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        검색결과 450

        326.
        2022.09 KCI 등재 서비스 종료(열람 제한)
        In this study, we improved the water-based condensation particle counter in Atmospheric Research Aircraft NARA and investigated the condensation particle number concentration over the Korean peninsula. Pump and set point information were changed to improve the instrument used by aircraft for observation. Ground-based observational result showed that the error between two instruments, which are water-based condensation particle counter and butanol-based condensation particle counter, was 4.7%. Aerial observational result revealed that the number concentration before improvement indicate large variation with unstable condition, whereas the number concentration after improvement indicate a reasonable variation. After improvement, the number concentration was 706±499 particle/㎤ in the West Sea and 257±80 particle/㎤ in Gangwon-do, and these are similar to the concentration range reported in previous studies. Notably, this is the first attempt to use aerial observation with water-based condensation particle counter to investigate condensation particle number concentration.
        327.
        2022.02 KCI 등재 서비스 종료(열람 제한)
        In this study, we investigated the characteristics of the meteorological and environmental conditions for a cloud seeding experiment over the Korean peninsula and estimated the available days for the same. The conditions of available days appropriate for a cloud seeding experiment were classified according to four purposes: water resources, drought relief, forest fire prevention, and air quality improvement. The average number of available days for a cloud seeding experiment were 91.27 (water resources), 45.93–51.11 (drought relief), 40.28–46.00 (forest fire prevention), and 42.19–44.60 days/year (air quality improvement). If six experiments were carried out per available day for a cloud seeding experiment, the number of times cloud seeding experiments could be conducted per year in a continuously operating system were estimated as 547.62 (water resources), 275.58–306.66 (drought relief), 241.68–276.00 (forest fire prevention), and 253.14–267.60 times/year (air quality improvement). From this result, it was possible to determine the appropriate meteorological and environmental conditions and statistically estimate the available days for a cloud seeding experiment. The data on the available days for a cloud seeding experiment might be useful for preparing and performing such an experiment.
        328.
        2021.12 KCI 등재 서비스 종료(열람 제한)
        In this study, we investigated the optimal meteorological conditions for cloud seeding using aircraft over the Korean Peninsula. The weather conditions were analyzed using various data sources such as a weather chart, upper air observation, aircraft observation, and a numerical model for cloud seeding experiments conducted from 2018 to 2019 by the National Institute of Meteorological Sciences, Korea Meteorological Administration. Cloud seeding experiments were performed in the seasons of autumn (37.0%) and winter (40.7%) in the West Sea and Gangwon-do. Silver iodide (70.4%) and calcium chloride (29.6%) were used as cloud seeding materials for the experiments. The cloud seeding experiments used silver iodide in cold clouds. Aircraft observation revealed relatively low temperatures, low liquid water content, and strong wind speeds in clouds with a weak updraft. In warm clouds, the cloud seeding experiments used calcium chloride. Observations included relatively high temperatures, high liquid water content, and weak wind speeds in clouds with a weak updraft. Based upon these results, we determined the comprehensive meteorological conditions for cloud seeding experiments using aircraft over the Korean Peninsula. The understanding of optimal weather conditions for cloud seeding gained from this study provide information critical for performing successful cloud seeding and rain enhancement.
        329.
        2020.11 KCI 등재 서비스 종료(열람 제한)
        The statistical characteristics of aerosol–cloud interactions over East Asia were investigated using Moderate Resolution Imaging Spectroradiometer satellite data. The long-term relationship between various aerosol and cloud parameters was estimated using correlation analysis, principle component analysis, and Aerosol Indirect Effect (AIE) estimation. In correlation analysis, Aerosol Optical Depth (AOD) was positively Correlated with Cloud Condensation Nuclei (CCN) and Cloud Fraction (CF), but negatively correlated with Cloud Top Temperature (CTT) and Cloud Top Pressure (CTP). Fine Mode Fraction (FMF) and CCN were positively correlated over the ocean because of sea spray. In principle component analysis, AOD and FMF were influenced by water vapor. In particular, AOD was positively influenced by CF, and negatively by CTT and CTP over the ocean. In AIE estimation, the AIE value in each cloud layer and type was mostly negative (Twomey effect) but sometimes positive (anti-Twomey effect). This is related to regional, environmental, seasonal, and meteorological effects. Rigorous and extensive studies on aerosol–cloud interactions over East Asia should be conducted via micro- and macro-scale investigations, to determine chemical characteristics using various meteorological instruments.
        330.
