Chaos controller for switching regulators aiming enhanced design-space towards miniaturization

This paper tackles the control of fast-scale instabilities in a buck switching power converter aiming to expand its design-space towards miniaturization. After briefly revisiting the working principle of existing chaos controllers, the paper explores an alternative approach based on amplifying the harmonic at the switching frequency. Numerical simulations show that the proposed controller can concurrently improve both fast-scale and slow-scale stability margins. Finally, the paper proposes a chaos controller combined with an output ripple reduction network and studies their interaction with the aim of achieving both low-ripple and improved stability.Preprin

Contribuciones a la flora de Palencia (España)

Se comentan una serie de citas de plantas vasculares encontradas en la provincia de Palencia (Castilla y León, España) que resultan raras en estos territorios.SUMMARY: Several new or rare taxa of vascular plants found in the region of Palencia (Castilla y León, Spain) are here commented

Effect of Degradation on Wood Hygroscopicity: The Case of a 400-Year-Old Coffin

The hygroscopicity and thermodynamic properties of Pinus sylvestris L. wood from a coffin allegedly holding the remains of famous Spanish author Miguel de Cervantes Saavedra (1547–1616) were studied using the 15 ◦C and 35 ◦C isotherms fitted to the Guggenheim–Anderson–de Boer model and comparing them with the isotherms of recently felled wood of the same species. In addition, using infrared spectroscopy (FTIR-ATR) and X-ray diffractograms, the functional groups were determined and the crystallinity and organization of the cell wall components were analyzed. The absence of the 1740 cm−1 group indicates hemicellulose degradation in the archaeological wood, and the X-ray diffractograms show a considerable decrease in cellulose crystallinity and disorganization of the cellulose crystallites. The greater availability of active –OH groups means that the archaeological wood isotherms are above the juvenile and mature wood isotherms, and therefore the thermodynamic balance in the sorption of the archaeological wood is greater

Multi-homing tunnel broker

A proper support for communications has to provide fault tolerance capabilities such as the preservation of established connections in case of failures. Multihoming addresses this issue, but the currently available solution based in massive BGP route injection presents serious scalability limitations, since it contributes to the exponential growth of the BGP table size. An alternative solution based on the configuration of tunnels between the multihomed site exit routers and the ISP border routers has been proposed for IPv6 in RFC 3178. However, the amount of manual configuration imposed by this solution on the ISP side prevents its wide adoption. In particular, this solution requires at the ISP the manual configuration of a tunnel endpoint per each multihomed client that it serves. We present a multihoming tunnel broker (MHTB) that provides automatic creation of the tunnel endpoint at the ISP side.This work was supported by the SAM (Advanced Servers with Mobility)project, funded by the Spanish National research and Development Programme as TIC2002-04531-C04-03.Publicad

Tests Management in CALIPSOneo: A MDE Solution

Testing in Software Engineering is one of the most important phases although, unfortunately, it cannot be always successfully fulfilled due to time constraints. In most cases, the development phase takes more time than it was estimated, entailing negative effects on the testing phase. The delay increases even more in Research and Development (R + D) projects, where the real time to execute tasks is more difficult to control. Model Driven Engineering (MDE) offers a solution to avoid testing costs without affecting the execution quality of the applied test. This paper presents a practical overview of a Model Driven Testing (MDT)-based methodology and its impact on CA LIPSOneo project, which was carried out in liaison with Airbus Defense and Space and, particularly, with the Product Lifecycle Management (PLM) departmentMinisterio de Ciencia e Innovación TIN2013-46928-C3-3-RJunta de Andalucía TIC-578

Creative and collective writing in the context of the new cultural practices

Se plantea en este artículo el cambio profundo que, en la nueva cultura del siglo XXI, ha sufrido el concepto de creación colectiva, por influencia de Internet. Las redes sociales, la cultura participativa, la convergencia de los medios y otros factores han favorecido nuevos modos de expresión, al margen de la escritura académica o profesional, como ha sido el caso de la ficción-manía. Sobre el concepto de creación colectiva se está escribiendo mucho, a propósito de la épica y de otros temas literarios y debe ser “iluminado” a la luz de lo que Internet o los nuevos fenómenos, como el auge de las sagas fantásticas o la ficción-manía, están suponiendo. Así, lo que actualmente se denomina escritura colaborativa es en realidad un concepto que ha ido evolucionando de forma acompasada con las poéticas y las prácticas sociales de la lectura en los últimos tiempos. Revisamos los rasgos de estas nuevas prácticas y se analizan las implicaciones para la educación del siglo XXI.The deep change that, in the new culture of the 21st century, has suffered the concept of collective creation, under the influence of the Internet is proposed in this article. Social networking, participatory culture, the convergence of media and other factors have favored new ways of expression, apart from academic or professional writing, as it has been the case of the fan fiction. There is a lot of studies nowadays on the concept of collective creation, with regard to epic and other literary topics and should be “enlightened” in the light of what Internet or new phenomena, such as the rise of fantasy sagas or the fan fiction, are involving. So, what is currently referred to as collaborative writing is actually a concept that has evolved in a measured way with the poetic and social practices of reading in last times. We review the features of these new practices and examine the implications for the education of the 21st century.peerReviewe