Journal articles: 'Rotation search'

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Li, Fei, and Can Tian. "Directed search and job rotation." Journal of Economic Theory 148, no. 3 (May 2013): 1268–81. http://dx.doi.org/10.1016/j.jet.2012.10.004.

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Misslisch, H., and D. Tweed. "Torsional dynamics and cross-coupling in the human vestibulo-ocular reflex during active head rotation." Journal of Vestibular Research 10, no. 2 (April 1, 2000): 119–25. http://dx.doi.org/10.3233/ves-2000-10207.

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Six subjects fixated an imagined space-fixed target in darkness, or a visible target against a structured visual background, while rotating their heads actively in yaw, pitch and roll at four different frequencies, from 0.3 to 2.4 Hz. We used search coils to measure the 3-dimensional rotations of the head and eye, and described the relation between them – the input-output function of the rotational vestibulo-ocular reflex (VOR) – using gain matrices. We found consistent cross-coupling in which torsional head rotation evoked horizontal eye rotation. The reason may be that the eyes are above the axis of torsional head rotation, and therefore may translate horizontally during the head motion, so the VOR rotates them horizontally to compensate. Torsional gain was lower than horizontal or vertical, more variable from subject to subject and decreased at low frequencies. One reason for the low gain may be that torsional head rotation produces little retinal slip near the fovea; hence little compensatory eye motion is needed, and so the VOR reduces its torsional gain to save energy or to approximate Listing's law by keeping ocular torsion near zero. In addition, the human VOR has little experience with purely torsional head rotations and so its adaptive networks may be poorly trained for such stimuli. The drop in torsional gain at low frequencies can be explained based on the leak in the neural integrator that helps convert torsional eye-velocity commands into eye-position commands.

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Barraza, L. F., R. L. Gomes, Y. S. Messias, I. C. Leão, L. A. Almeida, E. Janot-Pacheco, A. C. Brito, et al. "Rotation Signature of TESS B-type Stars. A Comprehensive Analysis." Astrophysical Journal 924, no. 2 (January 1, 2022): 117. http://dx.doi.org/10.3847/1538-4357/ac3335.

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Abstract Stellar rotation is a fundamental observable that drives different aspects of stellar and planetary evolution. In this work, we present an unprecedented manifold analysis of 160 B-type stars with light curves collected by the TESS space mission using three different procedures (fast Fourier transform, Lomb–Scargle, and wavelet techniques), accompanied by rigorous visual inspection in the search for rotation periodicities. This effort provides rotational periodicities for 6 new TESS B-type stars and confirmed periodicities for 22 targets with rotation periods previously listed in the literature. For the other 61 stars, already classified as possible rotational variables, we identify noisy, pulsational, binarity, or ambiguous variability behavior rather than rotation signatures. The total sample of 28 potential rotators shows an overlap of different classes of rotational variables, composed of α 2 Canum Venaticorum, rotating ellipsoidal, and SX Arietis stars. The combination of the three techniques applied in our analysis offers a solid path to overcome the challenges in the discrimination of rotation from other variabilities in stellar light curves, such as pulsation, binarity, or other effects that have no physical meaning. Finally, the rotational periodicities reported in the present study may represent important constraints for improving stellar evolution models with rotation, as well as asteroseismic studies of hot stars.

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Reiners, A., and J. H. M. M. Schmitt. "Measurements of Differential Rotation in Cool Stars." Symposium - International Astronomical Union 215 (2004): 138–43. http://dx.doi.org/10.1017/s0074180900195439.

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We have obtained high resolution (R ≈ 220000) - high signal-to-noise (S/N > 500) spectra of 142 field dwarfs of spectral types F–K and v sin i ≤ 45 km s–1. Using the Fourier Transform Method (FTM) we precisely determined rotational velocities (Δ v sin i < 1.0 km s–1). For stars with v sin i ≥ 12.0 km s–1 this method allows the detection of deviations from solid body rotation. In the case of symmetric profiles the differential rotation parameter α = (ωequator – ωpole) / ωequator can be determined. This was possible for 32 of our sample stars; ten stars show evidence for solar-like differential rotation with α > 0.0. Thus it becomes possible to search for connections between differential rotation, rotational velocities and other stellar parameters. Signatures of differential rotation could be found on stars rotating as fast as v sin i = 42 km s–1. Particularly the Li-depleted stars turned out to show strong signatures of differential rotation. Our measurements support the idea, that Li-depletion in fast rotators (v sin i > 15 km s–1) is closely connected to differential rotation.

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Hartley, Richard I., and Fredrik Kahl. "Global Optimization through Rotation Space Search." International Journal of Computer Vision 82, no. 1 (January 7, 2009): 64–79. http://dx.doi.org/10.1007/s11263-008-0186-9.

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Walker, Mark F., Jing Tian, and David S. Zee. "Kinematics of the Rotational Vestibuloocular Reflex: Role of the Cerebellum." Journal of Neurophysiology 98, no. 1 (July 2007): 295–302. http://dx.doi.org/10.1152/jn.00215.2007.

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We studied the effect of cerebellar lesions on the 3-D control of the rotational vestibuloocular reflex (RVOR) to abrupt yaw-axis head rotation. Using search coils, three-dimensional (3-D) eye movements were recorded from nine patients with cerebellar disease and seven normal subjects during brief chair rotations (200°/s2 to 40°/s) and manual head impulses. We determined the amount of eye-position dependent torsion during yaw-axis rotation by calculating the torsional-horizontal eye-velocity axis for each of three vertical eye positions (0°, ±15°) and performing a linear regression to determine the relationship of the 3-D velocity axis to vertical eye position. The slope of this regression is the tilt angle slope. Overall, cerebellar patients showed a clear increase in the tilt angle slope for both chair rotations and head impulses. For chair rotations, the effect was not seen at the onset of head rotation when both patients and normal subjects had nearly head-fixed responses (no eye-position-dependent torsion). Over time, however, both groups showed an increasing tilt-angle slope but to a much greater degree in cerebellar patients. Two important conclusions emerge from these findings: the axis of eye rotation at the onset of head rotation is set to a value close to head-fixed (i.e., optimal for gaze stabilization during head rotation), independent of the cerebellum and once the head rotation is in progress, the cerebellum plays a crucial role in keeping the axis of eye rotation about halfway between head-fixed and that required for Listing's Law to be obeyed.

