922 research outputs found

    Simulated Assessment of Interference Effects in Direct Sequence SpreadSpectrum (DSSS) QPSK Receiver

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    This research developed and validated a generic simulation for a direct sequence spread spectrum (DSSS), using differential phase shift keying (DPSK) and phase shift keying (PSK) modulations, providing the flexibility for assessing intentional interference effect using DSSS quadrature phase shift keying receiver (QPSK) with matched filtering as a reference. The evaluation compares a comprehensive pool of jamming waveforms at pass-band that include continuous wave (CW) interference, broad-band jamming, partial-band interference and pulsed interference. The methodology for jamming assessment included comparing the bit error rate (BER) versus required jamming to signal ratio (JSR) for different interferers using the Monte Carlo approach. This thesis also analyzes the effect of varying the jammer bandwidth for broad-band jammers including broad-band noise (BBN), frequency hopping interference (FHI), comb- spectrum interference (CSI), multi-tone jamming (MTJ), random frequency modulated interference (RFMI) and linear frequency modulated interference (LFMI). Also, the effect of changing the duty cycle for pulsed CW waveforms is compared with the worst case pulsed jamming equation. After the evaluation of different interferers, the research concludes that pulsed binary phase shift keying (BPSK) jamming is the most effective technique, whereas the CW tone jamming and CW BPSK interference result are least effective. It is also concluded that by finding an optimum bandwidth, FHI and BBN improves the required JSR by approximately 2.1 dB, RFMI and LFMI interference by 0.9 and 1.5 dB respectively. Alternately, MTJ and CSI improves their effectiveness in 4.1 dB and 3.6 dB respectively, matching the performance of the pulsed BPSK jammer

    Propiedades multiferroicas de la estructura multicapas BiFeO3 /CoFe2 O4 a temperatura ambiente

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    Las películas multicapa BiFeO3 /CoFe2 O4 se depositaron mediante recubrimiento por rotación sobre 3 2 4 sustratos de Pt (Pt / TiO2 / SiO2 / Si) y se recocieron a 700, 725 y 750 ° C. El precursor de BiFeO3/CoFe2O4 para la estructura de multicapas se sintetizó por el método de solución química. Los patrones de difracción de rayos X del sistema de multicapas revelaron la estructura de tipo compuesto. La corriente de fuga se encontró a menos de 10 Amp en el campo eléctrico por debajo de 100 kV / cm, que muestra el -6 comportamiento óhmico de BiFeO /CoFe O . La constante dieléctrica disminuye al aumentar en el rango de 3 2 4 frecuencia 103-106 Hz. El sistema BiFeO /CoFe O muestra la coexistencia de polarización ferroeléctrica 3 2 4 (Pr) = 65 y 51 μC / cm2 y magnetización (Mr) = 102 y 47 emu / cm3 a temperatura ambiente. Las respuestas ferromagnéticas y ferroeléctricas observadas en el sistema de multicapas pueden ser útiles para dispositivos bifuncionales

    Enrichment of guinea pig (Cavia porcellus) meat with omega-3 fatty acids by diets with fish oil and sacha inchi (Plukenetia volubilis) seeds

