Journal articles: 'Method polar'

1

Matsushima, T., and P. S. Marcus. "A Spectral Method for Polar Coordinates." Journal of Computational Physics 120, no. 2 (September 1995): 365–74. http://dx.doi.org/10.1006/jcph.1995.1171.

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2

Vannucci, Paolo. "Plane Anisotropy by the Polar Method*." Meccanica 40, no. 4-6 (December 2005): 437–54. http://dx.doi.org/10.1007/s11012-005-2132-z.

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3

Bourgeois, A., and P. Gutowski. "The reflectivity method with polar sampling." Bulletin of the Seismological Society of America 81, no. 1 (February 1, 1991): 222–31. http://dx.doi.org/10.1785/bssa0810010222.

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Abstract A modification to the reflectivity method that results in more accurate and efficiently computed theoretical seismograms is introduced. The reflectivity method involves an explosive point source and a radially symmetric earth, and in the temporal frequency domain the displacement field and the complex plane wave reflectivity are, to within a phase factor, Hankel transform pairs in the polar coordinate variables radial offset and wavenumber. This motivates formulation of the time-transformed displacement field into a Fourier-Bessel series over the reflectivity function, and replacement of the traditional method for sampling the plane-wave reflectivity with the proper polar sampling scheme, based on the finite Fourier transform representation for a band-limited signal. Several numerical examples are discussed.

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4

Shwetha. K and Dakshayani. K.R. "Morphometric study of the segmental branches of the splenic artery in human cadaver spleens by dissection method." International Journal of Anatomy and Research 9, no. 2.2 (May 11, 2021): 7965–69. http://dx.doi.org/10.16965/ijar.2021.103.

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Introduction: Spleen is the largest lymphoid organ. It is supplied by splenic artery the largest branch of coeliac trunk. It traverses through the lienorenal ligament to reach near the hilum of the spleen, where it divides into two or three primary branches, each of which is subdivided mostly into two or four secondary branches. Moreover, a superior polar arteries and inferior polar arteries are given from splenic trunk or from one of its primary branches, which goes to the poles of the spleen, without entering the hilum. The present study was undertaken to know about the morphometry of the segmental branches of splenic artery and polar arteries Material and method: The present study was conducted on 79 adult human cadaver spleens by dissection method of unknown sex, fixed in 10% formalin solution, collected from the Department of Anatomy and Forensic Medicine, Mysore Medical College and Research Institute, Mysore. Results: Two primary segmental branches were seen in 56 (70.9%) specimens, three primary segmental branches in 19(24.1%) specimens and four primary segmental branches in 4(5.1%) specimens. Superior polar artery was present in 18(22.8%) specimens and inferior polar artery was present in 32(40.5%) and both superior and inferior polar artery was seen in 5(6.3%) specimens. The length of primary segmental branches varied from 0.2 cm to 4.9 cm. The length of polar arteries varied from 0.7 cm to 5.7 cm. The diameter of primary segmental branches varied from 0.6 mm to 4.7 mm. The diameter of polar branches varied from 0.4 mm to 2.8 mm. Conclusion: The present study adds up to the existing knowledge regarding the morphometry of the segmental branches of splenic artery, as the various splenic conservative surgeries are dependent on better understanding of the vascular anatomy of the spleen. KEY WORDS: Splenic artery, Segmental branches, Polar artery.

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5

Zhang, Yingxian, Aijun Liu, Kegang Pan, Chao Gong, and Sixiang Yang. "A Practical Construction Method for Polar Codes." IEEE Communications Letters 18, no. 11 (November 2014): 1871–74. http://dx.doi.org/10.1109/lcomm.2014.2358228.

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Sun, X., Y. Liu, J. T. Hoeksema, K. Hayashi, and X. Zhao. "A New Method for Polar Field Interpolation." Solar Physics 270, no. 1 (April 14, 2011): 9–22. http://dx.doi.org/10.1007/s11207-011-9751-4.

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7

Mlynář, Jan. "Pixels method computer tomography in polar coordinates." Czechoslovak Journal of Physics 45, no. 10 (October 1995): 799–816. http://dx.doi.org/10.1007/bf01691393.

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8

Zhang, Yongjian, Lin Wang, Guo Wei, Xudong Yu, and Chunfeng Gao. "Covariance transformation method for polar integrated navigation." Journal of Physics: Conference Series 1939, no. 1 (May 1, 2021): 012030. http://dx.doi.org/10.1088/1742-6596/1939/1/012030.

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9

Germain-McCarthy, Yvelyne. "Demystifying Polar Graphing." Mathematics Teacher 87, no. 9 (December 1994): 728–35. http://dx.doi.org/10.5951/mt.87.9.0728.

