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        검색결과 1,429

        41.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to provide fundamental data that could guide high school students' night eating behavior by investigating habits of their night eating consumption during COVID-19 pandemic (From 2021/5/13 to 5/20). Association between their eating habits and the Nutrition Quotient for Korean Adolescents (NQ-A) were also explored. This study included a total of 604 students, among whom 441 students were identified as night eating consumers. Among all subjects, 30.5% consumed night eating 3~4 times a week, 27.3% consumed 1-2 times a week, and 27.0% did not consume any night eating at all. The high-night eating group had a higher score of total NQ-A than the non-night eating group for both male (p<0.05) and female (p<0.001) students. This was because male students in the high-night eating group reported significantly higher rates of daily dinner consumption compared to non-night eating group. Furthermore, both male (p<0.05) and female (p<0.001) students showed a significant increase in ‘Moderation’. ‘Diversity’ was also significantly increased in female studies (p<0.05) as subcategories of dietary habits according to night eating frequency. These findings highlight the need for practical research to develop nutritional guidelines for night eating that reflect preferences of students while providing adequate nutritional habits.
        4,500원
        42.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Polyethersulfone (PES)은 친수성과 상분리법의 용이성 덕분에 수처리 및 정제 분야에서 정밀여과 및 한외여과막 소재로 일반적으로 사용된다. 그러나, 비용매 유도 상분리법으로 제조된 PES 분리막, 특히 지지체가 없는 여과막의 경우 도 프의 조성과 기재의 특성에 따라 여과막 하부에 낮은 기공도를 갖는 치밀층이 형성되기 쉽고, 이러한 치밀층으로 인해 수투 과 저항이 증가하고 오염물질의 쌓임에 의한 막오염이 일어난다. 본 연구에서는 PES 여과막 제조 시 상전이 과정의 수축으 로 인해 분리막 하부에 물이 침투하여 치밀층을 형성, 심각한 막오염을 유발할 수 있음을 확인하였다. 동일한 선택층을 갖는 PES 여과막을 단일층 및 이중층 캐스팅법으로 각각 제조하여 하부 치밀층이 여과막의 투과성능 및 막오염에 미치는 영향을 파악하고자 하였다. 하부 치밀층이 없는 이중층 캐스팅된 여과막은 기존 여과막 대비 높은 투과성능 및 막오염에 대한 저항 성을 보였으며, 이를 통해 다공성 여과막의 내오염성을 향상시키기 위한 표면 기공도 및 기공 구조 등 물리적 구조의 최적화 가 중요함을 확인하였다.
        4,000원
        43.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Most Red bus1) (metropolitan bus) routes to Seoul need to increase supply by increasing the number of buses and number of trips because of the high level of congestion in buses, which also accommodate standing passengers. Due to the recent Itaewon disaster, people have been banned from standing on Red buses due to concerns over the excessive use of public transportation, adding to the inconvenience of passengers, such as increased travel time. However, some routes incur a large deficit owing to excess vehicles and trips relative to the number of passengers, thereby increasing the financial burden of Gyeonggi. Therefore, in this study, a reasonable operation plan is required based on the demand on Red bus routes. METHODS : Using accurate data from smart cards and a Bus Management System, the model was applied to consider bus usage, bus arrival distribution, waiting time, and operating conditions, such as actual bus usage time and bus dispatch interval. RESULTS : As a result of applying the model, buses between 7:00 and 9:00 and 16:00 and 18:00 were very crowded because of standing passengers, and passenger inconvenience costs decreased because of the longer waiting times for bus stops in Seoul. Currently, there are 15 buses in operation for the red bus G8110. However, considering the annual transportation cost, transportation income, and support fund limit, up to 12 buses can be operated per day. The G8110 route was analyzed at 23.6 million won for passenger discomfort cost, as 15 buses operated 97 times per day on weekdays. However, when establishing optimal scheduling, 12 buses per day operated 75 times per day, with a 19.7 million won passenger discomfort cost. CONCLUSIONS : As all red buses run from the starting point, passengers at the bus stop wait for more than an hour before entering Seoul, and the passenger discomfort cost of using demand-responsive chartered buses decreases only when commuting from Jeongja Station and Namdaemun Tax Office stops. Currently, many people commuting from Gyeonggi-do to Seoul are experiencing significant inconvenience owing to the ban on standing in Red buses; a suitable level of input can be suggested for the input and expansion of chartered buses.
