검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 8,685

        221.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적: 본 연구는 인지가 건강한 지역사회 중고령자 인구를 대상으로 한 인지적 여가활동 중재연구를 분석하여 국내 지역사회 적용을 위한 근거를 마련하고자 한다. 연구방법: 본 연구에서는 2013년 1월부터 2023년 12월까지 최근 10년간 국외 학술지에 게재된 문헌을 대상으로 PRISMA 지침에 따라 문헌고찰을 진행하였다. PubMed, EMBASE, Web of Science, CINAHL, APA PsycInfo 데이터베이스를 사용하였으며, 주요 검색어로 (“elderly” OR “older*”) AND (“leisure*” OR “leisure activities”) AND (“cognitive*”AND “dementia”)를 사용하였다. 대조군이 있는 실험연구를 선정하였으며, Physiotherapy Evidence Database (PEDro) scale을 통해 선정된 문헌의 질을 평가하였다. 결과: 최종 6편의 연구 분석결과, 인지적 여가활동 중재는 악기 연주, 독서, 보드게임, 직소 퍼즐의 네 가지 범주로 구분되었으며, 악기 연주와 보드게임 중재가 각 2편으로 가장 많았다. 직소 퍼즐을 제외한 중재에서 실험군은 대조군에 비해 인지기능에서 유의한 향상을 보였으며, 이는 음운언어 및 범주언어 유창성, 언어 및 시각 작업기억, 집행기능과 억제조절, 분리주의력, 시각적 스캐닝, 전반적인 인지기능 개선을 포함한다. 또한, 여가활동 수행기술, 기분상태, 신체적 및 심리적 건강 영역에서의 삶의 질의 개선 효과도 관찰되었다. 결론: 본 연구는 일부 인지적 여가활동 중재가 지역사회 중고령층부터 고령층에 이르는 지역사회 인구의 인지기능 및 심리사회적 영역에 긍정적인 영향을 줄 수 있음을 확인하였다. 향후 작업치료 분야에서 인지 건강 강화를 위해 다양한 인지적 여가활동이 일상생활의 일부로서 적극적으로 활용되기를 기대한다.
        4,900원
        222.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study aims to provide quantitative profile values for the objective evaluation of concrete surface profile (CSP) grades in concrete structures. The main aims are to quantify the CSP grade required for concrete surface pretreatment and proposing a more suitable CSP grade for structural maintenance. METHODS : Initially, the challenges in measuring concrete surface profiles were outlined by analyzing pretreatment work and profile samples of concrete pavements. Theoretical foundations for quantifying concrete surface roughness were established, and regression models including linear regression, cubic regression, and log regression were selected. Additionally, the interquartile range anomaly removal technique was employed to preprocess the data for regression modeling. RESULTS : Concrete CSP profiles were measured through indoor tests, and the measured data were quantified. Linear regression, cubic regression, and log regression models were applied to each CSP grade for comparative analysis of the results. Furthermore, comparative studies were conducted through adhesion strength tests based on the CSP grade. CONCLUSIONS : Our results are expected to establish objective standards for the pretreatment stage of concrete repair and reinforcement. The derived reference values can inform standards for the restoration and reinforcement of concrete structures, thereby contributing to performance improvement. Moreover, our results may serve as primary data for the repair and reinforcement of various concrete structures such as airports, bridges, highways, and buildings.
        4,200원
        223.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The study aimed to investigate the impact of varying levels of neutral detergent-soluble fiber (NDSF) in Hanwoo growing cattle diets on rumen fermentation and methane (CH4) emissions. An in vitro rumen fermentation experiment utilized feeds with different NDSF levels, incorporating ingredients such as corn grain, soybean meal, soybean hulls, palm kernel meal, beet pulp and timothy hay. The NDSF contents in the diets were 9.02% (T1), 10.09% (T2), 12.42% (T3) and 14.63% (T4). In vitro dry matter digestibility (IVDMD) at 48 h was 7.4% higher for T4 compared to T1 (p<0.05). Total gas production at 48 h was 6.6% higher for T4 than T1 (p<0.05). CH4 production significantly decreased at 9 h and 12 h for T1 and T2 (p<0.05). At 48 h, CH4 production was 5.6% higher for T4 compared to T1 and 6.7% higher compared to T2 (p<0.05). At 12 h ans 24 h, the ammonia nitrogen concentration of T4 was approximately 33.1% and 40.4% lower, respectively, compared to T1 (p<0.05). The acetate to propionate ratio at 48 h was approximately 18.8% higher for T4 than T1 (p<0.05). From 9 h to 48 h, the proportions of butyrate and valerate were significantly higher for T4 (p<0.05). At 48 h, the dominant phylum in T4's rumen microbial community was Candidatus Thermoplasmatota Methanomassiliicoccus, an Archaea. Therefore, this study confirmed that increasing the NDSF content in growing Hanwoo cattle diets up to 12.42% increases IVDMD without increasing CH4 emissions, which is expected to positively impact Hanwoo productivity.
