Staying together without being led

Representational Image (GETTY IMAGES)

A well-known instance is the collective behaviour, which is seen in groups of insects, birds, fish, and even bacteria. While there are no indicators that individual members of the groups are aware or conscious of more than a few neighbours, the whole group selforganises with coordination and cohesiveness, as if enclosed in an envelope, or a containing surface, and the group moves like a single, sentient being.

The phenomenon is of interest both in the study of the animal kingdom as well as one to mimic while managing groups of machines, or in robotics. A step to help understand the mechanism that translates the relationship among a handful of individuals into orchestration of the whole assembly may be finding the smallest size of the group that shows such behaviour. James G Puckett and Nicholas T Ouellette from Yale University, Connecticut, have examined this question and they report in Interface, the journal of the Royal Society, that it takes just 10 individuals of one species of insect to act essentially in the same way as a swarm of many more.

Swarming behaviour is seen most markedly in the movement of hordes of locusts, in the coordinated, short flight of thousands of birds, usually from one large perching area, like a set of trees to another, and in shoals of fish. Bacteria are found, when present in sufficient numbers, to slide en masse across surfaces and even microscopic plants, like phytoplankton, form themselves into vast rafts called "blooms". The characteristic is that the individuals in the groups are self-propelled and are not subject to any centralised control. "The group-level dynamics emerge spontaneously as a consequence of the low-level interactions between individuals," Puckett and Oullette say in the paper.

A mathematical model of a swarm could consist of several basic units, capable of motion, placed together and subject to simple rules.

The rules, for instance, could be that a unit should move the same way as its neighbour and stay close to neighbours, and yet a little away, so that it does not touch a neighbour. It is easy to imagine that if the members of a large group all follow these rules, there will be random shuffling and lead to general movement of the group in some direction, which may veer and swerve as individuals make their decisions to keep following the rules.

Another example of large numbers of individual particles following specific rules in bulk is that of the molecules of a gas. Here, the thermodynamic equilibrium, which is the pressure and volume given the temperature, is decided by the rules of statistics, of the number of different, equivalent combinations there can be of the molecules of the gas, distributing themselves in, for a given total energy. It works out that the distribution where the gas has the same pressure and temperature at all parts of the container is the distribution that can be arrived at in the most number of ways, and this distribution becomes more likely when the number of molecules increases. This is then the actual distribution, as different ways, like with the molecules on one side of the container moving faster than on the other side, in even a small volume of gas, are unlikely.

The units in swarms of animals, however, are capable of self-propulsion, unlike molecules whose speed and direction depends on collisions with other molecules. Collective movements of animals hence cannot be treated in a straightforward statistical way like a gas, but can still be viewed as the "large number" tendency as more and more self-propelled and mutually interacting units come together.

When the group is very large, the paper says, it is reasonable to suppose that one part of the swarm is not different from another and that the group behaviour represents a state that is shared by all units. This assumption, however, is not valid when the group is small and small groups would not have the cohesion and resilience of large groups. Discovering how large a group needs to be before it reaches the stage when adding numbers does not bring about appreciable change would help one understand the "low number" behaviour of groups, Puckett and Oullette say in the paper. This would impact bio-inspired engineering applications by setting the smallest number that must be there for group behaviour to emerge, they say.

Another way of looking at swarm behaviour is that the disorganised movement of smaller groups of individuals appears to become ordered and follow a pattern when the group reaches a threshold number. The transition is then seen as a kind of "phase change", like we see when water vapour condenses to liquid or when liquid water freezes to ice. Finding the threshold numbers for swarming would show the stage at which uniting effects of the rules of interaction overcome the fissiparous nature of groups of individuals, and hence keep the group together.

Puckett and Oullette considered the movements of swarms of midges, the annoying collection of flying insects that form a cloud around people's heads when they are out in the open. These swarms do not move over distances, like swarms of fish or birds, but the midges, in rapid motion themselves, stay together over a limited defined area, as a group.

"As collisions are disadvantageous and the sharp manoeuvres required to avoid a collision when two individuals come close together are energetically costly, midges tend to arrange themselves to maintain some empty space in their local neighbourhood," the researchers say. The researchers then used rapid, high speed photographs of 344 swarms of midges in motion, to analyse the changes in statistical features of the midges' local surroundings as the groups changed in size. With groups ranging from a single midge to groups of 60, a main feature analysis was of the average volume, as a fraction of the volume of the swarm, which each midge occupied in its flight, on the average, over a period.

