검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 264

        1.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated major constituents and anti-inflammatory effects of an ethanol extract of Platycodon grandiflorum leaves. Through HPLC analysis, chlorogenic acid and luteolin-7-O-glucoside were identified as predominant constituents in the ethanol extract. Their anti-inflammatory effects were evaluated using murine macrophage (RAW 264.7 cells) and human lung carcinoma cells (NCI-H292 & A549). The ethanol extract significantly (p<0.01) inhibited the production of nitrite, interleukin-6 (IL-6), and prostaglandin E2 (PGE2) induced by lipopolysaccharide (LPS) in RAW 264.7 cells. Furthermore, the ethanol extract suppressed the expression of cyclooxygenase-2 (COX-2) and inducible NO synthase (iNOS) proteins in RAW 264.7 cells stimulated with LPS. In NCI-H292 and A549 cells, treatment with the ethanol extract significantly (p<0.05) decreased levels of pro-inflammatory cytokines IL-6 and IL-8 induced by IL-1β. The phosphorylation of ERK rather than JNK in the mitogen-activated protein kinase signaling pathway was observed to be a more important mediator in the down-regulation of pro-inflammatory cytokines in NCI-H292 cells. These findings suggest that the ethanol extract of Platycodon grandiflorum leaves containing luteolin-7-O-glucoside exhibits promising anti-inflammatory properties.
        4,500원
        4.
        2024.04 구독 인증기관·개인회원 무료
        우리는 콘크리트 세상 속에 살고 있다고 해도 과언이 아니다. 콘크리트 도로를 달리고 콘크리트 건 물 속에서 살고 있다. 그런데 최근 노후화된 구조물의 붕괴 사례들이 지속적으로 발생하고 있으며 이 에 대한 원인 규명과 재발 방지, 그리고 기술적 사전 예측 등이 필요하다. 특히 우리나라의 경우 4계 절의 영향을 받는 철근콘크리트 구조물은 시간이 흐름에 따라 다양한 열화로 인해 강도가 저하되고, 이로 인해 건축물의 심각한 손상 및 붕괴가 발생하게 된다. 전국적으로 기온이 영하로 내려가는 겨울 철에는 동결융해의 영향으로 인한 강도 저하로 노후화가 진행되며, 콘크리트의 공기율에 따라 동결융 해로 인한 노후화 정도가 달라지게 된다. 이는 콘크리트 공기율에 따라 내구성지수가 변화하여 동결융 해의 영향 정도가 변화하기 때문이다. 그러나 기존의 콘크리트에 관한 동결융해 영향 연구는 재료에 대한 연구가 많지만, 상대적으로 큰 철근콘크리트 부재 단위에 대한 연구는 부족하다. 따라서 본 연구 에서는 철근콘크리트 부재를 대상으로 기중 동결융해 시험 방법을 통해 콘크리트의 공기율이 증가함 에 따른 재료 단위의 영향과 철근콘크리트 부재의 휨 거동 특성에 대한 영향을 분석하고자 한다.본 연 구에서는 동결융해를 입은 콘크리트가 공기율이 증가함에 따라 동탄성계수와 내구성지수를 비교하고, 이에 따른 압축강도 실험을 통해 동결융해의 영향을 평가하였으며 철근콘크리트 부재의 휨 실험을 통 해 동결융해가 콘크리트 공기율에 대하여 거동 특성, 탄성 강성 및 항복까지의 에너지 흡수 능력에 미 치는 영향을 비교하여 분석하였다. 또한 ABAQUS 해석 프로그램을 사용하여 유한요소 모델을 제안하 고 휨 거동 성능을 실험값과 비교하여 분석하였다.
        5.
        2024.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study divided the area capable of producing domestic forage into grazing pasture, hay production area, and silage crop area, calculated the required area according to the forage production volume, and examined whether self-sufficiency in forage leads to cost savings. When the self-sufficiency rate of forage for dairy cows and Hanwoo is 80%, the improvement in profitability per heaf ranges from 3% to 9%, typically around 5%, which is considered a significant benefit for both corporate and individual businesses. The average profit per ranch is expected to increase about KRW 50 million per year, and the country as a whole is expected to reduce forage costs by KRW 0.9 trillion per year. Recently, efforts are being made by the government and local authorities to cultivate summer forage at the rice fields for improving self-sufficiency in forage feed to stabilize rice supply and demand. Furthermore, it is also necessary to conduct research on reducing the cost of concentrated feed and TMR (Total mixed ration).
