GEMPAK5 user's guide, version 5.0

GEMPAK is a general meteorological software package used to analyze and display conventional meteorological data as well as satellite derived parameters. The User's Guide describes the GEMPAK5 programs and input parameters and details the algorithms used for the meteorological computations

Discrete Choice Models for Revenue Management

In the transportation field, the shift of airline and railway industries toward web-based distribution channels has provided passengers with better access to fare information. This has resulted in passengers becoming more strategic to price. Therefore, a better understanding of passenger choice behavior is required in order to support fare strategies. Methods based on discrete choice (DC) analysis have recently been introduced in revenue management (RM). However, applications of DC models in railway ticket pricing are limited and heterogeneity in choice behavior across different categories of travelers has mostly been ignored. Differences in individual taste are crucial for the RM sector. Additionally, strategic passenger behavior is significant, especially in markets with flexible refund and exchange policy, where ticket cancellation and exchange behavior has been recognized as having major impacts on revenues. This dissertation examines innovative approaches in discrete choice modeling to support RM systems for intercity passenger railway. The analysis, based on ticket reservation data, contributes to the existing literature in three main aspects. Firstly, this dissertation develops choice models of ticket purchase timing which account for heterogeneity across different categories of passengers. The methodology based on latent class (LC) and mixed logit (ML) model framework offers an alternative approach to demand segmentation without using trip purposes which are not available in the data set used for the analysis. Secondly, this dissertation develops RM optimization models which use parameters estimated from the choice models and demand functions as key inputs to represent passenger response to RM policy. The approach distinguishes between leisure and business travelers, depending on departure time and day of week. The formulated optimization problem maximizes ticket revenue by simultaneously solving for ticket pricing and seat allocation. Strategies are subjected to capacity constraints determined on the basis of the railway network characteristics. Finally, this dissertation develops ticket cancellation and exchange model using dynamic discrete choice model (DDCM) framework. The estimated model predicts the timing of ticket cancellations and exchanges in response to trip schedule uncertainty, fare, and refund/exchange policy of the railway service. The model is able to predict new departure times of the exchanged tickets and covers the full range of departure time alternatives offered by the railway company

Topology Optimized Reinforced Concrete Walls Constructed with 3D Printed Formwork

The construction industry continually evolves to adapt to gains in knowledge, market pressures and new technologies. However, two promising new technologies, 3D printing and computational topology optimization, have not yet penetrated the civil engineering industry despite being important drivers of change in other fields. The aim of this study was the potential to overcome the major barriers to adoption of both technologies by using them in combination. Both theoretical and practical problems must still be addressed, but the potential impacts are significant: lightweight, architecturally pleasing, reduced volume structures. Two small-scale specimens were constructed and tested to demonstrate the feasibility of using additively manufactured (3D printed) formwork to construct complex reinforced concrete (RC) structures. The concept was shown to be viable. Areas were identified where further development is necessary before 3D printing can be used for large-scale cost-competitive formwork. An approach, based on the rule of mixtures, was proposed for applying computational topology optimization to RC structures. This was necessary because the computational topology optimization algorithm employed in this study assumes a structure is homogenous but RC structures are not. The approach was shown to work for optimizing an RC wall for force demands within the linear-elastic range of response. The sensitivity of optimization outputs to modeling parameters was investigated. The effects and interdependencies of mesh size, element type, number of optimization cycles, and target volume ratio on optimization outcome were demonstrated. The importance of ISO and “percent reduction” parameters on the process of importing the optimized geometry to ABAQUS was also demonstrated. Finally, a parametric study was conducted to examine the relationships between volume ratio and member strength and stiffness (volume ratio refers to the volume of the optimized structure divided by the volume of the original structure). The study used finite element models of topology optimized slender structural walls subjected to pseudo-static lateral force. It was shown that reductions in volume are not proportional to reductions in stiffness, as expected for slender walls that are flexure-dominated. Reductions in volume of 10 to 20% cause only approximately 3 to 7% reductions in uncracked member stiffness. These reductions in stiffness can be compensated for with use of modestly higher-strength concrete

Planning of PEVs Parking Lots in Conjunction With Renewable Energy Resources and Battery Energy Storage Systems

The last few decades have seen growing concerns about climate change caused by global warming, which is cause primarily by CO2 emissions. Thus, the reduction of these emissions has become critically important. One of the effective methods for achieving this goal is to shift towards green electricity energy resources and green vehicles in transportation. For these reasons, the goal of the work presented in this thesis was to address the challenges associated with the planning of plug-in electric vehicles (PEVs) parking lots in combination with renewable energy sources (RES) and battery energy storage systems (BESS) in power distribution networks. This thesis introduces a new planning technique that aims to minimize the overall capital and operational costs, taking into consideration the operational aspects of distribution networks, such as 1) coordinated PEV charging, 2) smart inverter control of renewable distributed generation (DG) units, and 3) smart scheduling of BESS. Moreover, a new model for the PEV coordinated charging demand is introduced in this work. Due to the complexity of the proposed planning approach, a combination between metaheuristic technique and deterministic optimization techniques have been utilized to manage both the planning and operational aspects respectively

