65 research outputs found

    An analytical model for Loc/ID mappings caches

    Get PDF
    Concerns regarding the scalability of the interdomain routing have encouraged researchers to start elaborating a more robust Internet architecture. While consensus on the exact form of the solution is yet to be found, the need for a semantic decoupling of a node's location and identity is generally accepted as a promising way forward. However, this typically requires the use of caches that store temporal bindings between the two namespaces, to avoid hampering router packet forwarding speeds. In this article, we propose a methodology for an analytical analysis of cache performance that relies on the working-set theory. We first identify the conditions that network traffic must comply with for the theory to be applicable and then develop a model that predicts average cache miss rates relying on easily measurable traffic parameters. We validate the result by emulation, using real packet traces collected at the egress points of a campus and an academic network. To prove its versatility, we extend the model to consider cache polluting user traffic and observe that simple, low intensity attacks drastically reduce performance, whereby manufacturers should either overprovision router memory or implement more complex cache eviction policies.Peer ReviewedPostprint (author's final draft

    THE COST OF FORWARD CONTRACTING

    Get PDF
    The cost of forward contracting corn is estimated with weekly pre-harvest forward bases for seven regions of Illinois from 1975 to 2002. Given the panel structure of the forward basis dataset, we extend Townsend and Brorsen's univariate unit root model for forward bases to a panel unit root model. With the time series of forward bases modeled as unit root processes, the cost of forward contracting is estimated. The empirical results from the estimation show that the cost of forward contracting corn is about 1¢/bushel, one hundred days before the harvest, for all regions in Illinois as a whole. The results also indicates that the cost could vary across regions and that the cost of forward contracting could be substantially higher than that of futures hedging, especially at the beginning of the pre-harvest period.Marketing,

    The Pricing Performance of Market Advisory Services in Corn and Soybeans over 1995-2003

    Get PDF
    The purpose of this research report is to evaluate the pricing performance of market advisory services for the 1995-2003 corn and soybean crops. Four basic indicators of performance are applied to advisory program prices and revenues over 1995-2003. Test results provide little evidence that advisory programs as a group outperform market benchmarks, particularly after considering risk. The evidence is somewhat more positive with respect to the farmer benchmark, even after taking risk into account. For example, the average advisory return relative to the farmer benchmark is $7 per acre with only a negligible increase in risk. While this return is small it nonetheless represents a non-trivial increase in net farm income per acre for grain farms in Illinois. Test results also suggest that it is difficult to usefully predict the year-to-year pricing performance of advisory programs based on past pricing performance. However, there is some evidence that performance is more predictable over longer time horizons, particularly at the extremes of performance rankings.Marketing,

    The Pricing Performance of Market Advisory Services in Corn and Soybeans Over 1995-2003: A Non-Technical Summary

    Get PDF
    The purpose of this research report is to summarize the pricing performance of professional market advisory services for the 1995-2003 corn and soybean crops. First, advisory programs in corn do not consistently beat market benchmarks, but tend to consistently beat the farmer benchmark. Second, advisory programs in soybeans exhibit just the opposite pattern, consistently beating the market benchmarks but not the farmer benchmark. Third, in terms of 50/50 revenue, advisory programs show marginal consistency in beating both the market benchmarks and the farmer benchmark. So, the results provide mixed performance evidence with respect to both the market benchmarks and the farmer benchmark.Agricultural Finance,

    ADVISORY SERVICE MARKETING PROFILES FOR CORN OVER 1995-2000

    Get PDF
    This report presents marketing profiles and loan deficiency payment/marketing loan gain profiles for the advisory services followed by the AgMAS Project for the 1995 through 2000 corn crops. Marketing profiles are constructed by plotting the cumulative net amount priced under each program's set of recommendations throughout a crop year. Loan deficiency payment/marketing loan gain (LDP/MLG) profiles are constructed by plotting the cumulative percentage of the crop on which the LDP/MLG was claimed during the crop year. Marketing profiles provide information to evaluate the style of advisory services in several ways. The percentage of crop priced is a measure of within-crop year price risk. The higher the proportion of a crop priced, the lower the sensitivity of the farmer's position value to crop price changes. For example, when 100% of the crop is priced there is no price sensitivity, which means that changes in price do not affect the value of the farmer's position. On the other hand, when the amount priced is 0%, the value of the farmer's position will vary in the same proportion as the change in price. Marketing profiles, therefore, allow investigating the evolution of price sensitivity under each service's set of recommendations along the marketing window. Marketing profiles also provide other useful information. The number of steps in the profile lines and the location of these steps in the marketing window provide information about timing, frequency and size of recommended transactions. It is also possible to determine from the marketing profile figures how intensely a program uses options markets, since when options positions are open the profile line is irregular. In the same way, LDP/MLG profiles provide information about the size and timing of LDP/MLG claims.Marketing,

