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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Mesh regulations of bottom trawl for the protection of economic immature fishes off southwestern Taiwan

Huang, Meng-Hsun 09 September 2008 (has links)
The present research adopts with the application of the sequential mesh regulations on bottom trawl to study how to protect economic immature fishes. The experimental design includes first the determination of the relationships of fish size and the price per weight (PPW) of the economic demersal fishes sold as the one-hundred Dollars-a-plate manner in Tunkang and Zihguan fish markets in the southwestern coast of Taiwan. The obtained results were used to yield the catch of smaller size fishes and the lower PPW for regulating the economic immature fishes. The three kinds of regulated fish size were defined as the smallest surveyed size, smallest economic size, and smallest matured size. These regulated fish size were used as the body lengths of 50% selection (L50) to calculate the regulating mesh size. This study presents that four steps are needed for the sequential mesh regulations of bottom trawl in the southwestern Taiwan. The first step is to regulate the mesh size between 35 and 45 mm for banning bottom trawler to catch fishes smaller than the smallest surveyed fish size. The objective of first step is to reduce the bycatch without affecting the landings of economic immature fishes sold in the fish market. The second step is to regulate the mesh size between 50 and 60 mm for banning bottom trawler catch fishes smaller than the smallest economic fish size, and to reduce the catch of smaller size fishes and the lower PPW of economic immature fishes. The third step is to regulate the mesh size between 65 and 70 mm for banning bottom trawler to catch fishes smaller than the smallest matured fish size. This is also to reduce the catch of economic immature fishes, and to increase the recruitment. The fourth step is to regulate the mesh size between 70 and 82 mm for banning bottom trawler catching the lower PPW of economic fishes that is not large enough to reach their optimal PPW. The present research provides important data results for regulating the mesh size of bottom trawler operation for the achievement of sustainable coastal fishery in Taiwan.
2

Assessing the influence of observations on the generalization performance of the kernel Fisher discriminant classifier

Lamont, Morné Michael Connell 12 1900 (has links)
Thesis (PhD (Statistics and Actuarial Science))—Stellenbosch University, 2008. / Kernel Fisher discriminant analysis (KFDA) is a kernel-based technique that can be used to classify observations of unknown origin into predefined groups. Basically, KFDA can be viewed as a non-linear extension of Fisher’s linear discriminant analysis (FLDA). In this thesis we give a detailed explanation how FLDA is generalized to obtain KFDA. We also discuss two methods that are related to KFDA. Our focus is on binary classification. The influence of atypical cases in discriminant analysis has been investigated by many researchers. In this thesis we investigate the influence of atypical cases on certain aspects of KFDA. One important aspect of interest is the generalization performance of the KFD classifier. Several other aspects are also investigated with the aim of developing criteria that can be used to identify cases that are detrimental to the KFD generalization performance. The investigation is done via a Monte Carlo simulation study. The output of KFDA can also be used to obtain the posterior probabilities of belonging to the two classes. In this thesis we discuss two approaches to estimate posterior probabilities in KFDA. Two new KFD classifiers are also derived which use these probabilities to classify observations, and their performance is compared to that of the original KFD classifier. The main objective of this thesis is to develop criteria which can be used to identify cases that are detrimental to the KFD generalization performance. Nine such criteria are proposed and their merit investigated in a Monte Carlo simulation study as well as on real-world data sets. Evaluating the criteria on a leave-one-out basis poses a computational challenge, especially for large data sets. In this thesis we also propose using the smallest enclosing hypersphere as a filter, to reduce the amount of computations. The effectiveness of the filter is tested in a Monte Carlo simulation study as well as on real-world data sets.
3

Multivariate analysis of war crime behaviour : implications for the International Criminal Court