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    El objetivo del estudio fue enriquecer la carne de cuy (Cavia porcellus) con ácidos grasos omega-3 mediante el uso de dietas con fuentes de omega-3. Se utilizaron 48 cuyes machos de 42 días de edad y peso inicial de 615 g. Los cuyes se asignaron al azar a cuatro tratamientos con tres repeticiones (pozas) de cuatro cuyes cada una. Los tratamientos fueron: 1) Dieta control; 2) Dieta suplementada con 1.0% de aceite de pescado; 3) Dieta suplementada con 4.0% de semilla de sacha inchi (Plukenetia volubilis); y 4) Dieta suplementada con 1.0% de aceite de pescado + 4.0% de semilla de sacha inchi. La fase experimental tuvo una duración de 28 días. La carne de cuyes alimentados con la dieta con aceite de pescado presentó 1.36% de omega-3 de cadena larga (0.63% ácido eicosapentaenoico [EPA] + 0.73% ácido docosahexaenoico [DHA]) y aquella con dieta con aceite de pescado más sacha inchi alcanzó 0.99% de omega-3 (0.44% EPA + 0.55% DHA). Las carnes de cuyes alimentados con la dieta control o con semillas de sacha inchi no presentaron omega-3 de cadena larga EPA/DHA, pero si omega-3 de cadena corta α-linolénico (ALA). Asimismo, la carne de cuyes alimentados con la dieta con sacha inchi exhibió el más alto contenido de ácidos grasos poliinsaturados (51.35%) y el menor de ácidos grasos monoinsaturados (21.97%) y de ácidos grasos saturados (25.49%). Se concluye que la dieta con aceite de pescado produjo en la carne de cuy una retención de ácidos grasos omega-3 EPA y DHA, mientras que la dieta con semillas de sacha inchi solo hubo retención de omega-3 ALA.The aim of this study was to enrich guinea pig (Cavia porcellus) meat with omega3 polyunsaturated fatty acids by diets with omega-3 sources. A total of 48 male guinea pigs, 42 day old and 615 g body weight were used. The guinea pigs were randomly assigned to four treatments with three replicates (pens) with four individuals each. The dietary treatments were: 1) Control diet; 2) 1.0% fish oil supplemented diet; 3) 4.0% sacha inchi seeds (Plukenetia volubilis) supplemented diet; and 4) 1.0% fish oil + 4.0% sacha inchi seeds supplemented diet. The experiment lasted 28 days. The meat of guinea pig supplemented with fish oil contained 1.36% large chain omega-3 fatty acids (0.63% eicosapentaenoic acid [EPA] + 0.73% docosahexaenoic acid [DHA]) and those supplemented with the fish oil + sacha inchi had 0.99% large chain omega-3 fatty acids (0.44% EPA + 0.55% DHA). Guinea pigs on the control diet and those supplemented with sacha inchi seeds contained no large chain omega-3 fatty acids (EPA/DHA) but short chain omega-3 fatty acid α-linolenic acid (ALA). Furthermore, meat of guinea pig fed on the sacha inchi diet showed the highest level of polyunsaturated fatty acids (51.35%), the lowest content of monounsaturated fatty acids (21.97%) and the lowest concentration of saturated fatty acids (25.49%). It is concluded that the diet with fish oil produced retention of omega-3 EPA and DHA in guinea pig meat, while the diet with sacha inchi seeds only retained omega-3 ALA

    FLUCTUATIONS AND VOLATILITY OF WHITE EGGS CONSUMER PRICES IN THE MEXICO VALLEY

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    Objective: To develop a time series model and analyze the characteristic fluctuations of the average white eggs consumer prices in the Mexico Valley (AWECP), quantifying the seasonal and cyclical fluctuations of said prices. Design/methodology/approach: A Moving Average Time Series Smoothing method was used to reduce the variation of a data set, and separate cyclical, seasonal, and OLS variations to calculate the trend line. Results: The Seasonal Component (SC) indicates that in autumn-winter the AWECP is volatile above the annual average by 6.3 % while in spring-summer it declines by 9.13 % on average. The price volatility is largely explained by external factors and the biological process of poultry animals throughout one year. The cyclical component (CC) was 34 months and occurs irregularly. Limitations on study/implications: This research focused on finding the SC, T, and CC, but not their respective indices. To make short-term forecasts, it is necessary to calculate the indices and compare them to other time series analysis methodologies. Findings/conclusions: The analysis of the AWECP in the Mexico Valley indicates the presence of SC and an upward CC trend in the time series. The AWECP volatility has harmful effects on the basic basket of the middle and lower-class population in the Mexico Valley given that this food is the most complete, cheap, and accessible source of animal protein in the Mexican market

    Plan de negocios para la implementaci?n de un gimnasio inteligente que brinde un an?lisis predictivo acerca del desempe?o f?sico a trav?s del registro autom?tico mediante internet of things