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DeLano, W. L., and A. T. Brünger. "The direct rotation function: rotational Patterson correlation search applied to molecular replacement." Acta Crystallographica Section D Biological Crystallography 51, no. 5 (September 1, 1995): 740–48. http://dx.doi.org/10.1107/s0907444995001284.

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Rius, J., and C. Miravitlles. "An automated full-symmetry Patterson search method." Journal of Applied Crystallography 20, no. 3 (June 1, 1987): 261–64. http://dx.doi.org/10.1107/s0021889887086722.

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A full-symmetry Patterson search method is presented that performs a molecular coarse rotation search in vector space and orientation refinement using the σ function. The oriented molecule is positioned using the fast translation function τ 0, which is based on the automated interpretation of τ projections using the sum function. This strategy reduces the number of Patterson-function values to be stored in the rotation search, and the use of the τ 0 function minimizes the required time for the development of all probable rotation search solutions. The application of this method to five representative test examples is shown.

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Suppan, Laurent, Michèle Chan, Birgit Gartner, Simon Regard, Mathieu Campana, Ghislaine Chatellard, Philippe Cottet, Robert Larribau, François Pierre Sarasin, and Marc Niquille. "Evaluation of a Prehospital Rotation by Senior Residents: A Web-Based Survey." Healthcare 9, no. 1 (December 29, 2020): 24. http://dx.doi.org/10.3390/healthcare9010024.

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The added value of prehospital emergency medicine is usually assessed by measuring patient-centered outcomes. Prehospital rotations might however also help senior residents acquire specific skills and knowledge. To assess the perceived added value of the prehospital rotation in comparison with other rotations, we analyzed web-based questionnaires sent between September 2011 and August 2020 to senior residents who had just completed a prehospital rotation. The primary outcome was the perceived benefit of the prehospital rotation in comparison with other rotations regarding technical and non-technical skills. Secondary outcomes included resident satisfaction regarding the prehospital rotation and regarding supervision. A pre-specified subgroup analysis was performed to search for differences according to the participants’ service of origin (anesthesiology, emergency medicine, or internal medicine). The completion rate was of 71.5% (113/158), and 91 surveys were analyzed. Most senior residents found the prehospital rotation either more beneficial or much more beneficial than other rotations regarding the acquisition of technical and non-technical skills. Anesthesiology residents reported less benefits than other residents regarding pharmacological knowledge acquisition and confidence as to their ability to manage emergency situations. Simulation studies should now be carried out to confirm these findings.

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Jiang, Yan Ming, and Gui Xiong Liu. "A New Flatness Evaluation-Rotation Method Based on GA." Advanced Materials Research 139-141 (October 2010): 2033–37. http://dx.doi.org/10.4028/www.scientific.net/amr.139-141.2033.

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Flatness is one fundamental element of geometric forms, and the flatness evaluation is particularly important for ensuring the quality of industrial products. This paper presents a new flatness evaluation in the view of the minimum zone evaluation - rotation method based on genetic algorithm. This method determines the minimum zone through rotating measurement points in three dimensions coordinate. The points are firstly rotated about coordinate axes. Then they are projected in one axis, and the smallest projection length is the flatness value. The rotation angles are optimized by genetic algorithm to improve search efficiency. An exponential fitness function and the rotation angles range is designed on the basis of flatness characteristics. An adaptive mode of crossover and mutation probability is used to avoid local optimum. The results show this method can search the minimum zone and converge rapidly.

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Cotton, W. D., E. Kravchenko, Y. Y. Kovalev, and E. Fomalont. "Search for extreme rotation measures in CSS sources." Astronomische Nachrichten 337, no. 1-2 (February 2016): 87–90. http://dx.doi.org/10.1002/asna.201512270.

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Görgen, A., H. Hübel, D. Ward, S. Chmel, R. M. Clark, M. Cromaz, R. M. Diamond, et al. "Search for magnetic rotation in 202Pb and 203Pb." European Physical Journal A 9, no. 2 (November 2000): 161–64. http://dx.doi.org/10.1007/s100500070032.

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Cabezas, C., C. Bermúdez, B. Tercero, and J. Cernicharo. "The millimeter-wave spectrum and astronomical search for ethyl methyl sulfide." Astronomy & Astrophysics 639 (July 2020): A129. http://dx.doi.org/10.1051/0004-6361/202038177.

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Context. Sulfur-containing molecules constitute only 8% of the molecules observed in the interstellar medium (ISM), in spite of the fact that sulfur has been shown to be an abundant element in the ISM. In order to understand the chemical behavior of the ISM and specific cases like the missing sulfur reservoir, a detailed chemical molecular composition in the ISM must be mapped out. Aims. Our goal is to investigate the rotational spectrum of ethyl methyl sulfide, CH3CH2SCH3, which seems to be a potential candidate for observation in the ISM since the simpler analogs, CH3SH and CH3CH2SH, have already been detected. Rotational spectrum of ethyl methyl sulfide has been observed before, but its experimental rotational parameters are not precise enough to allow its detection in the ISM. Methods. The rotational spectrum of ethyl methyl sulfide in the frequency range 72−116.5 GHz was measured using a broadband millimeter-wave spectrometer based on radio astronomy receivers with fast Fourier transform backends. The spectral searches and identification of the vibrational excited states of ethyl methyl sulfide was supported by high-level ab initio calculations on the harmonic and anharmonic force fields. Results. The rotational spectra for the trans and gauche conformers of ethyl methyl sulfide was analyzed, and a total of 172 and 259 rotational transitions were observed for each one, respectively. The observation of A − E internal rotation splittings allowed the experimental determination of the V3 hindered internal rotation barrier height for both trans and gauche species. In addition, the vibrational excited states, resulting from the lowest frequency vibrational mode ν30 were identified for both conformers. The new experimental rotational parameters were employed to search for ethyl methyl sulfide in the warm and cold molecular clouds Orion KL, Sgr B2(N), B1-b and TMC-1, using the spectral surveys captured by IRAM 30 m at 3 mm and 2 mm.

