Thesis (M.H.S.A.)--University of Michigan, 1976.

Latency is becoming a significant factor in many Internet applications such as P2P sharing and online gaming. Coupled with the fact that an increasing number of people are using online services for backup and replication purposes and it is clear that congestion increases exponentially on the network. One of the ways in which the latency problem can be solved is to remove core network congestion or to limit it in such a way that it does not pose a problem. In South Africa, Telkom rolled out MSAN cabinets as part of their Fibre-to-the-curb (FTTC) upgrades. This created an unique opportunity to provide new services, like BaRaaS, by implementing micro data centres within the MSAN to reduce congestion on the core network. It is important to have background knowledge on what exactly latency is and what causes it on a network. It is also essential to have an understanding of how congestion (and thus latency) can be avoided on a network. The background literature covered helps to determine which tools are available to do this, as well as to highlight any possible gaps that exist for new congestion control mechanisms. A simulation study was performed to determine whether implementing micro data centres inside the MSAN will in fact reduce latency. Simulations must be done as realistically as possible to ensure that the results can be correlated to a real-world problem. Two different simulations were performed to model the behaviour of the network when backup and replication data is sent to the Internet and when it is sent to a local MSAN. In both models the core network throughput as well as the Round Trip Times (RTTs) from the client to the Internet and the MSAN cabinets, were recorded. The RTT results were then used to determine whether latency had been reduced. Once it was established that micro data centres will indeed help in reducing congestion and latency on the network, the design of a storage server, for inclusion inside the MSAN cabinet, was done. A cost benefit analysis was also performed to ensure that the project will be financially viable in the long term. The cost analysis took into account all the costs associated with the project and then expanded them over a certain period of time to determine initial expenses. Extra information was then taken into consideration to determine the possible income per year as well as extra expenditure. It was found that the inclusion of a micro data centre reduces latency on the core network due to the removal of large backup data traffic from the core network, which reduces congestion and improves latency. From the Cost Benefit Analysis (CBA) it was found that the BaRaaS service is viable from a subscription point of view. Finally, the relevant conclusions with regard to the effects of data centres in MSAN cabinets on latency and services were drawn. / Vertraagtyd word 'n belangrike faktor in baie Internet toepassings soos P2P-deel en aanlyn-speletjies. Gekoppel met die feit dat 'n toenemende getal mense internetdienste gebruik vir rugsteun en replisering, word opeenhoping in die datanetwerk eksponensieel verhoog. Een van die maniere waarop die vertraagtydsprobleem opgelos kan word, is om opeenhoping in die kern-datanetwerk te verwyder of om dit op so 'n manier te beperk dat dit nie 'n probleem veroorsaak nie. In Suid Afrika het Telkom MSAN-kaste uitgerol as deel van hulle "Fibre-to-the-Curb" (FTTC) opgraderings. Dit het 'n unieke geleentheid geskep om nuwe dienste te skep, soos BaRaaS, deur mikro-datasentrums in die MSAN-kas te implementeer om opeenhoping in die kernnetwerk te verminder. Dit is belangrik om agtergrondkennis te hê van presies wat vertraagtyd is en waardeur dit op die netwerk veroorsaak word. Dit is ook belangrik om 'n begrip te hê van hoe opeenhoping (en dus vertraagtyd) op die netwerk vermy kan word. Die agtergrondsliteratuur wat gedek is help om te bepaal watter instrumente beskikbaar is, asook om moontlikhede na vore te bring vir nuwe meganismes om opeenhoping te beheer. 'n Simulasiestudie is uitgevoer om vas te stel of die insluiting van datasentrums in die MSAN-kaste inderdaad 'n verskil sal maak aan die vertraagtyd in die datanetwerk. Twee simulasies is uitgevoer om die gedrag van die netwerk te modelleer wanneer rugsteun- en repliseringsdata na onderskeidelik die Internet en die plaaslike MSAN gestuur word. In altwee is die deurset van die kernnetwerk sowel as die sogenaamde Round Trip Times (RTTs) van die kliënt na die Internet en die MSAN-kaste aangeteken. Die RTTs-resultate sal gebruik word om te bepaal of vertraagtyd verminder is. Nadat dit bepaal is dat mikro-datasentrums wel die opeenhoping in die netwerk sal verminder, is die ontwerp van 'n stoorbediener gedoen, vir insluiting in die MSAN-kas. 'n Koste-ontleding neem alle koste wat met die projek verband hou in ag en versprei dit dan oor 'n bepaalde tydperk om die aanvanklike kostes te bepaal. Verdere inligting word voorts in ag geneem om die moontlike inkomste per jaar sowel as addisionele uitgawes te bepaal. Daar is bevind dat die insluiting van 'n mikro-datasentrum vertraagtyd verminder deur groot rugsteen-dataverkeer van die kernnetwerk af te verwyder. Die koste-ontleding het gewys dat uit 'n subskripsie-oogpunt, die BaRaaS diens lewensvatbaar is. Uiteindelik word relevante gevoltrekkings gemaak oor die effek van datasentrums in MSAN-kaste op vertraagtyd en dienste. / Dissertation (MEng)--University of Pretoria, 2017. / Electrical, Electronic and Computer Engineering / MEng / Unrestricted