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    Actualmente la tecnolog?a est? presente en todos los aspectos de la vida cotidiana y ha transformado la manera en que las personas perciben e interact?an con el mundo que los rodea. Entre las tecnolog?as modernas, se tiene el Internet of Things (IoT), la cual permite conectar a la red y a?adir funcionalidades inform?ticas a casi cualquier objeto de uso cotidiano, permitiendo llevar registro de todas las interacciones con dichos objetos, generando una data hist?rica que hace posible el an?lisis de la actividad mediante reportes y estad?sticas de uso. El principal objetivo del presente trabajo es aprovechar la aplicaci?n de la tecnolog?a IoT a una industria con alta demanda en la actualidad, que es la de los gimnasios. Se a?adir? valor a los servicios ofrecidos por un gimnasio tradicional, incluyendo componentes IoT que registren autom?ticamente las actividades del cliente en el gimnasio, para luego aplicar an?lisis predictivo sobre estos datos y brindar informaci?n que permita al cliente mejorar los resultados obtenidos en sus entrenamientos. Este grado de personalizaci?n y monitoreo, puede motivar al usuario a tratar de mejorar su desempe?o f?sico en el gimnasio, seg?n estudios previos consultados

    Imaging drug delivery to skin with stimulated Raman scattering microscopy

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    Efficient drug delivery to the skin is essential for the treatment of major dermatologic diseases, such as eczema, psoriasis and acne. However, many compounds penetrate the skin barrier poorly and require optimized formulations to ensure their bioavailability. Here, stimulated Raman scattering (SRS) microscopy, a recently-developed, label-free chemical imaging tool, is used to acquire high resolution images of multiple chemical components of a topical formulation as it penetrates into mammalian skin. This technique uniquely provides label-free, non-destructive, three-dimensional images with high spatiotemporal resolution. It reveals novel features of (trans)dermal drug delivery in the tissue environment: different rates of drug penetration via hair follicles as compared to the intercellular pathway across the stratum corneum are directly observed, and the precipitation of drug crystals on the skin surface is visualized after the percutaneous penetration of the co-solvent excipient in the formulation. The high speed three-dimensional imaging capability of SRS thus reveals features that cannot be seen with other techniques, providing both kinetic information and mechanistic insight into the (trans)dermal drug delivery process

    Agglomerations and firm performance: who benefits and how much?

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    [EN] Agglomerations and firm performance: who benefits and how much? Regional Studies. Agglomeration can generate gains. If it does, how does it work and how are those gains distributed across agglomerated firms? The paper examines the effect of localization externalities on innovation. Localization externalities are measured as industry specialization or a firm s colocation in a relatively high own-industry employment region. By analyzing a large dataset of 6697 firms integrated with another regional agglomeration-related dataset, results show that (1) co-location in an agglomeration has a positive influence on a firm s innovative performance; and (2) firms benefit heterogeneously from agglomerations, with benefits being distributed asymmetrically. Agglomeration gains exist but not all firms benefit equally.Financial support was provided by the Spanish Ministry of Economics, Industry and Competitiveness [research grant ECO:2015-63645-R] (Mineco/Feder), Open Innovation in Clusters.Hervás Oliver, JL.; Sempere-Ripoll, F.; Rojas Alvarado, RJ.; Estelles Miguel, S. (2018). Agglomerations and firm performance: who benefits and how much?. Regional Studies. 52(3):338-349. https://doi.org/10.1080/00343404.2017.1297895S33834952

    Plan de Negocio - Sitio web de comercio electr?nico para la venta de juegos de mesa modernos utilizando CRM en el Per?