        4,300원
        224.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 지구온난화로 인해 발생하는 폭우 및 강설과 같은 비정상적인 기상 패턴으로 인해 도로 표면 결빙(블랙 아이스)으로 인 한 사고와 인명 피해가 증가하고 있으며, 이는 주요 문제로 대두되고 있습니다. 이러한 문제를 완화하기 위해 본 연구에서는 열저장 능력을 갖춘 상변화 물질(PCM)을 시멘트 복합재료에 포함시켰습니다. PCM은 상변화 과정에서 열에너지를 흡수, 저장 및 방출할 수 있어 온도 변동으로 인한 결빙을 최소화할 수 있습니다. PCM은 먼저 미세 캡슐화된 후 시멘트 복합재료에 강화되어 기계적 및 열적 성능 검증 연구가 수행되었습니다. 또한, 열전달 효율과 기계적 특성을 향상시키기 위해 다중벽 탄소나노튜브(CNT)와 실리카 퓸이 추 가되었습니다. 미세 캡슐화된 PCM의 열 성능은 열 거동을 측정하기 위한 재료 실험을 통해 검증되었습니다. 이후, 제조된 시멘트 복 합재의 기계적 및 열적 성능 테스트가 그 효과를 평가하기 위해 수행되었습니다. 이러한 테스트 동안 일정 온도와 습도 챔버를 사용한 열 주기 테스트가 열 성능을 검증하기 위해 수행되었습니다. 기계적 성능 실험에서는 CNT와 실리카 퓸의 포함이 미세 캡슐화된 PCM 의 포함으로 인한 강도 저하를 완화하는 것을 확인하였습니다. 더욱이, 열 주기 테스트를 통해 고효율 열저장 시멘트 복합재가 결빙 조건에서도 영하의 온도를 유지할 수 있음을 보여주었으며, 이는 효율적인 열저장 성능을 입증하였습니다.
        4,000원
        225.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Recently, air pollution due to fine particulate matter has been increasing in Korea. Nitrogen oxides (NOx) are particulate matter precursors significantly contributing to air pollution. Increasing efforts have been dedicated to NOx removal from air, since it is particularly harmful. Application of titanium dioxide (TiO2) for concrete road structures is a suitable alternative to remove NOx. As the photocatalytic reaction of TiO2 is the mechanism that eliminates NOx, the ultraviolet rays in sunlight and TiO2 in existing concrete structures need to be contacted for the reaction process. For the application of vertical concrete road structures such as retaining walls, side ditches, and barriers, a pressurized TiO2 fixation method has been developed considering the pressure and pressurization time. In this study, longterm serviceability and repeatability were investigated on concrete specimens applying the dynamic pressurized TiO2 fixation method. Additionally, the environmental hazards of nitrate adsorbed on TiO2 particles were evaluated. METHODS : Concrete specimens to simulate roadside vertical concrete structures were manufactured and used to evaluate the long-term serviceability and repeatability of the dynamic pressurized TiO2 fixation method. The NOx removal efficiency was measured using NOx evaluation equipment based on ISO 22197-1. In addition, the nitrate concentration was measured using a comprehensive water quality analyzer for evaluating environmental hazards. RESULTS : As the experiment to evaluate the NOx removal efficiency of the dynamic pressurized TiO2 fixation method progressed from one to seven cycles, the nitrate concentration increased from 2.35 mg/L to 3.06 mg/L, and the NOx removal efficiency decreased from 53% to 25%. After seven cycles of NOx removal efficiency evaluation, the average nitrate concentration was 3.06 mg/L. The nitrate concentration collected immediately after the NOx removal efficiency test for each cycle was in the range of 2.51 to 2.57 mg/L. By contrast, it was confirmed that the nitrate concentration was lowered to approximately 2.1 mg/L when the surface was washed with water. CONCLUSIONS : The NOx removal efficiency was maintained at over 25% even after seven cycles of NOx removal efficiency evaluation, securing long-term serviceability. In addition, the harmful effects on the environment and human health are insignificant, since the nitrate concentration was less than 10 mg/L, in accordance with domestic and foreign standards. Practical applicability of the pressurized TiO2 fixation method was established by evaluating the long-term serviceability, repeatability, and environmental hazards.
        4,000원