A development method for deriving reusable concurrent programs from verified CSP models
- Authors: Dibley, James
- Date: 2019
- Subjects: CSP (Computer program language) , Sequential processing (Computer science) , Go (Computer program language) , CSPIDER (Open source tool)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/72329 , vital:30035
- Description: This work proposes and demonstrates a novel method for software development that applies formal verification techniques to the design and implementation of concurrent programs. This method is supported by a new software tool, CSPIDER, which translates machine-readable Communicating Sequential Processes (CSP) models into encapsulated, reusable components coded in the Go programming language. In relation to existing CSP implementation techniques, this work is only the second to implement a translator and it provides original support for some CSP language constructs and modelling approaches. The method is evaluated through three case studies: a concurrent sorting array, a trialdivision prime number generator, and a component node for the Ricart-Agrawala distributed mutual exclusion algorithm. Each of these case studies presents the formal verification of safety and functional requirements through CSP model-checking, and it is shown that CSPIDER is capable of generating reusable implementations from each model. The Ricart-Agrawala case study demonstrates the application of the method to the design of a protocol component. This method maintains full compatibility with the primary CSP verification tool. Applying the CSPIDER tool requires minimal commitment to an explicitly defined modelling style and a very small set of pre-translation annotations, but all of these measures can be instated prior to verification. The Go code that CSPIDER produces requires no intervention before it may be used as a component within a larger development. The translator provides a traceable, structured implementation of the CSP model, automatically deriving formal parameters and a channel-based client interface from its interpretation of the CSP model. Each case study demonstrates the use of the translated component within a simple test development.
- Full Text:
- Date Issued: 2019
- Authors: Dibley, James
- Date: 2019
- Subjects: CSP (Computer program language) , Sequential processing (Computer science) , Go (Computer program language) , CSPIDER (Open source tool)
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/72329 , vital:30035
- Description: This work proposes and demonstrates a novel method for software development that applies formal verification techniques to the design and implementation of concurrent programs. This method is supported by a new software tool, CSPIDER, which translates machine-readable Communicating Sequential Processes (CSP) models into encapsulated, reusable components coded in the Go programming language. In relation to existing CSP implementation techniques, this work is only the second to implement a translator and it provides original support for some CSP language constructs and modelling approaches. The method is evaluated through three case studies: a concurrent sorting array, a trialdivision prime number generator, and a component node for the Ricart-Agrawala distributed mutual exclusion algorithm. Each of these case studies presents the formal verification of safety and functional requirements through CSP model-checking, and it is shown that CSPIDER is capable of generating reusable implementations from each model. The Ricart-Agrawala case study demonstrates the application of the method to the design of a protocol component. This method maintains full compatibility with the primary CSP verification tool. Applying the CSPIDER tool requires minimal commitment to an explicitly defined modelling style and a very small set of pre-translation annotations, but all of these measures can be instated prior to verification. The Go code that CSPIDER produces requires no intervention before it may be used as a component within a larger development. The translator provides a traceable, structured implementation of the CSP model, automatically deriving formal parameters and a channel-based client interface from its interpretation of the CSP model. Each case study demonstrates the use of the translated component within a simple test development.
- Full Text:
- Date Issued: 2019
The application of rheological techniques in the characterization of semisolids in the pharmaceutical industry
- Authors: Jaganath, Nelesh
- Date: 2004
- Subjects: Drugs -- Dosage forms , Rheology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10128 , http://hdl.handle.net/10948/380 , Drugs -- Dosage forms , Rheology
- Description: Rheological characterization of pharmaceutical semisolids is of importance as it provides fundamental information required for the assessment of some of the final properties of a product such as viscosity, elasticity, quality and storage stability. The effect of formulation variables on product characteristics such as consistency and correlation of consumer evaluation of consistency can also be attained. (Ramachandran et al., 1999) This study focussed on using rheological techniques to fully characterize the properties of various semisolid formulations being developed or produced at a South African-based generic pharmaceutical company. Various tests were employed to characterize the semisolid dosage forms (creams and ointments), including continuous shear tests such as flow and viscosity curves and yield point measurements, oscillatory tests such as amplitude and frequency sweeps, as well as step and temperature ramp tests. A method to determine justifiable and meaningful viscosity specifications was developed, where excellent reproducibility of results were obtained when compared to the single-point viscosity determinations usually used. An evaluation as to whether rheology can be utilized as an assessment tool for product stability revealed varying results, with the oscillation-frequency sweep test displaying modest predictive capabilities. Observable differences in rheological character were found when evaluating ointment formulations exhibiting deviating quality characteristics. When analysing the effect of varying processing parameters, namely, cooling rate and mixing speed, during the manufacture of a cream, statistically significant rheological differences were obtained, while a thorough characterization of a scale-up procedure was also achieved upon analysis of various rheological properties.
