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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
791

An evaluation of moisture dynamics and productivity of Sphagnum and Tomenthypnum mosses in western boreal peatlands, Canada

Goetz, Jonathan Daniel January 2014 (has links)
Western boreal peatlands have diverse ground covers of Sphagnum and brown mosses that have important hydrological controls on peatland-atmosphere interactions. Since peatland mosses are non-vascular, their shoot structural morphologies and community growth forms affect the storage and fluxes of water that are critical for maintaining productivity and evaporative functions. While many of the mechanisms of capillary rise are fairly well understood for Sphagnum mosses, there is less information on the water dynamics in communities of Tomenthypnum nitens, a dominant brown moss species in northern rich fens. This study investigated how the different hydrophysical characteristics of moss and peat profiles of T. nitens from a rich fen and intermixed Sphagnum angustifolium and Sphagnum magellanicum, from a poor fen affect capillary flow and water retention to support evaporation and productivity; and how different groundwater and atmospheric sources of water affected these processes. Laboratory investigations indicated volumetric water content and gross ecosystem productivity decrease with water table depth for both mosses without the advent of precipitation, with Sphagnum capitula retaining 10-20% more water than T. nitens due to its moss structure and pore connectivity with the water table. Consequently, Sphagnum capillary rise was sufficient to sustain both high pore-water pressures for evaporation and high water content for productivity at all water table depths due to a gradual shift in average water-retaining pore sizes with depth. The structure of T. nitens moss turfs, consisting of live shoots and a basal layer of old, partially decomposed shoots sometimes overlying well-decomposed peat makes capillary rise more difficult, requiring extremely low matric pressures at the surface, sometimes causing desiccation of the uppermost portions of moss shoots, and hence reduced productivity. Additional nocturnal sources of atmospheric water from dew, distillation, and vapour fluxes provide small, but potentially critical sources of water to rewet desiccated moss shoots for early morning productivity for both T. nitens and Sphagnum mosses. Investigations in the field, however, indicated that with frequent precipitation to rewet the moss and the turf base to refill large pores, evaporative demands at the T. nitens moss canopy could drive capillary flow from the water table to maintain adequate θ for productivity. T. nitens mosses also can grow in turfs disconnected from the underlying iii peat, so that the basal layer temporarily retains water from precipitation for capillary rise. Thus, while capillary connection of the T. nitens moss turf with the underlying peat and water table is not critical to maintain productivity, it grows in a relatively large range of elevations from the water table, compared to Sphagnum and feather mosses. Rewetting of the capitula and the raising of the water table by precipitation provided higher water matric pressures within the moss matrix, and along with high evaporative demands, provided the mechanisms for sufficient capillary flow for productivity. Thus, Sphagnum could grow in habitats far from the water table like feather mosses, although the latter did not require capillary rise for productivity. Furthermore, disequilibrium between water vapour and liquid in the pores of T. nitens in the near-surface suggested pressures calculated with the Kelvin equation may not provide an accurate characterization of actual matric pressures in the moss. However, as the disequilibrium is caused by vapour pressure gradients between the moss and the atmosphere, it is likely a driving factor that helps maintain vapour and capillary water fluxes to provide moisture for T. nitens and other mosses. These results illustrate hydrological mechanisms that explain how moss growth form and habitat are linked. As such, the Sphagnum and T. nitens mosses are well adapted to maintain capillary in their poorly drained habitats in western boreal peatlands.
792

Work wellness, absenteeism and productivity in a call centre in the insurance industry / Adèle van Wyk

Van Wyk, Adèle January 2008 (has links)
Thesis (M.Comm. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2008.
793

Integration of tracking into horizontal underground transportation system / by Phillip Kingston Sales

