This thesis presents, discusses and compares a set of methodologies and several appropriate combinations of them, to provide accurate estimation of process variables, either for steady-state or dynamic systems. Firstly, the accuracy of estimated measurements is improved through the proposal of novel Data Reconciliation techniques. The proposal combines data-based and model-based filtering and also consider the presence of time-delays between sampled data.Secondly, measuring network design and its optimal use are addressed. Thus, the measuring device number, their type and their location for optimum reliability and accuracy of measurement at lowest possible cost are determined.The first part of this thesis provides procedures for accuracy estimation in dynamic evolving processes. These procedures rely on combining data-based filtering and model-based filtering. One technique combines a Moving Average filter and a steady-state Data Reconciliation technique sequentially. The resulting estimator presents the important statistic feature of being unbiased. Additionally, this estimator provides high accuracy estimation and good tracking for dramatic dynamic changes of process variables, when compared with other techniques. The other technique performs a wavelet analysis as a former step for reconciling dynamic systems. The wavelet technique catches or extracts the process measurement trends that are later made consistent with the dynamic process model. As a consequence of this technique high estimation accuracy is provided. Additional advantages of applying this technique over the current techniques are the easy handling of distinct sample times and evaluating the variance of dynamic variables. Furthermore, this thesis addresses an important aspect regarding dynamic Data Reconciliation: how to improve the accuracy estimation when the process is faced with the presence of time-delay. This problem was overcome in a simple and efficient way by proposing a time-delay estimation method that works in conjunction with the Measurement Model adopted within the Data Reconciliation technique.The presented time-delay estimation method determines the existing delay by maximizing the correlation of the process variables using genetic algorithms.The second part of this thesis addresses the design of sensor networks, the proposed strategy allows the optimal selection and placement of measuring devices. The proposal deal with different sensor placement aspects: variation in design, retrofit, hardware redundancy and available sensor type.The sensor placement procedure was extended to deal with dynamic systems by taking advantages of dynamic variable classification and dynamic Data Reconciliation.The procedure to locate sensors in dynamic systems aims at maximizing the performance of Kalman filtering using accuracy as its main performance index. To accomplish this, both the measurement noise and the observation matrices are manipulated. The solution strategy has been implemented in academic and in the Tennessee Eastman challenge problems showing promising results. The resulting optimization problem was solved satisfactorily either by exhaustive search or using genetic algorithms based optimization. The profile of the relative increase of the system performance along the sensor network and the associate investment cost gives the designer all the alternatives for making an adequate decision.Additionally, reliability is considered by combining quantitative process knowledge and fault tree analysis, providing an efficient way to improve its evaluation. It is important to state that the possibility to use inferential sensors based in an Artificial Neural Network model instead of physical sensors, and their incorporation within reliability and reconciliation procedures was a paramount consideration throughout this work.Finally, this thesis also provides two frameworks, one for sensor placement and the second for Data Reconciliation. Both proposed frameworks have been designed, specified and validated following the guidelines of the new standards and trends in developing component-based application (e.g. UMLTM, CAPE-OPEN). These frameworks can include the above mentioned algorithms and can be extended to include other existing or futures approaches efficiently.

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Thesis (MScIng)--University of Stellenbosch, 2006. / Bibliography. Also available via the Internet.

Thesis (Ph. D.)--University of Washington, 1991. / Vita. Includes bibliographical references (leaves [162]-168).

Thesis (M.S.)--Ohio University, June, 1995. / Title from PDF t.p.

Thesis (Ph. D.)--Kansas State University, 2004. / Includes bibliographical references.

Thesis (Ph. D.)--University of Sydney, 1996. / Title from title screen (viewed on February 3, 2009) Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Dept. of Chemical Engineering. Degree awarded 1996, thesis submitted 1995. Includes bibliographical references. Also issued in print.

Heshouwu, derived from the tuberous root of Polygonum multiflorum Thunb., has been widely used in Traditional Chinese Medicine for centuries. It has a purgative effect when unprocessed, while used as a tonic after processing, and according to historical records, heshouwu should be steamed and sun-dried nine times to generate processed materials. Up until recently, three aspects of heshouwu have not been sufficiently studied. First, it is necessary to understand the history of heshouwu, including the emergence in the literature, the descriptions of its appearance, its effects and controversies, as well as the evolution of heshouwu's processing. As historical texts open a window to the past and clarify the issues of important clinical concern in the modern world, historical bencao (materia medica) literature research should be conducted. Second, in commercial herbal markets, heshouwu is divided into different grades based on morphological features of size and weight. A heavier weight and larger size command a higher price, and both sellers and buyers accept this grading. However, two questions arise: Does the existing grading system accurately represent the quality of the herb? If not, is there another system, or are there other morphological criteria, that could be used to reliably represent quality? Lastly, while heshouwu has been processed for hundreds of years, including the present, the chemistry of that processing has not been well studied. To address these issues, this study is divided into four parts. First, a systematic review of the text and illustrations in historical bencao literature is conducted. The bencao literature study illustrates the origin, botanical characteristics, actions and processing of heshouwu, as well as the origin and historical evolution of baishouwu ("white heshouwu"). To assess the inherent quality of various grades and to explore whether the existing grading system of heshouwu accurately represent quality, we firstly analyze the chemical profiles in three different commercial grades of heshouwu raw materials, using UPLC-QTOF-MS/MS and UPLC-QqQ-MS/MS. The results reveal that production regions and specifications both influence the chemical constituents of heshouwu, but the influence of production regions is even more evident. Differences in the constituents among production regions are relatively large, while there are no significant differences among the existing commercials grades. As the relationship between bioactive components and morphological features can be found by analyzing the distribution patterns of chemical components in different tissues, in order to find other reliable morphological indicators of quality furtherly, a method combining laser microdissection (LMD), UPLC-QTOF-MS/MS and UPLC-QqQ-MS/MS is applied in the third part of this study. The results indicate that, heshouwu with broader cork and phloem, as seen in a transverse section, are typically of better quality as these parts are where the bioactive components accumulate. In the fourth part of this study, targeted and untargeted metabolomics analyses using UPLC-QTOF-MS/MS and UPLC-QqQ-MS/MS are integrated to investigate the processing chemistry of heshouwu. The results demonstrate that processing by nine cycles of steaming and drying can qualitatively and quantitatively alters the chemical profile of heshouwu, which suggests that the nine cycles might be necessary for the preparation of processed heshouwu. The historical bencao literature research, chemical basis for quality evaluation, as well as processing chemistry investigation of heshouwu have been conducted in depth in this study. The results will be helpful in providing scientific basis of heshouwu's application.