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Hoshino, Kiyoshi, and Motomasa Tomida. "3D Hand Pose Estimation Using a Single Camera for Unspecified Users." Journal of Robotics and Mechatronics 21, no. 6 (December 20, 2009): 749–57. http://dx.doi.org/10.20965/jrm.2009.p0749.

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The three-dimensional hand pose estimation this paper proposes uses a single camera to search a large database for the hand image most similar to the data input. It starts with coarse screening of proportional information on hand images roughly corresponding to forearm or hand rotation, or thumb or finger bending. Next, a detailed search is made for similarity among selected candidates. No separate processes were used to estimate corresponding joint angles when describing wrist’s rotation, flexion/extension, and abduction/adduction motions. By estimating sequential hand images this way, we estimated joint angle estimation error within several degrees - even when the wrist was freely rotating - within 80 fps using only a Notebook PC and high-speed camera, regardless of hand size and shape.

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Vida, Krisztián, and Katalin Oláh. "Detecting activity cycles of late-type dwarfs in Kepler data." Proceedings of the International Astronomical Union 9, S302 (August 2013): 224–27. http://dx.doi.org/10.1017/s1743921314002142.

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AbstractUsing data of fast-rotating active dwarf stars in the Kepler database, we perform time-frequency analysis of the light curves in order to search for signs of activity cycles. We use the phenomenon that the active region latitudes vary with the cycle (like the solar butterfly diagram), which causes the observed rotation period to change as a consequence of differential rotation. We find cycles in 8 cases of the 39 promising targets with periods between of 300–900 days.

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Decker, Jennie J., Craig J. Dye, Ko Kurokawa, and Charles J. C. Lloyd. "Effects of Display Failures and Symbol Rotation on Visual Search Using Dot-Matrix Symbols." Proceedings of the Human Factors Society Annual Meeting 32, no. 19 (October 1988): 1386–90. http://dx.doi.org/10.1177/154193128803201917.

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This study was conducted to investigate the effects of display failures and rotation of dot-matrix symbols on visual search performance. The type of display failure (cell, horizontal line, vertical line), failure mode (ON, failures matched the symbols; OFF, failures matched the background), percentage of failures (0, 1, 2, 3, 4%), and rotation angle (0, 70, 105 degrees) were the variables examined. Results showed that displays which exhibit ON cell failures greater than 1% significantly affect search time performance. Cell failures degrade performance more than line failures. Search time and accuracy were best when symbols were oriented upright. The effects of display failures and rotation angle were found to be independent. Implications for display design and suggestions for quantifying the distortion due to rotation are discussed.

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Álvarez-Rúa, Carmen, Javier Borge, and Santiago García-Granda. "OVIONE: a new vector-search rotation-function program for macromolecular crystallography." Journal of Applied Crystallography 33, no. 6 (December 1, 2000): 1436–44. http://dx.doi.org/10.1107/s0021889800011456.

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A computer program (OVIONE) that uses a new vector-search rotation function for crystal-structure determination by the molecular-replacement method has been developed. Image-seeking functions have proved to be useful rotation functions in macromolecular crystallography, provided that some conditions on the statistical parameters of both the crystal and the model Patterson maps are fulfilled. An appropriate selection of the vectors involved in the calculation of the image-seeking functions is crucial for the success of the proposed procedure. This selection relies on certain parameters, a careful analysis of which has been performed in order to establish optimal ranges in which the discrimination of the rotation function is enhanced. Finally, the refinement of the highest peaks of the rotation function is carried out by making use of a simple and quick minimization algorithm.

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Parra Bustos, Alvaro, Tat-Jun Chin, Anders Eriksson, Hongdong Li, and David Suter. "Fast Rotation Search with Stereographic Projections for 3D Registration." IEEE Transactions on Pattern Analysis and Machine Intelligence 38, no. 11 (November 1, 2016): 2227–40. http://dx.doi.org/10.1109/tpami.2016.2517636.

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Lucas, D. M., R. B. Warrington, D. N. Stacey, and C. D. Thompson. "Search for parity nonconserving optical rotation in atomic samarium." Physical Review A 58, no. 5 (November 1, 1998): 3457–71. http://dx.doi.org/10.1103/physreva.58.3457.

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Ong, Bun Theang, and Masao Fukushima. "Genetic algorithm with automatic termination and search space rotation." Memetic Computing 3, no. 2 (June 1, 2011): 111–27. http://dx.doi.org/10.1007/s12293-011-0057-8.

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Aizu, Ko, Makoto Inoue, Hiroto Tabara, and Tatsnji Kato. "Search for Extragalactic Radio Sources with Large Rotation Measure." Symposium - International Astronomical Union 140 (1990): 472. http://dx.doi.org/10.1017/s0074180900190904.

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Intrinsic large rotation measures (RM) were searched for 128 extragalactic sources based on polarization data obtained at the NRO 45–m telescope. The number of sources with RM > 500 rad m−2 is only seven.

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Labuschagne, Izelle, Amy Mulick Cassidy, Rachael I. Scahill, Eileanoir B. Johnson, Elin Rees, Alison O’Regan, Sarah Queller, et al. "Visuospatial Processing Deficits Linked to Posterior Brain Regions in Premanifest and Early Stage Huntington’s Disease." Journal of the International Neuropsychological Society 22, no. 6 (May 23, 2016): 595–608. http://dx.doi.org/10.1017/s1355617716000321.