High-elevation environments above 2500 metres above sea level (m.a.s.l.) were among the planet's last frontiers of human colonization. Research on the speed and tempo of this colonization process is active and holds implications for understanding rates of genetic, physiological and cultural adaptation in our species. Permanent occupation of high-elevation environments in the Andes Mountains of South America tentatively began with hunter-gatherers around 9 ka according to current archaeological estimates, though the timing is currently debated. Recent observations on the archaeological site of Soro Mik'aya Patjxa (8.0-6.5 ka), located at 3800 m.a.s.l. in the Andean Altiplano, offer an opportunity to independently test hypotheses for early permanent use of the region. This study observes low oxygen (delta O-18) and high carbon (delta C-13) isotope values in human bone, long travel distances to low-elevation zones, variable age and sex structure in the human population and an absence of non-local lithic materials. These independent lines of evidence converge to support a model of permanent occupation of high elevations and refute logistical and seasonal use models. The results constitute the strongest empirical support to date for permanent human occupation of the Andean highlands by hunter-gatherers before 7 ka.

Introduction: In Ontario, prior to 1994, planned home birth attended by midwives was a self-paid service. Since the introduction of regulated midwifery in 1994, home birth is a government-funded service, and uses common resources. As such, there is a need to examine the impact that choice of planned location of birth puts on scarce resources. To date, costs associated with planned place of birth in Ontario have not been evaluated. Objectives: The primary objective is to answer the question: Do planned midwifery-attended home births from the onset of labour cost the Ontario health care system more or less than planned midwifery-attended hospital births from the onset of labour among a comparable low-risk cohort of women? Specifically, this analysis examines the cost of midwifery intrapartum care, from the onset of labour until hospital discharge or the first two days after delivery. Methods: This cost-analysis used a third-party payer perspective (health services costs) to analyze data from the Ontario Midwifery Program, which included 12, 886 midwife-attended births that occurred between April 1, 2003 and March 31, 2006. Three main sources of information were used to determine unit cost and health care utilization: the Ontario Midwifery Program data (2003-2006); data from the Ontario Case Costing Initiative; and the 2010 Schedule of Benefits for Physician Services. Data was analyzed using an intention to treat approach, i.e. based on planned rather than actual location of delivery. Results: Hospital birth is more expensive than planned home-birth. Results were significant with a P value =< .001. The median cost from the onset of labour was $995.95 (IQR $995.95 to $995.95) for planned home birth compared to $2118.12 (IQR $1467.12 to $3610.00) for planned hospital birth. Conclusions: Home birth, a choice that women in Ontario will continue to choose, does not result in costing the Ontario health care system more money. / Thesis / Master of Science (MSc) / This thesis answers the question: Do midwifery-attended planned home births cost the Ontario health care system more or less than midwifery-attended planned hospital births? This thesis examined midwifery-attended births that occurred in Ontario between April 1, 2003 and March 31, 2006 and associated costs that were incurred for both the mother and the baby from the onset of labour until two days following the birth. Since 1994 when midwifery was legislated in Ontario, registered midwives have been providing care to women in both home and hospital settings. While there is general consensus within the midwifery community that home births do not cost the health care system more money, a thorough analysis of costs incurred by midwifery-attended births has not been meaningfully analyzed. Midwifery is the only group of health care professionals providing maternity care that is increasing in size. Given the shortage and the current crisis of maternity care providers, the number of midwives in this province is likely to continue growing. At the same time, a cost analysis of the resources consumed through the provision of maternity care – both at home and at hospital- has not been conducted. This study provides key stakeholders with information regarding resources used and needed and the costs associated with these resources so that resource allocation and planning can be conducted in a responsive manner.

