The Experts below are selected from a list of 11067 Experts worldwide ranked by ideXlab platform
Vivek K Arora - One of the best experts on this subject based on the ideXlab platform.
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modeling vegetation as a Dynamic Component in soil vegetation atmosphere transfer schemes and hydrological models
Reviews of Geophysics, 2002Co-Authors: Vivek K AroraAbstract:[1] Vegetation affects the climate by modifying the energy, momentum, and hydrologic balance of the land surface. Soil-vegetation-atmosphere transfer (SVAT) schemes explicitly consider the role of vegetation in affecting water and energy balance by taking into account its physiological properties, in particular, leaf area index (LAI) and stomatal conductance. These two physiological properties are also the basis of evapotranspiration parameterizations in physically based hydrological models. However, most current SVAT schemes and hydrological models do not parameterize vegetation as a Dynamic Component. The seasonal evolution of LAI is prescribed, and monthly LAI values are kept constant year after year. The effect of CO2 on the structure and physiological properties of vegetation is also neglected, which is likely to be important in transient climate simulations with increasing CO2 concentration and for hydrological models that are used to study climate change impact. The net carbon uptake by vegetation, which is the difference between photosynthesis and respiration, is allocated to leaves, stems, and roots. Carbon allocation to leaves determines their biomass and LAI. The timing of bud burst, leaf senescence, and leaf abscission (i.e., the phenology) determines the length of the growing season. Together, photosynthesis, respiration, allocation, and phenology, which are all strongly dependent on environmental conditions, make vegetation a Dynamic Component. This paper (1) familiarizes the reader with the basic physical processes associated with the functioning of the terrestrial biosphere using simple nonbiogeochemical terminology, (2) summarizes the range of parameterizations used to model these processes in the current generation of process-based vegetation and plant growth models and discusses their suitability for inclusion in SVAT schemes and hydrological models, and (3) illustrates the manner in which the coupling of vegetation models and SVAT schemes/hydrological models may be accomplished.
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MODELING VEGETATION AS A Dynamic Component IN SOIL‐VEGETATION‐ATMOSPHERE TRANSFER SCHEMES AND HYDROLOGICAL MODELS
Reviews of Geophysics, 2002Co-Authors: Vivek K AroraAbstract:[1] Vegetation affects the climate by modifying the energy, momentum, and hydrologic balance of the land surface. Soil-vegetation-atmosphere transfer (SVAT) schemes explicitly consider the role of vegetation in affecting water and energy balance by taking into account its physiological properties, in particular, leaf area index (LAI) and stomatal conductance. These two physiological properties are also the basis of evapotranspiration parameterizations in physically based hydrological models. However, most current SVAT schemes and hydrological models do not parameterize vegetation as a Dynamic Component. The seasonal evolution of LAI is prescribed, and monthly LAI values are kept constant year after year. The effect of CO2 on the structure and physiological properties of vegetation is also neglected, which is likely to be important in transient climate simulations with increasing CO2 concentration and for hydrological models that are used to study climate change impact. The net carbon uptake by vegetation, which is the difference between photosynthesis and respiration, is allocated to leaves, stems, and roots. Carbon allocation to leaves determines their biomass and LAI. The timing of bud burst, leaf senescence, and leaf abscission (i.e., the phenology) determines the length of the growing season. Together, photosynthesis, respiration, allocation, and phenology, which are all strongly dependent on environmental conditions, make vegetation a Dynamic Component. This paper (1) familiarizes the reader with the basic physical processes associated with the functioning of the terrestrial biosphere using simple nonbiogeochemical terminology, (2) summarizes the range of parameterizations used to model these processes in the current generation of process-based vegetation and plant growth models and discusses their suitability for inclusion in SVAT schemes and hydrological models, and (3) illustrates the manner in which the coupling of vegetation models and SVAT schemes/hydrological models may be accomplished.
P.a. Wilsey - One of the best experts on this subject based on the ideXlab platform.
