3,700 research outputs found
Ecology and power in the periphery of Maasina : the case of the Hayre in the nineteenth century
This article explores political tensions between successive nineteenth-century rulers of the inland delta of the Niger in central Mali (the Fulbe Diina of Hamdullahi and the Futanke successors of al-Hajj Umar) and the pastoral interests of the Fulbe chiefdoms on their eastern periphery, in a region known as the Hayre. A close study of changing forms of local governance and natural resource management demonstrates that although different strategies were employed by the Fulbe and Futanke states to control the Hayre, the internal dynamics of the region can only partly be explained by the influence of these central powers
Uniform asymptotics of the coefficients of unitary moment polynomials
Keating and Snaith showed that the absolute moment of the
characteristic polynomial of a random unitary matrix evaluated on the unit
circle is given by a polynomial of degree . In this article, uniform
asymptotics for the coefficients of that polynomial are derived, and a maximal
coefficient is located. Some of the asymptotics are given in explicit form.
Numerical data to support these calculations are presented. Some apparent
connections between random matrix theory and the Riemann zeta function are
discussed.Comment: 31 pages, 1 figure, 2 tables. A few minor misprints fixe
Entropy of complex relevant components of Boolean networks
Boolean network models of strongly connected modules are capable of capturing
the high regulatory complexity of many biological gene regulatory circuits. We
study numerically the previously introduced basin entropy, a parameter for the
dynamical uncertainty or information storage capacity of a network as well as
the average transient time in random relevant components as a function of their
connectivity. We also demonstrate that basin entropy can be estimated from
time-series data and is therefore also applicable to non-deterministic networks
models.Comment: 8 pages, 6 figure
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Session E8: Efficiency Measurements as Tool in Evaluating Fishways
Abstract:
The awareness of the importance of free fish migration in the Netherlands is reflected in the increasing number of fishways that has been built in the past decade. The intention is that all the bottlenecks will be solved before 2027.
Equally important as the realization of fishways, is the evaluation of the design. In other words, are all species and size classes that want to pass, truly able to pass the structure. The challenge in this type of research is to avoid interference of the measuring tools with the fish migrants. The conventional monitoring fyke, does not meet this requirement. Migration is obstructed and the gear is highly selective for small fish. Emerging electronic techniques offer this opportunity and makes it possible to watch fish migration behaviour on the road through the fishway. The use of a resistivity Fish Counter will be illustrated by means of a case study.
The counter detects the swimming direction and size of the passing fish. Species identification is achieved by the application of a camera, triggered by the passing fish. The placement of a counter station at both sides of the fishway, gives the unique opportunity to determine the efficiency in terms of the ratio between the number of fish entering the downstream side and the number of fish exiting at the upstream side. An example will be given of a fishway that originally was reviewed as a good functioning construction.
However, measurements of the efficiency showed that only a small part of the fish community was able to pass. The results also uncovered the weak spot in the design. This was not regarded as a failure, but as an opportunity to make use of the hidden potential of this fishway. It also contributed to the improvement of this type of design in general
Required Steps of Managing International Equity Placement Strategic Alliance
The purpose of the research is to unravel the steps of managing International equity placement strategic alliance (IEPSA). The steps of managing an IEPSA are obtained by conducting theoretical review. The theoretical reviews consist of theory of strategic alliance; definition, classification, and finding definition of an IEPSA, political and analytical considerations and the necessary steps. These steps of managing IEPSA can be classified into analyzing of macro consideration, micro consideration, domestic company's stakeholder support, cultural understanding, strategic planning, internal support, human resource management, organizational arrangement, management control system, evolved cultural understanding, and evaluating results. In this research, the domestic partners who formed the IEPSAs are limited to State-Owned Enterprises (SOEs). The IEPSA was one of the means of privatization. The research will be beneficial for both foreign and domestic partners who form an IEPSA in the previous SOEs. By knowing the steps of managing the IEPSA both partners will be able to secure a successful implementation of IEPSA. By identifying the steps of managing the IEPSA, the stakeholder will not see IEPSA as threat rather as an opportunity to improve performance, to create synergy, and generate benefits for both partners and stakeholder. By knowing the necessary steps of managing the IEPSA, the stakeholder including society and politician will envisage the IEPSA as a means of effectively improving the SOEs' performances.The research was espected to provide contributions for the research on strategic alliances. Apparently, there exist no literatures discussing about IEPSA in the domain of strategic alliances
Bond percolation on isoradial graphs: criticality and universality
In an investigation of percolation on isoradial graphs, we prove the
criticality of canonical bond percolation on isoradial embeddings of planar
graphs, thus extending celebrated earlier results for homogeneous and
inhomogeneous square, triangular, and other lattices. This is achieved via the
star-triangle transformation, by transporting the box-crossing property across
the family of isoradial graphs. As a consequence, we obtain the universality of
these models at the critical point, in the sense that the one-arm and
2j-alternating-arm critical exponents (and therefore also the connectivity and
volume exponents) are constant across the family of such percolation processes.
The isoradial graphs in question are those that satisfy certain weak conditions
on their embedding and on their track system. This class of graphs includes,
for example, isoradial embeddings of periodic graphs, and graphs derived from
rhombic Penrose tilings.Comment: In v2: extended title, and small changes in the tex
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Session B2: VisAdvies Protocol for Testing and Evaluating Pumping Station Pumps on Fish Survivability
Abstract:
In the context of fish welfare, pump manufacturers focus on the development of fish friendly pumps. The assessment of fish survivability in a field situation turns out to be difficult. Lack of migration (eels), presence of fish or insufficient species composition with a narrow range in length class at the moment of the research leads to unreliable conclusions. Therefore a guideline is developed, based on forced exposure of fish, to test and evaluate fish friendly pumps with a standardized method: “VisAdvies protocol for testing and evaluating pumping station pumps on fish survivability”. The protocol serves two purposes. First, the guideline gives direction to the way the test should be performed.
It advises in the fish species the numbers and size classes and the zero-groups (untreated fish) that should be used. It describes how damage and mortality should be categorized in different groups. Part of the test is the assessment of of delayed mortality that may take place a few days after the actual test.
In the second place is the guideline concerned with the evaluation of the results. The final outcome gives the score, based on the survivability rate of all species. A separate test should be carried out for all combinations of pump speed (rpm), discharge (m3/min), and head (m) that are of interest.
The protocol will be illustrated by means of a test in a dry dock in the Netherlands, on a pump of the Bedford company. The pump was especially designed to be fish friendly
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