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If we are to follow NCTM's Curriculum and Evaluation Standards (1989), teachers should connect various topics of mathematics so that students see the subject as a unified body of knowledge. This article discusses a method of graphing polar equations using information from the Cartesian graphs of trigonometric functions. This method will help students see relationships between the two types of graphs.

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10

Mason, Paul A. "On the Classification of Magnetic Cataclysmic Variables." International Astronomical Union Colloquium 194 (July 2004): 180–81. http://dx.doi.org/10.1017/s025292110015239x.

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AbstractThe classification scheme for Magnetic Cataclysmic Variables (MCVs) is addressed. When only ten or twenty MCVs had been discovered their classification was simple and based on direct observational properties. Now that the number of MCVs exceeds one hundred, the method of classification needs updating. One important consideration is the possibility that binaries might physically change their classification. For example will intermediate polars become polars as they evolve to shorter orbital periods? Or does a polar become an intermediate polar when synchronism is broken due to a nova?

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Wu, Feng, Tianyi Shao, Cong Gu, Qiangwen Fu, and Yafen Xu. "Virtual Polar Region Method Based on the Earth’s Transverse Ellipsoid Model." Mathematical Problems in Engineering 2021 (January 29, 2021): 1–9. http://dx.doi.org/10.1155/2021/6620068.

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Experimental verification is very important for the research of inertial navigation and integrated navigation technology, but most researchers do not have the opportunity to conduct experiments directly in the polar regions. In order to solve the problem of inertial navigation verification in high latitude areas, a virtual polar region method based on transverse ellipsoid model is proposed. The method converts the reference information, initial state, and inertial sensor data into polar regions based on the transverse geographic coordinate system and can ensure that the attitude, velocity, and altitude information relative to the local-level frame remain unchanged. Therefore, the actual test data in the middle and low latitudes can be reconstructed accurately in the polar region without singularities, trajectory deformation, and principle errors. Simulation and vehicle tests show that the proposed method can achieve the same verification effect as the actual polar experiment.

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12

Zhang, Zhi Jia, and Jing Chen. "The Method of Round Image Matching Based on Log-Polar Transform*." Key Engineering Materials 467-469 (February 2011): 1024–29. http://dx.doi.org/10.4028/www.scientific.net/kem.467-469.1024.

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Traditional image matching methods are not proper for the situation of the angle rotation. Aiming at this problem, This paper proposes an round image matching method based on log-polar transform. Log-polar image transform can convert the rotation changes in Descartes coordinate to shift changes in log-polar coordinate, which had such trait as invariance to rotation. Results show that this algorithm based on log-polar transform can match the images with rotation changes, Compared with existing algorithms, the new algorithm not only had higher matching rate and stronger adaptability, but also can effectively solve matching problem under the circumstance of brightness changes, contrast changes or noise interferences.

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13

Tian, Qichuan, Lanfang Zhang, and Xiaojia Wu. "Iris Boundary Localization Method Based on Polar Coordinate." Procedia Engineering 29 (2012): 2194–98. http://dx.doi.org/10.1016/j.proeng.2012.01.286.

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14

Dai, C. Y., and X. L. Zhang. "Bistatic Polar Format Algorithm Based on NUFFT Method." Journal of Electromagnetic Waves and Applications 25, no. 17-18 (January 2011): 2328–40. http://dx.doi.org/10.1163/156939311798806248.

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15

Vannucci, P., and G. Verchery. "Stiffness design of laminates using the polar method." International Journal of Solids and Structures 38, no. 50-51 (December 2001): 9281–94. http://dx.doi.org/10.1016/s0020-7683(01)00177-9.

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16

Izraeli, D., I. Mardor, E. Ø. Cohen, M. Duer, T. Y. Izraeli, I. Korover, J. Lichtenstadt, and E. Piasetzky. "Polar polarization: a new method for polarimetry analysis." Journal of Instrumentation 13, no. 07 (July 30, 2018): P07029. http://dx.doi.org/10.1088/1748-0221/13/07/p07029.

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17

Ronglin, Li, Ni Guangzheng, and Yu Jihui. "B-spline finite-element method in polar coordinates." Finite Elements in Analysis and Design 28, no. 4 (March 1998): 337–46. http://dx.doi.org/10.1016/s0168-874x(97)00044-9.

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18

Yamada, Akira, and Tomoaki Ohtsuki. "Discrete BP Polar Decoder Using Information Bottleneck Method." IEEE Access 9 (2021): 10645–56. http://dx.doi.org/10.1109/access.2021.3050411.