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AbstractObjectives: Visuospatial processing deficits have been reported in Huntington’s disease (HD). To date, no study has examined associations between visuospatial cognition and posterior brain findings in HD. Methods: We compared 119 premanifest (55> and 64<10.8 years to expected disease onset) and 104 early symptomatic (59 stage-1 and 45 stage-2) gene carriers, with 110 controls on visual search and mental rotation performance at baseline and 12 months. In the disease groups, we also examined associations between task performance and disease severity, functional capacity and structural brain measures. Results: Cross-sectionally, there were strong differences between all disease groups and controls on visual search, and between diagnosed groups and controls on mental rotation accuracy. Only the premanifest participants close to onset took longer than controls to respond correctly to mental rotation. Visual search negatively correlated with disease burden and motor symptoms in diagnosed individuals, and positively correlated with functional capacity. Mental rotation (“same”) was negatively correlated with motor symptoms in stage-2 individuals, and positively correlated with functional capacity. Visual search and mental rotation were associated with parieto-occipital (pre-/cuneus, calcarine, lingual) and temporal (posterior fusiform) volume and cortical thickness. Longitudinally, visual search deteriorated over 12 months in stage-2 individuals, with no evidence of declines in mental rotation. Conclusions: Our findings provide evidence linking early visuospatial deficits to functioning and posterior cortical dysfunction in HD. The findings are important since large research efforts have focused on fronto-striatal mediated cognitive changes, with little attention given to aspects of cognition outside of these areas. (JINS, 2016, 22, 595–608)

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Barmentloo, S., C. Dik, M. A. Kenworthy, E. E. Mamajek, F. J. Hambsch, D. E. Reichart, J. E. Rodriguez, and D. M. van Dam. "A search for transiting companions in the J1407 (V1400 Cen) system." Astronomy & Astrophysics 652 (August 2021): A117. http://dx.doi.org/10.1051/0004-6361/202140768.

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Context. In 2007, the young star 1SWASP J140747.93-394 542.6 (V1400 Cen) underwent a complex series of deep eclipses over 56 days. This was attributed to the transit of a ring system filling a large fraction of the Hill sphere of an unseen substellar companion. Subsequent photometric monitoring has not found any other deep transits from this candidate ring system, but if there are more substellar companions and if they are coplanar with the potential ring system, there is a chance that they will transit the star as well. This young star is active, and the light curves show a 5% modulation in amplitude with a dominant rotation period of 3.2 days due to starspots rotating into and out of view. Aims. We model and remove the rotational modulation of the J1407 light curve and search for additional transit signatures of substellar companions orbiting around J1407. Methods. We combine the photometry of J1407 from several observatories, spanning a 19 yr baseline. We remove the rotational modulation by modeling the variability as a periodic signal, whose periodicity changes slowly with time over several years due to the activity cycle of the star. A transit least squares (TLS) analysis is used to search for any periodic transiting signals within the cleaned light curve. Results. We identify an activity cycle of J1407 with a period of 5.4 yr. A TLS search does not find any plausible periodic eclipses in the light curve, from 1.2% amplitude at 5 days up to 1.9% at 20 days. This sensitivity is confirmed by injecting artificial transits into the light curve and determining the recovery fraction as a function of transit depth and orbital period. Conclusions. J1407 is confirmed as a young active star with an activity cycle consistent with a rapidly rotating solar mass star. With the rotational modulation removed, the TLS analysis reaches down to planetary mass radii for young exoplanets, ruling out transiting companions with radii larger than about 1 RJup.

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Kolesniková, L., B. Tercero, E. R. Alonso, J. C. Guillemin, J. Cernicharo, and J. L. Alonso. "Rotational spectrum of methoxyamine up to 480 GHz: a laboratory study and astronomical search." Astronomy & Astrophysics 609 (December 22, 2017): A24. http://dx.doi.org/10.1051/0004-6361/201730744.

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Aims.Methoxyamine is a potential interstellar amine that has been predicted by gas-grain chemical models for the formation of complex molecules. The aim of this work is to provide direct experimental frequencies of its ground-vibrational state in the millimeter- and submillimeter-wave regions to achieve its detection in the interstellar medium.Methods.Methoxyamine was chemically liberated from its hydrochloride salt, and its rotational spectrum was recorded at room temperature from 75 to 480 GHz using the millimeter-wave spectrometer in Valladolid. Many observed transitions revealedA−Esplitting caused by the internal rotation of the methyl group, which had to be treated with specific internal rotation codes.Results.Over 400 lines were newly assigned for the most stable conformer of methoxyamine, and a precise set of spectroscopic constants was obtained. Spectral features of methoxyamine were then searched for in the Orion KL, Sgr B2, B1-b, and TMC-1 molecular clouds. Upper limits to the column density of methoxyamine were derived.

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Crane, Benjamin T., and Joseph L. Demer. "Effect of Adaptation to Telescopic Spectacles on the Initial Human Horizontal Vestibuloocular Reflex." Journal of Neurophysiology 83, no. 1 (January 1, 2000): 38–49. http://dx.doi.org/10.1152/jn.2000.83.1.38.

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Gain of the vestibuloocular reflex (VOR) not only varies with target distance and rotational axis, but can be chronically modified in response to prolonged wearing of head-mounted magnifiers. This study examined the effect of adaptation to telescopic spectacles on the variation of the VOR with changes in target distance and yaw rotational axis for head velocity transients having peak accelerations of 2,800 and 1,000°/s2. Eye and head movements were recorded with search coils in 10 subjects who underwent whole body rotations around vertical axes that were 10 cm anterior to the eyes, centered between the eyes, between the otoliths, or 20 cm posterior to the eyes. Immediately before each rotation, subjects viewed a target 15 or 500 cm distant. Lighting was extinguished immediately before and was restored after completion of each rotation. After initial rotations, subjects wore 1.9× magnification binocular telescopic spectacles during their daily activities for at least 6 h. Test spectacles were removed and measurement rotations were repeated. Of the eight subjects tolerant of adaptation to the telescopes, six demonstrated VOR gain enhancement after adaptation, while gain in two subjects was not increased. For all subjects, the earliest VOR began 7–10 ms after onset of head rotation regardless of axis eccentricity or target distance. Regardless of adaptation, VOR gain for the proximate target exceeded that for the distant target beginning at 20 ms after onset of head rotation. Adaptation increased VOR gain as measured 90–100 ms after head rotation onset by an average of 0.12 ± 0.02 (SE) for the higher head acceleration and 0.19 ± 0.02 for the lower head acceleration. After adaptation, four subjects exhibited significant increases in the canal VOR gain only, whereas two subjects exhibited significant increases in both angular and linear VOR gains. The latencies of linear and early angular target distance effects on VOR gain were unaffected by adaptation. The earliest significant change in angular VOR gain in response to adaptation occurred 50 and 68 ms after onset of the 2,800 and 1,000°/s2 peak head accelerations, respectively. The latency of the adaptive increase in linear VOR gain was ∼50 ms for the peak head acceleration of 2,800°/s2, and 100 ms for the peak head acceleration of 1,000°/s2. Thus VOR gain changes and latency were consistent with modification in the angular VOR in most subjects, and additionally in the linear VOR in a minority of subjects.

