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        검색결과 218

        1.
        2023.10 구독 인증기관·개인회원 무료
        Drosophila suzukii (Diptera, Drosophilidae) can damage thin-skinned fruits (plums, cherries, peaches, blueberries, and strawberries) by laying eggs inside the fruit. In this study, a basic experiment was conducted to investigate the preference of D. suzukii to export table grape varieties. Four varieties of grapes (Kyoho grape, Shine muscat, Campbell grape, and Black sapphire) were placed in a cage containing more than 2,500 number of D. suzukii adults for 6, 8, 10, 12, and 24 hours and the egg-laying in grape has been induced. After 2 weeks, the number of pupae that emerged was counted. As a result, the largest number of pupae was generated in Kyoho grape among the four types of grapes, indicating that D. suzukii prefers to lay egg in Kyoho grape. Through this experiment, it was determined that 6 h was the appropriate inoculation time, and then an inoculation experiment was conducted on Kyoho grape. The total weight of the Kyoho grape used in the experiment was 36.119 kg, and a total of 2594 pupae were generated. The average number of D. suzukii per cluster was about 50. All stages of D. suzukii treated with low temperature(1℃) for 10 days were completely controlled.
        3.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The ‘Japanese Useful Fisheries Classification Table’, published in advance before the publication of the “Useful Fisheries of Japan”, is the first data to classify and introduce fisheries animals and plants in a single table. Therefore, it had received public attention immediately. However, The academy of animal studies at that time quickly pointed out that this classification table was a mixture of traditional and modern classifications, and that there were too many errors. However, Yoshio Tanaka, who was in charge of revising Yamamoto Arikatana, that wrote the classification table, was not an adherent of traditional taxonomy, nor was he ignorant of modern taxonomy. Nevertheless, the classification table, which was quite different from the well-known zoological classification at that time, was prepared. For example, the top classifications of marine organism are not at the same level, but rather a mixture of phylum and class, while the water insect contains several phylums, including Arthropoda, Echinodermata, Mollusca, and Coelenterata. As such, the method of classification of animals in the classification table was hard to understand in the zoological academy at that time. The reason for this unusual taxonomy was that the classification table showed classification of useful fisheries products, not intended to convey academic classification. In other words, it is not for the purpose of academic classification of all fishery products, but for the purpose of presenting standards that can be easily understood by those engaged in the collection, manufacture, and aquaculture of fishery products. This principle of ‘Useful Fisheries of Japan’ is also ascertained in the “Fishing Methods of Japan” and “Fishery Products of Japan”. Regarding the collection and processing of marine products, it could have shown how to catch whales, which are mammals, and how to dismantle whales and obtain oil and meat, according to academic classifications. However, the first appearances in the book include dried squid, abalone, shark fins, and sea cucumbers. In other words, the most important fishery products at that time are presented first. The contents of the classification table, which is considered somewhat bizarre, show where the purpose to compile Useful Fisheries of Japan.
        6,100원
        4.
        2023.05 구독 인증기관·개인회원 무료
        Currently, the development of evaluation technology for vibration and shock loads transmitted to spent nuclear fuel and structural integrity of spent nuclear fuel under normal conditions of transport is progressing in Korea by the present authors. Road transportation tests using surrogate spent nuclear fuel were performed in September, 2020 using a test model of KORAD-21 transportation cask and sea transportation tests were conducted from September 30 to October 4, 2021. Finally, the shake table tests and rolling test were conducted from October 31 to November 2, 2022. The shake table test was performed with the input load produced conservatively from the data obtained from the road and sea transportation tests. The test input was produced based on the power spectral densities and shock response spectrums from the transportation tests. In addition to the test inputs from the road and sea tests, sine sweep input and half sine input were used to verify the vibration characteristics of assemblies under boundary conditions during normal conditions of transport. Because the input load of the shake table test was produced conservatively, a slightly larger strain than the strain value measured in road and sea transportation tests was measured from the shake table tests. In the case of the sea test, it is considered that the process of enveloping the data in the 20 to 80 Hz range generated by the engine propeller system was performed excessively conservatively. As a result of analyzing the test results for the difference in boundary conditions, it was confirmed that the test conditions of loading the basket generated a relatively large strain compared to the conditions of loading the disk assembly for the same input load. Therefore, it is concluded that a transportation cask having a structure in which a basket and a disk are separated, such as KORAD-21, is more advantageous in terms of vibration shock load characteristics under normal conditions of transport than a transportation cask having an integral internal structure in which a basket and a disk are a single unit. However, this effect will be insignificant because the load itself transmitted to the disk assembly is very small.
