Geochemistry and stable isotope record of carbonate oozes and chalks of ODP Hole 130-807B

Light greenish gray and pale purple color bands are common in the ooze and chalk of the Ontong Java Plateau. Analyses of Pleistocene and Pliocene ooze samples that contain abundant bands indicate that the purple bands are colored by finely disseminated iron sulfide, whereas the green bands are colored by finely disseminated Fe- and Al-bearing silicates (probably clays). No local contrasts in the total organic carbon contents, carbon and oxygen isotopic compositions, and grain sizes were found. Band abundances, counted from core photographs of all Leg 130 holes, can be correlated from hole to hole on the basis of age rather than depth. The temporal distribution of these color bands is also comparable with that of the green bands described from the Lord Howe Rise, which were previously interpreted as products of altered volcanic glass. This may indicate that the green and purple bands on the Ontong Java Plateau originate from the early alteration of volcanic ash. The crosscutting relationships between the green and purple bands and original structures in the host sediment indicate that the bands have been locally altered by redox conditions in the sediments after the bands were formed.

Generating Automated News to Explain the Meaning of Sensor Data

An important competence of human data analysts is to interpret and explain the meaning of the results of data analysis to end-users. However, existing automatic solutions for intelligent data analysis provide limited help to interpret and communicate information to non-expert users. In this paper we present a general approach to generating explanatory descriptions about the meaning of quantitative sensor data. We propose a type of web application: a virtual newspaper with automatically generated news stories that describe the meaning of sensor data. This solution integrates a variety of techniques from intelligent data analysis into a web-based multimedia presentation system. We validated our approach in a real world problem and demonstrate its generality using data sets from several domains. Our experience shows that this solution can facilitate the use of sensor data by general users and, therefore, can increase the utility of sensor network infrastructures.

Programming with Global Analysis

Abstract is not available

Tracking recurrent concepts using context

The problem of recurring concepts in data stream classification is a special case of concept drift where concepts may reappear. Although several existing methods are able to learn in the presence of concept drift, few consider contextual information when tracking recurring concepts. Nevertheless, in many real-world scenarios context information is available and can be exploited to improve existing approaches in the detection or even anticipation of recurring concepts. In this work, we propose the extension of existing approaches to deal with the problem of recurring concepts by reusing previously learned decision models in situations where concepts reappear. The different underlying concepts are identified using an existing drift detection method, based on the error-rate of the learning process. A method to associate context information and learned decision models is proposed to improve the adaptation to recurring concepts. The method also addresses the challenge of retrieving the most appropriate concept for a particular context. Finally, to deal with situations of memory scarcity, an intelligent strategy to discard models is proposed. The experiments conducted so far, using synthetic and real datasets, show promising results and make it possible to analyze the trade-off between the accuracy gains and the learned models storage cost.

Sonar bat for visually impaired people

Visually impaired people have many difficulties when traveling because it is impossible for them to detect obstacles that stand in their way. Bats instead of using the sight to detect these obstacles use a method based on ultrasounds, as their sense of hearing is much more developed than that of sight. The aim of the project is to design and build a device based on the method used by the bats to detect obstacles and transmit this information to people with vision problems to improve their skills. The method involves sending ultrasonic waves and analyzing the echoes produced when these waves collide with an obstacle. The sent signals are pulses and the information needed is the time elapsed from we send a pulse to receive the echo produced. The speed of sound is fixed within the same environment, so measuring the time it takes the wave to make the return trip, we can easily know the distance where the object is located. To build the device we have to design the necessary circuits, fabricate printed circuit boards and mount the components. We also have to design a program that would work within the digital part, which will be responsible for performing distance calculations and generate the signals with the information for the user. The circuits are the emitter and the receiver. The transmitter circuit is responsible for generating the signals that we will use. We use an ultrasonic transmitter which operates at 40 kHz so the sent pulses have to be modulated with this frequency. For this we generate a 40 kHz wave with an astable multivibrator formed by NAND gates and a train of pulses with a timer. The signal is the product of these two signals. The circuit of the receiver is a signal conditioner which transforms the signals received by the ultrasonic receiver in square pulses. The received signals have a 40 kHz carrier, low voltage and very different shapes. In the signal conditioner we will amplify the voltage to appropriate levels, eliminate the component of 40 kHz and make the shape of the pulses square to use them digitally. To simplify the design and manufacturing process in the digital part of the device we will use the Arduino platform. The pulses sent and received echoes enter through input pins with suitable voltage levels. In the Arduino, our program will poll these two signals storing the time when a pulse occurs. These time values are analyzed and used to generate an audible signal with the user information. This information is stored in the frequency of the signal, so that the generated signal frequency varies depending on the distance at which the objects are. RESUMEN Las personas con discapacidad visual tienen muchas dificultades a la hora de desplazarse ya que les es imposible poder detectar los obstáculos que se interpongan en su camino. Los murciélagos en vez de usar la vista para detectar estos obstáculos utilizan un método basado en ultrasonidos, ya que su sentido del oído está mucho más desarrollado que el de la vista. El objetivo del proyecto es diseñar y construir un dispositivo basado en el método usado por los murciélagos para detectar obstáculos y que pueda ser usado por las personas con problemas en la vista para mejorar sus capacidades. El método utilizado consiste en enviar ondas de ultrasonidos y analizar el eco producido cuando estas ondas chocan con algún obstáculo. Las señales enviadas tendrán forma de pulsos y la información necesaria es el tiempo transcurrido entre que enviamos un pulso y recibimos el eco producido. La velocidad del sonido es fija dentro de un mismo entorno, por lo que midiendo el tiempo que tarda la onda en hacer el viaje de ida y vuelta podemos fácilmente conocer la distancia a la que se encuentra el objeto. Para construir el dispositivo tendremos que diseñar los circuitos necesarios, fabricar las placas de circuito impreso y montar los componentes. También deberemos diseñar el programa que funcionara dentro de la parte digital, que será el encargado de realizar los cálculos de la distancia y de generar las señales con la información para el usuario. Los circuitos diseñados corresponden uno al emisor y otro al receptor. El circuito emisor es el encargado de generar las señales que vamos a emitir. Vamos a usar un emisor de ultrasonidos que funciona a 40 kHz por lo que los pulsos que enviemos van a tener que estar modulados con esta frecuencia. Para ello generamos una onda de 40 kHz mediante un multivibrador aestable formado por puertas NAND y un tren de pulsos con un timer. La señal enviada es el producto de estas dos señales. El circuito de la parte del receptor es un acondicionador de señal que transforma las señales recibidas por el receptor de ultrasonidos en pulsos cuadrados. Las señales recibidas tienen una portadora de 40 kHz para poder usarlas con el receptor de ultrasonidos, bajo voltaje y formas muy diversas. En el acondicionador de señal amplificaremos el voltaje a niveles adecuados además de eliminar la componente de 40 kHz y conseguir pulsos cuadrados que podamos usar de forma digital. Para simplificar el proceso de diseño y fabricación en la parte digital del dispositivo usaremos la plataforma Arduino. Las señales correspondientes el envío de los pulsos y a la recepción de los ecos entraran por pines de entrada después de haber adaptado los niveles de voltaje. En el Arduino, nuestro programa sondeara estas dos señales almacenando el tiempo en el que se produce un pulso. Estos valores de tiempo se analizan y se usan para generar una señal audible con la información para el usuario. Esta información ira almacenada en la frecuencia de la señal, por lo que la señal generada variará su frecuencia en función de la distancia a la que se encuentren los objetos.