title: Modified serpentine motion of the snake robot

authors: Jin, Pinwei

subjects: snake robot

abstract: The frequent occurrence of earthquake in New Zealand drives the research on snake robot for search and rescue operation because of its elongated body shape and locomotion mimicry of the biological snake. Both features are in favour of moving the snake robot through the earthquake disaster area. To facilitate the robot control and information gathering, it is usually required to install a camera on the snake robot head so that the video images of the disaster area can be send back to the human operator. This thesis presents the simulation of a snake robot performing serpentine motion. A camera is attached on the snake robot head to obtain the video image along the line of sight. A remote controller is incorporated to control the advancement based on the video images. This simulation reveals that the video images from the camera oscillate seriously because the camera on the snake robot head follows serpenoid curve during the locomotion. As a result, both robot control and information gathering are affected. A solution is proposed to stabilize the snake robot head and its camera by introducing a correction at the joint between the robot head and its body. This correction aligns the camera sight direction with the moving direction of the snake robot to yield satisfactory video images. Finally, an actual snake robot is implemented with a wireless camera installed on the head to show the effect of correction. Experiments are conducted to control the advancement of snake robot remotely just based on the video images obtained from the camera. This greatly improves the performance of the snake robot.

text: Modified serpentine motion of the snake robot The frequent occurrence of earthquake in New Zealand drives the research on snake robot for search and rescue operation because of its elongated body shape and locomotion mimicry of the biological snake. Both features are in favour of moving the snake robot through the earthquake disaster area. To facilitate the robot control and information gathering, it is usually required to install a camera on the snake robot head so that the video images of the disaster area can be send back to the human operator. This thesis presents the simulation of a snake robot performing serpentine motion. A camera is attached on the snake robot head to obtain the video image along the line of sight. A remote controller is incorporated to control the advancement based on the video images. This simulation reveals that the video images from the camera oscillate seriously because the camera on the snake robot head follows serpenoid curve during the locomotion. As a result, both robot control and information gathering are affected. A solution is proposed to stabilize the snake robot head and its camera by introducing a correction at the joint between the robot head and its body. This correction aligns the camera sight direction with the moving direction of the snake robot to yield satisfactory video images. Finally, an actual snake robot is implemented with a wireless camera installed on the head to show the effect of correction. Experiments are conducted to control the advancement of snake robot remotely just based on the video images obtained from the camera. This greatly improves the performance of the snake robot.

year: 2015

title: Construction of lattice rules for multiple integration based on a weighted discrepancy

authors: Sinescu, Vasile

subjects: Lattice rules

abstract: High-dimensional integrals arise in a variety of areas, including quantum physics, the physics and chemistry of molecules, statistical mechanics and more recently, in financial applications.
In order to approximate multidimensional integrals, one may use Monte Carlo methods in which the quadrature points are generated randomly or quasi-Monte Carlo methods, in which points are generated deterministically. One particular class of quasi-Monte Carlo methods for multivariate integration is represented by lattice rules. Lattice rules constructed throughout this thesis allow good approximations to integrals of functions belonging to certain
weighted function spaces. These function spaces were proposed as an explanation as to why integrals in many variables appear to be successfully approximated although the standard theory indicates that the number of quadrature
points required for reasonable accuracy would be astronomical because of the large number of variables.
The purpose of this thesis is to contribute to theoretical results regarding the construction of lattice rules for multiple integration. We consider both lattice rules for integrals over the unit cube and lattice rules suitable for integrals over Euclidean space. The research reported throughout the thesis is devoted to finding the generating vector required to produce lattice rules that have what is termed a  low weighted discrepancy . In simple terms, the  discrepancy  is a measure of the uniformity of the distribution of the quadrature points or in other settings, a worst-case error. One of the assumptions used in these weighted function spaces is that variables are arranged in the decreasing order of their importance and the assignment of weights in this situation results in so-called  product weights . In other applications it is rather the importance of group of variables that matters. This situation is modelled by using function spaces in which the weights are  general . In the weighted
settings mentioned above, the quality of the lattice rules is assessed by the  weighted discrepancy  mentioned earlier. Under appropriate conditions on the weights, the lattice rules constructed here produce a convergence rate of the error that ranges 
from O(n−1/2) to the (believed) optimal O(n−1+δ) for any δ gt 0, with the involved constant independent of the dimension.

