Single-random phase encoding architecture using a focus tunable lens

We propose a new nonlinear optical architecture based on a focus tunable lens and an iterative phase retrieval algorithm. It constitutes a compact encryption system that uses a single-random phase key to simultaneously encrypt (decrypt) amplitude and phase data. Summarily, the information encoded in a transmittance object (phase and amplitude) is randomly modulated by a diffuser when a laser beam illuminates it; once the beam reaches a focus tunable lens, different subjective speckle distributions are registered at some image plane as the focal length is tuned to different values. This set of speckle patterns constitutes a delocalized ciphertext, which is used in an iterative phase retrieval algorithm to reconstruct a complex ciphertext. The original data are decrypted propagating this ciphertext through a virtual optical system. In this system, amplitude data are straightforwardly decrypted while phase data can only be restored if the random modulation produced in the encryption process is compensated. Thus, an encryption-decryption process and authentication protocol can simultaneously be performed. We validate the feasibility of our proposal with simulated and experimental results.Fil: Mosso Solano, Edward Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Pontificia Universidad Católica de Valparaíso; ChileFil: Bolognini, Nestor Alberto. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Ópticas. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones Ópticas. Universidad Nacional de La Plata. Centro de Investigaciones Ópticas; ArgentinaFil: Pérez, D.G.. Pontificia Universidad Católica de Valparaíso; Chil

Information on Transcriptional Regulation and Signal Transduction of _Escherichia coli_ K-12 Integrated in the Database RegulonDB.

Since its inception, RegulonDB ("http://regulondb.ccg.unam.mx/":http://regulondb.ccg.unam.mx/) has been a database that compiles information about the regulation of transcription initiation of _Escherichia coli_ K-12. However, we are aware that transcriptional regulation is not an isolated process; instead, it is the response to the different environmental conditions that trigger a series of concatenated reactions that end in transcriptional regulation, and it implies an adequate response in terms of induced and repressed gene products. We are working now to include all these new data in RegulonDB. As a consequence, transcriptional regulation in RegulonDB will be part of a unit that initiates with the signal, continues with the signal transduction to the core of regulation to modify expression of the affected set of target genes, and ends with an adequate response. We refer to these units as genetic sensory response units, or geSorgans.

The inclusion of geSorgans will bring a dramatic change and expansion of RegulonDB, due to the fact that we will be adding several new types of reactions and interactions. We started to collect data about signal transduction of the sigma factors, the two-component systems, of some transcription factors involved in carbon source utilization, and of genes involved in the synthesis of amino acids. We plan a high-level curation with super-pathways summarizing concatenated sets of reactions linked to those other databases that curate such information, while enabling with RegulonDB a compilation of complete geSorgans.

In addition, the number of DNA binding sites for some transcription factors has grown considerably, and therefore we decided to review systematically those sites whose lengths ranging from 40 to 60 bp with orientation and consensus sequences that are not easy to identify. The current version of RegulonDB is the beginning of a higher-level curation of gene regulation information, and eventually our database will include all regulatory mechanisms and their regulated genes. 
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Information on Transcriptional Regulation and Signal Transduction of _Escherichia coli_ K-12 Integrated in the Database RegulonDB.

Since its inception, RegulonDB ("http://regulondb.ccg.unam.mx/":http://regulondb.ccg.unam.mx/) has been a database that compiles information about the regulation of transcription initiation of _Escherichia coli_ K-12. However, we are aware that transcriptional regulation is not an isolated process; instead, it is the response to the different environmental conditions that trigger a series of concatenated reactions that end in transcriptional regulation, and it implies an adequate response in terms of induced and repressed gene products. We are working now to include all these new data in RegulonDB. As a consequence, transcriptional regulation in RegulonDB will be part of a unit that initiates with the signal, continues with the signal transduction to the core of regulation to modify expression of the affected set of target genes, and ends with an adequate response. We refer to these units as genetic sensory response units, or Gensor Units.

The inclusion of Gensor Units will bring a dramatic change and expansion of RegulonDB, due to the fact that we will be adding several new types of reactions and interactions. We started to collect data about signal transduction of the sigma factors, the two-component systems, of some transcription factors involved in carbon source utilization, and of genes involved in the synthesis of amino acids. We plan a high-level curation with super-pathways summarizing concatenated sets of reactions linked to those other databases that curate such information, while enabling with RegulonDB a compilation of complete Gensor Units.