        2020.10 KCI 등재 서비스 종료(열람 제한)
        구기자 잎을 이용한 특허제품 개발 및 기능성 식품소재에 관한 연구는 다수 진행되고 있으나 구기자 잎을 규격화 표준화하여 대량으로 공급할 수 있는 생산체계는 확립되어 있지 않다. 이에 구기자 육성품종 중에서 잎 생산에 알맞은 품종을 선발하고 가공용 잎을 대량으로 생산할 수 있는 예취시기를 확립코자 하였다. 구기자 11품종 중 잎 생산에 적합한 품종은 ‘명안’이었고, 다른 품종에 비하여 잎이 크고 분얼과 재생력이 왕성하였을 뿐만 아니라 잎 건물수량도 높았다. ‘명안’ 품종에서 구기자 잎 생산에 적합한 예취시기는 초장이 약 60 ~ 70 cm 자랐을 시기였고, 잎 수량은 5월 16일 수확 시 평균 106 ㎏/10a, 6월 20일 수확 시 평균 287 ㎏/10a로서 수확시기가 늦어질수록 직선적으로 증가되었다. 구기자의 지표성분인 베타인 함량을 1.43 ~ 2.63% 범위였고, 품종과 예취시기에 따라 함량이 다른데 생육이 진전 될수록 증가되는 경향이었다. 구기자나무 잎의 주요 생리기능성을 조사한 결과 항고혈압성을 나타내는 ACE 저해활성이 평균 84.4 ~ 90.8%로 높은 편이었고, 나머지 생리기능성은 20% 이하로 낮거나 검출되지 않았다.
        331.
        2019.10 서비스 종료(열람 제한)
        최근에는 건설 시장에서는 숙련노동자의 부족, 작업환경 개선, 시공 안정성 확보 그리고 구조물의 내진성능 확보 등을 위하여 PC 구조물의 선호도가 증가하고 있지만 PC 제품을 벽체 구조에 적용하기 위해서는 유효두께의 확대 기술, PC 패널의 강결 접합 기술 그리고 시공방법의 개발이 요구되고 있으므로 본 연구에서는.JPC 더블월 공법을 개발하여 PC 벽체의 단면 효율성을 개선하였으며, PC 부재로 단일 구조물을 형성하여 일체 구조물로 거동할 수 있도록 시공하기 위한 JPC 공법을 제시하였다.
        332.
        2019.09 KCI 등재 서비스 종료(열람 제한)
        Surface electromyogram (sEMG), which is a bio-electrical signal originated from action potentials of nerves and muscle fibers activated by motor neurons, has been widely used for recognizing motion intention of robotic prosthesis for amputees because it enables a device to be operated intuitively by users without any artificial and additional work. In this paper, we propose a training-free unsupervised sEMG pattern recognition algorithm. It is useful for the gesture recognition for the amputees from whom we cannot achieve motion labels for the previous supervised pattern recognition algorithms. Using the proposed algorithm, we can classify the sEMG signals for gesture recognition and the calculated threshold probability value can be used as a sensitivity parameter for pattern registration. The proposed algorithm was verified by a case study of a patient with partial-hand amputation.
        333.
        2019.08 KCI 등재 서비스 종료(열람 제한)
        본 연구는 에탄올과 염산으로 유도된 위염모델에 대해 익모초의 물 추출물이 위염예방효과를 나타내는지 알아보기 위해 진행하였고, 안전성 평가를 위해 유전독성평가인 소핵시험을 수행하였다. 익모초 물 추출물은 음성대조군 대비 위에서 분비되는 PGE2의 농도를 증가시켰을 뿐만 아니라 염산과 에탄올 투여에 의한 점막 표피세포 및 선상피세포의 손상과 울혈을 충분히 예방하는 것을 확인하였다. 또한 익모초 물 추출물에 대한 소핵시험을 실시한 결과, 익모초 물 추출물은 소핵을 유발하지 않는 것으로 나타났다. 결과를 종합하였을 때 익모초 물 추출물은 자체적으로 위염 예방효과를 나타냈지만 정확히 어떤 기전을 통해 예방하는지 추가적인 실험이 필요하다고 사료되며, 익모초에 포함된 여러 단일 성분을 이용해 위염 예방평가를 실시하여, 위염에 대한 익모초의 효능과 효율을 높이는 연구가 필요하다고 생각된다.
        334.