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19

Yongxing, Zhang, Li Liqun, Liu Juan, Wang Huiquan, and Zhang Dan. "A Real-Time Oocyte Polar Body Detection Method." Journal of Physics: Conference Series 1754, no. 1 (February 1, 2021): 012219. http://dx.doi.org/10.1088/1742-6596/1754/1/012219.

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20

Literathy, P. "Polar and non-polar aromatic micropollutants in water (drinking-water) resources." Water Supply 1, no. 4 (June 1, 2001): 149–57. http://dx.doi.org/10.2166/ws.2001.0079.

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Aromatic compounds are important contaminants that limit the intended uses of water resources. Both polar and non-polar substances, such as phenols, aromatic sulfonates, lignin-sulfonic acids, humic and fulvic substances (acids) and mono- and poly-aromatic hydrocarbons, their alkyl-substituted derivatives, respectively, are among the potential aromatic micropollutants. During the last 5 - 10 years, an analytical approach has been developed on the basis of total fluorescence measurement of the original water sample and its organic solvent (cyclohexane) extract. It has been demonstrated and verified that polar aromatic compounds fluoresce only in the original water sample, whereas non-polar (hydrophobic) compounds fluoresce in an organic solvent (e.g. cyclohexane) extract. During extraction, polar compounds remain in the water sample. This method has been used in a country-wide survey in drinking water aquifers, as well as in several environmental impact assessment studies, particularly for petroleum-related pollution. It is a very convenient method to determine the naturally occurring humic and fulvic substances in water and has proved to be an appropriate substitute of the infrared spectrophotometric method for oil pollution assessment in the environment, also having the advantage of signalling more harmful, toxic aromatic petroleum hydrocarbons.

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21

Chen, Qian-Bao, Tian-You Zeng, Lei Xia, Ze Zhang, Chun-Yan Hong, Gang Zou, and Ye-Zi You. "A RAFT/MADIX method finely regulating the copolymerization of ethylene and polar vinyl monomers under mild conditions." Chemical Communications 53, no. 78 (2017): 10780–83. http://dx.doi.org/10.1039/c7cc06341e.

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A RAFT/MADIX method can not only copolymerize ethylene with a diverse range of functionally polar monomers, but can also easily tune the polar composition and the polar monomer distribution along the produced copolymer chains.

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22

Wang, Yuqing, Yaowei Liu, Mingzhu Sun, and Xin Zhao. "Deep-Learning-Based Polar-Body Detection for Automatic Cell Manipulation." Micromachines 10, no. 2 (February 13, 2019): 120. http://dx.doi.org/10.3390/mi10020120.

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Polar-body detection is an essential and crucial procedure in various automatic cell manipulations. The polar body can only be observed when it is located near the focal plane of the microscope, so we need to detect the polar body during cell rotation in cell manipulations. However, three-dimensional cell rotation by micropipette causes polar-body defocus and cell/polar-body deformation, which have not been discussed in existing image-level polar-body-detection approaches. Moreover, varying sizes of the polar bodies increase the difficulty of polar-body detection. In this paper, we propose a deep-learning-based framework to realize polar-body detection in cell rotation. The detection problem is interpreted as image segmentation, which separates the polar body from the background. Then, we improve U-net, which is a typical convolutional neural network (CNN) for medical-image segmentation, so that the network can be applied to polar-body detection, especially for the detection of defocused polar bodies and polar bodies of different sizes. For CNN training, we also designed a particular image-transformation method to simulate more cell-rotation situations, including cell- and polar-body deformation, so that the deformed polar body in cell rotation would be detected by the proposed method. Experiment results show that our method achieves high detection accuracy of 98.7% on a test dataset of 1000 images, and performs well in cell-rotation processes. This method can be applied to various automatic cell manipulations in the future.

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23

Ren, Xiao Zhen, Yao Qin, and Hong Liang Fu. "A RELAX Based Method for Spotlight SAR Imaging." Key Engineering Materials 500 (January 2012): 362–67. http://dx.doi.org/10.4028/www.scientific.net/kem.500.362.

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The imaging problem of spotlight SAR is converted to a parameter estimation problem of several monochromatic signals in additive white Gaussian noisy condition in this paper. Moreover, a spotlight SAR imaging algorithm based on RELAX is presented in detail. Traditional polar format algorithm and the presented method are applied to spotlight SAR imaging respectively, and the imaging results are compared. Simulation results show that the polar format algorithm doesn’t give satisfactory imaging results, while the proposed method adapts the noisy environment better and obtains better results.

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24

Vetere, Alessandro. "An empirical method to evaluate the solubility of several gases in polar and non-polar solvents." Fluid Phase Equilibria 132, no. 1-2 (May 1997): 77–91. http://dx.doi.org/10.1016/s0378-3812(97)00019-8.

