37 research outputs found
Quantifying the social and economic benefits of the biological control of invasive alien plants in natural ecosystems
Invasive alien plants reduce ecosystem service delivery, resulting in environmental, economic and social costs. Here we review the returns on investment from biological control of alien plants that invade natural ecosystems. Quantifying the economic benefits of biological control requires estimates of the reductions in ecosystem goods and services arising from invasion. It also requires post-release monitoring to assess whether biological control can restore them, and conversion of these estimates to monetary values, which has seldom been done. Past studies, mainly from Australia and South Africa, indicate that biological control delivers positive and substantial returns on investment, with benefit:cost ratios ranging from 8:1 to over 3000:1. Recent studies are rare, but they confirm that successful biological control delivers attractive returns on investment, which increase over time as the value of avoided impacts accumulates
An experimental study to discriminate between the validity of diffraction theories for off-Bragg replay
We show that experiments clearly verify the assumptions made by the
first-order two-wave coupling theory for one dimensional lossless unslanted
planar volume holographic gratings using the beta-value method rather than
Kogelnik's K-vector closure method. Apart from the fact that the diffraction
process is elastic, a much more striking difference between the theories
becomes apparent particularly in the direction of the diffracted beam in
off-Bragg replay. We therefore monitored the direction of the diffracted beam
as a function of the off-Bragg replay angle in two distinct cases: [a] the
diffracted beam lies in the plane of incidence and [b] the sample surface
normal, the grating vector and the incoming beam do not form a plane which
calls for the vectorial theory and results in conical scattering.Comment: Corrected Eqs. (3) & (6); 14 pages, 8 figure
Analysis of the results of Federal incentives used to stimulate energy production
This study enhances the formulation of a national incentive policy for renewable resource utilization by examining past incentives for traditional energy forms. The research summarized builds on an analysis which estimated that in the years between 1918 and 1977 the Federal government expended $217.4 billion (1977 dollars), representing 33 distinct incentives, for incentives to stimulate energy production. The energy types considered were nuclear, hydroelectricity, coal, oil, natural gas, and electricity. The present study shows that extra production induced by the incentives considered was at least 61 quadrillion Btu (quad). A summary is presented of the results of the 33 incentives in terms of their effects on energy price and quantity as well as on nonquantifiable values such as Federal-state relations, competition, and capital formation. The findings are reported so that the dialog can continue to incorporate the lessons from past incentives to the production of energy from traditional sources into a Federal renewable resource energy policy. They are reported as a budget to serve as a point of departure for future debate centering on the cost of specific Federal actions over relatively short periods
Incentives to stimulate solar energy use- a proceedings of the second Seattle workshop
Nineteen papers are included. A separate abstract was prepared for each one. Summaries of workshop discussions on types of incentives are also included. (MHR
Local scour at complex bridge piers – experimental validation of current prediction methods
Agronomic effects from the control of Agropyron repens in barley by pre-harvest application of glyphosate
Comparison of the incentives used to stimulate energy production in Japan, France, West Germany, and the United States
This volume represents the culmination of a five-year research effort examining the incentives used to stimulate energy production in four countries, and the incentives used to stimulate energy consumption in one country. Following the theoretical approach developed for studying US energy incentives, the researchers in each country classified incentives into the following six categories: (1) Taxation, including exemption from or reduction of existing taxes; (2) Disbursements, in which the national government distributes money without requiring anything in return; (3) Requirements, including demands made by the government, backed by civil or criminal sanctions; (4) Traditional Services, including those almost always provided exclusively by a governmental entity; (5) Nontraditional Services, including those sometimes performed by non-governmental entities, as well as governmental entities (e.g., research and development); and (6) Market Activities, including government involvement in the market under conditions similar to those faced by non-governmental producers or consumers. A complete list of research reports prepared in the Federal Incentives series is provided in the Appendix
Analysis of federal incentives used to stimulate energy consumption
The purpose of the analysis is to identify and quantify Federal incentives that have increased the consumption of coal, oil, natural gas, and electricity. The introductory chapter is intended as a device for presenting the policy questions about the incentives that can be used to stimulate desired levels of energy development. In the theoretical chapter federal incentives were identified for the consumption of energy as Federal government actions whose major intent or result is to stimulate energy consumption. The stimulus comes through changing values of variables included in energy demand functions, thereby inducing energy consumers to move along the function in the direction of greater quantity of energy demanded, or through inducing a shift of the function to a position where more energy will be demanded at a given price. The demand variables fall into one of six categories: price of the energy form, price of complements, price of substitutes, preferences, income, and technology. The government can provide such incentives using six different policy instruments: taxation, disbursements, requirements, nontraditional services, traditional services, and market activity. The four major energy forms were examined. Six energy-consuming sectors were examined: residential, commercial, industrial, agricultural, transportation, and public. Two types of analyses of incentive actions are presented in this volume. The generic chapter focused on actions taken in 1978 across all energy forms. The subsequent chapters traced the patterns of incentive actions, energy form by energy form, from the beginning of the 20th century, to the present. The summary chapter includes the results of the previous chapters presented by energy form, incentive type, and user group. Finally, the implications of these results for solar policy are presented in the last chapter. (MCW
Monte-Carlo Tree Reductions for Stochastic Games
Monte-Carlo Tree Search (MCTS) is a powerful paradigm
for perfect information games. When considering stochastic games, the
tree model that represents the game has to take chance and a huge
branching factor into account. As effectiveness of MCTS may decrease
in such a setting, tree reductions may be useful. Chance-nodes are a
way to deal with random events. Move-groups are another way to deal
efficiently with a large branching factor by regrouping nodes. Group-
nodes are regrouping only reveal moves and enable a choice between
reveal moves and classical moves. We present various policies to use such
reductions for the stochastic game Chinese Dark Chess. Move-groups,
chance-nodes and group-nodes are compared