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        검색결과 830

        21.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Paddy fields provide important habitats for biodiversity conservation within the agricultural ecosystem. Their importance is gradually increasing as their ecological value is better understood. Benthic macroinvertebrates dominate paddy fields. They play an essential role in maintaining the biodiversity of paddy ecosystems. This study aimed to analyze characteristics of benthic macroinvertebrate communities and main environmental factors affecting the distribution of golden apple snails (Pomacea canaliculata). Results showed that the diversity index (H ′) of the benthic macroinvertebrate community was the highest at the Sangju site (St. 12) but the lowest at the Sancheong site (St. 18). Total Dissolved Solids (TDS), salinity, and Electrical Conductivity (EC) values were the highest in Gimhae and Yeongam based on Canonical Correspondence Analysis (CCA). Numbers of P. canaliculata (m-2) were relatively low in Gunsan and Iksan where water temperatures were high. Therefore, changes in geographical characteristics and environmental factors might affect the distribution of P. canaliculata and characteristics of benthic macroinvertebrate communities. Results of this study can be used as primary data for biodiversity conservation and ecosystem service evaluation in agroecosystems.
        4,300원
        23.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 국내 난대림 집단자생지인 전남 완도군 상왕산(644m) 일대의 식물상 조사를 통해 자생식물, 희귀식물 및 특산식 물 등 식물 분포와 특징을 밝히고 식물종다양성 보전과 난대림의 기후변화 대비 분포변화 연구를 위한 자료로 활용하고자 조사하였다. 2018년부터 2022년까지 총 32회의 현장조사를 실시하였다. 조사결과 132과 473속 708종 16아종 53변종 8품종으로 총 785분류군이 조사되었다. 환경부 지정 멸종위기야생식물은 새깃아재비(Woodwardia japonica (L.f.) Sm.), 칠보치마(Metanarthecium luteoviride Maxim.), 혹난초(Bulbophyllum inconspicuum Maxim.), 석곡(Dendrobium moniliforme (L.) Sw.), 지네발란(Pelatantheria scolopendrifolia (Makino) Aver.), 대흥란(Cymbidium macrorhizon Lindl.) 6분류군이 조사되었으며 산림청 지정 희귀식물은 총 26분류군이 조사되었다. 국립수목원에서 제시한 적색식물은 7분류군, 국립생물자원관에서 제시한 적색목록식물은 29분류군, 한국특산식물목록은 17분류군이 조사되었다. 식물구계학적 특정종은 총 200분류군으로 Ⅴ등급 6분류군, Ⅳ등급 13분류군, Ⅲ등급 73분류군, Ⅱ등급 29분류군, Ⅰ등급 79분류군이 조사되었다. 귀화식물은 총 73분류군, 생태계교란종은 6분류군이 조사되었다. 조사지역의 기후변화 적응 대상식물은 특산식물 8분류군, 남방계식물 46분류군, 북방계식물 1분류군으로 총 55분류군이 조사되었다.
        9,000원
        31.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : Currently, the domestic construction industry is dominated by large-scale projects such as roads, ports, airports, and buildings. Construction on such projects is generally conducted simultaneously, but the process and quality management are led by a small number of responsible managers. In the case of road pavements, owing to rapid industrial development, economic growth, and the expansion of social overhead capital investment in the road construction industry, highways and general national roads have been constructed on a large scale. Therefore, this study aimed to improve and develop domestic concrete production and construction quality management by improving the reliability and transparency of production quality management and simplifying business processes. This was accomplished through the development of an Internet of Things (IoT)-based cement quality management system capable of automated design and build (D/B) construction and real-time monitoring. METHODS : The "IQ" system is a quality management system for enabling real-time monitoring of D/B quality at the time of concrete production and according to the designated age by utilizing quality test equipment developed with an LTE-Bluetooth function. It is possible to immediately identify and respond to quality problems through real-time monitoring, secure a reliable quality D/B because the quality test results cannot be arbitrarily manipulated, and to simplify the work process through the automatic D/B construction. In addition, improved quality control can be achieved through real-time information sharing and feedback system operations between contractors, managers, and personnel involved in construction. The quality control test items for developing the IQ system are the compression and flexural strengths, as these can be used to determine the design standard strength of pre-curing concretes (such as their slump and unit quantity) and the adequacy of the workability and durability, as well as the air volume to predict the durability, and the chloride content in the sections where reinforcement is used. CONCLUSIONS : This study identified difficulties and limitations in quality management according to the operation method in the domestic quality management systems, and in the real-time monitoring between managers and contractors. Thus, it was necessary to establish an improved systematic and reliable quality management system. The IQ system was developed to solve this problem.
