Thesis (MEng)--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The goal of this thesis is to provide a stepping-stone for the design and development of a software package that implements the Goal System Algorithm, based on the Theory of Constraints (TOC). This includes the complete description and explanation of the Goal System Algorithm (GS), as well as the partial implementation of this algorithm using Microsoft Access as a Database Management System (DBMS) and Microsoft Visual C++ as programming language. The main development effort was put into the development of a scheduling algorithm and the implementation of a data structure that lies at the core of this algorithm. The reason for the development of such a package is that it will aid a production manager, working in a small to medium size job-shop, in generating a schedule for production that will increase throughput, while simultaneously reducing both inventory and operating expense thereby generating profits and cash flow. With regard to this thesis and the overall project goal the following have been achieved. 1. The complete project has been researched, scoped and each step has been explained. 2. The complete program structure has been defined and broken into two separate modules; the Data Mining and Conversion Module and the TOC Scheduling Algorithm. 3. The database containing all the MRP data necessary for scheduling has been designed and implemented using a MS Access database with an ODBC connection. An ODBC connection to the database was used so that a smooth transmission to other database management systems can be made. 4. The TOC Scheduling Algorithm has been developed and the following have been implemented: • A basic user interface has been created for the insertion of all the user input and to display the constraint schedule. • A data structure called a linked list has been developed and used to store the scheduling data in memory. • The complete GS algorithm had been researched and explained. • The GS algorithm has been and implemented and tested up to the point where it schedules the constraint. • The pseudo code for the part of the GS algorithm that was not implemented has been documented and included in this report. More development needs to be done and a proper Graphical User Interface must also be created to complete this project, but after completion a Toe software package will exist that is completely unique in South Africa and the market potential for this package will be considerable. / AFRIKAANSE OPSOMMING: Die doel van hierdie tesis is om die grondslag te skep vir die ontwerp en ontwikkeling van 'n sagteware pakket wat Goldratt se Doel Sisteem Algoritme, gebasseer op die 'Theory of Constraints', implementeer. Dit sluit die gedetaileerde beskrywing van die Doel Sisteem Algoritme in en 'n gedeeltelike implementasie van die algortime, deur gebruik te maak van 'n Microsoft Access databasis as databasis bestuur sisteem en Microsoft Visual C++ as 'n programerings taal. Die hoof klem is gelê op die ontwikkeling van die skedulerings algortime en die implementasie van die strukture wat deel van die kern uitmaak van die algoritme. Die hoof rede vir die ontwikkeling van so 'n pakket is sodat dit 'n produksie bestuurder van 'n klein to medium grootte vervaardigings besigheid sal help om 'n skedule vir produksie the genereer wat die vloer se deurset sal verhoog, terwyl dit voorraad en operasionele kostes sal verlaag. Met ander woorde dit sal die besigheid help om meer geld te maak huidiglik en in die toekoms. Met betrekking tot die tesis en die algehele projek doel is die volgende bereik: 1. Die hele projek is nagevors, uit een gesit en verduidelik. 2. Die hele program struktuur is gedefinieer en opgebreek in twee aparte modules; nl. die 'Data Mining and Conversion Module' en die 'TOC Scheduling Algorithm'. 3. Die databasis wat al die nodige MRP inligting bevat wat benodig word vir skedulering is ontwerp en geimplementeer deur gebruil te maak van 'n MS Access databasis met 'n ODBC konneksie. Daar is van 'n ODBC konneksie gebruik gemaak sodat as die nodig is, daar sonder enige moeite na ander databasis bestuurs sisteme oorgeskakel kan word. 4. Die 'TOC Scheduling Algorithm' is onwikkel en die volgende is geimplementeer. • A basisse gebruikers vlak is ontwikkel sodat al die nodig invoer data in die program ingevoer kan word. • 'n Geskakelde lys is ontwikkel en gebruik as die data struktuur om al die skedulerings informasie in geheue te stoor. • Die Doel Sisteem algorimte is in sy geheel verduidelik en gedokumenteer. Die Doel Sisteem algoritme is geïmplementeer tot op die punt waar dit die primêre bottelnek skeduleer. • Die pseudo kode vir die deel van die GS algoritme wat nie geimplementeer is nie is uitgelê in ingesluit as deel van die verslag. Verdere ontwikkeling word nog benodig en 'n beter gebruikers vlak moet nog geskep word om die projek te finaal afte handel, maar na dit gedoen is sal daar 'n TOe skedulering pakket bestaan wat heeltemal uniek is tot Suid-Afrika en 'n groot mark potensiaal sal hê.

