PL
 |
EN
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników
Powiadomienia systemowe
  • Sesja wygasła!
  • Sesja wygasła!

Znaleziono wyników: 5

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available remote A New Graph Theoretic Approach for Protein Threading
Song Y., Qu J., Xu Y., Cai L.
Fundamenta Informaticae
|
2016
|
Vol. 145, nr 2
151--170
EN
In this paper, we develop a novel graph theoretic approach for protein threading. In order to perform the protein sequence-structure alignment in threading both efficiently and accurately, we develop a graph model to describe the tertiary structure of a protein family and the alignment between a sequence and a family can be efficiently computed with a dynamic programming algorithm when the tree width of the graph model is a small integer. Our experiments show that this new approach is significantly faster than existing tools for threading and can achieve comparable prediction accuracy.
2
Content available remote Methods for large scale assessment of small mammal abundance in open habitats : plateau pika (Ochotona curzoniae) in alpine grassland
Qu J., Li W., Yang M., Li K., Zhang Y.
Polish Journal of Ecology
|
2011
|
Vol. 59, nr 4
829-833
EN
Quick and accurate estimation of population density in large scale is required in both scientific studies and wildlife management programs. However, effective estimation of small mammal abundance is usually difficult and timeconsuming due to the body size and wide distribution of these animals. To test the efficiency of different methods in assessing small mammal densities, population dynamics of plateau pikas (Ochotona curzoniae, Hodgson) were studied from April 2005 to August 2009 in alpine grassland (Kobresia humilis) at a height of of 3846 m a.s.l. We compared the precision of walked transects method with mark-recapture method using Efford's maximum likelihood spatial estimator (ML). Significant positive correlation was found between walked transects and Efford's ML estimator (r[^2] = 0.58, P <0.001). The densities calculated with walked transects were about twice lower than those obtained using the mark-recapture method over the study period (i.e., summer). Nevertheless, the walked transects method remains useful for relative density estimation. Hence, the walked transects method is recommended for use as an index of relative density in large-scale assessment in alpine grassland where most small mammals are active and easily detected in an open habitat.
3
Content available remote Propagation of a four-beamlets laser array through an apertured optical system
Yuan Y., Qu J., Shi J., Cui Z.
Optica Applicata
|
2010
|
Vol. 40, nr 1
155--164
EN
By expanding the hard-aperture function into a finite sum of complex Gaussian functions, an analytical formula for a four-beamlets laser array propagating through an apertured ABCD optical system is derived based on the generalized Collins formula. As a numerical example, the on-axis irradiance of a four-beamlets laser array focused by a squarely apertured bifocal thin lens is studied, and it is found that the focused irradiance is closely related to the parameters of the optical system and the laser array. Our formula provides a convenient way for studying the paraxial propagation of a four-beamlets laser array through an apertured ABCD optical system.
4
Content available remote Research od compound Nd: YAG phase-conjugate resonator with stimulated Brillouin scattering (SBS) cell
Qu J., Zhang W., Gao X.
Optica Applicata
|
2005
|
Vol. 35, nr 1
42-46
EN
How to improve the quality of output beam of phase conjungation cavity is a problem. In this paper, the output characteristic of compound phase-conjugate resonator with stimulated Brillouin scattering (SBS) cell was reported. The experimental results indicated it has high output energy and excellent stability. The output energy of the single pulse can reach 90 mJ, and the width of it is about 25ns. The results of pulse widths, output energies and beam profiles were given.
5
Content available remote Fluctuation of colliding-enhanced YAG phase-conjugate ring cavity in primary resonator stability
Qu J., Zhang W., Gao X., Liu A., Huang W., Pei S., Shao J., Yang Y.
Optica Applicata
|
2003
|
Vol. 33, nr 4
649-653
EN
In this paper, we report on a colliding-enhanced cavity. The fluctuation of output energy and divergence angle are in accordance with primary resonator. The results of output energy and fluctuation under different conditions are given
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.