A proxy approach to protocol interoperability within digital audio networks
- Authors: Igumbor, Osedum Peter
- Date: 2010
- Subjects: Digital communications , Local area networks (Computer networks) , Computer sound processing , Computer networks , Computer network protocols
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4601 , http://hdl.handle.net/10962/d1004852 , Digital communications , Local area networks (Computer networks) , Computer sound processing , Computer networks , Computer network protocols
- Description: Digital audio networks are becoming the preferred solution for the interconnection of professional audio devices. Prominent amongst their advantages are: reduced noise interference, signal multiplexing, and a reduction in the number of cables connecting networked devices. In the context of professional audio, digital networks have been used to connect devices including: mixers, effects units, preamplifiers, breakout boxes, computers, monitoring controllers, and synthesizers. Such networks are governed by protocols that define the connection management rocedures, and device synchronization processes of devices that conform to the protocols. A wide range of digital audio network control protocols exist, each defining specific hardware requirements of devices that conform to them. Device parameter control is achieved by sending a protocol message that indicates the target parameter, and the action that should be performed on the parameter. Typically, a device will conform to only one protocol. By implication, only devices that conform to a specific protocol can communicate with each other, and only a controller that conforms to the protocol can control such devices. This results in the isolation of devices that conform to disparate protocols, since devices of different protocols cannot communicate with each other. This is currently a challenge in the professional music industry, particularly where digital networks are used for audio device control. This investigation seeks to resolve the issue of interoperability between professional audio devices that conform to different digital audio network protocols. This thesis proposes the use of a proxy that allows for the translation of protocol messages, as a solution to the interoperability problem. The proxy abstracts devices of one protocol in terms of another, hence allowing all the networked devices to appear as conforming to the same protocol. The proxy receives messages on behalf of the abstracted device, and then fulfills them in accordance with the protocol that the abstracted device conforms to. Any number of protocol devices can be abstracted within such a proxy. This has the added advantage of allowing a common controller to control devices that conform to the different protocols.
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- Date Issued: 2010
Hydrogeology of the Queenstown 1:500 000 map region (Sheet 3126)
- Authors: Smart, Michael Charles
- Date: 1999
- Subjects: Hydrogeology , Hydrogeology Maps , Hydrogeology -- South Africa -- Queenstown
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4971 , http://hdl.handle.net/10962/d1005583 , Hydrogeology , Hydrogeology Maps , Hydrogeology -- South Africa -- Queenstown
- Description: The Groundwater characteristics of a portion of the Eastern Cape are depicted on a General Hydrogeological Map (Queenstown 3126) at 1 :500 000 scale. The purpose of the map and accompanying text is to provide a synoptic overview of the hydrogeology of the area. The "fractured and intergranular" aquifer type predominates in the more humid eastern part of the study area where the lithologies are more highly weathered whereas the fractured type predominates in the drier west. For the bulk of the area borehole yields are in the 0.5 - 2.0 ℓ/sec range. Higher yields (in the 2.0 - 5.0 ℓ/sec range) are common only in a small area in the south-west of the map. Lowest yields (0.1 - 0.5 ℓ/sec) are obtained in an area immediately north of East London and in the Dwyka Group near the NE coast. It is important to note that these yield ranges are merely a measure of the central tendency, and that higher yields - in excess of 3 ℓ/sec - could well be obtainable at optimal hydrogeological target features within these areas. Highest borehole yields are obtained in folded areas (restricted to the southern edge of the study area) followed by rocks with dolerite intrusions (common over the bulk of the study area). Other targets include fractured sedimentary and volcanic rock and unconsolidated deposits. Yields obtained from dolerite contact zones vary across the area; differences correspond to spatial variations in the style of intrusion. Highest success rates are obtained in areas intruded by a combination of dykes, ring-shaped sheets and irregular sheets while poor results are obtained in areas intruded by thick massive sills. Air photo and satellite image interpretation, geological mapping, magnetic, electrical resistivity and electromagnetic geophysical methods can be used to locate drilling target features. Groundwater quality is good since electrical conductivities over much of the area are lower than 70 mS/m and rarely exceed the South African Water quality guideline limit for human consumption of 300 mS/m. The volume of groundwater abstractable ranges between approximately 2 000 m³/km²/annum and 80 000 m³/km²/annum and is limited by either volumes of recharge or subsurface storage.
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- Date Issued: 1999
The influence of sex steroids on pineal enzymes
- Authors: Daya, Santylal
- Date: 1982 , 2013-03-28
- Subjects: Steroid hormones , Pineal gland , Testosterone , Progesterone
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3808 , http://hdl.handle.net/10962/d1003720 , Steroid hormones , Pineal gland , Testosterone , Progesterone
- Description: The influence of the gonadal sex steroids namely, estradiol, progesterone and testosterone on the two major enzymes responsible for the synthesis of melatonin in the pineal gland was investigated. These enzymes are Serotonin-N-acetyltransferase (SNAT) and Hydroxyindole-O-methyltransferase (Hl0MT). Testosterone was found to be the only sex steroid capable of influencing SNAT activity whereas all three of the sex steroids were found to influence Hl0MT activity in a biphasic dose-dependent manner. The influence of these sex steroids on radiolabeled serotonin metabolism by pineals in organ culture was also investigated. Ovariectomy, castration and the sex steroids were all found to alter the pattern of the radiolabeled serotonin metabolism by these pineal glands in organ culture. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
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- Date Issued: 1982