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25

Ozdemir, Halis, Gonca Coban Serbetcioglu, and Ali Ayhan. "New screening method for cervical cancer - polar prob, TruScreen." International Journal of Reproduction, Contraception, Obstetrics and Gynecology 9, no. 5 (April 28, 2020): 1900. http://dx.doi.org/10.18203/2320-1770.ijrcog20201777.

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Background: Although extensive screening methods had been developed, cervical cancer remains to be an essential health problem. Early detection and administration of appropriate therapy is still a lifesaving procedure, especially for cervical cancer. The most common screening method for cervical cancer is still the cervical cytology (Pap-test). We aim to find out the advantages and disadvantages of a recently developed method, which is called as TruScreen®.Methods: Two different approaches had been used (conventional Pap test and TruScreen®), and 1438 patients were included in the study. Of these, 819 had been screened with TruScreen®. All eligible patients were firstly screened using TruScreen® and then using the Pap-test. Each patient with an abnormal TruScreen® result was referred to colposcopy room, where she was re-evaluated using colposcopy.Results: The rate of abnormal smear result was 1.04%, and the corresponding percentage was calculated as 0.62% in LSIL, 0.34% in ASCUS, and 0.069% in HSIL. A total of 819 patients underwent TruScreen®, and the results were abnormal in 261 patients and normal in 558 patients Interception rates for cervical dysplasia with TruScreen® have been found to be better than the conventional Pap test. The need for colposcopy dramatically increased with the use of TruScreen®. Use of TruScreen® alone was not found to be cost effective.Conclusions: Combination with other methods of screening would decrease the cost of the process. Further studies needed to find out the possible effects for the combination of TruScreen® with other testing methods.

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26

Yamamoto, Hiroshi, and Katsumi Tochigi. "New Low Vapor Pressure Estimation Method for Polar Compounds." Journal of the Japan Petroleum Institute 50, no. 3 (2007): 117–22. http://dx.doi.org/10.1627/jpi.50.117.

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27

Ding, H. F., S. Pütter, H. P. Oepen, and J. Kirschner. "Experimental method for separating longitudinal and polar Kerr signals." Journal of Magnetism and Magnetic Materials 212, no. 1-2 (March 2000): 5–11. http://dx.doi.org/10.1016/s0304-8853(99)00790-8.

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28

Suarez-Garcia, E., D. Haas, W. Hajdas, G. Lamanna, C. Lechanoine-Leluc, R. Marcinkowski, A. Mtchedlishvili, et al. "A method to localize gamma-ray bursts using POLAR." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 624, no. 3 (December 2010): 624–34. http://dx.doi.org/10.1016/j.nima.2010.10.006.

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29

Elishakoff, I. "Adjustable parameter method for vibration of polar orthotropic plates." Journal of Sound and Vibration 116, no. 1 (July 1987): 181–84. http://dx.doi.org/10.1016/s0022-460x(87)81329-9.

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30

Ichikawa, Koji, Masanori Izumida, and Kenji Murakami. "A method of detecting lines using local polar coordinates." Systems and Computers in Japan 28, no. 13 (November 30, 1997): 46–54. http://dx.doi.org/10.1002/(sici)1520-684x(19971130)28:13<46::aid-scj6>3.0.co;2-h.

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31

Nagao, Tomoharu, Takeshi Agui, and Masayuki Nakajima. "A Method of Extracting Similar Figures Using Polar Features." Systems and Computers in Japan 21, no. 3 (1990): 66–75. http://dx.doi.org/10.1002/scj.4690210307.

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Nagao, Tomoharu, Takeshi Agui, and Masayuki Nakajima. "An extraction method for same figure using polar features." Systems and Computers in Japan 21, no. 8 (1990): 72–81. http://dx.doi.org/10.1002/scj.4690210807.

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33

Gai, Shaoyan, Feipeng Da, and Xu Fang. "A Novel Camera Calibration Method Based on Polar Coordinate." PLOS ONE 11, no. 10 (October 31, 2016): e0165487. http://dx.doi.org/10.1371/journal.pone.0165487.

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Li, S. Y., C. Li, and B. C. Zhu. "Polar format tomographic method for far-field RCS extraction." Electronics Letters 45, no. 22 (2009): 1143. http://dx.doi.org/10.1049/el.2009.1813.

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35

Qiu, Zhouhua, Zhong Zeng, Huan Mei, Liang Li, Liping Yao, and Liangqi Zhang. "A Fourier–Legendre spectral element method in polar coordinates." Journal of Computational Physics 231, no. 2 (January 2012): 666–75. http://dx.doi.org/10.1016/j.jcp.2011.10.003.

