Characterisation of the LMS200 laser beam under the influence of blockage surfaces. Influence on 3D scanning of tree orchards

The geometric characterisation of tree orchards is a high-precision activity comprising the accurate measurement and knowledge of the geometry and structure of the trees. Different types of sensors can be used to perform this characterisation. In this work a terrestrial LIDAR sensor (SICK LMS200) whose emission source was a 905-nm pulsed laser diode was used. Given the known dimensions of the laser beam cross-section (with diameters ranging from 12 mm at the point of emission to 47.2 mm at a distance of 8 m), and the known dimensions of the elements that make up the crops under study (flowers, leaves, fruits, branches, trunks), it was anticipated that, for much of the time, the laser beam would only partially hit a foreground target/object, with the consequent problem of mixed pixels or edge effects. Understanding what happens in such situations was the principal objective of this work. With this in mind, a series of tests were set up to determine the geometry of the emitted beam and to determine the response of the sensor to different beam blockage scenarios. The main conclusions that were drawn from the results obtained were: (i) in a partial beam blockage scenario, the distance value given by the sensor depends more on the blocked radiant power than on the blocked surface area; (ii) there is an area that influences the measurements obtained that is dependent on the percentage of blockage and which ranges from 1.5 to 2.5 m with respect to the foreground target/object. If the laser beam impacts on a second target/object located within this range, this will affect the measurement given by the sensor. To interpret the information obtained from the point clouds provided by the LIDAR sensors, such as the volume occupied and the enclosing area, it is necessary to know the resolution and the process for obtaining this mesh of points and also to be aware of the problem associated with mixed pixels.

Valuing equity-linked death benefits in jump diffusion models

The paper is motivated by the valuation problem of guaranteed minimum death benefits in various equity-linked products. At the time of death, a benefit payment is due. It may depend not only on the price of a stock or stock fund at that time, but also on prior prices. The problem is to calculate the expected discounted value of the benefit payment. Because the distribution of the time of death can be approximated by a combination of exponential distributions, it suffices to solve the problem for an exponentially distributed time of death. The stock price process is assumed to be the exponential of a Brownian motion plus an independent compound Poisson process whose upward and downward jumps are modeled by combinations (or mixtures) of exponential distributions. Results for exponential stopping of a Lévy process are used to derive a series of closed-form formulas for call, put, lookback, and barrier options, dynamic fund protection, and dynamic withdrawal benefit with guarantee. We also discuss how barrier options can be used to model lapses and surrenders.

Färglagda figurer öfver fyra af de sällsyntare djuren uti herr Lehmanns menagerie : der på stället afmålade af M. och W. von Wright - [Kansi]

Stockholm : C. von Scheéle 1829

Helsingfors från N.W.

Helsingfors : A.W. Gröndahl A.C. Öhman 1845 : Dresden, Adler u. Dietze

Hämäläinen Talvi voatteissaan : R. W. Ekman Kuv. ja piirittännytt

Tukhulmissa : Painettu M. G. Lundbergin Kirja-pajassa 1831

Someron pitäjässä talvi-ilta : pinx. R. W. Ekman

Helsingfors : K.E. Holm 1885, A. Weger

Maisema Pirkkalassa, Satakunnassa : pinx. W. Holmberg

Helsingfors : K. E. Holm 1885, A. Weger

Kuuston jäännökset Kuvaeltu v. 1826 A Grafströmmilta : W. v. Wright pir.

Tukhulmissa : Painettu M. G. Lundbergin Kirja-pajassa 1831

Ylä-Torneolaiset Kesä-voateisaan : W. v. Wright. p.

Tukhulmissa : Painettu M. G. Lundbergin Kirja-pajassa 1831

Jousi-Mies : W. v. Wright

Tukhulmissa : Painettu M. G. Lundbergin Kirja-pajassa 1831