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        검색결과 22

        1.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        횡하중에 작용하는 철근 콘크리트 기둥은 연성능력 확보를 위해 띠철근의 양 단부를 135° 구부려 시공하는 상세가 요구된다. 그러 나 이러한 띠철근 상세는 시공이 매우 까다로와 실제 현장에서는 제대로 시공이 되지 않기도 한다. 이를 대체하기 위해 본 논문에서는 강재 클립형 연결장치가 적용된 철근 콘크리트 기둥에 대해 횡방향 반복가력 실험을 수행하고 그 구조적 성능을 평가하였다. 총 4개 의 실험체가 제작되었으며 주요 실험변수는 강재 클립형 연결장치 및 고강도 콘크리트 사용 여부이다. 또한 대상 구조물에 대해 3차 원 유한요소해석 모델을 개발하고 이에 대한 비선형 해석을 수행하였으며, 해석 및 실험결과를 비교하고 분석하였다. 그 결과 강재 클 립형 연결장치가 설치된 콘크리트 기둥이 반복 횡하중에 대해 기존의 표준갈고리 상세를 지닌 콘크리트 기둥과 동등한 혹은 그 이상 의 성능을 지니고 있으며, 개발된 유한요소해석 모델이 실험결과를 정확히 잘 예측하는 것으로 나타났다.
        4,000원
        2.
        2017.10 구독 인증기관·개인회원 무료
        We have surveyed the current status of insect pollinator use for horticultural crops in 2016. The use rate and farmnumber of insect pollinators for 26 horticultural crops were 25.8% and 55,208, respectively. The colony number of insectpollinators used in this survey was 479,777, which include 344,690 for honeybees, 119,104 for bumblebees, 2,415 formason bees, 1,317 for flies, and 2,415 for the combination of bumblebees, honeybees, and mason bees. The use rateof insect pollinators was 59.4% for 11 vegetable crops and the colony number of insect pollinators used for 11 vegetablecrops was 449,287. The colony number of insect pollinators used for 15 fruit tree crops was 30,290, which include honeybees(66.3%), bumblebees (20.2%), mason bees (8.0%), flies (1.6%), and the combination (3.9%) of bumblebees, honeybees,and mason bees. Together, farms of 98% showed positive effect for the use of insect pollinators and most of farms (97.0%)planed for the continuous use of insect pollinators
        3.
        2017.04 구독 인증기관·개인회원 무료
        We collected four species of Osmia spp. consisting of O. cornifrons, O. pedicornis, O. taurus and O. satoi in Yeongwol, Bonghwa and Yechon locations. O. pedicornis was the dominant species, which accounts for 59.6% to 76.4% in the three locations. The sex ratio of Osmia spp. were from 1:1 to 1: 2.8 in O. cornifrons and from 1:2.8 to 1: 5.5 in O. pedicornis. The sex ratio of O. cornifrons and O. pedicornis was different in 3 locations. The female and male cocoons of O. cornifrons were the long elliptical-shaped and grey-brown color. The female and male cocoons of O. pedicornis were the long elliptical-shaped and polished dark-brown color. In both species of O. cornifrons and O. pedicornis, the cocoon size of the females was significantly larger than that of the male. Between those two species, the latter had a relatively bigger size than the former.
        4.
        2017.04 구독 인증기관·개인회원 무료
        In the age of sexual maturity of queen, mating occurred at 6.7% immediately after eclosion and it was the highest as 85.0% at 10 days after emergence. However, a remarkable decrease was occurred at 20 days after the emergence. With regard to oviposition rate, the highest rate was observed as 81.3-81.8% at 6 to 10 days of eclosion. The rate of colony foundation and progeny-queen production were the highest as 43.8% and 37.5%, respectively, at 8 days of eclosion. In the age of sexual maturity of male, mating rate was as high as 38.3% immediately after the eclosion, the highest as 80.0% at 25 days of eclosion, and 76.6% at 8 days of eclosion. The oviposition rate was the highest as 76.9% at 6 days of eclosion, and decreased to 75.0% at 8 days and 72.7% at 10 days of eclosion. Summarized, our results indicate that sexual maturity for mating of B. terrestris is most favorable 6-8 days after eclosion for queen and 6-10 days after for male.