The study has shown that while the statistics change as the number of participants increases, they settle down to a steady figure at the level of just 10 individuals. Thus, while one midge may roam freely around a central average position, two midges are somewhat more united and three midges even more so. But when we reach 10 midges, they form a swarm that stays basically unchanged as the numbers increase, even to thousands.

The writer can be contacted at response@simplescience.in.

Copyright © 2016 The Statesman Limited. All Rights Reserved.

Source

ETH computer expert wins national science award

German computer scientist Torsten Hoefler, a 34-year-old devotee of math and running, has won the 2015 Latsis Prize for his research on high-performance computing.

Based at the Swiss federal technology institute ETH Zurich, Hoefler is internationally regarded as a young scientific leader in the field of high-performance computing by combining theory and application at his Scalable Parallel Computing Laboratory.

The computer scientist, who is an assistant professor at ETH Zurich and has long been fascinated by numbers, previously taught and conducted research in the United States where he worked on developing one of the world’s most efficient supercomputers. He began his academic career studying for a master’s degree at Germany’s Chemnitz University of Technology.

The National Latsis Prize, one of Switzerland's most prestigious scientific awards, is awarded annually on behalf of the Geneva-based Latsis Foundation by the Swiss National Science Foundation. The prize carries an award of CHF100,000 and honours the outstanding scientific achievements of a research scientist under age 40 working in Switzerland.

The Latsis Foundation’s website cited Hoefler for outstanding “contributions to performance modelling, simulation, and optimization of large-scale parallel applications; topologies, routing, and host interfaces of large-scale networks; and advanced parallel programming techniques and runtime environments”.

Practical applications

On its website, ETH quoted Hoefler as constantly trying to find new ways to use numbers to improve his life, even going as far as creating a performance model for himself. It’s something he started doing as a child, when he would memorize as many car registration numbers as possible or count the distance to school in steps.

“I’ve definitely taken a bit of a mathematical view of life, but then my job is derived from my life,” he was quoted as saying.

Hoefler has tried to unite theory and practice whenever possible, by developing mathematical models that can be translated into software for running some of the nation’s supercomputers. He and his team have focused on developing a so-called heterogeneous compiler that can translate and optimize applications for computer architectures.

He also enjoys running, which he considers to be another passion. He calls it useful not only for maintaining a healthy body and mind, but also for discussing problems with students who join him on runs.

 

Source

How Big Banks Thread The Software Performance Needle

Timothy Prickett Morgan

While parallel programming on distributed systems is difficult, making applications scale across multiple machines – or hybrid compute elements that mix CPUs with FPGAs, GPUs, DSPs, or other motors – linked by a network is not the only problem that coders have to deal with. Inside each machine, the number of cores and threads have ballooned in the past decade, and each socket is as complex as a symmetric multiprocessing system from two decades ago was in its own right.

With so many cores and usually multiple threads per core to execute software, getting the performance out of software can be a tricky business. At the world’s hyperscalers, financial services behemoths, HPC centers, and database and middleware providers, the smartest programmers in the world are often off in a corner, with pencil and paper, mapping out the dependencies in the hairball of code they and their peers have created to find out the affinities between threads within that application. Having sorted out these dependencies, they engage in the unnatural act of pinning software processes or threads to specific cores in a physical system to optimize their performance.

Pinning threads is a bit like doing air traffic control in your head, and Leonardo Martins had such an onerous task a few years back. Martins got his start in the IT sector two decades ago as an engineer at middleware software makers Talarian and TIBCO before moving to Lehman Brothers to introduce Monte Carlo simulation systems for risk management to the bank. In 2004, he moved to Barclays Capital to introduce its first Linux-based systems as its senior middleware program manager and architect, and in 2010, he was the low latency senior architect at HSBC. While at HSBC, Martins was one of the wizards that would map out the applications and figure out how to pin their threads to specific cores in a system to maximize performance – a process that might take anywhere from two to eight weeks.

This is not big deal, right? Wrong. At the major financial institutions, the trading applications are updated at least monthly and sometimes as much as 200 times a year, so having the tuning process take weeks to months means code is never as optimized as it needs to be for a competitive edge. Martins looked around for a tool that would automate this thread pinning, and when he could not find one he found a few peers and set out to create one.

