title: Using Output Codes for Two-class Classification Problems

authors: Zeng, Fanhua

subjects: Machine Learning

abstract: Error-correcting output codes (ECOCs) have been widely used in many applications for multi-class classification problems. The problem is that ECOCs cannot be ap- plied directly on two-class datasets. The goal of this thesis is to design and evaluate an approach to solve this problem, and then investigate whether the approach can yield better classification models. To be able to use ECOCs, we turn two-class datasets into multi-class datasets first, by using clustering. With the resulting multi-class datasets in hand, we evalu- ate three different encoding methods for ECOCs: exhaustive coding, random coding and a “pre-defined” code that is found using random search. The exhaustive coding method has the highest error-correcting abilities. However, this method is limited due to the exponential growth of bit columns in the codeword matrix precluding it from being used for problems with large numbers of classes. Random coding can be used to cover situations with large numbers of classes in the data. To improve on completely random matrices, “pre-defined” codeword matrices can be generated by using random search that optimizes row separation yielding better error correction than a purely random matrix. To speed up the process of finding good matrices, GPU parallel programming is investigated in this thesis. From the empirical results, we can say that the new algorithm, which applies multi-class ECOCs on two-class data using clustering, does improve the performance for some base learners, when compared to applying them directly to the original two- class datasets.

text: Using Output Codes for Two-class Classification Problems Error-correcting output codes (ECOCs) have been widely used in many applications for multi-class classification problems. The problem is that ECOCs cannot be ap- plied directly on two-class datasets. The goal of this thesis is to design and evaluate an approach to solve this problem, and then investigate whether the approach can yield better classification models. To be able to use ECOCs, we turn two-class datasets into multi-class datasets first, by using clustering. With the resulting multi-class datasets in hand, we evalu- ate three different encoding methods for ECOCs: exhaustive coding, random coding and a “pre-defined” code that is found using random search. The exhaustive coding method has the highest error-correcting abilities. However, this method is limited due to the exponential growth of bit columns in the codeword matrix precluding it from being used for problems with large numbers of classes. Random coding can be used to cover situations with large numbers of classes in the data. To improve on completely random matrices, “pre-defined” codeword matrices can be generated by using random search that optimizes row separation yielding better error correction than a purely random matrix. To speed up the process of finding good matrices, GPU parallel programming is investigated in this thesis. From the empirical results, we can say that the new algorithm, which applies multi-class ECOCs on two-class data using clustering, does improve the performance for some base learners, when compared to applying them directly to the original two- class datasets.

year: 2011

title: Innovation of e-procurement: a case study

authors: Foulds, Les R.

subjects: project management

abstract: Many organisations are increasingly searching for innovative processes and methods to achieve competitive advantage and to more fully take advantage of what they have in order to improve. This article is an illustration of this in a particular company that investigated how to improve its e-procurement processes through business innovation. Specifically, it describes how the e-procurement process can be improved by taking advantage of information technology and systems for business innovation. We explore the possibility of applying Project Management (PM) principles in order to enhance e-procurement. An understanding of the issues involved has been gained through a case study of Motorola China Inc., which has implemented a fully functional e-procurement process since 2002. Our findings establish the potential benefits, feasibility and utility of applying PM technology as a way of enhancing the existing e-procurement process. The case study also indicates that the existing planning, reporting and database management systems are likely to enhance the PM process.

text: Innovation of e-procurement: a case study Many organisations are increasingly searching for innovative processes and methods to achieve competitive advantage and to more fully take advantage of what they have in order to improve. This article is an illustration of this in a particular company that investigated how to improve its e-procurement processes through business innovation. Specifically, it describes how the e-procurement process can be improved by taking advantage of information technology and systems for business innovation. We explore the possibility of applying Project Management (PM) principles in order to enhance e-procurement. An understanding of the issues involved has been gained through a case study of Motorola China Inc., which has implemented a fully functional e-procurement process since 2002. Our findings establish the potential benefits, feasibility and utility of applying PM technology as a way of enhancing the existing e-procurement process. The case study also indicates that the existing planning, reporting and database management systems are likely to enhance the PM process.

year: 2006

title: Radiocarbon dates on desiccated moa (Dinornithiformes) flesh from Inland Otago, New Zealand

authors: Anderson, Atholl

subjects: New Zealand

abstract: Remains of soft tissues from extinct moa (Dinornithiformes), mainly desiccated sinew, muscle, skin, and feathers have been recovered rather seldom but their distribution is distinctive. Of 22 records of such finds accumulated between 1864 and 1987, 15 came from inland Otago (Anderson 1989: 67–68, Table 5.2), west of Dunedin in the southern South Island. Most were found in the late nineteenth century (13 records) in rockshelters, clefts or alluvial sediments and were regarded at the time as evidence of the survival of moa up to about AD 1800 (Hutton and Coughtrey 1874a). Improbable as this latter point is, it has not been tested by radiocarbon dating until now. Our particular impetus to do so, however, arises in another way. It is from research, again largely within inland Otago, on Maori artefacts which have also been made from various other kinds of soft tissues (flax, grasses, dog skin, bird skin, feathers etc.). A series of accelerator mass spectrometry (AMS) radiocarbon dates on these (Anderson et al., n.d.) shows that they are exclusively late, post-AD 1650, which begs the question of why the age range does not extend across the full prehistoric period, beginning about AD 1300.

text: Radiocarbon dates on desiccated moa (Dinornithiformes) flesh from Inland Otago, New Zealand Remains of soft tissues from extinct moa (Dinornithiformes), mainly desiccated sinew, muscle, skin, and feathers have been recovered rather seldom but their distribution is distinctive. Of 22 records of such finds accumulated between 1864 and 1987, 15 came from inland Otago (Anderson 1989: 67–68, Table 5.2), west of Dunedin in the southern South Island. Most were found in the late nineteenth century (13 records) in rockshelters, clefts or alluvial sediments and were regarded at the time as evidence of the survival of moa up to about AD 1800 (Hutton and Coughtrey 1874a). Improbable as this latter point is, it has not been tested by radiocarbon dating until now. Our particular impetus to do so, however, arises in another way. It is from research, again largely within inland Otago, on Maori artefacts which have also been made from various other kinds of soft tissues (flax, grasses, dog skin, bird skin, feathers etc.). A series of accelerator mass spectrometry (AMS) radiocarbon dates on these (Anderson et al., n.d.) shows that they are exclusively late, post-AD 1650, which begs the question of why the age range does not extend across the full prehistoric period, beginning about AD 1300.

year: 2010