851 resultados para change impact
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In this paper we measure the impact of regulatory measures which affected the Spanish electricity wholesale market in the period 2002-2005. Our approach is based on the fact that regulation changes firms' incentives and therefore their market behavior. In the absence of any regulation firms would choose profit- maximizing prices on their residual demands so that the observed gap between optimal and actual prices provides a measure of the effect of regulation. Our results indicate that regulation has decreased wholesale prices considerably, but became less effective at the end of the sample period which explains the change of regulatory regime introduced in 2006.
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The paper investigates whether the growing GDP share of the services sector can contribute to explain the great moderation in the US. We identify and analyze three oil price shocks and use a SVAR analysis to measure their economic impact on the US economy at both the aggregate and the sectoral level. We find mixed support for the explanation of the great moderation in terms of shrinking oil shock volatilities and observe that increases (decreases) in oil shock volatilities are contrasted by a weakening (strengthening) in their transmission mechanism. Across sectors, services are the least affected by any oil shock. As the contribution of services to the GDP volatility increases over time, we conclude that a composition effect contributed to moderate the conditional volatility to oil shocks of the US GDP.
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From a manager’s perspective, oftentimes the publicly held concerns related to small docks and piers are not really related to the environment. They may be more related to visual impacts and aesthetic concerns, a sense of over-development of the shore, or simply change. While individuals may hold personal aesthetic values related to small docks in general or an individual structure in particular, techniques have evolved that appear to provide reproducible, predictive assessments of the visual impacts and aesthetic values of an area and how those might change with development, including an increase in numbers of small docks. These assessments may be used to develop regulatory or non-regulatory methods for the management of small docks based on state or community standards. Visual impact assessments are increasingly used in the regulatory review of proposed development—although this process is still in its infancy as regards small docks and piers. Some political jurisdictions have established visual impact or aesthetic standards as relate to docks and others are in the process of investigating how to go about such an effort. (PDF contains 42 pages)
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Evaluate the efficiency of your change initiative The Impact Calculator can be used to demonstrate the impact of a process redesign or system implementation by quantifying the tangible benefits or efficiency gains that can be derived from it: identifying and recording the efficiency savings and costs of a process redesign determine if and when a return on investment (ROI) is made identify and measure as many benefits as you wish quantifying efficiency savings in monetary and non-monetary terms
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This Green Guide provides a brief summary of the alarming evidence of changing climate in the Cayman Islands. As we illustrated in our first Green Guide (2008), our lives on these three magical islands are intimately connected to the land and the surrounding sea. Our economy depends on keeping our islands healthy, because our coral reefs, our beaches, our natural heritage, all draw many thousands of overseas visitors to our shores. It is our responsibility, as stakeholders sharing this beautiful environment, to do what we can to minimise our impact upon it... [PDF contains 32 pages]
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Port authorities from around the world were surveyed to ascertain how administrators feel climate change might impact their operations, what level of change would be problematic, and how they plan to adapt to new conditions. The survey was distributed to 350 major ports through two leading international port organizations, the International Association of Ports and Harbors and the American Association of Port Authorities. (PDF contains 4 pages)
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The Quedan and Rural Credit Guarantee Corporation (Quedancor) of the Philippine Department of Agriculture has the critical responsibility of providing and improving credit assistance to fishers, it also has the task of helping its beneficiaries meet the repayment obligations of their loans. One reason for defaults can be attributed to the devastating impact of natural calamities. Schemes in place are still insufficient to help safeguard lending programs and operations from non-repayment of loans due to production losses and damages to personal properties.(PDF contains 5 pages) Natural calamities include the uncertainties and vagaries of weather and climate that bring about typhoons, floods, and drought; earthquakes; volcanic eruption as well as pests and diseases that affect the productivity of fisheries. When natural calamities occur, small fishers are unable to pay their loans from Quedancor, moreover they have difficulty renewing their loan applications from Quedancor or accessing credit from other sources. Failure to access credit could disable them to continue venture on fishing activities and could eventually jeopardize the welfare of their entire household. The inability of creditors to pay their loans and meet their obligations also impair, to a large extent, the financial operation and viability of the lending institutions. Risk management schemes currently employed include price stabilization measures, targeted relief` to typhoons and drought victims, and crop insurance systems, to name a few. Some of these schemes are becoming very expensive to implement. Moreover, they fail to enable fishers regain sufficient resources so that they may continue production.
