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      • Economic Threshold for Diamondback Moth (Plutella xylostella (L.) ) on Leaf Broccoli (Brassica oleracea var. botrytis italiana)

        Seon-u Choi,Ju-Rak Lim,Ju-Hee Kim,Ki-Kwan Lee,Chang-yun Hwang 한국응용곤충학회 2009 한국응용곤충학회 학술대회논문집 Vol.2009 No.05

        This study was conducted to develop the economic threshold for the diamondback moth (Plutella xylostella (L.) on Leaf Broccoli (leaf vegetable) in 2007. To investigate the relationship between initial density of diamondback moth larvae and broccoli leaf yield, experimental plots with five treatments (0, 0.5, 1.0, 2.0, 4.0 larvae per plant) as initial density were established. We inoculated larvae in chesses cloth covering to survey larvae density change. When grown to eat, leaves of broccoli were harvested by periods. 60-70% of larvae were removed whenever we picked the leaves. High levels of larvae were associated with significant reductions in leaf yield. There were 85%, 64%, 58%, and 56% yield reductions from the diamond back moth larvae density in 0, 0.5, 1,0, 1.5, 2.0 per plant, respectively 25days after larvae inoculation. The regression equation used to predict leaf yield based on the number of initial larvae density per a plant was y=1635-393x(R2=0.79***). The economic injury level of diamondback moth on leaf broccoli was 2-3 larvae per 10 plants for a damage level of 5%. The economic thresholds was 1-2 larvae per 10 plants. Thus, the diamond back moth management should be initiated 1-2 larvae occurrence per plant.

      • Fatigue analysis of floating wind turbine support structure applying modified stress transfer function by artificial neural network

        Kim, Hyeon-Jin,Jang, Beom-Seon,Park, Chang-Kyu,Bae, Yoon Hyeok Elsevier 2018 Ocean engineering Vol.149 No.-

        <P><B>Abstract</B></P> <P>The frequency-domain approach has been studied as a potential replacement modality for the time-domain method in fatigue analysis of offshore wind turbine structures. It is assumed that in the frequency-domain approach, the stress response spectra induced by wind and wave loads can be expressed by a stress transfer function. To obtain the stress transfer function, coupled analysis should be performed in advance. However, since the response of a wind turbine to different average wind speeds is non-linear, the stress transfer function is bound to change with wind speed. This means that repeated simulation is needed in order to calculate the stress transfer function according to wind speed change. The problem, though, is that if the number of simulations is large, prohibitively high computational and time costs probably will be incurred. In this study, to reduce the number of simulations and, at the same time, increase the accuracy of results, a correction factor of the stress transfer function induced by wind load was artificial-neural-network-approximated as a function of mean wind speed and frequency. Sensitivity analysis was conducted to determine how many sample points are required and how to select them. Also, a superposition model is proposed to improve the accuracy of the ANN model. This model is designed so that the peaks in the stress spectrum have a dominant influence on fatigue damage. In order to better simulate the correction factor around the peak, the model considering only the data of the periphery of the peaks and the model reflecting the whole data are superimposed. The total stress spectrum were calculated by summing stress spectrum induced by wind load from the ANN model and induced by inertia load from motion analysis based on linear wave theory. Numerical analysis for a 10 MW class wave and offshore wind hybrid power generation (WWHybrid) system, which is a kind of semi-submersible wind turbine platform, was performed to verify the performance of the proposed model. It was confirmed that the superposition model improves the accuracy by 20–50% compared with the single ANN model.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This paper proposes a procedure to apply the regression model to predict the fatigue life of a floating wind turbine support structure. </LI> <LI> The proposed procedure shows the stress transfer function induced by wind loads as a function of mean wind speed and frequency through a neural network model. </LI> <LI> A sampling strategy for constructing a model and a superimposed model concept for reflecting different weights between samples to a model are suggested. </LI> </UL> </P>

      • 간 허혈성괴상의 CT소견에 대한 실험적 연구 : 간실질 및 피막의 경시적 변화와 병리조직의 비교 Changes of CT Findings of Liver Parenchyama and Capsule with Time Lapse Correlated with Histopathology