        5.
        2016.04 구독 인증기관·개인회원 무료
        Distillers dried grain (DDG) and makgeolli spent grain (MSG) are agricultural by-product to produce alcoholic beverage. However, they are known to contain enough nutrients. Mealworm is a promising insect resource for an animal feed ingredient as well as alternative human food. With low cost, DDG and MSG were investigated as a feed ingredient for rearing high quality mealworms. DDG and MSG were mixed with wheat bran and compared to control feed (only wheat bran) for its effects on larval survivorship, larval weight, duration for larval development, pupation rate, and pupal weight. Adding DDG on wheat bran showed positive results for larval weight, duration for larval developmental period, and pupation rate. However, adding MSG made longer duration for larval development, but it also improved larval weight, pupal weight with more than 90% pupation rate. We confirmed that adding 30~50% of DDG or MSG to conventional wheat bran have a strong potential to replace the conventional wheat bran insect feed for quality insect production.
        6.
        2015.10 구독 인증기관·개인회원 무료
        The post-hibernated queens of Korean native bumblebee, Bombus hypocrita saporoensis were collected in Jeong-Sun, Korea to investigate their ecological characteristics and reared under the laboratory conditions; 27℃, 65% R.H. and darkness. The average weight of collected queens was 0.87±0.14g and 0.8g class was most abundant (34.7%) among eight weight classes. The rates of colony initiation, colony foundation and progeny-queen production were 76.3%, 60.0% and 42.5%, respectively. The durations up to colony initiation and colony foundation were 12.0±6.7 days and 49.3±2.4 days, respectively. The duration up to first worker, male and queen emergence were 22.2±3.0 days, 63.4±6.5 days and 63.5±8.7 days, respectively. The number of progenies was 108.5±26.0 workers, 186.7±70.7 males and 39.1±30.3 queens. The longevity of colony founded queen was 90.2±19.9 days whereas that of non-colonized queen was 35.9±30.3 days. Copulation time was 29.5±9.6 min. The number of eggs per egg cell laid new queen was 9.3±2.3 grains. An egg shaped as banana and it’s size was 1.12±0.10 mm in a width, 3.54± 0.16 mm in a length and 2.26±0.34 mg in a weight.
        7.
        2015.10 구독 인증기관·개인회원 무료
        Insect is an important player in the ecosystem as a prey for animals. Moreover, they are a valuable candidate food source for rearing animal. Tenebrio molitor (Coeloptera: Tenebrionidae) larvae are known as a good food source with high protein, unsaturated fatty acid, minerals. Therefore, it has strong potential to substitute the conventional meat consumption. To utilize T. molitor as a feed, the standard mass-rearing protocol is required. To make standard mass-rearing protocol, we tested different temperature(17.5, 20, 22.5, 25, 27.5 and 30°C) conditions for egg, larvae, pupae and adult T. molitor to identify the optimal rearing condition. Hatching was occurred within 15~32.5°C range. However, 17.5~27.5°C was required to get more than 70 % hatching rete. When the eggs were treated in 22.5~27.5°C, all eggs were hatched within 10 days. As larval development, shorter developmental period, higher pupation and eclosion rates were observed within 25~27.5°C temperature range. In addition, we compared the number of egg, oviposition duration and time required to start egg-laying. The minimum egg-laying(258.40±10.86) was observed at 17.5°C, but the maximum(749.10±7.45) was at 27.5°C. The maximum oviposition duration (137.00±12.73 day (mean±S.D.)) was achieved at 27.5°C, but the minimum (87.50±3.54 day (mean±S.D.)) was at 30°C. The time required to start egg-laying was less than 10 days at 17.5, 27.5, and 30°C. To consider all the factors, we concluded that the optimal temperature is 27.5 °C.
