4,723 research outputs found
Economic Incentives Versus Command and Control: What's the Best Approach for Solving Environmental Problems?
Now, decades after the first environmental laws were passed in this country, policymakers face many choices when seeking to solve environmental problems. Will taxing polluters for their discharges be more effective than fining them for not meeting certain emissions standards? Will a regulatory agency find it less costly to enforce a ban or oversee a system of tradable permits? Which strategy will reduce a pollutant the quickest? Clearly, there are no "one-size-fits-all" answers. Many factors enter into the decision to favor either policies that lean more toward economic incentives (EI) and toward direct regulation, commonly referred to as command-and-control (CAC) policy. Underlying determinants include a country's governmental and regulatory infrastructure, along with the nature of the environmental problem itself. Even with these contextual factors to consider, we thought it would be useful to compare EI and CAC policies and their outcomes in a real-world setting. To do this, we looked at six environmental problems that the United States and at least one European country dealt with differently (see box on page 14.) For each problem, one approach was more of an EI measure, while the other relied more on CAC. For example, to reduce point-source industrial water pollution, the Netherlands implemented a system of fees for organic pollutants (EI), while the United States established a system of guidelines and permits (CAC). It turned out, in fact, that most policies had at least some elements of both approaches, but we categorized them as EI or CAC based on their dominant features. We then asked researchers who had previously studied these policies on either side of the Atlantic to update or prepare new case studies. We analyzed the 12 case studies (two for each of the six environmental problems) against a list of hypotheses frequently made for or against EI and CAC, such as which instrument is more effective or imposes less administrative burden
Investigation of LANDSAT follow-on thematic mapper spatial, radiometric and spectral resolution
The author has identified the following significant results. Fine resolution M7 multispectral scanner data collected during the Corn Blight Watch Experiment in 1971 served as the basis for this study. Different locations and times of year were studied. Definite improvement using 30-40 meter spatial resolution over present LANDSAT 1 resolution and over 50-60 meter resolution was observed, using crop area mensuration as the measure. Simulation studies carried out to extrapolate the empirical results to a range of field size distributions confirmed this effect, showing the improvement to be most pronounced for field sizes of 1-4 hectares. Radiometric sensitivity study showed significant degradation of crop classification accuracy immediately upon relaxation from the nominally specified values of 0.5% noise equivalent reflectance. This was especially the case for data which were spectrally similar such as that collected early in the growing season and also when attempting to accomplish crop stress detection
Recognition map analysis and crop acreage estimation using Skylab EREP data
There are no author-identified significant results in this report
Recognition map analysis and crop acreage estimation
There are no author-identified significant results in this report
Economic evaluation of crop acreage estimation by multispectral remote sensing
The author has identified the following significant results. Photointerpretation of S190A and S190B imagery showed significantly better resolution with the S190B system. A small tendancy to underestimate acreage was observed. This averaged 6 percent and varied with field size. The S190B system had adequate resolution for acreage measurement but the color film did not provide adequate contrast to allow detailed classification of ground cover from imagery of a single date. In total 78 percent of the fields were correctly classified but with 56 percent correct for the major crop, corn
quality assurance and support measures for solar cooling on system level
Abstract Within the IEA SHC Task 48 "Quality assurance and support measures for Solar Cooling" the analysis and evaluation of the systems has been one of the four main focuses. Here the activities are including the lab- and field-based characterization of the systems, the definition and application of performance figures, a guideline for a reliable monitoring procedure including methods for automated error detection and an updated overview on worldwide installed DEC systems including hints and good practice examples. They are furthermore leading to three different easy-to-use tools for solar cooling systems: The LCA tool considers environmental and energetic values for the evaluation, the PISTACHE tool offers a fast pre-sizing of the systems giving support for the planner in advance and finally an Excel tool allows a complete system evaluation using long term monitoring data
Nuclear alpha-clustering, superdeformation, and molecular resonances
Nuclear alpha-clustering has been the subject of intense study since the
advent of heavy-ion accelerators. Looking back for more than 40 years we are
able today to see the connection between quasimolecular resonances in heavy-ion
collisions and extremely deformed states in light nuclei. For example
superdeformed bands have been recently discovered in light N=Z nuclei such as
Ar, Ca, Cr, and Ni by -ray spectroscopy.