        4,200원
        44.
        2023.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 DFT 재배 시스템을 이용한 밀폐형 식물생산시스 템에 MB처리 유무에 따른 상추(Lactuca sativa L.)와 배초향 (Agastache rugosa Kuntze)의 생육과 양액 특성을 조사하기 위해 수행되었다. 상추와 배초향은 밀폐형 식물생산시스템에 서 23일간 재배되었다. MB는 매일 9시, 13시, 17시에 5분씩 16일간 처리하였다. 상추와 배초향의 엽장, 엽폭, 엽면적, 생 체중 및 건물중은 MB처리구에서 대조구에 비해 유의하게 낮 았다. 상추와 배초향의 총 뿌리길이, 뿌리 표면적, 근단 수도 MB처리구에서 유의적으로 낮게 나타났다. 평균 뿌리 직경의 경우, 상추는 처리 간에 차이가 없었으나, 배초향은 MB처리 구에서 유의적으로 굵어 종 간에 차이가 있음을 확인하였다. 본 연구 결과, DFT 방식으로 상추와 배초향을 재배할 때 MB 처리는 비생물적 스트레스를 유발하여 생육을 억제하는 것으 로 나타났다.
        4,000원
        45.
        2023.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        기계적 자극은 식물체의 형태적 변화를 유도하는 것으로 알 려져 있다. 본 연구에서는 기계적 자극을 적용한 토마토의 육 묘기 동안의 생육 변화를 확인하기 위해 수행되었다. 브러싱 처리가 기계적 자극으로 이용되었으며, 아크릴이 부착된 이 송장치를 이용하여 2시간 간격으로 파종 후 10일 이후부터 처 리를 진행하였다. 브러싱 처리 동안 생육 변화를 확인하기 위 해 3일 간격으로 생육을 조사하였다. 초장과 엽면적은 브러싱 처리에서 대조구에 비해 감소하는 결과를 보였으며 지상부의 생체중과 건물중은 대조구와 유사한 값을 보였다. 총 근장과 지하부 표면적은 브러싱 처리에서 대조구에 비해 증가하였으며, 지하부 부피는 대조구와 브러싱 처리가 유사한 값을 보였 다. 결론적으로 토마토 공정묘에 브러싱 처리는 지상부의 생 육 감소를 유도하였으며 지하부의 형태적 발달을 증가시키는 것으로 판단된다.
        4,000원
        46.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 간호대학생의 대면 및 비대면 임상실습스트레스와 스트레스 대처가 임상수행능력에 미치는 영향을 알아보고 각 요인 간 영향을 파악함으로써 간호대학생이 임상실습스트레스에 효율적으로 대처하고 임상수행능력을 증진할 수 있는 임상실습교육 전략의 근거를 제시하고자 시행되었다. 연구대상자 는 서울과 충청권 소재 간호대학생으로, 2021년 6월 10일부터 7월 10일까지 총 201부의 자료를 수집하였 다. 통계프로그램 SPSS 21.0을 이용하여 Pearson’s correlation coefficients로 대면 및 비대면 임상실습스트 레스, 스트레스 대처, 임상수행능력 간의 상관관계를, 위계적 다중회귀분석을 사용하여 임상수행능력에 미 치는 요인을 분석하였다. 연구결과, 1단계에서 간호대학생의 성적, 전공만족도, 대면실습만족도가 임상수행 능력의 19.4%를 설명하였고, 2단계에서는 스트레스 대처를 추가하여 19.6%의 설명력이 증가되어 총 39.0%의 변량을 설명할 수 있었다. 따라서 간호대학생의 임상수행능력 향상을 위해서는 임상실습스트레스 에 대한 원만한 스트레스 대처가 중요하며, 본 연구는 간호대학생의 스트레스 대처를 위한 상담 및 교육프 로그램을 개발하는 기초자료를 제공할 것이다.