        6.
        2023.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A new clamped mechanical splice system was proposed to develop structural performance and constructability for precast concrete connections. The proposed mechanical splice resists external loading immediately after the engagement. The mechanical splices applicable for both large-scale rebars for plants and small-scale rebars for buildings were developed with the same design concept. Quasi-static lateral cyclic loading tests were conducted with reinforced and precast concrete members to verify the seismic performance. Also, shaking table tests with three types of seismic wave excitation, 1) random wave with white noise, 2) the 2016 Gyeongju earthquake, and 3) the 1999 Chi-Chi earthquake, were conducted to confirm the dynamic performance. All tests were performed with real-scale concrete specimens. Sensors measured the lateral load, acceleration, displacement, crack pattern, and secant system stiffness, and energy dissipation was determined by lateral load-displacement relation. As a result, the precast specimen provided the emulative performance with RC. In the shaking table tests, PC frames’ maximum acceleration and displacement response were amplified 1.57 - 2.85 and 2.20 - 2.92 times compared to the ground motions. The precast specimens utilizing clamped mechanical splice showed ductile behavior with energy dissipation capacity against strong motion earthquakes.
        4,200원
        7.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구의 목적은 발달장애 아동을 위한 태블릿 기반의 인지평가를 통해 세부 인지기능의 프로파일 을 비교함으로써 본 평가가 진단그룹에 따른 인지기능 상태를 평가하는데 변별력이 있는지 알아보고자 하였다. 연구방법 : 총 80명의 만 4~12세 아동이 본 연구에 참여하였다. 진단명별로 자폐 스펙트럼(Autism Spectrum Disorders; ASD) 24명, 지적장애(Intellectual Disability; ID) 20명, 주의력결핍 및 과잉행 동 장애(Attention-Deficit Hyperactivity Disorder; ADHD) 7명, 정상발달 아동 29명이 참여하였다. 태블릿으로 개발된 인지평가는 총 8개 항목으로 공간작업기억, 작업기억용량, 시각적 작업기억, 시지각 처리기술, 집행기능(계획), 집행기능(반응억제 및 주의력), 집행기능(억제)의 세부 인지항목으로 구성되 어 있다. 평가를 시행한 후 진단그룹에 따른 차이를 Kruskal-Wallis 검정을 통해 비교하였다. 통계분석 은 Jamovi 1.6.23 을 사용하였다. 결과 : 정상발달 아동에 비해 자폐 스펙트럼, 지적장애, ADHD 아동의 인지평가 총점이 통계적으로 유의 미하게 다른 것으로 나타났다(χ²= 22.41, p < .001). 정상발달 아동에 비해 자폐 스펙트럼 아동은 시각 처리기술 및 억제기능의 항목에서 유의미한 기능 저하를 보였고, 지적장애 아동은 작업기억 용량, 시각적 작업기억과 반응억제 및 주의력 항목에서 유의미한 기능 저하를 보이는 것으로 나타났다. 한편, ADHD 아동의 경우 정상발달 아동에 비해 통계적으로 유의미한 차이를 보이는 인지평가 항목이 없었다. 결론 : 본 연구에서 개발된 태블릿 기반의 인지평가는 정상발달 아동과 발달장애 아동의 인지기능의 상태 를 변별함으로써 치료의 기초자료로써 활용 가치가 있다.
