Budget Profiles Research Articles

Turbulence in a wall-wake flow downstream of two horizontal cylinders

Experimental investigations of flow past two (one above other) horizontal cylinders have been presented in this paper. The experimental data captured over a rough-bed with double cylinders having three different diameters, were used for the analysis. Firstly, general characteristics such as streamwise velocity, Reynolds shear stress and turbulence intensity profiles have been elucidated at different downstream locations from cylinder position; then some advanced analysis such as length scales, turbulent kinetic energy (TKE) fluxes and budget have been investigated to exhibit their variations. Length scale profiles exhibit higher values in near bed; indicating comparatively larger eddies’ downstream of both cylinders. TKE budget profiles indicate highly negative pressure energy diffusion rate together with a sufficient TKE production rate, stabilized by the amplified TKE diffusion and dissipation rates. To determine one of the most prime behaviors of turbulence characteristics, namely TKE dissipation rate more accurately, the concept of structure function has been employed. Primarily velocity gradient method elucidates TKE dissipation rate, then it has been verified by Kolmogorov’s two-thirds law using second order structure function and Kolmogorov’s − 5/3 law using the method of power spectra.

Measuring public preferences for government spending under constraints: a conjoint-analytic approach

ABSTRACT Governmental budgets and the priorities they reflect are the subjects of recurring political debate. Research on political representation commonly focuses on relative spending preferences, mostly in isolated domains that are unconstrained, and so provides only limited information about people’s preferences. Recent survey work considers the effects of asking about absolute spending levels in different substantive areas and in the face of revenue constraints. No studies do all three, though two studies get close and provide more fine-grained measures of preferences for spending change. We follow their lead but in a more general way, offering budget profiles that include increases as well as decreases in spending levels, embedded in a conjoint experiment in Sweden. Our results reveal that people appear to hold preferences on specific magnitudes of spending change, budgetary constraints matter, and the effects of increases and decreases in spending are not symmetrical. Although the implied preferences for spending are similar in direction to expressed relative preferences that are unconstrained, the levels of support across domains are different. The findings have implications for assessments of opinion representation, as inferences about the responsiveness of policy to preferences – and the congruence between them – differ depending on measurement of the latter.

Defining project performance standards as parameters of the compliance risk regulatory system

Subject. This article discusses the problem of choosing the standards of project time and cash expenditures, taking into account their randomness. Objectives. The article aims to describe the task of setting standards for the values of project time and budget profiles, taking into account compliance risk, and analyze the dependence of the effectiveness of project profile norm setting on the compliance risk level. Methods. For the study, we used the methods of probability theory, mathematical statistics, and dynamic programming. Results. The article formulates a problem of project profile norm setting, taking into account compliance risk, and provides an algorithm for dynamic programming to establish standards and oversizes corresponding to risk appetite. It shows an example of the calculation of these design characteristics, where at each stage of the project there are fourteen types of independent random factors that negatively affect the costs of the project. The article also describes the dependence of efficiency and additional regulatory costs for managing compliance risk on the risk level. Conclusions. The task of project costs norm setting based on a risk-oriented approach is formulated and solved on the basis of the dynamic programming method. This can be used to design a compliance risk management system. For the example considered, we identify areas of unacceptable, acceptable and negligible risks.

