Two fast radiative transfer methods to improve the temporal sampling of clouds in numerical weather prediction and climate models

The high computational cost of calculating the radiative heating rates in numerical weather prediction (NWP) and climate models requires that calculations are made infrequently, leading to poor sampling of the fast-changing cloud field and a poor representation of the feedback that would occur. This paper presents two related schemes for improving the temporal sampling of the cloud field. Firstly, the ‘split time-stepping’ scheme takes advantage of the independent nature of the monochromatic calculations of the ‘correlated-k’ method to split the calculation into gaseous absorption terms that are highly dependent on changes in cloud (the optically thin terms) and those that are not (optically thick). The small number of optically thin terms can then be calculated more often to capture changes in the grey absorption and scattering associated with cloud droplets and ice crystals. Secondly, the ‘incremental time-stepping’ scheme uses a simple radiative transfer calculation using only one or two monochromatic calculations representing the optically thin part of the atmospheric spectrum. These are found to be sufficient to represent the heating rate increments caused by changes in the cloud field, which can then be added to the last full calculation of the radiation code. We test these schemes in an operational forecast model configuration and find a significant improvement is achieved, for a small computational cost, over the current scheme employed at the Met Office. The ‘incremental time-stepping’ scheme is recommended for operational use, along with a new scheme to correct the surface fluxes for the change in solar zenith angle between radiation calculations.

Berechnungsmodell zur Beschreibung des dynamischen Verhaltens eines Vibrationsförderers – Erläuterung anhand des Beispiels eines Linearvibrationsförderers

Die Möglichkeit der Berechnung des dynamischen Verhaltens eines Vibrationsförderers hat für die Praxis eine große Bedeutung. Es erleichtert die Optimierung des Förderprozesses sowie des Förderers selbst und dessen Anpassung auf das Einsatzgebiet. Das Grundprinzip des Modellaufbaus ist dabei für alle Vibrationsförderer ähnlich und wird anhand eines Beispiels vorgestellt. Weiterhin werden Möglichkeiten zur Nutzung der gewonnen Kenntnisse aus der Berechnung aufgezeigt. Damit schafft das Berechnungsmodell eine erheblich genauere Charakterisierung der Dynamik des Förderers.

Optimización del multiplex de televisión

Este proyecto versa sobre un modelo de evaluación de calidad de imagen aplicado a la optimización del ancho de banda del multiplex de televisión, mediante la realización de ensayos con distintas configuraciones de cabecera. Dicho modelo se basa en las medidas PQR y DMOS de Tektronix, destinadas a medir la percepción de las diferencias entre una secuencia antes y después de sufrir un procesado digital. Dado que actualmente, el modo de trabajo de una cabecera de televisión digital, es la multiplexación estadística (consistente en la codificación de diferentes servicios de vídeo con anchos de banda variables en función de la complejidad de las señales), las medidas estarán enfocadas a sacar conclusiones acerca de la cantidad de canales, complejidad de contenidos, y organización de los mismos en el ancho de banda disponible para emitir, manteniendo niveles de calidad Broadcast. Las medidas serán aplicadas en el proyecto para comparar el rendimiento de dos modelos de cabecera. En primer lugar serán configuradas en régimen binario constante, comparando el rendimiento de los codificadores en el área de trabajo habitual. Posteriormente se configuraran en régimen binario variable probando múltiples configuraciones, con el objetivo dar con el modelo y configuración óptima para su posterior implementación. ABSTRACT. This project concerns a picture quality assessment model applied to television multiplex bandwidth optimization by conducting test with different headend settings. This model is based on the PQR and DMOS Tektronix measures, designed to measure the differences between a sequence before and after a digital processing. Given that nowadays the working way of television headend is by statistical multiplexing (based on coding the different video services with variable bitrate depending on the complexity of the signals) measures will be focused to reach conclusions about the number of channels, complexity of content, and the way to organize them through the available bandwidth, keeping broadcast quality ratios. The measures will be applied comparing the performance of two headend models. First of all encoders will be set on constant bitrate, comparing the performance through the working bandwidth. Later on, both models will be set on variable bitrate testing multiple configurations, in order to find the optimal model/configuration for later implementation.