        4,000원
        6.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 항공서비스 전공 대학생의 전공선택동기를 내재적· 외재적 전공선택동기로 구분하여 전공선택동기가 전공만족도를 매개로 대학생활적응과 진로준비행동에 어떠한 영향을 미치는지를 알아보는데 있다. 이를 위해 충청지역 4년제 J대학의 항공서비스 전공 대학생 236명 을 대상으로 설문조사를 실시하였으며, 본 연구의 결과를 요약하면 다음 과 같다. 첫째, 내재적 전공선택동기는 대학생활적응 및 진로준비행동에 정(+)의 영향을 미치는 것으로 나타났다. 둘째, 외재적 전공선택동기는 전공만족도에 유의한 정(+)의 영향을 미치는 것으로 나타났다. 셋째, 전 공만족도는 대학생활적응과 진로준비행동에 유의한 정(+)의 효과가 있는 것으로 나타났다. 넷째, 매개효과 검증결과 내재적 전공선택동기는 전공 만족도를 매개로 한 간접효과는 없지만, 외재적 전공선택동기는 전공만 족도를 매개로한 간접효과가 있는 것으로 나타났다. 따라서 대학생의 성 공적인 대학생활적응을 위해서 학생들의 전공선택동기를 파악하는 것이 중요하며, 대학생활적응 및 진로준비행동을 향상시키기 위해서는 전공만 족도의 역할이 중요함을 확인할 수 있었다. 이러한 결과를 바탕으로 항 공서비스 전공 대학생의 건강한 대학생활적응을 돕고, 학생들의 진로상 담에 도움이 될 수 있는 기초자료를 제공하고자 한다.
        6,600원
        7.
        2024.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 대학 창의융합수업에서 Appreciative Inquiry 교수학습방법을 적용한 후 창의융합역량 학습 성과 효과를 분석하는 것을 목적으로 하였다. 이를 위하여 창의융합교육을 위한 창의융합역량 학습성과 평가도구를 개발하고 이를 타당화하였다. 이후, 경기도 소재 G 대학교 경영대학원에서 교육경영 교과목을 수강하는 대학원생 12명을 대상으로 교수학습 방법을 적용한 창의융합교육을 실시하고 창의융합역량 학 습성과 효과를 분석하였다. 연구결과, 팀기반 Appreciative Inquiry 교수학습 방법이 학습자의 창의융합역 량 학습성과 증진에 유의미한 역할을 하였다. 학습자-학습자간, 교수자-학습자간 평가로 실시한 학습성 과 평가에서 Appreciative Inquiry의 4D 활동이 혁신적 사고, 다양한 아이디어, 경험의 결합, 협력적 태도 역량 증진에 효과적인 것으로 분석하였다. 이를 통해 창의융합교육에서 학습자의 적극적인 참여와 협업을 바탕으로 긍정적인 분위기의 아이디어 발산과 공유의 팀기반 교수학습 방법이 창의융합역량 학습성과에 효과가 있다 결론을 도출하였다.
        5,500원
        8.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study is to analyze the reduction effect on road pavement damage from the installation of weigh-in-motion systems used for overloaded vehicle enforcement, from the perspective of traffic assignment. METHODS : Fixed-demand multi-class traffic assignment was conducted by VISUM, a macroscopic traffic simulation software. We considered three vehicle classes and calculated the traffic load for each road link using the ESAL(Equivalent Single Wheel Load) factor, as proposed by ASHTTO(American Association of State Highway and Transportation Officials). We set up scenarios with weigh-in-motion installations in certain sections and observed how the traffic load changed before and after the installation of weigh-in-motion for each scenario. RESULTS : Three main trends were observed. Firstly, at points where weigh-in-motion systems were installed, traffic load significantly decreased even with the influx of cars and trucks following the restriction of overloaded trucks, highlighting the significant influence of overweight vehicles on the traffic load. Secondly, even when overweight vehicles detoured, there was no significant change in the overall network's traffic load. Lastly, the detour of overweight vehicles led to an increase in the total driving distance and time for all vehicles. CONCLUSIONS : Installing weigh-in-motion systems in sections with a lower structure number, which indicates thinner road pavement, can prevent damage in those specific areas without affecting the entire road network.