Family vacations are an important part of life for many families. This paper will give an overview of family recreation and family vacations. Family recreation has many positive effects that influence family life and can lead to a better overall satisfaction for parents and children. This leads to certain advantages that many families experience while on vacation. Lastly, leisure constraints theory and family systems theory are described. These two theories serve as the theoretical framework of this study. In order to collect data a questionnaire was e-mailed to parents whose children attended a children's program while on family vacations. A qualitative approach was used to analyze the data from the structured electronic interview. The overall theme that emerged during this study is that stressful experiences that parents experience during family vacations can be eased through the children's program. Findings indicated that parents were very satisfied with the offered programs, children's participation in such programs provided opportunity for parental time alone, parents experienced positive emotions while their children were at the program, and the children's program eased general difficulties families may experience during family vacations. Future research needs to explore these findings more in-depth in order to better understand the benefits of such programs and to better explore what makes a successful youth program.

This study is concerned with migration of children/young people from northern to southern cities in Ghana. It focuses attention on the following specific research questions: What are young peoples’ motivations for migration, and negotiations surrounding the decision-making process? What are the precarious employment and living situation associated with young migrants? In what ways do social networks support young migrants in the migration process? What role does migration for work play in the lives of young migrants and their left behind families? What are young migrants’ aspirations for the future? To answer these questions, the study draws on the analytical insights gained from the concept of social navigation and social capital/network literatures, and primary research conducted in Ghana. A key finding from this study demonstrate that young peoples’ migration is closely linked to the unequal spatial development manifested in relative poverty conditions in rural northern Ghana, and the desires of children/young people to work and earn income in the south, where better economic prospect exists. Migration is also propelled by young migrants’ decisions to be free from strained and abusive relationships. It is evident that young migrants’ transitions into the labour market demonstrates their own agency and the important role that their networks can play in providing the finance necessary for travel and to secure work. The experiences of migration vary greatly involving both negative and positive aspects. Their precarious employment situation involves considerable uncertainty and risk, and exploitation by employers and clients. Incomes are low and irregular, which brings additional difficulties in fulfilling daily subsistence needs. Some of these difficulties are mitigated through social networks. These networks are fundamental in the life trajectories of young migrants, right from the time the decision to migrate is taken. However, they are also associated with discrimination and exploitative practices. Findings also reveal that migration offer opportunities for youngsters to see new places, undertake paid work, earn income, save and engage in popular global culture of consumerism and materialism, and sending of remittances to left-behind families. Access to mobile phones facilitates communication with families up north and this helps in maintaining intergenerational relations that are spread across spatial boundaries. Future aspirations of the youngsters centred on desires for better job prospects and greater stability although lack of financial and linking social capital serve as constraints. Overall this study makes an important contribution to the literature by providing new insight on the pathways that migration may be beneficial to young people and their left behind families. The findings suggest that addressing the internal geographical imbalance in development between the north and south is key to tackling the interlinked problems associated with child migration in Ghana. Findings also call for interventions to better strengthen the agency of young migrants in navigating hardships while improving their wellbeing.

The growth of network and distributed technologies in flight test instrumentation (FTI) has provided the benefits of flexibility, scalability, and compatibility with prevalent computing capabilities. However, to achieve these capabilities, the complexity of each piece of FTI and the overall system has increased dramatically. Even with systems composed of equipment from a single vendor, it is important to have management systems that provide the flexibility to adapt quickly to various system configurations and present unified information to the flight test users. The growth of network technologies and then standardized approaches such as iNET standards becoming accepted IRIG 106 standards is leading to the growth of multi-vendor systems. These multi-vendor systems further increase the need for rapidly reconfigurable management systems. This paper describes a constraints engine we have developed to enable flexible system management systems and reflects on how these techniques have been used successfully in the iNET System Manager.

