Overall properties of the Gaia DR1 reference frame

We compare quasar positions of the auxiliary quasar solution with ICRF2 sources using different samples and evaluate the influence on the {\it Gaia} DR1 reference frame owing to the Galactic aberration effect over the J2000.0-J20015.0 period. Then we estimate the global rotation between TGAS with {\it Tycho}-2 proper motion systems to investigate the property of the {\it Gaia} DR1 reference frame. Finally, the Galactic kinematics analysis using the K-M giant proper motions is performed to understand the property of {\it Gaia} DR1 reference frame. The positional comparison between the auxiliary quasar solution and ICRF2 shows negligible orientation and validates the declination bias of $\sim$$-0.1$\mas~in {\it Gaia} quasar positions with respect to ICRF2. Galactic aberration effect is thought to cause an offset $\sim$$0.01$\mas~of the $Z$ axis direction of {\it Gaia} DR1 reference frame. The global rotation between TGAS and {\it Tycho}-2 proper motion systems, obtained by different samples, shows a much smaller value than the claimed value $0.24$\masyr. For the Galactic kinematics analysis of the TGAS K-M giants, we find possible non-zero Galactic rotation components beyond the classical Oort constants: the rigid part $\omega_{Y_G} = -0.38 \pm 0.15$\masyr~and the differential part $\omega^\prime_{Y_G} = -0.29 \pm 0.19$\masyr~around the $Y_G$ axis of Galactic coordinates, which indicates possible residual rotation in {\it Gaia} DR1 reference frame or problems in the current Galactic kinematical model.Comment: 6 pages, 1 figure. Accepted for publication in A&

Performance analysis with network-enhanced complexities: On fading measurements, event-triggered mechanisms, and cyber attacks

Copyright © 2014 Derui Ding et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Nowadays, the real-world systems are usually subject to various complexities such as parameter uncertainties, time-delays, and nonlinear disturbances. For networked systems, especially large-scale systems such as multiagent systems and systems over sensor networks, the complexities are inevitably enhanced in terms of their degrees or intensities because of the usage of the communication networks. Therefore, it would be interesting to (1) examine how this kind of network-enhanced complexities affects the control or filtering performance; and (2) develop some suitable approaches for controller/filter design problems. In this paper, we aim to survey some recent advances on the performance analysis and synthesis with three sorts of fashionable network-enhanced complexities, namely, fading measurements, event-triggered mechanisms, and attack behaviors of adversaries. First, these three kinds of complexities are introduced in detail according to their engineering backgrounds, dynamical characteristic, and modelling techniques. Then, the developments of the performance analysis and synthesis issues for various networked systems are systematically reviewed. Furthermore, some challenges are illustrated by using a thorough literature review and some possible future research directions are highlighted.This work was supported in part by the National Natural Science Foundation of China under Grants 61134009, 61329301, 61203139, 61374127, and 61374010, the Royal Society of the UK, and the Alexander von Humboldt Foundation of Germany

Efectos fisiológicos, bioquímicos e histopatológicos de la acidosis fermentativa en la producción de rumiantes: una mini-revisión