        4,000원
        9.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to address the increasing demand for technologies preventing mushroom fly damage. By monitoring the annual occurrence patterns of pests over several years and accumulating data, we conducted an analysis to evaluate the efficacy of preventive measures applied before the surge in mushroom fly infestation, typically observed in May. For preemptive control, physical measures involved installing air curtains at cultivation facility entrances and placing sticky traps and insect traps around entry points to block external entry and reduce internal insect density. Additionally, we applied an organic agricultural material, Dalmatian chrysanthemum extract, weekly alongside chemical control measures. To assess the reduction in mushroom fly populations, yellow sticky traps (15×25 cm) were placed at three locations within the mushroom cultivation facility, and the occurrence patterns before and after implementing preventive measures were compared. Compared to conventional practices, the application of preventive techniques resulted in a significant reduction, with a 60% decrease from 15 levels of mushroom flies/m² to 6 levels of mushroom flies/m² in May and a 40% decrease from 10 levels of mushroom flies/m² to 6 levels of mushroom flies/m² in June. While achieving over 50% efficacy during the peak mushroom fly season with preventive measures, we identified complementary actions such as blocking external sources (gaps in cultivation facility doors) and maintaining cleanliness around cultivation facilities (proper disposal of spent substrate) for further improvement. Comprehensive analysis and safety studies, including correlation analysis with contaminants and pathogens, are recommended to ensure the widespread adoption of mushroom fly preventive techniques for safe and stable mushroom production in the agricultural sector.
        3,000원
        11.
        2023.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study aims to analyze and summarize test results related to permeable blocks used for sidewalks and roadways as an alternative to conventional urban road pavement technology, specifically focusing on low-impact development (LID) techniques. Furthermore, it aims to provide reference data on the feasibility of current policy implementation and future policy directions through a longterm analysis of the performance and durability of permeable blocks in sidewalk and roadway construction. METHODS : The research methodology involves (1) conducting a survey on the status and actual conditions of permeability sustainability tests based on the results of permeability persistence tests conducted in Seoul over nine years, from 2013 to 2021; (2) analyzing the differences between the permeability block rating system of Seoul City and that employed by the Ministry of Environment; (3) analyzing the permeability of graded pavement sections in permeable blocks for sidewalks after three years of public use and deriving a regression analysis formula to estimate the maintenance period; (4) analyzing the permeability of pavement sections in permeable blocks for roadways after five years of public use and deriving a regression analysis formula to estimate the maintenance period. RESULTS : This study revealed significant improvements in the performance and quality control of permeable blocks since the implementation of the permeability sustainability test in Seoul in 2013. An analysis of the differences in the permeability coefficient and distribution based on the rating systems of Seoul City and the Ministry of Environment showed that rating system of Seoul City has approximately twice the permeability coefficient quality standard compared to that of the Ministry of Environment. Regression analysis indicated that the firstgrade permeable block was predicted to maintain its permeability for approximately 5.1 years, whereas the third-grade permeable block was predicted to maintain its permeability for approximately 3.1 years. In roadway-permeable block pavements, the first-grade sections maintained excellent quality conditions even after five years, and regression analysis predicted a permeability maintenance period ranging from eight to 17 years. CONCLUSIONS : The correlation analysis of the permeability coefficients based on the common usage period of permeable blocks for sidewalks and roadways presented in this study can provide more accurate estimations of commonality. However, further research under various environmental conditions is required to supplement these findings. Considering the lack of studies on permeable block commonality analysis in Korea, this study highlights the significance of conducting long-term experimental follow-up research to establish commonality prediction formulas for different usage scenarios.
        4,000원
        12.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to investigate the effects of using AI chatbots in Korean English education from a macro perspective. For this purpose, 19 experimental studies are selected to conduct a meta-analysis, synthesizing the results of 51 individual study cases. The results of this study are as follows: First, it is found that the overall effect size of using chatbots is more than medium size meaning that a chatbot is an effective tool to learn English. Second, in the aspects of linguistic competence and affective categories, each shows over medium sizes like the overall effect size. In details of the dependent variables, vocabulary and speaking in linguistic competence and motivation in affective categories, large effect sizes are shown. Third, the effect sizes are getting larger, as the younger the students are, the longer the experiment period lasts, and the more purpose-built the chatbot is. But the differences in the effect sizes in terms of these moderators (e.g., school level, experiment period, and chatbot type) are not significant. Lastly, it is suggested that follow-up studies are needed to collect a sufficient number of experimental study cases and subdivide the variables for performing a more detailed meta-anlysis.