In addition, the number of DNA binding sites for some transcription factors has grown considerably, and therefore we decided to review systematically those sites whose lengths ranging from 40 to 60 bp with orientation and consensus sequences that are not easy to identify. The current version of RegulonDB is the beginning of a higher-level curation of gene regulation information, and eventually our database will include all regulatory mechanisms and their regulated genes. 
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Effects of environment correlations on the onset of collective decay in waveguide QED

We calculate the dynamics of one and two two-level atoms interacting with the electromagnetic vacuum field in the vicinity of an optical nanofiber without making either the Born or the Markov approximations. We use a constant dielectric function and the Drude-Lorentz model, observing deviations from the standard super- and sub-radiant decays. Despite the non-trivial environment correlations, we discuss the validity of approximating the speed of atom-atom communication to the group velocity of the guided field. Our work presents a deeper understanding of the validity of commonly used approximations in recent platforms for quantum optics applications in the context of waveguide QED.Comment: 10 pages, 17 figure

Pareto chart

Diariamente necesitamos solucionar un alto número de problemas y creemos que la mejor manera de actuar, es resolverlos todos a la vez, pero estamos equivocados pues empezamos a preocuparnos por muchos interrogantes que con el tiempo se responderán tna solo en forma parcial.Every day we need to solve a high number of problems and we believe that the best way to act is to solve them all at once, but we are wrong because we begin to worry about many questions that over time will only be partially answered

Diseño de la absorción y emisión ópticas de nanomateriales en entornos fotónicos controlados

El trabajo descrito en esta memoria es el resultado de cuatro años de investigación en el Instituto de Ciencia de Materiales de Sevilla bajo la dirección del Prof. Hernán Míguez y el Dr. Juan F. Galisteo-López y versa sobre el control de la absorción y emisión ópticas de nanomateriales integrados en entornos fotónicos controlados Tras un revisión del estado del arte y una introducción general a las estructuras fotónicas empleadas en este estudio (Cap. 1), se describen en detalle cada una de las herramientas utilizadas en la realización de esta tesis (Cap. 2), desde la simulación hasta la caracterización de los distintos materiales estudiados. En primer lugar se describen los métodos teóricos y en segundo lugar se hace una descripción completa de los métodos experimentales, incluyendo tanto fabricación como caracterización óptica de las distintas estructuras realizadas. En el Cap. 3 se presenta una aproximación para modificar de forma controlada la absorción óptica de nanopartículas metálicas integradas en resonadores ópticos unidimensionales. Se detalla cómo incorporar nanopartículas metálicas de tamaño y forma arbitrarios en las estructuras fotónicas así como la caracterización óptica del conjunto y se explican teóricamente los resultados obtenidos. En el Cap. 4 se demuestra la posibilidad de emplear métodos de procesado en solución para controlar de forma determinista la emisión de nanoemisores integrándolos en el interior de resonadores ópticos unidimensionales. Se detalla cómo integrar nanoesferas emisoras con un control nanométrico de su posición en el interior de la estructura fotónica así como la caracterización óptica del conjunto y la reproducción teórica de las modificaciones obtenidas. Además, se diseñan, fabrican y caracterizan estructuras tipo resonador óptico que integran nanosheets y nanoemisores como material base para el desarrollo de nuevos sensores fluorescentes de humedad. En el Cap. 5 se presenta una aproximación para maximizar la potencia radiada por una monocapa de nanoemisores integrada en cristales fotónicos unidimensionales auto-soportados acoplados de manera conformal a superficies metálicas de distinta composición y geometría. Se demuestra la versatilidad de estas estructuras híbridas, dieléctricas-metálicas, mediante el diseño, fabricación y caracterización de sistemas emisores cuasi-monocromáticos, direccionales o auto-focalizados. En los Apen. A y Apen. B se presentan resultados derivados de algunas de las herramientas desarrolladas durante el transcurso de esta tesis. Estos resultados muestran el uso de estructuras híbridas metal-dieléctrico basadas en metales de bajo coste como espejos solares de alta reflectancia y el diseño y fabricación de módulos fotovoltaicos que combinan un concentrador solar luminiscente y cristales fotónicos unidimensionales, respectivamente. Por último, en el Apen. C se presenta la aproximación numérica, basada en el método de las diferencias finitas en el dominio del tiempo, mediante la cual se obtiene información sobre la potencia extraída a través de la superficie de estructuras tipo multicapa que integran fuentes de luz nanométricas.Premio Extraordinario de Doctorado U

