SPATIAL SEARCH IN COMMERCIAL FISHING: A DISCRETE CHOICE DYNAMIC PROGRAMMING APPROACH

We specify a discrete choice dynamic programming model of commercial fishing participation and location choices. This approach allows us to examine how fishermen collect information about resource abundance and whether their behavior is forward-looking.Resource /Energy Economics and Policy,

Improving performance of bay irrigation through higher flow rates

Bay (border check) irrigation systems are utilised extensively throughout the Goulburn Murray Irrigation District (GMID). However, the performance of these systems have rarely been assessed, in part due to the difficulty in determining the soil intake function. The CRC for Irrigation Futures has recently completed a project to demonstrate the Irrimate™ performance evaluation process in bay irrigation through on-farm trials. The Irrimate™ approach originally developed for furrow irrigation has already provided real benefits to farmers and has been accepted across the cotton industry. Bay irrigation has a number of unique characteristics which presented a number of challenges for the tools used to evaluate furrow irrigation. Informed by field trials, new monitoring strategies were tested and new modelling approaches developed in order to provide the same robust evaluation procedure for bay systems. Evaluations provide objective information to irrigators both quantifying efficiencies of current practices and providing strategies to improve performance. Trials were conducted across 11 sites in order to benchmark current performance and to examine the potential advantages of higher flow rates. Performance varied widely between sites with application efficiencies ranging from 45.9% to 89.5%. Initial modelling indicated that higher flow rates offer potential to increase efficiency. Trials in the second season confirmed the modelling work demonstrating water savings in excess of 20% through flow rates approximately double the conventional rates. The results also show that higher flow rates do not automatically lead to higher efficiency. When adopting higher flow rates irrigators must have greater control over cut-off times. System evaluation is an essential step to reap the benefits of higher flows. The results of this study provide objective information for the modernisation of irrigation systems in the GMID

Evidencing Open Access Citation Advantage using SciVal

The author acknowledges the contrubution of publication data from Elsevier SciVal in developing this technique.This conference contribution introduces a technique that can be used to explore the relative citation performance of publication sets with various modes of open access (OA). We give two methods for distilling a publication list into Gold, Hybrid Gold, Green, Bronze OA and Closed publication sets. One method uses SciVal functionality with limited further data manipulation; whilst the other utilises the Unpaywall Simple Query Tool. A comparison of the results for an entity of approximately 4000 research outputs is shown. We suggest some metrics that may be useful in characterising citation advantage of open vs. not open research outputs.Non peer reviewe

Toward a Design Space for Categorized Overviews of Search Results

There is a burgeoning movement to create user interfaces that combine searching and browsing in order to facilitate knowledge discovery. Categorized overviews are promising techniques to improve the browsing capabilities and subject access of search results. Research is needed to examine the design space in order to promote the usability and understanding of such interfaces. This paper proposes a set of 14 dimensions grouped into three areas of the design space for categorized overviews. These dimensions emerged from a review of recent literature about exploratory search interface design and categorized overviews, an analysis of five examples that are seeking to meet the needs of knowledge discovery, and personal experience. Finally, this paper discusses the application of the dimensions on a case study of a categorized overview created for a bibliographic database

Disaggregated Spatial Modeling of Irrigated Land and Water Use

Land Economics/Use,

Up-thrust and Seal Failures on a Vertical Can Pump

Case StudyPine Bend, MN, 12x10, 9 stage vertical can pump, 600 hp, 1780 rpm A new smaller, higher efficiency motor was installed to replace the old motor and shortly after numerous mechanical seal failures occurred. The motor is a solid shaft motor that is connected to the pump with a rigid coupling. The motor hub is connected to the motor shaft with a split ring. On startup it was observed that the pump shaft would move about 3/8 inch upward and the mechanical seal would leak

Welfare Impacts of Property Rights in the Seed Industry

The paper examines the welfare impact of different intellectual property right (IPR) regimes in private sector seed research. The model takes into account the period after expiration of IPR protection, and requires a simultaneous equilibrium in the markets for R&D, seeds, and final product (grain). Simulation results show that with the exception of R&D productivity, the optimal level of IPR protection is remarkably insensitive to parameters of the model. There is a range of IPR appropriability levels where the interests of consumers and producers (taken together) are complementary to the interests of R&D firms, and another range of appropriability levels where the welfare of producers and consumers can be increased only at the expense of the welfare R&D firms. These results may explain some of the acrimony in the debate about plant gene patenting and genetic use-restriction technologies (GURTs). Results suggest that the optimum IPR appropriability level is greater than that which exists in the North American seed corn market, but lower than would exist if GURTs were to become widely used. The optimal appropriability level is much higher than that which is achieved in situations where crops are open pollinated or where IPR protection is limited, and this may help explain and justify the relevance of public research in these situations.Crop Production/Industries,

Music and Light: Bill Smith, Clarinet; David Shrader, Percussion; April 30, 1971

Centennial Recital HallApril 30, 19718:15 p.m

The end of the PPNA in southern Jordan: Insights from a preliminary analysis of chipped stone from WF16

Research on the PPNA of southern Jordan at WF16 suggests that a distinct Late PPNA phase develops at this site. It is visible in changes in lithic assemblages and architecture. Similar changes appear to occur at other sites in southern Jordan dated late in the PPNA. At WF16, the one site that appears to be occupied throughout the PPNA, the chipped stone assemblage appears to evolve during the later stages of the occupation, confirming that the process of transition is locally derived. The main features of the transition visible in the chipped stone at WF16 are a technological change, with an increasing focus on blade manufacture, and some evidence for the development of a bi-directional knapping strategy, and a change in typology. The earlier PPNA material contains both microliths and el-Khiam points. By the Late PPNA both artefact types have completely disappeared from the assemblage. While the difference between early and Late PPNA assemblages are clear, part of the evidence for a local transition is the presence of an assemblage that is intermediary in character, and always stratified between the early and late material. The chipped stone from WF16 has never supported the division of the southern Levantine PPNA into a short Khiamian followed by a long Sultanian phase that is associated with the development of sedentism. At WF16, the early phase appears to encompass the greater part of the PPNA, and to be associated with architecture from its outset, while the Late phase is a relatively short lived. The chipped stone from this Late PPNA phase is sufficiently similar to the preceding PPNA, and dissimilar to the EPPNB elsewhere to continue to describe it as form of PPN. Some of the distinctive traits of this phase, especially in blade production, parallel EPPNB developments elsewhere, and indicate that the southern Jordanian trajectory does not occur in isolation, but is informed by wider processes. We argue that this Late PPNA develops, with influences from elsewhere in the Levant, in particular the incorporation of Naviform technology, into the distinctive MPPNB of southern Jordan and that very early MPPNB dates from Beidha and Shkarat Msaiad support this local trajectory