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Part I.
We have developed a technique for measuring the depth time history of rigid body penetration into brittle materials (hard rocks and concretes) under a deceleration of ~ 105 g. The technique includes bar-coded projectile, sabot-projectile separation, detection and recording systems. Because the technique can give very dense data on penetration depth time history, penetration velocity can be deduced. Error analysis shows that the technique has a small intrinsic error of ~ 3-4 % in time during penetration, and 0.3 to 0.7 mm in penetration depth. A series of 4140 steel projectile penetration into G-mixture mortar targets have been conducted using the Caltech 40 mm gas/ powder gun in the velocity range of 100 to 500 m/s.
We report, for the first time, the whole depth-time history of rigid body penetration into brittle materials (the G-mixture mortar) under 105 g deceleration. Based on the experimental results, including penetration depth time history, damage of recovered target and projectile materials and theoretical analysis, we find:
1. Target materials are damaged via compacting in the region in front of a projectile and via brittle radial and lateral crack propagation in the region surrounding the penetration path. The results suggest that expected cracks in front of penetrators may be stopped by a comminuted region that is induced by wave propagation. Aggregate erosion on the projectile lateral surface is < 20% of the final penetration depth. This result suggests that the effect of lateral friction on the penetration process can be ignored.
2. Final penetration depth, Pmax, is linearly scaled with initial projectile energy per unit cross-section area, es , when targets are intact after impact. Based on the experimental data on the mortar targets, the relation is Pmax(mm) 1.15es (J/mm2 ) + 16.39.
3. Estimation of the energy needed to create an unit penetration volume suggests that the average pressure acting on the target material during penetration is ~ 10 to 20 times higher than the unconfined strength of target materials under quasi-static loading, and 3 to 4 times higher than the possible highest pressure due to friction and material strength and its rate dependence. In addition, the experimental data show that the interaction between cracks and the target free surface significantly affects the penetration process.
4. Based on the fact that the penetration duration, tmax, increases slowly with es and does not depend on projectile radius approximately, the dependence of tmax on projectile length is suggested to be described by tmax(μs) = 2.08es (J/mm2 + 349.0 x m/(πR2), in which m is the projectile mass in grams and R is the projectile radius in mm. The prediction from this relation is in reasonable agreement with the experimental data for different projectile lengths.
5. Deduced penetration velocity time histories suggest that whole penetration history is divided into three stages: (1) An initial stage in which the projectile velocity change is small due to very small contact area between the projectile and target materials; (2) A steady penetration stage in which projectile velocity continues to decrease smoothly; (3) A penetration stop stage in which projectile deceleration jumps up when velocities are close to a critical value of ~ 35 m/s.
6. Deduced averaged deceleration, a, in the steady penetration stage for projectiles with same dimensions is found to be a(g) = 192.4v + 1.89 x 104, where v is initial projectile velocity in m/s. The average pressure acting on target materials during penetration is estimated to be very comparable to shock wave pressure.
7. A similarity of penetration process is found to be described by a relation between normalized penetration depth, P/Pmax, and normalized penetration time, t/tmax, as P/Pmax = f(t/tmax, where f is a function of t/tmax. After f(t/tmax is determined using experimental data for projectiles with 150 mm length, the penetration depth time history for projectiles with 100 mm length predicted by this relation is in good agreement with experimental data. This similarity also predicts that average deceleration increases with decreasing projectile length, that is verified by the experimental data.