Optimización del uso de una rozadora para la excavación del túnel del Proyecto de Ampliación de la Planta Cachí

Proyecto de Graduación (Licenciatura en Ingeniería en Construcción) Instituto Tecnológico de Costa Rica, Escuela de Ingeniería en Construcción, 2011.The construction of tunnels is an activity that is performed in our country mainly as part of the works necessary for the generation of electrical energy, generally using the conventional methodology for excavation. As a result of a consultancy to the Cachí Plant Expansion project, was born the idea of using a roadheader, being this the first time that a miner would be used for digging a tunnel in Costa Rica. The intention of this project is, in addition to creating a spreadsheet of yields of progress that is reliable; to analyze scenarios in order to be able to propose ideas on how to optimize the use of the roadheader; taking into account the geometrical and geotechnical characteristics of the tunnel and at the same time that involve the necessary activities to comply with a cycle of excavation as the extraction of materials and implementation of temporary support. The performance calculations are based on cycles of excavation with times of activities already known and used, from these results, is the times that could be reduced and what activities can be done in parallel are discussed, due to the facilities that the riper presents. It is shown that the use of the roadheader significantly reduces the time of completion of the tunnel to dig, achieving compressed dead times and placing tasks in parallel, while this is not possible with the convetional method.Instituto Tecnológico de Costa Rica. Escuela Ingeniería en Construcción; Instituto Costarricense de Electricidad

How to measure productivity

En una empresa podemos tener muchas relaciones de productividad y cada área hablará un idioma diferente, por tal motivo es dífícil en muchas ocasiones calcular e interpretar la productividad.In a company we can have many productivity relationships and each area will speak a different language, for this reason it is often difficult to calculate and interpret productivity

Efficiency gains due to network function sharing in CDN-as-a-Service slicing scenarios

Proceedings of: IEEE 7th International Conference on Network Softwarization (NetSoft), 28 June-2 July 2021, Tokyo, Japan.The consumption of video contents is currently dominating the traffic observed in ISP networks. The distribution of that content is usually performed leveraging on CDN caches storing and delivering multimedia. The advent of virtualization is bringing attention to the CDN as use case for virtualizing the cache function. In parallel, there is a trend on sharing network infrastructures as a way of reducing deployment costs by ISPs. Then, an interesting scenario emerges when considering the possibility of sharing virtualized cache functions among ISPs sharing a common physical infrastructure, mostly considering that usually those ISPs offer similar content catalogues to final end users. This paper investigates through simulations the potential efficiencies that can be achieved when sharing a virtual cache function if compared to the classical approach of independent virtual caches operated per ISP.This work has been partly funded by the project 5GROWTH (Grant Agreement no. 856709)

Single-random phase encoding architecture using a focus tunable lens

We propose a new nonlinear optical architecture based on a focus tunable lens and an iterative phase retrieval algorithm. It constitutes a compact encryption system that uses a single-random phase key to simultaneously encrypt (decrypt) amplitude and phase data. Summarily, the information encoded in a transmittance object (phase and amplitude) is randomly modulated by a diffuser when a laser beam illuminates it; once the beam reaches a focus tunable lens, different subjective speckle distributions are registered at some image plane as the focal length is tuned to different values. This set of speckle patterns constitutes a delocalized ciphertext, which is used in an iterative phase retrieval algorithm to reconstruct a complex ciphertext. The original data are decrypted propagating this ciphertext through a virtual optical system. In this system, amplitude data are straightforwardly decrypted while phase data can only be restored if the random modulation produced in the encryption process is compensated. Thus, an encryption-decryption process and authentication protocol can simultaneously be performed. We validate the feasibility of our proposal with simulated and experimental results.Centro de Investigaciones Óptica