Novetats

First results of a GNSS-R experiment from a stratospheric balloon over boreal forests

UPCommons - dv., 03/24/2017 - 13:24
First results of a GNSS-R experiment from a stratospheric balloon over boreal forests Carreño Luengo, Hugo; Camps Carmona, Adriano José; Querol Borràs, Jorge; Forte Veliz, Giuseppe Francesco The empirical results of a global navigation satellite systems reflectometry (GNSS-R) experiment onboard the Balloon EXperiments for University Students (BEXUS) 17 stratospheric balloon performed north of Sweden over boreal forests show that the power of the reflected signals is nearly independent of the platform height for a high coherent integration time T-c = 20 ms. This experimental evidence shows a strong coherent component in the forward scattered signal, as compared with the incoherent component, that allows to be tracked. The bistatic coherent reflectivity is also evaluated as a function of the elevation angle, showing a decrease of similar to 6 dB when the elevation angle increases from 35. to 70 degrees. The received power presents a clearly multimodal behavior, which also suggests that the coherent scattering component may be taking place in different forest elements, i.e., soil, canopy, and through multiple reflections canopy-soil and soil-trunk. This experiment has provided the first GNSS-R data set over boreal forests. The evaluation of these results can be useful for the feasibility study of this technique to perform biomass monitoring that is a key factor to analyze the carbon cycle.
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Estudio del refuerzo externo de losas con FRP. Punzonamiento

UPCommons - dv., 03/24/2017 - 13:15
Estudio del refuerzo externo de losas con FRP. Punzonamiento Loyo Chagollán, Francisco Javier Los compuestos de polímeros reforzados con fibras (FRP), se han introducido desde los años 90 en el campo de la ingeniería civil a sus excelentes características mecánicas, su resistencia química y bajo peso. Estas características han despertado el interés en el campo estructural y han dado lugar al desarrollo de nuevos métodos de cálculo de las propiedades mecánicas de los elementos reforzados y a nuevas aplicaciones del material. El estudio de elementos estructurales reforzados con FRP es muy extenso, se han abierto diferentes líneas de investigación, desde el uso de barras de FRP a modo de refuerzo longitudinal o de tracción, hasta el uso de polímeros adheridos externamente para contribuir en la resistencia a flexión y/o cortante. Aunque se ha demostrado en bastantes investigaciones que el refuerzo externo con FRP es un sistema eficaz para incrementar la capacidad última frente a diferentes tipos de esfuerzos, es necesario profundizar aún más para poder entender el mecanismo resistente resultante de dicho refuerzo. Los esfuerzos producidos por cargas concentradas provocan el fallo frágil de los elementos estructurales, dando lugar a consecuencias no deseables. A este tipo de fallo producido por cargas concentradas se le llama punzonamiento y a pesar de que su complejo estudio está incluido en la gran mayoría de normativas de uso internacional, no se hace alusión al comportamiento de elementos reforzados externamente con FRP. En esta Tesis se hará un análisis de la capacidad que tiene parte de la formulación existente de punzonamiento para reproducir las características resistentes de las losas reforzadas externamente mediante FRP para resistir los esfuerzos provocados por el fenómeno de punzonamiento. Para ello se recogen especímenes (de diferentes autores) que han sido ensayados previamente y se calcula la resistencia a última frente a punzonamiento. Será necesario realizar modificaciones en la formulación utilizada para poder reproducir la resistencia aportada por el refuerzo con polímeros. Los resultados se analizarán calculando el cociente entre la resistencia última medida en los ensayos por sus respectivos autores entre la resistencia última teórica, calculada teniendo en cuenta la contribución del FRP. De igual manera se calcula la desviación estándar de las muestras estudiadas para verificar la dispersión de datos que se produce al cambiar las diferentes características del espécimen.; Fiber reinforced polymers (FRP) have been introduced since the 90s in the civil engineering field due to its excellent mechanical properties, chemical resistance and low weight. These characteristics have drawn attention in the structural field and led to the development of new calculating methods in order to know the mechanical properties of the reinforcing elements and new applications of this material. The study of structural elements reinforced with FRP is very extensive, different lines of research have been opened since then , from the use of FRP bars as a longitudinal reinforcement or tension reinforcement to the use of polymers externally attached to contribute to the flexural strength shear strength. Although considerable researches has shown that the external FRP reinforcement is an effective way to increase the ultimate capacity (flexural and shear capacity), it is necessary to further deepen understanding the mechanism resulting from such resistant reinforcement. Tensions produced by concentrated loads cause brittle failure of structural elements, leading to undesirable consequences. This type of failure caused by concentrated loads is called punching and despite its complex study is included in the vast majority of rules of international use, no reference is made to the behavior of externally reinforced with FRP elements. It will be aim of this thesis the analysis of the capacity of the existing punching formulation to predict the strength characteristics of externally reinforced elements to withstand the stresses caused by punching shear. In order to do this, specimens (from different authors) that have been tested and its final resistance against punching shear is calculated. There will be required modifications into these formulas so it can be used to reproduce the resistance provided by the FRP. The results will be analyzed by calculating the ratio of the ultimate measured resistance in tests by their respective authors between the theoretical ultimate strength, calculated taking into account the contribution of FRP. Likewise, the standard deviation of the samples will be studied to verify how data dispersion affects to the calculations.
Categories: Novetats

