Stochastic pulse coded arithmetic

Among the different pulse codification techniques, stochastic pulse codification has its own arithmetic based on the similarity between Boolean algebra and statistical algebra. Summation and multiplication are the two basic arithmetic operations treated in depth in the literature. In this paper we present two digital stochastic circuits that extend traditional stochastic algebra: a division circuit and a square-root circuit, and the interfaces between the analog and stochastic domain. As a result, we are able to process analog input signals with a simple and complete processing system. These circuits can be implemented in low-cost and low-power digital programmable devices

Small-Scale Abiotic Factors Influencing the Spatial Distribution of Phytophthora cinnamomi under Declining Quercus ilex Trees

Phytophthora root rot is considered one of the main factors associated with holm oak (Quercus ilex L.) mortality. The effectiveness and accuracy of soilborne pathogen and management could be influenced by soil spatial heterogeneity. This factor is of special relevance in many afforestation of southwestern Spain, which were carried out without phytosanitary control of the nursery seedlings. We selected a study area located in a 15 year-old afforestation of Q. ilex, known to be infested by Phytophthora cinnamomi Rands. Soil samples (ntotal = 132) were taken systematically from a grid under 4 trees, and analysed to quantify 12 variables, the colony forming units (cfu) of P. cinnamomi plus 11 physical and chemical soil properties. The combined analysis of all variables was performed with linear mixed models (GLMM), and the spatial patterns of cfu were characterised using an aggregation index (Ia) and a clustering index (ν) by SADIE. Cfu values ranged from 0 to 211 cfu g−1, and the GLMM built with the variables silt, P, K and soil moisture explained the cfu distribution to the greatest extent. The spatial analysis showed that 9 of the 12 variables presented spatial aggregation (Ia > 1), and the clustering of local patches (νi≥1.5) for organic matter, silt, and Ca. The spatial patterns of the P. cinnamomi cfu under planted holm oak trees are related to edaphic variables and canopy cover. Small-scale spatial analysis of microsite variability can predict which areas surrounding trees can influence lower oomycetes cfu availability

Bioclimatic habitat limitations for argan trees (Argania spinosa (L.) Skeels) in Northern Africa and Spain

Argania spinosa L. Skeels is an Algerian-Moroccan endemic tree. This species is part of various plant communities consisting of Mediterranean, Macaronesian and Saharan floristic elements. It has been introduced and perhaps sometimes naturalized in various regions of the Mediterranean basin. Due to its role in combating desertification, high socio-economic value, and traditional use as fodder and food, the southwestern Moroccan argan grove (Arganeraie) was declared Biosphere Reserve. It had already been subject to conservation and reforestation programs a century earlier. Its cultivation for oil production could be, besides an economic objective, an effective method to conserve its genetic diversity. Therefore, this study aims to estimate its potential distribution and establish efficient breeding programs by determining its ecological requirements, identifying its different habitats, and predicting habitat suitability models for Morocco, Algeria, Tunisia, and Spain. Using 53 occurrence points, wind speed and direction data, and 29 bioclimatic variables, multivariate methods were applied to describe the ecological profiles and characterize the heterogeneity of its habitat to subsequently, train a Maxent model that establishes, besides Morocco and Algeria, suitable cultivation areas in Tunisia and Spain. The North African potential area is limited to the western Mediterranean coast of Algeria and flat and coastal areas of eastern Tunisia. The increased likelihood of suitability remains in the southeast Iberian Peninsula. A high probability of argan cultivation is also evident in the Canary Islands. These results provide possibilities for future expansion of argan crop and a window of opportunity to improve its genetic diversity and conservation

12-Lead ECG modulator and demodulator equipment for telephony transmission

This paper describes a teleassistency system that consists of a modulator equipment for the acquisition. storage and FM transmission of the typical 12 lead ECG signals and a demodulalOf equipment for recovering the original sig- nals in a medical cemer. Switched telephone network and GSM network can be used to transmir the audio fre- quency modulated signal carrying ECG Information

SMT board for acquisition of electrocardiograph signals and GSM transmission

Portable equipments for telemedical applications is one of the most innovative sectors in biomedical engineering. Health departments of governments are interested in tele diagnostic systems to avoid collapses in hospital and urgency services. In this paper, we describe a potable electrocardiograph/holter equipment with telephony and GSM transmission, using a surface mount technology with low voltage battery supply. This project has been developed in collaboration with Teleasistencia Cardiotest, S.L. This prototype is patent pending

Analog controllers using digital stochastic logic

Stochastic logic is based on digital processing of a random pulse stream, where the information is codified as the probability of a high level in a finite sequence. The probability of the pulse stream codifies a continuous time variable. Subsequently, this pulse stream can be digitally processed to perform analog operations. In this paper we propose a stochastic approach to the digital implementation of complex controllers. This is approach allows for the realization of the controllers, and A/D and D/A converters within a digital programmable device, leading to simple circuit implementations. A practical realization of a classical PID and nonlinear dissipative controllers for the series switching power resonant converter is presented

Continuous time filter design using stochastic logic

Stochastic logic is based on digital processing of random pulse stream. In this paper we propose a stochastic approach to the digital implementation of continuous time filters. The similarity between probability and Boolean algebras is exploited to obtain simple realizations. A design of a fourth order filter is presented

Circuito ASIC para enlaces rápidos de comunicaciones por fibra óptica

El circuito integrado que aquí se describe ha sido diseñado con tecnología puramente digital, y tiene como función servir de interfase entre 8 enlaces rápidos de comunicaciones por fibra óptica y un procesador local que utiliza protocolo VME. Este trabajo se enmarca dentro del programa GAME y ha sido desarrollado en colaboración con la empresa SAINCO

MODASC: ASIC for mobile data acquisition systems using satellite communications

MODASC is an ASIC that performs wide area mobile data acquisition using satellite communication to provide global coverage. This circuit provides two operation modes: an autonomous mode, that periodically establishes connection with the control center, and a slave mode, working as a peripheral connected to a general purpose micro controller. This experiment has been realized under FUSE special action in collaboration with SAINSEL