Showing items 34661 - 34680 of 63333

Machipsa wateere muchikunda

- Umtali Chipisa Band, Composer not specified, Tracey, Hugh

Machipisa wateere muChiRunda

- Umtali Chipisa Band, performer not specified, Composer not specified, Tracey, Hugh

Machipisa wateere muchikunda

- Umtali Chipisa Band, Composer not specified, Tracey, Hugh

Machinery, washing Diamond Ground Premium Mine, Wesselton, De Beers Property

  • Subjects: Kalk Bay (South Africa)-- History -- Photographs
  • Type: Image
  • Identifier: http://hdl.handle.net/10962/29056 , vital:23710 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017. , PIC/A 2718_58
  • Description: Album of photographs,[collected by W.L. (?) perhaps W. Lawrence (?)] covering the following subjects: (1) Rhodesia; (2) Cape Town; (3) Cape Colony; (4) Mines; (5) Ships; (6) Misc.; (7) People. 1897-1899. , Gold Fields of South Africa Ltd. (donor)
  • Full Text: false

Machinery, washing Diamond Ground Premium Mine, Wesselton, De Beers Property

  • Subjects: (South Africa)-- History -- Photographs
  • Type: Image
  • Identifier: http://hdl.handle.net/10962/29037 , vital:23708 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017. , PIC/A 2718_59
  • Description: Album of photographs,[collected by W.L. (?) perhaps W. Lawrence (?)] covering the following subjects: (1) Rhodesia; (2) Cape Town; (3) Cape Colony; (4) Mines; (5) Ships; (6) Misc.; (7) People. 1897-1899. , Gold Fields of South Africa Ltd. (donor)
  • Full Text: false

Machine learning methods for calibrating radio interferometric data

- Zitha, Simphiwe Nhlanhla

  • Authors: Zitha, Simphiwe Nhlanhla
  • Date: 2019
  • Subjects: Calibration , Radio astronomy -- Data processing , Radio astronomy -- South Africa , Karoo Array Telescope (South Africa) , Radio telescopes -- South Africa , Common Astronomy Software Application (Computer software)
  • Language: English
  • Type: text , Thesis , Masters , MSc
  • Identifier: http://hdl.handle.net/10962/97096 , vital:31398
  • Description: The applications of machine learning have created an opportunity to deal with complex problems currently encountered in radio astronomy data processing. Calibration is one of the most important data processing steps required to produce high dynamic range images. This process involves the determination of calibration parameters, both instrumental and astronomical, to correct the collected data. Typically, astronomers use a package such as Common Astronomy Software Applications (CASA) to compute the gain solutions based on regular observations of a known calibrator source. In this work we present applications of machine learning to first generation calibration (1GC), using the KAT-7 telescope environmental and pointing sensor data recorded during observations. Applying machine learning to 1GC, as opposed to calculating the gain solutions in CASA, has shown evidence of reducing computation, as well as accurately predict the 1GC gain solutions representing the behaviour of the antenna during an observation. These methods are computationally less expensive, however they have not fully learned to generalise in predicting accurate 1GC solutions by looking at environmental and pointing sensors. We call this multi-output regression model ZCal, which is based on random forest, decision trees, extremely randomized trees and K-nearest neighbor algorithms. The prediction error obtained during the testing of our model on testing data is ≈ 0.01 < rmse < 0.09 for gain amplitude per antenna, and 0.2 rad < rmse <0.5 rad for gain phase. This shows that the instrumental parameters used to train our model more strongly correlate with gain amplitude effects than phase.
  • Full Text:
  • Date Issued: 2019

Machinability of rapidly solidified aluminium alloy for optical applications

- Abbas, Abdalla Abbas Said

  • Authors: Abbas, Abdalla Abbas Said
  • Date: 2020
  • Subjects: Aluminum alloys , Mechatronics
  • Language: English
  • Type: Thesis , Masters , MEng
  • Identifier: http://hdl.handle.net/10948/45975 , vital:39402
  • Description: The production of metal mirrors and critical components for optical devices and aerospace application requires extreme high accuracy and outstanding surface quality. Thus, to achieve such high dimensional accuracies, they are being mainly produced through ultra-high precision machining. Aluminium alloys have been used in the production of components for optics application as well as spaceborne for so many years but with the advancement in technology and demands for a superior material, a new modified grade of aluminium was developed by a rapid solidification process. These grades exhibit a much better mechanical and physical properties while having a finer microstructure. The only downside is the limited research in the correlation of surface roughness and reflectance when single point diamond turned. In this study, rapidly solidified aluminium RSA 905 were used to investigate the effect of varying the cutting parameters on the machined surface finish and its corresponding surface reflectance. The cutting parameters were cutting speed, feed rate and depth of cut. The surface roughness was measured using Taylor Hopson PGI Profilometer while the reflectance factor was measured by using VERTEX 80v Spectrometer. The results were used to develop two predictive models namely; response surface and artificial neural network which have indicated a very high accuracy to the experimental measurements. Finally, the results were very promising for the diamond turning of RSA 905 where it has achieved a very low values of surface roughness and high reflectance in the visual range without the need of any additional production/fabrication steps and to ensure that bi-metallic binding does not take place in extreme low temperatures. Therefore, RSA 905 is a very promising material for optical applications in the visual spectrum.
  • Full Text:
  • Date Issued: 2020