Spray distribution evaluation of different settings of a hand-held-trolley sprayer used in greenhouse tomato crops

UPCommons - dv., 03/24/2017 - 13:07
Spray distribution evaluation of different settings of a hand-held-trolley sprayer used in greenhouse tomato crops Llop Casamada, Jordi; Gil Moya, Emilio; Gallart González-Palacio, Montserrat; Contador, Felipe; Ercilla-Montserrat, Mireia Hand-held-trolley sprayers have recently been promoted to improve spray application techniques in greenhouses in south-eastern Spain. However, certain aspects remain to be improved. A modified hand-held-trolley sprayer was evaluated under two different canopy conditions (high and low canopy density) and with several sprayer settings (nozzle type, air assistance and spray volume). In this study, the deposition, coverage and uniformity of distribution of the spray on the canopy have been assessed. RESULTS The deposition on leaves was significantly higher when flat-fan nozzles and air assistance were used at both high and low spray volumes. No differences were detected between the reference system at a high spray volume and the modified trolley at a low spray volume. Flat-fan nozzles with air assistance increased penetrability into the canopy. CONCLUSIONS Air assistance and flat-fan nozzles allow volume rates to be reduced while maintaining or improving spray quality distribution. The working parameters of hand-held sprayers must be considered to reduce environmental risk and increase the efficacy of the spraying process. © 2015 Society of Chemical Industry
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Classification of unelaborated culinary products: scientific and culinary approaches meet face to face

UPCommons - dv., 03/24/2017 - 12:55
Classification of unelaborated culinary products: scientific and culinary approaches meet face to face d'Ambrosio, Ugo; Vila Rigat, Marta; Adrià, Ferran; Bayés-García, Laura; Calsamiglia, Sergio; Castells, Pere; Castro, Oriol; Garnatje, Teresa; Gosálbez, Joaquim; Jofre, Joan; Mariné, Abel; Reig Puig, Lourdes; Rubiralta, Màrius; Xatruch, Eduard; Vallés, Joan he ongoing academization of gastronomic studies indicates the necessity for a com-monly accepted classification system for cooks that does not contradict scientific approaches. This work discusses the fundamentals used by chefs and scientists to classify nelaborated food products; proposes taxonomic gastronomy as a new inter-disciplinary framework that studies the taxonomy surrounding gastronomy
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Phase opposition disposition PWM strategy and hardware in the loop validation for a 3-SM modular multilevel converter