Configuring flight test systems can be a complex process due to the large number of choices that must be made. Making these choices requires system knowledge to build a working configuration in an efficient and timely manner. Historically, flight test systems have embedded this system knowledge in code. The limitation with these approaches is that any change or addition to the system knowledge is costly due to the significant work required to update and maintain the software. We see the philosophy of constraints as a promising path toward addressing these issues. In the context of flight test configuration, a set of constraints defines the limits of how a system may be configured to perform specific tasks. This paper describes an approach for simplifying configuration by moving the system knowledge out of hardcoded business rules and into a flexible architecture that leverages constraints for validation of system configurations.

Structural shape optimisation is a field that has been studied since early on in the development of finite element methods. The sub-fields of shape and topology optimisation are continuously growing in industry and aim to leverage the benefits of technologies such as 3D printing and additive manufacturing. These fields are also being used to optimise designs to improve quality and reduce cost. Gradient-based optimisation is well understood as an efficient method of obtaining solutions. In order to implement gradient-based optimisation methods in the context of structural shape optimisation, sensitivities describing the change of the domain stiffness are required. To obtain the stiffness sensitivities, mesh deformation sensitivities are required. In this study, a mesh generating method is developed that provides mesh deformation sensitivities. For shape optimisation it is advantageous to employ an optimisation algorithm that allows for the manipulation of CAD geometry. This means that the CAD geometry is finalised upon completion of the optimisation process. This, however, necessitates the calculation of accurate sensitivities associated with non-linear geometries, such as NURBS (those present in CAD), by the mesher. The meshing method developed in this study is analogous to a linear truss system. The system is solved for static equilibrium through a geometrically non-linear finite element analysis using Newton’s method. Sensitivities are made available by Newton’s method for use in generating mesh sensitivities for the system. It is important for the mesher to be able to accurately describe the geometrical domain which approximates the geometry being modelled. To do so, nodes on the boundary may not depart from the boundary. Instead of prescribing all boundary nodes, this mesher frees the boundary nodes to move University of Pretoria ii Department of Mechanical and Aeronautical Engineering along, but not away from the boundary. This is achieved using multipoint constraints since they allow for an analytical relationship between boundary node movement and the boundary. Two multipoint constraint (MPC) methods are investigated for boundary discretisation, namely, the Lagrangian and master-slave elimination methods (MSEM). The MSEM presents several difficulties in obtaining convergence on non-linear boundaries in general when compared to the Lagrangian method. The MSEM has reduced computational requirements for a single Newton step, especially when direct solvers are used. However, when indirect solvers are implemented the time difference between the two MPC methods reduces significantly. For a “medium” curvature geometry the Lagrangian implementation has only a 6% time penalty. The Lagrangian method is selected as the preferred MPC method for implementation in the mesher to avoid the convergence problems associated with the MSEM. This is justified on the basis of reliability outweighing the 6% time penalty for what is intended to be a tool in the shape optimisation process. Analytical sensitivities are obtained for the truss system in order to account for the MPC boundaries. The analytical mesh sensitivities are proven to be accurate through comparison with numerical sensitivities. The method is demonstrated to be able to accurately described the mesh deformation throughout the domain for both uniform and non-uniform meshes in the presence of non-linear boundaries. / Dissertation (MEng)--University of Pretoria, 2020. / Mechanical and Aeronautical Engineering / MEng (Mech) / Unrestricted