Global coastal low‐level wind jets revisited through the new ERA5 reanalysis

AbstractThe recent ECMWF (European Centre of Medium‐Range Weather Forecasts) reanalysis product (ERA5) is a 3D‐atmospheric dataset of unparalleled value to advance the characterization and understanding of the main global coastal low‐level jet (CLLJ) systems, due to its finer resolution (horizontal and vertical) and hourly output. Regional climate studies have revealed the added value of higher spatial and temporal resolutions of models and reanalyses for the representation of CLLJs, which play an important role in the definition of the regional climate along the Eastern Boundary Current Systems. ERA5 reveals an improvement in the representation of the wind speed and temperature vertical profiles within the boundary layer in CLLJ regions. This improvement enables a better representation of CLLJs and therefore a new view on their features. ERA5 show larger CLLJ frequencies of occurrence and larger wind speed intensities, when compared with previous reanalysis. The maximum frequency of occurrence ranges from 20% in the West Australian and 73% in the Oman CLLJs, in the summer season, which constitutes an increase of 10% compared to ERA‐Interim. Moreover, a shift for higher wind speeds is also found, where the maximum wind speed approach 30 m·s−1. Typically, CLLJs are found below 500 m above sea level, where the finer vertical discretization results clearly in a better description of the CLLJ peak height. Regarding the diurnal cycles of CLLJs frequency of occurrence, ERA5 exposes higher peaks and larger amplitudes, where the maximum hourly frequency is about 38% in the Oman CLLJ and the diurnal amplitude can vary between 7 and 14%. The diurnal maximum and minimum frequency of CLLJ occurrence can be found between 1900 and 2200 UTC, and between 1000 and 1400 LST, respectively. The momentum and temperature budget profiles reveal significant differences between CLLJ regions and emphasize the relevance of local processes in its occurrences.

Discrete anisotropic radiative transfer modelling of solar-induced chlorophyll fluorescence: Structural impacts in geometrically explicit vegetation canopies

Solar-induced fluorescence (SIF) is a subtle but informative optical signal of vegetation photosynthesis. Remotely sensed SIF integrates environmental, physiological and structural changes that alter photosynthesis at leaf, plant and canopy scales. Radiative transfer models are ideally suited to investigate the complex sources of variability in the SIF signal to guide the interpretation of SIF retrievals from airborne and space-borne platforms. Here, we coupled the Fluspect-Cx model of leaf optical properties and chlorophyll-a fluorescence with the Discrete Anisotropic Radiative Transfer (DART) model to upscale SIF from individual leaves to three-dimensional (3D) structurally explicit canopies. For one-dimensional homogeneous (turbid-like) canopies, DART-SIF was nearly identical to SIF simulated in two existing models, SCOPE and mSCOPE (RMSE <0.221 W.m−2.μm−1.sr−1). DART simulations in geometrically explicit 3D canopies offered four important insights regarding the influence of vegetation structure on the multi-angular top-of-canopy SIF signal. First, changes in the 3D canopy architecture of maize crops, represented by leaf density (leaf area index), and plant clumping (canopy closure) had a larger impact on SIF than the modelled photosynthetic efficiency distinction between sun-adapted and shade-adapted foliage. Second, clumping of leaves at the crop and stand levels was identified as one of the key driving factors of multi-angular anisotropy of red and far-red SIF (686 and 740 nm) for both maize and eucalyptus canopies. Third, non-photosynthetic woody material had a significant impact on top-of-canopy SIF in modelled 3D forest stands. Wood shadowing decreased the photosynthetically active radiation absorbed by green leaves, and consequently the SIF emissions, by 10% in sparse and 17% in dense eucalyptus stands. The wood obstruction (blocking) effect, quantified as a relative difference of SIF escape probabilities from canopies with and without wood in the nadir viewing direction, decreased far-red SIF by 4–6% but it had a smaller and sometimes positive influence (by less than 2%) on red SIF. Fourth, DART 3D radiative budget profiles revealed that the majority of the SIF signal from a dense eucalyptus stand originated from the top 25% of the simulated canopy. Interestingly, the introduction of bark-covered woody elements did not alter the simulated balance and omnidirectional escape factor of red SIF in this upper canopy part but did raise significantly both of them in case of far-red SIF. These results demonstrate the importance of 3D radiative transfer and radiative budget simulations for investigating SIF interactions in structurally complex plant canopies and for a better understanding of spatiotemporal and multi-angular remote sensing SIF observations.

Mars habitat power consumption constraints, prioritization, and optimization

The Hawai'i Space Exploration Analog and Simulation (HI-SEAS) is an experiment simulating long-duration life in a Mars habitat. Power for the habitat is generated by a photovoltaic system that exhibits daily variation in production rates. During days with cloud cover, the crew need to adapt their work schedule and support systems to ensure they can continue to function under low-power constraints. This paper accordingly presents the development and implementation of power budget profiles for low-, medium-, and high-power production days during Mission 5 of the HI-SEAS experiment. The applied power budget profiles limit which systems and devices can be used and for what duration. To generate these profiles, the HI-SEAS power subsystem was first characterized though power audits and data from daily crew use trends. The methods used to determine a prioritized list of habitat equipment for crew-member usage and compliance with restrictions are then discussed. Finally, an optimization method is proposed to determine the most efficient schedule to match each power usage profile with respect to crew preferences. The data from this experiment provide a novel opportunity to gain insight into power usage in space exploration habitats, establishing a foundation for the development of proper power generation and management technologies. Thus, this research can be used to provide meaningful guidance to most manned space systems in ensuring optimal power consumption under a variety of power generation conditions.

