title: Applying machine learning to subject classification and subject description for information retrieval

authors: Cunningham, Sally Jo

subjects: computer science

abstract: This paper describes an experiment in applying standard supervised machine learning algorithms (C4.5 and Induct) to the problem of developing subject classification rules for documents. These algorithms are found to produce surprisingly concise models of document classifications. While the models are highly accurate on the training sets, evaluation over test sets or through cross-validation shows a significant decrease in classification accuracy. Given the difficult nature of the experimental task, however, the results of this investigation are promising and merit further study. An additional algorithm, 1R, is shown to be highly effective in generating lists of candidate terms for subject descriptions.

text: Applying machine learning to subject classification and subject description for information retrieval This paper describes an experiment in applying standard supervised machine learning algorithms (C4.5 and Induct) to the problem of developing subject classification rules for documents. These algorithms are found to produce surprisingly concise models of document classifications. While the models are highly accurate on the training sets, evaluation over test sets or through cross-validation shows a significant decrease in classification accuracy. Given the difficult nature of the experimental task, however, the results of this investigation are promising and merit further study. An additional algorithm, 1R, is shown to be highly effective in generating lists of candidate terms for subject descriptions.

year: 1995-06

title: Additive manufacturing of Ti-6Al-4V with added boron: Microstructure and hardness modification

authors: Jackson, Benjamin Ivan

abstract: Titanium alloy composites with titanium boride (TiB) discontinuous reinforcement have shown improved performance in terms of strength, stiffness, and hardness. Producing this composite through selective laser melting (SLM) can combine the advantages of freeform design with the ability to produce TiB reinforcement in-situ. In this study, SLM was used to consolidate a pre-alloyed Ti-6Al-4V (Ti64) and amorphous boron (B) powder mixture with the intent of producing 1.5wt% TiB reinforcement in a Ti64 matrix. The processing parameters of laser power and scanning speed were investigated for their effect on the density, microstructures, and hardness of the composite material. The results showed that the boron and Ti64 composite could achieve a density greater than 99.4%. Furthermore, it was found that processing parameters changed the microstructural features of the material. The higher the energy density employed the more homogenous the distribution of boron modified material. Macro features were also observed with laser paths being clearly evident in the subsurface microstructure. Micro-hardness testing and density measurement also showed a corresponding increase with increasing energy density. Maximum hardness of 392.4HV was achieved in the composite compared to 354.2HV in SLM fabricated Ti64.

text: Additive manufacturing of Ti-6Al-4V with added boron: Microstructure and hardness modification Titanium alloy composites with titanium boride (TiB) discontinuous reinforcement have shown improved performance in terms of strength, stiffness, and hardness. Producing this composite through selective laser melting (SLM) can combine the advantages of freeform design with the ability to produce TiB reinforcement in-situ. In this study, SLM was used to consolidate a pre-alloyed Ti-6Al-4V (Ti64) and amorphous boron (B) powder mixture with the intent of producing 1.5wt% TiB reinforcement in a Ti64 matrix. The processing parameters of laser power and scanning speed were investigated for their effect on the density, microstructures, and hardness of the composite material. The results showed that the boron and Ti64 composite could achieve a density greater than 99.4%. Furthermore, it was found that processing parameters changed the microstructural features of the material. The higher the energy density employed the more homogenous the distribution of boron modified material. Macro features were also observed with laser paths being clearly evident in the subsurface microstructure. Micro-hardness testing and density measurement also showed a corresponding increase with increasing energy density. Maximum hardness of 392.4HV was achieved in the composite compared to 354.2HV in SLM fabricated Ti64.

year: 2018

title: Tūturu whakamaua ko te kupu, haumi e, hui e, ko ngā kupu o te mātauranga ē!

authors: Dale, Hēmi

subjects: Reo Māori

abstract: Ko tā tēnei tuhinga he arotahi ki ētahi o ngā take reo e pā ana ki ngā mahi whakangungu pouako mā te huarahi o te reo Māori i roto i te whare wānanga. Ka mutu, ka kōrerorerotia ngā urupare a te Huarahi Māori (tētahi kaiwhakarato whakangungu pouako mā te huarahi o te reo Māori) ki ētahi o ēnei take reo.

text: Tūturu whakamaua ko te kupu, haumi e, hui e, ko ngā kupu o te mātauranga ē! Ko tā tēnei tuhinga he arotahi ki ētahi o ngā take reo e pā ana ki ngā mahi whakangungu pouako mā te huarahi o te reo Māori i roto i te whare wānanga. Ka mutu, ka kōrerorerotia ngā urupare a te Huarahi Māori (tētahi kaiwhakarato whakangungu pouako mā te huarahi o te reo Māori) ki ētahi o ēnei take reo.

year: 2017