Furphy, Patricia January 2015 (has links)
To prosecute perpetrators of war crimes the International Criminal Court (ICC) must connect the physical actions of the offence and ‘most responsible’ offenders charged with planning, instigating and intent on carrying out crimes of genocide, crimes against humanity, war crimes and crimes of aggression. To date there has been no empirical study of the types of physical actions that make up this offence. There is no baseline knowledge to contextualize the offence and enable the ICC to make links between the actions on the ground and a perpetrator’s culpability. The purpose of this study was to produce the first multivariate model of war crime ground action using cases of war crime offences in Cambodia and Rwanda. The aim was to first identify a representative range offence behaviours, and secondly determine if ground actions could be differentiated into distinct forms of offending that indicate culpability, that is, knowledge and intent in carrying out the crime. Lastly, offence behaviours assessed to determine if external factors could account for variances in offender behaviour, and help the ICC account for variances in behaviour when making inferences from the models. This was achieved through content analysis, cluster analysis, smallest space analysis and multivariate analysis of variance. It was found that as many as 44 different killing and disposal methods are used over the course of war crimes in Cambodia and Rwanda and that these offence actions can be classified into four distinct themes of behaviour. The indentified conservative, expressive, integrative and adaptive theme demonstrates that offenders were committing war crime offences in different ways. Using the underlying theories attached to each mode the ICC can infer the culpability of an offender based on which theme their actions fall into. In this case offenders subscribing to the conservative theme are likely to reflect the planning and instigation components of a war crime and offenders whose actions fall within the expressive theme are likely to be using war crimes as a cover for personal gratification and gain. Finally it was found that variances of behaviour can be attributed to the geographical location and timing of the event, and helps the ICC target their investigations to locations and periods linked to conservative behaviour, the offender who performs it and thus their culpability. This study shows that multivariate analysis can contextualize ground actions in manner that allows the ICC to make informed decisions of perpetrator culpability during war crimes.
4

Conjugacy Class Sizes of the Symmetric and Alternating Groups

Dickson, Cavan James 16 May 2014 (has links)
No description available.
5

Hur arbetar man i förskolan med fysik med de minsta? : En intervjustudie med förskollärare och förskolechefer. / How does one work in preschool with physics with the smallest children? : An interview study with preschool teachers and preschool directors.

Billman, Emil January 2014 (has links)
Syftet med undersökningen är att se på fysik med de minsta barnen på förskolan, hur det uppfattas och hur det arbetas med. Har man bra material för att arbeta med fysik och känner man att man kan det? Metoden som används i undersökningen är intervjuer av det kvalitativa slaget. Fyra förskollärare och två förskolechefer intervjuades utifrån 2 frågescheman som skiljde sig lite åt ifall man var förskollärare eller förskolechef.  Resultatet visade att förskollärarna ansåg att de inte hade så jättemycket kunskap inom fysikområdet och att det kan vara lite knepigt att arbeta med. Att se vilket material som passar att använda i en fysiksituation sågs inte som superlätt av två stycken medans två ansåg att det mesta gick att använda. / The purpose with this survey is to look at physics with the smallest children at the preschool, how it is perceived and how it is worked with. Do they have good materials to work with physics and do they feel that they can work with it? The method that is being used in this survey is interviews of the qualitative style. Four preschool teacher and two preschool directors was interviewed according to a schedule that was different if you were a preschool teacher or a preschool director. The result showed that the preschool teachers considered that they didn’t have that much knowledge in physics and that it was a little bit tricky to work with. To see which material that would fit best to use in a physics situation was perceived as hard by two teachers while two teachers thought that most materials could be used.
6

Úprava nanomanipulátoru používaného v elektronovém mikroskopu / Modification of nanomanipulator used in electron microscope

Habarka, Ondrej January 2016 (has links)
Cílem této diplomové práce je zlepšit chování nanomanipulátoru, používaného v elektronovém mikroskopu, při vykonávaní nejmenších kroků pohybu. První částí je analýza mechanismu za účelem nalezení možných řešení problému. Dále se práce zabývá testováním řešení jako je optimalizace tuhosti předepínacích pružin mechanismu anebo změna mazání šnekového převodu mechanismu. Výsledkem práce je výběr nejvhodnějšího řešení problému na základě výsledků testů a následná modifikace nanomanipulátoru.
7