        5,200원
        13.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 논문의 목적은 축사시설현대화 사업에 참여한 농가들이 사업 참여에 따라 생산성에 얼마나 향상을 가져왔는지를 계측하는 것이다. 분석 방법으로는 이중차분법을 사용하였다. 실험군 농가에 해당하는 사업참여농가들은 농협경제지주에서 보유한 사업참여농가들의 자료를 사용하였다. 대조군 농가에 해당하는 자료들은 통계청의 축산물생산비통계 조사를 위해 선정된 표본 농가들의 자료를 사용하였다. 이중차분법을 이용한 사업참여 의 순효과를 계측한 결과, 한우는 1등급 이상 출현율이 10.7%p 만큼 상승하였다. 젖소 농가들의 두당 착유량은 2.8% 증가하였다. 돼지 농가들의 PSY는 5.8% 증가하였다. 육계 농가들의 일당증체량은 4.5% 증가하였다. 산란계 농가들의 산란율은 5.2%p 상승한 것으로 나타났다. 이러한 결과는 선행연구들과 비교할 때 정도의 차이는 있지만 축사시설현대화 사업이 생산성에 긍정적인 영향을 미친다는 점에서 동일하다.
        4,000원
        14.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        혁신조달 제도는 전략적 공공조달 정책의 일환으로 혁신제품 지정 및 우선구매 제도를 활용해 기업의 혁신역량 향상과 공공부문의 사회문제 해결능력 향상을 동시에 추구하는 정책으로 도입됐다. 혁신제품에 대한 시범구매 사업은 2019년에 처음 도입됐으며 2020년부터 정부 부처의 혁신제품 지정·발굴 체계가 확립된 후 혁신제품 우선구매제도가 본격적으로 실시됐다. 이에 본 연구는 혁신조달 제도가 본격적으로 시행된 이후 해당 제도의 기업지원 효과에 초점을 맞춰 정량적 분석을 진행했다. 이를 위해 2017년에서 2021년까지의 기업 재무제표 및 고용 자료를 이용했으며, 분석방법으로 성향점수매칭(PSM) 및 이중차분(DID) 방법을 활용했다. 본 연구를 통해 혁신조달 제도가 기업성장과 고용증대에 기여했으며 추가적인 공공 및 민간판로 개척 효과를 창출했음을 확인할 수 있었다. 한편 혁신조달 참여기업이 제품지정 종료 이후에도 자생성을 갖추기 위해서는 혁신제품 지정기업과 기존의 중소기업 지원정책을 적극 매칭하는 등 혁신조달 제도를 고도화할 필요가 있다.
        7,000원
        15.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Kinesio taping (KT) is an intervention method used to improve early function after surgery; however, the effect of KT varies depending on the intervention method. Objectives: To investigated systematically review and quantitatively analyze the effect of KT randomized controlled trials (RCTs) applied to Total knee arthroplasty (TKA) to determine the value of the treatment method for TKA patients. Design: A systemic review and meta-analysis. Methods: Studies were identified by searching multiple electronic databases from January 2023 to February 2023. We selected RCTs comparing KT or no treatment, standard physical therapy, multimodal therapeutic approaches. When possible, we pooled data using random-effects meta-analysis. The Cochrane Bias Method Group's seven-item risk of bias (RoB) assessment tool was used for RCTs. The main outcomes were pain, swelling, and ROM. Results: Three trials (290 patients) provided sufficient data and were similar enough to be pooled for meta-analysis. The standardized mean difference for a reduction of pain was SMD = -1.02, 95 % CI -1.93 to -0.12; p= 0.03; I2= 92 %. The standardized mean difference for a reduction of swelling was SMD= - 0.23, 95 % CI -0.50 to -0.05; p= 0.10; I2= 58 %. The standardized mean difference for ROM was SMD= 1.06, 95 % CI -0.08 to 2.20; p= 0.07; I2= 95 %. Conclusion: KT has a large effect on pain reduction in TKA patients and could be used as an additional treatment option, but a small effect was observed in swelling and ROM.
        4,000원
        16.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Metal additive manufacturing (AM) has transformed conventional manufacturing processes by offering unprecedented opportunities for design innovation, reduced lead times, and cost-effective production. Aluminum alloy, a material used in metal 3D printing, is a representative lightweight structural material known for its high specific strength and corrosion resistance. Consequently, there is an increasing demand for 3D printed aluminum alloy components across industries, including aerospace, transportation, and consumer goods. To meet this demand, research on alloys and process conditions that satisfy the specific requirement of each industry is necessary. However, 3D printing processes exhibit different behaviors of alloy elements owing to rapid thermal dynamics, making it challenging to predict the microstructure and properties. In this study, we gathered published data on the relationship between alloy composition, processing conditions, and properties. Furthermore, we conducted a sensitivity analysis on the effects of the process variables on the density and hardness of aluminum alloys used in additive manufacturing.