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KE, SHIH-HAO, and TSU-TIAN LEE. "A MULTI-SCALE TWO-STEP FAST SEARCH ALGORITHM FOR BLOCK MOTION ESTIMATION." International Journal of Image and Graphics 02, no. 04 (October 2002): 633–53. http://dx.doi.org/10.1142/s0219467802000810.

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Block motion estimation using full search is computationally intensive. Previously proposed fast algorithms reduce computation by limiting the number of search locations and search directions in a predefined search region. This is accomplished at the expense of accuracy of motion estimation and a large mean squared error for motion-compensated images, especially for image sequences with large displacement and rotation. In this paper, a novel efficient search algorithm for block motion estimation is presented to produce better performance than some fast search algorithms that have been developed, such as three step search, orthogonal search, 2D-logarithmic search, four step search, and block-based gradient descent search, in large displacement and rotation image cases. The proposed algorithm is based on the notion of locally multi-scale operation, search of global minimum, and two layer search strategy. Experimental results show that the proposed algorithm produces anticipative performance while costing much less computation power than the full search algorithm.

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Toyama, F. M., and W. van Dijk. "Additive composition formulation of the iterative Grover algorithm." Canadian Journal of Physics 97, no. 7 (July 2019): 777–85. http://dx.doi.org/10.1139/cjp-2018-0452.

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In the Grover-type quantum search process a search operator is iteratively applied, say, k times, on the initial uniform superposition database state. We present an additive decomposition scheme such that the iteration process is expressed, in the computational space, as a linear combination of k operators, each of which consists of a single Grover-search followed by an overall phase-rotation. The value of k and the rotation phase are the same as those determined in the framework of the search with certainty. We discuss how the additive form can be effectively utilized and we propose an alternative gate that realizes the same outcome as the iterative search.

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Liu, Ya Jie, Yan Zhao, and Fa Lin Wu. "An Improved Geomagnetic Matching Algorithm Using Rotation Angle Search Technique." Advanced Materials Research 383-390 (November 2011): 7576–81. http://dx.doi.org/10.4028/www.scientific.net/amr.383-390.7576.

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The accumulation course angle error of inertial navigation system will decrease the accuracy and reliability of an geomagnetism aided inertial navigation system using a geomagnetic contour matching algorithm. To improve the matching accuracy, the matching track and true track should be as parallel as possible. An improved geomagnetic matching algorithm is presented by introducing rotation angle search technique. To reduce the computation burden, improve operation efficiency and reduce false matching probability, a new search area determination method is proposed, which redefines the search region and reduces the search range. Simulation results demonstrate the effectiveness of the proposed algorithm and the improvement in the matching accuracy.

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NIGAM, AKRITI, AJAY INDORIA, and R. C. TRIPATHI. "FUZZY CLUSTERING OF IMAGE TRADEMARK DATABASE AND PREPROCESSING USING ADAPTIVE FILTER AND KARHUNEN–LOÈVE TRANSFORM." International Journal of Image and Graphics 13, no. 02 (April 2013): 1340008. http://dx.doi.org/10.1142/s0219467813400081.

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In this paper, an efficient preprocessing module has been described which focuses on building a trademark database that can be used for developing a trademark retrieval system. The preprocessing module focuses on noise removal from the trademark images using an adaptive filtering technique using Wiener filters, followed by Karhunen–Loève transform that makes the trademark search process rotation invariant by rotating the object along positive y direction. Since the registered trademarks are huge in number and will increase invariantly in the future it will be strenuous for the search system to search for similarity in such huge database. Intention was to reduce the search space hence fuzzy clustering has been applied. All these preprocessing steps make a retrieval system more efficient and reduce computation cost.

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Costa, Marcela Porto, David Chadwick, Sophie Saget, Robert M. Rees, Michael Williams, and David Styles. "Representing crop rotations in life cycle assessment: a review of legume LCA studies." International Journal of Life Cycle Assessment 25, no. 10 (August 22, 2020): 1942–56. http://dx.doi.org/10.1007/s11367-020-01812-x.

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Abstract Purpose There is an imperative to accurately assess the environmental sustainability of crop system interventions in the context of food security and climate change. Previous studies have indicated that the incorporation of legumes into cereal rotations could reduce overall environmental burdens from cropping systems. However, most life cycle assessment (LCA) studies focus on individual crops and miss environmental consequences of inter-annual crop sequence and nutrient cycling effects. This review investigates state-of-the-art representation of inter-crop rotation effects within legume LCA studies. Methods A literature review was undertaken, starting with a search for all peer-reviewed articles with combinations of ‘LCA’, ‘legumes’ and ‘rotations’ or synonyms thereof. In total, 3180 articles were obtained. Articles were screened for compliance with all of the following requirements: (i) reporting results based on LCA or life cycle inventory methodology; (ii) inclusion of (a) legume(s); (iii) the legume(s) is/are analysed within the context of a wider cropping system (i.e. rotation or intercropping). Seventy articles satisfying these requirements were analysed. Results and discussion We identified three broad approaches to legume LCA. Most studies involved simple attributional LCA disregarding important interactions across years and crops in rotations. N-fertilizer reduction through legume residue N carryover is either disregarded or the benefit is attributed to the following crop in such studies, whilst N leaching burdens from residues are usually attributed to the legume crop. Some studies applied robust allocation approaches and/or complex functional units to enable analysis of entire rotation sequences, accounting for nutrient cycling and break crop effects. Finally, a few studies applied consequential LCA to identify downstream substitution effects, though these studies did not simultaneously account for agronomic effects of rotational sequence changes. Conclusions We recommend that LCA studies for legume cropping systems should (i) evaluate entire rotations; (ii) represent nitrogen and ideally carbon cycling; (iii) for attributional studies, define at least two functional units, where one should encompass the multifunctional outputs of an entire rotation and the other should enable product footprints to be calculated; (iv) for CLCA studies, account for both agronomic changes in rotations and markets effects; (v) include impact categories that reflect hotspots for agricultural production.

