• 제목/요약/키워드: Illinois

검색결과 1,000건 처리시간 0.03초

A Flight Mechanics-Centric Review of Bird-Scale Flapping Flight

  • Paranjape, Aditya A.;Dorothy, Michael R.;Chung, Soon-Jo;Lee, Ki-D.
    • International Journal of Aeronautical and Space Sciences
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    • 제13권3호
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    • pp.267-281
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    • 2012
  • This paper reviews the flight mechanics and control of birds and bird-size aircraft. It is intended to fill a niche in the current survey literature which focuses primarily on the aerodynamics, flight dynamics and control of insect scale flight. We review the flight mechanics from first principles and summarize some recent results on the stability and control of birds and bird-scale aircraft. Birds spend a considerable portion of their flight in the gliding (i.e., non-flapping) phase. Therefore, we also review the stability and control of gliding flight, and particularly those aspects which are derived from the unique control features of birds.

On-field Crop Stress Detection System Using Multi-spectral Imaging Sensor

  • Kim, Yunseop;Reid, John F.;Hansen, Alan;Zhang, Qin
    • Agricultural and Biosystems Engineering
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    • 제1권2호
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    • pp.88-94
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    • 2000
  • Nitrogen (N) management is critical for corn production. On the other hand, N leaching into the groundwater creates serious environmental problems. There is a demand for sensors that can assess the plant N deficiency throughout the growing season to allow producers to reach their production goals, while maintaining environmental quality. This paper reports on the performance of a vision-based reflectance sensor for real-time assessment of N stress level of corn crops. Data were collected representing the changes in crop reflectance in various spectral ranges over several stages of development in the growing season. The performance of this non-contact sensor was validated under various field conditions with reference measurement from a Minolta SPAD meter and stepped nitrogen treatments.

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Perspectives on the Quality Assurance of Ginseng Products in North America

  • Fitzloff, J.F.;Yat, P.;Lu, Z.Z.;Awng, D.V.C.;Arnason, J.T.;Breemen, R.B.van;Ha, T.ll;Blumenthal, M.;Fong, H.H.S.
    • 고려인삼학회:학술대회논문집
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    • 고려인삼학회 1998년도 Advances in Ginseng Research - Proceedings of the 7th International Symposium on Ginseng -
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    • pp.138-145
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    • 1998
  • A validated and reproducible HPLC method was developed for the profiling and quantitative analysis of ginsenosides in commercial products available in North America. Analysis of 280 Panax ginseng and Panax quinquefolius products showed profiles indicative of the presence of ginsenosides in the majority of these products. However, the quantitative contents of the products vary greatly, not only in products of different formulations, but also of products within each of the fromulations examined.

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An Empirical Study of Qualities of Association Rules from a Statistical View Point

  • Dorn, Maryann;Hou, Wen-Chi;Che, Dunren;Jiang, Zhewei
    • Journal of Information Processing Systems
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    • 제4권1호
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    • pp.27-32
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    • 2008
  • Minimum support and confidence have been used as criteria for generating association rules in all association rule mining algorithms. These criteria have their natural appeals, such as simplicity; few researchers have suspected the quality of generated rules. In this paper, we examine the rules from a more rigorous point of view by conducting statistical tests. Specifically, we use contingency tables and chi-square test to analyze the data. Experimental results show that one third of the association rules derived based on the support and confidence criteria are not significant, that is, the antecedent and consequent of the rules are not correlated. It indicates that minimum support and minimum confidence do not provide adequate discovery of meaningful associations. The chi-square test can be considered as an enhancement or an alternative solution.

Approximate Clustering on Data Streams Using Discrete Cosine Transform

  • Yu, Feng;Oyana, Damalie;Hou, Wen-Chi;Wainer, Michael
    • Journal of Information Processing Systems
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    • 제6권1호
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    • pp.67-78
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    • 2010
  • In this study, a clustering algorithm that uses DCT transformed data is presented. The algorithm is a grid density-based clustering algorithm that can identify clusters of arbitrary shape. Streaming data are transformed and reconstructed as needed for clustering. Experimental results show that DCT is able to approximate a data distribution efficiently using only a small number of coefficients and preserve the clusters well. The grid based clustering algorithm works well with DCT transformed data, demonstrating the viability of DCT for data stream clustering applications.

Aromatase Inhibitors from Isodon excisus var. coreanus

  • Jeong, Hyeh-Jean;Chang, Leng-Chee;Kim, Ho-Kyoung;Kim, Il-Hyuk;A.Douglas Kinghorn;John M.Pezzuto
    • Archives of Pharmacal Research
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    • 제23권3호
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    • pp.243-245
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    • 2000
  • The diethyl ether extract of isodon excisus var. coreanus exhibited significant inhibitory activity in aromatase assay. Bioactivity-guided fractionation of the extract led to the isolation of three active compounds: inflexin(ent-1${\alpha}$-hydroxy-3${\beta}$,6a-diacetoxykau r-16-en-11,15-dione) (1), ursolic acid (2), and ursolic acid 3-O-acetate (3).

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