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36

Morozov, R. A., and P. V. Trifonov. "Compact specification of polar codes." Information and Control Systems, no. 1 (February 19, 2019): 40–47. http://dx.doi.org/10.31799/1684-8853-2019-1-40-47.

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Introduction:Practical implementation of a communication system which employs a family of polar codes requires either to store a number of large specifications or to construct the codes by request. The first approach assumes extensive memory consumption, which is inappropriate for many applications, such as those for mobile devices. The second approach can be numerically unstable and hard to implement in low-end hardware. One of the solutions is specifying a family of codes by a sequence of subchannels sorted by reliability. However, this solution makes it impossible to separately optimize each code from the family.Purpose:Developing a method for compact specifications of polar codes and subcodes.Results:A method is proposed for compact specification of polar codes. It can be considered a trade-off between real-time construction and storing full-size specifications in memory. We propose to store compact specifications of polar codes which contain frozen set differences between the original pre-optimized polar codes and the polar codes constructed for a binary erasure channel with some erasure probability. Full-size specification needed for decoding can be restored from a compact one by a low-complexity hardware-friendly procedure. The proposed method can work with either polar codes or polar subcodes, allowing you to reduce the memory consumption by 15–50 times.Practical relevance:The method allows you to use families of individually optimized polar codes in devices with limited storage capacity.

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Tian, Yi Min, and Ao Zhang. "Generalized Polar Decompositions in Matrix Exponential." Applied Mechanics and Materials 130-134 (October 2011): 3023–26. http://dx.doi.org/10.4028/www.scientific.net/amm.130-134.3023.

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Matrix exponential computstion is a difficulty thing when the order of the matrix get big and big after discretion. When we use Lie group method to get numeric solution of a differential equation, we often face this problem.Li group method is a kind of prosperous method, its basic ideas is to keep the numeric solution in a manifold which is less than the Euclid space while bigger than the analytic solution manifold, so we can get more exact numeric solution than other method. So we discussed the generalized polar decompositions method for matrix exponential.

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Khaksar Haghani, F. "A Third-Order Newton-Type Method for Finding Polar Decomposition." Advances in Numerical Analysis 2014 (September 30, 2014): 1–5. http://dx.doi.org/10.1155/2014/576325.

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It is attempted to present an iteration method for finding polar decomposition. The approach is categorized in the scope of Newton-type methods. Error analysis and rate of convergence are studied. Some illustrations are also given to disclose the numerical behavior of the proposed method.

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Zhang, Mei-Tuo, Xiao-Xue Ye, Wei Lan, Yan-Ling Yang, Tsunghsueh Wu, Yu-Sang Li, and He-Bin Tang. "Strategic Combination of Isocratic and Gradient Elution for Simultaneous Separation of Polar Compounds in Traditional Chinese Medicines by HPLC." Journal of Analytical Methods in Chemistry 2018 (2018): 1–6. http://dx.doi.org/10.1155/2018/7569283.

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A simple high-performance liquid chromatography (HPLC) method for the simultaneous separation of the highly polar and weakly polar components of traditional Chinese medicines was developed via a strategic combination of isocratic and gradient elution methods. Liu-Shen-Wan and Liu-Wei-Di-Huang-Wan were used as representative examples of traditional Chinese medicines. This is the first time that 6 components of varying degrees of polarity in Liu-Shen-Wan had been successfully resolved in a single chromatographic run using an ultraviolet-visible detector with a fixed wavelength of 296 nm. In contrast to conventional gradient separation methods, this novel method offered a viable route for separation of the highly and weakly polar fractions simultaneously, thus greatly reducing the time and cost of analysis. This method therefore provides a more efficient way to determine the polar components present in traditional Chinese medicines. It would find potential application in drug screening, drug authentication, and product quality control.

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Junior, Tufy Kabbas, Cristiane de Moura, Mariana Araújo Vieira do Carmo, Luciana Azevedo, Luis Antônio Esmerino, Rosangela Capuano Tardivo, Petri Kilpeläinen, and Daniel Granato. "Chemical Composition, Antioxidant, Antimicrobial and Cytotoxic/Cytoprotective Activity of Non-Polar Extracts of Grape (Vitis labrusca cv. Bordeaux) and Blackberry (Rubus fruticosus) Seeds." Molecules 26, no. 13 (July 2, 2021): 4057. http://dx.doi.org/10.3390/molecules26134057.