Nesting success and nest site characteristics of four thrush species on a managed forest

Four thrush species breed sympatrically in the Allegheny Mountain region of West Virginia, U.S.A.: American Robin (Turdus migratorius), Hermit Thrush (Catharus guttatus), Veery (Catharus fuscescens), and Wood Thrush (Hylocichla mustelina). How nesting habitat is partitioned among the species is unclear, as is the effect of logging activities on the guild. My objectives were to identify nesting habitat characteristics that are partitioned among the species and to determine their effects on nest survival.;I conducted point count surveys and monitored nests of four thrush species on a managed forest. I measured habitat variables at three scales: (1) nest substrate, (2) nest site, and (3) territory. I also measured nest site variables at paired, random plots. Using GIS software, I then digitized land cover into five forest land covers based on harvesting practices.;Habitat partitioning among the four thrush species occurred at all three scales sampled, and the most important partitioning variables included nest height, distance to edge, sapling density, and elevation. Wood Thrushes occurred more often than would be expected in deciduous partial harvests, increased in occurrence as the percent of partial harvests increased on the landscape, and had higher nest survival in partially harvested stands than they did in mature forest. In contrast, the other three species selected against deciduous partial harvests and had lower nest survival within them than they did in mature forest. Hermit Thrushes selected for mature mixed forest and selected against mature deciduous forest, even-aged harvests, and harvested edges. American Robins, Veeries and Wood Thrushes did not avoid the edges of even-aged harvests, and nested within harvested stands beginning at four years post-harvest.;For the American Robin, Veery, and Wood Thrush, nest survival was highest in even-aged harvests; and for all but the Wood Thrush, it was lowest in partial harvests and intermediate in mature forest. Most of the variables I measured were unrelated to survival; thus, the guild appears to be partitioning the available habitat successfully and to be tolerant of forest disturbance at its current intensity

Driver-pressure-impact and response-recovery chains in European rivers: observed and predicted effects on BQEs

The report presented in the following is part of the outcome of WISER’s river Workpackage WP5.1 and as such part of the module on aquatic ecosystem management and restoration. The ultimate goal of WP5.1 is to provide guidance on best practice restoration and management to the practitioners in River Basin Management. Therefore, a series of analyses was undertaken, each of which used a part of the WP5.1 database in order to track two major pathways of biological response: 1) the response of riverine biota to environmental pressures (degradation) and 2) the response of biota to the reduction of these impacts (restoration). This report attempts to provide empirical evidence on the environment-biota relationships for both pathways

Verification and Comparison of Polar MM5 and AFWA MM5 Forecasts over Alaska

This research compares biases of the Reisner Mixed-Phase Explicit Moisture Microphysics graupel and non-granpel schemes to determine if including graupel and riming processes within the Fifth Generation Mesoscale Model (MM5) will lead to improved forecasts of winter precipitation for Korea and Japan. MM5 forecasts were generated every 12 hours for a 20 days case period from January 1998. Model derived meteorological fields were interpolated to the station coordinates of four verification sites within the East Asian domain and radiosonde observations were used to compare the differences between the average temperature and water vapor errors of the two cloud microphysics schemes. Analysis of the results shows significant differences between the schemes in the magnitude of humidity errors within the lower atmosphere of the model and provides evidence that the more complicated graupel and riming scheme will not increase the skill of the MM5 in forecasting winter precipitation for Japan and Korea. The underlying conclusion of this research is that AFWA should not alter the cloud microphysics scheme currently employed to determine winter precipitation type for its East Asian forecast window

Route Planning in Transportation Networks

We survey recent advances in algorithms for route planning in transportation networks. For road networks, we show that one can compute driving directions in milliseconds or less even at continental scale. A variety of techniques provide different trade-offs between preprocessing effort, space requirements, and query time. Some algorithms can answer queries in a fraction of a microsecond, while others can deal efficiently with real-time traffic. Journey planning on public transportation systems, although conceptually similar, is a significantly harder problem due to its inherent time-dependent and multicriteria nature. Although exact algorithms are fast enough for interactive queries on metropolitan transit systems, dealing with continent-sized instances requires simplifications or heavy preprocessing. The multimodal route planning problem, which seeks journeys combining schedule-based transportation (buses, trains) with unrestricted modes (walking, driving), is even harder, relying on approximate solutions even for metropolitan inputs.Comment: This is an updated version of the technical report MSR-TR-2014-4, previously published by Microsoft Research. This work was mostly done while the authors Daniel Delling, Andrew Goldberg, and Renato F. Werneck were at Microsoft Research Silicon Valle