Martins founded Pontus Networks back in 2010 as a consultancy specializing in the tuning of latency sensitive applications, and was joined by Martin Raumann, an FPGA designer and specialist in low latency, high frequency trading hardware, and Deepak Aggarwal, another C, C++, C#, and Java programmer with deep expertise in distributed systems who built front office and back office systems for equities, foreign exchange, and fixed income asset trading at Barclays Capital, Credit Suisse, Citigroup, ABN, and Standard Chartered. They started work on the Pontus Vision Thread Manager and filed their first patents relating to the automated thread pinning in August 2014. The alpha version of Thread Manager debuted quietly at the end of November last year with its first customer, and the product is now available and has been acquired by three customers – all of whom are in the financial services sector. It is a fair guess that these companies are probably the ones where the founders of Pontus Networks used to work and do such painstaking thread pinning work, but that is just a guess.

Several other HPC-related users in government and university labs as well as a few Formula One racing teams are kicking the tires to see how Thread Manager might remove the human bottleneck and help get tuned software into production faster. In this latter case, Thread Manager is expected to help boost the performance of the mechanical engineering design and simulation programs as well as some of the post-processing that is done on designs to test them.) The company is also getting ready to do some performance tests on Hadoop clusters as well, and thinks that performance boosts on HDFS storage will be similar to what it has seen on Extract-Test-Load (ETL) applications that front end data warehouses. (Informatica is working with Pontus Networks on these tests.)

And as you have learned to expect from reading The Next Platform, none of these organizations looking for a bleeding edge advantage are willing to go on the record with their experiences just yet – and they may never do it because of that advantage. But we can tell you anecdotally what is going on and give you the results of some synthetic benchmarks to get you started.

Thread Manager is new enough that Pontus Networks is not precisely sure how different kinds of applications will make use of the automatic thread pinning capabilities, and Robin Harker, business development director at the company, tells The Next Platform that the company is just now getting some benchmarks under its belt to prove what Thread Manager can do.

The first and most important thing is that Thread Manager is a dynamic tool, working behind the scenes as software is running and changing, rather than a static, human-based optimization process that has to be invoked every time the code (or the hardware for that matter) changes. The dynamism is import in another way.

“If you look at an Oracle Exadata, where the company owns the whole box, they pin processes, not threads, which is a bit coarser grain control,” explains Harker. “So Oracle is probably pretty well optimized to run on a single box, and even across a RAC cluster for that matter. However, if you want to add a web application server to the same box, you are adding a different application that is going to have an effect on the Oracle system. But Thread Manager doesn’t care because all it sees is threads that talk to each other, and we don’t care if they come from Oracle or Tomcat or Linux or whatever.”

So the thinking of Pontus Networks, as more and more cores and threads get stuffed into single machines because we cannot really increase clock speed anymore to goose performance, companies will want to run multiple applications on machines (even if they are clustered) and they will have an even more complex thread pinning nightmare to deal with. Hence, the automation.

Source

Robots para hacer la compra en el supermercado

Tally es la nueva creación de una empresa que ayudara en los supermercados y pronto los veremos en las grandes superficies. El robot controlara lo que falta en los estantes para reponerlo automáticamente.

Si un cliente no puede encontrar un producto deseado en la tienda, el producto no puede venderse, el cliente se va insatisfecho y la empresa deja de ganar dinero. Este nuevo robot, que la empresa Simbe Robotics ha desarrollado, pretende remediar la situación. Tally revisa los estantes con una exploración y automáticamente señala donde falta algo. Sus colegas humanos pueden reponer rápidamente el producto.

Tally es uno de una familia de robots puestos en marcha, que pretende avanzar en el sector de la logística, donde el trabajo rutinario podría automatizarse con la inteligencia artificial. Aquí los trabajos no son necesariamente eliminados. Los robots están sólo en las áreas de trabajo donde los humanos no trabajan tan bien.

Reponer los estantes suena simple, pero es muy importante para las grandes superficies. Miles de millones de euros se pierden todos los años porque faltan elementos, son incorrectos o mal ordenados. En una gran empresa pueden perderse a la semana cientos de horas para comprobar todos los estantes, según un estudio de la firma de investigación de mercado DIH.

Brad Bogolea, co-fundador de Simbe Robotics, explica el funcionamiento, un solo robot podría escanear los estantes de una tienda pequeña en una hora. Un mercado mayorista requeriría probablemente varios robots. El modelo de negocio de Simbe Robotics es inusual: la compañía no quiere vender sus robots, pero ofrecen un modelo de suscripción.

Tally se mueve entre los estantes autónomamente y no sólo si algo falta, también puede detectar si los productos se clasifican de forma incorrecta, son defectuosos o no coinciden con los precios. El robot tiene ruedas y cuatro cámaras. Por lo que explora los dos lados de la plataforma a la vez, desde el suelo hasta una altura de 2,4 metros.