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Zaleski, S. M., A. Valio, B. D. Carter, and S. C. Marsden. "Dynamo activity of the K dwarf KOI-883 from transit photometry mapping." Monthly Notices of the Royal Astronomical Society 510, no. 4 (January 3, 2022): 5348–61. http://dx.doi.org/10.1093/mnras/stab3788.

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ABSTRACT The Kepler mission target star KOI-883 is notable in being a low-mass K2V dwarf with moderately fast 8.99-d rotation and hosting a single transiting hot Jupiter in a 2.69-d orbit. This combination thus presents a particular opportunity to study star-spot activity by using the many deep planetary transits apparent in the light curve to map the stellar surface. The data have been analysed using spot modelling and temporal mapping methods we have used for other Kepler host stars, and a search for flares was conducted. Our results indicate a low-latitude region of the photosphere marked by distinct areas of individual or grouped star-spots with moderately high solar-type differential rotation of 0.102 ± 0.011 rad d−1, but with just two major flares observed across 400 d. These results imply a rotational shear significantly greater than that of our slower rotating Sun. The observed flares are more energetic than typical solar flares, but similar to those of other magnetically active cool dwarfs.

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Rauschenberger, Robert, and Hengqing Chu. "The effects of stimulus rotation and familiarity in visual search." Perception & Psychophysics 68, no. 5 (July 2006): 770–75. http://dx.doi.org/10.3758/bf03193700.

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Schill, Hayden M., Matthew S. Cain, Emilie L. Josephs, and Jeremy M. Wolfe. "Axis of rotation as a basic feature in visual search." Attention, Perception, & Psychophysics 82, no. 1 (August 19, 2019): 31–43. http://dx.doi.org/10.3758/s13414-019-01834-0.

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Liu, Yinlong, Yuan Dong, Zhijian Song, and Manning Wang. "2D-3D Point Set Registration Based on Global Rotation Search." IEEE Transactions on Image Processing 28, no. 5 (May 2019): 2599–613. http://dx.doi.org/10.1109/tip.2018.2887207.

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Wijers, Albertus A., Leun J. Otten, Steven Feenstra, Gijsbertus Mulder, and Lambertus J. M. Mulder. "Brain Potentials During Selective Attention, Memory Search, and Mental Rotation." Psychophysiology 26, no. 4 (July 1989): 452–67. http://dx.doi.org/10.1111/j.1469-8986.1989.tb01951.x.

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Yeates, T. O. "Simultaneous search for symmetry-related molecules in cross-rotation functions." Acta Crystallographica Section A Foundations of Crystallography 45, no. 5 (May 1, 1989): 309–14. http://dx.doi.org/10.1107/s0108767388013388.

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Löffler, W., M. P. van Exter, G. W. ’t Hooft, G. Nienhuis, D. J. Broer, and J. P. Woerdman. "Search for Hermite-Gauss mode rotation in cholesteric liquid crystals." Optics Express 19, no. 14 (June 21, 2011): 12978. http://dx.doi.org/10.1364/oe.19.012978.

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Carnahan, Brian J., Mark S. Redfern, and Bryan Norman. "Designing safe job rotation schedules using optimization and heuristic search." Ergonomics 43, no. 4 (April 2000): 543–60. http://dx.doi.org/10.1080/001401300184404.

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Borge, J., C. Alvarez-Rua, and S. Garcia-Granda. "Locating small structural fragments using a vector-search rotation function." Acta Crystallographica Section A Foundations of Crystallography 58, s1 (August 6, 2002): c79. http://dx.doi.org/10.1107/s0108767302088177.

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Chainarong, Suppachai, Rapeepan Pitakaso, Worapot Sirirak, Thanatkij Srichok, Surajet Khonjun, Kanchana Sethanan, and Thai Sangthean. "Multi-Objective Variable Neighborhood Strategy Adaptive Search for Tuning Optimal Parameters of SSM-ADC12 Aluminum Friction Stir Welding." Journal of Manufacturing and Materials Processing 5, no. 4 (November 16, 2021): 123. http://dx.doi.org/10.3390/jmmp5040123.

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This research presents a novel algorithm for finding the most promising parameters of friction stir welding to maximize the ultimate tensile strength (UTS) and maximum bending strength (MBS) of a butt joint made of the semi-solid material (SSM) ADC12 aluminum. The relevant welding parameters are rotational speed, welding speed, tool tilt, tool pin profile, and rotation. We used the multi-objective variable neighborhood strategy adaptive search (MOVaNSAS) to find the optimal parameters. We employed the D-optimal to find the regression model to predict for both objectives subjected to the given range of parameters. Afterward, we used MOVaNSAS to find the Pareto front of the objective functions, and TOPSIS to find the most promising set of parameters. The computational results show that the UTS and MBS of MOVaNSAS generate a 2.13% to 10.27% better solution than those of the genetic algorithm (GA), differential evolution algorithm (DE), and D-optimal solution. The optimal parameters obtained from MOVaNSAS were a rotation speed of 1469.44 rpm, a welding speed of 80.35 mm/min, a tool tilt of 1.01°, a cylindrical tool pin profile, and a clockwise rotational direction.

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González-Álvarez, E., M. R. Zapatero Osorio, J. A. Caballero, J. Sanz-Forcada, V. J. S. Béjar, L. González-Cuesta, S. Dreizler, et al. "The CARMENES search for exoplanets around M dwarfs." Astronomy & Astrophysics 637 (May 2020): A93. http://dx.doi.org/10.1051/0004-6361/201937050.

