Rammed Earth Construction: A Proposal for a Statistical Quality Control in the Execution Process

Unlike other common contemporary construction materials such as concrete, mortars, or fired clay bricks, which are widely supported by international standards and regulations, building with rammed earth is barely regulated. Furthermore, its quality control is usually problematic, which regularly encourages the rejection of this technique. In the literature, many authors have suggested ways to safely build a rammed earth wall, but only a few of them have delved into its quality control before and during the construction process. This paper introduces a preliminary methodology and establishes unified criteria, based in a statistical analysis, for both the production and the quality control of this constructive technique in cases dealing with both samples and walls

Fast Hardware Implementations of Static P Systems

In this article we present a simulator of non-deterministic static P systems using Field Programmable Gate Array (FPGA) technology. Its major feature is a high performance, achieving a constant processing time for each transition. Our approach is based on representing all possible applications as words of some regular context-free language. Then, using formal power series it is possible to obtain the number of possibilities and select one of them following a uniform distribution, in a fair and non-deterministic way. According to these ideas, we yield an implementation whose results show an important speed-up, with a strong independence from the size of the P system.Ministry of Science and Innovation of the Spanish Government under the project TEC2011-27936 (HIPERSYS)European Regional Development Fund (ERDF)Ministry of Education of Spain (FPU grant AP2009-3625)ANR project SynBioTI

Sea turtles in the eastern margin of the North Atlantic: the northern Ibero-Moroccan Gulf as an important neritic area for sea turtles

This study summarizes nearly 20 years (1997-2015) of tracking strandings of sea turtles along the Andalusian coast. In this period 2495 specimens were recorded, most of them loggerhead turtles Caretta caretta (92.6%) and leatherback turtles Demochelys coriacea (7.1%). Two other species were almost insinificant, green turtle Chelonia mydas (0.2%) and Kemp’s ridley Lepidochelys kempi (0.1%). Significant part of the turtles were recorded in the Atlantic coast, although in this area the incidence of alive specimens was low. Spring and summer were the seasons with more specimens stranded, probably related to warmer and more productive waters. The size of the loggerhead turtles observed highlights an important presence of inmature specimens in Andalusian waters, although mature individuals were not rare. In the case of leatherback turtles, adult stage is the only detected in the specimens recorded.These results, combined with the fact that the Atlantic coast has a large continental shelf and a high primary productivity near the coast, suggesting that the gulf of Cádiz may represent a neritic habitat used by the sea turtles. In this case, new and more effective politics of conservation are needed in order to protect sea turtles in this area

Network Time Synchronization: A Full Hardware Approach

Complex digital systems are typically built on top of several abstraction levels: digital, RTL, computer, operating system and software application. Each abstraction level greatly facilitates the design task at the cost of paying in performance and hardware resources usage. Network time synchronization is a good example of a complex system using several abstraction levels since the traditional solutions are a software application running on top of several software and hardware layers. In this contribution we study the case where a standards-compliant network time synchronization solution is fully implemented in hardware on a FPGA chip doing without any software layer. This solution makes it possible to implement very compact, inexpensive and accurate synchronization systems to be used either stand-alone or as embedded cores. Some general aspects of the design experience are commented together with some figures of merit. As a conclusion, full hardware implementations of complex digital systems should be seen as a feasible design option, from which great performance advantages can be expected, provided that we can find a suitable set of tools and control the design development costs

Inertial and Degradation Delay Model for CMOS Logic Gates

The authors present the Inertial and Degradation Delay Model (IDDM) for CMOS digital simulation. The model combines the Degradation Delay Model presented in previous papers with a new algorithm to handle the inertial effect, and is able to take account of the propagation and filtering of arbitrarily narrow pulses (glitches, etc.). The model clearly overcomes the limitations of conventional approaches

Mass strandings of cold-stunned loggerhead turtles in the south Iberian Peninsula: ethological implications

La versión posprint (aceptada) coincide con la publicada (pdf del editor)The loggerhead Caretta caretta is the most frequent marine turtle in the Mediterranean Sea and adjacent waters (Margaritoulis et al. 2003). In the Mediterranean Sea strandings of cold-stunned loggerheads have been rarely recorded (Bentivegna et al. 2002). However, similar events are frequent in others regions, e.g. the Atlantic Ocean and the Gulf of Mexico (Brongersma 1982, meylan 1986, morreale et al. 1992, Witherington & erhart 1989). A recent report of a group of cold-stunned loggerheads stranded in the Adriatic Sea was related to a temperature decrease of 6 ºC (Bentivegna et al. 2002). We report three new cases of groups of loggerheads stranded with symptoms of cold-stunning on the Andalusia coast (South of Spain), which is an outstanding area for the loggerhead in the North Atlantic-Mediterranean region, as it connects the West ern Mediterranean Sea with the Atlantic Ocean (e.g. Camiñas & De la serna 1995, Camiñas 1997). The aim of this work was to analyze the temporal variation of loggerheads strand ed with symptoms of cold-stunning along the Andalusian coastline, from 2001 to 2007. For this purpose, we tested the relationship between the stranding events and oceanographic factors. The ecological and ethological implications are discussed

NanoFS: a hardware-oriented file system

NanoFS is a novel file system for embedded systems and storage-class memories (like flash) and is specially designed to be directly implemented in hardware. NanoFS is based on an original internal layout intended to achieve an optimal hardware implementation of the file system’s file lookup and data fetch operations. File system spe-cification on a sample reader module completely implemented in a pro-grammable device is introduced

Minimalistic SDHC-SPI hardware reader module for boot loader applications

This paper introduces a low-footprint full hardware boot loading solution for FPGA-based Programmable Systems on Chip. The proposed module allows loading the system code and data from a standard SD card without having to re-program the whole embedded system. The hardware boot loader is processor independent and removes the need of a software boot loader and the related memory resources. The hardware overhead introduced is manageable, even in low-range FPGA chips, and negligible in mid- and high-range devices. The implementation of the SD card reader module is explained in detail and an example of a multi-boot loader is offered as well. The multi-boot loader is implemented and tested with the Xilinx's Picoblaze microcontroller