In his book The Limits of Morality, Shelly Kagan claims that contractarian approaches to ethics are incompatible with our common, everyday, "moderate" morality. In this thesis I defend a version of contractarianism that I believe leads to both deontological constraints and options; i.e., to a genuinely moderate morality. On my account, the parties to the agreement are conceived of as being motivated not only to promote self-interest, but also to formulate a code of ethics that gives proper respect to their moral status as persons. If such a picture of the bargainers' motivations is defensible, as I believe it is, then the 'moderate' may in fact have recourse to contractarianism in her defense of everyday morality, for - as my thesis argues - bargainers that are thus motivated will arrive at a moderate morality. / Master of Arts

Understanding the mechanisms that structure biological systems is a primary goal of biology. My research shows that the biological structure is constrained in important ways by general variables such as the number of base pairs in a genome and the number of individuals and species in a community. I used a combination of macroecology, bioinformatics, statistics, mathematics, and advanced computing to pursue my research and published several peer-reviewed scientific manuscripts and open-source software as a result.I was funded through a combination of fellowships and scholarships awarded by the Utah State University School of Graduate Studies, College of Science, and Department of Biology, as well as teaching assistantships awarded through the Department of Biology at Utah State University, and research assistantships funded through a CAREER grant from the U.S. National Science Foundation (DEB-0953694) awarded to my advisor, Dr. Ethan White. With the help of my advisor, I also obtained a computing grant from Amazon Web Services in the amount of $7,500. Altogether, funding for my research and education totaled approximately $123,500. Using over 9000 communities of plants, animals, fungi, and microorganisms, I demonstrated that the forms of empirical species abundance distributions (SADs) are constrained by total abundance and species richness. Using over 300 microbial genomes, I demonstrate that nucleotide aggregation is constrained by genome length and differs between regions of coding and noncoding DNA. General state variables of genomes and ecological communities (i.e. genome length, total abundance and species richness) constrain simple structural properties of each system.

No description available.

The purpose of the study was to thematically map and describe what motives and factors previous ice hockey women experienced as contributing to their dropout from ice hockey. The study involved 15 interviewees; women aged 17–42 (M = 23.3 SD = 6,8) where all participants previously played ice hockey but have now chosen to quit. In the study, interviews were conducted with all participants and the participants had been active in ice hockey between 3 and 24 years (Average = 13.3). The result was analyzed via a thematic analysis. The results show that the participants experience several different intrapersonal, interpersonal, and structural constraints as contributing reasons for terminated sports participation (i.e., negative emotions, low competence, coach's behavior, teammates' behaviors, and financial constraints). To reduce the number of dropouts from sports, federations, clubs, and districts are recommended, among other things, to work to increase coaches' knowledge of psychological and psychosocial aspects to create better and more pleasant environments in women's hockey. This together with strengthening the participants' three basic needs (competence, autonomy & relatedness). Future research in the field is recommended to focus on a broader societal perspective and how it is related to dropouts from sports. / Syftet med studien var att tematiskt kartlägga och beskriva vilka motiv och faktorer tidigare ishockeykvinnor upplevde bidragande till deras avhopp från ishockey. Studien involverade 15 intervjuade; kvinnor i åldrarna 17–42 år (M = 23,3 SD = 6,8) där samtliga deltagare tidigare spelat ishockey men nu har valt att sluta. I studien genomfördes intervjuer med samtliga deltagare och deltagarna hade varit aktiva i ishockey mellan 3 och 24 år (genomsnitt = 13,3). Resultatet analyserades via en tematisk analys. Resultaten visar att deltagarna upplever flera olika intrapersonella, interpersonella och strukturella begränsningar som bidragande orsaker till avslutat idrottsdeltagande (ex. negativa känslor, låg kompetens, tränares beteende,lagkamraters beteende och ekonomiska begränsningar). För att minska antalet bortfall från idrott rekommenderas förbund, klubbar och distrikt bland annat att arbeta för att öka tränarnas kunskap om psykologiska och psykosociala aspekter för att skapa bättre och trevligare miljöer inom damhockey. Detta tillsammans med att stärka deltagarna tre grundläggande behov (kompetens, autonomi och tillhörighet). Framtida forskning inom området rekommenderas att fokusera på ett bredare samhällsperspektiv och hur det är relaterat till bortfall från idrott.