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The aim of this study was to compare the influence of the extraction method, chemical composition, antimicrobial effects, antioxidant activity, and cytotoxicity on human cells of the non-polar extracts of grape (Vitis labrusca) and blackberry (Rubus fruticosus) seeds. The Soxhlet (Sox), Bligh–Dyer (BD), and ultrasound (US) methods were used for extractions. For blackberry non-polar seed extract, extraction via the BD method showed the highest mean values of total phenolic content (TPC), expressed in milligrams of gallic acid equivalent per 100 mL of non-polar seed extracts (102.37 mg GAE/100 mL), and higher antioxidant activity in relation to the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, expressed in milligrams of gallic acid equivalent per 100 mL of non-polar seed extracts (11.50 mg AAE/100 mL), if compared with the Sox and US extractions. Similar results were obtained for the non-polar grape seed extracts, where BD extraction obtained the highest values for TPC (28.61 mg GAE/100 mL) and DPPH (35.36 mg AAE/100 mL). The type of extraction method had an impact on the composition of fatty acids. Only the non-polar blackberry and grape seed extracts obtained via the Sox method showed some in vitro inhibitory effect against Escherichia coli (IAL 2064) and Staphylococcus aureus (ATCC 13565). Regardless of the extraction method used, the non-polar blackberry and grape seed extracts did not decrease the cell viability (IC50 >1000 µg/mL) of cancer and normal cell lines, thus indicating the relative safety of the extracts. All the seed extracts decreased the generation of reactive oxygen species in the cell lines. Blackberry and grape seed lipid fractions can be utilized as antioxidants, and the extraction methods used cause significant changes in relation to their bioactivity and chemical composition.

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Tejada, Arturo, and Arnold J. den Dekker. "Defocus Polar rOse Estimation Method (POEM): A Fast Defocus Estimation Method for STEM." IEEE Transactions on Instrumentation and Measurement 61, no. 10 (October 2012): 2723–30. http://dx.doi.org/10.1109/tim.2012.2193650.

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Chai, Xi Jun, Bao Min Wang, Ke Sun, and Chang Biao Chen. "Research on Calculation Method for Polar Moment of Inertia of Spline Shaft." Applied Mechanics and Materials 397-400 (September 2013): 326–29. http://dx.doi.org/10.4028/www.scientific.net/amm.397-400.326.

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This article is based on the concept and the calculation method of polar moment of inertia to derive the calculation formula for polar moment of inertia of rectangle spline shaft and involute spline shaft. Then verified the correctness of the calculation method and laid the foundation for the strength calculation of spline shaft.

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Medina, Jessica, Vera van der Velpen, Tony Teav, Yann Guitton, Hector Gallart-Ayala, and Julijana Ivanisevic. "Single-Step Extraction Coupled with Targeted HILIC-MS/MS Approach for Comprehensive Analysis of Human Plasma Lipidome and Polar Metabolome." Metabolites 10, no. 12 (December 2, 2020): 495. http://dx.doi.org/10.3390/metabo10120495.

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Expanding metabolome coverage to include complex lipids and polar metabolites is essential in the generation of well-founded hypotheses in biological assays. Traditionally, lipid extraction is performed by liquid-liquid extraction using either methyl-tert-butyl ether (MTBE) or chloroform, and polar metabolite extraction using methanol. Here, we evaluated the performance of single-step sample preparation methods for simultaneous extraction of the complex lipidome and polar metabolome from human plasma. The method performance was evaluated using high-coverage Hydrophilic Interaction Liquid Chromatography-ESI coupled to tandem mass spectrometry (HILIC-ESI-MS/MS) methodology targeting a panel of 1159 lipids and 374 polar metabolites. The criteria used for method evaluation comprised protein precipitation efficiency, and relative MS signal abundance and repeatability of detectable lipid and polar metabolites in human plasma. Among the tested methods, the isopropanol (IPA) and 1-butanol:methanol (BUME) mixtures were selected as the best compromises for the simultaneous extraction of complex lipids and polar metabolites, allowing for the detection of 584 lipid species and 116 polar metabolites. The extraction with IPA showed the greatest reproducibility with the highest number of lipid species detected with the coefficient of variation (CV) < 30%. Besides this difference, both IPA and BUME allowed for the high-throughput extraction and reproducible measurement of a large panel of complex lipids and polar metabolites, thus warranting their application in large-scale human population studies.

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Israelevich, P. L., and A. I. Ershkovich. "A new method to reconstruct the ionospheric convection patterns in the polar cap." Annales Geophysicae 17, no. 6 (June 30, 1999): 743–48. http://dx.doi.org/10.1007/s00585-999-0743-8.