Solar and thermal radiation profiles and radiative forcing measured through the atmosphere

Solar shortwave and thermal longwave radiation at the Earth's surface and at the top of the atmosphere is commonly measured at surface stations, from airplanes and from satellites. Here we show radiative flux profiles measured with radiosondes ascending from the Earth's surface to 35 km into the stratosphere. During two‐hour flights solar shortwave and thermal longwave radiation are measured both downward and upward with four individual sensors. Daytime solar and thermal radiation is compared to nighttime measurements and 24‐hour average radiation budget profiles are shown through the atmosphere. However, of even greater importance with regard to climate change are measured upward and downward longwave greenhouse radiation profiles. Their changes with temperature and water vapor enable direct measurement of radiative forcing through the atmosphere. Measurements during two cloud‐free nights with different temperature and different water vapor amount, show an almost equal but opposite net longwave radiation change, or water vapor greenhouse forcing, downwards to the surface and upward into space. Radiative flux profiles clearly illustrate the Earth's atmospheric greenhouse effect, and allow important investigations of clouds and other atmospheric constituents and their effects on shortwave reflection, as well as longwave emission towards the surface and into space.

Explaining Variation in Patterns of Fiscal Consolidation

The comparative study of debt and fiscal consolidation has acquired a new focus with the re-emergence of debt as a major problem consequent upon the global financial crisis. This leads us to re-evaluate the literature on fiscal consolidation that flourished during the 1980s and 1990s. We identify two broad schools of analysis, one which segments episodes of fiscal change into discrete observations, the other comparing budget profiles at two points in time. We argue that both strategies miss the dynamic features of government strategy, especially in the choices made between expenditure-based and revenue-based fiscal consolidation strategies. We propose a focus on pathways rather than episodes of adjustment, to recapture what Pierson terms ‘politics in time.’ We draw on classical explanatory tools of comparative political economy, including structures of interest intermediation, the role of ideas in shaping the set of feasible policy choices, and the situation of national economies in the international political economy. We support our argument with qualitative data based on paired comparisons of Ireland and Britain, and Greece and Spain.

Consequences of Urban Stability Conditions for Computational Fluid Dynamics Simulations of Urban Dispersion

Abstract The validity of omitting stability considerations when simulating transport and dispersion in the urban environment is explored using observations from the Joint Urban 2003 field experiment and computational fluid dynamics simulations of that experiment. Four releases of sulfur hexafluoride, during two daytime and two nighttime intensive observing periods (IOPs), are simulated using the building-resolving computational fluid dynamics model called the Finite Element Model in 3-Dimensions and Massively Parallelized (FEM3MP) to solve the Reynolds-averaged Navier–Stokes equations with two options of turbulence parameterizations. One option omits stability effects but has a superior turbulence parameterization using a nonlinear eddy viscosity (NEV) approach, and the other considers buoyancy effects with a simple linear eddy viscosity approach for turbulence parameterization. Model performance metrics are calculated by comparison with observed winds and tracer data in the downtown area and with observed winds and turbulence kinetic energy (TKE) profiles at a location immediately downwind of the central business district in the area labeled as the urban shadow. Model predictions of winds, concentrations, profiles of wind speed, wind direction, and friction velocity are generally consistent with and compare reasonably well to the field observations. Simulations using the NEV turbulence parameterization generally exhibit better agreement with observations. To explore further the assumption of a neutrally stable atmosphere within the urban area, TKE budget profiles slightly downwind of the urban wake region in the urban shadow are examined. Dissipation and shear production are the largest terms that may be calculated directly. The advection of TKE is calculated as a residual; as would be expected downwind of an urban area, the advection of TKE produced within the urban area is a very large term. Buoyancy effects may be neglected in favor of advection, shear production, and dissipation. For three of the IOPs, buoyancy production may be neglected entirely; for one IOP, buoyancy production contributes approximately 25% of the total TKE at this location. For both nighttime releases, the contribution of buoyancy to the total TKE budget is always negligible though positive. Results from the simulations provide estimates of the average TKE values in the upwind, downtown, downtown shadow, and urban wake zones of the computational domain. These values suggest that building-induced turbulence can cause the average turbulence intensity in the urban area to increase by as much as 7 times average upwind values, explaining the minimal role of buoyant forcing in the downtown region. The downtown shadow exhibits an exponential decay in average TKE, whereas the distant downwind wake region approaches the average upwind values. For long-duration releases in downtown and downtown shadow areas, the assumption of neutral stability is valid because building-induced turbulence dominates the budget. However, farther downwind in the urban wake region, which is found to be approximately 1500 m beyond the perimeter of downtown Oklahoma City, Oklahoma, the levels of building-induced turbulence greatly subside, and therefore the assumption of neutral stability is less valid.