8. Based on the penetration process analysis and the present data, a first principle model for rigid body penetration is suggested. The model incorporates the models for contact area between projectile and target materials, friction coefficient, penetration stop criterion, and normal stress on the projectile surface. The most important assumptions used in the model are: (1) The penetration process can be treated as a series of impact events, therefore, pressure normal to projectile surface is estimated using the Hugoniot relation of target material; (2) The necessary condition for penetration is that the pressure acting on target materials is not lower than the Hugoniot elastic limit; (3) The friction force on projectile lateral surface can be ignored due to cavitation during penetration. All the parameters involved in the model are determined based on independent experimental data. The penetration depth time histories predicted from the model are in good agreement with the experimental data.
9. Based on planar impact and previous quasi-static experimental data, the strain rate dependence of the mortar compressive strength is described by σf/σ0f = exp(0.0905(log(έ/έ_0) 1.14, in the strain rate range of 10-7/s to 103/s (σ0f and έ are reference compressive strength and strain rate, respectively). The non-dispersive Hugoniot elastic wave in the G-mixture has an amplitude of ~ 0.14 GPa and a velocity of ~ 4.3 km/s.
Part II.
Stress wave profiles in vitreous GeO2 were measured using piezoresistance gauges in the pressure range of 5 to 18 GPa under planar plate and spherical projectile impact. Experimental data show that the response of vitreous GeO2 to planar shock loading can be divided into three stages: (1) A ramp elastic precursor has peak amplitude of 4 GPa and peak particle velocity of 333 m/s. Wave velocity decreases from initial longitudinal elastic wave velocity of 3.5 km/s to 2.9 km/s at 4 GPa; (2) A ramp wave with amplitude of 2.11 GPa follows the precursor when peak loading pressure is 8.4 GPa. Wave velocity drops to the value below bulk wave velocity in this stage; (3) A shock wave achieving final shock state forms when peak pressure is > 6 GPa. The Hugoniot relation is D = 0.917 + 1.711u (km/s) using present data and the data of Jackson and Ahrens [1979] when shock wave pressure is between 6 and 40 GPa for ρ0 = 3.655 gj cm3 . Based on the present data, the phase change from 4-fold to 6-fold coordination of Ge+4 with O-2 in vitreous GeO2 occurs in the pressure range of 4 to 15 ± 1 GPa under planar shock loading. Comparison of the shock loading data for fused SiO2 to that on vitreous GeO2 demonstrates that transformation to the rutile structure in both media are similar. The Hugoniots of vitreous GeO2 and fused SiO2 are found to coincide approximately if pressure in fused SiO2 is scaled by the ratio of fused SiO2to vitreous GeO2 density. This result, as well as the same structure, provides the basis for considering vitreous Ge02 as an analogous material to fused SiO2 under shock loading. Experimental results from the spherical projectile impact demonstrate: (1) The supported elastic shock in fused SiO2 decays less rapidly than a linear elastic wave when elastic wave stress amplitude is higher than 4 GPa. The supported elastic shock in vitreous GeO2 decays faster than a linear elastic wave; (2) In vitreous GeO2 , unsupported shock waves decays with peak pressure in the phase transition range (4-15 GPa) with propagation distance, x, as α 1/x-3.35 , close to the prediction of Chen et al. [1998]. Based on a simple analysis on spherical wave propagation, we find that the different decay rates of a spherical elastic wave in fused SiO2 and vitreous GeO2 is predictable on the base of the compressibility variation with stress under one-dimensional strain condition in the two materials.