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Performance prediction of Dynamic Component substitutions
Proceedings of the Winter Simulation Conference, 2002Co-Authors: P.a. WilseyAbstract:The Web-based Environment for Systems Engineering (wese) is a Web-based modeling and simulation environment in which the level of abstraction of a model can be configured statically (prior to simulation) or Dynamically (during simulation) by substituting a module (set of Components) with an equivalent Component or vice versa through a process called Dynamic Component substitution (DCS). DCS can considerably improve the overall efficiency of simulations by enabling Dynamic tradeoffs between several modeling and simulation related parameters. However, identifying ideal sequence of DCS is a complicated task. This paper proposes a novel methodology called DCS performance prediction methodology (DCSPPM) to identify ideal sequences of DCS. DCSPPM utilizes estimates of the changes induced by each atomic DCS along with model characteristics to predict the changes induced by a combination of substitutions. Our studies indicate that the proposed methodology provides good estimates (maximum error
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Multi-resolution network simulations using Dynamic Component substitution
MASCOTS 2001 Proceedings Ninth International Symposium on Modeling Analysis and Simulation of Computer and Telecommunication Systems, 2001Co-Authors: P.a. WilseyAbstract:Modeling and simulation of large, high resolution network models is a time consuming task even when parallel simulation techniques are employed. Processing voluminous, detailed simulation data further increases the complexity of analysis. Consequently, the models (or parts of the models) are abstracted to improve performance of the simulations by trading-off model details and fidelity. However abstraction defeats the purpose of studying high resolution network models and magnifies the problems of validation! An alternative approach is to Dynamically (i.e., during the course of simulation) change the resolution of the model (or parts of the model). In our Component based network modeling and simulation framework (NMSF), we have enabled Dynamic changes to the resolution of a model using a novel methodology called Dynamic Component substitution (DCS). Using DCS, a set of Components can be substituted by a functionally equivalent Component (or vice versa) to change the resolution (or the level of abstraction) of a network model. DCS improves the overall efficiency of simulations through Dynamic tradeoffs between resolution of a model, simulation performance, and analysis overheads. This paper presents an overview of DCS and the issues involved in enabling DCS in NMSF, an optimistically synchronized parallel simulation framework. The experiments conducted to evaluate the effectiveness of DCS are also illustrated. Our studies indicate that DCS provides an effective technique to considerably improve the overall efficiency of network simulations.
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Dynamic Component substitution in Web-based simulation
2000 Winter Simulation Conference Proceedings (Cat. No.00CH37165), 2000Co-Authors: P.a. WilseyAbstract:Recent breakthroughs in communication and software engineering has resulted in significant growth of Web-based computing. Web-based techniques have been employed for modeling, simulation and analysis of systems. The models for simulation are usually developed using Component based techniques. In a Component based model, a system is represented as a set of interconnected Components. A Component is a well defined software module that is viewed as a black box, i.e., only its interface is of concern and not its implementation. However, the behavior of a Component, which is necessary for simulation, could be implemented by different modelers including third party manufacturers. Web-based simulation environments enable effective sharing and reuse of Components thereby minimizing model development overheads. In Component based simulations, one or more Components can be substituted during simulation with a functionally equivalent set of Components. Such Dynamic Component substitutions (DCS) provide an effective technique for selectively changing the level of abstraction of a model during simulation. It provides a tradeoff between simulation overheads and model details. It can be used to effectively study large systems and accelerate rare event simulations to desired scenarios of interest. DCS may also be used to achieve fault-tolerance in Web-based simulations. This paper presents the ongoing research to design and implement support for DCS in a Web-based Environment for Systems Engineering (WESE).
Hye Jin Choi - One of the best experts on this subject based on the ideXlab platform.
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a metal organic bilayer open framework with a Dynamic Component single crystal to single crystal transformations
Journal of the American Chemical Society, 2002Co-Authors: Jung Woo Ko, Hye Jin ChoiAbstract:A metal−organic bilayered open framework, [Ni2(C26H52N10)]3[BTC]4·6C5H5N·36H2O (BOF-1, 1), has been prepared by the self-assembly of a new bismacrocyclic nickel(II) complex [Ni2(C26H52N10)(Cl)4]·H2O (A) and sodium 1,3,5-benzenetricarboxylate (Na3BTC) in the mixture of water/DMSO/pyridine. The X-ray crystal structure of 1 shows that 2D layers with the cavities of brick-wall motifs (22.6 × 14.3 A2) are formed by the coordination of the nickel(II) complex with BTC3- ions and that the two 2D layers are linked with the p-xylyl bridging groups of the bismacrocycles as pillars to generate 3D channels in the bilayered framework. The voids of the channels occupy 61% of the total volume, which are filled with pyridine and water guest molecules. When 1 was dried at 75 °C for 1.5 h, [Ni2(C26H52N10)]3[BTC]4·4H2O (2) resulted by maintaining the single-crystallinity, which exhibited a dramatic decrease in the interlayer spacing as well as changes in the cell parameters. Solid 2 differentiates various alcohols such as Me...
