Increasing effectiveness of use of the agents of production (efficiency) is needed to compensate for steadily rising costs of labor and equipment. Efficiency can be measured in various ways, depending on the type and scope of an operation. The methods available and the circumstances under which they can, and should, be used are the major concern of this thesis. Due to some peculiarities of primary forest production such as highly variable work conditions and irregular stand characteristics, many well known techniques of industrial engineering have not been used widely in forestry. Although progress to date has been limited, time study and several other work measurement techniques can be applied successfully. Time measurements have to be supplemented by costs and other data, to allow for comparison of alternatives. The production methods themselves should be analysed more carefully to find means for technological improvements. The role of the woods worker also deserves more attention because of his heavy and often dangerous work and his outdoor working conditions. In recent years the various activities of forest management, logging and mill supply have been viewed as part of a system which should be optimized for overall efficiency. Operations research has greatly increased the possibilities of studying the influence of variables which govern the system, although the systems approach has not yet been applied fully to an existing forest enterprise. Parts of the system or sub-systems may be complex enough to warrant the application of operations research, and its success should encourage increased research in this field. / Forestry, Faculty of / Graduate

The aim of the diploma thesis is to measure and subsequently to evaluate microturbine characteristics. This is a new type of turbine, which was designed in the diploma thesis and is based on the theory of waterwheels. It is designed for low heads and low flow, where conventional turbines are not suitable. Taking advantage of this low heads area will be very important in the future as the hydroenergetic potential is getting gradually exhausted. The turbine has two ways of regulation - turning blades and shifting the drawer. In the first phase, two complex measurements were performed. The next step was to process the measured data gradually in three programs. The result is the rendering of the characteristics that describe the hydraulic parameters of the turbine. The last chapter shows the design proposals for automatic regulation.

Preliminary investigations on energy efficiency of manufacturing firms operating in South Africa have shown that no previous study on the barriers and drivers to energy efficiency was conducted. It was also found that South Africa is the only member within the Brazilian, Russian, Indian, Chinese and South African (BRICS) community that has not conducted any formal study on the drivers and barriers to Energy efficiency despite the current energy challenges the country faces. Whilst the National Energy Efficiency Strategy (NEES) was developed and targets were set to improve the country’s efficiency landscape, this strategy failed to account for the barriers and drivers to energy efficiency operating within the local context. This research study sets out to investigate whether an energy efficiency gap exists within manufacturing firms operating in the eThekwini Municipal Area (EMA) and by inference, the national context. It goes on further to analyse the drivers and barriers to Energy Efficiency (EE) within such firms. Such drivers and barriers are then analysed by firm characteristics and across manufacturing sectors. The results are interesting and contribute well to the general body of knowledge on EE in South Africa. It was found that whilst there is a degree of adoption and awareness of EE technologies amongst manufacturing firms, the quality of the adoption profile is poor. This poor quality profile suggests the possibility of an energy efficiency gap. The barriers and drivers that were found to be significant were also found to be mostly similar across manufacturing sectors. A main finding is that firms are very sensitive to cost and are mainly driven to adopt EE technologies only where there exists an opportunity for cost savings. It was also found that taken together, institutional barriers pose the greatest hurdle to EE adoption. Several interesting results were found in terms of how the barriers and drivers vary with the characteristics of the firm. The findings of this research indicate that more can be achieved in terms of energy efficiency within the manufacturing subsectors in South Africa. Policy-makers should take into consideration the salient findings of this research when drafting new policy on energy efficiency. / Dissertation (MEng)--University of Pretoria, 2017. / Graduate School of Technology Management (GSTM) / MEng / Unrestricted

Recent research has shown approximate computing and Course-Grained Reconfigurable Arrays (GGRAs) are promising computing paradigms to reduce energy consumption in a compute intensive environment. CGRAs provide a promising middle ground between energy inefficient yet flexible Freely Programmable Gate Arrays (FPGAs) and energy efficient yet inflexible Application Specific Integrated Circuits (ASICs). With the integration of approximate computing in CGRAs, there is substantial gains in energy efficiency at the cost of arithmetic precision. However, some applications require a certain percent of accuracy in calculation to effectively perform its task. The ability to control the accuracy of approximate computing during run-time is an emerging topic.

A statistic that summarizes an entire data set without losing any information about the family of distributions or the model is often called a sufficient statistic. Generally, one would like to use the statistic that contains the most information about the parameter space. Sometimes there are several sufficient statistics. At other times the only sufficient statistic is the entire data set. A large data set can be difficult to work with. In this case, can one use a statistic that, though not sufficient, does summarize the data set somewhat? How much information would be lost? How can one compare two statistics that aren't sufficient in terms of the amount of information each provides? A new method for comparing experiments and measuring information is introduced. No assumptions are made and no conditions are required in order for this new method to measure the amount of information contained in almost any statistic. Several properties of this new method are discussed and a new characterization of sufficiency based on this new method is presented. The new method is used to evaluate the expected efficiency of a statistic in discriminating between any two values of the parameter as compared to a sufficient statistic. This new method can be self-calibrated to give this expected efficiency a meaningful scale. It is shown that this new method has some advantages over existing methods of measuring information. This new method is applied to Casino Blackjack. Several card-counting statistics are compared by the amount of information each provides in discriminating between different deck compositions as compared to a sufficient statistic. This new method provides new insight about information in card-counting statistics by putting this information on a meaningful scale. / Ph. D.