What makes online grocers work? A case study analysis of factors contributing to online grocery store profitability

This research examined the factors contributing to the performance of online grocers prior to, and following, the 2000 dot.com collapse. The primary goals were to assess the relationship between a company’s business model(s) and its performance in the online grocery channel and to determine if there were other company and/or market related factors that could account for company performance. ^ To assess the primary goals, a case based theory building process was utilized. A three-way cross-case analysis comprising Peapod, GroceryWorks, and Tesco examined the common profit components, the structural category (e.g., pure-play, partnership, and hybrid) profit components, and the idiosyncratic profit components related to each specific company. ^ Based on the analysis, it was determined that online grocery store business models could be represented at three distinct, but hierarchically, related levels. The first level was termed the core model and represented the basic profit structure that all online grocers needed in order to conduct operations. The next model level was termed the structural model and represented the profit structure associated with the specific business model configuration (i.e., pure-play, partnership, hybrid). The last model level was termed the augmented model and represented the company’s business model when idiosyncratic profit components were included. In relation to the five company related factors, scalability, rate of expansion, and the automation level were potential candidates for helping to explain online grocer performance. In addition, all the market structure related factors were deemed possible candidates for helping to explain online grocer performance. ^ The study concluded by positing an alternative hypothesis concerning the performance of online grocers. Prior to this study, the prevailing wisdom was that the business models were the primary cause of online grocer performance. However, based on the core model analysis, it was hypothesized that the customer relationship activities (i.e., advertising, promotions, and loyalty program tie-ins) were the real drivers of online grocer performance. ^

What Makes Online Grocers Work? A Case Study Analysis of Factors Contributing to Online Grocery Store Profitability

This research examined the factors contributing to the performance of online grocers prior to, and following, the 2000 dot.com collapse. The primary goals were to assess the relationship between a company’s business model(s) and its performance in the online grocery channel and to determine if there were other company and/or market related factors that could account for company performance. To assess the primary goals, a case based theory building process was utilized. A three-way cross-case analysis comprising Peapod, GroceryWorks, and Tesco examined the common profit components, the structural category (e.g., pure-play, partnership, and hybrid) profit components, and the idiosyncratic profit components related to each specific company. Based on the analysis, it was determined that online grocery store business models could be represented at three distinct, but hierarchically, related levels. The first level was termed the core model and represented the basic profit structure that all online grocers needed in order to conduct operations. The next model level was termed the structural model and represented the profit structure associated with the specific business model configuration (i.e., pure-play, partnership, hybrid). The last model level was termed the augmented model and represented the company’s business model when idiosyncratic profit components were included. In relation to the five company related factors, scalability, rate of expansion, and the automation level were potential candidates for helping to explain online grocer performance. In addition, all the market structure related factors were deemed possible candidates for helping to explain online grocer performance. The study concluded by positing an alternative hypothesis concerning the performance of online grocers. Prior to this study, the prevailing wisdom was that the business models were the primary cause of online grocer performance. However, based on the core model analysis, it was hypothesized that the customer relationship activities (i.e., advertising, promotions, and loyalty program tie-ins) were the real drivers of online grocer performance.

Towards a Virtual-Acoustic String Instrument

In acoustic instruments, the controller and the sound producing system often are one and the same object. If virtualacoustic instruments are to be designed to not only simulate the vibrational behaviour of a real-world counterpart but also to inherit much of its interface dynamics, it would make sense that the physical form of the controller is similar to that of the emulated instrument. The specific physical model configuration discussed here reconnects a (silent) string controller with a modal synthesis string resonator across the real and virtual domains by direct routing of excitation signals and model parameters. The excitation signals are estimated in their original force-like form via careful calibration of the sensor, making use of adaptive filtering techniques to design an appropriate inverse filter. In addition, the excitation position is estimated from sensors mounted under the legs of the bridges on either end of the prototype string controller. The proposed methodology is explained and exemplified with preliminary results obtained with a number of off-line experiments.

How essential are Argo observations to constrain a global ocean data assimilation system?

Observing system experiments (OSEs) are carried out over a 1-year period to quantify the impact of Argo observations on the Mercator Ocean 0.25° global ocean analysis and forecasting system. The reference simulation assimilates sea surface temperature (SST), SSALTO/DUACS (Segment Sol multi-missions dALTimetrie, d'orbitographie et de localisation précise/Data unification and Altimeter combination system) altimeter data and Argo and other in situ observations from the Coriolis data center. Two other simulations are carried out where all Argo and half of the Argo data are withheld. Assimilating Argo observations has a significant impact on analyzed and forecast temperature and salinity fields at different depths. Without Argo data assimilation, large errors occur in analyzed fields as estimated from the differences when compared with in situ observations. For example, in the 0–300 m layer RMS (root mean square) differences between analyzed fields and observations reach 0.25 psu and 1.25 °C in the western boundary currents and 0.1 psu and 0.75 °C in the open ocean. The impact of the Argo data in reducing observation–model forecast differences is also significant from the surface down to a depth of 2000 m. Differences between in situ observations and forecast fields are thus reduced by 20 % in the upper layers and by up to 40 % at a depth of 2000 m when Argo data are assimilated. At depth, the most impacted regions in the global ocean are the Mediterranean outflow, the Gulf Stream region and the Labrador Sea. A significant degradation can be observed when only half of the data are assimilated. Therefore, Argo observations matter to constrain the model solution, even for an eddy-permitting model configuration. The impact of the Argo floats' data assimilation on other model variables is briefly assessed: the improvement of the fit to Argo profiles do not lead globally to unphysical corrections on the sea surface temperature and sea surface height. The main conclusion is that the performance of the Mercator Ocean 0.25° global data assimilation system is heavily dependent on the availability of Argo data.