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As the impacts and potential of climate change are realized at the governance level, states are moving towards adaptation strategies that include greater regulatory restrictions on development within coastal zones. The purpose of this paper is to outline the impacts of existing and planned regulatory mechanisms on the Fifth Amendment to the United States Constitution, which prevents the government taking of private property for public use without just compensation. A short history of regulatory takings is explained, and the potential legal issues surrounding mitigation and adaptation measures for coastal communities are discussed. The goal is to gain an understanding of the legal issues that must be resolved by governments to effectively deal with regulatory takings claims as coastal mitigation and adaptation plans are implemented. (PDF contains 3 pages)
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Rising global temperatures threaten the survival of many plant and animal species. Having already risen at an unprecedented rate in the past century, temperatures are predicted to rise between 0.3 and 7.5C in North America over the next 100 years (Hawkes et al. 2007). Studies have documented the effects of climate warming on phenology (timing of seasonal activities), with observations of early arrival at breeding grounds, earlier ends to the reproductive season, and delayed autumnal migrations (Pike et al. 2006). In addition, for species not suited to the physiological demands of cold winter temperatures, increasing temperatures could shift tolerable habitats to higher latitudes (Hawkes et al. 2007). More directly, climate warming will impact thermally sensitive species like sea turtles, who exhibit temperature-dependent sexual determination. Temperatures in the middle third of the incubation period determine the sex of sea turtle offspring, with higher temperatures resulting in a greater abundance of female offspring. Consequently, increasing temperatures from climate warming would drastically change the offspring sex ratio (Hawkes et al. 2007). Of the seven extant species of sea turtles, three (leatherback, Kemp’s ridley, and hawksbill) are critically endangered, two (olive ridley and green) are endangered, and one (loggerhead) is threatened. Considering the predicted scenarios of climate warming and the already tenuous status of sea turtle populations, it is essential that efforts are made to understand how increasing temperatures may affect sea turtle populations and how these species might adapt in the face of such changes. In this analysis, I seek to identify the impact of changing climate conditions over the next 50 years on the availability of sea turtle nesting habitat in Florida given predicted changes in temperature and precipitation. I predict that future conditions in Florida will be less suitable for sea turtle nesting during the historic nesting season. This may imply that sea turtles will nest at a different time of year, in more northern latitudes, to a lesser extent, or possibly not at all. It seems likely that changes in temperature and precipitation patterns will alter the distribution of sea turtle nesting locations worldwide, provided that beaches where the conditions are suitable for nesting still exist. Hijmans and Graham (2006) evaluate a range of climate envelope models in terms of their ability to predict species distributions under climate change scenarios. Their results suggested that the choice of species distribution model is dependent on the specifics of each individual study. Fuller et al. (2008) used a maximum entropy approach to model the potential distribution of 11 species in the Arctic Coastal Plain of Alaska under a series of projected climate scenarios. Recently, Pike (in press) developed Maxent models to investigate the impacts of climate change on green sea turtle nest distribution and timing. In each of these studies, a set of environmental predictor variables (including climate variables), for which ‘current’ conditions are available and ‘future’ conditions have been projected, is used in conjunction with species occurrence data to map potential species distribution under the projected conditions. In this study, I will take a similar approach in mapping the potential sea turtle nesting habitat in Florida by developing a Maxent model based on environmental and climate data and projecting the model for future climate data. (PDF contains 5 pages)
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This work seeks to understand past and present surface conditions on the Moon using two different but complementary approaches: topographic analysis using high-resolution elevation data from recent spacecraft missions and forward modeling of the dominant agent of lunar surface modification, impact cratering. The first investigation focuses on global surface roughness of the Moon, using a variety of statistical parameters to explore slopes at different scales and their relation to competing geological processes. We find that highlands topography behaves as a nearly self-similar fractal system on scales of order 100 meters, and there is a distinct change in this behavior above and below approximately 1 km. Chapter 2 focuses this analysis on two localized regions: the lunar south pole, including Shackleton crater, and the large mare-filled basins on the nearside of the Moon. In particular, we find that differential slope, a statistical measure of roughness related to the curvature of a topographic profile, is extremely useful in distinguishing between geologic units. Chapter 3 introduces a numerical model that simulates a cratered terrain by emplacing features of characteristic shape geometrically, allowing for tracking of both the topography and surviving rim fragments over time. The power spectral density of cratered terrains is estimated numerically from model results and benchmarked against a 1-dimensional analytic model. The power spectral slope is observed to vary predictably with the size-frequency distribution of craters, as well as the crater shape. The final chapter employs the rim-tracking feature of the cratered terrain model to analyze the evolving size-frequency distribution of craters under different criteria for identifying "visible" craters from surviving rim fragments. A geometric bias exists that systematically over counts large or small craters, depending on the rim fraction required to count a given feature as either visible or erased.
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