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Aims. We report on radial velocity time series for two M0.0 V stars, GJ 338 B and GJ 338 A, using the CARMENES spectrograph, complemented by ground-telescope photometry from Las Cumbres and Sierra Nevada observatories. We aim to explore the presence of small planets in tight orbits using the spectroscopic radial velocity technique. Methods. We obtained 159 and 70 radial velocity measurements of GJ 338 B and A, respectively, with the CARMENES visible channel between 2016 January and 2018 October. We also compiled additional relative radial velocity measurements from the literature and a collection of astrometric data that cover 200 a of observations to solve for the binary orbit. Results. We found dynamical masses of 0.64 ± 0.07 M⊙ for GJ 338 B and 0.69 ± 0.07 M⊙ for GJ 338 A. The CARMENES radial velocity periodograms show significant peaks at 16.61 ± 0.04 d (GJ 338 B) and 16.3−1.3+3.5 d (GJ 338 A), which have counterparts at the same frequencies in CARMENES activity indicators and photometric light curves. We attribute these to stellar rotation. GJ 338 B shows two additional, significant signals at 8.27 ± 0.01 and 24.45 ± 0.02 d, with no obvious counterparts in the stellar activity indices. The former is likely the first harmonic of the star’s rotation, while we ascribe the latter to the existence of a super-Earth planet with a minimum mass of 10.27−1.38+1.47 M⊕ orbiting GJ 338 B. We have not detected signals of likely planetary origin around GJ 338 A. Conclusions. GJ 338 Bb lies inside the inner boundary of the habitable zone around its parent star. It is one of the least massive planets ever found around any member of stellar binaries. The masses, spectral types, brightnesses, and even the rotational periods are very similar for both stars, which are likely coeval and formed from the same molecular cloud, yet they differ in the architecture of their planetary systems.

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Valsta, Lauri T. "A comparison of numerical methods for optimizing even aged stand management." Canadian Journal of Forest Research 20, no. 7 (July 1, 1990): 961–69. http://dx.doi.org/10.1139/x90-129.

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A two-species, whole-stand, deterministic growth model was combined with three optimization methods to derive management regimes for species composition, thinnings, and rotation age, with the objective of maximizing soil expectation value. The methods compared were discrete time – discrete state dynamic programming, direct search using the Hooke and Jeeves algorithm, and random search. Optimum solutions for each of the methods varied considerably, required unequal amounts of computational time, and were not equally stable. Dynamic programming located global optimal solutions but did not determine them accurately, owing to discretized state space. Direct search yielded the largest objective function values with comparable computational effort, although the likelihood of finding a global optimum solution was high only for smaller problems with up to two or three thinnings during the rotation. Random search solutions varied considerably with regard to growing stock level and species composition and did not define a consistent management guideline. In general, direct search and dynamic programming appeared to be superior to random search.

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Samadi-Ghadim, A., P. Lampens, D. M. Jassur, and P. Jofré. "KIC 8975515: A fast-rotating (γ Dor – δ Sct) hybrid star with Rossby modes and a slower δ Sct companion in a long-period orbit." Astronomy & Astrophysics 638 (June 2020): A57. http://dx.doi.org/10.1051/0004-6361/201936555.

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Aims. KIC 8975515 is a double-lined spectroscopic binary system with hybrid nature. Regular monitoring with the échelle spectrograph HERMES show that both components have matching atmospheric properties (Teff ∼ 7400 K), and that one of them is a fast rotator (v sin i = 162 versus 32 km s−1). Our aim is to study the Kepler light curve in order to determine the frequencies of the pulsations, to search for regular spacing patterns in the Fourier spectrum, if any, and to discuss their origin in the context of binarity and fast rotation. Methods. In this paper, we study the properties of the stellar pulsations based on a careful analysis of the Fourier spectrum. This was done by performing repeated frequency-search analyses with successive prewhitenings of all the significant frequencies detected in the spectrum. Moreover, we searched for regular period spacing among the g modes as well as frequency splitting among the g and p modes in frequency. Results. In the low-frequency regime, one series of prograde g modes and four series of retrograde r modes, were detected. The r modes are well-distributed with respect to the harmonics of the rotational frequency of the fast-rotating star frot = 1.647 d−1. The dominant g mode is f2 = 2.37 d−1. The strongest p mode is f1 = 13.97 d−1. We identified two multiplets of regularly split p modes with the mean values of 0.42 d−1 and 1.65 d−1. In addition, we also identified a few incidences of mode coupling (between f1 and a g or r mode). Conclusions. We detected five series of retrograde r and prograde g modes as well as two multiplets of p modes with rotational frequency splitttings related to both components of KIC 8975515. We identified the fast-rotating component as a hybrid pulsator with r modes, and the slowly-rotating component as a δ Sct pulsator.

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Chubukov, Dmitry V., Leonid V. Skripnikov, Vasily N. Kutuzov, Sergey D. Chekhovskoi, and Leonti N. Labzowsky. "Optical Rotation Approach to Search for the Electric Dipole Moment of the Electron." Atoms 7, no. 2 (June 7, 2019): 56. http://dx.doi.org/10.3390/atoms7020056.

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The P , T -odd Faraday effect (i.e., rotation of the polarization plane of light propagating through a medium in presence of the external electric field due to P , T symmetry violating interactions) is considered for several atomic species: Ra, Pb, Tl, Hg, Cs, and Xe. Corresponding theoretical simulation of P , T -odd Faraday experiment, with already achieved intracavity absorption spectroscopy characteristics and parameters, is performed. The results show that the magnetic dipole transitions in the Tl and Pb atoms as well as the electric dipole transitions in the Ra, Hg and Cs atoms are favorable for the observation of the P , T -odd Faraday optical rotation. The estimation of the rotation angle of the light polarization plane demonstrates that recently existing boundaries for the electron electric dipole moment can be improved by one-two orders of magnitude.

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MacDermott, Alexandra J., Laurence D. Barron, Andrè Brack, Thomas Buhse, John R. Cronin, Alex F. Drake, Roger J. Emery, et al. "Homochirality as the Signature of Extra-Terrestrial Life." International Astronomical Union Colloquium 161 (January 1997): 505–10. http://dx.doi.org/10.1017/s0252921100015037.