        4,000원
        32.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ecological occupation in irrigation ponds is a well-acknowledged fact that is essential for biodiversity conservation in agricultural ecosystems. However, there are few studies on the ecological functions and relationship between a paddy field and irrigation using macroinvertebrates in an environmentally friendly paddy field. The objective of this study is to identify the community and distribution characteristics of macroinvertebrates in an agricultural paddy field and irrigation pond ecosystems, and to provide basic data on the ecological function of an environmentally friendly paddy field. Macroinvertebrate sampling was conducted from May to September in an agricultural paddy field and irrigation pond in an environment-friendly paddy field in Boryeong city. We conducted a study to identify the distribution characteristics using macroinvertebrate species analysis, such as Functional Feeding Groups (FFGs), Habitat Oriented Groups (HOGs), rarefaction curve, and a two-way dendrogram. A total of 37 species of macroinvertebrates in 28 families, 13 orders were collected study during the period of the investigation. Dominant taxa of macroinvertebrates included Coleoptera, Hemiptera, and Odonata. In terms of FFGs, predators and gathering collectors accounted for approximately 70%, in relation to HOGs, and climbers and swimmers occupied more than 50% from both the paddy field and irrigation pond. With respect to the rarefaction curve, the irrigation pond (July) was high as E (S, 141)=18 species, while the paddy field (May) was comparatively low as E (S, 141)=9 species. In conclusion, our results revealed that macroinvertebrates, such as Notonecta triguttata, Peltodytes intermedius, Appasus major, Laccotrephes japonensis, Appasus japonicus, Sigara substriata, Enochrus simulans, and Sternolophus rufipes, were used as a habitat and spawning ground in both paddy field and irrigation pond. The irrigation pond appears to be a very important spawning ground for macroinvertebrates.
        4,000원
        33.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study was conducted to examine the effect of soybean silage as a crude protein supplement for corn silage in the diet of Hanwoo steers. The first experiment was conducted to evaluate the effect of replacing corn silage with soybean silage at different levels on rumen fermentation characteristics in vitro. Commercially-purchased corn silage was replaced with 0, 4, 8, or 12% of soybean silage. Half gram of the substrate was added to 50 mL of buffer and rumen fluid from Hanwoo cows, and then incubated at 39°C for 0, 3, 6, 12, 24, and 48 h. At 24 h, the pH of the control (corn silage only) was lower (p<0.05) than that of soybeansupplemented silages, and the pH numerically increased along with increasing proportions of soybean silage. Other rumen parameters, including gas production, ammonia nitrogen, and total volatile fatty acids, were variable. However, they tended to increase with increasing proportions of soybean silage. In the second experiment, 60 Hanwoo steers were allocated to one of three dietary treatments, namely, CON (concentrate with Italian ryegrass), CS (concentrate with corn silage), CS4% (concentrate with corn silage and 4% of soybean silage). Animals were offered experimental diets for 110 days during the growing period and then finished with typified beef diets that were commercially available to evaluate the effect of soybean silage on animal performance and meat quality. With the soybean silage, the weight gain and feed efficiency of the animal were more significant than those of the other treatments during the growing period (p<0.05). However, the dietary treatments had little effect on meat quality except for meat color. In conclusion, corn silage mixed with soybean silage even at a lower level provided a greater ruminal environment and animal performances, particularly with increased carcass weight and feed efficiency during growing period.
        4,300원
        34.
        2022.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Newborn piglets are routinely subjected to several treatments shortly after birth, one of which is tail-docking. Tail-docking, which is carried out without an anesthetic when the piglet is 3 to 4 days old, is intended to prevent the severe injuries that can occur when pigs bite each other’s tails. The study was performed in slaughterhouses to determine how much tail-docking prevented tail-biting and how much it caused clinical problems such as amputation neuroma. One thousand pigtails were collected from 3 slaughterhouses in different provinces and tail length and tail-biting injuries were examined. Among them, 659 tail tissues were examined for clinical problems like amputation neuroma. The collected tails were divided into 3 groups according to the length of the tail, which was defined as long (n=136, 75% of the tail remained compared to the referred intact tail length of 30.6±0.6 cm of crossbred Landrace×Yorkshire dam×Duroc sire; LYD), medium (n=694, 50% of the tail remained), and short (n=170, 25% of the tail remained). The results showed that 4.3% of 1000 tails had biting injuries and 58.7% of 659 tails had amputation neuromas. There was no significant association between the tail-biting injury and tail lengths (p=0.953). However, the tail-biting injuries differed significantly by the province (p<0.001), and the frequency of amputation neuromas also appeared more frequently in longer tail lengths (p<0.001). The results indicated that tail-biting behavior was not influenced by tail-docking but might be influenced by the housing system and/or management practices.
        4,000원
        40.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구의 목적은 예비 지구과학교사들이 학생에 의해 구성된 기후변화 모델을 평가하는 기준을 탐색하는 것이 다. 대도시 소재 대학 지구과학교육과 전공 수업에서 3주간 모델링 기반 과학 학습에 대한 강의를 수강한 예비 지구과 학교사 25명이 연구에 참여하였다. 예비 지구과학교사들이 작성한 고등학생들이 구성한 7개의 기후변화 모델을 평가하 는 보고서와 사후 인터뷰 자료를 수집하여 기후변화 모델 평가 기준을 귀납적으로 범주화하였다. 연구 결과 예비 지구 과학교사들이 기후변화 모델을 평가할 때 다양한 인식론적 기준과 의사소통 기준을 동원하였음을 확인하였다. 연구 결 과를 바탕으로 모델링 기반 기후변화 학습에 대한 시사점을 도출하였다.
        4,600원
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