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The Denavit-Hartenberg parameters define the relative location of successive joint axis systems in a robot arm. A recent justifiable criticism is that one of these parameters becomes extremely large when two successive joints have near-parallel rotational axes. Geometrically, this parameter then locates a joint axis system at an excessive distance from the robot arm and, computationally, leads to an ill-conditioned transformation matrix. In this paper, a simple modification (which results from constraining a transverse vector between successive joint rotational axes to be normal to one of the rotational axes, instead of both) overcomes this criticism and favorably locates the joint axis system. An example is given for near-parallel rotational axes of the elbow and shoulder joints in a robot arm. The regular and modified parameters are extracted by an algebraic method with simulated measurement data. Unlike the modified parameters, extracted values of the regular parameters are very sensitive to measurement accuracy.

A collection of folk tales mostly centered around Anansi. In West African lore Anansi is known as a trickster god, and is often depicted as either a spider, a human or a combination of both. Thus many of the stories are attempts by Anansi to trick others for his own gain. Other stories are about why certain animals act in certain ways. (Summary by Lizzie Driver)

2Station Life in New Zealand

By Mary Anne Barker

Station Life in New Zealand is a collection of cheerful and interesting letters written by Lady Mary Anne Barker (nee Mary Anne Stewart) that is a New Zealand "classic". These letters are described in the Preface as "the exact account of a lady's experience of the brighter and less practical side of colonisation". The letters were written between 1865 and 1868 and cover the time of her travel with her husband (Frederick Broomie) to New Zealand and life on a colonial sheep-station at their homestead "Broomielaw", located in the Province of Canterbury, South Island of New Zealand. Although these letters are written with great humour and fine story telling, her life was marred by tragedy while in Canterbury through the illness and eventual death of her baby son.<br><br>The first four ships of settlers that colonised the Canterbury region had only arrived in 1850. Consequently, little was known about, for example, the irregular Canterbury weather patterns that would dominate the lives of Lady Barker and her husband for those three short years. She describes the regular predations of the Canterbury nor'wester (a type of Fohn wind), including its role in completely blowing away her attempts at establishing a croquet lawn, the devastating effects of snow storm that killed over half of their sheep, and of a great flood that not only flooded Christchurch but demolished her poultry and nearly drowned her husband.<br><br>Lady Mary Anne Barker was a strong horse woman and very keen for all sorts of "adventures". She describes instigating a bitterly cold late autumn overnight camping trip to the top of their nearest hill, Flagpole, followed the next morning by a serene sunrise over the Canterbury plains. In other letters, she describes her pride and enjoyment at joining and keeping up with nine men, who doubted her abilities, for long hours of walking in untracked, untamed bush with the aim of hunting wild cattle; and her joy at setting ablaze the tussock grasslands on their sheep station in spite of the risk to her eyelashes. As one of the few women in her part of Canterbury at the time, she also helped provide the neighbourhood with books to read, and baptism and schools for children. Lady Mary Anne Barker and her husband returned to England at the end of 1868. (Summary by Gail Timmerman-Vaughan)

3Station Amusements in New Zealand

By Mary Anne Barker

Station Amusements in New Zealand is a collection of vignettes about life on a sheep station (high country farm) in colonial New Zealand during the 1860s and is a further embellishment of events presented in Mary Anne Barker’s first book "Station Life in New Zealand". Mary Anne Barker and her husband Frederick Broomie lived at their sheep station “Broomielaw” under the foothills of the Southern Alps of Canterbury, New Zealand for three years from 1865 – 1868. Mary Anne Barker wrote in Chapter I: “I purpose therefore in these sketches to describe some of the pursuits which afforded us a keen enjoyment at the time, --an enjoyment arising from perfect health, simple tastes, and an exquisite climate.” (Summary by Gail Timmerman Vaughan)