We present sharpened lower bounds on the size of cut free proofs for first-order logic. Prior lower bounds for eliminating cuts from a proof established superexponential lower bounds as a stack of exponentials, with the height of the stack proportional to the maximum depth d of the formulas in the original proof. Our results remove the constant of proportionality, giving an exponential stack of...

A design method for PID controllers base on internal model control (IMC) principles, direct synthesis method (DS), stability analysis (SA) system for pure integrating process with time delay is proposed. Analytical expressions for PID controllers are derived for several common types of process models, including first order and second-order plus time delay models and an integrator plus time dela...

This paper realized the 2-DOF controller structure for first order with time delay systems. The co-prime factorization is used to design observer based controller K(s), representing one degree of freedom. The problem is based on H∞ norm of mixed sensitivity and aims to achieve stability, robustness and disturbance rejection. Then, the other degree of freedom, prefilter F(s), is formulated as fi...

Load-balancing problem, which covers a large area in engineering fields where several parallel entities share the same load on the systems, is studied. A control technique for solving such problem, called differences control technique (DsCT), is investigated. Two types of systems whose parallel entities can be approximated respectively as an integral and a first-order-plus-dead-time (FOPDT) mod...

Objective of this paper is to design various controllers for a temperature process control. PID controller is the well known and most widely used in the industries. Internal Model Control (IMC) has become the leading form of advanced control in the process industry. Modified form of IMC-PID and Fuzzy PID Controllers are designed for First Order Plus Dead Time (FOPTD) process model. The comparat...

This paper is concerned with process identification by curve fitting step responses. Both open-loop and closed-loop identification are studied using simulated data for typical examples as well as experimental data from a laboratory plate heat exchanger. Timedomain curve fitting utilizing efficient local optimization techniques is employed to find the parameters of the process model. Process mod...

In this paper, a new tuning procedure for PI controllers in Two-Degree-of-Freedom (2DOF) structure is proposed. In design procedure, First Order plus Dead Time (FOPDT) model is used. The aim is to have good set point tracking and disturbance rejection and also maximum robustness to model uncertainties. The tuning strategy is based on using analytical rules and some conceptual rules about closed...

Dept. of Automation and Applied Informatics, Budapest University o f Technology and Economics, MTA-BME Control Research group (e-mail: [email protected], [email protected]) Dept. of Advanced Process Control, Shell Rheinland Refinery, Köln/Wesseling, Germany (e-mail: [email protected]) Inst. of Chemical Process Engineering and Plant Design, University of Applied Science Cologne, Ger...