UPCommons - dv., 03/24/2017 - 12:55
Phase opposition disposition PWM strategy and hardware in the loop validation for a 3-SM modular multilevel converter Ouerdani, Imen; Dagbagi, Mohamed; Ben Abdelghani, Afef Bennani; Slama-Belkhodja, Ilhem; Montesinos Miracle, Daniel This paper focuses on the carrier disposition Pulse Width Modulation (PWM) strategies for Modular Multilevel Converters (MMC). The authors propose a new Phase Opposition Disposition PWM (PODPWM) scheme applicable regardless of the converter’s sub-modules number. Moreover, a capacitor voltage sorting algorithm is synthesized aiming to ensure the converter’s balanced operation. Simulation re sults of a 3.6 MVA, 3-SM-MMC are presented and discussed. In addition, a Hardware In the Loop (HIL) validation of the proposed PODPWM has been made using Field Programmable Gate Array (FPGA) target. The actual power system (the 3-SM-MMC and the 3-phase RL load) is then replaced by its real-time emulator. The latter is interfaced to the PODPWM control under test and both are implemented and run altogether in the same Xilinx XC7Z020 Zynq FPGA device. The obtained real-time HIL emulation results are presented and compared to the offline simulation results.
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Cost-effective transceiver based on an RSOA and a VCSEL for flexible uDWDM networks

UPCommons - dv., 03/24/2017 - 12:54
Cost-effective transceiver based on an RSOA and a VCSEL for flexible uDWDM networks Altabas, Jose Antonio; Izquierdo, David; Lázaro Villa, José Antonio; Garces, Ignacio A cost-effective transceiver for a 1-Gb/s full-duplex ultra-dense wavelength division multiplexing optical link is proposed for flexible metro-access and 5G networks. The transceiver is based on a vertical cavity surface emitting laser, which is used as the local oscillator for a heterodyne receiver and also feeds a phase-modulated reflective semiconductor optical amplifier (RSOA) transmitter. The modulation format used in the RSOA is a nonreturn-to-zero differential binary phase shift keying (DPSK) for the uplink, while the downlink is based on a Nyquist DPSK format. The central frequencies of the links are 2 GHz separated, and both links can be placed inside a 6.25-GHz frequency slot. The sensitivity of this transceiver is -43.5 dBm over a 50-km fiber.
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Control de l'entorn en animals

UPCommons - dv., 03/24/2017 - 12:43
Control de l'entorn en animals Balcells Nuevo, Carlota En una carpeta hi ha el codi generat per Scriptcase i els webservices (incloent classes), i en l'altra el codi de l'Arduino i llibreries necessàries.
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Diseño y desarrollo de un vertical basado en Microsoft Dynamics CRM para el sector de Gran Consumo

UPCommons - dv., 03/24/2017 - 12:37
Diseño y desarrollo de un vertical basado en Microsoft Dynamics CRM para el sector de Gran Consumo Delgado Díaz, Jesús El objetivo principal de este proyecto es el de diseñar y construir un sistema de información CRM que permita a las organizaciones del sector de Gran Consumo tener un mayor control de sus clientes y haga más eficiente la gestión de los mismos. En concreto, nos centraremos en implementar un sistema que: o Proporcione a sus usuarios una visión 360º de los clientes (información básica del cliente, información concreta del sector, productos vendido al cliente,…). o Permita a sus usuarios la gestión integral de campañas y promociones. o Permita a sus usuarios la gestión de incidencias. Para ello se hará uso del producto Microsoft Dynamics CRM. Pese a que el producto ofrece muchas funcionalidades de manera estándar, será necesario realizar personalizaciones para adaptarlo al sector de Gran Consumo. Podemos dividir el proyecto en los siguientes objetivos más concretos: 1. Definición de una organización estándar del sector de Gran Consumo. Identificación de los procesos principales existentes en el sector de Gran Consumo. 2. Identificar aquellas de las funcionalidades a implantar que pueden ser cubiertas con la solución estándar de Dynamics, únicamente realizando parametrización. 3. Identificación de los GAPs entre el modelo objetivo y la funcionalidad estándar y el diseño técnico y desarrollo de los mismos. 4. Centralizar la información de los clientes, gestionada habitualmente por los comerciales de manera individual. 5. Proporcionar una herramienta colaborativa fácil de utilizar para fomentar la cooperación y reducir la competencia entre los trabajadores. 6. Crear componentes reutilizables en otros proyectos. 7. Construir una maqueta base de CRM ampliable en posteriores proyectos. 8. Realizar una demostración del vertical realizado a empresas del sector de Gran Consumo con el fin de captar nuevos clientes.
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Study of a marketing based solidary application