- Full Text:
- Date Issued: 2004
- Authors: Jaganath, Nelesh
- Date: 2004
- Subjects: Drugs -- Dosage forms , Rheology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10128 , http://hdl.handle.net/10948/380 , Drugs -- Dosage forms , Rheology
- Description: Rheological characterization of pharmaceutical semisolids is of importance as it provides fundamental information required for the assessment of some of the final properties of a product such as viscosity, elasticity, quality and storage stability. The effect of formulation variables on product characteristics such as consistency and correlation of consumer evaluation of consistency can also be attained. (Ramachandran et al., 1999) This study focussed on using rheological techniques to fully characterize the properties of various semisolid formulations being developed or produced at a South African-based generic pharmaceutical company. Various tests were employed to characterize the semisolid dosage forms (creams and ointments), including continuous shear tests such as flow and viscosity curves and yield point measurements, oscillatory tests such as amplitude and frequency sweeps, as well as step and temperature ramp tests. A method to determine justifiable and meaningful viscosity specifications was developed, where excellent reproducibility of results were obtained when compared to the single-point viscosity determinations usually used. An evaluation as to whether rheology can be utilized as an assessment tool for product stability revealed varying results, with the oscillation-frequency sweep test displaying modest predictive capabilities. Observable differences in rheological character were found when evaluating ointment formulations exhibiting deviating quality characteristics. When analysing the effect of varying processing parameters, namely, cooling rate and mixing speed, during the manufacture of a cream, statistically significant rheological differences were obtained, while a thorough characterization of a scale-up procedure was also achieved upon analysis of various rheological properties.
- Full Text:
- Date Issued: 2004
A history of Grahamstown, 1918-1945
- Torlesse, Ann Catherine Marjorie
- Authors: Torlesse, Ann Catherine Marjorie
- Date: 1993
- Subjects: Grahamstown (South Africa) -- History , Grahamstown (South Africa) -- Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2565 , http://hdl.handle.net/10962/d1002418 , Grahamstown (South Africa) -- History , Grahamstown (South Africa) -- Economic conditions
- Description: This study in local history describes socio-economic developments in Grahamstown between 1918 - 1945, and analyses the extent to which these developments mirrored trends in the macrocosm. During these years the city failed to become ndustrialised, but enhanced her reputation as an eminent educational centre. Despite being financially handicapped, the City Council undertook large public works schemes for the provision of essential services, such as electricity and an adequate supply of water. In addition a water-borne sewerage scheme was introduced, and roads were repaired and tarred. The influx of a large number of poor rural Blacks into the urban area placed a considerable strain on the city's health services, and housing projects had to be implemented. Local political affiliations and race relations are examined against the background of national developments, especially the growing entrenchment by the State of the policy of segregation. Attention is also devoted to the impact upon the community of international political crises. The cultural and sporting pursuits, as well as the entertainments enjoyed by Grahamstonians, are investigated; and a picture of the local "mentalite" is presented.
- Full Text:
- Date Issued: 1993
- Authors: Torlesse, Ann Catherine Marjorie
- Date: 1993
- Subjects: Grahamstown (South Africa) -- History , Grahamstown (South Africa) -- Economic conditions
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2565 , http://hdl.handle.net/10962/d1002418 , Grahamstown (South Africa) -- History , Grahamstown (South Africa) -- Economic conditions
- Description: This study in local history describes socio-economic developments in Grahamstown between 1918 - 1945, and analyses the extent to which these developments mirrored trends in the macrocosm. During these years the city failed to become ndustrialised, but enhanced her reputation as an eminent educational centre. Despite being financially handicapped, the City Council undertook large public works schemes for the provision of essential services, such as electricity and an adequate supply of water. In addition a water-borne sewerage scheme was introduced, and roads were repaired and tarred. The influx of a large number of poor rural Blacks into the urban area placed a considerable strain on the city's health services, and housing projects had to be implemented. Local political affiliations and race relations are examined against the background of national developments, especially the growing entrenchment by the State of the policy of segregation. Attention is also devoted to the impact upon the community of international political crises. The cultural and sporting pursuits, as well as the entertainments enjoyed by Grahamstonians, are investigated; and a picture of the local "mentalite" is presented.
- Full Text:
- Date Issued: 1993
- «
- ‹
- 1
- ›
- »