A coupled cloud physics–radiation parameterization of the bulk optical properties of cirrus and its impact on the Met Office unified model global atmosphere 5.0 configuration

A new coupled cloud physics–radiation parameterization of the bulk optical properties of ice clouds is presented. The parameterization is consistent with assumptions in the cloud physics scheme regarding particle size distributions (PSDs) and mass–dimensional relationships. The parameterization is based on a weighted ice crystal habit mixture model, and its bulk optical properties are parameterized as simple functions of wavelength and ice water content (IWC). This approach directly couples IWC to the bulk optical properties, negating the need for diagnosed variables, such as the ice crystal effective dimension. The parameterization is implemented into the Met Office Unified Model Global Atmosphere 5.0 (GA5) configuration. The GA5 configuration is used to simulate the annual 20-yr shortwave (SW) and longwave (LW) fluxes at the top of the atmosphere (TOA), as well as the temperature structure of the atmosphere, under various microphysical assumptions. The coupled parameterization is directly compared against the current operational radiation parameterization, while maintaining the same cloud physics assumptions. In this experiment, the impacts of the two parameterizations on the SW and LW radiative effects at TOA are also investigated and compared against observations. The 20-yr simulations are compared against the latest observations of the atmospheric temperature and radiative fluxes at TOA. The comparisons demonstrate that the choice of PSD and the assumed ice crystal shape distribution are as important as each other. Moreover, the consistent radiation parameterization removes a long-standing tropical troposphere cold temperature bias but slightly warms the southern midlatitudes by about 0.5 K.

The Met Office Global Coupled model 2.0 (GC2) configuration

The latest coupled configuration of the Met Office Unified Model (Global Coupled configuration 2, GC2) is presented. This paper documents the model components which make up the configuration (although the scientific description of these components is detailed elsewhere) and provides a description of the coupling between the components. The performance of GC2 in terms of its systematic errors is assessed using a variety of diagnostic techniques. The configuration is intended to be used by the Met Office and collaborating institutes across a range of timescales, with the seasonal forecast system (GloSea5) and climate projection system (HadGEM) being the initial users. In this paper GC2 is compared against the model currently used operationally in those two systems. Overall GC2 is shown to be an improvement on the configurations used currently, particularly in terms of modes of variability (e.g. mid-latitude and tropical cyclone intensities, the Madden–Julian Oscillation and El Niño Southern Oscillation). A number of outstanding errors are identified with the most significant being a considerable warm bias over the Southern Ocean and a dry precipitation bias in the Indian and West African summer monsoons. Research to address these is ongoing.

Scalable model-based configuration management of security services in complex enterprise networks

Security administrators face the challenge of designing, deploying and maintaining a variety of configuration files related to security systems, especially in large-scale networks. These files have heterogeneous syntaxes and follow differing semantic concepts. Nevertheless, they are interdependent due to security services having to cooperate and their configuration to be consistent with each other, so that global security policies are completely and correctly enforced. To tackle this problem, our approach supports a comfortable definition of an abstract high-level security policy and provides an automated derivation of the desired configuration files. It is an extension of policy-based management and policy hierarchies, combining model-based management (MBM) with system modularization. MBM employs an object-oriented model of the managed system to obtain the details needed for automated policy refinement. The modularization into abstract subsystems (ASs) segment the system-and the model-into units which more closely encapsulate related system components and provide focused abstract views. As a result, scalability is achieved and even comprehensive IT systems can be modelled in a unified manner. The associated tool MoBaSeC (Model-Based-Service-Configuration) supports interactive graphical modelling, automated model analysis and policy refinement with the derivation of configuration files. We describe the MBM and AS approaches, outline the tool functions and exemplify their applications and results obtained. Copyright (C) 2010 John Wiley & Sons, Ltd.

A stochastic shift model for economically designed charts constrained by the process stage configuration

An economic model including the labor resource and the process stage configuration is proposed to design g charts allowing for all the design parameters to be varied in an adaptive way. A random shift size is considered during the economic design selection. The results obtained for a benchmark of 64 process stage scenarios show that the activities configuration and some process operating parameters influence the selection of the best control chart strategy: to model the random shift size, its exact distribution can be approximately fitted by a discrete distribution obtained from a relatively small sample of historical data. However, an accurate estimation of the inspection costs associated to the SPC activities is far from being achieved. An illustrative example shows the implementation of the proposed economic model in a real industrial case. (C) 2011 Elsevier B.V. All rights reserved.

