Miscellaneous

A Tutorial of Linear Programming Using True Basic Program OPTLP
This tutorial aims to explain the basic calculation procedures for the simplest linear programming problem to the novice in a step by step fashion. Although many computer programs can be used to carry out similar tasks automatically, it is a good idea for the novice to fully understand the mechanics of the calculations, at least for some typical problems. A problem of linear programming (LP) is to find an optimum (minimum or maximum) of an objective function, expressed in linear form in relation to several original variables, subject to one or more linear constraints. The constraints can be of equality type, or inequality (greater than or less than) type. The solution of LP problem is due to Geoge Dantzig as published in 1963 as the Simplex method. Here we will use a program, OPTLP, by Hanna and Sandall (1995) to solve basic LP problems.


Ecophysiology of the Sandy Shrubs in the Mu Us Sandland-Structure and Function
This document is a Ph.D dissertation completed in 1997 dealing with shrub ecophysiology in the Mu US Sandland region of China.

ABSTRACT:

In the Mu Us Sandland, water is one of the limiting factors for the functioning of the
ecosystems and the shrubs are favored over trees and grasses in the sandy
substrate.The comprehensive understanding of the role of shrubs in the natural
ecosystems is very important but insufficient at present. In this research, the above
problems were approached by the methods of ecophysiology with emphasis on both
the structural and functional aspects of the sandy shrubs.The main results are given in
the following.

(1)The functional types of the indigenous shrubs can be distinguished as (a)
drought tolerator and (b) competitive consumer. This division scheme can be useful
in the ecological research and was obtained by considering (a) some important soil
physical an climatic characteristics in this area; (b) conspicuous differences in the
structure and function of the leaves obtained for the shrubs growing at the habitats of
different water availability; (c) leaf water relations parameters deduced from the
pressure volume method.(d) the constraint of water budget to the vegetation coverage
of the indigenous shrubs.
(2) Some new understanding of the ecology for some dominant shrubs were
obtained: (a) The very low transpiration rate of S. vulgaris can be explained directly
by the restricted stomatal distribution; (b) the dominance of A. sphaerocephala and A.
ordosica dominates at the different stages of the dune succession can partly be
explained by their differences in both the structural and functional features; (c)
although H.mongolicum has special features to adapt to drought stress , it is less
tolerant to drought than most shrub growing at similar habitats as indicated leaf
anatomy and water relations parameters;(d) the adaptation of S. psammophila to the
different micro habitats of the sand dune lies more in the morphological plasticity than
the physiological regulation.



LATEX For Efficient Scientific Presentation- an Illustration Using a Simple Example
This article discusses the use of LATEX as a tool for the preparation of scientific presentations. LATEX is widely used in computer and mathematics communities partly because it is well known for generating beautiful mathematical equations. The use in biological sciences so far seems to not be widespread. However, as biological sciences become more and more interdisciplinary, the use of LATEX is likely to increase.


Lectures on probability, statistics and econometrics
This site provides access to an e-book organized as an hypertext. It contains a series of lectures on probability, statistics and econometrics, as well as to a number of exercises on the same topics.