        4,900원
        8.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        충생태 분야에서 생명표와 관련된 연구는 곤충연구자들에게 많은 관심을 받는 주제중 하나이다. 보통 두 가지 방법으로 생명표 통계량중 내적자연증가율을 추정하고 있는데, 첫 번째 하나는 순증가율(R 0 )에 자연로그를 취하고 평균세대기간(T )으로 나누어 근사치를 계산하는 방법이다(세대기간-기반 추정법). 다른 하나는 로트카-볼테라 개체군 생장 방정식에서 유도하여 최대우도법으로 정확한 내적자연증가율을 추정하는 방법이다(로트카-오일러식-기반 추정법). 후자의 경우 대상 집단의 초기 연령등급을 “0” 또는 “1”로 설정함에 따라 추정값에 차이가 발생하여 적용에 혼란이 제기되었다. 본 고찰에서는 생명표 통계량 계산과정의 역사를 간단히 정리하고, 로트카-오일러식-기반 추정법에서 최초 연령등급을 1로설정한 경우             의 형식, 반면 최초 연령등급을 0으로 설정한 경우     검색어: 생명표, 로트카-오일러식, 연령등급, 개체군 인구통계학, 안정 연령분포            의 형식을 적용해야 함을 재확인하였다.
        4,000원
        12.
        2022.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Many piping systems installed in the power plant are directly related to the safety and operation of the plant. Various dampers have been applied to the piping system to reduce the damage caused by earthquakes. In order to reduce the vibration of the piping system, this study developed a steel coil damper (SCD) with a straightforward structure but excellent damping performance. SCD reduces the vibration of the objective structure by hysteretic damping. The new SCD damper can be applied to high-temperature environments since it consists of steel members. The paper introduces a design method for the elastoplastic coil spring, which is the critical element of SCD. The practical applicability of the design procedure was validated by comparing the nonlinear force-displacement curves calculated by design equations with the results obtained from nonlinear finite element analysis and repeated loading test. It was found that the designed SCD’s have a damping ratio higher than 25%. In addition, this study performed a set of seismic tests using a shaking table with an existing piping system to verify the vibration control capacity on the piping system by SCD. Test results prove that the SCD can effectively control the displacement vibration of the piping system up to 80%.
        4,000원
        13.
        2021.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to analyze the structure, status and economic ripple effects of the fisheries processing industry in Korea using interindustry analysis. Five input-output tables published over the past twenty years have been reclassified with a focus on the fisheries processing sector. Through these multi-period tables, we analyzed changes in the inducing effects in production, value added and employment as well as the backward-forward linkage effects. As a result of the analysis, it was found that the industrial scale of the fisheries processing industry is very small compared to other food manufacturing industries. The backward linkage effect of the fisheries processing industry was greater than that of other industries, but the forward linkage effect was rather low. This means that the fisheries processing industry can be greatly affected by industrial depression of the downstream industries such as fishery and aquaculture. Production and employment-inducing effects of the fisheries processing industry have shown a decreasing trend in recent years. This reflects the reality that intermediate inputs are gradually being replaced by imports from domestic production due to the expansion of market opening and the depletion of fishery resource. In the future, it is necessary to prepare a strategy to increase the value-added productivity of the fisheries processing sector and foster it as an export industry.
        5,400원
        14.
        2021.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the seismic safety of nuclear power plant structures is evaluated and verified by performing a vibration test on a relatively simple shear wall structure. The shear walls are the prominent members of nuclear power plants and resist the seismic load. The shear wall structure is designed and manufactured to perform shaking table tests and is used to increase the accuracy of the analytical method by comparing them with the numerical analysis results. Different results will be checked and more efficient application methods will be studied depending on the method of designing reinforced concrete structures.
        4,000원
        15.
        2021.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        After the manual shutdown of the Wolseong nuclear power plant due to an earthquake in Gyeongju in 2016, anxiety about the earthquake safety of nuclear power plants has become a major social issue. The shear wall structure used as a major structural element in nuclear power plants is widely used as a major structural member because of its high resistance to horizontal loads such as earthquakes. However, due to the complexity of the structure, it is challenging to predict the dynamic characteristics of the structure. In this study, a three-story shear wall structure is fabricated, and the in-structure response characteristics of the shear wall structure are evaluated through shaking table tests. The test is performed using the Gyeongju earthquake that occurred in 2016, and the response characteristics due to the domestic earthquake are evaluated.