        8.
        2014.12 구독 인증기관 무료, 개인회원 유료
        As basic research to develop HEV and EV agricultural field machinery, the present study analyzes the technical trend of electric agricultural field machinery through product analysis, paper analysis, and patent analysis concerning HEV and EV in the automobile, construction machinery, and agricultural machinery sectors. For product analysis, the homepages of companies in these sectors were consulted to analyze the number of products of each company. For paper analysis, key words related to HEV and EV were selected, a search formula was drawn up, and articles search sites were consulted. And for patent analysis too, key words were selected and then a search formula was drawn up to examine published patent applications or registered patent applications, and trends were analyzed by structure, country, and year. The number of HEV and EV products were 17 in the automobile area, 8 in construction machinery, and 4 in agricultural machinery. Notably, in the agricultural machinery area, all HEV and EV products were from advanced companies overseas. In terms of papers, papers published in the past 5 years were searched and 33,195 papers were from the automobile area, 3,806 were from construction machinery, and 2,687, the fewest papers, were from the agricultural machinery area. A search of patents in the electric drive technology area in Korea, USA, and Japan, and Europe showed 1,927 valid patents, with 1,120 in Japan, 497 in USA, 193 in Korea, and 117 in Europe. Analysis of the trend of research on electric agricultural field machinery by product, paper, and patent shows the development of HEV and EV technology in Korea is insufficient compared to USA, Japan, and Europe, which means rapid technological development is needed.
        4,000원
        9.
        2014.12 구독 인증기관 무료, 개인회원 유료
        The goal of this research was to develop a portable system that could be used to evaluate the quality of milk in real time at a raw milk production site. A real-time portable quality evaluation system for raw milk was developed to enable non-destructive quality evaluation of somatic cell count (SCC), fat, protein, lactose, and total solid (TS) in milk samples. A prediction model of SCC, fat, protein, lactose, and TS was constructed using partial least squares (PLS) and 200 milk samples were used to evaluate the prediction performance of the portable quality evaluation system and high performance spectroscopy. Through prediction model development and verification, it was found that the accuracy of high performance spectroscopy was 90% for SSC, 96% for fat, 96% for protein, 91% for lactose, and 97% for TS. In comparison, the accuracy of the portable quality evaluation system was relatively low, at 90% for SSC, 95% for fat, 92% for protein, 89% for lactose, 92% for TS. However, the measurement time for high performance spectroscopy was 10 minutes for 1 sample, while for the portable quality evaluation system it was 6 minutes. This means that the high performance spectroscopy system can measure 48 samples per day (8 hours), while the portable quality evaluation system can measure 80 (8 hours). Therefore, it was found that the portable qual ity evaluation system enables quick on-site quality evaluation of milk samples.
        4,000원
        10.
        2014.10 구독 인증기관·개인회원 무료
        Bumblebees are important pollinators of crops and wildflowers. Bumblebees generally produce one generation per year. One of the key stages for year-round rearing of bumblebees is breaking diapause. To evaluate the effects of a combination method of CO2-narcosis and cold treatment to break the diapause of B. ignitus and B. terrestris queens, we determined whether this method affected their ability to establish a colony after the diapause break. The diapause treatment regimes that were utilized were CO2(CO2– narcosis), CT-1M(cold treatment at 5°C for 1 month), CT-1M-CO2(CO2–narcosis after cold treatment for 1 month), CT-2M-CO2(CO2–narcosis after cold treatment for 2 months), CT-2M (cold treatment for 2 months), CT-2.5M-CO2(CO2–narcosis after cold treatment for 2.5 months) and CT-2.5M (cold treatment at 5°C for 2.5 months). In view of the effects on the colony developmental characteristics of B. ignitus queens, the most favorable diapause treatment was CT-1M-CO2. A combination method of CO2– narcosis and cold temperature treatment yielded better results than that of single CO2–narcosis or cold temperature treatment on the colony development of diapause-broken B. ignitus queens. In the case of B. terrestris queens, we concluded that a combination method of CO2 and cold temperature treatment yielded better results than that of a single cold-temperature(up to2 months) treatment. In conclusion, the findings of the present study indicated that the combined application of CO2 and cold temperature was a favorable method for the colony development of diapause-broken B. ignitus and B. terrestris queens compared with only CO2–narcosisorcoldtemperaturetreatments. A combination method of CO2 and cold treatment reduced the side effect of CO2–narcosis and shortened the duration of cold treatment by at least 1month.
