We show that the learned vocalizations of male and female large-billed crows (Corvus macrorhynchos) are similar and that their functions and physical features show significant differences from those of other oscine species. We investigate whether the song control nuclei of crows show any sexual differences in size, reflecting differences in their singing behavior, and whether these nuclei are different from those of other songbirds in terms of neural connectivity size and relative to the forebrain. Our Nissl staining results reveal that 1) of the four song nuclei examined (HVC; the robust nucleus of the arcopallium [RA]; Area X; and the dorsolateral medial nucleus [DLM]), HVC, RA, and Area X volumes are significantly larger in males than in females, but DLM volume and body and brain weights show no significant gender differences; and 2) the sizes of song nuclei relative to the forebrain are within the range of other oscines. By injecting a neural tract tracer (DiI) into various song nuclei in brain slices, we found that, as in other songbirds, HVC projects to RA and Area X, while Area X projects to the lateral magnocellular nucleus of the anterior nidopallium (IMAN) and DLM, DLM to IMAN, and IMAN to RA. Our results Indicate that, although the crow has songs very different from those of other oscine species, Its song nuclei and the connections between them are not obviously different.

No abstract

No abstract

In view of the performance requirements (e.g., ride comfort, road holding, and suspension space limitation) for vehicle suspension systems, this paper proposes an adaptive optimal control method for quarter-car active suspension system by using the approximate dynamic programming approach (ADP). Online optimal control law is obtained by using a single adaptive critic NN to approximate the solution of the Hamilton-Jacobi-Bellman (HJB) equation. Stability of the closed-loop system is proved by Lyapunov theory. Compared with the classic linear quadratic regulator (LQR) approach, the proposed ADP-based adaptive optimal control method demonstrates improved performance in the presence of parametric uncertainties (e.g., sprung mass) and unknown road displacement. Numerical simulation results of a sedan suspension system are presented to verify the effectiveness of the proposed control strategy.

No abstract

No abstract

Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team atPublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. Design of an advanced automatic inspection system for aircraft parts based on luorescent penetrant inspection analysisNon-destructive testing (NDT) of aircraft parts has become increasingly important in improving the safety and reliability of the aerospace industry, especially in the testing of high-temperature and high-pressure turbine engine parts. Among the various types of NDT methods available, luorescent penetrant inspection (FPI) is comparably more cost-eicient and is widely used in NDT on aircraft parts. However, current FPI still requires considerable labour forces in its processing, inspection and analysis procedures. In this paper, we have developed an advanced automatic inspection system (AAIS) that uses image processing and pattern recognition techniques to aid human inspectors. The system can automatically detect, measure and classify discontinuities from the FPI images of aircraft parts. Tests have been performed on the sample images provided by our industrial partners to evaluate our developed AAIS. The test results demonstrate that the developed system has signiicantly improved the eiciency of FPI with satisfactory accuracy.

No abstract