18 research outputs found

    CropPol: a dynamic, open and global database on crop pollination

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    Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop yield, as well as to anticipate changes in this service, develop predictions, and inform management actions. Here, we present CropPol, a dynamic, open and global database on crop pollination. It contains measurements recorded from 202 crop studies, covering 3,394 field observations, 2,552 yield measurements (i.e. berry weight, number of fruits and kg per hectare, among others), and 47,752 insect records from 48 commercial crops distributed around the globe. CropPol comprises 32 of the 87 leading global crops and commodities that are pollinator dependent. Malus domestica is the most represented crop (32 studies), followed by Brassica napus (22 studies), Vaccinium corymbosum (13 studies), and Citrullus lanatus (12 studies). The most abundant pollinator guilds recorded are honey bees (34.22% counts), bumblebees (19.19%), flies other than Syrphidae and Bombyliidae (13.18%), other wild bees (13.13%), beetles (10.97%), Syrphidae (4.87%), and Bombyliidae (0.05%). Locations comprise 34 countries distributed among Europe (76 studies), Northern America (60), Latin America and the Caribbean (29), Asia (20), Oceania (10), and Africa (7). Sampling spans three decades and is concentrated on 2001-05 (21 studies), 2006-10 (40), 2011-15 (88), and 2016-20 (50). This is the most comprehensive open global data set on measurements of crop flower visitors, crop pollinators and pollination to date, and we encourage researchers to add more datasets to this database in the future. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation), and the products generated with this database should be shared under the same license terms (CC BY-NC-SA). This article is protected by copyright. All rights reserved

    An Efficient Algorithm for the 0-1 Knapsack Problem

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    In this note we present an efficient algorithm for the 0-1 knapsack problem and announce the availability of a callable FORTRAN subroutine which solves this problem. Computational results show that 50 variable problems can be solved in an average of 4 milliseconds and 200 variable problems in an average of 7 milliseconds on an IBM 360/91.

    True Interest Cost in Municipal Bond Bidding: An Integer Programming Approach

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    Over $47 billion of tax exempt debt issues were sold to the public in 1982. A portion of this total was offered to municipal bond underwriters under a competitive bidding system using the criterion of minimum true interest cost (internal rate of return). The TIC bidding problem may be formulated as a nonlinear integer program. We develop a linearization which is embedded in a special purpose integer linear branch and bound algorithm. Computational results for several actual bidding problems are presented.integer programming, finance, mathematical programming, competitive bidding

    Theory and Application of an Optimizing Procedure for Lock Box Location Analysis

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    This paper describes the theory, development, and application of an optimizing procedure for solving lock box location problems. Such problems have become increasingly important to banks, corporations, and governmental agencies in their quest for more efficient cash management. Extensive discussion of practical data collection and modeling aspects is provided. An optimizing procedure for solving the problem is discussed, and computational results are reported.programming: integer, applications, financial institutions: banks
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