Zinc is the first modelling language which supports solver and technique independence. This means that a high level conceptual model can be automatically mapped into an appropriate low level design model for a specific solver or technique. To date, Zinc uses three different techniques to solve a model: Constraint Programming (CP), Local Search (LS), and Mixed Integer Programming (MIP). In this way, modellers can examine all solving techniques for their models and see which one gives them the best result. MIP solvers can only accept linear models. Therefore, to map a conceptual model to MIP solvers, the model must be linearized first. In this paper we explain the techniques used in Zinc to linearize high level data structures and expressions which may be appeared in a conceptual model. As a result, modellers can benefit of expressive modelling using nonlinear expressions as well as efficiency of MIP solvers.

pH control is a challenging problem due to its highly nonlinear nature. In this paper the performances of two different adaptive global linearizing controllers (GLC) are compared. Least squares technique has been used for identifying the titration curve. The first controller is a standard GLC based on material balances of each species. For implementation of this controller a nonlinear state estimator is used. Some modifications are proposed to avoid the singularity of the observer gain. The second controller is designed based on the reduced state equation. Through computer simulations, it has been shown that the performances of the second GLC is superior and it is more robust to process model mismatch. It should be also noted that the design of reduced state-based GLC is much easier and dose not need observer for implementation.

In this paper, multiobjective optimization problems with nondifferentiable quasiconvex functions are considered. We obtain some duality results and a linear representation for the considered problems. Since the well-known strong duality result is not valid for the problems, we present a weaker form of it, named quasi-strong duality result.

Information security is one of the important aspects of passive defense and cryptography has an undeniable role in realization of this security. Therefore, the main aim of using cryptographic hash functions is the integrity of information. Linearization is one of the important techniques in cryptanalysis of the hash functions that used for cryptanalysis of many hash functions. In this paper, we use idea of the cryptanalysis method with linear algebra and find some differential patterns for a linear variant of MD4 (LMD4) with a new search algorithm. Then using one of the patterns we find a collision for LMD4. Also we define another simplified variant of MD4 (CMD4) and present a successful collision attack with a complexity of 235on the CMD4 by using one of the so-called patterns is achieved. Finally, the collision attack on the MD4 is reconsidered.