Sales, Phillip Kingston January 2009 (has links)
The world, especially the business world, has changed from consisting of different countries and markets to one global market. This can be attributed to better transportation, communication and information systems. This new development has changed the rules of the business game. No more do companies compete with local players only but increasingly with foreign based entities. Many experts argue that top companies in the world today are those that have embraced new technologies to improve their entire operations. New information technology allows them to integrate their operations upstream with their suppliers, downstream with their clients as well as in-house to improve their efficiencies. This includes mining companies who have to introduce new information, communication and transportation systems to compete with their global counterparts. This study investigates the operation of South African underground mines operation. This is done with a focus on the integration of tracking technology into the horizontal transportation system. The objective is to improve productivity due to better process control. In order to achieve this objective the entire operational process had to be divided into key elements that had to be investigated. The following key elements were identified and investigated: Information and communication strategy, Organisation structure, Departmental integration, Organisational processes, Management information, Information management, Management information system, Solution selection criteria, Causes of low productivity, Problems with logistics system, Technology implementation methods, Outsourcing, Reasons for technology failure and Future challenges facing industry. The investigation was done in four phases. The first phase provided a framework for a literature study. The second phase comprised a literature study that would set the foundation for the empirical study. The third phase consisted of the empirical study, research methodology and data gathering. The fourth and final phase consisted of data grouping and analysis, conclusions and recommendations. Among the conclusions drawn, the following stand out: There is a general problem in the industry that can be attributed to logistics. There is also a problem of information quality and information flow among the different departments that lead to poor integration. Another problem that was highlighted is the non-involvement of end-users in technology selection and implementation. In terms of future challenges facing the industry, poor education levels, productivity and commodity prices were identified. In terms of solutions for the future, integrating technology, with the involvement of end users, were mentioned. All these findings were uniform across the different mining houses, which show the similarity of the industry culture. / Thesis (M.B.A.)--North-West University, Vaal Triangle Campus, 2009.
794

Integration of tracking into horizontal underground transportation system / by Phillip Kingston Sales

Sales, Phillip Kingston January 2009 (has links)
The world, especially the business world, has changed from consisting of different countries and markets to one global market. This can be attributed to better transportation, communication and information systems. This new development has changed the rules of the business game. No more do companies compete with local players only but increasingly with foreign based entities. Many experts argue that top companies in the world today are those that have embraced new technologies to improve their entire operations. New information technology allows them to integrate their operations upstream with their suppliers, downstream with their clients as well as in-house to improve their efficiencies. This includes mining companies who have to introduce new information, communication and transportation systems to compete with their global counterparts. This study investigates the operation of South African underground mines operation. This is done with a focus on the integration of tracking technology into the horizontal transportation system. The objective is to improve productivity due to better process control. In order to achieve this objective the entire operational process had to be divided into key elements that had to be investigated. The following key elements were identified and investigated: Information and communication strategy, Organisation structure, Departmental integration, Organisational processes, Management information, Information management, Management information system, Solution selection criteria, Causes of low productivity, Problems with logistics system, Technology implementation methods, Outsourcing, Reasons for technology failure and Future challenges facing industry. The investigation was done in four phases. The first phase provided a framework for a literature study. The second phase comprised a literature study that would set the foundation for the empirical study. The third phase consisted of the empirical study, research methodology and data gathering. The fourth and final phase consisted of data grouping and analysis, conclusions and recommendations. Among the conclusions drawn, the following stand out: There is a general problem in the industry that can be attributed to logistics. There is also a problem of information quality and information flow among the different departments that lead to poor integration. Another problem that was highlighted is the non-involvement of end-users in technology selection and implementation. In terms of future challenges facing the industry, poor education levels, productivity and commodity prices were identified. In terms of solutions for the future, integrating technology, with the involvement of end users, were mentioned. All these findings were uniform across the different mining houses, which show the similarity of the industry culture. / Thesis (M.B.A.)--North-West University, Vaal Triangle Campus, 2009.
795

Work wellness, absenteeism and productivity in a call centre in the insurance industry / Adèle van Wyk

Van Wyk, Adèle January 2008 (has links)
Thesis (M.Comm. (Industrial Psychology))--North-West University, Potchefstroom Campus, 2008.
796