        김창근,김강득,최시성,정선관,노병석,원종진 圓光大學校 醫科學硏究所 1994 圓光醫科學 Vol.10 No.1-2

        In order to evaluate CT findings with time and to confirm the capsular structure correlating with its histopathologic findings, we experimentally induced ischemic necrosis of liver in 20 rabbits. Incision of the abdomen was performed under anesthesia. Ligation of hepatic artery, portal vein and hepatic duct of right inferior posterior lobe of the liver after injection of macroaggregated albumin into right inferior posterior portal vein in order to prevent from developing collateral circulation as possible. Precontrast and postcontrast enhanced CT images were obtained at 1. 2. 4 days and 1, 2. 4. 6 weeks after induction of ischemic necrosis. Necrotic area in the liver showed homogeneous low density compared to normal liver, and no contrast enhancement after contrast material administration, and marked volume loss with time. CT attenuation value of necrotic area at 1 day(36.7±6.4 M±SD, Hounsfield unit) approached to two third of that of normal liver(56.3±7.3) and showed no significant change until two weeks but increased significantly after four weeks. On contrast enhanced CT images, capsular structure was obsereved as a high density rim along the liver surface of the necortic area in 8 of 15 cases. From the first day on, homogenous ischemic or coagulation necrosis was observed but rarely findings of edema, hemorrhage and cystic change were observed on histopathologic specimen. In all of the histologic samples taken from 10 cases during th 2nd to 6th week, fibrous thickening with rich vascularity was observed along the surface of the necrotic area. In conclusion, ischemic necrosis of the liver showed homogeneous low density and no contrast enhancement. CT attenuation value of necrotic area increased significantly with time associated with markedly decrease in volume. Capsular structure attributed to the hypertrophy of the liver capsule and rich vascularity within it.

      • CDMA 시스템의 Ec/Io 개선을 위한 순방향 채널의 전력분배에 관한 연구

        김선미,최동유,류광진,박창균 조선대학교 전자정보통신연구소 2002 電子情報通信硏究所論文誌 Vol.5 No.2

        This study defined the way to distribute power of forward channel and suggested a new model for prediction power in order to minimize the deterioration of call quality and performance in the CDMA mobile communication system of narrow band using 1.2288MHz of narrow band. Each change in Ec/Io was measured for the factors affecting wireless environment(e.g. the changes in power of overhead channel, the changes in a number of call channel, and the increase in interference from the additional facilities of adjacent base station or other systems) to know the influence on the wireless environment of forward link. The new way for power distribution to a base station in operation and its validity was checked by comparing before and after test.

      • SCOPUSKCI등재

        흰쥐에서 Iodine-131-Iododeoxyadenosine 의 생체분포 및 유방암 영상화에 관한 연구

        김혜원,원종진,최시성,이현철,김창근,김선구,Yang, David J,이강무,민병철,이종덕,Kim, E Edmund 대한핵의학회 1998 핵의학 분자영상 Vol.32 No.4

        Purpose: I-131 labeled (2'-deoxy-2-iodo-β-D-arabinofuranosyl) adenine (IAD) may be involved in DNA synthesis during active proliferation of tumor cells. We conducted this study to find out the biodistribution of IAD and its feasibility for scintigraphic tumor imaging. Materisls and Methods: Tosyl acetyl-adenosine was dissolved in acetonitrile, and I-131-NaI was added and heated to synthesize IAD. Female Fisher 344 rats innoculated with breast tumor cells were injected witb 0.27 MBq of IAD. Rats were sacrificed at 0.5, 1, 2, 4, 24h and the % of injected dose per gram of tissue (%ID/g) was determined. For scintigraphy, rats bearing breast cancer were administered with 1.11 MBq of IAD and imaging was perforrned after 2 and 24h. Then, rat body was fixed and rnicrotomized slice was placed on radiographic film for autoradiography, Results: %ID/g of tumor wa.' 0.74 (0.5h), 0.73 (1h), 0.55 (2h), 0.38 (4h), and 0.05 (24h), respectively. At 1h after injection, %ID/g of tumor was higher than that of heart (0.34), liver (0.42), spleen (0.47), kidney (0,69), muscle (0.14), bone (0.33) and intestine (0.51). However, %1D/g of tumor was lower than blood (1.06), lung (0.77), and thyroid (177.71). At 4h, %ID/g of tumor in comparison with other tissue did not change. Tumor contrast expressed by tumor to blood ratio was 0.69 and tumor to muscle ratio was 5.11 at 1h. However, these ratios did not improve through 24h. On autoradiogram and scintigraphy at 2 and 24 hour, the tumor was well visualized. Conclusion: This results suggest that Ial) may have a potential for tumor scintigraphy. However, further work is needed to improve localization in tumor tissue. (Korean J Nucl Med 1998;32:374-81)

      • KCI등재

        Performance Evaluation of an Electrometer for Quality Control and Dosimetry in Radiation Therapy

        Kim, Chang-Seon,Kim, Chul-Yong,Park, Myung-Sun Korean Society of Medical Physics 2000 의학물리 Vol.11 No.2