        4,500원
        47.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 국내 희귀 및 멸종위기야생식물 Ⅱ급인 초령목의 자생지에서의 분포와 생육 특성을 파악하고 보전지위를 평가하 고자 실시하였다. 초령목은 흑산도와 제주도에서 자생지가 확인되었는데, 4개의 개체군으로 구분되었다. 자생지에서 314개체 가 확인되었으며, 이중 약 45.9%(144개체)가 해발고도 401m~500m 범위에 분포하였다. 수고는 평균 2.7(±4.8)m였으며, 흉고직경은 12.6(±13.9)㎝였고 분지는 평균 1.0(±0.5)개로 나타났다. 초령목의 어린나무 개체들은 어미목에서 반경 30m 이내에 54.3%가 분포하였고, 31m~40m 사이에서 25.8%가 분포하였으며, 반경 60m 이내에 대부분(90.1%)이 확인되었다. 초령목의 어린나무 개체들이 일부 성숙목 주변에서도 확인되지 않고, 극히 한정된 지역에서만 출현하는 것은 자생지 환경뿐만 아니라 생육조건과 관계가 있는 것으로 판단된다. 초령목의 종자 산포는 천연하종과 더불어 조류가 관여하는 것으로 추정되는 데, 이는 천연하종의 범위 이상에서 발견되는 자생지는 조류가 쉴 수 있는 물웅덩이가 근처에 존재하는 공통적인 특징을 지녔기 때문이다. 초령목의 지역 및 국가수준의 IUCN 적색목록 평가기준의 범주는 위급(Critically Endangered) 범주에 해당하며 국내 개체군은 “CR B2ab(ⅴ); C2a(ⅰ); D” 범주로 평가되는 것으로 나타났다.
        4,000원
        52.
        2023.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Black Soldier Fly Larvae (Hermetia illucens, BSFL) is an environmental purification insect utilized as an animal feed source due to its high protein content. BSFL need to be dried to preserve quality, and the optimal drying method should be cost-effective. In this study, various drying methods (hot air (HD), freeze (FD), vacuum (VD), and combined-drying (CD)) were applied to BSFL, and then BSFL powders were characterized. Crude protein content was highest in HD and lowest in CD, and there was no significant difference in crude fat content (p>0.05). In the measurement of the total amino acid content of BSFL, glutamic acid and aspartic acid were the highest regardless of the drying method. The total amino acid content was the highest in HD and the lowest in CD. Total polyphenol content was higher in VD and FD than in HD and CD. Also, hydrogen peroxide and DPPH radical scavenging showed similar results. In the antioxidant measurement results, VD and FD showed higher antioxidant capacity, but considering cost-effectiveness, HD was the most available method for drying BSFL.
        4,000원
        53.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Codonopsis lanceolata (S. et Z.) Trautv. is mainly cultivated in Korea and China as a medicinal crop. C. lanceolata is difficult to produce plug seedlings in the summer, because C. lanceolata has a low germination rate and is vulnerable to high temperatures. Cold treatment is effective in breaking dormancy of seeds and increasing the germination rate. Shading cultivation can control the solar irradiance received by plants and reduce the damage by high temperatures and strong light. This study was conducted to examine the appropriate cold treatment period for the improving germination of C. lanceolata, and shading level during the summer seedling period. Cold treatment experiments were conducted for 0 (control), 1, 2, 3, and 4 weeks at 4°C before sowing. In the shading experiment, C. lanceolata was grown for 45 days with 0 (non-treatment), 45, 75% shading levels. Cold treatment for one week significantly improved the germination energy. The plant height, leaf area, and fresh and dry weights of C. lanceolata seedlings were significantly increased under the 45% shading level. Total root length, root surface area, and the number of root tips were significantly higher in shading treatment (45 and 75%) than in non-treatment. The C. lanceolata seedling’s compactness and Dickson’s quality index were the highest at 45% shading level. Therefore, these results recommended sowing C. lanceolata after cold treatment for one week at 4°C, and 45% shading level could stably culture C. lanceolata plug seedlings during the high temperature period.