text: Construction of lattice rules for multiple integration based on a weighted discrepancy High-dimensional integrals arise in a variety of areas, including quantum physics, the physics and chemistry of molecules, statistical mechanics and more recently, in financial applications.
In order to approximate multidimensional integrals, one may use Monte Carlo methods in which the quadrature points are generated randomly or quasi-Monte Carlo methods, in which points are generated deterministically. One particular class of quasi-Monte Carlo methods for multivariate integration is represented by lattice rules. Lattice rules constructed throughout this thesis allow good approximations to integrals of functions belonging to certain
weighted function spaces. These function spaces were proposed as an explanation as to why integrals in many variables appear to be successfully approximated although the standard theory indicates that the number of quadrature
points required for reasonable accuracy would be astronomical because of the large number of variables.
The purpose of this thesis is to contribute to theoretical results regarding the construction of lattice rules for multiple integration. We consider both lattice rules for integrals over the unit cube and lattice rules suitable for integrals over Euclidean space. The research reported throughout the thesis is devoted to finding the generating vector required to produce lattice rules that have what is termed a  low weighted discrepancy . In simple terms, the  discrepancy  is a measure of the uniformity of the distribution of the quadrature points or in other settings, a worst-case error. One of the assumptions used in these weighted function spaces is that variables are arranged in the decreasing order of their importance and the assignment of weights in this situation results in so-called  product weights . In other applications it is rather the importance of group of variables that matters. This situation is modelled by using function spaces in which the weights are  general . In the weighted
settings mentioned above, the quality of the lattice rules is assessed by the  weighted discrepancy  mentioned earlier. Under appropriate conditions on the weights, the lattice rules constructed here produce a convergence rate of the error that ranges 
from O(n−1/2) to the (believed) optimal O(n−1+δ) for any δ gt 0, with the involved constant independent of the dimension.

year: 2008

title: Te reo Maori, philosophy and colonialism: A conversation with Maori philosopher Carl Mika

authors: Peters, Michael A.

abstract: Kia ora Carl
Some advice if you have the time... I have been asked to give a paper at Uppsala on philosophy of language and autonomy. I want to focus on colonialism and use some examples from the colonial history concerning te reo Maori. I did a little research at the time of the Royal Commission in 1988 but have lost touch with the literature. Are there a couple of strategic texts you would recommend?
Nga Mihi

Kia ora Michael
You tend to get two types of writing about the language: its revitalisation; and its link to the natural or spiritual worlds – which is to do with philosophy in a particular sense, but in my view doesn’t have an eye towards the “autonomy” part you raise (i.e. isn’t cognisant enough of colonialism). The latter writing theorises around the traditional place of language, or describes it as a traditional phenomenon. I’ve been considering writing something for some time on it, but just haven’t gotten around to it.
You could discuss it in terms of how current uses of it in government policy etc. force the Maori language to become no more or no less than its English counterpart. So, for instance, language is an arbitrary (Saussure) thing that has very little in the way of “essence” in its own (autonomous) right. Terms like “whakapapa” equate precisely with “genealogy” but their interconnecting sense is lost in that translation. From a Maori belief, it could be argued that everything contains an essence, including words, and this essence precedes our interaction with language. In a way, language very much opens up a worldview, including the autonomy or essence of things in the world and their interconnectedness. pp. 101–110

text: Te reo Maori, philosophy and colonialism: A conversation with Maori philosopher Carl Mika Kia ora Carl
Some advice if you have the time... I have been asked to give a paper at Uppsala on philosophy of language and autonomy. I want to focus on colonialism and use some examples from the colonial history concerning te reo Maori. I did a little research at the time of the Royal Commission in 1988 but have lost touch with the literature. Are there a couple of strategic texts you would recommend?
Nga Mihi

Kia ora Michael
You tend to get two types of writing about the language: its revitalisation; and its link to the natural or spiritual worlds – which is to do with philosophy in a particular sense, but in my view doesn’t have an eye towards the “autonomy” part you raise (i.e. isn’t cognisant enough of colonialism). The latter writing theorises around the traditional place of language, or describes it as a traditional phenomenon. I’ve been considering writing something for some time on it, but just haven’t gotten around to it.
You could discuss it in terms of how current uses of it in government policy etc. force the Maori language to become no more or no less than its English counterpart. So, for instance, language is an arbitrary (Saussure) thing that has very little in the way of “essence” in its own (autonomous) right. Terms like “whakapapa” equate precisely with “genealogy” but their interconnecting sense is lost in that translation. From a Maori belief, it could be argued that everything contains an essence, including words, and this essence precedes our interaction with language. In a way, language very much opens up a worldview, including the autonomy or essence of things in the world and their interconnectedness. pp. 101–110

year: 2015