UPCommons - dv., 03/24/2017 - 12:31
Study of a marketing based solidary application Sant Albors, Joaquim In this study I present a personal idea: A marketing tool mobile application that generates funds for social projects. The idea can be extended to other devices. As a student of civil engineering from 2008, I was living in the university a huge economic crisis while Android mobiles appeared, in October 2008, and became incredibly popular to have internet in the phone, download applications etc. Mobile devices are a great source of opportunities, and social projects need now more than ever, the support of the individual people, to obtain funds, due to the public crisis. Matching the opportunities and the needs I had the idea of this application. First we introduce the marketing and the NOG’s that develop social programs. The application idea is presented with the explanation of similar cases, strengths, weakness and a technical feasibility study using Android as operating system. The economic analysis consist in the evaluation of marketing costs, analyzing the prices of publicity, and a profitability study that set the budget and requirements in terms of cash flow, to make the application successful. The nature of the costs is presented, and we try to translate the requirements in a user’s scale, estimating a minimum cash inflow for each user. After the study we developed a prototype of the application, and explained the deployment stages to follow, and main topics to care about while deploying the application.
Categories: Novetats

Process mining using convex polytopes

UPCommons - dv., 03/24/2017 - 12:28
Process mining using convex polytopes Alemany Puig, Lluís Process Mining is a relatively young field of study that highlights the difficulty to infer models of processes from which to extract enough information to make predictions about its behaviour, find bottlenecks and causality relationships so as to be able to answer as many questions as one can make about them. In this context, a process may be understood as any activity performed by humans or computers or the result between the interaction of the two. Research on this topic has provided many different solutions focused on “process discovery”, “conformance checking” and “model extension” and some of them led to the development of commercial software. However, most of the solutions research on “process discovery” has provided are not suitable to handle industrial cases. In this document we present a new approach to do Process Mining focusing on “process discovery”: using convex polytopes.; La Mineria de Procesos es un campo de estudio relativamente joven que pone de manifiesto la dificultad para inferir modelos de procesos de los que extraer suficiente información como para hacer predicciones sobre su comportamiento, encontrar cuellos de botella y relaciones de causalidad para ser capaces de responder tantas preguntas como sea posible hacer sobre estos modelos. En este contexto, un proceso se puede entender como cualquier actividad hecha por humanos o ordenadores o el resultade de la interacci´on entre ambos. Las investigaciones hechas sobre este tema han proporcionado soluciones variadas concentradas en “process discovery”, “conformance checking” y “extension model” y algunas de ellas se han llevago a desarrollar en software comercial. Aún así, muchas de las soluciones aportadas gracias a las investigaciones en “process discovery” no son suficientemente buenas como para tratar casos a nivel industrial. En este documento presentamos una nueva perspectiva de hacer Mineria de Procesos concentr´andonos en “process discovery”: usando politopos convexos.; La Mineria de Processos és un camp d’estudi relativament jove que posa de manifest la dificultat per inferir models de processos dels que extreure suficient informació com per poder fer prediccions sobre el seu comportament, trobar cuells d’ampolla i relacions de causalitat per a ser capaços de respondre tantes preguntes com sigui possible fer sobre aquests models. En aquest context, un procés es pot entendre com qualsevol activitat duta a terme per humans o ordinadors o el resultat de la interacció entre els dos. Les investigacions fetes sobre aquest tema han proporcionat solucions variades concentrades en “process discovery”, “conformance checking” i “extension model” i algunes d’elles han portat al desenvolupament de software comercial. Tot i així, moltes de les solucions aportades gràcies a les investigacions en “process discovery” no són suficientment bones com per tractar casos a nivell industrial. En aquest document presentem una nova manera de fer Mineria de Processos concentrant-nos en “process discovery”: fent servir politops convexos.
Categories: Novetats