        4,000원
        17.
        2023.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: Stroke is one of the causes affecting gait and balance. Taping is considered an effective method for improving balance and gait in stroke patients. Numerous studies have confirmed the functional effects of taping in stroke patients. However, there is still no consensus regarding the use of taping to improve gait and balance. Objects: The purpose of this review was to investigate the effects of taping on the balance and gait of patients with stroke through meta-analysis of studies. Methods: PubMed, Medline, Embase, Web of Science, Cochrane Review, RISS, DBPia, and Science on were used to collect articles on Kinesio and non-elastic taping. The key terms were “Stroke”, “Hemiplegia”, “Taping”, “Tape”, “Balance”, and “Gait” with cut-off of October, 2022. Taping group was compared with control groups with sham, placebo, and no taping. The outcome measures included the Berg Balance Scale (BBS), Timed Up and Go (TUG) test, and gait speed (cm/s). Eighteen studies (524 patients) were selected for the meta-analysis. Results: Overall, taping improved balance and gait in stroke patients, and Kinesio and nonelastic taping had similar effect sizes. Taping improved the BBS and TUG, and was most effective on gait speed. Contrary to the expectation that a longer duration of taping would be more affective, taping was most effective when the total taping duration was shorter than 500 minutes. In addition, the effect size of taping was greater when it was simultaneously attached to multiple locations. Conclusion: This meta-analysis supports the use of taping to improve gait and balance in stroke patients, and provides guidelines for the location, duration, and type of tape to increase taping efficiency.
        4,000원
        19.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Modi government has developed a somewhat unique affinity for Hindu nationalism, resulting in the adoption of radical policies to make Hindu nationalism rise significantly and become the mainstream ideology in India. However, this radicalisation has led to severe unrest in the society along with religious and ethnic lines, as well as serious antagonism, which in turn led to religious and ethnic dissent in the country. In order to divert nation's attention from pressing issues and channel the nationalists' energies, Modi government adopted aggressive policy orientation & posturing against neighbouring countries, including provoking border conflicts in Dong Lang, Galwan River Valley. This has exerted a significant impact on India's relations with its neighbours, particularly China. Consequently, India’s 'conscious resistance' and xenophobic attitude towards China is increasing which has led to a significant retreat from bilateral relations, obstruction of economic cooperation, and cultural exchanges between the two countries.
        6,600원
        20.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted in an indoor cultivation room and chamber where environmental control is possible to investigate the effect of temperature and irrigation interval on photosynthesis, growth and growth analysis of potted seedling cucumber. The light intensity (70 W·m-2) and humidity (65%) were set to be the same. The experimental treatments were six combinations of three different temperatures, 15/10℃, 25/20℃, and 35/25°C, and two irrigation intervals, 100 mL per day (S) and 200 mL every 2 days (L). The treatments were named 15S, 15L, 25S, 25L, 35S, and 35L. Seedlings at 0.5 cm in height were planted in pots (volume:1 L) filled with sandy loam and treated for 21 days. Photosynthesis, transpiration rate and stomatal conductance at 14 days after treatment were highest in 25S. These were higher in S treatments with a shorter irrigation interval than L treatments. Total amount of irrigation water was supplied evenly at 2 L, but the soil moisture content was highest at 15S and lowest at 25S > 15L > 25L, 35S and 35L in that order. Humidity showed a similar trend at 15/10℃ (61.1%) and 25/20℃ (67.2%), but it was as high at 35/25°C (80.5%). Cucumber growth (plant height, leaf length, leaf width, chlorophyll content, leaf area, fresh weight and dry weight) on day 21 was the highest in 25S. Growth parameters were higher in S with shorter irrigation intervals. Yellow symptom of leaf was occurred in 89.9% at 35S and 35L, where the temperature was high. Relative growth rate (RGR) and specific leaf weight (SLA) were high at 25/20℃ (25S, 25L), RGR tended to be high in the S treatment, and SLA in the L treatment. Water use efficiency (WUE) was high in the order of 25S, 25L > 15S > 15L, 35S, and 35L. As a result of the above, the growth and WUE were high at the temperature of 25/20℃.
        4,000원
        1 2 3 4 5