Contrasting Characteristics of Convection over the Northern and Southern South China Sea during SCSMEX

Abstract Observations from two enhanced sounding arrays during the May–June 1998 South China Sea Monsoon Experiment (SCSMEX) are used to determine and contrast the properties of convection over the northern and southern South China Sea (SCS). A regression analysis between SST data and monthly rainfall indicates that the ENSO signal exerted a strong influence on the rainfall distribution over the SCS during SCSMEX. This resulted in wetter-than-normal conditions along the south China coast and northern SCS, and generally drier-than-average conditions elsewhere, particularly over the Philippine Islands. The monsoon onset as determined by a shift in the low-level winds from easterly to southwesterly over the SCS occurred around mid-May. Over the southern enhanced sounding array (SESA), the onset was characterized by a rainy period associated with the passage of a convectively coupled Kelvin wave. This was followed by a weeklong break and then several episodic rain events with increasingly higher rain rates. Rainfall over the northern enhanced sounding array (NESA), which was largely out of phase with SESA rainfall events, occurred primarily during two 10-day periods separated by a weeklong break. Convective characteristics over the SESA, deduced primarily from heat and moisture budget profiles, indicate a high stratiform rain fraction consisting of alternating periods with decaying mesoscale systems that organized near the western Borneo coastline and shallower convective clouds. In contrast, NESA-averaged profiles were indicative of deep convection with a relatively small stratiform rain fraction, which was confirmed with radar analyses during the onset convective period. The diurnal cycle of convection is a dominant feature throughout much of the SCS. Over both budget regions, early morning (0500–0800 LT) convective systems were frequently initiated near the coasts, then gradually dissipated during the course of the day as the midlevel steering currents moved the systems away from the coastline. These decaying convective systems resulted in an early afternoon (1400 LT) rainfall peak over both sonde arrays.

Measuring turbulence energy with PIV in a backward-facing step flow

Turbulence energy is estimated in a backward-facing step flow with three-component (3C, stereo) particle image velocimetry (PIV). Estimates of turbulence energy transport equation for convection, turbulence transport, turbulence production, viscous diffusion, and viscous dissipation in addition to Reynolds stresses are computed directly from PIV data. Almost all the turbulence energy terms in the backward-facing step case can be measured with 3C PIV, except the pressure-transport term, which is obtained by difference of the other turbulence energy terms. The effect of the velocity spatial sampling resolution in derivative estimations is investigated with four two-dimensional PIV measurement sets. This sampling resolution information is used to calibrate the turbulence energies estimated by 3C PIV measurements. The focus of this study is on the separated shear layer of the backward-facing step. The measurements with 3C PIV are carried out in a turbulent water flow at Reynolds number of about 15,000, based on the step height h and the inlet streamwise maximum mean velocity U 0. The expansion ratio (ER) is 1.5. Turbulence energy budget profiles in locations x/h=4, x/h=6, and x/h=10 are compared with DNS data of a turbulent flow. The shapes of profiles agree well with each other. Different ERs between the PIV case (1.5) and the DNS case (1.2) cause higher values for the turbulence energies measured by PIV than the energies by DNS when x/h=10 is approached. PIV results also show that the turbulence energy level in these experiments is generally higher than that of the DNS data.