Simbe Robotics utiliza el hecho de que las grandes tiendas ya han proporcionado la estructura de datos de diseño de las estanterías en forma de base de datos, incluyendo la alineación. Por lo tanto Tally puede utilizar un mapa de la tienda para la navegación. Lo que ve se puede comparar con el denominado planograma que contiene la disposición ideal de todos los productos. Los datos recogidos por el robot se transmiten a un servidor, en el que se analizan.

Los fundadores de Simbe Robotics ya están muy familiarizados con el tema de la robótica, muchos de ellos trabajaron previamente en Willow Garage, una firma de investigación, que fue fundada por los primeros empleados de Google para crear un nuevo hardware y software del robot.

Tally no es el único robot que está en las áreas de trabajo que estaban reservadas para los humanos. Un estudio realizado por la firma consultora McKinsey dice que un robot podría realizar hasta el 46 por ciento de la mayoría de las tareas, independientemente del tipo de sector.

Simbe Robotics planea desarrollar otro robot para la industria minorista. “Nuestra visión principal es automatizar el área de retail”, dice Bogolea. “Creemos que es una gran oportunidad para automatizar tareas simples, por lo que los empleados pueden centrarse en el servicio al cliente.”

Sin embargo, aún queda un gran desafío que radica en el hecho de que el sistema funcione de forma fiable en el mundo real. En la vida real, el robot podría ser menos fiable que en el laboratorio o en el contexto de unas pruebas beta.

 

 

Source

Las propiedades nutritivas y medicinales de la guanábana

La pulpa de la guanábana está constituida principalmente por agua; además proporciona sales minerales, potasio, fósforo, hierro, calcio y lípidos y tiene un alto valor calórico debido a la presencia de hidratos de carbono; además es rica en vitamina C y provitamina A, así como en vitamina B.

La pulpa de la fruta puede consumirse en jugo o en agua y suele ser diurética. Las hojas se pueden consumir en té al igual que la corteza del árbol; las semillas pulverizadas sirven como repelente de insectos untándoselas en la piel y el agua de las hojas de la guanábana también está indicada contra los piojos.

La fruta es excelente para prevenir las gripes y cuando ya se tiene la enfermedad ayuda a la recuperación. Así mismo, descongestiona el pecho, por ello basta con cocer tres hojas de guanábana y un puñado de flores de la misma. El té se toma endulzado con miel. El fruto de la guanábana cuando se consume en verde es muy bueno contra la ictericia (coloración amarillenta de la piel, mucosas y conjuntivas oculares). Para eso basta con cortar tres trozos pequeños cuando la fruta cuando todavía no está madura, se les quitan las semillas y se licúan para después colar el líquido antes de consumirse. Se puede endulzar con miel para hacer un poco más agradable su sabor porque cuando la fruta no está madura puede ser un poco amarga.

También se pueden tomar licuadas 3 hojas con un vaso de agua. Se cuela esto y se toma en ayunas, pero se debe empezar con una hoja en una taza de agua que se debe beber por una semana.

Todos estos son tratamientos herbolarios y no son sustitutos de ningún medicamento o quimioterapia, pero tampoco se contraindican.

Fuente

Extranjeros unidos vía Facebook cuidan barrios pobres de Medellín

En la Medellín que es difícil ver desde el Centro, donde las condiciones de pobreza son extremas y tener un techo de eternit es casi un privilegio, ángeles sin alas, que hablan inglés y que llegaron sin mucho dinero, trabajan con la esperanza de reunir recursos para mejorar las condiciones de vida a familias vulnerables.

Marcos Kaseman es uno de esos ángeles. Hace seis años llegó a Medellín siguiendo a unos misioneros de Estados Unidos que lo llevaron hasta Regalo de Dios, un sector de invasión en límites con Bello al que, incluso, la pavimentación no ha llegado por completo.

Desde entonces, junto con 23 voluntarios de todo el mundo que lo han contactado a través de su grupo en Facebook, mientras llegan a conocer o a estudiar en la ciudad, Kaseman les arrebata los niños a las calles y les ofrece más oportunidades de vida a través de la fundación Ángeles de Medellín.