Digital Geometry and Khalimsky Spaces / Digital Geometri och Khalimskyrum

Melin, Erik January 2008 (has links)
<p>Digital geometry is the geometry of digital images. Compared to Euclid’s geometry, which has been studied for more than two thousand years, this field is very young.</p><p>Efim Khalimsky’s topology on the integers, invented in the 1970s, is a digital counterpart of the Euclidean topology on the real line. The Khalimsky topology became widely known to researchers in digital geometry and computer imagery during the early 1990s.</p><p>Suppose that a continuous function is defined on a subspace of an <i>n-</i>dimensional Khalimsky space. One question to ask is whether this function can be extended to a continuous function defined on the whole space. We solve this problem. A related problem is to characterize the subspaces on which every continuous function can be extended. Also this problem is solved.</p><p>We generalize and solve the extension problem for integer-valued, Khalimsky-continuous functions defined on arbitrary smallest-neighborhood spaces, also called Alexandrov spaces.</p><p>The notion of a digital straight line was clarified in 1974 by Azriel Rosenfeld. We introduce another type of digital straight line, a line that respects the Khalimsky topology in the sense that a line is a topological embedding of the Khalimsky line into the Khalimsky plane.</p><p>In higher dimensions, we generalize this construction to digital Khalimsky hyperplanes, surfaces and curves by digitization of real objects. In particular we study approximation properties and topological separation properties. </p><p>The last paper is about Khalimsky manifolds, spaces that are locally homeomorphic to <i>n-</i>dimensional Khalimsky space. We study different definitions and address basic questions such as uniqueness of dimension and existence of certain manifolds.</p>
8

Digital Geometry and Khalimsky Spaces / Digital Geometri och Khalimskyrum

Melin, Erik January 2008 (has links)
Digital geometry is the geometry of digital images. Compared to Euclid’s geometry, which has been studied for more than two thousand years, this field is very young. Efim Khalimsky’s topology on the integers, invented in the 1970s, is a digital counterpart of the Euclidean topology on the real line. The Khalimsky topology became widely known to researchers in digital geometry and computer imagery during the early 1990s. Suppose that a continuous function is defined on a subspace of an n-dimensional Khalimsky space. One question to ask is whether this function can be extended to a continuous function defined on the whole space. We solve this problem. A related problem is to characterize the subspaces on which every continuous function can be extended. Also this problem is solved. We generalize and solve the extension problem for integer-valued, Khalimsky-continuous functions defined on arbitrary smallest-neighborhood spaces, also called Alexandrov spaces. The notion of a digital straight line was clarified in 1974 by Azriel Rosenfeld. We introduce another type of digital straight line, a line that respects the Khalimsky topology in the sense that a line is a topological embedding of the Khalimsky line into the Khalimsky plane. In higher dimensions, we generalize this construction to digital Khalimsky hyperplanes, surfaces and curves by digitization of real objects. In particular we study approximation properties and topological separation properties. The last paper is about Khalimsky manifolds, spaces that are locally homeomorphic to n-dimensional Khalimsky space. We study different definitions and address basic questions such as uniqueness of dimension and existence of certain manifolds.
9

Methods for Blind Separation of Co-Channel BPSK Signals Arriving at an Antenna Array and Their Performance Analysis

Anand, K 07 1900 (has links)
Capacity improvement of Wireless Communication Systems is a very important area of current research. The goal is to increase the number of users supported by the system per unit bandwidth allotted. One important way of achieving this improvement is to use multiple antennas backed by intelligent signal processing. In this thesis, we present methods for blind separation of co-channel BPSK signals arriving at an antenna array. These methods consist of two parts, Constellation Estimation and Assignment. We give two methods for constellation estimation, the Smallest Distance Clustering and the Maximum Likelihood Estimation. While the latter is theoretically sound,the former is Computationally simple and intuitively appealing. We show that the Maximum Likelihood Constellation Estimation is well approximated by the Smallest Distance Clustering Algorithm at high SNR. The Assignment Algorithm exploits the structure of the BPSK signals. We observe that both the methods for estimating the constellation vectors perform very well at high SNR and nearly attain Cramer-Rao bounds. Using this fact and noting that the Assignment Algorithm causes negligble error at high SNR, we derive an upper bound on the probability of bit error for the above methods at high SNR. This upper bound falls very rapidly with increasing SNR, showing that our constellation estimation-assignment approach is very efficient. Simulation results are given to demonstrate the usefulness of the bounds.
10

Investigation into whether some key properties of BN under addition also apply in BN under multiplication and elaboration of some properties of the smallest ideal of a semigroup

Mweete, Kapaipi Hendrix 08 1900 (has links)
This dissertation will seek to explore if the properties of some of the key results on semigroups and their compacti cations under the operation of addition also apply under the operation of multiplication. Consider- able emphasis will be placed on the semigroup N of the set of natural numbers and its compacti cation N. Furthermore, the dissertation will discuss the smallest ideal of a semi- group and highlight some of its fundamental properties. / Mathematics / M. Sc. (Mathematics)

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