        4,000원
        54.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The emergence of micropollutants in natural water sources due to the overuse of anthropogenic chemicals in industry and households has threatened the production of clean and safe tap water in drinking water treatment plants. Conventional physicochemical processes such as coagulation/flocculation followed by sand filtration are not effective for the control of micropollutants, whereas chemical oxidation processes (applying chlorine, permanganate, ozone, etc.) are known to be promising alternatives. Determining the optimum oxidant dose is important issue related to the production of disinfection by-products as well as unnecessary operating cost, and is made possible by simulations of target-micropollutant abatement based on kinetic model equation consisting of second-order rate constant (between the oxidant and the target) and oxidant exposure. However, the difficulty in determining oxidant exposure as a function of complex water quality parameters limits the field application of kinetic model equation. With respect to representative oxidants used in drinking water treatment plants, this article reviews two main approaches for determining oxidant exposure: i) direct measurement in situ and ii) prediction by empirical models based on key water quality parameters. In addition, we discussed research requirements to improve the predictive accuracy of the empirical models for oxidant exposure and to develop a rational algorithm to determine optimal oxidant dose by considering the priority of the target pollutants to be treated.
        4,800원
        58.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, measurement errors of the X and Y axes were verified by using an 80-100 mm gauge block, an NPL type angle measuring device, and a spelling on a contact-type 3D measuring device surface plate. In addition, the measurement specimen was repeatedly measured 10 times at 10° intervals from 0° to 40° to confirm the average value and standard deviation. After confirming the statistical test value (P) through ANOVA analysis of the statistical program, the correlation between angle change and error was confirmed.
        4,000원
        59.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study investigated the quality characteristics of the traditional rice cake of Gijeongtteok added with an extract from Cudrania tricuspidate fruit and different amounts of kimchi broth. The pH measurement showed a significant decrease with the increase of the kimchi broth from pH 5.48 (control) to 4.86 (KG180). Hunter color L-values were decreased while redness and yellowness were increased as the amount of kimchi broth increased. Texture profile analysis showed that hardness and adhesiveness significantly increased and decreased as the amount of kimchi broth increased. Gijeongtteok with kimchi broth (KG180) had the lowest specific volume with increased gummy layers in the crumb structure. Sensory evaluation of color, flavor, taste, appearance, and overall acceptance for various levels of kimchi broth showed that the KG140 sample had the highest acceptability. Therefore, this study suggests that Gijeogtteok made with the KG140 mixing ratio has excellent quality and sensory characteristics.
        4,000원
        60.
        2023.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Roses are one of the most produced flower species in the world, and cut roses are produced in the greenhouses all year round. Recently, due to the increase in the temperature in the greenhouses in summer, the quality of cut roses is seriously deteriorated, such as shortening the stem length. This study was conducted to investigate the effects of the growing seasons on the qualities of cut roses and also to test the effect of cooling at night in high temperature season on the cut flower qualities of roses. Comparing the qualities and yields of cut roses for each season, the major cut flower qualities such as flower stem length, stem diameter and fresh weight were statistically significantly decreased in roses (‘Pink Beauty’ and ‘Pink Shine’) produced in summer. The yields didn’t show a statistically significant difference in both cultivars. Investigating the cut flower qualities, the flower stem length increased by 15% for ‘Pink Beauty’, 11% for ‘Ararat’, and 12% for ‘Pink Shine’ when treated with cooling at night in warm season than the untreated control. In addition, when treated with cooling at night in warm season, the fresh weight of all three cultivars increased by 20-30% statistically significantly than conventionally cultivated control. It is expected that cooling at night in warm season will be helpful to improve the cut flower quality deterioration in summer.
        4,000원
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