The wood supply system is a dynamic and complex structure. Traditionally, key components of the system have been treated as stand-alone entities with very little regard to the performance of the overall system. The central component, the logging contractor, is usually viewed as a service provider and largely ignored. A value chain approach is an excellent tool to examine the primary stakeholders’ contributions to the wood supply system. The value chain for forestry usually extends completely across the physical and political landscape, reaching into the most geographically and economically remote locations. A conceptual model was developed depicting the wood supply system value chain and the socioeconomic impacts of a logging firm’s cash flow contributions. Financial and production data were obtained from 93 independent logging firms from 18 Eastern US States. This analysis provided 690 business years of data, beginning with the 1988 financial year and concluding in 2005. In addition, three impact scenarios were modeled using Impact Analysis for Planning (IMPLAN) software to understand the effects of Hurricane Katrina. The first model addressed the economic impacts of a timber deficit from the landowner’s perspective, the second introduced a disruption in the wood supply system from a logger’s position in the value chain, and the third attempted to analyze the impacts of a mill closure. Data analysis showed that operating costs have increased drastically during the study period with payment for services failing to provide adequate compensation to contractors. Furthermore, no significant per unit cost incentive was found to justify expanding the scale of operation. Smaller-volume producers appeared to have more ability to generate a profit on operations than their larger-volume counterparts. Cash flow analyses revealed much of the economic activity generated by the wood supply system remained in the local community. Some deficiencies of IMPLAN appeared upon examining the models introduced in this research. Many rural communities across the Southeastern US are heavily dependent on production forestry. When the logging industry suffers, so does the entire economy of these regions. It is important to ensure that the socioeconomic impacts of the wood supply value chain for such communities remains intact.

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Yes / Cooling towers are a relatively inexpensive and consistent method of ejecting heat from several industries such as thermal power plants, refineries, and food processing. In this research, an earlier model from literature was to be validated across three different case studies. Unlike previous models, this model considers the height of the fill as the discretised domain, which produces results that give it in a distribution form along the height of the tower. As there are limitations with the software used (gPROMS) where differential equations with respect to independent variables in the numerator and denominator cannot be solved, a derivative of the saturation vapour pressure with respect to the temperature of the air was presented. Results shown were in agreement with the literature and a parametric sensitivity analysis of the cooling tower design and operating parameters were undertaken. In this work the height of fill, mass flowrates of water and air were studied with respect to sensitivity analysis. Results had shown large variations in the outlet temperatures of the water and air if the mass flows of water and air were significantly reduced. However, upon high values of either variable had shown only small gains in the rejection of heat from the water stream. With respect to the height of the fill, at larger heights of the fill, the outlet water temperature had reduced significantly. From a cost perspective, it was found that a change in the water flowrate had incurred the largest cost penalty with a 1% increase in flowrate had increased the average operating cost by 1.2%. In comparison, a change in air flowrate where a 1% increase in flowrate had yielded an average of 0.4% increase in operating cost.

Life Cycle Cost Analysis (LCCA) forms an important part of asset management practices and provides an informed decision support. The holistic nature of LCCA includes life cycle assessment (LCA) as an important component alongside economic life cycle cost analysis. The drinking water industry is right now lacking a reliable cost data structure which will ensure that all the utilities capture the same set of cost data. Also, models and tools currently available in the academia and industry are purely deterministic in nature and do not cater to uncertainty in the data. This study provides a framework for a holistic life cycle cost analysis tool which will help drinking water utilities to prioritize the activities and optimize the cost spending of the utility. The methodology includes the development of a cost data structure, a life cycle cost analysis and a life cycle assessment model in the form of an excel spreadsheet. The LCCA model has the capability to compare different pipe materials, installation, condition assessment, rehabilitation and replacement technologies. Whereas, LCA model can compare different pipe materials based on greenhouse gas emissions calculations. The final step of the methodology includes piloting the model with data from utility A. The analysis has been shown in the form of three case studies - comparison of two pipe materials, two pipe installation technologies and two pipe rehabilitation technologies. The case studies provide results in the form of comparison of total life cycle costs for different alternatives and hence a better alternative can be chosen. / Master of Science

During the evaluation of the seismic retrofitting option for risk reduction/mitigation measures to be applied over buildings, Benefit Cost Analysis is an often-used method. During this study of Benefit Cost Analysis, the condition that the earthquake can happen just after or sometime after retrofitting will be taken into consideration rather than some approaches that focus on the benefits and costs regarding the annual probability of the occurrence for possible earthquakes. The analysis will use conditional probability such that the earthquake will be assumed to occur at different periods of time (5, 10, 20 years etc.) after the mitigation measures are taken so that benefit-cost ratios and net social benefits can be observed over time using the results at these periods. Also during this study the indirect effects of earthquake such as business disruption, social disturbance will also be taken into consideration. As a final step, it is aimed to conclude with convincing financial results regarding the direct and indirect effects of the earthquake in terms of benefits and costs to encourage people and the public officials to reduce the potential vulnerability of the housing units people live by taking the necessary precautions against the earthquake.