        전리계의 성능은 방사선 선량측정의 정확도와 정밀도에 직접적으로 영향을 준다. 본 연구에서는 전리계의 성능을 유지하기 위한 정도관리의 항목들을 제시하고 구체적인 성능검사를 시행하고자 한다. 선정된 성능평가 항목들은 적절한 인가전압, 예열 및 고전압 후의 평형시간, 누설에 의한 상쇄 전류, 방사선 측정 전후의 영점이동 (배경전류), 장시간 안정성, 선형성, 외부조건의 영향 등이었다. 전리계에 연결된 자루가 단단한 전리함과 방사선원으로 스트론티움-90이 내장된 검사기가 성능검사용으로 이용되었다. 인가전압의 측정은 전리함의 입력단자에서 직접 측정하였고 평형시간의 측정은 전리계에 전원을 연결한 후와 인가전압을 바꾼 후 검사기에 연결된 전리함의 반응이 안정을 가져오는 시간으로 측정하였다. 누설은 전리계가 안정된 후 방사선을 조사하지 않은 상태에서 전리계의 측정값이 영점에서 이동하는 것으로 나타냈으며 배경전류는 안정된 전리계의 영점을 조정하고 전리계에 연결된 검사기에서 전리함을 10분 조사한 후 영점의 변화로 나타냈다. 장시간의 안정성 3개월에 걸쳐 측정되었으며 이때 검사기의 측정값을 온도-기압에 대한 보정을 한 후 그 값을 비교하였다. 선형성은 전리계에 연결된 전리함을 n번 연속하여 조사하여 그 전체의 측정값과 초기값을 n번 곱한 값을 비교하였다. 외부조건의 영향은 인위적으로 외부온도를 17-34 $^{\circ}C$ 로 변화시켜서 환경변화에 의한 전리계의 영점이동으로 나타냈다. 인가전압의 측정에서 명목상의 인가전압 300, 500V에 대한 측정값은 각각 2.5%와 5.8% 작게 나타났다. 전원을 연결한 후 전리계가 실제로 평형에 도달하는 시간은 20분으로 이는 전리계의 안정성 표시기보다 9분 지연되었으며 인가전압을 바꾼 경우에는 1분 이내에 평형에 도달하였다. 전리계의 누설의 측정에서 영점의 이동은 0.002(스케일)/15분이었고 10분 조사 후 영점의 이동은 발견되지 않았다. 전리계는 3개월 동안 99.4%의 안정성을 유지하였다. 스케일 영역 0.000-9.991 에서 전리계의 선형성에서의 이탈은 0.9% 이었다. 온도 범위 17 - 34 $^{\circ}C$ 에서 전리계의 영점이동은 0.2% 이내였다. 본 연구에서는 임상에서 사용하고 있는 전리계에 대한 성능을 평가하는 항목을 제시하고 이를 전리계의 정도관리에 이용하도록 하였다. 이러한 프로그램의 운용을 통하여 전리계에 의한 오차를 줄임으로써 방사선측정에서의 정확도와 정밀도를 향상시킬 수 있을 것으로 사료된다. The performance of an electrometer directly affects on the accuracy and precision in radiation dosimetry. This study is to list of the quality control for maintaining performance and to perform evaluation tests of an electrometer. Performance tests selected include proper polarizing voltages, warm-up and equalization time, leakages, long-term stability, linearity, and effect of ambient conditions. An electrometer connected with a rigid stem ionization chamber was evaluated with a Strontium-90 check device. Bias voltage was measured directly on the input socket. Equalization time is the time required for reaching threshold of charged state after the power is on or the bias voltage is changed. Pre- and post-signal leakages are defined as the accumulation of signal with no exposure and after exposure, respectively. Over three months period, the electrometer's long-term stability was measured by comparison of the temperature-pressure corrected readings. Linearity was expressed as the deviation of readings from multiple short exposures from one continuous exposure. Effect of ambient conditions was expressed as the zero drift of the electrometer over 17-34$^{\circ}C$ temperature ranges. For two nominal values, 300 and 500 volts, measured voltages were lower by 2.5 and 5.8%, respectively. The warm-up time, 20 minutes, was longer than the lamp time by 9 minutes and the equalization time was less than 1 minute. Without exposure, the zero-drift was 0.002 scale-unit in 15 minutes and the leakage after 10 minutes exposure was minimal. The IQ-4 was stable over 99.4% for three-month periods. Deviation from the linearity was 0.9% for measurement scale, 0.000-9.991. Over 17-34$^{\circ}C$ temperature range, the zero-drift was minimal, less than 0.2%. For a clinically-used electrometer, a list for the basic peformance evaluations is proposed. By running this program, the measurement error using an electrometer can be reduced and in turn the improvement in accuracy and precision of radiation dosimetry can be achieved.

      • SCOPUSKCI등재

        Which Environmental Factors Caused Lammas Shoot Growth of Korean Red Pine?