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    La presente tesis es un plan de negocios sobre el desarrollo de un sitio web para la venta de juegos de mesa modernos. As? mismo, se tendr? como factor clave la segmentaci?n por comportamiento de los clientes a trav?s del CRM BITRIX24, de manera que se puedan plantear promociones, comunicaci?n y ofertas de productos dirigidos a los consumidores, sustentados en los resultados que el programa nos pueda brindar. Como parte de este plan de negocios, se realizaron entrevistas a profundidad a los principales proveedores del sector, como tambi?n a los usuarios de juego de mesa modernos. Realizada la investigaci?n, destacan los principales resultados como: Las marcas no manejan ning?n tipo de Customer Relationship Management, lo que no les permite entender a cabalidad el comportamiento de los diferentes segmentos de clientes. Importante resultado de la investigaci?n fue conocer, de primera mano, que el sector viene en un constante crecimiento, sobre todo a ra?z de la pandemia que gatill? un incremento muy importante en las ventas desde el a?o 2020

    Desalination effects on macroalgae (part b): Transplantation experiments at brine-impacted sites with Dictyota spp. from the Pacific Ocean and Mediterranean Sea

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    Desalination residual brines are mostly discharged to marine environments, which can produce osmotic stress on sensitive benthic organisms. In this investigation, we performed transplantation experiments nearby desalination plants using two brown macroalgae species from a cosmopolitan genus: Dictyota kunthii (Chile) and Dictyota dichotoma (Spain). Parameters related to photosynthetic activity and oxidative stress were evaluated at 3 and 7 days for D. kunthii, and 3 and 6 days for D. dichotoma; each at 2 different impacted sites and 1 control. We observed that brine exposition at both impacted sites in Chile generated a marked stress response on D. kunthii, reflected in a decrease of primary productivity (ETRmax), light requirement (EkETR), and an excessive thermal dissipation (NPQmax), especially at 7 days. In D. dichotoma, similar impaired photosynthetic activity was recorded but only at the highest brine influence site during day 3. Regarding oxidative stress, both species displayed high levels of H2O2 when exposed to brine-influenced sites. Although in D. kunthii H2O2 content together with lipid peroxidation was higher after 3 days, these returned to baseline values towards day 7; instead, D. dichotoma H2O2 levels increased only at day 6. This easy and practical approach has proven to provide valuable data to address potential impacts of brine discharges at global scale coastal ecosystems.We gratefully thank financial support to ANID FONDECYT Postdoctoral fellowship #3180394, European Commission Marie Skłodowska-Curie Actions #888415, and ANID INES I+D # INID210013. Financial support for mobility granted from SEGIB Scholarship and Fundación Carolina of Spain to PM. Also, we thank TESPOST 04/19 PhD scholarship granted by Universidad de Playa Ancha to PM

    Optical and Infrared Diagnostics of SDSS galaxies in the SWIRE Survey

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    We present the rest-frame optical and infrared colours of a complete sample of 1114 z<0.3 galaxies from the Spitzer Wide-area InfraRed Extragalactic Legacy Survey (SWIRE) and the Sloan Digital Sky Survey (SDSS). We discuss the optical and infrared colours of our sample and analyse in detail the contribution of dusty star-forming galaxies and AGN to optically selected red sequence galaxies. We propose that the optical (g-r) colour and infrared log(L_{24}/L_{3.6}) colour of galaxies in our sample are determined primarily by a bulge-to-disk ratio. The (g-r) colour is found to be sensitive to the bulge-to-disk ratio for disk-dominated galaxies, whereas the log(L_{24}/L_{3.6}) colour is more sensitive for bulge-dominated systems. We identify ~18% (195 sources) of our sample as having red optical colours and infrared excess. Typically, the infrared luminosities of these galaxies are found to be at the high end of star-forming galaxies with blue optical colours. Using emission line diagnostic diagrams, 78 are found to have an AGN contribution, and 117 are identified as star-forming systems. The red (g-r) colour of the star-forming galaxies could be explained by extinction. However, their high optical luminosities cannot. We conclude that they have a significant bulge component. The number densities of optically red star-forming galaxies are found to correspond to ~13% of the total number density of our sample. In addition, these systems contribute ~13% of the total optical luminosity density, and 28% of the total infrared luminosity density of our SWIRE/SDSS sample. These objects may reduce the need for "dry-mergers".Comment: 14 pages, 8 figures, 4 tables. Accepted for publication in MNRA
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