Thesis (M.S.)--Ohio University, August, 1993. / Title from PDF t.p.

Thesis (M.S)--Ohio University, November, 2004. / Includes bibliographical references (p. 93-95)

Thesis (M. Phil.)--University of Hong Kong, 1990.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Vita. Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--Brigham Young University. Dept. of Mechanical Engineering, 2005. / Includes bibliographical references (p. 127-130).

Thesis (M.S.)--University of Louisville, 2008. / Department of Industrial Engineering. Vita. "December 2008." Includes bibliographical references (leaves 82-85).

Thesis (M.S)--Ohio University, November, 2004. / Title from PDF t.p. Includes bibliographical references (p. 93-95)

Thesis (M.Eng.)(Chemical Engineering)--University of Pretoria, 2005. / Includes summary. Includes bibliographical references. Available on the Internet via the World Wide Web.

Proportional, Integral and Derivative feedback control (PID) is a mature technology responsible for the majority of automated decision making in the process industry. Despite the high reliance on this technology, low levels of maintenance and performance measurement are the norm in the process industry. Several analysis techniques exist for identifying oscillation, and then highlighting the root cause of the problem. Several time and frequency domain statistical techniques, as well as wavelet analysis are used to diagnose loop performance. In this study, 127 different control loops are analysed, and in depth troubleshooting is performed on a selection of 18 different control loops. The performance of flow loop F1035 is tracked through a number of different analysis techniques, highlighting the pitfalls of using only a single analysis technique. Lower order statistics and minimum variance performance analysis show that the loop is performing well. Plotting the PV-OP relationship suggests non-linear tendencies on F1035, and this is corroborated using high order statistical analysis (bicoherence). Non-linear loop behaviour is often as a result of a slip stick cycle, a sign that valve maintenance may be required. Frequency (power spectrum) analysis shows a 43 minute dominant oscillation, suggesting a low frequency disturbance affecting loop performance. Process units are typically exposed to cyclic behaviour occurring at several different frequencies, each having a different effect on the control of the process. By using a frequency based approach based on sinusoidal basis functions (ie Fourier analysis), these different frequencies get aggregated. This smudging of specific frequency information makes it difficult to pin-point the root cause, and makes the grouping of common oscillations difficult. In order to address the above issue, F1035 is analysed using othornormal wavelet basis functions. The results show that the period of oscillation is affected between day and night, with roughly a 2 minute oscillation prevalent at mid night, compared to a 100 minute oscillation at mid day. Obviously the 12 hour day-night swing is also prevalent. This information is unique to this approach. Ways of visualising changes in oscillatory behaviour using the wavelet analysis are also presented. Technical analysis of controller performance is only a small subsection of the issues that need to be considered when implementing a loop monitoring and maintenance solution. Issues such as connectivity, configuration, analysis, reporting and auditing are key in designing a workable maintenance environment for PID loop maintenance. Several packages are available commercially to assist industry in performing loop maintenance. When evaluating which package is best suited to a specific requirement, it is important to consider several different issues. The different audiences with a vested interest in loop performance require special attention in terms of reporting requirements. Visualisation of results is often more important than the physical measure of performance. Finally, the ability of a company to benchmark itself against current best practices and performance is often perceived as a major advantage. The results presented and discussed were generated using real industrial data. Information regarding suggested best practice when evaluating commercially available products is based largely on the author’s personal experience in the large scale industrial installation of such a monitoring solution. / Dissertation (MEng (Process Control))--University of Pretoria, 2007. / Chemical Engineering / unrestricted

The major objective of this study was to establish a department in an organization, which would co-ordinate all new product planning activities. To attain this objective it was necessary to study the characteristics of a firm and then using these, develop a department which would utilize the firm's strengths and avoid its weaknesses. Initially the components required in a product policy were presented to act as a guide for management in establishing its new product planning department. The first step of the organizing process was the complete analysis of the basic stages that new product ideas pass through. This analysis included collection and screening of product ideas, the development of specifications for the product, and the testing of the product prior to commercialization. The decisions required, and the personnel involved at each stage were clearly indicated as the product idea evolved. Throughout the thesis, the need for an organized marketing research operation is emphasized. It is claimed that to have effective new product development there must be thorough and complete market knowledge available. Marketing research is an integral part of the activities proposed in this thesis. The department that is proposed consists of a committee with representatives from each of the major line functions in the firm. It is a staff department with functional authority. The new product development activities in the firm are guided and controlled by this coordinating body. The members of the new product planning department work in close co-operation with the line department managers and the executive committee. Management of a firm adopting the proposed system must be devoted to progress through new product development. For the new product planning department to be successful more than an organizational structure is required. The company as a whole must accept the premise that an organized approach to innovation is essential. This frame of mind must be prevalent before the proposed department will be able to work co-operatively with the various line functions in the firm. An integrated approach to new product development is therefore being proposed. To test the validity of the suggested system it was compared to the new product development operations in a leading Canadian chemical company. The operations of the firm are discussed in detail prior to analyzing them relative to the proposed system. Successful new product development is the key to the future for most industrial companies. Careful planning based on thorough and methodical analysis will result in new products being introduced with consistent success. To enable the planning process to take place a department must be established which will co-ordinate all new product activities and produce optimum results. The system proposed in this thesis, if properly implemented, will meet these requirements. / Business, Sauder School of / Graduate