Rumen acidosis is increasingly recognized as a significant disorder in ruminants that increases the morbidity and mortality of animals, especially for dairy cattle and sheep. Acidosis is not just D-lactate which disturbs the acid-base status and the severity of acidosis is related to many factors and not only due to the level of lactic acid production, resulting in difficulties in diagnosing acidosis. Therefore, an understanding of the physiological, biochemical, and histopathological effects of rumen acidosis is fundamental for developing effective methods of prevention and treatment of fermentative acidosis. The present review evaluates the physiology, biochemistry, and pathophysiology of fermentative acidosis as well as gives a conclusion and look-forward. The information will benefit the health and welfare of ruminants and contribute to modern systems of ruminant production.Cada vez está más reconocido que la acidosis ruminal es un trastorno importante de los rumiantes que aumenta la morbilidad y la mortalidad de los animales, especialmente de vacas lecheras y ovejas. La acidosis no es sólo D-lactato, que perturba el estado ácido-base; la gravedad de la acidosis se relaciona con muchos factores y no sólo con el nivel de producción de ácido láctico, lo que presenta dificultades para el diagnóstico de la acidosis. Por lo tanto, para el desarrollo de métodos eficaces de prevención y tratamiento de la acidosis fermentativa, es fundamental una comprensión de los efectos fisiológicos, bioquímicos e histopatológicos de la acidosis ruminal. La presente revisión evalúa y presenta conclusiones de la fisiología, bioquímica y fisiopatología de la acidosis fermentativa. Esta informaciónserá beneficiosa para la salud y el bienestar de los rumiantes y contribuirá a los sistemas actuales de producción derumiantes

Understanding the white-light flare on 2012 March 9 : Evidence of a two-step magnetic reconnection

We attempt to understand the white-light flare (WLF) that was observed on 2012 March 9 with a newly constructed multi-wavelength solar telescope called the Optical and Near-infrared Solar Eruption Tracer (ONSET). We analyzed WLF observations in radio, H-alpha, white-light, ultraviolet, and X-ray bands. We also studied the magnetic configuration of the flare via the nonlinear force-free field (NLFFF) extrapolation and the vector magnetic field observed by the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO). Continuum emission enhancement clearly appeared at the 3600 angstrom and 4250 angstrom bands, with peak contrasts of 25% and 12%, respectively. The continuum emission enhancement closely coincided with the impulsive increase in the hard X-ray emission and a microwave type III burst at 03:40 UT. We find that the WLF appeared at one end of either the sheared or twisted field lines or both. There was also a long-lasting phase in the H-alpha and soft X-ray bands after the white-light emission peak. In particular, a second, yet stronger, peak appeared at 03:56 UT in the microwave band. This event shows clear evidence that the white-light emission was caused by energetic particles bombarding the lower solar atmosphere. A two-step magnetic reconnection scenario is proposed to explain the entire process of flare evolution, i.e., the first-step magnetic reconnection between the field lines that are highly sheared or twisted or both, and the second-step one in the current sheet, which is stretched by the erupting flux rope. The WLF is supposed to be triggered in the first-step magnetic reconnection at a relatively low altitude.Comment: 4 pages, 4 figures, published in A&A Lette

Bidirectional optimization of the melting spinning process

This is the author's accepted manuscript (under the provisional title "Bi-directional optimization of the melting spinning process with an immune-enhanced neural network"). The final published article is available from the link below. Copyright 2014 @ IEEE.A bidirectional optimizing approach for the melting spinning process based on an immune-enhanced neural network is proposed. The proposed bidirectional model can not only reveal the internal nonlinear relationship between the process configuration and the quality indices of the fibers as final product, but also provide a tool for engineers to develop new fiber products with expected quality specifications. A neural network is taken as the basis for the bidirectional model, and an immune component is introduced to enlarge the searching scope of the solution field so that the neural network has a larger possibility to find the appropriate and reasonable solution, and the error of prediction can therefore be eliminated. The proposed intelligent model can also help to determine what kind of process configuration should be made in order to produce satisfactory fiber products. To make the proposed model practical to the manufacturing, a software platform is developed. Simulation results show that the proposed model can eliminate the approximation error raised by the neural network-based optimizing model, which is due to the extension of focusing scope by the artificial immune mechanism. Meanwhile, the proposed model with the corresponding software can conduct optimization in two directions, namely, the process optimization and category development, and the corresponding results outperform those with an ordinary neural network-based intelligent model. It is also proved that the proposed model has the potential to act as a valuable tool from which the engineers and decision makers of the spinning process could benefit.National Nature Science Foundation of China, Ministry of Education of China, the Shanghai Committee of Science and Technology), and the Fundamental Research Funds for the Central Universities