A Knowledge Model for Automatic Configuration of Traffic Messages

This paper describes a knowledge model for a configuration problem in the do-main of traffic control. The goal of this model is to help traffic engineers in the dynamic selection of a set of messages to be presented to drivers on variable message signals. This selection is done in a real-time context using data recorded by traffic detectors on motorways. The system follows an advanced knowledge-based solution that implements two abstract problem solving methods according to a model-based approach recently proposed in the knowledge engineering field. Finally, the paper presents a discussion about the advantages and drawbacks found for this problem as a consequence of the applied knowledge modeling ap-proach.

A proposal for a model-based approach for adapting software configuration to runtime environments

Las metodologías de desarrollo ágiles han sufrido un gran auge en entornos industriales durante los últimos años debido a la rapidez y fiabilidad de los procesos de desarrollo que proponen. La filosofía DevOps y específicamente las metodologías derivadas de ella como Continuous Delivery o Continuous Deployment promueven la gestión completamente automatizada del ciclo de vida de las aplicaciones, desde el código fuente a las aplicaciones ejecutándose en entornos de producción. La automatización se ve como un medio para producir procesos repetibles, fiables y rápidos. Sin embargo, no todas las partes de las metodologías Continuous están completamente automatizadas. En particular, la gestión de la configuración de los parámetros de ejecución es un problema que ha sido acrecentado por la elasticidad y escalabilidad que proporcionan las tecnologías de computación en la nube. La mayoría de las herramientas de despliegue actuales pueden automatizar el despliegue de la configuración de parámetros de ejecución, pero no ofrecen soporte a la hora de fijar esos parámetros o de validar los ficheros que despliegan, principalmente debido al gran abanico de opciones de configuración y el hecho de que el valor de muchos de esos parámetros es fijado en base a preferencias expresadas por el usuario. Esto hecho hace que pueda parecer que cualquier solución al problema debe estar ajustada a una aplicación específica en lugar de ofrecer una solución general. Con el objetivo de solucionar este problema, propongo un modelo de configuración que puede ser inferido a partir de instancias de configuración existentes y que puede reflejar las preferencias de los usuarios para ser usado para facilitar los procesos de configuración. El modelo de configuración puede ser usado como la base de un proceso de configuración interactivo capaz de guiar a un operador humano a través de la configuración de una aplicación para su despliegue en un entorno determinado o para detectar cambios de configuración automáticamente y producir una configuración válida que se ajuste a esos cambios. Además, el modelo de configuración debería ser gestionado como si se tratase de cualquier otro artefacto software y debería ser incorporado a las prácticas de gestión habituales. Por eso también propongo un modelo de gestión de servicios que incluya información relativa a la configuración de parámetros de ejecución y que además es capaz de describir y gestionar propuestas arquitectónicas actuales tales como los arquitecturas de microservicios. ABSTRACT Agile development methodologies have risen in popularity within the industry in recent years due to the speed and reliability of the processes they propose. The DevOps philosophy and specifically the methodologies derived from it such as Continuous Delivery and Continuous Deployment push for a totally automated management of the application lifecycle, from the source code to the software running in production environment. Automation in this regard is used as a means to produce repeatable, reliable and fast processes. However, not all parts of the Continuous methodologies are completely automatized. In particular, management of runtime parameter configuration is a problem that has increased its impact in deployment process due to the scalability and elasticity provided by cloud technologies. Most deployment tools nowadays can automate the deployment of runtime parameter configuration, but they offer no support for parameter setting o configuration validation, as the range of different configuration options and the fact that the value of many of those parameters is based on user preference seems to imply that any solution to the problem will have to be tailored to a specific application. With the aim to solve this problem I propose a configuration model that can be inferred from existing configurations and reflect user preferences in order to ease the configuration process. The configuration model can be used as the base of an interactive configuration process capable of guiding a human operator through the configuration of an application for its deployment in a specific environment or to automatically detect configuration changes and produce valid runtime parameter configurations that take into account those changes. Additionally, the configuration model should be managed as any other software artefact and should be incorporated into current management practices. I also propose a service management model that includes the configuration information and that is able to describe and manage current architectural practices such as the microservices architecture.

Operator, organizational, and direct support maintenance manual : air conditioner, base mounted, air cooled, electric motor driven, 120/208 volts, 3 phase, 50/60 cycle, 5 stack configuration (Thermo King model S18-104 TM 5) FSN 4120-926-1203, (Keco model F18000-6) FSN 4120-168-2044, (Mecom model 19099-G 18000-5-MEC) FSN 4120-406-3222.

Includes index.

Equipment serviceability criteria for electronic equipment configuration in Army model AH-1G and AH-1Q helicopter.

"15 July 1975."