We associate to certain symmetric or antisymmetric functions on the set ( E d+1 ) of (d+ 1)−subsets in a finite set E an equivalence relation on E and study some of its properties. 1 Definitions and main results We consider a finite set E and denote by (E d ) the set of subsets containing exactly d elements of E. In the sequel we move often freely from sets to sequences: we identify a subset {x...

We investigated Fraxinus excelsior breeding system using field data collected in a natural population and in a seed orchard. First, we attested functional trioecy (co-occurrence of males, hermaphrodites and females), with males producing pollen, hermaphrodites producing both pollen and seeds simultaneously, and females producing seeds. Second, we found that the reproductive system of F. excelsi...

Tree structure probing is a significant basic part of target precision spraying. Orchard tree structure digital test system, which consists of three components, is designed by using the ultrasonic sensors. The conveying platform is for fixing and precisely moving the sensor which is used for probing the tree profile. The lower computer can process the test data and communicate with upper comput...

15. Dillon JC, Weyman AE, Feigenbaum H, Eggleton RC, Johnston K: Cross-sectional echocardiographic examination of the interatrial septum. Circulation 55: 115, 1977 16. Lieppe W, Scallion R, Behar VS, Kisslo JA: Two-dimensional echocardiographic findings in atrial septal defect. Circulation 56: 447, 1977 17. Hagler DJ, Tajik AJ, Seward JB, Mair DD, Ritter DG: Realtime wide-angle sector echocardi...

forests as a renewable source has effective and useful role in economic and social activities of society. network of forest roads as infrastructure division’s forest planning units (compartments) of forest management plans, management, logging, exit of wood and plays a major role forest protection. aim of this study, designed forest road network according to multi-purpose forestry using the net...

A study was undertaken to determine if meadow voles, Microtus pennsylvanicus, use habitats adjacent to apple orchards. Considerations were given to how extensively these areas were used, if at all, and if a bulldozed strip would control their movements between the orchard and adjacent border habitats. Trapping and telemetry data showed that meadow voles do use the adjacent border habitats exten...

Let P be a set of n points in the plane, not all on a line. We show that if n is large then there are at least n/2 ordinary lines, that is to say lines passing through exactly two points of P . This confirms, for large n, a conjecture of Dirac and Motzkin. In fact we describe the exact extremisers for this problem, as well as all sets having fewer than n−C ordinary lines for some absolute const...

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The measurement and control of soil moisture are the key technologies of precision agriculture. In order to real-time detect soil moisture content faster and more accurately, a portable soil moisture sensor based on NIR spectroscopy was developed. With the sixty soil samples collected from a winter jujube orchard, a linear regression model was established. The determination coefficients of the ...