The efficiency of an internal combustion engine is highly dependent on the peak pressure at which the engine operates. A new compound engine concept, the double compression expansion engine (DCEE), utilizes a two-stage compression and expansion cycle to reach ultrahigh efficiencies. This engine takes advantage of its high-integrity structure, which is adapted to high pressures, and the peak motored pressure reaches up to 300 bar. However, this makes the use of conventional combustion cycles, such as the Seiliger–Sabathe (mixed) or Otto (isochoric) cycles, not feasible as they involve a further pressure rise due to combustion. This study investigates the concept of isobaric combustion at relatively high peak pressures and compares this concept with traditional diesel combustion cycles in terms of efficiency and emissions. Multiple consecutive injections through a single injector are used for controlling the heat release rate profile to achieve isobaric heat addition. In this study, the intake pressure is varied to enable a comparison between the isobaric cases with different peak pressures, up to 150 bar, and the mixed cycle cases. Tests are performed at several different levels of EGR. The experiments are performed on a 12.8 L displacement 6-cylinder Volvo D13C500 engine utilizing a single cylinder with a standard 17-compression-ratio piston. In this study, the cylinder represents the high-pressure unit of the DCEE. The fuel used in all the experiments is a standard EU diesel. In each target condition, the different injection strategies are compared with the total amount of fuel kept relatively constant. The results prove that the isobaric combustion concept is feasible with a traditional injection system and can achieve gross indicated efficiencies close to or higher than those of a conventional diesel combustion cycle. Moreover, the results show that with an isobaric cycle, heat transfer losses can be reduced by over 20%. However, the exhaust energy is higher, which can eventually be recovered in the second stage of expansion. Thus, this cycle could be suitable for the DCEE concept. The CO, UHC and soot emission levels are proven to be fairly similar to those of the conventional diesel combustion. However, the NOx emissions are significantly lower for the isobaric combustion.

The study examined contractor demographics, business and technological characteristics, costs, and production information for 15 independent logging firms in the Appalachians. Contractors represented nine states and were studied from 1995 to 1997. Each contractor's cost and production information was used to determine his economic efficiency for the study period. Total annual production for the firms ranged from 2,728.26 tons to 213,194.74 during the three-year period. Four contractors' median weekly production decreased from 1996 to 1997, while three contractors increased their weekly median production. Labor was the largest cost category for the smaller production contractors and contracted services tended to be the largest category for the larger producers. Regression analyses found that the cost of producing an additional ton increased from 1995 to 1996 and decreased from 1996 to 1997. Total cost per ton increased for four contractors from 1995 to 1996, while four showed decreasing cost per ton. For 1996 to 1997, five contractors had a cost per ton increase and seven showed a cost per ton decrease. Some of these shifts can be attributed to the fact that several of the mechanized contractors in the Central-Appalachians were "start-up" contractors when the study began. West Virginia contractors had the highest workers' compensation premiums per ton and Georgia contractors had the lowest. Labor costs per ton were highest for North-Central Appalachian contractors and lowest for the Southern Appalachian contractors. Contractors who produced predominantly sawlogs tended to have higher efficiency rankings than those who produced primarily pulpwood. / Master of Science

This thesis aimed to study some of the general principles underlying electrodeposition together with experimental facts regarding the effects of changing constituents of the plating solutions, variations in hydrogen-ion concentrations, and variation in current density used in the electrodeposition of lead.

<p> This thesis examines the allocation and relative efficiency of the agricultural labour input in North Grimsby Township. The relative efficiency of the labour input is determined by the construction of an Index of Labour Efficiency, in which the actual labour input is compared with the labour input requirement for the farm as determined from studies undertaken by the Ontario Department of Agriculture. Certain normative hypotheses are tested, relating elements of the farm economic structure and the physical environment to the Labour Efficiency Index.</p> / Thesis / Master of Arts (MA)

This study analyzed factors that affected catfish losses from diseases and weather events and factors that affected onarm efficiency. A double limit tobit model was used to determine the magnitudes of losses experienced by producers due to these events, while a linear regression model was used to determine factors that affect efficiency. Results from the weather model indicate all variables are significant and positively affect loss while producer experience and pond depth were the only significant variables that affected disease loss. The efficiency model results provide information that could be increased or decreased in order to obtain a more efficient level of production. Significant inputs in the catfish efficiency model were age, experience, age/experience (interactive), catfish survival percentage, and percentage of fry and fingerlings purchased offarm.