    ADVISORY SERVICE MARKETING PROFILES FOR SOYBEANS OVER 1995-2000

    Get PDF
    This report presents marketing profiles and loan deficiency payment/marketing loan gain profiles for the advisory services followed by the AgMAS Project for the 1995 through 2000 soybean crops. Marketing profiles are constructed by plotting the cumulative net amount priced under each program's set of recommendations throughout a crop year. Loan deficiency payment/marketing loan gain (LDP/MLG) profiles are constructed by plotting the cumulative percentage of the crop on which the LDP/MLG was claimed during the crop year. Marketing profiles provide information to evaluate the style of advisory services in several ways. The percentage of crop priced is a measure of within-crop year price risk. The higher the proportion of a crop priced, the lower the sensitivity of the farmer's position value to crop price changes. For example, when 100% of the crop is priced there is no price sensitivity, which means that changes in price do not affect the value of the farmer's position. On the other hand, when the amount priced is 0%, the value of the farmer's position will vary in the same proportion as the change in price. Marketing profiles, therefore, allow investigating the evolution of price sensitivity under each service's set of recommendations along the marketing window. Marketing profiles also provide other useful information. The number of steps in the profile lines and the location of these steps in the marketing window provide information about timing, frequency and size of recommended transactions. It is also possible to determine from the marketing profile figures how intensely a program uses options markets, since when options positions are open the profile line is irregular. In the same way, LDP/MLG profiles provide information about the size and timing of LDP/MLG claims.Marketing,

    Towards targeted screening for acute HIV infections in British Columbia

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Our objective was to describe the characteristics of acute and established HIV infections diagnosed in the Canadian province of British Columbia. Province-wide HIV testing and surveillance data were analyzed to inform recommendations for targeted use of screening algorithms to detect acute HIV infections.</p> <p>Methods</p> <p>Acute HIV infection was defined as a confirmed reactive HIV p24 antigen test (or HIV nucleic acid test), a non-reactive or reactive HIV EIA screening test and a non-reactive or indeterminate Western Blot. Characteristics of unique individuals were identified from the British Columbia HIV/AIDS Surveillance System. Primary drug resistance and HIV subtypes were identified by analyzing HIV <it>pol </it>sequences from residual sera from newly infected individuals.</p> <p>Results</p> <p>From February 2006 to October 2008, 61 individuals met the acute HIV infection case definition, representing 6.2% of the 987 newly diagnosed HIV infections during the analysis period. Acute HIV infection cases were more likely to be men who have sex with men (crude OR 1.71; 95% CI 1.01-2.89], to have had a documented previous negative HIV test result (crude OR 2.89; 95% CI 1.52-5.51), and to have reported a reason for testing due to suspected seroconversion symptoms (crude OR 5.16; 95% CI 2.88-9.23). HIV subtypes and rates of transmitted drug resistance across all classes of drugs were similar in persons with both acute and established HIV infections.</p> <p>Conclusions</p> <p>Targeted screening to detect acute HIV infection is a logical public health response to the HIV epidemic. Our findings suggest that acute HIV infection screening strategies, in our setting, are helpful for early diagnosis in men who have sex with men, in persons with seroconversion symptoms and in previously negative repeat testers.</p

    State Mandates, Housing Elements, and Low-income Housing Production

    Get PDF
    In order to create low-income housing opportunities and mitigate exclusionary zoning, in 1968 Congress mandated that municipalities receiving comprehensive planning funds must create a housing element. In tandem, many states mandated that municipal housing elements must accommodate low-income housing needs. After examining empirical research for California, Florida, Illinois, and Minnesota, this review found aspirational success because those states rewarded the municipal planning process. In order to increase low-income housing, this review argues for state housing policy reform. Under US Department of Housing and Urban Development’s revised fair housing rule, which requires an assessment of local data, states can no longer ignore the exclusionary behavior of municipalities
    corecore