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Abstract. A new method to reconstruct the instantaneous convection pattern in the Earth's polar ionosphere is suggested. Plasma convection in the polar cap ionosphere is described as a hydrodynamic incompressible flow. This description is valid in the region where the electric currents are field aligned (and hence, the Lorentz body force vanishes). The problem becomes two-dimensional, and may be described by means of stream function. The flow pattern may be found as a solution of the boundary value problem for stream function. Boundary conditions should be provided by measurements of the electric field or plasma velocity vectors along the satellite orbits. It is shown that the convection pattern may be reconstructed with a reasonable accuracy by means of this method, by using only the minimum number of satellite crossings of the polar cap. The method enables us to obtain a reasonable estimate of the convection pattern without knowledge of the ionospheric conductivity.Key words. Ionosphere (modelling and forecasting; plasma convection; polar ionosphere)

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Castillo, Oscar Daniel Garibaldi, and Ana Beltrán. "Identificación de Parámetros de Desempeño de un UAV a Través de Vuelos de Prueba." KnE Engineering 3, no. 1 (February 11, 2018): 482. http://dx.doi.org/10.18502/keg.v3i1.1452.

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The design and implementation of a autonomous navigation and control system for UAV, mandates simulating the system before in-flight testing. These simulations require a computational model of the aircraft, that can be obtained from the computation of aerodynamic parameters such as the drag polar. In this paper we present the identification of these parameters using two methods: one by flight testing techniques; the other by a combination of semi-empirical methods and computational fluid dynamics, dubbed the hybrid method. The hybrid method, which produces a parabolic polar drag, had the same qualitative trend compared to experiments. However, a detailed analysis of the parameters that shapes the polar drag, had significant differences, particularly in the parasite drag. This is probably due to propeller effects, low Reynolds Number and limitations of the piloting technique.Keywords: Drag polar, flight testing, parasite drag, UAV, VLM

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Curry, E., and T. L. Roth. "118 A RAPID, MINIMALLY INVASIVE METHOD OF COLLECTING SEMEN FROM POLAR BEARS." Reproduction, Fertility and Development 28, no. 2 (2016): 189. http://dx.doi.org/10.1071/rdv28n2ab118.

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Due to reproductive challenges faced by both captive and wild polar bears (Ursus maritimus), there is growing interest in developing assisted reproductive technologies (ART) to overcome infertility and preserve valuable genetics in this species. A polar bear sperm bank is essential in supporting ART endeavors; however, the traditional method of semen collection from wildlife, electro-ejaculation, has been relatively unsuccessful in polar bears. The goal of this study was to evaluate an alternative method of semen collection previously developed for use in cats. Medetomidine, an α2-adrenergic agonist commonly used to anesthetize captive polar bears, has side effects that facilitate semen collection: it stimulates epididymal receptors, causing semen to enter the urethra while concurrently stimulating receptors in the neck of the bladder, preventing urine contamination. The objective of this study was to assess the feasibility of collecting semen via urethral catheterization from male polar bears anesthetized with medetomidine. From 2012–2015, semen collection attempts (n = 9) were performed opportunistically on captive male polar bears (n = 8) in the USA. All males were considered sexually mature, with a mean age of 17.2 years (±2.8). Although all were housed with females, only 2 had sired offspring. Procedures were performed during breeding (n = 7) and nonbreeding seasons (n = 2). Individuals were anesthetized with medetomidine (0.025–0.060 mg kg–1) in conjunction with tiletamine/zolazepam or ketamine, and anesthesia was maintained using isoflurane. A sterile, lubricated, polypropylene urinary catheter (8 Fr) was inserted ~40 cm at the first 8 procedures and then 80 cm during the final procedure after a necropsy revealed the polar bear urethra is 100 cm in length. Catheters were left in place for 1 min and then retracted slowly while using a syringe to maintain negative pressure. Bears were catheterized 1–3 times during an immobilization. Any fluid recovered in the catheter was then flushed into a sterile tube and sperm motility was assessed microscopically. All values are presented as mean ± standard error of the mean. Semen containing motile spermatozoa was obtained at 8 of 9 (88.9%) procedures. Total semen volume was 509 ± 292 µL, with the highest volume (2500 µL) obtained using the longer (80 cm) catheter. Total sperm count was 2.6 ± 1.6 × 108. Sperm concentration and motility were 6.3 ± 3.7 × 108 mL–1 and 64.3 ± 9.0%, respectively. Although the percentage of motile sperm and sperm concentration appeared higher during the breeding season, seasonal differences could not be established statistically due to small sample sizes. This study demonstrates that urethral catheterization is an effective method of obtaining semen from polar bears anesthetized with medetomidine, and that longer catheters may be preferable for maximizing sample volume. Although polar bears are seasonal breeders, semen was recovered at both collections during the nonbreeding season, suggesting that spermatogenesis occurs year-round. This minimally invasive procedure is rapid and requires little equipment, rendering it practical for fieldwork.

