• Title/Summary/Keyword: quality inferential control

Search Result 3, Processing Time 0.019 seconds

Optimal Learning Control Combined with Quality Inferential Control for Batch and Semi-batch Processes

  • Chin, In-Sik;Lee, Kwang-Soon;Park, Jinhoon;Lee, Jay H.
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1999.10a
    • /
    • pp.57-60
    • /
    • 1999
  • An optimal control technique designed for simultaneous tracking and quality control for batch processes. The proposed technique is designed by transforming quadratic-criterion based iterative learning control(Q-ILC) into linear quadratic control problem. For real-time quality inferential control, the quality is modeled by linear combination of control input around target qualify and then the relationship between quality and control input can be transformed into time-varying linear state space model. With this state space model, the real-time quality inferential control can be incorporated to LQ control Problem. As a consequence, both the quality variable as well as other controlled variables can progressively reduce their control error as the batch number increases while rejecting real-time disturbances, and finally reach the best achievable states dictated by a quadratic criterion even in case that there is significant model error Also the computational burden is much reduced since the most computation is calculated in off-line. The Proposed control technique is applied to a semi-batch reactor model where series-parallelreactions take place.

  • PDF

Advances in Chemical Process Control and Operation -A view experienced in joint university-industry projects

  • Ohshima, Masahiro
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1994.10a
    • /
    • pp.1.2-6
    • /
    • 1994
  • A state or the arts in Japanese chemical process control is reviewed based on experience in applying advanced process control schemes to several industrial chemical processes. The applications validate model predictive control (MPC), the most popular advanced control scheme in the process control community, as, indeed, a powerful and practical control algorithm. However, at the same time, it is elucidated that MPC can solve only the control algorithm part of the problem and one needs chemical and systems engineering aspects to solve the entire problem. By illustrating several industrial process control problems, the need for chemical engineering aspects as well as the future direction for process control are addressed, especially in light or current attitudes toward product quality.

  • PDF

Does Portfolio Quality Influence Financial Sustainability? A Case of Microfinance Institutions in Kenya

  • BITOK, Stephen K.;CHEBOI, Josephat Y.;KEMBOI, Ambrose
    • Asian Journal of Business Environment
    • /
    • v.10 no.1
    • /
    • pp.37-43
    • /
    • 2020
  • Purpose: The purpose of this study was to examine the relationship between portfolio quality and financial sustainability of microfinance institutions in Kenya. Research Design, Data, and Methodology: The analysis was based on a panel dataset of 30 microfinance institutions for the period of 2010 to 2018. Data was obtained from the Microfinance information exchange (MIX) database, and it was analyzed through descriptive and inferential statistics with the aid of STATA. Based on the results of the Hausman test, the study adopted the fixed effect regression model to test the research hypothesis. Results: The study found that portfolio quality had a positive significant effect on financial sustainability of Microfinance institutions in Kenya (β= 0. 211; p-value < 0.05). For the control variables; firm age had a positive effect (β= 0.773; p-value <0.05), while firm size (β= -0. 749; p-value < 0.05) had a negative effect on financial sustainability. Conclusions: The study concluded that portfolio quality has an important influence on the financial sustainability of microfinance institution. The study recommends that managers of microfinance institutions should devise good collection policies to improve portfolio quality while lessening loan default rate. The portfolio quality may improve the overall profitability and enhance investor confidence in their strategic decision-making on refinancing.