Entrevista a la doctorand Carolina E. Leyton

UPCommons - dv., 03/24/2017 - 10:16
Entrevista a la doctorand Carolina E. Leyton Equip Landing at UPC
Categories: Novetats

Precoding in multigateway multibeam satellite systems

UPCommons - dv., 03/24/2017 - 09:35
Precoding in multigateway multibeam satellite systems Joroughi, Vahid; Vazquez, Miguel Angel; Pérez Neira, Ana Isabel This paper considers a multigateway multibeam satellite system with multiple feeds per beam. In these systems, each gateway serves a set of beams (cluster) so that the overall data traffic is generated at different geographical areas. Full frequency reuse among beams is considered so that interference mitigation techniques are mandatory. Precisely, this paper aims at designing the precoding scheme which, in contrast to single gateway schemes, entails two main challenges. First, the precoding matrix shall be separated into feed groups assigned to each gateway. Second, complete channel state information (CSI) is required at each gateway, leading to a large communication overhead. In order to solve these problems, a design based on a regularized singular value block decomposition of the channel matrix is presented so that both intercluster (i.e., beams of different clusters) and intracluster (i.e., beams of the same cluster) interference is minimized. In addition, different gateway cooperative schemes are analyzed in order to keep the inter-gateway communication low. Furthermore, the impact of the feeder link interference (i.e., interference between different feeder links) is analyzed and it is shown both numerically and analytically that the system performance is reduced severely whenever this interference occurs even though precoding reverts this additional interference. Finally, multicast transmission is also considered. Numerical simulations are shown considering the latest fixed broadband communication standard DVB-S2X so that the quantized feedback effect is evaluated. The proposed precoding technique results to achieve a performance close to the single gateway operation even when the cooperation among gateways is low.
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The TALP–UPC Spanish–English WMT biomedical task: bilingual embeddings and char-based neural language model rescoring in a phrase-based system

UPCommons - dj., 03/23/2017 - 21:22
The TALP–UPC Spanish–English WMT biomedical task: bilingual embeddings and char-based neural language model rescoring in a phrase-based system Ruiz Costa-Jussà, Marta; España-i-Bonet, Cristina; Madhyastha, Pranava; Escolano Peinado, Carlos; Rodríguez Fonollosa, José Adrián This paper describes the TALP–UPC system in the Spanish–English WMT 2016 biomedical shared task. Our system is a standard phrase-based system enhanced with vocabulary expansion using bilingual word embeddings and a characterbased neural language model with rescoring. The former focuses on resolving outof- vocabulary words, while the latter enhances the fluency of the system. The two modules progressively improve the final translation as measured by a combination of several lexical metrics.
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WMT 2016 Multimodal translation system description based on bidirectional recurrent neural networks with double-embeddings

UPCommons - dj., 03/23/2017 - 19:54
WMT 2016 Multimodal translation system description based on bidirectional recurrent neural networks with double-embeddings Rodríguez Guasch, Sergio; Ruiz Costa-Jussà, Marta Bidirectional Recurrent Neural Networks (BiRNNs) have shown outstanding results on sequence-to-sequence learning tasks. This architecture becomes specially interesting for multimodal machine translation task, since BiRNNs can deal with images and text. On most translation systems the same word embedding is fed to both BiRNN units. In this paper, we present several experiments to enhance a baseline sequence-to-sequence system (Elliott et al., 2015), for example, by using double embeddings. These embeddings are trained on the forward and backward direction of the input sequence. Our system is trained, validated and tested on the Multi30K dataset (Elliott et al., 2016) in the context of theWMT 2016Multimodal Translation Task. The obtained results show that thedouble-embedding approach performs significantly better than the traditional single-embedding one.
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Piratas del espacio: el uso inesperado del espacio a través del cine de acción

