5,949 research outputs found
CRFM Consultancy Report on Review of Existing Policy, Legal and Institutional Arrangements for Governance and Management of Flyingfish Fisheries in the Caribbean Large Marine Ecosystem
Many of the marine resources in the Caribbean are considered to be fully or overexploited. A Transboundary Diagnostic Analysis identified three priority transboundary problems that affect the CLME: unsustainable exploitation of fish and other living resources, the degradation and modification of natural habitats, pollution and contamination. The fourwing flyingfish fishery is the single most important small pelagic fishery in the southern Lesser Antilles. It is a shared resource, which has been traditionally exploited by seven different States, i.e. Barbados, Dominica, Grenada, Martinique, Saint Lucia, Saint Vincent and the Grenadines and Trinidad and Tobago. With expanding fleet capacity and limited cooperation among the States exploiting the flyingfish, there is concern that the resource may become overfished. While the flyingfish fishery is a directed fishery, it is at the same time part of a multi-species, multi-gear fishery, which also targets regional large pelagic species.This case study identifies and analyses the priority transboundary problems and issues. The policy, legal and institutional reforms needed to address such transboundary issues and achieve long-term conservation and sustainable use of the resources are also identified. A major and necessary component of the case study is an evaluation of the existing policy cycles and linkages among the countries and institutions involved with the flyingfish fishery
Output Feedback Invariants
The paper is concerned with the problem of determining a complete set of
invariants for output feedback. Using tools from geometric invariant theory it
is shown that there exists a quasi-projective variety whose points parameterize
the output feedback orbits in a unique way. If the McMillan degree ,
the product of number of inputs and number of outputs, then it is shown that in
the closure of every feedback orbit there is exactly one nondegenerate system.Comment: 15 page
Computational complexity and fundamental limitations to fermionic quantum Monte Carlo simulations
Quantum Monte Carlo simulations, while being efficient for bosons, suffer
from the "negative sign problem'' when applied to fermions - causing an
exponential increase of the computing time with the number of particles. A
polynomial time solution to the sign problem is highly desired since it would
provide an unbiased and numerically exact method to simulate correlated quantum
systems. Here we show, that such a solution is almost certainly unattainable by
proving that the sign problem is NP-hard, implying that a generic solution of
the sign problem would also solve all problems in the complexity class NP
(nondeterministic polynomial) in polynomial time.Comment: 4 page
Performance Pay, Risk Attitudes and Job Satisfaction
We present a sorting model in which workers with greater ability and greater risk tolerance move into performance pay jobs and contrast it with the classic agency model of performance pay. Estimates from the German Socio-Economic Panel confirm testable implications drawn from our sorting model. First, prior to controlling for earnings, workers in performance pay jobs have higher job satisfaction, a proxy for on-the-job utility. Second, after controlling for the higher earnings associated with performance pay, the job satisfaction of those in performance pay jobs is the same as those not in such jobs. Third, those workers in performance pay jobs who have greater risk tolerance routinely report greater job satisfaction. While these findings support the sorting model, they would not be suggested by the classic agency model.Performance Pay, Worker Heterogeneity, Ability, Risk Preferences, Sorting
Profit Sharing and Reciprocity: Theory and Survey Evidence
The 1/n problem potentially limits the effectiveness of profit sharing in motivating workers. While the economic literature suggests that reciprocity can mitigate this problem, it remains silent on the optimal degree of reciprocity. We present a representative model demonstrating that reciprocity may increase productive effort but may also increase unproductive effort such as socializing on the job. The model implies that reciprocity increases profit up to a point but decreases profit beyond that point. Using detailed survey measures of worker reciprocity, we show that the probability of receiving profit sharing takes an inverse U-shape as reciprocity increases. This supports the general implication of the model and is shown to exist for both positive and negative reciprocity and to remain when a series of ability proxies and detailed industry indicators are included.
Revised structure of haemoventosin
The structure of the lichen pigment haemoventosin has been revised to 3,4,6,9-tetrahydro-5,10-dihydroxy-7-methoxy-3S-methyl-1,6,9-trioxo-1H-naphtho-[2,3-c]pyran (3), mainly on the basis of long-range δC/δH correlations observed in 2D HMBC NMR experiments and long-range δH/δD isotope effects observed in partial deuteriation experiments with 10-O-acetylhaemoventosin; ortho- and para-quinonoid structures were distinguished by means of the transacetylation inferred in the sodium dithionite reduction of 10-O-acetylhaemoventosin
Coherent single atom shuttle between two Bose-Einstein condensates
We study an atomic quantum dot representing a single hyperfine "impurity"
atom which is coherently coupled to two well-separated Bose-Einstein
condensates, in the limit when the coupling between the dot and the condensates
dominates the inter-condensate tunneling coupling. It is demonstrated that the
quantum dot by itself can induce large-amplitude Josephson-like oscillations of
the particle imbalance between the condensates, which display a two-frequency
behavior. For noninteracting condensates, we provide an approximate solution to
the coupled nonlinear equations of motion which allows us to obtain these two
frequencies analytically.Comment: 4 pages of RevTex4, 4 figures; Rapid Communication in Physical Review
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