        2019.03 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to provide the demand information about services (S/W) and infrastructure (H/W) for rural welfare and culture. The survey was conducted on the overall satisfaction level, the condition change, the importance-satisfaction level of each field and the top priority items for administrative agencies and rural residents. In the overall satisfaction level, administrative agencies responded more than 'normal' to all fields, but the overall satisfaction level was lower than 'normal' in the fields excluding the healthcare field in the case of rural residents. In terms of condition changes compared to the past five years, both administrative institutions and local residents evaluated the improvement. IPA analysis was conducted to identify the priority ranking of each field and it was found that emergency medical facilities in the healthcare field, infant day care facilities in the social welfare field, movie theaters in the culture field, lifelong education institutions and academy facilities in the education field and private sports facilities in the leisure and sports field were most needed, respectively. The results of this study are expected to be helpful in increasing the efficiency and presenting the improvement direction about the development policy of the rural culture and welfare.
        335.
        2019.02 KCI 등재 서비스 종료(열람 제한)
        Background: Taraxacum platycarpum has been used in traditional medicine in Korea to treat intoxication and edema and as a diuretic. According to previous reports, it has anti-cancer, anti-gastritis, and anti-inflammation effects. However, the improvement effect of T. platycarpum on rheumatoid arthritis has not been investigated. The anti-oxidative and anti-inflammation effects of the aerial parts of T. platycarpum are different from those of its subterranean parts. Thus, we evaluated the effect of the water extracts of Taraxaci radix (WTR) on type II collagen-induced rheumatoid arthritis (CIA) in animal models. Methods and Results: Rheumatoid arthritis was induced by type II collagen. WTR (100㎎/㎏ and 500㎎/㎏) was administered to the animal models. Methotrexate was used as the positive control. The levels of interleukin-6, TNF-alpha, and type II collagen IgG in the animals were measured by using enzyme-linked immunosorbent assay. Treatment with 500㎎/㎏ WTR decreased the serum levels of interleukin-6, TNF-alpha, and collagen IgG in the CIA models. Moreover, treatment with WTR diminished the arthritisinduced swelling of the hind legs and monocyte infiltration in the bloodvessels of the animal models. Conclusions: These results indicate that WTR has the potential to improve rheumatoid arthritis by reducing the levels of inflammatory cytokines such as interleukin-6 and TNF-alpha. However, further experiments are required to elucidate the influence of WTR on signal transduction in vitro and in vivo.
        336.
        2018.10 서비스 종료(열람 제한)
        Monitored anesthesia care (MAC) has been described as a specific anesthesia service for diagnostic or therapeutic procedures performed under local anesthesia along with sedation and analgesia, titrated to a level preserving spontaneous breathing and airway reflexes. Radio-frequency ablation (RFA) is a kind of methods to remove benign thyroid nodules (BTNs) by inducing the irreversible injuries with the use of an ultrasound-guided RF electrode placed inside the nodules. A 37 years old, 157 cm, 81 kg woman underwent RFA of BTNs under MAC. We present with a case report where laryngospasm under MAC was resolved by the use of positive pressure ventilation without any complications.
        337.
        2018.10 서비스 종료(열람 제한)
        Recently, the use of PC(Precast Concrete) structure is increasing due to quality assurance and process shortening. In this study, we proposed a PPC method that improved the seismic performance of Half PC method by connecting the cast iron of PC wall to the foundation anchor using sleeve. In addition, the inner and outer PC walls are fabricated as one body, and the PPW method suitable for the high wall structure is proposed.
        338.
        2018.09 KCI 등재 서비스 종료(열람 제한)
        After it was reorganized as the rural center revitalization project recently, there is an opinion that the nature of the project was changed to solve long-time aspired projects of some districts unlike various projects according to the previous project purposes. Therefore, this study analyzes the current status of revitalization project plans and operation monitoring to make rural center villages, establishes plans that can be applied to the rural center village revitalization project and suggests the improvement plans for monitoring. With the necessity of connectivity with centrality analysis for long-term and sustainable growth of the rural center revitalization project, the analysis on the 8 districts' centrality analysis and the function of the master plan were compared and analyzed, but there is not enough interrelation. Regarding the consulting methods for weak districts to activate facility operation after the project is implemented, the field consulting performed by the collaboration of Gyeongsangnam-do government, Gyeongnam Rural Revitalization Support Center and Gyeongnam branch of Korea Rural Community Corporation shows 87.6% of satisfaction level, which indicates it is the most effective. Based on the above results, it is necessary to reinforce the methods on resident demand survey, dimension and the reflection process of the project when preliminary plans are established for effective implementation of the rural center village revitalization project. It is also necessary to revise relevant standards not to change preliminary plans excessively during the master plan establishment process, and to oblige preliminary investigation of experts. The joint monitoring and consulting systems of experts and local governments should be applied from the establishment stage of the master plan, so that it can be sustainable rural center village revitalization project.