        11.
        2013.04 구독 인증기관·개인회원 무료
        To substitute for bluebottle fly, Chrysomyia megacephala which is being used for pollinator in mango fruit, and improve the pollinating effect of mango fruit which is also being increased as high value added crop recently in Jeju island of korea, 2 kinds of pollinator were used in analyzing and surveying of foraging activities on mango fruit in Seogwipo province. This study was conducted using 3 species of pollinator, Apis mellifera, Bombus terrestris and Chrysomyia megacephala with 3 treatment in vinyl-house condition respectively. Species of mango fruit, Irwin, was used in this experiment. A number of foraging activity of Apis mellifera and Bombus terrestris in hive showed highest 11 AM, and showed normal foraging activity in high temperature condition(28℃). Pollinating ratio of Bombus terrestris was shown 100% and over 95% in case of Apis mellifera. This ratio suggest that the 2 species of insects is effective as pollinator on mango fruit compared with bluebottle fly. Daily pollinating activity of Apis mellifera and Bombus terrestris was shown peak in 11 AM, but showed even activity from 9 AM to 3 PM in case of Chrysomyia megacephala. The pollinating characteristics of 3 species depends on illuminance but temperature, especially in case of Bombus terrestris was more affected by change of illuminance. Visiting time of Bombus terrestris and Apis mellifera on this flower was shown 2.8 and 3.4 seconds respectively. But Chrysomyia megacephala showed longer 10 times with 32.5 seconds than other insects. This results suppose that Chrysomyia megacephala showed as resting behavior for almost time on the flower not foraging activity to pollinate.
        12.
        2011.10 구독 인증기관·개인회원 무료
        To increase the fruit quality and productivity of the apricot, 2 species of insects, Apis mellifer, and Bombus terrestris were used for pollination in apricot field in Yeongcheon province. This study was conducted using 3 kinds of methods for pollination effect, natural condition, net-house treatment and control method. Also this experiment carried out in 2 places, vinyl-house and field condition. In case of field treatment of Apis mellifera, heating lamp experiment was added in net-house to find out the reason for harmful efficacy of low temperature early in the spring. Species of apricot, Mangum, was used in this experiment. A number of foraging activity of Apis mellifera and Bombus terrestris in vinyl-house showed higher than in field condition. But after stoping heating, showed low efficacy after showing peak in 1 PM. In field, Apis mellifera showed peak of foraging activity from 1 to 3PM, heating lamp experiment of field condition showed peak in 3 PM and then lowest tendency to evening suddenly. The fruit set rate of Apis mellifera and Bombus terrestris in vinyl-house showed higher with 92% and 89% respectively than control with 83%. In field, heating lamp treatment of Apis melliferawas was highest with 28% compared to Bombus terrestris with 25% and control with 15%. This results suppose that apricot in field was to be harmed by low temperature and frost in blooming time early in spring
        15.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to obtain the basic data for using the Artemisia anuua as a new economic crop,thus Artemisia anuua was investigated their cultivation characteristics, yield, and variation of artemisinin contents by plantingdensity and harvesting times. Seed characteristics of A. anuua have observed micro-size, and their germination optimumtemperature was at 15 to 20 celsius degree. Planting density on the yield of A. anuua was increased high density better thanlow density. The highest yield was planted in the space of 30×10㎝. Moreover, optimum harvesting time of A. anuua wasinvestigated in early september and a periods of most highly detected artemisinin was time of before and after bloomingof A. anuua.Key Words : Art
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