Weibull-Based Forecasting of R&amp;D Program Budgets

Abstract Norden (1970) demonstrates that the Rayleigh function can model manpower on research and development (R&D) programs. Several research efforts extend his work to modeling R&D program expenditures. The Rayleigh distribution, which is a degenerative of the Weibull distribution, suffers from two theoretical limitations that make the Weibull function a better model for R&D program expenditures. Using 128 completed R&D programs, we develop regression models to predict the requisite Weibull scale and shape parameters. To determine the Weibull model's budget profile forecasting capability, we compare the completed R&D program budget profiles to Weibull modeled budget profiles and report an average correlation of 0.607. To determine the significance of our results we compare the same 128 completed program budget profiles to Rayleigh modeled budget profiles. Using the Weibull in lieu of the Rayleigh model we improve initial budget profile projections on average 60 percent.

The Relationship between Cost Analysis and Program Management

Abstract Cost analysis is often viewed as applying basic principles and cost methodologies to determine total system cost. These finished estimates then flow into a decision making process and the cost estimator leaves the stage. Reality shows that the cost estimator is actually one of the main contributors to the decision making process. Our introduction to this special issue explores the areas where cost estimating plays a major role in program management in areas beyond the normal program estimate. We have included articles that show the key role cost estimators can play in source selection strategies and evaluation; cost of delay analysis for management decisions, earned value management methods to predict program costs; decision criteria to rank competing projects that complement traditional cost-based methods; and a new methodology for determining research and development budget profiles.

Approximation of the Cost Effect from Business Base Changes

Abstract Cost analyses often ignore the effects of changes in the business base in estimating the costs of large development and production programs. These effects, however, may be significant, not just for the program being changed, but also for other programs produced by the same contractors. Indeed, these effects are important when dramatic reductions occur in the defense budget. The pattern of inter-locking subcontracted arrangements causes the business base effects to ripple through the defense industrial base and complicates assessment of the effects of program scope changes. This paper presents a coarse method for approximating the implications of program scale changes on both prime and major subcontractors that is relatively easy to apply. The method begins with budget profiles that form a base case for the programs of interest and for the other programs in the industrial sector. From the base case, we estimate contractors' revenues, specifically variable (direct plus variable indirect) costs and fixed costs. The model indicates how the fixed costs may be reallocated for revised budgets. If fixed costs equal 15 percent of the firms' variable costs, which is about the historical average for several defense firms, our model suggests budget reductions result in cost increases totaling about 20 percent of the budget reduction in the remaining programs produced by the same contractors. This cost effect occurs in the first year of a change; data indicate that the effect rapidly diminishes as we project into the future.

Turbulence Kinetic Energy Budget Profiles Derived from Doppler Sodar Measurements

Abstract Doppler sodar wind measurements made in light wind conditions in September 1979 near a power plant in Turbigo, Italy, are used to derive terms in the turbulence kinetic energy (TKE) budget. Measurements on five days are grouped into two classes: fair-weather conditions and boundary layer interaction with subsiding air. Profiles of σ3w/z are used to obtain the surface heat flux and the vertical velocity scaling parameter, as well as the buoyancy production term in the TKE budget. The vertical transport of TKE is derived from the profiles of (w′)3. The horizontal components are approximated using a parameterization based on the data of Lenschow et al. Dissipation in the TKE budget is obtained from a spectral analysis of the Doppler sodar data in the inertial subrange. The resulting TKE budget profiles for the two classes are compared with budgets obtained previously, using a number of different methods.

Changes in water level at Lake Vanda, Antarctica

Summary Work already done and that proposed at Lake Vandia is outlined. Water‐level measurements are not indicative of total river inflow, as summer saturation of grounded porous ice temporarily lowers the lake level; for accurate inflow measurements, construction of a weir at the river mouth is planned. To calculate the total lake budget, density and temperature profiles of the ice cover and knowledge of evaporation rates are needed.