        Lee, Chang-Seok,Song, Hye-Gyung,Kim, Hye-Soo,Lee, Bit-Na-Ra,Pi, Jeong-Hoon,Cho, Yong-Chan,Seol, Eun-Sil,Oh, Woo-Seok,Park, Sung-Ae,Lee, Seon-Mi The Ecological Society of Korea 2007 Journal of Ecology and Environment Vol.30 No.1

        Lammas growth, a rare phenomenon for Korean red pine (Pinus densiflora), occurred in 2006. Lammas shoots showed higher frequency and longer length in Seoul's hotter urban center than in urban boundary or suburban forest sites. Frequency and length showed a close correlation with urbanization density and vegetation cover expressed in NDVI. Air temperature in the late summer of 2006 was more than $1^{\circ}C$ higher than an average year. Of the predominant environmental signals that modulate bud flush, only temperature changed significantly during the year. Differences in temperature between the urban centers, urban boundaries and suburban forests correlated with varying land-use density. The rise in temperature likely spurred lammas growth of the Korean red pine. Symptoms of climate change are being detected throughout the world, and its consequences will be clearer in the future. Considerate interest in the responses of ecological systems to the variable changes is required to prepare for unforeseeable crises. Monitoring of diverse ecological phenomena at Long Term Ecological Research sites could offer harbingers of change.

      • KCI등재후보

        Sports and Culture: Exploration for the Thought of Diversity and Historical Approach

        Deok Seon CHANG,Hae Yu KIM,Hyuk Jin LEE 한국스포츠과학회 2020 스포츠과학연구(JSAS) Vol.4 No.4

        Purpose: This study started with interest in sport culture and is meaningful as an exploratory study to help with the basic understanding of sport culture research. Research design, data, and methodology: The approach of this study is the exploratory approach by literature reviews. This study carried out exploratory research on thinking about diversity of sports culture and the development process of sports culture by human history periods. Results: First, in thinking about cultural diversity, cultural absolutism and cultural relativism were identified. The characteristics of sports culture can identify universality, individuality and diffusion, and the attributes of sports culture included sharing, learning, accumulation, whole systematic relationship and change. Second, the characteristics of sports culture were identified by the approach of each historical era. The historical stages were divided into ancient civilizations, ancient Greece and Rome, middle ages and early modern period, and late modern period. Sports have historically been found to have a British-centered European origin or popularized in the United States. Conclusions: with the characteristics of modern sports culture, the globalization of sports culture, the prominence of sports industry and sports space marketing, and the symbiotic influence relationship of sports and mass media were examined and future directions were discussed.

      • 폭주과다 및 개선부족 환자에 대한 시기능 훈련 효과

        이창선 ( Chang Seon Lee ),김기홍 ( Ki Hong Kim ) 대구가톨릭대학교 자연과학연구소 2012 자연과학연구논문집 Vol.10 No.1

        This study was performed to investigate vision training was an effective way to influence fusional vergence and asthenopic symptoms in case of convergence excess and divergence excess. The change was examined weekly at the clinic during the 7 week vision training. According to the results, MISTERY CIRCLE vision training methods improved the binocular vision function and sensation symptoms. For Worth 4 Dot test, Howell test card and fusion reserve test showed fusion rate changes. The study proved that visio training methods for patients with binocular vision was effective for the improvement of the phoria, function and sensation symptoms of these patients.

      • SCIESCOPUSKCI등재

        The Effect of Coolant Boiling on the Molten Metal Pool Heat Transfer with Local Solidification

        Cho, Jea-Seon,Kune Y. Suh,Chung, Chang-Hyun,Park, Rae-Joon,Kim, Sang-Baik Korean Nuclear Society 2000 Nuclear Engineering and Technology Vol.32 No.1

        This study is concerned with the experimental test and numerical analysis of the heat transfer and solidification of the molten metal pool with overlying coolant with boiling. In the test, the metal pool is heated from the bottom surface and coolant is injected onto the molten metal pool. Experiments were performed by changing the test section bottom surface temperature of the metal layer and the coolant injection rate. The two-phase boiling coolant experimental results are compared against the dry test data without coolant or solidification of the molten metal pool, and against the crust formation experiment with subcooled coolant. Also, a numerical analysis is performed to check on the measured data. The numerical program is developed using the enthalpy method, the finite volume method and the SIMPLER algorithm. The experimental results of the heat transfer show general agreement with the calculated values. The present empirical test and numerical results of the heat transfer on the molten metal pool are apparently higher than those without coolant boiling. This is probably because this experiment was performed in concurrence of solidification in the molten metal pool and the rapid boiling of the coolant. The other experiments were performed without coolant boiling and the correlation was developed for the pure molten metal without phase change.

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