen content on microstructural and mechanical properties in specimens HO and LO. The higher oxygen concentration in specimen HO is found to significantly influence alpha lath sizes, resulting in a size of 0.5-1 μm, contrasting with the 1-1.5 μm size observed in specimen LO. Pore fraction, governed by oxygen concentration, is high in specimen HO, registering a value of 0.11%, whereas specimen LO exhibits a lower pore fraction (0.02%). Varied pore types in each specimen further underscore the role of oxygen concentration in shaping microstructural morphology. Despite these microstructural variations, the average hardness remains consistent at ~370 HV. This study emphasizes the pivotal role of oxygen content in influencing microstructural features, contributing to a comprehensive understanding of the intricate interplay between elemental composition and material properties.
        4,000원
        8.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, quantitative analysis is attempted on data collected from Chilgapsan Observatory Star Park in Cheongyang-gun, Chungcheongnam-do. The aim of this experimental study in which quantitative analysis of the Astronomical Science Museum in Korea is conducted is to investigate its current situation and secure basic data. As of July 31, 2023, it has had 283,931 cumulative visitors in total. It had the largest number of visitors when it opened (2009 year), after which their number reduced steadily until the pandemic (COVID-19, 2020–2022). Recently, however, the number of visitors has increased. Generally, the number of visitors is highest in August (20.8$\%$) and least in April (4.1$\%$). The visit rate is higher on weekends (Saturday and Sunday) than on weekdays (Monday–Friday), and groups comprise only about 5.3$\%$ of the total number of visitors. Moreover, it can be confirmed that the number of visitors increases sharply during events. Finally, it was confirmed that the visit rate was unaffected by weather conditions. Considering these results, we propose the following strategies: 1) Establish a special program that reflects “the weekend effect.” 2) Prepare a plan to attract group visitors during the weekdays using “the event effect.” 3) Arrange alternative programs (e.g., experiential activities) that can be conducted indoors regardless of weather conditions. We think that our findings will help establish a roadmap for the direction the Astronomical Science Museum should take and aid in preparing a strategic foundation to preemptively respond to unexpected situations (e.g., pandemics).
        4,500원
        10.
        2023.10 구독 인증기관·개인회원 무료
        2022년 캠벨얼리 재배면적은 4,397ha(32.7%)으로 샤인머스켓에 이어 두 번째로 많이 재배하는 품종이다. 또한 충랑은 2018년에 품종등록된 3배체(캠벨얼리×고처) 포도로 신품종 연구가 필요한 품종이다. 연무늬들명나방 (Syllepte pallidinotalis)은 캠벨얼리와 신품종 충랑에서 잎의 가장자리를 말고 그 속에서 잎을 갉아먹는 해충으로 잎에 피해가 관찰되었다. 연중 포도원에서 연무늬들명나방의 밀도는 7월 중순과 9월 하순에 2번의 peak를 보였 다. 알에서 부화한 유충이 2령이 되면 잎을 말고 안에 숨기 때문에 잎을 말은 이후 약제 살포시 잎 안에 잘 뭏지 않아 방제가가 떨어졌다. 특히 생물농약인 비티제를 이용해 방제를 할 경우 잎을 말기 직전인 6월 중순에 살포 했을 때 93.5%의 방제가를 보였으나, 5월 하순이나 7월 초순 방제할 경우 73.9, 43.6%로 낮은 방제가를 보였다. 따라서 잎을 말기 직전인 6월 중순, 8월 하순에 방제를 하는 것이 효율적임을 알 수 있었다.
        11.
        2023.10 구독 인증기관·개인회원 무료
        2022년 캠벨얼리 재배면적은 4,397ha(32.7%)으로 샤인머스켓에 이어 두 번째로 많이 재배하는 품종이다. 포도 과원에서 보고된 장님노린재에는 애무늬고리장님노린재와 초록장님노린재가 있으며, 포도 신초를 가해해 잎 이 자라면서 구멍이 나고, 포도알을 흡즙해 포도알 표피를 코르크화해 상품성을 떨어뜨린다. 애무늬고리장님노 린재는 약충은 3~4mm, 성충은 4~5mm 정도이며, 몸 색깔은 엷은 녹색을 띄고, 다리(설상부) 끝이 검어 초록장님노 린재와 구분된다. 조사지점에서는 애무늬고리장님노린재만 채집되었으며, 나무당 0~4.8마리가 발견되었다. 4월 하순 상대습도 40% 이상이고, 일평균기온이 13℃ 이상 10일 정도 경과하였을 때 알에서 부화해 신초를 가해 하기 시작했다. 5월 하순부터 성충이 되며, 포도원 살충제 살포로 인해 개체수가 감소하였다가 7월 초경에 초목성 식물에서 포도원으로 들어와 새로 나오는 포도 부초를 가해하였다. 방제시기에 따라 상품과일 무게가 차이가 났는데 잎전개기, 꽃송이분리기, 착과기 3회 방제시 수량감소율이 1%인데 비해 잎전개기에만 방제시 3.5%, 꽃송 이분리기에만 방제시 7.9%, 무처리구에서는 15.6%로 방제 시기에 따라 상품과일 감소량이 차이나는 것을 알 수 있었다.
