To reduce the effort and cost of model maintenance in model predictive control (MPC) systems, this paper explored a model deficiency diagnosis and improvement method by the assessment of model residual and optimization of disturbance model. A model quality index (MQI) method was first presented to evaluate the model performance with the routine input and output process data. Based on MQI, a leave-one-out method was proposed to further assess the performances of submodels in multi-input–multi-output (MIMO) MPC processes. The root deficient submodel could be diagnosed based on a comparison of the overall MQI with the submodel index by moving it to the disturbance channel. Further, a model performance improvement method through the upgraded optimal disturbance model was proposed to enhance the model performance without altering the control model. The experiment results on the Wood–Berry distillation column process and an industrial process indicated the validity of the proposed model diagnosis and improvement method.

Introduction: As the use of dietary supplements increases, botanical-drug interaction (BDI) potentials should be evaluated. Boswellia serrata extract (BSE) is traditionally used as an anti-inflammatory supplement. In the scientific literature, BSE has been shown to reduce the activity (55% to ‡65%) across major CYP450 enzymes, including CYP3A4/5 and CYP2C9, using baculovirus-infected insect cells. These reported results, contrasted with a seemingly history of safe use of BSE, led us to question the relevance of the results using pooled human liver microsomes (PHLM), when compared to a more physiologically relevant model such as primary human hepatocytes. Methods: This study compared PHLM and sandwich-cultured human hepatocytes (SCHH) by evaluating BSE potential inhibitory effects on CYP3A4/5 and CYP2C9 enzymatic activity. Results: In SCHH, inhibition of CYP3A4/5 by BSE was observed resulting in an IC 50 = 17.4 lg/mL with maximum inhibition effect of >70% at 75 lg/mL versus IC 50 = 1.4 lg/mL with a maximum inhibition effect of 98% at 50 lg/mL in PHLM. IC 50 values for CYP2C9 inhibition by BSE were >75 lg/mL with a maximum inhibition effect of <30% versus 11 lg/mL with a maximum inhibition effect of 84% at 50 lg/mL using SCHH and PHLM, respectively. Discussion and Conclusions: Potent CYP3A4/5 and CYP2C9 inhibition observed for BSE in microsomal systems was not observed in SCHH. SCHH are particularly useful for studying complex mixtures such as botanicals. Although our data would suggest that BDI with BSE is low for most drugs, narrow therapeutic drugs such as warfarin should still be used with caution when combined with BSE.

For an industrial control system, controller parameters are important factors that affect the control system performance. This article introduces a controller parameter performance assessment method based on disturbance characteristic variation for a dynamic matrix control system. Assuming that the process model is accurate and the setpoint is constant, disturbance characteristic variation without adjusting controller parameters leads to the degradation of system performance. Hence, the Markov parameters of a disturbance model, which inflect the variation of disturbance characteristics, are used to assess the controller parameter performance. These Markov parameters can be obtained from closed-loop data using the subspace identification method. The differences between the Markov parameters in an actual running state and those in a well-regulated state are used to design the assessing index of controller parameters. The simulation results in the Wood-Berry model and TE process show the validity of the proposed index.

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