UPCommons - dj., 03/23/2017 - 16:54
Piratas del espacio: el uso inesperado del espacio a través del cine de acción Muñoz Gris, Hugo Una mirada a la espacialidad cinematográfica del cine de acción, atendiendo a ámbitos de interior y exterior, para estudiar los usos imprevistos, inesperados y disruptores a los que se somete la arquitectura y la ciudad en el desarrollo de este tipo de secuencias. Desde la identificación inicial de los procesos de control que se establecen entre el espacio habitado y sus habitantes, hasta la conquista del entorno, se acompaña a diferentes héroes de acción en su manera explosivamente libre de aprovecharse de todo aquello que les rodea, tanto dentro de los edificios como en el espacio entre estos. Màster universitari en Estudis Avançats en Arquitectura: Projecte. Procés i Programació
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Compendio sobre la normativa de seguridad aplicable a yates

UPCommons - dj., 03/23/2017 - 16:51
Compendio sobre la normativa de seguridad aplicable a yates Goñi Díaz, Patxi
Categories: Novetats

Neural machine translation using bitmap fonts

UPCommons - dj., 03/23/2017 - 16:29
Neural machine translation using bitmap fonts Aldón Mínguez, David; Ruiz Costa-Jussà, Marta; Rodríguez Fonollosa, José Adrián Recently, translation systems based on neural networks are starting to compete with systems based on phrases. The systems which are based on neural networks use vectorial repre- sentations of words. However, one of the biggest challenges that machine translation still faces, is dealing with large vocabularies and morphologically rich languages. This work aims to adapt a neural machine translation system to translate from Chinese to Spanish, using as input different types of granularity: words, characters, bitmap fonts of Chinese characters or words. The fact of performing the interpretation of every character or word as a bitmap font allows for obtaining more informed vectorial representations. Best results are obtained when using the information of the word bitmap font.
Categories: Novetats

High performance doa trackers derived from paralell low resolution detectors

UPCommons - dj., 03/23/2017 - 16:20
High performance doa trackers derived from paralell low resolution detectors Pérez Neira, Ana Isabel; Lagunas Hernandez, Miguel A. Traditionally, high resolution spectral direction of arrival (DOA) estimation has been associated with algorithms rather than with a processing scheme or architecture. Motivated by previous work on feasible implementations of the expectation-maximization algorithm, the authors show that classical bank filter approach can get similar, even better, performance than the most sophisticated algorithms, in terms of performance versus complexity. In fact, the practicality and robustness required for DOA trackers, both in radar and in the mobile communication scenarios to alleviate data fusion and hand-over respectively, makes evident the use of filter-bank or scanning beams for DOA tracking at the expense of resolution. The herein reported tracker enhances complexity and robustness of these schemes, achieving high resolution from the EM architecture. The result is a low complexity tracker with robustness against coherent sources and a resolution close to singular value decomposition (SVD) based methods.
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Partition coding using multi-grid chain code and motion compensation

UPCommons - dj., 03/23/2017 - 16:14
Partition coding using multi-grid chain code and motion compensation Marqués Acosta, Fernando; Gasull Llampallas, Antoni In this paper, a lossy partition coding technique is presented which leads to decoded partitions with unnoticeable losses. It uses a hexagonal grid for contour representation and it is based on the concept of multi-grid chain code. This coding technique can be used in intra-frame mode or, in combination with partition prediction techniques, in interframe mode. In intra-frame mode, it leads to an average saving of 25% of the coding cost with respect to chain code techniques. The savings on inter-frame mode depend on the motion prediction approach. Results of coding binary shapes (concept of video object plane) as well as partitions with an arbitrary set of regions are presented.
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Blind multiuser detection using hidden markov models theory

UPCommons - dj., 03/23/2017 - 16:04
Blind multiuser detection using hidden markov models theory Antón Haro, Carles; Rodríguez Fonollosa, José Adrián; Rodríguez Fonollosa, Javier We present an adaptive algorithm based on the theory of hidden Markov models (HMM) which is capable of jointly detecting the users in a DS-CDMA system. The proposed technique is near-far resistant and completely blind in the sense that no knowledge of the signature sequences, channel state information or training sequences is required for any user. In addition to this, an estimate of the signature of each user convolved with its physical channel impulse response (CIR), and an estimate of the background noise variance are provided once convergence is achieved (as well as estimated data sequences). At this moment, and using that CIR estimate, we can switch to any decision-directed (DD) adaptation scheme.
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