        12.
        2023.10 구독 인증기관·개인회원 무료
        The genus Conicera Meigen is a group of necrophagous phorid flies mostly associated with carrion, including C. tibialis, commonly known as the “coffin fly” that breeds in buried corpses. In this study, specimens of the Conicera species collected from South Korea are examined morphologically on the basis of characteristics on male antennae, sensory organ on midfemora, and left and right surstyli on hypopygium. As a result, five species, viz. C. dauci, C. gracilis, C. orientalis, C. pacifica, C. quadrata are newly recorded from South Korea. Photographs of diagnostic characters, a distribution map and a key to males of South Korean species are provided.
        14.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper presents a study on the design and implementation of a secure contactless system leveraging Quick Response (QR) codes as a core component. The main goal of this system is to bridge the gap between strong security and improved user experience within the realm of digital interaction. The system's versatility can be expanded with broad compatibility with a variety of applications. Utility can be expanded to areas such as contactless payments, electronic ticketing, secure identity verification, and convenient access to medical records. The international standardization of QR codes ensures seamless cross-platform compatibility, strengthening their role in the digital ecosystem. We actually create and develop a non-contact security QR code system and check the expandability of the system. This study highlights the pivotal role of QR codes within the realm of secure contactless systems. Through its effective balance of digital security and user convenience, QR codes are emerging as an important element in the continued development of a secure and user-friendly digital environment. The potential for future research lies in exploring more complex use cases and further advancements that improve both security and user-centered design.
        4,000원
        19.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Elastic and non-elastic taping are widely used in clinical practice, but there are various methods of attachment. Objectives: To investigate the effect of the type and intensity of taping on the muscle strength and muscle endurance of healthy adults. Design: Experimental research. Methods: 38 healthy adults participated in this experiment. Before applying the taping to each participant, the muscle strength and endurance of the quadriceps femoris were measured. After applying three different taping intervention methods, muscle strength and muscle endurance changes were measured. Muscle strength and endurance were measured through CSMI. Repeated measures ANOVA was used for statistics on participant measurements. Results: All intervention methods influenced the muscle strength improvement of the quadriceps femoris. Elastic tape with 50% elasticity had a greater impact on muscle strength than 33% elastic tape and non-elastic tape, and secondly, elastic tape with 33% elasticity was effective, and non-elastic tape had the least impact. Muscle endurance improvement was affected by the order of 50% elasticity taping, 33% elasticity taping, and non-elastic taping. Conclusion: All three taping intervention methods showed significant effects on improving muscle strength and muscle endurance of the wide-legged quadruple muscles, but the best effect was to apply 50% elastic taping.
        4,000원
        20.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Pain Neuroscience Education (PNE) is an educational approach that deals with the physiology of the nervous system as well as the pain system and refers to educating patients with chronic musculoskeletal disorders such as chronic back pain. Objectives: This study examined the effects of pain neuroscience education on patients with low back pain. Design: Systematic review. Methods: Electronic bibliographic databases of a regional information sharing system (RISS) and PubMed were searched to identify randomized controlled studies. In the final outcome, 43 publications were identified, and 13 studies met the inclusion criteria. Results: There were a total of 13 pain-related studies, including 11 studies using NPRS (VAS) and 2 studies using other pain measurement instruments. In NPRS, the effect size was 0.683, which had a medium effect size. In Roland morris disability questionnaire (RMDQ), the effect size was 0.544, which had a medium effect size. In Oswestry disability index (ODI), the effect size was 0.951, indicating a large effect size, but the confidence interval could not be obtained because there was only one study. Conclusion: Pain neuroscience education has positive effects on low back pain and disability index in related patients.
        4,000원
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