381 research outputs found

    Air passenger demand forecasting and passenger terminal capacity expansion: A system dynamics framework

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    This paper deals with how to develop a model to forecast air passenger demand and to evaluate some policy scenarios related with runway and passenger terminal capacity expansion to meet the future demand. System dynamics frameworks can be used to model, to analyze and to generate scenario to increase the system performance because of its capability of representing physical and information flows, based on information feedback control that are continuously converted into decisions and actions. We found that airfare impact, level of service impact, GDP, population, number of flights per day and dwell time play an important roles in determining the air passenger volume, runway utilization and total additional area needed for passenger terminal capacity expansion

    Dynamic Simulation Of Air Cargo

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    This paper establishes an approach to forecast air cargo demand related to terminal capacity expansion. To balance capacity and demand, it is required to forecast the future demand based on optimistic and pessimistic projections to decide when and how much, the airport should expand the capacity. System dynamics simulation model can provide reliable forecast and generate scenarios to test alternative assumptions and decisions. It was found that GDP and FDI play an important role in fostering the demand. Terminal expansion would be required in 2014 and 2021 at the optimistic projection; meanwhile, based on pessimistic projection, capacity should be expanded in 2025

    Demand scenario analysis and planned capacity expansion: A system dynamics framework

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    This paper establishes an approach to develop models for forecasting demand and evaluating policy scenarios related to planned capacity expansion for meeting optimistic and pessimistic future demand projections. A system dynamics framework is used to model and to generate scenarios because of their capability of representing physical and information flows, which will enable us to understand the nonlinear dynamics behavior in uncertain conditions. These models can provide important inputs such as construction growth, GDP growth, and investment growth to specific business decisions such as planned capacity expansion policies that will improve the system performance

    A Methodology for Modeling, Performance Analysis, and Control of ATM Networks with Multi-Media Traffic

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    In this paper we review recent advances in developing a methodology for traffic modeling, performance evaluation, and control of ATM networks that can be used to support several aspects of Task 4.3 of the ATIRP project. Our methodology includes model matching and validation for multi-media traffic, analytical approximation techniques for time-efficient and accurate evaluation of end-to-end as well as intermediate node performance measures of multi-hop networks, and optimization of control (resource allocation) schemes

    Genetic analysis of fish iridoviruses isolated in Taiwan during 2001–2009

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    To investigate the genetic relationships between field strains of iridoviruses gathered from various fish species in Taiwan, viruses that were collected from 2001 to 2009 were analyzed. Open reading frames encoding the viral major capsid protein (MCP) and adenosine triphosphatase (ATPase) were sequenced for phylogenetic analysis. Our results indicated that iridoviruses from Taiwan aquaculture fishes could be classified into two groups: prior to 2005, the viruses were closely related to members of the genus Ranavirus; and after 2005, they were similar to members of the genus Megalocytivirus. Based on the analysis of MCP amino acid sequences, virus isolates were divided into 4 major genotypes that were related to ISKNV, RSIV, FLIV, and GIV, respectively. Pairwise comparisons of MCP genes showed that the ranavirus was an epidemic pathogen for economically important species in the major production regions and cultured marine fish, while the megalocytivirus isolates were sensitive to host range. In addition, the distribution of synonymous and non-synonymous changes in the MCP gene revealed that the iridoviruses were evolving slowly, and most of the variations were synonymous mutations. The Ka/Ks values were lower than one, and hence, the viruses were under negative selection

    Engineering of Escherichia coli protein expression process development

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    It almost 30% protein drugs are expression by Escherichia coli, because of rapid growth and high production yield. We have developed E.coli base system for recombinant protein expression, scFv, Fab and vaccine. In this study we introduce example about process development for nutrient components selection. Shaker flasks were used for different nitrogen and carbon components screening by DoE. Seven media formulations for E. coli fermentation were used in this study. By changing nitrogen and carbon source ratio, product titer of target protein could be optimized, at least 1.4 folds increased. The best result from shaker flask was used in 250 mL parallel fermenter and pH, dissolved oxygen, feeding/induction strategy were evaluated. The processes from seed culture to harvest only require 64 hours. The optimized time was reduced to 32 hours. The result showed that both target protein expression and cell density value were comparable, but the total process time was significantly reduced by half Please click Additional Files below to see the full abstract

    Tau Polarizations in the Three-body Slepton Decays with Stau as the NLSP

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    In the gauge-mediated supersymmetry breaking models with scalar tau as the next-to-lightest supersymmetric particle, a scalar lepton may decay dominantly into its superpartner, tau lepton, and the lightest scalar tau particle. We give detailed formulas for the three-body decay amplitudes and the polarization asymmetry of the outgoing tau lepton . We find that the tau polarizations are sensitive to the model parameters such as the stau mixing angle, the neutralino to slepton mass ratio and the neutralino mixing effect.Comment: 13 pages, 5 figures, RevTe

    Butterfly-shaped Dibenz[a,j]anthracenes: Synthesis and photophysical properties

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    A strategy for the synthesis of dibenz[a,j]anthracenes (DBAs) from cyclohexa-2,5-diene-1-carboxylic acids is presented. Our approach involves sequential C–H olefination, cycloaddition, and decarboxylative aromatization. In the key step for DBA skeleton construction, the bis-C–H olefination products, 1,3-dienes, are utilized as substrates for [4 + 2] cycloaddition with benzyne. This concise synthetic route allows for regioselective ring formation and functional group introduction. The structural features and photophysical properties of the resulting DBA molecules are discussed
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