Arvid Kappas - One of the best experts on this subject based on the ideXlab platform.
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Moving Smiles: The Role of Dynamic Components for the Perception of the Genuineness of Smiles
Journal of Nonverbal Behavior, 2005Co-Authors: Eva Krumhuber, Arvid KappasAbstract:Three experiments were conducted to examine whether the temporal Dynamics of Duchenne-smiles influenced the perception of smile authenticity. Realistic computer-generated Duchenne-smiles that varied in their onset- and offset-durations (Experiment 1), or only in their offset-duration (Experiment 2), or in both their onset- and apex-durations (Experiment 3), were created using Poser 4 software. Perceived genuineness varied monotonically with the duration of each manipulated Dynamic Component. The results are in accordance with Ekman and Friesen’s (1982) observations regarding the duration of smiles of enjoyment, which suggest that each Dynamic Component has a distinct duration range that can influence the perceived genuineness of smiles.
Frantisek Plasil - One of the best experts on this subject based on the ideXlab platform.
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DCUP: Dynamic Component Updating in Java/CORBA Environment
2020Co-Authors: Frantisek Plasil, Dušan Bálek, Radovan JanečekAbstract:In this paper, the authors present a novel architecture, called DCUP (Dynamic Component Updating), which allows for Dynamic Component updating at run time (Components are frameworks of objects). The following key problems of Dynamic Component updating are addressed: (1) making an update of a Component fully transparent to the rest of the application, (2) transition of state from the old to the new version of a Component, (3) transition of references which cross the Component boundary (in both directions), (4) Dynamic communication with a Component provider. In DCUP these problems are addressed by a small set of abstractions with a clear separation of their functionality. In contrast with the usual believe that it is difficult to map abstraction supporting Component based programming to concrete computer systems, the abstractions proposed by DCUP are very easy to map to the Java and CORBA programming environments.
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A language and framework for Dynamic Component ensembles in smart systems
International Journal on Software Tools for Technology Transfer, 2020Co-Authors: Tomas Bures, Frantisek Plasil, Ilias Gerostathopoulos, Petr Hnetynka, Filip Krijt, Jiri Vinarek, Jan KofronAbstract:Smart system applications (SSAs)—a heterogeneous landscape of applications of Internet of things, cyber-physical systems, and smart sensing systems—are composed of autonomous yet inherently cooperating Components. An important problem in this area is how to hoist the cooperation of software Components forming Dynamic groups—ensembles—at the architectural level of an SSA. This is hard since ensembles can overlap, be nested, and be Dynamically formed and dismantled based on several criteria. A related problem is how to combine Component and ensemble specification with a well-established language supported on multiple platforms. To target these problems, we propose a specification and implementation language Trait-based Component Ensemble Language (TCOEL) based on Scala internal DSL, to describe both the architecture and formation of Dynamic ensembles of Components and their functional internals. To raise the level of expressivity, we introduce the concept of domain-specific extensions (traits) to the TCOEL core to reflect different paradigms’ concerns—such as movement in a 2D map, state-space modeling of physical processes, and statistical reasoning about uncertainty. This allows for configuring TCOEL for the needs of a specific SSA use case and, at the same time, facilitates reuse. To evaluate TCOEL, we show how it can be beneficially used in addressing the coordination of agents in a RoboCup Rescue Simulation application.
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sofa dcup architecture for Component trading and Dynamic updating
Cooperative Distributed Systems, 1998Co-Authors: Frantisek Plasil, Dušan Bálek, Radovan JanečekAbstract:In this paper the authors address some of the challenges of the current technologies in the area of Component-based programming and automated software downloading. These challenges include: Component updating at runtime of affected applications, adopting the "true-push" model in order to allow for silent software modification (e.g., for removing minor implementation errors), and finding a way to integrate these technologies and electronic commerce in software Components. To respond to these challenges, the SOFA (SOFtware Appliances) architecture, the SOFA Component model and its extension, DCUP (Dynamic Component UPdating), are introduced. SOFA and DCUP provide a small set of well scaling orthogonal abstractions (easily mapped to Java and CORBA) which address three areas: the background for electronic commerce, the Component model, and support for Dynamic Component updating in running applications. The updating granularity can scale anything from minor implementation changes to a major reconfiguration.