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Miao, Xu Juan, and Xiao Fei Li. "Template Matching Based on Polar Coordinate." Advanced Materials Research 524-527 (May 2012): 3774–77. http://dx.doi.org/10.4028/www.scientific.net/amr.524-527.3774.

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A new template matching algorithm based on polar coordinate is proposed to improve the performance of the tracking system. The shape of the matching template is round, and the pixels in the template and the matching area are arranged into circle, which can ensure the rotation invariance of the method. Some differential matching information is added into the matching criterion function, which makes the method have higher recognition precision. In the long time target tracking process, template updating operation is adopted to avoid losing the target. Simulation results prove that the method can be applied in the TV tracking system. Using the same controller, the method has better tracking performance.

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Dong, Yunyun, Weili Jiao, Tengfei Long, Guojin He, and Chengjuan Gong. "An Extension of Phase Correlation-Based Image Registration to Estimate Similarity Transform Using Multiple Polar Fourier Transform." Remote Sensing 10, no. 11 (October 31, 2018): 1719. http://dx.doi.org/10.3390/rs10111719.

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Image registration is a core technology of many different image processing areas and is widely used in the remote sensing community. The accuracy of image registration largely determines the effect of subsequent applications. In recent years, phase correlation-based image registration has drawn much attention because of its high accuracy and efficiency as well as its robustness to gray difference and even slight changes in content. Many researchers have reported that the phase correlation method can acquire a sub-pixel accuracy of 1 / 10 or even 1 / 100 . However, its performance is acquired only in the case of translation, which limits the scope of the application of the method. However, there are few reports on the estimation of scales and angles based on the phase correlation method. To take advantage of the high accuracy property and other merits of phase correlation-based image registration and extend it to estimate the similarity transform, we proposed a novel algorithm, the Multilayer Polar Fourier Transform (MPFT), which uses a fast and accurate polar Fourier transform with different scaling factors to calculate the log-polar Fourier transform. The structure of the polar grids of MPFT is more similar to the one of the log-polar grid. In particular, for rotation estimation only, the polar grid of MPFT is the calculation grid. To validate its effectiveness and high accuracy in estimating angles and scales, both qualitative and quantitative experiments were carried out. The quantitative experiments included a numerical simulation as well as synthetic and real data experiments. The experimental results showed that the proposed method, MPFT, performs better than the existing phase correlation-based similarity transform estimation methods, the Pseudo-polar Fourier Transform (PPFT) and the Multilayer Fractional Fourier Transform method (MLFFT), and the classical feature-based registration method, Scale-Invariant Feature Transform (SIFT), and its variant, ms-SIFT.

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Adeel, Arooj, Muhammad Akram, and Ali N. A. Koam. "Group Decision-Making Based on m-Polar Fuzzy Linguistic TOPSIS Method." Symmetry 11, no. 6 (May 29, 2019): 735. http://dx.doi.org/10.3390/sym11060735.

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The fuzzy linguistic approach provides favorable outputs in several areas, whose description is relatively qualitative. The encouragement for the utilization of sentences or words instead of numbers is that linguistic characterizations or classifications are usually less absolute than algebraic or arithmetical ones. In this research article, we animate the m-polar fuzzy (mF) linguistic approach and elaborate it with real life examples and tabular representation to develop the affluence of linguistic variables based on mF approach. As an extension of the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method, we develop an m-polar fuzzy linguistic TOPSIS approach for multi-criteria group decision-making (MCGDM). It is used to evaluate the best alternative, to get more authentic and comparable results and to handle the real life problems of having multi-polar information in terms of linguistic variables and values. In this approach decision-makers contribute their estimations in the form of linguistic term sets. To show the efficiency and compatibility of the proposed approach, we compare it with the m-polar fuzzy linguistic ELECTRE-I (Elimination and Choice Translating Reality) approach. Finally, we draw a flow chart of our proposed approach as an algorithm and generate a computer programming code.

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Mukhina, I. V., E. D. Gribovа, E. A. Denisova, D. A. Dyagil, and A. V. Agaltsova. "DEVELOPMENT OF A METHOD FOR DETERMINATION OF ALCOHOLS IN FORMATION WATER." Bulletin of Dubna International University for Nature, Society, and Man. Series: Natural and engineering sciences, no. 2 (43) (December 24, 2019): 30–36. http://dx.doi.org/10.37005/1818-0744-2019-2-30-36.

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In this paper we propose an algorithm for the analysis of monohydric aliphatic alcohols in formation water, which makes it possible to eliminate the influence of non-polar components of oil. A sample of produced water is passed through a sorbent, removing non-polar organic compounds interfering with the analysis. In the resulting eluate add salting out agent and conduct a quantitative analysis of alcohols in the vapor phase by gas chromatography.

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Journal articles on the topic 'Method polar'

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