Machichimana

- Tabarirevu Muyambo, Tracey, Hugh

  • Authors: Tabarirevu Muyambo , Tracey, Hugh
  • Date: 1963
  • Subjects: Folk music--Africa , Music--Mozambique , Folk songs, Chopi , Chopi (African people) , Field recordings , Africa, Sub-Saharan , Africa Mozambique Mwanditura f-mz
  • Language: Ndau
  • Type: sound recordings , field recordings , sound recording-musical
  • Identifier: http://hdl.handle.net/10962/194257 , vital:45437 , International Library of African Music, Rhodes University, Grahamstown, South Africa , TR205-10
  • Description: This is one of a number of songs known as Machichimana, meaning 'the place which has been cleared (of trees).' The wife of Surudade, why is she so proud? (does she walk in the sky). At Marukana only..." The clearing of the bush refers to the open strips cut to prevent the spread of Tsetse fly. Topical song with Mbira dze chiNdau with external tin deze resonator.
  • Full Text: false
  • Date Issued: 1963

Machi (March)

- Johnnie Murithe Wambu and Kibunga Waita, Hugh Tracey

  • Authors: Johnnie Murithe Wambu and Kibunga Waita , Hugh Tracey
  • Date: 1950
  • Subjects: Folk songs, Kikuyu , Kikuyu (African people) , Songs, Kikuyu--Kenya , Folk music , Field recordings , Africa, Sub-Saharan , Africa Kenya Embu f-ke
  • Language: Kikuyu
  • Type: sound recordings , field recordings , sound recording-musical
  • Identifier: http://hdl.handle.net/10962/175607 , vital:42598 , International Library of African Music, Rhodes University, Grahamstown, South Africa , TR159-15
  • Description: The singer was a cycle repairer by trade, claimed to belong to the Njeudura age grade (his own age at the time being about 22 years in 1952). He, like other Kikuyu who buy these expensive accordians uses it as a noise maker rather than a melodic or harmonic accompaniment. As with the guitar players they rarely change key. This performance was remarkable for the understanding between the singer and his accompanist on the 'iron'. For the recording the man with his piece of iron and box had to be placed a considerable distance from the microphone. Mamboko dance with accordian and struck iron (-12.16-).
  • Full Text: false
  • Date Issued: 1950

Machi

- Wambu, Johnnie Murithe, Waita, Kibunga, Composer unknown, Tracey, Hugh

Machi

- Johnnie Murithe Wambu, Kibungu Waita, Composer not specified, Tracey, Hugh

Machi

- Wambu, Johnnie Murithe, Waita, Kibunga, Composer unknown, Tracey, Hugh

Machero nirdauka

- Coast social orchestra, Ayub, Alexander, Tracey, Hugh

  • Authors: Coast social orchestra , Ayub, Alexander , Tracey, Hugh
  • Date: 1952-09-27
  • Subjects: Folk music--Africa , Field recordings , Africa, Sub-Saharan , Africa Kenya Nairobi f-ke
  • Language: Swahili
  • Type: sound recordings , field recordings , sound recording-musical
  • Identifier: http://hdl.handle.net/10962/222861 , vital:48921 , International Library of African Music, Rhodes University, Makhanda, South Africa , Hugh Tracey Field Tapes, Rhodes University, Makhanda, South Africa , HTFT328-F128 , Research no. F5A8
  • Description: A rumba song played by a dance band accompanied by trumpet, saxophone, clarinet, piano, accordion, guitar, drums and a rattle.
  • Full Text: false
  • Date Issued: 1952-09-27

Machero nindauka

- Coast Social Orchestra, Performer not specified, Alexander Ayub, Tracey, Hugh

Machatini

- Maviya, Chopi women, Mwutamula, Tracey, Hugh

Machatini

- Maviya, Chopi women, Mwatamula Mahlatini, Tracey, Hugh

Machapa

- Shabani Abdullah, Dar es Salaam Jazz Band, Machapa, Tracey, Hugh

Machapa

- Dar-es-Salaam Jazz Band, Abdullah, Shabani, Tracey, Hugh

Machapa

- Dar-Es-Salaam Jazz Band, Composer not specified, Tracey, Hugh

Mabumbumbu 2

- Toiya wa Mayita, Giriyama drummers, Tracey, Hugh

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