        4,000원
        18.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        점박이응애는 광식성 초식자로서, 사과의 주요 해충 중 하나이다. 사과 품종에 따라 점박이응애의 밀도 형성이나 피해 규모가 다르게 나타난다. 세 가지 품종, 쓰가루, 홍로, 후지의 잎에 대한 점박이응애의 이동 선호성, 발육속도, 그리고 산란능력이 다른지를 시험하였다. 잎 절편을 이용한 실험 결과, 이동 선호성은 쓰가루나 홍로보다 후지 잎에서 높았다. 알에서 성충까지 발육기간은 후지 잎에서 가장 짧았고 홍로에서 가장 길었다. 암컷 성충 수명은 후지에서 가장 짧았다. 암컷의 총산란수는 사과 품종에 따라 다르지 않았지만, 일 평균 산란수는 후지에서 높았다. 생명표 분석 결과 홍로 잎에서 점박이응애의 적합도가 가장 낮게 나타났다. 이상의 결과는 사과원에서 품종에 따른 점박이응애 발생 양상의 차이를 설명 해주고 있으며, 향후 다양한 사과 품종에 대한 평가를 통해, 품종별 응애류 관리 전략 개발에 기초 자료가 될 것이다.
        4,000원
        19.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Earthquake preparedness has become more important with recent increase in the number of earthquakes in Korea, but many existing structures are not prepared for earthquakes. There are various types of liquefaction prevention method that can be applied, such as compaction, replacement, dewatering, and inhibition of shear strain. However, most of the liquefaction prevention methods are applied before construction, and it is important to find optimal methods that can be applied to existing structures and that have few effects on the environment, such as noise, vibration, and changes in underground water level. The purpose of this study is to estimate the correlation between the displacement of a structure and variations of pore water pressure on the ground in accordance with the depth of the sheet file when liquidation occurs. To achieve this, a shaking table test was performed for Joo-Mun-Jin standard sand and an earth pressure, accelerometer, pore water pressure transducer, and LVDT were installed in both the non-liquefiable layer and the liquefiable layer to measure the subsidence and excess pore water pressure in accordance with the time of each embedded depth. Then the results were analyzed. A comparison of the pore water pressure in accordance with Hsp/Hsl was shown to prevent lateral water flow at 1, 0.85 and confirmed that the pore water pressure increased. In addition, the relationship between Hsp/Hsl and subsidence was expressed as a trend line to calculate the expected settlement rate formula for the embedded depth ratio.
        4,000원
        20.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        차응애(Tetranychus kanzawai Kishida)의 기주식물에 대한 가치를 평가하기 위하여 기주식물로 제주 감귤의 주요 품종인 한라봉, 감귤원 에서 많이 서식하는 잡초인 왜제비꽃과 대조군으로 강낭콩을 선정하였다. 항온조건 20℃, 25℃, 30℃에서 발육실험과 산란실험을 진행하고 생명표 분석을 수행하였다. 차응애는 한라봉 어린잎, 왜제비꽃, 강낭콩에서 발육을 완료했지만 한라봉 구엽에서는 발육을 완료하지 못했다. 한라봉 어린잎을 섭식하는 차응애의 총 발육기간은 각 온도조건에서 17.4, 13.4, 10.2일로 강낭콩에서 조사된 16.1, 9.5, 7.0일보다 길었다. 한라봉 어린 잎에서의 차응애 성충의 수명은 각 온도에서 19.1, 15.0, 12.3일로 강낭콩에서 조사된 22.1, 14.1, 10.9일과 유의한 차이는 없었으며, 산란수는 각 온도에서 18.1, 23.9, 17.8개로 왜제비꽃(93.3, 105.8, 115.0개)과 강낭콩(127.4, 121.0, 117.1개)에서 보다 적었다. 조사된 발육데이터를 기반으로 생명표 통계량을 추정한 결과 서로 간 유의한 차이를 보였으며 내적자연증가율(rm)은 각 온도에서 강낭콩(0.1542, 0.2563, 0.3251), 왜제 비꽃(0.1087, 0.2007, 0.2673), 한라봉(0.0868, 0.1002, 0.1217)순으로 높게 나타났다. 이상의 결과를 종합하여 감귤원(한라봉)의 차응애 관리 전략에 대하여 고찰하였다.
        4,200원
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