        339.
        2018.05 서비스 종료(열람 제한)
        1급 발암물질로 지정된 석면은 과거 단열 및 건축자재로 활용이 되었다. 최근 석면이 함유된 건설 폐기물 등을 철거 및 처분하는 방법들이 많이 보고가 되고 있으나, 이를 처리하기 위한 방법들은 비교적 고온을 필요로 하는 에너지 다소비 공정이라는 단점이 존재한다. 산을 활용한 석면함유물질의 처리방법은 환경적인 부분의 2차 문제를 발생시킬 수 있다는 단점이 존재하며, 고온을 활용한 방법에 비교하여 완전 무해화에 대한 효율이 현저히 낮다는 단점이 존재한다. 석면 함유 폐기물의 다른 처리방법으로는 매립이 대표적이라고 할 수 있으나, 철거된 석면 물질들이 매립을 위해 이송되는 과정에서 비산될 수 있다는 단점이 있다. 따라서 본 연구는 앞서 언급한 석면처리 기술의 단점들을 보완할 수 있는 저에너지 소비 형태의 석면처리 방법을 연구하였다. 연구방법으로는 최근 화두가 되고 있는 이산화탄소 저장 및 활용(CCUS) 기법을 적용하여 석면을 포함한 폐기물의 표면을 탄산염의 형태로 전환하여, 석면의 이송과정에서 2차 비산을 막고 저에너지 소비 형태의 공정을 적용함으로써 경제성을 극복하고자 하였다. 연구결과 석면에 포함된 다양한 금속양이온은 상온, 상압의 조건에서 탄산염으로 형성이 되는 것을 확인하였으며, 형성된 탄산염은 석면폐기물의 표면에서 결정이 성장하여 석면을 코팅하는 효과가 있음을 나타내었다. 하지만 폐기물내 존재하는 금속양이온은 농도가 낮기 때문에 표면의 완전코팅을 위한 방편으로 건설폐기물의 침출수를 가정한 높은 pH의 칼슘함유 폐수를 투입하는 연구를 수행하였다. 2차 실험의 결과 칼슘이온은 이산화탄소와 반응하여 탄산칼슘의 형태로 전환이 되었으며, 투입된 폐수의 pH는 약 8.7의 값을 나타내어 폐수와 석면을 동시에 처리할 수 있는 가능성을 보였다. 생성된 탄산칼슘은 폐기물의 표면에서 결정이 성장하여 폐기물의 표면이 완전 코팅이 되었음을 알 수 있었다. 그러므로 본 연구에서 적용한 탄소광물화기법을 활용한 석면폐기물의 처분방법은 저비용으로 석면 함유 폐기물을 안정적으로 처리할 수 있는 가능성을 보여주었으며, pH가 높은 폐수를 중화하여 배출할 수 있는 추가적인 경제성을 지니는 결과를 보였다고 사료된다. 따라서 본 연구는 새로운 기법의 석면처리방법을 제시함으로써 추가적인 연구수행을 통하여 국내 석면 폐기물과 폐수, 이산화탄소를 동시에 처리할 수 있는 새로운 방향을 제시한다는 것에 의의가 있음을 알 수 있다.
        340.
        2018.03 KCI 등재 서비스 종료(열람 제한)
        본 연구는 다성분계 고유동 모르타르의 특성에 관한 연구이다. 보통 포틀랜드 시멘트(OPC), 고로슬래그 미분말(GGBFS), 칼슘설포알루미네이트(CSA) 그리고 초속경시멘트(URSC)를 혼합한 결합재이다. GGBFS는 OPC 질량에 대해 30%(P7 series), 50%(P5 series) 그리고 70%(P3 series)치환하였고, CSA와 URSC는 10%와 20%를 치환하였다. 혼화제는 폴리카르복실계를 사용하였다. 모든 배합의 물-결합재 비(w/b)는 0.35로 일정하다. 실험은 미니슬럼프, V-funnel, 압축강도 그리고 건조수축을 측정하였다. 실험결과 CSA와 URSC의 치환율이 증가하면 혼화제 사용량, V-funnel 시간 그리고 압축강도는 증가하였다. 또한 응결시간과 건조수축은 CSA와 URSC의 치환율이 증가함에 따라 감소하였다. CSA는 건조수축을 감소시키지만 URSC는 효과가 미미하다. CSA와 URSC를 혼합한 결합제는 상호보완 작용에 의해 건조수축 감소효과가 컸다. 이는 URSC의 초기강도 향상효과와 CSA의 팽창과 장기강도 향상효과 때문이다.