The effect of productivity on profitability : a case study at firm level

Theriou, Nikolaos G. January 2000 (has links)
No description available.
797

The labor organization of Samburu pastoralism /

Sperling, Louise. January 1987 (has links)
This study considers the labor organization of a group of northern Kenyan pastoralists. Since 1960, the Samburu have experienced substantial cattle loss and land circumscription and the work focuses both on herding and non-herding labor responses to a changing regional economy. The viability of Samburu pastoralism rests on specific labor forms which permit intensified production and economic diversification. / Based on twenty-four months of fieldwork, primarily during the 1983-84 drought, the study emphasizes the interplay between the social and technical organization of labor. Social institutions of descent and age guide natural resource and delineate work roles, while encouraging the varied forms of cooperation which greatly extend the family workforce. The diversity of technical strategies, which are strongly shaped by cultural preferences, contrasts with the paucity of production materials. / Several key findings have applicability to a range of pastoral locales, particularly proof of the positive relationship between labor input and animal output and of the higher efficiency of labor in larger versus smaller-scale herding units only under stable production conditions. Further, the quantitative material on dry season versus drought labor use as well as evidence for differential livestock survival rates represent unique accounts in themselves. / Beyond insights into pastoralism, however, the analysis is structured so as to contribute to several important issues in small-scale rural production. The accounts of the interconnection of technology and social forms and of the integration of "on-farm" and "off-farm" enterprise have implications for defining the scope of any labor investigation. The discussions of the terms "labor" and "technology" pose wider questions of the content of such basic concepts. Finally, the methodological discourse on labor measurement should assist those similarly trying to distinguish between "use" and "demand" in predominantly noncapitalist societies.
798

Primary and secondary production in Malpeque Bay, Prince Edward Island compared with one of its tributaries and the nearby gulf of St. Lawrence.

McIver, Alan R. January 1972 (has links)
No description available.
799

Computer Vision-based Solution to Monitor Earth Material Loading Activities

Rezazadeh Azar, Ehsan 09 August 2013 (has links)
Large-scale earthmoving activities make up a costly and air-polluting aspect of many construction projects and mining operations, which depend entirely on the use of heavy construction equipment. The long-term jobsites and manufacturing nature of the mining sector has encouraged the application of automated controlling systems, more specifically GPS, to control the earthmoving fleet. Computer vision-based methods are another potential tool to provide real-time information at low-cost and to reduce human error in surface earthmoving sites as relatively clear views can be selected and the equipment offer recognizable targets. Vision-based methods have some advantages over positioning devices as they are not intrusive, provide detailed data about the behaviour of each piece of equipment, and offer reliable documentation for future reviews. This dissertation explains the development of a vision-based system, named server-customer interaction planner (SCIT), to recognize and estimate earth material loading cycles. The SCIT system consists of three main modules: object recognition, tracking, and action recognition. Different object recognition and tracking algorithms were evaluated and modified, and then the ideal methods were used to develop the object recognition and tracking modules. A novel hybrid tracking framework was developed for the SCIT system to track dump trucks in the challenging views found in the loading zones. The object recognition and tracking engines provide spatiotemporal data about the equipment which are then analyzed by the action recognition module to estimate loading cycles. The entire framework was evaluated using videos taken under varying conditions. The results highlight the promising performance of the SCIT system with the hybrid tracking engine, thereby validating the possibility of its practical application.
800

Computer Vision-based Solution to Monitor Earth Material Loading Activities

Rezazadeh Azar, Ehsan 09 August 2013 (has links)
Large-scale earthmoving activities make up a costly and air-polluting aspect of many construction projects and mining operations, which depend entirely on the use of heavy construction equipment. The long-term jobsites and manufacturing nature of the mining sector has encouraged the application of automated controlling systems, more specifically GPS, to control the earthmoving fleet. Computer vision-based methods are another potential tool to provide real-time information at low-cost and to reduce human error in surface earthmoving sites as relatively clear views can be selected and the equipment offer recognizable targets. Vision-based methods have some advantages over positioning devices as they are not intrusive, provide detailed data about the behaviour of each piece of equipment, and offer reliable documentation for future reviews. This dissertation explains the development of a vision-based system, named server-customer interaction planner (SCIT), to recognize and estimate earth material loading cycles. The SCIT system consists of three main modules: object recognition, tracking, and action recognition. Different object recognition and tracking algorithms were evaluated and modified, and then the ideal methods were used to develop the object recognition and tracking modules. A novel hybrid tracking framework was developed for the SCIT system to track dump trucks in the challenging views found in the loading zones. The object recognition and tracking engines provide spatiotemporal data about the equipment which are then analyzed by the action recognition module to estimate loading cycles. The entire framework was evaluated using videos taken under varying conditions. The results highlight the promising performance of the SCIT system with the hybrid tracking engine, thereby validating the possibility of its practical application.

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