Catalina , por ejemplo, tiene siete años y asiste todos los días llena de entusiasmo a las clases de inglés, sistemas y hasta fútbol americano que el grupo de extranjeros ofrece de forma gratuita a ella y a cerca de 70 niños en Ángeles de Medellín. "Me gusta mucho aprender", dice la niña mientras se lava las manos antes de iniciar sus labores extracurriculares.

Hay otros menores que no pueden asistir a las clases y que necesitan otro tipo de ayudas de carácter urgente. Alexandra, de 10 años de edad, es una de ellos. Una fuerte dermatitis la tiene casi aislada y Alba David, su madre, no tiene los recursos para pagarle un buen especialista y menos para cubrirle las costosas medicinas del tratamiento.

Por eso Ángeles de Medellín ha tocado puertas para que con medicamentos y con la colaboración de algunos médicos y odontólogos casos como el de Alexandra no se repitan y tengan un mínimo de seguridad en salud.

"Más apoyo"
"Necesitamos libros, juguetes, medicinas, ropa y alimentos para las familias", dice el estadounidense, a través de su español lento, quien vive agradecido con todos los extranjeros que se han unido a esta causa, pero que con las donaciones que recibe no le es suficiente para los habitantes de Regalo de Dios y el barrio El Pinar.

"A veces donan mucho, o a veces nada, pero siempre logramos conseguir ayuda. Hace poco reuní una donación de 2.500 dólares de una persona de mi país", dijo el oriundo de Fairport, en Nueva York.

Para Marcos todas las ayudas son bien recibidas. Hace poco un amigo le ofreció los muebles de su casa. "Yo no lo pensé dos veces, porque varias familias no tienen nada y hasta les toca dormir en el piso, y otras han perdido muchas cosas por el invierno", dice este extranjero.

A Luz Tavera se le vino un alud de tierra en su casa y lo perdió todo. La colaboración recibida ha sido por medio de la fundación de Marcos.

"Ángeles de Medellín nos ayudó con comida y ropa porque nos quedamos solo con lo que teníamos puesto", dice la madre de cuatro hijos muy agradecida.

 

Fuente

Convoca UABCS a cursos intensivos de lenguas extranjeras

Como cada semestre, la Universidad Autónoma de Baja California Sur ofrece a sus estudiantes y público interesado cursos intensivos de lenguas extranjeras. Las inscripciones para este periodo se llevarán a cabo del 4 al 13 de febrero de 2014, en un horario de 9:00 a 13:30 y de 17:00 a 19:30 horas. Las clases iniciarán el 17 de febrero y concluirán el 10 de abril de 2014.

En esta ocasión, se ofrecen cursos intensivos de inglés, francés, italiano, alemán, ruso, japonés, árabe y español para extranjeros. Asimismo, se impartirán cursos de preparación para el examen TOEFL y de conversación. Los cursos se impartirán de lunes a jueves en el “Edificio 18” del Campus La Paz, de 8:00 a 14:00 y de 16:00 a 22:00 horas.

En el turno matutino se darán solamente las clases de inglés y español para extranjeros; por la tarde, corresponderá a los cursos de alemán, japonés, francés, italiano e inglés. Asimismo, en los días sábados se impartirán cursos de inglés y árabe para todo aquel interesado en el conocimiento de estas lenguas, del 24 de febrero al 19 de junio, de las 9:00 a las 13:00 horas. Los grupos son reducidos, aproximadamente de entre 10 y 15 personas, para llevar a cabo una atención más personalizada y directa.

El Departamento también ofrece diferentes servicios a la comunidad, como son: exámenes de perito traductor, exámenes de guía de turistas, comprensión de lectura y acreditación de niveles. Estos exámenes se aplican los lunes, a las 9:00 y 17:00 horas. Para mayores informes, comunicarse al Departamento de Lenguas Extranjeras de la UABCS en el teléfono 123-88-00, extensión 1840.

Es importante mencionar que toda persona que ingresa por primera vez a estudiar inglés en la Universidad, debe realizar como requisito un examen sin costo para conocer en qué nivel se ubicará, de acuerdo a sus conocimientos.

En cuanto al nivel de calidad, el Jefe del Departamento, profesor Julio Ortiz Manzo, aseguró la UABCS cuenta con excelentes profesores, quienes cuentan con certificaciones que los acreditan para realizar su actividad profesional, por lo que aseguró que quienes opten por alguna de las opciones de lenguas extranjeras, pueden tener la seguridad de estar invirtiendo correctamente su tiempo. Además, dijo, cada año los docentes se capacitan para actualizar sus conocimientos y mejorar sus habilidades pedagógicas. 

 

 

Fuente