The search for strongly deformed shapes in N=Z nuclei is also the domain of
charged-particle spectroscopy, and our experimental group at IReS Strasbourg
has studied a number of these nuclei with the charged particle multidetector
array {\sc Icare} at the {\sc Vivitron} Tandem facility in a systematical
manner. Recently the search for -decays in Mg has been
undertaken in a range of excitation energies where previously nuclear molecular
resonances were found in C+C collisions. The breakup reaction
MgC has been investigated at E(Mg) = 130 MeV, an
energy which corresponds to the appropriate excitation energy in Mg for
which the C+C resonance could be related to the breakup
resonance. Very exclusive data were collected with the Binary Reaction
Spectrometer in coincidence with {\sc Euroball IV} installed at the {\sc
Vivitron}.Comment: 10 pages, 4 eps figures included. Invited Talk 10th Nuclear Physics
Workshop Marie and Pierre Curie, Kazimierz Dolny Poland, Sep. 24-28, 2003; To
be published in International Journal of Modern Physics
Are Individuals Fickle-Minded?
Game theory has been used to model large-scale social events — such as constitutional law, democratic stability, standard setting, gender roles, social movements, communication, markets, the selection of officials by means of elections, coalition formation, resource allocation, distribution of goods, and war — as the aggregate result of individual choices in interdependent decision-making. Game theory in this way assumes methodological individualism. The widespread observation that game theory predictions do not in general match observation has led to many attempts to repair game theory by creating behavioral game theory, which adds corrective terms to the game theoretic predictions in the hope of making predictions that better match observations. But for game theory to be useful in making predictions, we must be able to generalize from an individual’s behavior in one situation to that individual’s behavior in very closely similar situations. In other words, behavioral game theory needs individuals to be reasonably consistent in action if the theory is to have predictive power. We argue on the basis of experimental evidence that the assumption of such consistency is unwarranted. More realistic models of individual agents must be developed that acknowledge the variance in behavior for a given individual
Probing two topological surface bands of Sb2Te3 by spin-polarized photoemission spectroscopy
Using high resolution spin- and angle-resolved photoemission spectroscopy, we
map the electronic structure and spin texture of the surface states of the
topological insulator Sb2Te3. In combination with density functional
calculations (DFT), we directly show that Sb2Te3 exhibits a partially occupied,
single spin-Dirac cone around the Fermi energy, which is topologically
protected. DFT obtains a spin polarization of the occupied Dirac cone states of
80-90%, which is in reasonable agreement with the experimental data after
careful background subtraction. Furthermore, we observe a strongly spin-orbit
split surface band at lower energy. This state is found at 0.8eV below the
Fermi level at the gamma-point, disperses upwards, and disappears at about
0.4eV below the Fermi level into two different bulk bands. Along the gamma-K
direction, the band is located within a spin-orbit gap. According to an
argument given by Pendry and Gurman in 1975, such a gap must contain a surface
state, if it is located away from the high symmetry points of the Brillouin
zone. Thus, the novel spin-split state is protected by symmetry, too.Comment: 8 pages, 10 figure
Wave function mapping in graphene quantum dots with soft confinement
Using low-temperature scanning tunneling spectroscopy, we map the local
density of states (LDOS) of graphene quantum dots supported on Ir(111). Due to
a band gap in the projected Ir band structure around the graphene K point, the
electronic properties of the QDs are dominantly graphene-like. Indeed, we
compare the results favorably with tight binding calculations on the honeycomb
lattice based on parameters derived from density functional theory. We find
that the interaction with the substrate near the edge of the island gradually
opens a gap in the Dirac cone, which implies soft-wall confinement.
Interestingly, this confinement results in highly symmetric wave functions.
Further influences of the substrate are given by the known moir{\'e} potential
and a 10% penetration of an Ir surface resonanceComment: 7 pages, 11 figures, DFT calculations directly showing the origin of
soft confinment, correct identification of the state penetrating from Ir(111)
into graphen
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