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AbstractThe most characteristic hallmark of life is its homochirality: all biomolecules are usually of one hand, e.g. on Earth life uses only L-amino acids for protein synthesis and not their D mirror images. We therefore suggest that a search for extra-terrestrial life can be approached as a Search for Extra- Terrestrial Homochirality (SETH). The natural choice for a SETH instrument is optical rotation, and we describe a novel miniaturized space polarimeter, called the SETH Cigar, which could be used to detect optical rotation as the homochiral signature of life on other planets. Moving parts are avoided by replacing the normal rotating polarizer by multiple fixed polarizers at different angles as in the eye of the bee. We believe that homochirality may be found in the subsurface layers on Mars as a relic of extinct life, and on other solar system bodies as a sign of advanced pre-biotic chemistry. We discuss the chiral GC-MS planned for the Roland lander of the Rosetta mission to a comet and conclude with theories of the physical origin of homochirality.

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Hadfield, Tom. "K-Homology of the Rotation Algebras Aθ." Canadian Journal of Mathematics 56, no. 5 (October 1, 2004): 926–44. http://dx.doi.org/10.4153/cjm-2004-042-x.

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AbstractWe study the K-homology of the rotation algebras Aθ using the six-term cyclic sequence for the K-homology of a crossed product by Z. In the case that θ is irrational, we use Pimsner and Voiculescu's work on AF-embeddings of the Aθ to search for the missing generator of the even K-homology.

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Song, Anping, Xiaokang Xu, and Xinyi Zhai. "SACN: A Novel Rotating Face Detector Based on Architecture Search." Electronics 10, no. 5 (February 27, 2021): 558. http://dx.doi.org/10.3390/electronics10050558.

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Rotation-Invariant Face Detection (RIPD) has been widely used in practical applications; however, the problem of the adjusting of the rotation-in-plane (RIP) angle of the human face still remains. Recently, several methods based on neural networks have been proposed to solve the RIP angle problem. However, these methods have various limitations, including low detecting speed, model size, and detecting accuracy. To solve the aforementioned problems, we propose a new network, called the Searching Architecture Calibration Network (SACN), which utilizes architecture search, fully convolutional network (FCN) and bounding box center cluster (CC). SACN was tested on the challenging Multi-Oriented Face Detection Data Set and Benchmark (MOFDDB) and achieved a higher detecting accuracy and almost the same speed as existing detectors. Moreover, the average angle error is optimized from the current 12.6° to 10.5°.

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Spraggon, Glen. "Envelope skeletonization as a means to determine monomer masks and non-crystallographic symmetry relationships: application in the solution of the structure of fibrinogen fragment D." Acta Crystallographica Section D Biological Crystallography 55, no. 2 (February 1, 1999): 458–63. http://dx.doi.org/10.1107/s0907444998009834.

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An algorithm is described which utilizes the solvent mask generated by the solvent-flattening technique to calculate a monomer molecular envelope. In the case where non-crystallographic symmetry (NCS) is present in the crystal and self-rotation angles are known from a self-rotation function, the resultant monomer envelopes can be used to search for the translation component of the NCS element by a three-dimensional search in real space. In the absence of self-rotation angles, the monomer envelope may be used to derive the NCS operators by reciprocal-space techniques. Thus, an automatic procedure for averaging directly from the solvent-flattening stage can be implemented. The procedure was instrumental in the structure solution of fibrinogen fragment D, which is presented as an example.

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Mathys, G., D. W. Kurtz, and D. L. Holdsworth. "Long-period Ap stars discovered with TESS data: The northern ecliptic hemisphere." Astronomy & Astrophysics 660 (April 2022): A70. http://dx.doi.org/10.1051/0004-6361/202142311.

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The rotation periods of the magnetic Ap stars span five to six orders of magnitude. While it is well established that period differentiation must have taken place at the pre-main sequence stage, the physical processes that lead to it remain elusive. The existence of Ap stars that have rotation periods of tens to hundreds of years is particularly intriguing, and their study represents a promising avenue to gain additional insight into the origin and evolution of rotation in Ap stars. Historically, almost all the longest period Ap stars known have been found to be strongly magnetic; very few weakly magnetic Ap stars with very long periods have been identified and studied. To remedy that, we showed how a systematic search based on the analysis of TESS photometric data could be performed to identify super-slowly rotating Ap (ssrAp) stars independently of the strengths of their magnetic fields, with the intention to characterise the distribution of the longest Ap star rotation periods in an unbiased manner. We successfully applied this method to the analysis of the TESS 2-min cadence observations of Ap stars of the southern ecliptic hemisphere. For our present study, we applied the same approach to the analysis of the TESS 2-min cadence observations of Ap stars of the northern ecliptic hemisphere. We confirm that the technique leads to the reliable identification of ssrAp star candidates in an unbiased manner. We find 67 Ap stars with no rotational variability in the northern ecliptic hemisphere TESS data. Among them, 46 are newly identified ssrAp star candidates, which is double the number found in the southern ecliptic hemisphere. We confirm that super-slow rotation tends to occur less frequently in weakly magnetic Ap stars than in strongly magnetic stars. We present new evidence of the existence of a gap between ∼2 kG and ∼3 kG in the distribution of the magnetic field strengths of long period Ap stars. We also confirm that the incidence of roAp stars is higher than average in slowly rotating Ap stars. We report the unexpected discovery of nine definite and five candidate δ Sct stars, and of two eclipsing binaries. This work paves the way for a systematic, unbiased study of the longest period Ap stars, with a view to characterise the correlations between their rotational, magnetic, and pulsational properties.

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Zhao, Junwei. "Helioseismic measurements of differential rotation and meridional flow." Proceedings of the International Astronomical Union 8, S294 (August 2012): 3–12. http://dx.doi.org/10.1017/s1743921313002159.

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AbstractSolar interior differential rotation and meridional flow play important roles in dynamo models. In this review, I briefly review results in interior rotational profiles and zonal flows obtained from helioseismology studies. Due to the new developments in recent years in interior meridional flow studies, this review focuses more on results on meridional flow. I describe new developments in the shallower poleward meridional flow, and the temporal evolution of these flows. Then I introduce a newly identified center-to-limb variation effect in helioseismology studies, and present recent results in the search of equatorward meridional flows. I also discuss how these results will effect the dynamo models.

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Journal articles on the topic 'Rotation search'

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